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Sample records for influence fitness variation

  1. Predation risk and longevity influence variation in fitness of female roe deer (Capreolus capreolus L.).

    PubMed Central

    Kjellander, Petter; Gaillard, Jean-Michel; Hewison, Mark; Liberg, Olof

    2004-01-01

    We studied the effects of population density, red fox predation risk, individual body mass and longevity on female fitness in a free-ranging roe deer population. During the study, population density varied from 9.3 to 36.1 deer km(-2), and red fox abundance varied strongly over years owing to a sarcoptic mange outbreak. In support of our predictions, long-lived females had higher fitness than short-lived ones. Further, fortunate female roe deer that gave birth in years of low red fox abundance attained much higher fitness than those that gave birth in years of high red fox abundance. Longevity and predation risk explained more than half the variation in fitness observed among roe deer females. As a possible effect of small sample size, we found no effect of female body mass or population density at birth. Our study demonstrates that predation risk, a component of environmental stochasticity, may prevent directional selection even when phenotypic quality influences individual fitness. PMID:15504011

  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. PMID:27547341

  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. Variationally fitting the total electron-electron interaction

    NASA Astrophysics Data System (ADS)

    Dunlap, Brett I.; Palenik, Mark C.

    2016-05-01

    Density fitting is used throughout quantum chemistry to simplify the electron-electron interaction energy (EE). A fundamental property of quantum chemistry, and DFT in particular, is that a variational principle connects the EE to a potential. Density fitting generally does not preserve this connection. Herein we describe the construction of a robust EE that is variationally connected to fitted potentials in all electronic structure methods. For DFT, this results in fitting equations that are satisfied at an energy saddle point in multidimensional fitting space.

  5. Genetic variation for total fitness in Drosophila melanogaster.

    PubMed Central

    Fowler, K; Semple, C; Barton, N H; Partridge, L

    1997-01-01

    We measured the heterozygous effects on net fitness of a sample of 12 wild-type third chromosomes in D. melanogaster. Effects on fitness were assessed by competing the wild-type chromosomes against balancer chromosomes, to prevent the production of recombinants. The measurements were carried out in the population cage environment in which the life history had been evolving, in an undisturbed population with overlapping generations, and replicated measurements were made on each chromosome to control for confounding effects such as mutation accumulation. We found significant variation among the wild type chromosomes in their additive genetic effect on net fitness. The system provides an opportunity to obtain an accurate estimate of the distribution of heterozygous effects on net fitness, the contribution of different fitness components including male mating success, and the role of intra-chromosomal epistasis in fitness variation. PMID:9061969

  6. 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. PMID:24843221

  7. Interindividual anatomical variations affect the plate-to-bone fit during osteosynthesis of distal radius fractures.

    PubMed

    Yoneda, Hidemasa; Iwatsuki, Katsuyuki; Hara, Tatsuya; Kurimoto, Shigeru; Yamamoto, Michiro; Hirata, Hitoshi

    2016-06-01

    We hypothesized that interindividual variations in the teardrop, which represents the volar projection of the lunate facet of the distal radius, cause unsatisfactory fitting of the volar locking plate to the bone. This can cause flexor tendon ruptures. Herein, we conducted a cross-sectional study and measured the ratio of teardrop height and the teardrop inclination angle as parameters of teardrop configuration for 200 standardized lateral radiographs (average age of the patients, 51 years). We also quantified the influence of the teardrop morphology by analyzing the fit of three locking plates to three radii with differing teardrop inclination angles using a three-dimensional computer-aided design system. The average ratios of the teardrop height and teardrop inclination angle were 0.42° (0.30-0.56°) and 28.8° (9.9-44.9°), respectively. The teardrop inclination angle was moderately correlated with age in men but not in women. In the plate-to-bone fit analyses, the fit of all the plates was significantly different between bones, with the configuration of the radius with the lowest teardrop inclination angle being the closest approximation to that of each plate. We demonstrated the interindividual variation in the shape of the teardrop and its influence on the fit of the volar plate, highlighting the importance of careful plate selection for achieving osteosynthesis of bones with a high teardrop inclination angle. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:953-960, 2016. PMID:26648456

  8. Fitness

    MedlinePlus

    ... gov home http://www.girlshealth.gov/ Home Fitness Fitness Want to look and feel your best? Physical ... are? Check out this info: What is physical fitness? top Physical fitness means you can do everyday ...

  9. 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…

  10. Fitness landscapes among many options under social influence.

    PubMed

    Caiado, Camila C S; Brock, William A; Bentley, R Alexander; O'Brien, Michael J

    2016-09-21

    Cultural learning represents a novel problem in that an optimal decision depends not only on intrinsic utility of the decision/behavior but also on transparency of costs and benefits, the degree of social versus individual learning, and the relative popularity of each possible choice in a population. In terms of a fitness-landscape function, this recursive relationship means that multiple equilibria can exist. Here we use discrete-choice theory to construct a fitness-landscape function for a bi-axial decision-making map that plots the magnitude of social influence in the learning process against the costs and payoffs of decisions. Specifically, we use econometric and statistical methods to estimate not only the fitness function but also movements along the map axes. To search for these equilibria, we employ a hill-climbing algorithm that leads to the expected values of optimal decisions, which we define as peaks on the fitness landscape. We illustrate how estimation of a measure of transparency, a measure of social influence, and the associated fitness landscape can be accomplished using panel data sets. PMID:26851173

  11. 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

  12. Factors influencing variation in dentist service rates.

    PubMed

    Grembowski, D; Milgrom, P; Fiset, L

    1990-01-01

    In the previous article, we calculated dentist service rates for 200 general dentists based on a homogeneous, well-educated, upper-middle-class population of patients. Wide variations in the rates were detected. In this analysis, factors influencing variation in the rates were identified. Variation in rates for categories of dental services was explained by practice characteristics, patient exposure to fluoridated water supplies, and non-price competition in the dental market. Rates were greatest in large, busy practices in markets with high fees. Older practices consistently had lower rates across services. As a whole, these variables explained between 5 and 30 percent of the variation in the rates. PMID:2118182

  13. 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

  14. Noise and Epigenetic Inheritance of Single-Cell Division Times Influence Population Fitness.

    PubMed

    Cerulus, Bram; New, Aaron M; Pougach, Ksenia; Verstrepen, Kevin J

    2016-05-01

    The fitness effect of biological noise remains unclear. For example, even within clonal microbial populations, individual cells grow at different speeds. Although it is known that the individuals' mean growth speed can affect population-level fitness, it is unclear how or whether growth speed heterogeneity itself is subject to natural selection. Here, we show that noisy single-cell division times can significantly affect population-level growth rate. Using time-lapse microscopy to measure the division times of thousands of individual S. cerevisiae cells across different genetic and environmental backgrounds, we find that the length of individual cells' division times can vary substantially between clonal individuals and that sublineages often show epigenetic inheritance of division times. By combining these experimental measurements with mathematical modeling, we find that, for a given mean division time, increasing heterogeneity and epigenetic inheritance of division times increases the population growth rate. Furthermore, we demonstrate that the heterogeneity and epigenetic inheritance of single-cell division times can be linked with variation in the expression of catabolic genes. Taken together, our results reveal how a change in noisy single-cell behaviors can directly influence fitness through dynamics that operate independently of effects caused by changes to the mean. These results not only allow a better understanding of microbial fitness but also help to more accurately predict fitness in other clonal populations, such as tumors. PMID:27068419

  15. Variation and fitness costs for tolerance to different types of herbivore damage in Boechera stricta genotypes with contrasting glucosinolate structures

    PubMed Central

    Manzaneda, Antonio J.; Prasad, Kasavajhala V. S. K.; Mitchell-Olds, Thomas

    2010-01-01

    Summary Analyses of plant tolerance in response to different modes of herbivory are essential to understand plant defense evolution, yet are still scarce. Allocation costs and trade-offs between tolerance and plant chemical defenses may influence genetic variation for tolerance. However, variation in defenses occurs also for presence or absence of discrete chemical structures, yet, effects of intra-specific polymorphisms on tolerance to multiple herbivores have not been evaluated.Here, in a glasshouse experiment, we investigated variation for tolerance to different types of herbivory damage, and direct allocation costs in 10 genotypes of Boechera stricta (Brassicaceae), a wild relative of Arabidopsis, with contrasting foliar glucosinolate chemical structures (methionine-derived glucosinolates vs glucosinolates derived from branched-chain amino acids).We found significant genetic variation for tolerance to different types of herbivory. Structural variations in the glucosinolate profile did not influence tolerance to damage, but predicted plant fitness. Levels of constitutive and induced glucosinolates varied between genotypes with different structural profiles, but we did not detect any cost of tolerance explaining genetic variation in tolerance among genotypes.Trade-offs among plant tolerance to multiple herbivores may not explain the existence of intermediate levels of tolerance to damage in plants with contrasting chemical defensive profiles. PMID:20663059

  16. 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…

  17. Natural genetic variation in Arabidopsis thaliana defense metabolism genes modulates field fitness

    PubMed Central

    Kerwin, Rachel; Feusier, Julie; Corwin, Jason; Rubin, Matthew; Lin, Catherine; Muok, Alise; Larson, Brandon; Li, Baohua; Joseph, Bindu; Francisco, Marta; Copeland, Daniel; Weinig, Cynthia; Kliebenstein, Daniel J

    2015-01-01

    Natural populations persist in complex environments, where biotic stressors, such as pathogen and insect communities, fluctuate temporally and spatially. These shifting biotic pressures generate heterogeneous selective forces that can maintain standing natural variation within a species. To directly test if genes containing causal variation for the Arabidopsis thaliana defensive compounds, glucosinolates (GSL) control field fitness and are therefore subject to natural selection, we conducted a multi-year field trial using lines that vary in only specific causal genes. Interestingly, we found that variation in these naturally polymorphic GSL genes affected fitness in each of our environments but the pattern fluctuated such that highly fit genotypes in one trial displayed lower fitness in another and that no GSL genotype or genotypes consistently out-performed the others. This was true both across locations and within the same location across years. These results indicate that environmental heterogeneity may contribute to the maintenance of GSL variation observed within Arabidopsis thaliana. DOI: http://dx.doi.org/10.7554/eLife.05604.001 PMID:25867014

  18. The Demographic Transition Influences Variance in Fitness and Selection on Height and BMI in Rural Gambia

    PubMed Central

    Courtiol, Alexandre; Rickard, Ian J.; Lummaa, Virpi; Prentice, Andrew M.; Fulford, Anthony J.C.; Stearns, Stephen C.

    2013-01-01

    Summary Recent human history is marked by demographic transitions characterized by declines in mortality and fertility [1]. By influencing the variance in those fitness components, demographic transitions can affect selection on other traits [2]. Parallel to changes in selection triggered by demography per se, relationships between fitness and anthropometric traits are also expected to change due to modification of the environment. Here we explore for the first time these two main evolutionary consequences of demographic transitions using a unique data set containing survival, fertility, and anthropometric data for thousands of women in rural Gambia from 1956–2010 [3]. We show how the demographic transition influenced directional selection on height and body mass index (BMI). We observed a change in selection for both traits mediated by variation in fertility: selection initially favored short females with high BMI values but shifted across the demographic transition to favor tall females with low BMI values. We demonstrate that these differences resulted both from changes in fitness variance that shape the strength of selection and from shifts in selective pressures triggered by environmental changes. These results suggest that demographic and environmental trends encountered by current human populations worldwide are likely to modify, but not stop, natural selection in humans. PMID:23623548

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

    PubMed

    Lee, Young Wha; Fishman, Lila; Kelly, John K; Willis, John H

    2016-04-01

    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 ofMimulus guttatus(yellow monkeyflower). We initially mappedinv6as a region of recombination suppression in three F2populations resulting from crosses among IM plants. In each case, the F1parent was heterozygous for a derived haplotype, homogenous across markers spanning over 5 Mb of chromsome 6. In the three F2populations,inv6reduced male and female fitness components. In addition,inv6carriers suffered an ∼30% loss of pollen viability in the field. Despite these costs,inv6exists at moderate frequency (∼8%) in the natural population, suggesting counterbalancing fitness benefits that maintain the polymorphism. Across 4 years of monitoring in the field,inv6had 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,inv6generates 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

  20. How within-group behavioural variation and task efficiency enhance fitness in a social group

    PubMed Central

    Pruitt, Jonathan N.; Riechert, Susan E.

    2011-01-01

    How task specialization, individual task performance and within-group behavioural variation affects fitness is a longstanding and unresolved problem in our understanding of animal societies. In the temperate social spider, Anelosimus studiosus, colony members exhibit a behavioural polymorphism; females either exhibit an aggressive ‘asocial’ or docile ‘social’ phenotype. We assessed individual prey-capture success for both phenotypes, and the role of phenotypic composition on group-level prey-capture success for three prey size classes. We then estimated the effect of group phenotypic composition on fitness in a common garden, as inferred from individual egg-case masses. On average, asocial females were more successful than social females at capturing large prey, and colony-level prey-capture success was positively associated with the frequency of the asocial phenotype. Asocial colony members were also more likely to engage in prey-capture behaviour in group-foraging situations. Interestingly, our fitness estimates indicate females of both phenotypes experience increased fitness when occupying colonies containing unlike individuals. These results imply a reciprocal fitness benefit of within-colony behavioural variation, and perhaps division of labour in a spider society. PMID:20943687

  1. The Influence of Childhood Aerobic Fitness on Learning and Memory

    PubMed Central

    Raine, Lauren B.; Lee, Hyun Kyu; Saliba, Brian J.; Chaddock-Heyman, Laura; Hillman, Charles H.; Kramer, Arthur F.

    2013-01-01

    Introduction There is a growing trend of inactivity among children, which may not only result in poorer physical health, but also poorer cognitive health. Previous research has shown that lower fitness has been related to decreased cognitive function for tasks requiring perception, memory, and cognitive control as well as lower academic achievement. Purpose To investigate the relationship between aerobic fitness, learning, and memory on a task that involved remembering names and locations on a fictitious map. Different learning strategies and recall procedures were employed to better understand fitness effects on learning novel material. Methods Forty-eight 9–10 year old children (n = 24 high fit; HF and n = 24 low fit; LF) performed a task requiring them to learn the names of specific regions on a map, under two learning conditions in which they only studied (SO) versus a condition in which they were tested during study (TS). The retention day occurred one day after initial learning and involved two different recall conditions: free recall and cued recall. Results There were no differences in performance at initial learning between higher fit and lower fit participants. However, during the retention session higher fit children outperformed lower fit children, particularly when the initial learning strategy involved relatively poor recall performance (i.e., study only versus test-study strategy). Conclusions We interpret these novel data to suggest that fitness can boost learning and memory of children and that these fitness-associated performance benefits are largest in conditions in which initial learning is the most challenging. Such data have important implications for both educational practice and policy. PMID:24039791

  2. Maternal investment mediates offspring life history variation with context-dependent fitness consequences.

    PubMed

    Moore, Michael P; Landberg, Tobias; Whiteman, Howard H

    2015-09-01

    Maternal effects, such as per capita maternal investment, often interact with environmental conditions to strongly affect traits expressed early in ontogeny. However, their impact on adult life history traits and fitness components is relatively unknown. Theory predicts that lower per capita maternal investment will have strong fitness costs when the offspring develop in unfavorable conditions, yet few studies have experimentally manipulated per capita maternal investment and followed offspring through adulthood. We used a surgical embryonic yolk removal technique to investigate how per capita maternal investment interacted with an important ecological factor, larval density, to mediate offspring life history traits through reproductive maturity in an amphibian, Ambystoma talpoideum. We predicted that increased larval density would reinforce the life history variation induced by differences in per capita investment (i.e., Controls vs. Reduced Yolk), with Reduced larvae ultimately expressing traits associated with lower fitness than Controls when raised at high densities. We found that Reduced individuals were initially smaller and more developed, caught up in size to Controls within the first month of the larval stage, but were smaller at the end of the larval stage in low densities. Reduced individuals also were more likely to undergo metamorphosis at high densities and mature 'females invested in more eggs for their body sizes than Controls. Together, our results do not support our hypothesis, but instead indicate that Reduced individuals express traits associated with higher fitness when they develop in high-density environments, but lower fitness in low-density environments. The observed life history and fitness patterns are consistent with the "maternal match" hypothesis, which predicts that when the maternal environment (e.g., high density) results in phenotypic variation that is transmitted to the offspring (e.g., reduced per capita yolk investment), and

  3. Tikhonov adaptively regularized gamma variate fitting to assess plasma clearance of inert renal markers

    PubMed Central

    Puetter, Richard C.; Ling, Lin; Babyn, Paul S.

    2010-01-01

    The Tk-GV model fits Gamma Variates (GV) to data by Tikhonov regularization (Tk) with shrinkage constant, λ, chosen to minimize the relative error in plasma clearance, CL (ml/min). Using 169Yb-DTPA and 99mTc-DTPA (n = 46, 8–9 samples, 5–240 min) bolus-dilution curves, results were obtained for fit methods: (1) Ordinary Least Squares (OLS) one and two exponential term (E1 and E2), (2) OLS-GV and (3) Tk-GV. Four tests examined the fit results for: (1) physicality of ranges of model parameters, (2) effects on parameter values when different data subsets are fit, (3) characterization of residuals, and (4) extrapolative error and agreement with published correction factors. Test 1 showed physical Tk-GV results, where OLS-GV fits sometimes-produced nonphysical CL. Test 2 showed the Tk-GV model produced good results with 4 or more samples drawn between 10 and 240 min. Test 3 showed that E1 and E2 failed goodness-of-fit testing whereas GV fits for t > 20 min were acceptably good. Test 4 showed CLTk-GV clearance values agreed with published CL corrections with the general result that CLE1 > CLE2 > CLTk-GV and finally that CLTk-GV were considerably more robust, precise and accurate than CLE2, and should replace the use of CLE2 for these renal markers. PMID:20865304

  4. Aerobic Fitness Does Not Modify the Effect of FTO Variation on Body Composition Traits

    PubMed Central

    Huuskonen, Antti; Lappalainen, Jani; Oksala, Niku; Santtila, Matti; Häkkinen, Keijo; Kyröläinen, Heikki; Atalay, Mustafa

    2012-01-01

    Purpose Poor physical fitness and obesity are risk factors for all cause morbidity and mortality. We aimed to clarify whether common genetic variants of key energy intake determinants in leptin (LEP), leptin receptor (LEPR), and fat mass and obesity-associated (FTO) are associated with aerobic and neuromuscular performance, and whether aerobic fitness can alter the effect of these genotypes on body composition. Methods 846 healthy Finnish males of Caucasian origin were genotyped for FTO (rs8050136), LEP (rs7799039) and LEPR (rs8179183 and rs1137101) single nucleotide polymorphisms (SNPs), and studied for associations with maximal oxygen consumption, body fat percent, serum leptin levels, waist circumference and maximal force of leg extensor muscles. Results Genotype AA of the FTO SNP rs8050136 associated with higher BMI and greater waist circumference compared to the genotype CC. In general linear model, no significant interaction for FTO genotype-relative VO2max (mL·kg−1·min−1) or FTO genotype-absolute VO2max (L·min−1) on BMI or waist circumference was found. Main effects of aerobic performance on body composition traits were significant (p<0.001). Logistic regression modelling found no significant interaction between aerobic fitness and FTO genotype. LEP SNP rs7799039, LEPR SNPs rs8179183 and rs1137101 did not associate with any of the measured variables, and no significant interactions of LEP or LEPR genotype with aerobic fitness were observed. In addition, none of the studied SNPs associated with aerobic or neuromuscular performance. Conclusions Aerobic fitness may not modify the effect of FTO variation on body composition traits. However, relative aerobic capacity associates with lower BMI and waist circumference regardless of the FTO genotype. FTO, LEP and LEPR genotypes unlikely associate with physical performance. PMID:23284729

  5. The influence of horizontal gene transfer on the mean fitness of unicellular populations in static environments.

    PubMed

    Raz, Yoav; Tannenbaum, Emmanuel

    2010-05-01

    Horizontal gene transfer (HGT) is believed to be a major source of genetic variation, particularly for prokaryotes. It is believed that horizontal gene transfer plays a major role in shaping bacterial genomes and is also believed to be responsible for the relatively rapid dissemination and acquisition of new, adaptive traits across bacterial strains. Despite the importance of horizontal gene transfer as a major source of genetic variation, the bulk of research on theoretical evolutionary dynamics and population genetics has focused on point mutations (sometimes coupled with gene duplication events) as the main engine of genomic change. Here, we seek to specifically model HGT processes in bacterial cells, by developing a mathematical model describing the influence that conjugation-mediated HGT has on the mutation-selection balance in an asexually reproducing population of unicellular, prokaryotic organisms. It is assumed that mutation-selection balance is reached in the presence of a fixed background concentration of antibiotic, to which the population must become resistant to survive. We find that HGT has a nontrivial effect on the mean fitness of the population. However, one of the central results that emerge from our analysis is that, at mutation-selection balance, conjugation-mediated HGT has a slightly deleterious effect on the mean fitness of a population. Therefore, we conclude that HGT does not confer a selection advantage in static environments. Rather, its advantage must lie in its ability to promote faster adaptation in dynamic environments, an interpretation that is consistent with the observation that HGT can be promoted by environmental stresses on a population. PMID:20194966

  6. 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…

  7. 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…

  8. 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.

  9. 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

  10. 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. PMID:19834268

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

    PubMed Central

    Joseph, Bindu; Corwin, Jason A; Li, Baohua; Atwell, Suzi; Kliebenstein, Daniel J

    2013-01-01

    Understanding genome to phenotype linkages has been greatly enabled by genomic sequencing. However, most genome analysis is typically confined to the nuclear genome. We conducted a metabolomic QTL analysis on a reciprocal RIL population structured to examine how variation in the organelle genomes affects phenotypic variation. This showed that the cytoplasmic variation had effects similar to, if not larger than, the largest individual nuclear locus. Inclusion of cytoplasmic variation into the genetic model greatly increased the explained phenotypic variation. Cytoplasmic genetic variation was a central hub in the epistatic network controlling the plant metabolome. This epistatic influence manifested such that the cytoplasmic background could alter or hide pairwise epistasis between nuclear loci. Thus, cytoplasmic genetic variation plays a central role in controlling natural variation in metabolomic networks. This suggests that cytoplasmic genomes must be included in any future analysis of natural variation. DOI: http://dx.doi.org/10.7554/eLife.00776.001 PMID:24150750

  12. Large-Scale Survey of Intraspecific Fitness and Cell Morphology Variation in a Protoploid Yeast Species

    PubMed Central

    Jung, Paul P.; Sigwalt, Anastasie; Ohnuki, Shinsuke; de Montigny, Jacky; Ohya, Yoshikazu; Schacherer, Joseph

    2016-01-01

    It is now clear that the exploration of the genetic and phenotypic diversity of nonmodel species greatly improves our knowledge in biology. In this context, we recently launched a population genomic analysis of the protoploid yeast Lachancea kluyveri (formerly Saccharomyces kluyveri), highlighting a broad genetic diversity (π = 17 × 10−3) compared to the yeast model organism, S. cerevisiae (π = 4 × 10−3). Here, we sought to generate a comprehensive view of the phenotypic diversity in this species. In total, 27 natural L. kluyveri isolates were subjected to trait profiling using the following independent approaches: (i) analyzing growth in 55 growth conditions and (ii) investigating 501 morphological changes at the cellular level. Despite higher genetic diversity, the fitness variance observed in L. kluyveri is lower than that in S. cerevisiae. However, morphological features show an opposite trend. In addition, there is no correlation between the origins (ecological or geographical) of the isolate and the phenotypic patterns, demonstrating that trait variation follows neither population history nor source environment in L. kluyveri. Finally, pairwise comparisons between growth rate correlation and genetic diversity show a clear decrease in phenotypic variability linked to genome variation increase, whereas no such a trend was identified for morphological changes. Overall, this study reveals for the first time the phenotypic diversity of a distantly related species to S. cerevisiae. Given its genetic properties, L. kluyveri might be useful in further linkage mapping analyses of complex traits, and could ultimately provide a better insight into the evolution of the genotype–phenotype relationship across yeast species. PMID:26888866

  13. 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

  14. 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. PMID:26470379

  15. A hierarchy of computationally derived surgical and patient influences on metal on metal press-fit acetabular cup failure.

    PubMed

    Clarke, S G; Phillips, A T M; Bull, A M J; Cobb, J P

    2012-06-01

    The impact of anatomical variation and surgical error on excessive wear and loosening of the acetabular component of large diameter metal-on-metal hip arthroplasties was measured using a multi-factorial analysis through 112 different simulations. Each surgical scenario was subject to eight different daily loading activities using finite element analysis. Excessive wear appears to be predominantly dependent on cup orientation, with inclination error having a higher influence than version error, according to the study findings. Acetabular cup loosening, as inferred from initial implant stability, appears to depend predominantly on factors concerning the area of cup-bone contact, specifically the level of cup seating achieved and the individual patient's anatomy. The extent of press fit obtained at time of surgery did not appear to influence either mechanism of failure in this study. PMID:22513086

  16. 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.

  17. 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…

  18. 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

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

    PubMed

    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

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

    PubMed

    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

  1. Variation in Fitness of the Longhorned Beetle, Dectes texanus, as a Function of Host Plant

    PubMed Central

    Michaud, J.P.; Grant, Angela K.

    2010-01-01

    Dectes texanus LeConte (Coleoptera: Cerambycidae) has become a serious pest of two different crops in the American Midwest, sunflower, Helianthus annuus L. and soybean, Glycines max (L.). Laboratory and field studies were used to compare the effects of these two host plants on D. texanus life history and behavior. Insects from soybean were 40–60% smaller than those from sunflower and larval weight at collection was strongly correlated with survival to adulthood, whereas it was not in sunflower, suggesting that body size was more limiting to immature survival in soybean. Pupal weights increased more rapidly with increasing stem diameter in soybean than in sunflower and the correlation was stronger, indicating that body size was more limited by plant size in soybean. Adults collected as larvae from soybean had shorter longevities when starved, fed soybean, or fed an alternating diet of soybean and cultivated sunflower, than did those collected from sunflower, suggesting a negative larval legacy of soybean on adult fitness. Adult beetles that developed in soybean lived longer when fed soybean than when starved, but an adult diet of sunflower doubled longevity compared to soybean for beetles that developed in sunflower, and tripled it for those that developed in soybean. An adult diet of wild H. annuus yielded survivorship equivalent to cultivated H. annuus in one trial, and slightly lower in another. Larval host plant did not influence the numbers of ovipunctures or eggs laid by females in field trials, but adult diet did. Sunflower-fed females punctured more, and laid more eggs, on sunflowers than on soybeans in field cages and the reverse trend was evident, but not significant, in soybean-fed females. It can be concluded that H. annuus is a superior food source to G. max for both larval and adult D. texanus, and that wild sunflowers may represent a valuable food for adults during the pre-reproductive period, prior to invasion of soybean fields, even though they

  2. 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

    2016-07-01

    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. PMID:26512761

  3. 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…

  4. 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. PMID:20434307

  5. 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

  6. Influence of sheet material shape on the thickness and fit of mouthguards.

    PubMed

    Takahashi, Mutsumi; Koide, Kaoru; Mizuhashi, Fumi

    2014-12-01

    The aim of this study was to evaluate the influence of sheet material shape on the thickness and fit of mouthguards. Mouthguards were fabricated using ethylene vinyl acetate sheets (4.0 mm thick) and a vacuum-forming machine. The working model was trimmed to a height of 20 mm at the incisor and 15 mm at the first molar. Three forming conditions were compared: Square sheets were fabricated while being secured by the clamping frames attached to the forming machine; round sheets were fabricated while secured by a circle tray; and square sheets were fabricated while secured by a circle tray. Each condition was defined when the sheet sagged by 15 mm below the level of the clamp. The thickness of the sheet was determined for the incisal and molar portion. Additionally, the difference in fit according to the forming conditions was analyzed. Differences in the material thickness or the fit due to forming conditions were analyzed using one-way analysis of variance (anova). Round sheets resulted in the thinnest mouthguard at the incisor and molar region and produced the best fit. For square sheets, no significant difference in thickness was observed between the clamping frame and circle tray methods. The fit of the mouthguard at the first molar was better when using square sheets fabricated by a circle tray than those fabricated by the clamping frame. In conclusion, when molding a mouthguard using square sheets, the thickness reduction was less and fit was better with using a circle tray, which may be clinically useful. PMID:24720352

  7. 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...

  8. 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

  9. Influence of physical exercise on simple reaction time: effect of physical fitness.

    PubMed

    Brisswalter, J; Arcelin, R; Audiffren, M; Delignières, D

    1997-12-01

    The influence of physical fitness and energy expenditure on a simple reaction time task performed during exercise was investigated. Two groups of 10 subjects were used, one was composed of trained middle-distance runners and one of students who had no regular physical training. The subjects performed a simple reaction time task while pedalling on a cycloergometer at different relative power output corresponding to 20, 40, 60, and 80% of their own maximal aerobic power and immediately after exercise. During exercise, the results showed a decrease in cognitive performance for both groups whereas no significant effect was found after exercise. A significant effect of physical fitness on simple reaction time was noted during exercise. The data are interpreted in terms of optimization of performance focusing particularly on the relations between energy cost of the physical task and attentional demand. PMID:9399313

  10. 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

  11. Climatic and Altitudinal Influences on Variation in Macaca Limb Morphology

    PubMed Central

    Weinstein, Karen J.

    2011-01-01

    This study compares limb lengths and joint diameters in the skeletons of six macaque species (Macaca assamensis, M. fascicularis, M. fuscata, M. mulatta, M. nemestrina, and M. thibetana) from a broad range of habitats and climates in order to test whether ambient temperatures, latitude, and altitude influence interspecific variation in limb morphology in this widely dispersed genus. Analysis of variance, principal component analysis, and partial correlation analysis reveal that species from temperate latitudes and high elevations tend to have short limbs and large joint diameters for their sizes while species from tropical latitudes and low elevations tend to have long limbs and small joint diameters. Interspecific variations in intra- and interlimb length proportions also reflect phylogeny and subtle differences in locomotion. The results of this study suggest that climatic conditions are important factors among many ecological variables that influence limb morphology in this geographically widespread genus. PMID:22567298

  12. 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

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

    PubMed

    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

  14. Experimental studies of adaptation in Clarkia xantiana. II. Fitness variation across a subspecies border.

    PubMed

    Geber, Monica A; Eckhart, Vincent M

    2005-03-01

    Because the range boundary is the locale beyond which a taxon fails to persist, it provides a unique opportunity for studying the limits on adaptive evolution. Adaptive constraints on range expansion are perplexing in view of widespread ecotypic differentiation by habitat and region within a species' range (regional adaptation) and rapid evolutionary response to novel environments. In this study of two parapatric subspecies, Clarkia xantiana ssp. xantiana and C. x. ssp. parviflora, we compared the fitness of population transplants within their native region, in a non-native region within the native range, and in the non-native range to assess whether range expansion might be limited by a greater intensity of selection on colonists of a new range versus a new region within the range. The combined range of the two subspecies spans a west-to-east gradient of declining precipitation in the Sierra Nevada of California, with ssp. xantiana in the west being replaced by ssp. parviflora in the east. Both subspecies had significantly higher fitness in the native range (range adaptation), whereas regional adaptation was weak and was found only in the predominantly outcrossing ssp. xantiana but was absent in the inbreeding ssp. parvifilora. Because selection intensity on transplants was much stronger in the non-native range relative to non-native regions, there is a larger adaptive barrier to range versus regional expansion. Three of five sequential fitness components accounted for regional and range adaptation, but only one of them, survivorship from germination to flowering, contributed to both. Flower number contributed to regional adaptation in ssp. xantiana and fruit set (number of fruits per flower) to range adaptation. Differential survivorship of the two taxa or regional populations of ssp. xantiana in non-native environments was attributable, in part, to biotic interactions, including competition, herbivory, and pollination. For example, low fruit set in ssp. xantiana

  15. Anthropometric influence on physical fitness among preschool children: gender-specific linear and curvilinear regression models.

    PubMed

    Kondric, Miran; Trajkovski, Biljana; Strbad, Maja; Foretić, Nikola; Zenić, Natasa

    2013-12-01

    There is evident lack of studies which investigated morphological influence on physical fitness (PF) among preschool children. The aim of this study was to (1) calculate and interpret linear and nonlinear relationships between simple anthropometric predictors and PF criteria among preschoolers of both genders, and (2) to find critical values of the anthropometric predictors which should be recognized as the breakpoint of the negative influence on the PF. The sample of subjects consisted of 413 preschoolers aged 4 to 6 (mean age, 5.08 years; 176 girls and 237 boys), from Rijeka, Croatia. The anthropometric variables included body height (BH), body weight (BW), sum of triceps and subscapular skinfold (SUMSF), and calculated BMI (BMI = BW (kg)/BH (m)2). The PF was screened throughout testing of flexibility, repetitive strength, explosive strength, and agility. Linear and nonlinear (general quadratic model y = a + bx + cx2) regressions were calculated and interpreted simultaneously. BH and BW are far better predictors of the physical fitness status than BMI and SUMSF. In all calculated regressions excluding flexibility criterion, linear and nonlinear prediction of the PF throughout BH and BW reached statistical significance, indicating influence of the advancement in maturity status on PF variables Differences between linear and nonlinear regressions are smaller in males than in females. There are some indices that the age of 4 to 6 years is a critical period in the prevention of obesity, mostly because the extensively studied and proven negative influence of overweight and adiposity on PF tests is not yet evident. In some cases we have found evident regression breakpoints (approximately 25 kg in boys), which should be interpreted as critical values of the anthropometric measures for the studied sample of subjects. PMID:24611341

  16. The influence of cardiorespiratory fitness on strategic, behavioral, and electrophysiological indices of arithmetic cognition in preadolescent children

    PubMed Central

    Moore, R. Davis; Drollette, Eric S.; Scudder, Mark R.; Bharij, Aashiv; Hillman, Charles H.

    2014-01-01

    The current study investigated the influence of cardiorespiratory fitness on arithmetic cognition in forty 9–10 year old children. Measures included a standardized mathematics achievement test to assess conceptual and computational knowledge, self-reported strategy selection, and an experimental arithmetic verification task (including small and large addition problems), which afforded the measurement of event-related brain potentials (ERPs). No differences in math achievement were observed as a function of fitness level, but all children performed better on math concepts relative to math computation. Higher fit children reported using retrieval more often to solve large arithmetic problems, relative to lower fit children. During the arithmetic verification task, higher fit children exhibited superior performance for large problems, as evidenced by greater d' scores, while all children exhibited decreased accuracy and longer reaction time for large relative to small problems, and incorrect relative to correct solutions. On the electrophysiological level, modulations of early (P1, N170) and late ERP components (P3, N400) were observed as a function of problem size and solution correctness. Higher fit children exhibited selective modulations for N170, P3, and N400 amplitude relative to lower fit children, suggesting that fitness influences symbolic encoding, attentional resource allocation and semantic processing during arithmetic tasks. The current study contributes to the fitness-cognition literature by demonstrating that the benefits of cardiorespiratory fitness extend to arithmetic cognition, which has important implications for the educational environment and the context of learning. PMID:24829556

  17. The influence of cardiorespiratory fitness on strategic, behavioral, and electrophysiological indices of arithmetic cognition in preadolescent children.

    PubMed

    Moore, R Davis; Drollette, Eric S; Scudder, Mark R; Bharij, Aashiv; Hillman, Charles H

    2014-01-01

    The current study investigated the influence of cardiorespiratory fitness on arithmetic cognition in forty 9-10 year old children. Measures included a standardized mathematics achievement test to assess conceptual and computational knowledge, self-reported strategy selection, and an experimental arithmetic verification task (including small and large addition problems), which afforded the measurement of event-related brain potentials (ERPs). No differences in math achievement were observed as a function of fitness level, but all children performed better on math concepts relative to math computation. Higher fit children reported using retrieval more often to solve large arithmetic problems, relative to lower fit children. During the arithmetic verification task, higher fit children exhibited superior performance for large problems, as evidenced by greater d' scores, while all children exhibited decreased accuracy and longer reaction time for large relative to small problems, and incorrect relative to correct solutions. On the electrophysiological level, modulations of early (P1, N170) and late ERP components (P3, N400) were observed as a function of problem size and solution correctness. Higher fit children exhibited selective modulations for N170, P3, and N400 amplitude relative to lower fit children, suggesting that fitness influences symbolic encoding, attentional resource allocation and semantic processing during arithmetic tasks. The current study contributes to the fitness-cognition literature by demonstrating that the benefits of cardiorespiratory fitness extend to arithmetic cognition, which has important implications for the educational environment and the context of learning. PMID:24829556

  18. 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

  19. 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. PMID:26784581

  20. 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…

  1. S100B and the influence of seasonal variation.

    PubMed

    Henriksson, Anders E

    2016-07-01

    Background A blood test for S100B can be used to rule out intracranial complications after minor head injury and thereby reduce the need for computed tomography (CT) examinations. The aim of this study was to investigate the clinical importance of a possible influence of seasonal variation on S100B. Methods The individual seasonal variation of S100B in 69 healthy volunteers living at latitudes with extremely variable seasonal exposure to sunlight was investigated. Results The mean serum concentration of S100B was 13% higher in August than in February, but however, not statistically significant (p = 0.068). A good agreement between summer and winter S100B values was confirmed by Bland-Altman analysis and a significant correlation (r = 0.317, p = 0.008) was shown between summer and winter S100B values. Conclusion This study did not show any clinical importance of seasonal variation of S100B that may influence the decision of CT scanning patients with head injuries. PMID:26982090

  2. 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

  3. 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

  4. 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

  5. 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. PMID:22992067

  6. 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. PMID:24863129

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

    PubMed

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

    2014-07-01

    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

  8. 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

  9. 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

  10. The influence of functional fitness and cognitive training of physical disabilities of institutions.

    PubMed

    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

  11. Factors influencing wear and osteolysis in press-fit condylar modular total knee replacements.

    PubMed

    Fehring, Thomas K; Murphy, Jeffrey A; Hayes, T David; Roberts, Donald W; Pomeroy, Donald L; Griffin, William L

    2004-11-01

    The purpose of this study was to determine the factors influencing wear and osteolysis in patients who have had total knee arthroplasty with the Press-Fit Condylar modular system. Two-thousand ninety-one primary total knee replacements in 1737 patients were done using the Press-Fit Condylar system at three centers. Radiographic and manufacturing data were obtained for 2016 of the 2091 implants (96.4%). For the 1287 of 2016 knees (64%) with more than 5 years of followup, the prevalence of wear-related failure was 8.3%. The 13-year survivorship for all patients was 82.6%. Cox hazards analysis revealed five variables that were correlated with wear-related failure: patient age, patient gender, polyethylene sheet vendor, polyethylene finishing method, and polyethylene shelf age. We were unable to identify one factor as the defining reason for these wear-related failures. The multiple changes in manufacturing methods during the life of this implant may have precluded such a determination. These results may be specific to inserts sterilized in air with gamma irradiation and should not be generalized to current manufacturing techniques. This study emphasizes the potential deleterious effects that small changes in the manufacturing process may have on the outcome of a prosthesis with an initially favorable survivorship. PMID:15534517

  12. Heat shock protein 101 effects in A. thaliana: genetic variation, fitness and pleiotropy in controlled temperature conditions

    PubMed Central

    TONSOR, S. J.; SCOTT, C.; BOUMAZA, I.; LISS, T. R.; BRODSKY, J. L.; VIERLING, E.

