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Sample records for underpin population variability

  1. Population dynamics in variable environments

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    Tuljapurkar, Shripad

    1990-01-01

    Demography relates observable facts about individuals to the dynamics of populations. If the dynamics are linear and do not change over time, the classical theory of Lotka (1907) and Leslie (1945) is the central tool of demography. This book addresses the situation when the assumption of constancy is dropped. In many practical situations, a population will display unpredictable variation over time in its vital rates, which must then be described in statistical terms. Most of this book is concerned with the theory of populations which are subject to random temporal changes in their vital rates, although other kinds of variation (e. g. , cyclical) are also dealt with. The central questions are: how does temporal variation work its way into a population's future, and how does it affect our interpretation of a population's past. The results here are directed at demographers of humans and at popula­ tion biologists. The uneven mathematical level is dictated by the material, but the book should be accessible to re...

  2. Metabolic variability in micro-populations.

    Science.gov (United States)

    Elhanati, Yuval; Brenner, Naama

    2012-01-01

    Biological cells in a population are variable in practically every property. Much is known about how variability of single cells is reflected in the statistical properties of infinitely large populations; however, many biologically relevant situations entail finite times and intermediate-sized populations. The statistical properties of an ensemble of finite populations then come into focus, raising questions concerning inter-population variability and dependence on initial conditions. Recent technologies of microfluidic and microdroplet-based population growth realize these situations and make them immediately relevant for experiments and biotechnological application. We here study the statistical properties, arising from metabolic variability of single cells, in an ensemble of micro-populations grown to saturation in a finite environment such as a micro-droplet. We develop a discrete stochastic model for this growth process, describing the possible histories as a random walk in a phenotypic space with an absorbing boundary. Using a mapping to Polya's Urn, a classic problem of probability theory, we find that distributions approach a limiting inoculum-dependent form after a large number of divisions. Thus, population size and structure are random variables whose mean, variance and in general their distribution can reflect initial conditions after many generations of growth. Implications of our results to experiments and to biotechnology are discussed.

  3. Metabolic variability in micro-populations.

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    Yuval Elhanati

    Full Text Available Biological cells in a population are variable in practically every property. Much is known about how variability of single cells is reflected in the statistical properties of infinitely large populations; however, many biologically relevant situations entail finite times and intermediate-sized populations. The statistical properties of an ensemble of finite populations then come into focus, raising questions concerning inter-population variability and dependence on initial conditions. Recent technologies of microfluidic and microdroplet-based population growth realize these situations and make them immediately relevant for experiments and biotechnological application. We here study the statistical properties, arising from metabolic variability of single cells, in an ensemble of micro-populations grown to saturation in a finite environment such as a micro-droplet. We develop a discrete stochastic model for this growth process, describing the possible histories as a random walk in a phenotypic space with an absorbing boundary. Using a mapping to Polya's Urn, a classic problem of probability theory, we find that distributions approach a limiting inoculum-dependent form after a large number of divisions. Thus, population size and structure are random variables whose mean, variance and in general their distribution can reflect initial conditions after many generations of growth. Implications of our results to experiments and to biotechnology are discussed.

  4. Heart rate variability in healthy population

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    Alamgir, M.; Hussain, M.M.

    2010-01-01

    Background: Heart rate variability has been considered as an indicator of autonomic status. Little work has been done on heart rate variability in normal healthy volunteers. We aimed at evolving the reference values of heart rate variability in our healthy population. Methods: Twenty-four hour holter monitoring of 37 healthy individuals was done using Holter ECG recorder 'Life card CF' from 'Reynolds Medical'. Heart rate variability in both time and frequency domains was analysed with 'Reynolds Medical Pathfinder Digital/700'. Results: The heart rate variability in normal healthy volunteers of our population was found in time domain using standard deviation of R-R intervals (SDNN), standard deviation of average NN intervals (SDANN), and Square root of the mean squared differences of successive NN intervals (RMSSD). Variation in heart rate variability indices was observed between local and foreign volunteers and RMSSD was found significantly increased (p<0.05) in local population. Conclusions: The values of heart rate variability (RMSSD) in healthy Pakistani volunteers were found increased compared to the foreign data reflecting parasympathetic dominance in our population. (author)

  5. Ubiquitous time variability of integrated stellar populations

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    Conroy, Charlie; van Dokkum, Pieter G.; Choi, Jieun

    2015-11-01

    Long-period variable stars arise in the final stages of the asymptotic giant branch phase of stellar evolution. They have periods of up to about 1,000 days and amplitudes that can exceed a factor of three in the I-band flux. These stars pulsate predominantly in their fundamental mode, which is a function of mass and radius, and so the pulsation periods are sensitive to the age of the underlying stellar population. The overall number of long-period variables in a population is directly related to their lifetimes, which is difficult to predict from first principles because of uncertainties associated with stellar mass-loss and convective mixing. The time variability of these stars has not previously been taken into account when modelling the spectral energy distributions of galaxies. Here we construct time-dependent stellar population models that include the effects of long-period variable stars, and report the ubiquitous detection of this expected ‘pixel shimmer’ in the massive metal-rich galaxy M87. The pixel light curves display a variety of behaviours. The observed variation of 0.1 to 1 per cent is very well matched to the predictions of our models. The data provide a strong constraint on the properties of variable stars in an old and metal-rich stellar population, and we infer that the lifetime of long-period variables in M87 is shorter by approximately 30 per cent compared to predictions from the latest stellar evolution models.

  6. Fish population persistence in hydrologically variable landscapes.

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    Bond, Nick R; Balcombe, Stephen R; Crook, David A; Marshall, Jonathan C; Menke, Norbert; Lobegeiger, Jaye S

    2015-06-01

    Forecasting population persistence in environments subjected to periodic disturbances represents a general challenge for ecologists. In arid and semiarid regions, climate change and human water use pose significant threats to the future persistence of aquatic biota whose populations typically depend on permanent refuge waterholes for their viability. As such, habitats are increasingly being lost as a result of decreasing runoff and increasing water extraction. We constructed a spatially explicit population model for golden perch Macquaria ambigua (Richardson), a native freshwater fish in the Murray-Darling Basin in eastern Australia. We then used the model to examine the effects of increased aridity, increased drought frequency, and localized human water extraction on population viability. Consistent with current observations, the model predicted golden perch population persistence under the current climate and levels of water use. Modeled increases in local water extraction greatly increased the risk of population decline, while scenarios of increasing aridity and drought frequency were associated with only minor increases in this risk. We conclude that natural variability in abundances and high turnover rates (extinction/recolonization) of local populations dictate the importance of spatial connectivity and periodic cycles of population growth. Our study also demonstrates an effective way to examine population persistence in intermittent and ephemeral river systems by integrating spatial and temporal dynamics of waterhole persistence with demographic processes (survival, recruitment, and dispersal) within a stochastic modeling framework. The approach can be used to help understand the impacts of natural and anthropogenic drivers, including water resource development, on the viability of biota inhabiting highly dynamic environments.

  7. Spatial and temporal variability in a butterfly population.

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    Thomas, C D

    1991-09-01

    The dynamics of a butterfly (Plebejus argus) population were analysed at two levels, (i) the population as a whole and (ii) sections within the population. Some sections of the population fluctuated out of synchrony with others, such that the variability [SD Log(Density+1)] shown by the population as a whole was less than the variability shown by each part of the population - overall temporal variability was dampened by spatial asynchrony. Since observed population variability depends on the spatial scale that is sampled, comparisons of population variability among taxa should be carried out only with caution. Implications for island biogeography and conservation biology are discussed.

  8. Photometric Variability of the Be Star Population

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    Labadie-Bartz, Jonathan; Pepper, Joshua; McSwain, M. Virginia [Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, PA 18015 (United States); Bjorkman, J. E.; Bjorkman, K. S. [Ritter Observatory, Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft, Toledo, OH 43606-3390 (United States); Lund, Michael B.; Rodriguez, Joseph E.; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Stevens, Daniel J. [Department of Astronomy, The Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); James, David J. [Cerro Tololo Inter-American Observatory, Casilla 603 La Serena (Chile); Kuhn, Rudolf B. [Southern African Large Telescope, P.O. Box 9, Observatory 7935, Cape Town (South Africa); Siverd, Robert J. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States); Beatty, Thomas G. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)

    2017-06-01

    Be stars have generally been characterized by the emission lines in their spectra, and especially the time variability of those spectroscopic features. They are known to also exhibit photometric variability at multiple timescales, but have not been broadly compared and analyzed by that behavior. We have taken advantage of the advent of wide-field, long-baseline, and high-cadence photometric surveys that search for transiting exoplanets to perform a comprehensive analysis of brightness variations among a large number of known Be stars. The photometric data comes from the KELT transit survey, with a typical cadence of 30 minutes, a baseline of up to 10 years, photometric precision of about 1%, and coverage of about 60% of the sky. We analyze KELT light curves of 610 known Be stars in both the northern and southern hemispheres in an effort to study their variability. Consistent with other studies of Be star variability, we find most of the stars to be photometrically variable. We derive lower limits on the fraction of stars in our sample that exhibit features consistent with non-radial pulsations (25%), outbursts (36%), and long-term trends in the circumstellar disk (37%), and show how these are correlated with spectral sub-types. Other types of variability, such as those owing to binarity, are also explored. Simultaneous spectroscopy for some of these systems from the Be Star Spectra database allow us to better understand the physical causes for the observed variability, especially in cases of outbursts and changes in the disk.

  9. Molecular genetic variability, population structure and mating system in tropical forages

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    Melissa Garcia

    2013-09-01

    Full Text Available Microsatellite (SSR markers were developed for the following tropical forage species, using accessions available from the plant genetic resources (PGR collections held by EMBRAPA (Brazilian Agricultural Research Corporation: Brachiaria brizantha, B. humidicola, Panicum maximum, Paspalum spp., Stylosanthes capitata, S. guianensis, S. macrocephala, Calopogonium mucunoides and Centrosema spp. The markers were used to analyze population structure and genetic diversity, evolution and origin of the genetic variability in the center of origin, mating systems and genetic resources in EMBRAPA’s germplasm bank. The results shed light on the amount of genetic variation within and between populations, revealed the need in some cases for further plant collection to adequately represent the species in PGR collections, allowed us to assemble core collections (subsets of the total collections that should contain most of the available diversity and (in the case of the legumes showed the need to avoid unwanted outcrossing when regenerating conserved material. The data will allow plant breeders to better select accessions for hybrid production, discriminate between genotypes and use marker-assisted selection in breeding programs. Our results will also underpin the construction of genetic maps, mapping of genes of agronomic interest and numerous other studies on genetic variability, population structure, gene flow and reproductive systems for the tropical forage species studied in this work.

  10. Linking environmental variability to population and community dynamics: Chapter 7

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    Pantel, Jelena H.; Pendleton, Daniel E.; Walters, Annika W.; Rogers, Lauren A.

    2014-01-01

    Linking population and community responses to environmental variability lies at the heart of ecology, yet methodological approaches vary and existence of broad patterns spanning taxonomic groups remains unclear. We review the characteristics of environmental and biological variability. Classic approaches to link environmental variability to population and community variability are discussed as are the importance of biotic factors such as life history and community interactions. In addition to classic approaches, newer techniques such as information theory and artificial neural networks are reviewed. The establishment and expansion of observing networks will provide new long-term ecological time-series data, and with it, opportunities to incorporate environmental variability into research. This review can help guide future research in the field of ecological and environmental variability.

  11. Stability of termite mound populations in a variable environment ...

    African Journals Online (AJOL)

    Of all the climatic variables in the environment of termites in southern Kenya, only rainfall shows marked seasonality and unpredictability. But despite the great variability in rainfall patterns, the populations of termite mounds of various species in three well-separated study areas remained remarkably constant over a period ...

  12. Using variable combination population analysis for variable selection in multivariate calibration.

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    Yun, Yong-Huan; Wang, Wei-Ting; Deng, Bai-Chuan; Lai, Guang-Bi; Liu, Xin-bo; Ren, Da-Bing; Liang, Yi-Zeng; Fan, Wei; Xu, Qing-Song

    2015-03-03

    Variable (wavelength or feature) selection techniques have become a critical step for the analysis of datasets with high number of variables and relatively few samples. In this study, a novel variable selection strategy, variable combination population analysis (VCPA), was proposed. This strategy consists of two crucial procedures. First, the exponentially decreasing function (EDF), which is the simple and effective principle of 'survival of the fittest' from Darwin's natural evolution theory, is employed to determine the number of variables to keep and continuously shrink the variable space. Second, in each EDF run, binary matrix sampling (BMS) strategy that gives each variable the same chance to be selected and generates different variable combinations, is used to produce a population of subsets to construct a population of sub-models. Then, model population analysis (MPA) is employed to find the variable subsets with the lower root mean squares error of cross validation (RMSECV). The frequency of each variable appearing in the best 10% sub-models is computed. The higher the frequency is, the more important the variable is. The performance of the proposed procedure was investigated using three real NIR datasets. The results indicate that VCPA is a good variable selection strategy when compared with four high performing variable selection methods: genetic algorithm-partial least squares (GA-PLS), Monte Carlo uninformative variable elimination by PLS (MC-UVE-PLS), competitive adaptive reweighted sampling (CARS) and iteratively retains informative variables (IRIV). The MATLAB source code of VCPA is available for academic research on the website: http://www.mathworks.com/matlabcentral/fileexchange/authors/498750. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Isoenzymatic variability in tropical maize populations under reciprocal recurrent selection

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    Pinto Luciana Rossini

    2003-01-01

    Full Text Available Maize (Zea mays L. is one of the crops in which the genetic variability has been extensively studied at isoenzymatic loci. The genetic variability of the maize populations BR-105 and BR-106, and the synthetics IG-3 and IG-4, obtained after one cycle of a high-intensity reciprocal recurrent selection (RRS, was investigated at seven isoenzymatic loci. A total of twenty alleles were identified, and most of the private alleles were found in the BR-106 population. One cycle of reciprocal recurrent selection (RRS caused reductions of 12% in the number of alleles in both populations. Changes in allele frequencies were also observed between populations and synthetics, mainly for the Est 2 locus. Populations presented similar values for the number of alleles per locus, percentage of polymorphic loci, and observed and expected heterozygosities. A decrease of the genetic variation values was observed for the synthetics as a consequence of genetic drift effects and reduction of the effective population sizes. The distribution of the genetic diversity within and between populations revealed that most of the diversity was maintained within them, i.e. BR-105 x BR-106 (G ST = 3.5% and IG-3 x IG-4 (G ST = 4.0%. The genetic distances between populations and synthetics increased approximately 21%. An increase in the genetic divergence between the populations occurred without limiting new selection procedures.

  14. Variable mutation rates as an adaptive strategy in replicator populations.

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    Michael Stich

    2010-06-01

    Full Text Available For evolving populations of replicators, there is much evidence that the effect of mutations on fitness depends on the degree of adaptation to the selective pressures at play. In optimized populations, most mutations have deleterious effects, such that low mutation rates are favoured. In contrast to this, in populations thriving in changing environments a larger fraction of mutations have beneficial effects, providing the diversity necessary to adapt to new conditions. What is more, non-adapted populations occasionally benefit from an increase in the mutation rate. Therefore, there is no optimal universal value of the mutation rate and species attempt to adjust it to their momentary adaptive needs. In this work we have used stationary populations of RNA molecules evolving in silico to investigate the relationship between the degree of adaptation of an optimized population and the value of the mutation rate promoting maximal adaptation in a short time to a new selective pressure. Our results show that this value can significantly differ from the optimal value at mutation-selection equilibrium, being strongly influenced by the structure of the population when the adaptive process begins. In the short-term, highly optimized populations containing little variability respond better to environmental changes upon an increase of the mutation rate, whereas populations with a lower degree of optimization but higher variability benefit from reducing the mutation rate to adapt rapidly. These findings show a good agreement with the behaviour exhibited by actual organisms that replicate their genomes under broadly different mutation rates.

  15. MHC variability in an isolated wolf population in Italy.

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    Galaverni, Marco; Caniglia, Romolo; Fabbri, Elena; Lapalombella, Silvana; Randi, Ettore

    2013-01-01

    Small, isolated populations may experience increased extinction risk due to reduced genetic variability at important functional genes, thus decreasing the population's adaptive potential. The major histocompatibility complex (MHC), a key immunological gene cluster, usually shows high variability maintained by positive or balancing selection in response to challenges by pathogens. Here we investigated for the first time, the variability of 3 MHC class II genes (DRB1, DQA1, and DQB1) in 94 samples collected from Italian wolves. The Italian wolf population has been long isolated south of the Alps and is presently recovering from a recent bottleneck that decreased the population to less than 100 individuals. Despite the bottleneck, Italian wolves show remarkable MHC variability with 6-9 alleles per locus, including 2 recently described alleles at DRB1. MHC sequences show signatures of historical selective pressures (high d N/d S ratio, ω > 1.74) but no evidence of ongoing selection. Variation at the MHC genes and 12 background microsatellite loci were not apparently affected by the recent bottleneck. Although MHC alleles of domestic dog origin were detected in 8 genetically admixed individuals, these alleles were rare or absent in nonadmixed wolves. Thus, despite known hybridization events between domestic dogs and Italian wolves, the Italian wolf population does not appear affected by deep introgression of domestic dog MHC alleles.

  16. The physiological homeostasis of human populations in variable environments.

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    Goudkova, Lioudmila K

    2005-07-01

    A close evolutionary relationship of physiology and ecology of organisms determines the dynamic dependence of the population physiological status in man on ecological factors. For the explanation of the stability and variability of population physiological status the concept of physiological homeostasis was applied. The investigation of physiological status in several populations of Middle Asia, Kazakhstan, North-East Asia and Khakassia has shown that reversible changes in the environment may temporarily destabilize the equilibrium in the "population-environment" system and prolonged stresses may cause a state of disadaptation. For estimation of population physiological homeostasis dependent on the environment, generalized dispersion, correlation and factor analyses are very informative. They not only mark the violation of population homeostasis, but also indicate changes in the environment.

  17. Cytogenetic variability in pinus sylvestris L. populations experiencing anthropogenic influence

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    Oudalova, A.; Geras'kin, S.; Vasiliev, D.; Dikarev, V.

    2004-01-01

    Techno-genic pollution has become one of the most significant ecological factors determining biosphere existence and development. An analysis of genetic consequences of the radiation accidents in the South Urals and Chernobyl has shown that mutation and recombination processes are considerably accelerated in plant and animal's populations experiencing techno-genic influence. This implies that there are complicated adaptation processes leading to changes in genetic structure of populations and increasing genetic load. Pinus sylvestris L. populations growing at the territory of the 'radon' Leningrad regional radioactive waste reprocessing enterprise and Sosnovy Bor town were monitored 6 years (1997-2002) by a set of cyto-genetical and morphological tests. Cytogenetic damage levels within intercalary meristem of needle as well as in root meristem of seedlings were found to significantly exceed corresponding controls. A higher radioresistance of the Scots pine seeds analyzed was demonstrated with an acute γ-radiation that also revealed a selection process directed at an enhancement of repair efficiency and resulting in a shift of mean values of radioresistance in populations towards higher values. An enlargement of variance of studied cytogenetic parameters was found in the populations experiencing techno-genic influence. This indicates, with an account of phenomenon of the enhanced radioresistance, that there are processes of cyto-genetical adaptation in the investigated regions. An analysis of the structure of ecological-genetical variability was carried out with the purpose of separating two components in the inter-population variability - the first is engaged to the genetically determined variability of biological characteristics intrinsic for this species, and the second is responsible for the variability originating from anthropogenic contamination of the natural habitat. Changes of these two types of variability were studied in dependence on time and techno

  18. Cytogenetic variability in pinus sylvestris L. populations experiencing anthropogenic influence

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    Oudalova, A.; Geras' kin, S.; Vasiliev, D.; Dikarev, V. [Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation)

    2004-07-01

    Techno-genic pollution has become one of the most significant ecological factors determining biosphere existence and development. An analysis of genetic consequences of the radiation accidents in the South Urals and Chernobyl has shown that mutation and recombination processes are considerably accelerated in plant and animal's populations experiencing techno-genic influence. This implies that there are complicated adaptation processes leading to changes in genetic structure of populations and increasing genetic load. Pinus sylvestris L. populations growing at the territory of the 'radon' Leningrad regional radioactive waste reprocessing enterprise and Sosnovy Bor town were monitored 6 years (1997-2002) by a set of cyto-genetical and morphological tests. Cytogenetic damage levels within intercalary meristem of needle as well as in root meristem of seedlings were found to significantly exceed corresponding controls. A higher radioresistance of the Scots pine seeds analyzed was demonstrated with an acute {gamma}-radiation that also revealed a selection process directed at an enhancement of repair efficiency and resulting in a shift of mean values of radioresistance in populations towards higher values. An enlargement of variance of studied cytogenetic parameters was found in the populations experiencing techno-genic influence. This indicates, with an account of phenomenon of the enhanced radioresistance, that there are processes of cyto-genetical adaptation in the investigated regions. An analysis of the structure of ecological-genetical variability was carried out with the purpose of separating two components in the inter-population variability - the first is engaged to the genetically determined variability of biological characteristics intrinsic for this species, and the second is responsible for the variability originating from anthropogenic contamination of the natural habitat. Changes of these two types of variability were studied in dependence on

  19. Estimation of temporal variability of survival in animal populations

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    Gould, W.R.; Nichols, J.D.

    1998-01-01

    Temporal variation of demographic characteristics for animal populations is of interest to both ecologists and biological modelers. The standard deviation of a series of estimated parameter values (e.g., estimated population size) or some function thereof (e.g, log of the estimated parameters) is commonly used as a measure of temporal variability. These measures of temporal variation overestimate the true temporal variation by not accounting for sampling variability inherent to the estimation of unknown population parameters. Using a variance-components approach to partitioning the total variability of an estimated parameter, we demonstrate the ease with which sampling variation can be removed from the observed total variation of parameter estimates. Estimates of temporal variability of survival are given after removal of sampling variation for three bird species: the federally listed Roseate Tern (Sterna dougallii), Black-capped Chickadees (Parus atricapillus), and Mallard ducks (Anas platyrhynchos). Sampling variation accounted for the majority of the total variation in the survival estimates for nearly all of the populations studied. Substantial differences in observed significance levels were observed when testing for demographic differences in temporal variation using temporal variance estimates adjusted and unadjusted for sampling variance.

  20. Seasonal Variability of Phytoplankton Population in the Brahmani ...

    African Journals Online (AJOL)

    Seasonal Variability of Phytoplankton Population in the Brahmani Estuary of Orissa, India. S Palleyi, RN Kar, CR Panda. Abstract. The dynamic relationship of water physico-chemical characteristics with phytoplankton has long been of great interest in both experimental ecology and environmental management. This study ...

  1. Population variability of Bemisia tabaci (Genn.) in different hosts.

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    do Valle, G E; Lourenção, A L; Zucchi, M I; Pinheiro, J B; de Abreu, A G

    2013-10-17

    The silverleaf whitefly, Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae), is a cryptic species complex that contains some of the most damaging pests in tropical and subtropical regions. Recent studies have indicated that this complex is composed of at least 24 distinct and morphologically indistinguishable species that mainly differ in their ability to transmit phytoviruses, adapt to hosts, and induce physiological changes in certain hosts. The importance of this species has been increasing worldwide, because it serves as a phytovirus vector, particularly for geminiviruses, in economically important crops. Here, we aimed to examine the population variability of B. tabaci populations inhabiting 6 agricultural crops grown in 5 regions of Brazil and 1 region of the USA; BRrep [Brasília (DF, Brazil) - cabbage], ILsoj [Urbana (IL/USA) - soybean], BJabo [Bom Jesus da Lapa (BA, Brazil) - pumpkin], CPsoj [Campinas (SP, Brazil) - soybean], UBman [Ubatuba (SP, Brazil) - cassava], and PEmel [Petrolina (PE, Brazil) - melon]. Thirteen polymorphic loci with 50 alleles were observed, with an average of 2.37 (range: 2.00-2.91) alleles per population. The UBman and PEmel B. tabaci populations were the most differentiated, which was probably caused by insect adaptation to the host plant and the use of insecticides. A 33.87% inter-population variation was observed, indicating that microsatellites may be used to measure differentiation among these B. tabaci populations. Based on the comparison of microsatellites in the current study, only the Middle East-Asia Minor 1 population of B. tabaci was found in the six populations.

  2. Influence of internal variability on population exposure to hydroclimatic changes

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    Mankin, Justin S.; Viviroli, Daniel; Mekonnen, Mesfin M.; Hoekstra, Arjen Y.; Horton, Radley M.; E Smerdon, Jason; Diffenbaugh, Noah S.

    2017-04-01

    Future freshwater supply, human water demand, and people’s exposure to water stress are subject to multiple sources of uncertainty, including unknown future pathways of fossil fuel and water consumption, and ‘irreducible’ uncertainty arising from internal climate system variability. Such internal variability can conceal forced hydroclimatic changes on multi-decadal timescales and near-continental spatial-scales. Using three projections of population growth, a large ensemble from a single Earth system model, and assuming stationary per capita water consumption, we quantify the likelihoods of future population exposure to increased hydroclimatic deficits, which we define as the average duration and magnitude by which evapotranspiration exceeds precipitation in a basin. We calculate that by 2060, ∽31%-35% of the global population will be exposed to >50% probability of hydroclimatic deficit increases that exceed existing hydrological storage, with up to 9% of people exposed to >90% probability. However, internal variability, which is an irreducible uncertainty in climate model predictions that is under-sampled in water resource projections, creates substantial uncertainty in predicted exposure: ∽86%-91% of people will reside where irreducible uncertainty spans the potential for both increases and decreases in sub-annual water deficits. In one population scenario, changes in exposure to large hydroclimate deficits vary from -3% to +6% of global population, a range arising entirely from internal variability. The uncertainty in risk arising from irreducible uncertainty in the precise pattern of hydroclimatic change, which is typically conflated with other uncertainties in projections, is critical for climate risk management that seeks to optimize adaptations that are robust to the full set of potential real-world outcomes.

  3. Population growth is a variable open to change

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    Potts, M.

    2016-12-01

    The absolute number of people and the rate of population growth have an impact on climate mitigation, adaptation and possible conflict. Half the pregnancies in the US are unintended. Robust quantitative evidence from California demonstrates that improving access to family planning is the single most cost-effective way of mitigating our carbon footprint. Globally, there are 80 million unintended pregnancies annually. Many non-evidence barriers deprive women of the information and means required to separate sex from childbearing. Between 1960 and 1990, meeting the need for family planning led to a rapid fall in family size in much of Asia. Since 1990, funding for family planning has collapsed and fertility decline has stalled. The UN projects that by 2100 global population will increase by 3.8 billion (equal to world population in 1975). 80% of this growth will be in Africa. Studies project that climate change will undermine crop yields in parts of Africa, especially the Sahel. A high ratio of young males to the rest of the population is a risk factor in conflict. Today, only 1% of overseas assistance is allocated to family planning. Based on analysis of the past, doubling that investment would accelerate fertility decline, facilitating climate mitigation and adaptation, and possibly reducing conflict. Population and family planning were pushed off the international agenda by unacceptably and tragic episodes of coercion in China and India. However, there is compelling data that when voluntary family planning is widely available then family size can fall rapidly, as occurred in the Islamic Republic of Iran, where fertility fell more rapidly than in any other country in history. Family planning is listening to what women want not telling people want to do. Population growth is a variable open to change in a human rights framework. Population and family planning are variables relevant to the scientific agenda of the AGU.

  4. CYP2D6 variability in populations from Venezuela.

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    Moreno, Nancy; Flores-Angulo, Carlos; Villegas, Cecilia; Mora, Yuselin

    2016-12-01

    CYP2D6 is an important cytochrome P450 enzyme that plays an important role in the metabolism of about 25% of currently prescribed drugs. The presence of polymorphisms in the CYP2D6 gene may modulate enzyme level and activity, thereby affecting individual responses to pharmacological treatments. The most prevalent diseases in the admixed population from Venezuela are cardiovascular and cancer, whereas viral, bacterial and parasitic diseases, particularly malaria, are prevalent in Amerindian populations; in the treatment of these diseases, several drugs that are metabolized by CYP2D6 are used. In this work, we reviewed the data on CYP2D6 variability and predicted metabolizer phenotypes, in healthy volunteers of two admixed and five Amerindian populations from Venezuela. The Venezuelan population is very heterogeneous as a result of the genetic admixture of three major ethnical components: Europeans, Africans and Amerindians. There are noticeable inter-regional and inter-population differences in the process of mixing of this population. Hitherto, there are few published studies in Venezuela on CYP2D6; therefore, it is necessary to increase research in this regard, in particular to develop studies with a larger sample size. There is a considerable amount of work remaining before CYP2D6 is integrated into clinical practice in Venezuela.

  5. Variability of Caltha palustris L. populations in garden culture

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    Krystyna Falińska

    2014-01-01

    Full Text Available On the basis of studies performed in the experimental garden the character of the variability of Caltha palustris L. populations is described. Individuals were bred under uniform conditions from diaspores of meadow, springwood, flood-plain forest and alder forest populations. The results obtained allow to evaluate the hypothesis concerning the ecological preference of cytotypes (S m i t 1967, 1968 and the somewhat different ecological requirements of two subspecies: C. palustris ssp. palustris and C. palustris ssp. cornuta. It was found that each population includes individuals with different cytotypes. The situation is similar as far as subspecies are concerned, distinguished on the basis of fruit morphology (Fig. 1. It should be stressed, however, that, investigations of many years duration raised serious doubts as to the diagnostic value of fruit morphology (Figs. 2, 3. On the basis of the preserved differences between the populations in shoot habitus, reproduction and phenology in garden culture, a springwood and an alder forest ecotype were distinguished. Meadow and flood-plain populations exhibited a transitional character with certain similarities both to the alder forest and to the springwood populations.

  6. Population structure of two black Venezuelan populations studied through their mating structure and other related variables.

    Science.gov (United States)

    Castro de Guerra, D; Arvelo, H; Pinto-Cisternas, J

    1999-01-01

    In order to obtain information about the population structure of two black Venezuelan populations with historical differences both in their origins and development, a variety of variables were utilized, especially on marital structure, including: frequency of surnames, isonymy, population genealogical consanguinity, multiple unions, and marital distances, all of which provided information and isolation, migration, endogamy, consanguinity, and patri-matrifocality. Results showed differences in the extent of isolation and endogamy, as well as differences in population structure, which can be directly related with historical conditions of each population. Results agree with those previously obtained with traditional genetic polymorphisms and with the historical information available. Thus, the usefulness of surnames for inferring about population structure is supported, as well as the usefulness of historical information for explaining genetic diversity.

  7. Genomic variability in Mexican chicken population using Copy Number Variation

    Directory of Open Access Journals (Sweden)

    Erica Gorla

    2017-05-01

    Full Text Available Copy number variants (CNVs are polymorphisms which influence phenotypic variation and are an important source of genetic variability [1]. In Mexico the backyard poultry population is a unique widespread Creole chicken (Gallus gallus domesticus population, an undefined cross among different breeds brought to Mexico from Europe and under natural selection for almost 500 years [2-3]. The aim of this study was to investigate genomic variation in the Mexican chicken population using CNVs. A total of 256 DNA samples genotyped with Axiom® Genome-Wide Chicken Genotyping Array were used in the analyses. The individual CNV calling, based on log-R ratio and B-allele frequency values, was performed using the Hidden Markov Model (HMM of PennCNV software on the autosomes [4-5]. CNVs were summarized to CNV regions (CNVRs at a population level (i.e. overlapping CNVs, using BEDTools. The HMM detected a total of 1924 CNVs in the genome of 256 samples resulting, at population level, in 1216 CNV regions, of which 959 gains, 226 losses and 31 complex CNVRs (i.e. containing both losses and gains, covering a total of 47 Mb of sequence length corresponding to 5,12 % of the chicken galGal4 assembly autosome. A comparison among this study and 7 previous reports about CNVs in chicken was performed, finding that the 1,216 CNVRs detected in this study overlap with 617 regions (51% mapped by others studies.   This study allowed a deep insight into the structural variation in the genome of unselected Mexican chicken population, which up to now has not been never genetically characterized with SNP markers. Based on a cluster analysis (pvclust – R package on CNV markers the population, even if presenting extreme morphological variation, does not resulted divided in differentiated genetic subpopulations. Finally this study provides a CNV map based on the 600K SNP chip array jointly with a genome-wide gene copy number estimates in Mexican chicken population.

  8. Physical Characteristics Underpinning Repetitive Lunging in Fencing.

    Science.gov (United States)

    Turner, Anthony N; Marshall, Geoff; Phillips, James; Noto, Angelo; Buttigieg, Conor; Chavda, Shyam; Downing, William; Atlay, Nathan; Dimitriou, Lygeri; Kilduff, Laim

    2016-11-01

    Turner, AN, Marshall, G, Phillips, J, Noto, A, Buttigieg, C, Chavda, S, Downing, W, Atlay, N, Dimitriou, L, and Kilduff, L. Physical characteristics underpinning repetitive lunging in fencing. J Strength Cond Res 30(11): 3134-3139, 2016-Given the repetitive demand to execute lunging and changes in direction within fencing, the ability to sustain these at maximal capacity is fundamental to performance. The aim of this study was threefold. First, to provide normative values for this variable referred to as repeat lunge ability (RLA) and second to identify the physical characteristics that underpin it. Third, was to establish if a cause and effect relationship existed by training the associated characteristics. Assessment of lower-body power, reactive strength, speed, change of direction speed (CODS), and a sport-specific RLA were conducted on senior and junior elite male fencers (n = 36). Fencers were on average (±SD) 18.9 ± 3.2 years of age, 174.35 ± 10.42 cm tall, 70.67 ± 7.35 kg in mass, and 8.5 ± 4.2 years fencing experience. The RLA test had average work times of 16.03 ± 1.40 seconds and demonstrated "large" to "very large" associations with all tested variables, but in particular CODS (r = 0.70) and standing broad jump (SBJ; r = -0.68). Through linear regression analysis, these also provided a 2-predictor model accounting for 61% of the common variance associated with RLA. A cause and effect relationship with SBJ and CODS was confirmed by the training group, where RLA performance in these fencers improved from 15.80 ± 1.07 to 14.90 ± 0.86 seconds, with the magnitude of change reported as "moderate" (effect size (ES) = 0.93). Concurrent improvements were also noted in both SBJ (216.86 ± 17.15 vs. 221.71 ± 17.59 cm) and CODS (4.44 ± 0.29 vs. 4.31 ± 0.09 seconds) and while differences were only significant in SBJ, magnitudes of change were classed as "small" (ES = 0.28) and "moderate" (ES = 0.61), respectively. In conclusion, to improve RLA strength

  9. Environmental variability and population dynamics: Do European and North American ducks play by the same rules?

    Science.gov (United States)

    Pöysä, Hannu; Rintala, Jukka; Johnson, Douglas H.; Kauppinen, Jukka; Lammi, Esa; Nudds, Thomas D.; Väänänen, Veli-Matti

    2016-01-01

    Density dependence, population regulation, and variability in population size are fundamental population processes, the manifestation and interrelationships of which are affected by environmental variability. However, there are surprisingly few empirical studies that distinguish the effect of environmental variability from the effects of population processes. We took advantage of a unique system, in which populations of the same duck species or close ecological counterparts live in highly variable (north American prairies) and in stable (north European lakes) environments, to distinguish the relative contributions of environmental variability (measured as between-year fluctuations in wetland numbers) and intraspecific interactions (density dependence) in driving population dynamics. We tested whether populations living in stable environments (in northern Europe) were more strongly governed by density dependence than populations living in variable environments (in North America). We also addressed whether relative population dynamical responses to environmental variability versus density corresponded to differences in life history strategies between dabbling (relatively “fast species” and governed by environmental variability) and diving (relatively “slow species” and governed by density) ducks. As expected, the variance component of population fluctuations caused by changes in breeding environments was greater in North America than in Europe. Contrary to expectations, however, populations in more stable environments were not less variable nor clearly more strongly density dependent than populations in highly variable environments. Also, contrary to expectations, populations of diving ducks were neither more stable nor stronger density dependent than populations of dabbling ducks, and the effect of environmental variability on population dynamics was greater in diving than in dabbling ducks. In general, irrespective of continent and species life history

  10. Influence of internal variability on population exposure to hydroclimatic changes

    NARCIS (Netherlands)

    Mankin, Justin S.; Viviroli, Daniel; Mekonnen, Mesfin; Hoekstra, Arjen Ysbert; Horton, Radley M.; Smerdon, Jason E.; Diggenbaugh, Noah S.

    2017-01-01

    Future freshwater supply, human water demand, and people's exposure to water stress are subject to multiple sources of uncertainty, including unknown future pathways of fossil fuel and water consumption, and 'irreducible' uncertainty arising from internal climate system variability. Such internal

  11. Wireless-accessible sensor populations for monitoring biological variables

    NARCIS (Netherlands)

    Mazzu, Marco; Scalvini, Simonetta; Giordano, A.; Frumento, E.; Wells, Hannah; Lokhorst, C.; Glisenti, Fulvio

    2008-01-01

    The current health-care infrastructure is generally considered to be inadequate to meet the needs of an increasingly older population. We have investigated the feasibility of a passive in-home monitoring system based on wireless accessible sensor populations (WASP). In an EU-funded project we have

  12. Investigating Factorial Invariance of Latent Variables Across Populations When Manifest Variables Are Missing Completely.

    Science.gov (United States)

    Widaman, Keith F; Grimm, Kevin J; Early, Dawnté R; Robins, Richard W; Conger, Rand D

    2013-07-01

    Difficulties arise in multiple-group evaluations of factorial invariance if particular manifest variables are missing completely in certain groups. Ad hoc analytic alternatives can be used in such situations (e.g., deleting manifest variables), but some common approaches, such as multiple imputation, are not viable. At least 3 solutions to this problem are viable: analyzing differing sets of variables across groups, using pattern mixture approaches, and a new method using random number generation. The latter solution, proposed in this article, is to generate pseudo-random normal deviates for all observations for manifest variables that are missing completely in a given sample and then to specify multiple-group models in a way that respects the random nature of these values. An empirical example is presented in detail comparing the 3 approaches. The proposed solution can enable quantitative comparisons at the latent variable level between groups using programs that require the same number of manifest variables in each group.

  13. Genetic variability of camel ( Camelus dromedarius ) populations in ...

    African Journals Online (AJOL)

    Camelus dromedarius) are poorly documented in Saudi Arabia. The present study was conducted to address some of these genetics using four Saudi Arabian camel populations namely; Magaheem (MG), Maghateer (MJ), Sofr (SO) and Shual (SH) ...

  14. Some Social Variables In Domestic Violence In A Nigerian Population

    African Journals Online (AJOL)

    Background:Domestic violence is any intentional abuse of a family member mostly women by a partner which causes pain or injury. It is a growing phenomenon and is affected by several social variables. In pregnancy, domestic violence causes adverse pregnancy outcomes and other reproductive health consequences to ...

  15. Estimates of genetic variability in mutated populations and the scope ...

    African Journals Online (AJOL)

    Grain legumes, commonly known as pulses, occupy a pivotal position in meeting the protein needs of people in developing countries like India. Mungbean (Vigna radiata (L.) Wilczek). (Papilionaceae) is an important, self-fertile pulse crop grown all over South East Asia. Due to lack of sufficient natural variability for yield and ...

  16. Effects of climate change and variability on population dynamics in a long-lived shorebird

    NARCIS (Netherlands)

    van de Pol, Martijn; Vindenes, Yngvild; Saether, Bernt-Erik; Engen, Steinar; Ens, Bruno J.; Oosterbeek, Kees; Tinbergen, Joost M.

    Climate change affects both the mean and variability of climatic variables, but their relative impact on the dynamics of populations is still largely unexplored. Based on a long-term study of the demography of a declining Eurasian Oystercatcher (Haematopus ostralegus) population, we quantify the

  17. Genetic variability and structure of an isolated population of ...

    Indian Academy of Sciences (India)

    ... 0.621); we also found a small population size (Ne = 8.8), the presence of historical (M = 0.486) and recent bottlenecks under IAM and TPM models, with a low, but significantcoefficient of inbreeding (FIS = −0.451). This information will help us to raise conservation strategies of this microendemic mole salamander species.

  18. Genetic variability in the population of the endemic bee Anthophora ...

    African Journals Online (AJOL)

    The genetic diversity and spatial genetic population structure of the solitary bee Anthophora pauperata Walker 1871, a species endemic to St Katherine Protectorate, were studied by RAPD markers in seven wadis in the St Katherine Protectorate, South Sinai, Egypt. High levels of genetic diversity were found, mostly within ...

  19. Galactic population of cataclysmic variables in soft X-rays

    Science.gov (United States)

    Kushwaha, Ankur; Girish, V.

    We study the statistical properties and estimate the spatial density (ρ) as well as the luminosity function (φ) for magnetic Cataclysmic Variables (mCVs) detected in solar vicinity by XMM - Newton Observatory in 2-10 keV. A total no. of 98 CVs (26 IPs, 47 Polars and 25 unclassified mCVs) have been selected for the task. The preliminary results of the study are presented here.

  20. Bayesian Hierarchical Structure for Quantifying Population Variability to Inform Probabilistic Health Risk Assessments.

    Science.gov (United States)

    Shao, Kan; Allen, Bruce C; Wheeler, Matthew W

    2017-10-01

    Human variability is a very important factor considered in human health risk assessment for protecting sensitive populations from chemical exposure. Traditionally, to account for this variability, an interhuman uncertainty factor is applied to lower the exposure limit. However, using a fixed uncertainty factor rather than probabilistically accounting for human variability can hardly support probabilistic risk assessment advocated by a number of researchers; new methods are needed to probabilistically quantify human population variability. We propose a Bayesian hierarchical model to quantify variability among different populations. This approach jointly characterizes the distribution of risk at background exposure and the sensitivity of response to exposure, which are commonly represented by model parameters. We demonstrate, through both an application to real data and a simulation study, that using the proposed hierarchical structure adequately characterizes variability across different populations. © 2016 Society for Risk Analysis.

  1. GENOMIC VARIABILITY AMONG CATTLE POPULATIONS BASED ON RUNS OF HOMOZYGOSITY

    Directory of Open Access Journals (Sweden)

    Veronika Šidlová

    2015-09-01

    Full Text Available In this work, the distribution of different lengths ROH (runs of homozygosity in six cattle breeds was described. A total of 122 animals from six cattle breeds (Holstein, Simmental, Austrian Pinzgau, Ayrshire, MRI-Meuse Rhine Issel and Slovak Pinzgau were analysed. The ROH approach was used to distinguish Slovak Pinzgau population from other investigated breeds as well as to differentiate between ancient and recent inbreeding. The average number of ROH per animal ranged from 17.06 in Holstein to 159.22 in Ayrshire. The highest number of short ROH (ancient inbreeding was found in Simmental, followed by Ayrshire. The Ayrshire and MRI had a higher proportion of longer ROH distributed across the whole genome, revealing recent inbreeding. ROH were identified and used to estimate molecular inbreeding coefficients (FROH. The highest level of inbreeding from the investigated breeds was found out in Ayrshire with the same tendency for all length categories compared to Slovak Pinzgau with higher ancient inbreeding. Ancient inbreeding was only observed in Holstein population. A similar trend is becoming apparent even for Slovak Pinzgau, showing the second smallest recent inbreeding. Therefore, it is necessary to preserve the given population in the original phenotype and prevent further increase of inbreeding especially in endangered breeds.

  2. The Influence of Individual Variability on Zooplankton Population Dynamics under Different Environmental Conditions

    Science.gov (United States)

    Bi, R.; Liu, H.

    2016-02-01

    Understanding how biological components respond to environmental changes could be insightful to predict ecosystem trajectories under different climate scenarios. Zooplankton are key components of marine ecosystems and changes in their dynamics could have major impact on ecosystem structure. We developed an individual-based model of a common coastal calanoid copepod Acartia tonsa to examine how environmental factors affect zooplankton population dynamics and explore the role of individual variability in sustaining population under various environmental conditions consisting of temperature, food concentration and salinity. Total abundance, egg production and proportion of survival were used to measure population success. Results suggested population benefits from high level of individual variability under extreme environmental conditions including unfavorable temperature, salinity, as well as low food concentration, and selection on fast-growers becomes stronger with increasing individual variability and increasing environmental stress. Multiple regression analysis showed that temperature, food concentration, salinity and individual variability have significant effects on survival of A. tonsa population. These results suggest that environmental factors have great influence on zooplankton population, and individual variability has important implications for population survivability under unfavorable conditions. Given that marine ecosystems are at risk from drastic environmental changes, understanding how individual variability sustains populations could increase our capability to predict population dynamics in a changing environment.

  3. [Demographic variables, inevitable passage. Irrigated areas and health of populations].

    Science.gov (United States)

    Ouedraogo, D

    1992-06-01

    The Kou Valley rice production area is the largest irrigated expanse in use by peasants in Burkina Faso. 1260 hectares of rice paddy provide two harvests each year for one thousand families, who are mostly in-migrants. The Kou Valley rice paddy was brought into production between 1970 and 1974 to reduce crowding in the overpopulated Mossi plateau, control emigration, increase national rice production, and improve living conditions. A research project in the area is intended to clarify relations between development policies and demographic trends, health conditions, and economic and social welfare of the population. A study compared the rice growing families with 1255 non-rice growing natives of the area and 4763 non-rice growing spontaneous in-migrants. The rice growers enjoyed an impressive increase in incomes, but their infant mortality rates did not decline as greatly as expected and were slightly higher than those of the spontaneous in-migrants. Contaminated water, malaria, schistosomiasis, and the lack of health infrastructure and education were probably factors in the high infant mortality. The incidence of child malnutrition was also greater among the rice growers than among the spontaneous migrants. Women in rice growing families work in the paddies all year. They no longer have access to their own lands and they have less time for child care. The improved economic conditions of the rice growers have not been accompanied by improved living conditions for their families. Women of rice growing families have an average of 6.8 children at age 50, compared to 6.1 among spontaneous in-migrants and 3.1 in the native population. Average household size fluctuated among the rice growers as families sought to add workers to maximize production and later to shed members in response to population pressure and reduced per capita income. The project experience suggests that greater thought should be given to the predictable demographic evolution of households and to the

  4. Variability in winter climate and winter extremes reduces population growth of an alpine butterfly.

    Science.gov (United States)

    Roland, Jens; Matter, Stephen F

    2013-01-01

    We examined the long-term, 15-year pattern of population change in a network of 21 Rocky Mountain populations of Parnassius smintheus butterflies in response to climatic variation. We found that winter values of the broadscale climate variable, the Pacific Decadal Oscillation (PDO) index, were a strong predictor of annual population growth, much more so than were endogenous biotic factors related to population density. The relationship between PDO and population growth was nonlinear. Populations declined in years with extreme winter PDO values, when there were either extremely warm or extremely cold sea surface temperatures in the eastern Pacific relative to that in the western Pacific. Results suggest that more variable winters, and more frequent extremely cold or warm winters, will result in more frequent decline of these populations, a pattern exacerbated by the trend for increasingly variable winters seen over the past century.

  5. Bayesian Population Physiologically-Based Pharmacokinetic (PBPK Approach for a Physiologically Realistic Characterization of Interindividual Variability in Clinically Relevant Populations.

    Directory of Open Access Journals (Sweden)

    Markus Krauss

    Full Text Available Interindividual variability in anatomical and physiological properties results in significant differences in drug pharmacokinetics. The consideration of such pharmacokinetic variability supports optimal drug efficacy and safety for each single individual, e.g. by identification of individual-specific dosings. One clear objective in clinical drug development is therefore a thorough characterization of the physiological sources of interindividual variability. In this work, we present a Bayesian population physiologically-based pharmacokinetic (PBPK approach for the mechanistically and physiologically realistic identification of interindividual variability. The consideration of a generic and highly detailed mechanistic PBPK model structure enables the integration of large amounts of prior physiological knowledge, which is then updated with new experimental data in a Bayesian framework. A covariate model integrates known relationships of physiological parameters to age, gender and body height. We further provide a framework for estimation of the a posteriori parameter dependency structure at the population level. The approach is demonstrated considering a cohort of healthy individuals and theophylline as an application example. The variability and co-variability of physiological parameters are specified within the population; respectively. Significant correlations are identified between population parameters and are applied for individual- and population-specific visual predictive checks of the pharmacokinetic behavior, which leads to improved results compared to present population approaches. In the future, the integration of a generic PBPK model into an hierarchical approach allows for extrapolations to other populations or drugs, while the Bayesian paradigm allows for an iterative application of the approach and thereby a continuous updating of physiological knowledge with new data. This will facilitate decision making e.g. from preclinical to

  6. An equivalence theorem concerning population growth in a variable environment

    Directory of Open Access Journals (Sweden)

    Ray Redheffer

    2003-01-01

    Full Text Available We give conditions under which two solutions x and y of the Kolmogorov equation x˙=xf(t,x satisfy limy(t/x(t=1 as t→∞. This conclusion is important for two reasons: it shows that the long-time behavior of the population is independent of the initial condition and it applies to ecological systems in which the coefficients are time dependent. Our first application is to an equation of Weissing and Huisman for growth and competition in a light gradient. Our second application is to a nonautonomous generalization of the Turner-Bradley-Kirk-Pruitt equation, which even before generalization, includes several problems of ecological interest.

  7. The variable star population in the globular cluster NGC 6934

    Science.gov (United States)

    Yepez, M. A.; Arellano Ferro, A.; Muneer, S.; Giridhar, Sunetra

    2018-04-01

    We report an analysis of new V and I CCD time-series photometry of the globular cluster NGC 6934. Through the Fourier decomposition of the RR Lyrae light curves the mean values of [Fe/H] and the distance of the cluster were estimated; we found: [Fe/H]UVES = - 1.48 ± 0.14 and d = 16.03 ± 0.42 kpc, and [Fe/H]UVES = - 1.43 ± 0.11 and d = 15.91 ± 0.39 kpc, from the calibrations of RRab and RRc stars respectively. Independent distance estimations from SX Phe and SR stars are also discussed. Individual absolute magnitudes, radii and masses are also reported for RR Lyrae stars. We found 12 new variables: 4 RRab, 3 SX Phe, 2 W Virginis (CW) and 3 semi-regular (SR). The inter-mode or "either-or" region in the instability strip is shared by the RRab and RRc stars. This characteristic, observed only in some OoI clusters and never seen in an OoII, is discussed in terms of mass distribution in the ZAHB.

  8. Five decades on: Use of historical weaning size data reveals that a decrease in maternal foraging success underpins the long-term decline in population of southern elephant seals (Mirounga leonina).

    Science.gov (United States)

    Clausius, Ella; McMahon, Clive R; Hindell, Mark A

    2017-01-01

    The population of Southern elephant seals (Mirounga leonina) at Macquarie Island has declined since the 1960s, and is thought to be due to changing oceanic conditions leading to reductions in the foraging success of Macquarie Island breeding females. To test this hypothesis, we used a 55-year-old data set on weaning size of southern elephant seals to quantify a decrease in weaning size from a period of population stability in 1950s to its present state of on-going decline. Being capital breeders, the size of elephant seal pups at weaning is a direct consequence of maternal foraging success in the preceding year. During the 1940-1950s, the mean of female pups at weaning was similar between the Heard and Macquarie Island populations, while the snout-tail-length length of male weaners from Heard Island were longer than their conspecifics at Macquarie Island. Additionally, the snout-tail-length of pups at weaning decreased by 3cm between the 1950s and 1990s in the Macquarie Island population, concurrent with the observed population decline. Given the importance of weaning size in determining first-year survival and recruitment rates, the decline in the size at weaning suggests that the decline in the Macquarie Island population has, to some extent, been driven by reduced maternal foraging success, consequent declines in the size of pups at weaning, leading to reduced first-year survival rates and recruitment of breeding females into the population 3 to 4 years later.

  9. Genetic variation in variability: phenotypic variability of fledging weight and its evolution in a songbird population

    NARCIS (Netherlands)

    Mulder, H.A.; Gienapp, P; Visser, ME

    2016-01-01

    Variation in traits is essential for natural selection to operate and genetic and environmental effects can contribute to this phenotypic variation. From domesticated populations, we know that families can differ in their level of within-family variance, which leads to the intriguing situation that

  10. Exploiting Fast-Variables to Understand Population Dynamics and Evolution

    Science.gov (United States)

    Constable, George W. A.; McKane, Alan J.

    2017-11-01

    We describe a continuous-time modelling framework for biological population dynamics that accounts for demographic noise. In the spirit of the methodology used by statistical physicists, transitions between the states of the system are caused by individual events while the dynamics are described in terms of the time-evolution of a probability density function. In general, the application of the diffusion approximation still leaves a description that is quite complex. However, in many biological applications one or more of the processes happen slowly relative to the system's other processes, and the dynamics can be approximated as occurring within a slow low-dimensional subspace. We review these time-scale separation arguments and analyse the more simple stochastic dynamics that result in a number of cases. We stress that it is important to retain the demographic noise derived in this way, and emphasise this point by showing that it can alter the direction of selection compared to the prediction made from an analysis of the corresponding deterministic model.

  11. Neural and psychological underpinnings of gambling disorder

    DEFF Research Database (Denmark)

    Grant, Jon E; Odlaug, Brian L; Chamberlain, Samuel R

    2016-01-01

    Gambling disorder affects 0.4 to 1.6% of adults worldwide, and is highly comorbid with other mental health disorders. This article provides a concise primer on the neural and psychological underpinnings of gambling disorder based on a selective review of the literature. Gambling disorder is assoc......Gambling disorder affects 0.4 to 1.6% of adults worldwide, and is highly comorbid with other mental health disorders. This article provides a concise primer on the neural and psychological underpinnings of gambling disorder based on a selective review of the literature. Gambling disorder...... is required to evaluate whether cognitive dysfunction and personality aspects influence the longitudinal course and treatment outcome for gambling disorder. It is hoped that improved understanding of the biological and psychological components of gambling disorder, and their interactions, may lead to improved...

  12. Genetic variation in variability: Phenotypic variability of fledging weight and its evolution in a songbird population.

    Science.gov (United States)

    Mulder, Han A; Gienapp, Philip; Visser, Marcel E

    2016-09-01

    Variation in traits is essential for natural selection to operate and genetic and environmental effects can contribute to this phenotypic variation. From domesticated populations, we know that families can differ in their level of within-family variance, which leads to the intriguing situation that within-family variance can be heritable. For offspring traits, such as birth weight, this implies that within-family variance in traits can vary among families and can thus be shaped by natural selection. Empirical evidence for this in wild populations is however lacking. We investigated whether within-family variance in fledging weight is heritable in a wild great tit (Parus major) population and whether these differences are associated with fitness. We found significant evidence for genetic variance in within-family variance. The genetic coefficient of variation (GCV) was 0.18 and 0.25, when considering fledging weight a parental or offspring trait, respectively. We found a significant quadratic relationship between within-family variance and fitness: families with low or high within-family variance had lower fitness than families with intermediate within-family variance. Our results show that within-family variance can respond to selection and provides evidence for stabilizing selection on within-family variance. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  13. Five decades on: Use of historical weaning size data reveals that a decrease in maternal foraging success underpins the long-term decline in population of southern elephant seals (Mirounga leonina.

    Directory of Open Access Journals (Sweden)

    Ella Clausius

    Full Text Available The population of Southern elephant seals (Mirounga leonina at Macquarie Island has declined since the 1960s, and is thought to be due to changing oceanic conditions leading to reductions in the foraging success of Macquarie Island breeding females. To test this hypothesis, we used a 55-year-old data set on weaning size of southern elephant seals to quantify a decrease in weaning size from a period of population stability in 1950s to its present state of on-going decline. Being capital breeders, the size of elephant seal pups at weaning is a direct consequence of maternal foraging success in the preceding year. During the 1940-1950s, the mean of female pups at weaning was similar between the Heard and Macquarie Island populations, while the snout-tail-length length of male weaners from Heard Island were longer than their conspecifics at Macquarie Island. Additionally, the snout-tail-length of pups at weaning decreased by 3cm between the 1950s and 1990s in the Macquarie Island population, concurrent with the observed population decline. Given the importance of weaning size in determining first-year survival and recruitment rates, the decline in the size at weaning suggests that the decline in the Macquarie Island population has, to some extent, been driven by reduced maternal foraging success, consequent declines in the size of pups at weaning, leading to reduced first-year survival rates and recruitment of breeding females into the population 3 to 4 years later.

  14. Molecular variability from two selection of BRT10 population in an ...

    African Journals Online (AJOL)

    Genetic variability of two groups of palms composed with four progenies selected in BRT10 improved populations resulting from successive self-fertilizations of two parents LM2T and LM10T was studied using four polymorphic microsatellites DNA markers of Elaeis guineensis Jacq. The molecular variability of those ...

  15. Breeding site heterogeneity reduces variability in frog recruitment and population dynamics

    Science.gov (United States)

    McCaffery, Rebecca M.; Eby, Lisa A.; Maxell, Bryce A.; Corn, Paul Stephen

    2013-01-01

    Environmental stochasticity can have profound effects on the dynamics and viability of wild populations, and habitat heterogeneity provides one mechanism by which populations may be buffered against the negative effects of environmental fluctuations. Heterogeneity in breeding pond hydroperiod across the landscape may allow amphibian populations to persist despite variable interannual precipitation. We examined recruitment dynamics over 10 yr in a high-elevation Columbia spotted frog (Rana luteiventris) population that breeds in ponds with a variety of hydroperiods. We combined these data with matrix population models to quantify the consequences of heterogeneity in pond hydroperiod on net recruitment (i.e. number of metamorphs produced) and population growth rates. We compared our heterogeneous system to hypothetical homogeneous environments with only ephemeral ponds, only semi-permanent ponds, and only permanent ponds. We also examined the effects of breeding pond habitat loss on population growth rates. Most eggs were laid in permanent ponds each year, but survival to metamorphosis was highest in the semi-permanent ponds. Recruitment success varied by both year and pond type. Net recruitment and stochastic population growth rate were highest under a scenario with homogeneous semi-permanent ponds, but variability in recruitment was lowest in the scenario with the observed heterogeneity in hydroperiods. Loss of pond habitat decreased population growth rate, with greater decreases associated with loss of permanent and semi-permanent habitat. The presence of a diversity of pond hydroperiods on the landscape will influence population dynamics, including reducing variability in recruitment in an uncertain climatic future.

  16. Estimation of Finite Population Ratio When Other Auxiliary Variables are Available in the Study

    Directory of Open Access Journals (Sweden)

    Jehad Al-Jararha

    2014-12-01

    Full Text Available The estimation of the population total $t_y,$ by using one or moreauxiliary variables, and the population ratio $\\theta_{xy}=t_y/t_x,$$t_x$ is the population total for the auxiliary variable $X$, for afinite population are heavily discussed in the literature. In thispaper, the idea of estimation the finite population ratio$\\theta_{xy}$ is extended to use the availability of auxiliaryvariable $Z$ in the study, such auxiliary variable  is not used inthe definition of the population ratio. This idea may be  supported by the fact that the variable $Z$  is highly correlated with the interest variable $Y$ than the correlation between the variables $X$ and $Y.$ The availability of such auxiliary variable can be used to improve the precision of the estimation of the population ratio.  To our knowledge, this idea is not discussed in the literature.  The bias, variance and the mean squares error  are given for our approach. Simulation from real data set,  the empirical relative bias and  the empirical relative mean squares error are computed for our approach and different estimators proposed in the literature  for estimating the population ratio $\\theta_{xy}.$ Analytically and the simulation results show that, by suitable choices, our approach gives negligible bias and has less mean squares error.  

  17. [Dynamics and ecological-genetic variability of cytogenetic disturbances in Scots pine populations experiencing technogenic impact].

    Science.gov (United States)

    Udalova, A A; Geras'kin, S A

    2011-01-01

    Scots pine (Pinus sylvestris L.) populations in the vicinity of nuclear industry facilities were monitored. Aberrant cells occurrence in root meristem of germinated seeds from the impacted pine populations was found to be significantly above the reference level during all six years of observations. In the reference population, changes of cytogenetic disturbances with time appeared to be cyclic while in the impacted populations, technogenic stress was strong enough to destroy the natural regularities. The increase in cytogenetic disturbances was accompanied by growth of fluctuations magnitude; deviations of basic oscillation parameters from the reference values rose along with technogenic impact level. Variability in cytogenetic response increased under technogenic stress. Inter-family component of variability predominated, though its contribution slightly decreased in impacted populations. A tendency for destabilization of a repetition coefficient dynamics was found under technogenic impact. A portion of the seeds was exposed to 15 Gy of gamma-rays, and higher radio-resistance in the impacted populations was observed. In the reference population, a family-related analysis of cytogenetic variability components after acute y-exposure revealed significant contributions of "family" and "germination conditions" factors as well as their interactions. On the contrary, in populations existing under chronic stress, considerable modifications in the structure of ecological-genetic variability were found, their degree increasing with technogenic impact severity.

  18. Intraregional and inter-regional variability of herbicide sensitivity in common arable weed populations

    DEFF Research Database (Denmark)

    de Mol, Friederike; Gerowitt, Bärbel; Kaczmarek, Sylwia

    2015-01-01

    The question on intraregional versus inter-regional variability in herbicide sensitivity for weed populations is of major importance, both in extrapolation of model parameters and in herbicide zonal approval procedures. We hypothesised that inter-regional variability in herbicide sensitivity...... for field populations would be the same as intraregional variability for regions with similar climatic conditions. Seeds of field weed populations were collected in a Danish, German and Polish region. Herbicide sensitivity was tested in dose–response experiments in the glasshouse with flufenacet...... and iodosulfuron (Apera spica-venti), florasulam and tribenuron (Tripleurospermum inodorum), diflufenican, diflufenican + flurtamone and pendimethalin (Viola arvensis). ED50 values and variance components of the ED50 values were estimated to describe the influence of region, year and population. The regions...

  19. The scaling of population persistence with carrying capacity does not asymptote in populations of a fish experiencing extreme climate variability.

    Science.gov (United States)

    White, Richard S A; Wintle, Brendan A; McHugh, Peter A; Booker, Douglas J; McIntosh, Angus R

    2017-06-14

    Despite growing concerns regarding increasing frequency of extreme climate events and declining population sizes, the influence of environmental stochasticity on the relationship between population carrying capacity and time-to-extinction has received little empirical attention. While time-to-extinction increases exponentially with carrying capacity in constant environments, theoretical models suggest increasing environmental stochasticity causes asymptotic scaling, thus making minimum viable carrying capacity vastly uncertain in variable environments. Using empirical estimates of environmental stochasticity in fish metapopulations, we showed that increasing environmental stochasticity resulting from extreme droughts was insufficient to create asymptotic scaling of time-to-extinction with carrying capacity in local populations as predicted by theory. Local time-to-extinction increased with carrying capacity due to declining sensitivity to demographic stochasticity, and the slope of this relationship declined significantly as environmental stochasticity increased. However, recent 1 in 25 yr extreme droughts were insufficient to extirpate populations with large carrying capacity. Consequently, large populations may be more resilient to environmental stochasticity than previously thought. The lack of carrying capacity-related asymptotes in persistence under extreme climate variability reveals how small populations affected by habitat loss or overharvesting, may be disproportionately threatened by increases in extreme climate events with global warming. © 2017 The Author(s).

  20. MORPHOLOGICAL VARIABILITY OF SEVERAL INDONESIAN POPULATIONS OF GIANT FRESHWATER PRAWN, Macrobrachium rosenbergii

    Directory of Open Access Journals (Sweden)

    Imron Imron

    2008-06-01

    Full Text Available Patterns in morphological variability have been the main basis for conventional genetic improvement program, particularly in selective breeding. Proper understanding on these patterns hence, is of crucial prerequisite before any scheme of breeding program is undertaken. This study was aimed to explore those morphological variations with emphasis on the assessment of among-population and among-trait variations and assessment of predictive traits that may serve for inter-population differentiation. A total 281 individuals representing four natural populations (Asahan, Ogan, Barito, and Ciasem and one domesticated stock (GIMacro were sampled and analyzed for variability in thirteen morphological traits. While descriptive analyses were applied to analyze both among-stock and among-trait variations, discriminant function analysis was used to search for the best traits for interpopulation differentiation. The relative variability, expressed in the coefficient of variation (CV, was used to compare the amount and patterns of morphometric variability both among traits and between stocks. Results showed that total body weight was the most variable trait while the length and meristic traits were of lower level. Discriminant analysis found that rostrum length and abdoment length to be the best morphological discriminators among intraspecific populations. However, the continuous natures of these traits make them have limited applicability for intraspecific population differentiation.

  1. Genetic Variability and Distribution of Mating Type Alleles in Field Populations of Leptosphaeria maculans from France

    Science.gov (United States)

    Gout, Lilian; Eckert, Maria; Rouxel, Thierry; Balesdent, Marie-Hélène

    2006-01-01

    Leptosphaeria maculans is the most ubiquitous fungal pathogen of Brassica crops and causes the devastating stem canker disease of oilseed rape worldwide. We used minisatellite markers to determine the genetic structure of L. maculans in four field populations from France. Isolates were collected at three different spatial scales (leaf, 2-m2 field plot, and field) enabling the evaluation of spatial distribution of the mating type alleles and of genetic variability within and among field populations. Within each field population, no gametic disequilibrium between the minisatellite loci was detected and the mating type alleles were present at equal frequencies. Both sexual and asexual reproduction occur in the field, but the genetic structure of these populations is consistent with annual cycles of randomly mating sexual reproduction. All L. maculans field populations had a high level of gene diversity (H = 0.68 to 0.75) and genotypic diversity. Within each field population, the number of genotypes often was very close to the number of isolates. Analysis of molecular variance indicated that >99.5% of the total genetic variability was distributed at a small spatial scale, i.e., within 2-m2 field plots. Population differentiation among the four field populations was low (GST < 0.02), suggesting a high degree of gene exchange between these populations. The high gene flow evidenced here in French populations of L. maculans suggests a rapid countrywide diffusion of novel virulence alleles whenever novel resistance sources are used. PMID:16391041

  2. Revisiting the role of individual variability in population persistence and stability.

    Directory of Open Access Journals (Sweden)

    Andrew Morozov

    Full Text Available Populations often exhibit a pronounced degree of individual variability and this can be important when constructing ecological models. In this paper, we revisit the role of inter-individual variability in population persistence and stability under predation pressure. As a case study, we consider interactions between a structured population of zooplankton grazers and their predators. Unlike previous structured population models, which only consider variability of individuals according to the age or body size, we focus on physiological and behavioural structuring. We first experimentally demonstrate a high degree of variation of individual consumption rates in three dominant species of herbivorous copepods (Calanus finmarchicus, Calanus glacialis, Calanus euxinus and show that this disparity implies a pronounced variation in the consumption capacities of individuals. Then we construct a parsimonious predator-prey model which takes into account the intra-population variability of prey individuals according to behavioural traits: effectively, each organism has a 'personality' of its own. Our modelling results show that structuring of prey according to their growth rate and vulnerability to predation can dampen predator-prey cycles and enhance persistence of a species, even if the resource stock for prey is unlimited. The main mechanism of efficient top-down regulation is shown to work by letting the prey population become dominated by less vulnerable individuals when predator densities are high, while the trait distribution recovers when the predator densities are low.

  3. Codon optimization underpins generalist parasitism in fungi.

    Science.gov (United States)

    Badet, Thomas; Peyraud, Remi; Mbengue, Malick; Navaud, Olivier; Derbyshire, Mark; Oliver, Richard P; Barbacci, Adelin; Raffaele, Sylvain

    2017-02-03

    The range of hosts that parasites can infect is a key determinant of the emergence and spread of disease. Yet, the impact of host range variation on the evolution of parasite genomes remains unknown. Here, we show that codon optimization underlies genome adaptation in broad host range parasites. We found that the longer proteins encoded by broad host range fungi likely increase natural selection on codon optimization in these species. Accordingly, codon optimization correlates with host range across the fungal kingdom. At the species level, biased patterns of synonymous substitutions underpin increased codon optimization in a generalist but not a specialist fungal pathogen. Virulence genes were consistently enriched in highly codon-optimized genes of generalist but not specialist species. We conclude that codon optimization is related to the capacity of parasites to colonize multiple hosts. Our results link genome evolution and translational regulation to the long-term persistence of generalist parasitism.

  4. Variability in population abundance is associated with thresholds between scaling regimes

    Science.gov (United States)

    Wardwell, D.; Allen, Craig R.

    2009-01-01

    Discontinuous structure in landscapes may result in discontinuous, aggregated species body-mass patterns, reflecting the scales of structure available to animal communities within a landscape. The edges of these body-mass aggregations reflect transitions between available scales of landscape structure. Such transitions, or scale breaks, are theoretically associated with increased biological variability. We hypothesized that variability in population abundance is greater in animal species near the edge of body-mass aggregations than it is in species that are situated in the interior of body-mass aggregations. We tested this hypothesis by examining both temporal and spatial variability in the abundance of species in the bird community of the Florida Everglades sub-ecoregion, USA. Analyses of both temporal and spatial variability in population abundance supported our hypothesis. Our results indicate that variability within complex systems may be non-random, and is heightened where transitions in scales of process and structure occur. This is the first explicit test of the hypothetical relationship between increased population variability and scale breaks. ?? 2009 by the author(s).

  5. [Genetic variability in Aedes aegypti (L.) (Diptera: Culicidae) populations using RAPD markers].

    Science.gov (United States)

    Hiragi, Cassia; Simões, Kenya; Martins, Erica; Queiroz, Paulo; Lima, Luzia; Monnerat, Rose

    2009-01-01

    Aedes aegypti (L.) is an important vector of diseases such as the yellow fever and dengue, present in tropical and subtropical regions. The objective of this study was to analyze the genetic variability of different A. aegypti populations using RAPD (Random Amplified Polymorphic DNA) markers as a basic study to support the use of biocontrol strategies. DNA of ten collected larvae from three different populations were analyzed using ten RAPD primers. The results indicated the existence of genetic variability inter and intrapopulation. This was confirmed by a dendrogram that grouped the populations in two main clusters with a genetic similarity of 24%. In one of these clusters, it was possible to distinguish two populations that showed 50% similarity. The molecular variance analysis indicated that the interpopulation genetic diversity (55,01%) was higher than the intrapopulation genetic diversity (44,99%). A high genetic polymorphism (Ht = 0.2656) and high levels of genetic differentiation between populations (Gst = 0.3689) were found. The adopted DNA extraction protocol proved to be efficient regardless the insect development stage used, avoiding the addition of reagents or additional stages of processing. Future experiments can be performed to confirm if the detected variability is related to the resistance characteristics of each population to a determined pesticide.

  6. Dispersal variability and associated population-level consequences in tree-killing bark beetles.

    Science.gov (United States)

    Kautz, Markus; Imron, Muhammad Ali; Dworschak, Kai; Schopf, Reinhard

    2016-01-01

    Dispersal is a key process in the response of insect populations to rapidly changing environmental conditions. Variability among individuals, regarding the timing of dispersal initiation and travelled distance from source, is assumed to contribute to increased population success through risk spreading. However, experiments are often limited in studying complex dispersal interactions over space and time. By applying a local-scaled individual-based simulation model we studied dispersal and emerging infestation patterns in a host - bark beetle system (Picea abies - Ips typgraphus). More specifically, we (i) investigated the effect of individual variability in beetle physiology (flight capacity) and environmental heterogeneity (host susceptibility level) on population-level dispersal success, and (ii) elucidated patterns of spatial and/or temporal variability in individual dispersal success, host selectivity, and the resulting beetle density within colonized hosts in differently susceptible environments. Individual variability in flight capacity of bark beetles causes predominantly positive effects on population-level dispersal success, yet these effects are strongly environment-dependent: Variability is most beneficial in purely resistant habitats, while positive effects are less pronounced in purely susceptible habitats, and largely absent in habitats where host susceptibility is spatially scattered. Despite success rates being highest in purely susceptible habitats, scattered host susceptibility appeared most suitable for dispersing bark beetle populations as it ensures population spread without drastically reducing success rates. At the individual level, dispersal success generally decreases with distance to source and is lowest in early flight cohorts, while host selectivity increased and colonization density decreased with increasing distance across all environments. Our modelling approach is demonstrated to be a powerful tool for studying movement ecology in

  7. Oxygen-rich Mira variables: Near-infrared luminosity calibrations. Populations and period-luminosity relations

    Science.gov (United States)

    Alvarez, R.; Mennessier, M.-O.; Barthes, D.; Luri, X.; Mattei, J. A.

