WorldWideScience

Sample records for dependent population processes

  1. Density dependence in a recovering osprey population: demographic and behavioural processes.

    Science.gov (United States)

    Bretagnolle, V; Mougeot, F; Thibault, J-C

    2008-09-01

    1. Understanding how density-dependent and independent processes influence demographic parameters, and hence regulate population size, is fundamental within population ecology. We investigated density dependence in growth rate and fecundity in a recovering population of a semicolonial raptor, the osprey Pandion haliaetus [Linnaeus, 1758], using 31 years of count and demographic data in Corsica. 2. The study population increased from three pairs in 1974 to an average of 22 pairs in the late 1990s, with two distinct phases during the recovery (increase followed by stability) and contrasted trends in breeding parameters in each phase. 3. We show density dependence in population growth rate in the second phase, indicating that the stabilized population was regulated. We also show density dependence in productivity (fledging success between years and hatching success within years). 4. Using long-term data on behavioural interactions at nest sites, and on diet and fish provisioning rate, we evaluated two possible mechanisms of density dependence in productivity, food depletion and behavioural interference. 5. As density increased, both provisioning rate and the size of prey increased, contrary to predictions of a food-depletion mechanism. In the time series, a reduction in fledging success coincided with an increase in the number of non-breeders. Hatching success decreased with increasing local density and frequency of interactions with conspecifics, suggesting that behavioural interference was influencing hatching success. 6. Our study shows that, taking into account the role of non-breeders, in particular in species or populations where there are many floaters and where competition for nest sites is intense, can improve our understanding of density-dependent processes and help conservation actions.

  2. Application of a time-dependent coalescence process for inferring the history of population size changes from DNA sequence data.

    Science.gov (United States)

    Polanski, A; Kimmel, M; Chakraborty, R

    1998-05-12

    Distribution of pairwise differences of nucleotides from data on a sample of DNA sequences from a given segment of the genome has been used in the past to draw inferences about the past history of population size changes. However, all earlier methods assume a given model of population size changes (such as sudden expansion), parameters of which (e.g., time and amplitude of expansion) are fitted to the observed distributions of nucleotide differences among pairwise comparisons of all DNA sequences in the sample. Our theory indicates that for any time-dependent population size, N(tau) (in which time tau is counted backward from present), a time-dependent coalescence process yields the distribution, p(tau), of the time of coalescence between two DNA sequences randomly drawn from the population. Prediction of p(tau) and N(tau) requires the use of a reverse Laplace transform known to be unstable. Nevertheless, simulated data obtained from three models of monotone population change (stepwise, exponential, and logistic) indicate that the pattern of a past population size change leaves its signature on the pattern of DNA polymorphism. Application of the theory to the published mtDNA sequences indicates that the current mtDNA sequence variation is not inconsistent with a logistic growth of the human population.

  3. Oxygen Dependent Biocatalytic Processes

    DEFF Research Database (Denmark)

    Pedersen, Asbjørn Toftgaard

    Enzyme catalysts have the potential to improve both the process economics and the environ-mental profile of many oxidation reactions especially in the fine- and specialty-chemical industry, due to their exquisite ability to perform stereo-, regio- and chemo-selective oxida-tions at ambient...... to aldehydes and ketones, oxyfunctionalization of C-H bonds, and epoxidation of C-C double bonds. Although oxygen dependent biocatalysis offers many possibilities, there are numerous chal-lenges to be overcome before an enzyme can be implemented in an industrial process. These challenges requires the combined...... far below their potential maximum catalytic rate at industrially relevant oxygen concentrations. Detailed knowledge of the en-zyme kinetics are therefore required in order to determine the best operating conditions and design oxygen supply to minimize processing costs. This is enabled...

  4. Maintenance of phenotypic variation: repeatibility, heritability, and size-dependent processes in a wild brook trout population

    Science.gov (United States)

    Benjamin H. Letcher; Jason A Coombs; Keith H. Nislow

    2011-01-01

    Phenotypic variation in body size can result from within-cohort variation in birth dates, among-individual growth variation and size-selective processes. We explore the relative effects of these processes on the maintenance of wide observed body size variation in stream-dwelling brook trout (Salvelinus fontinalis). Based on the analyses of multiple...

  5. A mechanistic analysis of density dependence in algal population dynamics

    Directory of Open Access Journals (Sweden)

    Adrian eBorlestean

    2015-04-01

    Full Text Available Population density regulation is a fundamental principle in ecology, but the specific process underlying functional expression of density dependence remains to be fully elucidated. One view contends that patterns of density dependence are largely fixed across a species irrespective of environmental conditions, whereas another is that the strength and expression of density dependence are fundamentally variable depending on the nature of exogenous or endogenous constraints acting on the population. We conducted a study investigating the expression of density dependence in Chlamydomonas spp. grown under a gradient from low to high nutrient density. We predicted that the relationship between per capita growth rate (pgr and population density would vary from concave up to concave down as nutrient density became less limiting and populations experienced weaker density regulation. Contrary to prediction, we found that the relationship between pgr and density became increasingly concave-up as nutrient levels increased. We also found that variation in pgr increased, and pgr levels reached higher maxima in nutrient-limited environments. Most likely, these results are attributable to population growth suppression in environments with high intraspecific competition due to limited nutrient resources. Our results suggest that density regulation is strongly variable depending on exogenous and endogenous processes acting on the population, implying that expression of density dependence depends extensively on local conditions. Additional experimental work should reveal the mechanisms influencing how the expression of density dependence varies across populations through space and time.

  6. Modelling interactions of toxicants and density dependence in wildlife populations

    Science.gov (United States)

    Schipper, Aafke M.; Hendriks, Harrie W.M.; Kauffman, Matthew J.; Hendriks, A. Jan; Huijbregts, Mark A.J.

    2013-01-01

    1. A major challenge in the conservation of threatened and endangered species is to predict population decline and design appropriate recovery measures. However, anthropogenic impacts on wildlife populations are notoriously difficult to predict due to potentially nonlinear responses and interactions with natural ecological processes like density dependence. 2. Here, we incorporated both density dependence and anthropogenic stressors in a stage-based matrix population model and parameterized it for a density-dependent population of peregrine falcons Falco peregrinus exposed to two anthropogenic toxicants [dichlorodiphenyldichloroethylene (DDE) and polybrominated diphenyl ethers (PBDEs)]. Log-logistic exposure–response relationships were used to translate toxicant concentrations in peregrine falcon eggs to effects on fecundity. Density dependence was modelled as the probability of a nonbreeding bird acquiring a breeding territory as a function of the current number of breeders. 3. The equilibrium size of the population, as represented by the number of breeders, responded nonlinearly to increasing toxicant concentrations, showing a gradual decrease followed by a relatively steep decline. Initially, toxicant-induced reductions in population size were mitigated by an alleviation of the density limitation, that is, an increasing probability of territory acquisition. Once population density was no longer limiting, the toxicant impacts were no longer buffered by an increasing proportion of nonbreeders shifting to the breeding stage, resulting in a strong decrease in the equilibrium number of breeders. 4. Median critical exposure concentrations, that is, median toxicant concentrations in eggs corresponding with an equilibrium population size of zero, were 33 and 46 μg g−1 fresh weight for DDE and PBDEs, respectively. 5. Synthesis and applications. Our modelling results showed that particular life stages of a density-limited population may be relatively insensitive to

  7. Information processing by neuronal populations

    National Research Council Canada - National Science Library

    Hölscher, Christian; Munk, Matthias

    2009-01-01

    ... simultaneously recorded spike trains 120 Mark Laubach, Nandakumar S. Narayanan, and Eyal Y. Kimchi Part III Neuronal population information coding and plasticity in specific brain areas 149 7 F...

  8. The psychological correlates of dependency in the Jamaican population.

    Science.gov (United States)

    Walcott, G; Hickling, F W

    2013-01-01

    To establish the prevalence of psychological dependency in the Jamaican society in order to examine the relationship between the psychological correlates of dependency and socio-political dependency in this post-colonial country. A total of 1506 adult individuals were sampled from 2150 households using a stratified sampling method and assessed using the 17 questions of the Jamaica Personality Disorder Inventory (JPDI) on the phenomenology of dependency that are grouped into the psychological features of physiological dependency, financial dependency, and psychological dependency. The database of responses to the demographic and JPDI questionnaires was created and analysed using the Statistical Package for the Social Sciences (SPSS) version 17. Of the national population sampled, 77.1% denied having any of these phenomenological symptoms of dependence while 22.63% of the population admitted to having some phenomenology of dependency, ranging from mild (5.6%), to moderate (12.1), or severe (4.9%). Substance use (physiological dependency) responders accounted for 21.23%, financial dependency responders for 43.45%, and psychological dependency responders for 15.96%. Significant gender and socio-economic class patterns of dependency were revealed. This substantial swathe of the Jamaican population acknowledged their own dependency and behavioural withdrawal response to physical or emotional loss in their life, and reported having dependency problems in managing their financial and monetary affairs. Three-quarters of the Jamaican responders of this survey ostensibly are free of the phenomenology of dependency while a more vulnerable one-quarter has insight that they are still locked in a struggle for psychological independence. The political and economic relations between psychological dependency and socio-political dependency are discussed.

  9. Density-dependent feedbacks can mask environmental drivers of populations

    DEFF Research Database (Denmark)

    Dahlgren, Johan Petter

    I present some results from studies identifying environmental drivers of vital rates and population dynamics when controlling for intraspecific density statistically or experimentally, show that density dependence can be strong even in populations of slow-growing species in stressful habitats, an...

  10. Asymptotic theory of weakly dependent random processes

    CERN Document Server

    Rio, Emmanuel

    2017-01-01

    Presenting tools to aid understanding of asymptotic theory and weakly dependent processes, this book is devoted to inequalities and limit theorems for sequences of random variables that are strongly mixing in the sense of Rosenblatt, or absolutely regular. The first chapter introduces covariance inequalities under strong mixing or absolute regularity. These covariance inequalities are applied in Chapters 2, 3 and 4 to moment inequalities, rates of convergence in the strong law, and central limit theorems. Chapter 5 concerns coupling. In Chapter 6 new deviation inequalities and new moment inequalities for partial sums via the coupling lemmas of Chapter 5 are derived and applied to the bounded law of the iterated logarithm. Chapters 7 and 8 deal with the theory of empirical processes under weak dependence. Lastly, Chapter 9 describes links between ergodicity, return times and rates of mixing in the case of irreducible Markov chains. Each chapter ends with a set of exercises. The book is an updated and extended ...

  11. Econometric model for age- and population-dependent radiation exposures

    International Nuclear Information System (INIS)

    Sandquist, G.M.; Slaughter, D.M.; Rogers, V.C.

    1991-01-01

    The economic impact associated with ionizing radiation exposures in a given human population depends on numerous factors including the individual's mean economic status as a function age, the age distribution of the population, the future life expectancy at each age, and the latency period for the occurrence of radiation-induced health effects. A simple mathematical model has been developed that provides an analytical methodology for estimating the societal econometrics associated with radiation effects are to be assessed and compared for economic evaluation

  12. Are elderly dependency ratios associated with general population suicide rates?

    Science.gov (United States)

    Shah, Ajit

    2011-05-01

    The elderly population size is increasing worldwide due to falling birth rates and increasing life expectancy. It has been hypothesized that as the elderly dependency ratio (the ratio of those over the age of 65 years to those under 65) increases, there will be fewer younger people available to care for older people and this, in turn, will increase the burden on younger carers with increased levels of psychiatric morbidity leading to an increase in general population suicide rates. A cross-national study examining the relationship between elderly dependency ratios and general population suicide rates was conducted using data from the World Health Organization and the United Nations websites. The main findings were of a significant and independent positive correlation between elderly dependency ratios and general population suicide rates in both genders. The contribution of cross-national differences in psychiatric morbidity in younger carers on general population suicide rates requires further study. The prevalence of psychiatric morbidity in younger carers of older people should be examined by: (i) cross-national studies using standardized measures of psychiatric morbidity that are education-free, culture-fair and language-fair; and (ii) within-country longitudinal studies with changing elderly dependency ratios over time.

  13. Stimulus-dependent maximum entropy models of neural population codes.

    Directory of Open Access Journals (Sweden)

    Einat Granot-Atedgi

    Full Text Available Neural populations encode information about their stimulus in a collective fashion, by joint activity patterns of spiking and silence. A full account of this mapping from stimulus to neural activity is given by the conditional probability distribution over neural codewords given the sensory input. For large populations, direct sampling of these distributions is impossible, and so we must rely on constructing appropriate models. We show here that in a population of 100 retinal ganglion cells in the salamander retina responding to temporal white-noise stimuli, dependencies between cells play an important encoding role. We introduce the stimulus-dependent maximum entropy (SDME model-a minimal extension of the canonical linear-nonlinear model of a single neuron, to a pairwise-coupled neural population. We find that the SDME model gives a more accurate account of single cell responses and in particular significantly outperforms uncoupled models in reproducing the distributions of population codewords emitted in response to a stimulus. We show how the SDME model, in conjunction with static maximum entropy models of population vocabulary, can be used to estimate information-theoretic quantities like average surprise and information transmission in a neural population.

  14. Dependence of adiabatic population transfer on pulse profile

    Indian Academy of Sciences (India)

    Control of population transfer by rapid adiabatic passage has been an established technique wherein the exact amplitude profile of the shaped pulse is considered to be insignificant. We study the effect of ultrafast shaped pulses for two-level systems, by density-matrix approach. However, we find that adiabaticity depends ...

  15. Stochastic processes and long range dependence

    CERN Document Server

    Samorodnitsky, Gennady

    2016-01-01

    This monograph is a gateway for researchers and graduate students to explore the profound, yet subtle, world of long-range dependence (also known as long memory). The text is organized around the probabilistic properties of stationary processes that are important for determining the presence or absence of long memory. The first few chapters serve as an overview of the general theory of stochastic processes which gives the reader sufficient background, language, and models for the subsequent discussion of long memory. The later chapters devoted to long memory begin with an introduction to the subject along with a brief history of its development, followed by a presentation of what is currently the best known approach, applicable to stationary processes with a finite second moment. The book concludes with a chapter devoted to the author’s own, less standard, point of view of long memory as a phase transition, and even includes some novel results. Most of the material in the book has not previously been publis...

  16. State-dependent neutral delay equations from population dynamics.

    Science.gov (United States)

    Barbarossa, M V; Hadeler, K P; Kuttler, C

    2014-10-01

    A novel class of state-dependent delay equations is derived from the balance laws of age-structured population dynamics, assuming that birth rates and death rates, as functions of age, are piece-wise constant and that the length of the juvenile phase depends on the total adult population size. The resulting class of equations includes also neutral delay equations. All these equations are very different from the standard delay equations with state-dependent delay since the balance laws require non-linear correction factors. These equations can be written as systems for two variables consisting of an ordinary differential equation (ODE) and a generalized shift, a form suitable for numerical calculations. It is shown that the neutral equation (and the corresponding ODE--shift system) is a limiting case of a system of two standard delay equations.

  17. Global asymptotic stability of density dependent integral population projection models.

    Science.gov (United States)

    Rebarber, Richard; Tenhumberg, Brigitte; Townley, Stuart

    2012-02-01

    Many stage-structured density dependent populations with a continuum of stages can be naturally modeled using nonlinear integral projection models. In this paper, we study a trichotomy of global stability result for a class of density dependent systems which include a Platte thistle model. Specifically, we identify those systems parameters for which zero is globally asymptotically stable, parameters for which there is a positive asymptotically stable equilibrium, and parameters for which there is no asymptotically stable equilibrium. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Timing intervals using population synchrony and spike timing dependent plasticity

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2016-12-01

    Full Text Available We present a computational model by which ensembles of regularly spiking neurons can encode different time intervals through synchronous firing. We show that a neuron responding to a large population of convergent inputs has the potential to learn to produce an appropriately-timed output via spike-time dependent plasticity. We explain why temporal variability of this population synchrony increases with increasing time intervals. We also show that the scalar property of timing and its violation at short intervals can be explained by the spike-wise accumulation of jitter in the inter-spike intervals of timing neurons. We explore how the challenge of encoding longer time intervals can be overcome and conclude that this may involve a switch to a different population of neurons with lower firing rate, with the added effect of producing an earlier bias in response. Experimental data on human timing performance show features in agreement with the model’s output.

  19. Alcohol dependence: international policy implications for prison populations.

    Science.gov (United States)

    Jones, Gail Yvonne; Hoffmann, Norman G

    2006-11-08

    In light of the emphasis on drug abuse, this study explored the relative prevalence of substance use disorders among United Kingdom (UK) prison inmates in the context of findings from a general inmate population in the United States (US). The lead author of the report conducted a structured diagnostic interview with 155 new admissions to one of two prisons in the UK using the CAAPE (Comprehensive Addiction And Psychological Evaluation), a structured diagnostic interview, to ensure consistent assessments. The US sample consisted of 6,881 male inmates in a state prison system evaluated with an automated version of the SUDDS-IV (Substance Use Disorder Diagnostic Schedule-IV) interview. Alcohol dependence emerged as the most prevalent substance use disorder in both UK prisons and in the US sample. Relative frequencies of abuse and dependence for alcohol and other drugs revealed that dependence on a given substance was more prevalent than abuse ad defined by the current diagnostic criteria. Despite the emphasis on drugs in correctional populations, alcohol dependence appears to be the most prominent substance use disorder among the incarcerated in both the US and UK and must be considered in developing treatment programs and policy priorities.

  20. Alcohol dependence: international policy implications for prison populations

    Directory of Open Access Journals (Sweden)

    Hoffmann Norman G

    2006-11-01

    Full Text Available Abstract Background In light of the emphasis on drug abuse, this study explored the relative prevalence of substance use disorders among United Kingdom (UK prison inmates in the context of findings from a general inmate population in the United States (US. The lead author of the report conducted a structured diagnostic interview with 155 new admissions to one of two prisons in the UK using the CAAPE (Comprehensive Addiction And Psychological Evaluation, a structured diagnostic interview, to ensure consistent assessments. The US sample consisted of 6,881 male inmates in a state prison system evaluated with an automated version of the SUDDS-IV (Substance Use Disorder Diagnostic Schedule-IV interview. Results Alcohol dependence emerged as the most prevalent substance use disorder in both UK prisons and in the US sample. Relative frequencies of abuse and dependence for alcohol and other drugs revealed that dependence on a given substance was more prevalent than abuse ad defined by the current diagnostic criteria. Conclusion Despite the emphasis on drugs in correctional populations, alcohol dependence appears to be the most prominent substance use disorder among the incarcerated in both the US and UK and must be considered in developing treatment programs and policy priorities.

  1. Population and prehistory I: Food-dependent population growth in constant environments.

    Science.gov (United States)

    Lee, Charlotte T; Tuljapurkar, Shripad

    2008-06-01

    We present a demographic model that describes the feedbacks between food supply, human mortality and fertility rates, and labor availability in expanding populations, where arable land area is not limiting. This model provides a quantitative framework to describe how environment, technology, and culture interact to influence the fates of preindustrial agricultural populations. We present equilibrium conditions and derive approximations for the equilibrium population growth rate, food availability, and other food-dependent measures of population well-being. We examine how the approximations respond to environmental changes and to human choices, and find that the impact of environmental quality depends upon whether it manifests through agricultural yield or maximum (food-independent) survival rates. Human choices can complement or offset environmental effects: greater labor investments increase both population growth and well-being, and therefore can counteract lower agricultural yield, while fertility control decreases the growth rate but can increase or decrease well-being. Finally we establish equilibrium stability criteria, and argue that the potential for loss of local stability at low population growth rates could have important consequences for populations that suffer significant environmental or demographic shocks.

  2. Methamphetamine use and dependence in vulnerable female populations.

    Science.gov (United States)

    Kittirattanapaiboon, Phunnapa; Srikosai, Soontaree; Wittayanookulluk, Apisak

    2017-07-01

    The study reviews recent publications on methamphetamine use and dependence women in term of their epidemic, physical health impact, psychosocial impacts, and also in the identified vulnerable issues. Studies of vulnerable populations of women are wide ranging and include sex workers, sexual minorities, homeless, psychiatric patients, suburban women, and pregnant women, in which amphetamine type stimulants (ATSs) are the most commonly reported illicit drug used among them. The prenatal exposure of ATS demonstrated the small for gestational age and low birth weight; however, more research is needed on long-term studies of methamphetamine-exposed children. Intimate partner violence (IPV) is commonly reported by female methamphetamine users as perpetrators and victims. However, statistics and gendered power dynamics suggest that methamphetamine-related IPV indicates a higher chance of femicide. Methamphetamine-abusing women often have unresolved childhood trauma and are introduced to ATS through families or partners. Vulnerable populations of women at risk of methamphetamine abuse and dependence. Impacts on their physical and mental health, IPV, and pregnancy have been reported continuing, which guide that empowering and holistic substance abuse are necessary for specific group.