    2009-01-01

    The Hsp100/ClpB heat shock protein family is ancient and required for high temperature survival, but natural variation in expression and its phenotypic effects is unexplored in plants. In controlled environment experiments, we examined the effects of variation in the Arabidopsis cytosolic AtHsp101 (hereafter Hsp101). Ten wild-collected ecotypes differed in Hsp101 expression responses across a 22 to 40 °C gradient. Genotypes from low latitudes expressed the least Hsp101. We tested fitness and pleiotropic consequences of varying Hsp101 expression in ‘control’ vs. mild thermal stress treatments (15/25 °C D/N vs. 15/25° D/N plus 3 h at 35 °C 3 days/week). Comparing wild type and null mutants, wt Columbia (Col) produced ~33% more fruits compared to its Hsp101 homozygous null mutant. There was no difference between Landsberg erecta null mutant NIL (Ler) and wt Ler; wt Ler showed very low Hsp101 expression. In an assay of six genotypes, fecundity was a saturating function of Hsp101 content, in both experimental treatments. Thus, in addition to its essential role in acquired thermal tolerance, Hsp101 provides a substantial fitness benefit under normal growth conditions. Knocking out Hsp101 decreased fruit production, days to germination and days to bolting, total dry mass, and number of inflorescences; it increased transpiration rate and allocation to root mass. Root : total mass ratio decayed exponentially with Hsp101 content. This study shows that Hsp101 expression is evolvable in natural populations. Our results further suggest that Hsp101 is primarily an emergency high-temperature tolerance mechanism, since expression levels are lower in low-latitude populations from warmer climates. Hsp101 expression appears to carry an important trade-off in reduced root growth. This trade-off may select for suppressed expression under chronically high temperatures. PMID:18321256

  13. Heat shock protein 101 effects in A. thaliana: genetic variation, fitness and pleiotropy in controlled temperature conditions.

    PubMed

    Tonsor, S J; Scott, C; Boumaza, I; Liss, T R; Brodsky, J L; Vierling, E

    2008-03-01

    The Hsp100/ClpB heat shock protein family is ancient and required for high temperature survival, but natural variation in expression and its phenotypic effects is unexplored in plants. In controlled environment experiments, we examined the effects of variation in the Arabidopsis cytosolic AtHsp101 (hereafter Hsp101). Ten wild-collected ecotypes differed in Hsp101 expression responses across a 22 to 40 degrees C gradient. Genotypes from low latitudes expressed the least Hsp101. We tested fitness and pleiotropic consequences of varying Hsp101 expression in 'control' vs. mild thermal stress treatments (15/25 degrees C D/N vs. 15/25 degrees D/N plus 3 h at 35 degrees C 3 days/week). Comparing wild type and null mutants, wt Columbia (Col) produced approximately 33% more fruits compared to its Hsp101 homozygous null mutant. There was no difference between Landsberg erecta null mutant NIL (Ler) and wt Ler; wt Ler showed very low Hsp101 expression. In an assay of six genotypes, fecundity was a saturating function of Hsp101 content, in both experimental treatments. Thus, in addition to its essential role in acquired thermal tolerance, Hsp101 provides a substantial fitness benefit under normal growth conditions. Knocking out Hsp101 decreased fruit production, days to germination and days to bolting, total dry mass, and number of inflorescences; it increased transpiration rate and allocation to root mass. Root : total mass ratio decayed exponentially with Hsp101 content. This study shows that Hsp101 expression is evolvable in natural populations. Our results further suggest that Hsp101 is primarily an emergency high-temperature tolerance mechanism, since expression levels are lower in low-latitude populations from warmer climates. Hsp101 expression appears to carry an important trade-off in reduced root growth. This trade-off may select for suppressed expression under chronically high temperatures. PMID:18321256

  14. 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

  15. 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

    2015-01-01

    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

  16. 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

  17. Influence of Cardiorespiratory Fitness on PPARG mRNA Expression Using Monozygotic Twin Case Control

    PubMed Central

    Queiroga, Marcos Roberto; Barbieri, Ricardo Augusto; Ferreira, Sandra Aires; Luchessi, André Ducati; Hirata, Rosario Dominguez Crespo; Hirata, Mario Hiroyuki; Kokubun, Eduardo

    2015-01-01

    The influence of cardiorespiratory fitness (VO2max) on anthropometric variables and PPARG mRNA expression was investigated. Monozygotic twin pairs aged 11–18 years were grouped into discordant (D) and concordant (C) high and low VO2max groups. VO2max was determined by progressive maximal exercise test on treadmill with gas exchange analysis. Body mass (BM), BMI, waist circumference (WC), triceps (TR), and subscapular (SB) skinfold thicknesses were measured. Twins from the discordant group had differences in VO2max values (D-high = 45.9 ± 10.0 versus D-low = 32.4 ± 10.6 mL·kg−1·min−1, P = 0.025), while no differences were found in the concordant group (C-high = 42.4 ± 9.2 versus C-low = 38.8 ± 9.8 mL·kg−1·min−1, P = 0.952). In discordant group, VO2max was negatively correlated with TR + SB (r = −0.540, P = 0.021) and positively correlated with PPARG expression in leukocytes (r = 0.952, P = 0.001). Moreover, PPARG expression was directly correlated with BM (r = 0.714, P = 0.047) and height (r = 0.762, P = 0.028). In concordant twins, VO2max was inversely correlated with BM (r = −0.290, P = 0.027), BMI (r = −0.472, P = 0.001), WC (r = −0.426, P = 0.001), and TR + SB (r = −0.739, P = 0.001). Twins D-high had 1.78-fold greater PPARG expression when compared with twins D-low (P = 0.048). In conclusion, the cardiorespiratory fitness may modulate PPARG expression in childhood and adolescence, independently of the genetic background. PMID:25879043

  18. The influence of solar spectral variations on global radiative balance

    NASA Astrophysics Data System (ADS)

    Gao, Feng-Ling; Tao, Le-Ren; Cui, Guo-Min; Xu, Jia-Liang; Hua, Tse-Chao

    2015-01-01

    The total solar irradiance (TSI) has been the sole solar input in many climate models for lack of long and reliable time series of solar spectral irradiance (SSI) measurements currently. However, based on the recent SSI measurements by the Solar Radiation and Climate Experiment, which is able to provide full and accurate SSI measurements, the influence of SSI variations on global radiative balance between the descending phase of previous solar cycle in December 2007 and the ascending phase of the current solar cycle in the first half 2010 has been studied in this paper. The results show that the relatively larger TSI in the first half 2010 was mainly due to the ultraviolet and near infrared radiation enhancements, with average increases of 0.11% in 200-400 nm and 0.05% in 760-4000 nm respectively, while the radiation in visible region of 400-760 nm decreased by 0.05%. According to the measurements of ozone from the Aura-Microwave Limb Sounder satellite, the global average stratospheric ozone increased markedly in the layer of 25-40 km at the same time. The visible radiation decrease and stratospheric ozone increase together contributed to the smaller solar radiation at the tropopause for each month of the first half 2010 as compared with that in December 2007, with the maximum decrease of 0.15 W m-2 in March 2010. The study reveals that SSI variations in the ascending solar phase may also cool the Earth-atmosphere system.

  19. 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

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

    PubMed

    Moon, Sunjin; Akey, Joshua M

    2016-06-01

    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

  1. Influence of Compositional Variations on Floc Size and Strength

    NASA Astrophysics Data System (ADS)

    Yin, H.; Tan, X.; Reed, A. H.; Furukawa, Y.; Zhang, G.

    2010-12-01

    Clay-biopolymer micro aggregates or flocs are abundant in waters, including rivers, lakes, and oceans. Owing to their small size and charged surfaces, fine-grained inorganic sediment particles, mainly clays, interact actively with organic substances, such as organic matter and biogenic polymers, to form aggregates or flocs, typically in the size of 10-1000 μm. The flocs in ocean waters are also termed “marine snow”. These flocs are typically porous, tenuous, and soft in nature. During transport in suspension, they may breakdown and decrease in size if the turbulent shear stress exceeds their strength. They may also collide and form larger ones if the shear stress is relatively small. Since flocs of different size and structure settle at different velocities, understanding their strength is also of essential importance for sediment hydrodynamics, transport, and management. Our study focuses on investigating the influence of compositional variations on floc size and strength so that a better understanding of floc dynamics can be achieved. A laser diffraction-based Cilas® particle size and shape analyzer with controllable fluid circulation velocity was employed to conduct floc size measurements and shape imaging, the latter achieved by a high resolution inverted optical microscope, which is also installed with the size analyzer. Totally two clay minerals, kaolinite and illite, were tested as the model inorganic solid skeleton minerals for floc formation, and two biopolymers, anionic xanthan gum and neutral guar gum, were chosen as analogs of naturally occurring organic matter or biopolymers to simulate clay-biopolymer floc formation. Moreover, the concentration of both organic and inorganic phases was varied. The floc breakage or tensile strength was indirectly estimated by the varied fluid flow velocity in the particle size analyzer’s circulation system. For each individual composition, stable flocs were formed by three different fluid circulating velocities

  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. Quantifying the influence of melt on velocity variations at a large Greenland outlet glacier

    NASA Astrophysics Data System (ADS)

    Andersen, M. L.; Nettles, M.; Elosegui, P.; Larsen, T.; Hamilton, G. S.; Stearns, L. A.

    2010-12-01

    The flow speed of Greenland outlet glaciers is governed by many factors, some of which are poorly understood. One such factor is surface-generated melt water, which has been shown to have a significant effect by enhancing basal lubrication. Previously, we have demonstrated a correlation between variations in glacier flow speed and meltwater input at Helheim Glacier, East Greenland. Here, we analyze local and across-glacier melt water estimates along with daily GPS-derived mean surface velocities from the same area to investigate spatial and temporal variations in glacier response to melt-water input. We perform linear least-squares fits of velocity to melt and thereby invert for a sensitivity value with which to produce predicted velocity records. We also investigate the seasonal variability of melt influence in 2008. We track the residual misfits for a sliding time window using steps of one day while performing the inversion for each step. We detect decreasing values of sensitivity with distance along the flowline from the calving front. Moreover, we observe that misfits drop gradually as the season progresses, accompanied by a steep increase in modeled sensitivity. Toward the end of the season, a very strong correlation between melt and surface displacement occurs and is sustained for ~6 days. We interpret this change as reflecting a gradual change in subglacial hydraulic routing from a tunnel-dominated to a linked-cavity dominated system and back. Investigations of melt-water influence on fast outlet glacier flow may be key in understanding solid mass loss from the Greenland Ice Sheet, which has been shown to comprise half of the current negative mass budget.

  4. 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. PMID:27453812

  5. The influence of aerobic fitness status on ventilatory efficiency in patients with coronary artery disease

    PubMed Central

    Prado, Danilo M L; Rocco, Enéas A; Silva, Alexandre G; Silva, Priscila F; Lazzari, Jaqueline M; Assumpção, Gabriela L; Thies, Sheyla B; Suzaki, Claudia Y; Puig, Raphael S; Furlan, Valter

    2015-01-01

    OBJECTIVE: To test the hypotheses that 1) coronary artery disease patients with lower aerobic fitness exhibit a lower ventilatory efficiency and 2) coronary artery disease patients with lower initial aerobic fitness exhibit greater improvements in ventilatory efficiency with aerobic exercise training. METHOD: A total of 123 patients (61.0±0.7 years) with coronary artery disease were divided according to aerobic fitness status into 3 groups: group 1 (n = 34, peak VO2<17.5 ml/kg/min), group 2 (n = 67, peak VO2>17.5 and <24.5 ml/kg/min) and group 3 (n = 22, peak VO2>24.5 ml/kg/min). All patients performed a cardiorespiratory exercise test on a treadmill. Ventilatory efficiency was determined by the lowest VE/VCO2 ratio observed. The exercise training program comprised moderate-intensity aerobic exercise performed 3 times per week for 3 months. Clinicaltrials.gov: NCT02106533 RESULTS: Before intervention, group 1 exhibited both lower peak VO2 and lower ventilatory efficiency compared with the other 2 groups (p<0.05). After the exercise training program, group 1 exhibited greater improvements in aerobic fitness and ventilatory efficiency compared with the 2 other groups (group 1: ▵ = -2.5±0.5 units; group 2: ▵ = -0.8±0.3 units; and group 3: ▵ = -1.4±0.6 units, respectively; p<0.05). CONCLUSIONS: Coronary artery disease patients with lower aerobic fitness status exhibited lower ventilatory efficiency during a graded exercise test. In addition, after 3 months of aerobic exercise training, only the patients with initially lower levels of aerobic fitness exhibited greater improvements in ventilatory efficiency. PMID:25672429

  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 influence of age and aerobic fitness on chromosomal damage in Austrian institutionalised elderly.

    PubMed

    Franzke, Bernhard; Halper, Barbara; Hofmann, Marlene; Oesen, Stefan; Peherstorfer, Heidemarie; Krejci, Klemens; Koller, Birgit; Geider, Karin; Baierl, Andreas; Tosevska, Anela; Strasser, Eva-Maria; Wessner, Barbara; Wagner, Karl-Heinz

    2014-11-01

    Ageing goes hand in hand with altered DNA repair and defence mechanisms against DNA damage. To improve the body's overall resistance against chromosomal damage, maintaining a healthy and active lifestyle is of great concern, especially in the elderly. As more and more people are getting older, they change from home living to an institutionalised situation, which is often accompanied by malnutrition, depression and inactivity. So far, there is a lack of data on chromosomal damage in relation to age and fitness status. The aim of this study was to examine the effect of age and aerobic fitness on endpoints of DNA damage in 105 institutionalised women and men (65-98 years) living in Vienna. Chromosomal damage was measured by conducting the cytokinesis block micronucleus cytome assay. Aerobic fitness of the participants was assessed using the 6-min walking test. To investigate the effect of age on micronuclei (MN) frequency and evaluate the particular age group, our data were merged with data from a recent study by Wallner et al. (Effects of unconjugated bilirubin on chromosomal damage in individuals with Gilbert's syndrome measured with the micronucleus cytome assay. Mutagenesis 2012; 27: 731-735). Age and MN frequency correlated significantly for squared regression (r = 0.577; P = 0.000) and showed a levelling-off at ~60 years of age. Furthermore, we observed a significant negative linear correlation (r = -0.222; P = 0.03) between MN frequency and 6-min walking performance. There was a plateau-like effect of the MN frequency above the age of 60-70 years, indicating a higher resistance against chromosomal damage of the 'survivors' of the regular lifespan. This study suggests that aerobic fitness 'protects' against chromosomal damage at high age. PMID:25217503

  8. Discovery and characterization of cryptic endophytes that influence ecological fitness of host vegetation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mechanisms by which seedborne endophytic microbes interact with host plants to influence larger ecological processes are widely unknown. Nonetheless, systems in which endophyte dynamics have been examined suggest high potential to utilize microbes for vegetative restoration. A long term, multidisc...

  9. 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. PMID:26799846

  10. 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. PMID:14769079

  11. 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. PMID:26166058

  12. 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…

  13. 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.

  14. [Seasonal variation and related influencing factors for tuberculosis].

    PubMed

    Zhang, Z B; Lu, Z Q; Xie, H; Duan, Q H

    2016-08-10

    Tuberculosis is recognized as a chronic respiratory infectious disease and still one of the important public health issues in the world. Douglas reported an unique seasonal pattern (summer peak) of tuberculosis, when compared with most other respiratory diseases in 1996. Since then, there had been many other researchers notified various patterns of seasonality on TB. This paper reviewed all the studies published in the last five years and analyzed the current findings on seasonal variability and influencing factors, in order to explore the risk factors to provide evidence for prevention and control strategies on tuberculosis. PMID:27539356

  15. 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. PMID:12005034

  16. Influence of thermal anisotropy on best-fit estimates of shock normals

    NASA Technical Reports Server (NTRS)

    Lepping, R. P.

    1971-01-01

    The influence of thermal anisotropy on the estimates of interplanetary shock parameters and the associated normals is discussed. A practical theorem is presented for quantitatively correcting for anisotropic effects by weighting the before and after magnetic fields by the same anisotropy parameter h. The quantity h depends only on the thermal anisotropies before and after the shock and on the angles between the magnetic fields and the shock normal. The theorem can be applied to most slow shocks, but in those cases h usually should be lower, and sometimes markedly lower, than unity. For the extreme values of h, little change results in the shock parameters or in the shock normal.

  17. Competitive fitness during feast and famine: how SOS DNA polymerases influence physiology and evolution in Escherichia coli.

    PubMed

    Corzett, Christopher H; Goodman, Myron F; Finkel, Steven E

    2013-06-01

    Escherichia coli DNA polymerases (Pol) II, IV, and V serve dual roles by facilitating efficient translesion DNA synthesis while simultaneously introducing genetic variation that can promote adaptive evolution. Here we show that these alternative polymerases are induced as cells transition from exponential to long-term stationary-phase growth in the absence of induction of the SOS regulon by external agents that damage DNA. By monitoring the relative fitness of isogenic mutant strains expressing only one alternative polymerase over time, spanning hours to weeks, we establish distinct growth phase-dependent hierarchies of polymerase mutant strain competitiveness. Pol II confers a significant physiological advantage by facilitating efficient replication and creating genetic diversity during periods of rapid growth. Pol IV and Pol V make the largest contributions to evolutionary fitness during long-term stationary phase. Consistent with their roles providing both a physiological and an adaptive advantage during stationary phase, the expression patterns of all three SOS polymerases change during the transition from log phase to long-term stationary phase. Compared to the alternative polymerases, Pol III transcription dominates during mid-exponential phase; however, its abundance decreases to <20% during long-term stationary phase. Pol IV transcription dominates as cells transition out of exponential phase into stationary phase and a burst of Pol V transcription is observed as cells transition from death phase to long-term stationary phase. These changes in alternative DNA polymerase transcription occur in the absence of SOS induction by exogenous agents and indicate that cell populations require appropriate expression of all three alternative DNA polymerases during exponential, stationary, and long-term stationary phases to attain optimal fitness and undergo adaptive evolution. PMID:23589461

  18. Brightness Variations of the Sun and Solar-like Stars over Space and Time: How does the Sun fit in?

    NASA Astrophysics Data System (ADS)

    Guinan, Edward Francis; DeWarf, Laurence E.

    2015-08-01

    We discuss the light variations of the Sun and solar-type stars as a function of age. As part of the "Sun in Time" Program we have studied solar-type (G0-G5 V) stars with ages from ~30 Myr up to 8 Gyr. This program reveals that young solar-type stars rotate rapidly (P< 2 days) and have significant periodic light variations arising from starspots and white light chromospheric plage structures on their surfaces. For young G0-5 V stars these light variations are typically ~3-10%. The present Sun (at ~4.57 Gyr) has a rotation period of P(rot) ~25.5 days and typically has rotational induced light variations of ~0.1-0.3% that arise primarily from sunspots and also from bright chromospheric structures. The brightness variations over the ~11 yr solar activity cycle typically are ~0.2%.The rotation periods of the Sun and related solar-type stars decrease with age as they lose angular momentum with time via magnetic winds. Excellent relations among rotation-age-magnetic activity have been found and will be presented. In addition to ground-based photometry, extensive ultra-high precision photometry for solar-type stars from the Kepler Mission are used to probe sunspot activity and spot distributions on solar-type stars with ages similar (=solar twins), and as well as for stars older than the Sun. This allows comparisons to be made to put the Sun "in context" with other "suns" and solar-twins with the same masses and ages as our Sun. The results of these studies will discussed.We acknowledge support for this research from grants from NASA (HST & Chandra) and NSF/RUI. We are very grateful for this support.

  19. 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.

  20. 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. PMID:21670858

  1. Art as an indicator of male fitness: does prenatal testosterone influence artistic ability?

    PubMed

    Crocchiola, Danae

    2014-01-01

    In his groundbreaking research, Geoffrey Miller (1999) suggests that artistic and creative displays are male-predominant behaviors and can be considered to be the result of an evolutionary advantage. The outcomes of several surveys conducted on jazz and rock musicians, contemporary painters, English writers (Miller, 1999), and scientists (Kanazawa, 2000) seem to be consistent with the Millerian hypothesis, showing a predominance of men carrying out these activities, with an output peak corresponding to the most fertile male period and a progressive decline in late maturity. One way to evaluate the sex-related hypothesis of artistic and cultural displays, considered as sexual indicators of male fitness, is to focus on sexually dimorphic traits. One of them, within our species, is the 2nd to 4th digit length (2D:4D), which is a marker for prenatal testosterone levels. This study combines the Millerian theories on sexual dimorphism in cultural displays with the digit ratio, using it as an indicator of androgen exposure in utero. If androgenic levels are positively correlated with artistic exhibition, both female and male artists should show low 2D:4D ratios. In this experiment we tested the association between 2D:4D and artistic ability by comparing the digit ratios of 50 artists (25 men and 25 women) to the digit ratios of 50 non-artists (25 men and 25 women). Both male and female artists had significantly lower 2D:4D ratios (indicating high testosterone) than male and female controls. These results support the hypothesis that art may represent a sexually selected, typically masculine behavior that advertises the carrier's good genes within a courtship context. PMID:25299990

  2. 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

  3. 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.

  4. The influence of statistical variations on image quality

    NASA Astrophysics Data System (ADS)

    Hultgren, Bror; Hertel, Dirk; Bullitt, Julian

    2006-01-01

    For more than thirty years imaging scientists have constructed metrics to predict psychovisually perceived image quality. Such metrics are based on a set of objectively measurable basis functions such as Noise Power Spectrum (NPS), Modulation Transfer Function (MTF), and characteristic curves of tone and color reproduction. Although these basis functions constitute a set of primitives that fully describe an imaging system from the standpoint of information theory, we found that in practical imaging systems the basis functions themselves are determined by system-specific primitives, i.e. technology parameters. In the example of a printer, MTF and NPS are largely determined by dot structure. In addition MTF is determined by color registration, and NPS by streaking and banding. Since any given imaging system is only a single representation of a class of more or less identical systems, the family of imaging systems and the single system are not described by a unique set of image primitives. For an image produced by a given imaging system, the set of image primitives describing that particular image will be a singular instantiation of the underlying statistical distribution of that primitive. If we know precisely the set of imaging primitives that describe the given image we should be able to predict its image quality. Since only the distributions are known, we can only predict the distribution in image quality for a given image as produced by the larger class of 'identical systems'. We will demonstrate the combinatorial effect of the underlying statistical variations in the image primitives on the objectively measured image quality of a population of printers as well as on the perceived image quality of a set of test images. We also will discuss the choice of test image sets and impact of scene content on the distribution of perceived image quality.

  5. Notch Ankyrin Repeat Domain Variation Influences Leukemogenesis and Myc Transactivation

    PubMed Central

    Aster, Jon C.; Bodnar, Nick; Xu, Lanwei; Karnell, Fredrick; Milholland, John M.; Maillard, Ivan; Histen, Gavin; Nam, Yunsun; Blacklow, Stephen C.; Pear, Warren S.

    2011-01-01

    Background The functional interchangeability of mammalian Notch receptors (Notch1-4) in normal and pathophysiologic contexts such as cancer is unsettled. We used complementary in vivo, cell-based and structural analyses to compare the abilities of activated Notch1-4 to support T cell development, induce T cell acute lymphoblastic leukemia/lymphoma (T-ALL), and maintain T-ALL cell growth and survival. Principal Findings We find that the activated intracellular domains of Notch1-4 (ICN1-4) all support T cell development in mice and thymic organ culture. However, unlike ICN1-3, ICN4 fails to induce T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) and is unable to rescue the growth of Notch1-dependent T-ALL cell lines. The ICN4 phenotype is mimicked by weak gain-of-function forms of Notch1, suggesting that it stems from a failure to transactivate one or more critical target genes above a necessary threshold. Experiments with chimeric receptors demonstrate that the Notch ankyrin repeat domains differ in their leukemogenic potential, and that this difference correlates with activation of Myc, a direct Notch target that has an important role in Notch-associated T-ALL. Conclusions/Significance We conclude that the leukemogenic potentials of Notch receptors vary, and that this functional difference stems in part from divergence among the highly conserved ankyrin repeats, which influence the transactivation of specific target genes involved in leukemogenesis. PMID:22022427

  6. Intraspecific variation influences natural settlement of eastern oysters.

    PubMed

    Smee, Delbert L; Overath, R Deborah; Johnson, Keith D; Sanchez, James A

    2013-11-01

    As populations decline, their intraspecific diversity also diminishes. Population decline may be exacerbated if a decrease in intraspecific diversity also reduces important ecological functions that maintain population numbers. Oyster reefs are severely overharvested, declining by ~85 % worldwide. We tested how increasing within-species diversity of eastern oysters (Crassostrea virginica) using transplants would affect recruitment of oyster larvae, a key function necessary to maintain future populations. If harvesting reduces population numbers, within-species diversity, and connectivity, then oysters may lose the ability to adapt to changing environmental conditions as well as incur lower levels of recruitment that may hasten their decline. Results from laboratory and field studies indicated that oyster larvae use chemical cues from adult oysters and not from associated fouling communities to select settlement sites. To test how increasing within-species diversity of oysters affected recruitment, we collected oysters from three distinct bay systems in Texas, USA, and compared natural settlement in treatments where all oysters were from a single bay to a mixture of all three bays. Significantly greater recruitment occurred in mixed treatments in 2010, 2011, and 2012 even though oyster recruitment varied by order of magnitude during this time. The net biodiversity effect was positive in all 3 years, indicating that increased recruitment in mixed treatments can be greater than the additive effect of the single bay treatments. Losing intraspecific diversity may reduce recruitment and lead to further declines in oyster populations, illustrating the need for understanding how intraspecific diversity influences ecological functions. PMID:23543216

  7. 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. PMID:26295154

  8. 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

  9. 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.

  10. 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

  11. Monitoring the press-fit insertion of an acetabular cup by impact measurements: influence of bone abrasion.

    PubMed

    Michel, Adrien; Bosc, Romain; Mathieu, Vincent; Hernigou, Philippe; Haiat, Guillaume

    2014-10-01

    Press-fit procedures used for the insertion of cementless hip prostheses aim at obtaining optimal implant primary stability. We have previously used the measurement of impact duration to follow the insertion of the acetabular cup implant within bone tissue. The aim of this study was to investigate the variation of the value of the impact momentum due to successive insertions of the acetabular cup into bone tissue. The results obtained with impact momentum and contact duration measurements were compared. A total of 10 bovine bone samples were subjected to three successive procedures consisting of 10 reproducible impacts (3.5 kg falling 40 mm). Each procedure aimed at inserting the acetabular cup implant into the same bone cavity. The time variation of force during each impact was recorded by a force sensor, allowing the measurement of the impact duration (I 1) and momentum (I 2). The value of I 2 increased as a function of the impact number and reached a constant value after N 2 = 5.07 ± 1.31 impacts. Moreover, statistical analyses show that N 2 decreased significantly as a function of the number of experiments, which may be due to abrasion phenomena at the bone-implant interface. Abrasion phenomena led to a faster insertion of the acetabular cup when the implant had been previously inserted into the same bone cavity. An empirical analytical model considering a flat punch configuration to model the bone-implant contact conditions was used to understand the trend of the variation of I 2 during the insertion of the acetabular cup. The measurement of the force during impacts is useful to assess the bone-implant interface properties, but needs to be validated in the clinic to be useful for orthopaedic surgeons intra-operatively. PMID:25258009

  12. 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

  13. Separating Pumping and Other Influences on Groundwater Head Variation

    NASA Astrophysics Data System (ADS)

    Shapoori, V.; Western, A. W.; Peterson, T. J.; Costelloe, J.

    2012-12-01

    The dynamics of unconfined groundwater levels are usually the result of numerous and interacting factors, such as land cover change, climate variability and groundwater pumping. Estimating the impact from pumping is highly significant for resource management but also very challenging. A variety of methods are used to model water-table dynamics influenced by pumping, ranging from spatially explicit, numerical models to stochastic approaches. Transfer function noise (TFN) modelling can be used to model the dynamic behaviour of a wide range of hydrologic variables, including time series of groundwater head. Recently, TFN models have been developed to better link water table dynamics with different types of individual stresses, including pumping (Von Asmuth et al. 2002). Peterson & Western (2011) advanced the transfer function noise model of Von Asmuth et al. (2002) to account for non-linear hydrological processes by inclusion of a parsimonious vertically lumped soil moisture storage(SMS). Shapoori et al. (2011) proposed an improved time series formulation for estimation of the impacts of pumping. That study undertook a synthetic assessment of the ability of a range of time series models to represent the impacts of pumping by applying them to groundwater head time series from a synthetic aquifer. This paper further expands the Shapoori at al. (2011) time series method for quantifying the impact of groundwater pumping within unconfined sedimentary aquifers by applying it to real data and by taking account of a surface water body. The study area is the Clydebank groundwater subregion located in Victoria Australia. Nine salinity control pumping bores are used in some of the worst salinity areas to lower the groundwater table and consequently reduce soil salinity. The method has been applied to 43 observation bores and the results show that the model has good predictive performance with mean and minimum coefficient efficiency values of 0.7 and 0.5 respectively. In addition

  14. Estimating the extent of stress influence by using earthquake triggering groundwater level variations in Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, Shih-Jung; Hsu, Kuo-Chin; Lai, Wen-Chi; Wang, Chein-Lee

    2015-11-01

    Groundwater level variations associated with earthquake events may reveal useful information. This study estimates the extent of stress influence, defined as the distance over which an earthquake can induce a step change of the groundwater level, using earthquake-triggering groundwater level variations in Taiwan. Groundwater variations were first characterized based on the dynamics of groundwater level changes dominantly triggered by earthquakes. The step-change data in co-seismic groundwater level variations were used to analyze the extent of stress influence for earthquakes. From the data analysis, the maximum extent of stress influence is 250 km around Taiwan. A two-dimensional approach was adopted to develop two models for estimating the maximum extent of stress influence for earthquakes. From the developed models, the extent of stress influence is proportional to the earthquake magnitude and inversely proportional to the groundwater level change. The model equations can be used to calculate the influence radius of stress from an earthquake by using the observed change of groundwater level and the earthquake magnitude. The models were applied to estimate the area of anomalous stress, defined as the possible areas where the strain energy is accumulated, using the cross areas method. The results show that the estimated area of anomalous stress is close to the epicenter. Complex geological structures and material heterogeneity and anisotropy may explain this disagreement. More data collection and model refinements can improve the proposed model. This study shows the potential of using groundwater level variations for capturing seismic information. The proposed concept of extent of stress influence can be used to estimate the earthquake effect in hydraulic engineering, mining engineering, and carbon dioxide sequestration, etc. This study provides a concept for estimating the possible areas of anomalous stress for a forthcoming earthquake.

  15. 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

  16. 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

  17. 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. PMID:26701120

  18. Individual Variation in Agrammatism: A Single Case Study of the Influence of Interaction

    ERIC Educational Resources Information Center

    Beeke, Suzanne; Wilkinson, Ray; Maxim, Jane

    2007-01-01

    Background: Agrammatic speech can manifest in different ways in the same speaker if task demands change. Individual variation is considered to reflect adaptation, driven by psycholinguistic factors such as underlying deficit. Recently, qualitative investigations have begun to show ways in which conversational interaction can influence the form of…

  19. Influence of magnetization variations in the free layer on a non-volatile magnetic flip flop

    NASA Astrophysics Data System (ADS)

    Windbacher, Thomas; Makarov, Alexander; Sverdlov, Viktor; Selberherr, Siegfried

    2015-06-01

    Recently, we proposed an alternative non-volatile magnetic flip flop which allows high integration density. This work extends the up to now gained results to the devices' functionality under statistically distributed magnetization variations of its free layer. Assuming position uncorrelated random fluctuations in the free layer, that the variations are fixed with respect to time, and that small deviations from its mean are more likely than big ones, a Gaussian distribution was chosen to model the random fluctuations. The random variations were added to the simulations as a position dependent Zeeman term and their influence was varied by changing the variance of the distribution scaled in percent of the free layers saturation magnetization. The results with and without thermal excitation show that the flip flop is capable of operating under high free layer field variations.

  20. 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. PMID:25092814

  1. 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. PMID:25956443

  2. The influence of floral symmetry, dependence on pollinators and pollination generalization on flower size variation

    PubMed Central

    Lázaro, A.; Totland, Ø.

    2014-01-01

    Background and Aims The pollinator-mediated stabilizing selection hypothesis suggests that the specialized pollination system of zygomorphic flowers might cause stabilizing selection, reducing their flower size variation compared with actinomorphic flowers. However, the degree of ecological generalization and of dependence on pollinators varies greatly among species of both flower symmetry types and this may also affect flower size variation. Methods Data on 43 species from two contrasting communities (one alpine and one lowland community) were used to test the relationships and interactions between flower size phenotypic variation, floral symmetry, ecological pollination generalization and species' dependence on pollinators. Key Results Contrary to what was expected, higher flower size variation was found in zygomorphic than in actinomorphic species in the lowland community, and no difference in flower size variation was found between symmetry types in the alpine community. The relationship between floral symmetry and flower size variation depended on ecological generalization and species' dependence on pollinators, although the influence of ecological generalization was only detected in the alpine community. Zygomorphic species that were highly dependent on pollinators and that were ecologically specialized were less variable in flower size than ecologically generalist and selfing zygomorphic species, supporting the pollinator-mediated stabilizing selection hypothesis. However, these relationships were not found in actinomorphic species, probably because they are not dependent on any particular pollinator for efficient pollination and therefore their flower size always shows moderate levels of variation. Conclusions The study suggests that the relationship between flower size variation and floral symmetry may be influenced by population-dependent factors, such as ecological generalization and species' dependence on pollinators. PMID:24838838

  3. 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.

  4. 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. PMID:18807420

  5. 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.

  6. The Influence of Spatial Variations of Diffusion Length on Charge Collected by Diffusion from Ion Tracks

    NASA Technical Reports Server (NTRS)

    Edmonds, L. D.

    1996-01-01

    Charge collected by diffusion from ion tracks in a semiconductor substrate may be influenced by the substrate diffusion length, which is related to recombination losses. A theoretical analysis shows that, excluding some extreme cases, charge collection is insensitive to spatial variations in the diffusion length funciton, so it is possible to define an effective diffusion length having the property that collected charge can be approximated by assuming a uniform diffusion length equal to this effective value.

  7. 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.

  8. Influence of traffic variations on exposure to wireless signals in realistic environments.

    PubMed

    Mahfouz, Zaher; Gati, Azeddine; Lautru, David; Wong, Man-Fai; Wiart, Joe; Hanna, Victor Fouad

    2012-05-01

    In this article, the general public daily exposure to broadcast signals and Global System for Mobile Communications (GSM) or Universal Mobile Telecommunications System (UMTS) mobile telephone signals in indoor areas is investigated. Temporal variations and traffic distributions during a day at different indoor sites in urban and rural zones are presented. The goal is to analyze the real exposure compared to the maximum assessment imposed by radio protection standards and to characterize the ratio between daily and maximum theoretical values. Hence, a realistic maximum is proposed based on the statistical analysis performed using measurements. Broadcast signals remain constant over the day so they are best fitted with a Normal distribution while the mobile telephone signals depend on the traffic demand during the day so they fit a three-Gaussian distribution model. A general mask is also constructed for underlining the maximum equivalent active traffic for different periods in the day. Also, relations between the mean values over 24 h, the realistic maximal values (at 99%) and the maximal theoretical values are presented. The realistic maximum is also presented with a sliding time average of 6 min applied to the measurements in accordance with international standards. An extrapolation factor is given for the different systems to easily assess the maximum values starting from an instantaneous measurement. The extrapolation factor is also given for a broadband measurement to estimate the maximum potential exposure during the day. PMID:21960463

  9. 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

  10. Influence of some sow characteristics on within-litter variation of piglet birth weight.

    PubMed

    Quesnel, H; Brossard, L; Valancogne, A; Quiniou, N

    2008-12-01

    Within-litter variation of piglet birth weight (BW0) is associated with an increased piglet mortality and a high variability in pig weight at weaning and weight or age at slaughter. Data collected in two experimental herds were used to quantify within-litter variability in BW0 and to assess the influence of factors mainly related to the sow. Within 24 h after birth, piglets born alive were individually weighed and stillborn piglets were collectively (first data set) or individually (second data set) weighed. The first data set was restricted to litters with no or only one stillborn piglet (3338 litters). It was used to assess the influence of genetic selection on BW0 variation by comparing litter characteristics before (1994 to 1996) and after (2001 to 2004) the development of hyperprolific sows in this herd. The second data set included all litters (n = 1596) from sows born between 2000 and 2004. For each litter, mean BW0 (mBW0) and its coefficient of variation (CVBW0) were calculated. Then, variance analyses were performed to test the influence of litter size, parity, year of sow birth and season at conception. Prolificacy improvement was associated with an increased CVBW0 in litters from pure Large White (LW) and Landrace × Large White (LR × LW) crossbred sows. The CVBW0 averaged 21% and was significantly influenced by litter size and parity. It increased from 15% to 24% when litter size varied from less than 10 piglets to more than 15 piglets. The proportion of small piglets (i.e. weighing less than 1 kg) increased concomitantly. The CVBW0 was not repeatable from a parity to the following. It was lowest for first and second parities (20%) and thereafter increased progressively. The CVBW0 was positively related to sow's backfat thickness gain during gestation. Taking into account litter size, parity, year of sow birth and season at conception explained 20% of BW0 variation. Thus, major part of heterogeneity is due to other factors, presumably including embryo

  11. Genetic Variation in Functional Traits Influences Arthropod Community Composition in Aspen (Populus tremula L.)

    PubMed Central

    Robinson, Kathryn M.; Ingvarsson, Pär K.; Jansson, Stefan; Albrectsen, Benedicte R.

    2012-01-01

    We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp) collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores. PMID:22662190

  12. 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.

  13. 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

  14. 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. PMID:26898051

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

    PubMed Central

    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. PMID:26372106

  16. Experimental study of the influence of flow passage subtle variation on mixed-flow pump performance

    NASA Astrophysics Data System (ADS)

    Bing, Hao; Cao, Shuliang

    2014-05-01

    In the mixed-flow pump design, the shape of the flow passage can directly affect the flow capacity and the internal flow, thus influencing hydraulic performance, cavitation performance and operation stability of the mixed-flow pump. However, there is currently a lack of experimental research on the influence mechanism. Therefore, in order to analyze the effects of subtle variations of the flow passage on the mixed-flow pump performance, the frustum cone surface of the end part of inlet contraction flow passage of the mixed-flow pump is processed into a cylindrical surface and a test rig is built to carry out the hydraulic performance experiment. In this experiment, parameters, such as the head, the efficiency, and the shaft power, are measured, and the pressure fluctuation and the noise signal are also collected. The research results suggest that after processing the inlet flow passage, the head of the mixed-flow pump significantly goes down; the best efficiency of the mixed-flow pump drops by approximately 1.5%, the efficiency decreases more significantly under the large flow rate; the shaft power slightly increases under the large flow rate, slightly decreases under the small flow rate. In addition, the pressure fluctuation amplitudes on both the impeller inlet and the diffuser outlet increase significantly with more drastic pressure fluctuations and significantly lower stability of the internal flow of the mixed-flow pump. At the same time, the noise dramatically increases. Overall speaking, the subtle variation of the inlet flow passage leads to a significant change of the mixed-flow pump performance, thus suggesting a special attention to the optimization of flow passage. This paper investigates the influence of the flow passage variation on the mixed-flow pump performance by experiment, which will benefit the optimal design of the flow passage of the mixed-flow pump.

  17. The influence of variations of vegetation and soil moisture on surface weather and atmospheric circulation

    SciTech Connect

    Yang, R.

    1992-01-01

    The influence of variations of vegetation and soil moisture on surface weather and atmospheric circulation is studied through the use of the Simple Biosphere Model (SiB) and the Center for Ocean-Land-Atmosphere interactions (COLA) GCM. Tests for the SiB sensitivity to the conversion of the forest to other short vegetation or bare soil were performed at Amazonian and Great Plains sites, and a North Wales spruce forest site respectively. The results show that deforestation has a significant influence on the local surface energy budget and surface weather. The influence is especially prominent at the Amazon and Great Plains sites, and larger in summer than in other seasons. The influence on the partitioning of surface incoming radiative energy is generally constrained by the local atmospheric boundary condition. The sensitivity of the COLA GCM to changes in initial soil wetness (ISW) is determined by repeating three 10-day model integrations with the same initial and boundary conditions as the control runs except the values of ISW, which are revised at 69 model grid points covering much of the continental U.S. It is found that the relations between the changes in the 5-day mean forecast surface air temperature/surface specific humidity and the changes in ISW depend upon vegetation type and the values of ISW, and can be approximated by regression equations. These relations are also confirmed with independent data. With the ISW revised based on these regression equations the surface forecasts of the revised runs are consistently improved. The spatial scale of the ISW anomaly determines the degree and range of the influence. The influence of a small regional ISW change is mainly confined to the local region and to low atmospheric levels. The influence on surface fluxes is strong and persists for more than one month, but the effects on precipitation are relatively weak, changeable, and complex, particularly when an interactive cloud scheme is used.