    1997-01-01

    Hipparcos astrometric and kinematical data of oxygen-rich Mira variables are used to calibrate absolute near-infrared magnitudes and kinematic parameters. Three distinct classes of stars with different kinematics and scale heights were identified. The two most significant groups present characteristics close to those usually assigned to extended/thick disk-halo populations and old disk populations, respectively, and thus they may differ by their metallicity abundance. Two parallel period-luminosity relations are found, one for each population. The shift between these relations is interpreted as the consequence of the effects of metallicity abundance on the luminosity.

  8. Population and prehistory III: food-dependent demography in variable environments.

    Science.gov (United States)

    Lee, Charlotte T; Puleston, Cedric O; Tuljapurkar, Shripad

    2009-11-01

    The population dynamics of preindustrial societies depend intimately on their surroundings, and food is a primary means through which environment influences population size and individual well-being. Food production requires labor; thus, dependence of survival and fertility on food involves dependence of a population's future on its current state. We use a perturbation approach to analyze the effects of random environmental variation on this nonlinear, age-structured system. We show that in expanding populations, direct environmental effects dominate induced population fluctuations, so environmental variability has little effect on mean hunger levels, although it does decrease population growth. The growth rate determines the time until population is limited by space. This limitation introduces a tradeoff between population density and well-being, so population effects become more important than the direct effects of the environment: environmental fluctuation increases mortality, releasing density dependence and raising average well-being for survivors. We discuss the social implications of these findings for the long-term fate of populations as they transition from expansion into limitation, given that conditions leading to high well-being during growth depress well-being during limitation.

  9. Genetic variability of CYP2C19 in a Mexican population: contribution ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 94; Issue 1. Genetic variability of CYP2C19 in a Mexican population: contribution to the knowledge of the inheritance pattern of CYP2C19*17 to develop the ultrarapid metabolizer phenotype. Alma Faviola Favela-Mendoza Gabriela Martinez-Cortes Marcelo ...

  10. Local variability mediates vulnerability of trout populations to land use and climate change

    Science.gov (United States)

    Brooke E. Penaluna; Jason B. Dunham; Steve F. Railsback; Ivan Arismendi; Sherri L. Johnson; Robert E. Bilby; Mohammad Safeeq; Arne E. Skaugset; James P. Meador

    2015-01-01

    Land use and climate change occur simultaneously around the globe. Fully understanding their separate and combined effects requires a mechanistic understanding at the local scale where their effects are ultimately realized. Here we applied an individual-based model of fish population dynamics to evaluate the role of local stream variability in modifying responses of...

  11. The Influence of Matching Populations on Kinematic and Kinetic Variables in Runners with Iliotibial Band Syndrome

    Science.gov (United States)

    Grau, Stefan; Maiwald, Christian; Krauss, Inga; Axmann, Detlef; Horstmann, Thomas

    2008-01-01

    The purpose of this study was to assess how participant matching influences biomechanical variables when comparing healthy runners and runners with iliotibial band syndrome (ITBS). We examined 52 healthy runners (CO) and 18 with ITBS, using three-dimensional kinematics and pressure distribution. The study population was matched in three ways and…

  12. Associations of benzodiazepine craving with other clinical variables in a population of general practice patients

    NARCIS (Netherlands)

    Mol, A.J.J.; Gorgels, W.J.M.J.; Oude Voshaar, R.C.; Breteler, M.H.M.; van Balkom, A.J.L.M.; van de Lisdonk, E.H.; Kan, C.C.; Zitman, F.G.

    2005-01-01

    BACKGROUND: The aim of this study was to (1) describe the characteristics of patients reporting craving for benzodiazepines (BZs) and (2) to search for associations between BZ craving and other clinical variables in a population of general practice (GP) patients who have made an attempt to

  13. Associations of benzodiazepine craving with other clinical variables in a population of general practice patients.

    NARCIS (Netherlands)

    Mol, A.J.J.; Gorgels, W.J.M.J.; Oude Voshaar, R.C.; Breteler, M.H.M.; Balkom, A.J.L.M. van; Lisdonk, E.H. van de; Kan, C.C.; Zitman, F.G.

    2005-01-01

    BACKGROUND: The aim of this study was to (1) describe the characteristics of patients reporting craving for benzodiazepines (BZs) and (2) to search for associations between BZ craving and other clinical variables in a population of general practice (GP) patients who have made an attempt to

  14. Genetic variability in captive populations of the stingless bee Tetragonisca angustula.

    Science.gov (United States)

    Santiago, Leandro R; Francisco, Flávio O; Jaffé, Rodolfo; Arias, Maria C

    2016-08-01

    Low genetic variability has normally been considered a consequence of animal husbandry and a major contributing factor to declining bee populations. Here, we performed a molecular analysis of captive and wild populations of the stingless bee Tetragonisca angustula, one of the most commonly kept species across South America. Microsatellite analyses showed similar genetic variability between wild and captive populations However, captive populations showed lower mitochondrial genetic variability. Male-mediated gene flow, transport and division of nests are suggested as the most probable explanations for the observed patterns of genetic structure. We conclude that increasing the number of colonies kept through nest divisions does not negatively affect nuclear genetic variability, which seems to be maintained by small-scale male dispersal and human-mediated nest transport. However, the transport of nests from distant localities should be practiced with caution given the high genetic differentiation observed between samples from western and eastern areas. The high genetic structure verified is the result of a long-term evolutionary process, and bees from distant localities may represent unique evolutionary lineages.

  15. Transients drive the demographic dynamics of plant populations in variable environments

    DEFF Research Database (Denmark)

    McDonald, Jenni L; Stott, Iain; Townley, Stuart

    2016-01-01

    The dynamics of structured plant populations in variable environments can be decomposed into the ‘asymptotic’ growth contributed by vital rates, and ‘transient’ growth caused by deviation from stable stage structure. We apply this framework to a large, global data base of longitudinal studies of ...

  16. Population activity statistics dissect subthreshold and spiking variability in V1.

    Science.gov (United States)

    Bányai, Mihály; Koman, Zsombor; Orbán, Gergő

    2017-07-01

    Response variability, as measured by fluctuating responses upon repeated performance of trials, is a major component of neural responses, and its characterization is key to interpret high dimensional population recordings. Response variability and covariability display predictable changes upon changes in stimulus and cognitive or behavioral state, providing an opportunity to test the predictive power of models of neural variability. Still, there is little agreement on which model to use as a building block for population-level analyses, and models of variability are often treated as a subject of choice. We investigate two competing models, the doubly stochastic Poisson (DSP) model assuming stochasticity at spike generation, and the rectified Gaussian (RG) model tracing variability back to membrane potential variance, to analyze stimulus-dependent modulation of both single-neuron and pairwise response statistics. Using a pair of model neurons, we demonstrate that the two models predict similar single-cell statistics. However, DSP and RG models have contradicting predictions on the joint statistics of spiking responses. To test the models against data, we build a population model to simulate stimulus change-related modulations in pairwise response statistics. We use single-unit data from the primary visual cortex (V1) of monkeys to show that while model predictions for variance are qualitatively similar to experimental data, only the RG model's predictions are compatible with joint statistics. These results suggest that models using Poisson-like variability might fail to capture important properties of response statistics. We argue that membrane potential-level modeling of stochasticity provides an efficient strategy to model correlations. NEW & NOTEWORTHY Neural variability and covariability are puzzling aspects of cortical computations. For efficient decoding and prediction, models of information encoding in neural populations hinge on an appropriate model of

  17. Disaggregating measurement uncertainty from population variability and Bayesian treatment of uncensored results

    Energy Technology Data Exchange (ETDEWEB)

    Strom, Daniel J.; Joyce, Kevin E.; Maclellan, Jay A.; Watson, David J.; Lynch, Timothy P.; Antonio, Cheryl L.; Birchall, Alan; Anderson, Kevin K.; Zharov, Peter

    2012-04-17

    In making low-level radioactivity measurements of populations, it is commonly observed that a substantial portion of net results are negative. Furthermore, the observed variance of the measurement results arises from a combination of measurement uncertainty and population variability. This paper presents a method for disaggregating measurement uncertainty from population variability to produce a probability density function (PDF) of possibly true results. To do this, simple, justifiable, and reasonable assumptions are made about the relationship of the measurements to the measurands (the 'true values'). The measurements are assumed to be unbiased, that is, that their average value is the average of the measurands. Using traditional estimates of each measurement's uncertainty to disaggregate population variability from measurement uncertainty, a PDF of measurands for the population is produced. Then, using Bayes's theorem, the same assumptions, and all the data from the population of individuals, a prior PDF is computed for each individual's measurand. These PDFs are non-negative, and their average is equal to the average of the measurement results for the population. The uncertainty in these Bayesian posterior PDFs is all Berkson with no remaining classical component. The methods are applied to baseline bioassay data from the Hanford site. The data include 90Sr urinalysis measurements on 128 people, 137Cs in vivo measurements on 5,337 people, and 239Pu urinalysis measurements on 3,270 people. The method produces excellent results for the 90Sr and 137Cs measurements, since there are nonzero concentrations of these global fallout radionuclides in people who have not been occupationally exposed. The method does not work for the 239Pu measurements in non-occupationally exposed people because the population average is essentially zero.

  18. Pan Genome of the Phytoplankton Emiliania Underpins its Global Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Read, Betsy A. [California State Univ. (CalState), San Marcos, CA (United States); Kegel, Jessica [Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany); Klute, Mary J. [Univ. of Alberta, Edmonton, AB (Canada); Kuo, Alan [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Lefebvre, Stephane C. [J. Craig Venter Inst., San Diego, CA (United States); Maumus, Florian [National Institute of Agricultural Research, Versailles (France); Mayer, Christoph [Alexander Koenig Research Museum, Bonn (Germany); Ruhr Univ., Bochum (Germany); Miller, John [Univ. of Maryland, College Park, MD (United States); Monier, Adam [Monterey Bay Aquarium Research Inst., Moss Landing, CA (United States); Salamov, Asaf [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Young, Jeremy [Univ. College London (United Kingdom); Aguilar, Maria [Univ. of Alberta, Edmonton, AB (Canada); Claverie, Jean-Michel [Aix-Marseille Univ. (France); Frickenhaus, Stephan [Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany); Univ. of Bremerhaven (Germany); Gonzalez, Karina [Harvard Medical School, Boston, MA (United States); Herman, Emily K. [Univ. of Alberta, Edmonton, AB (Canada); Lin, Yao-Cheng [Ghent Univ. (Belgium); Napier, Johnathan [Rothamstead Research, Harpenden (United Kingdom); Ogata, Hiroyuki [Aix-Marseille Univ. (France); Sarno, Analissa F. [California State Univ. (CalState), San Marcos, CA (United States); Schmutz, Jeremy [USDOE Joint Genome Inst., Walnut Creek, CA (United States); HudsonAlpha Genome Sequencing Center, Huntsville, AL (United States); Schroeder, Declan [Marine Biological Association of the UK, Plymouth (United Kingdom); de Vargas, Columban [CNRS. Univ. Pierre and Marie Curie (France).; Verret, Frederic [Univ. of Essex, Colchester (United Kingdom); von Dassow, Peter [Pontifical Catholic University of Chile, Santiago (Chile); Valentin, Klaus [Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany); Van de Peer, Yves [Ghent Univ. (Belgium); Wheeler, Glen [Marine Biological Association of the UK, Plymouth (United Kingdom); Plymouth Marine Lab. (United Kingdom); Annotation Consortium, Emiliania huxleyi; Dacks, Joel B. [Univ. of Alberta, Edmonton, AB (Canada); Delwiche, Charles F. [Univ. of Maryland, College Park, MD (United States); Dyhrman, Sonya T. [Woods Hole Oceanographic Inst., MA (United States); Columbia Univ., Palisades, NY (United States); Glockner, Gernot [Univ. of Cologne (Germany); John, Uwe [Alfred Wegener Inst. for Polar and Marine Research, Bremerhaven (Germany); Richards, Thomas [National History Museum, London (United Kingdom); Worden, Alexandra Z. [Monterey Bay Aquarium Research Inst., Moss Landing, CA (United States); Zhang, Xiaoyu [California State Univ. (CalState), San Marcos, CA (United States); Grigoriev, Igor V. [USDOE Joint Genome Inst., Walnut Creek, CA (United States)

    2012-06-18

    Coccolithophores have influenced the global climate for over 200 million years1. These marine phytoplankton can account for 20 per cent of total carbon fixation in some systems2. They form blooms that can occupy hundreds of thousands of square kilometres and are distinguished by their elegantly sculpted calcium carbonate exoskeletons (coccoliths), rendering themvisible fromspace3.Although coccolithophores export carbon in the form of organic matter and calcite to the sea floor, they also release CO2 in the calcification process. Hence, they have a complex influence on the carbon cycle, driving either CO2 production or uptake, sequestration and export to the deep ocean4. Here we report the first haptophyte reference genome, from the coccolithophore Emiliania huxleyi strain CCMP1516, and sequences from 13 additional isolates. Our analyses reveal a pan genome (core genes plus genes distributed variably between strains) probably supported by an atypical complement of repetitive sequence in the genome. Comparisons across strains demonstrate thatE. huxleyi, which has long been considered a single species, harbours extensive genome variability reflected in different metabolic repertoires. Genome variability within this species complex seems to underpin its capacity both to thrive in habitats ranging from the equator to the subarctic and to form large-scale episodic blooms under a wide variety of environmental conditions.

  19. Postpartum depression: psychoneuroimmunological underpinnings and treatment

    Directory of Open Access Journals (Sweden)

    Anderson G

    2013-02-01

    Full Text Available George Anderson,1 Michael Maes21CRC Clincial Research Centre/Communications, Glasgow, Scotland; 2Department of Psychiatry, Chulalongkorn University, Bangkok, ThailandAbstract: Postpartum depression (PPD is common, occurring in 10%–15% of women. Due to concerns about teratogenicity of medications in the suckling infant, the treatment of PPD has often been restricted to psychotherapy. We review here the biological underpinnings to PPD, suggesting a powerful role for the tryptophan catabolites, indoleamine 2,3-dixoygenase, serotonin, and autoimmunity in mediating the consequences of immuno-inflammation and oxidative and nitrosative stress. It is suggested that the increased inflammatory potential, the decreases in endogenous anti-inflammatory compounds together with decreased omega-3 poly-unsaturated fatty acids, in the postnatal period cause an inflammatory environment. The latter may result in the utilization of peripheral inflammatory products, especially kynurenine, in driving the central processes producing postnatal depression. The pharmacological treatment of PPD is placed in this context, and recommendations for more refined and safer treatments are made, including the better utilization of the antidepressant, and the anti-inflammatory and antioxidant effects of melatonin.Keywords: SSRI, kynurenine, IDO, TDO, melatonin

  20. Scientific underpinnings of biotechnology regulatory frameworks.

    Science.gov (United States)

    Gleim, Savannah; Smyth, Stuart J

    2018-05-25

    Part of what is presently missing at domestic regulatory levels (and that is important at the international level as well) is a detailed understanding of what the rules of, and for, regulation should be, who the actors, stakeholders and major decision makers are and finally, how to get agreement about the rules. Greater insights into the system of rules that underpin regulatory frameworks for agri-food and biotechnology products in genetically modified (GM) crop- adopting nations will provide value by clarifying the evidence used to commercialize these technologies. This article examines the public documents available from Canada, the United States, the European Union and the Organisation for Economic Cooperation and Development regarding the development of regulatory risk assessment frameworks for products of biotechnology to determine what science grounds these frameworks. The documentation used to provide the initial structure to the existing regulatory frameworks identifies the linkages, connections and relationships that exist between science, risk assessment and regulatory policy. The relationship between risk and regulation has never been more critical to the commercialization of innovative agricultural products. Documenting the role of science-based risk assessment in regulations and how this has changed over the 20 years of experience in regulating GM crops will identify changes in the risk/regulation relationship. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  1. Stable fly population dynamics in eastern Nebraska in relation to climatic variables.

    Science.gov (United States)

    Taylor, David B; Berkebile, Dennis R; Scholl, Philip J

    2007-09-01

    Stable flies, Stomoxys calcitrans (L.), are among the most economically important arthropod pests of livestock in North America. In this study, we monitored the seasonal dynamics of a stable fly population in eastern Nebraska for 5 yr. Models based upon temperature and precipitation were developed to determine the affects of these variables on population levels as well as to project population trends. Stable flies appear in eastern Nebraska in late March to early April, and they build to a peak population during the last week of June and first week of July. In most years, the population decreases in midsummer, and then it increases to a second peak in mid-September. Temperature 0 to 2 wk before collection and precipitation 3 to 6 wk before collection were the most important weather variables accounting for 63 and 11% of the variation, respectively. Temperature 7 wk before collection was also significant, accounting for 3% of the variation. Reduced precipitation levels explained the observed midsummer drop in the stable fly populations. Changes in stable fly population levels were positively correlated with precipitation 1 to 2 wk prior and temperature the week of the change. Population change was negatively correlated with precipitation 6-8 wk prior and temperature 6-15 wk prior. The addition of the previous weeks trap collections to the climate based model eliminated the significance of temperature 2 and 7 wk before collection. Temperature 0-1 wk before collection accounted for 60% of the variation, precipitation 3 to 6 wk prior 12% of the variation, and the previous weeks' trap collections accounted for 11% of the variation. Low temperatures during October through January were correlated with higher stable fly populations the following June and July.

  2. Speaker Input Variability Does Not Explain Why Larger Populations Have Simpler Languages.

    Science.gov (United States)

    Atkinson, Mark; Kirby, Simon; Smith, Kenny

    2015-01-01

    A learner's linguistic input is more variable if it comes from a greater number of speakers. Higher speaker input variability has been shown to facilitate the acquisition of phonemic boundaries, since data drawn from multiple speakers provides more information about the distribution of phonemes in a speech community. It has also been proposed that speaker input variability may have a systematic influence on individual-level learning of morphology, which can in turn influence the group-level characteristics of a language. Languages spoken by larger groups of people have less complex morphology than those spoken in smaller communities. While a mechanism by which the number of speakers could have such an effect is yet to be convincingly identified, differences in speaker input variability, which is thought to be larger in larger groups, may provide an explanation. By hindering the acquisition, and hence faithful cross-generational transfer, of complex morphology, higher speaker input variability may result in structural simplification. We assess this claim in two experiments which investigate the effect of such variability on language learning, considering its influence on a learner's ability to segment a continuous speech stream and acquire a morphologically complex miniature language. We ultimately find no evidence to support the proposal that speaker input variability influences language learning and so cannot support the hypothesis that it explains how population size determines the structural properties of language.

  3. Speaker Input Variability Does Not Explain Why Larger Populations Have Simpler Languages.

    Directory of Open Access Journals (Sweden)

    Mark Atkinson

    Full Text Available A learner's linguistic input is more variable if it comes from a greater number of speakers. Higher speaker input variability has been shown to facilitate the acquisition of phonemic boundaries, since data drawn from multiple speakers provides more information about the distribution of phonemes in a speech community. It has also been proposed that speaker input variability may have a systematic influence on individual-level learning of morphology, which can in turn influence the group-level characteristics of a language. Languages spoken by larger groups of people have less complex morphology than those spoken in smaller communities. While a mechanism by which the number of speakers could have such an effect is yet to be convincingly identified, differences in speaker input variability, which is thought to be larger in larger groups, may provide an explanation. By hindering the acquisition, and hence faithful cross-generational transfer, of complex morphology, higher speaker input variability may result in structural simplification. We assess this claim in two experiments which investigate the effect of such variability on language learning, considering its influence on a learner's ability to segment a continuous speech stream and acquire a morphologically complex miniature language. We ultimately find no evidence to support the proposal that speaker input variability influences language learning and so cannot support the hypothesis that it explains how population size determines the structural properties of language.

  4. Use of the IRAP marker to study genetic variability in Pseudocercospora fijiensis populations.

    Science.gov (United States)

    de Queiroz, Casley Borges; Santana, Mateus Ferreira; da Silva, Gilvan Ferreira; Mizubuti, Eduardo Seiti Gomide; de Araújo, Elza Fernandes; de Queiroz, Marisa Vieira

    2014-03-01

    Pseudocercospora fijiensis is the etiological agent of black Sigatoka, which is currently considered as one of the most destructive banana diseases in all locations where it occurs. It is estimated that a large portion of the P. fijiensis genome consists of transposable elements, which allows researchers to use transposon-based molecular markers in the analysis of genetic variability in populations of this pathogen. In this context, the inter-retrotransposon-amplified polymorphism (IRAP) was used to study the genetic variability in P. fijiensis populations from different hosts and different geographical origins in Brazil. A total of 22 loci were amplified and 77.3 % showed a polymorphism. Cluster analysis revealed two major groups in Brazil. The observed genetic diversity (H E) was 0.22, and through molecular analysis of variance, it was determined that the greatest genetic variability occurs within populations. The discriminant analysis of principal components revealed no structuring related to the geographical origin of culture of the host. The IRAP-based marker system is a suitable tool for the study of genetic variability in P. fijiensis.

  5. Genetic variability and population structure of Plasmodium falciparum parasite populations from different malaria ecological regions of Kenya.

    Science.gov (United States)

    Ingasia, Luicer A; Cheruiyot, Jelagat; Okoth, Sheila Akinyi; Andagalu, Ben; Kamau, Edwin

    2016-04-01

    Transmission intensity, movement of human and vector hosts, biogeographical features, and malaria control measures are some of the important factors that determine Plasmodium falciparum parasite genetic variability and population structure. Kenya has different malaria ecologies which might require different disease intervention methods. Refined parasite population genetic studies are critical for informing malaria control and elimination strategies. This study describes the genetic diversity and population structure of P. falciparum parasites from the different malaria ecological zones in Kenya. Twelve multi-locus microsatellite (MS) loci previously described were genotyped in 225 P. falciparum isolates collected between 2012 and 2013 from five sites; three in lowland endemic regions (Kisumu, Kombewa, and Malindi) and two in highland, epidemic regions (Kisii and Kericho). Parasites from the lowland endemic and highland epidemic regions of western Kenya had high genetic diversity compared to coastal lowland endemic region of Kenya [Malindi]. The Kenyan parasites had a mean genetic differentiation index (FST) of 0.072 (p=0.011). The multi-locus genetic analysis of the 12 MS revealed all the parasites had unique haplotypes. Significant linkage disequilibrium (LD) was observed in all the five parasite populations. Kisumu had the most significant index of association values (0.16; pKenya after introduction of the artemether-lumefantrine is important in refining the spread of drug resistant strains and malaria transmission for more effective control and eventual elimination of malaria in Kenya. Copyright © 2015. Published by Elsevier B.V.

  6. Population, education and sustainable development.

    Science.gov (United States)

    Johnston, T

    1992-12-01

    The author examines the interrelationships between population growth and education, with a focus on Sub-Saharan Africa. "The gross body of evidence suggests that for all developing regions (and for sub-saharan Africa specifically) rapid population growth deleteriously impacts upon the quantity and quality of schooling. In a reciprocal fashion, the variables which underpin rapid and differential growth (fertility, mortality and migration) are themselves influenced by quantum of formal schooling and by other educational processes." excerpt

  7. Dynamics of sexual populations structured by a space variable and a phenotypical trait

    KAUST Repository

    Mirrahimi, Sepideh

    2013-03-01

    We study sexual populations structured by a phenotypic trait and a space variable, in a non-homogeneous environment. Departing from an infinitesimal model, we perform an asymptotic limit to derive the system introduced in Kirkpatrick and Barton (1997). We then perform a further simplification to obtain a simple model. Thanks to this simpler equation, we can describe rigorously the dynamics of the population. In particular, we provide an explicit estimate of the invasion speed, or extinction speed of the species. Numerical computations show that this simple model provides a good approximation of the original infinitesimal model, and in particular describes quite well the evolution of the species\\' range. © 2013 Elsevier Inc.

  8. Heirloom tomato cultivars and local populations as sources of genetic variability for breeding

    Directory of Open Access Journals (Sweden)

    Glogovac Svetlana

    2010-01-01

    Full Text Available Five local tomato populations and fourteen heirloom cultivars were analyzed in this study. The analyzed genotypes represent a part of tomato collection of Institute of Field and Vegetable Crops in Novi Sad. The following fruit and plant traits were analyzed: growth type, fruit color, fruit shape index, fruit weight, number of locules and dry matter content. Cluster analysis was performed so as to group the analyzed genotypes by homology and divergence. The aim of this article was to determine the importance of heirloom cultivars and local populations as sources of genetic variability in tomato breeding process.

  9. Microsatellite variability reveals high genetic diversity and low genetic differentiation in a critical giant panda population

    Directory of Open Access Journals (Sweden)

    Jiandong YANG, Zhihe ZHANG, Fujun SHEN, Xuyu YANG, Liang ZHANG, Limin CHEN, Wenping ZHANG, Qing ZHU, Rong HOU

    2011-12-01

    Full Text Available Understanding present patterns of genetic diversity is critical in order to design effective conservation and management strategies for endangered species. Tangjiahe Nature Reserve (NR is one of the most important national reserves for giant pandas Ailuropoda melanoleuca in China. Previous studies have shown that giant pandas in Tangjiahe NR may be threatened by population decline and fragmentation. Here we used 10 microsatellite DNA markers to assess the genetic variability in the Tangjiahe population. The results indicate a low level of genetic differentiation between the Hongshihe and Motianling subpopulations in the reserve. Assignment tests using the Bayesian clustering method in STRUCTURE identified one genetic cluster from 42 individuals of the two subpopulations. All individuals from the same subpopulation were assigned to one cluster. This indicates high gene flow between subpopulations. F statistic analyses revealed a low FIS-value of 0.024 in the total population and implies a randomly mating population in Tangjiahe NR. Additionally, our data show a high level of genetic diversity for the Tangjiahe population. Mean allele number (A, Allelic richness (AR and mean expected heterozygosity (HE for the Tangjiahe population was 5.9, 5.173 and 0.703, respectively. This wild giant panda population can be restored through concerted effort [Current Zoology 57 (6: 717–724, 2011].

  10. Comparison of Three Plot Selection Methods for Estimating Change in Temporally Variable, Spatially Clustered Populations.

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, William L. [Bonneville Power Administration, Portland, OR (US). Environment, Fish and Wildlife

    2001-07-01

    Monitoring population numbers is important for assessing trends and meeting various legislative mandates. However, sampling across time introduces a temporal aspect to survey design in addition to the spatial one. For instance, a sample that is initially representative may lose this attribute if there is a shift in numbers and/or spatial distribution in the underlying population that is not reflected in later sampled plots. Plot selection methods that account for this temporal variability will produce the best trend estimates. Consequently, I used simulation to compare bias and relative precision of estimates of population change among stratified and unstratified sampling designs based on permanent, temporary, and partial replacement plots under varying levels of spatial clustering, density, and temporal shifting of populations. Permanent plots produced more precise estimates of change than temporary plots across all factors. Further, permanent plots performed better than partial replacement plots except for high density (5 and 10 individuals per plot) and 25% - 50% shifts in the population. Stratified designs always produced less precise estimates of population change for all three plot selection methods, and often produced biased change estimates and greatly inflated variance estimates under sampling with partial replacement. Hence, stratification that remains fixed across time should be avoided when monitoring populations that are likely to exhibit large changes in numbers and/or spatial distribution during the study period. Key words: bias; change estimation; monitoring; permanent plots; relative precision; sampling with partial replacement; temporary plots.

  11. Effects of Population Growth and Climate Variability on Sustainable Groundwater in Mali, West Africa

    Directory of Open Access Journals (Sweden)

    Alexandra Lutz

    2010-12-01

    Full Text Available Groundwater is increasingly relied on as a source of potable water in developing countries, but factors such as population growth, development, and climate variability, pose potential challenges for ongoing sustainable supply. The effect of these factors on the groundwater system was considered in four scenarios using a numerical model to represent the Bani area of Mali, West Africa. By 2040, population growth, climate variability, and development as urbanization, agriculture, and industry creates scenarios in which groundwater extraction is an increasingly larger percentage of the groundwater system. Consumption from agriculture and industry increases extraction rates from less than 1 to 3.8% of mean annual precipitation, which will likely affect the groundwater system. For instance, concentrated pumping in local areas may result in water level declines. The results of this study contribute to an ongoing evaluation of sustainable groundwater resources in West Africa.

  12. Effects of uncertainty and variability on population declines and IUCN Red List classifications.

    Science.gov (United States)

    Rueda-Cediel, Pamela; Anderson, Kurt E; Regan, Tracey J; Regan, Helen M

    2018-01-22

    The International Union for Conservation of Nature (IUCN) Red List Categories and Criteria is a quantitative framework for classifying species according to extinction risk. Population models may be used to estimate extinction risk or population declines. Uncertainty and variability arise in threat classifications through measurement and process error in empirical data and uncertainty in the models used to estimate extinction risk and population declines. Furthermore, species traits are known to affect extinction risk. We investigated the effects of measurement and process error, model type, population growth rate, and age at first reproduction on the reliability of risk classifications based on projected population declines on IUCN Red List classifications. We used an age-structured population model to simulate true population trajectories with different growth rates, reproductive ages and levels of variation, and subjected them to measurement error. We evaluated the ability of scalar and matrix models parameterized with these simulated time series to accurately capture the IUCN Red List classification generated with true population declines. Under all levels of measurement error tested and low process error, classifications were reasonably accurate; scalar and matrix models yielded roughly the same rate of misclassifications, but the distribution of errors differed; matrix models led to greater overestimation of extinction risk than underestimations; process error tended to contribute to misclassifications to a greater extent than measurement error; and more misclassifications occurred for fast, rather than slow, life histories. These results indicate that classifications of highly threatened taxa (i.e., taxa with low growth rates) under criterion A are more likely to be reliable than for less threatened taxa when assessed with population models. Greater scrutiny needs to be placed on data used to parameterize population models for species with high growth rates

  13. Variability of innate immune system genes in Native American populations-relationship with history and epidemiology.

    Science.gov (United States)

    Lindenau, Juliana Dal-Ri; Salzano, Francisco Mauro; Hurtado, Ana Magdalena; Hill, Kim R; Petzl-Erler, Maria Luiza; Tsuneto, Luiza Tamie; Hutz, Mara Helena

    2016-04-01

    The immune system of a host, defending him/her against invading pathogens, has two main subsystems: innate immunity and acquired immunity. There are several evidences showing that Native American populations are immunologically different from non-Native populations. Our aim was to describe the variability of innate immune system genes in Native American populations. We investigated heterozygozities and patterns of population differentiation (FST ) of 14 polymorphisms related to the innate immune response in five Native American populations (Aché, Guarani-Kaiowá, Guarani-Ñandeva, Kaingang, and Xavante) and the results were compared with the three major world population data (YRI, CEU, and CHB) available at the 1,000 genomes database. Mean heterozygosities ranged between 0.241 ± 0.057 (Aché) and 0.343 ± 0.033 (Kaingang), but no significant differences were observed (Friedman test, P = 0.197). Mean heterozygosities were also not significantly different when Amerindians were pooled and compared with the 1000 genomes populations (Friedman test, P = 0.506). When the Native American populations were grouped as Amerindians, a significantly higher FST value (0.194) was observed between the Amerindian and African populations. The Ewens-Watterson neutrality test showed that these markers are not under strong selective pressure. Native American populations present similar levels of heterozygosity as those of other continents, but are different from Africans in the frequency of polymorphisms of innate immune genes. This higher differentiation is probably due to demographic processes that occurred during the out-of-Africa event. © 2015 Wiley Periodicals, Inc.

  14. Genetic variability in populations of sweet corn, common corn and teosinte

    OpenAIRE

    Almeida,Cicero; Amorim,Edson Perito; Barbosa Neto,José Fernandes; Cardoso Filho,Julio Alves; Sereno,Maria Jane Cruz de Melo

    2011-01-01

    The maize (Zea mays L. ssp. mays) has several related species, called teosinte, which are distributed in various subspecies of Zea and other genera. Among the different types of corn, sweet corn shows a great potential for human food. This type was originated from mutations, which increased the amount of polysaccharide in the endosperm. In Brazil there are populations of sweet corn, common maize and teosinte, however, little is known about their genetic variability. Hence, the aim of this pre...

  15. Genetic variability in populations of sweet corn, common corn and teosinte.

    OpenAIRE

    Cicero Almeida; Edson Perito Amorim; José Fernandes Barbosa Neto; Julio Alves Cardoso Filho; Maria Jane Cruz de Melo Sereno

    2011-01-01

    The maize (Zea mays L. ssp. mays) has several related species, called teosinte, which are distributed in varioussubspecies of Zea and other genera. Among the different types of corn, sweet corn shows a great potential for human food. This typewas originated from mutations, which increased the amount of polysaccharide in the endosperm. In Brazil there are populations ofsweet corn, common maize and teosinte, however, little is known about their genetic variability. Hence, the aim of this presen...

  16. Genetic variability in chronic irradiated plant populations - Polymorphism and activity of antioxidant enzymes in chronic irradiated plant populations

    Energy Technology Data Exchange (ETDEWEB)

    Volkova, Polina Y.; Geras' kin, Stanislav A. [Russian Institute of Agricultural Radiology and Agroecology, 249030, Obninsk, Kievskoe shosse 109 km (Russian Federation)

    2014-07-01

    Introduction: The gene pool of natural population is constantly changing in order to provide the greatest fitness at this time. Ability of population to adapt to changing environmental conditions depends on genetic polymorphism of traits which are operates by selection. Chronic stress exposure can change amount or structure intra-population variability. Therefore, it is necessary to analyze the relationships between genetic polymorphism and stress factors, such as radiation exposure. This studies my assist in the development of new bio-indication methods. Materials and methods: Studying sites: Bryansk region is the most contaminated region of Russia as a result of Chernobyl accident. The initial activity by {sup 137}Cs on this territory reached 1 MBq/m{sup 2} above surface. Our study conducted in several districts of Bryansk region, which are characterized the most dose rate. Experimental sites similar to climate characteristics, stand of trees is homogeneous, pine trees take up a significant part of phytocenosis. Heavy metals content in soils and cones be within background. Dose rates vary from 0.14 to 130 mGy/year. Object: Pinus sylvestris L.,the dominant tree species in North European and Asian boreal forests. Scots pine has a long maturation period (18-20 month), which means that significant DNA damage may accumulate in the undifferentiated stem cells, even at low doses (or dose rates) during exposure to low concentrations of contaminants Isozyme analysis: We evaluated isozyme polymorphism of three antioxidant enzymes: superoxide dismutase, glutatione reductase and glutatione peroxidase. Analysis of enzymes activities: We chose key enzymes of antioxidant system for this experiment: superoxide dismutase, catalase and peroxidase. Results and conclusions: We estimated frequency of each allele in reference and experimental populations. based It was showed that frequency of rare alleles increase in chronic irradiated populations, i.e. increase the sampling variance

  17. Karyotype Variability and Inter-Population Genomic Differences in Freshwater Ostracods (Crustacea Showing Geographical Parthenogenesis

    Directory of Open Access Journals (Sweden)

    Radka Symonová

    2018-03-01

    Full Text Available Transitions from sexual to asexual reproduction are often associated with polyploidy and increased chromosomal plasticity in asexuals. We investigated chromosomes in the freshwater ostracod species Eucypris virens (Jurine, 1820, where sexual, asexual and mixed populations can be found. Our initial karyotyping of multiple populations from Europe and North Africa, both sexual and asexual, revealed a striking variability in chromosome numbers. This would suggest that chromosomal changes are likely to be accelerated in asexuals because the constraints of meiosis are removed. Hence, we employed comparative genomic hybridization (CGH within and among sexual and asexual populations to get insights into E. virens genome arrangements. CGH disclosed substantial genomic imbalances among the populations analyzed, and three patterns of genome arrangement between these populations: 1. Only putative ribosomal DNA (rDNA-bearing regions were conserved in the two populations compared indicating a high sequence divergence between these populations. This pattern is comparable with our findings at the interspecies level of comparison; 2. Chromosomal regions were shared by both populations to a varying extent with a distinct copy number variation in pericentromeric and presumable rDNA-bearing regions. This indicates a different rate of evolution in repetitive sequences; 3. A mosaic pattern of distribution of genomic material that can be explained as non-reciprocal genetic introgression and evidence of a hybrid origin of these individuals. We show an overall increased chromosomal dynamics in E. virens that is complementary with available phylogenetic and population genetic data reporting highly differentiated diploid sexual and asexual lineages with a wide variety of genetic backgrounds.

  18. Role of Obesity Variables in Detecting Hypertension in an Iranian Population.

    Science.gov (United States)

    Khashayar, Patricia; Aghaei Meybodi, Hamidreza; Rezaei Hemami, Mohsen; Larijani, Bagher

    2017-09-01

    As the high incidence of hypertension has been in conjunction with dramatic increase in the prevalence of obesity, many studies have suggested obesity as its underlying cause in diverse race and ethnic groups. The present study was designed to quantify the relationship between obesity variables and hypertension in Iranian population. A ROC curve analysis was also used to determine an optimal BMI cutoff for obesity with the aim of representing elevated incidence of hypertension in this population. The study population comprised of apparently healthy men and women who participated in the Iranian Multi-centric Osteoporosis Studies (IMOS), a multi-centric cross-sectional study carried out in urban areas of five great cities (Tehran, Tabriz, Mashhad, Shiraz and Bushehr). The anthropometric (weight, height, waist and hip circumferences) and blood pressure measures were reported in some 5724 subjects. The influence of these factors on systolic and diastolic blood pressure was assessed based on a list-wise method. There was a significant difference in the studied subjects anthropometric (weight classes (BMI), WC and HC, and WHR) and blood pressure variables; age, gender and weight, however, were the only factors significantly influencing SBP and DBP. Furthermore, BMI showed a significant impact on the overall risk of developing hypertension. General obesity rather than abdominal obesity is directly linked with higher blood pressure levels in Iranian population.

  19. Genomic variability ofHelicobacter pyloriisolates of gastric regions from two Colombian populations.

    Science.gov (United States)

    Matta, Andrés Jenuer; Pazos, Alvaro Jairo; Bustamante-Rengifo, Javier Andrés; Bravo, Luis Eduardo

    2017-02-07

    To compare the genomic variability and the multiple colonization of Helicobacter pylori ( H. pylori ) in patients with chronic gastritis from two Colombian populations with contrast in the risk of developing gastric cancer (GC): Túquerres-Nariño (High risk) and Tumaco-Nariño (Low risk). Four hundred and nine patients from both genders with dyspeptic symptoms were studied. Seventy-two patients were included in whom H. pylori was isolated from three anatomic regions of the gastric mucosa, (31/206) of the high risk population of GC (Túquerres) and (41/203) of the low risk population of GC (Tumaco). The isolates were genotyped by PCR-RAPD. Genetic diversity between the isolates was evaluated by conglomerates analysis and multiple correspondence analyses. The proportion of virulent genotypes of H. pylori was 99% in Túquerres and 94% in Tumaco. The coefficient of similarity of Nei-Li showed greater genetic diversity among isolates of Túquerres (0.13) than those of Tumaco (0.07). After adjusting by age, gender and type of gastritis, the multiple colonization was 1.7 times more frequent in Túquerres than in Tumaco ( P = 0.05). In Túquerres, high risk of GC there was a greater probability of multiple colonization by H. pylori . From the analysis of the results of the PCR-RAPD, it was found higher genetic variability in the isolates of H. pylori in the population of high risk for the development of GC.

  20. Genomic variability of Helicobacter pylori isolates of gastric regions from two Colombian populations

    Science.gov (United States)

    Matta, Andrés Jenuer; Pazos, Alvaro Jairo; Bustamante-Rengifo, Javier Andrés; Bravo, Luis Eduardo

    2017-01-01

    AIM To compare the genomic variability and the multiple colonization of Helicobacter pylori (H. pylori) in patients with chronic gastritis from two Colombian populations with contrast in the risk of developing gastric cancer (GC): Túquerres-Nariño (High risk) and Tumaco-Nariño (Low risk). METHODS Four hundred and nine patients from both genders with dyspeptic symptoms were studied. Seventy-two patients were included in whom H. pylori was isolated from three anatomic regions of the gastric mucosa, (31/206) of the high risk population of GC (Túquerres) and (41/203) of the low risk population of GC (Tumaco). The isolates were genotyped by PCR-RAPD. Genetic diversity between the isolates was evaluated by conglomerates analysis and multiple correspondence analyses. RESULTS The proportion of virulent genotypes of H. pylori was 99% in Túquerres and 94% in Tumaco. The coefficient of similarity of Nei-Li showed greater genetic diversity among isolates of Túquerres (0.13) than those of Tumaco (0.07). After adjusting by age, gender and type of gastritis, the multiple colonization was 1.7 times more frequent in Túquerres than in Tumaco (P = 0.05). CONCLUSION In Túquerres, high risk of GC there was a greater probability of multiple colonization by H. pylori. From the analysis of the results of the PCR-RAPD, it was found higher genetic variability in the isolates of H. pylori in the population of high risk for the development of GC. PMID:28223724

  1. Genetic and phenotypic variability of iris color in Buenos Aires population.

    Science.gov (United States)

    Hohl, Diana María; Bezus, Brenda; Ratowiecki, Julia; Catanesi, Cecilia Inés

    2018-01-01

    The aim of this work was to describe the phenotypic and genotypic variability related to iris color for the population of Buenos Aires province (Argentina), and to assess the usefulness of current methods of analysis for this country. We studied five Single Nucleotide Polymorphisms (SNPs) included in the IrisPlex kit, in 118 individuals, and we quantified eye color with Digital Iris Analysis Tool. The markers fit Hardy-Weinberg equilibrium for the whole sample, but not for rs12913832 within the group of brown eyes (LR=8.429; p=0.004). We found a remarkable association of HERC2 rs12913832 GG with blue color (p iris color. The results for the Buenos Aires population differ from those of other populations of the world for these polymorphisms (p iris color.

  2. Breast dose variability in a bi-racial population undergoing screening mammography

    International Nuclear Information System (INIS)

    Schubauer-Berigan, M.K.; Baron, L.; Frey, G.D.; Hoel, D.G.

    2002-01-01

    This study evaluated individual and population dose variability during screening mammography among 570 white and black women in South Carolina, USA. Aspects of dosimetry that were considered include compressed breast thickness (CBT), number of films per screening session, and dose in previous or subsequent sessions. Breast dose was log-normally distributed in the population, with a geometric mean of 6.6 mGy per session. Doses were significantly higher for black women, for women with high CBT or who receive more than two views per breast, and for the mediolateral oblique, compared to the craniocaudal view. No relationship was observed between age and dose. Total dose per breast varied by a factor of 20 across the study population, but the individual's dose varied little among repeat screening sessions, especially after adjusting for the number of films received per session. These results may inform assessments of the projected risks of inducing breast cancer from screening mammography. (author)

  3. Mitochondrial Control Region Variability in Mytilus galloprovincialis Populations from the Central-Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Ioannis A. Giantsis

    2014-06-01

    Full Text Available The variable domain 1 (VD1 domain of the control region and a small segment of the rrnaL gene of the F mtDNA type were sequenced and analyzed in 174 specimens of Mytilus galloprovincialis. Samples were collected from eight locations in four Central-Eastern (CE Mediterranean countries (Italy, Croatia, Greece and Turkey. A new primer, specific for the F mtDNA type, was designed for the sequencing procedure. In total 40 different haplotypes were recorded, 24 of which were unique. Aside from the two populations situated in Thermaikos gulf (Northern Aegean, Greece, relatively high levels of haplotype and nucleotide diversity were estimated for both Central and Eastern Mediterranean populations. Eight out of the 40 haplotypes were shared by at least three populations while two of them were found in all populations. ΦST and cluster analysis revealed lack of structuring among CE Mediterranean populations with the exception of those located at the Sea of Marmara and Croatian coast which were highly differentiated. Apart from the species’ inherit dispersal ability, anthropogenic activities, such as the repeated translocations of mussel spat, seem to have played an important role in shaping the current genetic population structure of CE M. galloprovincialis mussels.

  4. Essential oil variability in natural populations of Picea omorika, a rare European conifer.

    Science.gov (United States)

    Nikolić, Biljana; Tesević, Vele; Ethordević, Iris; Marin, Petar D; Bojović, Srdjan

    2009-02-01

    This study is the first report on the composition and variability of essential oil in the relic, endemic, and vulnerable tree species Serbian spruce, Picea omorika, in its natural populations. In the needles of 108 trees of four natural populations, 49 components of essential oils were identified. The main compounds were bornyl acetate (29.2%), camphene (18.7%), and alpha-pinene (12.9%). Fourteen additional components had the contents of up to 0.5%: alpha-cadinol (6.1%), limonene (5.8%), santene (3.5%), (E)-hex-2-enal (2.9%), T-cadinol (2.9%), delta-cadinene (2.3%), tricyclene (2.1%), myrcene (1.6%), beta-pinene (1.2%), borneol (0.9%), germacrene D (0.9%), alpha-muurolene (0.6%), and two unidentified compounds. Population IV from Milesevka Canyon had a much higher content of bornyl acetate (42.9%). Populations I-III from Mt. Tara were more abundant in sesquiterpenes (up to 18.2%). The content of bornyl acetate, the multi-variation analyses according to seven selected components, especially the cluster analysis and genetic analysis of alpha-cadinol, which suggested the monogenic type of heredity, showed a clear differentiation of the two geographic areas, the similarity of populations I-III from the area of Mt. Tara, and the separation of the population IV from Milesevka Canyon.

  5. Variability of n-alkanes and nonacosan-10-ol in natural populations of Picea omorika.

    Science.gov (United States)

    Nikolić, Biljana; Tešević, Vele; Ðorđević, Iris; Todosijević, Marina; Jadranin, Milka; Bojović, Srdjan; Marin, Petar D

    2013-03-01

    This is the first report of population variability of the contents of n-alkanes and nonacosan-10-ol in the needle epicuticular waxes of Serbian spruce (Picea omorika). The hexane extracts of needle samples originated from three natural populations in Serbia (Vranjak, Zmajevački potok, and Mileševka Canyon) were investigated by GC and GC/MS analyses. The amount of nonacosan-10-ol varied individually from 50.05 to 74.42% (65.74% in average), but the differences between the three investigated populations were not statistically confirmed. The results exhibited variability of the composition of n-alkanes in the epicuticular waxes with their size ranging from C(18) to C(35). The most abundant n-alkanes were C(29), C(31), and C(27) (35.22, 13.77, and 12.28% in average, resp.). The carbon preference index of all the n-alkanes (CPI(total)) of the P. omorika populations (average of populations I-III) ranged from 3.3 to 11.5 (mean of 5.9), while the average chain length (ACL) ranged from 26.6 to 29.2. The principal component and cluster analyses of the contents of nine n-alkanes showed the greatest difference for the population growing in the Mileševka Canyon. The obtained results were compared with previous literature data given for other Picea species, and this comparison was briefly discussed. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  6. Variability characteristics and comparison of Carex arenaria L. and Carex ligerica Gay populations based on rhizome characters

    Directory of Open Access Journals (Sweden)

    Lech Urbaniak

    2014-01-01

    Full Text Available The studies included 9 populations of Carex arenaria L. and 7 populations of Carex ligerica Gay, compared with each other on grounds of variability analysis, related to rhizome characters. The sedges reach in the area of Poland their eastern range limits, with isolated populations spread along the range margins. The studied plants were placed in a greenhouse in homogenous conditions,which made possible an analysis of genetic variability in the populations. The obtained results point to the absence of gene flow between the studied species and, thus, to their clearly distinct character. Genetic drift was postulated as one of the causes of the obtained variability pattern.

  7. Interpolating a consumption variable for scaling and generalizing potential population pressure on urbanizing natural areas

    Science.gov (United States)

    Varanka, Dalia; Jiang, Bin; Yao, Xiaobai

    2010-01-01

    Measures of population pressure, referring in general to the stress upon the environment by human consumption of resources, are imperative for environmental sustainability studies and management. Development based on resource consumption is the predominant factor of population pressure. This paper presents a spatial model of population pressure by linking consumption associated with regional urbanism and ecosystem services. Maps representing relative geographic degree and extent of natural resource consumption and degree and extent of impacts on surrounding areas are new, and this research represents the theoretical research toward this goal. With development, such maps offer a visualization tool for planners of various services, amenities for people, and conservation planning for ecologist. Urbanization is commonly generalized by census numbers or impervious surface area. The potential geographical extent of urbanism encompasses the environmental resources of the surrounding region that sustain cities. This extent is interpolated using kriging of a variable based on population wealth data from the U.S. Census Bureau. When overlayed with land-use/land-cover data, the results indicate that the greatest estimates of population pressure fall within mixed forest areas. Mixed forest areas result from the spread of cedar woods in previously disturbed areas where further disturbance is then suppressed. Low density areas, such as suburbanization and abandoned farmland are characteristic of mixed forest areas.

  8. Two-Locus Likelihoods Under Variable Population Size and Fine-Scale Recombination Rate Estimation.

    Science.gov (United States)

    Kamm, John A; Spence, Jeffrey P; Chan, Jeffrey; Song, Yun S

    2016-07-01

    Two-locus sampling probabilities have played a central role in devising an efficient composite-likelihood method for estimating fine-scale recombination rates. Due to mathematical and computational challenges, these sampling probabilities are typically computed under the unrealistic assumption of a constant population size, and simulation studies have shown that resulting recombination rate estimates can be severely biased in certain cases of historical population size changes. To alleviate this problem, we develop here new methods to compute the sampling probability for variable population size functions that are piecewise constant. Our main theoretical result, implemented in a new software package called LDpop, is a novel formula for the sampling probability that can be evaluated by numerically exponentiating a large but sparse matrix. This formula can handle moderate sample sizes ([Formula: see text]) and demographic size histories with a large number of epochs ([Formula: see text]). In addition, LDpop implements an approximate formula for the sampling probability that is reasonably accurate and scales to hundreds in sample size ([Formula: see text]). Finally, LDpop includes an importance sampler for the posterior distribution of two-locus genealogies, based on a new result for the optimal proposal distribution in the variable-size setting. Using our methods, we study how a sharp population bottleneck followed by rapid growth affects the correlation between partially linked sites. Then, through an extensive simulation study, we show that accounting for population size changes under such a demographic model leads to substantial improvements in fine-scale recombination rate estimation. Copyright © 2016 by the Genetics Society of America.

  9. Comparative performance of different stochastic methods to simulate drug exposure and variability in a population.

    Science.gov (United States)

    Tam, Vincent H; Kabbara, Samer

    2006-10-01

    Monte Carlo simulations (MCSs) are increasingly being used to predict the pharmacokinetic variability of antimicrobials in a population. However, various MCS approaches may differ in the accuracy of the predictions. We compared the performance of 3 different MCS approaches using a data set with known parameter values and dispersion. Ten concentration-time profiles were randomly generated and used to determine the best-fit parameter estimates. Three MCS methods were subsequently used to simulate the AUC(0-infinity) of the population, using the central tendency and dispersion of the following in the subject sample: 1) K and V; 2) clearance and V; 3) AUC(0-infinity). In each scenario, 10000 subject simulations were performed. Compared to true AUC(0-infinity) of the population, mean biases by various methods were 1) 58.4, 2) 380.7, and 3) 12.5 mg h L(-1), respectively. Our results suggest that the most realistic MCS approach appeared to be based on the variability of AUC(0-infinity) in the subject sample.

  10. Cellular and circuit mechanisms maintain low spike co-variability and enhance population coding in somatosensory cortex

    Directory of Open Access Journals (Sweden)

    Cheng eLy

    2012-03-01

    Full Text Available The responses of cortical neurons are highly variable across repeated presentations of a stimulus. Understanding this variability is critical for theories of both sensory and motor processing, since response variance affects the accuracy of neural codes. Despite this influence, the cellular and circuit mechanisms that shape the trial-to-trial variability of population responses remain poorly understood. We used a combination of experimental and computational techniques to uncover the mechanisms underlying response variability of populations of pyramidal (E cells in layer 2/3 of rat whisker barrel cortex. Spike trains recorded from pairs of E-cells during either spontaneous activity or whisker deflected responses show similarly low levels of spiking co-variability, despite large differences in network activation between the two states. We developed network models that show how spike threshold nonlinearities dilutes E-cell spiking co-variability during spontaneous activity and low velocity whisker deflections. In contrast, during high velocity whisker deflections, cancelation mechanisms mediated by feedforward inhibition maintain low E-cell pairwise co-variability. Thus, the combination of these two mechanisms ensure low E-cell population variability over a wide range of whisker deflection velocities. Finally, we show how this active decorrelation of population variability leads to a drastic increase in the population information about whisker velocity. The canonical cellular and circuit components of our study suggest that low network variability over a broad range of neural states may generalize across the nervous system.

  11. GSTM1, GSTP1, and GSTT1 genetic variability in Turkish and worldwide populations.

    Science.gov (United States)

    Karaca, Sefayet; Karaca, Mehmet; Cesuroglu, Tomris; Erge, Sema; Polimanti, Renato

    2015-01-01

    Glutathione S-transferase (GST) variants have been widely investigated to better understand their role in several pathologic conditions. To our knowledge, no data about these genetic polymorphisms within the Turkish population are currently available. The aim of this study was to analyze GSTM1 positive/null, GSTT1 positive/null, GSTP1*I105V (rs1695), and GSTP1*A114V (rs1138272) variants in the general Turkish population, to provide information about its genetic diversity, and predisposition to GST-related diseases. Genotyping was performed in 500 Turkish individuals using the Sequenom MassARRAY platform. A comparative analysis was executed using the data from the HapMap and Human Genome Diversity Projects (HGDP). Sequence variation was deeply explored using the Phase 1 data of the 1,000 Genomes Project. The variability of GSTM1, GSTT1, and GSTP1 polymorphisms in the Turkish population was similar to that observed in Central Asian, European, and Middle Eastern populations. The high linkage disequilibrium between GSTP1*I105V and GSTP1*A114V in these populations may have a confounding effect on GSTP1 genetic association studies. In analyzing GSTM1, GSTT1, and GSTP1 sequence variation, we observed other common functional variants that may be candidates for associated studies of diseases related to GST genes (e.g., cancer, cardiovascular disease, and allergy). This study provides novel data about GSTM1 positive/null, GSTT1 positive/null, GSTP1*I105V, and GSTP1*A114V variants in the Turkish population, and other functional variants that may affect GSTM1, GSTT1, and GSTP1 functions among worldwide populations. This information can assist in the design of future genetic association studies investigating oxidative stress-related diseases. © 2014 Wiley Periodicals, Inc.

  12. The neural underpinnings of music listening under different attention conditions.

    Science.gov (United States)

    Jäncke, Lutz; Leipold, Simon; Burkhard, Anja

    2018-05-02

    Most studies examining the neural underpinnings of music listening have no specific instruction on how to process the presented musical pieces. In this study, we explicitly manipulated the participants' focus of attention while they listened to the musical pieces. We used an ecologically valid experimental setting by presenting the musical stimuli simultaneously with naturalistic film sequences. In one condition, the participants were instructed to focus their attention on the musical piece (attentive listening), whereas in the second condition, the participants directed their attention to the film sequence (passive listening). We used two instrumental musical pieces: an electronic pop song, which was a major hit at the time of testing, and a classical musical piece. During music presentation, we measured electroencephalographic oscillations and responses from the autonomic nervous system (heart rate and high-frequency heart rate variability). During passive listening to the pop song, we found strong event-related synchronizations in all analyzed frequency bands (theta, lower alpha, upper alpha, lower beta, and upper beta). The neurophysiological responses during attentive listening to the pop song were similar to those of the classical musical piece during both listening conditions. Thus, the focus of attention had a strong influence on the neurophysiological responses to the pop song, but not on the responses to the classical musical piece. The electroencephalographic responses during passive listening to the pop song are interpreted as a neurophysiological and psychological state typically observed when the participants are 'drawn into the music'.

  13. Flares of Orion population variables in the association Taurus T3

    International Nuclear Information System (INIS)

    Khodzhaev, A.S.; AN Armyanskoj SSR, Byurakan. Astrofizicheskaya Observatoriya)

    1987-01-01

    Thirteen new flare stars, proved to be irregular variables of Orion Population, were discovered from a study of the Taurus Dark Cloud region by the homogeneous photographic multipose method on the wide angle Schmidt telescopes of the Byurakan Astorphysical Observatory. Seventeen flares on these stars were detected for about 750 hours of the effective observing time. The analysis of the complicated light curves of these flares shows a great variety and multiplicity of this phenomenon and various dynamics of flare energy release processes. The existence of flare stars with some properties typical for both of the T Tauri and UV Ceti stars simulteneously indicates nonstable stars. The population of flare stars in the Taurus Dark Cloud region is apparently as young as in Orion and Monoceros

  14. Predicting farm-level animal populations using environmental and socioeconomic variables.

    Science.gov (United States)

    van Andel, Mary; Jewell, Christopher; McKenzie, Joanna; Hollings, Tracey; Robinson, Andrew; Burgman, Mark; Bingham, Paul; Carpenter, Tim

    2017-09-15

    Accurate information on the geographic distribution of domestic animal populations helps biosecurity authorities to efficiently prepare for and rapidly eradicate exotic diseases, such as Foot and Mouth Disease (FMD). Developing and maintaining sufficiently high-quality data resources is expensive and time consuming. Statistical modelling of population density and distribution has only begun to be applied to farm animal populations, although it is commonly used in wildlife ecology. We developed zero-inflated Poisson regression models in a Bayesian framework using environmental and socioeconomic variables to predict the counts of livestock units (LSUs) and of cattle on spatially referenced farm polygons in a commercially available New Zealand farm database, Agribase. Farm-level counts of cattle and of LSUs varied considerably by region, because of the heterogeneous farming landscape in New Zealand. The amount of high quality pasture per farm was significantly associated with the presence of both cattle and LSUs. Internal model validation (predictive performance) showed that the models were able to predict the count of the animal population on groups of farms that were located in randomly selected 3km zones with a high level of accuracy. Predicting cattle or LSU counts on individual farms was less accurate. Predicted counts were statistically significantly more variable for farms that were contract grazing dry stock, such as replacement dairy heifers and dairy cattle not currently producing milk, compared with other farm types. This analysis presents a way to predict numbers of LSUs and cattle for farms using environmental and socio-economic data. The technique has the potential to be extrapolated to predicting other pastoral based livestock species. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. HLA-E regulatory and coding region variability and haplotypes in a Brazilian population sample.

    Science.gov (United States)

    Ramalho, Jaqueline; Veiga-Castelli, Luciana C; Donadi, Eduardo A; Mendes-Junior, Celso T; Castelli, Erick C

    2017-11-01

    The HLA-E gene is characterized by low but wide expression on different tissues. HLA-E is considered a conserved gene, being one of the least polymorphic class I HLA genes. The HLA-E molecule interacts with Natural Killer cell receptors and T lymphocytes receptors, and might activate or inhibit immune responses depending on the peptide associated with HLA-E and with which receptors HLA-E interacts to. Variable sites within the HLA-E regulatory and coding segments may influence the gene function by modifying its expression pattern or encoded molecule, thus, influencing its interaction with receptors and the peptide. Here we propose an approach to evaluate the gene structure, haplotype pattern and the complete HLA-E variability, including regulatory (promoter and 3'UTR) and coding segments (with introns), by using massively parallel sequencing. We investigated the variability of 420 samples from a very admixed population such as Brazilians by using this approach. Considering a segment of about 7kb, 63 variable sites were detected, arranged into 75 extended haplotypes. We detected 37 different promoter sequences (but few frequent ones), 27 different coding sequences (15 representing new HLA-E alleles) and 12 haplotypes at the 3'UTR segment, two of them presenting a summed frequency of 90%. Despite the number of coding alleles, they encode mainly two different full-length molecules, known as E*01:01 and E*01:03, which corresponds to about 90% of all. In addition, differently from what has been previously observed for other non classical HLA genes, the relationship among the HLA-E promoter, coding and 3'UTR haplotypes is not straightforward because the same promoter and 3'UTR haplotypes were many times associated with different HLA-E coding haplotypes. This data reinforces the presence of only two main full-length HLA-E molecules encoded by the many HLA-E alleles detected in our population sample. In addition, this data does indicate that the distal HLA-E promoter is by

  16. Essential oil composition and variability of Hypericum perforatum L. from wild population in Kosovo

    Directory of Open Access Journals (Sweden)

    Hajdari Avni

    2014-06-01

    Full Text Available Aerial parts of Hypericum perforatum L. (Hypericaceae were collected from five wild populations in Kosovo, with aim to investigate the chemical composition and natural variation of essential oils between wild populations. This species could be considered of economic potential as it is widespread in Kosovo, on the other hand H. perforatum is one of the best-known medicinal herbs used in Kosovo folk medicine. Essential oils were obtained by steam distillation and analysed by GC-FID and GC-MS. Sixty-seven components were identified. The yields of essential oils differed depending on the population and ranged from 0.04 to 0.26% based on dry weight. The aerial parts of H. perforatum were characterized by the following main constituents: 2-methyl-octane (1.1-15.5%, α-pinene (3.7-36.5%, β-caryophyllene (1.2-12.4%, caryophyllene oxide (3.3-17.7% and n-tetradecanol (3.6- 10.4%. Hierarchical cluster analysis revealed that the concentration of components depends on the origin of the plant populations, thus α-pinene and 2-methyl-octane were present in the highest concentration in population originating from Gjakove, Prizren and Ferizaj, whereas in the populations originating from Peje and Prishtine the most abundant constituents were caryophyllene oxide, β-caryophyllene and n-tetradecanol. Further investigation is needed to establish the natural variability and chemopolymorphism of this species in the territory of Kosovo, which should be supported by molecular level analyses.

  17. Mixing times towards demographic equilibrium in insect populations with temperature variable age structures.

    Science.gov (United States)

    Damos, Petros

    2015-08-01

    In this study, we use entropy related mixing rate modules to measure the effects of temperature on insect population stability and demographic breakdown. The uncertainty in the age of the mother of a randomly chosen newborn, and how it is moved after a finite act of time steps, is modeled using a stochastic transformation of the Leslie matrix. Age classes are represented as a cycle graph and its transitions towards the stable age distribution are brought forth as an exact Markov chain. The dynamics of divergence, from a non equilibrium state towards equilibrium, are evaluated using the Kolmogorov-Sinai entropy. Moreover, Kullback-Leibler distance is applied as information-theoretic measure to estimate exact mixing times of age transitions probabilities towards equilibrium. Using empirically data, we show that on the initial conditions and simulated projection's trough time, that population entropy can effectively be applied to detect demographic variability towards equilibrium under different temperature conditions. Changes in entropy are correlated with the fluctuations of the insect population decay rates (i.e. demographic stability towards equilibrium). Moreover, shorter mixing times are directly linked to lower entropy rates and vice versa. This may be linked to the properties of the insect model system, which in contrast to warm blooded animals has the ability to greatly change its metabolic and demographic rates. Moreover, population entropy and the related distance measures that are applied, provide a means to measure these rates. The current results and model projections provide clear biological evidence why dynamic population entropy may be useful to measure population stability. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Genetic variability of CYP2B6 polymorphisms in four southern Chinese populations

    Science.gov (United States)

    Xu, Bing-Ying; Guo, Li-Ping; Lee, Shui-Shan; Dong, Qing-Ming; Tan, Yi; Yao, Hong; Li, Li-Hua; Lin, Che-Kit; Kung, Hsiang-Fu; He, Ming-Liang

    2007-01-01

    AIM: To investigate the genotype and allelic frequencies of Cytochrome P450 2B6 polymorphisms in four southern Chinese populations. METHODS: DNA was obtained from blood samples from Han Chinese from Hong Kong and three minority groups, the Wa, Bulang and Lahu from Yunnan in southern China. Genotyping was performed using real-time PCR and confirmed by direct sequencing. RESULTS: A total of 507 subjects from southern China were studied. Results showed there is a high prevalence of 516G > T (34.5%) in ethnic Chinese compared to literature reports on other Asian populations and Caucasians. The frequency of the 516TT genotype is higher in the Han majority (23.1%) than in three other ethnic minority groups (i.e., 7.4%, 9.1% and 15.8%) in southern China. CONCLUSION: This was the first study to document the spectrum of CYP2B6 allelic variants and genotypes in a southern Chinese population. The 516G > T allele is associated with a defective metabolism of efavirenz (EFV), which therefore may predispose to drug toxicity. Treatment regimens for human immunodeficiency virus (HIV) and heroin addiction may need to be optimized in different populations because of the marked variability of the key metabolizing enzyme. PMID:17465455

  19. Eyes to See: The Foothold of Jihadi Underpinnings

    National Research Council Canada - National Science Library

    Klein, Jr, John M

    2007-01-01

    .... These underpinnings are well-established and rigorously authenticated precepts that serve as a foothold for Jihadi conduct, making Islam a ready-made ideology that suits the Jihadis' insatiable goals...

  20. Variability of stomatal conductance in a small and isolated population of silver fir (Abies alba Mill.).

    Science.gov (United States)

    Piovani, Paolo; Leonardi, Stefano; Magnani, Federico; Menozzi, Paolo

    2011-05-01

    We analyzed the response to drought of 420 individuals from eight half-sib families from a small and isolated population of silver fir (Abies alba Mill.): 105 of them were kept in well-watered conditions as control while the remaining 315 were exposed to drought for 27 days. A model describing stomatal behavior derived from Monteith and developed in beech by Leonardi et al. was fitted to experimental transpiration data obtained simply from the difference between two daily pot weighings. The estimated parameters were maximum stomatal conductance, maximum transpiration in well-watered conditions and sensitivity to soil water deficit. The model worked well: convergence for all but four individuals and concordance between experimental and fitted data were good (R(2)=0.86). Inter-individual variability for all three estimated parameters was high and two of them (maximum stomatal conductance and sensitivity to soil water deficit) were significantly different among families, suggesting genetic control. Our results validate the simplified method used to evaluate individual stomatal parameters. We also show that in the small and isolated population of our study substantial adaptive variability remains, a crucial prerequisite to endure environmental conditions determined by climatic change foreseen for the next decades. © The Author 2011. Published by Oxford University Press. All rights reserved.

  1. The influence of climatic variability on local population dynamics of Cercidium microphyllum (foothill paloverde)

    Science.gov (United States)

    Bowers, Janice E.; Turner, R.M.

    2002-01-01

    This study investigated correlations among climatic variability, population age structure, and seedling survival of a dominant Sonoran Desert tree, Cercidium microphyllum (foothill paloverde), at Tucson, Arizona, USA. A major goal was to determine whether wet years promote seedling establishment and thereby determine population structure. Plant age was estimated from basal circumference for a sample of 980 living and dead trees in twelve 0.5-ha plots. Ages ranged from 1 to 181 years. Age frequency distribution showed that the population is in decline. Most (51.2%) of the 814 living trees were 40-80 years old; only 6.5% were younger than 20 years. The average age of the 166 dead trees was 78 years. Fifty-nine percent of dead trees were aged 60-100 years. Survival of newly emerged seedlings was monitored for 7 years in a 557-m2 permanent plot. Mean survival in the 1st year of life was 1.7%. Only 2 of 1,008 seedlings lived longer than 1 year. Length of survival was not correlated with rainfall. Residual regeneration, an index of the difference between predicted and observed cohort size, showed that regeneration was high during the first half of the twentieth century and poor after the mid-1950s. Trends in regeneration did not reflect interannual variation in seasonal temperature or rain before 1950, that is, in the years before urban warming. Taken together, the seedling study and the regeneration analysis suggest that local population dynamics reflect biotic factors to such an extent that population age structure might not always be a reliable clue to past climatic influences.

  2. A NEW MODIFIED RATIO ESTIMATOR FOR ESTIMATION OF POPULATION MEAN WHEN MEDIAN OF THE AUXILIARY VARIABLE IS KNOWN

    Directory of Open Access Journals (Sweden)

    Jambulingam Subramani

    2013-10-01

    Full Text Available The present paper deals with a modified ratio estimator for estimation of population mean of the study variable when the population median of the auxiliary variable is known. The bias and mean squared error of the proposed estimator are derived and are compared with that of existing modified ratio estimators for certain known populations. Further we have also derived the conditions for which the proposed estimator performs better than the existing modified ratio estimators. From the numerical study it is also observed that the proposed modified ratio estimator performs better than the existing modified ratio estimators for certain known populations.

  3. Variable population exposure and distributed travel speeds in least-cost tsunami evacuation modelling

    Science.gov (United States)

    Fraser, Stuart A.; Wood, Nathan J.; Johnston, David A.; Leonard, Graham S.; Greening, Paul D.; Rossetto, Tiziana

    2014-01-01

    Evacuation of the population from a tsunami hazard zone is vital to reduce life-loss due to inundation. Geospatial least-cost distance modelling provides one approach to assessing tsunami evacuation potential. Previous models have generally used two static exposure scenarios and fixed travel speeds to represent population movement. Some analyses have assumed immediate departure or a common evacuation departure time for all exposed population. Here, a method is proposed to incorporate time-variable exposure, distributed travel speeds, and uncertain evacuation departure time into an existing anisotropic least-cost path distance framework. The method is demonstrated for hypothetical local-source tsunami evacuation in Napier City, Hawke's Bay, New Zealand. There is significant diurnal variation in pedestrian evacuation potential at the suburb level, although the total number of people unable to evacuate is stable across all scenarios. Whilst some fixed travel speeds approximate a distributed speed approach, others may overestimate evacuation potential. The impact of evacuation departure time is a significant contributor to total evacuation time. This method improves least-cost modelling of evacuation dynamics for evacuation planning, casualty modelling, and development of emergency response training scenarios. However, it requires detailed exposure data, which may preclude its use in many situations.

  4. Variability in permanent tooth size of three ancient populations in Xi'an, northern China.

    Science.gov (United States)

    Huang, Shi-You; Kang, Ting; Liu, Dai-Yun; Duan, Yin-Zhong; Shao, Jin-Ling

    2012-11-01

    This paper compares permanent dental dimensions between three ancient populations that belonged to the same biological population throughout a temporal range of 2000 years to detect temporal trends and metric variation in dentition. The samples analysed were dental remains of 4502 permanent teeth from 321 individuals, which were excavated from three archaeological sites: Chang'an (1000-1300 years BP), Shanren (2200 years BP) and Shaolingyuan (3000 years BP) in the Xi'an region (northern China). For each tooth three standard measurements were taken: Mesiodistal (MD) diameter of crown, labiolingual or buccolingual (BL) diameter of crown and length of root (LR). Three ancient population samples generally displayed the same dental dimensions (p>0.05), whereas some tooth types varied. The Shaolingyuan had larger canine and the smallest maxillary second molars and the Chang'an had the largest mandibular first molars in the MD dimension. The Shanren had the smallest maxillary third molars and mandibular central incisors, and the Chang'an had the smallest maxillary lateral incisors in the BL dimension. In the LR measures, statistically significant differences of five tooth types showed that the Chang'an were smaller than the Shaolingyuan and the Shanren. Comparisons of coefficients of variation for teeth showed that the length of root and third molar usually displayed greater variation. Decreasing or increasing trend for crown size does not occur between the ancient populations, while changes in crown size of a few tooth types fluctuate. The root size is more variable than the crown size and is likely to reflect a degenerated trend in a few tooth types. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Short-term practice effects and variability in cognitive testing in a healthy elderly population

    DEFF Research Database (Denmark)

    Krenk, L.; Rasmussen, L.S.; Siersma, V.

    2012-01-01

    BACKGROUND: Cognitive decline in the elderly is a subject of intense focus. However, there is a lack of consensus regarding definition of significant decline in connection with repeated testing and the interpretation of cognitive tests results must take into account the practice effect and variab......BACKGROUND: Cognitive decline in the elderly is a subject of intense focus. However, there is a lack of consensus regarding definition of significant decline in connection with repeated testing and the interpretation of cognitive tests results must take into account the practice effect...... and variability in test performance. The aim of this study was to collect cognitive test results with repeated testing in an elderly healthy population. METHODS: 161 healthy controls =60years were included. Cognitive testing was performed upon entry into the study, at 1week and 3months. Practice effect...