  3. Stochastic seasonality and nonlinear density-dependent factors regulate population size in an African rodent

    DEFF Research Database (Denmark)

    Leirs, Herwig; Steneth, Nils Chr.; Nichols, James D.

    1997-01-01

    , but clear examples of both processes acting in the same population are rare(7,8). Key-factor analysis (regression of population changes on possible causal factors) and time-series analysis are often used to investigate the presence of density dependence, but such approaches may be biased and provide...... no information on actual demographic rates(9,10). Here we report on both density-dependent and density-independent effects in a murid rodent pest species, the multimammute rat Mastomys natalensis (Smith, 1834), using statistical capture-recapture models, Both effects occur simultaneously, but we also demonstrate...

  4. Efficient bootstrap with weakly dependent processes

    NARCIS (Netherlands)

    Bravo, Francesco; Crudu, Federico

    The efficient bootstrap methodology is developed for overidentified moment conditions models with weakly dependent observation. The resulting bootstrap procedure is shown to be asymptotically valid and can be used to approximate the distributions of t-statistics, the J-statistic for overidentifying

  5. Dispersal, density dependence, and population dynamics of a fungal microbe on leaf surfaces.

    Science.gov (United States)

    Woody, Scott T; Ives, Anthony R; Nordheim, Erik V; Andrews, John H

    2007-06-01

    Despite the ubiquity and importance of microbes in nature, little is known about their natural population dynamics, especially for those that occupy terrestrial habitats. Here we investigate the dynamics of the yeast-like fungus Aureobasidium pullulans (Ap) on apple leaves in an orchard. We asked three questions. (1) Is variation in fungal population density among leaves caused by variation in leaf carrying capacities and strong density-dependent population growth that maintains densities near carrying capacity? (2) Do resident populations have competitive advantages over immigrant cells? (3) Do Ap dynamics differ at different times during the growing season? To address these questions, we performed two experiments at different times in the growing season. Both experiments used a 2 x 2 factorial design: treatment 1 removed fungal cells from leaves to reveal density-dependent population growth, and treatment 2 inoculated leaves with an Ap strain engineered to express green fluorescent protein (GFP), which made it possible to track the fate of immigrant cells. The experiments showed that natural populations of Ap vary greatly in density due to sustained differences in carrying capacities among leaves. The maintenance of populations close to carrying capacities indicates strong density-dependent processes. Furthermore, resident populations are strongly competitive against immigrants, while immigrants have little impact on residents. Finally, statistical models showed high population growth rates of resident cells in one experiment but not in the other, suggesting that Ap experiences relatively "good" and "bad" periods for population growth. This picture of Ap dynamics conforms to commonly held, but rarely demonstrated, expectations of microbe dynamics in nature. It also highlights the importance of local processes, as opposed to immigration, in determining the abundance and dynamics of microbes on surfaces in terrestrial systems.

  6. Critical mutation rate has an exponential dependence on population size in haploid and diploid populations.

    Directory of Open Access Journals (Sweden)

    Elizabeth Aston

    Full Text Available Understanding the effect of population size on the key parameters of evolution is particularly important for populations nearing extinction. There are evolutionary pressures to evolve sequences that are both fit and robust. At high mutation rates, individuals with greater mutational robustness can outcompete those with higher fitness. This is survival-of-the-flattest, and has been observed in digital organisms, theoretically, in simulated RNA evolution, and in RNA viruses. We introduce an algorithmic method capable of determining the relationship between population size, the critical mutation rate at which individuals with greater robustness to mutation are favoured over individuals with greater fitness, and the error threshold. Verification for this method is provided against analytical models for the error threshold. We show that the critical mutation rate for increasing haploid population sizes can be approximated by an exponential function, with much lower mutation rates tolerated by small populations. This is in contrast to previous studies which identified that critical mutation rate was independent of population size. The algorithm is extended to diploid populations in a system modelled on the biological process of meiosis. The results confirm that the relationship remains exponential, but show that both the critical mutation rate and error threshold are lower for diploids, rather than higher as might have been expected. Analyzing the transition from critical mutation rate to error threshold provides an improved definition of critical mutation rate. Natural populations with their numbers in decline can be expected to lose genetic material in line with the exponential model, accelerating and potentially irreversibly advancing their decline, and this could potentially affect extinction, recovery and population management strategy. The effect of population size is particularly strong in small populations with 100 individuals or less; the

  7. Disentangling the effects of climate, density dependence, and harvest on an iconic large herbivore's population dynamics

    DEFF Research Database (Denmark)

    Koons, David; Colchero, Fernando; Hersey, Kent

    2015-01-01

    Understanding the relative effects of climate, harvest, and density dependence on population dynamics is critical for guiding sound population management, especially for ungulates in arid and semi-arid environments experiencing climate change. To address these issues for bison in southern Utah, we...... than precipitation and other temperature-related variables (model weight > 3 times more than that for other climate variables). Although we hypothesized that harvest is the primary driving force of bison population dynamics in southern Utah, our elasticity analysis indicated that changes in early...... spring temperature could have a greater ‘relative effect’ on equilibrium abundance than either harvest or the strength of density dependence. Our findings highlight the utility of incorporating elasticity analyses into state-space population models, and the need to include climatic processes in wildlife...

  8. Intensity-dependent point spread image processing

    International Nuclear Information System (INIS)

    Cornsweet, T.N.; Yellott, J.I.

    1984-01-01

    There is ample anatomical, physiological and psychophysical evidence that the mammilian retina contains networks that mediate interactions among neighboring receptors, resulting in intersecting transformations between input images and their corresponding neural output patterns. The almost universally accepted view is that the principal form of interaction involves lateral inhibition, resulting in an output pattern that is the convolution of the input with a ''Mexican hat'' or difference-of-Gaussians spread function, having a positive center and a negative surround. A closely related process is widely applied in digital image processing, and in photography as ''unsharp masking''. The authors show that a simple and fundamentally different process, involving no inhibitory or subtractive terms can also account for the physiological and psychophysical findings that have been attributed to lateral inhibition. This process also results in a number of fundamental effects that occur in mammalian vision and that would be of considerable significance in robotic vision, but which cannot be explained by lateral inhibitory interaction

  9. Dependency Grammar in Lithuanian Language Processing

    OpenAIRE

    Grigonytė, Gintarė

    2006-01-01

    Lithuanian language is quite in an early stage of language processing. And therefore has a high demand on automated tools like taggers, parsers, word sense disambiguators etc. During the last 10 years only a few researchers were attempting to create a parser for Lithuanian language. However none of them are used in practices nowadays. The process of designing and implementing rule based parser for Lithuanian language is presented in this paper. Rules and constraints of the formal grammar foll...

  10. Is There Dependence Between Process Maturity and Process Performance?

    NARCIS (Netherlands)

    Joost Spekschoor; Pascal Ravesteijn; Roeland Loggen; dr. Martijn Zoet

    2012-01-01

    During recent years the world has seen rapid changes such as globalization, the Internet, and the rise of new economies. To survive these changes organizations need to be in control of their processes, and be able to continuously improve the process performance. Therefore many organizations are

  11. Modeling spatial processes with unknown extremal dependence class

    KAUST Repository

    Huser, Raphaë l G.; Wadsworth, Jennifer L.

    2017-01-01

    Many environmental processes exhibit weakening spatial dependence as events become more extreme. Well-known limiting models, such as max-stable or generalized Pareto processes, cannot capture this, which can lead to a preference for models

  12. [Alimentation dependent health disorders among adult population of Bashkortostan Republic and their relation with nutritional traits].

    Science.gov (United States)

    Takaev, R M; Kondrova, N S; Baĭkina, I M; Larionova, T K

    2008-01-01

    The authors demonstrated relationship between alimentation dependent diseases among adult population of the Republic and nutritional traits of the population, defined major directions of program to optimize nutrition of the population.

  13. Critical Age-Dependent Branching Markov Processes and their ...

    Indian Academy of Sciences (India)

    This paper studies: (i) the long-time behaviour of the empirical distribution of age and normalized position of an age-dependent critical branching Markov process conditioned on non-extinction; and (ii) the super-process limit of a sequence of age-dependent critical branching Brownian motions.

  14. Identifying influential factors of business process performance using dependency analysis

    Science.gov (United States)

    Wetzstein, Branimir; Leitner, Philipp; Rosenberg, Florian; Dustdar, Schahram; Leymann, Frank

    2011-02-01

    We present a comprehensive framework for identifying influential factors of business process performance. In particular, our approach combines monitoring of process events and Quality of Service (QoS) measurements with dependency analysis to effectively identify influential factors. The framework uses data mining techniques to construct tree structures to represent dependencies of a key performance indicator (KPI) on process and QoS metrics. These dependency trees allow business analysts to determine how process KPIs depend on lower-level process metrics and QoS characteristics of the IT infrastructure. The structure of the dependencies enables a drill-down analysis of single factors of influence to gain a deeper knowledge why certain KPI targets are not met.

  15. Statistical Processing Algorithms for Human Population Databases

    Directory of Open Access Journals (Sweden)

    Camelia COLESCU

    2012-01-01

    Full Text Available The article is describing some algoritms for statistic functions aplied to a human population database. The samples are specific for the most interesting periods, when the evolution of statistical datas has spectacolous value. The article describes the most usefull form of grafical prezentation of the results

  16. Image quality dependence on image processing software in ...

    African Journals Online (AJOL)

    Image quality dependence on image processing software in computed radiography. ... Agfa CR readers use MUSICA software, and an upgrade with significantly different image ... Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  17. Modeling spatial processes with unknown extremal dependence class

    KAUST Repository

    Huser, Raphaël G.

    2017-03-17

    Many environmental processes exhibit weakening spatial dependence as events become more extreme. Well-known limiting models, such as max-stable or generalized Pareto processes, cannot capture this, which can lead to a preference for models that exhibit a property known as asymptotic independence. However, weakening dependence does not automatically imply asymptotic independence, and whether the process is truly asymptotically (in)dependent is usually far from clear. The distinction is key as it can have a large impact upon extrapolation, i.e., the estimated probabilities of events more extreme than those observed. In this work, we present a single spatial model that is able to capture both dependence classes in a parsimonious manner, and with a smooth transition between the two cases. The model covers a wide range of possibilities from asymptotic independence through to complete dependence, and permits weakening dependence of extremes even under asymptotic dependence. Censored likelihood-based inference for the implied copula is feasible in moderate dimensions due to closed-form margins. The model is applied to oceanographic datasets with ambiguous true limiting dependence structure.

  18. Figurative language processing in atypical populations: The ASD perspective

    Directory of Open Access Journals (Sweden)

    Mila eVulchanova

    2015-02-01

    Full Text Available This paper is intended to provide a critical overview of experimental and clinical research documenting problems in figurative language processing in atypical populations with a focus on the Autistic Spectrum. Research in the comprehension and processing of figurative language in autism invariably documents problems in this area. The greater paradox is that even at the higher end of the spectrum or in the cases of linguistically talented individuals with Asperger syndrome, where structural language competence is intact, problems with extended language persist. If we assume that figurative and extended uses of language essentially depend on the perception and processing of more concrete core concepts and phenomena, the commonly observed failure in atypical populations to understand figurative language remains a puzzle.Various accounts have been offered to explain this issue, ranging from linking potential failure directly to overall structural language competence (Brock et al., 2008; Norbury, 2005 to right-hemispheric involvement (Gold and Faust, 2010. We argue that the dissociation between structural language and figurative language competence in autism should be sought in more general cognitive mechanisms and traits in the autistic phenotype (e.g., in terms of weak central coherence, Vulchanova et al., 2012b, as well as failure at on-line semantic integration with increased complexity and diversity of the stimuli (Coulson and van Petten, 2002. This perspective is even more compelling in light of similar problems in a number of conditions, including both acquired (e.g., Aphasia and developmental disorders (Williams Syndrome. This dissociation argues against a simple continuity view of language interpretation.

  19. Figurative language processing in atypical populations: the ASD perspective.

    Science.gov (United States)

    Vulchanova, Mila; Saldaña, David; Chahboun, Sobh; Vulchanov, Valentin

    2015-01-01

    This paper is intended to provide a critical overview of experimental and clinical research documenting problems in figurative language processing in atypical populations with a focus on the Autistic Spectrum. Research in the comprehension and processing of figurative language in autism invariably documents problems in this area. The greater paradox is that even at the higher end of the spectrum or in the cases of linguistically talented individuals with Asperger syndrome, where structural language competence is intact, problems with extended language persist. If we assume that figurative and extended uses of language essentially depend on the perception and processing of more concrete core concepts and phenomena, the commonly observed failure in atypical populations to understand figurative language remains a puzzle. Various accounts have been offered to explain this issue, ranging from linking potential failure directly to overall structural language competence (Norbury, 2005; Brock et al., 2008) to right-hemispheric involvement (Gold and Faust, 2010). We argue that the dissociation between structural language and figurative language competence in autism should be sought in more general cognitive mechanisms and traits in the autistic phenotype (e.g., in terms of weak central coherence, Vulchanova et al., 2012b), as well as failure at on-line semantic integration with increased complexity and diversity of the stimuli (Coulson and Van Petten, 2002). This perspective is even more compelling in light of similar problems in a number of conditions, including both acquired (e.g., Aphasia) and developmental disorders (Williams Syndrome). This dissociation argues against a simple continuity view of language interpretation.

  20. Figurative language processing in atypical populations: the ASD perspective

    Science.gov (United States)

    Vulchanova, Mila; Saldaña, David; Chahboun, Sobh; Vulchanov, Valentin

    2015-01-01

    This paper is intended to provide a critical overview of experimental and clinical research documenting problems in figurative language processing in atypical populations with a focus on the Autistic Spectrum. Research in the comprehension and processing of figurative language in autism invariably documents problems in this area. The greater paradox is that even at the higher end of the spectrum or in the cases of linguistically talented individuals with Asperger syndrome, where structural language competence is intact, problems with extended language persist. If we assume that figurative and extended uses of language essentially depend on the perception and processing of more concrete core concepts and phenomena, the commonly observed failure in atypical populations to understand figurative language remains a puzzle. Various accounts have been offered to explain this issue, ranging from linking potential failure directly to overall structural language competence (Norbury, 2005; Brock et al., 2008) to right-hemispheric involvement (Gold and Faust, 2010). We argue that the dissociation between structural language and figurative language competence in autism should be sought in more general cognitive mechanisms and traits in the autistic phenotype (e.g., in terms of weak central coherence, Vulchanova et al., 2012b), as well as failure at on-line semantic integration with increased complexity and diversity of the stimuli (Coulson and Van Petten, 2002). This perspective is even more compelling in light of similar problems in a number of conditions, including both acquired (e.g., Aphasia) and developmental disorders (Williams Syndrome). This dissociation argues against a simple continuity view of language interpretation. PMID:25741261

  1. Founder takes all: density-dependent processes structure biodiversity.

    Science.gov (United States)

    Waters, Jonathan M; Fraser, Ceridwen I; Hewitt, Godfrey M

    2013-02-01

    Density-dependent processes play a key role in the spatial structuring of biodiversity. Specifically, interrelated demographic processes, such as gene surfing, high-density blocking, and competitive exclusion, can generate striking geographic contrasts in the distributions of genes and species. Here, we propose that well-studied evolutionary and ecological biogeographic patterns of postglacial recolonization, progressive island colonization, microbial sectoring, and even the 'Out of Africa' pattern of human expansion, are fundamentally similar, underpinned by a 'founder takes all' density-dependent principle. Additionally, we hypothesize that older historic constraints of density-dependent processes are seen today in the dramatic biogeographic shifts that occur in response to human-mediated extinction events, whereby surviving lineages rapidly expand their ranges to replace extinct sister taxa. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Intertime jump statistics of state-dependent Poisson processes.

    Science.gov (United States)

    Daly, Edoardo; Porporato, Amilcare

    2007-01-01

    A method to obtain the probability distribution of the interarrival times of jump occurrences in systems driven by state-dependent Poisson noise is proposed. Such a method uses the survivor function obtained by a modified version of the master equation associated to the stochastic process under analysis. A model for the timing of human activities shows the capability of state-dependent Poisson noise to generate power-law distributions. The application of the method to a model for neuron dynamics and to a hydrological model accounting for land-atmosphere interaction elucidates the origin of characteristic recurrence intervals and possible persistence in state-dependent Poisson models.

  3. Dynamics of a recovering Arctic bird population: the importance of climate, density dependence, and site quality

    Science.gov (United States)

    Bruggeman, Jason E.; Swem, Ted; Andersen, David E.; Kennedy, Patricia L.; Nigro, Debora A.

    2015-01-01

    Intrinsic and extrinsic factors affect vital rates and population-level processes, and understanding these factors is paramount to devising successful management plans for wildlife species. For example, birds time migration in response, in part, to local and broadscale climate fluctuations to initiate breeding upon arrival to nesting territories, and prolonged inclement weather early in the breeding season can inhibit egg-laying and reduce productivity. Also, density-dependent regulation occurs in raptor populations, as territory size is related to resource availability. Arctic Peregrine Falcons (Falco peregrinus tundrius; hereafter Arctic peregrine) have a limited and northern breeding distribution, including the Colville River Special Area (CRSA) in the National Petroleum Reserve–Alaska, USA. We quantified influences of climate, topography, nest productivity, prey habitat, density dependence, and interspecific competition affecting Arctic peregrines in the CRSA by applying the Dail-Madsen model to estimate abundance and vital rates of adults on nesting cliffs from 1981 through 2002. Arctic peregrine abundance increased throughout the 1980s, which spanned the population's recovery from DDT-induced reproductive failure, until exhibiting a stationary trend in the 1990s. Apparent survival rate (i.e., emigration; death) was negatively correlated with the number of adult Arctic peregrines on the cliff the previous year, suggesting effects of density-dependent population regulation. Apparent survival and arrival rates (i.e., immigration; recruitment) were higher during years with earlier snowmelt and milder winters, and apparent survival was positively correlated with nesting season maximum daily temperature. Arrival rate was positively correlated with average Arctic peregrine productivity along a cliff segment from the previous year and initial abundance was positively correlated with cliff height. Higher cliffs with documented higher productivity (presumably

  4. Seasonal dependence of aerosol processing in urban Philadelphia

    Science.gov (United States)

    Avery, A. M.; Waring, M. S.; DeCarlo, P. F.

    2017-12-01

    Urban aerosols pose an important threat to human health due to the conflation of emissions and concentrated population exposed. Winter and summer aerosol and trace gas measurements were taken in downtown Philadelphia in 2016. Measurements included aerosol composition and size with an Aerodyne Aerosol Mass Spectrometer (AMS), particle size distributions with an SMPS, and an aethalometer. Trace gas measurements of O3, NO, CH4, CO, and CO2 were taken concurrently. Sampling in seasonal extremes provided contrast in aerosol and trace gas composition, aerosol processing, and emission factors. Inorganic aerosol components contributed approximately 60% of the submicron aerosol mass, while summertime aerosol composition was roughly 70% organic matter. Positive Matrix Factorization (PMF) on the organic aerosol (OA) matrix revealed three factors in common in each season, including an oxygenated organic aerosol (OOA) factor with different temporal behavior in each season. In summertime, OOA varied diurnally with ozone and daytime temperature, but in the wintertime, it was anti-correlated with ozone and temperature, and instead trended with calculated liquid water, indicating a seasonally-dependent processing of organic aerosol in Philadelphia's urban environment. Due to the inorganic dominant winter aerosol, liquid water much higher (2.65 μg/m3) in winter than in summer (1.54 μg/m3). Diurnally varying concentrations of background gas phase species (CH4, CO2) were higher in winter and varied less as a result of boundary layer conditions; ozone was also higher in background in winter than summer. Winter stagnation events with low windspeed showed large buildup of trace gases CH4, CO, CO2, and NO. Traffic related aerosol was also elevated with black carbon and hydrocarbon-like OA (HOA) plumes of each at 3-5 times higher than the winter the average value for each. Winter ratios of HOA to black carbon were significantly higher in the winter than the summer due to lower

  5. Age-dependent dose coefficients for tritium in Asian populations

    International Nuclear Information System (INIS)

    Trivedi, A.