  18. Influence of smoking and gender on diurnal variations of heart rate reactivity in humans.

    PubMed

    Adan, A; Sánchez-Turet, M

    2001-01-12

    We evaluated the influence of smoking and gender on diurnal variations of heart rate reactivity during performance of two vigilance tasks (auditory and visual) and a working memory task. Heart rate was measured hourly (08:00-21:00 h) at rest and during performance tasks in 20 smokers (ten men, ten women) and 20 non-smokers (ten men, ten women). Smoking and gender influenced reactivity only at certain times, especially at the earliest and latest hours and during the post-lunch period. Smokers displayed major post-lunch interference and a pattern of lowered stress in the second half of the day. Women showed greater reactivity at the first daily recording, although their levels later became similar to the men's and were even lower. The statement that women are myocardial hyperreactors must be further investigated, as it seems women may take longer than men to adapt to a task. PMID:11121882

  19. 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 ...

  20. 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.

  1. 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. PMID:24635649

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

    PubMed Central

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

    2015-01-01

    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. PMID:25833849

  3. 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

    2015-05-01

    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. PMID:25833849

  4. Fitness and physiology in a variable environment.

    PubMed

    Kimball, Sarah; Gremer, Jennifer R; Angert, Amy L; Huxman, Travis E; Venable, D Lawrence

    2012-06-01

    The relationship between physiological traits and fitness often depends on environmental conditions. In variable environments, different species may be favored through time, which can influence both the nature of trait evolution and the ecological dynamics underlying community composition. To determine how fluctuating environmental conditions favor species with different physiological traits over time, we combined long-term data on survival and fecundity of species in a desert annual plant community with data on weather and physiological traits. For each year, we regressed the standardized annual fitness of each species on its position along a tradeoff between relative growth rate and water-use efficiency. Next, we determined how variations in the slopes and intercepts of these fitness-physiology functions related to year-to-year variations in temperature and precipitation. Years with a relatively high percentage of small rain events and a greater number of days between precipitation pulse events tended to be worse, on average, for all desert annual species. Species with high relative growth rates and low water-use efficiency had greater standardized annual fitness than other species in years with greater numbers of large rain events. Conversely, species with high water-use efficiency had greater standardized annual fitness in years with small rain events and warm temperatures late in the growing season. These results reveal how weather variables interact with physiological traits of co-occurring species to determine interannual variations in survival and fecundity, which has important implications for understanding population and community dynamics. PMID:22116505

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

    PubMed Central

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

    2015-01-01

    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. DOI: http://dx.doi.org/10.7554/eLife.11814.001 PMID:26701914

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

    PubMed Central

    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.

    2015-01-01

    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 (rp) and genetic (rg) correlations were observed between left amygdala volume and positive emotionality (rp = .16, p < .01; rg = .23, p < .05, respectively). In addition, after adjusting for mean cortical thickness, genetic and nonshared-environmental correlations (re) between left medial orbitofrontal cortex thickness and negative emotionality were also observed (rg = .34, p < .01; re = −.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. PMID:25263286

  7. 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

  8. 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

  9. Influence of interannual variations in transport on summertime abundances of ozone over the Middle East

    NASA Astrophysics Data System (ADS)

    Liu, Jane J.; Jones, Dylan B. A.; Zhang, Shunli; Kar, Jay

    2011-10-01

    We used the GEOS-Chem model to investigate the impact of interannual variations in transport on summertime ozone abundances (between 1987 and 2006) in the middle troposphere over the Middle East. We found that ozone abundances fluctuated interannually by about ±7% (or ±6 ppbv from the 20-year mean of ˜80 ppbv). In the 20-year mean, ozone transported from Asia and ozone produced locally were the dominant sources of ozone, accounting for 31% and 23%, respectively, of ozone abundances over the Middle East, with an interannual variability of ±30% and ±15%, respectively. We found that the interannual variations in the Asian and local sources were related to the strengths of the South Asian High and the Arabian anticyclone, respectively. In years when the Asian influence was weaker in the region, transport from other areas, such as North America, was enhanced. Consequently, variations in ozone transported from Asia were strongly anti-correlated with variations in ozone transported from North America, for example, with a correlation coefficient of r = -0.75. This trade-off between transport from Asia and other regions was found to be linked to the position and strength of the subtropical westerly jet over central Asia. When the westerly jet is displaced poleward, transport of ozone from Asia is enhanced and transport from North America and other regions in the Northern Hemisphere is diminished. In contrast, when the jet is displaced equatorward, transport of ozone from Asia is diminished and transport from North America and other regions in the Northern Hemisphere is enhanced. These results suggest that climate-related changes in the position of the westerly jet will have implications for the transport of pollution into the Middle East.

  10. Isotopic variation in five species of stream fishes under the influence of different land uses.

    PubMed

    Carvalho, D R; Castro, D; Callisto, M; Moreira, M Z; Pompeu, P S

    2015-09-01

    The aim of this study was to test if changes in land use alter the isotopic signature of fish species, promoting changes in the trophic position and food resource partitioning between these consumers. Three different systems were investigated: pasture streams (n = 3), streams in sugar cane plantations (n = 3) and reference streams (n = 3). Fish species Aspidoras fuscoguttatus, Astyanax altiparanae, Characidium zebra, Hisonotus piracanjuba and Knodus moenkhausii were selected, and their nitrogen and carbon isotopic compositions were estimated to assess changes in the trophic level and partitioning of food items consumed. The composition of δ(13) C (‰) only differed among the land use categories for A. altiparanae, H. piracanjuba and K. moenkhausii. Resource partitioning was different for all species, with changes in the sources or proportions they consumed in each land use category, but only A. altiparanae introduced new food sources in large quantity in altered land uses. It is important to note, however, that the results from the resource partitioning analysis are limited due to large overlapping of isotopic signatures between the analysed food resources. All fish species exhibited variation in δ(15) N (‰), with the highest values found in streams under sugar cane or pasture influence. Despite the variation in nitrogen isotopic values, only C. zebra and H. piracanjuba displayed changes in trophic level. Therefore, it is believed that the increase in the δ(15) N (‰) value of the individuals collected in streams under the influence of sugar cane or pasture was due to the greater influence of livestock dung and chemical and organic fertilizers. The results also highlight the importance of studying consumer species along with all forms of resources available at each location separately, because the signatures of these resources also vary within different land uses. PMID:26201419

  11. 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

  12. 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

  13. Factors Influencing Measurement of Serum Iron Concentration in Dogs: Diurnal Variation and Hyperferritinemia

    PubMed Central

    CHIKAZAWA, Seishiro; HORI, Yasutomo; KANAI, Kazutaka; ITO, Naoyuki; HOSHI, Fumio; ORINO, Koichi; WATANABE, Kiyotaka; HIGUCHI, Seiichi

    2013-01-01

    ABSTRACT We evaluated diurnal variation and hyperferritinemia as factors that influence the values of serum iron concentration in dogs, using the International Committee for Standardization in Hematology (ICSH) colorimetric method. Serum iron levels were significantly higher in the morning than in the evening in 6 clinically healthy beagle dogs, and the maximum decrease in serum iron concentration was 47.3%. Moreover, the change in serum iron concentrations in 22 clinical canine cases with various serum ferritin levels was evaluated by immunoprecipitation of ferritin. The rate of decline in the serum iron concentrations positively correlated with serum ferritin levels (r=0.48, P=0.024). These results show that it is necessary to consider the sampling time and serum ferritin level for accurate interpretation of serum iron concentrations in dogs. PMID:23877842

  14. Defining the Influence of Germline Variation on Metastasis Using Systems Genetics Approaches.

    PubMed

    Lee, M; Crawford, N P S

    2016-01-01

    Cancer is estimated to be responsible for 8 million deaths worldwide and over half a million deaths every year in the United States. The majority of cancer-related deaths in solid tumors is directly associated with the effects of metastasis. While the influence of germline factors on cancer risk and development has long been recognized, the contribution of hereditary variation to tumor progression and metastasis has only gained acceptance more recently. A variety of approaches have been used to define how hereditary variation influences tumor progression and metastasis. One approach that garnered much early attention was epidemiological studies of cohorts of cancer patients, which demonstrated that specific loci within the human genome are associated with a differential propensity for aggressive tumor development. However, a powerful, and somewhat underutilized approach has been the use of systems genetics approaches in transgenic mouse models of human cancer. Such approaches are typically multifaceted, and involve integration of multiple lines of evidence derived, for example, from genetic and transcriptomic screens of genetically diverse mouse models of cancer, coupled with bioinformatics analysis of human cancer datasets, and functional analysis of candidate genes. These methodologies have allowed for the identification of multiple hereditary metastasis susceptibility genes, with wide-ranging cellular functions including regulation of gene transcription, cell proliferation, and cell-cell adhesion. In this chapter, we review how each of these approaches have facilitated the identification of these hereditary metastasis modifiers, the molecular functions of these metastasis-associated genes, and the implications of these findings upon patient survival. PMID:27613130

  15. 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. PMID:16176387

  16. 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. PMID:24118787

  17. Axillary dissection in primary breast cancer: variations of the surgical technique and influence on morbidity

    PubMed Central

    Wojcinski, Sebastian; Nuengsri, Sirin; Hillemanns, Peter; Schmidt, Werner; Deryal, Mustafa; Ertan, Kubilay; Degenhardt, Friedrich

    2012-01-01

    Lymphedema of the arm is the most common and impairing complication after breast cancer surgery with axillary lymph node dissection (ALND). Our prospective study evaluated the effect of two different surgical techniques for ALND on postoperative morbidity. Patients were scheduled to undergo ALND. Patients in group 1 (n = 17) underwent the most common and standard technique of ALND, which uses sharp dissection of the tissue and subsequent electro-coagulation of bleedings. Patients in group 2 (n = 17) underwent a modified standard technique of ALND with clamping and ligatures of all resection margins. Postoperative wound secretion was quantified and patients were followed up for 6 months to assess long-term morbidity. The variations in surgical technique had no significant influence on the outcome variables. However, patients in group 2 showed a tendency to less wound secretion (713 versus 802 mL; P = nonsignificant), a decreased rate of immediate postoperative seromas (11.8 versus 23.5%; P = nonsignificant) and less lymphedema after 3 months (29.4 versus 41.2%; P = nonsignificant). Moreover, the number of resected lymph nodes correlated with the total amount of drained fluid (P = 0.006), the duration of the drain (P = 0.015), and the risk for the development of lymphedema after 3 months (P = 0.016). The described variations in surgical technique had no influence on the outcomes of the patients. The number of resected axillary lymph nodes remains the most important risk factor for treatment-related morbidity. Therefore, a well-balanced choice of the extent of the axillary dissection should be the surgeon’s main concern. PMID:22570566

  18. Axillary dissection in primary breast cancer: variations of the surgical technique and influence on morbidity.

    PubMed

    Wojcinski, Sebastian; Nuengsri, Sirin; Hillemanns, Peter; Schmidt, Werner; Deryal, Mustafa; Ertan, Kubilay; Degenhardt, Friedrich

    2012-01-01

    Lymphedema of the arm is the most common and impairing complication after breast cancer surgery with axillary lymph node dissection (ALND). Our prospective study evaluated the effect of two different surgical techniques for ALND on postoperative morbidity. Patients were scheduled to undergo ALND. Patients in group 1 (n = 17) underwent the most common and standard technique of ALND, which uses sharp dissection of the tissue and subsequent electro-coagulation of bleedings. Patients in group 2 (n = 17) underwent a modified standard technique of ALND with clamping and ligatures of all resection margins. Postoperative wound secretion was quantified and patients were followed up for 6 months to assess long-term morbidity. The variations in surgical technique had no significant influence on the outcome variables. However, patients in group 2 showed a tendency to less wound secretion (713 versus 802 mL; P = nonsignificant), a decreased rate of immediate postoperative seromas (11.8 versus 23.5%; P = nonsignificant) and less lymphedema after 3 months (29.4 versus 41.2%; P = nonsignificant). Moreover, the number of resected lymph nodes correlated with the total amount of drained fluid (P = 0.006), the duration of the drain (P = 0.015), and the risk for the development of lymphedema after 3 months (P = 0.016). The described variations in surgical technique had no influence on the outcomes of the patients. The number of resected axillary lymph nodes remains the most important risk factor for treatment-related morbidity. Therefore, a well-balanced choice of the extent of the axillary dissection should be the surgeon's main concern. PMID:22570566

  19. The influence of scan mode and circle fitting on tree stem detection, stem diameter and volume extraction from terrestrial laser scans

    NASA Astrophysics Data System (ADS)

    Pueschel, Pyare; Newnham, Glenn; Rock, Gilles; Udelhoven, Thomas; Werner, Willy; Hill, Joachim

    2013-03-01

    Terrestrial laser scanning (TLS) has been used to estimate a number of biophysical and structural vegetation parameters. Of these stem diameter is a primary input to traditional forest inventory. While many experimental studies have confirmed the potential for TLS to successfully extract stem diameter, the estimation accuracies differ strongly for these studies - due to differences in experimental design, data processing and test plot characteristics. In order to provide consistency and maximize estimation accuracy, a systematic study into the impact of these variables is required. To contribute to such an approach, 12 scans were acquired with a FARO photon 120 at two test plots (Beech, Douglas fir) to assess the effects of scan mode and circle fitting on the extraction of stem diameter and volume. An automated tree stem detection algorithm based on the range images of single scans was developed and applied to the data. Extraction of stem diameter was achieved by slicing the point cloud and fitting circles to the slices using three different algorithms (Lemen, Pratt and Taubin), resulting in diameter profiles for each detected tree. Diameter at breast height (DBH) was determined using both the single value for the diameter fitted at the nominal breast height and by a linear fit of the stem diameter vertical profile. The latter is intended to reduce the influence of outliers and errors in the ground level determination. TLS-extracted DBH was compared to tape-measured DBH. Results show that tree stems with an unobstructed view to the scanner can be successfully extracted automatically from range images of the TLS data with detection rates of 94% for Beech and 96% for Douglas fir. If occlusion of trees is accounted for stem detection rates decrease to 85% (Beech) and 84% (Douglas fir). As far as the DBH estimation is concerned, both DBH extraction methods yield estimates which agree with reference measurements, however, the linear fit based approach proved to be more

  20. 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.

  1. 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. PMID:23389399

  2. Influence of climate on malaria transmission depends on daily temperature variation.

    PubMed

    Paaijmans, Krijn P; Blanford, Simon; Bell, Andrew S; Blanford, Justine I; Read, Andrew F; Thomas, Matthew B

    2010-08-24

    Malaria transmission is strongly influenced by environmental temperature, but the biological drivers remain poorly quantified. Most studies analyzing malaria-temperature relations, including those investigating malaria risk and the possible impacts of climate change, are based solely on mean temperatures and extrapolate from functions determined under unrealistic laboratory conditions. Here, we present empirical evidence to show that, in addition to mean temperatures, daily fluctuations in temperature affect parasite infection, the rate of parasite development, and the essential elements of mosquito biology that combine to determine malaria transmission intensity. In general, we find that, compared with rates at equivalent constant mean temperatures, temperature fluctuation around low mean temperatures acts to speed up rate processes, whereas fluctuation around high mean temperatures acts to slow processes down. At the extremes (conditions representative of the fringes of malaria transmission, where range expansions or contractions will occur), fluctuation makes transmission possible at lower mean temperatures than currently predicted and can potentially block transmission at higher mean temperatures. If we are to optimize control efforts and develop appropriate adaptation or mitigation strategies for future climates, we need to incorporate into predictive models the effects of daily temperature variation and how that variation is altered by climate change. PMID:20696913

  3. Do differences in Toxoplasma prevalence influence global variation in secondary sex ratio? Preliminary ecological regression study.

    PubMed

    Dama, Madhukar S; Martinec Nováková, Lenka; Flegr, Jaroslav

    2016-08-01

    Sex of the fetus is genetically determined such that an equal number of sons and daughters are born in large populations. However, the ratio of female to male births across human populations varies significantly. Many factors have been implicated in this. The theory that natural selection should favour female offspring under suboptimal environmental conditions implies that pathogens may affect secondary sex ratio (ratio of male to female births). Using regression models containing 13 potential confounding factors, we have found that variation of the secondary sex ratio can be predicted by seroprevalence of Toxoplasma across 94 populations distributed across African, American, Asian and European continents. Toxoplasma seroprevalence was the third strongest predictor of secondary sex ratio, β = -0·097, P < 0·01, after son preference, β = 0·261, P < 0·05, and fertility, β = -0·145, P < 0·001. Our preliminary results suggest that Toxoplasma gondii infection could be one of the most important environmental factors influencing the global variation of offspring sex ratio in humans. The effect of latent toxoplasmosis on public health could be much more serious than it is usually supposed to be. PMID:27350331

  4. 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

  5. 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

  6. 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.

  7. 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

  8. Variation in normal mood state influences sensitivity to dynamic changes in emotional expression.

    PubMed

    Jackson, Margaret C; Arlegui-Prieto, Maritxu

    2016-03-01

    Normal social functioning depends on the ability to efficiently and accurately detect when someone's facial expression changes to convey positive or negative emotion. While observer mood state has been shown to influence emotion recognition, how variations in normal mood might influence sensitivity to the dynamic emergence of expressions has not yet been addressed. To investigate this, we modified an existing face-morphing paradigm in which a central face gradually changes from neutral to expressive (angry, sad, happy, surprised). Our sample comprised healthy young adults, and current mood state was measured using the PANAS-X. Participants pressed a key as soon as they (1) noticed a physical change in expression (perceptual sensitivity-novel task element), and (2) could clearly conceptualize which expression was emerging (conceptual sensitivity). A final unspeeded response required participants to explicitly label the expression as a measure of recognition accuracy. We measured the percentage morph (expression intensity) at which a perceptual and conceptual change was detected, where greater intensity equates to poorer sensitivity. Increased positive mood reduced perceptual and conceptual sensitivity to angry and sad expressions only (a mood incongruency effect). Of particular interest, increased negative mood decreased conceptual sensitivity for all expressions, but had limited impact on perceptual sensitivity. Thus, heightened negative mood is particularly detrimental for effectively decoding someone else's mood change. This may reflect greater introspection and consumption of attentional resources directed toward the negative self, leaving fewer resources to process emotional signals conveyed by others. This could have important consequences for human social interaction. PMID:26479773

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

    PubMed

    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

  10. 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

  11. 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

  12. 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.

  13. Fitness of outbreak and environmental strains of Escherichia coli O157:H7 in aerosolizable soil and association of clonal variation in stress gene regulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Airborne dust from feedlots is a potential mechanism of contamination of nearby vegetable crops with Escherichia coli O157:H7 (EcO157). We compared the fitness of clinical and environmental strains of EcO157 in <45 µm soil from a spinach farm. Differences in survival were observed among the 35 strai...

  14. Understanding Host-Switching by Ecological Fitting.

    PubMed

    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

  15. 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

  16. 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

  17. Synergistic influences of phase, density, and climatic variation on the dynamics of fluctuating populations.

    PubMed

    Goswami, Varun R; Getz, Lowell L; Hostetler, Jeffrey A; Ozgul, Arpat; Oli, Madan K

    2011-08-01

    Although ecologists have long recognized that certain mammalian species exhibit high-amplitude, often multiannual, fluctuations in abundance, their causes have remained poorly understood and the subject of intense debate. A key contention has been the relative role of density-dependent and density-independent processes in governing population dynamics. We applied capture-mark-recapture analysis to 25 years of monthly trapping data from a fluctuating prairie vole Microtus ochrogaster population in Illinois, USA, to estimate realized population growth rates and associated vital rates (survival and recruitment) and modeled them as a function of vole density and density-independent climatic variation. We also tested for phase dependence and seasonality in the effects of the above processes. Variation in the realized population growth rate was best explained by phase-specific changes in vole density lagged by one month and mean monthly temperatures with no time lags. The underlying vital rates, survival and recruitment, were influenced by the additive and interactive effects of phase, vole density, and mean monthly temperatures. Our results are consistent with the observation that large-scale population fluctuations are characterized by phase-specific changes in demographic and physiological characteristics. Our findings also support the growing realization that the interaction between climatic variables and density-dependent factors may be a widespread phenomenon, and they suggest that the direction and magnitude of such interactive effects may be phase specific. We conclude that density-dependent and density-independent climatic variables work in tandem during each phase of density fluctuations to drive the dynamics of fluctuating populations. PMID:21905434

  18. [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. PMID:25055686

  19. Latitudinal range influences the seasonal variation in the foraging behavior of marine top predators.

    PubMed

    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

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

    PubMed

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

    2015-11-01

    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 1000-1500ms post stimulus during the source memory task and the left anterior superior ROI 300-500ms 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

  1. 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.

  2. 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

  3. Influence of hemodynamic variations on the pharmacokinetics of landiolol in patients undergoing cardiovascular surgery.

    PubMed

    Matsumoto, Naoki; Aomori, Tohru; Kanamoto, Masafumi; Usui, Tadashi; Shiga, Tatsuya; Yamamoto, Koujirou; Saito, Shigeru

    2012-01-01

    Although landiolol is useful in the emergency management of atrial fibrillation, atrial flutter, and tachycardia, as well as in perioperative arrhythmia control, the influence of hemodynamic changes on the pharmacokinetics of landiolol is unknown. We investigated the influence of hemodynamic variation and the following hepatocirculatory changes after systemic heparinization on the pharmacokinetics of landiolol in patients undergoing cardiovascular surgery under cardiopulmonary bypass. Cardiac output and cardiac index (CI) were continuously monitored in 19 patients using an arterial pressure-based cardiac output monitor. The middle and right hepatic venous blood flow indexes (mHVBFI and rHVBFI) were measured by transesophageal echocardiography, and hemodynamic data were collected at points (T1-T3) as follows: T1, before administration of heparin and after sternotomy; T2, just before systemic heparinization (300 U/kg); T3, 10 min after T2. The plasma concentration of landiolol was measured by HPLC at the same point. After administration of heparin, mean arterial blood pressure, CI, mHVBFI, and rHVBFI were significantly decreased (<0.05). Heart rate was not significantly changed. After systemic heparinization, the landiolol concentration was significantly decreased from 0.407±0.251 µg·mL(-1) to 0.232±0.207 µg·mL(-1) (<0.01). There was no significant difference between T1 and T2 (=0.88). In conclusion, the plasma concentration of landiolol was decreased by diminished CI due to systemic heparinization, but not affected by the change of hepatic blood flow. PMID:22864018

  4. 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

  5. Individual variation in the propensity to attribute incentive salience to a food cue: influence of sex.

    PubMed

    Pitchers, Kyle K; Flagel, Shelly B; O'Donnell, Elizabeth G; Woods, Leah C Solberg; Sarter, Martin; Robinson, Terry E

    2015-02-01

    There is considerable individual variation in the propensity of animals to attribute incentive salience to discrete reward cues, but to date most of this research has been conducted in male rats. The purpose of this study was to determine whether sex influences the propensity to attribute incentive salience to a food cue, using rats from two different outbred strains (Sprague-Dawley [SD] and Heterogeneous Stock [HS]). The motivational value of a food cue was assessed in two ways: (i) by the ability of the cue to elicit approach toward it and (ii) by its ability to act as a conditioned reinforcer. We found that female SD rats acquired Pavlovian conditioned approach behavior slightly faster than males, but no sex difference was detected in HS rats, and neither strain showed a sex difference in asymptotic performance of approach behavior. Moreover, female approach behavior did not differ across estrous cycle. Compared to males, females made more active responses during the test for conditioned reinforcement, although they made more inactive responses as well. We conclude that although there are small sex differences in performance on these tasks, these are probably not due to a notable sex difference in the propensity to attribute incentive salience to a food cue. PMID:25446811

  6. Individual variation in the propensity to attribute incentive salience to a food cue: influence of sex

    PubMed Central

    Pitchers, Kyle K.; Flagel, Shelly B.; O’Donnell, Elizabeth G.; Solberg Woods, Leah C.; Sarter, M.; Robinson, Terry E.

    2014-01-01

    There is considerable individual variation in the propensity of animals to attribute incentive salience to discrete reward cues, but to date most of this research has been conducted in male rats. The purpose of this study was to determine whether sex influences the propensity to attribute incentive salience to a food cue, using rats from two different outbred strains (Sprague-Dawley [SD] and Heterogeneous Stock [HS]). The motivational value of a food cue was assessed in two ways: (i) by the ability of the cue to elicit approach towards it and (ii) by its ability to act as a conditioned reinforcer. We found that female SD rats acquired Pavlovian conditioned approach behavior slightly faster than males, but no sex difference was detected in HS rats, and neither strain showed a sex difference in asymptotic performance of approach behavior. Moreover, female approach behavior did not differ across estrous cycle. Compared to males, females made more active responses during the test for conditioned reinforcement, although they made more inactive responses as well. We conclude that although there are small sex differences in performance on these tasks, these are probably not due to a notable sex difference in the propensity to attribute incentive salience to a food cue. PMID:25446811

  7. Lead in Chinese villager house dust: Geographical variation and influencing factors.

    PubMed

    Bi, Xiangyang; Liu, Jinling; Han, Zhixuan; Yang, Wenlin

    2015-12-01

    House dust has been recognized as an important contributor to Pb exposure of children. Here we conducted a comprehensive study to investigate geographical variation of Pb in Chinese villager house dust. The influences of outdoor soil Pb concentrations, dates of construction, house decoration materials, heating types, and site specific pollution on Pb concentrations in house dust were evaluated. The concentrations of Pb in 477 house dust samples collected from twenty eight areas throughout China varied from 12 to 2510 mg/kg, with a median concentration of 42 mg/kg. The median Pb concentrations in different geographical areas ranged from 16 (Zhangjiakou, Hebei) to 195 mg/kg (Loudi, Hunan). No correlations were found between the house dust Pb concentrations and the age of houses, as well as house decoration materials. Whereas outdoor soil, coal combustion, and site specific pollution may be potential Pb sources. Principal component analysis (PCA) confirmed that elemental compositions of the house dust were controlled by both anthropogenic and geogenic sources. Using scanning electron microscopy (SEM), the Pb bearing particles in the house dust were also studied. PMID:26381088

  8. Using PCDS to study the influence of UV flux variation on the middle atmosphere

    NASA Technical Reports Server (NTRS)

    Heilman, W.

    1986-01-01

    The value of the Pilot Climate Data System (PCDS) in examining the influences of short-period solar flux variations on the middle atmosphere was demonstrated. Several Nimbus satellite data sets proposed for the study exist in the PCDS. Planned for retrieval through the PCDS are ozone mixing ratios and cumulative ozone profiles available from the Backscatter Ultraviolet Spectrophotometer on Nimbus-4. Also to be accessed are Nimbus-7 data sets that will provide ozone and nitrogen dioxide mixing ratios, temperature profiles from the Limb Infrared Monitor of the Stratosphere, and ozone mixing ratio profiles from the Solar Backscatter Ultraviolet Spectrophotometer. Bypassing the time-consuming process of reading raw data tapes, the researchers plan to transfer the PCDS processed data to an IBM PC at Iowa State University. The IBM PC will serve as an intermediate vehicle for transferring the data to the NOAA CYBER 840 at Boulder, Colorado, where research will continue on both an eight-layer radiative-photochemical numerical model and on a nonlinear dynamical model. in this research are the FGGE and ERB data sets. These relevant data sets also reside in the PCDS. Problems associated with remote access to the PCDS were discussed in regard to all the PCDS data sets.

  9. Seasonal variation and factors influencing perchlorate in water, snow, soil and corns in Northeastern China.

    PubMed

    Ye, Long; You, Hong; Yao, Jie; Kang, Xi; Tang, Lu

    2013-03-01

    Seasonal variation and influencing factors of perchlorate in snow, surface soil, rain, surface water, groundwater and corn were studied. Seven hundreds and seventy samples were collected in different periods in Harbin and its vicinity, China. Perchlorate concentrations were analyzed by ion chromatography-electrospray mass spectrometry. Results indicate that fireworks and firecrackers display from the Spring Festival to the Lantern Festival (February 2, 2011-February 17, 2011) can result in the occurrence of perchlorate in surface soil and snow. Perchlorate distribution is affected by wind direction in winter. Melting snow which contained perchlorate can dissolve perchlorate in surface soil, and then perchlorate can percolate into groundwater so that perchlorate concentrations in groundwater increased in spring. Perchlorate concentrations in groundwater and surface water decrease after rainy season in summer. Groundwater samples collected in the floodplain areas of the Songhua River and the Ashi River contained higher perchlorate concentrations than that far away with the rivers. The corns have the ability to accumulate perchlorate. PMID:23287025

  10. 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, M.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.

  11. 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

  12. 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

  13. The influence of task variation on manifestation of fatigue is ambiguous - a literature review.

    PubMed

    Luger, Tessy; Bosch, Tim; Veeger, Dirkjan; de Looze, Michiel

    2014-01-01

    Task variation has been proposed to reduce shoulder fatigue resulting from repetitive hand-arm tasks. This review analyses the effect of task variation, both 'temporal (i.e. change of work-rest ratio)' and 'activity (i.e. job rotation)' variation, on physiological responses, endurance time (ET) and subjective feelings. Pubmed was searched and complemented with references from selected articles, resulting in 17 articles. Temporal variation had some positive effects on the objective parameters, as blood pressure decreased and ET increased, and on the subjective feelings, as perceived discomfort decreased. The observed findings of activity variation showed both positive and negative effects of increased activity variation, while hardly any effects were found on electromyography manifestations of fatigue. In conclusion, the evidence for positive effects of increasing the level of variation is scarce. The number of studies on variation is limited, while in most studies the findings were not controlled for the amount or intensity of work. PMID:24552472

  14. 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

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

    PubMed

    Sicuro, Fernando L; 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

  16. 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

  17. Fitness Basics

    MedlinePlus

    ... that gets your heart pumping, such as dancing, running, or swimming laps. How hard you exercise matters, too. You can learn how to measure your workout to see if it is light, medium, or intense. Fitness for all Do you have an illness or ...

  18. 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. PMID:18159786

  19. The Influence of Social Systems on Patterns of Mitochondrial DNA Variation in Baboons.

    PubMed

    Kopp, G H; Ferreira da Silva, M J; Fischer, J; Brito, J C; Regnaut, S; Roos, C; Zinner, D

    2014-01-01

    Behavior is influenced by genes but can also shape the genetic structure of natural populations. Investigating this link is of great importance because behavioral processes can alter the genetic diversity on which selection acts. Gene flow is one of the main determinants of the genetic structure of a population and dispersal is the behavior that mediates gene flow. Baboons (genus Papio) are among the most intensely studied primate species and serve as a model system to investigate the evolution of social systems using a comparative approach. The general mammalian pattern of male dispersal and female philopatry has thus far been found in baboons, with the exception of hamadryas baboons (Papio hamadryas). As yet, the lack of data on Guinea baboons (Papio papio) creates a taxonomic gap in genus-wide comparative analyses. In our study we investigated the sex-biased dispersal pattern of Guinea baboons in comparison to hamadryas, olive, yellow, and chacma baboons using sequences of the maternally transmitted mitochondrial hypervariable region I. Analyzing whole-range georeferenced samples (N = 777), we found strong evidence for female-biased gene flow in Guinea baboons and confirmed this pattern for hamadryas baboons, as shown by a lack of genetic-geographic structuring. In addition, most genetic variation was found within and not among demes, in sharp contrast to the pattern observed in matrilocal primates including the other baboon taxa. Our results corroborate the notion that the Guinea baboons' social system shares some important features with that of hamadryas baboons, suggesting similar evolutionary forces have acted to distinguish them from all other baboons. PMID:24523566

  20. 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.

  1. Metabarcoding reveals environmental factors influencing spatio-temporal variation in pelagic micro-eukaryotes.

    PubMed

    Brannock, Pamela M; Ortmann, Alice C; Moss, Anthony G; Halanych, Kenneth M

    2016-08-01

    Marine environments harbour a vast diversity of micro-eukaryotic organisms (protists and other small eukaryotes) that play important roles in structuring marine ecosystems. However, micro-eukaryote diversity is not well understood. Likewise, knowledge is limited regarding micro-eukaryote spatial and seasonal distribution, especially over long temporal scales. Given the importance of this group for mobilizing energy from lower trophic levels near the base of the food chain to larger organisms, assessing community stability, diversity and resilience is important to understand ecosystem health. Herein, we use a metabarcoding approach to examine pelagic micro-eukaryote communities over a 2.5-year time series. Bimonthly surface sampling (July 2009 to December 2011) was conducted at four locations within Mobile Bay (Bay) and along the Alabama continental shelf (Shelf). Alpha-diversity only showed significant differences in Shelf sites, with the greatest differences observed between summer and winter. Beta-diversity showed significant differences in community composition in relation to season and the Bay was dominated by diatoms, while the Shelf was characterized by dinoflagellates and copepods. The northern Gulf of Mexico is heavily influenced by the Mobile River Basin, which brings low-salinity nutrient-rich water mostly during winter and spring. Community composition was correlated with salinity, temperature and dissolved silicate. However, species interactions (e.g. predation and parasitism) may also contribute to the observed variation, especially on the Shelf, which warrants further exploration. Metabarcoding revealed clear patterns in surface pelagic micro-eukaryote communities that were consistent over multiple years, demonstrating how these techniques could be greatly beneficial to ecological monitoring and management over temporal scales. PMID:27238767

  2. Seasonal variation influences outcomes following lung cancer resections⋆, ⋆⋆

    PubMed Central

    LaPar, Damien J.; Nagji, Alykhan S.; Bhamidipati, Castigliano M.; Kozower, Benjamin D.; Lau, Christine L.; Ailawadi, Gorav; Jones, David R.

    2011-01-01

    Objective The effect of seasonal variation on postoperative outcomes following lung cancer resections is unknown. We hypothesized that postoperative outcomes following surgical resection for lung cancer within the United States would not be impacted by operative season. Methods From 2002 to 2007, 182 507 isolated lung cancer resections (lobectomy (n = 147 937), sublobar resection (n = 21 650), and pneumonectomy (n = 13 916)) were evaluated using the Nationwide Inpatient Sample (NIS) database. Patients were stratified according to operative season: spring (n = 47 382), summer (n = 46 131), fall (n = 45 370) and winter (n = 43 624). Multivariate regression models were applied to assess the effect of operative season on adjusted postoperative outcomes. Results Patient co-morbidities and risk factors were similar despite the operative season. Lobectomy was the most common operation performed: spring (80.0%), summer (81.3%), fall (81.8%), and winter (81.1%). Lung cancer resections were more commonly performed at large, high-volume (>75th percentile operative volume) centers (P < 0.001). Unadjusted mortality was lowest during the spring (2.6%, P < 0.001) season compared with summer (3.1%), fall (3.0%) and winter (3.2%), while complications were most common in the fall (31.7%, P < 0.001). Hospital length of stay was longest for operations performed in the winter season (8.92 ± 0.11 days, P < 0.001). Importantly, multivariable logistic regression revealed that operative season was an independent predictor of in-hospital mortality (P < 0.001) and of postoperative complications (P < 0.001). Risk-adjusted odds of in-hospital mortality were increased for lung cancer resections occurring during all other seasons compared with those occurring in the spring. Conclusions Outcomes following surgical resection for lung cancer are independently influenced by time of year. Risk-adjusted in-hospital mortality and hospital length of stay were lowest during the spring season. PMID

  3. Influence of the interplanetary shock on the heliocentric radial variations of gradual SEP events

    NASA Astrophysics Data System (ADS)

    Aran, Angels; Jacobs, Carla; Sanahuja, Blai; Poedts, Stefaan; Lario, David; Rodriguez-Gasen, Rosa

    The inclusion of a travelling shock as a source of energetic particles during gradual solar ener-getic particle (SEP) events is a key element to assess the radiation encountered by a mission in the inner heliosphere. We have developed, in the frame of the Solar Energetic Particle Envi-ronment Model (SEPEM) project, a new two dimensional (2D) magnetohydrodynamic (MHD) model to describe the shock propagation from 4 solar radii up to 1.6 AU. The outputs of this model are used to simulate the transport of SEPs from the shock front up to a given observer. The combination of the shock and particle transport models allows us to study the influence of both the shock properties and the observer's magnetic connection on the radial and longitudinal variation of proton peak intensities and fluences in gradual SEP events. We have simulated the propagation of six shocks characterized by three different transit times to 1 AU and two different angular widths (narrow and wide). Two sets of spacecraft are placed along two nominal interplanetary magnetic field lines in the undisturbed solar wind but at different radial distances from the Sun. The two observers at 1 AU are located at central meridian and western positions with respect to the nose of each shock. For each spacecraft, synthetic proton time-intensity profiles at several energies (1.0 < E < 128 MeV) are produced. By tracking the shock from close to the Sun, we obtain the peak intensity of high energy particles at the prompt component of the SEP events, without assuming ad-hoc conditions for particle injection at the corona. We discuss how the resulting power-law dependences of the peak intensities (and fluences) on the observer's radial distance vary with the particle energy, the characteristics of the shock, and the different evolving conditions for particle injection at the cobpoint.

  4. Sequence Variations and Protein Expression Levels of the Two Immune Evasion Proteins Gpm1 and Pra1 Influence Virulence of Clinical Candida albicans Isolates

    PubMed Central

    Luo, Shanshan; Hipler, Uta-Christina; Münzberg, Christin; Skerka, Christine; Zipfel, Peter F.

    2015-01-01

    Candida albicans, the important human fungal pathogen uses multiple evasion strategies to control, modulate and inhibit host complement and innate immune attack. Clinical C. albicans strains vary in pathogenicity and in serum resistance, in this work we analyzed sequence polymorphisms and variations in the expression levels of two central fungal complement evasion proteins, Gpm1 (phosphoglycerate mutase 1) and Pra1 (pH-regulated antigen 1) in thirteen clinical C. albicans isolates. Four nucleotide (nt) exchanges, all representing synonymous exchanges, were identified within the 747-nt long GPM1 gene. For the 900-nt long PRA1 gene, sixteen nucleotide exchanges were identified, which represented synonymous, as well as non-synonymous exchanges. All thirteen clinical isolates had a homozygous exchange (A to G) at position 73 of the PRA1 gene. Surface levels of Gpm1 varied by 8.2, and Pra1 levels by 3.3 fold in thirteen tested isolates and these differences influenced fungal immune fitness. The high Gpm1/Pra1 expressing candida strains bound the three human immune regulators more efficiently, than the low expression strains. The difference was 44% for Factor H binding, 51% for C4BP binding and 23% for plasminogen binding. This higher Gpm1/Pra1 expressing strains result in enhanced survival upon challenge with complement active, Factor H depleted human serum (difference 40%). In addition adhesion to and infection of human endothelial cells was increased (difference 60%), and C3b surface deposition was less effective (difference 27%). Thus, variable expression levels of central immune evasion protein influences immune fitness of the human fungal pathogen C. albicans and thus contribute to fungal virulence. PMID:25692293

  5. Influence of dominance, leptokurtosis and pleiotropy of deleterious mutations on quantitative genetic variation at mutation-selection balance.

    PubMed Central

    Zhang, Xu-Sheng; Wang, Jinliang; Hill, William G

    2004-01-01

    In models of maintenance of genetic variance (V (G)) it has often been assumed that mutant alleles act additively. However, experimental data show that the dominance coefficient varies among mutant alleles and those of large effect tend to be recessive. On the basis of empirical knowledge of mutations, a joint-effect model of pleiotropic and real stabilizing selection that includes dominance is constructed and analyzed. It is shown that dominance can dramatically alter the prediction of equilibrium V (G). Analysis indicates that for the situations where mutations are more recessive for fitness than for a quantitative trait, as supported by the available data, the joint-effect model predicts a significantly higher V (G) than does an additive model. Importantly, for what seem to be realistic distributions of mutational effects (i.e., many mutants may not affect the quantitative trait substantially but are likely to affect fitness), the observed high levels of genetic variation in the quantitative trait under strong apparent stabilizing selection can be generated. This investigation supports the hypothesis that most V (G) comes from the alleles nearly neutral for fitness in heterozygotes while apparent stabilizing selection is contributed mainly by the alleles of large effect on the quantitative trait. Thus considerations of dominance coefficients of mutations lend further support to our previous conclusion that mutation-selection balance is a plausible mechanism of the maintenance of the genetic variance in natural populations. PMID:15020447

  6. The influence of RBE variations in a clinical proton treatment plan for a hypopharynx cancer

    NASA Astrophysics Data System (ADS)

    Tilly, N.; Johansson, J.; Isacsson, U.; Medin, J.; Blomquist, E.; Grusell, E.; Glimelius, B.