  6. Environmental forcing and Southern Ocean marine predator populations: effects of climate change and variability.

    Science.gov (United States)

    Trathan, P N; Forcada, J; Murphy, E J

    2007-12-29

    The Southern Ocean is a major component within the global ocean and climate system and potentially the location where the most rapid climate change is most likely to happen, particularly in the high-latitude polar regions. In these regions, even small temperature changes can potentially lead to major environmental perturbations. Climate change is likely to be regional and may be expressed in various ways, including alterations to climate and weather patterns across a variety of time-scales that include changes to the long interdecadal background signals such as the development of the El Niño-Southern Oscillation (ENSO). Oscillating climate signals such as ENSO potentially provide a unique opportunity to explore how biological communities respond to change. This approach is based on the premise that biological responses to shorter-term sub-decadal climate variability signals are potentially the best predictor of biological responses over longer time-scales. Around the Southern Ocean, marine predator populations show periodicity in breeding performance and productivity, with relationships with the environment driven by physical forcing from the ENSO region in the Pacific. Wherever examined, these relationships are congruent with mid-trophic-level processes that are also correlated with environmental variability. The short-term changes to ecosystem structure and function observed during ENSO events herald potential long-term changes that may ensue following regional climate change. For example, in the South Atlantic, failure of Antarctic krill recruitment will inevitably foreshadow recruitment failures in a range of higher trophic-level marine predators. Where predator species are not able to accommodate by switching to other prey species, population-level changes will follow. The Southern Ocean, though oceanographically interconnected, is not a single ecosystem and different areas are dominated by different food webs. Where species occupy different positions in

  7. Heart rate variability findings as a predictor of atrial fibrillation in middle-aged population.

    Science.gov (United States)

    Perkiömäki, Juha; Ukkola, Olavi; Kiviniemi, Antti; Tulppo, Mikko; Ylitalo, Antti; Kesäniemi, Y Antero; Huikuri, Heikki

    2014-07-01

    Autonomic nervous system modifies atrial electrophysiologic properties and arrhythmia vulnerability. Heart rate (HR) variability, an indicator of cardiac autonomic regulation, was measured in 784 subjects (mean age 51 ± 6 years; 54% males) from a standardized 45-minute period in a study population (n = 1,045), which consisted of randomly selected hypertensive and age- and sex-matched control subjects at the time of recruitment in 1991-1992 (the OPERA study). During a mean follow-up of 16.5 ± 3.5 years, 76 subjects (9.7%) had developed symptomatic atrial fibrillation (AF), needing hospitalization. HR did not predict the occurrence of AF. Among the various spectral and time-domain HR variability indexes, only the low-frequency (LF) spectral component independently predicted AF. In the Cox regression analysis, the hazard ratio of reduced HR corrected LF (LFccv ≤ 1.59%, optimal cutoff from the ROC curve) in predicting the AF was 3.28 (95% CI: 2.06-5.24; P system in the genesis of symptomatic AF. © 2014 Wiley Periodicals, Inc.

  8. Variables associated with olfactory disorders in adults: A U.S. population-based analysis

    Directory of Open Access Journals (Sweden)

    Julia Noel

    2017-03-01

    Full Text Available Objective: Olfactory dysfunction is known to have significant social, psychological, and safety implications. Despite increasingly recognized prevalence, potential risk factors for olfactory loss have been arbitrarily documented and knowledge is limited in scale. The aim of this study is to identify potential demographic and exposure variables correlating with olfactory dysfunction. Methods: Cross-sectional analysis of the 2011–2012 and 2013–2014 editions of the National Health Examination and Nutrition Survey was performed. The utilized survey reports from a nationally representative sample of about 5000 persons each year located in counties across the United States. There is an interview and physical examination component which includes demographic, socioeconomic, dietary, and health-related questions as well as medical, dental, physiologic measurements, and laboratory tests. 3594 adult respondents from 2011 to 2012 and 3708 respondents from 2013 to 2014 were identified from the above population-based database. The frequency of self-reported disorders as well as performance on odor identification testing was determined in relation to demographic factors, occupational or environmental exposures, and urinary levels of environmental and industrial compounds. Results: In both subjective and objective analysis, smell disorders were significantly more common with increasing age. While the non-Hispanic Black and non-Hispanic Asian populations were less likely to report subjective olfactory loss, they, along with Hispanics, performed more poorly on odor identification than Caucasians. Those with limited education had a decreased prevalence of hyposmia. Women outperformed men on smell testing. Those reporting exposure to vapors were more likely to experience olfactory dysfunction, and urinary levels of manganese, 2-Thioxothiazolidine-4-carboxylic acid, and 2-Aminothiazoline-4-carboxylic acid were lower among respondents with subjective smell

  9. Essential oil composition variability among natural populations of Pinus mugo Turra in Kosovo.

    Science.gov (United States)

    Hajdari, Avni; Mustafa, Behxhet; Ahmeti, Gresa; Pulaj, Bledar; Lukas, Brigitte; Ibraliu, Alban; Stefkov, Gjoshe; Quave, Cassandra L; Novak, Johannes

    2015-01-01

    Pinus mugo Turra, is a native pine species in central and southern Europe, growing in high mountains area (altitudes 1.800-2.300 m.a.s.l.). In Kosovo, it is one of the native pines too, distributed in high altitudes in the Sharri Mountains and Albanian Alps Mountains. Its populations represent an important wealth of essential oil resources available, which make this species very important in terms of economic values. The chemical composition and yields of the essential oils of dwarf pine (Pinus mugo Turra) needles, twigs and cones from six wild populations in Kosovo were investigated with the aim to assess their natural variability. The identity of P. mugo was confirmed by morphology and DNA barcoding. Sixty-two compounds were identified representing 69-95 % of the total identified compounds. The yield ranged from 0.3-0.8 % v/w in needles, 1.0-2.4 % v/w in twigs and 0.1-0.5 % v/w in cones, depending on the origin of plant material and plant organs. α-Pinene (needles: 16.9-24.5 %; twigs: 4.5-8.8 %; cones: 3.1-5.6 %), β-pinene (needles: 1.5-5.4 %; twigs: 2.2-15.4 %; cones: 1.3-14.2 %), δ-3-carene (needles: 15.4-27.8 %; twigs: 24.0-51.6 %; cones: 10.5-31.5 %), limonene + β-phellandrene (needles: 1.9-5.9 %; twigs: 12.6-24.2 %; cones: 2.1-9.3 %), (E)-caryophyllene (needles: 4.4-8.9 %; twigs: 4.0-10.8 %; cones: 10.3-26.9 %) and germacrene D (needles: 4.0-8.3 %; twigs: 0.2-6.19 %; cones: 0.1-12.4 %) were the major components of the essential oil. Principal component analysis (PCA) and hierarchical cluster analyses (HCA) suggests that the population of P. mugo clustering is not related to their geographic location, but rather seemed to be linked to local selective forces acting on chemotype diversity. Low variability related to their geographic location has an economic importance since samples originating from different locations in Kosovo can treated with same standards.

  10. A highly variable segment of human subterminal 16p reveals a history of population growth for modern humans outside Africa

    Science.gov (United States)

    Alonso, Santos; Armour, John A. L.

    2001-01-01

    We have sequenced a highly polymorphic subterminal noncoding region from human chromosome 16p13.3, flanking the 5′ end of the hypervariable minisatellite MS205, in 100 chromosomes sampled from different African and Euroasiatic populations. Coalescence analysis indicates that the time to the most recent common ancestor (approximately 1 million years) predates the appearance of anatomically modern human forms. The root of the network describing this variability lies in Africa. African populations show a greater level of diversity and deeper branches. Most Euroasiatic variability seems to have been generated after a recent out-of-Africa range expansion. A history of population growth is the most likely scenario for the Euroasiatic populations. This pattern of nuclear variability can be reconciled with inferences based on mitochondrial DNA. PMID:11158547

  11. Variable Stars and Stellar Populations in Andromeda XXVII. IV. An Off-centered, Disrupted Galaxy

    Science.gov (United States)

    Cusano, Felice; Garofalo, Alessia; Clementini, Gisella; Cignoni, Michele; Muraveva, Tatiana; Tessicini, Gianni; Testa, Vincenzo; Paris, Diego; Federici, Luciana; Marconi, Marcella; Ripepi, Vincenzo; Musella, Ilaria

    2017-12-01

    We present B and V time-series photometry of the M31 satellite galaxy Andromeda XXVII (And XXVII) that we observed with the Large Binocular Cameras of the Large Binocular Telescope. In the field of And XXVII we have discovered a total of 90 variables: 89 RR Lyrae stars and 1 Anomalous Cepheid. The average period of the fundamental mode RR Lyrae stars (RRab) =0.59 {days} (σ = 0.05 day) and the period-amplitude diagram place And XXVII in the class of Oosterhoff I/Intermediate objects. Combining information from the color-magnitude diagram (CMD) and the variable stars, we find evidence for a single old and metal-poor stellar population with [Fe/H] ˜ -1.8 dex and t ˜ 13 Gyr in And XXVII. The spatial distributions of RR Lyrae and red giant branch (RGB) stars give clear indication that And XXVII is a completely disrupted system. This is also supported by the spread observed along the line of sight in the distance to the RR Lyrae stars. The highest concentration of RGB and RR Lyrae stars is found in a circular area of 4 arcmin in radius, centered about 0.°2 in the southeast direction from Richardson et al.’s center coordinates of And XXVII. The CMD of this region is well-defined, with a prominent RGB and 15 RR Lyrae stars (out of the 18 found in the region) tracing a very tight horizontal branch at =25.24 {mag} σ = 0.06 mag (average over 15 stars). We show that And XXVII is a strong candidate building block of the M31 halo. Based on data collected with the Large Binocular Cameras at the Large Binocular Telescope, PI: G. Clementini.

  12. Epidemiology and genetic variability of HHV-8/KSHV in Pygmy and Bantu populations in Cameroon.

    Directory of Open Access Journals (Sweden)

    Edouard Betsem

    2014-05-01

    Full Text Available BACKGROUND: Kaposi's sarcoma associated herpesvirus (KSHV/HHV-8 is the causal agent of all forms of Kaposi sarcoma. Molecular epidemiology of the variable K1 region identified five major subtypes exhibiting a clear geographical clustering. The present study is designed to gain new insights into the KSHV epidemiology and genetic diversity in Cameroon. METHODOLOGY/PRINCIPAL FINDINGS: Bantu and Pygmy populations from remote rural villages were studied. Antibodies directed against latent nuclear antigens (LANA were detected by indirect immunofluorescence using BC3 cells. Peripheral blood cell DNAs were subjected to a nested PCR amplifying a 737 bp K1 gene fragment. Consensus sequences were phylogenetically analyzed. We studied 2,063 persons (967 females, 1,096 males, mean age 39 years, either Bantus (1,276 or Pygmies (787. The Bantu group was older (42 versus 35 years: P<10(-4. KSHV anti-LANA seroprevalence was of 37.2% (768/2063, with a significant increase with age (P<10(-4 but no difference according to sex. Seroprevalence, as well as the anti-LANA antibodies titres, were higher in Bantus (43.2% than in Pygmies (27.6% (P<10(-4, independently of age. We generated 29 K1 sequences, comprising 24 Bantus and five Pygmies. These sequences belonged to A5 (24 cases or B (five cases subtypes. They exhibited neither geographical nor ethnic aggregation. A5 strains showed a wide genetic diversity while the B strains were more homogenous and belonged to the B1 subgroup. CONCLUSION: These data demonstrate high KSHV seroprevalence in the two major populations living in Southern and Eastern Cameroon with presence of mostly genetically diverse A5 but also B K1 subtypes.

  13. Population growth rate and genetic variability of small and large populations of Red flour beetle (Tribolium castaneum) following multigenerational exposure to copper.

    Science.gov (United States)

    Laskowski, Ryszard; Radwan, Jacek; Kuduk, Katarzyna; Mendrok, Magdalena; Kramarz, Paulina

    2015-07-01

    We reared large (1000 individuals) and small (20 individuals) populations of Tribolium castaneum on diet contaminated with copper in order to determine if the size of a population affects its ability to adapt to adverse environmental conditions. After 10 generations, we used microsatellite markers to estimate and subsequently compare the genetic variability of the copper-treated populations with that of the control populations, which were reared on uncontaminated medium. Additionally, we conducted a full cross-factorial experiment which evaluated the effects of 10 generations of "pre-exposure" to copper on a population's fitness in control and copper-contaminated environments. In order to distinguish results potentially arising from genetic adaptation from those due to non-genetic effects associated to parental exposure to copper, we subjected also F11 generation, originating from parents not exposed to copper, to the same cross-factorial experiment. The effects of long-term exposure to copper depended on population size: the growth rates of small populations that were pre-exposed to copper were inhibited compared to those of small populations reared in uncontaminated environments. Large Cu-exposed populations had a higher growth rate in the F10 generation compared to the control groups, while the growth rate of the F11 generation was unaffected by copper exposure history. The only factor that had a significant effect on genetic variability was population size, but this was to be expected given the large difference in the number of individuals between large and small populations. Neither copper contamination nor its interaction with population size affected the number of microsatellite alleles retained in the F10 generation.

  14. Marxism and the Theoretical Underpinnings of the Bolshevic ...

    African Journals Online (AJOL)

    Research has identified in Marxism, a useful political strength in an aggrieved masses, the unforgivable hatred of victims of capitalism for the system and an unwavering passion in an oppressed class for change, as some of the theoretical underpinnings behind all communist revolutions. This essay discusses Marxism while ...

  15. Heterogeneity within the fibromyalgia population: theoretical implications of variable tender point severity ratings.

    Science.gov (United States)

    Wilson, Hilary D; Starz, Terence W; Robinson, James P; Turk, Dennis C

    2009-12-01

    The American College of Rheumatology (ACR) tender point (TP) criterion is used in diagnosing fibromyalgia syndrome (FM). There has been little research investigating patterns of positive TP. We investigated response patterns of TP in a sample of patients with FM. Manual TP survey data were available on 1433 patients with FM. Factor analysis was conducted on ACR TP and control (CON) points. Factor scores were cluster analyzed to identify subgroups based on TP scores. Subgroups were compared on demographic and psychosocial variables. Factor analysis resulted in 4 TP groupings: neck/shoulder girdle, gluteal/trochanteric, and upper extremity regions, and a set of CON TP. Cluster analysis revealed 3 clusters. Group 1 was high on all 3 TP regions and the CON set; Group 2 moderate on the 3 TP regions, low on the CON set; and Group 3 was relatively low on all 3 TP regions and the CON set. The group highest on the CON and TP regions reported the greatest pain (7.58 +/- 1.23; p symptom reporting and, perhaps, disease severity. Research is needed to elucidate mechanisms underlying heterogeneity among the FM population.

  16. Tetrodotoxin Concentrations in Pleurobranchaea maculata: Temporal, Spatial and Individual Variability from New Zealand Populations

    Science.gov (United States)

    Wood, Susanna A.; Taylor, David I.; McNabb, Paul; Walker, Jarrod; Adamson, Janet; Cary, Stephen Craig

    2012-01-01

    Tetrodotoxin (TTX) is a potent neurotoxin that has been identified in a range of phylogenetically unrelated marine and terrestrial organisms. Tetrodotoxin was recently detected in New Zealand in Pleurobranchaea maculata (the grey side-gilled sea slug). From June 2010 to June 2011 wild specimens were collected from 10 locations around New Zealand. At one site (Narrow Neck Beach, Auckland) up to 10 individuals were collected monthly for 6 months. Attempts were also made to rear P. maculata in captivity. Tetrodotoxin was detected in samples from eight of the ten sites. The highest average (368.7 mg kg−1) and maximum (1414.0 mg kg−1) concentrations were measured in samples from Illiomama Rock (Auckland). Of the toxic populations tested there was significant variability in TTX concentrations among individuals, with the highest difference (62 fold) measured at Illiomama Rock. Tetrodotoxin concentrations in samples from Narrow Neck Beach varied temporally, ranging from an average of 184 mg kg−1 in June 2010 to 17.5 mg kg−1 by December 2010. There was no correlation between TTX levels and mass. The highest levels correspond with the egg laying season (June–August) and this, in concert with the detection of high levels of TTX in eggs and early larval stages, suggests that TTX may have a defensive function in P. maculata. Only one larva was successfully reared to full maturation and no TTX was detected. PMID:22363228

  17. An Integrated Workflow To Assess Technical and Biological Variability of Cell Population Frequencies in Human Peripheral Blood by Flow Cytometry.

    Science.gov (United States)

    Burel, Julie G; Qian, Yu; Lindestam Arlehamn, Cecilia; Weiskopf, Daniela; Zapardiel-Gonzalo, Jose; Taplitz, Randy; Gilman, Robert H; Saito, Mayuko; de Silva, Aruna D; Vijayanand, Pandurangan; Scheuermann, Richard H; Sette, Alessandro; Peters, Bjoern

    2017-02-15

    In the context of large-scale human system immunology studies, controlling for technical and biological variability is crucial to ensure that experimental data support research conclusions. In this study, we report on a universal workflow to evaluate both technical and biological variation in multiparameter flow cytometry, applied to the development of a 10-color panel to identify all major cell populations and T cell subsets in cryopreserved PBMC. Replicate runs from a control donation and comparison of different gating strategies assessed the technical variability associated with each cell population and permitted the calculation of a quality control score. Applying our panel to a large collection of PBMC samples, we found that most cell populations showed low intraindividual variability over time. In contrast, certain subpopulations such as CD56 T cells and Temra CD4 T cells were associated with high interindividual variability. Age but not gender had a significant effect on the frequency of several populations, with a drastic decrease in naive T cells observed in older donors. Ethnicity also influenced a significant proportion of immune cell population frequencies, emphasizing the need to account for these covariates in immune profiling studies. We also exemplify the usefulness of our workflow by identifying a novel cell-subset signature of latent tuberculosis infection. Thus, our study provides a universal workflow to establish and evaluate any flow cytometry panel in systems immunology studies. Copyright © 2017 by The American Association of Immunologists, Inc.

  18. Distribution of microbial populations and their relationship with environmental variables in the North Yellow Sea, China

    Science.gov (United States)

    Bai, Xiaoge; Wang, Min; Liang, Yantao; Zhang, Zhifeng; Wang, Fang; Jiang, Xuejiao

    2012-03-01

    In order to understand the large-scale spatial distribution characteristics of picoplankton, nanophytoplankton and virioplankton and their relationship with environmental variables in coastal and offshore waters, flow cytometry (FCM) was used to analyze microbial abundance of samples collected in summer from four depths at 36 stations in the North Yellow Sea (NYS). The data revealed spatial heterogeneity in microbial populations in the offshore and near-shore waters of the NYS during the summer. For the surface layer, picoeukaryotes were abundant in the near-shore waters, Synechococcus was abundant in the offshore areas, and bacterial and viral abundances were high in the near-shore waters around the Liaodong peninsula. In the near-shore waters, no significant vertical variation of picophytoplankton (0.2-2μm) abundance was found. However, the nanophytoplankton abundance was higher in the upper layers (from the surface to 10 m depth) than in the bottom layer. For the offshore waters, both pico- and nanophytoplankton (2-20μm) abundance decreased sharply with depth in the North Yellow Sea Cold Water Mass (NYSCWM). But, for the vertical distribution of virus and bacteria abundance, no significant variation was observed in both near-shore and offshore waters. Autotrophic microbes were more sensitive to environmental change than heterotrophic microbes and viruses. Viruses showed a positive correlation with bacterial abundance, suggesting that the bacteriophage might be prominent for virioplankton (about 0.45μm) in summer in the NYS and that viral abundance might play an important role in microbial loop functions.

  19. A simple approach to ignoring irrelevant variables by population decoding based on multisensory neurons

    Science.gov (United States)

    Kim, HyungGoo R.; Pitkow, Xaq; Angelaki, Dora E.

    2016-01-01

    Sensory input reflects events that occur in the environment, but multiple events may be confounded in sensory signals. For example, under many natural viewing conditions, retinal image motion reflects some combination of self-motion and movement of objects in the world. To estimate one stimulus event and ignore others, the brain can perform marginalization operations, but the neural bases of these operations are poorly understood. Using computational modeling, we examine how multisensory signals may be processed to estimate the direction of self-motion (i.e., heading) and to marginalize out effects of object motion. Multisensory neurons represent heading based on both visual and vestibular inputs and come in two basic types: “congruent” and “opposite” cells. Congruent cells have matched heading tuning for visual and vestibular cues and have been linked to perceptual benefits of cue integration during heading discrimination. Opposite cells have mismatched visual and vestibular heading preferences and are ill-suited for cue integration. We show that decoding a mixed population of congruent and opposite cells substantially reduces errors in heading estimation caused by object motion. In addition, we present a general formulation of an optimal linear decoding scheme that approximates marginalization and can be implemented biologically by simple reinforcement learning mechanisms. We also show that neural response correlations induced by task-irrelevant variables may greatly exceed intrinsic noise correlations. Overall, our findings suggest a general computational strategy by which neurons with mismatched tuning for two different sensory cues may be decoded to perform marginalization operations that dissociate possible causes of sensory inputs. PMID:27334948

  20. Relative roles of weather variables and change in human population in malaria: comparison over different states of India.

    Directory of Open Access Journals (Sweden)

    Prashant Goswami

    Full Text Available Pro-active and effective control as well as quantitative assessment of impact of climate change on malaria requires identification of the major drivers of the epidemic. Malaria depends on vector abundance which, in turn, depends on a combination of weather variables. However, there remain several gaps in our understanding and assessment of malaria in a changing climate. Most of the studies have considered weekly or even monthly mean values of weather variables, while the malaria vector is sensitive to daily variations. Secondly, rarely all the relevant meteorological variables have been considered together. An important question is the relative roles of weather variables (vector abundance and change in host (human population, in the change in disease load.We consider the 28 states of India, characterized by diverse climatic zones and changing population as well as complex variability in malaria, as a natural test bed. An annual vector load for each of the 28 states is defined based on the number of vector genesis days computed using daily values of temperature, rainfall and humidity from NCEP daily Reanalysis; a prediction of potential malaria load is defined by taking into consideration changes in the human population and compared with the reported number of malaria cases.For most states, the number of malaria cases is very well correlated with the vector load calculated with the combined conditions of daily values of temperature, rainfall and humidity; no single weather variable has any significant association with the observed disease prevalence.The association between vector-load and daily values of weather variables is robust and holds for different climatic regions (states of India. Thus use of all the three weather variables provides a reliable means of pro-active and efficient vector sanitation and control as well as assessment of impact of climate change on malaria.

  1. Relative roles of weather variables and change in human population in malaria: comparison over different states of India.

    Science.gov (United States)

    Goswami, Prashant; Murty, Upadhayula Suryanarayana; Mutheneni, Srinivasa Rao; Krishnan, Swathi Trithala

    2014-01-01

    Pro-active and effective control as well as quantitative assessment of impact of climate change on malaria requires identification of the major drivers of the epidemic. Malaria depends on vector abundance which, in turn, depends on a combination of weather variables. However, there remain several gaps in our understanding and assessment of malaria in a changing climate. Most of the studies have considered weekly or even monthly mean values of weather variables, while the malaria vector is sensitive to daily variations. Secondly, rarely all the relevant meteorological variables have been considered together. An important question is the relative roles of weather variables (vector abundance) and change in host (human) population, in the change in disease load. We consider the 28 states of India, characterized by diverse climatic zones and changing population as well as complex variability in malaria, as a natural test bed. An annual vector load for each of the 28 states is defined based on the number of vector genesis days computed using daily values of temperature, rainfall and humidity from NCEP daily Reanalysis; a prediction of potential malaria load is defined by taking into consideration changes in the human population and compared with the reported number of malaria cases. For most states, the number of malaria cases is very well correlated with the vector load calculated with the combined conditions of daily values of temperature, rainfall and humidity; no single weather variable has any significant association with the observed disease prevalence. The association between vector-load and daily values of weather variables is robust and holds for different climatic regions (states of India). Thus use of all the three weather variables provides a reliable means of pro-active and efficient vector sanitation and control as well as assessment of impact of climate change on malaria.

  2. Prognostic value of reading-to-reading blood pressure variability over 24 hours in 8938 subjects from 11 populations

    DEFF Research Database (Denmark)

    Hansen, Tine W; Thijs, Lutgarde; Li, Yan

    2010-01-01

    In previous studies, of which several were underpowered, the relation between cardiovascular outcome and blood pressure (BP) variability was inconsistent. We followed health outcomes in 8938 subjects (mean age: 53.0 years; 46.8% women) randomly recruited from 11 populations. At baseline, we asses...

  3. Distribution of peak expiratory flow variability by age, gender and smoking habits in a random population sample aged 20-70 yrs

    NARCIS (Netherlands)

    Boezen, H M; Schouten, J. P.; Postma, D S; Rijcken, B

    1994-01-01

    Peak expiratory flow (PEF) variability can be considered as an index of bronchial lability. Population studies on PEF variability are few. The purpose of the current paper is to describe the distribution of PEF variability in a random population sample of adults with a wide age range (20-70 yrs),

  4. Neural and psychological underpinnings of gambling disorder: A review

    OpenAIRE

    Grant, Jon E; Odlaug, Brian L; Chamberlain, Sam

    2015-01-01

    Gambling disorder affects 0.4 to 1.6% of adults worldwide, and is highly comorbid with other mental health disorders. This article provides a concise primer on the neural and psychological underpinnings of gambling disorder based on a selective review of the literature. Gambling disorder is associated with dysfunction across multiple cognitive domains which can be considered in terms of impulsivity and compulsivity. Neuroimaging data suggest structural and functional abnormalities of networks...

  5. Status of vulnerable Cystoseira populations along the Italian infralittoral fringe, and relationships with environmental and anthropogenic variables.

    Science.gov (United States)

    Mancuso, F P; Strain, E M A; Piccioni, E; De Clerck, O; Sarà, G; Airoldi, L

    2017-11-03

    We analyzed the occurrence and status of infralittoral fringe populations of Cystoseira spp. (Fucales) at thirteen rocky sites around the Italian coastline, and explored the relationships with relevant environmental and anthropogenic variables. We found Cystoseira populations at 11 sites: most were scattered and comprised monospecific stands of C. compressa, and only 6 sites also supported sparse specimens of either C. amentacea var. stricta or C. brachycarpa. Coastal human population density, Chlorophyll a seawater concentrations, sea surface temperature, annual range of sea surface temperature and wave fetch explained most of the variation of the status of C. compressa. We hypothesize a generally unhealthy state of the Italian Cystoseira infralittoral fringe populations and identify multiple co-occurring anthropogenic stressors as the likely drivers of these poor conditions. Extensive baseline monitoring is needed to describe how Cystoseira populations are changing, and implement a management framework for the conservation of these valuable but vulnerable habitats. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Topological variability of fingerprint ridge density in a sub-Saharan population sample for application in personal identification.

    Science.gov (United States)

    Gutiérrez-Redomero, Esperanza; Quirós, Juan A; Rivaldería, Noemí; Alonso, María C

    2013-05-01

    Variability in ridge density in a sub-Saharan population sample was studied by counting ridges in three fingerprint areas (two distal regions, radial and ulnar, and one proximal region) on the epidermal surface of the distal phalanx. Study material was obtained from the fingerprint impressions of 100 male sub-Saharan subjects aged between 18- and 48-years old. The results were compared with those obtained from a Spanish population sample. Sub-Saharan males presented lower ridge density than Spanish males in the distal regions (radial and ulnar) of all fingers, whereas differences in the proximal region were only observed on some fingers. Using the differences observed between these populations, the likelihood ratio for inferring membership of one of the populations from a fingerprint of unknown origin was calculated; therefore, a ridge density of 14 or less for both areas (ulnar and radial), support an origin sub-Saharan versus Spanish population. © 2013 American Academy of Forensic Sciences.

  7. Effects on life history variables and population dynamics following maternal metal exposure in the live-bearing fish Gambusia affinis.

    Science.gov (United States)

    Cazan, Alfy Morales; Klerks, Paul L

    2015-04-01

    This study investigated the effect of maternal copper and maternal cadmium exposure on life history variables and population dynamics in a live-bearing fish species. Gravid females were exposed to copper, cadmium, or background metal levels (control); maternal transfer of the metals was previously demonstrated using the exact same design. Each female's first brood, born after the exposure, was subdivided into two groups. One group was raised in the laboratory, to assess time-to and size-at sexual maturity, reproductive output and other life history variables. Offspring from the other group were used to start four mesocosm populations for each treatment. These populations were sampled monthly, for about 18 months, to assess population dynamics. For the laboratory-reared fish, offspring of copper-exposed females reached sexual maturity at a smaller size than did offspring from the other treatments. Maternal copper exposure and maternal cadmium exposure both resulted in fewer broods and an increase in gestation time. No impacts were detected for brood size, inter-brood interval, time-to-sexual-maturity, or life span. In the greenhouse population study, no effect of maternal copper or cadmium exposure was evident for population parameters, other than that the relative abundance of juveniles and/or newborns was reduced in populations established with offspring of the exposed females. This study provided evidence that a short-term metal exposure of gravid females can negatively affect their offspring's life history variables and potentially influence population dynamics in a life-bearing fish species.

  8. Allozyme polymorphism and variability in permethrin tolerance in British populations of the parthenogenetic stored product pest Liposcelis bostrychophila (Liposcelididae, Psocoptera).

    Science.gov (United States)

    Ali; Turner

    2001-04-01

    Variability in allozyme patterns is demonstrated among 111 British populations of Liposcelis bostrychophila (Badonnel), an obligatory parthenogenetic liposcelid species that is a common domestic pest in the United Kingdom. In addition four tropical strains and a laboratory culture were included in the analysis. Permethrin toxicity was measured in a subset of the populations.Using cellulose acetate paper electrophoresis, 16 of 34 enzymes tested were found in the liposcelid material and, of these, four were polymorphic. A total of 47 distinct morphs were recognised. This enzyme variation appears to be random with respect to geography throughout the country.Permethrin tolerance was highly variable among populations. A significant relationship was demonstrated between the mean LC(50) for permethrin and latitude such that there appears to be higher levels of tolerance in southern, than in northern, Britain.No link could be established between the allozyme polymorphisms, particularly in the esterases, and permethrin tolerance.

  9. Effects of subsidized predators, resource variability, and human population density on desert tortoise populations in the Mojave Desert, USA

    Science.gov (United States)

    Esque, Todd C.; Nussear, Kenneth E.; Drake, K. Kristina; Walde, Andrew D.; Berry, Kristin H.; Averill-Murray, Roy C.; Woodman, A. Peter; Boarman, William I.; Medica, Phil A.; Mack, Jeremy S.; Heaton, Jill S.

    2010-01-01

    Understanding predator–prey relationships can be pivotal in the conservation of species. For 2 decades, desert tortoise Gopherus agassizii populations have declined, yet quantitative evidence regarding the causes of declines is scarce. In 2005, Ft. Irwin National Training Center, California, USA, implemented a translocation project including 2 yr of baseline monitoring of desert tortoises. Unusually high predation on tortoises was observed after translocation occurred. We conducted a retrospective analysis of predation and found that translocation did not affect the probability of predation: translocated, resident, and control tortoises all had similar levels of predation. However, predation rates were higher near human population concentrations, at lower elevation sites, and for smaller tortoises and females. Furthermore, high mortality rates were not limited to the National Training Center. In 2008, elevated mortality (as high as 43%) occurred throughout the listed range of the desert tortoise. Although no temporal prey base data are available for analysis from any of the study sites, we hypothesize that low population levels of typical coyote Canis latrans prey (i.e. jackrabbits Lepus californicus and other small animals) due to drought conditions influenced high predation rates in previous years. Predation may have been exacerbated in areas with high levels of subsidized predators. Many historical reports of increased predation, and our observation of a range-wide pattern, may indicate that high predation rates are more common than generally considered and may impact recovery of the desert tortoise throughout its range.

  10. Microsatellite variability reveals the necessity for genetic input from wild giant pandas (Ailuropoda melanoleuca) into the captive population.

    Science.gov (United States)

    Shen, Fujun; Zhang, Zhihe; He, Wei; Yue, Bisong; Zhang, Anju; Zhang, Liang; Hou, Rong; Wang, Chengdong; Watanabe, Toshi

    2009-03-01

    Recent success in breeding giant pandas in captivity has encouraged panda conservationists to believe that the ex situ population is ready to serve as a source for supporting the wild population. In this study, we used 11 microsatellite DNA markers to assess the amount and distribution of genetic variability present in the two largest captive populations (Chengdu Research Base of Giant Panda Breeding, Sichuan Province and the China Research and Conservation Center for the Giant Panda at Wolong, Sichuan Province). The data were compared with those samples from wild pandas living in two key giant panda nature reserves (Baoxing Nature Reserve and Wanglang Nature Reserve). The results show that the captive populations have retained lower levels of allelic diversity and heterozygosity compared to isolated wild populations. However, low inbreeding coefficients indicate that captive populations are under careful genetic management. Excessive heterozygosity suggests that the two captive populations have experienced a genetic bottleneck, presumably caused by founder effects. Moreover, evidence of increased genetic divergence demonstrates restricted breeding options within facilities. Based on these results, we conclude that the genetic diversity in the captive populations is not optimal. Introduction of genetic materials from wild pandas and improved exchange of genetic materials among institutions will be necessary for the captive pandas to be representative of the wild populations.

  11. Predictability of Social-anamnestic Variables on Receptive Vocabulary and Cognitive Functioning of the Elderly Population.

    Science.gov (United States)

    Ibrahimagic, Amela; Zunic, Lejla Junuzovic; Rasidovic, Mirsada; Radic, Bojan; Kantic, Ahmet

    2016-12-01

    Aging, as an irrepressible biological process involves a series of physiological and pathological changes. The main aim of this study was to examine the correlation and predictability of receptive vocabulary and cognitive functioning of elderly people with anamnestic variables: chronological age, sex, level of formal education, marital status, years of work and retirement and years spent in an institution for the elderly. The sample of participants consisted of 120 elderly people, average age was 78 years, placed in institutional care for elderly people in four cities in Bosnia and Herzegovina. It was three groups of variables: anamnestic, receptive vocabulary assessment, and cognitive assessments. A Montreal Cognitive Assessment Scale (MoCA) was used for the assessment of cognitive abilities. In order to estimate the receptive vocabulary Peabody Picture Vocabulary Test (PPVT-III-HR) was used. Results of multiple regression analysis show that part of the variance of receptive language which is explained by the model (anamnestic variables) was 44.0% and of cognitive functioning was 33.7%. The biggest single contribution to explaining the development of receptive vocabulary was given by predictor variable of college education (β = 0.417) then variable university education (β = 0.293), while the smallest single contribution was given by variable secondary education (β = 0.167). The biggest single contribution to explaining the results of tests of cognitive function was given by predictor variable College education (β = 0.328) and variable unskilled (β = -0.229), which has a negative effect on the increase in recent cognitive functioning. Anamnestic variables were valid predictors of receptive vocabulary and cognitive functioning of elderly people. The highest individual contribution was given by variables describing the level of formal education of elderly.

  12. Adaptive genetic variability and differentiation of Croatian and Austrian Quercus robur L. populations at a drought prone field trial

    Directory of Open Access Journals (Sweden)

    Saša Bogdan

    2017-07-01

    Full Text Available Provenance trials, where populations of different geographical origin are tested in a common environment (common garden test, are a tool suited to allow the study of intraspecific adaptive genetic variation. Research of pedunculate oak (Quercus robur L. adaptive genetic variability through analyses of populations in common garden tests has a long tradition. However, pedunculated oak populations originating south-eastern from the Alps have been scarcely studied in this way. This study addresses the adaptive genetic variability and differentiation of pedunculate oak populations originating from Austria and Croatia in a provenance/progeny field trial. Studied plants were six years old and were growing at the trial for three years. After two years of unusually low precipitations height and survival were analysed. The total mean height of all plants in the trial was 137.8 cm and ranged from 123.0 cm to 151.8 cm. The overall mean survival rate was rather high (0.85. Mean population survival ranged from 0.64 to 0.94. Individual narrow-sense heritabilities (hi2, family mean heritabilities (hf2, the coefficients of additive genetic variation (CVA and quantitative genetic differentiation coefficients (QST were calculated. A multivariate regression tree (MRT analysis was used to determine the pattern of genetic differentiation of the populations. Individual heritabilities for height ranged between 0.00 and 0.39. Family mean heritabilities for height were rather low in most populations as well (<0.5. Family mean heritabilities for survival were higher than for height (ranging between 0.00 and 0.77. Calculated QST coefficients (0.25 for height and 0.14 for survival indicated between-population genetic differentiation. The populations were separated into two clusters by MRT analysis regarding a climatic variable, namely Hargreaves’ reference evapotranspiration. Populations originating from comparatively more humid habitats were grouped in the first

  13. Uncertain population dynamic and state variables of alfonsino (Beryx splendens Dinámica poblacional incierta y variables de estado en alfonsino (Beryx splendens

    Directory of Open Access Journals (Sweden)

    Rodrigo Wiff

    2012-03-01

    Full Text Available Alfonsino (Beryx splendens is a species associated with seamounts, with an important fishery in Juan Fernandez archipelago, Chile (33°40'S, 79°00'W. Since 2004, this resource has been managed by catch quotas estimated from stock assessment models. The alfonsino model involves high levels of uncertainty for several reasons including a lack of knowledge of aspects of the population dynamics and poorly informative time-series that feed the proposed evaluation models. This work evaluated three hypotheses regarding population dynamics and their influence on the main state variables (biomass, recruitment of the model using age-structured and dynamic biomass models. The hypotheses corresponded to de-recruitment of older individuals, non-linearity between standardized catch per unit effort, and population abundance as well as variations of the relative importance of length structures. According to the results, the depletion of the spawning biomass between 1998 and 2008 varied between 9 and 56%, depending on the combination of hypotheses used in the model. This indicates that state variables in alfonsino are not robust to the available information; rather, they depend strongly on the hypothesis of population dynamics. The discussion is focused on interpreting the causes of the changes in the state variables in light of a conceptual model for population dynamics in alfonsino and which pieces of information would be necessary to reduce the associated uncertainty.El alfonsino (Beryx splendens es una especie asociada a montes submarinos. En Chile sustenta una importante pesquería en el archipiélago de Juan Fernández (33°40'S, 79°00'W. Desde el año 2004, este recurso es administrado a través de cuotas anuales de capturas, las cuales son estimadas desde un modelo de evaluación de stock. La modelación de la población de alfonsino se caracteriza por una alta incertidumbre, debido a diversas fuentes, como son desconocimiento de aspectos de su din

  14. Genetic variability of Echinococcus granulosus complex in various geographical populations of Iran inferred by mitochondrial DNA sequences.

    Science.gov (United States)

    Spotin, Adel; Mahami-Oskouei, Mahmoud; Harandi, Majid Fasihi; Baratchian, Mehdi; Bordbar, Ali; Ahmadpour, Ehsan; Ebrahimi, Sahar

    2017-01-01

    To investigate the genetic variability and population structure of Echinococcus granulosus complex, 79 isolates were sequenced from different host species covering human, dog, camel, goat, sheep and cattle as of various geographical sub-populations of Iran (Northwestern, Northern, and Southeastern). In addition, 36 sequences of other geographical populations (Western, Southeastern and Central Iran), were directly retrieved from GenBank database for the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. The confirmed isolates were grouped as G1 genotype (n=92), G6 genotype (n=14), G3 genotype (n=8) and G2 genotype (n=1). 50 unique haplotypes were identified based on the analyzed sequences of cox1. A parsimonious network of the sequence haplotypes displayed star-like features in the overall population containing IR23 (22: 19.1%) as the most common haplotype. According to the analysis of molecular variance (AMOVA) test, the high value of haplotype diversity of E. granulosus complex was shown the total genetic variability within populations while nucleotide diversity was low in all populations. Neutrality indices of the cox1 (Tajima's D and Fu's Fs tests) were shown negative values in Western-Northwestern, Northern and Southeastern populations which indicating significant divergence from neutrality and positive but not significant in Central isolates. A pairwise fixation index (Fst) as a degree of gene flow was generally low value for all populations (0.00647-0.15198). The statistically Fst values indicate that Echinococcus sensu stricto (genotype G1-G3) populations are not genetically well differentiated in various geographical regions of Iran. To appraise the hypothetical evolutionary scenario, further study is needed to analyze concatenated mitogenomes and as well a panel of single locus nuclear markers should be considered in wider areas of Iran and neighboring countries. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Variability of haloxylon ammodendron (C. A. Mey) bunge populations from different habitats

    International Nuclear Information System (INIS)

    Lv, C.

    2015-01-01

    Haloxylon ammodendron (C.A. Mey) Bunge occupies a wide range of different habitats in north-west China. The aim of this study was to quantify variation in population growth characteristics of H. ammodendron from different sites and to relate this variation to different environmental conditions. To this end, 6 populations with visible differences were chosen and a range of morphological as well as seed-related characteristics like density, height, crown, basal diameter, seed mass, 1000 seed weight, seed number, seed diameter and germination rate were measured. The variations in the averages of overall traits were explained. The differences between-populations were 33 percentage, whereas those within population were 67 percentage. The largest variation was detected in morphological-related traits between-populations (38 percentage). In particular, the density, height, 1000 seed weight and germination rate differed strongly between populations. The population growth characteristics were closely related to the soil property at the sites of origin. The soil property can explain most of the variations in the morphological-related traits. They were concluded that the diversity of population growth characteristics in different habitats provides the potential of population reproduction and the protection of original habitats is extremely important. (author)

  16. Validation of the Oral Hygiene Habits Scale: Relationships with sociodemographic variables in the general and clinical population of Monterrey, Mexico.

    Directory of Open Access Journals (Sweden)

    Norma Rodríguez

    2016-12-01

    Full Text Available Several socioeconomic factors are associated with poor oral hygiene habits. A version of the Oral Hygiene Habits Scale (OHHS was developed in Mexico to measure these factors; however, its relationship with sociodemographic variables has not been studied. The verification of these relationships could contribute to the validation of the scale. Objective: To evaluate the relationship between oral hygiene habits and sociodemographic variables of sex, age, schooling, self-defined socioeconomic stratum, occupation and marital status in the general and clinical population of Monterrey, Mexico. Materials and Methods: A general population sample (GPS of 256 participants and a clinical sample (CPS of 240 participants were studied. The OHHS consisted of an eight-item Likert scale of 4 points ranging from 0 to 4. A descriptive correlational study was performed with a cross-sectional design. Data were analyzed using the Mann-Whitney U test, Kruskal-Wallis test, Spearman correlation coefficient, Cramer's V coefficient, and multivariate aligned rank test. Results: In GPS and CPS groups, OHHS was related to sex, schooling, socioeconomic stratum, occupation and marital status, but not to age. There were no significant interactions between the samples (GPS and CPS and sociodemographic variables. Conclusion: There is a statistically significant relationship between oral hygiene habits and some sociodemographic variables in the general and clinical population. This relationship supports the validity of the OHHS.

  17. Non-invasive single-trial detection of variable population spike responses in human somatosensory evoked potentials.

    Science.gov (United States)

    Waterstraat, Gunnar; Scheuermann, Manuel; Curio, Gabriel

    2016-03-01

    Somatosensory evoked potentials (SEPs) around 600 Hz ('σ-bursts') are correlates of cortical population spikes. Recently, single-trial σ-bursts were detected in human scalp EEG using 29-channel low-noise recordings in an electromagnetically shielded room. To achieve clinical applicability, this study aimed to establish a protocol using only 8 EEG channels in an unshielded environment and to quantify the variability of σ-bursts. Median nerve SEPs were recorded in 10 healthy subjects using a custom-built low-noise EEG amplifier. A detection algorithm for single-trial σ-bursts was trained as combination of spatio-temporal filters and a non-linear classifier. The single-trial responses were probed for the presence of significant increases of amplitude and variability. Single-trial σ-burst detection succeeded with Detection Rates and Positive Predictive Values above 80% in subjects with high SNR. A significant inter-trial variability in the amplitudes of early low-frequency SEPs and σ-bursts could be demonstrated. Single-trial σ-bursts can be detected on scalp-EEG using only 8 EEG channels in an electromagnetically disturbed environment. The combination of dedicated hardware and detection algorithms allows quantifying and describing their variability. The variability of population spikes in the human somatosensory cortex can be traced non-invasively in a clinical setting. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  18. Effects of population variability on the accuracy of detection probability estimates

    DEFF Research Database (Denmark)

    Ordonez Gloria, Alejandro

    2011-01-01

    Observing a constant fraction of the population over time, locations, or species is virtually impossible. Hence, quantifying this proportion (i.e. detection probability) is an important task in quantitative population ecology. In this study we determined, via computer simulations, the ef- fect of...

  19. Population viability of the narrow endemic Helianthemum juliae (CISTACEAE) in relation to climate variability

    NARCIS (Netherlands)

    Marrero-Gomez, M.V.; Oostermeijer, J.G.B.; Carque-Alamo, E.; Banares-Baudet, A.

    2007-01-01

    Narrow endemic plants are highly vulnerable to extinction as a result of human disturbance and climate change. We investigated the factors affecting the population viability of Helianthemum juliae, a perennial plant endemic to the Teide National Park on Tenerife, Canary Islands. One population was

  20. Climate variability, human wildlife conflict and population dynamics of lions Panthera leo

    Science.gov (United States)

    Trinkel, Martina

    2013-04-01

    Large carnivores are threatened by habitat loss, declining prey populations and direct persecution. Pride dynamics of eight lion prides in the centre of the Etosha National Park, Namibia are described during a 16-year study. Since the beginning of the 1980s, the number of adult and subadult lions declined continuously to two third of its initial population size, and reached a new equilibrium in the 1990s. Pride sizes decreased from 6.3 adult females in 1989 to 2.8 lionesses in 1997. While the number of adult females declined continuously, the number of adult males, subadult females and subadult males remained constant over the years. A severe drought period, lasting for more than 20 years, led to declining prey populations inside the lions' territory. Besides declining prey populations, conflict with humans at the border of Etosha puts substantial pressure onto the lion population: 82 % of all known lion mortalities were caused by humans, and most of these consisted of adult females (28 %) and subadult males (29 %). I postulate that the considerable decline in the lion population is a response to declining prey populations, and although the human predator conflict is severe, it does not seem to limit the size of Etosha's lion population.

  1. Climate variability, human wildlife conflict and population dynamics of lions Panthera leo.

    Science.gov (United States)

    Trinkel, Martina

    2013-04-01

    Large carnivores are threatened by habitat loss, declining prey populations and direct persecution. Pride dynamics of eight lion prides in the centre of the Etosha National Park, Namibia are described during a 16-year study. Since the beginning of the 1980s, the number of adult and subadult lions declined continuously to two third of its initial population size, and reached a new equilibrium in the 1990s. Pride sizes decreased from 6.3 adult females in 1989 to 2.8 lionesses in 1997. While the number of adult females declined continuously, the number of adult males, subadult females and subadult males remained constant over the years. A severe drought period, lasting for more than 20 years, led to declining prey populations inside the lions' territory. Besides declining prey populations, conflict with humans at the border of Etosha puts substantial pressure onto the lion population: 82% of all known lion mortalities were caused by humans, and most of these consisted of adult females (28%) and subadult males (29%). I postulate that the considerable decline in the lion population is a response to declining prey populations, and although the human predator conflict is severe, it does not seem to limit the size of Etosha's lion population.

  2. Dynamics of the population structure and genetic variability within Iranian isolates of grapevine fanleaf virus: evidence for polyphyletic origin.

    Science.gov (United States)

    Gholampour, Z; Kargar, M; Zakiaghl, M; Siampour, M; Mehrvar, M; Izadpanah, K

    To determine the genetic diversity and population structure of grapevine fanleaf virus (GFLV), the complete nucleotide sequence of the coat protein gene of 41 isolates from different regions in Iran was determined. Phylogenetic analyses of these isolates together with those available in the GenBank revealed two evolutionary divergent lineages, designated GFLV-G and GFLV-Ir that reflect origin of the isolates. Analysis of the genetic variability in the coat protein of these isolates revealed 37 genotype groups in GFLV population. Analyses indicate that GFLV-G and GFLV-Ir clades are significantly differentiated populations of GFLV. Also, geographical subpopulations of the virus in Iran were completely distinct from each other. Examination of nonsynonymous/synonymous nucleotide diversity showed that the CP gene has been under purifying selection. The neutrality tests indicate balancing selection operating within isolates of the northwest of Iran and purifying selection within the other populations.

  3. No evidence for mitochondrial genetic variability in the largest population of critically endangered Tonkin snub-nosed monkeys in Vietnam.

    Science.gov (United States)

    Ang, Andie; Srivathsan, Amrita; Meier, Rudolf; Luu, Tuong Bach; Le, Quyet Khac; Covert, Herbert

    2016-10-01

    The Tonkin snub-nosed monkey (Rhinopithecus avunculus) with a global population of Vietnam and was feared extinct until its rediscovery in 1989. The largest single population of R. avunculus consists of 125-130 individuals in an area of forest called Khau Ca in Ha Giang Province. We used non-invasively collected fecal samples to establish the amount of genetic diversity in this population based on mitochondrial information. We amplified and sequenced a 467- to 650-bp section of the hypervariable region I (HVI) of the mitochondrial D-loop for 201 samples and reconstructed the full mitochondrial genomes for five samples based on metagenomic data. All 201 HVI sequences were identical and no variability was found in the five mitochondrial genomes. Our results highlight the immediate need for a comprehensive assessment of the genetic diversity of all populations of R. avunculus based on mitochondrial and nuclear markers. The latter need to be developed for this species.

  4. GENETIC VARIABILITY OF POLYMESODA EROSA POPULATION IN THE SEGARA ANAKAN CILACAP

    Directory of Open Access Journals (Sweden)

    AGUS NURYANTO

    2010-01-01

    Full Text Available Mud clams, Polymesoda erosa, in the Segara Anakan Cilacap are highly exploited by the local communities for daily consumption. This is presumed causing population decline and potentially causing loss of genetic diversity. Genetic diversity level within population can be obtained by population genetic study using molecular marker such as randomly amplified polymorphic DNA (RAPD. Here we amplified RAPD marker using ten arbitrary primers to assess genetic diversity of P. erosa population in the Segara Anakan Cilacap to provide genetic data for its sustainable use. The results proved that the use of RAPD marker has high polymorphisms. The mud clam population also showed a high level of heterozygosity and genetic diversity. This has important implication for the management plan towards sustainable use of P. erosa in the Segara Anakan Cilacap.

  5. Fish population studies using parasites from the Southeastern Pacific Ocean: considering host population changes and species body size as sources of variability of parasite communities.

    Science.gov (United States)

    George-Nascimento, Mario; Oliva, Marcelo

    2015-01-01

    Research using parasites in fish population studies in the South Eastern Pacific (SEP) is summarized. There are 27 such studies (snapshots mainly) in single host species sampled at different geographic localities and at somewhat similar times. They have been devoted mainly to economically important species, though others on coastal and intertidal fish or on less- or non-commercial species provide insights on scales of temporal and spatial variation of parasite infracommunities. Later, we assess whether the probability of harbouring parasites depends on the host species body size. Our results indicate that a stronger tool for fish population studies may be developed under regular (long term) scrutiny of parasite communities, especially of small fish host species, due to their larger variability in richness, abundance and total biomass, than in large fish species. Finally, it might also be necessary to consider the effects of fishing on parasite communities as well as the natural oscillations (coupled or not) of host and parasite populations.

  6. Gait variability analysed using an accelerometer is associated with locomotive syndrome among the general elderly population: The GAINA study.

    Science.gov (United States)

    Matsumoto, Hiromi; Hagino, Hiroshi; Osaki, Mari; Tanishima, Shinji; Tanimura, Chika; Matsuura, Akihiro; Makabe, Tomoyuki

    2016-05-01

    Gait variability analysed using an accelerometer provides a unique measurement of locomotive dysfunction in patients with musculoskeletal disease or in frail elderly subjects. Therefore, assessing gait variability may become a clinical screening method for the locomotive syndrome. The purpose of this study was to investigate whether gait variability analysed using an accelerometer was associated with locomotive syndrome in the general elderly population. A total of 273 residents were screened after a yearly medical check-up, and of these, 223 subjects (mean age, 73.6 ± 8.3 years) met the eligibility criteria. Demographic information, body function and structure measurements (bone mass, grip strength, muscle mass, and postural alignment), and gait parameters were assessed. Gait variability analysis was based on acceleration using a wireless tri-axial accelerometer attached to the 3rd lumbar vertebra process by a trunk belt. Autocorrelation coefficients were used to represent gait variability in three directions: vertical, mediolateral, and anteroposterior. The subjects were classified as either having or not having the locomotive syndrome based on the 5-question Geriatric Locomotive Function Scale. Of the 223 subjects, 41 (18.3%) had the locomotive syndrome. Autocorrelation coefficients in three directions were lower in the subjects with locomotive syndrome. Using multivariate logistic regression analysis with adjustment factors, of the autocorrelation coefficients only gait variability in the vertical axis remained a significant independent associated with the locomotive syndrome. This finding suggested that gait variability based on evaluation of autocorrelation coefficients in the vertical axis measured using an accelerometer has the potential to become a screening method for the locomotive syndrome in the general elderly population. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  7. Genetic variability and bottleneck detection of four Tricholoma matsutake populations from northeastern and southwestern China.

    Science.gov (United States)

    Zeng, Dong-Fang; Chen, Bin

    2015-08-01

    The excessive commercial collection of matsutake mushrooms can lead to extreme reduction of population size, which may cause genetic bottleneck and decrease genetic diversity of Tricholoma matsutake. Here, six polymorphic microsatellite loci markers were used to examine the genetic diversity of four natural T. matsutake populations from two main producing regions of China. The minimum combinations of four loci were able to discriminate total 86 sampled individuals with distinctive multilocus genotypes. Our analysis of molecular variance (AMOVA) revealed that about 80% and 20% of the overall genetic variation were respectively partitioned within and among populations. The principal-coordinate analyses (PCA) distinguished the four tested populations into three genetic clusters, each of which was correlated with respective endemic host plants on a geographical basis. The AMOVA, PCA and pairwise population FST estimates consistently displayed the same genetic divergence patterns and spatial structure of T. matsutake mediated by host plants in China. The significant heterozygosity excesses demonstrated that a recent genetic bottleneck occurred in each population tested. The complementary M-ratio test indicated past genetic bottleneck events over longer periods. Only four individuals were identified as putative first generation migrants within northeastern China, which implies restricted interpopulation gene flow in T. matsutake. We discuss that the significant genetic differentiation among populations of T. matsutake is most likely a function of host adaptation, host specificity, genetic bottleneck, limited dispersal and habitat fragmentation. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  8. Genetic variability of populations of Nyssomyia neivai in the Northern State of Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Jaqueline de Carvalho Gasparotto

    Full Text Available ABSTRACT The genetic study of sandfly populations needs to be further explored given the importance of these insects for public health. Were sequenced the NDH4 mitochondrial gene from populations of Nyssomyia neivai from Doutor Camargo, Lobato, Japira, and Porto Rico, municipalities in the State of Paraná, Brazil, to understand the genetic structure and gene flow. Eighty specimens of Ny. Neivai were sequenced, 20 from each municipality, and 269 base pairs were obtained. A total of 27 haplotypes and 28 polymorphic sites were found, along with a haplotypic diversity of 0.80696 and a nucleotide diversity of 0.00567. Haplotype H5, with 33 specimens, was the most common among the four populations. Only haplotypes H5 and H7 were present in all four populations. The population from Doutor Camargo showed the highest genetic diversity, and only this population shared haplotypes with those from the other municipalities. The highest number of haplotypes was sheared with Lobato which also had the highest number of unique haplotypes. This probably occurred because of constant anthropic changes that happened in the environment during the first half of the twentieth century, mainly after 1998. There was no significant correlation between genetic and geographical distances regarding these populations. However, the highest genetic and geographical distances, and the lowest gene flow were observed between Japira and Porto Rico. Geographical distance is a possible barrier between these municipalities through the blocking of haplotype sharing.

  9. Effects of developmental variability on the dynamics and self-organization of cell populations

    Science.gov (United States)

    Prabhakara, Kaumudi H.; Gholami, Azam; Zykov, Vladimir S.; Bodenschatz, Eberhard

    2017-11-01

    We report experimental and theoretical results for spatiotemporal pattern formation in cell populations, where the parameters vary in space and time due to mechanisms intrinsic to the system, namely Dictyostelium discoideum (D.d.) in the starvation phase. We find that different patterns are formed when the populations are initialized at different developmental stages, or when populations at different initial developmental stages are mixed. The experimentally observed patterns can be understood with a modified Kessler–Levine model that takes into account the initial spatial heterogeneity of the cell populations and a developmental path introduced by us, i.e. the time dependence of the various biochemical parameters. The dynamics of the parameters agree with known biochemical studies. Most importantly, the modified model reproduces not only our results, but also the observations of an independent experiment published earlier. This shows that pattern formation can be used to understand and quantify the temporal evolution of the system parameters.

  10. Sensitivity of Anopheles gambiae population dynamics to meteo-hydrological variability: a mechanistic approach

    Directory of Open Access Journals (Sweden)

    Gilioli Gianni

    2011-10-01

    Full Text Available Abstract Background Mechanistic models play an important role in many biological disciplines, and they can effectively contribute to evaluate the spatial-temporal evolution of mosquito populations, in the light of the increasing knowledge of the crucial driving role on vector dynamics played by meteo-climatic features as well as other physical-biological characteristics of the landscape. Methods In malaria eco-epidemiology landscape components (atmosphere, water bodies, land use interact with the epidemiological system (interacting populations of vector, human, and parasite. In the background of the eco-epidemiological approach, a mosquito population model is here proposed to evaluate the sensitivity of An. gambiae s.s. population to some peculiar thermal-pluviometric scenarios. The scenarios are obtained perturbing meteorological time series data referred to four Kenyan sites (Nairobi, Nyabondo, Kibwesi, and Malindi representing four different eco-epidemiological settings. Results Simulations highlight a strong dependence of mosquito population abundance on temperature variation with well-defined site-specific patterns. The upper extreme of thermal perturbation interval (+ 3°C gives rise to an increase in adult population abundance at Nairobi (+111% and Nyabondo (+61%, and a decrease at Kibwezi (-2% and Malindi (-36%. At the lower extreme perturbation (-3°C is observed a reduction in both immature and adult mosquito population in three sites (Nairobi -74%, Nyabondo -66%, Kibwezi -39%, and an increase in Malindi (+11%. A coherent non-linear pattern of population variation emerges. The maximum rate of variation is +30% population abundance for +1°C of temperature change, but also almost null and negative values are obtained. Mosquitoes are less sensitive to rainfall and both adults and immature populations display a positive quasi-linear response pattern to rainfall variation. Conclusions The non-linear temperature-dependent response is in

  11. Population of computational rabbit-specific ventricular action potential models for investigating sources of variability in cellular repolarisation.

    Science.gov (United States)

    Gemmell, Philip; Burrage, Kevin; Rodriguez, Blanca; Quinn, T Alexander

    2014-01-01

    Variability is observed at all levels of cardiac electrophysiology. Yet, the underlying causes and importance of this variability are generally unknown, and difficult to investigate with current experimental techniques. The aim of the present study was to generate populations of computational ventricular action potential models that reproduce experimentally observed intercellular variability of repolarisation (represented by action potential duration) and to identify its potential causes. A systematic exploration of the effects of simultaneously varying the magnitude of six transmembrane current conductances (transient outward, rapid and slow delayed rectifier K(+), inward rectifying K(+), L-type Ca(2+), and Na(+)/K(+) pump currents) in two rabbit-specific ventricular action potential models (Shannon et al. and Mahajan et al.) at multiple cycle lengths (400, 600, 1,000 ms) was performed. This was accomplished with distributed computing software specialised for multi-dimensional parameter sweeps and grid execution. An initial population of 15,625 parameter sets was generated for both models at each cycle length. Action potential durations of these populations were compared to experimentally derived ranges for rabbit ventricular myocytes. 1,352 parameter sets for the Shannon model and 779 parameter sets for the Mahajan model yielded action potential duration within the experimental range, demonstrating that a wide array of ionic conductance values can be used to simulate a physiological rabbit ventricular action potential. Furthermore, by using clutter-based dimension reordering, a technique that allows visualisation of multi-dimensional spaces in two dimensions, the interaction of current conductances and their relative importance to the ventricular action potential at different cycle lengths were revealed. Overall, this work represents an important step towards a better understanding of the role that variability in current conductances may play in experimentally

  12. Population of computational rabbit-specific ventricular action potential models for investigating sources of variability in cellular repolarisation.

    Directory of Open Access Journals (Sweden)

    Philip Gemmell

    Full Text Available Variability is observed at all levels of cardiac electrophysiology. Yet, the underlying causes and importance of this variability are generally unknown, and difficult to investigate with current experimental techniques. The aim of the present study was to generate populations of computational ventricular action potential models that reproduce experimentally observed intercellular variability of repolarisation (represented by action potential duration and to identify its potential causes. A systematic exploration of the effects of simultaneously varying the magnitude of six transmembrane current conductances (transient outward, rapid and slow delayed rectifier K(+, inward rectifying K(+, L-type Ca(2+, and Na(+/K(+ pump currents in two rabbit-specific ventricular action potential models (Shannon et al. and Mahajan et al. at multiple cycle lengths (400, 600, 1,000 ms was performed. This was accomplished with distributed computing software specialised for multi-dimensional parameter sweeps and grid execution. An initial population of 15,625 parameter sets was generated for both models at each cycle length. Action potential durations of these populations were compared to experimentally derived ranges for rabbit ventricular myocytes. 1,352 parameter sets for the Shannon model and 779 parameter sets for the Mahajan model yielded action potential duration within the experimental range, demonstrating that a wide array of ionic conductance values can be used to simulate a physiological rabbit ventricular action potential. Furthermore, by using clutter-based dimension reordering, a technique that allows visualisation of multi-dimensional spaces in two dimensions, the interaction of current conductances and their relative importance to the ventricular action potential at different cycle lengths were revealed. Overall, this work represents an important step towards a better understanding of the role that variability in current conductances may play in

  13. Modelling the effects of cell-to-cell variability on the output of interconnected gene networks in bacterial populations.

    Science.gov (United States)

    Politi, Nicolò; Pasotti, Lorenzo; Zucca, Susanna; Magni, Paolo

    2015-01-01

    The interconnection of quantitatively characterized biological devices may lead to composite systems with apparently unpredictable behaviour. Context-dependent variability of biological parts has been investigated in several studies, measuring its entity and identifying the factors contributing to variability. Such studies rely on the experimental analysis of model systems, by quantifying reporter genes via population or single-cell approaches. However, cell-to-cell variability is not commonly included in predictability analyses, thus relying on predictive models trained and tested on central tendency values. This work aims to study in silico the effects of cell-to-cell variability on the population-averaged output of interconnected biological circuits. The steady-state deterministic transfer function of individual devices was described by Hill equations and lognormal synthetic noise was applied to their output. Two- and three-module networks were studied, where individual devices implemented inducible/repressible functions. The single-cell output of such networks was simulated as a function of noise entity; their population-averaged output was computed and used to investigate the expected variability in transfer function identification. The study was extended by testing different noise models, module logic, intrinsic/extrinsic noise proportions and network configurations. First, the transfer function of an individual module was identified from simulated data of a two-module network. The estimated parameter variability among different noise entities was limited (14%), while a larger difference was observed (up to 62%) when estimated and true parameters were compared. Thus, low-variability parameter estimates can be obtained for different noise entities, although deviating from the true parameters, whose measurement requires noise knowledge. Second, the black-box input-output function of a two/three-module network was predicted from the knowledge of the transfer

  14. Examining the infrared variable star population discovered in the Small Magellanic Cloud using the SAGE-SMC survey

    International Nuclear Information System (INIS)

    Polsdofer, Elizabeth; Marengo, M.; Seale, J.; Sewiło, M.; Vijh, U. P.; Terrazas, M.; Meixner, M.

    2015-01-01

    We present our study on the infrared variability of point sources in the Small Magellanic Cloud (SMC). We use the data from the Spitzer Space Telescope Legacy Program “Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud” (SAGE-SMC) and the “Spitzer Survey of the Small Magellanic Cloud” (S 3 MC) survey, over three different epochs, separated by several months to 3 years. Variability in the thermal infrared is identified using a combination of Spitzer’s InfraRed Array Camera 3.6, 4.5, 5.8, and 8.0 μm bands, and the Multiband Imaging Photometer for Spitzer 24 μm band. An error-weighted flux difference between each pair of three epochs (“variability index”) is used to assess the variability of each source. A visual source inspection is used to validate the photometry and image quality. Out of ∼2 million sources in the SAGE-SMC catalog, 814 meet our variability criteria. We matched the list of variable star candidates to the catalogs of SMC sources classified with other methods, available in the literature. Carbon-rich Asymptotic Giant Branch (AGB) stars make up the majority (61%) of our variable sources, with about a third of all of our sources being classified as extreme AGB stars. We find a small, but significant population of oxygen-rich (O-rich) AGB (8.6%), Red Supergiant (2.8%), and Red Giant Branch (<1%) stars. Other matches to the literature include Cepheid variable stars (8.6%), early type stars (2.8%), Young-stellar objects (5.8%), and background galaxies (1.2%). We found a candidate OH maser star, SSTISAGE1C J005212.88-730852.8, which is a variable O-rich AGB star, and would be the first OH/IR star in the SMC, if confirmed. We measured the infrared variability of a rare RV Tau variable (a post-AGB star) that has recently left the AGB phase. 59 variable stars from our list remain unclassified.

  15. Analysis of genetic variability in the Czech Dachshund population using microsatellite markers

    Czech Academy of Sciences Publication Activity Database

    Přibáňová, M.; Horák, Pavel; Schröffelová, D.; Urban, T.; Bechyňová, Renata; Musilová, L.

    2009-01-01

    Roč. 126, - (2009), s. 311-318 ISSN 0931-2668 R&D Projects: GA AV ČR 1QS500450578; GA ČR GD523/03/H076 Institutional research plan: CEZ:AV0Z50450515 Keywords : dachshund * dog * genetic variability * microsatellite Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.706, year: 2009

  16. Genetic variability and population structure of Disanthus cercidifolius subsp. longipes (Hamamelidaceae based on AFLP analysis.

    Directory of Open Access Journals (Sweden)

    Yi Yu

    Full Text Available Disanthus cercidifolius subsp. longipes is an endangered species in China. Genetic diversity and structure analysis of this species was investigated using amplified fragments length polymorphism (AFLP fingerprinting. Nei's gene diversity ranged from 0.1290 to 0.1394. The AMOVA indicated that 75.06% of variation was distributed within populations, while the between-group component 5.04% was smaller than the between populations-within-group component 19.90%. Significant genetic differentiation was detected between populations. Genetic and geographical distances were not correlated. PCA and genetic structure analysis showed that populations from East China were together with those of the Nanling Range. These patterns of genetic diversity and levels of genetic variation may be the result of D. c. subsp. longipes restricted to several isolated habitats and "excess flowers production, but little fruit set". It is necessary to protect all existing populations of D. c. subsp. longipes in order to preserve as much genetic variation as possible.

  17. Genomic patterns inAcropora cervicornisshow extensive population structure and variable genetic diversity.

    Science.gov (United States)

    Drury, Crawford; Schopmeyer, Stephanie; Goergen, Elizabeth; Bartels, Erich; Nedimyer, Ken; Johnson, Meaghan; Maxwell, Kerry; Galvan, Victor; Manfrino, Carrie; Lirman, Diego

    2017-08-01

    Threatened Caribbean coral communities can benefit from high-resolution genetic data used to inform management and conservation action. We use Genotyping by Sequencing (GBS) to investigate genetic patterns in the threatened coral, Acropora cervicornis , across the Florida Reef Tract (FRT) and the western Caribbean. Results show extensive population structure at regional scales and resolve previously unknown structure within the FRT. Different regions also exhibit up to threefold differences in genetic diversity (He), suggesting targeted management based on the goals and resources of each population is needed. Patterns of genetic diversity have a strong spatial component, and our results show Broward and the Lower Keys are among the most diverse populations in Florida. The genetic diversity of Caribbean staghorn coral is concentrated within populations and within individual reefs (AMOVA), highlighting the complex mosaic of population structure. This variance structure is similar over regional and local scales, which suggests that in situ nurseries are adequately capturing natural patterns of diversity, representing a resource that can replicate the average diversity of wild assemblages, serving to increase intraspecific diversity and potentially leading to improved biodiversity and ecosystem function. Results presented here can be translated into specific goals for the recovery of A. cervicornis , including active focus on low diversity areas, protection of high diversity and connectivity, and practical thresholds for responsible restoration.

  18. Spatio-temporal environmental correlation and population variability in simple metacommunities.

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    Lasse Ruokolainen

    Full Text Available Natural populations experience environmental conditions that vary across space and over time. This variation is often correlated between localities depending on the geographical separation between them, and different species can respond to local environmental fluctuations similarly or differently, depending on their adaptation. How this emerging structure in environmental correlation (between-patches and between-species affects spatial community dynamics is an open question. This paper aims at a general understanding of the interactions between the environmental correlation structure and population dynamics in spatial networks of local communities (metacommunities, by studying simple two-patch, two-species systems. Three different pairs of interspecific interactions are considered: competition, consumer-resource interaction, and host-parasitoid interaction. While the results paint a relatively complex picture of the effect of environmental correlation, the interaction between environmental forcing, dispersal, and local interactions can be understood via two mechanisms. While increasing between-patch environmental correlation couples immigration and local densities (destabilising effect, the coupling between local populations under increased between-species environmental correlation can either amplify or dampen population fluctuations, depending on the patterns in density dependence. This work provides a unifying framework for modelling stochastic metacommunities, and forms a foundation for a better understanding of population responses to environmental fluctuations in natural systems.

  19. Genetic variability of a population of Aedes aegypti from Paraná, Brazil, using the mitochondrial ND4 gene

    Directory of Open Access Journals (Sweden)

    Adriana L. Twerdochlib

    2012-06-01

    Full Text Available Genetic variability of a population of Aedes aegypti from Paraná, Brazil, using the mitochondrial ND4 gene. To analyze the genetic variability of populations of Aedes aegypti, 156 samples were collected from 10 municipalities in the state of Paraná, Brazil. A 311 base pairs (bp region of the NADH dehydrogenase subunit 4 (ND4 mitochondrial gene was examined. An analysis of this fragment identified eight distinct haplotypes. The mean genetic diversity was high (h = 0.702; p = 0.01556. AMOVA analysis indicated that most of the variation (67% occurred within populations and the F ST value (0.32996 was highly significant. F ST values were significant in most comparisons among cities. The isolation by distance was not significant (r = -0.1216 and p = 0, 7550, indicating that genetic distance is not related to geographic distance. Neighbor-joining analysis showed two genetically distinct groups within Paraná. The DNA polymorphism and AMOVA data indicate a decreased gene flow in populations from Paraná, which can result in increased vectorial competence.

  20. Within-population isotopic niche variability in savanna mammals: disparity between carnivores and herbivores

    Directory of Open Access Journals (Sweden)

    Daryl eCodron

    2016-02-01

    Full Text Available Large mammal ecosystems have relatively simple food webs, usually comprising three – and sometimes only two – trophic links. Since many syntopic species from the same trophic level therefore share resources, dietary niche partitioning features prominently within these systems. In African and other subtropical savannas, stable carbon isotopes readily distinguish between herbivore species for which foliage and other parts of dicot plants (13C-depleted C3 vegetation are the primary resource (browsers and those for which grasses (13C-enriched C4 vegetation are staples (grazers. Similarly, carbon isotopes distinguish between carnivore diets that may be richer in either browser, grazer, or intermediate-feeding prey. Here, we investigate levels of carbon and nitrogen isotopic niche variation and niche partitioning within populations (or species of carnivores and herbivores from South African savannas. We emphasize predictable differences in within-population trends across trophic levels: we expect that herbivore populations, which require more foraging effort due to higher intake requirements, are far less likely to display within-population resource partitioning than carnivore populations. Our results reveal generally narrower isotopic niche breadths in herbivore than carnivore populations, but more importantly we find lower levels of isotopic differentiation across individuals within herbivore species. While these results offer some support for our general hypothesis, the current paucity of isotopic data for African carnivores limits our ability to test the complete set of predictions arising from our hypothesis. Nevertheless, given the different ecological and ecophysiological constraints to foraging behaviour within each trophic level, comparisons across carnivores and herbivores, which are possible within such simplified foodwebs, make these systems ideal for developing a process-based understanding of conditions underlying the evolution of

  1. Population pharmacokinetics and relationship between demographic and clinical variables and pharmacokinetics of gentamicin in neonates

    NARCIS (Netherlands)

    Stolk, L M L; Degraeuwe, P L J; Nieman, F H M; de Wolf, M C; de Boer, A|info:eu-repo/dai/nl/075097346

    Population pharmacokinetic parameter estimates were calculated from 725 routine plasma gentamicin concentrations obtained in 177 neonates of 24 to 42 weeks' gestational age in their first week of life. Kel increases and V/W decreases with increasing gestational age. Almost identical results were

  2. Genetic variability of CYP2C19 in a Mexican population: contribution ...

    Indian Academy of Sciences (India)

    Abstract. CYP2C19 is a polymorphic enzyme that metabolizes a wide variety of therapeutic drugs that has been associated with altered enzymatic activity and adverse drug reactions. Differences in allele frequencies of the CYP2C19 gene have been detected in populations worldwide. Thus, we analysed the alleles ...