    1999-10-01

    The International Commission on Radiological Protection (ICRP) Publications 56 (1989) and 67 (1993) have prescribed the biokinetic models and age-dependent dose coefficients for tritiated water and organically bound tritium. The dose coefficients are computed from values selected to specify the anatomical, morphological and physiological characteristics of a three-month-old, one-year-old, five-year-old, 10-year-old, 15-year-old and adult (Reference Man) Caucasian living in North America and Western Europe. However, values for Reference Man and other age groups are not directly applicable to Asians, because of differences in race, custom, dietary habits and climatic conditions. An Asian Man model, including five age groups, has been proposed by Tanaka and Kawamura (1996, 1998) for use in internal dosimetry. The basic concept of the ICRP Reference Man and the system describing body composition in ICRP Publication 23 (1975) were used. Reference values for Asians were given for the body weight and height, the mass of soft tissue, the mass of body water and the daily fluid balance, and are used to compute the dose coefficients for tritium. The age-dependent dose coefficients for Asians for tritiated water intakes are smaller by 20 to 30% of the currently prescribed values (Trivedi, 1998). The reduction in the dose coefficient values is caused by the increased daily fluid balance among Asians. The dose coefficient for tritiated water is 1.4 x 10 -11 Sv Bq -1 for Asian Man compared to 2.0 x 10 -11 Sv Bq -1 for Reference Man. The dose coefficients for organically bound tritium are only marginally different from those of the ICRP values. The dose coefficient for organically bound tritium for Asian Man is 4.0 x 10 -11 Sv Bq -11 compared to 4.6 x 10 -11 Sv Bq -1 for Reference Man. (author)

  6. Age-dependent dose coefficients for tritium in Asian populations

    Energy Technology Data Exchange (ETDEWEB)

    Trivedi, A

    1999-10-01

    The International Commission on Radiological Protection (ICRP) Publications 56 (1989) and 67 (1993) have prescribed the biokinetic models and age-dependent dose coefficients for tritiated water and organically bound tritium. The dose coefficients are computed from values selected to specify the anatomical, morphological and physiological characteristics of a three-month-old, one-year-old, five-year-old, 10-year-old, 15-year-old and adult (Reference Man) Caucasian living in North America and Western Europe. However, values for Reference Man and other age groups are not directly applicable to Asians, because of differences in race, custom, dietary habits and climatic conditions. An Asian Man model, including five age groups, has been proposed by Tanaka and Kawamura (1996, 1998) for use in internal dosimetry. The basic concept of the ICRP Reference Man and the system describing body composition in ICRP Publication 23 (1975) were used. Reference values for Asians were given for the body weight and height, the mass of soft tissue, the mass of body water and the daily fluid balance, and are used to compute the dose coefficients for tritium. The age-dependent dose coefficients for Asians for tritiated water intakes are smaller by 20 to 30% of the currently prescribed values (Trivedi, 1998). The reduction in the dose coefficient values is caused by the increased daily fluid balance among Asians. The dose coefficient for tritiated water is 1.4 x 10{sup -11} Sv Bq{sup -1} for Asian Man compared to 2.0 x 10{sup -11} Sv Bq{sup -1} for Reference Man. The dose coefficients for organically bound tritium are only marginally different from those of the ICRP values. The dose coefficient for organically bound tritium for Asian Man is 4.0 x 10{sup -11} Sv Bq{sup -11} compared to 4.6 x 10{sup -11} Sv Bq{sup -1} for Reference Man. (author)

  7. Backwards and Forwards: Behavioral and Neurophysiological Investigations into Dependency Processing

    Science.gov (United States)

    Witzel, Jeffrey D.

    2010-01-01

    This dissertation examines the processing of sentences involving long-distance linguistic dependencies, or sentences containing elements that must be linked across intervening words and phrases. Specifically, both behavioral (self-paced reading and eye tracking) and neurophysiological (electroencephalography) methods were used (a) to evaluate the…

  8. Bayesian inference on the effect of density dependence and weather on a guanaco population from Chile

    DEFF Research Database (Denmark)

    Zubillaga, Maria; Skewes, Oscar; Soto, Nicolás

    2014-01-01

    Understanding the mechanisms that drive population dynamics is fundamental for management of wild populations. The guanaco (Lama guanicoe) is one of two wild camelid species in South America. We evaluated the effects of density dependence and weather variables on population regulation based...

  9. Evolutionary Game Dynamics in a Fitness-Dependent Wright-Fisher Process with Noise

    International Nuclear Information System (INIS)

    Quan Ji; Wang Xianjia

    2011-01-01

    Evolutionary game dynamics in finite size populations can be described by a fitness-dependent Wright-Fisher process. We consider symmetric 2x2 games in a well-mixed population. In our model, two parameters to describe the level of player's rationality and noise intensity in environment are introduced. In contrast with the fixation probability method that used in a noiseless case, the introducing of the noise intensity parameter makes the process an ergodic Markov process and based on the limit distribution of the process, we can analysis the evolutionary stable strategy (ESS) of the games. We illustrate the effects of the two parameters on the ESS of games using the Prisoner's dilemma games (PDG) and the snowdrift games (SG). We also compare the ESS of our model with that of the replicator dynamics in infinite size populations. The results are determined by simulation experiments. (general)

  10. Neural correlates of affect processing and aggression in methamphetamine dependence.

    Science.gov (United States)

    Payer, Doris E; Lieberman, Matthew D; London, Edythe D

    2011-03-01

    Methamphetamine abuse is associated with high rates of aggression but few studies have addressed the contributing neurobiological factors. To quantify aggression, investigate function in the amygdala and prefrontal cortex, and assess relationships between brain function and behavior in methamphetamine-dependent individuals. In a case-control study, aggression and brain activation were compared between methamphetamine-dependent and control participants. Participants were recruited from the general community to an academic research center. Thirty-nine methamphetamine-dependent volunteers (16 women) who were abstinent for 7 to 10 days and 37 drug-free control volunteers (18 women) participated in the study; subsets completed self-report and behavioral measures. Functional magnetic resonance imaging (fMRI) was performed on 25 methamphetamine-dependent and 23 control participants. We measured self-reported and perpetrated aggression and self-reported alexithymia. Brain activation was assessed using fMRI during visual processing of facial affect (affect matching) and symbolic processing (affect labeling), the latter representing an incidental form of emotion regulation. Methamphetamine-dependent participants self-reported more aggression and alexithymia than control participants and escalated perpetrated aggression more following provocation. Alexithymia scores correlated with measures of aggression. During affect matching, fMRI showed no differences between groups in amygdala activation but found lower activation in methamphetamine-dependent than control participants in the bilateral ventral inferior frontal gyrus. During affect labeling, participants recruited the dorsal inferior frontal gyrus and exhibited decreased amygdala activity, consistent with successful emotion regulation; there was no group difference in this effect. The magnitude of decrease in amygdala activity during affect labeling correlated inversely with self-reported aggression in control participants

  11. Minimizing the dependency ratio in a population with below-replacement fertility through immigration

    Science.gov (United States)

    Simon, C.; Belyakov, A.O.; Feichtinger, G.

    2012-01-01

    Many industrialized countries face fertility rates below replacement level, combined with declining mortality especially in older ages. Consequently, the populations of these countries have started to age. One important indicator of age structures is the dependency ratio which is the ratio of the nonworking age population to the working age population. In this work we find the age-specific immigration profile that minimizes the dependency ratio in a stationary population with below-replacement fertility. It is assumed that the number of immigrants per age is limited. We consider two alternative policies. In the first one, we fix the total number of people who annually immigrate to a country. In the second one, we prescribe the size of the receiving country’s population. For both cases we provide numerical results for the optimal immigration profile, for the resulting age structure of the population, as well as for the dependency ratio. PMID:22781918

  12. Novel synthetic Medea selfish genetic elements drive population replacement in Drosophila; a theoretical exploration of Medea-dependent population suppression.

    Science.gov (United States)

    Akbari, Omar S; Chen, Chun-Hong; Marshall, John M; Huang, Haixia; Antoshechkin, Igor; Hay, Bruce A

    2014-12-19

    Insects act as vectors for diseases of plants, animals, and humans. Replacement of wild insect populations with genetically modified individuals unable to transmit disease provides a potentially self-perpetuating method of disease prevention. Population replacement requires a gene drive mechanism in order to spread linked genes mediating disease refractoriness through wild populations. We previously reported the creation of synthetic Medea selfish genetic elements able to drive population replacement in Drosophila. These elements use microRNA-mediated silencing of myd88, a maternally expressed gene required for embryonic dorso-ventral pattern formation, coupled with early zygotic expression of a rescuing transgene, to bring about gene drive. Medea elements that work through additional mechanisms are needed in order to be able to carry out cycles of population replacement and/or remove existing transgenes from the population, using second-generation elements that spread while driving first-generation elements out of the population. Here we report the synthesis and population genetic behavior of two new synthetic Medea elements that drive population replacement through manipulation of signaling pathways involved in cellular blastoderm formation or Notch signaling, demonstrating that in Drosophila Medea elements can be generated through manipulation of diverse signaling pathways. We also describe the mRNA and small RNA changes in ovaries and early embryos associated from Medea-bearing females. Finally, we use modeling to illustrate how Medea elements carrying genes that result in diapause-dependent female lethality could be used to bring about population suppression.

  13. 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.

  14. Geometry dependence of the magnetization reversal process in bridged dots

    International Nuclear Information System (INIS)

    Escobar, R.A.; Lage, E.; D’Albuquerque e Castro, J.; Altbir, D.; Ross, C.A.

    2017-01-01

    Based on Monte Carlo numerical simulations: results for the magnetization reversal process in thin circular Ni dots connected by a bridge are presented. The dependence of the process on both the width of the bridge and the orientation of the applied magnetic field has been investigated. It was found that when the applied magnetic field is set parallel to the bridge, the hysteresis curves are weakly dependent on the width of the bridge, being rather close to that of a single dot of the same diameter. On the other hand, when the magnetic field is applied perpendicularly to the bridge, a significant reduction in the coercivity of the system is obtained, even in the case of narrower bridges.

  15. Geometry dependence of the magnetization reversal process in bridged dots

    Energy Technology Data Exchange (ETDEWEB)

    Escobar, R.A. [Departamento de Física, CEDENNA, Universidad de Santiago de Chile, USACH, Av. Ecuador 3493, Santiago (Chile); Lage, E. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 02139 Cambridge, MA (United States); D’Albuquerque e Castro, J. [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, RJ 21945-970 (Brazil); Altbir, D., E-mail: dora.altbir@usach.cl [Departamento de Física, CEDENNA, Universidad de Santiago de Chile, USACH, Av. Ecuador 3493, Santiago (Chile); Ross, C.A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 02139 Cambridge, MA (United States)

    2017-06-15

    Based on Monte Carlo numerical simulations: results for the magnetization reversal process in thin circular Ni dots connected by a bridge are presented. The dependence of the process on both the width of the bridge and the orientation of the applied magnetic field has been investigated. It was found that when the applied magnetic field is set parallel to the bridge, the hysteresis curves are weakly dependent on the width of the bridge, being rather close to that of a single dot of the same diameter. On the other hand, when the magnetic field is applied perpendicularly to the bridge, a significant reduction in the coercivity of the system is obtained, even in the case of narrower bridges.

  16. Histogram bin width selection for time-dependent Poisson processes

    International Nuclear Information System (INIS)

    Koyama, Shinsuke; Shinomoto, Shigeru

    2004-01-01

    In constructing a time histogram of the event sequences derived from a nonstationary point process, we wish to determine the bin width such that the mean squared error of the histogram from the underlying rate of occurrence is minimized. We find that the optimal bin widths obtained for a doubly stochastic Poisson process and a sinusoidally regulated Poisson process exhibit different scaling relations with respect to the number of sequences, time scale and amplitude of rate modulation, but both diverge under similar parametric conditions. This implies that under these conditions, no determination of the time-dependent rate can be made. We also apply the kernel method to these point processes, and find that the optimal kernels do not exhibit any critical phenomena, unlike the time histogram method

  17. Histogram bin width selection for time-dependent Poisson processes

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, Shinsuke; Shinomoto, Shigeru [Department of Physics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)

    2004-07-23

    In constructing a time histogram of the event sequences derived from a nonstationary point process, we wish to determine the bin width such that the mean squared error of the histogram from the underlying rate of occurrence is minimized. We find that the optimal bin widths obtained for a doubly stochastic Poisson process and a sinusoidally regulated Poisson process exhibit different scaling relations with respect to the number of sequences, time scale and amplitude of rate modulation, but both diverge under similar parametric conditions. This implies that under these conditions, no determination of the time-dependent rate can be made. We also apply the kernel method to these point processes, and find that the optimal kernels do not exhibit any critical phenomena, unlike the time histogram method.

  18. Process depending morphology and resulting physical properties of TPU

    Energy Technology Data Exchange (ETDEWEB)

    Frick, Achim, E-mail: achim.frick@hs-aalen.de; Spadaro, Marcel, E-mail: marcel.spadaro@hs-aalen.de [Institute of Polymer Science and Processing (iPSP), Aalen University (Germany)

    2015-12-17

    Thermoplastic polyurethane (TPU) is a rubber like material with outstanding properties, e.g. for seal applications. TPU basically provides high strength, low frictional behavior and excellent wear resistance. Though, due to segmented structure of TPU, which is composed of hard segments (HSs) and soft segments (SSs), physical properties depend strongly on the morphological arrangement of the phase separated HSs at a certain ratio of HSs to SSs. It is obvious that the TPU deforms differently depending on its bulk morphology. Basically, the morphology can either consist of HSs segregated into small domains, which are well dispersed in the SS matrix or of few strongly phase separated large size HS domains embedded in the SS matrix. The morphology development is hardly ruled by the melt processing conditions of the TPU. Depending on the morphology, TPU provides quite different physical properties with respect to strength, deformation behavior, thermal stability, creep resistance and tribological performance. The paper deals with the influence of important melt processing parameters, such as temperature, pressure and shear conditions, on the resulting physical properties tested by tensile and relaxation experiments. Furthermore the morphology is studied employing differential scanning calorimeter (DSC), transmission light microscopy (TLM), scanning electron beam microscopy (SEM) and transmission electron beam microscopy (TEM) investigations. Correlations between processing conditions and resulting TPU material properties are elaborated. Flow and shear simulations contribute to the understanding of thermal and flow induced morphology development.

  19. Effective size of density-dependent two-sex populations: the effect of mating systems.

    Science.gov (United States)

    Myhre, A M; Engen, S; SAEther, B-E

    2017-08-01

    Density dependence in vital rates is a key feature affecting temporal fluctuations of natural populations. This has important implications for the rate of random genetic drift. Mating systems also greatly affect effective population sizes, but knowledge of how mating system and density regulation interact to affect random genetic drift is poor. Using theoretical models and simulations, we compare N e in short-lived, density-dependent animal populations with different mating systems. We study the impact of a fluctuating, density-dependent sex ratio and consider both a stable and a fluctuating environment. We find a negative relationship between annual N e /N and adult population size N due to density dependence, suggesting that loss of genetic variation is reduced at small densities. The magnitude of this decrease was affected by mating system and life history. A male-biased, density-dependent sex ratio reduces the rate of genetic drift compared to an equal, density-independent sex ratio, but a stochastic change towards male bias reduces the N e /N ratio. Environmental stochasticity amplifies temporal fluctuations in population size and is thus vital to consider in estimation of effective population sizes over longer time periods. Our results on the reduced loss of genetic variation at small densities, particularly in polygamous populations, indicate that density regulation may facilitate adaptive evolution at small population sizes. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  20. On common noise-induced synchronization in complex networks with state-dependent noise diffusion processes

    Science.gov (United States)

    Russo, Giovanni; Shorten, Robert

    2018-04-01

    This paper is concerned with the study of common noise-induced synchronization phenomena in complex networks of diffusively coupled nonlinear systems. We consider the case where common noise propagation depends on the network state and, as a result, the noise diffusion process at the nodes depends on the state of the network. For such networks, we present an algebraic sufficient condition for the onset of synchronization, which depends on the network topology, the dynamics at the nodes, the coupling strength and the noise diffusion. Our result explicitly shows that certain noise diffusion processes can drive an unsynchronized network towards synchronization. In order to illustrate the effectiveness of our result, we consider two applications: collective decision processes and synchronization of chaotic systems. We explicitly show that, in the former application, a sufficiently large noise can drive a population towards a common decision, while, in the latter, we show how common noise can synchronize a network of Lorentz chaotic systems.

  1. Peculiarities of dermatoglyphic values among the people of Uzbek population dependently on sex

    OpenAIRE

    Kuziyev, Otabek; ORTIQBOYEV JAKHONGIR ORTIQBOY OGLI; Khakimova, Gulnoz; Aripdjanova, Nigina

    2015-01-01

    : This article describes a study conducted to determine the basic dermatoglyphic traits, located in relation to gender in persons of Uzbek population. Provides definitions of the differences in rate of dermatoglyphic depending on nationality.

  2. Hybrid colored noise process with space-dependent switching rates

    Science.gov (United States)

    Bressloff, Paul C.; Lawley, Sean D.

    2017-07-01

    A fundamental issue in the theory of continuous stochastic process is the interpretation of multiplicative white noise, which is often referred to as the Itô-Stratonovich dilemma. From a physical perspective, this reflects the need to introduce additional constraints in order to specify the nature of the noise, whereas from a mathematical perspective it reflects an ambiguity in the formulation of stochastic differential equations (SDEs). Recently, we have identified a mechanism for obtaining an Itô SDE based on a form of temporal disorder. Motivated by switching processes in molecular biology, we considered a Brownian particle that randomly switches between two distinct conformational states with different diffusivities. In each state, the particle undergoes normal diffusion (additive noise) so there is no ambiguity in the interpretation of the noise. However, if the switching rates depend on position, then in the fast switching limit one obtains Brownian motion with a space-dependent diffusivity of the Itô form. In this paper, we extend our theory to include colored additive noise. We show that the nature of the effective multiplicative noise process obtained by taking both the white-noise limit (κ →0 ) and fast switching limit (ɛ →0 ) depends on the order the two limits are taken. If the white-noise limit is taken first, then we obtain Itô, and if the fast switching limit is taken first, then we obtain Stratonovich. Moreover, the form of the effective diffusion coefficient differs in the two cases. The latter result holds even in the case of space-independent transition rates, where one obtains additive noise processes with different diffusion coefficients. Finally, we show that yet another form of multiplicative noise is obtained in the simultaneous limit ɛ ,κ →0 with ɛ /κ2 fixed.

  3. Stabilization process of human population: a descriptive approach.

    Science.gov (United States)

    Kayani, A K; Krotki, K J

    1981-01-01

    An attempt is made to inquire into the process of stabilization of a human population. The same age distribution distorted by past variations in fertility is subjected to several fixed schedules of fertility. The schedules are different from each other monotonically over a narrow range. The primary concern is with the process, almost year by year, through which the populations become stable. There is particular interest in the differential impact in the same original age distribution of the narrowly different fixed fertility schedules. The exercise is prepared in 3 stages: general background of the process of stabilization; methodology and data used; and analysis and discussion of the stabilization process. Among the several approaches through which the analysis of stable population is possible, 2 are popular: the integral equation and the projection matrix. In this presentation the interest is in evaluating the effects of fertility on the stabilization process of a population. Therefore, only 1 initial age distribution and only 1 life table but a variety of narrowly different schedules of fertility have been used. Specifically, the U.S. 1963 female population is treated as the initial population. The process of stabilization is viewed in the light of the changes in the slopes between 2 successive age groups of an age distribution. A high fertility schedule with the given initial age distribution and mortality level overcomes the oscillations more quickly than the low fertility schedule. Simulation confirms the intuitively expected positive relationship between the mean of the slope and the level of fertility. The variance of the slope distribution is an indicator of the aging of the distribution.

  4. Explaining density-dependent regulation in earthworm populations using life-history analysis

    NARCIS (Netherlands)

    Kammenga, J.E.; Spurgeon, D.J.; Svendsen, C.; Weeks, J.M.

    2003-01-01

    At present there is little knowledge about how density regulates population growth rate and to what extent this is determined by life-history patterns. We compared density dependent population consequences in the Nicholsonian sense based oil experimental observations and life-history modeling for

  5. Alternating event processes during lifetimes: population dynamics and statistical inference.

    Science.gov (United States)

    Shinohara, Russell T; Sun, Yifei; Wang, Mei-Cheng

    2018-01-01

    In the literature studying recurrent event data, a large amount of work has been focused on univariate recurrent event processes where the occurrence of each event is treated as a single point in time. There are many applications, however, in which univariate recurrent events are insufficient to characterize the feature of the process because patients experience nontrivial durations associated with each event. This results in an alternating event process where the disease status of a patient alternates between exacerbations and remissions. In this paper, we consider the dynamics of a chronic disease and its associated exacerbation-remission process over two time scales: calendar time and time-since-onset. In particular, over calendar time, we explore population dynamics and the relationship between incidence, prevalence and duration for such alternating event processes. We provide nonparametric estimation techniques for characteristic quantities of the process. In some settings, exacerbation processes are observed from an onset time until death; to account for the relationship between the survival and alternating event processes, nonparametric approaches are developed for estimating exacerbation process over lifetime. By understanding the population dynamics and within-process structure, the paper provide a new and general way to study alternating event processes.