    2005-06-01

    Currently, most clinical range-modulated proton beams are assumed to have a fixed overall relative biological effectiveness (RBE) of 1.1. However, it is well known that the RBE increases with depth in the spread-out Bragg peak (SOBP) and becomes about 10% higher than mid-SOBP RBE at 2 mm from the distal edge (Paganetti 2003 Technol. Cancer Res. Treat. 2 413-26) and can reach values of 1.3-1.4 in vitro at the distal edge (Robertson et al 1975 Cancer 35 1664-77, Courdi et al 1994 Br. J. Radiol. 67 800-4). We present a fast method for applying a variable RBE correction with linear energy transfer (LET) dependent tissue-specific parameters based on the αref/βref ratios suitable for implementation in a treatment planning system. The influence of applying this variable RBE correction on a clinical multiple beam proton dose plan is presented here. The treatment plan is evaluated by RBE weighted dose volume histograms (DVHs) and the calculation of tumour control probability (TCP) and normal tissue complication probability (NTCP) values. The variable RBE correction yields DVHs for the clinical target volumes (CTVs), a primary advanced hypopharynx cancer and subclinical disease in the lymph nodes, that are slightly higher than those achieved by multiplying the absorbed dose with RBE = 1.1. Although, more importantly, the RBE weighted DVH for an organ at risk, the spinal cord is considerably increased for the variable RBE. As the spinal cord in this particular case is located 8 mm behind the planning target volume (PTV) and hence receives only low total doses, the NTCP values are zero in spite of the significant increase in the RBE weighted DVHs for the variable RBE. However, high NTCP values for the non-target normal tissue were obtained when applying the variable RBE correction. As RBE variations tend to be smaller for in vivo systems, this study—based on in vitro data since human tissue RBE values are scarce and have large uncertainties—can be interpreted as showing

  7. Factors influencing the short-term variation in phytoplankton composition and biomass in coral reef waters

    NASA Astrophysics Data System (ADS)

    van Duyl, F.; Gast, G.; Steinhoff, W.; Kloff, S.; Veldhuis, M.; Bak, R.

    2002-09-01

    The short-term temporal dynamics of phytoplankton composition was compared among coral reef waters, the adjacent ocean and polluted harbour water from July until October along the south-western coast of Curaçao, southern Caribbean. Temporal variations in phytoplankton pigment 'fingerprints' (zeaxanthin, chlorophyll b, 19'-hexanoyloxyfucoxanthin, fucoxanthin, 19'-butanoyloxyfucoxanthin, chlorophyll c 2 and c 3 relative to chlorophyll a) in the ocean were also observed in waters overlying the reef. However, with respect to specific pigments and algal-size distribution, the algal composition in reef waters was usually slightly different from that in the oceanic water. Phytoplankton biomass (chlorophyll a) was either higher or lower than in the oceanic water. The relative amount of fucoxanthin and peridinin was usually higher, and the relative and absolute amount of zeaxanthin was significantly lower than in oceanic water. Zeaxanthin-containing Synechococci were significantly reduced in reef water. Average algal cell size increased from the open water to the reef and the harbour entrance. Large centric diatoms (>20 m Ø) were better represented in reef than in oceanic water. In reef-overlying waters, the nitrate and nitrite concentrations were higher than in oceanic water. In front of the town, anthropogenic eutrophication (sewage discharge and ground water seepage) resulted in higher NH4, NO3 and PO4 concentrations than at other reef stations. This concurred with significantly enhanced phytoplankton biomass (chlorophyll a), chlorophyll c 2 and peridinin amounts at Town Reef compared with the other reef stations. Polluted harbour water usually showed the highest phytoplankton biomass of all stations, dominated by diatoms and dinoflagellates. Conditions in reef waters and harbour water promoted the occurrence and the relative abundance of diatoms and dinoflagellates. Harbour water did not influence the phytoplankton composition and biomass at reef stations situated >5

  8. 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. PMID:24571421

  9. 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).

  10. Solar activity influence on climatic variations of stratosphere and mesosphere in mid-latitudes

    NASA Technical Reports Server (NTRS)

    Taubenheim, J.; Entzian, G.; Voncossart, G.

    1989-01-01

    The direct modulation of temperature of the mid-latitude mesosphere by the solar-cycle EUV variation, which leads to greater heat input at higher solar activity, is well established. Middle atmosphere temperature modulation by the solar cycle is independently confirmed by the variation of reflection heights of low frequency radio waves in the lower ionosphere, which are regularly monitored over about 30 years. As explained elsewhere in detail, these reflection heights depend on the geometric altitude of a certain isobaric surface (near 80 k), and on the solar ionizing Lyman-alpha radiation flux. Knowing the solar cycle variation of Lyman-alpha how much the measured reflection heights would be lowered with the transition from solar minimum to maximum can be calculated, if the vertical baric structure of the neutral atmosphere would remain unchanged. An discrepancy between expected and observed height change must be explained by an uplifting of the isobaric level from solar minimum to maximum, caused by the temperature rise in the mesosphere. By integrating the solar cycle temperature changes over the height region of the middle atmosphere, and assuming that the lower boundary (tropopause) has no solar cycle variation, the magnitude of this uplifting can be estimated. It is given for the Lidar-derived and for the rocket-measured temperature variations. Comparison suggests that the real amplitude of the solar cycle temperature variation in the mesosphere is underestimated when using the rocket data, but probably overestimated with the Lidar data.

  11. Both male and female identity influence variation in male signalling effort

    PubMed Central

    2011-01-01

    Background Male sexual displays play an important role in sexual selection by affecting reproductive success. However, for such displays to be useful for female mate choice, courtship should vary more among than within individual males. In this regard, a potentially important source of within male variation is adjustment of male courtship effort in response to female traits. Accordingly, we set out to dissect sources of variation in male courtship effort in a fish, the desert goby (Chlamydogobius eremius). We did so by designing an experiment that allowed simultaneous estimation of within and between male variation in courtship, while also assessing the importance of the males and females as sources of courtship variation. Results Although males adjusted their courtship depending on the identity of the female (a potentially important source of within-male variation), among-male differences were considerably greater. In addition, male courtship effort towards a pair of females was highly repeatable over a short time frame. Conclusion Despite the plasticity in male courtship effort, courtship displays had the potential to reliably convey information about the male to mate-searching females. Our experiment therefore underscores the importance of addressing the different sources contributing to variation in the expression of sexually-selected traits. PMID:21827657

  12. Influence of glucocorticoids on a time-of-day-dependent variation in intradermal reactivity to histamine in dogs.

    PubMed

    Goto, Shun; Shimizu, Sunao; Watanabe, Miwa; Osada, Hironari; Sasaki, Kazuaki; Shimoda, Minoru; Nagai, Makoto; Shirai, Junsuke; Itoh, Hiroshi; Ohmori, Keitaro

    2016-08-01

    The objectives of this study were to determine daily variation in intradermal reactivity to histamine in dogs and to evaluate a potential influence of glucocorticoids on reactivity. Wheal sizes formed after intradermal injections of histamine were measured every 6 h during a single 24 h period in six healthy dogs. To determine whether glucocorticoids were implicated in daily variation, intradermal reactivity to histamine was evaluated at 9:00 h and at 21:00 h during a single day in dogs that received oral prednisolone (a synthetic glucocorticoid) or oral trilostane (an inhibitor of endogenous glucocorticoid synthesis). Finally, the time required for the histamine reaction to diminish after an intravenous injection of hydrocortisone was also assessed. A significant time-of-day-dependent variation in intradermal reactivity to histamine was detected in dogs, with a larger wheal size observed at 9:00 h than at 21:00 h. Administration of prednisolone or trilostane disrupted this variation. Intradermal reactivity to histamine was significantly reduced 6 h after an intravenous injection of hydrocortisone. These results suggest that glucocorticoid secretion from the adrenal glands could be involved in the regulation of daily variation in histamine-mediated reactions in dogs. PMID:27387732

  13. 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.

  14. Influence of variation of etching conditions on the sensitivity of PADC detectors with a new evaluation method.

    PubMed

    Fiechtner-Scharrer, A; Mayer, S; Boschung, M; Whitelaw, A

    2011-03-01

    At the Paul Scherrer Institut, a personal neutron dosimetry system based on chemically etched poly allyl diglycol carbonate (PADC) detectors and an automatic track counting (Autoscan 60) for neutron dose evaluations has been in routine use since 1998. Today, the hardware and the software of the Autoscan 60 are out of date, no spare components are available anymore and more sophisticated image-analysis systems are already developed. Therefore, a new evaluation system, the 'TASLIMAGE', was tested thoroughly in 2009 for linearity, reproducibility, influence of etching conditions and so forth, with the intention of replacing the Autoscan 60 in routine evaluations. The TASLIMAGE system is based on a microscope (high-quality Nikon optics) and an ultra-fast three-axis motorised control for scanning the detectors. In this paper, the TASLIMAGE system and its possibilities for neutron dose calculation are explained in more detail and the study of the influence of the variation of etching conditions on the sensitivity and background of the PADC detectors is described. The etching temperature and etching duration were varied, which showed that the etching conditions do not have a significant influence on the results of non-irradiated detectors. However, the sensitivity of irradiated detectors decreases by 5 % per 1°C when increasing the etching temperature. For the variation of the etching duration, the influence on the sensitivity of irradiated detectors is less pronounced. PMID:21212078

  15. 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…

  16. 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.

  17. Influence of geometry variations on the gravitational focusing of timelike geodesic congruences

    NASA Astrophysics Data System (ADS)

    Seriu, Masafumi

    2015-10-01

    We derive a set of equations describing the linear response of the convergence properties of a geodesic congruence to arbitrary geometry variations. It is a combination of equations describing the deviations from the standard Raychaudhuri-type equations due to the geodesic shifts and an equation describing the geodesic shifts due to the geometry variations. In this framework, the geometry variations, which can be chosen arbitrarily, serve as probes to investigate the gravitational contraction processes from various angles. We apply the obtained framework to the case of conformal geometry variations, characterized by an arbitrary function f (x ), and see that the formulas get simplified to a great extent. We investigate the response of the convergence properties of geodesics in the latest phase of gravitational contractions by restricting the class of conformal geometry variations to the one satisfying the strong energy condition. We then find out that in the final stage, f and D .D f control the overall contraction behavior and that the contraction rate gets larger when f is negative and |f | is so large as to overwhelm |D .D f |. (Here D .D is the Laplacian operator on the spatial hypersurfaces orthogonal to the geodesic congruence in concern.) To get more concrete insights, we also apply the framework to the time-reversed Friedmann-Robertson-Walker model as the simplest case of the singularity formations.

  18. Variations in stress and immune responses of cattle: Natural deviations and nutritional influences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Given the importance of the innate immune response with regard to the overall health and survival of domestic livestock, the primary immunological focus of this manuscript is on variations that exist within the innate immune system, and efforts to selectively and precisely modulate this system in a ...

  19. 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…

  20. Solar influence on meteor rates and atmospheric density variations at meteor heights

    NASA Technical Reports Server (NTRS)

    Ellyett, C.

    1977-01-01

    Lindblad (1967) has concluded that there was an inverse relation between meteor rates and the solar cycle brought about by an increase in atmospheric density gradient at the height of meteor ionization. The present paper investigates Lindblad's conclusion more fully by using three long series of continuous radar meteor data from New Zealand and Canada. The results confirm a clear variation of total rate from year to year, inversely correlated with the annual sunspot number. Although meteor rates call for a density gradient variation inversely related to the solar cycle, direct evidence for such a variation remains nonexistant. Possibly the effect is being obscured by other density changes occurring at these heights. Analysis of meteor rates within the same one-year period in the two hemispheres has established that seasonal rate changes brought about by the variation of the angle between the latitude of the observing station and the apex of the earth's way override change of density gradient in at least one of the hemispheres and possibly both in controlling meteor rates within the year.

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

    USGS Publications Warehouse

    Laakkonen, J.; Fisher, R.N.; Case, T.J.

    2003-01-01

    We examined the temporal variation in capture rates of shrews Notiosorex crawfordi (Coues, 1877) and Sorex ornatus (Merriam, 1895) in 20 sites representing fragmented and continuous habitats in southern California, USA. In N. 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 of N. crawfordi. In S. 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.

  2. Brain modularity across the theropod-bird transition: testing the influence of flight on neuroanatomical variation.

    PubMed

    Balanoff, Amy M; Smaers, Jeroen B; Turner, Alan H

    2016-08-01

    Living birds constitute the only vertebrate group whose brain volume relative to body size approaches the uniquely expanded values expressed by mammals. The broad suite of complex behaviors exhibited by crown-group birds, including sociality, vocal learning, parental care, and flying, suggests the origins of their encephalization was likely driven by a mosaic of selective pressures. If true, the historical pattern of brain expansion may be more complex than either a gradual expansion, as proposed by early studies of the avian brain, or a sudden expansion correlating with the appearance of flight. The origins of modern avian neuroanatomy are obscured by the more than 100 million years of evolution along their phylogenetic stem (from the origin of the modern radiation in the Middle Jurassic to the split from crocodile-line archosaurs). Here we use phylogenetic comparative approaches to explore which evolutionary scenarios best explain variation in measured volumes of digitally partitioned endocasts of modern birds and their non-avian ancestors. Our analyses suggest that variation in the relative volumes of the endocranium and cerebrum explain most of the structural variation in this lineage. Generalized multi-regime Ornstein-Uhlenbeck (OU) models suggest that powered flight does not appear to be a driver of observed variation, reinforcing the hypothesis that the deep history of the avian brain is complex, with nuances still to be discovered. PMID:26538376

  3. 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...

  4. 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 ...

  5. The influence of sensitisation to pollens and moulds on seasonal variations in asthma attacks

    PubMed Central

    Canova, Cristina; Heinrich, Joachim; Anto, Josep Maria; Leynaert, Benedicte; Smith, Matthew; Kuenzli, Nino; Zock, Jan-Paul; Janson, Christer; Cerveri, Isa; de Marco, Roberto; Toren, Kjell; Gislason, Thorarinn; Nowak, Dennis; Pin, Isabelle; Wjst, Matthias; Manfreda, Jure; Svanes, Cecilie; Crane, Julian; Abramson, Michael; Burr, Michael; Burney, Peter; Jarvis, Deborah

    2013-01-01

    No large study has described the seasonal variation in asthma attacks in population-based asthmatics in whom sensitisation to allergen has been measured. 2637 young adults with asthma living in 15 countries reported the months in which they usually had attacks of asthma and had skin-prick tests performed. Differences in seasonal patterns by sensitisation status were assessed using generalised estimating equations. Most young adults with asthma reported periods of the year when their asthma attacks were more common (range: 47% in Sweden to 86% in Spain). Seasonal variation in asthma was not modified by sensitisation to house dust mite or cat allergens. Asthmatics sensitised to grass, birch and Alternaria allergens had different seasonal patterns to those not sensitised to each allergen, with some geographical variation. In southern Europe, those sensitised to grass allergens were more likely to report attacks occurred in spring or summer than in winter (OR March/April 2.60, 95% CI 1.70–3.97; OR May/June 4.43, 95% CI 2.34–8.39) and smaller later peaks were observed in northern Europe (OR May/June 1.25, 95% CI 0.60–2.64; OR July/August 1.66, 95% CI 0.89–3.10). Asthmatics reporting hay fever but who were not sensitised to grass showed no seasonal variations. Seasonal variations in asthma attacks in young adults are common and are different depending on sensitisation to outdoor, but not indoor, allergens. PMID:23471350

  6. 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. PMID:24820296

  7. 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…

  8. 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

  9. The fragmentation of molecular clouds - Critical (Jeans) mass in the vicinity of thermal instability and influence of visible extinction variations

    NASA Astrophysics Data System (ADS)

    Renard, M.; Chieze, J. P.

    1993-01-01

    We adapt the classical Jeans analysis of gravitational stability to a molecular gas subject to thermal exchanges of the interstellar medium. At the onset of thermal instability the compressibility of a gas vanishes and so does the critical Jeans mass which is proportional to the 3/2 power of the compressibility. A spherical geometry is adopted, taking into account self-consistent variations of the opacity driven by radial density gravitational modes. The variation of the critical mass in the vicinity of thermal instabilities is presented. Nonlinear and nonequilibrium simulations of spherical clouds have been performed to study: the gravitational evolution of a thermally unstable cooling gas, and the influence of ambient radiation field variations upon stability of molecular clumps in the outer envelopes of molecular complexes. Accordingly, the following consequences are discussed: the critical mass reduction by self-consistent variations of the opacity which may occur for example when the ratio of dust to gas is locally enhanced; the location of stable hydrostatic equilibrium of the most massive clumps in large molecular clouds; and the early thermal and gravitational fragmentation of giant molecular clouds during the cooling period of large amounts of warm interstellar gas.

  10. 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. PMID:26741491

  11. Exploring neighborhood influences on small-area variations in intimate partner violence risk: a Bayesian random-effects modeling approach.

    PubMed

    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

  12. 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

  13. 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

  14. The Influence of Weather and Lemmings on Spatiotemporal Variation in the Abundance of Multiple Avian Guilds in the Arctic

    PubMed Central

    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

  15. 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

  16. 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 ...

  17. On how spatial variations of channel width influence river profile curvature

    NASA Astrophysics Data System (ADS)

    Ferrer-Boix, Carles; Chartrand, Shawn M.; Hassan, Marwan A.; Martín-Vide, Juan P.; Parker, Gary

    2016-06-01

    Longitudinal profiles of alluvial rivers usually exhibit upward-concave curvatures at equilibrium. River profile concavity has been primarily attributed to sediment downstream fining and to streamwise increments of water discharge. Conversely, upward-convex profiles have been typically associated with tectonic and geologic controls and with outlet base-level drops. Equations to describe river profiles at equilibrium developed from mass conservation principles do not consider longitudinal changes in channel width. This study addresses how variations in channel width can also act to control the curvature of longitudinal profiles. We develop a new theoretical framework in which the role on river profiles of downstream variations of channel width, flow discharge, bed roughness, and surface texture are explicitly shown. Unlike classical approaches for river profile evolution, this novel framework identifies physical domains for rivers to develop upward-concave/convex longitudinal profiles depending on channel width and flow discharge gradients flow intensity and surface texture.

  18. 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. PMID:25812468

  19. The Influence of Variational Crimes on the Finite Element Approximation of a Maxwell Eigenvalue Problem

    NASA Astrophysics Data System (ADS)

    Hamelinck, Wouter

    2008-09-01

    Cavity resonators are modelled using a Maxwell eigenvalue problem. In order to obtain a reliable finite element approximation one has to carefully use an appropriate discrete finite element space. In the present paper we extend the known conditions to assure a correct approximation of the spectrum to the case where numerical integration occurs and where curvilinear boundaries are present. We present a set of sufficient conditions which are similar to the case where those so called variational crimes are absent.

  20. 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.

  1. Influence of host age on critical fitness parameters of Spathius galinae (Hymenoptera: Braconidae), a new parasitoid of the emerald ash borer (Coleoptera: Buprestidae).

    PubMed

    Watt, Timothy J; Duan, Jian J

    2014-08-01

    Spathius galinae Belokobylskij and Strazenac (Hymenoptera: Braconidae) is a recently discovered gregarious idiobiont larval ectoparasitoid currently being evaluated for biological control against the invasive emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in the United States. To aid in the development of laboratory rearing protocols, we assessed the influence of various emerald ash borer stages on critical fitness parameters of S. galinae. We exposed gravid S. galinae females to emerald ash borer host larvae of various ages (3.5, 5, 7, and 10 wk post egg oviposition) that were reared naturally in tropical (evergreen) ash (Fraxinus uhdei (Wenzig) Lingelsh) logs, or to field-collected, late-stage emerald ash borers (nonfeeding J-shaped larvae termed "J-larvae," prepupae, and pupae) that were artificially inserted into green ash logs. When exposed to larvae in tropical ash logs, S. galinae attacked 5 and 7 wk hosts more frequently (68-76%) than 3.5 wk (23%) and 10 wk (12%) hosts. Subsample dissections of the these logs revealed that 3.5, 5, 7 and 10 wk host logs contained mostly second, third, fourth, and J-larvae, respectively, that had already bored into the sapwood for diapause. No J-larvae were attacked by S. galinae when naturally reared in tropical ash logs. When parasitized by S. galinae, 7 and 10 wk hosts produced the largest broods (approximately 6.7 offspring per parasitized host), and the progenies that emerged from these logs had larger anatomical measurements and more female-biased sex ratios. When exposed to emerald ash borer J-larvae, prepupae, or pupae artificially inserted into green ash logs, S. galinae attacked 53% ofJ-larvae, but did not attack any prepupae or pupae. We conclude that large (fourth instar) emerald ash borer larvae should be used to rear S. galinae. PMID:25195418

  2. 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

  3. 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. PMID:25604919

  4. Influence of the three dimensionality of the HF electromagnetic field on resistivity variations in Si single crystals during FZ growth

    NASA Astrophysics Data System (ADS)

    Ratnieks, G.; Muiznieks, A.; Buligins, L.; Raming, G.; Mühlbauer, A.; Lüdge, A.; Riemann, H.

    2000-06-01

    Three-dimensional numerical modelling is carried out to analyse the floating zone crystal growth with the needle-eye technique used for the production of high-quality silicon single crystals with large diameters ( ⩾100 mm ). Since the pancake inductor has only one turn, the EM field and the distribution of heat sources and EM forces are only roughly axisymmetric. The non-symmetry together with crystal rotation reflects itself on the hydrodynamic, thermal and dopant concentration fields in the molten zone and causes variations of resistivity in the grown single crystal, which are known as the so-called rotational striations. The non-symmetric high-frequency electromagnetic field of the pancake inductor is calculated by boundary element method. The obtained non-symmetric power distribution on the free melt surface and the corresponding EM forces are used for the coupled calculation of the 3D steady-state hydrodynamic and temperature fields in the molten zone on a body fitted structured 3D grid by a commercial program package with control volume approach. The buoyancy, Marangoni and EM forces are considered. The afterwards calculated corresponding 3D dopant concentration field is used to derive the variations of resistivity in a longitudinal cut of the grown crystal. The results are compared with experimental measurements (photo-scanning method) and with results of 2D transient flow calculations. Rotational striations are found in both 3D-calculated and experimental resistivity distributions and show a qualitative agreement. A Fourier analysis for the resistivity variations is performed and the observed differences are explained by modelling limitations.

  5. Environmental variation influences the magnitude of inbreeding depression in Cucurbita pepo ssp. texana (Cucurbitaceae).

    PubMed

    Hayes, C Nelson; Winsor, James A; Stephenson, Andrew G

    2005-01-01

    We grew inbred and outcrossed Cucurbita pepo ssp. texana plants and measured inbreeding depression for several male and female fitness traits 4 years in a row in adjacent fields at the same field station under the same cultivation conditions. We found that the magnitude of inbreeding depression varied from 0.16 to 0.53 from year to year and that those traits which were most affected tended to vary with year. We also grew inbred and outcrossed C. pepo ssp. texana plants in two adjacent fields differing only in the presence of nitrogen fertilizer to examine the effect of nutrient limitation as a form of environmental stress on the magnitude of inbreeding depression. We found that inbreeding depression was more severe in the unfertilized field. Overall, this study illustrates the notion that any estimate of inbreeding depression represents a single point in a cluster of possible estimates that can vary (often dramatically) with growing conditions. PMID:15669971

  6. The influence of different space-related physiological variations on exercise capacity determined by oxygen uptake kinetics

    NASA Astrophysics Data System (ADS)

    Stegemann, J.

    Oxygen uptake kinetics, following defined variations of work load changes allow to estimate the contribution of aerob and anaerob energy supply which is the base for determining work capacity. Under the aspect of long duration missions with application of adequate dosed countermeasures, a reliable estimate of the astronaut's work capacity is important to adjust the necessary inflight training. Since the kinetics of oxygen uptake originate in the working muscle group itself, while measurements are performed at the mouth, various influences within the oxygen transport system might disturb the determinations. There are not only detraining effects but also well-known other influences, such as blood- and fluid shifts induced by weightlessness. They might have an impact on the circulatory system. Some of these factors have been simulated by immersion, blood donation, and changing of the body position.

  7. 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

  8. Genetic variations of FACL4 have no obvious influence on cognitive ability in young Chinese children.

    PubMed

    Zhang, Kejin; Zheng, Zijian; An, Caiyan; Gao, Xiaocai; Zhang, Fuchang

    2010-06-30

    The influence of genetic variants of FACL4 on individual cognitive ability was examined in a random sample of 213 boys and 224 girls. Both conventional genetic methods and analysis of variance were applied in this study. We found no significant relationship between FACL4 and cognitive function. PMID:20452052

  9. 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…

  10. 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. PMID:24412324

  11. The provision of orthodontic services by general dental practitioners. 2. Factors influencing variation in service provision.

    PubMed

    Lawrence, A J; Wright, F A; D'Adamo, S P

    1995-12-01

    Previous work has shown that variations exist amongst general dental practitioners in the volume and type of orthodontic services provided, the type of orthodontic appliances used, and the objectives of the orthodontic treatment. The aims of this survey were to identify practitioner characteristics that account for variations in the level of orthodontic services provided and which distinguish providers and non-providers of orthodontic services. Multiple regression analysis revealed that four practitioner characteristics explained 41 per cent of the variance in the number of orthodontic patients treated. Dentists who treated more orthodontic patients: 1) treated more general practice patients; 2) frequently used multiple sources to keep up to date in orthodontics; 3) perceived their patient base to contain more children; and 4) were likely to have attended a Truitt course. Eleven variables best distinguished providers from non-providers of orthodontic treatment; 1, 2 and 3 above had the highest correlation with the discriminant function. The Null Hypothesis that selected characteristics of dentists providing orthodontic services were no different from those of dentists not providing orthodontic services was rejected. The provision of orthodontic services was associated with a higher level of continuing orthodontic education as well as treating more general practice patients, especially children. PMID:8615740

  12. 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.

  13. Case study of polychlorinated naphthalene emissions and factors influencing emission variations in secondary aluminum production.

    PubMed

    Jiang, Xiaoxu; Liu, Guorui; Wang, Mei; Liu, Wenbin; Tang, Chen; Li, Li; Zheng, Minghui

    2015-04-01

    Secondary aluminum production has been recognized as an important source of polychlorinated naphthalenes (PCNs). Large variations in PCN emissions as the smelting process proceeds have not been determined. In this study, solid and gaseous discharges, including fly ash, slag, and stack gas samples collected from four secondary smelting plants during different smelting stages were analyzed for PCNs. The average emission factor of ∑(1-8)PCNs to air was calculated to be 17.4 mg t(-1), with a range of 4.3-29.5 mg t(-1). The average emission factors of ∑(1-8)PCNs from fly ash and slag were 55.5 ng t(-1) and 0.13 ng t(-1), respectively. The derived emission factors may enable a more accurate estimation of annual emissions and a more comprehensive knowledge of the distribution of PCNs emitted from secondary aluminum production. The emission levels and characteristics of PCNs during different smelting stages were compared. Possible factors, including the organic impurities from aluminum scrap, fuel, and chloride additives, which could contribute to variations in PCN emissions and characteristics were discussed. These results may provide useful information for developing better control strategies for reducing PCN emissions in secondary aluminum production. PMID:25637821

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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

    2016-05-01

    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.

  20. 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. PMID:25655781

  1. Factors influencing development of management strategies for the Abou Ali River in Lebanon II: seasonal and annual variation.

    PubMed

    Massoud, May A; El-Fadel, Mutasem; Scrimshaw, Mark D; Lester, John N

    2006-06-01

    The water quality of a river at any point reflects several major influences including but are not limited to climatic conditions and anthropogenic inputs. Assessing these influences is essential for managing land and water resources within a particular river catchment. The objectives of this study were to identify the causes of increasing or decreasing trends in the concentrations of various water quality parameters in the Abou Ali River in North Lebanon and to account for the consequential variations both annual and seasonal (low/high flow). The assessment was conducted at the end of the dry season in October 2002 and 2003 and the end of the wet season in March 2003 and 2004. Results established that dissolved oxygen levels were consistently higher at the end of the wet season. The concentrations of biochemical oxygen demand, ammonia nitrogen and ortho-phosphates did not exhibit a clear seasonal or annual variation. While the levels of total dissolved solids and nitrate nitrogen exhibited a decreasing trend in urban catchments, an increasing trend was observed in rural, agricultural and forested areas. The findings of this study reinforce the notion that management of point and non-point sources should be integrated as the combination of both sources connected with land use results in deleterious effects on water quality. The lack of good quality water hinders economic development and the potential for long term sustainability. PMID:16336989

  2. The influence of sleep onset on the diurnal variation in cardiac activity and cardiac control.

    PubMed

    Carrington, Melinda; Walsh, Michelle; Stambas, Thalia; Kleiman, Jan; Trinder, John

    2003-09-01

    Heart rate (HR), blood pressure (BP) and autonomic nervous system (ANS) activity vary diurnally, with a reduction in HR and BP, and a shift to vagal dominance during the dark phase. However, the cause of these changes, particularly the relative influence of sleep and circadian mechanisms, remains uncertain. The present study assessed the effect of sleep onset on HR, BP, high frequency (HF) component of heart rate variability (HRV), low frequency/high frequency (LF/HF) ratio and pre-ejection period (PEP). Sleep onset was dissociated from circadian influences by having subjects go to sleep at two different circadian phases, their normal time of sleep onset (normal sleep onset, NSO), and after a delay of 3 h (delayed sleep onset, DSO). The assumption was that changes caused by sleep onset would occur in association with sleep onset, irrespective of its timing, while circadian effects would have a consistent circadian phase and be independent of when sleep onset occurred. Thirteen and 17 subjects were run in the NSO and DSO conditions, respectively. Following a 1-h adaptation period, data collection began 2 h before subjects' normal time of sleep onset and continued until morning awakening. The lights were turned out after 2 h in the NSO condition and 5 h in the DSO condition. Subjects were required to maintain a supine position throughout the experimental sessions. The night-time decrease in HR was found to be due to both sleep onset and a circadian influence, with the circadian component being more prominent. In contrast, the fall in BP was largely due to a sleep onset effect. Increased vagal activity, as reflected in the HF component and a shift to vagal dominance in the LF/HF ratio, appeared to be primarily a function of the sleep system, while sympathetic activity, as assessed by PEP, reflected a circadian influence. PMID:12941060

  3. Influence of structural length-scale variations on azimuth-resolved light scattering patterns of inhomogeneous cell models

    NASA Astrophysics Data System (ADS)

    Arifler, Dizem; Guillaud, Martial

    2015-07-01

    Optical scattering provides an intrinsic contrast mechanism for the diagnosis of early precancerous changes in tissues. There have been a multitude of numerical studies targeted at delineating the relationship between cancer-related alterations in morphology and internal structure of cells and the resulting changes in their optical scattering properties. Despite these efforts, we still need to further our understanding of inherent scattering signatures that can be linked to precancer progression. As such, computational studies aimed at relating electromagnetic wave interactions to cellular and subcellular structural alterations are likely to provide a quantitative framework for a better assessment of the diagnostic content of optical signals. In this study, we aim to determine the influence of structural length-scale variations on two-dimensional light scattering properties of cells. We numerically construct cell models with different lower bounds on the size of refractive index heterogeneities and we employ the finite-difference time-domain method to compute their azimuth-resolved light scattering patterns. The results indicate that changes in length-scale variations can significantly alter the two-dimensional scattering patterns of cell models. More specifically, the degree of azimuthal asymmetry characterizing these patterns is observed to be highly dependent on the range of length-scale variations. Overall, the study described here is expected to offer useful insights into whether azimuth-resolved measurements can be explored for diagnostic purposes.

  4. Soil moisture influence on the interannual variation in temperature sensitivity of soil organic carbon mineralization in the Loess Plateau

    NASA Astrophysics Data System (ADS)

    Zhang, Y. J.; Guo, S. L.; Zhao, M.; Du, L. L.; Li, R. J.; Jiang, J. S.; Wang, R.; Li, N. N.

    2015-06-01

    Temperature sensitivity of soil organic carbon (SOC) mineralization (i.e., Q10) determines how strong the feedback from global warming may be on the atmospheric CO2 concentration; thus, understanding the factors influencing the interannual variation in Q10 is important for accurately estimating local soil carbon cycle. In situ SOC mineralization rate was measured using an automated CO2 flux system (Li-8100) in long-term bare fallow soil in the Loess Plateau (35°12' N, 107°40' E) in Changwu, Shaanxi, China from 2008 to 2013. The results showed that the annual cumulative SOC mineralization ranged from 226 to 298 g C m-2 yr-1, with a mean of 253 g C m-2 yr-1 and a coefficient of variation (CV) of 13%, annual Q10 ranged from 1.48 to 1.94, with a mean of 1.70 and a CV of 10%, and annual soil moisture content ranged from 38.6 to 50.7% soil water-filled pore space (WFPS), with a mean of 43.8% WFPS and a CV of 11%, which were mainly affected by the frequency and distribution of precipitation. Annual Q10 showed a quadratic correlation with annual mean soil moisture content. In conclusion, understanding of the relationships between interannual variation in Q10, soil moisture, and precipitation are important to accurately estimate the local carbon cycle, especially under the changing climate.

  5. Variation in Inflammatory Response during Pneumococcal Infection Is Influenced by Host-Pathogen Interactions but Associated with Animal Survival

    PubMed Central

    Escudero, Laura; Sylvius, Nicolas; Norman, Martin; Henriques-Normark, Birgitta

    2016-01-01

    Inflammation is a crucial part of innate immune responses but, if imbalanced, can lead to serious clinical conditions or even death. Cytokines regulate inflammation, and studies report their impact on clinical outcome. However, host and pathogen genetic backgrounds influence cytokine production, making it difficult to evaluate which inflammatory profiles (if any) relate to improved prognosis. Streptococcus pneumoniae is a common human pathogen associated with asymptomatic nasopharyngeal carriage. Infrequently, it can lead to a wide range of diseases with high morbidity and mortality rates. Studies show that both pneumococcal serotype and host genetic background affect the development of disease and contribute to variation in inflammatory responses. In this study, we investigated the impact of the host and pneumococcal genetic backgrounds on pulmonary cytokine responses and their relationship to animal survival. Two inbred mouse strains, BALB/c and CBA/Ca, were infected with 10 pneumococcal strains, and the concentrations of six pulmonary cytokines were measured at 6 h and 24 h postinfection. Collected data were analyzed by principal-component analysis to identify whether there is any pattern in the observed cytokine variation. Our results show that host-pneumococcus combination was at the core of observed variation in cytokine responses, yet the resulting cytokine profile discriminated only between survivors and fatalities but not mouse or pneumococcal strains used during infection. Therefore, our results indicate that although alternative inflammatory profiles are generated during pneumococcal infection, a common pattern emerged, which determined the clinical outcome of pneumococcal infections. PMID:26787718

  6. Variation partitioning of diatom species data matrices: Understanding the influence of multiple factors on benthic diatom communities in tropical streams.

    PubMed

    Bere, Taurai; Mangadze, Tinotenda; Mwedzi, Tongai

    2016-10-01

    Elucidating the confounding influence of multiple environmental factors on benthic diatom communities is important in developing water quality predictive models for better guidance of stream management efforts. The objective of this study was to explore the relative impact of metal pollution and hydromorphological alterations in, addition to nutrient enrichment and organic pollution, on diatom taxonomic composition with the view to improve stream diatom-based water quality inference models. Samples were collected twice at 20 sampling stations in the tropical Manyame Catchment, Zimbabwe. Diatom, macroinvertebrate communities and environmental factors were sampled and analysed. The variations in diatom community composition explained by different categories of environmental factors were analysed using canonical correspondence analysis using variance partitioning (partial CCA). The following variations were explained by the different predictor matrices: nutrient levels and organic pollution - 10.4%, metal pollution - 8.3% and hydromorphological factors - 7.9%. Thus, factors other than nutrient levels and organic pollution explain additional significant variation in these diatom communities. Development of diatom-based stream water quality inference models that incorporate metal pollution and hydromorphological alterations, where these are key issues, is thus deemed necessary. PMID:27320742

  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. Variation in Inflammatory Response during Pneumococcal Infection Is Influenced by Host-Pathogen Interactions but Associated with Animal Survival.

    PubMed

    Jonczyk, Magda S; Escudero, Laura; Sylvius, Nicolas; Norman, Martin; Henriques-Normark, Birgitta; Andrew, Peter W

    2016-04-01

    Inflammation is a crucial part of innate immune responses but, if imbalanced, can lead to serious clinical conditions or even death. Cytokines regulate inflammation, and studies report their impact on clinical outcome. However, host and pathogen genetic backgrounds influence cytokine production, making it difficult to evaluate which inflammatory profiles (if any) relate to improved prognosis.Streptococcus pneumonia is a common human pathogen associated with asymptomatic nasopharyngeal carriage. Infrequently, it can lead to a wide range of diseases with high morbidity and mortality rates. Studies show that both pneumococcal serotype and host genetic background affect the development of disease and contribute to variation in inflammatory responses. In this study, we investigated the impact of the host and pneumococcal genetic backgrounds on pulmonary cytokine responses and their relationship to animal survival. Two inbred mouse strains, BALB/c and CBA/Ca, were infected with 10 pneumococcal strains, and the concentrations of six pulmonary cytokines were measured at 6 h and 24 h postinfection. Collected data were analyzed by principal-component analysis to identify whether there is any pattern in the observed cytokine variation. Our results show that host-pneumococcus combination was at the core of observed variation in cytokine responses, yet the resulting cytokine profile discriminated only between survivors and fatalities but not mouse or pneumococcal strains used during infection. Therefore, our results indicate that although alternative inflammatory profiles are generated during pneumococcal infection, a common pattern emerged, which determined the clinical outcome of pneumococcal infections. PMID:26787718

  9. Characterisation of the influence of genetic variations on the enzyme activity of a recombinant human glycine N-acyltransferase.

    PubMed

    van der Sluis, Rencia; Badenhorst, Christoffel P S; van der Westhuizen, Francois H; van Dijk, Alberdina A

    2013-02-25

    Human glycine N-acyltransferase (human GLYAT) detoxifies a wide range of endogenous and xenobiotic metabolites, including benzoate and salicylate. Significant inter-individual variation exists in glycine conjugation capacity. The molecular basis for this variability is not known. To investigate the influence of single nucleotide polymorphisms (SNPs) in the GLYAT coding sequence on enzyme activity, we expressed and characterised a recombinant human GLYAT. Site-directed mutagenesis was used to generate six non-synonymous SNP variants of the enzyme (K16N; S17T; R131H; N156S; F168L; R199C). The variants were expressed, purified, and enzymatically characterised. The enzyme activities of the K16N, S17T and R131H variants were similar to that of the wild-type, whereas the N156S variant was more active, the F168L variant less active, and the R199C variant was inactive. We also generated an E227Q mutant, which lacks the catalytic residue proposed by Badenhorst et al. (2012). This mutant was inactive compared to the wild-type recombinant human GLYAT. A molecular model of human GLYAT containing coenzyme A (CoA) was generated which revealed that the inactivity of the R199C variant could be due to the substitution of the highly conserved Arg(199) and destabilisation of an α-loop-α motif which is important for substrate binding in the GNAT superfamily. The finding that SNP variations in the human GLYAT gene influence the kinetic properties of the enzyme may explain some of the inter-individual variation in glycine conjugation capacity, which is relevant to the metabolism of xenobiotics such as aspirin and the industrial solvent xylene, and to the treatment of some metabolic disorders. PMID:23237781

  10. 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.

  11. One hundred years of Arctic surface temperature variation due to anthropogenic influence.

    PubMed

    Fyfe, John C; von Salzen, Knut; Gillett, Nathan P; Arora, Vivek K; Flato, Gregory M; McConnell, Joseph R

    2013-01-01

    Observations show that Arctic-average surface temperature increased from 1900 to 1940, decreased from 1940 to 1970, and increased from 1970 to present. Here, using new observational data and improved climate models employing observed natural and anthropogenic forcings, we demonstrate that contributions from greenhouse gas and aerosol emissions, along with explosive volcanic eruptions, explain most of this observed variation in Arctic surface temperature since 1900. In addition, climate model simulations without natural and anthropogenic forcings indicate very low probabilities that the observed trends in each of these periods were due to internal climate variability alone. Arctic climate change has important environmental and economic impacts and these results improve our understanding of past Arctic climate change and our confidence in future projections. PMID:24025852

  12. 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

  13. 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.