  3. Determination of hardiness by psychosocial and behavioural variables in a representative Czech population sample

    Czech Academy of Sciences Publication Activity Database

    Kebza, V.; Šolcová, Iva

    2008-01-01

    Roč. 23, Suppl. 1 (2008), s. 158 ISSN 0887-0446 R&D Projects: GA AV ČR(CZ) IAA 700250701 Institutional research plan: CEZ:AV0Z70250504 Keywords : hardiness * Czech population sample * social support Subject RIV: AN - Psychology

  4. Driving factors of small-scale variability in a savanna plant population after a fire

    Science.gov (United States)

    Dodonov, Pavel; Xavier, Rafael de Oliveira; Tiberio, Fernanda Cristina dos Santos; Lucena, Isabela Codolo de; Zanelli, Carolina Brandão; Silva Matos, Dalva Maria da

    2014-04-01

    The severity of fire impacts on fire-prone vegetation is often spatially heterogeneous, and may lead to small-scale patchiness in the structure of plant populations by affecting mortality, topkill, and reproduction. This patchiness, however, is not usually taken into account in fire ecology studies. We show that a dry-season fire may result in small-scale patchiness in the population structure of the common shrub Miconia albicans, mostly by differential topkill and resprouting. We related fire severity to population structure parameters of the study species and assessed the effects of fire on its soil seed bank. Basal area of non-woody live stems and of dead stems increased with fire severity, whereas that of woody live stems decreased, indicating topkill and resprouting. However, there was no relationship between fire severity and the total number of live or dead plants, showing that mortality in the fire was low. We found very few seedlings, indicating that resprouting, not germination from the soil seed bank, is the main recovery strategy of this species. The fire also affected the soil seed bank, as there were fewer seedlings emerging from soil collected in burned patches. Although this study was performed with a single species, it is likely that other species, especially those with basal resprouting, will show similar patterns of post-fire patchiness in population structure. This patchiness, in turn, may affect the spatial distribution of future fires, and should be taken into account in studies of fire ecology.

  5. Ecotype variability and edaphic characteristics for cogongrass (Imperata cylindrica) populations in Mississippi

    Science.gov (United States)

    Cogongrass (Imperata cylindrica) is a highly invasive perennial grass in the southeastern United States and is found on all continents except Antartica. It has been reported from a wide array of habitats; however, soils from cogongrass populations have never been characterized. Live cogongrass pla...

  6. Genetic consequences of forest population dynamics influenced by historic climatic variability in the western USA

    Science.gov (United States)

    Robert D. Westfall; Constance I. Millar

    2004-01-01

    We review recent advances in climate science that show cyclic climatic variation over multiple time scales and give examples of the impacts of this variation on plant populations in the western USA. The paleohistorical reconstructions we review and others indicate that plant specles track these cycles in individualistically complex ways. These dynamic histories suggest...

  7. Population dynamics of mottled sculpin (PISCES) in a variable environment: information theoretic approaches

    Science.gov (United States)

    Gary D. Grossman; Robert E Ratajczak; J. Todd Petty; Mark D. Hunter; James T. Peterson; Gael Grenouillet

    2006-01-01

    We used strong inference with Akaike's Information Criterion (AIC) to assess the processes capable of explaining long-term (1984-1995) variation in the per capita rate of change of mottled sculpin (Cottus bairdi) populations in the Coweeta Creek drainage (USA). We sampled two fourth- and one fifth-order sites (BCA [uppermost], BCB, and CC [lowermost])...

  8. Comorbid Disorders and Sociodemographic Variables in Temporomandibular Pain in the General Dutch Population

    NARCIS (Netherlands)

    Visscher, Corine M.; Ligthart, Lannie; Schuller, Annemarie A.; Lobbezoo, Frank; de Jongh, Ad; van Houtem, Caroline M. H. H.; Boomsma, Dorret I.

    2015-01-01

    Aims: (1) To determine the prevalence of temporomandibular disorder (TMD) pain complaints in the general Dutch population; (2) to investigate its relationship with age, sex, educational attainment, and country of birth; (3) to determine its association with other pain complaints; and (4) to

  9. Comorbid disorders and sociodemographic variables in temporomandibular pain in the general Dutch population

    NARCIS (Netherlands)

    Visscher, C.M.; Ligthart, L.; Schuller, A.A.; Lobbezoo, F.; de Jongh, A.; van Houtem, C.M.H.H.; Boomsma, D.I.

    2015-01-01

    Aims: (1) To determine the prevalence of temporomandibular disorder (TMD)-pain complaints in the general Dutch population; (2) to investigate its relationship with age, sex, educational attainment, and country of birth; (3) to determine its association with other pain complaints; and (4) to

  10. Genetic variability of Appaloosa horses: a study of a closed breeding population from Argentina

    Directory of Open Access Journals (Sweden)

    Claudia Malena CORBI-BOTTO,Sebastian Andres SADABA,Elina Ines FRANCISCO,Paula Belen KALEMKERIAN,Juan Pedro LIRON,Egle Etel VILLEGAS-CASTAGNASSO,Guillermo GIOVAMBATTISTA,Pilar PERAL-GARCIA,Silvina DIAZ

    2014-09-01

    Full Text Available The genetic diversity and structure of 72 Appaloosa horses belonging to a closed breeding population from an ecological reserve in Buenos Aires, Argentina, was investigated using eight microsatellite markers from the International Society for Animal Genetics panel. Our data showed that this Appaloosa horse population had an elevated degree of genetic diversity (He= 0.746 and did not present a significant increase of homozygous individuals (FIS~0. However, the short tandem repeats, AHT5, ASB2, HTG10 and VHL20, were not in Hardy–Weinberg equilibrium (P-value<0.05. Genetic relationships between this population and other well known horse breeds showed that Appaloosa horses from Argentina could have had their origin in the horses of the Nez Perce's people in Idaho while other Appaloosa horses may have had influences from Andalusian and Lusitano breeds. This closed breeding population conserves an important degree of Appaloosa genetic diversity and notwithstanding its particular breeding characteristics, represents a valuable genetic resource for conservation.

  11. Chromosomal Variability Between Populations of Electrophorus electricus Gill, 1864 (Pisces: Gymnotiformes: Gymnotidae).

    Science.gov (United States)

    Cardoso, Adauto Lima; Ready, Jonathan Stuart; Pieczarka, Julio Cesar; Milhomem, Susana Suely Rodrigues; de Figueiredo-Ready, Wilsea Maria Batista; Silva, Fernando Henrique Ramos; Nagamachi, Cleusa Yoshiko

    2015-12-01

    The electric eel, Electrophorus electricus, the only species of its genus, has a wide distribution in the Amazon and Orinoco drainages. There is little previous information regarding the population variation in E. electricus, with only basic karyotype data from two populations (Amazon and Araguaia Rivers). Karyotypic description and analysis of CO1 barcode sequences were performed for E. electricus from three localities (Caripetuba, Irituia, and Maicuru Rivers). All samples share the 2n=52 (42 m-sm [meta-submetacentric] +10 st-a [subtelo-acrocentric]) with previously studied material. However, the Maicuru River samples differ from the other populations, as they have B chromosomes. The distribution of noncentromeric constitutive heterochromatin between samples is relatively divergent. All samples analyzed present the Nucleolar Organizer Region (NOR) located in a single chromosome pair. In the samples from Caripetuba, NORs were colocalized with a heterochromatin block, whereas the NOR was flanked by heterochromatin in Maicuru River samples and pericentromeric heterochromatin adjacent NOR was found in Irituia River samples. Alignment of CO1 barcode sequences indicated no significant differentiation between the samples analyzed. Results suggest that karyotypic differences between samples from the Caripetuba, Irituia, and Amazon Rivers represent chromosome polymorphisms. However, differences between the samples from the Maicuru and Araguaia Rivers and the remaining populations could represent interpopulation differentiation, which has not had time to accrue divergence at the CO1 gene level.

  12. Individual variability and mortality required for constant final yield in simulated plant populations

    Czech Academy of Sciences Publication Activity Database

    Fibich, P.; Lepš, Jan; Weiner, J.

    2014-01-01

    Roč. 7, č. 3 (2014), s. 263-271 ISSN 1874-1738 Grant - others:GA ČR(CZ) GA-1317118S; GA MŠk(CZ) LM2010005 Institutional support: RVO:60077344 Keywords : constant final yield * variability * mortality Subject RIV: EH - Ecology, Behaviour Impact factor: 1.553, year: 2014 http://link.springer.com/article/10.1007%2Fs12080-014-0216-x#

  13. Variable Isotopic Compositions of Host Plant Populations Preclude Assessment of Aphid Overwintering Sites

    Directory of Open Access Journals (Sweden)

    Michael S. Crossley

    2017-12-01

    Full Text Available Soybean aphid (Aphis glycines Matsumura is a pest of soybean in the northern Midwest whose migratory patterns have been difficult to quantify. Improved knowledge of soybean aphid overwintering sites could facilitate the development of control efforts with exponential impacts on aphid densities on a regional scale. In this preliminary study, we explored the utility of variation in stable isotopes of carbon and nitrogen to distinguish soybean aphid overwintering origins. We compared variation in bulk 13C and 15N content in buckthorn (Rhamnus cathartica L. and soybean aphids in Wisconsin, among known overwintering locations in the northern Midwest. Specifically, we looked for associations between buckthorn and environmental variables that could aid in identifying overwintering habitats. We detected significant evidence of correlation between the bulk 13C and 15N signals of soybean aphids and buckthorn, despite high variability in stable isotope composition within and among buckthorn plants. Further, the 15N signal in buckthorn varied predictably with soil composition. However, lack of sufficient differentiation of geographic areas along axes of isotopic and environmental variation appears to preclude the use of carbon and nitrogen isotopic signals as effective predictors of likely aphid overwintering sites. These preliminary data suggest the need for future work that can further account for variability in 13C and 15N within/among buckthorn plants, and that explores the utility of other stable isotopes in assessing likely aphid overwintering sites.

  14. Leukocyte Populations are Associated with Heart Rate Variability After a Triathlon

    Directory of Open Access Journals (Sweden)

    Cruz Germán Hernández

    2016-12-01

    Full Text Available The purpose of this study was to analyze cellular immune components and their association with heart rate variability in triathlon athletes. Twelve athletes were included (age 36.41 ± 5.57 years, body mass 81.84 ± 10.97 kg and blood samples were taken one week before, immediately, at 2 and 48 hours, and one week after competition. Total lymphocytes and their subpopulations, neutrophils, basophils, eosinophils and monocytes were analyzed. At the same time, heart rate variability was recorded for 30 minutes using Polar Team2®. A significant difference between lymphocyte subpopulations and heart rate variability was found in the different study periods. A positive correlation was found between total lymphocytes and rMSSD (r = .736, p <0.05, CD3+ and rMSSD (r = .785, p <0.05, and CD4+ and rMSSD (r = .795, p < 0.05 at the end of the competition. After one week of competition, a negative correlation was found between eosinophils and MRR, SDNN, pNN50, and rMSSD (p <0.01; and basophils and MRR, SDNN, pNN50, and rMSSD (p <0.01; while a positive correlation was found between CD19+ (B cells and pNN50 (r = .678, p <0.05. Our results suggest that it is possible to predict the effect of training with regard to the athlete's performance.

  15. Variability and genetic structure of the population of watermelon mosaic virus infecting melon in Spain

    International Nuclear Information System (INIS)

    Moreno, I.M.; Malpica, J.M.; Diaz-Pendon, J.A.; Moriones, E.; Fraile, A.; Garcia-Arenal, F.

    2004-01-01

    The genetic structure of the population of Watermelon mosaic virus (WMV) in Spain was analysed by the biological and molecular characterisation of isolates sampled from its main host plant, melon. The population was a highly homogeneous one, built of a single pathotype, and comprising isolates closely related genetically. There was indication of temporal replacement of genotypes, but not of spatial structure of the population. Analyses of nucleotide sequences in three genomic regions, that is, in the cistrons for the P1, cylindrical inclusion (CI) and capsid (CP) proteins, showed lower similar values of nucleotide diversity for the P1 than for the CI or CP cistrons. The CI protein and the CP were under tighter evolutionary constraints than the P1 protein. Also, for the CI and CP cistrons, but not for the P1 cistron, two groups of sequences, defining two genetic strains, were apparent. Thus, different genomic regions of WMV show different evolutionary dynamics. Interestingly, for the CI and CP cistrons, sequences were clustered into two regions of the sequence space, defining the two strains above, and no intermediary sequences were identified. Recombinant isolates were found, accounting for at least 7% of the population. These recombinants presented two interesting features: (i) crossover points were detected between the analysed regions in the CI and CP cistrons, but not between those in the P1 and CI cistrons, (ii) crossover points were not observed within the analysed coding regions for the P1, CI or CP proteins. This indicates strong selection against isolates with recombinant proteins, even when originated from closely related strains. Hence, data indicate that genotypes of WMV, generated by mutation or recombination, outside of acceptable, discrete, regions in the evolutionary space, are eliminated from the virus population by negative selection

  16. Normative references of heart rate variability and salivary alpha-amylase in a healthy young male population

    Directory of Open Access Journals (Sweden)

    Kobayashi Hiromitsu

    2012-04-01

    Full Text Available Abstract Background This study aimed to present normative reference values of heart rate variability and salivary alpha-amylase in a healthy young male population with a particular focus on their distribution and reproducibility. Methods The short-term heart rate variability of 417 young healthy Japanese men was studied. Furthermore, salivary alpha-amylase was measured in 430 men. The average age of the subjects were 21.9 years with standard deviation of 1.6 years. Interindividual variations in heart rate variability indices and salivary alpha-amylase levels were plotted as histograms. Data are presented as the mean, median, standard deviation, coefficient of variation, skewness, kurtosis, and fifth and 95th percentiles of each physiological index. Results Mean recorded values were heart period 945.85 ms, log-transformed high frequency component 9.84 ln-ms2, log-transformed low frequency component 10.42 ln-ms2, log-transformed low frequency to high frequency ratio 0.58 ln-ratio, standard deviation of beat-to-beat interval 27.17 ms and root mean square of successive difference 37.49 ms. The mean value of raw salivary alpha-amylase was 17.48 U/mL, square root salivary alpha-amylase 3.96 sqrt[U/mL] and log-transformed salivary alpha-amylase 2.65 ln[U/mL]. Log-transformed heart rate variability indices exhibited almost symmetrical distributions; however, time-domain indices of heart rate variability (standard deviation of beat-to-beat interval and root mean square of successive difference exhibited right-skewed (positive skewness distributions. A considerable right-skewed distribution was observed for raw salivary alpha-amylase. Logarithmic transformation improved the distribution of salivary alpha-amylase, although square root transformation was insufficient. The day-to-day reproducibility of these indices was assessed using intraclass correlation coefficients. Intraclass correlation coefficients of most heart rate variability and salivary indices

  17. Population structure and genetic variability in the Murrah dairy breed of water buffalo in Brazil accessed via pedigree analysis.

    Science.gov (United States)

    Malhado, Carlos Henrique Mendes; Malhado, Ana Claudia Mendes; Carneiro, Paulo Luiz Souza; Ramos, Alcides Amorim; Ambrosini, Diego Pagung; Pala, Akin

    2012-12-01

    The objective of this study was to use pedigree analysis to evaluate the population structure and genetic variability in the Murrah dairy breed of water buffalo (Bubalus bubalis) in Brazil. Pedigree analysis was performed on 5,061 animals born between 1972 and 2002. The effective number of founders (fe) was 60, representing 6.32 % of the potential number of founders. The effective number of ancestors (fa) was 36 and the genetic contribution of the 17 most influent ancestors explained 50 % of the genetic variability in the population. The ratio fe/fa (effective number of founders/effective number of ancestors), which expresses the effect of population bottlenecks, was 1.66. Completeness level for the whole pedigree was 76.8, 49.2, 27.7, and 12.8 % for, respectively, the first, second, third, and fourth known parental generations. The average inbreeding values for the whole analyzed pedigree and for inbreed animals were, respectively, 1.28 and 7.64 %. The average relatedness coefficient between individuals of the population was estimated to be 2.05 %-the highest individual coefficient was 10.31 %. The actual inbreeding and average relatedness coefficient are probably higher than estimated due to low levels of pedigree completeness. Moreover, the inbreeding coefficient increased with the addition of each generation to the pedigree, indicating that incomplete pedigrees tend to underestimate the level of inbreeding. Introduction of new sires with the lowest possible average relatedness coefficient and the use of appropriate mating strategies are recommended to keep inbreeding at acceptable levels and increase the genetic variability in this economically important species, which has relatively low numbers compared to other commercial cattle breeds. The inclusion of additional parameters, such as effective number of founders, effective number of ancestors, and fe/fa ratio, provides better resolution as compared to the inclusion of inbreeding coefficient and may help

  18. Estimation of the morphological variability of Rossiulus kessleri (Diplopoda, Julida populations

    Directory of Open Access Journals (Sweden)

    A. P. Pokhylenko

    2014-05-01

    Full Text Available On condition of anthropogenic pressure soil biota is one of the first reacting on environment changes. As long as natural selection occurs by phenotypes, it is important that on the urban land the organisms’ adaptations to changes in natural factors can be revealed with phenetic methods. The paper analyzes the ecological modification of the diplopoda Rossiulus kessleri (Lohmander, 1927 in the Samarskyi Forest region environment (Novomoskovskyj forestry is the ravine ecosystem, and Kocherezhskyi forestry is short-term-flooded ecosystem and State Reservation “Voloshanskaya Dacha” (“Zatishnoye”. Such investigation for this region is conducted for the first time. Space samples consisted of 30 individuals (males and females, proportionally for each plot. Among others, 14 basic morphometric in-line parameters and its relation were chosen: length/width of the body, amount of segments, length of hindleg, length of telson, length/width of antenna, length/width of gnathochilarium, length/width of semiflosculous blades, length/width of promenthum, length of collum. Morphometric interconnections within the given populations were established with the help of the factor analysis. The most changeable morphometric characteristics between populations and sexes were revealed. For all the given populations sex dimorphism is pointed out for the size of gna-thochilarium and the length of collum. Basing on obtained results from specimen measuring from Novomoskovsky forestry district we pointed out that both the majority of the given in-line parameters and its relation had no sex dimorphism. It also shows the stability of the environment. It is estimated that females from Kocherezhskyi forestry population have longer antennae (males have 10,2% less and body width (females are on 14,0% wider. Body width is stable characteristic for many Diplopoda species. With high signification level for both basic in-line characters (length and width, sex dimorphism is

  19. Education and Successful Aging Trajectories: A Longitudinal Population-Based Latent Variable Modelling Analysis.

    Science.gov (United States)

    Cosco, Theodore D; Stephan, Blossom C M; Brayne, Carol; Muniz, Graciela

    2017-12-01

    As the population ages, interest is increasing in studying aging well. However, more refined means of examining predictors of biopsychosocial conceptualizations of successful aging (SA) are required. Existing evidence of the relationship between early-life education and later-life SA is unclear. The Successful Aging Index (SAI) was mapped onto the Cognitive Function and Aging Study (CFAS), a longitudinal population-based cohort (n = 1,141). SAI scores were examined using growth mixture modelling (GMM) to identify SA trajectories. Unadjusted and adjusted (age, sex, occupational status) ordinal logistic regressions were conducted to examine the association between trajectory membership and education level. GMM identified a three-class model, capturing high, moderate, and low functioning trajectories. Adjusted ordinal logistic regression models indicated that individuals in higher SAI classes were significantly more likely to have higher educational attainment than individuals in the lower SAI classes. These results provide evidence of a life course link between education and SA.

  20. Genetic variability within the Polish population of red fox (Vulpes vulpes – preliminary results

    Directory of Open Access Journals (Sweden)

    Magdalena Zatoń-Dobrowolska

    2016-09-01

    Full Text Available Red fox (Vulpes vulpes represents family Canidae and is a very common predator in Poland. Foxes are present throughout all the country in a different geographical regions and habitats. The analyzed dataset consisted of 130 red foxes (Vulpes vulpes. There were 24 microsatellite sequences studied. The observed (HO and expected (HS heterozygosities were comparable within respective loci. The low genetic diversity of the population was found.

  1. The Relationship Between Pedometer-Determined Ambulatory Activity and Balance Variables Within an Older Adult Population

    OpenAIRE

    Campbell, Candice; Kress, Jeff; Schroeder, Jan; Donlin, Ayla; Rozenek, Ralph

    2016-01-01

    The purpose of this investigation was to determine the differences between gender, physical activity level, and balance in an older adult population. A secondary purpose was to examine the relationship between pedometer-determined ambulatory activity and balance. Forty-six older adults aged 73.7 ± 6.2 years participated in the study. Participants completed the Fullerton Advanced Balance (FAB) Scale and completed a 2-week daily step recording to determine average steps taken per day. Low-level...

  2. Consequences of an uncertain mass mortality regime triggered by climate variability on giant clam population management in the Pacific Ocean.

    Science.gov (United States)

    Van Wynsberge, Simon; Andréfouët, Serge; Gaertner-Mazouni, Nabila; Remoissenet, Georges

    2018-02-01

    Despite actions to manage sustainably tropical Pacific Ocean reef fisheries, managers have faced failures and frustrations because of unpredicted mass mortality events triggered by climate variability. The consequences of these events on the long-term population dynamics of living resources need to be better understood for better management decisions. Here, we use a giant clam (Tridacna maxima) spatially explicit population model to compare the efficiency of several management strategies under various scenarios of natural mortality, including mass mortality due to climatic anomalies. The model was parameterized by in situ estimations of growth and mortality and fishing effort, and was validated by historical and new in situ surveys of giant clam stocks in two French Polynesia lagoons. Projections on the long run (100 years) suggested that the best management strategy was a decrease of fishing pressure through quota implementation, regardless of the mortality regime considered. In contrast, increasing the minimum legal size of catch and closing areas to fishing were less efficient. When high mortality occurred due to climate variability, the efficiency of all management scenarios decreased markedly. Simulating El Niño Southern Oscillation event by adding temporal autocorrelation in natural mortality rates increased the natural variability of stocks, and also decreased the efficiency of management. These results highlight the difficulties that managers in small Pacific islands can expect in the future in the face of global warming, climate anomalies and new mass mortalities. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. HLA-F coding and regulatory segments variability determined by massively parallel sequencing procedures in a Brazilian population sample.

    Science.gov (United States)

    Lima, Thálitta Hetamaro Ayala; Buttura, Renato Vidal; Donadi, Eduardo Antônio; Veiga-Castelli, Luciana Caricati; Mendes-Junior, Celso Teixeira; Castelli, Erick C

    2016-10-01

    Human Leucocyte Antigen F (HLA-F) is a non-classical HLA class I gene distinguished from its classical counterparts by low allelic polymorphism and distinctive expression patterns. Its exact function remains unknown. It is believed that HLA-F has tolerogenic and immune modulatory properties. Currently, there is little information regarding the HLA-F allelic variation among human populations and the available studies have evaluated only a fraction of the HLA-F gene segment and/or have searched for known alleles only. Here we present a strategy to evaluate the complete HLA-F variability including its 5' upstream, coding and 3' downstream segments by using massively parallel sequencing procedures. HLA-F variability was surveyed on 196 individuals from the Brazilian Southeast. The results indicate that the HLA-F gene is indeed conserved at the protein level, where thirty coding haplotypes or coding alleles were detected, encoding only four different HLA-F full-length protein molecules. Moreover, a same protein molecule is encoded by 82.45% of all coding alleles detected in this Brazilian population sample. However, the HLA-F nucleotide and haplotype variability is much higher than our current knowledge both in Brazilians and considering the 1000 Genomes Project data. This protein conservation is probably a consequence of the key role of HLA-F in the immune system physiology. Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  4. Selection variability for Arg48His in alcohol dehydrogenase ADH1B among Asian populations.

    Science.gov (United States)

    Evsyukov, Alexey; Ivanov, Denis

    2013-08-01

    The variant His at codon 48 of the alcohol dehydrogenase gene (ADH1B) results in more efficient ethanol metabolism than with the "typical" codon 48Arg. In this study we introduced selection properties of Arg48His genotypes of ADH1B and estimated fitness in four ethnic-geographical clusters in Asia. Population genetics models were employed that derive observed gene frequencies from fitness relationships among genotypes, to infer the selection pattern of polymorphisms in an indirect manner. The data were analyzed using the model of "complete stationary distribution" by Wright that takes into account random genetic drift, pressure of migrations, mutations, and selection as influential factors of gene frequency. We found that the different population groups showed some variation in the types of selection for Arg48His. Han Chinese from eastern and southeastern China and the Japanese and Korean populations showed stabilizing selection, while the groups from Central Asian and Indochina showed divergent selection. However, all the groups demonstrated a strong positive selection for Arg48His. Copyright © 2013 Wayne State University Press, Detroit, Michigan 48201-1309.

  5. Supplemental Dietary Inulin of Variable Chain Lengths Alters Intestinal Bacterial Populations in Young Pigs123

    Science.gov (United States)

    Patterson, Jannine K.; Yasuda, Koji; Welch, Ross M.; Miller, Dennis D.; Lei, Xin Gen

    2010-01-01

    Previously, we showed that supplementation of diets with short-chain inulin (P95), long-chain inulin (HP), and a 50:50 mixture of both (Synergy 1) improved body iron status and altered expression of the genes involved in iron homeostasis and inflammation in young pigs. However, the effects of these 3 types of inulin on intestinal bacteria remain unknown. Applying terminal restriction fragment length polymorphism analysis, we determined the abundances of luminal and adherent bacterial populations from 6 segments of the small and large intestines of pigs (n = 4 for each group) fed an iron-deficient basal diet (BD) or the BD supplemented with 4% of P95, Synergy 1, or HP for 5 wk. Compared with BD, all 3 types of inulin enhanced (P inulin on bacterial populations in the lumen contents were found. Meanwhile, all 3 types of inulin suppressed the less desirable bacteria Clostridium spp. and members of the Enterobacteriaceae in the lumen and mucosa of various gut segments. Our findings suggest that the ability of dietary inulin to alter intestinal bacterial populations may partially account for its iron bioavailability-promoting effect and possibly other health benefits. PMID:20980641

  6. Non-genetic phenotypic variability and its effect on population performance.

    Science.gov (United States)

    Emonet, Thierry; Waite, Adam J.; Frankel, Nicholas W.; Dufour, Yann S.; Long, Junjiajia; Johnston, Jessica F.

    Substantial non-genetic diversity in complex behaviors, such as chemotaxis in E. coli, has been observed for decades, but the relevance of this diversity for the population is not well understood. What are the trade-offs that bacteria face in performing chemotaxis in different environments? Can population diversity be tailored to resolve these trade-offs? We examined the functional role of non-genetic diversity in cellular migration by measuring the phenotype and chemotactic performance of tens of thousands of individual, freely-swimming Escherichia coli as they climbed a gradient of attractant. We discovered that spatial structure spontaneously emerged from initially well-mixed wild type populations due to non-genetic diversity. By manipulating the expression of a key chemotaxis protein, we established a causal relationship between protein expression, non-genetic diversity, and performance that was theoretically predicted. This approach generated a complete phenotype-to-performance map, in which we found a nonlinear regime. We used this map to demonstrate how the shape of a phenotypic distribution can have as large of an effect on performance as changing the mean phenotype, suggesting that evolution could act on both during the process of adaptation. We thank Yale HPC, NIGMS 1R01GM106189, and the Allen Distinguished Investigator Program through The Paul G. Allen Frontiers Group for support.

  7. Analysis of sequence variability in the CART gene in relation to obesity in a Caucasian population

    Directory of Open Access Journals (Sweden)

    Hercberg Serge

    2005-04-01

    Full Text Available Abstract Background Cocaine and amphetamine regulated transcript (CART is an anorectic neuropeptide located principally in hypothalamus. CART has been shown to be involved in control of feeding behavior, but a direct relationship with obesity has not been established. The aim of this study was to evaluate the effect of polymorphisms within the CART gene with regards to a possible association with obesity in a Caucasian population. Results Screening of the entire gene as well as a 3.7 kb region of 5' upstream sequence revealed 31 SNPs and 3 rare variants ; 14 of which were subsequently genotyped in 292 French morbidly obese subjects and 368 controls. Haplotype analysis suggested an association with obesity which was found to be mainly due to SNP-3608T>C (rs7379701 (p = 0.009. Genotyping additional cases and controls also of European Caucasian origin supported further this possible association between the CART SNP -3608T>C T allele and obesity (global p-value = 0.0005. Functional studies also suggested that the SNP -3608T>C could modulate nuclear protein binding. Conclusion CART SNP -3608T>C may possibly contribute to the genetic risk for obesity in the Caucasian population. However confirmation of the importance of the role of the CART gene in energy homeostasis and obesity will require investigation and replication in further populations.

  8. Breeding biology and variable mating system of a population of introduced dunnocks (Prunella modularis in New Zealand.

    Directory of Open Access Journals (Sweden)

    Eduardo S A Santos

    Full Text Available Species with variable mating systems provide a unique opportunity to investigate whether females receive direct fitness benefits from additional male partners. The direct benefits provide an obvious explanation for why females would breed polyandrously, in a situation where males clearly do not attain their optimal reproductive success. Evidence for these direct benefits is, however, mixed. Here, we present a detailed study of the breeding biology of the dunnock, Prunella modularis, which inform an investigation into the effects of the social mating system on the reproductive success in a population of dunnocks in Southern New Zealand. We studied 80 different social groups over the course of three breeding seasons. Dunnocks in our population presented a variable mating system, with socially monogamous (45%, socially polyandrous (54% and socially polygynandrous (1% groups being observed in the same breeding season. We did not observe any polygynous social units in our study period although polygyny exists in the population. We found little difference in the numbers of eggs laid, and egg volume between monogamous and polyandrous nests. However, polyandrous groups had better hatching and fledging success than monogamous groups (composite d = 0.385, 95% CI: 0.307 to 0.463. Overall our results support the notion that polyandry is beneficial for females.

  9. Symptom Science: Omics Supports Common Biological Underpinnings Across Symptoms.

    Science.gov (United States)

    McCall, Maura K; Stanfill, Ansley Grimes; Skrovanek, Elizabeth; Pforr, Jessica Renee; Wesmiller, Susan W; Conley, Yvette P

    2018-03-01

    For precision health care to be successful, an in-depth understanding of the biological mechanisms for symptom development and severity is essential. Omics-based research approaches facilitate identification of the biological underpinnings of symptoms. We reviewed literature for omics-based approaches and exemplar symptoms (sleep disruption, cognitive impairment, fatigue, gastrointestinal [GI] distress, and pain) to identify genes associated with the symptom or symptoms across disease processes. The review yielded 27 genes associated with more than one symptom. ABCB1 (MDR1), APOE, BDNF, CNR1, COMT, DAT1 (SLC6A3), DRD4, ESR1, HLA-DRB1, IL10, IL1B, IL6, LTA, PTGS2 (COX-2), SLC6A4, and TNF were associated with cognitive impairment and pain, which had the most genes in common. COMT and TNF were related to all symptoms except sleep disruption. IL1B was associated with all symptoms except cognitive impairment. IL10, IL1A, IL1B, IL1RN, IL6, and IL8 (CXCL8) were linked with all the exemplar symptoms in various combinations. ABCB1 (MDR1) and SLC6A4 were associated with cognitive impairment, GI distress, and pain. IL10 and IL6 were linked to cognitive impairment, fatigue, and pain. APOE and BDNF were associated with sleep disruption, cognitive impairment, and pain. The 27 genes were associated with canonical pathways including immune, inflammatory, and cell signaling. The pathway analysis generated a 15-gene model from the 27 as well as 3 networks, which incorporated new candidate genes. The findings support the hypothesis of overlapping biological underpinnings across the exemplar symptoms. Candidate genes may be targeted in future omics research to identify mechanisms of co-occurring symptoms for potential precision treatments.

  10. Inverse problem for a physiologically structured population model with variable-effort harvesting

    Directory of Open Access Journals (Sweden)

    Andrusyak Ruslan V.

    2017-04-01

    Full Text Available We consider the inverse problem of determining how the physiological structure of a harvested population evolves in time, and of finding the time-dependent effort to be expended in harvesting, so that the weighted integral of the density, which may be, for example, the total number of individuals or the total biomass, has prescribed dynamics. We give conditions for the existence of a unique, global, weak solution to the problem. Our investigation is carried out using the method of characteristics and a generalization of the Banach fixed-point theorem.

  11. Variable BCG efficacy in rhesus populations: Pulmonary BCG provides protection where standard intra-dermal vaccination fails.

    Science.gov (United States)

    Verreck, Frank A W; Tchilian, Elma Z; Vervenne, Richard A W; Sombroek, Claudia C; Kondova, Ivanela; Eissen, Okke A; Sommandas, Vinod; van der Werff, Nicole M; Verschoor, Ernst; Braskamp, Gerco; Bakker, Jaco; Langermans, Jan A M; Heidt, Peter J; Ottenhoff, Tom H M; van Kralingen, Klaas W; Thomas, Alan W; Beverley, Peter C L; Kocken, Clemens H M

    2017-05-01

    M.bovis BCG vaccination against tuberculosis (TB) notoriously displays variable protective efficacy in different human populations. In non-human primate studies using rhesus macaques, despite efforts to standardise the model, we have also observed variable efficacy of BCG upon subsequent experimental M. tuberculosis challenge. In the present head-to-head study, we establish that the protective efficacy of standard parenteral BCG immunisation varies among different rhesus cohorts. This provides different dynamic ranges for evaluation of investigational vaccines, opportunities for identifying possible correlates of protective immunity and for determining why parenteral BCG immunisation sometimes fails. We also show that pulmonary mucosal BCG vaccination confers reduced local pathology and improves haematological and immunological parameters post-infection in animals that are not responsive to induction of protection by standard intra-dermal BCG. These results have important implications for pulmonary TB vaccination strategies in the future. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. [Variables associated with the use of dental services among preschool population in Spain: a national health survey analysis].

    Science.gov (United States)

    Barriuso Lapresa, Laura; Sanz-Barbero, Belén

    2012-01-01

    oral health is integral to health from the eruption of the first tooth. To achieving, it is necessary an early establishment of healthy oral habits as regular dental checkups. In developed countries, caries is the most prevalent chronic pediatric disease and it may be increasing in preschool age. a) assessing prevalence of oral health services use among Spanish preschool population, b) quantifying and analyzing the existence of variability among autonomous community and c) identifying variables associated with such use. cross-sectional study about Spanish National health Survey (2006). 2,172 children aged between 2 and 5 years (both inclusive). have gone to dental services at least once during life. sociodemographic, self-referred dental health, habits and family socioeconomic status variables. Multivariate logistic regression analysis. 20.8% of Spanish preschoolers reported had attended dental services. Probability of use increased with age (OR: 1,88; IC:1,53-2,31), frequency of daily tooth brushing (three or more times per day vrs less than once: OR: 2,94; IC: 1,47-5,87) and presence of caries (OR: 2,60; IC: 1,22-5,51). There is a socioeconomic gradient about probability of use: it increased with family socioeconomic status measured by social class (low vrs high: OR: 0,41; IC: 0,19-0,86) and maternal educational level (OR: 1,62; IC: 1,13-2,32). There was not variability in the oral health services use attributable to the autonomous community. the use of dental health services among Spanish preschool population is lower than desirable. The promotion of its use should be intensified in children from disadvantaged families.

  13. Genetic variability of wild and captivity populations of Colossoma macropomum (Cuvier, 1818 - doi: 10.4025/actascibiolsci.v34i2.7149

    Directory of Open Access Journals (Sweden)

    Vera Maria Fonseca de Almeida-Val

    2012-03-01

    Full Text Available Tambaqui (Colossoma macropomum is among the most important fish species of the Amazon and one of the most cultivated in Brazil. In the present work we have evaluated the genetic variability of wild and captivity populations of C. macropomum. Enzymatic markers were used to estimate the genetic variability of 41 specimens from a wild group; and 30, 33 and 45 from three captivity groups, which came from Pentecostes (Ceará State, Jaboticabal (São Paulo State and Itacoatiara (Amazonas State, respectively. Nine isoenzymic systems were used to evaluate the genetic variability of these populations. Using zimogram data we obtained the polymorphism level, allele number, allelic frequency, observed and expected heterozigosity, Wright F statistics (FIS, FST, genetic distance, level of similarity and group analysis. The isoenzymic data showed that, from the nine systems, six presented polymorphic loci (Fbp-2, G6pdh-2, G6pdh-3, Pgi-1, Pgi-2 and Pgm-1. The populations from Pentecostes and Jaboticabal presented loss of genetic variability and low heterozigosity, compared to the wild population and to the artificial population acquired at Itacoatiara fish farm. Based on these results and on fish farmer information we could consider the population from Itacoatiara as recently derived from a wild population. Concluding, we suggest that the artificial populations of tambaqui, which contain animals originated from this funding population at Pentecostes, should be renewed with the introduction of a new group of individuals with genetic variability equivalent to the wild population.

  14. Variability in body mass and sexual dimorphism in Danish red foxes (Vulpes vulpes) in relation to population density

    DEFF Research Database (Denmark)

    Pagh, Sussie; Hansen, Mette Sif; Jensen, Birger

    2017-01-01

    For the first time, temporal variability in body size and sexual dimorphism is revealed in foxes Vulpes vulpes from the same geographical area at over time. The weights and lengths of 552 Danish foxes were documented during three different periods: 1965–1977, 2012–2014 and the winter of 2015....../2016. During the first and the third periods, the fox population was below the carrying capacity due to hunting pressure and canine distemper, respectively. Adult males were significantly (p ...–1977 and compared to 2015/2016, compared to 2012–2014, when population density was high (the mean weight: 6.8 kg). However, no significant differences were found in the weight of females. Hence, sexual dimorphism ranged from 7.6 to 3.6 in adult foxes in low and high-density periods, respectively. During the winters...

  15. [GENETIC VARIABILITY OF MATERNAL PLANTS AND SEED EMBRYOS OF KOCH PINE POPULATIONS (PINUS KOCHIANA KLOTZSCH EX KOCH) IN CRIMEA].

    Science.gov (United States)

    Korshykov, I I; Kalafat, L O; Vynogradova, O M; Podgornyi, D Y

    2016-01-01

    Comparative studies of genetic variability were undertaken for 12 allozyme loci selections of trees and embryos of seed, and also for the crossing systems in five populations of Koch pine of (Pinus kochiana Klotzsch ex Koch) in Crimea. It was shown that in seed embryos the allelic variety peculiar to the maternal plants was restored, however the level of the available (H₀) heterozygosity was considerably lower, 0.286 and 0.189 respectively. For the embryos unlike the trees, in the majority of the analyzed loci the considerable divergence was specific in the actual distribution of genotypes from the theoretically expected according to Hardy- Weinberg law. The proportion of cross pollination at the unilocal (t(s)) estimation varied from 0.384 to 0.673 in the populations, while at the multilocal ones (t(m)) it was 0.639-0.841.

  16. Population Density, Climate Variables and Poverty Synergistically Structure Spatial Risk in Urban Malaria in India.

    Directory of Open Access Journals (Sweden)

    Mauricio Santos-Vega

    2016-12-01

    Full Text Available The world is rapidly becoming urban with the global population living in cities projected to double by 2050. This increase in urbanization poses new challenges for the spread and control of communicable diseases such as malaria. In particular, urban environments create highly heterogeneous socio-economic and environmental conditions that can affect the transmission of vector-borne diseases dependent on human water storage and waste water management. Interestingly India, as opposed to Africa, harbors a mosquito vector, Anopheles stephensi, which thrives in the man-made environments of cities and acts as the vector for both Plasmodium vivax and Plasmodium falciparum, making the malaria problem a truly urban phenomenon. Here we address the role and determinants of within-city spatial heterogeneity in the incidence patterns of vivax malaria, and then draw comparisons with results for falciparum malaria.Statistical analyses and a phenomenological transmission model are applied to an extensive spatio-temporal dataset on cases of Plasmodium vivax in the city of Ahmedabad (Gujarat, India that spans 12 years monthly at the level of wards. A spatial pattern in malaria incidence is described that is largely stationary in time for this parasite. Malaria risk is then shown to be associated with socioeconomic indicators and environmental parameters, temperature and humidity. In a more dynamical perspective, an Inhomogeneous Markov Chain Model is used to predict vivax malaria risk. Models that account for climate factors, socioeconomic level and population size show the highest predictive skill. A comparison to the transmission dynamics of falciparum malaria reinforces the conclusion that the spatio-temporal patterns of risk are strongly driven by extrinsic factors.Climate forcing and socio-economic heterogeneity act synergistically at local scales on the population dynamics of urban malaria in this city. The stationarity of malaria risk patterns provides a

  17. Population Density, Climate Variables and Poverty Synergistically Structure Spatial Risk in Urban Malaria in India.

    Science.gov (United States)

    Santos-Vega, Mauricio; Bouma, Menno J; Kohli, Vijay; Pascual, Mercedes

    2016-12-01

    The world is rapidly becoming urban with the global population living in cities projected to double by 2050. This increase in urbanization poses new challenges for the spread and control of communicable diseases such as malaria. In particular, urban environments create highly heterogeneous socio-economic and environmental conditions that can affect the transmission of vector-borne diseases dependent on human water storage and waste water management. Interestingly India, as opposed to Africa, harbors a mosquito vector, Anopheles stephensi, which thrives in the man-made environments of cities and acts as the vector for both Plasmodium vivax and Plasmodium falciparum, making the malaria problem a truly urban phenomenon. Here we address the role and determinants of within-city spatial heterogeneity in the incidence patterns of vivax malaria, and then draw comparisons with results for falciparum malaria. Statistical analyses and a phenomenological transmission model are applied to an extensive spatio-temporal dataset on cases of Plasmodium vivax in the city of Ahmedabad (Gujarat, India) that spans 12 years monthly at the level of wards. A spatial pattern in malaria incidence is described that is largely stationary in time for this parasite. Malaria risk is then shown to be associated with socioeconomic indicators and environmental parameters, temperature and humidity. In a more dynamical perspective, an Inhomogeneous Markov Chain Model is used to predict vivax malaria risk. Models that account for climate factors, socioeconomic level and population size show the highest predictive skill. A comparison to the transmission dynamics of falciparum malaria reinforces the conclusion that the spatio-temporal patterns of risk are strongly driven by extrinsic factors. Climate forcing and socio-economic heterogeneity act synergistically at local scales on the population dynamics of urban malaria in this city. The stationarity of malaria risk patterns provides a basis for more

  18. Stress-induced tradeoffs in a free-living lizard across a variable landscape: consequences for individuals and populations.

    Science.gov (United States)

    Lucas, Leilani D; French, Susannah S

    2012-01-01

    Current life history theory suggests that the allocation of energetic resources between competing physiological needs should be dictated by an individual's longevity and pace of life. One key physiological pathway likely to contribute to the partitioning of resources is the vertebrate stress response. By increasing circulating glucocorticoids the stress response can exert a suite of physiological effects, such as altering immune function. We investigated the effects of stress physiology on individual immunity, reproduction and oxidative stress, across an urban landscape. We sampled populations in and around St. George, Utah, examining corticosterone in response to restraint stress, two innate immune measures, reproductive output, and the presence of both reactive oxygen metabolites and antioxidant binding capacity, in populations of common side-blotched lizards (Uta stansburiana) experiencing variable levels of environmental stress. Additionally, using capture-mark-recapture techniques, we examined the relationships between these physiological parameters and population-level differences. Our results reveal elevated physiological stress corresponds with suppressed immunity and increased oxidative stress. Interestingly, urban populations experiencing the most physiological stress also exhibited greater reproductive output and decreased survival relative to rural populations experiencing less physiological stress, demonstrating a tradeoff between reproduction and life maintenance processes. Our results suggest that environmental stress may augment life history strategy in this fast-paced species, and that shifts in life history strategy can in turn affect the population at large. Finally, the urban environment poses definite challenges for organisms, and while it appears that side-blotched lizards are adjusting physiologically, it is unknown what fitness costs these physiological adjustments accrue.

  19. Association of Climatic Variability, Vector Population and Malarial Disease in District of Visakhapatnam, India: A Modeling and Prediction Analysis.

    Science.gov (United States)

    Srimath-Tirumula-Peddinti, Ravi Chandra Pavan Kumar; Neelapu, Nageswara Rao Reddy; Sidagam, Naresh

    2015-01-01

    Malarial incidence, severity, dynamics and distribution of malaria are strongly determined by climatic factors, i.e., temperature, precipitation, and relative humidity. The objectives of the current study were to analyse and model the relationships among climate, vector and malaria disease in district of Visakhapatnam, India to understand malaria transmission mechanism (MTM). Epidemiological, vector and climate data were analysed for the years 2005 to 2011 in Visakhapatnam to understand the magnitude, trends and seasonal patterns of the malarial disease. Statistical software MINITAB ver. 14 was used for performing correlation, linear and multiple regression analysis. Perennial malaria disease incidence and mosquito population was observed in the district of Visakhapatnam with peaks in seasons. All the climatic variables have a significant influence on disease incidence as well as on mosquito populations. Correlation coefficient analysis, seasonal index and seasonal analysis demonstrated significant relationships among climatic factors, mosquito population and malaria disease incidence in the district of Visakhapatnam, India. Multiple regression and ARIMA (I) models are best suited models for modeling and prediction of disease incidences and mosquito population. Predicted values of average temperature, mosquito population and malarial cases increased along with the year. Developed MTM algorithm observed a major MTM cycle following the June to August rains and occurring between June to September and minor MTM cycles following March to April rains and occurring between March to April in the district of Visakhapatnam. Fluctuations in climatic factors favored an increase in mosquito populations and thereby increasing the number of malarial cases. Rainfall, temperatures (20°C to 33°C) and humidity (66% to 81%) maintained a warmer, wetter climate for mosquito growth, parasite development and malaria transmission. Changes in climatic factors influence malaria directly by

  20. Association of Climatic Variability, Vector Population and Malarial Disease in District of Visakhapatnam, India: A Modeling and Prediction Analysis.

    Directory of Open Access Journals (Sweden)

    Ravi Chandra Pavan Kumar Srimath-Tirumula-Peddinti

    Full Text Available Malarial incidence, severity, dynamics and distribution of malaria are strongly determined by climatic factors, i.e., temperature, precipitation, and relative humidity. The objectives of the current study were to analyse and model the relationships among climate, vector and malaria disease in district of Visakhapatnam, India to understand malaria transmission mechanism (MTM.Epidemiological, vector and climate data were analysed for the years 2005 to 2011 in Visakhapatnam to understand the magnitude, trends and seasonal patterns of the malarial disease. Statistical software MINITAB ver. 14 was used for performing correlation, linear and multiple regression analysis.Perennial malaria disease incidence and mosquito population was observed in the district of Visakhapatnam with peaks in seasons. All the climatic variables have a significant influence on disease incidence as well as on mosquito populations. Correlation coefficient analysis, seasonal index and seasonal analysis demonstrated significant relationships among climatic factors, mosquito population and malaria disease incidence in the district of Visakhapatnam, India. Multiple regression and ARIMA (I models are best suited models for modeling and prediction of disease incidences and mosquito population. Predicted values of average temperature, mosquito population and malarial cases increased along with the year. Developed MTM algorithm observed a major MTM cycle following the June to August rains and occurring between June to September and minor MTM cycles following March to April rains and occurring between March to April in the district of Visakhapatnam. Fluctuations in climatic factors favored an increase in mosquito populations and thereby increasing the number of malarial cases. Rainfall, temperatures (20°C to 33°C and humidity (66% to 81% maintained a warmer, wetter climate for mosquito growth, parasite development and malaria transmission.Changes in climatic factors influence

  1. History-dependent variability in population dynamics during evidence accumulation in cortex.

    Science.gov (United States)

    Morcos, Ari S; Harvey, Christopher D

    2016-12-01

    We studied how the posterior parietal cortex combines new information with ongoing activity dynamics as mice accumulate evidence during a virtual navigation task. Using new methods to analyze population activity on single trials, we found that activity transitioned rapidly between different sets of active neurons. Each event in a trial, whether an evidence cue or a behavioral choice, caused seconds-long modifications to the probabilities that govern how one activity pattern transitions to the next, forming a short-term memory. A sequence of evidence cues triggered a chain of these modifications resulting in a signal for accumulated evidence. Multiple distinguishable activity patterns were possible for the same accumulated evidence because representations of ongoing events were influenced by previous within- and across-trial events. Therefore, evidence accumulation need not require the explicit competition between groups of neurons, as in winner-take-all models, but could instead emerge implicitly from general dynamical properties that instantiate short-term memory.

  2. The Relationship Between Pedometer-Determined Ambulatory Activity and Balance Variables Within an Older Adult Population.

    Science.gov (United States)

    Campbell, Candice; Kress, Jeff; Schroeder, Jan; Donlin, Ayla; Rozenek, Ralph

    2016-01-01

    The purpose of this investigation was to determine the differences between gender, physical activity level, and balance in an older adult population. A secondary purpose was to examine the relationship between pedometer-determined ambulatory activity and balance. Forty-six older adults aged 73.7 ± 6.2 years participated in the study. Participants completed the Fullerton Advanced Balance (FAB) Scale and completed a 2-week daily step recording to determine average steps taken per day. Low-level activity participants (7,500 steps/day) in weight, age, and the number of medications reported. Males performed better than females on the two-footed jump test and reactive postural test FAB assessments. High-level activity participants performed significantly better than low-level activity participants on all FAB assessments except stand with feet together and eyes closed, reach forward to object, and walk with head turns.

  3. The Relationship Between Pedometer-Determined Ambulatory Activity and Balance Variables Within an Older Adult Population

    Directory of Open Access Journals (Sweden)

    Candice Campbell MS

    2016-12-01

    Full Text Available The purpose of this investigation was to determine the differences between gender, physical activity level, and balance in an older adult population. A secondary purpose was to examine the relationship between pedometer-determined ambulatory activity and balance. Forty-six older adults aged 73.7 ± 6.2 years participated in the study. Participants completed the Fullerton Advanced Balance (FAB Scale and completed a 2-week daily step recording to determine average steps taken per day. Low-level activity participants (7,500 steps/day in weight, age, and the number of medications reported. Males performed better than females on the two-footed jump test and reactive postural test FAB assessments. High-level activity participants performed significantly better than low-level activity participants on all FAB assessments except stand with feet together and eyes closed, reach forward to object, and walk with head turns.

  4. Contribution of insertions and deletions to the variability of hepatitis C virus populations.

    Science.gov (United States)

    Torres-Puente, Manuela; Cuevas, José M; Jiménez-Hernández, Nuria; Bracho, María A; García-Robles, Inmaculada; Carnicer, Fernando; del Olmo, Juan; Ortega, Enrique; Moya, Andrés; González-Candelas, Fernando

    2007-08-01

    Little is known about the potential effects of insertions and deletions (indels) on the evolutionary dynamics of hepatitis C virus (HCV). In fact, the consequences of indels on antiviral treatment response are a field of investigation completely unexplored. Here, an extensive sequencing project was undertaken by cloning and sequencing serum samples from 25 patients infected with HCV subtype 1a and 48 patients with subtype 1b. For 23 patients, samples obtained after treatment with alpha interferon plus ribavirin were also available. Two genome fragments containing the hypervariable regions in the envelope 2 glycoprotein and the PKR-BD domain in NS5A were sequenced, yielding almost 16 000 sequences. Our results show that insertions are quite rare, but they are often present in biologically relevant domains of the HCV genome. Moreover, their frequency distributions between different time samples reflect the quasispecies dynamics of HCV populations. Deletions seem to be subject to negative selection.

  5. Intra-specific variability of hindlimb length in the palmate newt: an indicator of population isolation induced by habitat fragmentation?

    Science.gov (United States)

    Trochet, Audrey; Le Chevalier, Hugo; Baillat, Boris; Barthe, Laurent; Pottier, Gilles; Calvez, Olivier; Ribéron, Alexandre; Blanchet, Simon

    2016-04-01

    Habitat fragmentation is one of the main drivers of global amphibian decline. Anthropogenic landscape elements can act as barriers, hindering the dispersal that is essential for maintaining gene flow between populations. Dispersal ability can be influenced by locomotor performance, which in turn can depend on morphological traits, such as hindlimb length (HLL) in amphibians. Here, we tested relationships between HLL and environmental variables--road types, forests and agricultural lands--among 35 sub-populations of palmate newts (Lissotriton helveticus) in southwestern France. We expected roads to select for short-legged newts due to a higher mortality of more mobile individuals (long-legged newts) when crossing roads. Accordingly, short-legged newts were found in the vicinity of roads, whereas long-legged newts were found closer to forests and in ponds close geographically to another water body. HLL in newts was hence influenced by habitat types in a heterogeneous landscape, and could therefore be used as an indicator of population isolation in a meta-population system. © 2016 The Author(s).

  6. Relative Importance of Climate Variables to Population Vital Rates: A Quantitative Synthesis for the Lesser Prairie-Chicken.

    Directory of Open Access Journals (Sweden)

    Julia E Earl

    Full Text Available Climate change is expected to affect temperature and precipitation means and extremes, which can affect population vital rates. With the added complexity of accounting for both means and extremes, it is important to understand whether one aspect is sufficient to predict a particular vital rate or if both are necessary. To compare the predictive ability of climate means and extremes with geographic, individual, and habitat variables, we performed a quantitative synthesis on the vital rates of lesser prairie-chickens (Tympanuchus pallidictinus across their geographic range. We used an information theoretic approach to rank models predicting vital rates. We were able to rank climate models for three vital rates: clutch size, nest success, and subadult/adult seasonal survival. Of these three vital rates, a climate model was never the best predictor even when accounting for potentially different relationships between climate variables and vital rates between different ecoregions. Clutch size and nest success were both influenced by nesting attempt with larger clutches and greater success for first nesting attempts than second nesting attempts. Clutch size also increased with latitude for first nesting attempts but decreased with latitude for second nesting attempts. This resulted in similar clutch sizes for first and second nest attempts at southern latitudes but larger clutches for first nest attempts than second nest attempts at northern latitudes. Survival was greater for subadults than adults, but there were few estimates of subadult survival for comparison. Our results show that individual characteristics and geographic variables are better for predicting vital rates than climate variables. This may due to low samples sizes, which restricted our statistical power, or lack of precision in climate estimates relative to microclimates actually experienced by individuals. Alternatively, relationships between climate variables and vital rates may be

  7. Nutrient intake variability in a pediatric population: implications for study design.

    Science.gov (United States)

    Miller, J Z; Kimes, T; Hui, S; Andon, M B; Johnston, C C

    1991-02-01

    Estimates of an individual's intake of specific nutrients is important in epidemiologic investigations of disease-diet relationships. The object of the present investigation was to determine the minimum number of daily food records required to estimate intake of specific nutrients in children. Both members of 70 pairs of twins (n = 140 children) completed a minimum of 3 and a maximum of 23 food records throughout a 2-y period. All subjects were white and range in age from 5 to 14 y. Assuming an attenuation of the correlation coefficient of 80%, the minimum number of daily food records required to estimate energy intake was seven for boys and eight for girls. As a group, the vitamin intakes were the most variable for both boys and girls, often requiring more than 20 records for either sex. Requirements for other nutrients generally fell between these two extremes. The results of the present investigation are particularly relevant to the interpretation and design of studies of associations with nutrient intake.

  8. Association of Quantitative and Qualitative Dermatoglyphic Variable and DNA Polymorphism in Female Breast Cancer Population

    Directory of Open Access Journals (Sweden)

    Lavanya Prathap

    2017-07-01

    Full Text Available Objective: To investigate the association between dermatoglyphics and the DNA repair genetic variants in female breast carcinoma. Methodology: The distinct dermatoglyphic variables include ≥ six whorls, Finger ridge counts, A-B Ridge Count, ATD angle and Pattern intensity Index are analyzed for its association with the DNA repair variants namely XRCC1 Arg194Trp, XRCC3Thr241Met, ERCC4Arg 415Gln, and ERCC5 Asp1104His. The statistical procedure used to analyze the frequency of association is odds ratio and relative risk ratio. Result:The results suggests that the relative risk is about 2 to 4 times with statistical significance for breast cancer and high risk group for the genes XRCC1 Arg194Trp, ERCC4 Arg 415 Gln, ERCC5 Asp1104His in their dominant model in both breast cancer and high risk group for six or more whorls, Pattern Intensity Index, A-B RC. Conclusion: It can be suggested that dermal ridges can be used as an effective biomarker of genomic instability in breast cancer.

  9. Variability in Population Density of House Dust Mites of Bitlis and Muş, Turkey.

    Science.gov (United States)

    Aykut, M; Erman, O K; Doğan, S

    2016-05-01

    This study was conducted to investigate the relationship between the number of house dust mites/g dust and different physical and environmental variables. A total of 1,040 house dust samples were collected from houses in Bitlis and Muş Provinces, Turkey, between May 2010 and February 2012. Overall, 751 (72.2%) of dust samples were mite positive. The number of mites/g dust varied between 20 and 1,840 in mite-positive houses. A significant correlation was detected between mean number of mites and altitude of houses, frequency of monthly vacuum cleaning, number of individuals in the household, and relative humidity. No association was found between the number of mites and temperature, type of heating, existence of allergic diseases, age and structure of houses. A maximum number of mites were detected in summer and a minimum number was detected in autumn. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Social psychological variables in populations contrasted by income and suicide rate: Durkheim revisited.

    Science.gov (United States)

    Ferrada-Noli, M

    1997-08-01

    The ten richest and ten poorest municipalities of Sweden were investigated with respect to national statistics to assess the relationship between suicide incidence, discrete social psychological variables associated with welfare admittance among the elderly, and income of municipality. The relative frequency of suicide was 1.6 times greater for Swedes from the low-income municipalities than for those from the high-income ones. The group of municipalities with the highest suicide rate had a significantly higher proportion of older people in need of municipal social assistance at their homes and also a significantly higher proportion of elderly living in municipality-managed 'service-homes.' The findings replicate earlier investigations and suggest social psychological indicators denoting less favourable economic and social resources are also associated with both an increased suicide rate and a decreased county or municipal income. Some theoretical issues of the socioeconomic and of the external restraint hypotheses of the incidence of suicide, contradicted by the present findings as well as of Durkheim's hypothesis of social control are discussed. Further, we suggest the consideration of negative socioeconomic conditions as a risk factor amid psychiatric clinical assessments of risk for suicidal behaviour.

  11. Clinical Research in Vulnerable Populations: Variability and Focus of Institutional Review Boards' Responses.

    Directory of Open Access Journals (Sweden)

    Bärbel Kästner

    Full Text Available Children and patients with cognitive deficits may find it difficult to understand the implication of research. In the European Union (EU, clinical studies outside the EU directives concerning medicinal products or medical devices, i.e., "miscellaneous clinical studies", have no legally mandated timelines for institutional review boards' (IRB decisions.To evaluate the review process of IRBs for two different "miscellaneous" multicenter clinical research protocols involving vulnerable subjects (children and adult stroke patients.Descriptive and comparative statistics. Protocol 1 is a prospective, multicenter, cross-sectional screening study of a symptomatic pediatric population at risk for Fabry disease involving genetic testing (NCT02152189. Protocol 2 is a prospective, multicenter, randomized, controlled, open-label, blinded endpoint post-market study to evaluate the effectiveness of stent retrievers (NCT02135926. After having obtained positive initial IRB votes at the main study site, both protocols were subsequently submitted to the remaining IRBs.Protocol 1 was submitted to 19 IRBs. No IRB objected to the study. Median time-to-final vote was 34 (IQR 10-65; range 0 to 130 days. Two IRBs accepted the coordinating center's IRB votes without re-evaluation. Changes to the informed consent documents were asked by 7/19 IRBs, amendments to the protocol by 2. Protocol 2 was submitted to 16 IRBs. Fifteen decisions were made. No IRB objected to the study. Median time-to final vote was 59 (IQR 10 to 65; range 0 to 128 days, which was not statistically significantly different compared with protocol 1 (Wilcoxon test. Two IRBs accepted a previous IRB decision and did not conduct an independent review. Eight/16 IRBs required changes to the informed consent documents; two IRBs recommended an amendment of the protocol.Both clinical research protocols involving vulnerable populations were well accepted. IRB workflows and decision times varied substantially

  12. Relationships between ecological variables and four organochlorine pollutants in an artic glaucous gull (Larus hyperboreus) population

    Energy Technology Data Exchange (ETDEWEB)

    Bustnes, Jan Ove [Norwegian Institute for Nature Research, Division for Arctic Ecology, Polar Environmental Centre, N-9296 Tromsoe (Norway)]. E-mail: jan.o.bustnes@nina.no; Miland, Oystein [Norwegian Institute for Nature Research, Division for Arctic Ecology, Polar Environmental Centre, N-9296 Tromsoe (Norway); Fjeld, Magnus [Norwegian Institute for Nature Research, Division for Arctic Ecology, Polar Environmental Centre, N-9296 Tromsoe (Norway); Erikstad, Kjell Einar [Norwegian Institute for Nature Research, Division for Arctic Ecology, Polar Environmental Centre, N-9296 Tromsoe (Norway); Skaare, Janneche Utne [National Veterinary Institute, P.O. Box 8156 Dep., N-0033 Oslo (Norway)

    2005-07-15

    The Arctic has become a sink for organochlorine contaminants (OCs) from lower latitudes, and relatively high levels have been found in different biota. Recent studies of the glaucous gull, Larus hyperboreus, a top predator in the arctic food web, have documented that high blood residues of various OCs are related to lower reproductive performance and reduced adult survival. Here we provide additional evidence that OCs are having ecological effects in the glaucous gull population at Bear Island in the Norwegian Arctic, and compare the effects of the four major OCs found in the glaucous gulls: HCB, oxychlordane, DDE and PCBs, which made up >95% of measured OCs. Firstly; it has previously been shown that gulls with high levels of PCBs in their blood spent more time away from the nest site during incubation than gulls with low levels. Here we reanalyzed the data and found that PCBs (P<0.02) and oxychlordane (P<0.05) were positive and significantly related to time away from the nest site, while DDE and HCB were not related to this trait. Secondly, among females which bred in an area where fish dominated the diet, and thus had high flight costs during feeding, early chick growth was negatively related to maternal levels of all four OCs, especially HCB and DDE (P<0.01). On the contrary, among females breeding in an area where the diet was dominated by eggs and young from nearby seabird colonies, and thus feeding costs were low, there were no effects of OC levels on early chick growth. This indicates that additional stress may be fundamental in causing reproductive effects of OCs in this population. Finally, during three breeding seasons we examined the probability of adults returning to the breeding grounds in the subsequent season, as a function of blood concentration of the four OCs. Overall, return rate from one year to the next was negatively related to blood residues of oxychlordane (P=0.02), but not significantly related to the other three compounds. Further support

  13. Relationships between ecological variables and four organochlorine pollutants in an artic glaucous gull (Larus hyperboreus) population

    International Nuclear Information System (INIS)

    Bustnes, Jan Ove; Miland, Oystein; Fjeld, Magnus; Erikstad, Kjell Einar; Skaare, Janneche Utne

    2005-01-01

    The Arctic has become a sink for organochlorine contaminants (OCs) from lower latitudes, and relatively high levels have been found in different biota. Recent studies of the glaucous gull, Larus hyperboreus, a top predator in the arctic food web, have documented that high blood residues of various OCs are related to lower reproductive performance and reduced adult survival. Here we provide additional evidence that OCs are having ecological effects in the glaucous gull population at Bear Island in the Norwegian Arctic, and compare the effects of the four major OCs found in the glaucous gulls: HCB, oxychlordane, DDE and PCBs, which made up >95% of measured OCs. Firstly; it has previously been shown that gulls with high levels of PCBs in their blood spent more time away from the nest site during incubation than gulls with low levels. Here we reanalyzed the data and found that PCBs (P<0.02) and oxychlordane (P<0.05) were positive and significantly related to time away from the nest site, while DDE and HCB were not related to this trait. Secondly, among females which bred in an area where fish dominated the diet, and thus had high flight costs during feeding, early chick growth was negatively related to maternal levels of all four OCs, especially HCB and DDE (P<0.01). On the contrary, among females breeding in an area where the diet was dominated by eggs and young from nearby seabird colonies, and thus feeding costs were low, there were no effects of OC levels on early chick growth. This indicates that additional stress may be fundamental in causing reproductive effects of OCs in this population. Finally, during three breeding seasons we examined the probability of adults returning to the breeding grounds in the subsequent season, as a function of blood concentration of the four OCs. Overall, return rate from one year to the next was negatively related to blood residues of oxychlordane (P=0.02), but not significantly related to the other three compounds. Further support

  14. High Levels of Genetic Diversity of Plasmodium falciparum Populations in Papua New Guinea despite Variable Infection Prevalence

    Science.gov (United States)

    Barry, Alyssa E.; Schultz, Lee; Senn, Nicholas; Nale, Joe; Kiniboro, Benson; Siba, Peter M.; Mueller, Ivo; Reeder, John C.

    2013-01-01

    High levels of genetic diversity in Plasmodium falciparum populations are an obstacle to malaria control. Here, we investigate the relationship between local variation in malaria epidemiology and parasite genetic diversity in Papua New Guinea (PNG). Cross-sectional malaria surveys were performed in 14 villages spanning four distinct malaria-endemic areas on the north coast, including one area that was sampled during the dry season. High-resolution msp2 genotyping of 2,147 blood samples identified 761 P. falciparum infections containing a total of 1,392 clones whose genotypes were used to measure genetic diversity. Considerable variability in infection prevalence and mean multiplicity of infection was observed at all of the study sites, with the area sampled during the dry season showing particularly striking local variability. Genetic diversity was strongly associated with multiplicity of infection but not with infection prevalence. In highly endemic areas, differences in infection prevalence may not translate into a decrease in parasite population diversity. PMID:23400571

  15. CHEMICAL COMPOSITION VARIABILITY IN THE Uncaria tomentosa (cat’s claw WILD POPULATION

    Directory of Open Access Journals (Sweden)

    Evelyn Maribel Condori Peñaloza

    2015-03-01

    Full Text Available Uncaria tomentosa (cat's claw is a vine widely distributed throughout the South-American rainforest. Many studies investigating the chemical composition of cat's claw have focused on the pentacyclic (POA and tetracyclic oxindole alkaloids (TOA, quinovic acid glycosides (QAG, and polyphenols (PPH. Nevertheless, it is still uncertain how environmental factors affect chemical groups. The aim of this work was to better understand the influence of environmental factors (geographic origin, altitude, and season on cat's claw chemical composition. Stem bark, branches and leaf samples were extracted and analyzed by HPLC-PDA. The data obtained were explored by multivariate analysis (HCA and PCA. Higher amounts of oxindole alkaloids and PPH were found in leaves, followed by stem bark and branches. No clear relationship was verified among geographic origin or altitude and chemical composition, which remained unchanged regardless of season (dry or rainy. However, three oxindole alkaloid chemotypes were clearly recognized: chemotype I (POA with cis D/E ring junction; chemotype II (POA with trans D/E ring junction; and chemotype III (TOA. Thus, environmental factors appear to have only a minor influence on the chemical heterogeneity of the cat's claw wild population. Nevertheless, the occurrence of different chemotypes based on alkaloid profiles seems to be clear.

  16. [Environmental pollution, climate variability and climate change: a review of health impacts on the Peruvian population].

    Science.gov (United States)

    Gonzales, Gustavo F; Zevallos, Alisson; Gonzales-Castañeda, Cynthia; Nuñez, Denisse; Gastañaga, Carmen; Cabezas, César; Naeher, Luke; Levy, Karen; Steenland, Kyle

    2014-01-01

    This article is a review of the pollution of water, air and the effect of climate change on the health of the Peruvian population. A major air pollutant is particulate matter less than 2.5 μ (PM 2.5). In Lima, 2,300 premature deaths annually are attributable to this pollutant. Another problem is household air pollution by using stoves burning biomass fuels, where excessive indoor exposure to PM 2.5 inside the household is responsible for approximately 3,000 annual premature deaths among adults, with another unknown number of deaths among children due to respiratory infections. Water pollution is caused by sewage discharges into rivers, minerals (arsenic) from various sources, and failure of water treatment plants. In Peru, climate change may impact the frequency and severity of El Niño Southern Oscillation (ENSO), which has been associated with an increase in cases of diseases such as cholera, malaria and dengue. Climate change increases the temperature and can extend the areas affected by vector-borne diseases, have impact on the availability of water and contamination of the air. In conclusion, Peru is going through a transition of environmental risk factors, where traditional and modern risks coexist and infectious and chronic problems remain, some of which are associated with problems of pollution of water and air.

  17. Brucella Genetic Variability in Wildlife Marine Mammals Populations Relates to Host Preference and Ocean Distribution.

    Science.gov (United States)

    Suárez-Esquivel, Marcela; Baker, Kate S; Ruiz-Villalobos, Nazareth; Hernández-Mora, Gabriela; Barquero-Calvo, Elías; González-Barrientos, Rocío; Castillo-Zeledón, Amanda; Jiménez-Rojas, César; Chacón-Díaz, Carlos; Cloeckaert, Axel; Chaves-Olarte, Esteban; Thomson, Nicholas R; Moreno, Edgardo; Guzmán-Verri, Caterina

    2017-07-01

    Intracellular bacterial pathogens probably arose when their ancestor adapted from a free-living environment to an intracellular one, leading to clonal bacteria with smaller genomes and less sources of genetic plasticity. Still, this plasticity is needed to respond to the challenges posed by the host. Members of the Brucella genus are facultative-extracellular intracellular bacteria responsible for causing brucellosis in a variety of mammals. The various species keep different host preferences, virulence, and zoonotic potential despite having 97-99% similarity at genome level. Here, we describe elements of genetic variation in Brucella ceti isolated from wildlife dolphins inhabiting the Pacific Ocean and the Mediterranean Sea. Comparison with isolates obtained from marine mammals from the Atlantic Ocean and the broader Brucella genus showed distinctive traits according to oceanic distribution and preferred host. Marine mammal isolates display genetic variability, represented by an important number of IS711 elements as well as specific IS711 and SNPs genomic distribution clustering patterns. Extensive pseudogenization was found among isolates from marine mammals as compared with terrestrial ones, causing degradation in pathways related to energy, transport of metabolites, and regulation/transcription. Brucella ceti isolates infecting particularly dolphin hosts, showed further degradation of metabolite transport pathways as well as pathways related to cell wall/membrane/envelope biogenesis and motility. Thus, gene loss through pseudogenization is a source of genetic variation in Brucella, which in turn, relates to adaptation to different hosts. This is relevant to understand the natural history of bacterial diseases, their zoonotic potential, and the impact of human interventions such as domestication. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. The digital national framework - underpinning the knowledge economy

    Directory of Open Access Journals (Sweden)

    K J Murray

    2003-10-01

    Full Text Available Providing a sustainable spatial data infrastructure creates responsibility and high demand by continually meeting and satisfying the needs of all kinds of users. It is essential to provide the right information at the right level of quality and reliability and at the right time. Geographic information (GI is today being universally recognised as a key part of the national information infrastructure, especially by government. GI is an enabler in the knowledge economy since the power of geography can be used to underpin the sharing (and trading of vital georeferenced information collected by all kinds of organisations. From this information reliable conclusions can and will be drawn and decisions made. However, achieving such an environment does not just happen. It has to be led, nurtured and developed in line with user needs. Funding requires sustained investment, and it all has to be implemented and maintained whether the economy enjoys good times or bad, and through periods of political change. These are all big challenges encountered by just about every national economy. The aim of many national governments around the world is to establish a reliable and integrated reference base for GI that can underpin the e-economy. This base needs to support government and the commercial sector who need to reference information, and potentially share it with others (eg land ownership or link it up to form an application.(eg location based services. To achieve this a consistent method of georefererencing is required and the Digital National Framework is intended to fulfil that need in Great Britain. This paper will describe what has been happening in Great Britain to build on the firm foundations of the past, and develop a modern and sustainable framework for geographic information for the future. In particular it will be shown that the business model adopted by Ordnance Survey in recent years (ie the users pay for the data has played a key role in securing

  19. Detailed analysis of the microbial population in Malaysian spontaneous cocoa pulp fermentations reveals a core and variable microbiota.