  6. Comparing Sensory Information Processing and Alexithymia between People with Substance Dependency and Normal.

    Science.gov (United States)

    Bashapoor, Sajjad; Hosseini-Kiasari, Seyyedeh Tayebeh; Daneshvar, Somayeh; Kazemi-Taskooh, Zeinab

    2015-01-01

    Sensory information processing and alexithymia are two important factors in determining behavioral reactions. Some studies explain the effect of the sensitivity of sensory processing and alexithymia in the tendency to substance abuse. Giving that, the aim of the current study was to compare the styles of sensory information processing and alexithymia between substance-dependent people and normal ones. The research method was cross-sectional and the statistical population of the current study comprised of all substance-dependent men who are present in substance quitting camps of Masal, Iran, in October 2013 (n = 78). 36 persons were selected randomly by simple randomly sampling method from this population as the study group, and 36 persons were also selected among the normal population in the same way as the comparison group. Both groups was evaluated by using Toronto alexithymia scale (TAS) and adult sensory profile, and the multivariate analysis of variance (MANOVA) test was applied to analyze data. The results showed that there are significance differences between two groups in low registration (P processing and difficulty in describing emotions (P process sensory information in a different way than normal people and show more alexithymia features than them.

  7. Affective reactions and context-dependent processing of negations

    Directory of Open Access Journals (Sweden)

    Enrico Rubaltelli

    2008-12-01

    Full Text Available Three experiments demonstrate how the processing of negations is contingent on the evaluation context in which the negative information is presented. In addition, the strategy used to process the negations induced different affective reactions toward the stimuli, leading to inconsistency of preference. Participants were presented with stimuli described by either stating the presence of positive features (explicitly positive alternative or negating the presence of negative features (non-negative alternative. Alternatives were presented for either joint (JE or separate evaluation (SE. Experiment 1 showed that the non-negative stimuli were judged less attractive than the positive ones in JE but not in SE. Experiment 2 revealed that the non-negative stimuli induced a less clear and less positive feeling when they were paired with explicitly positive stimuli rather than evaluated separately. Non-negative options were also found less easy to judge than the positive ones in JE but not in SE. Finally, Experiment 3 showed that people process negations using two different models depending on the evaluation mode. Through a memory task, we found that in JE people process the non-negative attributes as negations of negative features, whereas in SE they directly process the non-negative attributes as positive features.

  8. Selection processes in a citrus hybrid population using RAPD markers

    Directory of Open Access Journals (Sweden)

    Oliveira Roberto Pedroso de

    2003-01-01

    Full Text Available The objective of this work was to evaluate the processes of selection in a citrus hybrid population using segregation analysis of RAPD markers. The segregation of 123 RAPD markers between 'Cravo' mandarin (Citrus reticulata Blanco and 'Pêra' sweet orange (C. sinensis (L. Osbeck was analysed in a F1 progeny of 94 hybrids. Genetic composition, diversity, heterozygosity, differences in chromosomal structure and the presence of deleterious recessive genes are discussed based on the segregation ratios obtained. A high percentage of markers had a skeweness of the 1:1 expected segregation ratio in the F1 population. Many markers showed a 3:1 segregation ratio in both varieties and 1:3 in 'Pêra' sweet orange, probably due to directional selection processes. The distribution analysis of the frequencies of the segregant markers in a hybrid population is a simple method which allows a better understanding of the genetics of citrus group.

  9. Innovations in Play Therapy: Issues, Process, and Special Populations.

    Science.gov (United States)

    Landreth, Garry L., Ed.

    This book is a compilation of discussions on current issues in play therapy. It is designed to help therapists fill in the gaps about working with special populations, which is often not directly addressed in other play therapy resources. The object of the book is to bring together information related to issues and dynamics of the process of this…

  10. Population density equations for stochastic processes with memory kernels

    Science.gov (United States)

    Lai, Yi Ming; de Kamps, Marc

    2017-06-01

    We present a method for solving population density equations (PDEs)-a mean-field technique describing homogeneous populations of uncoupled neurons—where the populations can be subject to non-Markov noise for arbitrary distributions of jump sizes. The method combines recent developments in two different disciplines that traditionally have had limited interaction: computational neuroscience and the theory of random networks. The method uses a geometric binning scheme, based on the method of characteristics, to capture the deterministic neurodynamics of the population, separating the deterministic and stochastic process cleanly. We can independently vary the choice of the deterministic model and the model for the stochastic process, leading to a highly modular numerical solution strategy. We demonstrate this by replacing the master equation implicit in many formulations of the PDE formalism by a generalization called the generalized Montroll-Weiss equation—a recent result from random network theory—describing a random walker subject to transitions realized by a non-Markovian process. We demonstrate the method for leaky- and quadratic-integrate and fire neurons subject to spike trains with Poisson and gamma-distributed interspike intervals. We are able to model jump responses for both models accurately to both excitatory and inhibitory input under the assumption that all inputs are generated by one renewal process.

  11. Anomalous dependence of population growth on the birth rate in the plant-herbivore system

    International Nuclear Information System (INIS)

    Cui, Xue M.; Han, Seung K.; Chung, Jean S.

    2010-01-01

    We performed a simulation of the two-species plant-herbivore system by using the agent-based NetLogo program and constructed a dynamic model of populations consistent with the simulation results. The dynamic model is a three-dimensional system including the mean energy of the herbivore in addition to two variables denoting the populations of plants and herbivores. A steady-state analysis of the dynamic model shows that the dependence of the herbivore population on the birth and the death rates observed from the agent model is consistent with the prediction of the dynamic model. Especially, the anomalous dependence of the herbivore population on the birth rate, where the population decreases with the birth rate for small death rate, is consistently explained by a phase plane analysis of the dynamic model.

  12. Complete FDTD analysis of microwave heating processes in frequency-dependent and temperature dependent media

    Energy Technology Data Exchange (ETDEWEB)

    Torres, F.; Jecko, B. [Univ. de Limoges (France). Inst. de Recherche en Communications Optiques et Microondes

    1997-01-01

    It is well known that the temperature rise in a material modifies its physical properties and, particularly, its dielectric permittivity. The dissipated electromagnetic power involved in microwave heating processes depending on {var_epsilon}({omega}), the electrical characteristics of the heated media must vary with the temperature to achieve realistic simulations. In this paper, the authors present a fast and accurate algorithm allowing, through a combined electromagnetic and thermal procedure, to take into account the influence of the temperature on the electrical properties of materials. First, the temperature dependence of the complex permittivity ruled by a Debye relaxation equation is investigated, and a realistic model is proposed and validated. Then, a frequency-dependent finite-differences time-domain ((FD){sup 2}TD) method is used to assess the instantaneous electromagnetic power lost by dielectric hysteresis. Within the same iteration, a time-scaled form of the heat transfer equation allows one to calculate the temperature distribution in the heated medium and then to correct the dielectric properties of the material using the proposed model. These new characteristics will be taken into account by the EM solver at the next iteration. This combined algorithm allows a significant reduction of computation time. An application to a microwave oven is proposed.

  13. Response of single bacterial cells to stress gives rise to complex history dependence at the population level

    Science.gov (United States)

    Mathis, Roland; Ackermann, Martin

    2016-01-01

    Most bacteria live in ever-changing environments where periods of stress are common. One fundamental question is whether individual bacterial cells have an increased tolerance to stress if they recently have been exposed to lower levels of the same stressor. To address this question, we worked with the bacterium Caulobacter crescentus and asked whether exposure to a moderate concentration of sodium chloride would affect survival during later exposure to a higher concentration. We found that the effects measured at the population level depended in a surprising and complex way on the time interval between the two exposure events: The effect of the first exposure on survival of the second exposure was positive for some time intervals but negative for others. We hypothesized that the complex pattern of history dependence at the population level was a consequence of the responses of individual cells to sodium chloride that we observed: (i) exposure to moderate concentrations of sodium chloride caused delays in cell division and led to cell-cycle synchronization, and (ii) whether a bacterium would survive subsequent exposure to higher concentrations was dependent on the cell-cycle state. Using computational modeling, we demonstrated that indeed the combination of these two effects could explain the complex patterns of history dependence observed at the population level. Our insight into how the behavior of single cells scales up to processes at the population level provides a perspective on how organisms operate in dynamic environments with fluctuating stress exposure. PMID:26960998

  14. Bicarbonate-dependent secretion and proteolytic processing of recombinant myocilin.

    Directory of Open Access Journals (Sweden)

    José-Daniel Aroca-Aguilar

    Full Text Available Myocilin is an extracellular glycoprotein of poorly understood function. Mutations of this protein are involved in glaucoma, an optic neuropathy characterized by a progressive and irreversible visual loss and frequently associated with elevated intraocular pressure. We previously showed that recombinant myocilin undergoes an intracellular proteolytic processing by calpain II which cleaves the central region of the protein, releasing one N- and one C-terminal fragment. Myocilin cleavage is reduced by glaucoma mutations and it has been proposed to participate in intraocular pressure modulation. To identify possible factors regulating the proteolytic processing of recombinant myocilin, we used a cellular model in which we analyzed how different culture medium parameters (i.e., culture time, cell density, pH, bicarbonate concentration, etc. affect the presence of the extracellular C-terminal fragment. Extracellular bicarbonate depletion associated with culture medium acidification produced a reversible intracellular accumulation of full-length recombinant myocilin and incremented its intracellular proteolytic processing, raising the extracellular C-terminal fragment percentage. It was also determined that myocilin intracellular accumulation depends on its N-terminal region. These data suggest that aqueous humor bicarbonate variations could also modulate the secretion and cleavage of myocilin present in ocular tissues.

  15. Coding of time-dependent stimuli in homogeneous and heterogeneous neural populations.

    Science.gov (United States)

    Beiran, Manuel; Kruscha, Alexandra; Benda, Jan; Lindner, Benjamin

    2018-04-01

    We compare the information transmission of a time-dependent signal by two types of uncoupled neuron populations that differ in their sources of variability: i) a homogeneous population whose units receive independent noise and ii) a deterministic heterogeneous population, where each unit exhibits a different baseline firing rate ('disorder'). Our criterion for making both sources of variability quantitatively comparable is that the interspike-interval distributions are identical for both systems. Numerical simulations using leaky integrate-and-fire neurons unveil that a non-zero amount of both noise or disorder maximizes the encoding efficiency of the homogeneous and heterogeneous system, respectively, as a particular case of suprathreshold stochastic resonance. Our findings thus illustrate that heterogeneity can render similarly profitable effects for neuronal populations as dynamic noise. The optimal noise/disorder depends on the system size and the properties of the stimulus such as its intensity or cutoff frequency. We find that weak stimuli are better encoded by a noiseless heterogeneous population, whereas for strong stimuli a homogeneous population outperforms an equivalent heterogeneous system up to a moderate noise level. Furthermore, we derive analytical expressions of the coherence function for the cases of very strong noise and of vanishing intrinsic noise or heterogeneity, which predict the existence of an optimal noise intensity. Our results show that, depending on the type of signal, noise as well as heterogeneity can enhance the encoding performance of neuronal populations.

  16. Propagation of Data Dependency through Distributed Cooperating Processes

    Science.gov (United States)

    1988-09-01

    12 The External Data Dependency Analyzer ( EDDA ) .................................................. 12 The new EPL...47 EDDA Patch Files for the Dining Philosophers Example [Figure 23] ................... 49 L im itations...dependencies is evident. The External Data Dependency Analyzer ( EDDA ) The EDDA derives external data dependencies by performing two levels of analysis

  17. Stress hormones link food availability and population processes in seabirds

    Science.gov (United States)

    Kitaysky, A.S.; Piatt, John F.; Wingfield, J.C.

    2007-01-01

    Catastrophic population declines in marine top predators in the northern Pacific have been hypothesized to result from nutritional stress affecting reproduction and survival of individuals. However, empirical evidence for food-related stress in wild animals is frequently lacking or inconclusive. We used a field endocrinology approach to measure stress, identify its causes, and examine a link between stress and population processes in the common murre Uria aalge. We tested the empirical relationship between variations in the stress hormone corticosterone (CORT) and food abundance, reproduction, and persistence of individuals at declining and increasing colonies in Cook Inlet, Alaska, from 1996 to 2001. We found that CORT secretion in murres is independent of colony, reproductive stage effects, and gender of individuals, but is directly negatively correlated with abundance of their food. Baseline CORT reflected current food abundance, whereas acute stress-induced CORT reflected food abundance in the previous month. As food supply diminished, increased CORT secretion predicted a decrease in reproductive performance. At a declining colony, increased baseline levels of CORT during reproduction predicted disappearance of individuals from the population. Persistence of individuals in a growing colony was independent of CORT during reproduction. The obtained results support the hypothesis that nutritional stress during reproduction affects reproduction and survival in seabirds. This study provides the first unequivocal evidence for CORT secretion as a mechanistic link between fluctuations in food abundance and population processes in seabirds. ?? Inter-Research 2007.

  18. An experimental field study of delayed density dependence in natural populations of Aedes albopictus.

    Directory of Open Access Journals (Sweden)

    Rachael K Walsh

    Full Text Available Aedes albopictus, a species known to transmit dengue and chikungunya viruses, is primarily a container-inhabiting mosquito. The potential for pathogen transmission by Ae. albopictus has increased our need to understand its ecology and population dynamics. Two parameters that we know little about are the impact of direct density-dependence and delayed density-dependence in the larval stage. The present study uses a manipulative experimental design, under field conditions, to understand the impact of delayed density dependence in a natural population of Ae. albopictus in Raleigh, North Carolina. Twenty liter buckets, divided in half prior to experimentation, placed in the field accumulated rainwater and detritus, providing oviposition and larval production sites for natural populations of Ae. albopictus. Two treatments, a larvae present and larvae absent treatment, were produced in each bucket. After five weeks all larvae were removed from both treatments and the buckets were covered with fine mesh cloth. Equal numbers of first instars were added to both treatments in every bucket. Pupae were collected daily and adults were frozen as they emerged. We found a significant impact of delayed density-dependence on larval survival, development time and adult body size in containers with high larval densities. Our results indicate that delayed density-dependence will have negative impacts on the mosquito population when larval densities are high enough to deplete accessible nutrients faster than the rate of natural food accumulation.

  19. Radio pulsar glitches as a state-dependent Poisson process

    Science.gov (United States)

    Fulgenzi, W.; Melatos, A.; Hughes, B. D.

    2017-10-01

    Gross-Pitaevskii simulations of vortex avalanches in a neutron star superfluid are limited computationally to ≲102 vortices and ≲102 avalanches, making it hard to study the long-term statistics of radio pulsar glitches in realistically sized systems. Here, an idealized, mean-field model of the observed Gross-Pitaevskii dynamics is presented, in which vortex unpinning is approximated as a state-dependent, compound Poisson process in a single random variable, the spatially averaged crust-superfluid lag. Both the lag-dependent Poisson rate and the conditional distribution of avalanche-driven lag decrements are inputs into the model, which is solved numerically (via Monte Carlo simulations) and analytically (via a master equation). The output statistics are controlled by two dimensionless free parameters: α, the glitch rate at a reference lag, multiplied by the critical lag for unpinning, divided by the spin-down rate; and β, the minimum fraction of the lag that can be restored by a glitch. The system evolves naturally to a self-regulated stationary state, whose properties are determined by α/αc(β), where αc(β) ≈ β-1/2 is a transition value. In the regime α ≳ αc(β), one recovers qualitatively the power-law size and exponential waiting-time distributions observed in many radio pulsars and Gross-Pitaevskii simulations. For α ≪ αc(β), the size and waiting-time distributions are both power-law-like, and a correlation emerges between size and waiting time until the next glitch, contrary to what is observed in most pulsars. Comparisons with astrophysical data are restricted by the small sample sizes available at present, with ≤35 events observed per pulsar.

  20. Cigarette smoking, nicotine dependence and anxiety disorders: a systematic review of population-based, epidemiological studies

    Directory of Open Access Journals (Sweden)

    Moylan Steven

    2012-10-01

    Full Text Available Abstract Background Multiple studies have demonstrated that rates of smoking and nicotine dependence are increased in individuals with anxiety disorders. However, significant variability exists in the epidemiological literature exploring this relationship, including study design (cross-sectional versus prospective, the population assessed (random sample versus clinical population and diagnostic instrument utilized. Methods We undertook a systematic review of population-based observational studies that utilized recognized structured clinical diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders (DSM or International Classification of Diseases (ICD for anxiety disorder diagnosis to investigate the relationship between cigarette smoking, nicotine dependence and anxiety disorders. Results In total, 47 studies met the predefined inclusion criteria, with 12 studies providing prospective information and 5 studies providing quasiprospective information. The available evidence suggests that some baseline anxiety disorders are a risk factor for initiation of smoking and nicotine dependence, although the evidence is heterogeneous and many studies did not control for the effect of comorbid substance use disorders. The identified evidence however appeared to more consistently support cigarette smoking and nicotine dependence as being a risk factor for development of some anxiety disorders (for example, panic disorder, generalized anxiety disorder, although these findings were not replicated in all studies. A number of inconsistencies in the literature were identified. Conclusions Although many studies have demonstrated increased rates of smoking and nicotine dependence in individuals with anxiety disorders, there is a limited and heterogeneous literature that has prospectively examined this relationship in population studies using validated diagnostic criteria. The most consistent evidence supports smoking and nicotine dependence as

  1. Consumption of processed food dietary patterns in four African populations.

    Science.gov (United States)

    Holmes, Michelle D; Dalal, Shona; Sewram, Vikash; Diamond, Megan B; Adebamowo, Sally N; Ajayi, Ikeoluwapo O; Adebamowo, Clement; Chiwanga, Faraja S; Njelekela, Marina; Laurence, Carien; Volmink, Jimmy; Bajunirwe, Francis; Nankya-Mutyoba, Joan; Guwatudde, David; Reid, Todd G; Willett, Walter C; Adami, Hans-Olov; Fung, Teresa T

    2018-06-01

    To identify predominant dietary patterns in four African populations and examine their association with obesity. Cross-sectional study.Setting/SubjectsWe used data from the Africa/Harvard School of Public Health Partnership for Cohort Research and Training (PaCT) pilot study established to investigate the feasibility of a multi-country longitudinal study of non-communicable chronic disease in sub-Saharan Africa. We applied principal component analysis to dietary intake data collected from an FFQ developed for PaCT to ascertain dietary patterns in Tanzania, South Africa, and peri-urban and rural Uganda. The sample consisted of 444 women and 294 men. We identified two dietary patterns: the Mixed Diet pattern characterized by high intakes of unprocessed foods such as vegetables and fresh fish, but also cold cuts and refined grains; and the Processed Diet pattern characterized by high intakes of salad dressing, cold cuts and sweets. Women in the highest tertile of the Processed Diet pattern score were 3·00 times more likely to be overweight (95 % CI 1·66, 5·45; prevalence=74 %) and 4·24 times more likely to be obese (95 % CI 2·23, 8·05; prevalence=44 %) than women in this pattern's lowest tertile (both Pobesity. We identified two major dietary patterns in several African populations, a Mixed Diet pattern and a Processed Diet pattern. The Processed Diet pattern was associated with obesity.

  2. Density dependence governs when population responses to multiple stressors are magnified or mitigated.

    Science.gov (United States)

    Hodgson, Emma E; Essington, Timothy E; Halpern, Benjamin S

    2017-10-01

    Population endangerment typically arises from multiple, potentially interacting anthropogenic stressors. Extensive research has investigated the consequences of multiple stressors on organisms, frequently focusing on individual life stages. Less is known about population-level consequences of exposure to multiple stressors, especially when exposure varies through life. We provide the first theoretical basis for identifying species at risk of magnified effects from multiple stressors across life history. By applying a population modeling framework, we reveal conditions under which population responses from stressors applied to distinct life stages are either magnified (synergistic) or mitigated. We find that magnification or mitigation critically depends on the shape of density dependence, but not the life stage in which it occurs. Stressors are always magnified when density dependence is linear or concave, and magnified or mitigated when it is convex. Using Bayesian numerical methods, we estimated the shape of density dependence for eight species across diverse taxa, finding support for all three shapes. © 2017 by the Ecological Society of America.