  14. Influence of quaternary sea-level variations on a land bird endemic to Pacific atolls

    PubMed Central

    Cibois, Alice; Thibault, Jean-Claude; Pasquet, Eric

    2010-01-01

    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. PMID:20554555

  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. PMID:20554555

  16. 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.

  17. One hundred years of Arctic surface temperature variation due to anthropogenic influence

    PubMed Central

    Fyfe, John C.; von Salzen, Knut; Gillett, Nathan P.; Arora, Vivek K.; Flato, Gregory M.; McConnell, Joseph R.

    2013-01-01

    Observations show that Arctic-average surface temperature increased from 1900 to 1940, decreased from 1940 to 1970, and increased from 1970 to present. Here, using new observational data and improved climate models employing observed natural and anthropogenic forcings, we demonstrate that contributions from greenhouse gas and aerosol emissions, along with explosive volcanic eruptions, explain most of this observed variation in Arctic surface temperature since 1900. In addition, climate model simulations without natural and anthropogenic forcings indicate very low probabilities that the observed trends in each of these periods were due to internal climate variability alone. Arctic climate change has important environmental and economic impacts and these results improve our understanding of past Arctic climate change and our confidence in future projections. PMID:24025852

  18. Influence of azimuthal coil size variations on magnetic field harmonics of superconducting particle accelerator magnets

    SciTech Connect

    Ogitsu, T. ); Devred, A. )

    1994-06-01

    The superconducting super collider (SSC) would have required dipole and quadrupole magnets with a very high field quality. The field quality is determined mainly by the dimensions of the magnet coils and their positions with respect to the iron yoke. It is thus very sensitive to manufacturing errors. A model is here developed to estimate the field distortions in a dipole magnet due to azimuthal coil size variations. This model is applied to the data collected during the fabrication and testing of a series of 5 cm aperture, 15 m long SSC dipole magnet prototypes. A clear correlation is observed between the predicted field distortions from the azimuthal coil sizes and the measured skew quadrupole and skew sextupole coefficients.

  19. 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.

  20. An influence of solar spectral variations on radiative forcing of climate.

    PubMed

    Haigh, Joanna D; Winning, Ann R; Toumi, Ralf; Harder, Jerald W

    2010-10-01

    The thermal structure and composition of the atmosphere is determined fundamentally by the incoming solar irradiance. Radiation at ultraviolet wavelengths dissociates atmospheric molecules, initiating chains of chemical reactions-specifically those producing stratospheric ozone-and providing the major source of heating for the middle atmosphere, while radiation at visible and near-infrared wavelengths mainly reaches and warms the lower atmosphere and the Earth's surface. Thus the spectral composition of solar radiation is crucial in determining atmospheric structure, as well as surface temperature, and it follows that the response of the atmosphere to variations in solar irradiance depends on the spectrum. Daily measurements of the solar spectrum between 0.2 µm and 2.4 µm, made by the Spectral Irradiance Monitor (SIM) instrument on the Solar Radiation and Climate Experiment (SORCE) satellite since April 2004, have revealed that over this declining phase of the solar cycle there was a four to six times larger decline in ultraviolet than would have been predicted on the basis of our previous understanding. This reduction was partially compensated in the total solar output by an increase in radiation at visible wavelengths. Here we show that these spectral changes appear to have led to a significant decline from 2004 to 2007 in stratospheric ozone below an altitude of 45 km, with an increase above this altitude. Our results, simulated with a radiative-photochemical model, are consistent with contemporaneous measurements of ozone from the Aura-MLS satellite, although the short time period makes precise attribution to solar effects difficult. We also show, using the SIM data, that solar radiative forcing of surface climate is out of phase with solar activity. Currently there is insufficient observational evidence to validate the spectral variations observed by SIM, or to fully characterize other solar cycles, but our findings raise the possibility that the

  1. Influence of altered low cloud parameterizations for seasonal variation of Arctic cloud amount on climate feedbacks

    NASA Astrophysics Data System (ADS)

    Kim, Yoojin; Choi, Yong-Sang; Kim, Baek-Min; Kim, Hyerim

    2015-12-01

    This study investigates the alteration of climate feedbacks due to overestimated wintertime low-level cloud amount bias over the Arctic region (60°N-90°N) in a climate model. The climate feedback was quantitatively examined through radiative kernels that are pre-calculated radiative responses of climate variables to doubling of carbon dioxide concentration in NCAR Community Atmosphere Model version 3 (CAM3). Climate models have various annual cycle of the Arctic cloud amount at the low-level particularly with large uncertainty in winter and CAM3 may tend to overestimate the Arctic low-level cloud. In this study, the seasonal variation of low-level cloud amount was modified by reducing the wintertime cloud amount by up to 35 %, and then compared with the original without seasonal variation. Thus, we investigate how that bias may affect climate feedbacks and the projections of future Arctic warming. The results show that the decrease in low-level cloud amount slightly affected the radiation budgets because of a small amount of incident solar insolation in winter, but considerably changed water vapor and temperature profiles. Consequently, the most distinctive was decreases in water vapor feedback and contribution of heat transport (by -0.20 and -0.55 W m-2 K-1, respectively) and increases in the lapse rate feedback and cloud feedback (by 0.13 and 0.58 W m-2 K-1, respectively) during winter in this model experiment. This study suggests that the change in Arctic cloud amount effectively reforms the contributions of individual climate feedbacks to Arctic climate system and leads to opposing effects on different feedbacks, which cancel out in the model.

  2. Quasi-decadal variability of the stratosphere: Influence of long-term solar ultraviolet variations

    NASA Technical Reports Server (NTRS)

    Hood, L. L.; Jirikowic, J. L.; Mccormack, J. P.

    1993-01-01

    A multiple regression statistical model is applied to investigate the existence of upper-stratospheric ozone, temperature, and zonal wind responses to long-term (solar cycle) changes in solar ultraviolet radiation using 11.5 years of reprocessed Nimbus-7 Solar Backscattered Ultraviolet (SBUV) data and 12.4 years of National Meteorological Center (NMC) data. A positive solar cycle variation of independently measured ozone and temperature occurs with maximum amplitude near the low-latitude stratopause. The seasonal solar regression coefficients near 1 mb for both ozone and temperature occur at low latitudes supporting a role for photochemical and radiative forcing in their origin. Zonal wind perturbations that correlate with long-term solar ultraviolet variations are a strong function of season and pressure level. Above approximately 2 mbar, the largest solar-correlated zonal wind enhancements occur at middle winter latitudes near the time of winter solstice in both hemispheres. The Northern Hemisphere December enhancement at 1 mb was especially large, 23 +/- 9 m/s from solar minimum to maximum during the last solar cycle. The derived ozone, temperature, and zonal wind increases with increasing solar ultraviolet flux near the stratopause are larger than predicted by models that consider primarily photochemical and radiative processes. The higher ozone and temperature response amplitudes at low latitudes may be due to modified ozone transport and adiabatic temperature changes induced by the dynamical response. If the midlatitude winter solstice wind enhancements are solar induced, their high amplitudes require a positive feedback due to wave-mean flow interaction such that the planetary wave drag on the flow is reduced under solar maximum conditions.

  3. 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).

  4. 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.

  5. 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.

  6. Amygdala Volume in Offspring from Multiplex for Alcohol Dependence Families: The Moderating Influence of Childhood Environment and 5-HTTLPR Variation

    PubMed Central

    Hill, Shirley Y; Wang, Shuhui; Carter, Howard; McDermott, Michael D; Zezza, Nicholas; Stiffler, Scott

    2014-01-01

    Background The increased susceptibility for developing alcohol dependence seen in offspring from families with alcohol dependence may be related to structural and functional differences in brain circuits that influence emotional processing. Early childhood environment, genetic variation in the serotonin transporter-linked polymorphic region (5-HTTLPR) of the SLCA4 gene and allelic variation in the Brain Derived Neurotrophic Factor (BDNF) gene have each been reported to be related to volumetric differences in the temporal lobe especially the amygdala Methods Magnetic resonance imaging was used to obtain amygdala volumes for 129 adolescent/young adult individuals who were either High-Risk (HR) offspring from families with multiple cases of alcohol dependence (N=71) or Low-Risk (LR) controls (N=58). Childhood family environment was measured prospectively using age-appropriate versions of the Family Environment Scale during a longitudinal follow-up study. The subjects were genotyped for Brain-Derived Neurotrophic Factor (BDNF) Val66Met and the serotonin transporter polymorphism (5-HTTLPR). Two family environment scale scores (Cohesion and Conflict), genotypic variation, and their interaction were tested for their association with amygdala volumes. Personal and prenatal exposure to alcohol and drugs were considered in statistical analyses in order to more accurately determine the effects of familial risk group differences. Results Amygdala volume was reduced in offspring from families with multiple alcohol dependent members in comparison to offspring from control families. High-Risk offspring who were carriers of the S variant of the 5-HTTLPR polymorphism had reduced amygdala volume in comparison to those with an LL genotype. Larger amygdala volume was associated with greater family cohesion but only in Low-Risk control offspring. Conclusions Familial risk for alcohol dependence is an important predictor of amygdala volume even when removing cases with significant

  7. [Diel variations of hydrochemistry and influencing factors in a surface stream in subtropical karst area, SW China].

    PubMed

    Zhang, Tao; Pu, Jun-Bing; Yuan, Dao-Xian; Zhang, Cheng; He, Shi-Yi; Yu, Shi; Liu, Wen; Mo, Xue; Zhou, Jian-Chao; Yang, Hui; Tang, Wei

    2014-08-01

    In order to understand the diel variation and influencing factors of hydrochemistry in a surface creek fed by karst subterranean river in a subtropical area, where is located at Guancun Village, Daliang Township, Rong'an County of Guangxi Zhuang Autonomous Region, China, two monitoring sites were set simultaneously to launch Guancun subterranean river outlet (G1) and surface creek mouth (G2), respectively. Physical and hydrochemical parameters including pH, dissolved oxygen (DO), water temperature (T) and specific conductivity (Spc) were measured at 15-minute intervals and water samples for analyzing major ions such as Ca2+, HCO3- and NO3- as well as delta3C(DIC) were collected at 2-hour intervals. The results showed that: (1) G1 and G2 sites were both HCO3- Ca type water, however the two monitoring sites showed different diel variations of hydrogeochemical process; (2) The physical and hydrochemical parameters (T, DO, pH, Spc) and major ions (Ca2+, Mg2+, Na+, K+, HCO3-, SO4(2-), NO3-, Cl- in G1 site were basically stable, while the physical and hydrochemical parameters (T, DO, pH, Spc) and major ions (Ca2+, HCO3- and NO3-) in G2 site displayed regular diel variation during monitoring; (3) The dissolved inorganic carbon (DIC) and delta13C values in G2 monitoring site showed reverse characteristics in diurnal fluctuations, where DIC decreased in daylight and increased at night while the delta13C value increased in daylight and decreased at night, DIC also showed a negative correlation with the delta13C value (correlation coefficient is -0. 87, P < 0.01) in G2 site. These results indicated that photosynthesis and respiration of aquatic plants, water temperature and degassing jointly affected diurnal variation of hydrochemistry and controlled the cycling process of internal matter in this surface creek fed by karst subterranean river. PMID:25338364

  8. North-South differences in the Earth's high-latitude upper atmosphere dynamics: Influence of solar activity and seasonal variations

    NASA Astrophysics Data System (ADS)

    Förster, Matthias; Cnossen, Ingrid

    2014-05-01

    Recent observations have shown that the upper thermospheric/ionospheric response to solar wind and IMF dependent drivers of the magnetosphere-ionosphere-thermosphere (M-I-T) system can be very dissimilar in the Northern and Southern Hemisphere. We present statistical studies of the high-latitude upper thermospheric neutral wind circulation patterns obtained from almost a decade of measurements with an accelerometer on board the CHAMP spacecraft. The influence of the solar activity and the dependence on seasonal variations is analysed with respect to average cross-polar wind velocities and high-latitude neutral wind vorticity values. Using the Coupled Magnetosphere-Ionosphere-Thermosphere (CMIT) model, on the other hand, we simulated representative equinox as well as solstice intervals for low and high solar activity conditions. For the simulations, we used on the one hand side symmetric dipole and on the other realistic (IGRF) geomagnetic field configurations. The comparative survey of both the numerical simulation and the statistical observation results show some prominent asymmetries between the two hemispheres, which are caused by the different geographic-geomagnetic offsets and/or the different patterns of geomagnetic flux densities. The average cross-polar neutral wind velocities show a distinct seasonal variation with minimum values during the respective hemispheric winter solstice. The neutral wind vorticity values are generally larger in the Northern than the Southern Hemisphere, except for northern winter solstice conditions. The hemispheric differences become larger for higher solar activity and show a semidiurnal variation. In contrast, the spatial variance of the upper thermospheric neutral wind is usually considerably larger in the polar region of the Southern Hemisphere compared with the Northern, and the hemispheric difference shows a strong semidiurnal variation.

  9. Vertical variations in the influence of the amount effect: South American Summer Monsoon Region

    NASA Astrophysics Data System (ADS)

    Samuels-Crow, K. E.; Galewsky, J.; Worden, J. R.

    2014-12-01

    Recent theoretical studies have shown that convective recycling of atmospheric water vapor gives rise to the isotope "amount effect" in which d values are lower than predicted by simple Rayleigh distillation processes (i.e. (DdD = dDvapor ­- dDRayleigh < 0‰). Several studies have linked isotopes in precipitation [e.g. Vimeux et al., 2009] and atmospheric water vapor [e.g. Samuels-Crow et al., 2014] in the tropical Andes to upwind convection associated with the South American Summer Monsoon (SASM). The vertical structure of this convective influence, however, remains unknown. Understanding the vertical structure of the amount effect over South America is essential for improving theoretical constraints and developing better models of the influence of the SASM on southern hemisphere humidity. Additionally, evaluating the vertical and lateral extent of the SASM's convective influence can provide important constraints for interpreting paleoclimate proxies in the region. We use data from the Tropospheric Emission Spectrometer (TES) to examine the vertical structure of the amount effect associated with the SASM and relate these results to regional convective precipitation and local subcloud equivalent potential temperature. Preliminary results show that DdD is below 0‰ from the boundary layer through the mid-troposphere over tropical South America during austral summer, and meridional averages show that convective precipitation is highest over these areas where DdD < 0‰ extends higher in the atmosphere. We hypothesize that the depth of convection in the monsoon region controls the vertical structure of DdD, which should also be coherently linked to local equivalent potential temperature. References Vimeux et al. (2009), Palaeogeogr Palaeocl, 281(3-4), 229-241, doi:10.1016/j.palaeo.2008.03.054. Samuels-Crow et al. (2014), J Geophys Res-Atmos, doi:10.1002/(ISSN)2169-8996.

  10. 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.

  11. Large-scale spatial variation in parasite communities influenced by anthropogenic factors.

    PubMed

    Altman, Irit; Byers, James E

    2014-07-01

    Parasites are integral members of natural communities, but large-scale determinants of their abundance and diversity, including the importance of biotic and abiotic factors, both natural and anthropogenic, are often not well understood. Here, we examine which factors best predict larval trematode communities in the mudsnail host Ilyanassa obsoleta across a regional landscape. At 15 salt marsh sites spanning 200 km, we quantified the diversity of trematodes and the prevalence (i.e., proportion) of infected hosts and sampled a broad array of potential parasite predictors including abundance of intermediate and definitive hosts, habitat, nutrients, metals, roads, and sediment characteristics. We identified the set of best performing models to explain variability associated with five metrics of trematode prevalence and diversity using an information-theoretic approach. Results indicate that several anthropogenic factors associate with this trematode community and that the direction of their influence differs. Road density around sites was a strong negative predictor of all trematode prevalence and species richness metrics. Nitrogen, another human influenced variable, was a strong positive predictor for the most abundant trematode species in the system. In addition, the abundance of definitive fish hosts was a positive predictor in several models, confirming the importance of this direct biological link to parasites. Other influential variables included sediment composition and heavy metals (arsenic, copper, lead, and zinc). We discuss possible direct and indirect mechanisms to explain these findings including that anthropogenic factors may be directly influencing free-living stages of trematodes, or be acting as proxies of hard-to-measure hosts. PMID:25163120

  12. 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.

  13. 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

  14. Sea level variations during snowball Earth formation and evolution: 2. The influence of Earth's rotation

    NASA Astrophysics Data System (ADS)

    Liu, Yonggang; Peltier, W. Richard

    2013-08-01

    Preliminary analyses are described of the influence of snowball Earth formation on the rotational state of the Earth as well as its feedback onto relative sea level. We demonstrate that a sufficiently large excess ellipticity of the Earth as might be expected to arise due to the mantle convection process acts to stabilize the rotational axis significantly so that the associated relative sea level change would be negligible. If no such excess ellipticity were characteristic of Neoproterozoic time, then increasing the thickness of the elastic lithosphere significantly promotes true polar wander (TPW) and the associated relative sea level change. On the contrary, increasing the viscosity of the lower mantle has an equally significant but opposite effect. TPW due to ice sheets formation for the 720 Ma and 570 Ma continental configurations (approximate Marinoan) can reach more than 5° and 10° in 10 Myr for viscosity model VM5a, and the associated maximum relative sea level changes at this time reach 26 m and 49 m, respectively. However, if a 1°/Myr TPW due to the action of the mantle convection process is assumed to be superimposed, then these values increase to 70 m and 101 m respectively. Compared to the analyses in which rotational influence is entirely neglected, the probability density distribution of freeboard values obtained here is almost the same except that the tails of the distribution are broadened, making it more difficult to accurately infer continental ice volume during snowball Earth events from observed freeboard changes.

  15. Size variation of 0-group plaice: Are earlier influences on growth potential a contributing factor?

    NASA Astrophysics Data System (ADS)

    Fox, Clive J.; Targett, Timothy E.; Ciotti, Benjamin J.; de Kroon, Kasper; Hortsmeyer, Lena; Burrows, Michael T.

    2014-04-01

    Over a decade of sampling has shown that there are consistent differences in the sizes of 0-group plaice by late summer comparing 21 nursery sites on the Scottish west coast. However, when young fish were collected from two sites which produce particularly small and large fish and reared using a common garden design, growth rates between fish from the two sites were indistinguishable. Either there is little selection for fast or slow growth up to a few weeks post-settlement, or such effects do not persist sufficiently strongly to influence later growth. There were also no significant correlations between the time-series of fish size comparing sites, although within some sites there was evidence of inter-annual density-dependent effects. Any influences of offshore regional-scale factors, such as sea temperature or pelagic primary productivity on growth thus appear to be heavily modified by local conditions on the nursery grounds. The field observations combined with the experimental results lead us to conclude that the size 0-group plaice attain in late summer is mainly controlled by post-settlement habitat quality.

  16. The Influence of Diurnal Temperature Variation on Degree-Day Accumulation and Insect Life History

    PubMed Central

    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. PMID:25790195

  17. 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

  18. Novel candidate genes influencing natural variation in potato tuber cold sweetening identified by comparative proteomics and association mapping

    PubMed Central

    2013-01-01

    Background Higher plants evolved various strategies to adapt to chilling conditions. Among other transcriptional and metabolic responses to cold temperatures plants accumulate a range of solutes including sugars. The accumulation of the reducing sugars glucose and fructose in mature potato tubers during exposure to cold temperatures is referred to as cold induced sweetening (CIS). The molecular basis of CIS in potato tubers is of interest not only in basic research on plant adaptation to environmental stress but also in applied research, since high amounts of reducing sugars affect negatively the quality of processed food products such as potato chips. CIS-tolerance varies considerably among potato cultivars. Our objective was to identify by an unbiased approach genes and cellular processes influencing natural variation of tuber sugar content before and during cold storage in potato cultivars used in breeding programs. We compared by two-dimensional polyacrylamide gel electrophoresis the tuber proteomes of cultivars highly diverse for CIS. DNA polymorphisms in genomic sequences encoding differentially expressed proteins were tested for association with tuber starch content, starch yield and processing quality. Results Pronounced natural variation of CIS was detected in tubers of a population of 40 tetraploid potato cultivars. Significant differences in protein expression were detected between CIS-tolerant and CIS-sensitive cultivars before the onset as well as during cold storage. Identifiable differential proteins corresponded to protease inhibitors, patatins, heat shock proteins, lipoxygenase, phospholipase A1 and leucine aminopeptidase (Lap). Association mapping based on single nucleotide polymorphisms supported a role of Lap in the natural variation of the quantitative traits tuber starch and sugar content. Conclusions The combination of comparative proteomics and association genetics led to the discovery of novel candidate genes for influencing the natural

  19. Influence of Chemical Composition Variations on Densification During the Sintering of MOX Materials

    NASA Astrophysics Data System (ADS)

    Vaudez, S.; Marlot, C.; Lechelle, J.

    2016-04-01

    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.

  20. Variations of the wood smoke microstructure under the influence of external factors

    NASA Astrophysics Data System (ADS)

    Kozlov, Valerii S.; Rakhimov, R. F.; Makienko, E. V.; Panchenko, Mikhail V.; Shmargunov, V.

    2004-02-01

    We analyze the variations of optical and microphysical properties of aerosol formed due to thermal effect on the wood materials in closed volumes. It is shown that particles with similar peculiarities of the disperse composition are formed at low-temperature pyrolysis of wood (300 to 500°C) and thermal sublimation of coniferous resins. As a rule, polymodal volume size distribution is observed at the initial stage after generation of the dense wood smoke. The maxima are located in the ranges of finely dispersed accumulative fraction (with modal radius of 0.1 to 0l8 μm), intermediately dispersed particles (o9.4 to 0.7μm) and coarse particles (0.9 to 1.2 μm). Experiments in humidified air show that, if a smoke mixture (with high concentration of aerosol particles and vapor of aerosol-bearing species) crosses temperature inhomogeneities many times, then two quasi-water-droplet fractions of the modal radius 0.55 and 0.9 μm are formed. Measurements reavealed that, even in the case of a weak (~55°C) heating of surface of a coniferous tree wood, the achieved emission of aerosol particles and vapor of aerosol-bearing species (in closed volumes) has a rate sufficient for formation of finely dispersed fraction (0.05-0.2 μm).

  1. The Influence of Aircraft Speed Variations on Sensible Heat-Flux Measurements by Different Airborne Systems

    NASA Astrophysics Data System (ADS)

    Martin, Sabrina; Bange, Jens

    2014-01-01

    Crawford et al. (Boundary-Layer Meteorol 66:237-245, 1993) showed that the time average is inappropriate for airborne eddy-covariance flux calculations. The aircraft's ground speed through a turbulent field is not constant. One reason can be a correlation with vertical air motion, so that some types of structures are sampled more densely than others. To avoid this, the time-sampled data are adjusted for the varying ground speed so that the modified estimates are equivalent to spatially-sampled data. A comparison of sensible heat-flux calculations using temporal and spatial averaging methods is presented and discussed. Data of the airborne measurement systems , Helipod and Dornier 128-6 are used for the analysis. These systems vary in size, weight and aerodynamic characteristics, since the is a small unmanned aerial vehicle (UAV), the Helipod a helicopter-borne turbulence probe and the Dornier 128-6 a manned research aircraft. The systematic bias anticipated in covariance computations due to speed variations was neither found when averaging over Dornier, Helipod nor UAV flight legs. However, the random differences between spatial and temporal averaging fluxes were found to be up to 30 % on the individual flight legs.

  2. 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.

  3. 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.

  4. 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

    2016-04-01

    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

  5. The influence of ethnic group variation on victimization and help seeking among Latino women.

    PubMed

    Sabina, Chiara; Cuevas, Carlos A; Schally, Jennifer L

    2015-01-01

    Interpersonal violence research on Latinos has largely ignored the ethnic group variations that are included under the pan-ethnic term Latino. The current study adds to the literature by utilizing a national sample of Latino women to examine the interpersonal victimization experiences and help-seeking responses to victimization by ethnic group. The sample was drawn from the Sexual Assault Among Latinas Study (SALAS; Cuevas & Sabina, 2010) that surveyed 2,000 self-identified adult Latino women. For the purpose of this study, victimization in the United States was examined among Mexican ethnics (73.3% of sample), Cuban ethnics (14%), and other ethnics (12.8%). Mexican ethnicity was found to be significantly associated with increased odds of experiencing any, physical, sexual, threat, and stalking victimization. Findings also show that higher levels of Latino orientation and being an immigrant were associated with decreased odds of experiencing any victimization, whereas Anglo orientation, as measured by the Brief ARSMA-II (Cuéllar, Arnold, & Maldonado, 1995), was associated with greater odds of experiencing any victimization. Anglo orientation was significantly associated with formal help seeking. Taken as a whole, these findings emphasize the importance of bilingual and culturally competent services and also reveal that culturally competent services includes developing an understanding of the cultural differences between Latino ethnic groups. Specifically, service providers should be aware that Latinos of Mexican ethnicity may face unique risks for victimization. PMID:25111549

  6. 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

  7. Recollection-Based Retrieval Is Influenced by Contextual Variation at Encoding but Not at Retrieval

    PubMed Central

    Rosenstreich, Eyal; Goshen-Gottstein, Yonatan

    2015-01-01

    In this article, we investigated the effects of variations at encoding and retrieval on recollection. We argue that recollection is more likely to be affected by the processing that information undergoes at encoding than at retrieval. To date, manipulations shown to affect recollection were typically carried out at encoding. Therefore, an open question is whether these same manipulations would also affect recollection when carried out at retrieval, or whether there is an inherent connection between their effects on recollection and the encoding stage. We therefore manipulated, at either encoding or retrieval, fluency of processing (Experiment 1)—typically found not to affect recollection—and the amount of attentional resources available for processing (Experiments 2 and 3)—typically reported to affect recollection. We found that regardless of the type of manipulation, recollection was affected more by manipulations carried out at encoding and was essentially unaffected when these manipulations were carried out at retrieval. These findings suggest an inherent dependency between recollection-based retrieval and the encoding stage. It seems that because recollection is a contextual-based retrieval process, it is determined by the processing information undergoes at encoding—at the time when context is bound with the items—but not at retrieval—when context is only recovered. PMID:26135583

  8. 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

  9. Variation in winter snowpack depth and duration influences summer soil respiration in a subalpine meadow

    NASA Astrophysics Data System (ADS)

    Arnold, C. L.; Ghezzehei, T. A.; Berhe, A. A.

    2012-12-01

    Subalpine meadows in the Sierra Nevada rely on the depth and duration of the winter snowpack to supply ample water to restore the water table in the meadow during the spring snowmelt. This study examines the role that interannual variability in the winter snowpack plays in the overall rate of summer soil respiration along a hydrologic gradient in a subalpine meadow. Carbon dioxide efflux from the meadow was measured from June through September in 2011 and 2012 using soil collars and a LICOR 8100A infrared gas analyzer. Preliminary results show that soil respiration rates are influenced by the hydrologic gradient across the meadow, with drier regions peaking earlier in the summer as compared to wetter regions. We also show that high snowpack years can suppress soil respiration in the meadow until late in the summer season as compared to low snowpack years, where soil respiration peaks early in the summer.

  10. 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

    2012-07-01

    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 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. PMID:22634755

  11. 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.

  12. Oxygen isotope variation in primitive achondrites: The influence of primordial, asteroidal and terrestrial processes

    NASA Astrophysics Data System (ADS)

    Greenwood, R. C.; Franchi, I. A.; Gibson, J. M.; Benedix, G. K.

    2012-10-01

    A detailed oxygen isotope study of the acapulcoites, lodranites, winonaites, brachinites and various related achondrites has been undertaken to investigate the nature of their precursor materials. High levels of terrestrial alteration displayed by many of these samples have been mitigated by leaching in ethanolamine thioglycollate (EATG) solution. Due to their high metal and sulphide content, acapulcoite, lodranite and winonaite samples show much greater isotopic shifts during weathering than brachinites. As observed in previous studies, Antarctic weathered finds are displaced to lighter oxygen isotope compositions and non-Antarctic finds to heavier values. Leached primitive achondrite residues continue to show high levels of oxygen isotope heterogeneity. This variation is reflected in the 2σ error on group mean Δ17O values, which decrease in the following order: acapulcoite-lodranite clan > brachinites > winonaites. On an oxygen three-isotope diagram, the acapulcoite--lodranite clan define a limited trend with a slope of 0.61 ± 0.08 and an intercept of -1.43 ± 0.27 (R2 = 0.78). A broad positive correlation between Δ17O and olivine fayalite contents displayed by both acapulcoite and lodranite samples may be the result of early aqueous alteration and subsequent dehydration. Winonaites experienced a greater degree of differentiation than the acapulcoite-lodranite clan and define a distinct mass fractionation line, with a slope of 0.53 ± 0.01 and an intercept of -0.53 ± 0.04 (R2 = 1). A number of samples currently classified as acapulcoites (NWA 725, NWA 1052 and Dho 1222) have oxygen isotope compositions indicating that they are winonaites. The relatively high level of oxygen isotope heterogeneity displayed by the brachinites supports their designation as primitive achondrites. A number of ungrouped olivine-rich achondrites (Divnoe, NWA 4042, NWA 4363, NWA 4518, NWA 5400, Zag (b)) as well as the unique plagioclase-rich achondrites GRA 06128 and GRA 06129 have

  13. How do starspots influence the transit timing variations of exoplanets? Simulations of individual and consecutive transits

    NASA Astrophysics Data System (ADS)

    Ioannidis, P.; Huber, K. F.; Schmitt, J. H. M. M.

    2016-01-01

    Transit timing variations (TTVs) of exoplanets are normally interpreted as the consequence of gravitational interaction with additional bodies in the system. However, TTVs can also be caused by deformations of the system transits by starspots, which might thus pose a serious complication in their interpretation. We therefore simulate transit light curves deformed by spot-crossing events for different properties of the stellar surface and the planet, such as starspot position, limb darkening, planetary period, and impact parameter. Mid-transit times determined from these simulations can be significantly shifted with respect to the input values; these shifts cannot be larger than 1% of the transit duration and depend very strongly on the longitudinal position of the spot during the transit and the transit duration. Consequently, TTVs with amplitudes larger than the above limit are very unlikely to be caused by starspots. We also investigate whether TTVs from sequences of consecutive transits with spot-crossing anomalies can be misinterpreted as the result of an additional body in the system. We use the Generalized Lomb-Scargle periodogram to search for periods in TTVs and conclude that low-amplitude TTVs with statistically significant periods around active stars are the most problematic cases. In those cases where the photometric precision is high enough to inspect the transit shapes for deformations it should be possible to identify TTVs caused by starspots; however, especially for cases with low signal-to-noise in transit (TSNR ≲ 15) light curves it becomes quite difficult to reliably decide whether these periods come from starspots, physical companions in the system, or if they are random noise artifacts.

  14. 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.

  15. Nuclear estradiol binding in rat adipocytes. Regional variations and regulatory influences of hormones.

    PubMed

    Pedersen, S B; Børglum, J D; Eriksen, E F; Richelsen, B

    1991-06-01

    The nuclear estrogen receptor was characterised in isolated rat adipocytes. The binding reaction with [3H]estradiol was performed with intact isolated rat adipocytes and the radioactivity associated with the nucleus was subsequently determined after cell lysis. The nuclear uptake of [3H]estrogen in rat adipocytes was temperature dependent and steroid specific. The steady-state binding was achieved after 30 min at 37 degrees C and was constant for several hours. Estradiol was found to bind to a homogeneous class of nuclear receptors in epididymal adipocytes with an apparent Kd of 3.1 +/- 0.76 nM and a Bmax of 7.98 +/- 1.11 fmol/10(6) cells corresponding to about 4800 receptors per nucleus. The estradiol binding exhibited regional variations in isolated adipocytes. In lean rats the highest receptor number was found in epididymal adipocytes, whereas there was a significantly lower number of nuclear binding sites in perirenal and subcutaneous adipocytes (P less than 0.05), unlike in older and more obese rats where the nuclear estradiol binding was greatest in adipocytes from the perirenal fat depot. Incubations with isoproterenol (10 microM) and dibutyryl-cAMP (2.5 mM) both reduced estradiol binding by 56% (P less than 0.005), while insulin (1 nM) enhanced the estradiol binding by 37% (P less than 0.01). In conclusion, a specific and high affinity nuclear estradiol receptor was demonstrated in rat adipocytes and regional differences in nuclear estradiol binding were detected. Furthermore, it was demonstrated that nuclear estradiol binding could be modulated by other agents known to affect adipocyte metabolism. PMID:1646650

  16. Variation at the mu-opioid receptor gene (OPRM1) influences attachment behavior in infant primates.

    PubMed

    Barr, Christina S; Schwandt, Melanie L; Lindell, Stephen G; Higley, J Dee; Maestripieri, Dario; Goldman, David; Suomi, Stephen J; Heilig, Markus

    2008-04-01

    In a variety of species, development of attachment to a caregiver is crucial for infant survival and partly mediated by the endogenous opioids. Functional mu-opioid receptor gene polymorphisms are present in humans (OPRM1 A118G) and rhesus macaques (OPRM1 C77G). We hypothesized that rhesus infants carrying a gain-of-function OPRM1 77G allele would experience increased reward during maternal contact and would, therefore, display increased measures of attachment. We collected behavioral data from rhesus macaques (n = 97) during early infancy and at 6 months of age, across four cycles of maternal separation (4 days) and reunion (3 days). Animals were genotyped for the OPRM1 C77G polymorphism, and the effects of this allele on attachment-related behaviors were analyzed. Infants carrying the G allele exhibited higher levels of attachment behavior during early infancy. During prolonged periods of maternal separation, although infant macaques homozygous for the C allele exhibited decreases in their levels of distress vocalization with repeated separation, this response persisted in G allele carriers. The OPRM1 77G allele also affected social preference during reunion. C/G infants spent increasing amounts of time in social contact with their mothers as a function of repeated separation and were less likely to interact with other individuals in the social group, a pattern not observed among infants with the C/C genotype. These findings suggest a role for OPRM1 variation in the expression of attachment behavior in human subjects, especially as a function of separation from the caregiver. PMID:18378897

  17. Variation in the location of the shoe sole flexion point influences plantar loading patterns during gait

    PubMed Central

    2014-01-01

    Background Several footwear design characteristics are known to have detrimental effects on the foot. However, one characteristic that has received relatively little attention is the point where the sole flexes in the sagittal plane. Several footwear assessment forms assume that this should ideally be located directly under the metarsophalangeal joints (MTPJs), but this has not been directly evaluated. The aim of this study was therefore to assess the influence on plantar loading of different locations of the shoe sole flexion point. Method Twenty-one asymptomatic females with normal foot posture participated. Standardised shoes were incised directly underneath the metatarsophalangeal joints, proximal to the MTPJs or underneath the midfoot. The participants walked in a randomised sequence of the three shoes whilst plantar loading patterns were obtained using the Pedar® in-shoe pressure measurement system. The foot was divided into nine anatomically important masks, and peak pressure (PP), contact time (CT) and pressure time integral (PTI) were determined. A ratio of PP and PTI between MTPJ2-3/MTPJ1 was also calculated. Results Wearing the shoe with the sole flexion point located proximal to the MTPJs resulted in increased PP under MTPJ 4–5 (6.2%) and decreased PP under the medial midfoot compared to the sub-MTPJ flexion point (−8.4%). Wearing the shoe with the sole flexion point located under the midfoot resulted in decreased PP, CT and PTI in the medial and lateral hindfoot (PP: −4.2% and −5.1%, CT: −3.4% and −6.6%, PTI: −6.9% and −5.7%) and medial midfoot (PP: −5.9% CT: −2.9% PTI: −12.2%) compared to the other two shoes. Conclusion The findings of this study indicate that the location of the sole flexion point of the shoe influences plantar loading patterns during gait. Specifically, shoes with a sole flexion point located under the midfoot significantly decrease the magnitude and duration of loading under the midfoot and hindfoot, which

  18. 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

  19. Defect Generation and Propagation in MC-Si Ingots: Influence on Cell-to-Cell Performance Variation

    SciTech Connect

    Sopori, B.; Rupnowski, P.; Shet, S.; Mehta, V.; Seacrist, M.; Shi, G.; Chen, J.; Deshpande, A.

    2011-01-01

    This paper describes results of our study aimed at understanding mechanism(s) of dislocation generation and propagation in multicrystalline silicon (mc-Si) ingots, and evaluating their influence on the solar cell performance. This work was done in two parts: (i) Measurement of dislocation distributions along various bricks, selected from strategic locations within several ingots; and (ii) Theoretical modeling of the cell performance corresponding to the measured dislocation distributions. Solar cells were fabricated on wafers of known dislocation distribution, and the results were compared with the theory. These results show that cell performance can be accurately predicted from the dislocation distribution, and the changes in the dislocation distribution are the primary cause for variations in the cell-to-cell performance. The dislocation generation and propagation mechanisms, suggested by our results, are described in this paper.

  20. Methylation interactions in Arabidopsis hybrids require RNA-directed DNA methylation and are influenced by genetic variation.

    PubMed

    Zhang, Qingzhu; Wang, Dong; Lang, Zhaobo; He, Li; Yang, Lan; Zeng, Liang; Li, Yanqiang; Zhao, Cheng; Huang, Huan; Zhang, Heng; Zhang, Huiming; Zhu, Jian-Kang

    2016-07-19

    DNA methylation is a conserved epigenetic mark in plants and many animals. How parental alleles interact in progeny to influence the epigenome is poorly understood. We analyzed the DNA methylomes of Arabidopsis Col and C24 ecotypes, and their hybrid progeny. Hybrids displayed nonadditive DNA methylation levels, termed methylation interactions, throughout the genome. Approximately 2,500 methylation interactions occurred at regions where parental DNA methylation levels are similar, whereas almost 1,000 were at differentially methylated regions in parents. Methylation interactions were characterized by an abundance of 24-nt small interfering RNAs. Furthermore, dysfunction of the RNA-directed DNA methylation pathway abolished methylation interactions but did not affect the increased biomass observed in hybrid progeny. Methylation interactions correlated with altered genetic variation within the genome, suggesting that they may play a role in genome evolution. PMID:27382183

  1. Influence of Temperature Variation on Field Effect Transistor Properties Using a Solution-Processed Liquid Crystalline Semiconductor, 8TNAT8.

    PubMed

    Monobe, Hirosato; Kimoto, Masaomi; Shimizu, Yo

    2016-04-01

    In this study, we used a liquid crystalline (LC) semiconductor, 8TNAT8, solution (e.g., 0.1 wt% in toluene) for forming an organic semiconductor layer by solution casting method, and fabricated bottom-gate/bottom-contact type field effect transistors (FETs). These LC semiconductors show FET characteristic properties and have high carrier mobility of 0.01 cm2 V-1 s-1. We have investigated the surface morphology and the influence of temperature variation on LC FET properties across the phase transition from crystal to mesophase of a LC semiconductor, 8TNAT8. In the most cases, FET mobility was irreversibly decreased after. temperature heat stress above the melting point of 8TNAT8, owing to the morphological change of LC layer. PMID:27451617

  2. Influence of influent wastewater communities on temporal variation of activated sludge communities.

    PubMed

    Lee, Sang-Hoon; Kang, Hyun-Jin; Park, Hee-Deung

    2015-04-15

    Continuously feeding influent wastewater containing diverse bacterial species to a wastewater treatment activated sludge bioreactor may influence the activated sludge bacterial community temporal dynamics. To explore this possibility, this study tracked influent wastewater and activated sludge bacterial communities by pyrosequencing 16S rRNA genes from four full-scale wastewater treatment plants over a 9-month period. The activated sludge communities showed significantly higher richness and evenness than the influent wastewater communities. Furthermore, the two communities were different in composition and temporal dynamics. These results demonstrate that the impact of the influent wastewater communities on the activated sludge communities was weak. Nevertheless, 4.3-9.3% of the operational taxonomic units (OTUs) detected in the activated sludge were shared with the influent wastewater, implying contribution from influent wastewater communities to some extent. However, the relative OTU abundance of the influent wastewater was not maintained in the activated sludge communities (i.e., weak neutral assembly). In addition, the variability of the communities of the shared OTUs was moderately correlated with abiotic factors imposed to the bioreactors. Taken together, temporal dynamics of activated sludge communities appear to be predominantly explained by species sorting processes in response to influent wastewater communities. PMID:25655320

  3. Cut marks on bone surfaces: influences on variation in the form of traces of ancient behaviour.

    PubMed

    Braun, David R; Pante, Michael; Archer, William

    2016-06-01

    Although we know that our lineage has been producing sharp-edged tools for over 2.6 Myr, our knowledge of what they were doing with these tools is far less complete. Studies of these sharp-edged stone tools show that they were most probably used as cutting implements. However, the only substantial evidence of this is the presence of cut marks on the bones of animals found in association with stone tools in ancient deposits. Numerous studies have aimed to quantify the frequency and placement of these marks. At present there is little consensus on the meaning of these marks and how the frequency relates to specific behaviours in the past. Here we investigate the possibility that mechanical properties associated with edges of stone tools as well as the properties of bones themselves may contribute to the overall morphology of these marks and ultimately their placement in the archaeological record. Standardized tests of rock mechanics (Young's modulus and Vickers hardness) indicate that the hardness of tool edges significantly affects cut-mark morphology. In addition, we show that indentation hardness of bones also impacts the overall morphology of cut marks. Our results show that rock type and bone portions influence the shape and prevalence of cut marks on animal bones. PMID:27274806

  4. 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. PMID:16002273

  5. Influence of resonant transducer variations on long range guided wave monitoring of rail track

    NASA Astrophysics Data System (ADS)

    Loveday, Philip W.; Long, Craig S.