    Directory of Open Access Journals (Sweden)

    Esther Meersman

    Full Text Available The fermentation of cocoa pulp is one of the few remaining large-scale spontaneous microbial processes in today's food industry. The microbiota involved in cocoa pulp fermentations is complex and variable, which leads to inconsistent production efficiency and cocoa quality. Despite intensive research in the field, a detailed and comprehensive analysis of the microbiota is still lacking, especially for the expanding Asian production region. Here, we report a large-scale, comprehensive analysis of four spontaneous Malaysian cocoa pulp fermentations across two time points in the harvest season and two fermentation methods. Our results show that the cocoa microbiota consists of a "core" and a "variable" part. The bacterial populations show a remarkable consistency, with only two dominant species, Lactobacillus fermentum and Acetobacter pasteurianus. The fungal diversity is much larger, with four dominant species occurring in all fermentations ("core" yeasts, and a large number of yeasts that only occur in lower numbers and specific fermentations ("variable" yeasts. Despite this diversity, a clear pattern emerges, with early dominance of apiculate yeasts and late dominance of Saccharomyces cerevisiae. Our results provide new insights into the microbial diversity in Malaysian cocoa pulp fermentations and pave the way for the selection of starter cultures to increase efficiency and consistency.

  20. Mapping the Centimeter-Scale Spatial Variability of PAHs and Microbial Populations in the Rhizosphere of Two Plants.

    Directory of Open Access Journals (Sweden)

    Amélia Bourceret

    Full Text Available Rhizoremediation uses root development and exudation to favor microbial activity. Thus it can enhance polycyclic aromatic hydrocarbon (PAH biodegradation in contaminated soils. Spatial heterogeneity of rhizosphere processes, mainly linked to the root development stage and to the plant species, could explain the contrasted rhizoremediation efficiency levels reported in the literature. Aim of the present study was to test if spatial variability in the whole plant rhizosphere, explored at the centimetre-scale, would influence the abundance of microorganisms (bacteria and fungi, and the abundance and activity of PAH-degrading bacteria, leading to spatial variability in PAH concentrations. Two contrasted rhizospheres were compared after 37 days of alfalfa or ryegrass growth in independent rhizotron devices. Almost all spiked PAHs were degraded, and the density of the PAH-degrading bacterial populations increased in both rhizospheres during the incubation period. Mapping of multiparametric data through geostatistical estimation (kriging revealed that although root biomass was spatially structured, PAH distribution was not. However a greater variability of the PAH content was observed in the rhizosphere of alfalfa. Yet, in the ryegrass-planted rhizotron, the Gram-positive PAH-degraders followed a reverse depth gradient to root biomass, but were positively correlated to the soil pH and carbohydrate concentrations. The two rhizospheres structured the microbial community differently: a fungus-to-bacterium depth gradient similar to the root biomass gradient only formed in the alfalfa rhizotron.

  1. Detailed analysis of the microbial population in Malaysian spontaneous cocoa pulp fermentations reveals a core and variable microbiota.

    Science.gov (United States)

    Meersman, Esther; Steensels, Jan; Mathawan, Melissa; Wittocx, Pieter-Jan; Saels, Veerle; Struyf, Nore; Bernaert, Herwig; Vrancken, Gino; Verstrepen, Kevin J

    2013-01-01

    The fermentation of cocoa pulp is one of the few remaining large-scale spontaneous microbial processes in today's food industry. The microbiota involved in cocoa pulp fermentations is complex and variable, which leads to inconsistent production efficiency and cocoa quality. Despite intensive research in the field, a detailed and comprehensive analysis of the microbiota is still lacking, especially for the expanding Asian production region. Here, we report a large-scale, comprehensive analysis of four spontaneous Malaysian cocoa pulp fermentations across two time points in the harvest season and two fermentation methods. Our results show that the cocoa microbiota consists of a "core" and a "variable" part. The bacterial populations show a remarkable consistency, with only two dominant species, Lactobacillus fermentum and Acetobacter pasteurianus. The fungal diversity is much larger, with four dominant species occurring in all fermentations ("core" yeasts), and a large number of yeasts that only occur in lower numbers and specific fermentations ("variable" yeasts). Despite this diversity, a clear pattern emerges, with early dominance of apiculate yeasts and late dominance of Saccharomyces cerevisiae. Our results provide new insights into the microbial diversity in Malaysian cocoa pulp fermentations and pave the way for the selection of starter cultures to increase efficiency and consistency.

  2. Population variability of phthalate metabolites and bisphenol A concentrations in spot urine samples versus 24- or 48-h collections.

    Science.gov (United States)

    Christensen, Krista L Yorita; Lorber, Matthew; Koch, Holger M; Kolossa-Gehring, Marike; Morgan, Marsha K

    2012-11-01

    Human exposure to phthalates and bisphenol A (BPA) can be assessed through urinary biomonitoring, but methods to infer daily intakes assume that spot sample concentrations are comparable to daily average concentrations. We evaluate this assumption using human biomonitoring data from Germany and the United States (US). The German data comprised three regional studies with spot samples and one with full-day samples analyzed for phthalate metabolites. The US data included: a study on DEHP metabolites and BPA involving eight persons supplying all urine voids (from which 24-h samples were constructed) for seven consecutive days; NHANES spot sample data on DEHP metabolites and BPA; and a regional study of children with 48-h samples analyzed for BPA. In the German data, measures of central tendency differed, but spot and 24-h samples showed generally comparable variance including 95th percentiles and maxima equidistant from central tendency measures. In contrast, the US adult data from the eight-person study showed similar central tendencies for phthalate metabolites and BPA, but generally greater variability for the spot samples, including higher 95th percentiles and maxima. When comparing children's BPA concentrations in NHANES spot and 48-h samples, distributions showed similar central tendency and variability. Overall, spot urinary concentrations of DEHP metabolites and BPA have variability roughly comparable with corresponding 24-h average concentrations obtained from a comparable population, suggesting that spot samples can be used to characterize population distributions of intakes. However, the analysis also suggests that caution should be exercised when interpreting the high end of spot sample data sets.

  3. Effect of variable consumption habits in the Nordic populations on ECOSYS model predictions of ingestion dose

    International Nuclear Information System (INIS)

    Nielsen, Sven P.; Andersson, Kasper G.; Hansen, Hanne S.; Thoerring, Haavard; Joensen, Hans P.; Isaksson, Mats; Kostiainen, Eila; Suolanen, Vesa; Sigurgeirsson, Magnus A.; Palsson, Sigurour E.

    2008-01-01

    the northernmost areas used for grain crops, the crops are entirely spring grain crops, whereas in Denmark and Germany, winter crops are dominant. This gives large deviations in growth periods and development stages of the crops, particularly in the spring. This implies that first year doses from the same contaminant plume can be very different in different Nordic countries. Thus we conclude that the food habits of the population in the Nordic countries affected the calculated ingestion dose significantly. Also it is important to ascertain the use of state-of-the-art data for the more generic model parameters and to test the effect of other parameters to improve the decision support system used in the Nordic countries. (author)

  4. Maximum entropy principle for stationary states underpinned by stochastic thermodynamics.

    Science.gov (United States)

    Ford, Ian J

    2015-11-01

    The selection of an equilibrium state by maximizing the entropy of a system, subject to certain constraints, is often powerfully motivated as an exercise in logical inference, a procedure where conclusions are reached on the basis of incomplete information. But such a framework can be more compelling if it is underpinned by dynamical arguments, and we show how this can be provided by stochastic thermodynamics, where an explicit link is made between the production of entropy and the stochastic dynamics of a system coupled to an environment. The separation of entropy production into three components allows us to select a stationary state by maximizing the change, averaged over all realizations of the motion, in the principal relaxational or nonadiabatic component, equivalent to requiring that this contribution to the entropy production should become time independent for all realizations. We show that this recovers the usual equilibrium probability density function (pdf) for a conservative system in an isothermal environment, as well as the stationary nonequilibrium pdf for a particle confined to a potential under nonisothermal conditions, and a particle subject to a constant nonconservative force under isothermal conditions. The two remaining components of entropy production account for a recently discussed thermodynamic anomaly between over- and underdamped treatments of the dynamics in the nonisothermal stationary state.

  5. The educational theory underpinning a clinical workbook for VERT

    International Nuclear Information System (INIS)

    Nisbet, Heather; Matthews, Sara

    2011-01-01

    The introduction of VERT (Virtual Environment for Radiotherapy Training) into radiotherapy departments across England was in response to the National Radiotherapy Advisory Group's (NRAG) recommendation to the Department of Health that it may assist in enhancing the clinical learning experience of student radiotherapy radiographers. It was suggested that this may help to reduce the high attrition rate of students currently experienced, particularly in the first year of training. This paper investigates how VERT may be used in the clinical setting to develop the skills of students, in order to meet this vision. We argue that using an epistemological approach, i.e. using the theory of knowledge, to support the design of the learning resource, is key to enabling the educator to fulfil these expectations. We describe the design of a generic VERT workbook for use in the clinical departments that train students for the University of Hertfordshire. The use of educational theory to underpin the aims and inform the development of the workbook is examined. We then discuss the alignment of the workbook with the curriculum in order to enhance the students' learning experience and nurture their clinical competence. Finally, we will consider the teaching strategies used during the delivered sessions and discuss how we believe they will allow us to achieve these aims.

  6. The Traceable Radiometry Underpinning Terrestrial and Helio Studies (TRUTHS) mission

    Science.gov (United States)

    Green, Paul D.; Fox, Nigel P.; Lobb, Daniel; Friend, Jonathan

    2015-10-01

    TRUTHS (Traceable Radiometry Underpinning Terrestrial- and Helio-Studies) is a proposed small satellite mission to enable a space-based climate observing system capable of delivering data of the quality needed to provide the information needed by policy makers to make robust mitigation and adaptation decisions. This is achieved by embedding trust and confidence in the data and derived information (tied to international standards) from both its own measurements and by upgrading the performance and interoperability of other EO platforms, such as the Sentinels by in-flight reference calibration. TRUTHS would provide measurements of incoming (total and spectrally resolved) and global reflected spectrally and spatially (50 m) solar radiation at the 0.3% uncertainty level. These fundamental climate data products can be convolved into the building blocks for many ECVs and EO applications as envisaged by the 2015 ESA science strategy; in a cost effective manner. We describe the scientific drivers for the TRUTHS mission and how the requirements for the climate benchmarking and cross-calibration reference sensor are both complementary and simply implemented, with a small additional complexity on top of heritage calibration schemes. The calibration scheme components and the route to SI-traceable Earth-reflected solar spectral radiance and solar spectral irradiance are described.

  7. False memories with age: Neural and cognitive underpinnings.

    Science.gov (United States)

    Devitt, Aleea L; Schacter, Daniel L

    2016-10-01

    As we age we become increasingly susceptible to memory distortions and inaccuracies. Over the past decade numerous neuroimaging studies have attempted to illuminate the neural underpinnings of aging and false memory. Here we review these studies, and link their findings with those concerning the cognitive properties of age-related changes in memory accuracy. Collectively this evidence points towards a prominent role for age-related declines in medial temporal and prefrontal brain areas, and corresponding impairments in associative binding and strategic monitoring. A resulting cascade of cognitive changes contributes to the heightened vulnerability to false memories with age, including reduced recollective ability, a reliance on gist information and familiarity-based monitoring mechanisms, as well as a reduced ability to inhibit irrelevant information and erroneous binding of features between memory traces. We consider both theoretical and applied implications of research on aging and false memories, as well as questions remaining to be addressed in future research. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Renewable energy technology from underpinning physics to engineering application

    International Nuclear Information System (INIS)

    Infield, D G

    2008-01-01

    The UK Energy Research Centre (UKERC) in it's submission to the DTI's 2006 Energy Review reminded us that the 'UK has abundant wind, wave and tidal resources available; its mild climate lends itself to bio-energy production, and solar radiation levels are sufficient to sustain a viable solar industry'. These technologies are at different stages of development but they all draw on basic and applied Science and Engineering. The paper will briefly review the renewable energy technologies and their potential for contributing to a sustainable energy supply. Three research topics will be highlighted that bridge the gap between the physics underpinning the energy conversion, and the engineering aspects of development and deployment; all three are highly relevant to the Government's programme on micro-generation. Two are these are taken from field of thin film photovoltaics (PV), one related to novel device development and the other to a measurement technique for assessing the manufacturing quality of PV modules and their performance. The third topic concerns the development of small building integrated wind turbines and examines the complex flow associated with such applications. The paper will conclude by listing key research challenges that are central to the search for efficient and cost-effective renewable energy generation

  9. Triangulation of the neurocomputational architecture underpinning reading aloud

    Science.gov (United States)

    Hoffman, Paul; Lambon Ralph, Matthew A.; Woollams, Anna M.

    2015-01-01

    The goal of cognitive neuroscience is to integrate cognitive models with knowledge about underlying neural machinery. This significant challenge was explored in relation to word reading, where sophisticated computational-cognitive models exist but have made limited contact with neural data. Using distortion-corrected functional MRI and dynamic causal modeling, we investigated the interactions between brain regions dedicated to orthographic, semantic, and phonological processing while participants read words aloud. We found that the lateral anterior temporal lobe exhibited increased activation when participants read words with irregular spellings. This area is implicated in semantic processing but has not previously been considered part of the reading network. We also found meaningful individual differences in the activation of this region: Activity was predicted by an independent measure of the degree to which participants use semantic knowledge to read. These characteristics are predicted by the connectionist Triangle Model of reading and indicate a key role for semantic knowledge in reading aloud. Premotor regions associated with phonological processing displayed the reverse characteristics. Changes in the functional connectivity of the reading network during irregular word reading also were consistent with semantic recruitment. These data support the view that reading aloud is underpinned by the joint operation of two neural pathways. They reveal that (i) the ATL is an important element of the ventral semantic pathway and (ii) the division of labor between the two routes varies according to both the properties of the words being read and individual differences in the degree to which participants rely on each route. PMID:26124121

  10. Emerging Technological Risk Underpinning the Risk of Technology Innovation

    CERN Document Server

    Anderson, Stuart

    2012-01-01

    Classes of socio-technical hazards allow a characterization of the risk in technology innovation and clarify the mechanisms underpinning emergent technological risk. Emerging Technological Risk provides an interdisciplinary account of risk in socio-technical systems including hazards which highlight: ·         How technological risk crosses organizational boundaries, ·         How technological trajectories and evolution develop from resolving tensions emerging between social aspects of organisations and technologies and ·         How social behaviour shapes, and is shaped by, technology. Addressing an audience from a range of academic and professional backgrounds, Emerging Technological Risk is a key source for those who wish to benefit from a detail and methodical exposure to multiple perspectives on technological risk. By providing a synthesis of recent work on risk that captures the complex mechanisms that characterize the emergence of risk in technology innovation, Emerging Tec...

  11. Effect of conservation efforts and ecological variables on waterbird population sizes in wetlands of the Yangtze River

    Science.gov (United States)

    Zhang, Yong; Jia, Qiang; Prins, Herbert H. T.; Cao, Lei; de Boer, Willem Frederik

    2015-11-01

    Forage quality and availability, climatic factors, and a wetland’s conservation status are expected to affect the densities of wetland birds. However, the conservation effectiveness is often poorly studied. Here, using twelve years’ census data collected from 78 wetlands in the Yangtze River floodplain, we aimed to understand the effect of these variables on five Anatidae species, and evaluate the effectiveness of the conservation measures by comparing population trends of these species among wetlands that differ in conservations status. We showed that the slope angle of a wetland and the variation thereof best explain the differences in densities of four species. We also found that the population abundances of the Anatidae species generally declined in wetlands along the Yangtze River floodplain over time, with a steeper decline in wetlands with a lower protection status, indicating that current conservation policies might deliver benefits for wintering Anatidae species in China, as population sizes of the species were buffered to some extent against decline in numbers in wetlands with a higher level protection status. We recommend several protection measures to stop the decline of these Anatidae species in wetlands along the Yangtze River floodplain, which are of great importance for the East Asian-Australasian Flyway.

  12. Risky business: The impact of climate and climate variability on human population dynamics in Western Europe during the Last Glacial Maximum

    Science.gov (United States)

    Burke, Ariane; Kageyama, Masa; Latombe, Guilllaume; Fasel, Marc; Vrac, Mathieu; Ramstein, Gilles; James, Patrick M. A.

    2017-05-01

    The extent to which climate change has affected the course of human evolution is an enduring question. The ability to maintain spatially extensive social networks and a fluid social structure allows human foragers to ;map onto; the landscape, mitigating the impact of ecological risk and conferring resilience. But what are the limits of resilience and to which environmental variables are foraging populations sensitive? We address this question by testing the impact of a suite of environmental variables, including climate variability, on the distribution of human populations in Western Europe during the Last Glacial Maximum (LGM). Climate variability affects the distribution of plant and animal resources unpredictably, creating an element of risk for foragers for whom mobility comes at a cost. We produce a model of habitat suitability that allows us to generate predictions about the probable distribution of human populations and discuss the implications of these predictions for the structure of human populations and their social and cultural evolution during the LGM.

  13. Population genetic analysis and bioclimatic modeling in Agave striata in the Chihuahuan Desert indicate higher genetic variation and lower differentiation in drier and more variable environments.

    Science.gov (United States)

    Trejo, Laura; Alvarado-Cárdenas, Leonardo O; Scheinvar, Enrique; Eguiarte, Luis E

    2016-06-01

    Is there an association between bioclimatic variables and genetic variation within species? This question can be approached by a detailed analysis of population genetics parameters along environmental gradients in recently originated species (so genetic drift does not further obscure the patterns). The genus Agave, with more than 200 recent species encompassing a diversity of morphologies and distributional patterns, is an adequate system for such analyses. We studied Agave striata, a widely distributed species from the Chihuahuan Desert, with a distinctive iteroparous reproductive ecology and two recognized subspecies with clear morphological differences. We used population genetic analyses along with bioclimatic studies to understand the effect of environment on the genetic variation and differentiation of this species. We analyzed six populations of the subspecies A. striata subsp. striata, with a southern distribution, and six populations of A. striata subsp. falcata, with a northern distribution, using 48 ISSR loci and a total of 541 individuals (averaging 45 individuals per population). We assessed correlations between population genetics parameters (the levels of genetic variation and differentiation) and the bioclimatic variables of each population. We modeled each subspecies distribution and used linear correlations and multifactorial analysis of variance. Genetic variation (measured as expected heterozygosity) increased at higher latitudes. Higher levels of genetic variation in populations were associated with a higher variation in environmental temperature and lower precipitation. Stronger population differentiation was associated with wetter and more variable precipitation in the southern distribution of the species. The two subspecies have genetic differences, which coincide with their climatic differences and potential distributions. Differences in genetic variation among populations and the genetic differentiation between A. striata subsp. striata

  14. Analysis of the populations genetic variability of Tagosodes orizicolus (Homoptera: Delphacidae), virus vector of the rice white leaf

    International Nuclear Information System (INIS)

    Hernandez Alfaro, Myriam

    2006-01-01

    Tagosodes orizicolus (Homoptera: Delphacidae), is a monophagous insect of the rice and virus vector of the white leaf (RHBV). It is distributed in America Central, El Caribe, part of the America del Sur and in Costa Rica it is in all the producing zones of rice. The genetic variability was analyzed by means of RAPD-PCR of individuals from three populations of Costa Rica: Parrita, Guanacaste (Liberia) y San Carlos (Santa Clara), that they are found separated geographically. The technique consisted of amplifying regions at random of the genome of these insects utilizing five primers. A total of 72 polymorphic bands were obtained, that upon being analyzed statistically by means of the multivariate analysis program of numerical taxonomy could show a clear genetic distancing among said populations. The genetic distance observed in the molecular analysis can be explained for the climatic and/or geographical isolation of the populations or by the incident of Wolbachia, riquettsia that induces cytoplasmic sterility in insects. These symbionts are transmitted of generation in generation, of the mother to their offspring and they cause reproductive alterations as cytoplasmic incompatibility, parthenogenesis and feminization. The presence of Wolbachia was determined by means of transmission electronic microscopy being observed in the greasy and muscular weave of the abdomen of T. orizicolus. Rickettsias present pleomorphic morphology and form small groups, that are characterized for the presence of electrondense material semidetached to the cell wall with an interior electronlucent. Its size in transverse cuts ranged between 520 nm of length X 470 nm of width. In addition, its presence was detected by means of the amplification by PCR of the genomic DNA of the insects; a specific primer for the DNA ribosomal 16S of Wolbachia was utilized for it. A 86% of insects of the San Carlos population were positive, a 96% was determined for Guanacaste, a 37% for Parrita and a 100% for

  15. Neuroendocrine underpinnings of sex differences in circadian timing systems.

    Science.gov (United States)

    Yan, Lily; Silver, Rae

    2016-06-01

    There are compelling reasons to study the role of steroids and sex differences in the circadian timing system. A solid history of research demonstrates the ubiquity of circadian changes that impact virtually all behavioral and biological responses. Furthermore, steroid hormones can modulate every attribute of circadian responses including the period, amplitude and phase. Finally, desynchronization of circadian rhythmicity, and either enhancing or damping amplitude of various circadian responses can produce different effects in the sexes. Studies of the neuroendocrine underpinnings of circadian timing systems and underlying sex differences have paralleled the overall development of the field as a whole. Early experimental studies established the ubiquity of circadian rhythms by cataloging daily and seasonal changes in whole organism responses. The next generation of experiments demonstrated that daily changes are not a result of environmental synchronizing cues, and are internally orchestrated, and that these differ in the sexes. This work was followed by the revelation of molecular circadian rhythms within individual cells. At present, there is a proliferation of work on the consequences of these daily oscillations in health and in disease, and awareness that these may differ in the sexes. In the present discourse we describe the paradigms used to examine circadian oscillation, to characterize how these internal timing signals are synchronized to local environmental conditions, and how hormones of gonadal and/or adrenal origin modulate circadian responses. Evidence pointing to endocrinologically and genetically mediated sex differences in circadian timing systems can be seen at many levels of the neuroendocrine and endocrine systems, from the cell, the gland and organ, and to whole animal behavior, including sleep/wake or rest/activity cycles, responses to external stimuli, and responses to drugs. We review evidence indicating that the analysis of the circadian

  16. Conserving genomic variability in large mammals: Effect of population fluctuations and variance in male reproductive success on variability in Yellowstone bison

    Science.gov (United States)

    Andres Perez-Figueroa; Rick L. Wallen; Tiago Antao; Jason A. Coombs; Michael K. Schwartz; P. J. White; Gordon Luikart

    2012-01-01

    Loss of genetic variation through genetic drift can reduce population viability. However, relatively little is known about loss of variation caused by the combination of fluctuating population size and variance in reproductive success in age structured populations. We built an individual-based computer simulation model to examine how actual culling and hunting...

  17. Identical genetic influences underpin behavior problems in adolescence and basic traits of personality.

    Science.gov (United States)

    Lewis, Gary J; Haworth, Claire M A; Plomin, Robert

    2014-08-01

    Understanding the etiology of adolescent problem behavior has been of enduring interest. Only relatively recently, however, has this issue been examined within a normal personality trait framework. Research suggests that problem behaviors in adolescence and beyond may be adequately explained by the taxonomy provided by the basic dimensions of normal personality: Such problem behaviors are suggested to be extreme points on a distribution of the full range of the underlying traits. We extend work in this field examining the extent to which genetic factors underlying the five-factor model of personality are common with genetic influences on adolescent behavior problems (namely, anxiety, peer problems, conduct, hyperactivity, and low prosociality). A nationally representative twin sample (Twins Early Development Study) from the general population of England and Wales, including 2031 pairs of twins aged 16 years old, was used to decompose variation into genetic and environmental components. Behavioral problems in adolescence were assessed by self-report with the Strengths and Difficulties Questionnaire. Adolescent behavior problems were moderately associated with normal personality: Specifically, a fifth to a third of phenotypic variance in problem behaviors was accounted for by five-factor model personality traits. Of central importance here, genetic influences underpinning personality were entirely overlapping with those genetic factors underlying adolescent behavior problems. These findings suggest that adolescent behavior problems can be understood, at least in part, within a model of normal personality trait variation, with the genetic bases of these behavior problems the same as those genetic influences underpinning normal personality. © 2013 The Authors. Journal of Child Psychology and Psychiatry. © 2013 Association for Child and Adolescent Mental Health.

  18. Trimester-Specific Population Pharmacokinetics and Other Correlates of Variability in Sulphadoxine-Pyrimethamine Disposition Among Ugandan Pregnant Women.

    Science.gov (United States)

    Odongo, Charles O; Bisaso, Kuteesa R; Ntale, Muhammad; Odia, Gordon; Ojara, Francis W; Byamugisha, Josaphat; Mukonzo, Jackson K; Obua, Celestino

    2015-12-01

    Sulphadoxine-pyrimethamine (SP) is widely used as an intermittent preventive treatment for malaria in pregnancy (IPTp). However, pharmacokinetic studies in pregnancy show variable and often contradictory findings. We describe population and trimester-specific differences in SP pharmacokinetics among Ugandan women. SP (three tablets) were administered to 34 nonpregnant and 87 pregnant women in the second trimester. Seventy-eight pregnant women were redosed in the third trimester. Blood was collected over time points ranging from 0.5 h to 42 days postdose. Data on the variables age, body weight, height, parity, gestational age, and serum creatinine, alanine transaminase and albumin levels were collected at baseline. Plasma drug assays were performed using high-performance liquid chromatography with ultraviolet detection. Population pharmacokinetic analysis was done using NONMEM software. A two-compartment model with first-order absorption and a lag time best described both the sulphadoxine and pyrimethamine data. Between trimesters, statistically significant differences in central volumes of distribution (V(2)) were observed for both drugs, while differences in the distribution half-life and the terminal elimination half-life were observed for pyrimethamine and sulphadoxine, respectively. Significant covariate relationships were identified on clearance (pregnancy status and serum albumin level) and V(2) (gestational age) for sulphadoxine. For pyrimethamine, clearance (pregnancy status and age) and V(2) (gestational age and body weight) were significant. Considering a 25 % threshold for clinical relevance, only differences in clearance of both drugs between pregnant and nonpregnant women were significant. While clinically relevant differences in SP disposition between trimesters were not seen, increased clearance with pregnancy and the increasing volume of distribution in the central compartment with gestational age lend support to the revised World Health

  19. Application of data mining to predict the dosage of vancomycin as an outcome variable in a teaching hospital population.

    Science.gov (United States)

    Chan, A L F; Chen, J-X; Wang, H-Y

    2006-11-01

    Data mining is a process used to extract potentially valuable information hidden in large volumes of raw data. The aim of this study was to explore the possibility of using easy to implement and effective supervised learning techniques to predict the dosage of vancomycin. To reach this goal, we considered the prediction of the dosage of vancomycin as a classification problem. We chose the C4.5 decision tree technique for the dosage prediction process and supplied it with a boosting technique to enhance its performance. The potential predictor variables were collected from 833 patients with methicillin-resistant Staphylococcus aureus, or penicillin intolerance who were being treated with vancomycin and undergoing therapeutic drug monitoring (TDM) after attainment of steady state blood concentrations. Attributes tested as potential predictors included age, sex, weight, serum creatinine concentration, dosing interval, and variables from 1-compartment model kinetics such as Kd, Vd, and t(1/2). The results showed that the proposed method can utilize a variety of parameters to predict the dosage of vancomycin in the population used and that it performs well over a range of patient ages and renal function. The method may offer an alternative to existing methods used to support decision-making in clinical practice.

  20. Population variability in biological adaptive responses to DNA damage and the shapes of carcinogen dose-response curves

    International Nuclear Information System (INIS)

    Conolly, Rory B.; Gaylor, David W.; Lutz, Werner K.

    2005-01-01

    Carcinogen dose-response curves for both ionizing radiation and chemicals are typically assumed to be linear at environmentally relevant doses. This assumption is used to ensure protection of the public health in the absence of relevant dose-response data. A theoretical justification for the assumption has been provided by the argument that low dose linearity is expected when an exogenous agent adds to an ongoing endogenous process. Here, we use computational modeling to evaluate (1) how two biological adaptive processes, induction of DNA repair and cell cycle checkpoint control, may affect the shapes of dose-response curves for DNA-damaging carcinogens and (2) how the resulting dose-response behaviors may vary within a population. Each model incorporating an adaptive process was capable of generating not only monotonic dose-responses but also nonmonotonic (J-shaped) and threshold responses. Monte Carlo analysis suggested that all these dose-response behaviors could coexist within a population, as the spectrum of qualitative differences arose from quantitative changes in parameter values. While this analysis is largely theoretical, it suggests that (a) accurate prediction of the qualitative form of the dose-response requires a quantitative understanding of the mechanism (b) significant uncertainty is associated with human health risk prediction in the absence of such quantitative understanding and (c) a stronger experimental and regulatory focus on biological mechanisms and interindividual variability would allow flexibility in regulatory treatment of environmental carcinogens without compromising human health

  1. IN SITU COMPARISON OF TREE-RING RESPONSES TO CLIMATE AND POPULATION GENETICS: THE NEED TO CONTROL FOR LOCAL CLIMATE AND SITE VARIABLES

    Directory of Open Access Journals (Sweden)

    Johann Mathias Housset

    2016-10-01

    Full Text Available Tree species responses to climate change will be greatly influenced by their evolutionary potential and their phenotypic plasticity. Investigating tree-rings responses to climate and population genetics at the regional scale is therefore crucial in assessing the tree behaviour to climate change. This study combined in situ dendroclimatology and population genetics over a latitudinal gradient and compared the variations between the two at the intra- and inter-population levels. This approach was applied on the northern marginal populations of Thuja occidentalis (eastern white-cedar in the Canadian boreal forest. We aimed first to assess the radial growth variability (response functional trait within populations across the gradient and to compare it with the genetic diversity (microsatellites. Second, we investigated the variability in the growth response to climate at the regional scale through the radial growth-climate relationships, and tested its correlation with environmental variables and population genetic structure. Model selection based on the Akaike Information Criteria revealed that the growth synchronicity between pairs of trees of a population covariates with both the genetic diversity of this population and the amount of precipitation (inverse correlation, although these variables only explained a small fraction of the observed variance. At the regional scale, variance partitioning and partial redundancy analysis indicate that the growth response to climate was greatly modulated by stand environmental variables, suggesting predominant plastic variations in growth-response to climate. Combining in situ dendroclimatology and population genetics is a promising way to investigate species’ response capacity to climate change in natural stands. We stress the need to control for local climate and site conditions effects on dendroclimatic response to climate to avoid misleading conclusions regarding the associations with genetic variables.

  2. Dealing with incomplete and variable detectability in multi-year, multi-site monitoring of ecological populations

    Science.gov (United States)

    Converse, Sarah J.; Royle, J. Andrew; Gitzen, Robert A.; Millspaugh, Joshua J.; Cooper, Andrew B.; Licht, Daniel S.

    2012-01-01

    An ecological monitoring program should be viewed as a component of a larger framework designed to advance science and/or management, rather than as a stand-alone activity. Monitoring targets (the ecological variables of interest; e.g. abundance or occurrence of a species) should be set based on the needs of that framework (Nichols and Williams 2006; e.g. Chapters 2–4). Once such monitoring targets are set, the subsequent step in monitoring design involves consideration of the field and analytical methods that will be used to measure monitoring targets with adequate accuracy and precision. Long-term monitoring programs will involve replication of measurements over time, and possibly over space; that is, one location or each of multiple locations will be monitored multiple times, producing a collection of site visits (replicates). Clearly this replication is important for addressing spatial and temporal variability in the ecological resources of interest (Chapters 7–10), but it is worth considering how this replication can further be exploited to increase the effectiveness of monitoring. In particular, defensible monitoring of the majority of animal, and to a lesser degree plant, populations and communities will generally require investigators to account for imperfect detection (Chapters 4, 18). Raw indices of population state variables, such as abundance or occupancy (sensu MacKenzie et al. 2002), are rarely defensible when detection probabilities are failing to correct for differences in detection, resulting in indices that have an unknown relationship to the parameters of interest (e.g. Nichols 1992, Anderson 2001, MacKenzie et al. 2002, Williams et al. 2002, Anderson 2003, White 2005, Kéry and Schmidt 2008). While others have argued that indices may be preferable in some cases due to the challenges associated with estimating detection probabilities (e.g. McKelvey and Pearson 2001, Johnson 2008), we do not attempt to resolve this debate here. Rather, we are

  3. The origin and evolution of variable number tandem repeat of CLEC4M gene in the global human population.

    Directory of Open Access Journals (Sweden)

    Hui Li

    Full Text Available CLEC4M is a C-type lectin gene serving as cell adhesion receptor and pathogen recognition receptor. It recognizes several pathogens of important public health concern. In particular, a highly polymorphic variable number tandem repeat (VNTR at the neck-region of CLEC4M had been associated with genetic predisposition to some infectious diseases. To gain insight into the origin and evolution of this VNTR in CLEC4M, we studied 21 Africans, 20 Middle Easterns, 35 Europeans, 38 Asians, 13 Oceania, and 18 Americans (a total of 290 chromosomes from the (Human Genome Diversity Panel HGDP-CEPH panel; these samples covered most of alleles of this VNTR locus present in human populations. We identified a limited number of haplotypes among the basic repeat subunits that is 69 base pairs in length. Only 8 haplotypes were found. Their sequence identities were determined in the 290 chromosomes. VNTR alleles of different repeat length (from 4 to 9 repeats were analyzed for composition and orientation of these subunits. Our results showed that the subunit configuration of the same repeat number of VNTR locus from different populations were, in fact, virtually identical. It implies that most of the VNTR alleles existed before dispersion of modern humans outside Africa. Further analyses indicate that the present diversity profile of this locus in worldwide populations is generated from the effect of migration of different tribes and neutral evolution. Our findings do not support the hypothesis that the origin of the VNTR alleles were arisen by independent (separate mutation events and caused by differential allele advantage and natural selection as suggested by previous report based on SNP data.

  4. [Patterns of morphological variability in reintroduced populations with two beaver subspecies Castor fiber orientoeuropaeus and Castor fiber belorussicus (Castoridae, Rodentia) as an example].

    Science.gov (United States)

    Korablev, N P; Korablev, P N

    2012-01-01

    Taking as an example two beaver subspecies (Castor fiber orientoeuropaeus and Castor fiber belorussicus) with documented history of population formation, the patterns of morphological variability in translocated groups of mammals are studied. The variability of quantitative and qualitative traits in the formed populations is not characterized by a single direction. The main trend consists in increasing of adaptive norms diversity as related to body size. There observed a slight increase in the level of fluctuating asymmetry, reduction in polymorphism of nonmetric traits, and increase in fraction of rare aberrations. All these may be caused by inbreeding taking place during the period of prapopulations formation. The results of the study allow for considering the intraspecific differentiation as a consequence of adaptive variability (adaptatiogenesis) or subspecies hybridization. As for stochastic processes (genetic drift, founder effect), they seem to not influence the morphological variability significantly. The differences between discrete and dimensional traits are indicative of population groups' peculiarity.

  5. Day-to-Day Blood Pressure Variability and Risk of Dementia in a General Japanese Elderly Population: The Hisayama Study.

    Science.gov (United States)

    Oishi, Emi; Ohara, Tomoyuki; Sakata, Satoko; Fukuhara, Masayo; Hata, Jun; Yoshida, Daigo; Shibata, Mao; Ohtsubo, Toshio; Kitazono, Takanari; Kiyohara, Yutaka; Ninomiya, Toshiharu

    2017-08-08

    Several observational studies have reported that higher visit-to-visit blood pressure variability is a risk factor for cognitive impairment and dementia. However, no studies have investigated the association of day-to-day blood pressure variability assessed by home blood pressure measurement with the development of dementia. A total of 1674 community-dwelling Japanese elderly without dementia, ≥60 years of age, were followed up for 5 years (2007-2012). Home blood pressure was measured 3 times every morning for a median of 28 days. Day-to-day systolic (SBP) and diastolic blood pressure variabilities, calculated as coefficients of variation (CoV) of home SBP and diastolic blood pressure, were categorized into quartiles. The hazard ratios and their 95% confidence intervals of the CoV levels of home blood pressure on the development of all-cause dementia, vascular dementia (VaD), and Alzheimer disease (AD) were computed with a Cox proportional hazards model. During the follow-up, 194 subjects developed all-cause dementia; of these, 47 had VaD and 134 had AD. The age- and sex-adjusted incidences of all-cause dementia, VaD, and AD increased significantly with increasing CoV levels of home SBP (all P for trend dementia, VaD, and AD were significantly higher in those in the fourth quartile (hazard ratio=2.27, 95% confidence interval=1.45-3.55, P dementia; hazard ratio=2.79, 95% confidence interval=1.04-7.51, P =0.03 for VaD; hazard ratio=2.22, 95% confidence interval=1.31-3.75, P dementia and AD. There was no interaction between home SBP levels and CoV levels of home SBP on the risk of each subtype of dementia. Our findings suggest that increased day-to-day blood pressure variability is, independently of average home blood pressure, a significant risk factor for the development of all-cause dementia, VaD, and AD in the general elderly Japanese population. © 2017 The Authors.

  6. Conditions underpinning success in joint service-education workforce planning

    OpenAIRE

    Styles Laureen; Stevenson Lynn; Herringer Barbara; Purkis Mary; Van Neste-Kenny Jocelyne

    2009-01-01

    Abstract Vancouver Island lies just off the southwest coast of Canada. Separated from the large urban area of Greater Vancouver (estimated population 2.17 million) by the Georgia Strait, this geographical location poses unique challenges in delivering health care to a mixed urban, rural and remote population of approximately 730 000 people living on the main island and the surrounding Gulf Islands. These challenges are offset by opportunities for the Vancouver Island Health Authority (VIHA) t...

  7. Studying variability in human brain aging in a population-based German cohort – Rationale and design of 1000BRAINS

    Directory of Open Access Journals (Sweden)

    Svenja eCaspers

    2014-07-01

    Full Text Available The ongoing 1000 brains study (1000BRAINS is an epidemiological and neuroscientific investigation of structural and functional variability in the human brain during aging. The two recruitment sources are the 10-year follow-up cohort of the German Heinz Nixdorf Recall (HNR Study, and the HNR MultiGeneration Study cohort, which comprises spouses and offspring of HNR subjects. The HNR is a longitudinal epidemiological investigation of cardiovascular risk factors, with a comprehensive collection of clinical, laboratory, socioeconomic, and environmental data from population-based subjects aged 45-75 years on inclusion. HNR subjects underwent detailed assessments in 2000, 2006, and 2011, and completed annual postal questionnaires on health status. 1000BRAINS accesses these HNR data and applies a separate protocol comprising: neuropsychological tests of attention, memory, executive functions & language; examination of motor skills; ratings of personality, life quality, mood & daily activities; analysis of laboratory and genetic data; and state-of-the-art magnetic resonance imaging (MRI, 3 Tesla of the brain. The latter includes (i 3D-T1- and 3D-T2-weighted scans for structural analyses and myelin mapping; (ii three diffusion imaging sequences optimized for diffusion tensor imaging, high-angular resolution diffusion imaging for detailed fibre tracking and for diffusion kurtosis imaging; (iii resting-state and task-based functional MRI; and (iv fluid-attenuated inversion recovery and MR angiography for the detection of vascular lesions and the mapping of white matter lesions. The unique design of 1000BRAINS allows: (i comprehensive investigation of various influences including genetics, environment and health status on variability in brain structure and function during aging; and (ii identification of the impact of selected influencing factors on specific cognitive subsystems and their anatomical correlates.

  8. Testing efficacy of teaching food safety and identifying variables that affect learning in a low-literacy population.

    Science.gov (United States)

    Mosby, Terezie Tolar; Romero, Angélica Lissette Hernández; Linares, Ana Lucía Molina; Challinor, Julia M; Day, Sara W; Caniza, Miguela

    2015-03-01

    Nurses at a meeting of the Asociación de Hemato Oncología Pediátrica de Centroamérica y El Caribe recognized food safety as one of the main issues affecting patient care. The objective was to increase awareness of food safety issues among caregivers for pediatric cancer patients in Guatemala and El Salvador. A low-literacy booklet about food safety, "Alimentación del niño con cáncer (Feeding the child with cancer)," was developed for caregivers. Tests were developed to assess information acquisition and retention. An educator's guide was developed for consistency of education along with a demographics questionnaire. The efficacy of the booklet was tested with 162 caregivers of patients with newly diagnosed leukemia. Information retention was tested 1 and 3 months after the initial education. The booklet was found to be efficient for food safety education. There was no significant difference between post-educational knowledge in either country at 1 month or in Guatemala at 3 months. Pre-educational knowledge was not associated with any demographic variable except for self-reported ability to read in El Salvador. There was no significant association between learning ability and demographic variables in either country. Caregivers from El Salvador had a better ability to learn than caregivers from Guatemala. Education using the booklet greatly improved food safety knowledge, which remained high 1 and 3 months later. Education with the booklet was efficacious for teaching a low-literacy population about food safety. However, it is unknown which part of the education contributed to the significant improvement in knowledge.

  9. Genetic variability of wild populations of Leporinus elongatus in the São Domingos River - MS Brazil: a preliminary view on the construction of the hydroelectric plant

    Directory of Open Access Journals (Sweden)

    Ricardo Pereira Ribeiro

    2016-09-01

    Full Text Available Most of the electricity used in Brazil comes from hydroelectric plants, mainly due to the great availability of its water resources. However, the construction of these plants denotes serious problems related to migration of native fish and the genetic conservation of stocks. Current study evaluates two wild population of Leporinus elongatus (piapara located downstream (Population A - PopA and upstream (Population B - PopB of the Cachoeira Branca before the construction of the São Domingos hydroelectric plant (HPP in the Mato Grosso do Sul State, Brazil. Thirty samples from caudal fins were collected and analyzed for each population. Eighty-nine fragments, including 72 polymorphic ones (80.9%, were analyzed. Low fragments (less than 0.100 in both populations (PopA = 2 and PopB = 3 were identified. Nine fixed fragments (frequency 1.000 (PopA = 3 and PopB = 6, and four exclusive fragments (PopA = 3 and PopB = 1 were also reported. The genetic variability within populations, calculated by Shannon Index and by percentage of polymorphic fragments, indicated high rates of intrapopulation variability (PopA = 0.309 and 61.80% and PopB = 0.392 and 71.90%, respectively. Genetic distance and identity rates (0.089 and 0.915, respectively were different between populations, whilst AMOVA showed that most variations lie within the populations and not between them. Fst and Nm rates showed moderate genetic differentiation with low numbers of migrants. Results reveal populations with high intra-population genetic variability and genetic differentiation, with low gene flow. The passage ladders of São Domingos HPP should control fish transposition to preserve genetic variability.

  10. Genetic variability and natural selection at the ligand domain of the Duffy binding protein in Brazilian Plasmodium vivax populations.

    Science.gov (United States)

    Sousa, Taís N; Tarazona-Santos, Eduardo M; Wilson, Daniel J; Madureira, Ana P; Falcão, Paula R K; Fontes, Cor J F; Gil, Luiz H S; Ferreira, Marcelo U; Carvalho, Luzia H; Brito, Cristiana F A

    2010-11-22

    Plasmodium vivax malaria is a major public health challenge in Latin America, Asia and Oceania, with 130-435 million clinical cases per year worldwide. Invasion of host blood cells by P. vivax mainly depends on a type I membrane protein called Duffy binding protein (PvDBP). The erythrocyte-binding motif of PvDBP is a 170 amino-acid stretch located in its cysteine-rich region II (PvDBPII), which is the most variable segment of the protein. To test whether diversifying natural selection has shaped the nucleotide diversity of PvDBPII in Brazilian populations, this region was sequenced in 122 isolates from six different geographic areas. A Bayesian method was applied to test for the action of natural selection under a population genetic model that incorporates recombination. The analysis was integrated with a structural model of PvDBPII, and T- and B-cell epitopes were localized on the 3-D structure. The results suggest that: (i) recombination plays an important role in determining the haplotype structure of PvDBPII, and (ii) PvDBPII appears to contain neutrally evolving codons as well as codons evolving under natural selection. Diversifying selection preferentially acts on sites identified as epitopes, particularly on amino acid residues 417, 419, and 424, which show strong linkage disequilibrium. This study shows that some polymorphisms of PvDBPII are present near the erythrocyte-binding domain and might serve to elude antibodies that inhibit cell invasion. Therefore, these polymorphisms should be taken into account when designing vaccines aimed at eliciting antibodies to inhibit erythrocyte invasion.

  11. Estimation of expected number of accidents and workforce unavailability through Bayesian population variability analysis and Markov-based model

    International Nuclear Information System (INIS)

    Chagas Moura, Márcio das; Azevedo, Rafael Valença; Droguett, Enrique López; Chaves, Leandro Rego; Lins, Isis Didier

    2016-01-01

    Occupational accidents pose several negative consequences to employees, employers, environment and people surrounding the locale where the accident takes place. Some types of accidents correspond to low frequency-high consequence (long sick leaves) events, and then classical statistical approaches are ineffective in these cases because the available dataset is generally sparse and contain censored recordings. In this context, we propose a Bayesian population variability method for the estimation of the distributions of the rates of accident and recovery. Given these distributions, a Markov-based model will be used to estimate the uncertainty over the expected number of accidents and the work time loss. Thus, the use of Bayesian analysis along with the Markov approach aims at investigating future trends regarding occupational accidents in a workplace as well as enabling a better management of the labor force and prevention efforts. One application example is presented in order to validate the proposed approach; this case uses available data gathered from a hydropower company in Brazil. - Highlights: • This paper proposes a Bayesian method to estimate rates of accident and recovery. • The model requires simple data likely to be available in the company database. • These results show the proposed model is not too sensitive to the prior estimates.

  12. Levels of immunity parameters underpin bleaching and disease susceptibility of reef corals.

    Science.gov (United States)

    Palmer, Caroline V; Bythell, John C; Willis, Bette L

    2010-06-01

    Immunity is a key life history trait that may explain hierarchies in the susceptibility of corals to disease and thermal bleaching, two of the greatest current threats to coral health and the persistence of tropical reefs. Despite their ongoing and rapid global decline, there have been few investigations into the immunity mechanisms of reef-building corals. Variables commonly associated with invertebrate immunity, including the presence of melanin, size of melanin-containing granular cells, and phenoloxidase (PO) activity, as well as concentrations of fluorescent proteins (FPs), were investigated in hard (Scleractinia) and soft (Alcyonacea) corals spanning 10 families from the Great Barrier Reef. Detectable levels of these indicators were present in all corals investigated, although relative investment differed among coral taxa. Overall levels of investment were inversely correlated to thermal bleaching and disease susceptibility. In addition, PO activity, melanin-containing granular cell size, and FP concentration were each found to be significant predictors of susceptibility and thus may play key roles in coral immunity. Correlative evidence that taxonomic (family-level) variation in the levels of these constituent immunity parameters underpins susceptibility to both thermal bleaching and disease indicates that baseline immunity underlies the vulnerability of corals to these two threats. This reinforces the necessity of a holistic approach to understanding bleaching and disease in order to accurately determine the resilience of coral reefs.

  13. Conditions underpinning success in joint service-education workforce planning

    Directory of Open Access Journals (Sweden)

    Styles Laureen

    2009-02-01

    Full Text Available Abstract Vancouver Island lies just off the southwest coast of Canada. Separated from the large urban area of Greater Vancouver (estimated population 2.17 million by the Georgia Strait, this geographical location poses unique challenges in delivering health care to a mixed urban, rural and remote population of approximately 730 000 people living on the main island and the surrounding Gulf Islands. These challenges are offset by opportunities for the Vancouver Island Health Authority (VIHA to collaborate with four publicly funded post-secondary institutions in planning and implementing responses to existing and emerging health care workforce needs. In this commentary, we outline strategies we have found successful in aligning health education and training with local health needs in ways that demonstrate socially accountable outcomes. Challenges encountered through this process (i.e. regulatory reform, post-secondary policy reform, impacts of an ageing population, impact of private, for-profit educational institutions have placed demands on us to establish and build on open and collaborative working relationships. Some of our successes can be attributed to evidence-informed decision-making. Other successes result from less tangible but no less important factors. We argue that both rational and "accidental" factors are significant – and that strategic use of "accidental" features may prove most significant in our efforts to ensure the delivery of high-quality health care to our communities.

  14. Conditions underpinning success in joint service-education workforce planning.

    Science.gov (United States)

    Purkis, Mary Ellen; Herringer, Barbara; Stevenson, Lynn; Styles, Laureen; Van Neste-Kenny, Jocelyne

    2009-02-25

    Vancouver Island lies just off the southwest coast of Canada. Separated from the large urban area of Greater Vancouver (estimated population 2.17 million) by the Georgia Strait, this geographical location poses unique challenges in delivering health care to a mixed urban, rural and remote population of approximately 730,000 people living on the main island and the surrounding Gulf Islands. These challenges are offset by opportunities for the Vancouver Island Health Authority (VIHA) to collaborate with four publicly funded post-secondary institutions in planning and implementing responses to existing and emerging health care workforce needs. In this commentary, we outline strategies we have found successful in aligning health education and training with local health needs in ways that demonstrate socially accountable outcomes. Challenges encountered through this process (i.e. regulatory reform, post-secondary policy reform, impacts of an ageing population, impact of private, for-profit educational institutions) have placed demands on us to establish and build on open and collaborative working relationships. Some of our successes can be attributed to evidence-informed decision-making. Other successes result from less tangible but no less important factors. We argue that both rational and "accidental" factors are significant--and that strategic use of "accidental" features may prove most significant in our efforts to ensure the delivery of high-quality health care to our communities.

  15. Combination of Single Nucleotide Polymorphism and Variable-Number Tandem Repeats for Genotyping a Homogenous Population of Mycobacterium tuberculosis Beijing Strains in China

    OpenAIRE

    Luo, Tao; Yang, Chongguang; Gagneux, Sebastien; Gicquel, Brigitte; Mei, Jian; Gao, Qian

    2012-01-01

    The standard 15- and 24-locus variable-number tandem repeat (VNTR) genotyping methods have demonstrated adequate discriminatory power and a small homoplasy effect for tracing tuberculosis (TB) transmission and predicting Mycobacterium tuberculosis lineages in European and North American countries. However, its validity for the definition of transmission in homogenous M. tuberculosis populations in settings with high TB burdens has been questioned. Here, we genotyped a population-based collect...

  16. Population.

    Science.gov (United States)

    International Planned Parenthood Federation, London (England).

    In an effort to help meet the growing interest and concern about the problems created by the rapid growth of population, The International Planned Parenthood Federation has prepared this booklet with the aim of assisting the study of the history and future trends of population growth and its impact on individual and family welfare, national,…

  17. China's new oil import status underpins world's most dynamic petroleum scene

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    China is poised to become a net importer of oil in 1994--95. That sets the stage for China importing more than 1 million b/d of crude oil and refined products on a net basis by the turn of the century. That development underpins a bigger story -- arguably the biggest story on the petroleum scene today. The turnabout that is seeing the world's fifth biggest oil producer go from significant oil exporter in recent years to major oil importer by the turn of the century points to several other truisms in the petroleum industry: That an oil demand surge in the Asia-Pacific region led by China will fuel overall world oil demand growth for years to come; that a refining and petrochemical boom in a country that accounts for about one fifth of the world's population has dramatic implications for those two industries; that privatization has gathered so much momentum in the global petroleum industry that even Communist China has embraced some form of it; that China's domestic crude supply shortfall is creating unprecedented opportunities for foreign upstream investors in one of the world's most prospective yet underexplored and underexploited regions; and that the same new openness that is distinguishing China's petroleum industry today is turning some of its state owned companies into major competitors to be reckoned with on the international scene, upstream and downstream. The paper discusses China's oil export/import balance, supply/demand outlook, policy changes, and new regulations governing export of crude oil and products

  18. Contact networks structured by sex underpin sex-specific epidemiology of infection.

    Science.gov (United States)

    Silk, Matthew J; Weber, Nicola L; Steward, Lucy C; Hodgson, David J; Boots, Mike; Croft, Darren P; Delahay, Richard J; McDonald, Robbie A

    2018-02-01

    Contact networks are fundamental to the transmission of infection and host sex often affects the acquisition and progression of infection. However, the epidemiological impacts of sex-related variation in animal contact networks have rarely been investigated. We test the hypothesis that sex-biases in infection are related to variation in multilayer contact networks structured by sex in a population of European badgers Meles meles naturally infected with Mycobacterium bovis. Our key results are that male-male and between-sex networks are structured at broader spatial scales than female-female networks and that in male-male and between-sex contact networks, but not female-female networks, there is a significant relationship between infection and contacts with individuals in other groups. These sex differences in social behaviour may underpin male-biased acquisition of infection and may result in males being responsible for more between-group transmission. This highlights the importance of sex-related variation in host behaviour when managing animal diseases. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

  19. Probing the Perceptual and Cognitive Underpinnings of Braille Reading. An Estonian Population Study

    Science.gov (United States)

    Veispak, Anneli; Boets, Bart; Mannamaa, Mairi; Ghesquiere, Pol

    2012-01-01

    Similar to many sighted children who struggle with learning to read, a proportion of blind children have specific difficulties related to reading braille which cannot be easily explained. A lot of research has been conducted to investigate the perceptual and cognitive processes behind (impairments in) print reading. Very few studies, however, have…

  20. Theoretical and Empirical Underpinnings of Parent-Child Interaction Therapy with Child Physical Abuse Populations

    Science.gov (United States)

    Herschell, Amy D.; McNeil, Cheryl B.

    2005-01-01

    Children who experience physical abuse often suffer numerous negative short- and long-term difficulties in comparison to non-abused children. Considerable effort has been invested in developing and identifying treatment interventions to attenuate these negative outcomes. Parent-Child Interaction Therapy (PCIT), originally developed for the…

  1. Defining constant versus variable phenotypic features of women with polycystic ovary syndrome using different ethnic groups and populations.

    Science.gov (United States)

    Welt, C K; Arason, G; Gudmundsson, J A; Adams, J; Palsdóttir, H; Gudlaugsdóttir, G; Ingadóttir, G; Crowley, W F

    2006-11-01

    The phenotype of women with polycystic ovary syndrome (PCOS) is variable, depending on the ethnic background. The phenotypes of women with PCOS in Iceland and Boston were compared. The study was observational with a parallel design. Subjects were studied in an outpatient setting. Women, aged 18-45 yr, with PCOS defined by hyperandrogenism and fewer than nine menses per year, were examined in Iceland (n = 105) and Boston (n = 262). PCOS subjects underwent a physical exam, fasting blood samples for androgens, gonadotropins, metabolic parameters, and a transvaginal ultrasound. The phenotype of women with PCOS was compared between Caucasian women in Iceland and Boston and among Caucasian, African-American, Hispanic, and Asian women in Boston. Androstenedione (4.0 +/- 1.3 vs. 3.5 +/- 1.2 ng/ml; P testosterone (54.0 +/- 25.7 vs. 66.2 +/- 35.6 ng/dl; P Caucasian Icelandic compared with Boston women with PCOS. There were no differences in fasting blood glucose, insulin, or homeostasis model assessment in body mass index-matched Caucasian subjects from Iceland or Boston or in different ethnic groups in Boston. Polycystic ovary morphology was demonstrated in 93-100% of women with PCOS in all ethnic groups. The data demonstrate differences in the reproductive features of PCOS without differences in glucose and insulin in body mass index-matched populations. These studies also suggest that measuring androstenedione is important for the documentation of hyperandrogenism in Icelandic women. Finally, polycystic ovary morphology by ultrasound is an almost universal finding in women with PCOS as defined by hyperandrogenism and irregular menses.

  2. Density dependence and climate effects in Rocky Mountain elk: an application of regression with instrumental variables for population time series with sampling error.

    Science.gov (United States)

    Creel, Scott; Creel, Michael

    2009-11-01

    1. Sampling error in annual estimates of population size creates two widely recognized problems for the analysis of population growth. First, if sampling error is mistakenly treated as process error, one obtains inflated estimates of the variation in true population trajectories (Staples, Taper & Dennis 2004). Second, treating sampling error as process error is thought to overestimate the importance of density dependence in population growth (Viljugrein et al. 2005; Dennis et al. 2006). 2. In ecology, state-space models are used to account for sampling error when estimating the effects of density and other variables on population growth (Staples et al. 2004; Dennis et al. 2006). In econometrics, regression with instrumental variables is a well-established method that addresses the problem of correlation between regressors and the error term, but requires fewer assumptions than state-space models (Davidson & MacKinnon 1993; Cameron & Trivedi 2005). 3. We used instrumental variables to account for sampling error and fit a generalized linear model to 472 annual observations of population size for 35 Elk Management Units in Montana, from 1928 to 2004. We compared this model with state-space models fit with the likelihood function of Dennis et al. (2006). We discuss the general advantages and disadvantages of each method. Briefly, regression with instrumental variables is valid with fewer distributional assumptions, but state-space models are more efficient when their distributional assumptions are met. 4. Both methods found that population growth was negatively related to population density and winter snow accumulation. Summer rainfall and wolf (Canis lupus) presence had much weaker effects on elk (Cervus elaphus) dynamics [though limitation by wolves is strong in some elk populations with well-established wolf populations (Creel et al. 2007; Creel & Christianson 2008)]. 5. Coupled with predictions for Montana from global and regional climate models, our results

  3. Energy-water-environment nexus underpinning future desalination sustainability

    KAUST Repository

    Shahzad, Muhammad Wakil

    2017-03-11

    Energy-water-environment nexus is very important to attain COP21 goal, maintaining environment temperature increase below 2°C, but unfortunately two third share of CO2 emission has already been used and the remaining will be exhausted by 2050. A number of technological developments in power and desalination sectors improved their efficiencies to save energy and carbon emission but still they are operating at 35% and 10% of their thermodynamic limits. Research in desalination processes contributing to fuel World population for their improved living standard and to reduce specific energy consumption and to protect environment. Recently developed highly efficient nature-inspired membranes (aquaporin & graphene) and trend in thermally driven cycle\\'s hybridization could potentially lower then energy requirement for water purification. This paper presents a state of art review on energy, water and environment interconnection and future energy efficient desalination possibilities to save energy and protect environment.

  4. Policy processes underpinning universal health insurance in Vietnam

    Directory of Open Access Journals (Sweden)

    Bui T. T. Ha

    2014-09-01

    Full Text Available Background: In almost 30 years since economic reforms or ‘renovation’ (Doimoi were launched, Vietnam has achieved remarkably good health results, in many cases matching those in much higher income countries. This study explores the contribution made by Universal Health Insurance (UHI policies, focusing on the past 15 years. We conducted a mixed method study to describe and assess the policy process relating to health insurance, from agenda setting through implementation and evaluation. Design: The qualitative research methods implemented in this study were 30 in-depth interviews, 4 focus group discussions, expert consultancy, and 420 secondary data review. The data were analyzed by NVivo 7.0. Results: Health insurance in Vietnam was introduced in 1992 and has been elaborated over a 20-year time frame. These processes relate to moving from a contingent to a gradually expanded target population, expanding the scope of the benefit package, and reducing the financial contribution from the insured. The target groups expanded to include 66.8% of the population by 2012. We characterized the policy process relating to UHI as incremental with a learning-by-doing approach, with an emphasis on increasing coverage rather than ensuring a basic service package and financial protection. There was limited involvement of civil society organizations and users in all policy processes. Intertwined political economy factors influenced the policy processes. Conclusions: Incremental policy processes, characterized by a learning-by-doing approach, is appropriate for countries attempting to introduce new health institutions, such as health insurance in Vietnam. Vietnam should continue to mobilize resources in sustainable and viable ways to support the target groups. The country should also adopt a multi-pronged approach to achieving universal access to health services, beyond health insurance.

  5. Policy processes underpinning universal health insurance in Vietnam.

    Science.gov (United States)

    Ha, Bui T T; Frizen, Scott; Thi, Le M; Duong, Doan T T; Duc, Duong M

    2014-01-01

    In almost 30 years since economic reforms or 'renovation' (Doimoi) were launched, Vietnam has achieved remarkably good health results, in many cases matching those in much higher income countries. This study explores the contribution made by Universal Health Insurance (UHI) policies, focusing on the past 15 years. We conducted a mixed method study to describe and assess the policy process relating to health insurance, from agenda setting through implementation and evaluation. The qualitative research methods implemented in this study were 30 in-depth interviews, 4 focus group discussions, expert consultancy, and 420 secondary data review. The data were analyzed by NVivo 7.0. Health insurance in Vietnam was introduced in 1992 and has been elaborated over a 20-year time frame. These processes relate to moving from a contingent to a gradually expanded target population, expanding the scope of the benefit package, and reducing the financial contribution from the insured. The target groups expanded to include 66.8% of the population by 2012. We characterized the policy process relating to UHI as incremental with a learning-by-doing approach, with an emphasis on increasing coverage rather than ensuring a basic service package and financial protection. There was limited involvement of civil society organizations and users in all policy processes. Intertwined political economy factors influenced the policy processes. Incremental policy processes, characterized by a learning-by-doing approach, is appropriate for countries attempting to introduce new health institutions, such as health insurance in Vietnam. Vietnam should continue to mobilize resources in sustainable and viable ways to support the target groups. The country should also adopt a multi-pronged approach to achieving universal access to health services, beyond health insurance.

  6. THE MASSIVE STAR POPULATION IN M101. III. SPECTRA AND PHOTOMETRY OF THE LUMINOUS AND VARIABLE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Grammer, Skyler H.; Humphreys, Roberta M. [Minnesota Institute for Astrophysics, 116 Church Street SE, University of Minnesota , Minneapolis, MN 55455 (United States); Gerke, Jill, E-mail: grammer@astro.umn.edu, E-mail: roberta@umn.edu [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)

    2015-05-15

    We discuss moderate-resolution spectra, multicolor photometry, and light curves of 31 of the most luminous stars and variables in the giant spiral M101. The majority are intermediate A- to F-type supergiants. We present new photometry and light curves for three known “irregular blue variables,” V2, V4, and V9, and identify a new candidate. Their spectra and variability confirm that they are luminous blue variable (LBV) candidates and V9 may be in an LBV-like maximum light state or eruption.

  7. Metaphysical and value underpinnings of traditional medicine in West Africa.

    Science.gov (United States)

    Omonzejele, Peter F; Maduka, Chukwugozie

    2011-02-01

    This study investigated the extent to which recourse to traditional healers depended on biometric variables; ways of knowing in good time what ailments were more likely to be better handled by traditional healers; rationale behind traditional healing methodologies. On the whole, four research questions were engaged. The sample for the study included residents in urban (Benin City) and rural (Ehime Mbano) communities in Nigeria. The instruments comprised of two questionnaires. The traditional healers were also interviewed in addition. The findings of the research included the following: in both rural and urban areas, women and more elderly persons had more recourse than other groups to traditional medicine; Christians, less educated persons, self-employed persons and women affirmed most strongly to the efficacy of traditional medicine over Western medicine with respect to certain ailments; ways for averting spiritual illnesses included obeying instructions from ancestors and offering regular sacrifices to the gods; methods used by traditional healers to determine whether an ailment was "spiritual" or as a result of home problems included diagnosis linked to divination, interpretation of dreams particularly those involving visits by ancestors, interpretation of nightmares and omens such as the appearance of owls; methods for curing patients included use of herbs particularly those believed to have magical powers, offering of sacrifices, use of incantations and wearing of protective medicine.

  8. The immunological underpinnings of vaccinations to prevent cytomegalovirus disease.

    Science.gov (United States)

    McCormick, A Louise; Mocarski, Edward S

    2015-03-01

    A universal cytomegalovirus (CMV) vaccination promises to reduce the burden of the developmental damage that afflicts up to 0.5% of live births worldwide. An effective vaccination that prevents transplacental transmission would reduce CMV congenital disease and CMV-associated still births and leave populations less susceptible to opportunistic CMV disease. Thus, a vaccination against this virus has long been recognized for the potential of enormous health-care savings because congenital damage is life-long and existing anti-viral options are limited. Vaccine researchers, industry leaders, and regulatory representatives have discussed the challenges posed by clinical efficacy trials that would lead to a universal CMV vaccine, reviewing the links between infection and disease, and identifying settings where disrupting viral transmission might provide a surrogate endpoint for disease prevention. Reducing the complexity of such trials would facilitate vaccine development. Children and adolescents are the targets for universal vaccination, with the expectation of protecting the offspring of immunized women. Given that a majority of females worldwide experience CMV infection during childhood, a universal vaccine must boost natural immunity and reduce transmission due to reactivation and re-infection as well as primary infection during pregnancy. Although current vaccine strategies recognize the value of humoral and cellular immunity, the precise mechanisms that act at the placental interface remain elusive. Immunity resulting from natural infection appears to limit rather than prevent reactivation of latent viruses and susceptibility to re-infection, leaving a challenge for universal vaccination to improve upon natural immunity levels. Despite these hurdles, early phase clinical trials have achieved primary end points in CMV seronegative subjects. Efficacy studies must be expanded to mixed populations of CMV-naive and naturally infected subjects to understand the overall

  9. Genetic and Toxigenic Variability within Aspergillus flavus Population Isolated from Maize in Two Diverse Environments in Kenya

    Directory of Open Access Journals (Sweden)

    Sheila Okoth

    2018-01-01

    Full Text Available Aspergillus flavus is the main producer of carcinogenic aflatoxins in agricultural commodities such as maize. This fungus occurs naturally on crops, and produces aflatoxins when environmental conditions are favorable. The aim of this study is to analyse the genetic variability among 109 A. flavus isolates previously recovered from maize sampled from a known aflatoxin-hotspot (Eastern region, Kenya and the major maize-growing area in the Rift Valley (Kenya, and to determine their toxigenic potential. DNA analyses of internal transcribed spacer (ITS regions of ribosomal DNA, partial β-tubulin gene (benA and calmodulin gene (CaM sequences were used. The strains were further analyzed for the presence of four aflatoxin-biosynthesis genes in relation to their capability to produce aflatoxins and other metabolites, targeting the regulatory gene aflR and the structural genes aflP, aflD, and aflQ. In addition, the metabolic profile of the fungal strains was unraveled using state-of-the-art LC-MS/MS instrumentation. The three gene-sequence data grouped the isolates into two major clades, A. minisclerotigenes and A. flavus. A. minisclerotigenes was most prevalent in Eastern Kenya, while A. flavus was common in both regions. A. parasiticus was represented by a single isolate collected from Rift Valley. Diversity existed within the A. flavus population, which formed several subclades. An inconsistency in identification of some isolates using the three markers was observed. The calmodulin gene sequences showed wider variation of polymorphisms. The aflatoxin production pattern was not consistent with the presence of aflatoxigenic genes, suggesting an inability of the primers to always detect the genes or presence of genetic mutations. Significant variation was observed in toxin profiles of the isolates. This is the first time that a profound metabolic profiling of A. flavus isolates was done in Kenya. Positive associations were evident for some metabolites

  10. Genetic and Toxigenic Variability within Aspergillus flavus Population Isolated from Maize in Two Diverse Environments in Kenya.

    Science.gov (United States)

    Okoth, Sheila; De Boevre, Marthe; Vidal, Arnau; Diana Di Mavungu, José; Landschoot, Sofie; Kyallo, Martina; Njuguna, Joyce; Harvey, Jagger; De Saeger, Sarah

    2018-01-01

    Aspergillus flavus is the main producer of carcinogenic aflatoxins in agricultural commodities such as maize. This fungus occurs naturally on crops, and produces aflatoxins when environmental conditions are favorable. The aim of this study is to analyse the genetic variability among 109 A. flavus isolates previously recovered from maize sampled from a known aflatoxin-hotspot (Eastern region, Kenya) and the major maize-growing area in the Rift Valley (Kenya), and to determine their toxigenic potential. DNA analyses of internal transcribed spacer (ITS) regions of ribosomal DNA, partial β-tubulin gene (benA) and calmodulin gene (CaM) sequences were used. The strains were further analyzed for the presence of four aflatoxin-biosynthesis genes in relation to their capability to produce aflatoxins and other metabolites, targeting the regulatory gene aflR and the structural genes aflP, aflD, and aflQ. In addition, the metabolic profile of the fungal strains was unraveled using state-of-the-art LC-MS/MS instrumentation. The three gene-sequence data grouped the isolates into two major clades, A. minisclerotigenes and A. flavus . A. minisclerotigenes was most prevalent in Eastern Kenya, while A. flavus was common in both regions. A. parasiticus was represented by a single isolate collected from Rift Valley. Diversity existed within the A. flavus population, which formed several subclades. An inconsistency in identification of some isolates using the three markers was observed. The calmodulin gene sequences showed wider variation of polymorphisms. The aflatoxin production pattern was not consistent with the presence of aflatoxigenic genes, suggesting an inability of the primers to always detect the genes or presence of genetic mutations. Significant variation was observed in toxin profiles of the isolates. This is the first time that a profound metabolic profiling of A. flavus isolates was done in Kenya. Positive associations were evident for some metabolites, while for

  11. Variability and connectivity of plaice populations from the Eastern North Sea to the Baltic Sea, part II. Biological evidence of population mixing

    DEFF Research Database (Denmark)

    Ulrich, Clara; Hansen, Jakob Hemmer; Boje, Jesper

    2016-01-01

    in parallel. Genetic markers suggested the existence of different genetic populations in the transition area. Growth backcalculation with otoliths resulted in significant although limited differences in growth rates between North Sea and Skagerrak, indicating weak differentiation or important mixing......A multi-disciplinary study was conducted to clarify stock identity and connectivity patterns in the populations of European plaice (Pleuronectes platessa) in the Skagerrak-Kattegat transition area between the Eastern North Sea and the Baltic Sea. Five independent biological studies were carried out...... constitute a large share of the catches in this area. The mixing of different populations within a management area has implications for stock assessment and management. Choice must be made to either lump or split the populations, and the feasibility and constraints of both options are discussed. The outcomes...

  12. Analysis of genetic variability in soursop Annona muricata L populations from Central Java and East Java based on random amplified polymorphic DNA RAPD marker

    Directory of Open Access Journals (Sweden)

    Suratman Suratman

    2014-08-01

    Full Text Available The objective of this research was to determine genetic variability of the soursop (Annona muricata L. populations from Central Java and East Java based on RAPD markers. Leaves of 40 individuals were collected from 4 soursop populations in Central Java and East Java, include : Sukoharjo, Karanganyar (Central Java, and Ngawi, Pacitan (East Java. Genomic DNA was extracted from the leaves by the CTAB extraction procedure with some modifications. A total of 15 RAPD primers were purchased from commercial source and tested to find specific diagnostic markers for each individuals by RAPD-PCR. The measurement of soursop population genetic distance was based on similarity coefficient using method of Group Average Clustering and Unweight Pair Group Method Arithmetic (UPGMA of NTSYS program version 2.02i. Results showed that each soursop population collected from different localities seemed have variability in RAPD profiles by using different primers. Four RAPD polymorphic primer was selected from 15 RAPD primers, namely A18, A20, P10 and P11. A total of 58 bands produced, varying from 9 to 20 bands per primer. The selected four RAPD primers produced 57 polymorphic bands, whereas polymorphism for each primer ranged from 95 % to 100 %. Dendrogram indicated that four soursop populations tend to segregate form two separated clade. The sample collected from Sukoharjo formed a separate cluster while the sample collected from Ngawi, Pacitan and Karanganyar grouped together in other cluster and diverged from population Sukoharjo.

  13. Genetic variation of the greenhouse whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), among populations from Serbia and neighbouring countries, as inferred from COI sequence variability.