  3. The ideal free distribution as an evolutionarily stable state in density-dependent population games

    Czech Academy of Sciences Publication Activity Database

    Cressman, R.; Křivan, Vlastimil

    2010-01-01

    Roč. 119, č. 8 (2010), s. 1231-1242 ISSN 0030-1299 R&D Projects: GA AV ČR IAA100070601 Institutional research plan: CEZ:AV0Z50070508 Keywords : density-dependent population games Subject RIV: EH - Ecology, Behaviour Impact factor: 3.393, year: 2010

  4. Cortical processes of speech illusions in the general population.

    Science.gov (United States)

    Schepers, E; Bodar, L; van Os, J; Lousberg, R

    2016-10-18

    There is evidence that experimentally elicited auditory illusions in the general population index risk for psychotic symptoms. As little is known about underlying cortical mechanisms of auditory illusions, an experiment was conducted to analyze processing of auditory illusions in a general population sample. In a follow-up design with two measurement moments (baseline and 6 months), participants (n = 83) underwent the White Noise task under simultaneous recording with a 14-lead EEG. An auditory illusion was defined as hearing any speech in a sound fragment containing white noise. A total number of 256 speech illusions (SI) were observed over the two measurements, with a high degree of stability of SI over time. There were 7 main effects of speech illusion on the EEG alpha band-the most significant indicating a decrease in activity at T3 (t = -4.05). Other EEG frequency bands (slow beta, fast beta, gamma, delta, theta) showed no significant associations with SI. SIs are characterized by reduced alpha activity in non-clinical populations. Given the association of SIs with psychosis, follow-up research is required to examine the possibility of reduced alpha activity mediating SIs in high risk and symptomatic populations.

  5. Study of a tri-trophic prey-dependent food chain model of interacting populations.

    Science.gov (United States)

    Haque, Mainul; Ali, Nijamuddin; Chakravarty, Santabrata

    2013-11-01

    The current paper accounts for the influence of intra-specific competition among predators in a prey dependent tri-trophic food chain model of interacting populations. We offer a detailed mathematical analysis of the proposed food chain model to illustrate some of the significant results that has arisen from the interplay of deterministic ecological phenomena and processes. Biologically feasible equilibria of the system are observed and the behaviours of the system around each of them are described. In particular, persistence, stability (local and global) and bifurcation (saddle-node, transcritical, Hopf-Andronov) analysis of this model are obtained. Relevant results from previous well known food chain models are compared with the current findings. Global stability analysis is also carried out by constructing appropriate Lyapunov functions. Numerical simulations show that the present system is capable enough to produce chaotic dynamics when the rate of self-interaction is very low. On the other hand such chaotic behaviour disappears for a certain value of the rate of self interaction. In addition, numerical simulations with experimented parameters values confirm the analytical results and shows that intra-specific competitions bears a potential role in controlling the chaotic dynamics of the system; and thus the role of self interactions in food chain model is illustrated first time. Finally, a discussion of the ecological applications of the analytical and numerical findings concludes the paper. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Population Consequences of Age-Dependent Maternal Effects in Rockfish (Sebastes spp.)

    OpenAIRE

    Lucero, Yasmin

    2007-01-01

    I present a model of the early life history of a rockfish that includes an age-dependent maternal effect. The model is designed to accurately reflect the diverse uncertainties we have about early life history processes. The first portion of this thesis is devoted to an analytical treatment of the deterministic early life history model. I emphasize uncertainty about the functional form of density-dependent processes in the juvenile stage. The remainder of the thesis is devoted to demonstrating...

  7. Individualism in plant populations: using stochastic differential equations to model individual neighbourhood-dependent plant growth.

    Science.gov (United States)

    Lv, Qiming; Schneider, Manuel K; Pitchford, Jonathan W

    2008-08-01

    We study individual plant growth and size hierarchy formation in an experimental population of Arabidopsis thaliana, within an integrated analysis that explicitly accounts for size-dependent growth, size- and space-dependent competition, and environmental stochasticity. It is shown that a Gompertz-type stochastic differential equation (SDE) model, involving asymmetric competition kernels and a stochastic term which decreases with the logarithm of plant weight, efficiently describes individual plant growth, competition, and variability in the studied population. The model is evaluated within a Bayesian framework and compared to its deterministic counterpart, and to several simplified stochastic models, using distributional validation. We show that stochasticity is an important determinant of size hierarchy and that SDE models outperform the deterministic model if and only if structural components of competition (asymmetry; size- and space-dependence) are accounted for. Implications of these results are discussed in the context of plant ecology and in more general modelling situations.

  8. Density regulation in Northeast Atlantic fish populations: Density dependence is stronger in recruitment than in somatic growth.

    Science.gov (United States)

    Zimmermann, Fabian; Ricard, Daniel; Heino, Mikko

    2018-05-01

    Population regulation is a central concept in ecology, yet in many cases its presence and the underlying mechanisms are difficult to demonstrate. The current paradigm maintains that marine fish populations are predominantly regulated by density-dependent recruitment. While it is known that density-dependent somatic growth can be present too, its general importance remains unknown and most practical applications neglect it. This study aimed to close this gap by for the first time quantifying and comparing density dependence in growth and recruitment over a large set of fish populations. We fitted density-dependent models to time-series data on population size, recruitment and age-specific weight from commercially exploited fish populations in the Northeast Atlantic Ocean and the Baltic Sea. Data were standardized to enable a direct comparison within and among populations, and estimated parameters were used to quantify the impact of density regulation on population biomass. Statistically significant density dependence in recruitment was detected in a large proportion of populations (70%), whereas for density dependence in somatic growth the prevalence of density dependence depended heavily on the method (26% and 69%). Despite age-dependent variability, the density dependence in recruitment was consistently stronger among age groups and between alternative approaches that use weight-at-age or weight increments to assess growth. Estimates of density-dependent reduction in biomass underlined these results: 97% of populations with statistically significant parameters for growth and recruitment showed a larger impact of density-dependent recruitment on population biomass. The results reaffirm the importance of density-dependent recruitment in marine fishes, yet they also show that density dependence in somatic growth is not uncommon. Furthermore, the results are important from an applied perspective because density dependence in somatic growth affects productivity and

  9. Real time process algebra with time-dependent conditions

    NARCIS (Netherlands)

    Baeten, J.C.M.; Middelburg, C.A.

    We extend the main real time version of ACP presented in [6] with conditionals in which the condition depends on time. This extension facilitates flexible dependence of proccess behaviour on initialization time. We show that the conditions concerned generalize the conditions introduced earlier

  10. Social deprivation, population dependency ratio and an extended hospital episode - Insights from acute medicine.

    Science.gov (United States)

    Cournane, Seán; Dalton, Ann; Byrne, Declan; Conway, Richard; O'Riordan, Deirdre; Coveney, Seamus; Silke, Bernard

    2015-11-01

    Patients from deprived backgrounds have a higher in-patient mortality following an emergency medical admission; this study aimed to investigate the extent to which Deprivation status and the population Dependency Ratio influenced extended hospital episodes. All Emergency Medical admissions (75,018 episodes of 41,728 patients) over 12 years (2002-2013) categorized by quintile of Deprivation Index and Population Dependency Rates (proportion of non-working/working) were evaluated against length of stay (LOS). Patients with an Extended LOS (ELOS), >30 days, were investigated, by Deprivation status, Illness Severity and Co-morbidity status. Univariate and multi-variable risk estimates (Odds Rates or Incidence Rate Ratios) were calculated, using truncated Poisson regression. Hospital episodes with ELOS had a frequency of 11.5%; their median LOS (IQR) was 55.0 (38.8, 97.6) days utilizing 57.6% of all bed days by all 75,018 emergency medical admissions. The Deprivation Index independently predicted the rate of such ELOS admissions; these increased approximately five-fold (rate/1000 population) over the Deprivation Quintiles with model adjusted predicted admission rates of for Q1 0.93 (95% CI: 0.86, 0.99), Q22.63 (95% CI: 2.55, 2.71), Q3 3.84 (95% CI: 3.77, 3.91), Q4 3.42 (95% CI: 3.37, 3.48) and Q5 4.38 (95% CI: 4.22, 4.54). Similarly the Population Dependency Ratio Quintiles (dependent to working structure of the population by small area units) independently predicted extended LOS admissions. The admission of patients with an ELOS is strongly influenced by the Deprivation status and the population Dependency Ratio of the catchment area. These factors interact, with both high deprivation and Dependency cohorts having a major influence on the numbers of emergency medical admission patients with an extended hospital episode. Copyright © 2015 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  11. Mild Traumatic Brain Injury Chronically Impairs Sleep- and Wake-Dependent Emotional Processing.

    Science.gov (United States)

    Mantua, Janna; Henry, Owen S; Garskovas, Nolan F; Spencer, Rebecca M C

    2017-06-01

    A single traumatic brain injury (TBI), even when mild (ie, concussion), can cause lasting consequences. Individuals with a history of chronic (>1-year prior) mild TBI have an increased risk of mood disturbances (eg, depression, suicide). This population also has lingering sleep alterations, including poor sleep quality and changes in sleep stage proportions. Given these sleep deficits, we aimed to test whether sleep-dependent emotional memory consolidation is reduced in this population. We utilized a mild TBI group (3.7 ± 2.9 years post injury) and an uninjured (non-TBI) population. Participants viewed negative and neutral images both before and after a 12-hour period containing sleep ("Sleep" group) or an equivalent period of time spent awake ("Wake" group). Participants rated images for valence/arousal at both sessions, and memory recognition was tested at session two. The TBI group had less rapid eye movement (REM), longer REM latency, and more sleep complaints. Sleep-dependent memory consolidation of nonemotional images was present in all participants. However, consolidation of negative images was only present in the non-TBI group. A lack of differentiation between the TBI Sleep and Wake groups was due to poor performance in the sleep group and, unexpectedly, enhanced performance in the wake group. Additionally, although the non-TBI participants habituated to negative images over a waking period, the TBI participants did not. We propose disrupted sleep- and wake-dependent emotional processing contributes to poor emotional outcomes following chronic, mild TBI. This work has broad implications, as roughly one-third of the US population will sustain a mild TBI during their lifetime. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  12. CHRNA3 genotype, nicotine dependence, lung function and disease in the general population

    DEFF Research Database (Denmark)

    Kaur-Knudsen, Diljit; Nordestgaard, Børge G; Bojesen, Stig E

    2012-01-01

    The CHRNA3 rs1051730 polymorphism has been associated to chronic obstructive pulmonary disease (COPD), lung cancer and nicotine dependence in case-control studies with high smoking exposure; however, its influence on lung function and COPD severity in the general population is largely unknown. We...... genotyped 57,657 adult individuals from the Copenhagen General Population Study, of whom 34,592 were ever-smokers. Information on spirometry, hospital admissions, smoking behaviour and use of nicotinic replacement therapy was recorded. In homozygous (11%), heterozygous (44%) and noncarrier (45%) ever...

  13. Sub-national mapping of population pyramids and dependency ratios in Africa and Asia

    Science.gov (United States)

    Pezzulo, Carla; Hornby, Graeme M.; Sorichetta, Alessandro; Gaughan, Andrea E.; Linard, Catherine; Bird, Tomas J.; Kerr, David; Lloyd, Christopher T.; Tatem, Andrew J.

    2017-07-01

    The age group composition of populations varies substantially across continents and within countries, and is linked to levels of development, health status and poverty. The subnational variability in the shape of the population pyramid as well as the respective dependency ratio are reflective of the different levels of development of a country and are drivers for a country's economic prospects and health burdens. Whether measured as the ratio between those of working age and those young and old who are dependent upon them, or through separate young and old-age metrics, dependency ratios are often highly heterogeneous between and within countries. Assessments of subnational dependency ratio and age structure patterns have been undertaken for specific countries and across high income regions, but to a lesser extent across the low income regions. In the framework of the WorldPop Project, through the assembly of over 100 million records across 6,389 subnational administrative units, subnational dependency ratio and high resolution gridded age/sex group datasets were produced for 87 countries in Africa and Asia.

  14. Ghrelin precursor gene polymorphism and methamphetamine dependence in the Korean population.

    Science.gov (United States)

    Yoon, Su-Jung; Pae, Chi-Un; Lee, Heejin; Choi, Bomoon; Kim, Tae-Suk; Lyoo, In Kyoon; Kwon, Do-Hoon; Kim, Dai-Jin

    2005-12-01

    Ghrelin is a recently isolated brain-gut peptide that has growth hormone-releasing and appetite-inducing activities. Several recent studies have suggested that ghrelin plays a major role in the pathophysiology of drug-seeking behavior and anxiety. Therefore, we assessed the effect of the ghrelin precursor polymorphism on methamphetamine dependence in the Korean population. One hundred and eighteen patients with methamphetamine dependence, according to the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria, and the 144 healthy controls were enrolled in this study. Genotyping for the ghrelin precursor polymorphism was performed by the polymerase chain reaction-restriction fragment length polymorphism-based technique. The genotypic and allelic distributions of the ghrelin precursor polymorphism in the patients with methamphetamine dependence were not significantly different from those of the control subjects. However, the Met72 carriers were associated with the emotional problems of methamphetamine dependence. The patients with the Met72 allele were more depressed and anxious than the homozygous patients with the wild Leu72 allele. The present study suggests that the ghrelin precursor polymorphism may not confer a susceptibility to the development of methamphetamine dependence in the Korean population. However, the Leu72Met polymorphism could have a potential role in the emotional problems that are associated with this disease.

  15. Modelling Anopheles gambiae s.s. Population Dynamics with Temperature- and Age-Dependent Survival

    Directory of Open Access Journals (Sweden)

    Céline Christiansen-Jucht

    2015-05-01

    Full Text Available Climate change and global warming are emerging as important threats to human health, particularly through the potential increase in vector- and water-borne diseases. Environmental variables are known to affect substantially the population dynamics and abundance of the poikilothermic vectors of disease, but the exact extent of this sensitivity is not well established. Focusing on malaria and its main vector in Africa, Anopheles gambiae sensu stricto, we present a set of novel mathematical models of climate-driven mosquito population dynamics motivated by experimental data suggesting that in An. gambiae, mortality is temperature and age dependent. We compared the performance of these models to that of a “standard” model ignoring age dependence. We used a longitudinal dataset of vector abundance over 36 months in sub-Saharan Africa for comparison between models that incorporate age dependence and one that does not, and observe that age-dependent models consistently fitted the data better than the reference model. This highlights that including age dependence in the vector component of mosquito-borne disease models may be important to predict more reliably disease transmission dynamics. Further data and studies are needed to enable improved fitting, leading to more accurate and informative model predictions for the An. gambiae malaria vector as well as for other disease vectors.

  16. Integration of Density Dependence and Concentration Response Models Provides an Ecologically Relevant Assessment of Populations Exposed to Toxicants

    Science.gov (United States)

    The assessment of toxic exposure on wildlife populations involves the integration of organism level effects measured in toxicity tests (e.g., chronic life cycle) and population models. These modeling exercises typically ignore density dependence, primarily because information on ...

  17. Hemispheric differences in processing of vocalizations depend on early experience

    OpenAIRE

    Phan, Mimi L.; Vicario, David S.

    2010-01-01

    An intriguing phenomenon in the neurobiology of language is lateralization: the dominant role of one hemisphere in a particular function. Lateralization is not exclusive to language because lateral differences are observed in other sensory modalities, behaviors, and animal species. Despite much scientific attention, the function of lateralization, its possible dependence on experience, and the functional implications of such dependence have yet to be clearly determined. We have explored the r...

  18. On the numerical simulation of population dynamics with density-dependent migrations and the Allee effects

    International Nuclear Information System (INIS)

    Sweilam, H N; Khader, M M; Al-Bar, F R

    2008-01-01

    In this paper, the variational iteration method (VIM) and the Adomian decomposition method (ADM) are presented for the numerical simulation of the population dynamics model with density-dependent migrations and the Allee effects. The convergence of ADM is proved for the model problem. The results obtained by these methods are compared to the exact solution. It is found that these methods are always converges to the right solutions with high accuracy. Furthermore, VIM needs relative less computational work than ADM

  19. Scale-dependent seasonal pool habitat use by sympatric Wild Brook Trout and Brown Trout populations

    Science.gov (United States)

    Davis, Lori A.; Wagner, Tyler

    2016-01-01

    Sympatric populations of native Brook Trout Salvelinus fontinalis and naturalized Brown Trout Salmo truttaexist throughout the eastern USA. An understanding of habitat use by sympatric populations is of importance for fisheries management agencies because of the close association between habitat and population dynamics. Moreover, habitat use by stream-dwelling salmonids may be further complicated by several factors, including the potential for fish to display scale-dependent habitat use. Discrete-choice models were used to (1) evaluate fall and early winter daytime habitat use by sympatric Brook Trout and Brown Trout populations based on available residual pool habitat within a stream network and (2) assess the sensitivity of inferred habitat use to changes in the spatial scale of the assumed available habitat. Trout exhibited an overall preference for pool habitats over nonpool habitats; however, the use of pools was nonlinear over time. Brook Trout displayed a greater preference for deep residual pool habitats than for shallow pool and nonpool habitats, whereas Brown Trout selected for all pool habitat categories similarly. Habitat use by both species was found to be scale dependent. At the smallest spatial scale (50 m), habitat use was primarily related to the time of year and fish weight. However, at larger spatial scales (250 and 450 m), habitat use varied over time according to the study stream in which a fish was located. Scale-dependent relationships in seasonal habitat use by Brook Trout and Brown Trout highlight the importance of considering scale when attempting to make inferences about habitat use; fisheries managers may want to consider identifying the appropriate spatial scale when devising actions to restore and protect Brook Trout populations and their habitats.

  20. Holistic Processing in the Composite Task Depends on Face Size.

    Science.gov (United States)

    Ross, David A; Gauthier, Isabel

    Holistic processing is a hallmark of face processing. There is evidence that holistic processing is strongest for faces at identification distance, 2 - 10 meters from the observer. However, this evidence is based on tasks that have been little used in the literature and that are indirect measures of holistic processing. We use the composite task- a well validated and frequently used paradigm - to measure the effect of viewing distance on holistic processing. In line with previous work, we find a congruency x alignment effect that is strongest for faces that are close (2m equivalent distance) than for faces that are further away (24m equivalent distance). In contrast, the alignment effect for same trials, used by several authors to measure holistic processing, produced results that are difficult to interpret. We conclude that our results converge with previous findings providing more direct evidence for an effect of size on holistic processing.

  1. Introduction of article-processing charges for Population Health Metrics

    Directory of Open Access Journals (Sweden)

    Murray Christopher JL

    2003-11-01

    Full Text Available Abstract Population Health Metrics is an open-access online electronic journal published by BioMed Central – it is universally and freely available online to everyone, its authors retain copyright, and it is archived in at least one internationally recognised free repository. To fund this, from November 1 2003, authors of articles accepted for publication will be asked to pay an article-processing charge of US$500. This editorial outlines the reasons for the introduction of article-processing charges and the way in which this policy will work. Waiver requests will be considered on a case-by-case basis, by the Editor-in-Chief. Article-processing charges will not apply to authors whose institutions are 'members' of BioMed Central. Current members include NHS England, the World Health Organization, the US National Institutes of Health, Harvard, Princeton and Yale universities, and all UK universities. No charge is made for articles that are rejected after peer review. Many funding agencies have also realized the importance of open access publishing and have specified that their grants may be used directly to pay APCs.

  2. Age-dependent branching processes for surveillance of vaccine-preventable diseases with incubation period

    Directory of Open Access Journals (Sweden)

    Marusia N Bojkova

    2010-10-01

    Full Text Available The purpose of this paper is to review the recent results of the authors in the area of infectious disease modelling by means of branching stochastic processes. This is a new approach involving age-dependent branching models, which turned out to be more appropriate and flexible for describing the spread of an infection in a given population, than discrete time ones. Concretely, Bellman-Harris and Sevast’yanov’s branching processes are investigated. It is justified that the proposed models are proper candidates as models of infectious diseases with incubation period like measles, mumps, avian flu, etc. It is worth to notice that in general the developed methodology is applicable to the diseases that follow the so-called SIR (susceptible- infected-removed scheme in terms of epidemiological models. Two policies of extra-vaccination level are proposed and compared on the ground of simulation examples.

  3. Population dynamics of minimally cognitive individuals. Part 2: Dynamics of time-dependent knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Schmieder, R.W.

    1995-07-01

    The dynamical principle for a population of interacting individuals with mutual pairwise knowledge, presented by the author in a previous paper for the case of constant knowledge, is extended to include the possibility that the knowledge is time-dependent. Several mechanisms are presented by which the mutual knowledge, represented by a matrix K, can be altered, leading to dynamical equations for K(t). The author presents various examples of the transient and long time asymptotic behavior of K(t) for populations of relatively isolated individuals interacting infrequently in local binary collisions. Among the effects observed in the numerical experiments are knowledge diffusion, learning transients, and fluctuating equilibria. This approach will be most appropriate to small populations of complex individuals such as simple animals, robots, computer networks, agent-mediated traffic, simple ecosystems, and games. Evidence of metastable states and intermittent switching leads them to envision a spectroscopy associated with such transitions that is independent of the specific physical individuals and the population. Such spectra may serve as good lumped descriptors of the collective emergent behavior of large classes of populations in which mutual knowledge is an important part of the dynamics.