    2016-02-01

    The ability of certain guided wave modes to propagate long distances in continuously welded rail track is exploited in permanently installed monitoring systems. Previous work demonstrated that reflections from thermite welds could be measured at distances of the order of 1 km from a transducer array. The availability of numerous thermite welds is useful during the development of a monitoring system as real defects are not available. Measurements of reflections from welds were performed over an eleven month period with two permanently installed transducers. Phased array processing was performed and the true location of a weld is indicated by a strong reflection but there is generally also a smaller, spurious replica reflection, at the same distance but in the incorrect direction. In addition, the relative reflection from different welds appears to change over time. The influence of differences between the two resonant transducers was investigated using a model. It was found that estimating the attenuation in either direction and scaling the reflections in either direction decreased the variability in the reflection measurements. Transducer interaction effects, where the transducer closer to the weld records a greater reflection than the second transducer were observed and can be used to determine the direction of a weld. This feature was used to demonstrate a simple alternative to phased array processing that can be used with resonant transducers.

  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. 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

  8. 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

  9. Patient, Physician and Organizational Influences on Variation in Antipsychotic Prescribing Behavior

    PubMed Central

    Tang, Yan; Chang, Chung-Chou H.; Lave, Judith R.; Gellad, Walid F.; Huskamp, Haiden A.; Donohue, Julie M.

    2016-01-01

    Background Physicians face the choice of multiple ingredients when prescribing drugs in many therapeutic categories. For conditions with considerable patient heterogeneity in treatment response, customizing treatment to individual patient needs and preferences may improve outcomes. Aims of the Study To assess variation in the diversity of antipsychotic prescribing for mental health conditions, a necessary although not sufficient condition for personalizing treatment. To identify patient caseload, physician, and organizational factors associated with the diversity of antipsychotic prescribing. Methods Using 2011 data from Pennsylvania’s Medicaid program, IMS Health’s HCOS™ database, and the AMA Masterfile, we identified 764 psychiatrists who prescribed antipsychotics to ≥10 patients. We constructed three physician-level measures of diversity/concentration of antipsychotic prescribing: number of ingredients prescribed, share of prescriptions for most preferred ingredient, and Herfindahl-Hirschman index (HHI). We used multiple membership linear mixed models to examine patient caseload, physician, and healthcare organizational predictors of physician concentration of antipsychotic prescribing. Results There was substantial variability in antipsychotic prescribing concentration among psychiatrists, with number of ingredients ranging from 2-17, share for most preferred ingredient from 16%-85%, and HHI from 1,088-7,270. On average, psychiatrist prescribing behavior was relatively diversified; however, 11% of psychiatrists wrote an average of 55% of their prescriptions for their most preferred ingredient. Female prescribers and those with smaller shares of disabled or serious mental illness patients had more concentrated prescribing behavior on average. Discussion Antipsychotic prescribing by individual psychiatrists in a large state Medicaid program varied substantially across psychiatrists. Our findings illustrate the importance of understanding physicians

  10. 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.

  11. Soil moisture influenced the interannual variation in temperature sensitivity of soil organic carbon mineralization in the Loess Plateau

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Guo, S.; Zhao, M.; Du, L.; Li, R.; Jiang, J.; Wang, R.; Li, N.

    2015-01-01

    Temperature sensitivity of SOC mineralization (Q10) determines how strong the feedback from global warming may be on the atmospheric CO2 concentration, thus understanding the factors influencing the interannual variation in Q10 is important to accurately estimate the local soil carbon cycle. In situ SOC mineralization was measured using an automated CO2 flux system (Li-8100) in long-term bare fallow soil in the Loess Plateau (35° 12' N, 107° 40' E) in Changwu, Shaanxi, China form 2008 to 2013. The results showed that the annual cumulative SOC mineralization ranged from 226 to 298 g C m-2 y-1 (mean =253 g C m-2 y-1; CV =13%), annual Q10 ranged from 1.48 to 1.94 (mean =1.70; CV =10%), and annual soil moisture content ranged from 38.6 to 50.7% WFPS (mean =43.8% WFPS; CV =11%), which were mainly affected by the frequency and distribution of precipitation. Annual Q10 showed a negative quadratic correlation with soil moisture. In conclusion, understanding of the relationships between interannual variation in Q10 of SOC mineralization, soil moisture and precipitation is important to accurately estimate the local carbon cycle, especially under the changing climate.

  12. Vitamins, stress and growth: the availability of antioxidants in early life influences the expression of cryptic genetic variation.

    PubMed

    Kim, S-Y; Noguera, J C; Tato, A; Velando, A

    2013-06-01

    Environmental inputs during early development can shape the expression of phenotypes, which has long-lasting consequences in physiology and life history of an organism. Here, we study whether experimentally manipulated availability of dietary antioxidants, vitamins C and E, influences the expression of genetic variance for antioxidant defence, endocrine signal and body mass in yellow-legged gull chicks using quantitative genetic models based on full siblings. Our experimental study in a natural population reveals that the expression of genetic variance in total antioxidant capacity in plasma increased in chicks supplemented with vitamins C and E despite the negligible effects on the average phenotype. This suggests that individuals differ in their ability to capture and transport dietary antioxidants or to respond to these extra resources, and importantly, this ability has a genetic basis. Corticosterone level in plasma and body mass were negatively correlated at the phenotypic level. Significant genetic variance of corticosterone level appeared only in control chicks nonsupplemented with vitamins, suggesting that the genetic variation of endocrine system, which transmits environmental cues to adaptively control chick development, appeared in stressful conditions (i.e. poor antioxidant availability). Therefore, environmental inputs may shape evolutionary trajectories of antioxidant capacity and endocrine system by affecting the expression of cryptic genetic variation. PMID:23517061

  13. 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

  14. Genetic Variation Throughout the Folate Metabolic Pathway Influences Negative Symptom Severity in Schizophrenia

    PubMed Central

    Roffman, Joshua L.; Brohawn, David G.; Nitenson, Adam Z.; Macklin, Eric A.; Smoller, Jordan W.; Goff, Donald C.

    2013-01-01

    Low serum folate levels previously have been associated with negative symptom risk in schizophrenia, as has the hypofunctional 677C>T variant of the MTHFR gene. This study examined whether other missense polymorphisms in folate-regulating enzymes, in concert with MTHFR, influence negative symptoms in schizophrenia, and whether total risk allele load interacts with serum folate status to further stratify negative symptom risk. Medicated outpatients with schizophrenia (n = 219), all of European origin and some included in a previous report, were rated with the Positive and Negative Syndrome Scale. A subset of 82 patients also underwent nonfasting serum folate testing. Patients were genotyped for the MTHFR 677C>T (rs1801133), MTHFR 1298A>C (rs1801131), MTR 2756A>G (rs1805087), MTRR 203A>G (rs1801394), FOLH1 484T>C (rs202676), RFC 80A>G (rs1051266), and COMT 675G>A (rs4680) polymorphisms. All genotypes were entered into a linear regression model to determine significant predictors of negative symptoms, and risk scores were calculated based on total risk allele dose. Four variants, MTHFR 677T, MTR 2756A, FOLH1 484C, and COMT 675A, emerged as significant independent predictors of negative symptom severity, accounting for significantly greater variance in negative symptoms than MTHFR 677C>T alone. Total allele dose across the 4 variants predicted negative symptom severity only among patients with low folate levels. These findings indicate that multiple genetic variants within the folate metabolic pathway contribute to negative symptoms of schizophrenia. A relationship between folate level and negative symptom severity among patients with greater genetic vulnerability is biologically plausible and suggests the utility of folate supplementation in these patients. PMID:22021659

  15. 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

  16. An Assessment of the Factors that Influence the Promotion and Delivery of Sport, Fitness, and Health Courses: Contributors of Marketing to Physical Education.

    ERIC Educational Resources Information Center

    Armstrong, Ketra L.; O'Bryant, Camille; Costa, Carla

    2002-01-01

    Examined the demographics of college students enrolled in sport, fitness, and health program (SFHP) courses, investigating frequency of enrollment in courses, reasons for enrolling, and evaluation of course quality. Student surveys indicated that the main reasons for enrolling related to skill development or enhancement of knowledge about health…

  17. 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

  18. 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

  19. [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

  20. 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. PMID:20403840

  1. DRD1 5′UTR Variation, Sex and Early Infant Stress Influence Ethanol Consumption in Rhesus Macaques

    PubMed Central

    Newman, Timothy K.; Parker, Clarissa C.; Suomi, Stephen J.; Goldman, David; Barr, Christina S.; Higley, J. Dee

    2009-01-01

    The mesolimbic dopamine system plays an important role in mediating a variety of behaviors and is involved in mediating the reinforcing effects of ethanol. Genes encoding dopamine receptor subtypes are thus good candidate loci for understanding the genetic etiologies of susceptibility to alcohol dependence and its antecedent behavioral phenotypes. We tested whether variation in DRD1 influences alcohol consumption in rhesus macaques and whether its influence is mediated by sex and early rearing experience. We genotyped a single nucleotide polymorphism (-111 G/T) in the 5′ UTR of DRD1 in 96 subjects raised with their mothers until six months of age (n=43) or in peer-only groups (n=53). As young adults they underwent a seven-week voluntary ethanol consumption experiment. ANOVA revealed a significant main effect of sex (F (1,95) = 6.3, p = .014) and an interaction between genotype, sex and rearing on ethanol consumption (F (7,95) = 4.63, p =.0002). Maternally deprived males heterozygous for the T allele consumed significantly more ethanol (Prob > t = <.0001) than the other sub-groups. Maternal deprivation can produce individuals that are anxious and impulsive, both of which are known risk factors for alcohol dependence. Our work demonstrates a potential role for the dopamine D1 receptor gene in modulating alcohol consumption, especially in the context of early environmental stress. PMID:19563515

  2. The influence of the Indian Ocean Dipole on interannual variations in phytoplankton size structure as revealed by Earth Observation

    NASA Astrophysics Data System (ADS)

    Brewin, Robert J. W.; Hirata, Takafumi; Hardman-Mountford, Nick J.; Lavender, Samantha J.; Sathyendranath, Shubha; Barlow, Ray

    2012-11-01

    Using a decade of satellite ocean-colour observations and a model that links chlorophyll-a to the size of the phytoplankton cells, parameterised using pigment data from the Indian Ocean, we examine the implications of the Indian Ocean Dipole (IOD) for phytoplankton size structure. The inferred interannual anomalies in phytoplankton size structure are related to those in sea-surface temperature (SST) and sea-surface height (SSH), derived using satellite radiometry and altimetry, and stratification, derived using the Simple Ocean Data Assimilation (SODA) database. In regions influenced by the Indian Ocean Dipole, we observe a tight correlation between phytoplankton size structure and the physical variables, such that interannual variations in the physical variables accounts for up to 70% of the total variance in phytoplankton size structure. For much of the Indian Ocean, low temperature, low SSH and low stratification (indicative of a turbulent environment) are correlated with larger size classes, consistent with theories on coupling between physical-chemical processes and ecosystem structure. To the extent that phytoplankton function is related to its size structure, changes in physical forcing are likely to influence biogeochemical cycles in the region and the pelagic food web. The limitations of our approach are discussed and we highlight future challenges in satellite ocean-colour monitoring, should climate change lead to any modification in our marine ecosystem.

  3. 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.

  4. 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.

  5. 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…

  6. Partnerships for the Fit.

    ERIC Educational Resources Information Center

    Golding, Lawrence A.

    1984-01-01

    The YMCA has helped train and employ fitness leaders while educating the public on physical fitness. Colleges and universities can help develop careers in fitness while maintaining their traditional role of developing teachers and coaches. (DF)

  7. 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.

  8. Reading fitness landscape diagrams through HSAB concepts

    NASA Astrophysics Data System (ADS)

    Vigneresse, Jean-Louis

    2014-10-01

    Fitness landscapes are conceived as range of mountains, with local peaks and valleys. In terms of potential, such topographic variations indicate places of local instability or stability. The chemical potential, or electronegativity, its value changed of sign, carries similar information. In addition to chemical descriptors defined through hard-soft acid-base (HSAB) concepts and computed through density functional theory (DFT), the principles that rule chemical reactions allow the design of such landscape diagrams. The simplest diagram uses electrophilicity and hardness as coordinates. It allows examining the influence of maximum hardness or minimum electrophilicity principles. A third dimension is introduced within such a diagram by mapping the topography of electronegativity, polarizability or charge exchange. Introducing charge exchange during chemical reactions, or mapping a third parameter (f.i. polarizability) reinforces the information carried by a simple binary diagram. Examples of such diagrams are provided, using data from Earth Sciences, simple oxides or ligands.

  9. Spatial and temporal variations in dissolved and particulate organic nitrogen in the equatorial Pacific: biological regulations and physical influences

    NASA Astrophysics Data System (ADS)

    Wang, X. J.; Le Borgne, R.; Murtugudde, R.; Busalacchi, A. J.; Behrenfeld, M.

    2008-08-01

    To quote Libby and Wheeler (1997), "we have only a cursory knowledge of the distributions of dissolved and particulate organic nitrogen" in the equatorial Pacific. A decade later, we are still in need of spatial and temporal analyses of these organic nitrogen pools. To address this issue, we employ a basin scale physical-biogeochemical model to study the spatial and temporal variations of dissolved organic nitrogen (DON) and particulate organic nitrogen (PON). The model is able to reproduce many observed features of nitrate, ammonium, DON and PON in the central and eastern equatorial Pacific, including the asymmetries of nitrate and ammonium, and the meridional distributions of DON and PON. Modeled DON (5 8 mmol m-3) shows small zonal and meridional variations in the mixed layer whereas modeled PON (0.4 1.5 mmol m-3) shows considerable spatial variability. While there is a moderate seasonality in both DON and PON in the mixed layer, there is a much weaker interannual variability in DON than in PON. The interannual variability in PON is largely associated with the El Niño/Southern Oscillation (ENSO) phenomenon, showing high values during cold ENSO phase but low values during warm ENSO phase. Overall, DON and PON have significant positive correlations with phytoplankton and zooplankton in the mixed layer. However, the relationships with phytoplankton and zooplankton are much weaker for DON (r=0.18 0.71) than for PON (r=0.25 0.97). Such a difference is ascribed to a larger degree of physical control (e.g., upwelling of low-organic-N deep waters into the surface) on DON than PON. On the whole, distribution of organic nitrogen appears to be controlled by biological influences in the equatorial Pacific.

  10. The influence of landfall variation on tropical cyclone losses in the United States as simulated by HAZUS

    NASA Astrophysics Data System (ADS)

    Sharp, Kevin Joseph

    Tropical cyclone losses in the United States have shown an increasing trend since the beginning of the 20th century. This is mainly due to increased exposure along America's coast. The amount of coastal property at risk persistently increases due to inflation, wealth increase, and population growth. When researchers have normalized the loss record to remove the influence of exposure and vulnerability change, no trend can be discerned in the damage record. This has been used to refute the claim that tropical cyclones are becoming more potentially destructive, and to keep the locus of explanation firmly in socio-demographic trends. But physical variation, in storm size, intensity and location, still make a significant difference in the impact of any individual storm event. This fact occasionally induces calls for renewed efforts at hurricane modification and routinely evokes a sense of either relief or alarm at "close calls" that, except for a difference of a few miles in landfall location or a modest weakening of peak winds, separate hurricane disasters from catastrophes. This project examined the effect of landfall location on storm damage using the Federal Emergency Management Agency's (FEMA) risk assessment model, HAZUS. Thirty-mile track shifts were prescribed for the top 10 most damaging storms in the normalized record since 1988. The alternate storms yielded drastically different damage estimates from the original storms, indicating large spatial variations in exposure. Each landfall shift resulted in a rank change in the overall normalized record. The damage record is dominated by individual extreme events like those used in this analysis, and although random, differences in landfall location would presumably average out in a long record. The fact that a few storms account for a large majority of losses, and that small differences in their landfall yield large differences in impact, points to a very large noise to signal ratio that would make it difficult to

  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. PMID:26678991

  12. 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

  13. Development of Graphite/Epoxy Corner Fittings

    NASA Technical Reports Server (NTRS)

    Faile, G.; Hollis, R.; Ledbetter, F.; Maldonado, J.; Sledd, J.; Stuckey, J.; Waggoner, G.; Engler, E.

    1986-01-01

    Report documents development project aimed at improving design and load-carrying ability of complicated corner fitting for optical bench. New fitting made of graphite filaments in epoxy-resin matrix. Composite material selected as replacement for titanium because lighter and dimensions change little with temperature variations.

  14. 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

  15. Influence of exercise adherence level on modifiable coronary heart disease risk factors and functional-fitness levels in middle-aged men.

    PubMed Central

    Wallace, E S; White, J A; Downie, A; Dalzell, G; Doran, D

    1993-01-01

    The study investigated the potential health benefits of two levels of short-term exercise intervention, compared with non-intervention, on selected modifiable coronary heart disease (CHD) risk factors and functional fitness states in middle-aged men. All subjects underwent medical screening and signed informed consent before carrying out a standardized graded treadmill walk which required exercise up to 85% of age-predicted maximal heart rate. The results of the test were used together with musculoskeletal fitness assessments, for the prescription of a personalized exercise programme lasting 14 weeks. In all, 55 subjects were classified by adherence into high (HA, n = 20), low (LA, n = 19), or non-adherence (NA, n = 16) groups according to the degree of documented participation in the programme based on standard criteria (American College of Sports Medicine 1978, 1990). In addition, the respective groups of subjects were classified according to other modifiable and non-modifiable CHD risk factors and compared by self-reported levels of activity and sport involvement as well as perceived body weight classification. The results indicated that there were more comprehensive improvements in functional fitness including significant gains in aerobic endurance capacity, muscular endurance and flexibility in the HA group compared with the LA and NA groups. However, there was little or no change in the modifiable CHD risk factors in any of the respective groups, although anthropometric indices of weight, body mass index (BMI), skinfolds and waist:hips ratio tended to decrease in the HA and LA groups but increased marginally in the NA group.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8358578

  16. 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

    Ponce-Bravo, Hernán; Ponce, Christian; Feriche, Belén; Padial, Paulino

    2015-12-01

    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 pointsBetter cognitive processes can be achieved as physical condition improvesExercise 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 adultsThe improvement of cognitive function, as assessed through reaction times, seems more linked to the workload and strength component of the training program. PMID:26664267

  17. 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

  18. Leucine-responsive regulatory protein Lrp and PapI homologues influence phase variation of CS31A fimbriae.

    PubMed

    Graveline, Richard; Garneau, Philippe; Martin, Christine; Mourez, Michaël; Hancock, Mark A; Lavoie, Rémi; Harel, Josée

    2014-08-15

    CS31A, a K88-related surface antigen specified by the clp operon, is a member of the type P family of adhesive factors and plays a key role in the establishment of disease caused by septicemic and enterotoxigenic Escherichia coli strains. Its expression is under the control of methylation-dependent transcriptional regulation, for which the leucine-responsive regulatory protein (Lrp) is essential. CS31A is preferentially in the OFF state and exhibits distinct regulatory features compared to the regulation of other P family members. In the present study, surface plasmon resonance and DNase I protection assays showed that Lrp binds to the distal moiety of the clp regulatory region with low micromolar affinity compared to its binding to the proximal moiety, which exhibits stronger, nanomolar affinity. The complex formation was also influenced by the addition of PapI or FooI, which increased the affinity of Lrp for the clp distal and proximal regions and was required to induce phase variation. The influence of PapI or FooI, however, was predominantly associated with a more complete shutdown of clp expression, in contrast to what has previously been observed with AfaF (a PapI ortholog). Taken together, these results suggest that the preferential OFF state observed in CS31A cells is mainly due to the weak interaction of the leucine-responsive regulatory protein with the clp distal region and that the PapI homolog favors the OFF phase. Within the large repertoire of fimbrial variants in the P family, our study illustrates that having a fimbrial operon that lacks its own PapI ortholog allows it to be more flexibly regulated by other orthologs in the cell. PMID:24914179

  19. Physical Fitness Assessment.

    ERIC Educational Resources Information Center

    Valdes, Alice

    This document presents baseline data on physical fitness that provides an outline for assessing the physical fitness of students. It consists of 4 tasks and a 13-item questionnaire on fitness-related behaviors. The fitness test evaluates cardiorespiratory endurance by a steady state jog; muscular strength and endurance with a two-minute bent-knee…

  20. Influence of genome-scale RNA structure disruption on the replication of murine norovirus—similar replication kinetics in cell culture but attenuation of viral fitness in vivo

    PubMed Central

    McFadden, Nora; Arias, Armando; Dry, Inga; Bailey, Dalan; Witteveldt, Jeroen; Evans, David J.; Goodfellow, Ian; Simmonds, Peter

    2013-01-01

    Mechanisms by which certain RNA viruses, such as hepatitis C virus, establish persistent infections and cause chronic disease are of fundamental importance in viral pathogenesis. Mammalian positive-stranded RNA viruses establishing persistence typically possess genome-scale ordered RNA secondary structure (GORS) in their genomes. Murine norovirus (MNV) persists in immunocompetent mice and provides an experimental model to functionally characterize GORS. Substitution mutants were constructed with coding sequences in NS3/4- and NS6/7-coding regions replaced with sequences with identical coding and (di-)nucleotide composition but disrupted RNA secondary structure (F1, F2, F1/F2 mutants). Mutants replicated with similar kinetics to wild-type (WT) MNV3 in RAW264.7 cells and primary macrophages, exhibited similar (highly restricted) induction and susceptibility to interferon-coupled cellular responses and equal replication fitness by serial passaging of co-cultures. In vivo, both WT and F1/F2 mutant viruses persistently infected mice, although F1, F2 and F1/F2 mutant viruses were rapidly eliminated 1–7 days post-inoculation in competition experiments with WT. F1/F2 mutants recovered from tissues at 9 months showed higher synonymous substitution rates than WT and nucleotide substitutions that potentially restored of RNA secondary structure. GORS plays no role in basic replication of MNV but potentially contributes to viral fitness and persistence in vivo. PMID:23630317

  1. Preliminary evidence that allelic variation in the LMX1A gene influences training-related working memory improvement.

    PubMed

    Bellander, Martin; Brehmer, Yvonne; Westerberg, Helena; Karlsson, Sari; Fürth, Daniel; Bergman, Olle; Eriksson, Elias; Bäckman, Lars

    2011-06-01

    LMX1A is a transcription factor involved in the development of dopamine (DA)-producing neurons in midbrain. Previous research has shown that allelic variations in three LMX1A single nucleotide polymorphisms (SNPs) were related to risk of Parkinson's disease (PD), suggesting that these SNPs may influence the number of mesencephalic DA neurons. Prompted by the established link between striatal DA functions and working memory (WM) performance, we examined two of these SNPs in relation to the ability to benefit from 4 weeks of WM training. One SNP (rs4657412) was strongly associated with the magnitude of training-related gains in verbal WM. The allele linked to larger gains has previously been suggested to be associated with higher dopaminergic nerve cell density. No differential gains of either SNP were observed for spatial WM, and the genotype groups were also indistinguishable in tests of attention, interference control, episodic memory, perceptual speed, and reasoning for both SNPs. This pattern of data is in agreement with previous findings from our group, suggesting that cognitive effects of DA-related genes may be more easily detected in a training context than for single-assessment performance scores. PMID:21435346

  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

    2016-09-01

    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. PMID:27187059

  3. Expression of stemness markers in mouse parthenogenetic-diploid blastocysts is influenced by slight variation of activation protocol adopted.

    PubMed

    Bianchi, Enrica; Geremia, Raffaele; Sette, Claudio

    2010-07-01

    The importance of obtaining stem cells through alternative methods has increased progressively in the recent years due to the potential role that embryonic stem (ES) cells play in the field of regenerative medicine. In this regard, generation of parthenogenetic blastocysts allows the production of ethic-free ES cells without the need to manipulate normal embryos. Our work was aimed at clarifying whether variations in the method adopted to generate diploid parthenogenetic blastocysts could determine differences in the quality of blastocysts produced. In vitro development of mouse oocytes activated with three protocols, using Sr2+ and cytochalasin for different time, was compared with that of in vivo fertilized embryos. We have evaluated the efficiency of blastocyst formation and analysed the expression pattern of the stemness markers OCT4, CDX2, and NANOG. Our results indicate that the yield of diploid parthenogenotes and the segregation of the stemness marker OCT4 in the developing blastocyst are influenced by the parthenogenetic protocol adopted. Particularly, even if all methods tested allowed the production of blastocysts in vitro, the correct segregation of OCT4 occurred only in blastocysts developed from oocytes concomitantly treated for 4 h with Sr2+ and cytochalasin D. Our results indicate that the protocol employed to develop parthenogenetic blastocysts in vitro affects the quality of cells in the inner cell mass. PMID:20376706

  4. 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. PMID:22987581

  5. Influence of seasonal variation and methyl jasmonate mediated induction of glucosinolate biosynthesis on quinone reductase activity in broccoli florets.

    PubMed

    Ku, Kang Mo; Jeffery, Elizabeth H; Juvik, John A

    2013-10-01

    Methyl jasmonate spray treatments (250 μM) were utilized to alter glucosinolate composition in the florets of the commercial broccoli F1 hybrids 'Pirate', 'Expo', 'Green Magic', 'Imperial', and 'Gypsy' grown in replicated field plantings in 2009 and 2010. MeJA treatment significantly increased glucoraphanin (11%), gluconasturtiin (59%), and neoglucobrassicin (248%) concentrations and their hydrolysis products including sulforaphane (152%), phenethyl isothiocyanate (318%), N-methoxyindole-3-carbinol (313%), and neoascorbigen (232%) extracted from florets of these genotypes over two seasons. Increased quinone reductase (QR) activity was significantly correlated with increased levels of sulforaphane, N-methoxyindole-3-carbinol, and neoascorbigen. Partitioning experiment-wide trait variances indicated that the variability in concentrations of sulforaphane (29%), neoascorbigen (48%), and QR activity (72%) was influenced by year-associated weather variables, whereas variation in neoglucobrassicin (63%) and N-methoxyindole-3-carbinol (46%) concentrations was primarily attributed to methyl jasmonate treatment. These results suggest that methyl jasmonate treatment can enhance QR inducing activity by increased hydrolysis of glucoraphanin into sulforaphane and the hydrolysis products of neoglucobrassicin. PMID:24032372

  6. Spatial and seasonal variation of salt ions under the influence of halophytes, in a coastal flat in eastern China

    NASA Astrophysics Data System (ADS)

    Wu, Yanyou; Liu, Rongcheng; Zhao, Yuguo; Li, Pingping; Liu, Congqiang

    2009-06-01

    The high salinity of coastal saline field is a key factor limiting the reclamation. Halophytes have been utilized in the reclamation of saline land. The study area is in Yancheng, China. An analysis of the concentrations of Rb, Cs, Sr, and Ba, the ratio of Rb/Cs, and Sr/Ba in soils in autumn shows that the soil of this study area has great homogeneity. Artemisia halodendron, Gossypium hirsutum, and Sesbania cannabina were selected as the reclamation plants in the present study. In order to know the spatial-temporal distribution of soil salinity, the influence of plant-specific vegetation, and the difference of desalination among these halophytes in coastal flat, the authors analyze the soil-layers and seasonal variation in salt ions. Sodium chloride was accumulated in 0-5 cm topsoil with no vegetation during the winter and spring. The effect of desalinization of halophytes is significant. Of the three plant species, Sesbania cannabina has the greatest desalinization. The difference of ions composition of soils covered with various plant species is significant. It can be concluded that halophytes have better amelioration of coastal soil salinity. Special attention should be paid to the selection of plant species and measures to plant and cultivate crops in the reclamation of saline land.

  7. 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.

  8. The diastolic function to cyclic variation of myocardial ultrasonic backscatter relation: the influence of parameterized diastolic filling (PDF) formalism determined chamber properties.

    PubMed

    Lloyd, Christopher W; Shmuylovich, Leonid; Holland, Mark R; Miller, James G; Kovács, Sándor J

    2011-08-01

    Myocardial tissue characterization represents an extension of currently available echocardiographic imaging. The systematic variation of backscattered energy during the cardiac cycle (the "cyclic variation" of backscatter) has been employed to characterize cardiac function in a wide range of investigations. However, the mechanisms responsible for observed cyclic variation remain incompletely understood. As a step toward determining the features of cardiac structure and function that are responsible for the observed cyclic variation, the present study makes use of a kinematic approach of diastolic function quantitation to identify diastolic function determinants that influence the magnitude and timing of cyclic variation. Echocardiographic measurements of 32 subjects provided data for determination of the cyclic variation of backscatter to diastolic function relation characterized in terms of E-wave determined, kinematic model-based parameters of chamber stiffness, viscosity/relaxation and load. The normalized time delay of cyclic variation appears to be related to the relative viscoelasticity of the chamber and predictive of the kinematic filling dynamics as determined using the parameterized diastolic filling formalism (with r-values ranging from .44 to .59). The magnitude of cyclic variation does not appear to be strongly related to the kinematic parameters. PMID:21683506

  9. 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.

  10. 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

  11. 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

  12. Evidence for an age-dependent influence of environmental variations on a long-lived seabird's life-history traits.

    PubMed

    Pardo, Deborah; Barbraud, Christophe; Authier, Matthieu; Weimerskirch, Henri

    2013-01-01

    Theoretical and empirical studies have highlighted the effects of age on several life-history traits in wild populations. There is also increasing evidence for environmental effects on their demographic traits. However, quantifying how individuals differentially respond to environmental variations according to their age remains a challenge in ecology. In a population of Black-browed Albatrosses monitored during 43 years, we analyzed how life-history traits varied according to age, and whether individuals of different ages responded in different ways to environmental conditions. To do so, we: (1) examined how age affected seven life-history traits, (2) investigated differences in temporal variance of demographic traits between age classes, and (3) tested for age-dependent effects of climate and fisheries covariates on demographic traits. Overall, there was a tendency for traits to improve during the first years of life (5-10 years), to peak and remain stable at middle age (10-30 years), and decline at old ages. At young ages, survival and reproductive parameters increased, except offspring body condition at fledging, suggesting that younger parents had already acquired good foraging capacities. However, they suffered from inexperience in breeding as suggested by their higher breeding failures during incubation. There was evidence for reproductive and actuarial senescence. In particular, breeding success and offspring body condition declined abruptly, suggesting altered foraging capacities of old individuals. Middle-aged individuals had the lowest temporal variance of demographic traits. Although this is predicted by the theory of environmental canalization, it could also results from a higher susceptibility of young and old birds due to their respective inexperience and senescence. The highest temporal variances were found in old individuals. Survival was significantly influenced by sea surface temperatures in the foraging zone of this albatross population during

  13. Spatial and Temporal Variations of Rice Paddy as Influenced by Climate Change in the Sanjiang Plain, Northeastern China

    NASA Astrophysics Data System (ADS)

    Chen, J.; Liu, Q.; Ma, L.; Hou, S.; Tao, B.

    2014-12-01

    The Sanjiang Plain is located in the eastern part of Heilongjiang Province, Northeastern China, and represents one of major agricultural regions nationwide. Over past decades, this region has seen intensive cropland reclamation and a sharp shrinkage of natural vegetation and water bodies, driven by not only policy-making and economic development, but also a warming climate. However, it still remains unclear how climate change has influenced the magnitude and spatial patterns of land use changes. In this study, we examined spatial and temporal variations of rice paddy planting area during 1980-2008 through an integration of the remote-sensing images, the census data, and other existing land use/cover data sets. The daily gridded climate data sets were generated by using an interpolation method of thin plate smoothing splines, based on observations from over 70 meteorological stations across the study area. Our results suggest that the rice paddy planting area increased by more than 10-fold during 1980-2008, with more obvious upward trends during two sub-periods, i.e. 1995-1998 and 2004-2008. Further analyses indicated that the rice paddy planting area accounted for approximately 20.3% of total cropland area in 2008, increasing more than seven-fold as compared to 1980. When investigating spatially, we found that the planting boundary of rice paddy expanded northward for roughly 2 degree, comparing to 1984 when most of rice paddies were found in the north of the 48o N. Most of increases of rice paddy planting area occurred in the northeast of the study region. The climate analyses showed a significant warming trend, with a slightly decrease in precipitation. During the study period, the suitable areas for rice production increased about 25% and expanded northward clearly. Our study demonstrated how climate change influenced the magnitude and spatial patterns of rice paddy planting area in the Sanjiang Plain, which could provide scientific information for the

  14. The influence of variations of the Earth' magnetic field on the elaboration of geomagnetic observations in Poland

    NASA Astrophysics Data System (ADS)

    Welker, E.

    2012-06-01

    The increase of accuracy of magnetic measurements generated the need of testing of the influence of variations of the geomagnetic field on their elaboration. On the basis of the magnetic data obtained from European observatories and from magnetic stations operating in 2010 and 2011, the chart of amplitude changes of Y magnetic field component (magnetic declination too) in Poland and the chart of time shift between the records of Belsk Observatory - considered as central observatory - as well as the records from other measurement points were processed. Data from some geomagnetic stations operating in the 1960. (with records of D, H and Z components) stored in the database at the Institute of Geodesy and Cartography, Warsaw, were re used to analyse geomagnetic field intensity changes (Uhrynowski, 1962, 1964). The error of transforming analogue data from paper records to the digital form is bigger than amplitude changes of declination D and H component. The results of Fourier transformation of millions of data from magnetic observatories allowed for mapping the distribution of amplitude changes of Y component and time shift of records from chosen European observatories with respect to Belsk Observatory. The range of amplitude changes of the X, Y and Z components of the geomagnetic field intensity in Poland is exceptionally small. It reaches only ±2-3 nT which is at the level of the error of geomagnetic data elaboration. The range of time shift of the record from points by eastern border of Poland with respect to those by western border of Poland vary from -6 to +15 minutes for Y component. The test made with data from secular point (repeat station) measurements from 2009-2011 shows that the differences between results obtained without and with time corrections reach only 10-302 for declination and inclination, and 5 nT for total intensity vector length. The use of the magnetograms from Belsk Observatory for the geomagnetic measurement reduction without any time

  15. [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

  16. Influence of age and physical fitness on miRNA-21, TGF-β and its receptors in leukocytes of healthy women.

    PubMed

    Halper, Barbara; Hofmann, Marlene; Oesen, Stefan; Franzke, Bernhard; Stuparits, Petra; Vidotto, Claudia; Tschan, Harald; Bachl, Norbert; Strasser, Eva-Maria; Quittan, Michael; Wagner, Karl-Heinz; Wessner, Barbara

    2015-01-01

    The TGF-β superfamily has been shown to play an important role in a wide range of physiological as well as pathological processes including ageing, immune modulation, atherosclerosis and cancer development. The aim of the current study was to investigate (i) whether TGF-β signalling in peripheral blood mononuclear cells (PBMCs) would differ between young and old females and (ii) whether physical performance parameters of elderly women would be related to the expression of TGF-β or its receptors. Sixteen healthy young (22-28 years; YF) and 90 healthy older (65-92 years; OF) females participated in the study. In addition to several components of health-related physical fitness, circulating CRP and TGF-β levels were determined together with the mRNA expression of TGF-β, TGF-βRI, TGF-βRII, and miRNA-21 (known to interfere with TGF-β signalling) in PBMCs. Physical fitness as determined by 6-minutes walking test (YF:median 932 (range 573-1254) m; OF:360 (114-558) m), handgrip strength (YF: 32 (24-39) kg; OF:18(10-30) kg), relative isokinetic peak torque of knee extensors (YF:1.9 (1.2- 2.3) Nm/kg; OF:1.0 (0.2-1.9) Nm/kg and flexors (YF: 1.1 (0.7- 1.5) Nm/kg; OF: 0.5 (0.2-1.0) Nm/kg was substantially lower in older women (p<0.001 for all comparisons). These changes were paralleled by an increase in hs-CRP (YF: 0.9 (0.1-4.3)mg/L; OF: 2.3 (0.3-56.7)mg/L,p<0.001). Serum levels of TGF-β and TGF-β mRNA levels from PBMCs did not differ between young and old women whereas, both TGF- βRI/GAPDH (YF: 4.07 (1.38-14.60); OF: 2.08 (0.14-28.81); p=0.020) and TGF-βRII/GAPDH levels (YF: 3.16 (1.14- 10.25); OF: 1.71 (0.51-14.86); p=0.020) were lower with respect to old age. In elderly women, only TGF-βRΙ expression correlated negatively with miRNA-21 expression in PBMCs (ρ=-0.315; p=0.004). Interestingly, hs-CRP and miRNA correlated positively with handgrip strength (ρ=0.237 and ρ=243, p<0.05), while none of the TGF-β-related parameters were related to physical

  17. Lateral variations in mylonite zone thickness as influenced by fluid-rock interactions, Linville falls fault, North Carolina

    NASA Astrophysics Data System (ADS)

    Newman, J.; Mitra, G.

    1993-07-01

    Over a distance of approximately 20 km, along strike, the Linville Falls mylonite varies in thickness from 1 m at Linville Falls to >60 m at Banner Elk. Along strike, pressure, temperature and displacement variations are minimized, allowing this study to focus on the influences of fluid behavior and protolith mineralogy on fault zone development. The protolith at Linville Falls contains mainly K-feldspar, perthite and quartz, while at Banner Elk the protolith contains plagioclase and quartz. At Linville Falls, quartz deformed by dynamic recrystallization, feldspar by intragranular fracturing and alteration to quartz and mica, and mica by sliding along cleavage planes. Modal mineralogies change from the protolith to the mylonite with quartz decreasing from 39 to 19% and feldspar from 59 to 1.5%; muscovite increases from <1 to 80%. Mean grain size of the quartz and feldspar also decreased, from 30 to 20 μm and from 110 to 50 μm, respectively. At Banner Elk, deformation occurred predominantly by dynamic recrystallization within the quartz and by sliding along cleavage planes in mica; no feldspar remains within the mylonite zone. Modal mineralogies change from the protolith to the mylonite with quartz and muscovite increasing from 21 to 50% and from < 1 to 44%, respectively. Mean grain size of quartz decreases from 60 to 24 μm. Mass-balance calculations, based on major- and trace-element geochemistry, indicate approximately 75% volume loss at Linville Falls and 20% at Banner Elk. Fluid-rock ratios estimated from the calculated depletions of Si are an order of magnitude higher at Linville Falls than at Banner Elk. Fluids infiltrated the fault zone over a thicker zone at Banner Elk than at Linville Falls because the plagioclase altered more readily than K-feldspar, creating new pathways for fluids. Fluids migrated preferentially through channels along the fault zone, creating a three-dimensional network of higher fluid flow.

  18. Influence of landscape features on variation of δ2H and δ18O in seasonal mountain snowpack

    NASA Astrophysics Data System (ADS)

    Kipnis, E. L.; Chapple, W.; Frank, J. M.; Traver, E.; Ewers, B. E.; Williams, D. G.