    Science.gov (United States)

    Prijović, M; Skaljac, M; Drobnjaković, T; Zanić, K; Perić, P; Marčić, D; Puizina, J

    2014-06-01

    The greenhouse whitefly Trialeurodes vaporariorum Westwood, 1856 (Hemiptera: Aleyrodidae) is an invasive and highly polyphagous phloem-feeding pest of vegetables and ornamentals. Trialeurodes vaporariorum causes serious damage due to direct feeding and transmits several important plant viruses. Excessive use of insecticides has resulted in significantly reduced levels of susceptibility of various T. vaporariorum populations. To determine the genetic variability within and among populations of T. vaporariorum from Serbia and to explore their genetic relatedness with other T. vaporariorum populations, we analysed the mitochondrial cytochrome c oxidase I (COI) sequences of 16 populations from Serbia and six neighbouring countries: Montenegro (three populations), Macedonia (one population) and Croatia (two populations), for a total of 198 analysed specimens. A low overall level of sequence divergence and only five variable nucleotides and six haplotypes were found. The most frequent haplotype, H1, was identified in all Serbian populations and in all specimens from distant localities in Croatia and Macedonia. The COI sequence data that was retrieved from GenBank and the data from our study indicated that H1 is the most globally widespread T. vaporariorum haplotype. A lack of spatial genetic structure among the studied T. vaporariorum populations, as well as two demographic tests that we performed (Tajima's D value and Fu's Fs statistics), indicate a recent colonisation event and population growth. Phylogenetic analyses of the COI haplotypes in this study and other T. vaporariorum haplotypes that were retrieved from GenBank were performed using Bayesian inference and median-joining (MJ) network analysis. Two major haplogroups with only a single unique nucleotide difference were found: haplogroup 1 (containing the five Serbian haplotypes and those previously identified in India, China, the Netherlands, the United Kingdom, Morocco, Reunion and the USA) and haplogroup 3

  14. Genetic Variability and Geographic Diversity of the Common Bed Bug (Hemiptera: Cimicidae) Populations from the Midwest Using Microsatellite Markers.

    Science.gov (United States)

    Narain, Ralph B; Lalithambika, Sreedevi; Kamble, Shripat T

    2015-07-01

    With the recent global resurgence of the bed bugs (Cimex lectularius L.), there is a need to better understand its biology, ecology, and ability to establish populations. Bed bugs are domestic pests that feed mainly on mammalian blood. Although bed bugs have not been implicated as vectors of pathogens, their biting activity inflicts severe insomnia and allergic reactions. Moreover, they have recently developed resistance to various insecticides, which requires further molecular research to determine genetic variation and appropriate interventions. Population dynamics, including genetic differentiation and genetic distance of 10 populations from the Midwest were analyzed in this study. The bed bug samples collected by pest control companies were genotyped using eight species-specific microsatellite markers. Results showed all eight markers were polymorphic, with 8-16 alleles per locus, suggesting high genetic diversity. The FST values were >0.25, signifying pronounced genetic differentiation. The G-test results also indicated high genetic differentiation among populations. The frequency of the most common allele across all eight loci was 0.42. The coefficient of relatedness between each of the populations was >0.5, indicative of sibling or parent-offspring relationships, while the FIS and its confidence interval values were statistically insignificant within the populations tested. The populations departed from Hardy-Weinberg equilibrium, possibly because of high heterozygosity. The genetic distance analysis using a neighbor-joining tree showed that the populations from Kansas City, MO, were genetically separate from most of those from Nebraska, indicating a geographic pattern of genetic structure. Our study demonstrated the effectiveness of using microsatellite markers to study bed bugs population structure, thereby improving our understanding of bed bug population dynamics in the Midwest. Overall, this study showed a high genetic diversity and identified several

  15. MHC ANTIGEN-BINDING LOCUS SHOWS STRONG SIGNAL OF SELECTION AND HIGH VARIABILITY IN FUNDULUS HETEROCLITUS POPULATIONS

    Science.gov (United States)

    The major histocompatibility system provides a unique genetic locus in vertebrates to assess genetic diversity and to look for the effects of selecti.on on the immune system. Fish population studies using MHC are fairly new, and thus far they have focused on endangered population...

  16. Integrating vital rate variability into perturbation analysis: an evaluation for matrix population models of six plant species

    NARCIS (Netherlands)

    Zuidema, P.A.; Franco, M.

    2001-01-01

    1 Matrix population models are usually constructed by employing average values of vital rates (survival, growth and reproduction) for each size category. Perturbation analyses of matrix models assess the influence of vital rates or matrix elements on population growth rate. They consider the impact

  17. Geographic variability in response to azinphos-methyl in field-collected populations of Cydia pomonella (Lepidoptera: Tortricidae) from Argentina.

    Science.gov (United States)

    Soleño, Jimena; Anguiano, Olga L; Cichón, Liliana B; Garrido, Silvina A; Montagna, Cristina M

    2012-11-01

    Resistance to insecticides has been related to application history, genetic factors of the pest and the dynamic within the treated area. The aim of this study was to assess the geographic variation in azinphos-methyl response and the role of esterase and cytochrome P450 monooxygenase enzymes in codling moth populations collected within different areas of the Río Negro and Neuquén Valley, Argentina. Diapausing field-collected populations showed resistance ratios at the LC(50) that were 0.7-8.7 times higher than that of the susceptible strain. Mean esterase (EST) and cytochrome P450 monooxygenase activities (expressed as α-N min(-1) mg(-1) prot(-1) and pg 7-OHC insect(-1) min(-1) respectively) were significantly correlated with LD(50) values from the field-collected populations. In addition, azinphos-methyl response was associated with the geographic area where the insect population was collected: populations from isolated and more recent productive areas presented significantly lower resistance ratios in comparison with populations from older and more intensive productive areas. The populations assayed presented different resistance levels to azinphos-methyl. The response was highly correlated with the orchard's geographic location. EST and ECOD activities were involved in azinphos-methyl response in the given region. Copyright © 2012 Society of Chemical Industry.

  18. Variability of Selected Traits of Ips Typographus (L. (Col.: Scolytinae Populations In Beskid Żwiecki (Western Carpathians, Poland Region Affected By Bark Beetle Outbreak

    Directory of Open Access Journals (Sweden)

    Grodzki Wojciech

    2014-06-01

    Full Text Available In 2010-2012, investigations on Ips typographus populations were carried out in Norway spruce stands recently affected by bark beetle outbreak in the Beskid Żywiecki Mts. in Poland. The aim of the study was to test the usefulness of several traits describing I. typographus populations for evaluation of their actual outbreak tendency. Infestation density, sex ratio, gallery length, progeny number and beetle length were used as the traits. Trait variability was analyzed in relation to infested tree mortality in the current year of observation and outbreak tendency defined by the comparison of data on tree mortality in the current year and that in the year before.

  19. Variability and connectivity of plaice populations from the Eastern North Sea to the Baltic Sea, part II. Biological evidence of population mixing

    Science.gov (United States)

    Ulrich, Clara; Hemmer-Hansen, Jakob; Boje, Jesper; Christensen, Asbjørn; Hüssy, Karin; Sun, Hailu; Clausen, Lotte Worsøe

    2017-02-01

    A multi-disciplinary study was conducted to clarify stock identity and connectivity patterns in the populations of European plaice (Pleuronectes platessa) in the Skagerrak-Kattegat transition area between the Eastern North Sea and the Baltic Sea. Five independent biological studies were carried out in parallel. Genetic markers suggested the existence of different genetic populations in the transition area. Growth backcalculation with otoliths resulted in significant although limited differences in growth rates between North Sea and Skagerrak, indicating weak differentiation or important mixing. Hydrogeographical drift modelling suggested that some North Sea juveniles could settle along the coast line of the Skagerrak and the Kattegat. Tagging data suggested that both juveniles and adult fish from the North Sea perform feeding migrations into Skagerrak in summer/autumn. Finally, survey data suggested that Skagerrak also belongs to the area distribution of North Sea plaice. The outcomes of the individual studies were then combined into an overall synthesis. The existence of some resident components was evidenced, but it was also demonstrated that North Sea plaice migrate for feeding into Skagerrak and might constitute a large share of the catches in this area. The mixing of different populations within a management area has implications for stock assessment and management. Choice must be made to either lump or split the populations, and the feasibility and constraints of both options are discussed. The outcomes of this work have directly influenced the management decisions in 2015.

  20. Association of Lutzomyia longipalpis (Diptera: Psychodidae) population density with climate variables in Montes Claros, an area of American visceral leishmaniasis transmission in the state of Minas Gerais, Brazil.

    Science.gov (United States)

    Michalsky, Erika Monteiro; Fortes-Dias, Consuelo Latorre; França-Silva, João Carlos; Rocha, Marilia Fonseca; Barata, Ricardo Andrade; Dias, Edelberto Santos

    2009-12-01

    In the present paper, we evaluate the relationship between climate variables and population density of Lutzomyia longipalpis in Montes Claros, an area of active transmission of American visceral leishmaniasis (AVL) in Brazil. Entomological captures were performed in 10 selected districts of the city, between September 2002-August 2003. A total of 773 specimens of L. longipalpiswere captured in the period and the population density could be associated with local climate variables (cumulative rainfall, average temperature and relative humidity) through a mathematical linear model with a determination coefficient (Rsqr) of 0.752. Although based on an oversimplified statistical analysis, as far as the vector is concerned, this approach showed to be potentially useful as a starting point to guide control measures for AVL in Montes Claros.

  1. Association of Lutzomyia longipalpis (Diptera: Psychodidae population density with climate variables in Montes Claros, an area of American visceral leishmaniasis transmission in the state of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Érika Monteiro Michalsky

    2009-12-01

    Full Text Available In the present paper, we evaluate the relationship between climate variables and population density of Lutzomyia longipalpis in Montes Claros, an area of active transmission of American visceral leishmaniasis (AVL in Brazil. Entomological captures were performed in 10 selected districts of the city, between September 2002-August 2003. A total of 773 specimens of L. longipalpiswere captured in the period and the population density could be associated with local climate variables (cumulative rainfall, average temperature and relative humidity through a mathematical linear model with a determination coefficient (Rsqr of 0.752. Although based on an oversimplified statistical analysis, as far as the vector is concerned, this approach showed to be potentially useful as a starting point to guide control measures for AVL in Montes Claros.

  2. Population Genetic Structure and Life History Variability in Oncorhynchus Nerka from the Snake River Basin, 1991-1993 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Waples, Robin S.; Aebersold, Paul B.; Winans, Gary A. (Northwest and Alaska Fisheries Science Center, Coastal Zone and Estuarine Studies Division, Seattle, WA)

    1997-05-01

    A detailed examination of O. nerka from lakes in the Sawtooth Valley of Idaho was undertaken to help guide recovery planning for the endangered Redfish Lake population and to help resolve relationships between resident and anadromous forms.

  3. Genetic Variability and Population Structure of the Potential Bioenergy Crop Miscanthus sinensis (Poaceae in Southwest China Based on SRAP Markers

    Directory of Open Access Journals (Sweden)

    Gang Nie

    2014-08-01

    Full Text Available The genus Miscanthus has great potential as a biofuel feedstock because of its high biomass, good burning quality, environmental tolerance, and good adaptability to marginal land. In this study, the genetic diversity and the relationship of 24 different natural Miscanthus sinensis populations collected from Southwestern China were analyzed by using 33 pairs of Sequence Related Amplified Polymorphism (SRAP primers. A total of 688 bands were detected with 646 polymorphic bands, an average of 19.58 polymorphic bands per primer pair. The average percentage of polymorphic loci (P, gene diversity (H, and Shannon’s diversity index (I among the 24 populations are 70.59%, 0.2589, and 0.3836, respectively. The mean value of total gene diversity (HT was 0.3373 ± 0.0221, while the allelic diversity within populations (HS was 0.2589 ± 0.0136 and the allelic diversity among populations (DST was 0.0784. The mean genetic differentiation coefficient (Gst = 0.2326 estimated from the detected 688 loci indicated that there was 76.74% genetic differentiation within the populations, which is consistent with the results from Analysis of Molecular Variance (AMOVA analysis. Based upon population structure and phylogenetic analysis, five groups were formed and a special population with mixed ancestry was inferred indicating that human-mediated dispersal may have had a significant effect on population structure of M. sinensis. Evaluating the genetic structure and genetic diversity at morphological and molecular levels of the wild M. sinensis in Southwest China is critical to further utilize the wild M. sinensis germplasm in the breeding program. The results in this study will facilitate the biofuel feedstock breeding program and germplasm conservation.

  4. Brief communication genotyping of Burkholderia pseudomallei revealed high genetic variability among isolates from a single population group

    OpenAIRE

    Zueter, Abdelrahman Mohammad; Rahman, Zaidah Abdul; Yean, Chan Yean; Harun, Azian

    2015-01-01

    Burkholderia pseudomallei is a soil dwelling Gram-negative bacteria predominates in Southeast Asia zone and the tropical part of Australia. Genetic diversity has been explored among various populations and environments worldwide. To date, little data is available on MLST profiling of clinical B. pseudomallei isolates in peninsular Malaysia. In this brief report, thirteen culture positive B. pseudomallei cases collected from a single population of Terengganu state in the Western Peninsular Mal...

  5. Investigating the effect of recruitment variability on length-based recruitment indices for antarctic krill using an individual-based population dynamics model.

    Directory of Open Access Journals (Sweden)

    Stéphane Thanassekos

    Full Text Available Antarctic krill (Euphausia superba; herein krill is monitored as part of an on-going fisheries observer program that collects length-frequency data. A krill feedback management programme is currently being developed, and as part of this development, the utility of data-derived indices describing population level processes is being assessed. To date, however, little work has been carried out on the selection of optimum recruitment indices and it has not been possible to assess the performance of length-based recruitment indices across a range of recruitment variability. Neither has there been an assessment of uncertainty in the relationship between an index and the actual level of recruitment. Thus, until now, it has not been possible to take into account recruitment index uncertainty in krill stock management or when investigating relationships between recruitment and environmental drivers. Using length-frequency samples from a simulated population - where recruitment is known - the performance of six potential length-based recruitment indices is assessed, by exploring the index-to-recruitment relationship under increasing levels of recruitment variability (from ±10% to ±100% around a mean annual recruitment. The annual minimum of the proportion of individuals smaller than 40 mm (F40 min, % was selected because it had the most robust index-to-recruitment relationship across differing levels of recruitment variability. The relationship was curvilinear and best described by a power law. Model uncertainty was described using the 95% prediction intervals, which were used to calculate coverage probabilities and assess model performance. Despite being the optimum recruitment index, the performance of F40 min degraded under high (>50% recruitment variability. Due to the persistence of cohorts in the population over several years, the inclusion of F40 min values from preceding years in the relationship used to estimate recruitment in a given year

  6. Evaluating within-population variability in behavior and demography for the adaptive potential of a dispersal-limited species to climate change

    Science.gov (United States)

    Muñoz, David J.; Miller Hesed, Kyle; Grant, Evan H. Campbell; Miller, David A.W.

    2016-01-01

    Multiple pathways exist for species to respond to changing climates. However, responses of dispersal-limited species will be more strongly tied to ability to adapt within existing populations as rates of environmental change will likely exceed movement rates. Here, we assess adaptive capacity in Plethodon cinereus, a dispersal-limited woodland salamander. We quantify plasticity in behavior and variation in demography to observed variation in environmental variables over a 5-year period. We found strong evidence that temperature and rainfall influence P. cinereus surface presence, indicating changes in climate are likely to affect seasonal activity patterns. We also found that warmer summer temperatures reduced individual growth rates into the autumn, which is likely to have negative demographic consequences. Reduced growth rates may delay reproductive maturity and lead to reductions in size-specific fecundity, potentially reducing population-level persistence. To better understand within-population variability in responses, we examined differences between two common color morphs. Previous evidence suggests that the color polymorphism may be linked to physiological differences in heat and moisture tolerance. We found only moderate support for morph-specific differences for the relationship between individual growth and temperature. Measuring environmental sensitivity to climatic variability is the first step in predicting species' responses to climate change. Our results suggest phenological shifts and changes in growth rates are likely responses under scenarios where further warming occurs, and we discuss possible adaptive strategies for resulting selective pressures.

  7. Chemical Composition of Juniperus communis L. Cone Essential Oil and Its Variability among Wild Populations in Kosovo.

    Science.gov (United States)

    Hajdari, Avni; Mustafa, Behxhet; Nebija, Dashnor; Miftari, Elheme; Quave, Cassandra L; Novak, Johannes

    2015-11-01

    Ripe cones of Juniperus communis L. (Cupressaceae) were collected from five wild populations in Kosovo, with the aim of investigating the chemical composition and natural variation of essential oils between and within wild populations. Ripe cones were collected, air dried, crushed, and the essential oils obtained by hydrodistillation. The essential-oil constituents were identified by GC-FID and GC/MS analyses. The yield of essential oil differed depending on the population origins and ranged from 0.4 to 3.8% (v/w, based on the dry weight). In total, 42 compounds were identified in the essential oils of all populations. The principal components of the cone-essential oils were α-pinene, followed by β-myrcene, sabinene, and D-limonene. Taking into consideration the yield and chemical composition, the essential oil originating from various collection sites in Kosovo fulfilled the minimum requirements for J. communis essential oils of the European Pharmacopoeia. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to determine the influence of the geographical variations on the essential-oil composition. These statistical analyses suggested that the clustering of populations was not related to their geographic location, but rather appeared to be linked to local selective forces acting on the chemotype diversity. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

  8. The effects of six antipsychotic agents on QTc--an attempt to mimic clinical trial through simulation including variability in the population.

    Science.gov (United States)

    Glinka, Anna; Polak, Sebastian

    2014-04-01

    Many drugs (belonging to different chemical groups) have the potential for QT interval prolongation associated with ionic channel blockade in the cardiomyocyte membrane. Due to the fact that this phenomenon is linked to a higher risk of TdP, the ability to predict its scale is one of the most important outcomes of cardiotoxicity assessment of new agents. With use of the Cardiac Safety Simulator (CSS), the effect of six antipsychotic drugs was predicted in silico. Separate simulations were carried out for each studied population taking the drug. The aim of this study was to predict both the mean values of delta QTc and the results range. To be able to observe individual variability after drug administration, each patient was randomly assigned to the individual drug concentration. Also, appropriate diversity in heart rate, plasma electrolytes concentrations, morphometric parameters of ventricular myocytes, and one common hERG polymorphism frequency in population were added. Analyzing the results of simulation with Student's t-test, in five of six cases, there were no statistically significant differences between observed and predicted mean values. The diversity of results in all populations studied, however, was not fully reconstructed. The model was able to accurately reproduce the average effect of the drug on the length when the phenomenon is associated purely with blocking of ionic channels. Nevertheless, the problem of variability in the population and its effect on the QT interval requires further study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Cardiovascular disease, risk factors and heart rate variability in the elderly general population: Design and objectives of the CARdiovascular disease, Living and Ageing in Halle (CARLA Study

    Directory of Open Access Journals (Sweden)

    Kuss Oliver

    2005-11-01

    Full Text Available Abstract Background The increasing burden of cardiovascular diseases (CVD in the ageing population of industrialized nations requires an intensive search for means of reducing this epidemic. In order to improve prevention, detection, therapy and prognosis of cardiovascular diseases on the population level in Eastern Germany, it is necessary to examine reasons for the East-West gradient of CVD morbidity and mortality, potential causal mechanisms and prognostic factors in the elderly. Psychosocial and nutritional factors have previously been discussed as possible causes for the unexplained part of the East-West gradient. A reduced heart rate variability appears to be associated with cardiovascular disease as well as with psychosocial and other cardiovascular risk factors and decreases with age. Nevertheless, there is a lack of population-based data to examine the role of heart rate variability and its interaction with psychosocial and nutritional factors regarding the effect on cardiovascular disease in the ageing population. There also is a paucity of epidemiological data describing the health situation in Eastern Germany. Therefore, we conduct a population-based study to examine the distribution of CVD, heart rate variability and CVD risk factors and their associations in an elderly East German population. This paper describes the design and objectives of the CARLA Study. Methods/design For this study, a random sample of 45–80 year-old inhabitants of the city of Halle (Saale in Eastern Germany was drawn from the population registry. By the end of the baseline examination (2002–2005, 1750 study participants will have been examined. A multi-step recruitment strategy aims at achieving a 70 % response rate. Detailed information is collected on own and family medical history, socioeconomic, psychosocial, behavioural and biomedical factors. Medical examinations include anthropometric measures, blood pressure of arm and ankle, a 10-second and a 20

  10. Varying herbivore population structure correlates with lack of local adaptation in a geographic variable plant-herbivore interaction.

    Directory of Open Access Journals (Sweden)

    Rodrigo Cogni

    Full Text Available Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid moth Utetheisa ornatrix to its host plant, the pyrrolizidine alkaloid-bearing legume Crotalaria pallida, at the continental scale, but found no differentiation at the regional scale. In the present study, we sampled the same sites to investigate factors that may contribute to the lack of differentiation at the regional scale. We performed field observations that show that specialist and non-specialist polyphagous herbivore incidence varies among populations at both scales. With a series of common-garden experiments we show that some plant traits that may affect herbivory (pyrrolizidine alkaloids and extrafloral nectaries vary at the regional scale, while other traits (trichomes and nitrogen content just vary at the continental scale. These results, combined with our previous evidence for plant population differentiation based on larval performance on fresh fruits, suggest that U. ornatrix is subjected to divergent selection even at the regional scale. Finally, with a microsatellite study we investigated population structure of U. ornatrix. We found that population structure is not stable over time: we found population differentiation at the regional scale in the first year of sampling, but not in the second year. Unstable population structure of the herbivore is the most likely cause of the lack of regional adaptation.

  11. Varying Herbivore Population Structure Correlates with Lack of Local Adaptation in a Geographic Variable Plant-Herbivore Interaction

    Science.gov (United States)

    Cogni, Rodrigo; Trigo, José R.; Futuyma, Douglas J.

    2011-01-01

    Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid moth Utetheisa ornatrix to its host plant, the pyrrolizidine alkaloid-bearing legume Crotalaria pallida, at the continental scale, but found no differentiation at the regional scale. In the present study, we sampled the same sites to investigate factors that may contribute to the lack of differentiation at the regional scale. We performed field observations that show that specialist and non-specialist polyphagous herbivore incidence varies among populations at both scales. With a series of common-garden experiments we show that some plant traits that may affect herbivory (pyrrolizidine alkaloids and extrafloral nectaries) vary at the regional scale, while other traits (trichomes and nitrogen content) just vary at the continental scale. These results, combined with our previous evidence for plant population differentiation based on larval performance on fresh fruits, suggest that U. ornatrix is subjected to divergent selection even at the regional scale. Finally, with a microsatellite study we investigated population structure of U. ornatrix. We found that population structure is not stable over time: we found population differentiation at the regional scale in the first year of sampling, but not in the second year. Unstable population structure of the herbivore is the most likely cause of the lack of regional adaptation. PMID:22220208

  12. Variability in body mass and sexual dimorphism in Danish red foxes (Vulpes vulpes) in relation to population density

    DEFF Research Database (Denmark)

    Pagh, Sussie; Hansen, Mette Sif; Jensen, Birger

    2018-01-01

    /2016. During the first and the third periods, the fox population was below the carrying capacity due to hunting pressure and canine distemper, respectively. Adult males were significantly (p density, i.e. 1965......–1977 and compared to 2015/2016, compared to 2012–2014, when population density was high (the mean weight: 6.8 kg). However, no significant differences were found in the weight of females. Hence, sexual dimorphism ranged from 7.6 to 3.6 in adult foxes in low and high-density periods, respectively. During the winters...

  13. Leptin and variables of body adiposity, energy balance, and insulin resistance in a population-based study. The Hoorn Study

    NARCIS (Netherlands)

    Ruige, J B; Dekker, J M; Blum, W F; Stehouwer, C D; Nijpels, G; Mooy, J; Kostense, P J; Bouter, L M; Heine, R J

    OBJECTIVE: Leptin is thought to play a key role in the control of body weight. There is a complex interrelationship between leptin and insulin or insulin resistance, but it is unknown how leptin is regulated. We therefore explored, in a large population-based study of 2,484 Caucasian subjects aged

  14. Measuring local genetic variability in populations of codling moth (Lepidoptera: Tortricidae) across an unmanaged / commercial orchard interface

    Science.gov (United States)

    The genetic structure of adult codling moth Cydia pomonella L., populations was characterized both inside a managed apple, Malus domestica Borkdhausen, orchard and in surrounding unmanaged hosts and non-host trees in central Chile during 2006-2007. Adult males were collected using an array of sex ph...

  15. T-cell receptor variable alpha (TCRAV) polymorphisms in European, Chinese, South American, AfroCaribbean, and Gambian populations.

    Science.gov (United States)

    Ibberson, M R; Copier, J P; Llop, E; Navarrete, C; Hill, A V; Cruickshank, J K; So, A K

    1998-01-01

    Interactions involving the T-cell receptor (TCR) and major histocompatibility complex (MHC) are fundamental to the generation of a specific immune response. The study of interpopulation differences in TCR genes may identify those genes which are subject to selection, and also provides useful information for future genetic studies in these populations. In this study we present analysis of five TCRAV polymorphisms, for V5S1, V6S1, V8S1, V17S1, and V21S1 loci in five human populations by single-strand conformational polymorphism (SSCP) analysis. Caucasian, Chinese, Gambian, AfroCaribbean, and South American Indians (Mapuches) showed marked interpopulation variation for both the silent (V5S1, V17S1, and V21S1) and coding (V6S1 and V8S1) polymorphisms. In general the alleles were conserved in the different populations, but new, additional variants were found for V5S1 and V17S1 in Gambians and Caucasians. V6S1 overall showed the highest nucleotide diversity, and V6S1 genotype distributions were skewed away from expected values in Chinese and Mapuches. Analysis of allelic associations showed a general lack of linkage disequilibrium between the loci, which was reflected by the absence of strong population-specific haplotypes.

  16. Edaphic history over seedling characters predicts integration and plasticity of integration across geologically variable populations of Arabidopsis thaliana.

    Science.gov (United States)

    Cousins, Elsa A; Murren, Courtney J

    2017-12-01

    Studies on phenotypic plasticity and plasticity of integration have uncovered functionally linked modules of aboveground traits and seedlings of Arabidopsis thaliana , but we lack details about belowground variation in adult plants. Functional modules can be comprised of additional suites of traits that respond to environmental variation. We assessed whether shoot and root responses to nutrient environments in adult A. thaliana were predictable from seedling traits or population-specific geologic soil characteristics at the site of origin. We compared 17 natural accessions from across the native range of A. thaliana using 14-day-old seedlings grown on agar or sand and plants grown to maturity across nutrient treatments in sand. We measured aboveground size, reproduction, timing traits, root length, and root diameter. Edaphic characteristics were obtained from a global-scale dataset and related to field data. We detected significant among-population variation in root traits of seedlings and adults and in plasticity in aboveground and belowground traits of adult plants. Phenotypic integration of roots and shoots varied by population and environment. Relative integration was greater in roots than in shoots, and integration was predicted by edaphic soil history, particularly organic carbon content, whereas seedling traits did not predict later ontogenetic stages. Soil environment of origin has significant effects on phenotypic plasticity in response to nutrients, and on phenotypic integration of root modules and shoot modules. Root traits varied among populations in reproductively mature individuals, indicating potential for adaptive and integrated functional responses of root systems in annuals. © 2017 Botanical Society of America.

  17. Paleoecological studies on variability in marine fish populations: A long-term perspective on the impacts of climatic change on marine ecosystems

    Science.gov (United States)

    Finney, Bruce P.; Alheit, Jürgen; Emeis, Kay-Christian; Field, David B.; Gutiérrez, Dimitri; Struck, Ulrich

    2010-02-01

    The use of historical fishing records to understand relationships between climatic change and fish abundance is limited by the relatively short duration of these records, and complications due to the strong influence of human activity in addition to climatic change. Sedimentary records containing scales, bones or geochemical proxies of variability in fish populations provide unique insights on long-term ecosystem dynamics and relationships with climatic change. Available records from Holocene sediments are summarized and synthesized. The records are from several widespread locations near or along the continental margins of the South Atlantic and Pacific oceans, including Alaska, USA (Pacific salmon), Saanich and Effingham Inlets, British Columbia, Canada (pelagic fish), Santa Barbara Basin, California, USA (Northern anchovies and Pacific sardines), Gulf of California, Mexico (Pacific sardines, Northern anchovies and Pacific hake), Peru upwelling system (sardines, anchovies and hake), and Benguela Current System, South Africa (sardines, anchovies and hake). These records demonstrate that fish population sizes are not constant, and varied significantly over a range of time scales prior to the advent of large-scale commercial fishing. In addition to the decadal-scale variability commonly observed in historical records, the long-term records reveal substantial variability over centennial and millennial time scales. Shifts in abundance are often, but not always, correlated with regional and/or global climatic changes. The long-term perspective reveals different patterns of variability in fish populations, as well as fish-climate relationships, than suggested by analysis of historical records. Many records suggest prominent changes in fish abundance at ca. 1000-1200 AD, during the Little Ice Age, and during the transition at the end of the Little Ice Age in the 19th century that may be correlative, and that were likely driven by major hemispheric or global

  18. The X-Ray Binary Population of the Nearby Dwarf Starburst Galaxy IC 10: Variable and Transient X-Ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Laycock, Silas; Cappallo, Rigel [Department of Physics and Applied Physics, University of Massachusetts Lowell, MA, 01854 (United States); Williams, Benjamin F.; Binder, Breanna [University of Washington, Department of Astronomy, Box 351580, Seattle, WA 98195 (United States); Prestwich, Andrea [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, 02138 (United States); Christodoulou, Dimitris M. [Department of Mathematical Sciences, University of Massachusetts Lowell, MA, 01854 (United States)

    2017-02-10

    We have monitored the Cassiopeia dwarf galaxy (IC 10) in a series of 10 Chandra ACIS-S observations to capture its variable and transient X-ray source population, which is expected to be dominated by High Mass X-ray Binaries (HMXBs). We present a sample of 21 X-ray sources that are variable between observations at the 3 σ level, from a catalog of 110 unique point sources. We find four transients (flux variability ratio greater than 10) and a further eight objects with ratios >5. The observations span the years 2003–2010 and reach a limiting luminosity of >10{sup 35} erg s{sup −1}, providing sensitivity to X-ray binaries in IC 10 as well as flare stars in the foreground Milky Way. The nature of the variable sources is investigated from light curves, X-ray spectra, energy quantiles, and optical counterparts. The purpose of this study is to discover the composition of the X-ray binary population in a young starburst environment. IC 10 provides a sharp contrast in stellar population age (<10 My) when compared to the Magellanic Clouds (40–200 My) where most of the known HMXBs reside. We find 10 strong HMXB candidates, 2 probable background Active Galactic Nuclei, 4 foreground flare-stars or active binaries, and 5 not yet classifiable sources. Complete classification of the sample requires optical spectroscopy for radial velocity analysis and deeper X-ray observations to obtain higher S/N spectra and search for pulsations. A catalog and supporting data set are provided.

  19. Assessment on induced genetic variability and divergence in the mutagenized lentil populations of microsperma and macrosperma cultivars developed using physical and chemical mutagenesis.

    Directory of Open Access Journals (Sweden)

    Rafiul Amin Laskar

    Full Text Available Induced mutagenesis was employed to create genetic variation in the lentil cultivars for yield improvement. The assessments were made on genetic variability, character association, and genetic divergence among the twelve mutagenized populations and one parent population of each of the two lentil cultivars, developed by single and combination treatments with gamma rays and hydrazine hydrates. Analysis of variance revealed significant inter-population differences for the observed quantitative phenotypic traits. The sample mean of six treatment populations in each of the cultivar exhibited highly superior quantitative phenotypic traits compared to their parent cultivars. The higher values of heritability and genetic advance with a high genotypic coefficient of variation for most of the yield attributing traits confirmed the possibilities of lentil yield improvement through phenotypic selection. The number of pods and seeds per plant appeared to be priority traits in selection for higher yield due to their strong direct association with yield. The cluster analysis divided the total populations into three divergent groups in each lentil cultivar with parent genotypes in an independent group showing the high efficacy of the mutagens. Considering the highest contribution of yield trait to the genetic divergence among the clustered population, it was confirmed that the mutagenic treatments created a wide heritable variation for the trait in the mutant populations. The selection of high yielding mutants from the mutant populations of DPL 62 (100 Gy and Pant L 406 (100Gy + 0.1% HZ in the subsequent generation is expected to give elite lentil cultivars. Also, hybridization between members of the divergent group would produce diverse segregants for crop improvement. Apart from this, the induced mutations at loci controlling economically important traits in the selected high yielding mutants have successfully contributed in diversifying the accessible lentil

  20. Wearing the T-shirt: an exploration of the ideological underpinnings ...

    African Journals Online (AJOL)

    Wearing the T-shirt: an exploration of the ideological underpinnings of visual representations of the African body with HIV or AIDS. ... currency in relation to colonialism; 2) A matter of mor(t)ality examines the relationship between morality and the mortality of the African body; 3) The legacies endure analyses selected images ...

  1. Implementing AAC with Children with Profound and Multiple Learning Disabilities: A Study in Rationale Underpinning Intervention

    Science.gov (United States)

    Harding, Celia; Lindsay, Gemma; O'Brien, Aoife; Dipper, Lucy; Wright, Julie

    2011-01-01

    There is a developing research base to support the rationale underpinning augmentative and alternative communication (AAC) for people with learning disabilities. However, there is a paucity of research examining the process involved in implementing AAC support for people who have profound disabilities. This paper seeks to explore the processes…

  2. Perceived Sacrifice and Few Alternatives Commitments: The Motivational Underpinnings of Continuance Commitment's Subdimensions

    Science.gov (United States)

    Vandenberghe, Christian; Panaccio, Alexandra

    2012-01-01

    Using work on self-concepts and Conservation of Resources theory, the present research examined the motivational underpinnings of continuance commitment's subcomponents of perceived sacrifice and few alternatives. Study 1 (N=208) found job scope to be positively related to perceived sacrifice commitment, and negatively related to few alternatives…

  3. Cognitive Underpinnings of Moral Reasoning in Adolescence: The Contribution of Executive Functions

    Science.gov (United States)

    Vera-Estay, E.; Dooley, J. J.; Beauchamp, M. H.

    2015-01-01

    Adolescence is a developmental period characterized by intense changes, which impact the interaction between individuals and their environments. Moral reasoning (MR) is an important skill during adolescence because it guides social decisions between right and wrong. Identifying the cognitive underpinnings of MR is essential to understanding the…

  4. The Impact of Different Habitat Conditions on the Variability of Wild Populations of a Medicinal Plant Betonica officinalis L.

    Directory of Open Access Journals (Sweden)

    Kinga Kostrakiewicz-Gierałt

    2015-06-01

    Full Text Available Plants are important source of beneficial bioactive compounds which may find various applications as functional ingredients, such as components of food supplements, cosmetics, and pharmaceuticals. One such medicinal plant is Betonica officinalis, populations of which were investigated in 2012‒13. The studies were conducted in patches of Molinietum caeruleae dominated by: small meadow taxa (patch I; the shrub willow Salix repens ssp. rosmarinifolia (patch II; large tussock grasses Deschampsia caespitosa and Molinia caerulaea (patch III; tall-growing macroforbs Filipendula ulmaria and Solidago canadensis (patch IV. Over successive patches, the average height of plant cover increased, as did soil moisture, while light availability at ground level decreased. Much greater abundance and density of the Betonica officinalis population were found in patches I, III and IV, while lower values for these parameters were noted in patch II. Individuals in pre-reproductive stages were absent during whole study period in all study plots, vegetative ramet clusters were observed in plots situated in patches I and III in the first year of observations, while only generative ramet clusters occurred in plots set in patches II and IV. The number of rosettes per ramet cluster, number and dimensions of rosette leaves, height of flowering stems, number of cauline leaves, length of inflorescences, as well as number and length of flowers increased gradually over successive patches, whereas the number of generative stems per ramet cluster did not differ remarkably among populations. On the basis of the performed studies it might be concluded that the condition of populations deteriorated from patches overgrown by large-tussock grasses and characterized by considerable share of native and alien tall-growing macroforbs, via patch dominated by small meadow taxa, to patch prevailed by shrub willows.

  5. Intraspecific niche models for ponderosa pine (Pinus ponderosa) suggest potential variability in population-level response to climate change

    Science.gov (United States)

    Maguire, Kaitlin C.; Shinneman, Douglas; Potter, Kevin M.; Hipkins, Valerie D.

    2018-01-01

    Unique responses to climate change can occur across intraspecific levels, resulting in individualistic adaptation or movement patterns among populations within a given species. Thus, the need to model potential responses among genetically distinct populations within a species is increasingly recognized. However, predictive models of future distributions are regularly fit at the species level, often because intraspecific variation is unknown or is identified only within limited sample locations. In this study, we considered the role of intraspecific variation to shape the geographic distribution of ponderosa pine (Pinus ponderosa), an ecologically and economically important tree species in North America. Morphological and genetic variation across the distribution of ponderosa pine suggest the need to model intraspecific populations: the two varieties (var. ponderosa and var. scopulorum) and several haplotype groups within each variety have been shown to occupy unique climatic niches, suggesting populations have distinct evolutionary lineages adapted to different environmental conditions. We utilized a recently-available, geographically-widespread dataset of intraspecific variation (haplotypes) for ponderosa pine and a recently-devised lineage distance modeling approach to derive additional, likely intraspecific occurrence locations. We confirmed the relative uniqueness of each haplotype-climate relationship using a niche-overlap analysis, and developed ecological niche models (ENMs) to project the distribution for two varieties and eight haplotypes under future climate forecasts. Future projections of haplotype niche distributions generally revealed greater potential range loss than predicted for the varieties. This difference may reflect intraspecific responses of distinct evolutionary lineages. However, directional trends are generally consistent across intraspecific levels, and include a loss of distributional area and an upward shift in elevation. Our results

  6. Genetic Diversity and Structure of Populations of Annona crassiflora Mart. of Brazilian Savanna and Its Association with Chemical Variability.

    Science.gov (United States)

    Egydio-Brandão, Anary Priscila Monteiro; Furlan, Claudia Maria; Dos Santos, Déborah Yara Alves Cursino

    2016-08-01

    Annona crassiflora Mart. is a native tree from Brazilian savanna. Isoquinoline alkaloids are characteristic of species of Annonaceae. This work aimed to assess the magnitude of genetic diversity among different populations of A. crassiflora using AFLP markers, and verify the existence of any correlation between the AFLP data and previous reported alkaloid composition. A. crassiflora from eight populations in the states of São Paulo, Goiás, Minas Gerais, and Distrito Federal were analyzed. The data suggest a low, moderate, and high level of genetic diversity from different populations of A. crassiflora. Concentration of alkaloids was significantly correlated with AFLP data, suggesting interaction between chemical and molecular markers in A. crassiflora. The data of association between the chemical and genetic differentiation of A. crassiflora may be useful to establish cultivation areas allowing the definition of strategies to preserve their genetic diversity with an interest in specific chemotypes for genetic improvement programs focused on sustainable utilization of this specie. © 2016 Wiley-VHCA AG, Zürich.

  7. Variability of kokanee and rainbow trout food habits, distribution, and population dynamics, in an ultraoligotrophic lake with no manipulative management

    Science.gov (United States)

    Buktenica, M.W.; Girdner, S.F.; Larson, G.L.; McIntire, C.D.

    2007-01-01

    Crater Lake is a unique environment to evaluate the ecology of introduced kokanee and rainbow trout because of its otherwise pristine state, low productivity, absence of manipulative management, and lack of lotic systems for fish spawning. Between 1986 and 2004, kokanee displayed a great deal of variation in population demographics with a pattern that reoccurred in about 10 years. We believe that the reoccurring pattern resulted from density dependent growth, and associated changes in reproduction and abundance, driven by prey resource limitation that resulted from low lake productivity exacerbated by prey consumption when kokanee were abundant. Kokanee fed primarily on small-bodied prey from the mid-water column; whereas rainbow trout fed on large-bodied prey from the benthos and lake surface. Cladoceran zooplankton abundance may be regulated by kokanee. And kokanee growth and reproductive success may be influenced by the availability of Daphnia pulicaria, which was absent in zooplankton samples collected annually from 1990 to 1995, and after 1999. Distribution and diel migration of kokanee varied over the duration of the study and appeared to be most closely associated with prey availability, maximization of bioenergetic efficiency, and fish density. Rainbow trout were less abundant than were kokanee and exhibited less variation in population demographics, distribution, and food habits. There is some evidence that the population dynamics of rainbow trout were in-part related to the availability of kokanee as prey. ?? 2007 Springer Science+Business Media B.V.

  8. Mitochondrial DNA variability and development of a PCR diagnostic test for populations of the whitefly Bemisia afer (Priesner and Hosny).

    Science.gov (United States)

    Maruthi, M N; Rekha, A R; Sseruwagi, P; Hillocks, R J

    2007-01-01

    The whitefly, Bemisia afer (Hemiptera; Aleyrodidae), is emerging as a major agricultural pest. The current identification methods based on adult and pupal morphology are laborious and unreliable. A diagnostic polymerase chain reaction (PCR) protocol was developed for the first time in this study to discriminate B. afer from other whitefly species. Primers specific to mitochondrial cytochrome oxidase I gene (mtCOI) were designed to amplify a band of approx 650 bp. The PCR products were sequenced from B. afer samples collected from Malawi, Tanzania, Uganda, Zanzibar, and the United Kingdom. Phylogenetic analyses of mtCOI sequences and those of reference B. afer sequences clustered the African B. afer separately from the UK and Chinese populations and from other whitefly species. The African cluster was divided into two clades by parsimony and neighbor-joining methods. This indicates the existence of at least two genotypic clusters of B. afer, which are diverged by 0.8 to 3.2% nucleotide (nt) identities. Analysis of molecular variance indicated that these differences were the result of within population variation but were insufficient to identify discrete populations. Among the whitefly species used in the analysis, B. afer was equally dissimilar to Bemisia tabaci and Bemisia tuberculata (21.3-26.2% nt identities). As is the case for B. tabaci, these data show that mtCOI sequences are informative also for identifying B. afer variants, which lack distinguishing morphological features.

  9. Systematic characterization and comparison of the CYP2C9 variability of the Orang Asli in Malaysia with 12 populations.

    Science.gov (United States)

    Teh, Lay Kek; Subramaniam, Vinothini; Tuan Abdu Aziz, Tuan Azlin; Lee, Lian Shien; Ismail, Mohamed Izwan; Yu, Choo Yee; Ang, Geik Yong; James Johari, Richard; Ismet, Rose Iszati; Sahak, Noor Saadah; Ahmad, Aminuddin; Rahman, Thuhairah Abdul; Nor Ghazali, Fadzilah Mohd; Shaari, SyahrulAzlin; Omar, Mustaffa; Ismail, Adzrool Idzwan; Md Isa, Kamarudzaman; Salleh, Hood; Salleh, Mohd Zaki

    2016-08-01

    We conducted a systematic characterization of CYP2C9 variants in 61 Orang Asli and 96 Singaporean Malays using the whole genome sequences data and compared the variants with the other 11 HapMap populations. The frequency of rs1057910 (CYP2C9*3) is the highest in the Orang Asli compared to other populations. Three alleles with clinical implication were detected in the Orang Asli while 2 were found in the Singaporean Malays. Large numbers of the Orang Asli are predicted to have reduced metabolic capacity and therefore they would require a lower dose of drugs which are metabolized by CYP2C9. They are also at increased risks of adverse effects and therapeutic failures. A large number of CYP2C9 variants in the Orang Asli were not in the Hardy Weinberg Equilibrium which could be due to small sample size or mutations that disrupt the equilibrium of allele frequencies. In conclusion, different polymorphism patterns, allele frequencies, genotype frequencies and LD blocks are observed between the Orang Asli, the Singaporean Malays and the other populations. The study provided new information on the genetic polymorphism of CYP2C9 which is important for the implementation of precision medicine for the Orang Asli. Copyright © 2016 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  10. Brief communication genotyping of Burkholderia pseudomallei revealed high genetic variability among isolates from a single population group.

    Science.gov (United States)

    Zueter, Abdelrahman Mohammad; Rahman, Zaidah Abdul; Yean, Chan Yean; Harun, Azian

    2015-01-01

    Burkholderia pseudomallei is a soil dwelling Gram-negative bacteria predominates in Southeast Asia zone and the tropical part of Australia. Genetic diversity has been explored among various populations and environments worldwide. To date, little data is available on MLST profiling of clinical B. pseudomallei isolates in peninsular Malaysia. In this brief report, thirteen culture positive B. pseudomallei cases collected from a single population of Terengganu state in the Western Peninsular Malaysia and were confirmed by In-house TTS1-PCR. Isolates were subjected for multi-locus sequence typing (MLST) to explore their genotypic diversity and to investigate for possible clonal clustering of a certain sequence type. Patient's clinical information was examined to investigate for clinical correlation among the different genotypes. In spite of small sample set, MLST results indicated predictive results; considerable genotypic diversity, predominance and novelty among B. pseudomallei collected over a single geographically-located population in Malaysia. Massive genotypic heterogeneity was observed; 8 different sequence types with predominance of sequence type 54 and discovery of two novel sequence types. However, no clear pathogenomic or organ tropism clonal relationships were predicted.

  11. Socio-environmental variables associated with malnutrition and intestinal parasitoses in the child population of Misiones, Argentina.

    Science.gov (United States)

    Zonta, María L; Oyhenart, Evelia E; Navone, Graciela T

    2014-01-01

    The aim was to analyze the socio-environmental variables associated with malnutrition and intestinal parasitoses in children from Aristóbulo del Valle, Province of Misiones (Argentina). A cross-sectional study was performed in 2,291 schoolchildren (age, 4-14 years). Body weight and height were measured and body mass index was calculated. NHANES III reference was used to estimate the nutritional status-underweight, stunting, wasting, overweight, and obesity. The parasitological analysis was performed by fecal and anal brush samples. The socio-environmental variables were surveyed using a semi-structured questionnaire. These variables were processed by categorical principal component analysis (cat-PCA). The two first axes defined four subgroups of schoolchildren: three of these were associated with urban characteristics (high, middle, and periurban), whereas the remaining subgroup was considered rural. Stunting and parasitic infections occurred mainly in the periurban group, that is the group of higher socio-environmental vulnerability. On the other hand, the highest prevalence of overweight and obesity and the lowest parasitism was observed in the high urban group. The similarity between rural and middle urban groups in stunting prevalence reveals that cities are not healthier than rural environments. On the contrary, the fact that the rural group presents the lowest prevalence of overweight reaffirms that poverty and malnutrition are progressively moving from rural to urban areas, and that rural children have still more diverse and healthy diets favored by the consumption of homemade products (i.e., orchards, animal husbandry, etc.), placing them at an earlier stage of the nutrition transition. © 2014 Wiley Periodicals, Inc.

  12. Temporal trends of selected POPs and the potential influence of climate variability in a Greenland ringed seal population.

    Science.gov (United States)

    Rigét, Frank; Vorkamp, Katrin; Hobson, Keith A; Muir, Derek C G; Dietz, Rune

    2013-09-01

    Temporal trends of selected POPs (PCB-52 and 153, p,p'-DDE, HCB, α- and β-HCH) in blubber of ringed seals (Pusa hispida) collected from the early 1990s to 2010 from central West Greenland were studied. In this period, the climate of Greenland warmed and the influences of climate indices such as winter sea-ice coverage (November-May), the number of sea-ice days during winter in Disko Bay, water temperature and salinity at Fyllas Banke during the preceding summer and the Arctic Oscillation Index (AOI) during the preceding winter on concentrations of selected POPs were evaluated using multiple regressions and an information-theoretic approach. Biological co-variables such as age, sex and trophic position (as determined by δ(15)N analysis) of seals were also evaluated. Decreasing levels of the selected POPs were found in all cases and with the highest rate for α-HCH (-10.5% annually) and the lowest rate for β-HCH (-1.9% annually). Sex and age were found to have strong predictive power in the case of PCB-52 and trophic position in the case of p,p'-DDE. Among the climate indices the strongest predictive power was found for the number of sea-ice days in the case of PCB-52, the AOI winter index in the case of α-HCH and salinity at Fyllas Banke during the preceding summer in the case of β-HCH. The present study documents the need for including both biological variables and climate variability parameters in temporal trend studies of POPs in Arctic biota.

  13. Exploring the links between population dynamics of total and active bacteria and the variables influencing a full-scale membrane bioreactor (MBR).

    Science.gov (United States)

    Gómez-Silván, C; Arévalo, J; González-López, J; Rodelas, B

    2014-06-01

    Long-term dynamics of total and active bacterial populations in a full-scale membrane bioreactor (MBR) treating urban wastewater were monitored during nine months by temperature-gradient gel electrophoresis (TGGE) of partial 16S-rRNA genes, amplified from community DNA and RNA templates. The bacterial community, dominated by Alphaproteobacteria, displayed the required characteristics for a successful and steady contaminant removal under real operating conditions. The evolution of population dynamics showed that a fully-stable microbial community was not developed even after technical stabilization and steady performance of the MBR were achieved. Non-metric multidimensional scaling and BIO-ENV demonstrated that the trends of the populations were often mostly explained by temperature, followed by the concentration of volatile suspended solids and C/N ratio of the influent. These variables were mainly responsible for triggering the shifts between functionally redundant populations. These conclusions contribute to the prediction of the complex profiles of adaptation and response of bacterial populations under changing conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Genetic Variability of the Grey Wolf Canis lupus in the Caucasus in Comparison with Europe and the Middle East: Distinct or Intermediary Population?

    Science.gov (United States)

    Pilot, Małgorzata; Dąbrowski, Michał J.; Hayrapetyan, Vahram; Yavruyan, Eduard G.; Kopaliani, Natia; Tsingarska, Elena; Bujalska, Barbara; Kamiński, Stanisław; Bogdanowicz, Wiesław

    2014-01-01

    Despite continuous historical distribution of the grey wolf (Canis lupus) throughout Eurasia, the species displays considerable morphological differentiation that resulted in delimitation of a number of subspecies. However, these morphological discontinuities are not always consistent with patterns of genetic differentiation. Here we assess genetic distinctiveness of grey wolves from the Caucasus (a region at the border between Europe and West Asia) that have been classified as a distinct subspecies C. l. cubanensis. We analysed their genetic variability based on mtDNA control region, microsatellite loci and genome-wide SNP genotypes (obtained for a subset of the samples), and found similar or higher levels of genetic diversity at all these types of loci as compared with other Eurasian populations. Although we found no evidence for a recent genetic bottleneck, genome-wide linkage disequilibrium patterns suggest a long-term demographic decline in the Caucasian population – a trend consistent with other Eurasian populations. Caucasian wolves share mtDNA haplotypes with both Eastern European and West Asian wolves, suggesting past or ongoing gene flow. Microsatellite data also suggest gene flow between the Caucasus and Eastern Europe. We found evidence for moderate admixture between the Caucasian wolves and domestic dogs, at a level comparable with other Eurasian populations. Taken together, our results show that Caucasian wolves are not genetically isolated from other Eurasian populations, share with them the same demographic trends, and are affected by similar conservation problems. PMID:24714198

  15. Morphological variability of hairs in malva alcea l. (malvaceae) populations from central and eastern europe, and consideration of the status of malva excisa rchb

    International Nuclear Information System (INIS)

    Celka, Z.; Olejnik, N.; Szkudlarz, P.; Drapikowska, M.; Jusik, S.

    2015-01-01

    Among the relics of medieval cultivation, Malva alcea L. is one of the most thoroughly studied species. In Central and Eastern Europe, a similar taxon Malva excisa Rchb. It has been recognized. The key diagnostic characters used so far to distinguish the 2 species include the depth of petal sinus and types of stem hairs. This study was aimed to analyse the variability of stem and leaf hairs and their usefulness as diagnostic characters for both taxa. The research material was collected from 19 localities in Poland, Germany, Czech Republic, Belarus and Ukraine. Several types of hairs were observed on the stems and leaves of M. alcea: single, bifurcate and stellate. Single and bifurcate hairs were found on stems and leaves of plants from all the studied populations, more frequently on the lower part of the stem, as well as on the upper (adaxial) surface of the leaf. Stellate hairs, with 3-10 branches, were observed on stems, mainly in their upper parts, and on the lower (abaxial) surface of leaves. The principal component analysis for hairs from the upper and lower part of the stem showed that individuals from most of the studied populations were clustered in one large group and only single individuals from several different populations were outside this group. Based on the graphic presentation of the Manhattan distances, calculated with the use of the Ward method, 2 groups were distinguished, but they included a mixture of individuals from various populations and geographic regions. The studied populations are not distinguishable by their key morphological characters, so all samples can be considered as M. alcea. The results of this study show that Malva alcea is a highly variable species, and its specific morphological forms are not correlated with geographical or ecological factors. There are also scientific grounds to question the distinction of M. excisa as a separate species or subspecies. (author)

  16. Intra-fraction setup variability: IR optical localization vs. X-ray imaging in a hypofractionated patient population

    Directory of Open Access Journals (Sweden)

    Piperno Gaia

    2011-04-01

    Full Text Available Abstract Background The purpose of this study is to investigate intra-fraction setup variability in hypo-fractionated cranial and body radiotherapy; this is achieved by means of integrated infrared optical localization and stereoscopic kV X-ray imaging. Method and Materials We analyzed data coming from 87 patients treated with hypo-fractionated radiotherapy at cranial and extra-cranial sites. Patient setup was realized through the ExacTrac X-ray 6D system (BrainLAB, Germany, consisting of 2 infrared TV cameras for external fiducial localization and X-ray imaging in double projection for image registration. Before irradiation, patients were pre-aligned relying on optical marker localization. Patient position was refined through the automatic matching of X-ray images to digitally reconstructed radiographs, providing 6 corrective parameters that were automatically applied using a robotic couch. Infrared patient localization and X-ray imaging were performed at the end of treatment, thus providing independent measures of intra-fraction motion. Results According to optical measurements, the size of intra-fraction motion was (median ± quartile 0.3 ± 0.3 mm, 0.6 ± 0.6 mm, 0.7 ± 0.6 mm for cranial, abdominal and lung patients, respectively. X-ray image registration estimated larger intra-fraction motion, equal to 0.9 ± 0.8 mm, 1.3 ± 1.2 mm, 1.8 ± 2.2 mm, correspondingly. Conclusion Optical tracking highlighted negligible intra-fraction motion at both cranial and extra-cranial sites. The larger motion detected by X-ray image registration showed significant inter-patient variability, in contrast to infrared optical tracking measurement. Infrared localization is put forward as the optimal strategy to monitor intra-fraction motion, featuring robustness, flexibility and less invasivity with respect to X-ray based techniques.

  17. Genetic variability and population structure in loci related to milk production traits in native Argentine Creole and commercial Argentine Holstein cattle

    Directory of Open Access Journals (Sweden)

    Golijow C.D.

    1999-01-01

    Full Text Available Many cattle breeds have been subjected to high selection pressure for production traits. Consequently, population genetic structure and allelic distribution could differ in breeds under high selection pressure compared to unselected breeds. Analysis of k-casein, aS1-casein and prolactin gene frequencies was made for Argentine Creole (AC and Argentine Holstein (AH cattle herds. The calculated FST values measured the degree of genetic differentiation of subpopulations, depending on the variances of gene frequencies.The AC breed had considerably more variation among herds at the aS1-casein and k-casein loci. Conservation strategies should consider the entire AC population in order to maintain the genetic variability found in this native breed.

  18. Environmental variables and tree population structures in deciduous forests of central Brazil with different levels of logging

    Directory of Open Access Journals (Sweden)

    Daniel Luis Mascia Vieira

    2008-04-01

    Full Text Available Population structures of six tree species in three fragments of intact seasonal deciduous forest and three fragments disturbed by logging were studied in the northeastern Goiás. Forty random 400 m² plots were allocated in each fragment to survey plant population structures, number of stumps, cattle feces, burnt logs, and canopy openness. Soil cover by life forms was estimated in 1m² sub-plots. Lianas were abundant in intermediately logged fragments and invasive herbs in the most disturbed fragment. Cattle avoided dense herbaceous strata, such as liana tangles. Cavanillesia arborea, Eugenia dysenterica and Swartzia multijuga trees occurred at very low densities in all the fragments and their seedlings were practically absent, which might endanger their future populations in these fragments. Myracrodruon urundeuva, Tabebuia impetiginosa and Astronium fraxinifolium, the most logged species, had high density of seedlings in all the fragments. However, the highest density of saplings and juvenile individuals occurred in the most disturbed fragment.As estruturas populacionais de seis espécies de árvores foram estudadas em três fragmentos de floresta estacional decidual intactos e três fragmentos impactados pela exploração seletiva de madeira no nordeste goiano. Quarenta parcelas de 400m² foram estabelecidas em cada fragmento para a amostragem de populações, número de tocos, fezes de gado, troncos queimados e abertura de dossel. A cobertura do solo por formas de vida foi estimada em sub-parcelas de 1m². Lianas foram mais abundantes em fragmentos com perturbação intermediária, enquanto herbáceas invasoras no fragmento mais perturbado. Cavanillesia arborea, Eugenia dysenterica e Swartzia multijuga ocorreram em densidades muito baixas em todos os fragmentos e plântulas foram praticamente ausentes, o que pode ameaçar o futuro de suas populações. Myracrodruon urundeuva, Tabebuia impetiginosa e Astronium fraxinifolium, as espécies mais

  19. The influence of climate variability on polar bear (Ursus maritimus) and ringed seal (Pusa hispida) population dynamics

    DEFF Research Database (Denmark)

    Rosing-Asvid, A.

    2006-01-01

    Unusually high polar bear (Ursus maritimus Phipps, 1774) predation on ringed seal (Pusa hispida (Schreber, 1775)) pups and increased survival of polar bear cubs during mild springs is documented in published articles. Strong predation on newborn ringed seal pups in early spring, however, is likely...... to lower the overall energy intake of polar bears if ringed seal pups are their main food, because the energetic value of ringed seal pups increases 7-8 times during the 6 week lactation period. So although hunting success in early spring increases cub survival during the period after den emergence......,when they are most vulnerable, it is likely to increase the number of starving bears later in the season. This negative-feedback effect of strong spring predation will not occur in areas where other seal species are abundant during summer, and polar bears in such areas are likely to exhibit population growth during...

  20. Characterization of mandibular molar root and canal morphology using cone beam computed tomography and its variability in Belgian and Chilean population samples

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Andres; Jacobs, Reinhilde; Lambrechts, Paul [Katholieke Universiteit Leuven, Leuven (Belgium); Brizuela, Claudia; Cabrera, Carolina; Concha, Guillermo; Pedemonte, Maria Eugenia [Universidad de los Andes, Santiago (Chile)

    2015-06-15

    This study used cone-beam computed tomography (CBCT) to characterize mandibular molar root and canal morphology and its variability in Belgian and Chilean population samples. We analyzed the CBCT images of 515 mandibular molars (257 from Belgium and 258 from Chile). Molars meeting the inclusion criteria were analyzed to determine (1) the number of roots; (2) the root canal configuration; (3) the presence of a curved canal in the cross-sectional image of the distal root in the mandibular first molar and (4) the presence of a C-shaped canal in the second mandibular molar. A descriptive analysis was performed. The association between national origin and the presence of a curved or C-shaped canal was evaluated using the chi-squared test. The most common configurations in the mesial root of both molars were type V and type III. In the distal root, type I canal configuration was the most common. Curvature in the cross-sectional image was found in 25% of the distal canals of the mandibular first molars in the Belgian population, compared to 11% in the Chilean population. The prevalence of C-shaped canals was 10% or less in both populations. In cases of unclear or complex root and canal morphology in the mandibular molars, CBCT imaging might assist endodontic specialists in making an accurate diagnosis and in treatment planning.

  1. Forage Yield and Quality Performance of Rabi Cereals Sown Alone and In Blended Population of Variable Seed Ratios

    International Nuclear Information System (INIS)

    Tahir, M.; Zafar, N.

    2016-01-01

    Fodder crops are the main source of animal feed in Pakistan. However, the yield per acre is still far below than optimum production level of the livestock. From this perspective, a field trial was conducted using seeds of three cereal crops wheat, oat and barley sown alone and blended together at different seed proportions (100 percent: 0 percent, 75 percent + 25 percent, 50 percent + 50 percent and 25 percent + 75 percent) at the Agronomic Research Area, Department of Agronomy, University of Agriculture, Faisalabad, during 2013-14. The results showed that the crop mixtures and their variable seed ratios showed significant effects on fodder yield and quality traits. The maximum number of tillers, number of leaves plant/sup -1/, leaf area, crop growth rate, fresh weight plant/sup -1/, dry weight plant/sup -1/, green forage yield and dry matter yield were obtained in plots where barley was sown alone at 100 percent seed ratio. The highest crude fiber and total ash percentage was observed in plots where oat was sown alone at 100 percent seed ratio and crude protein percentage was highest when oat was blended together with barley at 75 percent + 25 percent seed ratios. (author)

  2. Spatial and overwinter changes in clam populations of San Pablo Bay, a semiarid estuary with highly variable freshwater inflow

    Science.gov (United States)

    Poulton, V.K.; Lovvorn, J.R.; Takekawa, John Y.

    2004-01-01

    In many estuaries worldwide, climate trends together with human diversion of fresh water have dramatically impacted the benthos. Such impacts have sometimes been complicated by exotic species, whose invasion and persistence can be mediated by wide variations in freshwater inflow. Monitoring such changes usually involves periodic samples at a few sites; but sampling that does not recognize variation at a range of spatial and seasonal scales may not reveal important benthic trends. San Pablo Bay, in northern San Francisco Bay, has extreme fluctuations in freshwater inflow. This bay also experienced a major benthic change with introduction of the Asian clam (Potamocorbula amurensis) in 1986. This species initially displaced the former community, but later appeared to vary in abundance depending on site and freshwater inflow. To investigate such patterns and provide guidelines for research and monitoring, we took 1746 core samples at six sites around San Pablo Bay from 19 October to 17 December 1999 and from 6 March to 19 April 2000. Most biomass consisted of the clams P. amurensis,Macoma balthica and Mya arenaria. Potamocorbula amurensis dominated the benthos at most sites in the fall and recruited a new cohort during winter, while there was weak recruitment in M. balthica and none in M. arenaria. At most but not all sites, densities of P. amurensis and M. arenaria declined dramatically over winter while M. balthica declined only slightly. The dominant clams had patch diameters >5 m at most but not all sites, and some showed inconsistent patch structure at scales of 100–1400 m. In this semiarid estuary with highly variable freshwater inflow, samples for research and monitoring should include multiple sites and seasons, and samples within sites should be ≥5 m apart to account for between-patch variation. Species abundance in winter 1999–2000 appeared to be affected by high freshwater inflows in 1997–1999, while spatial patterns were probably most affected by

  3. SoTL Inquiry in Broader Curricular and Institutional Contexts: Theoretical Underpinnings and Emerging Trends

    Directory of Open Access Journals (Sweden)

    Harry Hubball

    2013-03-01

    reforms. This paper calls for a more expansive view and strategic use of SoTL inquiry in order to make substantive contributions to curriculum renewal, educational leadership practices, and, most importantly, the quality of undergraduate and graduate degree programs. Theoretical underpinnings, emerging trends, challenges, and strategic supports to enhance the effectiveness and efficiency of curricula within and across diverse disciplinary contexts are discussed.

  4. A Population-Based Approach to Restore and Manage Ruppia Maritima (Wigeongrass) in the Highly Variable Everglades-Florida Bay Ecotone

    Science.gov (United States)

    Strazisar, T. M.; Koch, M.; Madden, C. J.

    2016-02-01

    Seagrasses and submerged aquatic vegetation (SAV) continue to decline globally from human-induced disturbance and habitat loss in estuarine and coastal ecosystems. The SAV Ruppia maritima historically created critical habitat at the Everglades-Florida Bay ecotone, but hydrological modifications and lower freshwater flows have resulted in significant declines in recent decades. We used a population-based approach to examine factors controlling Ruppia presence and abundance at the ecotone to expand the scientific base for management and restoration of SAV species in highly variable environments and examine factors required for Ruppia restoration in the Everglades. Life history transitions from seed through sexual reproduction were established under a range of field conditions critical to seagrass and SAV persistence, including salinity, temperature, light, sediment nutrients (P) and competitor SAV. We found multiple constraints to Ruppia life history development, including an ephemeral seed bank, low rates of successful germination and seedling survival and clonal reproduction limited by variable salinity, nutrients, light and competition with the macroalga Chara hornemannii. Because of low survival rates and limited clonal reproduction, Ruppia at the Evergaldes ecotone currently depends on high rates of viable seed production. However, development of large reproductive meadows requires high vegetative shoot densities. Thus, Everglades restoration should establish lower salinities to create higher seedling and adult survival and clonal reproduction to support successful sexual reproduction that can build up the seed bank for years when adult survival is limited. This population-based data from field experiments and surveys is being incorporated into a seagrass model to enable forecasting of population sustainability and evaluate Everglades restoration targets which includes restoring Ruppia to the southern Everglades-Florida Bay ecotone.

  5. Development of a Multiple Loci Variable Number of Tandem Repeats Analysis (MLVA) to Unravel the Intra-Pathovar Structure of Pseudomonas syringae pv. actinidiae Populations Worldwide

    Science.gov (United States)

    Ciarroni, Serena; Gallipoli, Lorenzo; Taratufolo, Maria C.; Butler, Margi I.; Poulter, Russell T. M.; Pourcel, Christine; Vergnaud, Gilles; Balestra, Giorgio M.; Mazzaglia, Angelo

    2015-01-01

    The bacterial canker of kiwifruit by Pseudomonas syringae pv. actinidiae is an emblematic example of a catastrophic disease of fruit crops. In 2008 a new, extremely virulent form of the pathogen emerged and rapidly devastated many Actinidia spp. orchards all over the world. In order to understand differences in populations within this pathovar and to elucidate their diffusion and movements on world scale, it is necessary to be able to quickly and on a routine basis compare new isolates with previous records. In this report a worldwide collection of 142 strains was analyzed by MLVA, chosen as investigative technique for its efficacy, reproducibility, simplicity and low cost. A panel of 13 Variable Number of Tandem Repeats (VNTR) loci was identified and used to describe the pathogen population. The MLVA clustering is highly congruent with the population structure as previously established by other molecular approaches including whole genome sequencing and correlates with geographic origin, time of isolation and virulence. For convenience, we divided the VNTR loci in two panels. Panel 1 assay, using six loci, recognizes 23 different haplotypes, clustered into ten complexes with highest congruence with previous classifications. Panel 2, with seven VNTR loci, provides discriminatory power. Using the total set of 13 VNTR loci, 58 haplotypes can be distinguished. The recent hypervirulent type shows very limited diversity and includes, beside the strains from Europe, New Zealand and Chile, a few strains from Shaanxi, China. A broad genetic variability is observed in China, but different types are also retrievable in Japan and Korea. The low virulent strains cluster together and are very different from the other MLVA genotypes. Data were used to generate a public database in MLVAbank. MLVA represents a very promising first-line assay for large-scale routine genotyping, prior to whole genome sequencing of only the most relevant samples. PMID:26262683

  6. Mechanisms underpinning effective peer support: a qualitative analysis of interactions between expert peers and patients newly-diagnosed with bipolar disorder

    Directory of Open Access Journals (Sweden)

    Proudfoot Judith G

    2012-11-01

    Full Text Available Abstract Background The increasing burden on mental health services has led to the growing use of peer support in psychological interventions. Four theoretical mechanisms have been proposed to underpin effective peer support: advice grounded in experiential knowledge, social support, social comparison and the helper therapy principle. However, there has been a lack of studies examining whether these mechanisms are also evident in clinical populations in which interpersonal dysfunction is common, such as bipolar disorder. Method This qualitative study, conducted alongside a randomized controlled trial, examined whether the four mechanisms proposed to underpin effective peer support were expressed in the email exchange between 44 individuals newly-diagnosed with bipolar disorder and their Informed Supporters (n = 4, over the course of a supported online psychoeducation program for bipolar disorder. A total of 104 text segments were extracted and coded. The data were complemented by face-to-face interviews with three of the four Informed Supporters who participated in the study. Results Qualitative analyses of the email interchange and interview transcripts revealed rich examples of all four mechanisms. The data illustrated how the involvement of Informed Supporters resulted in numerous benefits for the newly-diagnosed individuals, including the provision of practical strategies for illness management as well as emotional support throughout the intervention. The Informed Supporters encouraged the development of positive relationships with mental health services, and acted as role models for treatment adherence. The Informed Supporters themselves reported gaining a number of benefits from helping, including a greater sense of connectedness with the mental health system, as well as a broader knowledge of illness management strategies. Conclusions Examples of the mechanisms underpinning effective peer support were found in the sample of emails from

  7. Posttraumatic Growth in Populations with Posttraumatic Stress Disorder-A Systematic Review on Growth-Related Psychological Constructs and Biological Variables.

    Science.gov (United States)

    Schubert, Christine F; Schmidt, Ulrike; Rosner, Rita

    2016-11-01

    Posttraumatic growth (PTG) and Posttraumatic Stress Disorder (PTSD) are possible consequences of trauma. PTG is supposed to emerge from cognitive processes and can have functional and dysfunctional aspects. This systematic review aims to identify and evaluate publications assessing PTG in adults diagnosed with PTSD in order to analyse the relationship between both constructs, how PTG is related to specific psychological variables and if there are biological variables linked to PTG. This extended review evaluates the quality of measures applied and is the first to study PTG only in populations meeting full PTSD criteria. In addition, the relationship between PTG and other relevant constructs, such as openness, optimism and social support, is explored. Our systematic literature search identified 140 studies of which 19 fulfilled our inclusion criteria; most of them used the Post-Traumatic Growth Inventory. Results indicate that trauma survivors with PTSD exhibit more PTG than those without PTSD and that PTG can be intensified during the therapeutic process whereat it is unclear whether PTG is a desirable outcome of PTSD therapy. Positive correlations between PTG and PTSD are reported. For diagnosed populations, we could not find strong evidence of a quadratic relationship between PTG and PTSD, although some studies support this hypothesis. Findings regarding the association of PTG with psychological variables are heterogeneous. Only one study focused on PTG as well as on biological variables (salivary cortisol) but did not discuss possible links between these two so far unconnected research fields in PTSD. Copyright © 2015 John Wiley & Sons, Ltd. Trauma survivors with PTSD develop more PTG than those without PTSD, it remains unclear whether PTSD and PTG are curvilinearly related. PTG can be enhanced through PTSD therapy, nevertheless one must not assume that PTG is a favorable treatment outcome since we do not know if the development of PTG during therapy promotes

  8. Magic three-qubit Veldkamp line: A finite geometric underpinning for form theories of gravity and black hole entropy

    Science.gov (United States)

    Lévay, Péter; Holweck, Frédéric; Saniga, Metod

    2017-07-01

    We investigate the structure of the three-qubit magic Veldkamp line (MVL). This mathematical notion has recently shown up as a tool for understanding the structures of the set of Mermin pentagrams, objects that are used to rule out certain classes of hidden variable theories. Here we show that this object also provides a unifying finite geometric underpinning for understanding the structure of functionals used in form theories of gravity and black hole entropy. We clarify the representation theoretic, finite geometric and physical meaning of the different parts of our MVL. The upshot of our considerations is that the basic finite geometric objects enabling such a diversity of physical applications of the MVL are the unique generalized quadrangles with lines of size three, their one-point extensions as well as their other extensions isomorphic to affine polar spaces of rank 3 and order 2. In a previous work we have already connected generalized quadrangles to the structure of cubic Jordan algebras related to entropy fomulas of black holes and strings in five dimensions. In some respect the present paper can be regarded as a generalization of that analysis for also providing a finite geometric understanding of four-dimensional black hole entropy formulas. However, we find many more structures whose physical meaning is yet to be explored. As a familiar special case our work provides a finite geometric representation of the algebraic extension from cubic Jordan algebras to Freudenthal systems based on such algebras.

  9. Stable carbon isotope variability of bone collagen and hair within a modern population of red kangaroos (Macropus rufus) in south western Queensland: some implications for palaeoecological research

    Energy Technology Data Exchange (ETDEWEB)

    Witt, G.B. [Queensland Univ., St. Lucia, QLD (Australia)

    1997-12-31

    Full text: Before any palaeo-reconstruction work can be attempted using stable isotope analysis of macropod remains it will be necessary to determine the nature of natural variability within contemporary populations. This research indicates that {delta}{sup 13}C of bone collagen is strongly related to age. Furthermore, bone collagen {delta}{sup 13}C not at equilibrium with dietary {delta}{sup 13}C, as indicated by analysis of hair, until animals are several years old. These preliminary data suggest that in younger macropods most carbon in bone collagen has been derived via the mother`s milk which may have undergone fractionation. These findings have significant implications for any palaeoecological research using bone or tooth. Teeth of macropods erupt from the rear of the jaw and move forward in molar progression. Since the rate of eruption is variable, and many of the forward molars are well formed while the joey is still at the pouch, teeth formed early in the life of a macropod may be isotopically distinct from those that develop later. This hypothesis is currently under investigation.

  10. The lactase -13910C>T polymorphism (rs4988235) is associated with overweight/obesity and obesity-related variables in a population sample of Portuguese young adults.