  4. Time-dependent effects of corticosteroids on human amygdala processing

    NARCIS (Netherlands)

    Henckens, M.J.A.G.; van Wingen, G.A.; Joëls, M.; Fernández, G.

    2010-01-01

    Acute stress is associated with a sensitized amygdala. Corticosteroids, released in response to stress, are suggested to restore homeostasis by normalizing/desensitizing brain processing in the aftermath of stress. Here, we investigated the effects of corticosteroids on amygdala processing using

  5. FINAL PROCESS DEPENDENT DIMENSIONAL CHANGES OF DOUBLE KNIT FABRICS

    Directory of Open Access Journals (Sweden)

    Vedat ÖZYAZGAN

    2012-01-01

    Full Text Available In this paper Ne 30/1 cotton yarn obtained by using pure cotton fibers is employed. 1x1, 2x1 and 3x1 Rib fabrics were knitted with yarns at different gauges. During the knitting process, the tension was kept constant. In order to investigate the relaxation on the knitting process fabric samples were treated using three relaxation processes; dry, wet and full respectively. After each relaxation process, stitches dimensions were measured. As a result of these measurements, it is observed that as the relaxation increases the stitches length decreases while the stitches width increases. In rib knitting, As the fabric stretches increases the stitch length increases. As a result it is observed that as the stitch length increases, the width of the stitches increases linearly. In all rib fabrics, increase in the stitch density leads to an increase in the weight of the fabric.

  6. Impaired ecosystem process despite little effects on populations: modeling combined effects of warming and toxicants.

    Science.gov (United States)

    Galic, Nika; Grimm, Volker; Forbes, Valery E

    2017-08-01

    Freshwater ecosystems are exposed to many stressors, including toxic chemicals and global warming, which can impair, separately or in combination, important processes in organisms and hence higher levels of organization. Investigating combined effects of warming and toxicants has been a topic of little research, but neglecting their combined effects may seriously misguide management efforts. To explore how toxic chemicals and warming, alone and in combination, propagate across levels of biological organization, including a key ecosystem process, we developed an individual-based model (IBM) of a freshwater amphipod detritivore, Gammarus pseudolimnaeus, feeding on leaf litter. In this IBM, life history emerges from the individuals' energy budgets. We quantified, in different warming scenarios (+1-+4 °C), the effects of hypothetical toxicants on suborganismal processes, including feeding, somatic and maturity maintenance, growth, and reproduction. Warming reduced mean adult body sizes and population abundance and biomass, but only in the warmest scenarios. Leaf litter processing, a key contributor to ecosystem functioning and service delivery in streams, was consistently enhanced by warming, through strengthened interaction between the detritivorous consumer and its resource. Toxicant effects on feeding and maintenance resulted in initially small adverse effects on consumers, but ultimately led to population extinction and loss of ecosystem process. Warming in combination with toxicants had little effect at the individual and population levels, but ecosystem process was impaired in the warmer scenarios. Our results suggest that exposure to the same amount of toxicants can disproportionately compromise ecosystem processing depending on global warming scenarios; for example, reducing organismal feeding rates by 50% will reduce resource processing by 50% in current temperature conditions, but by up to 200% with warming of 4 °C. Our study has implications for

  7. Evidence of population resistance to extreme low flows in a fluvial-dependent fish species

    Science.gov (United States)

    Katz, Rachel A.; Freeman, Mary C.

    2015-01-01

    Extreme low streamflows are natural disturbances to aquatic populations. Species in naturally intermittent streams display adaptations that enhance persistence during extreme events; however, the fate of populations in perennial streams during unprecedented low-flow periods is not well-understood. Biota requiring swift-flowing habitats may be especially vulnerable to flow reductions. We estimated the abundance and local survival of a native fluvial-dependent fish species (Etheostoma inscriptum) across 5 years encompassing historic low flows in a sixth-order southeastern USA perennial river. Based on capturemark-recapture data, the study shoal may have acted as a refuge during severe drought, with increased young-of-the-year (YOY) recruitment and occasionally high adult immigration. Contrary to expectations, summer and autumn survival rates (30 days) were not strongly depressed during low-flow periods, despite 25%-80% reductions in monthly discharge. Instead, YOY survival increased with lower minimum discharge and in response to small rain events that increased low-flow variability. Age-1+ fish showed the opposite pattern, with survival decreasing in response to increasing low-flow variability. Results from this population dynamics study of a small fish in a perennial river suggest that fluvial-dependent species can be resistant to extreme flow reductions through enhanced YOY recruitment and high survival

  8. A consumer-resource approach to the density-dependent population dynamics of mutualism.

    Science.gov (United States)

    Holland, J Nathaniel; DeAngelis, Donald L

    2010-05-01

    Like predation and competition, mutualism is now recognized as a consumer-resource (C-R) interaction, including, in particular, bi-directional (e.g., coral, plant-mycorrhizae) and uni-directional (e.g., ant-plant defense, plant-pollinator) C-R mutualisms. Here, we develop general theory for the density-dependent population dynamics of mutualism based on the C-R mechanism of interspecific interaction. To test the influence of C-R interactions on the dynamics and stability of bi- and uni-directional C-R mutualisms, we developed simple models that link consumer functional response of one mutualistic species with the resources supplied by another. Phase-plane analyses show that the ecological dynamics of C-R mutualisms are stable in general. Most transient behavior leads to an equilibrium of mutualistic coexistence, at which both species densities are greater than in the absence of interactions. However, due to the basic nature of C-R interactions, certain density-dependent conditions can lead to C-R dynamics characteristic of predator-prey interactions, in which one species overexploits and causes the other to go extinct. Consistent with empirical phenomena, these results suggest that the C-R interaction can provide a broad mechanism for understanding density-dependent population dynamics of mutualism. By unifying predation, competition, and mutualism under the common ecological framework of consumer-resource theory, we may also gain a better understanding of the universal features of interspecific interactions in general.

  9. Alcohol consumption, hazardous drinking, and alcohol dependency among the population of Andaman and Nicobar Islands, India.

    Science.gov (United States)

    Manimunda, Sathya Prakash; Sugunan, Attayuru Purushottaman; Thennarasu, Kandavelu; Pandian, Dhanasekara; Pesala, Kasturi S; Benegal, Vivek

    2017-01-01

    Harmful use of alcohol is one of the globally recognized causes of health hazards. There are no data on alcohol consumption from Andaman and Nicobar Islands. The objective of the study was to assess the prevalence and pattern of alcohol use among the population of Andaman and Nicobar Islands, India. A representative sample of 18,018 individuals aged ≥14 years were chosen by multistage random sampling and administered a structured instrument, a modified version of the Gender, Alcohol, and Culture: An International Study (GENACIS) which included sociodemographic details and Alcohol Use Disorders Identification Test (AUDIT). The overall prevalence of alcohol consumption was 35% among males and over 6.0% in females, aged 14 and above. Two out of every five alcohol users fit into a category of hazardous drinkers. One-fourth of the total users (23%) are alcohol dependents. Both the hazardous drinking and dependent use are high among males compared to females. Almost 18.0% of male drinkers and 12.0% of female drinkers reported heavy drinking on typical drinking occasions. The predominant beverages consumed were in the category of homebrews such as toddy and handia. The present study highlights the magnitude of hazardous drinking and alcohol dependence in Andaman and Nicobar Islands, India and the complex sociocultural differences in the pattern of alcohol use. Based on the AUDIT data, among the population of Andaman and Nicobar Islands (aged 14 and above), one out of ten requires active interventions to manage the harmful impact of alcohol misuse.

  10. A consumer-resource approach to the density-dependent population dynamics of mutualism

    Science.gov (United States)

    Holland, J. Nathaniel; DeAngelis, Donald L.

    2010-01-01

    Like predation and competition, mutualism is now recognized as a consumer resource (C-R) interaction, including, in particular, bi-directional (e.g., coral, plant- mycorrhizae) and uni-directional (e.g., ant-plant defense, plant-pollinator) C-R mutualisms. Here, we develop general theory for the density-dependent population dynamics of mutualism based on the C-R mechanism of interspecific interaction. To test the influence of C-R interactions on the dynamics and stability of bi- and uni-directional C-R mutualisms, we developed simple models that link consumer functional response of one mutualistic species with the resources supplied by another. Phase-plane analyses show that the ecological dynamics of C-R mutualisms are stable in general. Most transient behavior leads to an equilibrium of mutualistic coexistence, at which both species densities are greater than in the absence of interactions. However, due to the basic nature of C-R interactions, certain density-dependent conditions can lead to C-R dynamics characteristic of predator-prey interactions, in which one species overexploits and causes the other to go extinct. Consistent with empirical phenomena, these results suggest that the C-R interaction can provide a broad mechanism for understanding density-dependent population dynamics of mutualism. By unifying predation, competition, and mutualism under the common ecological framework of consumer-resource theory, we may also gain a better understanding of the universal features of interspecific interactions in general.

  11. Childhood ADHD and Risk for Substance Dependence in Adulthood: A Longitudinal, Population-Based Study

    Science.gov (United States)

    Levy, Sharon; Katusic, Slavica K.; Colligan, Robert C.; Weaver, Amy L.; Killian, Jill M.; Voigt, Robert G.; Barbaresi, William J.

    2014-01-01

    Background Adolescents with attention-deficit/hyperactivity disorder (ADHD) are known to be at significantly greater risk for the development of substance use disorders (SUD) compared to peers. Impulsivity, which could lead to higher levels of drug use, is a known symptom of ADHD and likely accounts, in part, for this relationship. Other factors, such as a biologically increased susceptibility to substance dependence (addiction), may also play a role. Objective This report further examines the relationships between childhood ADHD, adolescent- onset SUD, and substance abuse and substance dependence in adulthood. Method Individuals with childhood ADHD and non-ADHD controls from the same population-based birth cohort were invited to participate in a prospective outcome study. Participants completed a structured neuropsychiatric interview with modules for SUD and a psychosocial questionnaire. Information on adolescent SUD was obtained retrospectively, in a previous study, from medical and school records. Associations were summarized using odds ratios (OR) and 95% CIs estimated from logistic regression models adjusted for age and gender. Results A total of 232 ADHD cases and 335 non-ADHD controls participated (mean age, 27.0 and 28.6 years, respectively). ADHD cases were more likely than controls to have a SUD diagnosed in adolescence and were more likely to have alcohol (adjusted OR 14.38, 95% CI 1.49–138.88) and drug (adjusted OR 3.48, 95% CI 1.38–8.79) dependence in adulthood. The subgroup of participating ADHD cases who did not have SUD during adolescence were no more likely than controls to develop new onset alcohol dependence as adults, although they were significantly more likely to develop new onset drug dependence. Conclusions Our study found preliminary evidence that adults with childhood ADHD are more susceptible than peers to developing drug dependence, a disorder associated with neurological changes in the brain. The relationship between ADHD and

  12. Distance-dependent processing of pictures and words.

    Science.gov (United States)

    Amit, Elinor; Algom, Daniel; Trope, Yaacov

    2009-08-01

    A series of 8 experiments investigated the association between pictorial and verbal representations and the psychological distance of the referent objects from the observer. The results showed that people better process pictures that represent proximal objects and words that represent distal objects than pictures that represent distal objects and words that represent proximal objects. These results were obtained with various psychological distance dimensions (spatial, temporal, and social), different tasks (classification and categorization), and different measures (speed of processing and selective attention). The authors argue that differences in the processing of pictures and words emanate from the physical similarity of pictures, but not words, to the referents. Consequently, perceptual analysis is commonly applied to pictures but not to words. Pictures thus impart a sense of closeness to the referent objects and are preferably used to represent such objects, whereas words do not convey proximity and are preferably used to represent distal objects in space, time, and social perspective.

  13. Processing methods for temperature-dependent MCNP libraries

    International Nuclear Information System (INIS)

    Li Songyang; Wang Kan; Yu Ganglin

    2008-01-01

    In this paper,the processing method of NJOY which transfers ENDF files to ACE (A Compact ENDF) files (point-wise cross-Section file used for MCNP program) is discussed. Temperatures that cover the range for reactor design and operation are considered. Three benchmarks are used for testing the method: Jezebel Benchmark, 28 cm-thick Slab Core Benchmark and LWR Benchmark with Burnable Absorbers. The calculation results showed the precision of the neutron cross-section library and verified the correct processing methods in usage of NJOY. (authors)

  14. Search for entrance-channel dependence in the population of superdeformed bands in {sup 191}Hg

    Energy Technology Data Exchange (ETDEWEB)

    Soramel, F.; Khoo, T.L.; Janssens, R.V.F. [and others

    1995-08-01

    The population intensity of some SD bands in the mass 150 region were observed to depend on the mass symmetry of the entrance channel in the fusion reaction. The authors raised the possibility that the population of SD bands had a memory of the entrance channel. To check this interesting possibility, we made measurements of the population intensities of superdeformed (SD) bands in the {sup 160}Gd({sup 36}S,5n){sup 191}Hg and {sup 130}Te({sup 64}Ni,3n){sup 191}Hg reactions. To ensure that any observed effect was not due to a simple angular momentum difference in the entrance channels, we also measured the average entry points and spin distributions of normal and SD states in {sup 191}Hg in the two reactions. The entry points and spin distributions for {sup 191}Hg are the same and, indeed, so are the SD intensities in the two reactions. Hence, no entrance-channel effect is observed in the population of the SD band in {sup 191}Hg, in contrast with data for SD bands in the mass 150 regions. We suggest that the effect observed previously in the mass 150 region is due to an angular momentum effect. A letter reporting our results was submitted for publication.

  15. Assay dependence of Brucella antibody prevalence in a declining Alaskan harbor seal (Phoca vitulina population

    Directory of Open Access Journals (Sweden)

    Hueffer Karsten

    2013-01-01

    Full Text Available Abstract Background Brucella is a group of bacteria that causes brucellosis, which can affect population health and reproductive success in many marine mammals. We investigated the serological prevalence of antibodies against Brucella bacteria in a declining harbor seal population in Glacier Bay National Park, Alaska. Results Prevalence ranged from 16 to 74 percent for those tests detecting antibodies, indicating that harbor seals in Glacier Bay have been exposed to Brucella bacteria. However, the actual level of serological prevalence could not be determined because results were strongly assay-dependent. Conclusions This study reinforces the need to carefully consider assay choice when comparing different studies on the prevalence of anti–Brucella antibodies in pinnipeds and further highlights the need for species- or taxon-specific assay validation for both pathogen and host species.

  16. Distance-Dependent Processing of Pictures and Words

    Science.gov (United States)

    Amit, Elinor; Algom, Daniel; Trope, Yaacov

    2009-01-01

    A series of 8 experiments investigated the association between pictorial and verbal representations and the psychological distance of the referent objects from the observer. The results showed that people better process pictures that represent proximal objects and words that represent distal objects than pictures that represent distal objects and…

  17. The environmental dependence of inbreeding depression in a wild bird population.

    Directory of Open Access Journals (Sweden)

    Marta Szulkin

    2007-10-01

    Full Text Available Inbreeding depression occurs when the offspring produced as a result of matings between relatives show reduced fitness, and is generally understood as a consequence of the elevated expression of deleterious recessive alleles. How inbreeding depression varies across environments is of importance for the evolution of inbreeding avoidance behaviour, and for understanding extinction risks in small populations. However, inbreeding-by-environment (IxE interactions have rarely been investigated in wild populations.We analysed 41 years of breeding events from a wild great tit (Parus major population and used 11 measures of the environment to categorise environments as relatively good or poor, testing whether these measures influenced inbreeding depression. Although inbreeding always, and environmental quality often, significantly affected reproductive success, there was little evidence for statistically significant I x E interactions at the level of individual analyses. However, point estimates of the effect of the environment on inbreeding depression were sometimes considerable, and we show that variation in the magnitude of the I x E interaction across environments is consistent with the expectation that this interaction is more marked across environmental axes with a closer link to overall fitness, with the environmental dependence of inbreeding depression being elevated under such conditions. Hence, our analyses provide evidence for an environmental dependence of the inbreeding x environment interaction: effectively an I x E x E.Overall, our analyses suggest that I x E interactions may be substantial in wild populations, when measured across relevant environmental contrasts, although their detection for single traits may require very large samples, or high rates of inbreeding.

  18. Compensatory immigration depends on adjacent population size and habitat quality but not on landscape connectivity.

    Science.gov (United States)

    Turgeon, Katrine; Kramer, Donald L

    2012-11-01

    1. Populations experiencing localized mortality can recover in the short term by net movement of individuals from adjacent areas, a process called compensatory immigration or spillover. Little is known about the factors influencing the magnitude of compensatory immigration or its impact on source populations. Such information is important for understanding metapopulation dynamics, the use of protected areas for conservation, management of exploited populations and pest control. 2. Using two small, territorial damselfish species (Stegastes diencaeus and S. adustus) in their naturally fragmented habitat, we quantified compensatory immigration in response to localized mortality, assessed its impact on adjacent source populations and examined the importance of potential immigrants, habitat quality and landscape connectivity as limiting factors. On seven experimental sites, we repeatedly removed 15% of the initial population size until none remained and immigration ceased. 3. Immigrants replaced 16-72% of original residents in S. diencaeus and 0-69% in S. adustus. The proportion of the source population that immigrated into depleted areas varied from 9% to 61% in S. diencaeus and from 3% to 21% in S. adustus. In S. diencaeus, compensatory immigration was strongly affected by habitat quality, to a lesser extent by the abundance of potential immigrants and not by landscape connectivity. In S. adustus, immigration was strongly affected by the density of potential migrants and not by habitat quality and landscape connectivity. On two control sites, immigration in the absence of creation of vacancies was extremely rare. 4. Immigration occurred in response to localized mortality and was therefore compensatory. It was highly variable, sometimes producing substantial impacts on both depleted and source populations. The magnitude of compensatory immigration was influenced primarily by the availability of immigrants and by the potential improvement in territory quality that they

  19. Latin America Region: Between Dependence and Autonomy in Regional Processes

    Directory of Open Access Journals (Sweden)

    Wendy Vaca Hernández

    2017-01-01

    Full Text Available The space called Latin America has a particular history marked by centuries of colonialism and coloniality. The latter concept implies that the basic structure of the colonial system has not changed even though formal independence has been achieved. For this reason, the subcontinent has fluctuated between dependence and the quest for autonomy. These successive cycles have manifested themselves both in the internal configurations and in the regional schemes that have been undertaken. This paper analyzes the construction and evolution of the idea of a region: Latin America and the Caribbean. To that end it examines the concepts of region, regionalism, what Latin America and the Caribbean implies, and what are the transformations in these ideas that have emerged from the regional configurations of the Union of South American Nations (UNASUR and the Community of Latin American and Caribbean States (CELAC as plural organisms with broad objectives.

  20. Discrete bivariate population balance modelling of heteroaggregation processes.

    Science.gov (United States)

    Rollié, Sascha; Briesen, Heiko; Sundmacher, Kai

    2009-08-15

    Heteroaggregation in binary particle mixtures was simulated with a discrete population balance model in terms of two internal coordinates describing the particle properties. The considered particle species are of different size and zeta-potential. Property space is reduced with a semi-heuristic approach to enable an efficient solution. Aggregation rates are based on deterministic models for Brownian motion and stability, under consideration of DLVO interaction potentials. A charge-balance kernel is presented, relating the electrostatic surface potential to the property space by a simple charge balance. Parameter sensitivity with respect to the fractal dimension, aggregate size, hydrodynamic correction, ionic strength and absolute particle concentration was assessed. Results were compared to simulations with the literature kernel based on geometric coverage effects for clusters with heterogeneous surface properties. In both cases electrostatic phenomena, which dominate the aggregation process, show identical trends: impeded cluster-cluster aggregation at low particle mixing ratio (1:1), restabilisation at high mixing ratios (100:1) and formation of complex clusters for intermediate ratios (10:1). The particle mixing ratio controls the surface coverage extent of the larger particle species. Simulation results are compared to experimental flow cytometric data and show very satisfactory agreement.

  1. Lipschitz continuous data dependence of sweeping processes in BV spaces

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Pavel; Roche, T.