    2014-12-01

    Streamflow contributions from snowpack remain difficult to predict in snow dominated headwater catchments in the Rocky Mountains. There remains considerable uncertainty in how environmental change in mountain watersheds alter seasonal snowpack accumulation and development and how these relationships translate from gaged to ungaged catchments. Stable isotope analysis is a valuable tool for determining the contribution and changes of different source inputs to catchment water budgets. Stable isotope values in snowpack integrate source inputs and processes such as water vapor exchange, selective redistribution, and melt. For better understanding of how these physical processes vary at local and catchment scales, snowpack density, depth, snow water equivalence (SWE), δ2H and δ18O were examined at peak snowpack in spring 2013 and 2014 and at monthly time steps throughout the winter of 2013-2014. Distributed data and sample collection occurred between 2400 and 3300 m elevation across two pine beetle and spruce beetle impacted forest stands with variable canopy cover in the Libby Creek and Nash Fork Little Laramie River basins, Medicine Bow Range, Wyoming. Peak snowpack within these watersheds was 10% below historic average in 2013 and 50% above average in 2014 (NRCS Snotel data). Even with these contrasting peak snowpack patterns, elevation described less than 40% of the spatial variation of snow water equivalents (SWE) across the watersheds for both seasons. Hydrogen and oxygen isotope ratio values of snowpack sampled monthly in 2014 revealed early season separation from the local meteoric water line, suggesting some kinetic isotope effects. However, isotope ratio values at peak snowpack in 2013 reflected no such signal at any sampling location. The influence of landscape position and canopy cover will be modeled to detect and scale spatial and temporal changes in SWE and stable isotope composition of snowpack. Such an approach will provide increased understanding of

  19. 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.

  20. 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

  1. ACSM Fit Society Page

    MedlinePlus

    ... Exercise Current Sports Medicine Reports Exercise and Sport Sciences Reviews ACSM's Health & Fitness Journal Guidelines Books & Multimedia Sports Medicine Basics Fact Sheets Sports Medicine & Physical Activity Marketplace Health & Physical Activity Reference Database Fit ...

  2. Proper fitting shoes (image)

    MedlinePlus

    ... should be comfortable and fit well when you buy them. Never buy shoes that are tight, hoping they will stretch ... should be comfortable and fit well when you buy them. Never buy shoes that are tight, hoping ...

  3. Fitness Shoes and Clothes

    MedlinePlus

    ... My Go4Life Get Free Stuff Be a Partner Fitness Shoes and Clothes Choosing the right clothing and ... be a great motivator! Download the Tip Sheet Fitness Shoes and Clothes (PDF, 436.87 KB) You ...

  4. 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.

  5. ACSM Fit Society Page

    MedlinePlus

    ... Physical Activity Marketplace Health & Physical Activity Reference Database Public Information Newsletters ACSM Blog ACSM Blog Search By ... Activity Marketplace Health & Physical Activity Reference Database Home Public Information Newsletters Fit Society Page ACSM Fit Society ® ...

  6. Interannual Variation in Baseline Ozone on the Western Coast of North America and Its Influence on Urban Air Quality

    NASA Astrophysics Data System (ADS)

    Wigder, N. L.; Jaffe, D. A.; Lin, M.; Fiore, A. M.; Macdonald, A.; Gong, S.

    2011-12-01

    Baseline ozone (O3) has been defined as the distribution of mixing ratios from a site when it is not influenced by locally emitted pollution (McDonald-Buller et al., 2011; NRC, 2009; TF HTAP, 2007). In this study, we set out to understand the interannual variation (IAV) in baseline O3 along the western coast of North America and its influence on surface air quality in urban environments. Baseline data for this study comes from Trinidad Head, CA, Mount Bachelor, OR, Cheeka Peak, WA, Jackson Visitor Center, WA and Whistler Mountain, BC. We address four key questions:

    1. Do baseline observations on the western coast of North America exhibit similar IAV?
    2. How well can satellites identify IAV in baseline O3 along the western coast of North America?
    3. How does the baseline IAV influence urban air quality and O3 regulatory exceedance days?
    4. How well can global chemical transport models capture the IAV in baseline O3?
    We examine the deseasonalized baseline data to identify IAV in boundary layer air and free tropospheric air separately, as well as the combination of these datasets. Preliminary results show that the IAV (one sigma) in monthly mean O3 at the baseline sites ranges from 2.3-4.0 ppbv, based on data available from 2002-2010. All sites show some degree of correlation in IAV, with Pearson's correlation values of r=0.3-0.6 (p≤0.05). Using level 3 monthly averaged Tropospheric Emission Spectrometer (TES) data, we find correlations in O3 IAV with the baseline sites (r=0.4, p≤0.01). This analysis is being repeated with level 2 TES data. An analysis of the O3 IAV in urban/suburban areas near the baseline sites shows a relationship between the IAV present in the baseline sites and the IAV of these urban/suburban regions (r=0.3-0.6, p≤0.05), which can contribute to air quality regulation exceedances. We will also examine the baseline IAV with two global chemical transport models, the Canadian GEM-MACH model and the GFDL AM3

  7. 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...

  8. 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…

  9. Autism as the Low-Fitness Extreme of a Parentally Selected Fitness Indicator.

    PubMed

    Shaner, Andrew; Miller, Geoffrey; Mintz, Jim

    2008-12-01

    Siblings compete for parental care and feeding, while parents must allocate scarce resources to those offspring most likely to survive and reproduce. This could cause offspring to evolve traits that advertise health, and thereby attract parental resources. For example, experimental evidence suggests that bright orange filaments covering the heads of North American coot chicks may have evolved for this fitness-advertising purpose. Could any human mental disorders be the equivalent of dull filaments in coot chicks-low-fitness extremes of mental abilities that evolved as fitness indicators? One possibility is autism. Suppose that the ability of very young children to charm their parents evolved as a parentally selected fitness indicator. Young children would vary greatly in their ability to charm parents, that variation would correlate with underlying fitness, and autism could be the low-fitness extreme of this variation. This view explains many seemingly disparate facts about autism and leads to some surprising and testable predictions. PMID:26181749

  10. Reaching Your Fitness Goals

    MedlinePlus

    Everyday Fitness Ideas from the National Institute on Aging at NIH www.nia.nih.gov/Go4Life Reaching Your Fitness Goals You’ll begin to see results in ... longer, and more easily. As you increase your fitness level, you also might find that you need ...

  11. 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

  12. Influence of common genetic variation on blood lipid levels, cardiovascular risk, and coronary events in two British prospective cohort studies

    PubMed Central

    Shah, Sonia; Casas, Juan P.; Gaunt, Tom R.; Cooper, Jackie; Drenos, Fotios; Zabaneh, Delilah; Swerdlow, Daniel I.; Shah, Tina; Sofat, Reecha; Palmen, Jutta; Kumari, Meena; Kivimaki, Mika; Ebrahim, Shah; Smith, George Davey; Lawlor, Debbie A.; Talmud, Philippa J.; Whittaker, John; Day, Ian N.M.; Hingorani, Aroon D.; Humphries, Steve E.

    2013-01-01

    Aims The aim of this study was to quantify the collective effect of common lipid-associated single nucleotide polymorphisms (SNPs) on blood lipid levels, cardiovascular risk, use of lipid-lowering medication, and risk of coronary heart disease (CHD) events. Methods and results Analysis was performed in two prospective cohorts: Whitehall II (WHII; N = 5059) and the British Women’s Heart and Health Study (BWHHS; N = 3414). For each participant, scores were calculated based on the cumulative effect of multiple genetic variants influencing total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG). Compared with the bottom quintile, individuals in the top quintile of the LDL-C genetic score distribution had higher LDL-C {mean difference of 0.85 [95% confidence interval, (CI) = 0.76–0.94] and 0.63 [95% CI = 0.50–0.76] mmol/l in WHII and BWHHS, respectively}. They also tended to have greater odds of having ‘high-risk’ status (Framingham 10-year cardiovascular disease risk >20%) [WHII: odds ratio (OR) = 1.36 (0.93–1.98), BWHHS: OR = 1.49 (1.14–1.94)]; receiving lipid-lowering treatment [WHII: OR = 2.38 (1.57–3.59), BWHHS: OR = 2.24 (1.52–3.29)]; and CHD events [WHII: OR = 1.43 (1.02–2.00), BWHHS: OR = 1.31 (0.99–1.72)]. Similar associations were observed for the TC score in both studies. The TG score was associated with high-risk status and medication use in both studies. Neither HDL nor TG scores were associated with the risk of coronary events. The genetic scores did not improve discrimination over the Framingham risk score. Conclusion At the population level, common SNPs associated with LDL-C and TC contribute to blood lipid variation, cardiovascular risk, use of lipid-lowering medications and coronary events. However, their effects are too small to discriminate future lipid-lowering medication requirements or coronary events. PMID:22977227

  13. 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. PMID:20309747

  14. Natural variation in the histone demethylase, KDM4C, influences expression levels of specific genes including those that affect cell growth

    PubMed Central

    Gregory, Brittany L.; Cheung, Vivian G.

    2014-01-01

    DNA sequence variants influence gene expression and cellular phenotypes. In this study, we focused on natural variation in the gene encoding the histone demethylase, KDM4C, which promotes transcriptional activation by removing the repressive histone mark, H3K9me3, from its target genes. We uncovered cis-acting variants that contribute to extensive individual differences in KDM4C expression. We also identified the target genes of KDM4C and demonstrated that variation in KDM4C expression leads to differences in the growth of normal and some cancer cells. Together, our results from genetic mapping and molecular analysis provide an example of how genetic variation affects epigenetic regulation of gene expression and cellular phenotype. PMID:24285722

  15. 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, M.; Nowak, E.M.; Taylor, E.N.; Schuett, G.W.; Repp, R.A.; Rosen, P.C.; Hardy, D.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. ?? 2010 Elsevier Ltd.

  16. Spatial-Temporal Variations of Chlorophyll-a in the Adjacent Sea Area of the Yangtze River Estuary Influenced by Yangtze River Discharge

    PubMed Central

    Wang, Ying; Jiang, Hong; Jin, Jiaxin; Zhang, Xiuying; Lu, Xuehe; Wang, Yueqi

    2015-01-01

    Carrying abundant nutrition, terrigenous freshwater has a great impact on the spatial and temporal heterogeneity of phytoplankton in coastal waters. The present study analyzed the spatial-temporal variations of Chlorophyll-a (Chl-a) concentration under the influence of discharge from the Yangtze River, based on remotely sensed Chl-a concentrations. The study area was initially zoned to quantitatively investigate the spatial variation patterns of Chl-a. Then, the temporal variation of Chl-a in each zone was simulated by a sinusoidal curve model. The results showed that in the inshore waters, the terrigenous discharge was the predominant driving force determining the pattern of Chl-a, which brings the risk of red tide disasters; while in the open sea areas, Chl-a was mainly affected by meteorological factors. Furthermore, a diversity of spatial and temporal variations of Chl-a existed based on the degree of influences from discharge. The diluted water extended from inshore to the east of Jeju Island. This process affected the Chl-a concentration flowing through the area, and had a potential impact on the marine environment. The Chl-a from September to November showed an obvious response to the discharge from July to September with a lag of 1 to 2 months. PMID:26006121

  17. Spatial-Temporal Variations of Chlorophyll-a in the Adjacent Sea Area of the Yangtze River Estuary Influenced by Yangtze River Discharge.

    PubMed

    Wang, Ying; Jiang, Hong; Jin, Jiaxin; Zhang, Xiuying; Lu, Xuehe; Wang, Yueqi

    2015-05-01

    Carrying abundant nutrition, terrigenous freshwater has a great impact on the spatial and temporal heterogeneity of phytoplankton in coastal waters. The present study analyzed the spatial-temporal variations of Chlorophyll-a (Chl-a) concentration under the influence of discharge from the Yangtze River, based on remotely sensed Chl-a concentrations. The study area was initially zoned to quantitatively investigate the spatial variation patterns of Chl-a. Then, the temporal variation of Chl-a in each zone was simulated by a sinusoidal curve model. The results showed that in the inshore waters, the terrigenous discharge was the predominant driving force determining the pattern of Chl-a, which brings the risk of red tide disasters; while in the open sea areas, Chl-a was mainly affected by meteorological factors. Furthermore, a diversity of spatial and temporal variations of Chl-a existed based on the degree of influences from discharge. The diluted water extended from inshore to the east of Jeju Island. This process affected the Chl-a concentration flowing through the area, and had a potential impact on the marine environment. The Chl-a from September to November showed an obvious response to the discharge from July to September with a lag of 1 to 2 months. PMID:26006121

  18. Distribution of Fitness in Populations of Dengue Viruses

    PubMed Central

    Choudhury, Md Abu; Lott, William B.; Aaskov, John

    2014-01-01

    Genetically diverse RNA viruses like dengue viruses (DENVs) segregate into multiple, genetically distinct, lineages that temporally arise and disappear on a regular basis. Lineage turnover may occur through multiple processes such as, stochastic or due to variations in fitness. To determine the variation of fitness, we measured the distribution of fitness within DENV populations and correlated it with lineage extinction and replacement. The fitness of most members within a population proved lower than the aggregate fitness of populations from which they were drawn, but lineage replacement events were not associated with changes in the distribution of fitness. These data provide insights into variations in fitness of DENV populations, extending our understanding of the complexity between members of individual populations. PMID:25222471

  19. Parental, peer, school, and neighborhood influences on adolescent substance use: direct and indirect effects and ethnic variations.

    PubMed

    Su, Jinni; Supple, Andrew J

    2014-01-01

    The current study examined how contextual influences are related to adolescent substance use using an ethnically diverse sample of adolescents. A total of 5,992 adolescents (5,185 European American, 330 African American, 160 Hispanic American, 179 Asian American, and 138 Southeast Asian American) from Dane county, Wisconsin, completed surveys at school. Structural equation modeling was conducted to examine direct versus indirect effects of parental, peer, school, and neighborhood influences and differences in associations across ethnicity. Results indicated that contextual influences on adolescent substance use were both direct and indirect; the strength of associations between contextual influences and adolescent substance use varied across ethnic groups. PMID:25176117

  20. 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.

  1. 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.

  2. Selection and sex-biased dispersal in a coastal shark: the influence of philopatry on adaptive variation.

    PubMed

    Portnoy, D S; Puritz, J B; Hollenbeck, C M; Gelsleichter, J; Chapman, D; Gold, J R

    2015-12-01

    Sex-biased dispersal is expected to homogenize nuclear genetic variation relative to variation in genetic material inherited through the philopatric sex. When site fidelity occurs across a heterogeneous environment, local selective regimes may alter this pattern. We assessed spatial patterns of variation in nuclear-encoded, single nucleotide polymorphisms (SNPs) and sequences of the mitochondrial control region in bonnethead sharks (Sphyrna tiburo), a species thought to exhibit female philopatry, collected from summer habitats used for gestation. Geographic patterns of mtDNA haplotypes and putatively neutral SNPs confirmed female philopatry and male-mediated gene flow along the northeastern coast of the Gulf of Mexico. A total of 30 outlier SNP loci were identified; alleles at over half of these loci exhibited signatures of latitude-associated selection. Our results indicate that in species with sex-biased dispersal, philopatry can facilitate sorting of locally adaptive variation, with the dispersing sex facilitating movement of potentially adaptive variation among locations and environments. PMID:26518727

  3. Factoring in weather variation to capture the influence of urban design and built environment on globally recommended levels of moderate to vigorous physical activity in children

    PubMed Central

    Katapally, Tarun Reddy; Muhajarine, Nazeem

    2015-01-01

    Objectives In curbing physical inactivity, as behavioural interventions directed at individuals have not produced a population-level change, an ecological perspective called active living research has gained prominence. However, active living research consistently underexplores the role played by a perennial phenomenon encompassing all other environmental exposures—variation in weather. After factoring in weather variation, this study investigated the influence of diverse environmental exposures (including urban design and built environment) on the accumulation of globally recommended moderate to vigorous physical activity levels (MVPA) in children. Design This cross-sectional observational study is part of an active living initiative set in the Canadian prairie city of Saskatoon. As part of this study, Saskatoon's neighbourhoods were classified based on urban street design into grid-pattern, fractured grid-pattern and curvilinear types of neighbourhoods. Moreover, diverse environmental exposures were measured including, neighbourhood built environment, and neighbourhood and household socioeconomic environment. Actical accelerometers were deployed between April and June 2010 (spring-summer) to derive MVPA of 331 10–14-year-old children in 25 1-week cycles. Each cycle of accelerometry was conducted on a different cohort of children within the total sample and matched with weather data obtained from Environment Canada. Multilevel modelling using Hierarchical Linear and Non-linear Modelling software was conducted by factoring in weather variation to depict the influence of diverse environmental exposures on the accumulation of recommended MVPA. Results Urban design, including diversity of destinations within neighbourhoods played a significant role in the accumulation of MVPA. After factoring in weather variation, it was observed that children living in neighbourhoods closer to the city centre (with higher diversity of destinations) were more likely to accumulate

  4. Mapping the Genetic Basis of Symbiotic Variation in Legume-Rhizobium Interactions in Medicago truncatula

    PubMed Central

    Gorton, Amanda J.; Heath, Katy D.; Pilet-Nayel, Marie-Laure; Baranger, Alain

    2012-01-01

    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. PMID:23173081

  5. Fun Fitness Runs.

    ERIC Educational Resources Information Center

    Scantling, Ed; Strand, Brad

    1997-01-01

    Fitness runs are planned activities that make running more interesting. The paper outlines five types of fitness runs, all of which can be modified to conform to different facilities, age groups, or available time. The activities have students playing detective, playing cards, deciphering words, learning about calories, and playing wolf. (SM)

  6. 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…

  7. 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…

  8. 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…

  9. 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…

  10. Fit 2-B FATHERS.

    ERIC Educational Resources Information Center

    Maiorano, Joseph J.

    2001-01-01

    Fit 2-B FATHERS is a parenting-skills education program for incarcerated adult males. The goals of this program are for participants to have reduced recidivism rates and a reduced risk of their children acquiring criminal records. These goals are accomplished by helping participants become physically, practically, and socially fit for the demands…

  11. 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,…

  12. 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

  13. 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. PMID:26995033

  14. Phenotypic differences in a cryptic predator: factors influencing morphological variation in the terciopelo Bothrops asper (Garman, 1884; Serpentes: Viperidae).

    PubMed

    Saldarriaga-Córdoba, Mónica María; Sasa, Mahmood; Pardo, Rodrigo; Méndez, Marco Antonio

    2009-12-01

    The terciopelo Bothrops asper, is a cryptic lancehead pitviper widely distributed in humid environments of Middle America and the north-western portion of South America. Throughout its extensive distribution range, the terciopelo exhibits great morphological variation in external characters, a situation that has complicated its proper separation from other related species. In this paper, we analyzed the phenotypic variation of B. asper based in a sample of 514 specimens from nine distinct physiographic regions. Univariate and multivariate analyses demonstrated great phenotypic differentiation among most pre-established groups, and the pattern is fairly congruent between sexes. However, no correspondence was observed between morphological variation and molecular divergence, inferred from mDNA sequences, between individuals representing the physiographical regions under study. Geographic variation in the number of interrictals, ventral scales, subcaudal scales and dorsal blotches was positively correlated with latitude and number of dry months, but inversely related with precipitation. However, other variables do not exhibit such an effect. The observed relationships between scale counts and environmental variables are explained in terms of selective pressures to improve water balance along the distributional range of the species. PMID:19505490

  15. 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. PMID:15278844

  16. 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…

  17. Inter-season and interannual variations in fish and macrocrustacean community structure on a eastern English Channel sandy beach: Influence of environmental factors

    NASA Astrophysics Data System (ADS)

    Selleslagh, Jonathan; Amara, Rachid

    2008-05-01

    The intertidal zone of an exposed sandy beach on the French coast of the English Channel was sampled with a 1.5 m beam-trawl over five years (2000 and 2003-2006) at weekly intervals. The fish and macrocrustacean catches were analysed to determine the inter-season and interannual variation in community structure and relate these variations to changes in the major environmental variables. Only six species (plaice Pleuronectes platessa, common goby Pomatoschistus microps, sprat Sprattus sprattus, sand eel Ammodytes tobianus, brown shrimp Crangon crangon and shore crab Carcinus maenas) from the 27 species captured can be considered as dominant species of the intertidal zone, and they accounted for >90% of total numbers. Most individuals caught were young-of-the-year or juvenile. Analysis of similarities (ANOSIM) and similarities percentage (SIMPER) indicated that inter-season variability of community structure (mean average similarity = 47%) was more pronounced than interannual variability (mean average similarity = 65%). Canonical correspondence analysis (CCA) indicates that a substantial component (32.2%) of the measured inter-season variation in community structure can be explained by environmental factors (mainly water temperature). The main inter-season changes in the abundance and community structure were due to the variation of the six key species and reflect the different times of their recruitment. During the five years of the study, the structure of the fish and macrocrustacean spring community persisted from year to year, with the dominant species reappearing consistently even though their abundances fluctuated from year to year. This interannual variation probably reflects variable recruitment success influenced by physico-chemical conditions. In spite of the considerable interannual variation (40 times) in the spring bloom of the prymnesiophyte alga Phaeocystis globosa we found no effect of this bloom on either fish and macrocrustacean species densities or

  18. 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...

  19. 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

  20. Use of an oral stable isotope label to confirm variation in red blood cell mean age that influences HbA1c interpretation

    PubMed Central

    Lindsell, Christopher J.; Rogge, Mary Colleen; Haggerty, Shannon; Wagner, David A.; Palascak, Mary B.; Mehta, Shilpa; Hibbert, Jacqueline M.; Joiner, Clinton H.; Franco, Robert S.; Cohen, Robert M.

    2014-01-01

    HbA1c is commonly used to monitor glycemic control. However, there is growing evidence that the relationship between HbA1c and mean blood glucose (MBG) is influenced by variation in red blood cell (RBC) lifespan in hematologically normal individuals. Correction of HbA1c for mean RBC age (MRBC) requires a noninvasive, accurate, and affordable method to measure RBC survival. In this study, we evaluated whether a stable isotope approach would satisfy these requirements. RBC lifespan and MRBC were determined in a group of nine hematologically normal diabetic and nondiabetic subjects using oral 15N-glycine to label heme in an age cohort of RBC. The MRBC was 58.7 ± 9.1 (2SD) days and RBC lifespan was 106 ± 21 (2SD) days. This degree of variation (±15 - 20%) is consistent with previous studies using other techniques. In a subset of seven subjects, MRBC determined with the biotin label technique were available from approximately five years prior, and strongly correlated with the stable isotope values (R2 = 0.79). This study suggests that the MRBC is stable over time but varies substantially among individuals, and supports the importance of its variation in HbA1c interpretation. The characteristics of the stable isotope method support its suitability for studies to directly evaluate the impact of variation in MRBC on the interpretation of HbA1c. PMID:25293624

  1. 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

    2016-06-01

    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. PMID:27171980

  2. Theoretical investigation of core geometry variation influence on a few-mode optical signal distortion during propagation over silica graded-index multimode fiber with low DMD

    NASA Astrophysics Data System (ADS)

    Bourdine, Anton V.

    2012-01-01

    In recent works an alternative method for design of silica GeO2-doped graded-index multimode optical fibers 50/125 with low differential mode delay (DMD) was introduced. It is based on synthesis of special refractive index profile, providing the equalization of guided mode group velocities. A theoretical approbation of introduced fibers under the modeling of fiber optic link showed good results for a few-mode regime of high-speed laser-based serial data transmission. However on practice a different distributed core geometry parameter variation occurs in real optical fibers due to techniques features of preform manufacturing and fiber drawing. Here results of fiber optic link modeling with proposed multimode fibers 50/125 with low DMD under core diameter variation and refractive index profile deviation from the optimal form, and estimation of their influence on a few-mode optical signal distortion are represented.

  3. Theoretical investigation of core geometry variation influence on a few-mode optical signal distortion during propagation over silica graded-index multimode fiber with low DMD

    NASA Astrophysics Data System (ADS)

    Bourdine, Anton V.

    2011-12-01

    In recent works an alternative method for design of silica GeO2-doped graded-index multimode optical fibers 50/125 with low differential mode delay (DMD) was introduced. It is based on synthesis of special refractive index profile, providing the equalization of guided mode group velocities. A theoretical approbation of introduced fibers under the modeling of fiber optic link showed good results for a few-mode regime of high-speed laser-based serial data transmission. However on practice a different distributed core geometry parameter variation occurs in real optical fibers due to techniques features of preform manufacturing and fiber drawing. Here results of fiber optic link modeling with proposed multimode fibers 50/125 with low DMD under core diameter variation and refractive index profile deviation from the optimal form, and estimation of their influence on a few-mode optical signal distortion are represented.

  4. Limitations of inclusive fitness.

    PubMed

    Allen, Benjamin; Nowak, Martin A; Wilson, Edward O

    2013-12-10

    Until recently, inclusive fitness has been widely accepted as a general method to explain the evolution of social behavior. Affirming and expanding earlier criticism, we demonstrate that inclusive fitness is instead a limited concept, which exists only for a small subset of evolutionary processes. Inclusive fitness assumes that personal fitness is the sum of additive components caused by individual actions. This assumption does not hold for the majority of evolutionary processes or scenarios. To sidestep this limitation, inclusive fitness theorists have proposed a method using linear regression. On the basis of this method, it is claimed that inclusive fitness theory (i) predicts the direction of allele frequency changes, (ii) reveals the reasons for these changes, (iii) is as general as natural selection, and (iv) provides a universal design principle for evolution. In this paper we evaluate these claims, and show that all of them are unfounded. If the objective is to analyze whether mutations that modify social behavior are favored or opposed by natural selection, then no aspect of inclusive fitness theory is needed. PMID:24277847

  5. Limitations of inclusive fitness

    PubMed Central

    Allen, Benjamin; Nowak, Martin A.; Wilson, Edward O.

    2013-01-01

    Until recently, inclusive fitness has been widely accepted as a general method to explain the evolution of social behavior. Affirming and expanding earlier criticism, we demonstrate that inclusive fitness is instead a limited concept, which exists only for a small subset of evolutionary processes. Inclusive fitness assumes that personal fitness is the sum of additive components caused by individual actions. This assumption does not hold for the majority of evolutionary processes or scenarios. To sidestep this limitation, inclusive fitness theorists have proposed a method using linear regression. On the basis of this method, it is claimed that inclusive fitness theory (i) predicts the direction of allele frequency changes, (ii) reveals the reasons for these changes, (iii) is as general as natural selection, and (iv) provides a universal design principle for evolution. In this paper we evaluate these claims, and show that all of them are unfounded. If the objective is to analyze whether mutations that modify social behavior are favored or opposed by natural selection, then no aspect of inclusive fitness theory is needed. PMID:24277847

  6. 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.

  7. [Influence of dehydration and diurnal variation on characteristics of chlorophyll fluorescence of leaves in Haloxylon ammodendron and H. persicum].

    PubMed

    Shen, Liang; Chen, Jun; Liu, Sai; Xu, Rong; Xu, Chang-qing; Liu, Tong-ning

    2015-08-01

    To evaluate the ecological adaptation mechanism of Haloxylon ammodendron and H. persicum from Ningxia, the host of Cistanche deserticola, the chlorophyll fluorescence under dehydration and diurnal variation was determined by IMAGING-PAM method. The results showed that H. ammodendron had higher photosynthetic electron transport activity (Fv/Fm), photosynthetic efficiency (qP), and PS II electron transport activity (ETR) than H. persicum. After 48 h dehydration, the chlorophyll fluorescence and water-retaining property of H. ammodendron were significantly higher than those of H. persicum. The significant difference in diurnal variation between H. ammo- dendron and H. persicum was observed and a 'V' trend was exhibited. It suggested that H. ammodendron had a stronger ability to adapt to the environment and had wider distribution, while H. persicum was limited by water and light and had narrow distribution. PMID:26685594

  8. Flared tube attachment fitting

    NASA Technical Reports Server (NTRS)

    Alkire, I. D.; King, J. P., Jr.

    1980-01-01

    Tubes can be flared first, then attached to valves and other flow line components, with new fitting that can be disassembled and reused. Installed fitting can be disassembled so parts can be inspected. It can be salvaged and reused without damaging flared tube; tube can be coated, tempered, or otherwise treated after it has been flared, rather than before, as was previously required. Fitting consists of threaded male portion with conical seating surface, hexagonal nut with hole larger than other diameter of flared end of tube, and split ferrule.

  9. Influence of variations in the chromophoric ligand on the properties of metal-to-ligand charge-transfer excited states

    SciTech Connect

    Johnson, S.R.; Westmoreland, T.D.; Caspar, J.V.; Barqawi, K.R.; Meyer, T.J.

    1988-09-07

    The effects of variations in the chromophoric ligand on the properties of the metal-to-ligand charge-transfer (MLCT) excited states in the series (Os(PP)/sub 3/)/sup 2+/, ((PP)/sub 2/Os(py)/sub 2/)/sup 2+/, and ((PP)/sub 2/Os(LL))/sup 2+/ (PP = 2,2'-bipyridine, 1,10-phenanthroline, or a substituted derivative; py = pyridine; LL = das, dppm, dppb, dppene) have been investigated. From a series of electrochemical and photophysical measurements it has been determined that (1) substituent variations in the chromophoric ligands have a relatively minor effect on the d/pi/(Os) levels as evidenced by variations in E/sub 1/2/ values for the ground-state Os(III/II) couples, (2) linear correlations exist between metal-to-ligand charge-transfer (MLCT) absorption or emission band energies and the difference in metal-based oxidation and ligand-based reduction potentials, E/sub 1/2/(Os/sup III/II/) - E/sub 1/2/(PP/sup 0//minus//), and (3) a linear relationship between 1n k/sub nr/ and the emission energy, E/sub em/, exists, consistent with the energy gap law. It appears that for nonradiative decay both the pattern of acceptor vibrations and the vibrationally induced electronic coupling term remain relatively constant as the chromophoric ligand is varied. 26 references, 4 figures, 2 tables.

  10. 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.

  11. Compositional variation among black tea across geographies and their potential influence on endothelial nitric oxide and antioxidant activity.

    PubMed

    Dias, Paul Mark; Changarath, Jayashree; Damodaran, Anita; Joshi, Manoj Kumar

    2014-07-16

    Black tea (C. sinensis) consumption is well associated with enhanced endothelial function (EF) and reduced cardiovascular (CV) risk. This clinical end benefit is endorsed to flavonoids in tea. The black tea flavonoid composition varies across geographies and may impact its health benefits. Moreover, the underlying functional species and a precise working mechanism responsible for the observed health benefit also remain to be investigated. In this Article, we investigated the effect of black teas from various geographies (WoBTs) on different working mechanisms (antioxidant potential and endothelial function) proposed to influence certain risk factors of CVH, in vitro. Pearson correlation analysis showed that the antioxidant benefits are fairly influenced by majority of tea actives such as catechins, theaflavins, thearubigins, and phenolic acids, while NO potentiating effects are mainly regulated by catechins in black tea. The data also suggest that the net vascular function benefit of black tea is majorly influenced by NO enhancement, while mildly contributed by its antioxidant benefit. PMID:24990074

  12. 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…

  13. Exercise and Physical Fitness

    MedlinePlus

    ... Increase your chances of living longer Fitting regular exercise into your daily schedule may seem difficult at ... fine. The key is to find the right exercise for you. It should be fun and should ...

  14. WOLF: FITS file processor

    NASA Astrophysics Data System (ADS)

    Shamir, Lior

    2012-12-01

    WOLF processes FITS files and generates photometry files, annotated JPGs, opacity maps, background, transient detection and luminance changes detection. This software was used to process data for the Night Sky Live project.

  15. Exercise and Physical Fitness

    MedlinePlus

    ... cancers Strengthen your bones and muscles Improve your mental health and mood Improve your ability to do daily activities and prevent falls, if you're an older adult Increase your chances of living longer Fitting regular exercise ...

  16. Spatial and temporal variation of biochemical biomarkers in Gobius niger (Gobiidae) from a southern Mediterranean lagoon (Bizerta lagoon, Tunisia): Influence of biotic and abiotic factors.

    PubMed

    Louiz, Ibtissem; Ben Hassine, Oum Kalthoum; Palluel, Olivier; Ben-Attia, Mossadok; Aït-Aïssa, Sélim

    2016-06-15

    This study aims at evaluating both the influence of natural and some anthropogenic pressures on spatio-temporal variations on biomarker responses in sedentary benthic fish Gobius niger. For this purpose, variability of biotransformation enzymes and oxidative stress parameters response were studied in six stations from Bizerta lagoon as well as a reference station located in Ghar El Melh lagoon. Biomarker responses were shown to vary according to both physico-chemical parameters and anthropogenic pressures, but no influence of sex was reported. Based on multivariate analyses, the responses of biomarkers, obtained after covariate analysis in order to weigh the effect of physico-chemical parameters, allowed us to discriminate all stations, with a good classification rate for those that are highly contaminated. Altogether, this study shows the usefulness of G. niger as a sentinel species and stresses the necessity of integrating natural variables for data interpretation. PMID:27085596

  17. 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…

  18. The Langley Fitness Center

    NASA Technical Reports Server (NTRS)

    1993-01-01

    NASA Langley recognizes the importance of healthy employees by committing itself to offering a complete fitness program. The scope of the program focuses on promoting overall health and wellness in an effort to reduce the risks of illness and disease and to increase productivity. This is accomplished through a comprehensive Health and Fitness Program offered to all NASA employees. Various aspects of the program are discussed.

  19. 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…

  20. 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...

  1. 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,...

  2. Inclusive fitness in agriculture

    PubMed Central

    Kiers, E. Toby; Denison, R. Ford

    2014-01-01

    Trade-offs between individual fitness and the collective performance of crop and below-ground symbiont communities are common in agriculture. Plant competitiveness for light and soil resources is key to individual fitness, but higher investments in stems and roots by a plant community to compete for those resources ultimately reduce crop yields. Similarly, rhizobia and mycorrhizal fungi may increase their individual fitness by diverting resources to their own reproduction, even if they could have benefited collectively by providing their shared crop host with more nitrogen and phosphorus, respectively. Past selection for inclusive fitness (benefits to others, weighted by their relatedness) is unlikely to have favoured community performance over individual fitness. The limited evidence for kin recognition in plants and microbes changes this conclusion only slightly. We therefore argue that there is still ample opportunity for human-imposed selection to improve cooperation among crop plants and their symbionts so that they use limited resources more efficiently. This evolutionarily informed approach will require a better understanding of how interactions among crops, and interactions with their symbionts, affected their inclusive fitness in the past and what that implies for current interactions. PMID:24686938

  3. Inclusive fitness in agriculture.

    PubMed

    Kiers, E Toby; Denison, R Ford

    2014-05-19

    Trade-offs between individual fitness and the collective performance of crop and below-ground symbiont communities are common in agriculture. Plant competitiveness for light and soil resources is key to individual fitness, but higher investments in stems and roots by a plant community to compete for those resources ultimately reduce crop yields. Similarly, rhizobia and mycorrhizal fungi may increase their individual fitness by diverting resources to their own reproduction, even if they could have benefited collectively by providing their shared crop host with more nitrogen and phosphorus, respectively. Past selection for inclusive fitness (benefits to others, weighted by their relatedness) is unlikely to have favoured community performance over individual fitness. The limited evidence for kin recognition in plants and microbes changes this conclusion only slightly. We therefore argue that there is still ample opportunity for human-imposed selection to improve cooperation among crop plants and their symbionts so that they use limited resources more efficiently. This evolutionarily informed approach will require a better understanding of how interactions among crops, and interactions with their symbionts, affected their inclusive fitness in the past and what that implies for current interactions. PMID:24686938

  4. 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

  5. How do variations in Urban Heat Islands in space and time influence household water use? The case of Phoenix, Arizona

    NASA Astrophysics Data System (ADS)

    Aggarwal, Rimjhim M.; Guhathakurta, Subhrajit; Grossman-Clarke, Susanne; Lathey, Vasudha

    2012-06-01

    This paper explores how urbanization, through its role in the evolution of Urban Heat Island (UHI), affects residential water consumption. Using longitudinal data and drawing on a mesoscale atmospheric model, we examine how variations in surface temperature at the census tract level have affected water use in single family residences in Phoenix, Arizona. Results show that each Fahrenheit rise in nighttime temperature increases water consumption by 1.4%. This temperature effect is found to vary significantly with lot size and pool size. The study provides insights into the links between urban form and water use, through the dynamics of UHI.

  6. Recognition of wave-dominated, tide-influenced shoreline systems in the rock record: Variations from a microtidal shoreline model

    NASA Astrophysics Data System (ADS)

    Vakarelov, Boyan K.; Ainsworth, R. Bruce; MacEachern, James A.

    2012-11-01

    Existing wave-dominated facies models are based on microtidal coastlines and do not adequately address wave-dominated environments influenced by significant tidal ranges. Observations from modern environments show that such systems are abundant along tide-influenced shorelines facing wide shelves and large embayments, such as much of the northern Australia coast; yet equivalent deposits have been rarely recognized from the ancient record. Geomorphological literature shows that tidal influence on wave-dominated shorelines has the effect of shifting the shoaling, breaking, and swash wave zones up and down the beach profile; when the tidal range is appreciable, sedimentation is affected significantly. Many macrotidal, wave-dominated systems (tidal range > 4 m), for example, are non-barred and are characterized by poor development of dune-scale bedforms in the subtidal zone and along the beach profile. Other systems do develop cross stratification, but this occurs in the intertidal zone rather than the subtidal zone as is implied in existing wave-dominated facies models. The association of many wave-dominated, tide-influenced environments with shallow shelves also suggests that major storms may be capable of reworking sediment significant distances from the shoreline. We present an ancient example of a wave-dominated, tide-influenced, fluvial-affected system (Wtf) from the Campanian Bearpaw to Horseshoe Canyon Formation transition near Drumheller, Alberta, Canada, which has been described in closely spaced outcrop exposures and core. Wave domination in the coarsening-upward interval is unambiguous and is represented by abundance of micro-hummocky cross stratification and other storm beds in the mudstone-dominated portions, a well-defined swaley cross stratified sandstone interval, and an up to four meter thick, horizontal planar stratified interval interpreted to have been formed by swash waves. Tide influence is suggested by common double carbonaceous and mud drapes

  7. Analysis of streamflow variations in the Heihe River Basin: Trends, abrupt change, driving factors and ecological influences

    NASA Astrophysics Data System (ADS)

    Zhang, A.; Wang, S.; Zheng, C.

    2013-12-01

    With increasing water demands from domestic, agricultural, and industrial sectors, the Heihe River Basin (HRB), as the second largest inland river basin in the arid regions of northwest China, has been increasingly undergoing water resources shortage and eco-environmental degradation, especially in the lower HRB. Determining the trends and any abrupt changes in the streamflow over the river basin could help understand the causes and effects of historical variations in the water resources. This study was undertaken to analyze annual and seasonal streamflow variations over the past 50 years in the HRB. Statistical methods for detecting trends, abrupt and gradual changes were applied to the long-term precipitation and streamflow gage data along the main stream channel. The findings indicated that although the streamflow coming from the upper reaches have risen slightly, those flowing to the lower reaches have dropped significantly. Analysis of the correlation between precipitation and runoff and assessment of the changes in population, land use and irrigation water use revealed that human activities in the middle reaches of HRB rather than climate changes were likely to be primarily responsible for the water shortage and ecological deterioration of the lower HRB.