    Science.gov (United States)

    Manco, L; Dias, H; Muc, M; Padez, C

    2017-01-01

    Several studies reported associations of the lactase gene (LCT) polymorphism -13910C>T (rs4988235) with obesity-related variables and obesity in adults. This study aimed to replicate previously reported associations in a population sample of Portuguese young adults. We genotyped 447 subjects from central and northern regions of Portugal (mean age 20.81±4.24 years) for the lactase variant -13910C>T (rs4988235), using TaqMan probes. Anthropometric variables (weight, height and body fat) were measured using standardized procedures and body mass index (BMI) (kg/m 2 ) was calculated. Frequency of genotypes was 35.8% CC (lactase nonpersistent, LNP), 48.1% CT and 16.1% TT, consistent with Hardy-Weinberg equilibrium (P=1). The frequency for the minor -13910 T allele was 0.402. Assuming a dominance model for the lactase persistence (LP) minor T-allele, linear regression models showed statistically significant associations between the LP genotype CT/TT and BMI, fat mass and weight (β=1.114, P=0.003; β=1.309, P=0.007 and β=2.67, P=0.021, respectively) after adjustment for age and sex. In concordance, logistic regression showed significant association between LP genotype CT/TT and overweight/obesity (OR=1.77; CI 1.08-2.92; P=0.023), as well as with high fat percentage ranges (OR=1.58; CI 1.01-2.46; P=0.041), when adjusting for age and sex. No significant interaction was obtained between the LCT polymorphism and physical activity for BMI (P int =0.454) or FAT % (P int =0.421). In the Portuguese sample of young adults, the lactase -13910C>T polymorphism revealed significant associations with the obesity-related anthropometric variables BMI, fat mass and weight, and previously observed associations with the obesity risk were also confirmed.

  11. Aquatic acidification: a mechanism underpinning maintained oxygen transport and performance in fish experiencing elevated carbon dioxide conditions.

    Science.gov (United States)

    Hannan, Kelly D; Rummer, Jodie L

    2018-03-07

    Aquatic acidification, caused by elevating levels of atmospheric carbon dioxide (CO 2 ), is increasing in both freshwater and marine ecosystems worldwide. However, few studies have examined how acidification will affect oxygen (O 2 ) transport and, therefore, performance in fishes. Although data are generally lacking, the majority of fishes investigated in this meta-analysis exhibited no effect of elevated CO 2 at the level of O 2 uptake, suggesting that they are able to maintain metabolic performance during a period of acidosis. Notably, the mechanisms that fish employ to maintain performance and O 2 uptake have yet to be verified. Here, we summarize current data related to one recently proposed mechanism underpinning the maintenance of O 2 uptake during exposure to aquatic acidification, and reveal knowledge gaps that could be targeted for future research. Most studies have examined O 2 uptake rates while fishes were resting and did not calculate aerobic scope, even though aerobic scope can aid in predicting changes to whole-animal metabolic performance. Furthermore, research is lacking on different age classes, freshwater species and elasmobranchs, all of which might be impacted by future acidification conditions. Finally, this Review further seeks to emphasize the importance of developing collaborative efforts between molecular, physiological and ecological approaches in order to provide more comprehensive predictions as to how future fish populations will be affected by climate change. © 2018. Published by The Company of Biologists Ltd.

  12. Biocomplexity in Populations of European Anchovy in the Adriatic Sea.

    Science.gov (United States)

    Ruggeri, Paolo; Splendiani, Andrea; Occhipinti, Giulia; Fioravanti, Tatiana; Santojanni, Alberto; Leonori, Iole; De Felice, Andrea; Arneri, Enrico; Procaccini, Gabriele; Catanese, Gaetano; Tičina, Vjekoslav; Bonanno, Angelo; Nisi Cerioni, Paola; Giovannotti, Massimo; Grant, William Stewart; Caputo Barucchi, Vincenzo

    2016-01-01

    The sustained exploitation of marine populations requires an understanding of a species' adaptive seascape so that populations can track environmental changes from short- and long-term climate cycles and from human development. The analysis of the distributions of genetic markers among populations, together with correlates of life-history and environmental variability, can provide insights into the extent of adaptive variation. Here, we examined genetic variability among populations of mature European anchovies (n = 531) in the Adriatic (13 samples) and Tyrrhenian seas (2 samples) with neutral and putative non-neutral microsatellite loci. These genetic markers failed to confirm the occurrence of two anchovy species in the Adriatic Sea, as previously postulated. However, we found fine-scale population structure in the Adriatic, especially in northern areas, that was associated with four of the 13 environmental variables tested. Geographic gradients in sea temperature, salinity and dissolved oxygen appear to drive adaptive differences in spawning time and early larval development among populations. Resolving adaptive seascapes in Adriatic anchovies provides a means to understand mechanisms underpinning local adaptation and a basis for optimizing exploitation strategies for sustainable harvests.

  13. Morphological, Phenological And Agronomical Characterisation Of Variability Among Common Bean (Phaseolus Vulgaris L. Local Populations From The National Centre For Plant Genetic Resources: Polish Genebank

    Directory of Open Access Journals (Sweden)

    Boros Lech

    2014-12-01

    Full Text Available The main purpose of this work was to analyse the morphological, phenological and agronomical variability among common bean local populations from The National Centre for Plant Genetic Resources, Polish Genebank, in order to know the relation among them, and to identify potentially useful accessions for future production and breeding. A considerable genotypic variation for number of seeds per plant, number of pods per plant and weight of seeds per plant were found. Studied bean accessions differed significantly in terms of thousand seeds weight (TSW as well as severity of bacterial halo blight and anthracnose, the major bean diseases. The lowest genotypic diversity was found for the percentage of protein in the seeds, the length of the vegetation period and lodging. The cluster analysis allowed identification of five groups of bean accessions. Genotypes from the first cluster (POLPOD 98-77, KOS 002 and Raba cv. and from the second cluster (WUKR 06-573a, KRA 4, WUKR 06-0534 together with Prosna cv. are of the highest usefulness for breeding purposes. There was no grouping of local populations depending on region of origin.

  14. Marital status as a candidate moderator variable of male-female differences in sexual jealousy: the need for representative population samples.

    Science.gov (United States)

    Voracek, M

    2001-04-01

    Evolutionary psychological theories predict pronounced and universal male-female differences in sexual jealousy. Recent cross-cultural research, using the forced-choice jealousy items pioneered by Buss, et al., 1992, repeatedly found a large sex differential on these self-report measures: men significantly more often than women choose their mate's imagined sexual infidelity to be more distressing or upsetting to them than an imagined emotional infidelity. However, this body of evidence is solely based on undergraduate samples and does not take into account demographic factors. This study examined male-female differences in sexual jealousy in a community sample (N = 335, Eastern Austria). Within a logistic regression model, with other variables controlled for, marital status was a stronger predictor for sexual jealousy than respondents' sex. Contrary to previous research, the sex differential's effect size was only modest. These findings stress the pitfalls of prematurely generalizing evidence from undergraduate samples to the general population and the need for representative population samples in this research area.

  15. Artificial wetlands as tools for frog conservation: stability and variability of reproduction characteristics in Sahara frog populations in Tunisian man-made lakes.

    Science.gov (United States)

    Bellakhal, Meher; Neveu, André; Fertouna-Bellakhal, Mouna; Aleya, Lotfi

    2017-12-01

    Amphibian populations are in decline principally due to climate change, environmental contaminants, and the reduction in wetlands. Even though data concerning current population trends are scarce, artificial wetlands appear to play a vital role in amphibian conservation. This study concerns the reproductive biology of the Sahara frog over a 2-year period in four Tunisian man-made lakes. Each month, gonad state (parameters: K, GSI, LCI), fecundity, and fertility of females (using 1227 clutches) were evaluated in the field under controlled conditions. Clutches were present for 110-130 days at two of the sites, but only for 60-80 days at the other two. Maximum egg laying occurred in May, corresponding to the highest point in the gonad somatic index. Clutch densities were higher in the smaller lakes. Female fecundity was in relation to body size; mean clutch fecundity attained 1416 eggs, with no differences observed according to site. Egg fertility varied over a 1-year period, with a maximum in May followed by a decrease when water temperature was at its highest. Eggs were smaller at the beginning of spawning; maximum size was in May, which might explain the higher fertility, but no maternal influence was detected. Embryonic development was strictly dependent on temperature. The population at each site appeared as a small patch within a metapopulation in overall good health, as shown by the relative temporal stability in reproduction variables. Constructed wetlands may therefore play an important role in the conservation of amphibians, especially in semi-arid zones.

  16. Identifying the latent failures underpinning medication administration errors: an exploratory study.

    Science.gov (United States)

    Lawton, Rebecca; Carruthers, Sam; Gardner, Peter; Wright, John; McEachan, Rosie R C

    2012-08-01

    The primary aim of this article was to identify the latent failures that are perceived to underpin medication errors. The study was conducted within three medical wards in a hospital in the United Kingdom. The study employed a cross-sectional qualitative design. Interviews were conducted with 12 nurses and eight managers. Interviews were transcribed and subject to thematic content analysis. A two-step inter-rater comparison tested the reliability of the themes. Ten latent failures were identified based on the analysis of the interviews. These were ward climate, local working environment, workload, human resources, team communication, routine procedures, bed management, written policies and procedures, supervision and leadership, and training. The discussion focuses on ward climate, the most prevalent theme, which is conceptualized here as interacting with failures in the nine other organizational structures and processes. This study is the first of its kind to identify the latent failures perceived to underpin medication errors in a systematic way. The findings can be used as a platform for researchers to test the impact of organization-level patient safety interventions and to design proactive error management tools and incident reporting systems in hospitals. © Health Research and Educational Trust.

  17. Genomic epidemiology of Cryptococcus yeasts identifies adaptation to environmental niches underpinning infection across an African HIV/AIDS cohort.

    Science.gov (United States)

    Vanhove, Mathieu; Beale, Mathew A; Rhodes, Johanna; Chanda, Duncan; Lakhi, Shabir; Kwenda, Geoffrey; Molloy, Sile; Karunaharan, Natasha; Stone, Neil; Harrison, Thomas S; Bicanic, Tihana; Fisher, Matthew C

    2017-04-01

    Emerging infections caused by fungi have become a widely recognized global phenomenon and are causing an increasing burden of disease. Genomic techniques are providing new insights into the structure of fungal populations, revealing hitherto undescribed fine-scale adaptations to environments and hosts that govern their emergence as infections. Cryptococcal meningitis is a neglected tropical disease that is responsible for a large proportion of AIDS-related deaths across Africa; however, the ecological determinants that underlie a patient's risk of infection remain largely unexplored. Here, we use genome sequencing and ecological genomics to decipher the evolutionary ecology of the aetiological agents of cryptococcal meningitis, Cryptococcus neoformans and Cryptococcus gattii, across the central African country of Zambia. We show that the occurrence of these two pathogens is differentially associated with biotic (macroecological) and abiotic (physical) factors across two key African ecoregions, Central Miombo woodlands and Zambezi Mopane woodlands. We show that speciation of Cryptococcus has resulted in adaptation to occupy different ecological niches, with C. neoformans found to occupy Zambezi Mopane woodlands and C. gattii primarily recovered from Central Miombo woodlands. Genome sequencing shows that C. neoformans causes 95% of human infections in this region, of which over three-quarters belonged to the globalized lineage VNI. We show that VNI infections are largely associated with urbanized populations in Zambia. Conversely, the majority of C. neoformans isolates recovered in the environment belong to the genetically diverse African-endemic lineage VNB, and we show hitherto unmapped levels of genomic diversity within this lineage. Our results reveal the complex evolutionary ecology that underpins the reservoirs of infection for this, and likely other, deadly pathogenic fungi. © 2016 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  18. An analysis of factors associated with influenza, pneumoccocal, Tdap, and herpes zoster vaccine uptake in the US adult population and corresponding inter-state variability.

    Science.gov (United States)

    La, Elizabeth M; Trantham, Laurel; Kurosky, Samantha K; Odom, Dawn; Aris, Emmanuel; Hogea, Cosmina

    2018-02-01

    Despite longstanding recommendations for routine vaccination against influenza; pneumococcal; tetanus, diphtheria, acellular pertussis (Tdap); and herpes zoster (HZ) among the United States general adult population, vaccine uptake remains low. Understanding factors that influence adult vaccination and coverage variability beyond the national level are important steps toward developing targeted strategies for increasing vaccination coverage. A retrospective analysis was conducted using data from the Behavioral Risk Factor Surveillance System (2011-2014). Multivariable logistic regression modeling was employed to identify individual factors associated with vaccination (socio-demographics, health status, healthcare utilization, state of residence) and generate adjusted vaccination coverage and compliance estimates nationally and by state. Results indicated that multiple characteristics were consistently associated with a higher likelihood of vaccination across all four vaccines, including female sex, increased educational attainment, and annual household income. Model-adjusted vaccination coverage estimates varied widely by state, with inter-state variability for the most recent year of data as follows: influenza (aged ≥18 years) 30.2-49.5%; pneumococcal (aged ≥65 years) 64.0-74.7%; Tdap (aged ≥18 years) 18.7-46.6%; and HZ (aged ≥60 years) 21.3-42.9%. Model-adjusted compliance with age-appropriate recommendations across vaccines was low and also varied by state: influenza+Tdap (aged 18-59 years) 7.9-24.7%; influenza+Tdap+HZ (aged 60-64 years) 4.1-14.4%; and influenza+Tdap+HZ+pneumococcal (aged ≥65 years) 3.0-18.3%. In summary, after adjusting for individual characteristics associated with vaccination, substantial heterogeneity across states remained, suggesting that other local factors (e.g. state policies) may be impacting adult vaccines uptake. Further research is needed to understand such factors, focusing on differences between states with high versus

  19. Improving quality in population surveys of headache prevalence, burden and cost

    DEFF Research Database (Denmark)

    Steiner, Timothy J; Stovner, Lars Jacob; Al Jumah, Mohammed

    2013-01-01

    , methodological differences and variable quality are notable among published studies of headache prevalence, burden and cost.The purpose here was to start the process of developing standardized and better methodology in these studies. An expert consensus group was assembled to identify the key methodological......Population-based studies of headache disorders are important. They inform needs assessment and underpin service policy for a set of disorders that are a public-health priority. On the one hand, our knowledge of the global burden of headache is incomplete, with major geographical gaps; on the other...

  20. Multiple comorbidities of 21 psychological disorders and relationships with psychosocial variables: a study of the online assessment and diagnostic system within a web-based population.

    Science.gov (United States)

    Al-Asadi, Ali M; Klein, Britt; Meyer, Denny

    2015-02-26

    While research in the area of e-mental health has received considerable attention over the last decade, there are still many areas that have not been addressed. One such area is the comorbidity of psychological disorders in a Web-based sample using online assessment and diagnostic tools, and the relationships between comorbidities and psychosocial variables. We aimed to identify comorbidities of psychological disorders of an online sample using an online diagnostic tool. Based on diagnoses made by an automated online assessment and diagnostic system administered to a large group of online participants, multiple comorbidities (co-occurrences) of 21 psychological disorders for males and females were identified. We examined the relationships between dyadic comorbidities of anxiety and depressive disorders and the psychosocial variables sex, age, suicidal ideation, social support, and quality of life. An online complex algorithm based on the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Text Revision, was used to assign primary and secondary diagnoses of 21 psychological disorders to 12,665 online participants. The frequency of co-occurrences of psychological disorders for males and females were calculated for all disorders. A series of hierarchical loglinear analyses were performed to examine the relationships between the dyadic comorbidities of depression and various anxiety disorders and the variables suicidal ideation, social support, quality of life, sex, and age. A 21-by-21 frequency of co-occurrences of psychological disorders matrix revealed the presence of multiple significant dyadic comorbidities for males and females. Also, for those with some of the dyadic depression and the anxiety disorders, the odds for having suicidal ideation, reporting inadequate social support, and poorer quality of life increased for those with two-disorder comorbidity than for those with only one of the same two disorders. Comorbidities of

  1. Unified underpinning of human mobility in the real world and cyberspace

    Science.gov (United States)

    Zhao, Yi-Ming; Zeng, An; Yan, Xiao-Yong; Wang, Wen-Xu; Lai, Ying-Cheng

    2016-05-01

    Human movements in the real world and in cyberspace affect not only dynamical processes such as epidemic spreading and information diffusion but also social and economical activities such as urban planning and personalized recommendation in online shopping. Despite recent efforts in characterizing and modeling human behaviors in both the real and cyber worlds, the fundamental dynamics underlying human mobility have not been well understood. We develop a minimal, memory-based random walk model in limited space for reproducing, with a single parameter, the key statistical behaviors characterizing human movements in both cases. The model is validated using relatively big data from mobile phone and online commerce, suggesting memory-based random walk dynamics as the unified underpinning for human mobility, regardless of whether it occurs in the real world or in cyberspace.

  2. The relational underpinnings of quality internal auditing in medical clinics in Israel.

    Science.gov (United States)

    Carmeli, Abraham; Zisu, Malka

    2009-03-01

    Internal auditing is a key mechanism in enhancing organizational reliability. However, research on the ways quality internal auditing is enabled through learning, deterrence, motivation and process improvement is scant. In particular, the relational underpinnings of internal auditing have been understudied. This study attempts to address this need by examining how organizational trust, perceived organizational support and psychological safety enable internal auditing. Data collected from employees in medical clinics of one of the largest healthcare organizations in Israel at two points in time six months apart. Our results show that organizational trust and perceived organizational support are positively related to psychological safety (measured at time 1), which, in turn, is associated with internal auditing (measured at time 2).

  3. Kolb's Experiential Learning Theory as a Theoretical Underpinning for Interprofessional Education.

    Science.gov (United States)

    Fewster-Thuente, Lori; Batteson, Tamzin J

    2018-01-01

    It is imperative to incorporate education on interprofessional competencies into the curriculum of healthcare provider students in order to meet the individual program accreditation standards. However, what is missing is a theoretical foundation for the education. The purpose of this paper was to examine if the qualitative data from a mixed-methods study using low-fidelity simulation of a case study that demonstrated changes in interprofessional attitudes and behaviors in healthcare provider students aligned with Kolb's Experiential Learning Theory (ELT). First-year students (n=515) from 8 professional healthcare programs participated in the 90-minute study which included a scripted scenario of the patient care rounding process. Using thematic analysis, the qualitative results demonstrated a significant alignment with the four stages of Kolb's ELT. Based on the results of this study, ELT appears to provide a solid theoretical underpinning for the education through which to teach interprofessional competencies to healthcare provider students.

  4. The Safe and Effective Use of Shared Data Underpinned by Stakeholder Engagement and Evaluation Practice.

    Science.gov (United States)

    Georgiou, Andrew; Magrabi, Farah; Hypponen, Hannele; Wong, Zoie Shui-Yee; Nykänen, Pirkko; Scott, Philip J; Ammenwerth, Elske; Rigby, Michael

    2018-04-22

     The paper draws attention to: i) key considerations involving the confidentiality, privacy, and security of shared data; and ii) the requirements needed to build collaborative arrangements encompassing all stakeholders with the goal of ensuring safe, secure, and quality use of shared data.  A narrative review of existing research and policy approaches along with expert perspectives drawn from the International Medical Informatics Association (IMIA) Working Group on Technology Assessment and Quality Development in Health Care and the European Federation for Medical Informatics (EFMI) Working Group for Assessment of Health Information Systems.  The technological ability to merge, link, re-use, and exchange data has outpaced the establishment of policies, procedures, and processes to monitor the ethics and legality of shared use of data. Questions remain about how to guarantee the security of shared data, and how to establish and maintain public trust across large-scale shared data enterprises. This paper identifies the importance of data governance frameworks (incorporating engagement with all stakeholders) to underpin the management of the ethics and legality of shared data use. The paper also provides some key considerations for the establishment of national approaches and measures to monitor compliance with best practice. Data sharing endeavours can help to underpin new collaborative models of health care which provide shared information, engagement, and accountability amongst all stakeholders. We believe that commitment to rigorous evaluation and stakeholder engagement will be critical to delivering health data benefits and the establishment of collaborative models of health care into the future. Georg Thieme Verlag KG Stuttgart.

  5. Ethical underpinnings for the development of health literacy in schools: ethical premises ('why'), orientations ('what') and tone ('how').

    Science.gov (United States)

    Paakkari, Leena; George, Shanti

    2018-03-06

    Schools are seen as crucial environments to influence and develop the health literacy of new generations, but without sufficient reflection on the ethical underpinnings of intentions and interventions around health literacy. In contrast, we argue here that ethics are fundamental to all education. The article adopts a 'One world' approach that generalizes broadly across the so-called Global North and Global South. It also generalizes across various age groups among school pupils, advocating age appropriate application of the arguments advanced. Our analysis examines why health literacy should be promoted in schools and argues that the purpose should embrace the values of social justice and should not stop at individual and national cost benefit analysis. Discussion about the orientation of health literacy highlights meta-cognitive skills around critical thinking, self-awareness and citizenship rather than lists of practical skills. Finally, approaches to health literacy in classrooms are presented with an ethical tone that draws attention to the power relations responsible for health inequities and that does not assume that such power relations are the given framework for health literacy interventions and activities. These arguments are reinforced by urging that related debates address dynamic social realities such as international migration. We reiterate the need for ethical questions to be consciously and systematically addressed from early on, beginning with intentions to promote health literacy even before these intentions are translated into action, within the political space where education meets public health and health promotion. We underline again the context of fluidity and dynamism, as new challenges emerge within pedagogies and curricula, especially in response to changing populations in the society around.

  6. Asthma and risk of selective IgA deficiency or common variable immunodeficiency: a population-based case-control study.

    Science.gov (United States)

    Urm, Sang-Hwa; Yun, Hyun Don; Fenta, Yilma A; Yoo, Kwang Ha; Abraham, Roshini S; Hagan, John; Juhn, Young J

    2013-08-01

    To determine the association between a history of asthma and a diagnosis of selective IgA deficiency (sIgAD)/common variable immunodeficiency (CVID). This population-based case-control study included residents of Olmsted County, Minnesota, who met the Pan-American Group for Immunodeficiency/European Society for Immunodeficiencies diagnostic criteria for sIgAD/CVID between January 1, 1964, through December 31, 2008. Each case had 4 age- and sex-matched controls (2 from the community and 2 from a list of individuals who had undergone an immune work-up). We ascertained asthma status by applying predetermined criteria for asthma. We identified 39 cases: 26 (66.7%) had sIgAD and 13 (33.3%) had CVID. Of the 39 cases, 51.3% were men (n=20) and 97.1% were white (33 of 34 patients). The mean age at the index date (the time when criteria were met) of sIgAD/CVID was 34.2 years. Of the 39 cases, 9 (23.1%) had a history of asthma before the index date of sIgAD/CVID; of the 156 controls, 16 (10.3%) had a history of asthma before the index date (odds ratio, 2.77; 95% CI, 1.09-7.06; P=.03). A history of asthma (before or after the index date of sIgAD/CVID) was more prevalent in sIgAD/CVID cases (30.8%; n=12) than in matched controls (11.5%; n=18) (odds ratio, 3.57; 95% CI, 1.50-8.51; P=.01). Asthmatic patients are more likely to have a diagnosis of sIgAD/CVID than nonasthmatic individuals. This association may potentially account for the increased risks of bacterial infections in some individuals with asthma. Copyright © 2013 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  7. Prevalence of asthma with airflow limitation, COPD, and COPD with variable airflow limitation in older subjects in a general Japanese population: the Hisayama Study.

    Science.gov (United States)

    Matsumoto, Koichiro; Seki, Nanae; Fukuyama, Satoru; Moriwaki, Atsushi; Kan-o, Keiko; Matsunaga, Yuko; Noda, Naotaka; Yoshida, Makoto; Koto, Hiroshi; Takata, Shohei; Nakanishi, Yoichi; Kiyohara, Yutaka; Inoue, Hiromasa

    2015-01-01

    Elucidating the prevalence of asthma and chronic obstructive pulmonary disease (COPD) is important for designing a public health strategy. Recent studies have discriminated a phenotype of COPD with variable airflow limitation (COPD-VAL) associated with asthma-COPD overlap syndrome. Its prevalence remains uncertain. The age and occupational distributions in the town of Hisayama and in Japan are nearly identical. Each disease's prevalence was estimated for the town's residents. In 2008, town residents (≥ 40 years) were solicited to participate in a health checkup. Individuals with abnormal spirometry (forced expiratory volume in 1s/forced vital capacity [FEV1/FVC]fashion reviewed their medical records, including bronchodilator reversibility. Individuals with airflow limitation were classified as having asthma, COPD, COPD-VAL, or other diseases. The prevalence of each disease was then estimated. A total of 2100 residents (43.4% of residents in the age group) completed spirometry. In 455 residents with abnormal spirometry, 190 residents had further evaluations, and the medical records of 174 residents were reviewed. The prevalence of asthma with airflow limitation, COPD, and COPD-VAL, were 2.0%, 8.4%, and 0.9%, respectively. The prevalence of COPD and COPD-VAL were higher in men and smokers than in women and never-smokers. The prevalence of COPD, but not COPD-VAL or asthma, increased with age. The prevalence of asthma with airflow limitation, COPD, and COPD-VAL were estimated in a population of residents (≥ 40 years) in Hisayama. Copyright © 2014 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

  8. Systematic review of evidence underpinning non-pharmacological therapies in dementia.

    Science.gov (United States)

    Olley, Richard; Morales, Andrea

    2017-05-15

    underpin the use of these therapies. This report on a PRISMA systematic review of the available literature demonstrates that only two therapies have some evidence to underpin the use of these non-pharmaceutical therapies and that a significant research gap is exists. What are the implications for practitioners? The implications for practitioners is that significant research effort is required to determine the efficacy of many of the therapies that are currently deployed, and thus many of the therapies used lack an evidence base at this time.

  9. Population Ethics

    OpenAIRE

    BLACKORBY, Charles; BOSSERT, Walter; DONALDSON, David

    2006-01-01

    This paper reviews the welfarist approach to population ethics. We provide an overview of the critical-level utilitarian population principles and their generalized counterparts, examine important properties of these principles and discuss their relationships to other variable-population social-evaluation rules. We illustrate the difficulties arising in population ethics by means of an impossibility result and present characterizations of the critical-level generalized-utilitarian principles ...

  10. High levels of genetic variability and differentiation in hilsa shad, Tenualosa ilisha (Clupeidae, Clupeiformes populations revealed by PCR-RFLP analysis of the mitochondrial DNA D-loop region

    Directory of Open Access Journals (Sweden)

    Sabuj Kanti Mazumder

    2009-01-01

    Full Text Available The hilsa shad, Tenualosa ilisha (Clupeidae, Clupeiformes is an important anadromous clupeid species from the Western division of the Indo-Pacific region. It constitutes the largest single fishable species in Bangladesh. Information on genetic variability and population structure is very important for both management and conservation purposes. Past reports on the population structure of T. ilisha involving morphometric, allozyme and RAPD analyses are contradictory. We examined genetic variability and divergence in two riverine (the Jamuna and the Meghna, two estuarine (Kuakata and Sundarbans and one marine (Cox's Bazar populations of T. ilisha by applying PCR-RFLP analysis of the mtDNA D-loop region. The amplified PCR products were restricted with four restriction enzymes namely, XbaI, EcoRI, EcoRV, and HaeIII. High levels of haplotype and gene diversity within and significant differentiations among, populations of T. ilisha were observed in this study. Significant F ST values indicated differentiation among the river, estuary and marine populations. The UPGMA dendrogram based on genetic distance resulted in two major clusters, although, these were subsequently divided into three, corresponding to the riverine, estuarine and marine populations. The study underlines the usefulness of RFLP of mtDNA D-loop region as molecular markers, and detected at least two differentiated populations of T. ilisha in Bangladesh waters.

  11. Biological phenotypes underpin the physio-somatic symptoms of somatization, depression, and chronic fatigue syndrome.

    Science.gov (United States)

    Anderson, G; Berk, M; Maes, M

    2014-02-01

    Somatization is a symptom cluster characterized by 'psychosomatic' symptoms, that is, medically unexplained symptoms, and is a common component of other conditions, including depression and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This article reviews the data regarding the pathophysiological foundations of 'psychosomatic' symptoms and the implications that this has for conceptualization of what may more appropriately be termed physio-somatic symptoms. This narrative review used papers published in PubMed, Scopus, and Google Scholar electronic databases using the keywords: depression and chronic fatigue, depression and somatization, somatization and chronic fatigue syndrome, each combined with inflammation, inflammatory, tryptophan, and cell-mediated immune (CMI). The physio-somatic symptoms of depression, ME/CFS, and somatization are associated with specific biomarkers of inflammation and CMI activation, which are correlated with, and causally linked to, changes in the tryptophan catabolite (TRYCAT) pathway. Oxidative and nitrosative stress induces damage that increases neoepitopes and autoimmunity that contribute to the immuno-inflammatory processes. These pathways are all known to cause physio-somatic symptoms, including fatigue, malaise, autonomic symptoms, hyperalgesia, intestinal hypermotility, peripheral neuropathy, etc. Biological underpinnings, such as immune-inflammatory pathways, may explain, at least in part, the occurrence of physio-somatic symptoms in depression, somatization, or myalgic encephalomyelitis/chronic fatigue syndrome and thus the clinical overlap among these disorders. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Memory underpinnings of future intentions: Would you like to see the sequel?

    Science.gov (United States)

    Stragà, Marta; Del Missier, Fabio; Marcatto, Francesco; Ferrante, Donatella

    2017-01-01

    In two studies, we investigated the memory underpinnings of future intentions related to past hedonic experiences. Preceding research did not make clear whether the specific memory processes supporting the expression of intentions about the future involve global judgments of the past experience (general affective evaluations formed on-line) or judgments derived from the episodic recollection of the past. Adapting a correlational paradigm previously employed to study future intentions, and applying it to the experience of watching a movie, we comparatively tested the influence of global retrospective evaluations vs. episodic-derived evaluations on future intentions. In Study 1, in which the intentions involved a future experience that was very similar to an overall past one (e.g., seeing the movie sequel), the findings showed that participants relied only on global judgments to form future intentions. In Study 2, in which the global judgment on the past was less diagnostic because the future intentions referred to specific parts of the past experience (e.g., watching a movie centered on a minor character in the previously seen movie), the results indicated that relevant episodic memories provided an essential contribution to the prediction of future intentions. These findings are in agreement with the predictions of the accessibility-diagnosticity framework and they show that global judgments and episodic memories of a past experience contribute differentially to diverse kinds of future intentions.

  13. Neural computations underpinning the strategic management of influence in advice giving.

    Science.gov (United States)

    Hertz, Uri; Palminteri, Stefano; Brunetti, Silvia; Olesen, Cecilie; Frith, Chris D; Bahrami, Bahador

    2017-12-19

    Research on social influence has focused mainly on the target of influence (e.g., consumer and voter); thus, the cognitive and neurobiological underpinnings of the source of the influence (e.g., politicians and salesmen) remain unknown. Here, in a three-sided advice-giving game, two advisers competed to influence a client by modulating their own confidence in their advice about which lottery the client should choose. We report that advisers' strategy depends on their level of influence on the client and their merit relative to one another. Moreover, blood-oxygenation-level-dependent (BOLD) signal in the temporo-parietal junction is modulated by adviser's current level of influence on the client, and relative merit prediction error affects activity in medial-prefrontal cortex. Both types of social information modulate ventral striatum response. By demonstrating what happens in our mind and brain when we try to influence others, these results begin to explain the biological mechanisms that shape inter-individual differences in social conduct.

  14. An Ontology-Underpinned Emergency Response System for Water Pollution Accidents

    Directory of Open Access Journals (Sweden)

    Xiaoliang Meng

    2018-02-01

    Full Text Available With the unceasing development and maturation of environment geographic information system, the response to water pollution accidents has been digitalized through the combination of monitoring sensors, management servers, and application software. However, most of these systems only achieve the basic and general geospatial data management and functional process tasks by adopting mechanistic water-quality models. To satisfy the sustainable monitoring and real-time emergency response application demand of the government and public users, it is a hotspot to study how to make the water pollution information being semantic and make the referred applications intelligent. Thus, the architecture of the ontology-underpinned emergency response system for water pollution accidents is proposed in this paper. This paper also makes a case study for usability testing of the water ontology models, and emergency response rules through an online water pollution emergency response system. The system contributes scientifically to the safety and sustainability of drinking water by providing emergency response and decision-making to the government and public in a timely manner.

  15. Interpersonal factors associated with depression in adolescents: are these consistent with theories underpinning interpersonal psychotherapy?

    Science.gov (United States)

    O'Shea, Gabrielle; Spence, Susan H; Donovan, Caroline L

    2014-01-01

    The aim of this study was to investigate whether depressed adolescents differed from non-depressed adolescents in terms of constructs consistent with those that are proposed to underpin interpersonal psychotherapy. In particular, it was hypothesized that compared with non-depressed adolescents, depressed adolescents would demonstrate a greater number of negative life events associated with interpersonal loss and major life transitions, a more insecure attachment style and poorer communication skills, interpersonal relationships and social support. Thirty-one clinically diagnosed depressed adolescents were matched with 31 non-depressed adolescents on age, gender and socio-economic status. The 62 participants were aged between 12 and 19 years and comprised 18 male and 44 female adolescents. On a self-report questionnaire, depressed adolescents reported a greater number of negative interpersonal life events, a less secure attachment style and scored higher on all insecure attachment styles compared with the non-depressed adolescents. In addition, depressed adolescents demonstrated lower levels of social skill (on both adolescent and parent report), a poorer quality of relationship with parents (on both adolescent and parent report) and lower social competence (adolescent report only). Parents of depressed adolescents also reported more negative parental attitudes and behaviours towards their adolescent compared with parents of non-depressed adolescents. Thus, the results of this study are consistent with the constructs underlying interpersonal psychotherapy and suggest their usefulness in the assessment, conceptualization and treatment of adolescent depression. Clinical implications are discussed. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Harnessing the Toxocara Genome to Underpin Toxocariasis Research and New Interventions.

    Science.gov (United States)

    Gasser, Robin B; Korhonen, Pasi K; Zhu, Xing-Quan; Young, Neil D

    2016-01-01

    Parasitic worms, such as flatworms (platyhelminths) and roundworms (nematodes), cause substantial morbidity and mortality in animals and people globally. The ascaridoid nematode Toxocara canis is a zoonotic parasite of socioeconomic significance worldwide. In humans, this worm causes toxocariasis (disease) mainly in underprivileged communities in both the developed and developing worlds. While reasonably well studied from clinical and epidemiological perspectives, little is understood about the molecular biology of T. canis, its relationship with its hosts and the disease that it causes. However, a recent report of the draft genome and transcriptomes of T. canis should underpin many fundamental and applied research areas in the future. The present article gives a background on Toxocara and toxocariasis, a brief account of diagnostic approaches for specific identification and genetic analysis, and gives a perspective on the impact that the genome of T. canis and advanced molecular technologies could have on our understanding of the parasite and the diseases that it causes as well as the design of new and improved approaches for the diagnosis, treatment and control of toxocariasis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Frontopolar cortical inefficiency may underpin reward and working memory dysfunction in bipolar disorder.

    Science.gov (United States)

    Jogia, Jigar; Dima, Danai; Kumari, Veena; Frangou, Sophia

    2012-12-01

    Emotional dysregulation in bipolar disorder is thought to arise from dysfunction within prefrontal cortical regions involved in cognitive control coupled with increased or aberrant activation within regions engaged in emotional processing. The aim of this study was to determine the common and distinct patterns of functional brain abnormalities during reward and working memory processing in patients with bipolar disorder. Participants were 36 euthymic bipolar disorder patients and 37 healthy comparison subjects matched for age, sex and IQ. Functional magnetic resonance imaging (fMRI) was conducted during the Iowa Gambling Task (IGT) and the n-back working memory task. During both tasks, patients with bipolar disorder demonstrated a pattern of inefficient engagement within the ventral frontopolar prefrontal cortex with evidence of segregation along the medial-lateral dimension for reward and working memory processing, respectively. Moreover, patients also showed greater activation in the anterior cingulate cortex during the Iowa Gambling Task and in the insula during the n-back task. Our data implicate ventral frontopolar dysfunction as a core abnormality underpinning bipolar disorder and confirm that overactivation in regions involved in emotional arousal is present even in tasks that do not typically engage emotional systems.

  18. Theoretical underpinnings of state institutionalisation of inclusion and struggles in collective health in Latin America.

    Science.gov (United States)

    Mahmood, Qamar; Muntaner, Carles

    2018-03-28

    Community participation as a strategy in health aims to increase the role of citizens in health decision-making which are contextualised within the institutions of democracy. Electoral representation as the dominant model of democracy globally is based on the elite theory of democracy that sees political decision-making a prerogative of political elites. Such political elitism is counter to the idea of democratic participation. Neoliberalism together with elitism in political sphere have worsened social inequities by undermining working class interests. Latin America has seen adverse consequences of these social inequities. In response, social movements representing collective struggles of organised citizens arose in the region. This paper explores the theoretical underpinnings of democratic participation in contemporary Latin American context at the nexus of emerging social movement activism and policy responses. The paper will use empirical examples to highlight how such democratic practices at the societal level evolved while demanding political inclusion. These societal democratic practices in Latin America are redefining democracy, which continues to be seen in the political sphere only. Health reforms promoting participatory democracy in several Latin American countries have demonstrated that establishing institutions and mechanisms of democratic participation facilitate collective participation by the organised citizenry in state affairs.

  19. Recent advances in exploring the neural underpinnings of auditory scene perception.

    Science.gov (United States)

    Snyder, Joel S; Elhilali, Mounya

    2017-05-01

    Studies of auditory scene analysis have traditionally relied on paradigms using artificial sounds-and conventional behavioral techniques-to elucidate how we perceptually segregate auditory objects or streams from each other. In the past few decades, however, there has been growing interest in uncovering the neural underpinnings of auditory segregation using human and animal neuroscience techniques, as well as computational modeling. This largely reflects the growth in the fields of cognitive neuroscience and computational neuroscience and has led to new theories of how the auditory system segregates sounds in complex arrays. The current review focuses on neural and computational studies of auditory scene perception published in the last few years. Following the progress that has been made in these studies, we describe (1) theoretical advances in our understanding of the most well-studied aspects of auditory scene perception, namely segregation of sequential patterns of sounds and concurrently presented sounds; (2) the diversification of topics and paradigms that have been investigated; and (3) how new neuroscience techniques (including invasive neurophysiology in awake humans, genotyping, and brain stimulation) have been used in this field. © 2017 New York Academy of Sciences.

  20. Neural underpinnings of divergent production of rules in numerical analogical reasoning.

    Science.gov (United States)

    Wu, Xiaofei; Jung, Rex E; Zhang, Hao

    2016-05-01

    Creativity plays an important role in numerical problem solving. Although the neural underpinnings of creativity have been studied over decades, very little is known about neural mechanisms of the creative process that relates to numerical problem solving. In the present study, we employed a numerical analogical reasoning task with functional Magnetic Resonance Imaging (fMRI) to investigate the neural correlates of divergent production of rules in numerical analogical reasoning. Participants performed two tasks: a multiple solution analogical reasoning task and a single solution analogical reasoning task. Results revealed that divergent production of rules involves significant activations at Brodmann area (BA) 10 in the right middle frontal cortex, BA 40 in the left inferior parietal lobule, and BA 8 in the superior frontal cortex. The results suggest that right BA 10 and left BA 40 are involved in the generation of novel rules, and BA 8 is associated with the inhibition of initial rules in numerical analogical reasoning. The findings shed light on the neural mechanisms of creativity in numerical processing. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. An Exploratory Qualitative Exploration of the Personal Values Underpinning Taiwanese and Malaysians’ Wine Consumption Behaviors

    Directory of Open Access Journals (Sweden)

    Miranda Mirosa

    2016-01-01

    Full Text Available Augmented buying power of East Asian consumers has resulted in increased interest in these markets. Wine is a particularly promising sector to target as the number of East Asians choosing to drink wine rises. In order to serve these markets, companies must understand factors influencing consumers’ choices. The objective of this research was to understand how Taiwanese and Malaysian consumers’ personal values influenced their consumption decisions about wine. The means–end chain framework and associated semi-structured interview technique, value laddering, was used to elicit consumers’ preferred product attributes, the consequences of these attributes and the values that underpin these consequences. Data collection involved intercepting foreign travelers from Malaysia and Taiwan in New Zealand (20 Taiwanese and 20 Malaysian to partake in a wine choice interview. The resulting findings are exploratory in nature. Analysis revealed the most preferred wine attributes for Taiwanese were “Price” and “Sensory Aspects”—that these attributes were linked to consequences “Financial Considerations” and “Satisfy Senses”—which in turn were linked to personal values “Self Direction” and “Achievement”. For the Malaysian participants, the attribute “Sensory Aspects” of wine was most important, as was the value “Hedonism”. This study adds to literature related to beverage consumption decision making by exploring cultural aspects. It also offers suggestions for practitioners interested in targeting these consumers.

  2. What Is Our Current Understanding of PrPSc-Associated Neurotoxicity and Its Molecular Underpinnings?

    Science.gov (United States)

    Hughes, Daniel; Halliday, Mark

    2017-12-01

    The prion diseases are a collection of fatal, transmissible neurodegenerative diseases that cause rapid onset dementia and ultimately death. Uniquely, the infectious agent is a misfolded form of the endogenous cellular prion protein, termed PrP Sc . Despite the identity of the molecular agent remaining the same, PrP Sc can cause a range of diseases with hereditary, spontaneous or iatrogenic aetiologies. However, the link between PrP Sc and toxicity is complex, with subclinical cases of prion disease discovered, and prion neurodegeneration without obvious PrP Sc deposition. The toxic mechanisms by which PrP Sc causes the extensive neuropathology are still poorly understood, although recent advances are beginning to unravel the molecular underpinnings, including oxidative stress, disruption of proteostasis and induction of the unfolded protein response. This review will discuss the diseases caused by PrP Sc toxicity, the nature of the toxicity of PrP Sc , and our current understanding of the downstream toxic signaling events triggered by the presence of PrP Sc .

  3. Associative learning mechanisms underpinning the transition from recreational drug use to addiction.

    Science.gov (United States)

    Hogarth, Lee; Balleine, Bernard W; Corbit, Laura H; Killcross, Simon

    2013-04-01

    Learning theory proposes that drug seeking is a synthesis of multiple controllers. Whereas goal-directed drug seeking is determined by the anticipated incentive value of the drug, habitual drug seeking is elicited by stimuli that have formed a direct association with the response. Moreover, drug-paired stimuli can transfer control over separately trained drug seeking responses by retrieving an expectation of the drug's identity (specific transfer) or incentive value (general transfer). This review covers outcome devaluation and transfer of stimulus-control procedures in humans and animals, which isolate the differential governance of drug seeking by these four controllers following various degrees of contingent and noncontingent drug exposure. The neural mechanisms underpinning these four controllers are also reviewed. These studies suggest that although initial drug seeking is goal-directed, chronic drug exposure confers a progressive loss of control over action selection by specific outcome representations (impaired outcome devaluation and specific transfer), and a concomitant increase in control over action selection by antecedent stimuli (enhanced habit and general transfer). The prefrontal cortex and mediodorsal thalamus may play a role in this drug-induced transition to behavioral autonomy. © 2012 New York Academy of Sciences.

  4. Linking the biological underpinnings of depression: Role of mitochondria interactions with melatonin, inflammation, sirtuins, tryptophan catabolites, DNA repair and oxidative and nitrosative stress, with consequences for classification and cognition.

    Science.gov (United States)

    Anderson, George

    2018-01-03

    The pathophysiological underpinnings of neuroprogressive processes in recurrent major depressive disorder (rMDD) are reviewed. A wide array of biochemical processes underlie MDD presentations and their shift to a recurrent, neuroprogressive course, including: increased immune-inflammation, tryptophan catabolites (TRYCATs), mitochondrial dysfunction, aryl hydrocarbonn receptor activation, and oxidative and nitrosative stress (O&NS), as well as decreased sirtuins and melatonergic pathway activity. These biochemical changes may have their roots in central, systemic and/or peripheral sites, including in the gut, as well as in developmental processes, such as prenatal stressors and breastfeeding consequences. Consequently, conceptualizations of MDD have dramatically moved from simple psychological and central biochemical models, such as lowered brain serotonin, to a conceptualization that incorporates whole body processes over a lifespan developmental timescale. However, important hubs are proposed, including the gut-brain axis, and mitochondrial functioning, which may provide achievable common treatment targets despite considerable inter-individual variability in biochemical changes. This provides a more realistic model of the complexity of MDD and the pathophysiological processes that underpin the shift to rMDD and consequent cognitive deficits. Such accumulating data on the pathophysiological processes underpinning MDD highlights the need in psychiatry to shift to a classification system that is based on biochemical processes, rather than subjective phenomenology. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. On the inference of agency in operant action : an examination of the cognitive and neural underpinnings in health and schizophrenia

    NARCIS (Netherlands)

    Renes, R.A.

    2016-01-01

    This dissertation elucidates cognitive and neural underpinnings of the sense of agency, which is the feeling that we are in control of our actions and the subsequent consequences. This consciously accessible sensation of control is pervasive, sometimes subtle, and can even be illusory in nature.

  6. From Chicken Breath to the Killers Lake of Cameroon: Uniting Seven Interesting Phenomena with a Single Chemical Underpinning

    Science.gov (United States)

    Delorenzo, Ron

    2001-02-01

    By using a single equation prototype, seven interesting mysteries and phenomena can be seen as sharing a common chemical underpinning. The applications discussed are the Killer Lakes of Cameroon, chicken breath, the Permian Ocean, the snow line, boiler scale, the Fizz Keeper, and stalactites and stalagmites.

  7. Chains of (dis)trust : Exploring the underpinnings of knowledge-sharing and quality care across mental health services

    NARCIS (Netherlands)

    Brown, P.R.; Calnan, M.W.

    Quality and safety in healthcare settings are underpinned by organisational cultures, which facilitate or impede the refinement, sharing and application of knowledge. Avoiding the use of the term culture as a residual category, we focus specifically on describing chains of (dis)trust, analysing

  8. Empirical evaluation of the conceptual model underpinning a regional aquatic long-term monitoring program using causal modelling

    Science.gov (United States)

    Irvine, Kathryn M.; Miller, Scott; Al-Chokhachy, Robert K.; Archer, Erik; Roper, Brett B.; Kershner, Jeffrey L.

    2015-01-01

    Conceptual models are an integral facet of long-term monitoring programs. Proposed linkages between drivers, stressors, and ecological indicators are identified within the conceptual model of most mandated programs. We empirically evaluate a conceptual model developed for a regional aquatic and riparian monitoring program using causal models (i.e., Bayesian path analysis). We assess whether data gathered for regional status and trend estimation can also provide insights on why a stream may deviate from reference conditions. We target the hypothesized causal pathways for how anthropogenic drivers of road density, percent grazing, and percent forest within a catchment affect instream biological condition. We found instream temperature and fine sediments in arid sites and only fine sediments in mesic sites accounted for a significant portion of the maximum possible variation explainable in biological condition among managed sites. However, the biological significance of the direct effects of anthropogenic drivers on instream temperature and fine sediments were minimal or not detected. Consequently, there was weak to no biological support for causal pathways related to anthropogenic drivers’ impact on biological condition. With weak biological and statistical effect sizes, ignoring environmental contextual variables and covariates that explain natural heterogeneity would have resulted in no evidence of human impacts on biological integrity in some instances. For programs targeting the effects of anthropogenic activities, it is imperative to identify both land use practices and mechanisms that have led to degraded conditions (i.e., moving beyond simple status and trend estimation). Our empirical evaluation of the conceptual model underpinning the long-term monitoring program provided an opportunity for learning and, consequently, we discuss survey design elements that require modification to achieve question driven monitoring, a necessary step in the practice of

  9. ANALYSE DE LA VARIABILITÉ DE LA CROISSANCE D'UNE POPULATION DE TRUITE COMMUNE (SALMO TRUTTA L. DANS UN TORRENT PYRÉNÉEN. GROWTH VARIABILITY ANALYSIS OF A BROWN TROUT (SALMO TRUTTA L. POPULATION IN A PYRENEAN MOUNTAIN STREAM.

    Directory of Open Access Journals (Sweden)

    LAGARRIGUE T.

    2008-05-01

    discuté. The brown trout population of the Neste d'Oueil, a Pyrenean tributary of the Garonne river, was studied between July 1996 and March 1999. During the period of two years and nine months, nine sampling experiments were carried out in February-March, July and September on two sectors of the river. Thus, we could follow the seasonal variation of growth, total density and total biomass of brown trout. Moreover, 652 brown trouts of age ranging between 1+ and 6+ years, for sizes ranging between 100 and 290 mm, were marked individually by visible implants in March 1998. The recapture rates observed varied from 19.5 to 74%, following the season considered. Growth rates showed a strong seasonal variability, validated by individual tagging experiments. Because of reproduction and rigorous temperatures experienced by trout during autumn and winter, growth rates observed were almost null and individuals >1+ lost weight during this period. In spite of theoretically non-optimal thermal conditions, growth occurred almost exclusively in spring. Poor growth rates observed during summer are not due to thermal factor which was theoretically optimal for growth in this season and could be attributed to the sexual maturation, to the saturation of the carrying capacity of physical habitat and to the strong intraspecific competition caused by i likely arrivals of 1+ and 2+ individuals emigrating from tributaries and ii reduction in "quantity and quality" of physical habitat at low-flow limiting accessibility and availability of energetically profitable prey. The role of growth in the dynamics of the brown trout population of the Neste d'Oueil River is discussed.

  10. In situ Comparison of Tree-Ring Responses to Climate and Population Genetics: The Need to Control for Local Climate and Site Variables

    OpenAIRE

    Housset, Johann M.; Carcaillet, Christopher; Girardin, Martin P.; Xu, Huaitong; Tremblay, Francine; Bergeron, Yves

    2016-01-01

    Tree species responses to climate change will be greatly influenced by their evolutionary potential and their phenotypic plasticity. Investigating tree-rings responses to climate and population genetics at the regional scale is crucial in assessing the tree behavior to climate change. This study combined in situ dendroclimatology and population genetics over a latitudinal gradient and compared the variations between the two at the intra- and inter-population levels. This approach was applied ...

  11. The danger within: the role of genetic, behavioural and ecological factors in population persistence of colour polymorphic species.

    Science.gov (United States)

    Bolton, Peri E; Rollins, Lee A; Griffith, Simon C

    2015-06-01

    Polymorphic species have been the focus of important work in evolutionary biology. It has been suggested that colour polymorphic species have specific evolutionary and population dynamics that enable them to persist through environmental changes better than less variable species. We suggest that recent empirical and theoretical work indicates that polymorphic species may be more vulnerable to extinction than previously thought. This vulnerability arises because these species often have a number of correlated sexual, behavioural, life history and ecological traits, which can have a simple genetic underpinning. When exacerbated by environmental change, these alternate strategies can lead to conflict between morphs at the genomic and population levels, which can directly or indirectly affect population and evolutionary dynamics. In this perspective, we identify a number of ways in which the nature of the correlated traits, their underpinning genetic architecture, and the inevitable interactions between colour morphs can result in a reduction in population fitness. The principles illustrated here apply to all kinds of discrete polymorphism (e.g. behavioural syndromes), but we focus primarily on colour polymorphism because they are well studied. We urge further empirical investigation of the genetic architecture and interactions in polymorphic species to elucidate the impact on population fitness. © 2015 John Wiley & Sons Ltd.

  12. Parrotfish erosion underpins reef growth, sand talus development and island building in the Maldives

    Science.gov (United States)

    Morgan, Kyle M.; Kench, Paul S.

    2016-07-01

    Parrotfish play a key functional role on coral reefs as external bioerosion agents and produce large quantities of carbonate sediment as a by-product of grazing on reef surfaces. Parrotfish are therefore an important potential source of sediment for island construction and maintenance within atoll reef environments, particularly under future scenarios of sea level rise and island morphological change. Here, we present the first field-based estimates of excavating parrotfish erosion (Chlorurus sordidus and Chlorurus strongylocephalus) within the Indian Ocean and quantify the contribution of parrotfish to the carbonate and sediment budgets of an atoll interior reef platform in the Maldives. We note that parrotfish erosion rates are high (6.3 kg m- 2 y- 1), generating large amounts of new coral-based sediment (2.6 kg m- 2 y- 1) that has a comparable grain size distribution to island deposits. Mean erosion rates by individual C. strongylocephalus (405 kg individual y- 1) were higher than C. sordidus (55 kg individual y- 1), but their contribution to erosion per unit area of reef was less due to a lower relative biomass (C. strongylocephalus: 1.3 kg m- 2 y- 1; C. sordidus: 5.0 kg m- 2 y- 1). Parrotfish also facilitate sediment export from reefs (0.7 kg m- 2 y- 1), which contributes extensively to the development of the sand talus on the fore-reef slope and to the evolution of the wider atoll basin. Our results provide strong evidence that parrotfish erosion (and sediment generation) underpins island morphology on Maldivian reefs and highlight the importance of larger parrotfish as producers of island-grade sediment. Ecological processes must therefore be considered within future coastal management strategies for enhancing island stability.

  13. [Self-regulation and virtual reality in forensic psychiatry: An emphasis on theoretical underpinnings].

    Science.gov (United States)

    Benbouriche, M; Renaud, P; Pelletier, J-F; De Loor, P

    2016-12-01

    Forensic psychiatry is the field whose expertise is the assessment and treatment of offending behaviours, in particular when offenses are related to mental illness. An underlying question for all etiological models concerns the manner in which an individual's behaviours are organized. Specifically, it becomes crucial to understand how certain individuals come to display maladaptive behaviours in a given environment, especially when considering issues such as offenders' responsibility and their ability to change their behaviours. Thanks to its ability to generate specific environments, associated with a high experimental control on generated simulations, virtual reality is gaining recognition in forensic psychiatry. Virtual reality has generated promising research data and may turn out to be a remarkable clinical tool in the near future. While research has increased, a conceptual work about its theoretical underpinnings is still lacking. However, no important benefit should be expected from the introduction of a new tool (as innovative as virtual reality) without an explicit and heuristic theoretical framework capable of clarifying its benefits in forensic psychiatry. Our paper introduces self-regulation perspective as the most suitable theoretical framework for virtual reality in forensic psychiatry. It will be argued that virtual reality does not solely help to increase ecological validity. However, it does allow one to grant access to an improved understanding of violent offending behaviours by probing into the underlying mechanisms involved in the self-regulation of behaviours in a dynamical environment. Illustrations are given as well as a discussion regarding perspectives in the use of virtual reality in forensic psychiatry. Copyright © 2015 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

  14. Lung eQTLs to help reveal the molecular underpinnings of asthma.

    Directory of Open Access Journals (Sweden)

    Ke Hao

    Full Text Available Genome-wide association studies (GWAS have identified loci reproducibly associated with pulmonary diseases; however, the molecular mechanism underlying these associations are largely unknown. The objectives of this study were to discover genetic variants affecting gene expression in human lung tissue, to refine susceptibility loci for asthma identified in GWAS studies, and to use the genetics of gene expression and network analyses to find key molecular drivers of asthma. We performed a genome-wide search for expression quantitative trait loci (eQTL in 1,111 human lung samples. The lung eQTL dataset was then used to inform asthma genetic studies reported in the literature. The top ranked lung eQTLs were integrated with the GWAS on asthma reported by the GABRIEL consortium to generate a Bayesian gene expression network for discovery of novel molecular pathways underpinning asthma. We detected 17,178 cis- and 593 trans- lung eQTLs, which can be used to explore the functional consequences of loci associated with lung diseases and traits. Some strong eQTLs are also asthma susceptibility loci. For example, rs3859192 on chr17q21 is robustly associated with the mRNA levels of GSDMA (P = 3.55 × 10(-151. The genetic-gene expression network identified the SOCS3 pathway as one of the key drivers of asthma. The eQTLs and gene networks identified in this study are powerful tools for elucidating the causal mechanisms underlying pulmonary disease. This data resource offers much-needed support to pinpoint the causal genes and characterize the molecular function of gene variants associated with lung diseases.

  15. A model for the molecular underpinnings of tooth defects in Axenfeld–Rieger syndrome

    Science.gov (United States)

    Li, Xiao; Venugopalan, Shankar R.; Cao, Huojun; Pinho, Flavia O.; Paine, Michael L.; Snead, Malcolm L.; Semina, Elena V.; Amendt, Brad A.

    2014-01-01

    Patients with Axenfeld–Rieger Syndrome (ARS) present various dental abnormalities, including hypodontia, and enamel hypoplasia. ARS is genetically associated with mutations in the PITX2 gene, which encodes one of the earliest transcription factors to initiate tooth development. Thus, Pitx2 has long been considered as an upstream regulator of the transcriptional hierarchy in early tooth development. However, because Pitx2 is also a major regulator of later stages of tooth development, especially during amelogenesis, it is unclear how mutant forms cause ARS dental anomalies. In this report, we outline the transcriptional mechanism that is defective in ARS. We demonstrate that during normal tooth development Pitx2 activates Amelogenin (Amel) expression, whose product is required for enamel formation, and that this regulation is perturbed by missense PITX2 mutations found in ARS patients. We further show that Pitx2-mediated Amel activation is controlled by chromatin-associated factor Hmgn2, and that Hmgn2 prevents Pitx2 from efficiently binding to and activating the Amel promoter. Consistent with a physiological significance to this interaction, we show that K14-Hmgn2 transgenic mice display a severe loss of Amel expression on the labial side of the lower incisors, as well as enamel hypoplasia—consistent with the human ARS phenotype. Collectively, these findings define transcriptional mechanisms involved in normal tooth development and shed light on the molecular underpinnings of the enamel defect observed in ARS patients who carry PITX2 mutations. Moreover, our findings validate the etiology of the enamel defect in a novel mouse model of ARS. PMID:23975681

  16. Matrix Expansion and Syncytial Aggregation of Syndecan-1+ Cells Underpin Villous Atrophy in Coeliac Disease

    Science.gov (United States)

    Salvestrini, Camilla; Lucas, Mark; Lionetti, Paolo; Torrente, Franco; James, Sean; Phillips, Alan D.; Murch, Simon H.

    2014-01-01

    Background We studied the expression of sulphated glycosaminoglycans (GAGs) in coeliac disease (CD) mucosa, as they are critical determinants of tissue volume, which increases in active disease. We also examined mucosal expression of IL-6, which stimulates excess GAG synthesis in disorders such as Grave's ophthalmopathy. Methods We stained archival jejunal biopsies from 5 children with CD at diagnosis, on gluten-free diet and challenge for sulphated GAGs. We then examined duodenal biopsies from 9 children with CD compared to 9 histological normal controls, staining for sulphated GAGs, heparan sulphate proteoglycans (HSPG), short-chain HSPG (Δ-HSPG) and the proteoglycan syndecan-1 (CD138), which is expressed on epithelium and plasma cells. We confirmed findings with a second monoclonal in another 12 coeliac children. We determined mucosal IL-6 expression by immunohistochemistry and PCR in 9 further cases and controls, and used quantitative real time PCR for other Th17 pathway cytokines in an additional 10 cases and controls. Results In CD, HSPG expression was lost in the epithelial compartment but contrastingly maintained within an expanded lamina propria. Within the upper lamina propria, clusters of syndecan-1+ plasma cells formed extensive syncytial sheets, comprising adherent plasma cells, lysed cells with punctate cytoplasmic staining and shed syndecan ectodomains. A dense infiltrate of IL-6+ mononuclear cells was detected in active coeliac disease, also localised to the upper lamina propria, with significantly increased mRNA expression of IL-6 and IL-17A but not IL-23 p19. Conclusions Matrix expansion, through syndecan-1+ cell recruitment and lamina propria GAG increase, underpins villous atrophy in coeliac disease. The syndecan-1+ cell syncytia and excess GAG production recapitulate elements of the invertebrate encapsulation reaction, itself dependent on insect transglutaminase and glutaminated early response proteins. As in other matrix expansion disorders

  17. Cis-regulatory underpinnings of human GLI3 expression in embryonic craniofacial structures and internal organs.

    Science.gov (United States)

    Abbasi, Amir A; Minhas, Rashid; Schmidt, Ansgar; Koch, Sabine; Grzeschik, Karl-Heinz

    2013-10-01

    The zinc finger transcription factor Gli3 is an important mediator of Sonic hedgehog (Shh) signaling. During early embryonic development Gli3 participates in patterning and growth of the central nervous system, face, skeleton, limb, tooth and gut. Precise regulation of the temporal and spatial expression of Gli3 is crucial for the proper specification of these structures in mammals and other vertebrates. Previously we reported a set of human intronic cis-regulators controlling almost the entire known repertoire of endogenous Gli3 expression in mouse neural tube and limbs. However, the genetic underpinning of GLI3 expression in other embryonic domains such as craniofacial structures and internal organs remain elusive. Here we demonstrate in a transgenic mice assay the potential of a subset of human/fish conserved non-coding sequences (CNEs) residing within GLI3 intronic intervals to induce reporter gene expression at known regions of endogenous Gli3 transcription in embryonic domains other than central nervous system (CNS) and limbs. Highly specific reporter expression was observed in craniofacial structures, eye, gut, and genitourinary system. Moreover, the comparison of expression patterns directed by these intronic cis-acting regulatory elements in mouse and zebrafish embryos suggests that in accordance with sequence conservation, the target site specificity of a subset of these elements remains preserved among these two lineages. Taken together with our recent investigations, it is proposed here that during vertebrate evolution the Gli3 expression control acquired multiple, independently acting, intronic enhancers for spatiotemporal patterning of CNS, limbs, craniofacial structures and internal organs. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

  18. Digital games for type 1 and type 2 diabetes: underpinning theory with three illustrative examples.

    Science.gov (United States)

    Kamel Boulos, Maged N; Gammon, Shauna; Dixon, Mavis C; MacRury, Sandra M; Fergusson, Michael J; Miranda Rodrigues, Francisco; Mourinho Baptista, Telmo; Yang, Stephen P

    2015-03-18

    Digital games are an important class of eHealth interventions in diabetes, made possible by the Internet and a good range of affordable mobile devices (eg, mobile phones and tablets) available to consumers these days. Gamifying disease management can help children, adolescents, and adults with diabetes to better cope with their lifelong condition. Gamification and social in-game components are used to motivate players/patients and positively change their behavior and lifestyle. In this paper, we start by presenting the main challenges facing people with diabetes-children/adolescents and adults-from a clinical perspective, followed by three short illustrative examples of mobile and desktop game apps and platforms designed by Ayogo Health, Inc. (Vancouver, BC, Canada) for type 1 diabetes (one example) and type 2 diabetes (two examples). The games target different age groups with different needs-children with type 1 diabetes versus adults with type 2 diabetes. The paper is not meant to be an exhaustive review of all digital game offerings available for people with type 1 and type 2 diabetes, but rather to serve as a taster of a few of the game genres on offer today for both types of diabetes, with a brief discussion of (1) some of the underpinning psychological mechanisms of gamified digital interventions and platforms as self-management adherence tools, and more, in diabetes, and (2) some of the hypothesized potential benefits that might be gained from their routine use by people with diabetes. More research evidence from full-scale evaluation studies is needed and expected in the near future that will quantify, qualify, and establish the evidence base concerning this gamification potential, such as what works in each age group/patient type, what does not, and under which settings and criteria.

  19. The importance of professional skills alongside scientific and technical excellence to underpin ethical geoscience practice

    Science.gov (United States)

    Allington, Ruth; Fernandez-Fuentes, Isabel

    2013-04-01

    There is consensus that reliable ground models, based on a sound understanding of the geology and surface processes are vital as a basis for natural hazard identification and risk assessment, and there is a great deal of skill and experience in the geoscience community with mapping, modelling and predicting natural hazards and their likely impacts. This presentation will highlight the contributions of geology and geomorphology in the identification of natural hazards and mitigation of their impacts. It will then consider a range of "professional skills" that are needed by geoscientists working with other specialists and non-specialists (e.g. engineers, emergency services, land-use planners, architects responsible for building codes, politicians, regulators, the public etc) alongside technical and scientific excellence. It will argue that development and application of both scientific/technical and professional skills is essential to ensure that the maps, models and other data relevant to natural hazards and environmental change are used to provide effective public protection through communication, land-use planning and planning for resilience. The professional skills of particular importance include interdisciplinary collaboration; project management; cost-benefit analysis; effective communication with specialists and non specialists (especially the public); and facilitative skills. All the technical, scientific and professional skills need to be applied competently and with the highest standards of ethical underpinning. The contribution will consider how this can be achieved (or at least facilitated) through professional training, award of professional titles, licensure etc, drawing on international examples of best practice in professional codes of conduct and regulation directed to the protection of the public.

  20. Does legume nitrogen fixation underpin host quality for the hemiparasitic plant Rhinanthus minor?

    Science.gov (United States)

    Jiang, Fan; Jeschke, W Dieter; Hartung, Wolfram; Cameron, Duncan D

    2008-01-01

    The high quality of leguminous hosts for the parasitic plant Rhinanthus minor (in terms of growth and fecundity), compared with forbs (non-leguminous dicots) has long been assumed to be a function of the legume's ability to fix atmospheric nitrogen (N) from the air and the potential for direct transfer of compatible amino compounds to the parasite. Using associations between Rhinanthus minor and Vicia faba (Fabaceae) that receive N either exclusively via symbiotic associations with rhizobia supplying organic N fixed from N(2) or exclusively through the supply of inorganic nitrate to the substrate, the underlying reasons for the quality of legumes as hosts for this parasite are unravelled. It is shown that sole dependence of the host, V. faba, on N fixation results in lower growth of the attached parasite than when the host is grown in a substrate supplied exclusively with inorganic N. In contrast, the host plants themselves achieved a similar biomass irrespective of their N source. The physiological basis for this is investigated in terms of N and abscisic acid (ABA) partitioning, haustorial penetration, and xylem sap amino acid profiles. It is concluded that legume N fixation does not underpin the quality of legumes as hosts for Rhinanthus but rather the well-developed haustorium formed by the parasite, coupled with the lack of defensive response of the host tissues to the invading haustorium and the presence of sufficient nitrogenous compounds in the xylem sap accessible to the parasite haustoria, would appear to be the primary factors influencing host quality of the legumes.

  1. Digital Games for Type 1 and Type 2 Diabetes: Underpinning Theory With Three Illustrative Examples

    Science.gov (United States)

    Gammon, Shauna; Dixon, Mavis C; MacRury, Sandra M; Fergusson, Michael J; Miranda Rodrigues, Francisco; Mourinho Baptista, Telmo; Yang, Stephen P

    2015-01-01

    Digital games are an important class of eHealth interventions in diabetes, made possible by the Internet and a good range of affordable mobile devices (eg, mobile phones and tablets) available to consumers these days. Gamifying disease management can help children, adolescents, and adults with diabetes to better cope with their lifelong condition. Gamification and social in-game components are used to motivate players/patients and positively change their behavior and lifestyle. In this paper, we start by presenting the main challenges facing people with diabetes—children/adolescents and adults—from a clinical perspective, followed by three short illustrative examples of mobile and desktop game apps and platforms designed by Ayogo Health, Inc. (Vancouver, BC, Canada) for type 1 diabetes (one example) and type 2 diabetes (two examples). The games target different age groups with different needs—children with type 1 diabetes versus adults with type 2 diabetes. The paper is not meant to be an exhaustive review of all digital game offerings available for people with type 1 and type 2 diabetes, but rather to serve as a taster of a few of the game genres on offer today for both types of diabetes, with a brief discussion of (1) some of the underpinning psychological mechanisms of gamified digital interventions and platforms as self-management adherence tools, and more, in diabetes, and (2) some of the hypothesized potential benefits that might be gained from their routine use by people with diabetes. More research evidence from full-scale evaluation studies is needed and expected in the near future that will quantify, qualify, and establish the evidence base concerning this gamification potential, such as what works in each age group/patient type, what does not, and under which settings and criteria. PMID:25791276

  2. Neural underpinnings of distortions in the experience of time across senses.

    Science.gov (United States)

    Harrington, Deborah L; Castillo, Gabriel N; Fong, Christopher H; Reed, Jason D

    2011-01-01

    Auditory signals (A) are perceived as lasting longer than visual signals (V) of the same physical duration when they are compared together. Despite considerable debate about how this illusion arises psychologically, the neural underpinnings have not been studied. We used functional magnetic resonance imaging (fMRI) to investigate the neural bases of audiovisual temporal distortions and more generally, intersensory timing. Adults underwent fMRI while judging the relative duration of successively presented standard interval-comparison interval (CI) pairs, which were unimodal (A-A, V-V) or crossmodal (V-A, A-V). Mechanisms of time dilation and compression were identified by comparing the two crossmodal pairs. Mechanisms of intersensory timing were identified by comparing the unimodal and crossmodal conditions. The behavioral results showed that auditory CIs were perceived as lasting longer than visual CIs. There were three novel fMRI results. First, time dilation and compression were distinguished by differential activation of higher-sensory areas (superior temporal, posterior insula, middle occipital), which typically showed stronger effective connectivity when time was dilated (V-A). Second, when time was compressed (A-V) activation was greater in frontal cognitive-control centers, which guide decision making. These areas did not exhibit effective connectivity. Third, intrasensory timing was distinguished from intersensory timing partly by decreased striatal and increased superior parietal activation. These regions showed stronger connectivity with visual, memory, and cognitive-control centers during intersensory timing. Altogether, the results indicate that time dilation and compression arise from the connectivity strength of higher-sensory systems with other areas. Conversely, more extensive network interactions are needed with core timing (striatum) and attention (superior parietal) centers to integrate time codes for intersensory signals.

  3. Partial diel migration: A facultative migration underpinned by long-term inter-individual variation.

    Science.gov (United States)

    Harrison, Philip M; Gutowsky, Lee F G; Martins, Eduardo G; Patterson, David A; Cooke, Steven J; Power, Michael

    2017-09-01

    The variations in migration that comprise partial diel migrations, putatively occur entirely as a consequence of behavioural flexibility. However, seasonal partial migrations are increasingly recognised to be mediated by a combination of reversible plasticity in response to environmental variation and individual variation due to genetic and environmental effects. Here, we test the hypothesis that while partial diel migration heterogeneity occurs primarily due to short-term within-individual flexibility in behaviour, long-term individual differences in migratory behaviour also underpin this migration variation. Specifically, we use a hierarchical behavioural reaction norm approach to partition within- and among-individual variation in depth use and diel plasticity in depth use, across short- and long-term time-scales, in a group of 47 burbot (Lota lota) tagged with depth-sensing acoustic telemetry transmitters. We found that within-individual variation at the among-dates-within-seasons and among-seasons scale, explained the dominant proportion of phenotypic variation. However, individuals also repeatedly differed in their expression of migration behaviour over the 2 year study duration. These results reveal that diel migration variation occurs primarily due to short-term within-individual flexibility in depth use and diel migration behaviour. However, repeatable individual differences also played a key role in mediating partial diel migration. These findings represent a significant advancement of our understanding of the mechanisms generating the important, yet poorly understood phenomena of partial diel migration. Moreover, given the pervasive occurrence of diel migrations across aquatic taxa, these findings indicate that individual differences have an important, yet previously unacknowledged role in structuring the temporal and vertical dynamics of aquatic ecosystems. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  4. [Incomplete congruence between morphobiological characters and sex-specific molecular markers in Pacific salmons: II. Population and temporal variability of the phenomenon].

    Science.gov (United States)

    Brykov, V A; Kukhlevskiĭ, A D; Podlesnykh, A V

    2010-11-01

    The congruence between secondary sexual characters and molecular markers, linked to the Y chromosome was examined in Asian populations of five Pacific salmon species of the genus Oncorhynchus. Our results support the existence of discrepancy between secondary sexual characters and sex-linked molecular markers in all species examined, which suggests the existence of similar or identical mechanism responsible for this phenomenon in Pacific salmons. Clinal latitudinal directional variation of the character confirmed the possibility that this phenomenon could be adaptively important, including its importance for regulation of the population number. In addition to natural factors affecting the degree of discrepancy between morphobiological characters and molecular markers in the Pacific salmon populations, anthropogenic factors, in particular intense fishery of certain population or population group, is also important.