    2011-01-01

    Roč. 15, č. 3 (2011), s. 637-650 ISSN 1531-3492 R&D Projects: GA ČR GAP201/10/2315; GA MŠk LC06052 Institutional research plan: CEZ:AV0Z10190503 Keywords : rate independence * discontinuous sweeping process * Kurzweil integral Subject RIV: BA - General Mathematics Impact factor: 0.921, year: 2011 http://aimsciences.org/journals/pdfs.jsp?paperID=5943&mode=full

  2. Spin-Dependent Processes Measured without a Permanent Magnet.

    Science.gov (United States)

    Fontanesi, Claudio; Capua, Eyal; Paltiel, Yossi; Waldeck, David H; Naaman, Ron

    2018-05-07

    A novel Hall circuit design that can be incorporated into a working electrode, which is used to probe spin-selective charge transfer and charge displacement processes, is reviewed herein. The general design of a Hall circuit based on a semiconductor heterostructure, which forms a shallow 2D electron gas and is used as an electrode, is described. Three different types of spin-selective processes have been studied with this device in the past: i) photoinduced charge exchange between quantum dots and the working electrode through chiral molecules is associated with spin polarization that creates a local magnetization and generates a Hall voltage; ii) charge polarization of chiral molecules by an applied voltage is accompanied by a spin polarization that generates a Hall voltage; and iii) cyclic voltammetry (current-voltage) measurements of electrochemical redox reactions that can be spin-analyzed by the Hall circuit to provide a third dimension (spin) in addition to the well-known current and voltage dimensions. The three studies reviewed open new doors into understanding both the spin current and the charge current in electronic materials and electrochemical processes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Evidence that logical reasoning depends on conscious processing.

    Science.gov (United States)

    DeWall, C Nathan; Baumeister, Roy F; Masicampo, E J

    2008-09-01

    Humans, unlike other animals, are equipped with a powerful brain that permits conscious awareness and reflection. A growing trend in psychological science has questioned the benefits of consciousness, however. Testing a hypothesis advanced by [Lieberman, M. D., Gaunt, R., Gilbert, D. T., & Trope, Y. (2002). Reflection and reflexion: A social cognitive neuroscience approach to attributional inference. Advances in Experimental Social Psychology, 34, 199-249], four studies suggested that the conscious, reflective processing system is vital for logical reasoning. Substantial decrements in logical reasoning were found when a cognitive load manipulation preoccupied conscious processing, while hampering the nonconscious system with consciously suppressed thoughts failed to impair reasoning (Experiment 1). Nonconscious activation (priming) of the idea of logical reasoning increased the activation of logic-relevant concepts, but failed to improve logical reasoning performance (Experiments 2a-2c) unless the logical conclusions were largely intuitive and thus not reliant on logical reasoning (Experiment 3). Meanwhile, stimulating the conscious goal of reasoning well led to improvements in reasoning performance (Experiment 4). These findings offer evidence that logical reasoning is aided by the conscious, reflective processing system.

  4. Modelling the PCR amplification process by a size-dependent branching process and estimation of the efficiency

    NARCIS (Netherlands)

    Lalam, N.; Jacob, C.; Jagers, P.

    2004-01-01

    We propose a stochastic modelling of the PCR amplification process by a size-dependent branching process starting as a supercritical Bienaymé-Galton-Watson transient phase and then having a saturation near-critical size-dependent phase. This model allows us to estimate the probability of replication

  5. Dependence on supernovae light-curve processing in void models

    Energy Technology Data Exchange (ETDEWEB)

    Bengochea, Gabriel R., E-mail: gabriel@iafe.uba.ar [Instituto de Astronomía y Física del Espacio (IAFE), UBA-CONICET, CC 67, Suc. 28, 1428 Buenos Aires (Argentina); De Rossi, Maria E., E-mail: derossi@iafe.uba.ar [Instituto de Astronomía y Física del Espacio (IAFE), UBA-CONICET, CC 67, Suc. 28, 1428 Buenos Aires (Argentina); Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina)

    2014-06-02

    In this work, we show that when supernova Ia (SN Ia) data sets are used to put constraints on the free parameters of inhomogeneous models, certain extra information regarding the light-curve fitter used in the supernovae Ia luminosity fluxes processing should be taken into account. We found that the size of the void as well as other parameters of these models might be suffering extra degenerations or additional systematic errors due to the fitter. A recent proposal to relieve the tension between the results from Planck satellite and SNe Ia is re-analyzed in the framework of these subjects.

  6. Population Structures in Russia: Optimality and Dependence on Parameters of Global Evolution

    Directory of Open Access Journals (Sweden)

    Yuri Yegorov

    2016-07-01

    Full Text Available The paper is devoted to analytical investigation of the division of geographical space into urban and rural areas with application to Russia. Yegorov (2005, 2006, 2009 has suggested the role of population density on economics. A city has an attractive potential based on scale economies. The optimal city size depends on the balance between its attractive potential and the cost of living that can be approximated by equilibrium land rent and commuting cost. For moderate scale effects optimal population of a city depends negatively on transport costs that are related positively with energy price index. The optimal agricultural density of population can also be constructed. The larger is a land slot per peasant, the higher will be the output from one unit of his labour force applied to this slot. But at the same time, larger farm size results in increase of energy costs, related to land development, collecting the crop and bringing it to the market. In the last 10 years we have observed substantial rise of both food and energy prices at the world stock markets. However, the income of farmers did not grow as fast as food price index. This can shift optimal rural population density to lower level, causing migration to cities (and we observe this tendency globally. Any change in those prices results in suboptimality of existing spatial structures. If changes are slow, the optimal infrastructure can be adjusted by simple migration. If the shocks are high, adaptation may be impossible and shock will persist. This took place in early 1990es in the former USSR, where after transition to world price for oil in domestic markets existing spatial infrastructure became suboptimal and resulted in persistent crisis, leading to deterioration of both industry and agriculture. Russia is the largest country but this is also its problem. Having large resource endowment per capita, it is problematic to build sufficient infrastructure. Russia has too low population

  7. Demographic processes in a local population: seasonal dynamics of ...

    African Journals Online (AJOL)

    ... differences in daily recruitment and within-patch survival rates. Males were most abundant relative to females early in the season, indicating protandry. Total adult population size was small and showed dramatic variation between the two years, indicating how vulnerable the local population is to demographic extinction.

  8. Evaluating models of population process in a threatened population of Steller’s eiders: A retrospective approach

    Science.gov (United States)

    Dunham, Kylee; Grand, James B.

    2016-10-11

    The Alaskan breeding population of Steller’s eiders (Polysticta stelleri) was listed as threatened under the Endangered Species Act in 1997 in response to perceived declines in abundance throughout their breeding and nesting range. Aerial surveys suggest the breeding population is small and highly variable in number, with zero birds counted in 5 of the last 25 years. Research was conducted to evaluate competing population process models of Alaskan-breeding Steller’s eiders through comparison of model projections to aerial survey data. To evaluate model efficacy and estimate demographic parameters, a Bayesian state-space modeling framework was used and each model was fit to counts from the annual aerial surveys, using sequential importance sampling and resampling. The results strongly support that the Alaskan breeding population experiences population level nonbreeding events and is open to exchange with the larger Russian-Pacific breeding population. Current recovery criteria for the Alaskan breeding population rely heavily on the ability to estimate population viability. The results of this investigation provide an informative model of the population process that can be used to examine future population states and assess the population in terms of the current recovery and reclassification criteria.

  9. Single Machine Scheduling and Due Date Assignment with Past-Sequence-Dependent Setup Time and Position-Dependent Processing Time

    Directory of Open Access Journals (Sweden)

    Chuan-Li Zhao

    2014-01-01

    Full Text Available This paper considers single machine scheduling and due date assignment with setup time. The setup time is proportional to the length of the already processed jobs; that is, the setup time is past-sequence-dependent (p-s-d. It is assumed that a job's processing time depends on its position in a sequence. The objective functions include total earliness, the weighted number of tardy jobs, and the cost of due date assignment. We analyze these problems with two different due date assignment methods. We first consider the model with job-dependent position effects. For each case, by converting the problem to a series of assignment problems, we proved that the problems can be solved in On4 time. For the model with job-independent position effects, we proved that the problems can be solved in On3 time by providing a dynamic programming algorithm.

  10. [Study of defense styles, defenses and coping strategies in alcohol-dependent population].

    Science.gov (United States)

    Ribadier, A; Varescon, I

    2017-05-01

    Defense mechanisms have been seen to greatly change over time and across different definitions made by different theoretical currents. Recently with the definition provided by the DSM IV, defense mechanisms have integrated the concept of coping as a defensive factor. These mechanisms are no longer considered just through a psychodynamic approach but also through a cognitive and behavioral one. In recent years, new theories have therefore integrated these two components of the defensive operation. According to Chabrol and Callahan (2013), defense mechanisms precede coping strategies. In individuals with psychopathological disorders, these authors indicate a relative stability of these mechanisms. Also, we asked about the presence of unique characteristics among people with alcohol dependence. Indeed, studies conducted with people with alcohol dependence highlight the presence of a neurotic defense style and some highly immature defenses (projection, acting out, splitting and somatization). In terms of coping strategies, persons with alcohol dependence preferentially use avoidant strategies and strategies focused on emotion. However, although several studies have been conducted to assess coping strategies and defense styles within a population of individuals with an alcohol problem, at the present time none of them has taken into account all these aspects of defense mechanisms. The aim of this study is therefore to study the defenses and defense styles and coping strategies in an alcohol-dependent population. This multicenter study (3 CHU, 1 center of supportive care and prevention in addiction and 1 clinic) received a favorable opinion of an Institutional Review Board (IRB Registration #: 00001072). Eighty alcohol-dependent individuals responded to a questionnaire assessing sociodemographic characteristics and elements related to the course of consumption. Coping strategies were assessed by means of a questionnaire validated in French: the Brief Cope. The Defense

  11. Evidences Dependent Population Distribution Patterns of Tiger and Leopard in Similipal Tiger Reserve, Odisha, India

    Directory of Open Access Journals (Sweden)

    Sandeep Ranjan Mishra

    2015-10-01

    Full Text Available The Tiger (Panthera tigris is an endangered carnivore with uncertain demographic status spanning 13 Asian countries. Due to its larger body size and carnivorous diet in nature it always occurs at low population densities. Further prey depletion due to overhunting (Karanth & Stith, 1998, poaching, habitat shrinkage (Kenny et al., 1995, Wcs, 1995 and direct killing altogether have also become a major factor for depletion of wild tiger populations tiger. Monitoring the abundance and its alteration is always important for the effective management of endangered species. Tiger is categorized as “Endangered” on the IUCN Red List (IUCN, 2008 and listed under Schedule-I of Wildlife (Protection Act, 1972 in India and Appendix-I of the CITES. Leopard (Panthera pardus is also included in the Schedule- I of the Indian Wildlife Protection Act, 1972 and is placed under “Least Concern” category of 2002 IUCN Red List of threatened animals. Similipal Tiger Reserve is one of the largest Tiger Reserves of India with an area of 2750 km2. Therefore we have to depend mainly on the direct sightings and evidence records of the animals to analysis the status and distribution pattern of these two big cats in the core area of this Tiger Reserve.

  12. Mutational jackpot events generate effective frequency-dependent selection in adapting populations

    Science.gov (United States)

    Hallatschek, Oskar

    The site-frequency spectrum is one the most easily measurable quantities that characterize the genetic diversity of a population. While most neutral models predict that site frequency spectra should decay with increasing frequency, a high-frequency uptick has been reported in many populations. Anomalies in the high-frequency tail are particularly unsettling because the highest frequencies can be measured with greatest accuracy. Here, we show that an uptick in the spectrum of neutral mutations generally arises when mutant frequencies are dominated by rare jackpot events, mutational events with large descendant numbers. This leads to an effective pattern of frequency-dependent selection (or unstable internal equilibrium at one half frequency) that causes an accumulation of high-frequency polymorphic sites. We reproduce the known uptick occurring for recurrent hitchhiking (genetic draft) as well as rapid adaptation, and (in the future) generalize the shape of the high-frequency tail to other scenarios that are dominated by jackpot events, such as frequent range expansions. We also tackle (in the future) the inverse approach to use the high-frequency uptick for learning about the tail of the offspring number distribution. Positively selected alleles need to surpass, typically, an u NSF Career Award (PoLS), NIH NIGMS R01, Simons Foundation.

  13. Designing dependable process-oriented software - a CSP-based approach

    NARCIS (Netherlands)

    Jovanovic, D.S.

    2006-01-01

    This thesis advocates dependability as a crucial aspect of software quality. Process orientation,as it is defined in this thesis, concentrates on the notion of a process as a basic building component of a dataflow-centred software architecture. The dependability approach in the proposed variant of

  14. Estimation of the PCR efficiency based on a size-dependent modelling of the amplification process

    NARCIS (Netherlands)

    Lalam, N.; Jacob, C.; Jagers, P.

    2005-01-01

    We propose a stochastic modelling of the PCR amplification process by a size-dependent branching process starting as a supercritical Bienaymé–Galton–Watson transient phase and then having a saturation near-critical size-dependent phase. This model based on the concept of saturation allows one to

  15. Vitamin D Status in Population of Bukovyna and Subcarpathia Depending on Residence above Sea Level

    Directory of Open Access Journals (Sweden)

    V.V. Povoroznyuk

    2016-04-01

    ding on the residence above sea level. Objective: to determine the level of vitamin D in the blood serum of people, who live in different regions of the Subcarpathia and Bukovyna, depending on the location of the settlement above sea le-vel. Material and methods. In the cross-sectional study, we have examined 353 individuals, aged 18 to 86 years, permanently residing in different parts of the Subcarpathia (Kolomyia, Kosiv, Verhovyna districts and Bukovyna (Vyzhny-tsia district. Results. Only in 28 cases (7.9 %, the content of 25(OHD in the blood serum was in the normal range, and in other cases (92.1 %, there was a deficiency and a lack of vitamin D. The severe form of vitamin D deficiency has been detected in 7 (1.9 % patients. When comparing the performance of 25(OHD in the areas of inspection, it was found that the level of vitamin D in the blood serum was significantly higher in residents of Verkhovyna and Kosiv districts (located higher than 450 meters above sea level as compared with residents of Vyzhnytsia and Kolomyia. Conclusion. The average level of vitamin D in the blood serum of the adult population depends on residence and increases with height above sea level.

  16. Psychosocial Status and Economic Dependence for Healthcare and Nonhealthcare among Elderly Population in Rural Coastal Karnataka.

    Science.gov (United States)

    Rent, Priyanka Dsouza; Kumar, Sudeep; Dmello, Mackwin Kenwood; Purushotham, Jagannath

    2017-01-01

    The elderly who will constitute 10% of the Indian population by 2021 face problems such as deteriorating healthcare status, loneliness, and economic constraints among others. All these factors together may affect the psychosocial status of the elderly and their health-seeking behavior. With this background, the current study tried to evaluate the psychosocial status, economic dependence for health and nonhealth expenses and awareness regarding geriatric welfare services (GWS) among elderly patients. The study was carried out among 599 men and women aged above 60 who visited rural healthcare centers in two districts of Karnataka during September-December 2016. A semi-structured interview schedule was administered by a trained medical professional after taking informed consent. Majority of the respondents said that they had company at home, interacted with people outside home and that their advice was honored. About 75.8% of the respondents reported that they were either partially or completely financially dependent on someone else. The mean cost of hospitalization was reported to be Rs. 11,086. Majority of those hospitalized depended on their children to pay for healthcare (66.9%), whereas 16.9% had availed government insurance schemes and 14.6% paid out of pocket. Nearly 64.9% of the respondents were aware of the GWS while 32.6% had used them. The absence of financial risk pooling mechanisms and social support may cause elderly to forego treatment because of the need to pay for healthcare and further deteriorate their psychosocial status. Government initiatives to improve healthcare and social services to the elderly maybe advocated.

  17. Psychosocial status and economic dependence for healthcare and nonhealthcare among elderly population in rural coastal Karnataka

    Directory of Open Access Journals (Sweden)

    Priyanka Dsouza Rent

    2017-01-01

    Full Text Available Introduction: The elderly who will constitute 10% of the Indian population by 2021 face problems such as deteriorating healthcare status, loneliness, and economic constraints among others. All these factors together may affect the psychosocial status of the elderly and their health-seeking behavior. With this background, the current study tried to evaluate the psychosocial status, economic dependence for health and nonhealth expenses and awareness regarding geriatric welfare services (GWS among elderly patients. Materials and Methods: The study was carried out among 599 men and women aged above 60 who visited rural healthcare centers in two districts of Karnataka during September–December 2016. A semi-structured interview schedule was administered by a trained medical professional after taking informed consent. Results: Majority of the respondents said that they had company at home, interacted with people outside home and that their advice was honored. About 75.8% of the respondents reported that they were either partially or completely financially dependent on someone else. The mean cost of hospitalization was reported to be Rs. 11,086. Majority of those hospitalized depended on their children to pay for healthcare (66.9%, whereas 16.9% had availed government insurance schemes and 14.6% paid out of pocket. Nearly 64.9% of the respondents were aware of the GWS while 32.6% had used them. Conclusion: The absence of financial risk pooling mechanisms and social support may cause elderly to forego treatment because of the need to pay for healthcare and further deteriorate their psychosocial status. Government initiatives to improve healthcare and social services to the elderly maybe advocated.

  18. Dependent Neyman type A processes based on common shock Poisson approach

    Science.gov (United States)

    Kadilar, Gamze Özel; Kadilar, Cem

    2016-04-01

    The Neyman type A process is used for describing clustered data since the Poisson process is insufficient for clustering of events. In a multivariate setting, there may be dependencies between multivarite Neyman type A processes. In this study, dependent form of the Neyman type A process is considered under common shock approach. Then, the joint probability function are derived for the dependent Neyman type A Poisson processes. Then, an application based on forest fires in Turkey are given. The results show that the joint probability function of the dependent Neyman type A processes, which is obtained in this study, can be a good tool for the probabilistic fitness for the total number of burned trees in Turkey.

  19. Novel Synthetic Medea selfish genetic elements drive population replacement in Drosophila, and a theoretical exploration of Medea-dependent population suppression

    Science.gov (United States)

    Akbari, Omar S.; Chen, Chun-Hong; Marshall, John M.; Huang, Haixia; Antoshechkin, Igor; Hay, Bruce A.

    2013-01-01

    Insects act as vectors for diseases of plants, animals and humans. Replacement of wild insect populations with genetically modified individuals unable to transmit disease provides a potentially self-perpetuating method of disease prevention. Population replacement requires a gene drive mechanism in order to spread linked genes mediating disease refractoriness through wild populations. We previously reported the creation of synthetic Medea selfish genetic elements able to drive population replacement in Drosophila. These elements use microRNA-mediated silencing of myd88, a maternally expressed gene required for embryonic dorso-ventral pattern formation, coupled with early zygotic expression of a rescuing transgene, to bring about gene drive. Medea elements that work through additional mechanisms are needed in order to be able to carry out cycles of population replacement and/or remove existing transgenes from the population, using second-generation elements that spread while driving first-generation elements out of the population. Here we report the synthesis and population genetic behavior of two new synthetic Medea elements that drive population replacement through manipulation of signaling pathways involved in cellular blastoderm formation or Notch signaling, demonstrating that in Drosophila Medea elements can be generated through manipulation of diverse signaling pathways. We also describe the mRNA and small RNA changes in ovaries and early embryos associated from Medea-bearing females. Finally, we use modeling to illustrate how Medea elements carrying genes that result in diapause-dependent female lethality could be used to bring about population suppression. PMID:23654248

  20. Cortical depth dependent population receptive field attraction by spatial attention in human V1.

    Science.gov (United States)

    Klein, Barrie P; Fracasso, Alessio; van Dijk, Jelle A; Paffen, Chris L E; Te Pas, Susan F; Dumoulin, Serge O

    2018-04-27

    Visual spatial attention concentrates neural resources at the attended location. Recently, we demonstrated that voluntary spatial attention attracts population receptive fields (pRFs) toward its location throughout the visual hierarchy. Theoretically, both a feed forward or feedback mechanism could underlie pRF attraction in a given cortical area. Here, we use sub-millimeter ultra-high field functional MRI to measure pRF attraction across cortical depth and assess the contribution of feed forward and feedback signals to pRF attraction. In line with previous findings, we find consistent attraction of pRFs with voluntary spatial attention in V1. When assessed as a function of cortical depth, we find pRF attraction in every cortical portion (deep, center and superficial), although the attraction is strongest in deep cortical portions (near the gray-white matter boundary). Following the organization of feed forward and feedback processing across V1, we speculate that a mixture of feed forward and feedback processing underlies pRF attraction in V1. Specifically, we propose that feedback processing contributes to the pRF attraction in deep cortical portions. Copyright © 2018. Published by Elsevier Inc.

  1. Scaling up population dynamic processes in a ladybird–aphid

    Czech Academy of Sciences Publication Activity Database

    Houdková, Kateřina; Kindlmann, Pavel

    2006-01-01

    Roč. 48, - (2006), s. 323-332 ISSN 1438-3896 R&D Projects: GA ČR(CZ) GEDIV/06/E013; GA MŠk(CZ) LC06073; GA AV ČR(CZ) IAA6087301; GA ČR(CZ) GD206/03/H034 Keywords : Aphids * Egg window * Ladybirds * Metapopulation * Model * Population dynamics Subject RIV: EH - Ecology, Behaviour Impact factor: 1.534, year: 2006

  2. A novel quantitative model of cell cycle progression based on cyclin-dependent kinases activity and population balances.