  8. Influence of ATM-Mediated DNA Damage Response on Genomic Variation in Human Induced Pluripotent Stem Cells.

    PubMed

    Lu, Junjie; Li, Hu; Baccei, Anna; Sasaki, Takayo; Gilbert, David M; Lerou, Paul H

    2016-05-01

    Genome instability is a potential limitation to the research and therapeutic application of induced pluripotent stem cells (iPSCs). Observed genomic variations reflect the combined activities of DNA damage, cellular DNA damage response (DDR), and selection pressure in culture. To understand the contribution of DDR on the distribution of copy number variations (CNVs) in iPSCs, we mapped CNVs of iPSCs with mutations in the central DDR gene ATM onto genome organization landscapes defined by genome-wide replication timing profiles. We show that following reprogramming the early and late replicating genome is differentially affected by CNVs in ATM-deficient iPSCs relative to wild-type iPSCs. Specifically, the early replicating regions had increased CNV losses during retroviral (RV) reprogramming. This differential CNV distribution was not present after later passage or after episomal reprogramming. Comparison of different reprogramming methods in the setting of defective DDR reveals unique vulnerability of early replicating open chromatin to RV vectors. PMID:26935587

  9. Influence of monsoon over the warm pool on interannual variation on tropical cyclone activity over the western North Pacific

    NASA Astrophysics Data System (ADS)

    Chen, Guanghua; Huang, Ronghui

    2008-03-01

    The relationship between the interannual variation in tropical cyclone (TC) activity over the western North Pacific (WNP) and the thermal state over the warm pool (WP) is examined in this paper. The results show that the subsurface temperature in the WP is well correlated with TC geographical distribution and track type. Their relation is linked by the East Asian monsoon trough. During the warm years, the westward-retreating monsoon trough creates convergence and vorticity fields that are favorable for tropical cyclogenesis in the northwest of the WNP, whereas more TCs concentrating in the southeast result from eastward penetration of the monsoon trough during the cold years. The steering flows at 500 hPa lead to a westward displacement track in the warm years and recurving prevailing track in the cold years. The two types of distinct processes in the monsoon environment triggering tropical cyclogenesis are hypothesized by composites centered for TC genesis location corresponding to two kinds of thermal states of the WP. During the warm years, low-frequency intraseasonal oscillation is active in the west of the WNP such that eastward-propagating westerlies cluster TC genesis in that region. In contrast, during the cold years, the increased cyclogenesis in the southeast of the WNP is mainly associated with tropical depression type disturbances transiting from equatorially trapped mixed Rossby gravity waves. Both of the processes may be fundamental mechanisms for the inherent interannual variation in TC activity over the WNP.

  10. Detecting anthropogenic influences on climate with an atmospheric model forced with observed variations in sea surface temperature

    SciTech Connect

    Folland, C.K.; Sexton, D.; Karoly, D.

    1997-11-01

    Six ensembles of four simulations with the Hadley Centre atmospheric general circulation model (HADAM2a) have been carried out for late 1948 to the end of 1994 with different specified atmospheric forcing distributions. These simulations are being used to understand the role of different forcing processes in determining the observed climate variations during the second half of the twentieth century. All ensembles started from different initial conditions and were forced with specified global observed monthly sea ice and sea surface temperature distributions using the GISST1.1 data set. The approach used deterministic sampling of observed variations in climate rather than a coupled model. The technique was also different in that it looked at the smaller residual climate signal due to direct anthropogenic over and above those captured in ocean surface temperatures. The results indicate that this method is a useful complement to approaches based on coupled models, aided by the fact that some of the residual climate signals are almost as large as the full signals seen in coupled models, particularly in the stratosphere. 9 refs., 4 figs.

  11. Influence of cloud fraction and snow cover to the variation of surface UV radiation at King Sejong station, Antarctica

    NASA Astrophysics Data System (ADS)

    Lee, Yun Gon; Koo, Ja-Ho; Kim, Jhoon

    2015-10-01

    This study investigated how cloud fraction and snow cover affect the variation of surface ultraviolet (UV) radiation by using surface Erythemal UV (EUV) and Near UV (NUV) observed at the King Sejong Station, Antarctica. First the Radiative Amplification Factor (RAF), the relative change of surface EUV according to the total-column ozone amount, is compared for different cloud fractions and solar zenith angles (SZAs). Generally, all cloudy conditions show that the increase of RAF as SZA becomes larger, showing the larger effects of vertical columnar ozone. For given SZA cases, the EUV transmission through mean cloud layer gradually decreases as cloud fraction increases, but sometimes the maximum of surface EUV appears under partly cloudy conditions. The high surface EUV transmittance under broken cloud conditions seems due to the re-radiation of scattered EUV by cloud particles. NUV transmission through mean cloud layer also decreases as cloud amount increases but the sensitivity to the cloud fraction is larger than EUV. Both EUV and NUV radiations at the surface are also enhanced by the snow cover, and their enhancement becomes higher as SZA increases implying the diurnal variation of surface albedo. This effect of snow cover seems large under the overcast sky because of the stronger interaction between snow surface and cloudy sky.

  12. The influence of pressure-dependent variation of the elastic constants on tunnelling systems in amorphous solids

    NASA Astrophysics Data System (ADS)

    Eggert, Th.; Geilenkeuser, R.; Jäckel, M.

    2000-07-01

    We have measured the dielectric response ε( ω) and the thermal conductivity κ of polystyrene (PS) and of polycarbonate (PC) under high hydrostatic pressure (0.1 MPainfluence on the minimum temperature of Δ ε‧/ ε‧ and on κ. With the pressure dependence of the density and sound velocity of PC and PS the influence of pressure on the tunnelling constant Ci can be determined. These results show that the product P¯γ l,t2 of the standard tunnelling model (STM) scales with the pressure-dependent elastic constants c11 and c44.

  13. Variation in riparian consumer diet composition and differential bioaccumulation by prey influence the risk of exposure to elements from a recently remediated fly ash spill.

    PubMed

    Beck, Michelle L; Hopkins, William A; Jackson, Brian P

    2014-11-01

    Emerging aquatic insects play a key role in transporting aquatic nutrients and contaminants to riparian consumers. However, little is known about how within- and between-year variation in the diet or patterns of element bioaccumulation in emerging insect taxa may influence the risk of exposure to wildlife. During 2 breeding seasons, the composition of the diet of tree swallows (Tachycineta bicolor) was examined at several colonies that were exposed to element contamination from a remediated coal fly ash spill to determine how variation in the diet influenced the risk of exposure to elements. The proportion of the diet that consisted of insects with an aquatic larval stage was positively related to concentrations of As, Fe, Se, and Tl in the samples. The proportion of the diet that consisted of Chironomidae (midges) was positively related to exposure to these elements at most colonies within and between years. Ephemeroptera (mayflies) contained higher concentrations of Se than midges, including 17 samples with concentrations of Se above 5 µg/g dry mass, the threshold of toxicological concern for birds. This was even the case at colonies several kilometers downstream from the spill. The results indicate that greater consideration should be given to the pattern of element bioaccumulation among different prey taxa and their relative importance in the diet to better assess the risk of contaminant exposure. PMID:25113541

  14. Individual variation in the neural processes of motor decisions in the stop signal task: the influence of novelty seeking and harm avoidance personality traits.

    PubMed

    Hu, Jianping; Lee, Dianne; Hu, Sien; Zhang, Sheng; Chao, Herta; Li, Chiang-Shan R

    2016-06-01

    Personality traits contribute to variation in human behavior, including the propensity to take risk. Extant work targeted risk-taking processes with an explicit manipulation of reward, but it remains unclear whether personality traits influence simple decisions such as speeded versus delayed responses during cognitive control. We explored this issue in an fMRI study of the stop signal task, in which participants varied in response time trial by trial, speeding up and risking a stop error or slowing down to avoid errors. Regional brain activations to speeded versus delayed motor responses (risk-taking) were correlated to novelty seeking (NS), harm avoidance (HA) and reward dependence (RD), with age and gender as covariates, in a whole brain regression. At a corrected threshold, the results showed a positive correlation between NS and risk-taking responses in the dorsomedial prefrontal, bilateral orbitofrontal, and frontopolar cortex, and between HA and risk-taking responses in the parahippocampal gyrus and putamen. No regional activations varied with RD. These findings demonstrate that personality traits influence the neural processes of executive control beyond behavioral tasks that involve explicit monetary reward. The results also speak broadly to the importance of characterizing inter-subject variation in studies of cognition and brain functions. PMID:25989852

  15. Influence of process parameter variation on the reflectivity of sputter-deposited W-C multilayer diffraction gratings

    NASA Technical Reports Server (NTRS)

    Sager, B.; Benson, P.; Jahoda, K.; Jacobs, J. R.; Bloch, J. J.

    1986-01-01

    Multilayer W-C diffraction gratings with nominal d spacings of 35 A have been fabricated by magnetron sputter deposition. The peak and integrated reflectivities of these films have been measured with Al K-alpha X-rays and compared to theoretical values. The rms surface roughness has been evaluated. The influence of several sputtering-system process parameters on the reflectivities has been investigated.

  16. Rules, culture, and fitness.

    PubMed

    Baum, W M

    1995-01-01

    Behavior analysis risks intellectual isolation unless it integrates its explanations with evolutionary theory. Rule-governed behavior is an example of a topic that requires an evolutionary perspective for a full understanding. A rule may be defined as a verbal discriminative stimulus produced by the behavior of a speaker under the stimulus control of a long-term contingency between the behavior and fitness. As a discriminative stimulus, the rule strengthens listener behavior that is reinforced in the short run by socially mediated contingencies, but which also enters into the long-term contingency that enhances the listener's fitness. The long-term contingency constitutes the global context for the speaker's giving the rule. When a rule is said to be "internalized," the listener's behavior has switched from short- to long-term control. The fitness-enhancing consequences of long-term contingencies are health, resources, relationships, or reproduction. This view ties rules both to evolutionary theory and to culture. Stating a rule is a cultural practice. The practice strengthens, with short-term reinforcement, behavior that usually enhances fitness in the long run. The practice evolves because of its effect on fitness. The standard definition of a rule as a verbal statement that points to a contingency fails to distinguish between a rule and a bargain ("If you'll do X, then I'll do Y"), which signifies only a single short-term contingency that provides mutual reinforcement for speaker and listener. In contrast, the giving and following of a rule ("Dress warmly; it's cold outside") can be understood only by reference also to a contingency providing long-term enhancement of the listener's fitness or the fitness of the listener's genes. Such a perspective may change the way both behavior analysts and evolutionary biologists think about rule-governed behavior. PMID:22478201

  17. Influence of microstructural variations in the weldment on the high-temperature corrosion of 2.25Cr-1Mo steel

    SciTech Connect

    Singh Raman, R.K.

    1995-07-01

    In order to study the influence of microstructural variation on the oxidation of the weldment of 2.25Cr-1Mo steel, regions with different microstructures were identified by optical microscopy. The weld metal, the base metal, and the heat-affected zone (HAZ), as well as the subzones within the HAZ, i.e., the intercritical (ICR), the fine-grain bainite (FGB), and the coarse-grain bainite (CGB) regions were separated from the weldment by precise steps of metallography. Transmission electron microscopic examinations for the identification of the secondary phases in microstructurally different regions and subzones have suggested that M{sub 23}C{sub 6} and M{sub 7}C{sub 3} precipitates form predominantly in the subzones of HAZ, whereas the Mo{sub 2}C type of carbide forms exclusively in the weld-metal and base-metal regions of the weldment. However, population and distribution of the secondary phases were different in the three subzones of the HAZ. In order to understand the influence of these microstructural variations on the oxidation behavior, the various regions and subzones were oxidized at 773 and 873 K. The HAZ and its constituents were found to oxidize at much higher rates than the weld metal and the base metal. Relative compositions and morphologies of the scales were compared by scanning electron microscopy with energy-dispersive analyses of X-rays (SEM/EDX), and secondary ion mass spectrometry (SIMS). Scale formed over the weld metal shows a greater tendency for spallation, as suggested by tests monitoring acoustic emission. Results of the SEM/EDX, SIMS, and XRD investigations suggest formation of inner scales with less Cr over the HAZ than over the weld-metal and the base-metal regions. Variation in the Cr contents of the scales formed over the various regions is proposed to arise from the difference in microstructural features in different regions of the weldments.

  18. On the influence of the diurnal variations of aerosol content to estimate direct aerosol radiative forcing using MODIS data

    NASA Astrophysics Data System (ADS)

    Xu, Hui; Guo, Jianping; Ceamanos, Xavier; Roujean, Jean-Louis; Min, Min; Carrer, Dominique

    2016-09-01

    Long-term measurements of aerosol optical depth (AOD) from the Aerosol Robotic Network (AERONET) located in Beijing reveal a strong diurnal cycle of aerosol load staged by seasonal patterns. Such pronounced variability is matter of importance in respect to the estimation of daily averaged direct aerosol radiative forcing (DARF). Polar-orbiting satellites could only offer a daily revisit, which turns in fact to be even much less in case of frequent cloudiness. Indeed, this places a severe limit to properly capture the diurnal variations of AOD and thus estimate daily DARF. Bearing this in mind, the objective of the present study is however to evaluate the impact of AOD diurnal variations for conducting quantitative assessment of DARF using Moderate Resolution Imaging Spectroradiometer (MODIS) AOD data over Beijing. We provide assessments of DARF with two different assumptions about diurnal AOD variability: taking the observed hourly-averaged AOD cycle into account and assuming constant MODIS (including Terra and Aqua) AOD value throughout the daytime. Due to the AOD diurnal variability, the absolute differences in annual daily mean DARFs, if the constant MODIS/Terra (MODIS/Aqua) AOD value is used instead of accounting for the observed hourly-averaged daily variability, is 1.2 (1.3) Wm-2 at the top of the atmosphere, 27.5 (30.6) Wm-2 at the surface, and 26.4 (29.3) Wm-2 in the atmosphere, respectively. During the summertime, the impact of the diurnal AOD variability on seasonal daily mean DARF estimates using MODIS Terra (Aqua) data can reach up to 2.2 (3.9) Wm-2 at the top of the atmosphere, 43.7 (72.7) Wm-2 at the surface, and 41.4 (68.8) Wm-2 in the atmosphere, respectively. Overall, the diurnal variation in AOD tends to cause large bias in the estimated DARF on both seasonal and annual scales. In summertime, the higher the surface albedo, the stronger impact on DARF at the top of the atmosphere caused by dust and biomass burning (continental) aerosol. This

  19. 1958-2008: 50 Years of Youth Fitness Tests in the United States

    ERIC Educational Resources Information Center

    Morrow, James R., Jr.; Zhu, Weimo; Franks, B. Don; Meredith, Marilu D.; Spain, Christine

    2009-01-01

    The AAHPER Youth Fitness Test, the first U.S. national fitness test, was published 50 years ago. The seminal work of Krause and Hirschland influenced the fitness world and continues to do so today. Important youth fitness test initiatives in the last half century are summarized. Key elements leading to continued interest in youth fitness testing…

  20. Ames Fitness Program

    NASA Technical Reports Server (NTRS)

    Pratt, Randy

    1993-01-01

    The Ames Fitness Program services 5,000 civil servants and contractors working at Ames Research Center. A 3,000 square foot fitness center, equipped with cardiovascular machines, weight training machines, and free weight equipment is on site. Thirty exercise classes are held each week at the Center. A weight loss program is offered, including individual exercise prescriptions, fitness testing, and organized monthly runs. The Fitness Center is staffed by one full-time program coordinator and 15 hours per week of part-time help. Membership is available to all employees at Ames at no charge, and there are no fees for participation in any of the program activities. Prior to using the Center, employees must obtain a physical examination and complete a membership package. Funding for the Ames Fitness Program was in jeopardy in December 1992; however, the employees circulated a petition in support of the program and collected more than 1500 signatures in only three days. Funding has been approved through October 1993.

  1. Optimization of inclusive fitness.

    PubMed

    Grafen, Alan

    2006-02-01

    The first fully explicit argument is given that broadly supports a widespread belief among whole-organism biologists that natural selection tends to lead to organisms acting as if maximizing their inclusive fitness. The use of optimization programs permits a clear statement of what this belief should be understood to mean, in contradistinction to the common mathematical presumption that it should be formalized as some kind of Lyapunov or even potential function. The argument reveals new details and uncovers latent assumptions. A very general genetic architecture is allowed, and there is arbitrary uncertainty. However, frequency dependence of fitnesses is not permitted. The logic of inclusive fitness immediately draws together various kinds of intra-genomic conflict, and the concept of 'p-family' is introduced. Inclusive fitness is thus incorporated into the formal Darwinism project, which aims to link the mathematics of motion (difference and differential equations) used to describe gene frequency trajectories with the mathematics of optimization used to describe purpose and design. Important questions remain to be answered in the fundamental theory of inclusive fitness. PMID:16046225

  2. Midwestern streamflow, precipitation, and atmospheric vorticity influenced by Pacific sea-surface temperatures and total solar-irradiance variations

    USGS Publications Warehouse

    Perry, C.A.

    2006-01-01

    A solar effect on streamflow in the Midwestern United States is described and supported in a six-step physical connection between total solar irradiance (TSI), tropical sea-surface temperatures (SSTs), extratropical SSTs, jet-stream vorticity, surface-layer vorticity, precipitation, and streamflow. Variations in the correlations among the individual steps indicate that the solar/hydroclimatic mechanism is complex and has a time element (lag) that may not be constant. Correct phasing, supported by consistent spectral peaks between 0.092 and 0.096 cycles per year in all data sets within the mechanism is strong evidence for its existence. A significant correlation exists between total solar irradiance and the 3-year moving average of annual streamflow for Iowa (R = 0.67) and for the Mississippi River at St Louis, Missouri (R = 0.60), during the period 1950-2000. Published in 2005 by John Wiley & Sons, Ltd.

  3. Variations in the free chlorine content of the stratosphere (1991-1997): Anthropogenic, volcanic, and methane influences

    SciTech Connect

    Froidevaux, L.; Waters, J. W.; Read, W. G.; Connell, P. S.; Kinnison, D. E.; Russell, J. M. III

    2000-02-27

    Remote sensing of chlorine monoxide (ClO) by the Microwave Limb Sounder experiment aboard the Upper Atmosphere Research Satellite (UARS) has provided global measurements of variations in stratospheric free chlorine for 1991-1997. Linear trends were obtained from a multiple regression analysis of this data set at low latitudes and midlatitudes. ClO increases in the upper stratosphere (2 hPa) are significantly larger than expected from trends in chlorine source gases alone. Much of the upper stratospheric ClO variability can be explained by changes in CH{sub 4}, as measured by the UARS Halogen Occultation Experiment. Decreasing ClO in the lower stratosphere is consistent with a relaxation from a chemically perturbed state attributed to the 1991 Mt. Pinatubo eruption. (c) 2000 American Geophysical Union.

  4. Spatial and temporal variations in dissolved and particulate organic nitrogen in the equatorial Pacific: biological and physical influences

    NASA Astrophysics Data System (ADS)

    Wang, X. J.; Le Borgne, R.; Murtugudde, R.; Busalacchi, A. J.; Behrenfeld, M.

    2008-12-01

    To quote Libby and Wheeler (1997), "we have only a cursory knowledge of the distributions of dissolved and particulate organic nitrogen" in the equatorial Pacific. A decade later, we are still in need of spatial and temporal analyses of these organic nitrogen pools. To address this issue, we employ a basin scale physical-biogeochemical model to study the spatial and temporal variations of dissolved organic nitrogen (DON) and particulate organic nitrogen (PON). The model is able to reproduce many observed features of nitrate, ammonium, DON and PON in the central and eastern equatorial Pacific, including the asymmetries of nitrate and ammonium, and the meridional distributions of DON and PON. Modeled DON (5-8 mmol m-3) shows small zonal and meridional variations in the mixed layer whereas modeled PON (0.4-1.5 mmol m-3) shows considerable spatial variability. While there is a moderate seasonality in both DON and PON in the mixed layer, there is a much weaker interannual variability in DON than in PON. The interannual variability in PON is largely associated with the El Niño/Southern Oscillation (ENSO) phenomenon, showing high values during cold ENSO phase but low values during warm ENSO phase. Overall, DON and PON have significant positive correlations with phytoplankton and zooplankton in the mixed layer, indicting the biological regulation on distribution of organic nitrogen. However, the relationships with phytoplankton and zooplankton are much weaker for DON (r=0.18-0.71) than for PON (r=0.25-0.97). Such a difference is ascribed to a relatively larger degree of physical control (e.g., upwelling of low-organic-N deep waters into the surface) on DON than PON.

  5. The Influence of Wind and Basin Eddies in Controlling Sea Level Variations in the Coastal Red Sea

    NASA Astrophysics Data System (ADS)

    Abualnaja, Yasser O.; Churchill, James H.; Nellayaputhenpeedika, Mohammedali; Limeburner, Richard

    2015-04-01

    Sea level variations in the central Red Sea coastal zone span a range of roughly 1.2 m. Though relatively small, these water level changes can significantly impact the environment over the shallow reef tops prevalent in the central Red Sea, altering the water depth by a factor or two or more. Roughly half of the coastal sea level variance in central Red Sea is due to elevation changes in an 'intermediate' frequency band, with periods between 2 days and 1 month. We examined the sea level signal in this band using the data from pressure sensors maintained for more than five years at a number of locations in Saudi Arabian coastal waters between 20.1 and 23.5 oN. We find that the intermediate-band sea level variations are strongly correlated with the local wind stress measured at a meteorological buoy. The maximum pressure-wind correlation occurs at wind direction closely aligned with the alongshore orientation and at a lag (wind leading) of 45 hr, which is consistent with the expected response of the coastal sea level to local wind forcing. However, less than half of the sea level variance in the intermediate band is related, through linear correlation, with local wind forcing. Our analysis indicates that the residual coastal sea level signal, not associated with wind forcing, is largely driven remotely by the passage of mesoscale eddies, revealed by satellite altimeter-derived sea level anomaly fields of the central Red Sea. These eddy-driven coastal sea level changes occur on time scales of 10-30 days. They span a range of 0.5 m, and thus constitute an import component of the sea level signal in the coastal Red Sea.

  6. Analysis of sudden variations in photospheric magnetic fields during a large flare and their influences in the solar atmosphere

    NASA Astrophysics Data System (ADS)

    Kumar, Brajesh; Raja Bayanna, Ankala; Venkatakrishnan, Parameswaran; Kuchandy Mathew, Shibu

    2016-08-01

    The solar active region NOAA 11719 produced a large two-ribbon flare on 2013 April 11. We have investigated sudden variations in the photospheric magnetic fields in this active region during the flare by employing magnetograms obtained in the spectral line Fe I 6173 Å acquired by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) spacecraft. The analysis of the line-of-sight magnetograms from HMI show sudden and persistent magnetic field changes at different locations of the active region before the onset of the flare and during the flare. The vector magnetic field observations available from HMI also show coincident variations in the total magnetic field strength and its inclination angle at these locations. Using the simultaneous Dopplergrams obtained from HMI, we observe perturbations in the photospheric Doppler signals following the sudden changes in the magnetic fields in the aforementioned locations. The power spectrum analysis of these velocity signals shows enhanced acoustic power in these affected locations during the flare as compared to the pre-flare condition. Accompanying these observations, we have also used nearly simultaneous chromospheric observations obtained in the spectral line Hα 6562.8 Å by the Global Oscillation Network Group (GONG) to study the evolution of flare-ribbons and intensity oscillations in this active region. The Hα intensity oscillations also show enhanced oscillatory power during the flare in the aforementioned locations. These results indicate that the transient Lorentz force associated with sudden changes in the magnetic fields could drive localized photospheric and chromospheric oscillations, like the flare-induced oscillations in the solar atmosphere.

  7. Spatial variation in ambient air toxics concentrations and health risks between industrial-influenced, urban, and rural sites.

    PubMed

    Logue, Jennifer M; Small, Mitchell J; Stern, Darrell; Maranche, Jason; Robinson, Allen L

    2010-03-01

    Concentrations of 38 gas-phase organic air toxics were measured over a 2-yr period at four different sites in and around Pittsburgh, PA, to investigate spatial variations in health risks from chronic exposure. The sites were chosen to represent different exposure regimes: a downtown site with substantial mobile source emissions; two residential sites adjacent to one of the most heavily industrialized zones in Pittsburgh; and a regional background site. Lifetime cancer risks and non-cancer hazard quotients were estimated using a traditional and interactive risk models. Although study average concentrations of specific air toxics varied by as a much as a factor of 26 between the sites, the additive cancer risks of the gas-phase organic air toxics varied by less than a factor of 2, ranging from 6.1 x 10(-5) to 9.5 x 10(-5). The modest variation in risks reflects the fact that two regionally distributed toxics, formaldehyde and carbon tetrachloride (CCl4), contributed more than half of the cancer risk at all four sites. Benzene contributed substantial cancer risks at all sites, whereas trichloroethene and 1,4-dichlorobenzene only contributed substantial cancer risks at the downtown site. Only acrolein posed a non-cancer risk. Diesel particulate matter is estimated to pose a much greater cancer risk in Pittsburgh than other classes of air toxics including gas-phase organic, metals, polycyclic aromatic hydrocarbons, and coke oven emissions. Health risks of air toxics in Pittsburgh are comparable with those in other urban areas in the United States. PMID:20397557

  8. Magnetic grain-size variations through an ash flow sheet: Influence on magnetic properties and implications for cooling history

    SciTech Connect

    Rosenbaum, J.G.

    1993-07-10

    Rock magnetic studies of tuffs are essential to the interpretation of paleomagnetic data derived from such rocks, provide a basis for interpretation of aeromagnetic data over volcanic terranes, and yield insights into the depositional and cooling histories of ash flow sheets. A rhyolitic ash flow sheet, the Miocene-aged Tiva Canyon Member of the Paintbrush Tuff, contains both titanomagnetite phenocrysts, present in the magma prior to eruption, and cubic Fe-oxide microcrystals that grew after emplacement. Systematic variations in the quantity and magnetic grain size of the microcrystals produce large variations in magnetic properties through a section of the ash flow sheet penetrated in a borehole on the Nevada Test Site. Natural remanent magnetization varies from less than 1 x 10{sup {minus}4} to more than 8 x 10{sup {minus}4} A m{sup 3} kg{sup {minus}1}, and in-phase magnetic susceptibility varies from less than 1 x 10{sup {minus}6} to more than 10 x 10{sup {minus}6} m{sup 3} kg{sup {minus}1}. The microcrystals, which include both magnetite and maghemite, have Curie points and maximum unblocking temperatures between 580{degrees}C and 640{degrees}C. Rock magnetic data, including in-phase and quadrature magnetic susceptibilities as well as hysteresis parameters, demonstrate that these microcrystals are of superparamagnetic and single-domain sizes. Titanomagnetite phenocrysts are the dominant remanence carriers in the central 50 m of the section, whereas microcrystals are important contributors to remanent magnetization and magnetic susceptibility in two 15-m-thick zones at the top and bottom. Within these zones the size of microcrystals decreases both toward the quenched margins and toward the interior of the sheet. The decrease in microcrystal size toward the interior of the sheet is interpreted to indicate the presence of a cooling break; possibly represented by a concentration of pumice. 32 refs., 11 figs.

  9. Lunar regolith thickness estimation using dual frequency microwave brightness temperature and influence of vertical variation of FeO+TiO2

    NASA Astrophysics Data System (ADS)

    Vijayan, S.; Mohan, Shiv; Murty, SripadaV. S.

    2015-01-01

    Desiccated lunar regolith emits substantial amount of radiation in microwave region, which can be used to decipher regolith thickness distribution. We have evolved a dual frequency microwave brightness index for the estimation of regolith thickness using simulated passive microwave brightness temperature (TB) expected from Chandrayaan-2 at L (1.25 GHz)- and S (2.1 GHz)-bands. We used a three-layer model to simulate TB by varying the dominant parameters like bulk density (ρ), dielectric permittivity and FeO+TiO2 (S) content. The inversion of regolith thickness is carried out using simulation of TB for both the frequencies under a variety of ρ and S contents. Subsequently, a first order empirical model for regolith thickness estimation is evolved using a new dual frequency index involving both the TB. Inverted regolith thickness has been shown to be in good agreement with in-situ measurements at Apollo regions, using single (L-band) and dual frequency index. Inverted thickness for the Apollo14 and Apollo17 locations differ from mare and highland region estimation, which is further analysed to elucidate the role of vertical variation of FeO+TiO2 content. With the FeO+TiO2 variation vertically by ±1-2 wt%, the first order assessment of estimated regolith thickness is found to vary by ~0.5 m and ~1 m, respectively, by single- and dual-frequency approaches. Impact basin ejecta (Apollo14) and mare-highland transition region (Apollo17) are probable zones where vertical variation of FeO+TiO2 occurs along with lateral variations. This lateral- and vertical-mixing of FeO+TiO2 may influence the emitted TB from lunar regolith.

  10. Diurnal variation of particle-bound PAHs in an urban area of Spain using TD-GC/MS: Influence of meteorological parameters and emission sources

    NASA Astrophysics Data System (ADS)

    Elorduy, I.; Elcoroaristizabal, S.; Durana, N.; García, J. A.; Alonso, L.

    2016-08-01

    Short -term particulate concentrations of 13 polycyclic aromatic hydrocarbons (PAHs) in PM10 were determined in the urban area of Bilbao (Spain). The analysis was performed by thermal desorption coupled with gas chromatography-mass spectrometry (TD-GC/MS), which enabled to use three diurnal periods of 8 h sampling basis time resolution. A total of 105 PM10 samples were collected during 5 months in 2013. Diurnal average concentration of total PAHs (∑13 PAHs) ranged from 1.18 to 9.78 ng m-3; and from 0.06 to 0.70 ng m-3 for benzo[a]pyrene. The presence of high concentrations of benzo[b]fluoranthene, pyrene, fluoranthene and chrysene, and the significant PAHs diurnal variations due to the sampling period, pointed out the influence of mixing anthropogenic sources and meteorological conditions. The diurnal pattern of source contributions was assessed by binary diagnostic ratios and principal component analysis (PCA). These results showed the prevalence of pyrogenic sources coming from traffic and coal/coke combustion sources. Moreover, the PCA differentiated a diurnal pattern of source contributions. The influence of meteorological factors was studied by Pearson correlation analysis and multiple linear regression. Three factors, temperature, wind speed and atmospheric pressure, were identified as the most significant ones affecting diurnal PAHs concentrations. Finally, PCA of the PAHs levels, regulated atmospheric pollutants and meteorological parameters showed that diurnal PAHs concentrations were mainly influenced by variations in the emission sources, atmospheric oxidants such as ozone, and temperature conditions. These results provide further insight into the PAHs diurnal patterns in urban areas by using higher temporal resolutions.

  11. Seasonal and size-dependent variations in the phytoplankton growth and microzooplankton grazing in the southern South China Sea under the influence of the East Asian monsoon

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Tan, Y.; Huang, L.; Hu, Z.; Ke, Z.

    2015-11-01

    To examine seasonal and size-dependent variations in the phytoplankton growth and microzooplankton grazing in oligotrophic tropical waters under the influence of seasonal reversing monsoon, dilution experiments were conducted during the summer of 2009 (21 May to 9 June) and winter 2010 (9 to 18 November) in the southern South China Sea (SSCS). The results showed that environmental variables, phytoplankton biomass, phytoplankton growth rate (μ), microzooplankton grazing rate (m), and correlationship (coupling) between the μ and m, rather than the microzooplankton grazing impact on phytoplankton (m/μ) significantly varied between the two seasons. Higher relative preference index (RPI) for the larger-sized (> 3 μm) phytoplankton than pico-phytoplankton (< 3 μm), indicating significant size-selective grazing by microzooplankton on the larger-sized phytoplankton, were also observed. The μ and m were significantly correlated with seawater salinity and temperature, and phytoplankton biomass, which indicated that salient seasonal variations in the phytoplankton growth and microzooplankton grazing in the SSCS were closely related to the environmental variables under the influence of the East Asian monsoon. We propose that intermittent arrivals of the northeast winter monsoon could lead to the low μ and m, and the decoupling between the μ and m in the SSCS, through influencing nutrient supply to the surface water, and inducing surface seawater salinity decrease. The low m/μ (< 50 % on average) indicates low remineralization of organic matter mediated by microzooplankton and mismatch between the μ and m, and thus probably accounts for part of the high vertical biogenic particle fluxes in the prevailing periods of the monsoons in the SSCS. The size-selective grazing suggests that microzooplankton grazing partially contributes to the pico-phytoplankton dominance in the oligotrophic tropical waters such as that of the SSCS.

  12. Seasonal and size-dependent variations in the phytoplankton growth and microzooplankton grazing in the southern South China Sea under the influence of the East Asian monsoon

    NASA Astrophysics Data System (ADS)

    Zhou, L.; Tan, Y.; Huang, L.; Hu, Z.; Ke, Z.

    2015-04-01

    To examine seasonal and size-dependent variations in the phytoplankton growth and microzooplankton grazing in oligotrophic tropical waters under the influence of seasonal reversing monsoon, dilution experiments were conducted during the summer 2009 (21 May to 9 June) and winter 2010 (9 to 18 November) in the southern South China Sea (SSCS). The results showed that environmental variables, phytoplankton biomass, phytoplankton growth rate (μ), microzooplankton grazing rate (m), and correlationship (coupling) between the μ and m, but the microzooplankton grazing impact on phytoplankton (m/μ) significantly varied between the two seasons. Higher relative preference index (RPI) for and m on the larger-sized (>3 μm) phytoplankton than pico-phytoplankton (<3 μm), indicating significant size-selective grazing by microzooplankton on the larger-sized phytoplankton, were also observed. The μ and m were significantly correlated with salinity and dissolved inorganic nutrients, which indicated that salient seasonal variations in the phytoplankton growth and microzooplankton grazing in the SSCS were closely related to the environmental variables under the influence of the East Asian monsoon. We propose that intermittent arrivals of the northeast winter monsoon could lead to the low μ and m, and the decoupling between the μ and m in the SSCS, through influencing nutrient supply to the surface water, and inducing surface seawater salinity decrease. The low m/μ (<50% on average) indicates low remineralization of organic matter mediated by microzooplankton and the increased importance of the phytoplankton-mesozooplankton grazing pathway, and thus probably accounts for part of the high vertical biogenic particle fluxes in the prevailing periods of the monsoons in the SSCS. The size-selective grazing suggests that microzooplankton grazing contributes to the pico-phytoplankton dominance in the oligotrophic tropical waters such as that of the SSCS.

  13. Personality and reproductive fitness.

    PubMed

    Eaves, L J; Martin, N G; Heath, A C; Hewitt, J K; Neale, M C

    1990-09-01

    The relationship between reproductive success (number of biological children) and personality was explored in 1101 postmenopausal females from the Australian twin registry. The quadratic response surface relating fitness to extraversion (E) and neuroticism (N) showed a saddle point at intermediate levels of E and N. Selection was shown to be stabilizing, i.e., having an intermediate optimum, along the axis low E, low N-high E, high N and more mildly disruptive, having greater fitness in the extremes, along the axis low N, high E-high N, low E. Neither dimension of personality considered by itself showed a significant linear or quadratic relationship to reproductive success. Sections through the fitness surface, however, show selection tends to favor high neuroticism levels in introverts and low neuroticism levels in extroverts. PMID:2288546

  14. Assessing differential effects: Applying regression mixture models to identify variations in the influence of family resources on academic achievement

    PubMed Central

    Van Horn, M. Lee; Jaki, Thomas; Masyn, Katherine; Ramey, Sharon Landesman; Smith, Jessalyn A.; Antaramian, Susan

    2015-01-01

    Developmental scientists frequently seek to understand effects of environmental contexts on development. Traditional analytic strategies assume similar environmental effects on all children, sometimes exploring possible moderating influences or exceptions (e.g. outliers) as a secondary step. These strategies are poorly matched to ecological models of human development which posit complex individual by environment interactions. An alternative conceptual framework is proposed that tests the hypothesis that the environment has differential (non-uniform) effects on children. A demonstration of the utility of this framework is provided by examining the effects of family resources on children’s academic outcomes in a multisite study (N=6305). Three distinctive groups of children were identified, including one group particularly resilient to influence of low levels of family resources. Predictors of group differences including parenting and child demographics are tested, the replicability of the results are examined, and findings are contrasted with those using traditional regression interaction effects. This approach is proposed as a partial solution to advance theories of the environment, social ecological systems research, and behavioral genetics in order to create well-tailored environments for children. PMID:19702393

  15. Assessing differential effects: applying regression mixture models to identify variations in the influence of family resources on academic achievement.

    PubMed

    Van Horn, M Lee; Jaki, Thomas; Masyn, Katherine; Ramey, Sharon Landesman; Smith, Jessalyn A; Antaramian, Susan

    2009-09-01

    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 models of human development that posit complex individual by environment interactions. An alternative conceptual framework is proposed that tests the hypothesis that the environment has differential (nonuniform) effects on children. A demonstration of the utility of this framework is provided by examining the effects of family resources on children's academic outcomes in a multisite study (N = 6,305). Three distinctive groups of children were identified, including 1 group particularly resilient to influence of low levels of family resources. Predictors of group differences including parenting and child demographics are tested, the replicability of the results are examined, and findings are contrasted with those obtained with traditional regression interaction effects. This approach is proposed as a partial solution to advance theories of the environment, social ecological systems research, and behavioral genetics to create well-tailored environments for children. PMID:19702393

  16. The changing influences of the AMO and PDO on the decadal variation of the Santa Ana winds

    NASA Astrophysics Data System (ADS)

    Li, Andy K.; Paek, Houk; Yu, Jin-Yi

    2016-06-01

    Santa Ana wind (SAW) events have great implications for the environment of Southern California, but the cause of their decadal variability has not been fully understood. We show with observational analysis that the Atlantic multi-decadal oscillation (AMO) has a stronger influence than the Pacific decadal oscillation (PDO) in modulating SAW activity through two mechanisms: the Great Basin pressure gradient mechanism, in which a strengthened Great Basin high promotes SAW activity and vice versa through the northeast–southwest pressure gradient across Southern California, and the Pacific jetstream displacement mechanism, in which a strengthened Pacific subtropical high (PSH) prohibits mid-latitude cyclones from traveling toward California, consequently encouraging SAW development and vice versa. While the AMO strengthens or weakens both the Great Basin and PSHs to strongly modulate SAW activity through these two mechanisms, the PDO strengthens one of the highs but weakens the other, causing the two mechanisms to cancel each other, producing little influence on SAW activity. A projection based on the AMO and PDO indicates that the above-average SAW activity observed since the beginning of the 21st century is likely to terminate after 2016, after which Southern California may experience an extended period of below-average SAW activity through 2030.

  17. Physics of evolution: Selection without fitness

    NASA Astrophysics Data System (ADS)

    Thurner, Stefan; Hanel, Rudolf; Klimek, Peter

    2010-02-01

    Traditionally evolution is seen as a process where from a pool of possible variations of a population (e.g. biological species or industrial goods) a few variations get selected which survive and proliferate, whereas the others vanish. Survival probabilities and proliferation rates are typically associated with the ‘fitness’ of particular variations. In this paper we argue that the notion of fitness is an a posteriori concept, in the sense that one can assign higher fitness to species that survive but one can generally not derive or predict fitness per se. Proliferation rates can be measured, whereas fitness landscapes, i.e. the inter-dependence of proliferation rates, cannot. For this reason we think that in a physical theory of evolution such notions should be avoided. In this spirit, here we propose a random matrix model of evolution where selection mechanisms are encoded in interaction matrices of species, thereby extending the previous work of ours by a control parameter describing suppressors in the system. We are able to recover some key facts of evolution dynamics endogenously, such as punctuated equilibrium, i.e. the existence of intrinsic large extinction events, and, at the same time, periods of dramatic diversification, as known e.g. from the fossil record. Further, we comment on two fundamental technical problems of a ‘physics of evolution’, the non-closedness of its phase space and the problem of co-evolving boundary conditions, apparent in all systems subject to evolution.

  18. Monsoon-influenced variations in morphology and sediment of a mesotidal beach on the Mekong River delta coast

    NASA Astrophysics Data System (ADS)

    Tamura, Toru; Horaguchi, Keishi; Saito, Yoshiki; Nguyen, Van Lap; Tateishi, Masaaki; Ta, Thi Kim Oanh; Nanayama, Futoshi; Watanabe, Kazuaki

    2010-03-01

    A mesotidal beach on the Mekong River delta coast exhibits unique patterns of river sediment discharge and experiences reversals of ocean wave directions in response to the summer and winter monsoons. We analyzed long-term changes of the shoreline since 1936 from past topographic maps and satellite images, and short-term changes in geomorphology and sedimentology by undertaking repeated field surveys between November 2005 and February 2008 along six shore-normal beach transects. The shoreline of the Mekong River delta coast has changed asymmetrically over the last 70 years in response to net southwestward sediment transport related to dry northeasterly winter monsoons. During the summer rainy season, large volumes of sediments are discharged from the river; at this time, wave direction is reversed in response to the relatively weak southwesterly summer monsoon. Mud and very fine sand in the surface sediments of the northeastern (updrift) beach transects tend to be removed during winter, suggesting that the sediment suppli