  5. Free and Open Source Software underpinning the European Forest Data Centre

    Science.gov (United States)

    Rodriguez Aseretto, Dario; Di Leo, Margherita; de Rigo, Daniele; Corti, Paolo; McInerney, Daniel; Camia, Andrea; San-Miguel-Ayanz, Jesús

    2013-04-01

    Worldwide, governments are growingly focusing [1] on free and open source software (FOSS) as a move toward transparency and the freedom to run, copy, study, change and improve the software [2]. The European Commission (EC) is also supporting the development of FOSS (see e.g., [3]). In addition to the financial savings, FOSS contributes to scientific knowledge freedom in computational science (CS) [4] and is increasingly rewarded in the science-policy interface within the emerging paradigm of open science [5-8]. Since complex computational science applications may be affected by software uncertainty [4,9-11], FOSS may help to mitigate part of the impact of software errors by CS community-driven open review, correction and evolution of scientific code [10,12-15]. The continental scale of EC science-based policy support implies wide networks of scientific collaboration. Thematic information systems also may benefit from this approach within reproducible [16] integrated modelling [4]. This is supported by the EC strategy on FOSS: "for the development of new information systems, where deployment is foreseen by parties outside of the EC infrastructure, [F]OSS will be the preferred choice and in any case used whenever possible" [17]. The aim of this contribution is to highlight how a continental scale information system may exploit and integrate FOSS technologies within the transdisciplinary research underpinning such a complex system. A European example is discussed where FOSS innervates both the structure of the information system itself and the inherent transdisciplinary research for modelling the data and information which constitute the system content. The information system. The European Forest Data Centre (EFDAC, http://forest.jrc.ec.europa.eu/efdac/) has been established at the EC Joint Research Centre (JRC) as the focal point for forest data and information in Europe to supply European decision-makers with processed, quality checked and timely policy relevant

  6. Storytelling: A Qualitative Tool to Promote Health Among Vulnerable Populations.

    Science.gov (United States)

    Palacios, Janelle F; Salem, Benissa; Hodge, Felicia Schanche; Albarrán, Cyndi R; Anaebere, Ann; Hayes-Bautista, Teodocia Maria

    2015-09-01

    Storytelling is a basic cultural phenomenon that has recently been recognized as a valuable method for collecting research data and developing multidisciplinary interventions. The purpose of this article is to present a collection of nursing scholarship wherein the concept of storytelling, underpinned by cultural phenomena, is explored for data collection and intervention. A conceptual analysis of storytelling reveals key variables. Following a brief review of current research focused on storytelling used within health care, three case studies among three vulnerable populations (American Indian teen mothers, American Indian cancer survivors, and African American women at risk for HIV/AIDS) demonstrate the uses of storytelling for data collection and intervention. Implications for transcultural nursing regarding storytelling are discussed. © The Author(s) 2014.

  7. Variability in the contribution of different life stages to population growth as a key factor in the invasion success of Pinus strobus.

    Directory of Open Access Journals (Sweden)

    Zuzana Münzbergová

    Full Text Available BACKGROUND: Despite the increasing number of studies attempting to model population growth in various organisms, we still know relatively little about the population dynamics of long-lived species that reproduce only in the later stages of their life cycle, such as trees. Predictions of the dynamics of these species are, however, urgently needed for planning management actions when species are either endangered or invasive. In long-lived species, a single management intervention may have consequences for several decades, and detailed knowledge of long-term performance can therefore elucidate possible outcomes during the management planning phase. METHODOLOGY AND PRINCIPAL FINDINGS: We studied the population dynamics of an invasive tree species, Pinus strobus, in three habitat types represented by their position along the elevation gradient occupied by the species. In agreement with previous studies on the population dynamics of long-lived perennials, our results show that the survival of the largest trees exhibits the highest elasticity in all of the studied habitats. In contrast, life table response experiments (LTRE analysis showed that different stages contribute the most to population growth rates in different habitats, with generative reproduction being more important in lower slopes and valley bottoms and survival being more important on rock tops and upper slopes. CONCLUSIONS: The results indicate that P. strobus exhibits different growth strategies in different habitats that result in similar population growth rates. We propose that this plasticity in growth strategies is a key factor in the invasion success of the white pine. In all of the investigated habitats, the population growth rates are above 1, indicating that the population of the species is still increasing and has the ability to spread and occupy a wide range of habitats.

  8. Elucidating the atomistic mechanisms underpinning plasticity in Li-Si nanostructures

    Science.gov (United States)

    Yan, Xin; Gouissem, Afif; Guduru, Pradeep R.; Sharma, Pradeep

    2017-10-01

    Amorphous lithium-silicon (a-Li-Si), especially in nanostructure form, is an attractive high-capacity anode material for next-generation Li-ion batteries. During cycles of charging and discharging, a-Li-Si undergoes substantive inelastic deformation and exhibits microcracking. The mechanical response to repeated lithiation-delithiation eventually results in the loss of electrical contact and consequent decrease of capacity, thus underscoring the importance of studying the plasticity of a-Li-Si nanostructures. In recent years, a variety of phenomenological continuum theories have been introduced that purport to model plasticity and the electro-chemo-mechanical behavior of a-Li-Si. Unfortunately, the micromechanisms and atomistic considerations underlying plasticity in Li-Si material are not yet fully understood and this impedes the development of physics-based constitutive models. Conventional molecular dynamics, although extensively used to study this material, is grossly inadequate to resolve this matter. As is well known, conventional molecular dynamics simulations can only address phenomena with characteristic time scales of (at most) a microsecond. Accordingly, in such simulations, the mechanical behavior is deduced under conditions of very high strain rates (usually, 108s-1 or even higher). This limitation severely impacts a realistic assessment of rate-dependent effects. In this work, we attempt to circumvent the time-scale bottleneck of conventional molecular dynamics and provide novel insights into the mechanisms underpinning plastic deformation of Li-Si nanostructures. We utilize an approach that allows imposition of slow strain rates and involves the employment of a new and recently developed potential energy surface sampling method—the so-called autonomous basin climbing—to identify the local minima in the potential energy surface. Combined with other techniques, such as nudged elastic band, kinetic Monte Carlo and transition state theory, we assess

  9. Heart rate variability and first cardiovascular event in populations without known cardiovascular disease: meta-analysis and dose-response meta-regression

    NARCIS (Netherlands)

    Hillebrand, Stefanie; Gast, Karin B.; de Mutsert, Renée; Swenne, Cees A.; Jukema, J. Wouter; Middeldorp, Saskia; Rosendaal, Frits R.; Dekkers, Olaf M.

    2013-01-01

    Heart rate variability (HRV) is associated with cardiovascular disease (CVD) in individuals with known CVD. It is less clear whether HRV is associated with a first cardiovascular event. Therefore, we performed a meta-analysis to study the association between HRV and incident cardiovascular events in

  10. Associations among the Five Components within COSO Internal Control-Integrated Framework as the Underpinning of Quality Corporate Governance

    OpenAIRE

    Kirsten Rae; John Sands; Nava Subramaniam

    2017-01-01

    This paper examines the associations among COSO components and how they affect the monitoring function of organisations. Five components of an effective internal control system are described using the framework designed by COSO (1992) and have been selected because they have been identified as underpinning quality corporate governance. Structural equation modelling (SEM) was used first to run confirmatory factor analysis to determine the measurement models for the five COSO compon...

  11. Host differentiation and variability of Orobanche crenata populations from legume species in Morocco as revealed by cross-infestation and molecular analysis.

    Science.gov (United States)

    Ennami, Mounia; Briache, Fatima Zahra; Gaboun, Fatima; Abdelwahd, Rabha; Ghaouti, Lamiae; Belqadi, Loubna; Westwood, James; Mentag, Rachid

    2017-08-01

    Orobanche crenata represents a major biotic constraint to production of faba bean and lentil in Morocco. While this parasitic plant attacks both of these crops, the extent to which Orobanche biotypes specialise in parasitising specific crops is unknown. To address this question, we studied O. crenata that grew on different hosts and quantified their host specificity to faba bean and lentil. The virulence of O. crenata populations on each host was investigated through field trials, pot and Petri dishes assays. Genetic diversity of the parasite populations was also assessed through molecular analyses. The two legume species showed distinct patterns of specificity. Faba bean was more susceptible to both O. crenata populations, while the specificity for lentil by lentil-grown O. crenata was evident at the final stage of the parasite life cycle as shown by correspondence factorial analyses. Considerable internal variation (81%) within O. crenata populations parasitising both legume species was observed by molecular analyses, but significant divergence (19%; Ø = 0.189; P = 0.010) among the populations was detected. These results indicate that O. crenata can adapt to specific host species, which is important knowledge when developing integrated pest management practices for parasitic weed control. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Reader strategies: variability and error- methodology, findings, and health policy implications from a study of the U.S. population of mammographers

    Science.gov (United States)

    Beam, Craig A.

    2002-04-01

    Each year, approximately 60% of all US women over the age of 40 utilize mammography. Through the matrix of an imaging technology, this Population of Patients (POP) interacts with a population of approximately 20,000 physicians who interpret mammograms in the US. This latter Population of Diagnosticians (POD) operationally serves as the interface between an image-centric healthcare technology system and patient. Methods: using data collected from a large POD and POP based study, I evaluate the distribution of several ROC curve-related parameters in the POD and explore the health policy implications of a population ROC curve for mammography. Results and Conclusions: Principal Components Analysis suggests that two Binormal parameters are sufficient to explain variation in the POD and implies that the Binormal model is foundational to Health Policy Research in Mammography. A population ROC curve based on percentiles of the POD can be used to set targets to achieve national health policy goals. Medical Image Perception science provides the framework. Alternatively, a restrictive policy can be envisioned using performance criteria based on area. However, the data suggests this sort of policy would be too costly in terms of reduced healthcare service capacity in the US in the face of burgeoning demands.

  13. Variability and connectivity of plaice populations from the Eastern North Sea to the Western Baltic Sea, and implications for assessment and management

    DEFF Research Database (Denmark)

    Ulrich, Clara; Boje, Jesper; Cardinale, Massimiliano

    2013-01-01

    An essential prerequisite of sustainable fisheries is the match between biologically relevant processes and management action. Various populations may however co-occur on fishing grounds, although they might not belong to the same stock, leading to poor performance of stock assessment and managem......An essential prerequisite of sustainable fisheries is the match between biologically relevant processes and management action. Various populations may however co-occur on fishing grounds, although they might not belong to the same stock, leading to poor performance of stock assessment...... in this area is performed, including published and unpublished literature together with the analyses of commercial and survey data and historical tagging data. The results suggest that plaice in Skagerrak is closely associated with plaice in the North Sea, although local populations are present in the area...

  14. Cardiovascular disease, risk factors and heart rate variability in the elderly general population: Design and objectives of the CARdiovascular disease, Living and Ageing in Halle (CARLA) Study

    NARCIS (Netherlands)

    K.H. Greiser (Karin Halina); A. Kluttig (Alexander); B. Schumann (Barbara); J.A. Kors (Jan); C.A. Swenne (Cees); O. Kuss (Oliver); K. Werdan (Karl); J. Haerting (Johannes)

    2005-01-01

    textabstractBackground: The increasing burden of cardiovascular diseases (CVD) in the ageing population of industrialized nations requires an intensive search for means of reducing this epidemic. In order to improve prevention, detection, therapy and prognosis of cardiovascular diseases on the

  15. Population Genetics and Genetic Variability ofBulinus globosus (Gastropoda: Planorbidae) From the Two Main River Systems in Zimbabwe

    DEFF Research Database (Denmark)

    Mukaratirwa, S.; Siegismund, Hans Redlef; Kristensen, Thomas K.

    1996-01-01

    Bullnus globosus is the only known vector of Schistosoma haematoblum in Zimbabwe. The population genetic structure of this vector snail from the two main river drainage systems, represented by 27 localities, was determined from starch gel lsoenzyme electrophoretic data. Out of 11 enzyme systems s...

  16. Population variability of essential oils of Pinus heldreichii from the Scardo-Pindic mountains Ošljak and Galičica.

    Science.gov (United States)

    Nikolić, Biljana; Ristić, Mihailo; Bojović, Srdjan; Krivošej, Zoran; Matevski, Vlado; Marin, Petar D

    2015-02-01

    The needle-terpene profiles of two natural Pinus heldreichii populations from Mts. Ošljak and Galičica (Scardo-Pindic mountain system) were analyzed. Among the 68 detected compounds, 66 were identified. The dominant constituents were germacrene D (28.7%), limonene (27.1%), and α-pinene (16.2%). β-Caryophyllene (6.9%), β-pinene (5.2%), β-myrcene (2.3%), pimaric acid (2.0%), α-humulene (1.2%), and seven additional components were found to be present in medium-to-high amounts (0.5-10%). Although the general needle-terpene profile of the population from Galičica was similar to those of the populations from Lovćen, Zeletin, Bjelasica, and Zlatibor-Pešter (belonging to the Dinaric Alps), the principle-component analysis (PCA) of seven terpenes (β-myrcene, limonene, β-elemene, β-caryophyllene, α-humulene, δ-cadinene, and germacrene D-4-ol) in 121 tree samples suggested a partial divergence in the needle-terpene profiles between the populations from the Scardo-Pindic mountain system and the Dinaric Alps. According to previously reported data, the P. heldreichii samples from the Balkan-Rhodope mountains lack β-caryophyllene and germacrene D, but contain γ-muurolene in their terpene profile. Differences in the terpene composition between populations growing in the three above-mentioned mountain systems were compared and discussed. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

  17. There is more to climate than the North Atlantic Oscillation: a new perspective from climate dynamics to explain the variability in population growth rates of a long-lived seabird

    Directory of Open Access Journals (Sweden)

    Michel D. S. Mesquita

    2015-04-01

    Full Text Available Predicting the impact of global climate change on the biosphere has become one of the most important efforts in ecology. Ecosystems worldwide are changing rapidly as a consequence of global warming, yet our understanding of the consequences of these changes on populations is limited. The North Atlantic Oscillation (NAO has been used as a proxy for climate in several ecological studies, but this index may not always explain the patterns of variation in populations examined. Other techniques to study the relationship between ecological time series and climate are therefore needed. A standard method used in climatology is to work with point maps, where point correlation, point regression or other techniques are used to identify hotspots of regions that can explain the variability observed in the time series. These hotspots may be part of a teleconnection, which is an atmospheric mode of variability that affects remote regions around the globe. The NAO is one type of teleconnection, but not all climate variability can be explained through it. In the present study we have used climate-related techniques and analyzed the yearly variation in the population growth of a Common Guillemot Uria aalge colony in the Barents Sea area spanning 30 years. We show that the NAO does not explain this variation, but that point analysis can help identify indices that can explain a significant part of it. These indices are related to changes of mean sea level pressure in the Barents Sea via the Pacific – forming a teleconnection-type pattern. The dynamics are as follows: in years when the population growth rate is higher, the patterns observed are that of an anomalous low-pressure system in the Barents Sea. These low-pressure systems are a source of heat transport into the region and they force upwelling mixing in the ocean, thus creating favorable conditions for a more successful survival and breeding of the Common Guillemot.

  18. Espesor corneal y variables epidemiológicas y fisiológicas en población de riesgo de glaucoma Corneal thickness and the epidemiological and physiological variables seen in the glaucoma risk population

    Directory of Open Access Journals (Sweden)

    Idalia Triana Casado

    2012-12-01

    Full Text Available Objetivo: caracterizar el espesor corneal central en pacientes con factores de riesgo de glaucoma crónico simple. Métodos: se realizó un estudio epidemiológico, observacional, descriptivo y longitudinal prospectivo, en el Servicio de Glaucoma del Hospital "Dr. Salvador Allende" durante el año 2010. El universo estuvo constituido por 1 238 pacientes que acudieron a la consulta de oftalmología por síntomas astenópicos. La muestra, aplicados los criterios de inclusión y exclusión, quedó conformada por 656 pacientes con factores de riesgo de la enfermedad, de estos se desecharon 19 por una diferencia entre los ojos de 10 µm o más de espesor corneal. Las variables analizadas fueron: espesor corneal, edad, sexo, color de la piel y presión intraocular. Resultados: de los pacientes con factores de riesgo de glaucoma, predominaron aquellos entre 50 y 59 años de edad (22,76 %, masculinos (60,28 % y de piel no blanca (57,29 %. El espesor corneal estuvo disminuido (61,85 % y la presión intraocular aumentada (55,41 %, aún con ajuste (46,93 %. Conclusiones: la disminución del espesor corneal estuvo relacionada con la edad, el sexo femenino, la piel no blanca y el aumento de la presión intraocular en aquellos pacientes sospechosos de glaucoma.Objective: to characterize the central corneal thickness seen in patients with simple chronic glaucoma risk factors. Methods: a prospective longitudinal, descriptive, observational, and epidemiological study was conducted in the Glaucoma Service of “Dr. Salvador Allende” hospital during 2010. The universe of study was made up of 1 238 patients that went to the ophthalmological service due to asthenopic symptoms. Taking the inclusion and exclusion criteria into account, the final sample was composed by 656 patients with glaucoma risk factors, 19 of whom were excluded because of 10 µm and over difference in the corneal thickness between the eyes. The analyzed variables were corneal thickness, age

  19. Genetic variability of HLA in the Dariusleut Hutterites. A comparative genetic analysis of the Hutterities, the Amish, and other selected Caucasian populations.

    OpenAIRE

    Morgan, K; Holmes, T M; Schlaut, J; Marchuk, L; Kovithavongs, T; Pazderka, F; Dossetor, J B

    1980-01-01

    There are three endogamous subdivisions of the Hutterite population, a North American religious isolate. These individuals live on communal farms, and residence is strictly patrilocal. We report on the distributions of HLA-A and B alleles and haplotypes in 203 married women from one subdivision--the Dariusleut--in Alberta, Canada. We demonstrate that there is significant linkage disequilbrium among a large fraction of the distinct haplotypes in the Dariusleut Hutterite data; there is a restri...

  20. Brassica aphid (Hemiptera: Aphididae) populations are conditioned by climatic variables and parasitism level: a study case of Triângulo Mineiro, Brazil.

    Science.gov (United States)

    Sampaio, M V; Korndörfer, A P; Pujade-Villar, J; Hubaide, J E A; Ferreira, S E; Arantes, S O; Bortoletto, D M; Guimarães, C M; Sánchez-Espigares, J A; Caballero-López, B

    2017-06-01

    Cosmopolitan pests such as Brevicoryne brassicae, Lipaphis pseudobrassicae, and Myzus persicae (Aphididae) cause significant damage to Brassicaceae crops. Assessment of the important biotic and abiotic factors that regulate these pests is an essential step in the development of effective Integrated Pest Management programs for these aphids. This study evaluated the influence of leaf position, precipitation, temperature, and parasitism on populations of L. pseudobrassicae, M. persicae, and B. brassicae in collard greens fields in the Triângulo Mineiro region (Minas Gerais state), Brazil. Similar numbers of B. brassicae were found on all parts of the collard green plants, whereas M. persicae and L. pseudobrassicae were found in greatest numbers on the middle and lower parts of the plant. While temperature and precipitation were positively related to aphid population size, their effects were not accumulative, as indicated by a negative interaction term. Although Diaeretiella rapae was the main parasitoid of these aphids, hyperparasitism was dominant; the main hyperparasitoid species recovered from plant samples was Alloxysta fuscicornis. Parasitoids seem to have similar distributions on plants as their hosts. These results may help predict aphid outbreaks and gives clues for specific intra-plant locations when searching for and monitoring aphid populations.

  1. Interethnic variability of plasma paraoxonase (PON1) activity towards organophosphates and PON1 polymorphisms among Asian populations--a short review.

    Science.gov (United States)

    Mohamed Ali, Safiyya; Chia, Sin Eng

    2008-08-01

    Organophosphate (OP) poisoning is a progressively worrying phenomenon as worldwide pesticide production and consumption has doubled. On average, WHO estimates that 3% of agricultural workers in developing Asian countries suffer an episode of pesticide poisoning every year. Furthermore, the threat of OP usage in terrorism is existent, as seen by the subway tragedy in Tokyo in 1995 where sarin was used. Despite these alarming facts, there is currently no global system to track poisonings related to pesticide use. Human serum paraoxonase (PON1) is the enzyme that hydrolyses OP compounds. Serum PON1 levels and activity vary widely among different ethnic populations. Two commonly studied polymorphisms of PON1 are PON1Q192R and PON1L55M. PON1R192 hydrolyses paraoxon faster than PON1Q192 but hydrolyses diazoxon, sarin and soman eight times slower, and vice versa. PON1M55 has lower plasma levels of PON1 than PON1L55. As the prevalence of the different alleles and genotypic distribution vary between the Asian populations we studied, we propose the necessity to study PON1 polymorphisms and its role in OP toxicity in Asian populations. This would help safeguard the proper care of agricultural workers who might be affected by OP poisoning, and alert relevant anti biological terrorism agencies on possible risks involved in the event of an OP attack and provide effective counter measures.

  2. Testosterone metabolism: a possible biological underpinning of non-verbal IQ in intellectually gifted girls.

    Science.gov (United States)

    Durdiaková, Jaroslava; Celec, Peter; Laznibatová, Jolana; Minárik, Gabriel; Ostatníková, Daniela

    2016-01-01

    The extraordinary giftedness is apparently a unique manifestation of a mutual interconnection between genes and environment. One of the possible etiological factors of intellectual giftedness is testosterone which is believed to affect the brain organization and function. The aim of our study was to analyze associations between 2D:4D digit ratio (a proxy of prenatal testosterone) and/or salivary testosterone levels with non-verbal IQ in intellectually gifted girls. Fifty-one girls with an age range of 10 to18 years and IQ scores higher than 130 were tested. Saliva samples were collected to obtain levels of salivary testosterone. 2D:4D digit ratio was measured on both hands as an indicator of prenatal testosterone. IQ parameters were assessed employing standardized set of tests. The CAG repeat polymorphism in exon 1 of the androgen receptor gene was analyzed to assess the sensitivity of androgen receptor. Testing of between-subjects effects proved significant interactions between right and left 2D:4D ratio, genetic variability in androgen receptor, and also salivary testosterone level with non-verbal IQ in gifted girls. Our results point out that the variability in parameters of androgenicity contributes to the variability of nonverbal IQ in gifted girls. However, the exact molecular mechanism of how testosterone acts on the brain and affects this cognitive domain remains still unclear.

  3. Variabilidad genética de poblaciones en cautiverio de Crocodylus moreletii (Crocodylia: Crocodylidae mediante el uso de marcadores microsatelitales Genetic variability in captive populations of Crocodylus moreletii (Crocodylia: Crocodylidae using microsatellites markers

    Directory of Open Access Journals (Sweden)

    Ricardo Serna-Lagunes

    2012-03-01

    Full Text Available Crocodylus moreletii representa un emblema para los ecosistemas tropicales de México pero actualmente está amenazada por extinción. Sorprendentemente, hay una falta de información de su constitución genética, que debe ser evaluada para un manejo apropiado ex situ y para toma de decisiones en la liberación de cocodrilos a su hábitat natural. El objetivo del estudio fue caracterizar y comparar la variabilidad genética de cuatro grupos poblacionales de C. moreletii (dos silvestres y dos nacidas ex situ. Mediante PCR se amplificaron siete loci de microsatélites polimórficos, sin embargo se encontró déficit de heterocigotos en las poblaciones (promedio H O=0.02 mermado por la presencia de alelos nulos. El AMOVA indicó que la mayor proporción de variabilidad genética se encuentra dentro de las poblaciones y una limitada diferenciación genética entre poblaciones (promedio F ST =0.03, probablemente debida al alto índice de endogamia (promedio F IS=0.97. Al comparar la variabilidad genética inter e intra especies de cocodrilianos, encontramos que en C. moreletii está muy por debajo de los reportados. Se concluye que la limitada variabilidad genética de las poblaciones nacidas ex situ probablemente se debe al efecto fundador derivado de la estructura social de sus progenitores, y de las poblaciones silvestres, por el efecto cuello de botella, inferido por el limitado tamaño efectivo de población que presentó históricamente en su distribución natural.Genetic variability in captive populations of Crocodylus moreletii (Crocodylia: Crocodylidae using microsatellites markers. Crocodylus moreletii, an extinction threatened species, represents an emblem for tropical ecosystems in Mexico. Surprisingly, there is a lack of information about their genetic constitution, which should be evaluated for a proper management ex situ and for making decisions on the release of crocodiles into natural habitats. The aim of this study was to

  4. Variability in seroprevalence of rabies virus neutralizing antibodies and associated factors in a Colorado population of big brown bats (Eptesicus fuscus)

    Science.gov (United States)

    O’Shea, Thomas J.; Bowen, Richard A.; Stanley, Thomas R.; Shankar, Vidya; Rupprecht, Charles E.

    2014-01-01

    In 2001–2005 we sampled permanently marked big brown bats (Eptesicus fuscus) at summer roosts in buildings at Fort Collins, Colorado, for rabies virus neutralizing antibodies (RVNA). Seroprevalence was higher in adult females (17.9%, n = 2,332) than males (9.4%, n = 128; P = 0.007) or volant juveniles (10.2%, n = 738; Plogistic regression, the only ranking model in our candidate set of explanatory variables for serological status at first sampling included year, day of season, and a year by day of season interaction that varied with relative drought conditions. The presence or absence of antibodies in individual bats showed temporal variability. Year alone provided the best model to explain the likelihood of adult female bats showing a transition to seronegative from a previously seropositive state. Day of the season was the only competitive model to explain the likelihood of a transition from seronegative to seropositive, which increased as the season progressed. We found no rabies viral RNA in oropharyngeal secretions of 261 seropositive bats or in organs of 13 euthanized seropositive bats. Survival of seropositive and seronegative bats did not differ. The presence of RVNA in serum of bats should not be interpreted as evidence for ongoing rabies infection.

  5. Bleeding profile in users of an etonogestrel sub-dermal implant: effects of anthropometric variables. An observational uncontrolled preliminary study in Italian population.

    Science.gov (United States)

    Di Carlo, Costantino; Guida, Maurizio; De Rosa, Nicoletta; Sansone, Anna; Gargano, Virginia; Cagnacci, Angelo; Nappi, Carmine

    2015-06-01

    The purpose of this study is to evaluate the menstrual profile in users of the etonogestrel (ENG)-releasing implant (Nexplanon®) and the possible correlation with anthropometric variables. Ninety-two healthy women, desiring long-term contraception with the ENG implant were enrolled in a prospective observational study. Anthropometric variables were measured at baseline and after 3, 6, 9, and 12 months. Patients recorded daily the occurrence of any bleeding or spotting. The bleeding/spotting pattern was evaluated over consecutive 90-day intervals ("Reference Periods" - RPs). Patients who showed a favourable bleeding profile (amenorrhoea, infrequent, or normal bleeding) for 50% or more of the RPs were assigned to group A, while patients with a favourable bleeding profile for less than 50% of the RPs were assigned to group B. Sixty-eight women (79%) were assigned to group A; 18 (21%) to group B. Group B had a lower baseline body mass index (BMI) than group A (24.84 ± 4.95 kg/m(2) versus 20.75 ± 4.41 kg/m(2); p < 0.005). The ENG sub-dermal implant is a well-tolerated contraceptive method, with a high proportion of women experiencing a favourable bleeding profile. The lower basal BMI in Group B in comparison with Group A may account for the higher percentage of irregular bleeding.

  6. Snake population venomics and antivenomics of Bothrops atrox: Paedomorphism along its transamazonian dispersal and implications of geographic venom variability on snakebite management.

    Science.gov (United States)

    Calvete, Juan J; Sanz, Libia; Pérez, Alicia; Borges, Adolfo; Vargas, Alba M; Lomonte, Bruno; Angulo, Yamileth; Gutiérrez, José María; Chalkidis, Hipócrates M; Mourão, Rosa H V; Furtado, M Fatima D; Moura-Da-Silva, Ana M

    2011-04-01

    We describe two geographically differentiated venom phenotypes across the wide distribution range of Bothrops atrox, from the Colombian Magdalena Medio Valley through Puerto Ayacucho and El Paují, in the Venezuelan States of Amazonas and Orinoquia, respectively, and São Bento in the Brazilian State of Maranhão. Colombian and Venezuelan venoms show an ontogenetic toxin profile phenotype whereas Brazilian venoms exhibit paedomorphic phenotypes. Venoms from each of the 16 localities sampled contain both population-specific toxins and proteins shared by neighboring B. atrox populations. Mapping the molecular similarity between conspecific populations onto a physical map of B. atrox range provides clues for tracing dispersal routes that account for the current biogeographic distribution of the species. The proteomic pattern is consistent with a model of southeast and southwest dispersal and allopatric fragmentation northern of the Amazon Basin, and trans-Amazonian expansion through the Andean Corridor and across the Amazon river between Monte Alegre and Santarém. An antivenomic approach applied to assess the efficacy towards B. atrox venoms of two antivenoms raised in Costa Rica and Brazil using Bothrops venoms different than B. atrox in the immunization mixtures showed that both antivenoms immunodepleted very efficiently the major toxins (PIII-SVMPs, serine proteinases, CRISP, LAO) of paedomorphic venoms from Puerto Ayacucho (Venezuelan Amazonia) through São Bento, but had impaired reactivity towards PLA(2) and P-I SVMP molecules abundantly present in ontogenetic venoms. The degree of immunodepletion achieved suggests that each of these antivenoms may be effective against envenomations by paedomorphic, and some ontogenetic, B. atrox venoms. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. How does Calanus helgolandicus maintain its population in a variable environment? Analysis of a 25-year time series from the English Channel

    DEFF Research Database (Denmark)

    Maud, J.L.; Atkinson, A.; Hirst, Andrew G.

    2015-01-01

    . Here we examine the degree to which these changes translate into variation in reproductive output and subsequently C. helgolandicus population size. Egg production rates (eggs female-1 day-1) were maximal in the spring to early-summer period of diatom blooms and high ciliate abundance, rather than...... during the equally large autumn blooms of autotrophic dinoflagellates. Egg hatch success was lower in spring however, with a greater proportion of naupliar deformities then also. Both the timing and the mean summer abundance of C. helgolandicus (CI-CVI) reflected those of spring total reproductive output...

  8. On the use of Arion ater to biomonitor environmental pollution by Cd, Cu, Fe, Mn and Zn, with a special insight into the population variability.

    Science.gov (United States)

    Crespo, D; Bolón, M; Aboal, J R; Fernández, J A; Carballeira, A

    2015-05-01

    The suitability of Arion ater as a biomonitor of Cd, Cu, Fe, Mn and Zn was assessed. Individual specimens were collected from 22 sampling sites. Slugs from 3 of the sites were analysed individually, whereas the slugs from the other sites were pooled to make a composite sample for each site. The tissue burdens did not differ between individuals from contaminated and uncontaminated sites, and there was no gradient of bioaccumulation of any of the elements in the surroundings of the smelter. Analysis of the individual specimens from the 3 sites revealed very high coefficients of variation for the metal concentrations. As a result of the high level of variation, large numbers of slugs are required to produce a low error in characterizing the mean concentration at each site. Furthermore, as a consequence of the similar mean concentrations and high variability, large numbers of samples are needed to detect significant differences between pairs of sites.

  9. Geographical variability of the venoms of four populations of Bothrops asper from Panama: Toxicological analysis and neutralization by a polyvalent antivenom.

    Science.gov (United States)

    Vélez, Sara María; Salazar, Marcos; Acosta de Patiño, Hildaura; Gómez, Leandra; Rodriguez, Abdiel; Correa, David; Saldaña, Julio; Navarro, Deyvi; Lomonte, Bruno; Otero-Patiño, Rafael; Gutiérrez, José María

    2017-06-15

    Bothrops asper is the medically most important venomous snake in Central America. In Panama, the country having the highest incidence of snakebites in Latin America, B. asper is widely distributed throughout the country and is responsible for the vast majority of snakebites. This study was performed to analyze whether there are variations in the toxicological profile and in some biochemical parameters between the venoms of B. asper from four different regions in Panama. The venoms showed a similar profile of lethal, hemorrhagic, in vitro coagulant, defibrinogenating, edema-forming, myotoxic and indirect hemolytic activities, with subtle quantitative variations between samples of some regions. The venoms also had similar SDS-PAGE patterns and reverse phase HPLC profiles. A polyvalent antivenom manufactured in Costa Rica, and regularly used in Panama, was effective in the neutralization of lethal activity of the venoms of the four populations, with Mean Effective Doses (ED 50 ) ranging from 5.98 to 9.72 mg venom/mL antivenom. In agreement, a widespread pattern of cross-reactivity between this antivenom and the four venoms was observed by immunoblotting. Overall, results highlight the lack of marked differences between the venoms of the various populations of B. asper in Panama, and that the antivenom from Costa Rica is effective in neutralizing lethality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. [Climate variables, living conditions and the health of the population: leptospirosis in the city of Rio de Janeiro from 1996 to 2009].

    Science.gov (United States)

    de Oliveira, Teresa Vieira dos Santos; Marinho, Diana Pinheiro; Costa Neto, Cristina; Kligerman, Débora Cynamon

    2012-06-01

    Extreme climate events have major repercussions on the health of the population, especially when they cause disease or even result in victims due to accidents. The population of Rio de Janeiro is vulnerable to climate variations, mainly due to the socio-economic factors, as the city has a topography and climate that enhance this vulnerability. This article discusses the evolution of leptospirosis in the thirty-two administrative regions of the city of Rio de Janeiro from 1996 through 2009, testing the hypothesis that climate variations lead to an increase in the number of cases of the disease. The meteorological data examined were provided by the National Meteorology Institute and the Brazilian Airport Infrastructure Company. Data on the morbidity and mortality of leptospirosis was collected from Rio de Janeiro's Municipal Health and Civil Defense Department. In this work, it was concluded that there is a direct correlation between the incidence of leptospirosis and rainfall. However, in the final analysis, it must be emphasized that the oscillation of the number of cases is not only determined by rainfall, since other factors influence this dynamic, such as sanitation, in addition to environmental and social factors.

  11. Evaluation of potential variables contributing to the development and duration of plantar lesions in a population of aquarium-maintained African penguins (Spheniscus demersus).

    Science.gov (United States)

    Erlacher-Reid, Claire; Dunn, J Lawrence; Camp, Tracy; Macha, Laurie; Mazzaro, Lisa; Tuttle, Allison D

    2012-01-01

    Bumblefoot (pododermatitis), often described as the most significant environmental disease of captive penguins, is commonly due to excessive pressure or trauma on the plantar surface of the avian foot, resulting in inflammation or necrosis and causing severe swelling, abrasions, or cracks in the skin. Although not formally evaluated in penguins, contributing factors for bumblefoot are thought to be similar to those initiating the condition in raptors and poultry. These factors include substrate, body weight, and lack of exercise. The primary purpose of this retrospective study was to evaluate variables potentially contributing to the development and duration of plantar lesions in aquarium-maintained African penguins (Spheniscus demersus), including sex, weight, age, season, exhibit activity, and territory substrate. Results indicate that males develop significantly more plantar lesions than females. Penguins weighing between 3.51 and 4.0 kg develop plantar lesions significantly more often than penguins weighing between 2.5 and 3.5 kg, and because male African penguins ordinarily weigh significantly more than females, weight is likely a contributing factor in the development of lesions in males compared with females. Significantly more plantar lesions were observed in penguins standing for greater than 50% of their time on exhibit than swimming. Penguins occupying smooth concrete territories developed more plantar lesions compared with penguins occupying grate territories. Recommendations for minimizing bumblefoot in African penguins include training penguins for monthly foot examinations for early detection of plantar lesions predisposing for the disease, encouraging swimming activity, and replacing smooth surfaces on exhibit with surfaces providing variable degrees of pressure and texture on the feet. © 2011 Wiley Periodicals, Inc.

  12. Population fluctuations of Pyrodinium bahamense and Ceratium furca (Dinophyceae in Laguna Grande, Puerto Rico, and environmental variables associated during a three-year period

    Directory of Open Access Journals (Sweden)

    Miguel P. Sastre

    2013-12-01

    Full Text Available Bioluminescent bays and lagoons are unique natural environments and popular tourist attractions. However, the bioluminescence in many of these water bodies has declined, principally due to anthropogenic activities. In the Caribbean, the bioluminescence in these bays and lagoons is mostly produced by the dinoflagellate Pyrodinium bahamense var. bahamense. Laguna Grande is one of the three year-round bioluminescent water bodies in Puerto Rico that are known to remain but P. bahamense var. bahamense density fluctuations have not been studied. In this study we describe water quality parameters and density fluctuations of the most common dinoflagellates in Laguna Grande, P. bahamense var. bahamense and Ceratium furca, over a three-year period. For this, three sampling stations were established in Laguna Grande from which water samples were collected in triplicate and analyzed for temperature, phosphates, nitrates, salinity, water transparency, fluorescence, and dinoflagellate densities, at the water surface and at 2m depth, from May 2003 to May 2006. The results showed a density fluctuation pattern for P. bahamense var. bahamense, where higher densities were observed mainly from April to September, and lower densities from October to February. Density fluctuations of C. furca were more erratic and a repetitive pattern was not observed. Densities of P. bahamense var. bahamense ranged from 0.48 to 90 978 cells/L and densities of C. furca ranged from 0 to 11 200 cells/L. The mean population density throughout the sampling period was significantly higher in P. bahamense var. bahamense (mean=18 958.5 cells/L than in C. furca (mean=2 601.9 cells/L. Population densities of P. bahamense var. bahamense were negatively correlated with C. furca densities during the first year of sampling; however, they were positively correlated during the third year. Non-significant differences between surface and 2m depth samples were observed for temperature

  13. Variability Bugs:

    DEFF Research Database (Denmark)

    Melo, Jean

    Many modern software systems are highly configurable. They embrace variability to increase adaptability and to lower cost. To implement configurable software, developers often use the C preprocessor (CPP), which is a well-known technique, mainly in industry, to deal with variability in code....... Although many researchers suggest that preprocessor-based variability amplifies maintenance problems, there is little to no hard evidence on how actually variability affects programs and programmers. Specifically, how does variability affect programmers during maintenance tasks (bug finding in particular...... be exploited. Variability bugs are not confined to any particular type of bug, error-prone feature, or location. In addition to introducing an exponential number of program variants, variability increases the complexity of bugs due to unintended feature interactions, hidden features, combinations of layers...

  14. Relevance of the ancestry for the variability of the Drug-Metabolizing Enzymes CYP2C9, CYP2C19 and CYP2D6 polymorphisms in a multiethnic Costa Rican population.

    Science.gov (United States)

    Céspedes-Garro, Carolina; Rodrigues-Soares, Fernanda; Jiménez-Arce, Gerardo; Naranjo, María-Eugenia G; Tarazona-Santos, Eduardo; Fariñas, Humberto; Barrantes, Ramiro; Llerena, Adrián

    2016-09-01

    CYP2C9, CYP2C19 and CYP2D6 metabolize around 40% of drugs and their genes vary across populations. The Costa Rican population has a trihybrid ancestry and its key geographic location turns it into a suitable scenario to evaluate interethnic differences across populations. This study aims to describe the diversity of CYP2C9, CYP2C19 and CYP2D6 polymorphisms in Costa Rican populations in the context of their ancestry. A total of 448 healthy individuals were included in the study: Bribri (n= 47), Cabécar (n= 27), Maleku (n= 16), Guaymí (n= 30), Huetar (n= 48), Chorotega (n= 41), Admixed/Mestizos from the Central Valley/Guanacaste (n= 189), and Afro-Caribbeans (n= 50) from Limón. CYP2C9 (alleles *2, *3, *6) and CYP2C19 (*2, *3, *4, *5, *17) genotypes were determined by Real-Time PCR. African, European and Native American ancestry were inferred using 87 ancestry informative markers. The frequency of the decreased activity allele CYP2C9*2 is lower in the self-reported Amerindian groups compared to the admixed population, and the highest frequencies of CYP2C19*2 (null activity) and the CYP2C19*17 (increased activity) were found in the self-reported Afro-Caribbean population. Moreover, a frequency of 0.7 % CYP2C9 gPMs in the Admixed population and a variable frequency of CYP2C19 gUMs (0.0-32.6 %, more prevalent in Afro-Caribbeans) in Costa Rican populations, was found. Finally, the following alleles were positively correlated with genomic African ancestry and negatively correlated with genomic Native American ancestry: CYP2D6*5 (null activity), CYP2D6*17 (decreased activity), CYP2D6*29 (decreased activity) and CYP2C19*17 (increased activity). No correlation for CYP2C9 polymorphisms and genomic ancestry was found. Further studies assessing the CYP2C9 and CYP2C19 sequence in these populations, preferentially by sequencing these genes, are warranted.

  15. A systematic review of the neurobiological underpinnings of borderline personality disorder (BPD) in childhood and adolescence.

    Science.gov (United States)

    Winsper, Catherine; Marwaha, Steven; Lereya, Suzet Tanya; Thompson, Andrew; Eyden, Julie; Singh, Swaran P

    2016-12-01

    Contemporary theories for the aetiology of borderline personality disorder (BPD) take a lifespan approach asserting that inborn biological predisposition is potentiated across development by environmental risk factors. In this review, we present and critically evaluate evidence on the neurobiology of BPD in childhood and adolescence, compare this evidence to the adult literature, and contextualise within a neurodevelopmental framework. A systematic review was conducted to identify studies examining the neurobiological (i.e. genetic, structural neuroimaging, neurophysiological, and neuropsychological) correlates of BPD symptoms in children and adolescents aged 19 years or under. We identified, quality assessed, and narratively summarised 34 studies published between 1980 and June 2016. Similar to findings in adult populations, twin studies indicated moderate to high levels of heritability of BPD, and there was some evidence for gene-environment interactions. Also consistent with adult reports is that some adolescents with BPD demonstrated structural (grey and white matter) alterations in frontolimbic regions and neuropsychological abnormalities (i.e. reduced executive function and disturbances in social cognition). These findings suggest that neurobiological abnormalities observed in adult BPD may not solely be the consequence of chronic morbidity or prolonged medication use. They also provide tentative support for neurodevelopmental theories of BPD by demonstrating that neurobiological markers may be observed from childhood onwards and interact with environmental factors to increase risk of BPD in young populations. Prospective studies with a range of repeated measures are now required to elucidate the temporal unfurling of neurobiological features and further delineate the complex pathways to BPD.

  16. Risk Assessment to Underpin Food Regulatory Decisions: An Example of Public Health Nutritional Epidemiology

    Science.gov (United States)

    Baines, Janis; Cunningham, Judy; Leemhuis, Christel; Hambridge, Tracy; Mackerras, Dorothy

    2011-01-01

    The approach used by food regulation agencies to examine the literature and forecast the impact of possible food regulations has many similar features to the approach used in nutritional epidemiological research. We outline the Risk Analysis Framework described by FAO/WHO, in which there is formal progression from identification of the nutrient or food chemical of interest, through to describing its effect on health and then assessing whether there is a risk to the population based on dietary exposure estimates. We then discuss some important considerations for the dietary modeling component of the Framework, including several methodological issues that also exist in research nutritional epidemiology. Finally, we give several case studies that illustrate how the different methodological components are used together to inform decisions about how to manage the regulatory problem. PMID:22254081

  17. Association between the variability of the ABCA13 gene and the risk of major depressive disorder and schizophrenia in the Han Chinese population.

    Science.gov (United States)

    Chen, Jianhua; Khan, Raja Amjad Waheed; Wang, Meng; He, Kuanjun; Wang, Qingzhong; Li, Zhiqiang; Li, Wenjin; Wen, Zujia; Song, Zhijian; Shen, Jiawei; Xu, Yifeng; Shi, Yongyong

    2017-10-01

    The ATP-binding cassette transporter superfamily is one of the largest membrane protein families, which is responsible for transportation of substances across the membranes by utilising energy. Some research has bridged the variations in ABCA13 with occurrence of psychiatric disorders. To investigate the overlapping risk conferred by ABCA13 for both major depressive disorder and schizophrenia, we analysed tag single nucleotide polymorphisms (tag SNPs). We used TaqMan ® technology to genotype 1045 major depressive disorder patients, 1235 schizophrenia patients and 1235 healthy controls of Han Chinese origin. We found that rs7789493 (P allele  =   7.23E-04, P genotype  =.001) was associated with major depressive disorder, while rs17132388 (P allele  =   1.63E-04, P genotype  =   7.50E-04) and rs6583476 (P allele  =   5.50E-04, P genotype  =.002) showed statistically significant association with schizophrenia. Our results indicate that the ABCA13 gene may contain overlapping common genetic risk factors for both major depressive disorder and schizophrenia in the Han Chinese population. The study on variants conferring overlapping risk for multiple psychiatric disorders could be tangible pathogenesis support in clinical or diagnostic references.

  18. The Variability of Seed Viability and Seed Vigour of Mindi (Melia azedarachlinn. from Several Populations in The Community Forest of West Java

    Directory of Open Access Journals (Sweden)

    Yulianti Bramasto

    2016-12-01

    Full Text Available The procurement of good quality seeds for the development of mindi (Melia azedarach L. in the community forest is absolutely necessary. The purpose of this research is to investigate the diversity of the viability and seedling vigor of mindi from different populations with various treatments of dormancy breaking. The sample materials were mindi seeds that were collected from 6 locations (6 seed lots or seed sources which were located in the community forest of West Java. There are 10 treatments of dormancy breaking that were applied in this study. The experiment design was Randomized Complete Design (RAL. The breaking dormancy  was focused to the delignification of hard seed coat.  Results showed that the most effective dormancy breaking for mindi seed was soaking in consentrated Sulfuric Acid (H2SO4 as long as 30 to 45 minutes. The first count for germination of mindi was on the 16 day and the final count was on the 31 day.The average value of germination percentage (DB for all seed sources was 40 %, while the highest which is 60% was mindi from Sumedang seed source. The highest value of germination rate that is 6,543%/etmal was seed  from Sumedangand seed from Gambung was the lowest (1,400 %/etmal. Keywords : community forest, Melia azedarach L., variation, viability, vigor.

  19. Influence of Adiposity-Related Genetic Markers in a Population of Saudi Arabians Where Other Variables Influencing Obesity May Be Reduced

    Directory of Open Access Journals (Sweden)

    Khalid K. Alharbi

    2014-01-01

    Full Text Available Large scale studies in Europeans have clearly identified common polymorphism affecting BMI and obesity. We undertook a genotype study to examine the impact of variants, known to influence obesity, in a sample from the Saudi Arabian population, notable for its profound combination of low mean physical activity indices and high energy intake. Anthropometry measures and genotypes were obtained for 367 Saudis, taken from King Saud University and Biomarker Screening Project in Riyadh (Riyadh Cohort. We observed large effect sizes with obesity for rs10767664 (BDNF (OR = 1.923, P=0.00072 and rs3751812 (FTO (OR = 1.523, P=0.016 in our sample and, using weighted genetic risk scores, we found strong evidence of a cumulative effect using 11 SNPs taken predominantly from loci principally affecting appetite (OR = 2.57, P=0.00092. We used conditional analyses to discern which of our three highly correlated FTO SNPs were responsible for the observed signal, although we were unable to determine with confidence which best marked the causal site. Our analysis indicates that markers located in loci known to influence fat mass through increased appetite affect obesity in Saudi Arabians to an extent possibly greater than in Europeans. Larger scale studies will be necessary to obtain a precise comparison.

  20. The Variability of Seed Viability and Seed Vigour of Mindi (Melia azedarachlinn. from Several Populations in The Community Forest of West Java

    Directory of Open Access Journals (Sweden)

    Yulianti Bramasto

    2016-12-01

    Full Text Available The procurement of good quality seeds for the development of mindi (Melia azedarach L. in the community forest is absolutely necessary. The purpose of this research is to investigate the diversity of the viability and seedling vigor of mindi from different populations with various treatments of dormancy breaking. The sample mat erials were mindi seeds that were collected from 6 locations (6 seed lots or seed sources which were located in the community forest of West Java. There are 10 treatments of dormancy breaking that were applied in this study. The experiment design was Randomized Complete Design (RAL. The breaking dormancy was focused to the delignification of hard seed coat. Results showed that the most effective dormancy breaking for mindi seed was soaking in consentrated Sulfuric Acid (H2SO4 as long as 30 to 45 minutes. The first count for germination of mindi was on the 16 day and the final count was on the 31 day. The average value of germination percentage (DB for all seed sources was 40 %, while the highest which is 60 % was mindi from Sumedang seed source. The highest value of germination rate that is 6,543 %/etmal was seed from Sumedang and seed from Gambung was the lowest (1,400 %/etmal.

  1. Pulsating variables

    International Nuclear Information System (INIS)

    1989-01-01

    The study of stellar pulsations is a major route to the understanding of stellar structure and evolution. At the South African Astronomical Observatory (SAAO) the following stellar pulsation studies were undertaken: rapidly oscillating Ap stars; solar-like oscillations in stars; 8-Scuti type variability in a classical Am star; Beta Cephei variables; a pulsating white dwarf and its companion; RR Lyrae variables and galactic Cepheids. 4 figs

  2. An integrated organisation-wide data quality management and information governance framework: theoretical underpinnings.

    Science.gov (United States)

    Liaw, Siaw-Teng; Pearce, Christopher; Liyanage, Harshana; Liaw, Gladys S S; de Lusignan, Simon

    2014-01-01

    Increasing investment in eHealth aims to improve cost effectiveness and safety of care. Data extraction and aggregation can create new data products to improve professional practice and provide feedback to improve the quality of source data. A previous systematic review concluded that locally relevant clinical indicators and use of clinical record systems could support clinical governance. We aimed to extend and update the review with a theoretical framework. We searched PubMed, Medline, Web of Science, ABI Inform (Proquest) and Business Source Premier (EBSCO) using the terms curation, information ecosystem, data quality management (DQM), data governance, information governance (IG) and data stewardship. We focused on and analysed the scope of DQM and IG processes, theoretical frameworks, and determinants of the processing, quality assurance, presentation and sharing of data across the enterprise. There are good theoretical reasons for integrated governance, but there is variable alignment of DQM, IG and health system objectives across the health enterprise. Ethical constraints exist that require health information ecosystems to process data in ways that are aligned with improving health and system efficiency and ensuring patient safety. Despite an increasingly 'big-data' environment, DQM and IG in health services are still fragmented across the data production cycle. We extend current work on DQM and IG with a theoretical framework for integrated IG across the data cycle. The dimensions of this theory-based framework would require testing with qualitative and quantitative studies to examine the applicability and utility, along with an evaluation of its impact on data quality across the health enterprise.

  3. An integrated organisation-wide data quality management and information governance framework: theoretical underpinnings

    Directory of Open Access Journals (Sweden)

    Siaw-Teng Liaw

    2014-10-01

    Full Text Available Introduction Increasing investment in eHealth aims to improve cost effectiveness and safety of care. Data extraction and aggregation can create new data products to improve professional practice and provide feedback to improve the quality of source data. A previous systematic review concluded that locally relevant clinical indicators and use of clinical record systems could support clinical governance. We aimed to extend and update the review with a theoretical framework.Methods We searched PubMed, Medline, Web of Science, ABI Inform (Proquest and Business Source Premier (EBSCO using the terms curation, information ecosystem, data quality management (DQM, data governance, information governance (IG and data stewardship. We focused on and analysed the scope of DQM and IG processes, theoretical frameworks, and determinants of the processing, quality assurance, presentation and sharing of data across the enterprise.Findings There are good theoretical reasons for integrated governance, but there is variable alignment of DQM, IG and health system objectives across the health enterprise. Ethical constraints exist that require health information ecosystems to process data in ways that are aligned with improving health and system efficiency and ensuring patient safety. Despite an increasingly ‘big-data’ environment, DQM and IG in health services are still fragmented across the data production cycle. We extend current work on DQM and IG with a theoretical framework for integrated IG across the data cycle.Conclusions The dimensions of this theory-based framework would require testing with qualitative and quantitative studies to examine the applicability and utility, along with an evaluation of its impact on data quality across the health enterprise.

  4. Topological characteristics underpin intermittency and anomalous transport behavior in soil-like porous media

    Science.gov (United States)

    Holzner, M.; Morales, V.; Willmann, M.; Jerjen, I.; Kaufmann, R.; Dentz, M.

    2016-12-01

    Continuum models of porous media are based on the validity of the Darcy equation for fluid and Fick's law for scalar fluxes on a representative elementary volume. Fluctuations of pore-scale flow and scalar transport are averaged out and represented in terms of effective parameters such as hydrodynamic dispersion. However, the intermittent behavior of pore-scale flow impacts on the nature of particle and scalar transport, and it determines the way dissolved substances mix and react. The understanding of the origin of these processes is of both fundamental and practical importance in applications ranging from reactive transport in groundwater flow to diffusion in fuel cells or biological systems. A central issue in porous medium flow is therefore to relate intermittent behavior of Lagrangian velocity at pore scale imposed by the complex pore network geometry to transport properties at larger scales. Lagrangian measurements in porous systems are nonetheless scarce and most experimental techniques do not provide access to all three velocity components. In this contribution we report 3D measurements of Lagrangian velocity in soil-like porous media. We complement these measurements with detailed X-ray scans of the pore network. We find sharp velocity transitions close to pore throats, and low flow variability in the pore bodies, which gives rise to stretched exponential Lagrangian velocity and acceleration distributions characterized by a sharp peak at low velocity and a superlinear evolution of particle dispersion. We demonstrate that porosity and pore size distribution alone cannot explain the observed features of the flow. Rather, anomalous transport is better interpreted in terms of how pores of various geometries are interconnected. We reproduce the main observations using a continuous-time random walk (CTRW) model revealing the main features that control the system and showing the potential of this simple model to capture transport in complex geometries.

  5. The cut-off values of anthropometric variables for predicting mild cognitive impairment in Malaysian older adults: a large population based cross-sectional study

    Directory of Open Access Journals (Sweden)

    Won H

    2017-02-01

    Full Text Available Huiloo Won,1 Zahara Abdul Manaf,2 Arimi Fitri Mat Ludin,3 Mohd Azahadi Omar,4 Rosdinom Razali,5 Suzana Shahar2 1Nutrition Program, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 2Dietetics Program, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 3Biomedical Science Program, School of Diagnostic and Applied Health Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 4Centre for Burden of Disease Research, Institute for Public Health, Ministry of Health Malaysia, 5Department of Psychiatry, Faculty of Medicine, Hospital Canselor Tuanku Muhriz, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia Purpose: Older adults are at risk of mild cognitive impairment (MCI, and simple anthropometric measurements can be used to screen for this condition. Thus, the aim of this study was to explore the cut-off values of body mass index (BMI and waist circumference (WC for predicting the risk of MCI in older Malaysian adults.Methods: A total of 2,240 Malaysian older adults aged ≥60 years were recruited using multistage random sampling in a population based cross-sectional study. Receiver operating characteristic (ROC curve was used to determine the cut-off values of BMI and WC with optimum sensitivity and specificity for the detection of MCI. Age, gender, years of education, smoking habit, alcohol consumption, depression, and medical conditions were used as confounding factors in this analysis.Results: A BMI cut-off value of 26 kg/m2 (area under the receiver operating characteristic curve [AUC] 0.725; sensitivity 90.5%; specificity 38.8% was appropriate in identifying the risk of getting MCI in both men and women. The optimum WC cut-offs for likelihood of MCI were 90 cm (AUC 0.745; sensitivity 78.0%; specificity 59.8% for men and 82 cm (AUC 0.714; sensitivity 84.3%; specificity 49.7% for women. The optimum calf circumference (CC cut-off values for identifying MCI were 29 cm (AUC 0.731; sensitivity 72.6%; specificity

  6. Cognitive Variability

    Science.gov (United States)

    Siegler, Robert S.

    2007-01-01

    Children's thinking is highly variable at every level of analysis, from neural and associative levels to the level of strategies, theories, and other aspects of high-level cognition. This variability exists within people as well as between them; individual children often rely on different strategies or representations on closely related problems…

  7. Individual differences in brain structure underpin empathizing-systemizing cognitive styles in male adults.

    Science.gov (United States)

    Lai, Meng-Chuan; Lombardo, Michael V; Chakrabarti, Bhismadev; Ecker, Christine; Sadek, Susan A; Wheelwright, Sally J; Murphy, Declan G M; Suckling, John; Bullmore, Edward T; Baron-Cohen, Simon

    2012-07-16

    Individual differences in cognitive style can be characterized along two dimensions: 'systemizing' (S, the drive to analyze or build 'rule-based' systems) and 'empathizing' (E, the drive to identify another's mental state and respond to this with an appropriate emotion). Discrepancies between these two dimensions in one direction (S>E) or the other (E>S) are associated with sex differences in cognition: on average more males show an S>E cognitive style, while on average more females show an E>S profile. The neurobiological basis of these different profiles remains unknown. Since individuals may be typical or atypical for their sex, it is important to move away from the study of sex differences and towards the study of differences in cognitive style. Using structural magnetic resonance imaging we examined how neuroanatomy varies as a function of the discrepancy between E and S in 88 adult males from the general population. Selecting just males allows us to study discrepant E-S profiles in a pure way, unconfounded by other factors related to sex and gender. An increasing S>E profile was associated with increased gray matter volume in cingulate and dorsal medial prefrontal areas which have been implicated in processes related to cognitive control, monitoring, error detection, and probabilistic inference. An increasing E>S profile was associated with larger hypothalamic and ventral basal ganglia regions which have been implicated in neuroendocrine control, motivation and reward. These results suggest an underlying neuroanatomical basis linked to the discrepancy between these two important dimensions of individual differences in cognitive style. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Transactive System: Part I: Theoretical Underpinnings of Payoff Functions, Control Decisions, Information Privacy, and Solution Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Jianming [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhang, Wei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sun, Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Marinovici, Laurentiu D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kalsi, Karanjit [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Widergren, Steven E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2018-01-17

    The increased penetration of renewable energy has significantly changed the conditions and the operational timing of the electricity grid. More flexible, faster ramping resources are needed to compensate for the uncertainty and variability introduced by renewable energy. Distributed energy resources (DERs) such as distributed generators, energy storage, and controllable loads could help manage the power grid in terms of both economic efficiency and operational reliability. In order to realize the benefits of DERs, coordination and control approaches must be designed to enable seamless integration of DERs into the power grid. Transactive coordination and control is a new approach for DER integration, where individual resources are automated and engaged through market interaction. Transactive approaches use economic signals—prices or incentives—to engage DERs. These economic signals must reflect the true value of the DER contributions, so that they seamlessly and equitably compete for the opportunities that today are only available to grid-owned assets. Value signals must be communicated to the DERs in near-real time, the assets must be imbued with new forms of distributed intelligence and control to take advantage of the opportunities presented by these signals, and they must be capable of negotiating and transacting a range of market-driven energy services. The concepts of transactive energy systems are not new, but build upon evolutionary economic changes in financial and electric power markets. These concepts also recognize the different regional structures of wholesale power markets, electricity delivery markets, retail markets, and vertically integrated service provider markets. Although transactive energy systems are not revolutionary, they will be transformational in their ability to provide flexibility and operational efficiency. A main goal of this research is to establish useful foundation for analysis of transactive energy systems and to facilitate

  9. Variability and component composition

    NARCIS (Netherlands)

    T. van der Storm (Tijs)

    2004-01-01

    textabstractIn component-based product populations, feature models have to be described at the component level to be able to benefit from a product family approach. As a consequence, composition of components becomes very complex. We describe how component-level variability can be managed in the

  10. Practice as ‘Research’ Within The Context of Art and Design Academia: A Brief Excursion Into Its Philosophical Underpinnings

    Directory of Open Access Journals (Sweden)

    Dominique Rio Adiwijaya

    2015-07-01

    Full Text Available Integration of many fields of human endeavor including art and design into academic system is not at all surprising in our modern world that continues to modernize itself in the quest for ever increasing welfare of humanity. The backbone of modern welfare is unmistakably techno-scientific academic research, explaining current expansion of its ‘standardized’ paradigm, regulation and infrastructure without exception into the field of art and design. This is where the problem precisely arises, since their own nature, art and design as ‘creative’ fields, are incompatible with scientific paradigm which emphasizes a uniform reproducibility of research findings. ‘The heart of the arts’, in contrast, is its singularities. The industry actually has recognized the difference by assigning ‘patents’ to technological invention and ‘copyright’ to singular artworks. The question is then how to incorporate such creatively plural fields into uniform academic research system. Fortunately within the past 20 years, there were developments within international art and design academia that came up with a keystone principle called practice-based research. It relies upon philosophical underpinnings of phenomenology and hermeneutics which has been critically acclaimed in showing inadequacies of positivistic (natural science-based paradigm in understanding cultural phenomena exemplified by art and design. It is the intention of this article to briefly explain this new principle and its philosophical underpinnings in order to let us appreciate its positive contribution for our understanding of art and design. This understanding in turn would allow us to cultivate those creative fields within academic context in a more appropriate way. 

  11. Genetic Variability, Genotype × Environment Interaction, Correlation, and GGE Biplot Analysis for Grain Iron and Zinc Concentration and Other Agronomic Traits in RIL Population of Sorghum (Sorghum bicolor L. Moench)

    Science.gov (United States)

    Phuke, Rahul M.; Anuradha, Kotla; Radhika, Kommineni; Jabeen, Farzana; Anuradha, Ghanta; Ramesh, Thatikunta; Hariprasanna, K.; Mehtre, Shivaji P.; Deshpande, Santosh P.; Anil, Gaddameedi; Das, Roma R.; Rathore, Abhishek; Hash, Tom; Reddy, Belum V. S.; Kumar, Are Ashok

    2017-01-01

    The low grain iron and zinc densities are well documented problems in food crops, affecting crop nutritional quality especially in cereals. Sorghum is a major source of energy and micronutrients for majority of population in Africa and central India. Understanding genetic variation, genotype × environment interaction and association between these traits is critical for development of improved cultivars with high iron and zinc. A total of 336 sorghum RILs (Recombinant Inbred Lines) were evaluated for grain iron and zinc concentration along with other agronomic traits for 2 years at three locations. The results showed that large variability exists in RIL population for both micronutrients (Iron = 10.8 to 76.4 mg kg−1 and Zinc = 10.2 to 58.7 mg kg−1, across environments) and agronomic traits. Genotype × environment interaction for both micronutrients (iron and zinc) was highly significant. GGE biplots comparison for grain iron and zinc showed greater variation across environments. The results also showed that G × E was substantial for grain iron and zinc, hence wider testing needed for taking care of G × E interaction to breed micronutrient rich sorghum lines. Iron and zinc concentration showed high significant positive correlation (across environment = 0.79; p 0.60, in individual environments) for Fe and Zn and other traits studied indicating its suitability to map QTL for iron and zinc. PMID:28529518

  12. Genetic variability and bottleneck analyses of Kanni adu goat population using microsatellite markers [Also published in The Indian Journal of Small Ruminants, 2015, 21(2): 216-22

    International Nuclear Information System (INIS)

    Jeyakumar, M.; Thiruvenkadan, R.; Saravana, R.; Periasamy, K.

    2016-01-01

    Full text: Microsatellite data on 25 loci were generated and utilized to evaluate the genetic architecture and mutation drift equilibrium of Kanni Adu goats of southern Tamil Nadu. The genetic diversity analysis of Kanni Adu goats displayed higher level of within breed variability in terms of mean number of alleles per locus (11.24±0.87) and heterozygosity values (Ho= 0.677±0.041, He=0.857±0.016). Within population inbreeding estimate (FIS=0.215±0.040) showed moderate level of inbreeding, which warrant adoption of appropriate breeding strategies under field conditions. The polymorphism information content (PIC) value ranged from 0.531 to 0.915 suggested higher polymorphism in this breed. In general, the sign, standardized differences and Wilcoxon rank tests indicated heterozygosity excess in Kanni Adu goat population in infinite alleles and two-phase model and non-significant in stepwise mutation model. Hence, the mode-shift indicator test was utilized and it indicated the absence of genetic bottleneck in the recent past in Kanni Adu goats. It suggests that any unique alleles present in this breed may not have been lost. The study indicated that Kanni adu goats exhibited substantial amount of genetic variation as reflected from the heterozygosity and number of alleles per locus. (author)

  13. Genetic variability in natural populations of Zeyheria montana mart. from the Brazilian Cerrado Variabilidade genética entre e dentro de populações naturais de Zeyheria montana mart. do Cerrado brasileiro

    Directory of Open Access Journals (Sweden)

    Bianca Waléria Bertoni

    2007-08-01

    Full Text Available Zeyheria montana, an endemic species of the Bignoniaceae family from the Brazilian Cerrado's known for its anti-cancer properties, is widely used as imuno stimulant in the popular medicine and its therapeutic activity must be validated by scientific data. The objective of this work was to evaluate the genetic variability of eight plant populations collected within the state of São Paulo, Brazil, via Random Amplification of Polymorphic DNA (RAPD used as molecular markers. After an optimized protocol for the amplification reaction, nine selected primers generated 105 reproducible bands, indicating up to 60% polymorphism. Analysis of molecular variance (AMOVA revealed higher genetic variation within populations (84.03% than among populations (15.97%. The variation values estimated by phiST (0.160 indicated moderate to high inter population structuration. Levels of similarity inter plants with genetic and geographical distances, estimated by the unweighted pair-group method analysis (UPGMA clustering and non-metric multidimensional scaling (NMDS ordination methods and by the Mantel test (-0.2345 p = 0.118 denoted that the structure found follows the island model, which assumes that a single population of infinite size may have initiated the existing populations of Zeyheria montana, with no spatial position correlation. Based on the obtained data, a germplasm bank from individuals representing the species variability was established. Furthermore the information here reported can be of importance to develop strategies for the conservation of Z. montana.Zeyheria montana, planta arbustiva da família Bignoniaceae, é uma espécie endêmica do Cerrado e possui atividade anti-câncer, sendo utilizada como estimulante na medicina popular. O objetivo deste estudo foi avaliar a variabilidade genética de oito populações localizadas no estado de São Paulo, utilizando marcadores moleculares de Polimorfismo de DNA Amplificado ao Acaso (RAPD. Após a otimiza

  14. Mesoscale spatiotemporal variability in a complex host-parasite system influenced by intermediate host body size

    Directory of Open Access Journals (Sweden)

    Sara M. Rodríguez

    2017-08-01

    Full Text Available Background Parasites are essential components of natural communities, but the factors that generate skewed distributions of parasite occurrences and abundances across host populations are not well understood. Methods Here, we analyse at a seascape scale the spatiotemporal relationships of parasite exposure and host body-size with the proportion of infected hosts (i.e., prevalence and aggregation of parasite burden across ca. 150 km of the coast and over 22 months. We predicted that the effects of parasite exposure on prevalence and aggregation are dependent on host body-sizes. We used an indirect host-parasite interaction in which migratory seagulls, sandy-shore molecrabs, and an acanthocephalan worm constitute the definitive hosts, intermediate hosts, and endoparasite, respectively. In such complex systems, increments in the abundance of definitive hosts imply increments in intermediate hosts’ exposure to the parasite’s dispersive stages. Results Linear mixed-effects models showed a significant, albeit highly variable, positive relationship between seagull density and prevalence. This relationship was stronger for small (cephalothorax length >15 mm than large molecrabs (<15 mm. Independently of seagull density, large molecrabs carried significantly more parasites than small molecrabs. The analysis of the variance-to-mean ratio of per capita parasite burden showed no relationship between seagull density and mean parasite aggregation across host populations. However, the amount of unexplained variability in aggregation was strikingly higher in larger than smaller intermediate hosts. This unexplained variability was driven by a decrease in the mean-variance scaling in heavily infected large molecrabs. Conclusions These results show complex interdependencies between extrinsic and intrinsic population attributes on the structure of host-parasite interactions. We suggest that parasite accumulation—a characteristic of indirect host

  15. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  16. Underpinning Land Management

    DEFF Research Database (Denmark)

    Enemark, Stig

    This paper provides an overall understanding of the concept of land administration systems for dealing with rights, restrictions and responsibilities in future spatially enabled government. Further, the paper presents the role of FIG with regard to building the capacity in this area and responding...

  17. Social Assistance: Theoretical Underpinnings

    African Journals Online (AJOL)

    user

    obligation to the poor. Whether virtue or beneficence or piety, these concepts have come to characterize much of the stance of society towards the poor. The Judeo Christian tradition went further in making care for others as the epitome of the love that it advances. Islam regards. 1. PhD, Hope University College.

  18. Neural underpinnings of music

    DEFF Research Database (Denmark)

    Vuust, Peter; Gebauer, Line K; Witek, Maria A G

    2014-01-01

    Musical rhythm, consisting of apparently abstract intervals of accented temporal events, has the remarkable ability to move our minds and bodies. Why do certain rhythms make us want to tap our feet, bop our heads or even get up and dance? And how does the brain process rhythmically complex rhythms...... during our experiences of music? In this chapter, we describe some common forms of rhythmic complexity in music and propose that the theory of predictive coding can explain how rhythm and rhythmic complexity are processed in the brain. We also consider how this theory may reveal why we feel so compelled...... by rhythmic tension in music. First, musical-theoretical and neuroscientific frameworks of rhythm are presented, in which rhythm perception is conceptualized as an interaction between what is heard (‘rhythm’) and the brain’s anticipatory structuring of music (‘the meter’). Second, three different examples...

  19. Impaired endocannabinoid signalling in the rostral ventromedial medulla underpins genotype-dependent hyper-responsivity to noxious stimuli.

    Science.gov (United States)

    Rea, Kieran; Olango, Weredeselam M; Okine, Bright N; Madasu, Manish K; McGuire, Iseult C; Coyle, Kathleen; Harhen, Brendan; Roche, Michelle; Finn, David P

    2014-01-01

    Pain is both a sensory and an emotional experience, and is subject to modulation by a number of factors including genetic background modulating stress/affect. The Wistar-Kyoto (WKY) rat exhibits a stress-hyper-responsive and depressive-like phenotype and increased sensitivity to noxious stimuli, compared with other rat strains. Here, we show that this genotype-dependent hyperalgesia is associated with impaired pain-related mobilisation of endocannabinoids and transcription of their synthesising enzymes in the rostral ventromedial medulla (RVM). Pharmacological blockade of the Cannabinoid1 (CB1) receptor potentiates the hyperalgesia in WKY rats, whereas inhibition of the endocannabinoid catabolising enzyme, fatty acid amide hydrolase, attenuates the hyperalgesia. The latter effect is mediated by CB1 receptors in the RVM. Together, these behavioural, neurochemical, and molecular data indicate that impaired endocannabinoid signalling in the RVM underpins hyper-responsivity to noxious stimuli in a genetic background prone to heightened stress/affect. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  20. Personality dimensions emerging during adolescence and young adulthood are underpinned by a single latent trait indexing impairment in social functioning.

    Science.gov (United States)

    Polek, Ela; Jones, Peter B; Fearon, Pasco; Brodbeck, Jeannette; Moutoussis, Michael; Nspn Consortium; Dolan, Ray; Fonagy, Peter; Bullmore, Edward T; Goodyer, Ian M

    2018-01-26

    Personality with stable behavioural traits emerges in the adolescent and young adult years. Models of putatively distinct, but correlated, personality traits have been developed to describe behavioural styles including schizotypal, narcissistic, callous-unemotional, negative emotionality, antisocial and impulsivity traits. These traits have influenced the classification of their related personality disorders. We tested if a bifactor model fits the data better than correlated-factor and orthogonal-factor models and subsequently validated the obtained factors with mental health measures and treatment history. A set of self-report questionnaires measuring the above traits together with measures of mental health and service use were collected from a volunteer community sample of adolescents and young adults aged 14 to 25 years (N = 2443). The bifactor model with one general and four specific factors emerged in exploratory analysis, which fit data better than models with correlated or orthogonal factors. The general factor showed high reliability and validity. The findings suggest that a selected range of putatively distinct personality traits is underpinned by a general latent personality trait that may be interpreted as a severity factor, with higher scores indexing more impairment in social functioning. The results are in line with ICD-11, which suggest an explicit link between personality disorders and compromised interpersonal or social function. The obtained general factor was akin to the overarching dimension of personality functioning (describing one's relation to the self and others) proposed by DSM-5 Section III.

  1. Essentials of Advocacy in Case Management: Part 1: Ethical Underpinnings of Advocacy-Theories, Principles, and Concepts.

    Science.gov (United States)

    Tahan, Hussein M

    2016-01-01

    This article describes the meaning and underpinnings of advocacy in the field of case management and shares essential principles and concepts for effective client advocacy. All practice settings across the continuum of health and human services and case managers of diverse professional backgrounds. Advocacy is vital to case management practice and a primary role of the professional case manager. It is rooted in ethical theory and principles. Successful case managers apply advocacy at every step of the case management process and in every action they take. Part I of this 2-part article explores the ethical theories and principles of advocacy, the perception of case management-related professional organizations of advocacy, and types of advocacy. Part II then presents a client advocacy model for case managers to apply in their practice, describes the role of advocacy in client engagement, and identifies important strategies and a set of essentia