    Science.gov (United States)

    Pisu, Massimo; Concas, Alessandro; Cao, Giacomo

    2015-04-01

    Cell cycle regulates proliferative cell capacity under normal or pathologic conditions, and in general it governs all in vivo/in vitro cell growth and proliferation processes. Mathematical simulation by means of reliable and predictive models represents an important tool to interpret experiment results, to facilitate the definition of the optimal operating conditions for in vitro cultivation, or to predict the effect of a specific drug in normal/pathologic mammalian cells. Along these lines, a novel model of cell cycle progression is proposed in this work. Specifically, it is based on a population balance (PB) approach that allows one to quantitatively describe cell cycle progression through the different phases experienced by each cell of the entire population during its own life. The transition between two consecutive cell cycle phases is simulated by taking advantage of the biochemical kinetic model developed by Gérard and Goldbeter (2009) which involves cyclin-dependent kinases (CDKs) whose regulation is achieved through a variety of mechanisms that include association with cyclins and protein inhibitors, phosphorylation-dephosphorylation, and cyclin synthesis or degradation. This biochemical model properly describes the entire cell cycle of mammalian cells by maintaining a sufficient level of detail useful to identify check point for transition and to estimate phase duration required by PB. Specific examples are discussed to illustrate the ability of the proposed model to simulate the effect of drugs for in vitro trials of interest in oncology, regenerative medicine and tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Prevalence of eating disorder attitudes among men and women with exercise dependence symptoms: a non-athlete population study

    Directory of Open Access Journals (Sweden)

    Elaine Fernanda da Silva

    2013-09-01

    Full Text Available The present study sought to describe the prevalence of Secondary Exercise Dependence (ScED, i.e. eating disorders attitudes along with exercise dependence symptoms may differ between men and women in a broader exercising population. In this study, 174 regularly exerciser, aged 18-62 years old, who were invited to respond the Exercise Dependence Scale (EDS and the Eating Attitudes Test (EAT-26. There were more women than men with ScED. However, only men in the sample presented exercise dependence symptoms without eating disorders attitudes. Eating disorders may or may not exist in those who are exercise dependent in the broad exercising population, although there is a higher prevalence of ScED in women than men.

  4. The young star cluster population of M51 with LEGUS - II. Testing environmental dependences

    Science.gov (United States)

    Messa, Matteo; Adamo, A.; Calzetti, D.; Reina-Campos, M.; Colombo, D.; Schinnerer, E.; Chandar, R.; Dale, D. A.; Gouliermis, D. A.; Grasha, K.; Grebel, E. K.; Elmegreen, B. G.; Fumagalli, M.; Johnson, K. E.; Kruijssen, J. M. D.; Östlin, G.; Shabani, F.; Smith, L. J.; Whitmore, B. C.

    2018-06-01

    It has recently been established that the properties of young star clusters (YSCs) can vary as a function of the galactic environment in which they are found. We use the cluster catalogue produced by the Legacy Extragalactic UV Survey (LEGUS) collaboration to investigate cluster properties in the spiral galaxy M51. We analyse the cluster population as a function of galactocentric distance and in arm and inter-arm regions. The cluster mass function exhibits a similar shape at all radial bins, described by a power law with a slope close to -2 and an exponential truncation around 105 M⊙. While the mass functions of the YSCs in the spiral arm and inter-arm regions have similar truncation masses, the inter-arm region mass function has a significantly steeper slope than the one in the arm region, a trend that is also observed in the giant molecular cloud mass function and predicted by simulations. The age distribution of clusters is dependent on the region considered, and is consistent with rapid disruption only in dense regions, while little disruption is observed at large galactocentric distances and in the inter-arm region. The fraction of stars forming in clusters does not show radial variations, despite the drop in the H2 surface density measured as a function of galactocentric distance. We suggest that the higher disruption rate observed in the inner part of the galaxy is likely at the origin of the observed flat cluster formation efficiency radial profile.

  5. Salt processed food and gastric cancer in a Chinese population.

    Science.gov (United States)

    Lin, Si-Hao; Li, Yuan-Hang; Leung, Kayee; Huang, Cheng-Yu; Wang, Xiao-Rong

    2014-01-01

    To investigate the association between salt processed food and gastric cancer, a hospital based case-control study was conducted in a high risk area of China. One hundred and seven newly diagnosed cases with histological confirmation of gastric cancer and 209 controls were recruited. Information on dietary intake was collected with a validated food frequency questionnaire. Unconditional logistic regression was applied to estimate the odds ratios with adjustment for other potential confounders. Comparing the high intake group with never consumption of salt processed foods, salted meat, pickled vegetables and preserved vegetables were significantly associated with increased risk of gastric cancer. Meanwhile, salt taste preference in diet showed a dose-response relationship with gastric cancer. Our results suggest that consumption of salted meat, pickled and preserved vegetables, are positively associated with gastric cancer. Reduction of salt and salt processed food in diets might be one practical measure to preventing gastric cancer.

  6. Cigarette craving is associated with blunted reward processing in nicotine-dependent smokers.

    Science.gov (United States)

    Peechatka, Alyssa L; Whitton, Alexis E; Farmer, Stacey L; Pizzagalli, Diego A; Janes, Amy C

    2015-10-01

    Dysfunctional reward processing leading to the undervaluation of non-drug rewards is hypothesized to play a crucial role in nicotine dependence. However, it is unclear if blunted reward responsivity and the desire to use nicotine are directly linked after a brief period of abstinence. Such an association would suggest that individuals with reduced reward responsivity may be at increased risk to experience nicotine craving. Reward function was evaluated with a probabilistic reward task (PRT), which measures reward responsivity to monetary incentives. To identify whether smoking status influenced reward function, PRT performance was compared between non-depressed, nicotine-dependent smokers and non-smokers. Within smokers, correlations were conducted to determine if blunted reward responsivity on the PRT was associated with increased nicotine craving. Time since last nicotine exposure was standardized to 4h for all smokers. Smokers and non-smokers did not differ in reward responsivity on the PRT. However, within smokers, a significant negative correlation was found between reward responsivity and intensity of nicotine craving. The current findings show that, among smokers, the intensity of nicotine craving is linked to lower sensitivity to non-drug rewards. This finding is in line with prior theories that suggest reward dysfunction in some clinical populations (e.g., depressive disorders, schizophrenia) may facilitate nicotine use. The current study expands on such theories by indicating that sub-clinical variations in reward function are related to motivation for nicotine use. Identifying smokers who show blunted sensitivity to non-drug rewards may help guide treatments aimed at mitigating the motivation to smoke. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Processes influencing the population dynamics and conservation of ...

    African Journals Online (AJOL)

    ... adjacent colonies in years of high fish abundance or shifts in prey distribution. Less than 1 500 pairs were breeding on Dyer Island in 2013. Available knowledge on demographic parameters was collated and ecological processes were quantified. Juvenile and adult survival probabilities estimated for birds ringed on Dyer ...

  8. Linking individual phenotype to density-dependent population growth: the influence of body size on the population dynamics of malaria vectors

    Science.gov (United States)

    Russell, Tanya L.; Lwetoijera, Dickson W.; Knols, Bart G. J.; Takken, Willem; Killeen, Gerry F.; Ferguson, Heather M.

    2011-01-01

    Understanding the endogenous factors that drive the population dynamics of malaria mosquitoes will facilitate more accurate predictions about vector control effectiveness and our ability to destabilize the growth of either low- or high-density insect populations. We assessed whether variation in phenotypic traits predict the dynamics of Anopheles gambiae sensu lato mosquitoes, the most important vectors of human malaria. Anopheles gambiae dynamics were monitored over a six-month period of seasonal growth and decline. The population exhibited density-dependent feedback, with the carrying capacity being modified by rainfall (97% wAICc support). The individual phenotypic expression of the maternal (p = 0.0001) and current (p = 0.040) body size positively influenced population growth. Our field-based evidence uniquely demonstrates that individual fitness can have population-level impacts and, furthermore, can mitigate the impact of exogenous drivers (e.g. rainfall) in species whose reproduction depends upon it. Once frontline interventions have suppressed mosquito densities, attempts to eliminate malaria with supplementary vector control tools may be attenuated by increased population growth and individual fitness. PMID:21389034

  9. Population death sequences and Cox processes driven by interacting Feller diffusions

    CERN Document Server

    Wei Gang; Feng Jian Feng

    2002-01-01

    We carry out a complete study on the relationship between Cox processes driven by interacting Feller diffusions and death sequences of immigration-emigration linked population networks. It is first proved that the Cox process driven by a Feller diffusion is equivalent to the death sequence of a birth and death process. The conclusion is then generalized to the case of Cox processes driven by interacting Feller diffusions and death sequences of interacting populations.

  10. Population death sequences and Cox processes driven by interacting Feller diffusions

    International Nuclear Information System (INIS)

    Wei Gang; Clifford, Peter; Feng Jianfeng

    2002-01-01

    We carry out a complete study on the relationship between Cox processes driven by interacting Feller diffusions and death sequences of immigration-emigration linked population networks. It is first proved that the Cox process driven by a Feller diffusion is equivalent to the death sequence of a birth and death process. The conclusion is then generalized to the case of Cox processes driven by interacting Feller diffusions and death sequences of interacting populations

  11. Population death sequences and Cox processes driven by interacting Feller diffusions

    Energy Technology Data Exchange (ETDEWEB)

    Wei Gang [Department of Mathematics, Baptist University, Hong Kong (China); Clifford, Peter [Department of Statistics, 1 South Parks Road, Oxford (United Kingdom); Feng Jianfeng [COGS, Sussex University, Brighton (United Kingdom)

    2002-11-08

    We carry out a complete study on the relationship between Cox processes driven by interacting Feller diffusions and death sequences of immigration-emigration linked population networks. It is first proved that the Cox process driven by a Feller diffusion is equivalent to the death sequence of a birth and death process. The conclusion is then generalized to the case of Cox processes driven by interacting Feller diffusions and death sequences of interacting populations.

  12. Context-dependent survival, fecundity and predicted population-level consequences of brucellosis in African buffalo

    Science.gov (United States)

    Gorsich, Erin E.; Ezenwa, Vanessa O.; Cross, Paul C.; Bengis, Roy G.; Jolles, Anna E.

    2015-01-01

    Chronic infections may have negative impacts on wildlife populations, yet their effects are difficult to detect in the absence of long-term population monitoring. Brucella abortus, the bacteria responsible for bovine brucellosis, causes chronic infections and abortions in wild and domestic ungulates, but its impact on population dynamics is not well understood.

  13. Vector population growth and condition-dependent movement drive the spread of plant pathogens.

    Science.gov (United States)

    Shaw, Allison K; Peace, Angela; Power, Alison G; Bosque-Pérez, Nilsa A

    2017-08-01

    Plant viruses, often spread by arthropod vectors, impact natural and agricultural ecosystems worldwide. Intuitively, the movement behavior and life history of vectors influence pathogen spread, but the relative contribution of each factor has not been examined. Recent research has highlighted the influence of host infection status on vector behavior and life history. Here, we developed a model to explore how vector traits influence the spread of vector-borne plant viruses. We allowed vector life history (growth rate, carrying capacity) and movement behavior (departure and settlement rates) parameters to be conditional on whether the plant host is infected or healthy and whether the vector is viruliferous (carrying the virus) or not. We ran simulations under a wide range of parameter combinations and quantified the fraction of hosts infected over time. We also ran case studies of the model for Barley yellow dwarf virus, a persistently transmitted virus, and for Potato virus Y, a non-persistently transmitted virus. We quantified the relative importance of each parameter on pathogen spread using Latin hypercube sampling with the statistical partial rank correlation coefficient technique. We found two general types of mechanisms in our model that increased the rate of pathogen spread. First, increasing factors such as vector intrinsic growth rate, carrying capacity, and departure rate from hosts (independent of whether these factors were condition-dependent) led to more vectors moving between hosts, which increased pathogen spread. Second, changing condition-dependent factors such as a vector's preference for settling on a host with a different infection status than itself, and vector tendency to leave a host of the same infection status, led to increased contact between hosts and vectors with different infection statuses, which also increased pathogen spread. Overall, our findings suggest that vector population growth rates had the greatest influence on rates of virus

  14. Human Health Risk Assessment Applied to Rural Populations Dependent on Unregulated Drinking Water Sources: A Scoping Review.

    Science.gov (United States)

    Ford, Lorelei; Bharadwaj, Lalita; McLeod, Lianne; Waldner, Cheryl

    2017-07-28

    Safe drinking water is a global challenge for rural populations dependent on unregulated water. A scoping review of research on human health risk assessments (HHRA) applied to this vulnerable population may be used to improve assessments applied by government and researchers. This review aims to summarize and describe the characteristics of HHRA methods, publications, and current literature gaps of HHRA studies on rural populations dependent on unregulated or unspecified drinking water. Peer-reviewed literature was systematically searched (January 2000 to May 2014) and identified at least one drinking water source as unregulated (21%) or unspecified (79%) in 100 studies. Only 7% of reviewed studies identified a rural community dependent on unregulated drinking water. Source water and hazards most frequently cited included groundwater (67%) and chemical water hazards (82%). Most HHRAs (86%) applied deterministic methods with 14% reporting probabilistic and stochastic methods. Publications increased over time with 57% set in Asia, and 47% of studies identified at least one literature gap in the areas of research, risk management, and community exposure. HHRAs applied to rural populations dependent on unregulated water are poorly represented in the literature even though almost half of the global population is rural.

  15. Understanding the time dependence of atomic level populations in evolving plasmas

    International Nuclear Information System (INIS)

    Judge, Philip G.

    2005-01-01

    The time dependence of atomic level populations in evolving plasmas is studied using an eigenfunction expansion of the non-LTE rate equations. The work aims to develop understanding without the need for, and as an aid to, numerical solutions. The discussion is mostly limited to linear systems, especially those for optically thin plasmas, but the implicitly non-linear case of non-LTE radiative transfer is briefly discussed. Eigenvalue spectra for typical atomic systems are examined using results compiled by Hearon. Diagonal dominance and sign symmetry of rate matrices show that just one eigenvalue is zero (corresponding to the equilibrium state), that the remaining eigenvalues have negative real parts, and that oscillations, if any, are necessarily damped. Gershgorin's theorems are used to show that many eigenvalues are determined by the radiative lifetimes of certain levels, because of diagonal dominance. With other properties, this demonstrates the existence of both 'slow' and 'fast' time-scales, where the 'slow' evolution is controlled by properties of meta-stable levels. It is shown that, when collisions are present, Rydberg states contribute only 'fast' eigenvalues. This justifies use of the quasi-static approximation, in which atoms containing just meta-stable levels can suffice to determine the atomic evolution on time-scales long compared with typical radiative lifetimes. Analytic solutions for two- and three-level atoms are used to examine the basis of earlier intuitive ideas, such as the 'ionizing plasma' approximation. The power and limitations of Gershgorin's theorems are examined through examples taken from the solar atmosphere. The methods should help in the planning and interpretation of both experimental and numerical experiments in which atomic evolution is important. While the examples are astrophysical, the methods and results are applicable to plasmas in general

  16. [Incidence of dependence-related lesions in a population of critical patients].

    Science.gov (United States)

    Roca-Biosca, Alba; Rubio-Rico, Lourdes; de Molina-Fernández, María Inmaculada; Tuset-Garijo, Gemma; Colodrero-Díaz, Encarnación; García-Fernández, Francisco Pedro

    2016-01-01

    To determine the incidence of various types of dependence-related lesions (DRL) on a population of critically ill patients. Descriptive, longitudinal and prospective study in an Intensive Care Unit from January 2014 to January 2015. Adult patients who did not present DRL at the moment of admission were included. Those with brain death and/or stay at the unit for more than two days were excluded. Patients were studied till they developed DRL, were exitus, discharged or stayed for more than 14 days. Each patient was evaluated daily till DRL did develop or was excluded from the study. If DRL did develop it was photographed and related data were recorded. The comparison between quantitative variables of normal distribution was done with the t de Student. The Mann-Whitney U was used to compare the other variables. Qualitative variables were compared through Pearson's chi square. In both cases p≤.05 was considered significant. 295 patients were included, 27.45% of them developed DRL. The density of incidence was 41 DRL/1,000 days at risk. 50.62% of DRL were categorized as PU. 17.28% were moisture injuries, 13.58% were due to friction and the rest were combined injuries. The risk according to EMINA and Braden scale was significantly different in the group of patients with lesions compared to the group without them. Not all injuries were caused by pressure. Specific prevention strategies based on different causal mechanisms are required. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  17. Gamma processes and peaks-over-threshold distributions for time-dependent reliability

    International Nuclear Information System (INIS)

    Noortwijk, J.M. van; Weide, J.A.M. van der; Kallen, M.J.; Pandey, M.D.

    2007-01-01

    In the evaluation of structural reliability, a failure is defined as the event in which stress exceeds a resistance that is liable to deterioration. This paper presents a method to combine the two stochastic processes of deteriorating resistance and fluctuating load for computing the time-dependent reliability of a structural component. The deterioration process is modelled as a gamma process, which is a stochastic process with independent non-negative increments having a gamma distribution with identical scale parameter. The stochastic process of loads is generated by a Poisson process. The variability of the random loads is modelled by a peaks-over-threshold distribution (such as the generalised Pareto distribution). These stochastic processes of deterioration and load are combined to evaluate the time-dependent reliability

  18. Location-Dependent Query Processing Under Soft Real-Time Constraints

    Directory of Open Access Journals (Sweden)

    Zoubir Mammeri

    2009-01-01

    Full Text Available In recent years, mobile devices and applications achieved an increasing development. In database field, this development required methods to consider new query types like location-dependent queries (i.e. the query results depend on the query issuer location. Although several researches addressed problems related to location-dependent query processing, a few works considered timing requirements that may be associated with queries (i.e., the query results must be delivered to mobile clients on time. The main objective of this paper is to propose a solution for location-dependent query processing under soft real-time constraints. Hence, we propose methods to take into account client location-dependency and to maximize the percentage of queries respecting their deadlines. We validate our proposal by implementing a prototype based on Oracle DBMS. Performance evaluation results show that the proposed solution optimizes the percentage of queries meeting their deadlines and the communication cost.

  19. Evidential analytic hierarchy process dependence assessment methodology in human reliability analysis

    International Nuclear Information System (INIS)

    Chen, Lu Yuan; Zhou, Xinyi; Xiao, Fuyuan; Deng, Yong; Mahadevan, Sankaran

    2017-01-01

    In human reliability analysis, dependence assessment is an important issue in risky large complex systems, such as operation of a nuclear power plant. Many existing methods depend on an expert's judgment, which contributes to the subjectivity and restrictions of results. Recently, a computational method, based on the Dempster-Shafer evidence theory and analytic hierarchy process, has been proposed to handle the dependence in human reliability analysis. The model can deal with uncertainty in an analyst's judgment and reduce the subjectivity in the evaluation process. However, the computation is heavy and complicated to some degree. The most important issue is that the existing method is in a positive aspect, which may cause an underestimation of the risk. In this study, a new evidential analytic hierarchy process dependence assessment methodology, based on the improvement of existing methods, has been proposed, which is expected to be easier and more effective

  20. Evidential Analytic Hierarchy Process Dependence Assessment Methodology in Human Reliability Analysis

    Directory of Open Access Journals (Sweden)

    Luyuan Chen

    2017-02-01

    Full Text Available In human reliability analysis, dependence assessment is an important issue in risky large complex systems, such as operation of a nuclear power plant. Many existing methods depend on an expert's judgment, which contributes to the subjectivity and restrictions of results. Recently, a computational method, based on the Dempster–Shafer evidence theory and analytic hierarchy process, has been proposed to handle the dependence in human reliability analysis. The model can deal with uncertainty in an analyst's judgment and reduce the subjectivity in the evaluation process. However, the computation is heavy and complicated to some degree. The most important issue is that the existing method is in a positive aspect, which may cause an underestimation of the risk. In this study, a new evidential analytic hierarchy process dependence assessment methodology, based on the improvement of existing methods, has been proposed, which is expected to be easier and more effective.

  1. Evidential analytic hierarchy process dependence assessment methodology in human reliability analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Lu Yuan; Zhou, Xinyi; Xiao, Fuyuan; Deng, Yong [School of Computer and Information Science, Southwest University, Chongqing (China); Mahadevan, Sankaran [School of Engineering, Vanderbilt University, Nashville (United States)

    2017-02-15

    In human reliability analysis, dependence assessment is an important issue in risky large complex systems, such as operation of a nuclear power plant. Many existing methods depend on an expert's judgment, which contributes to the subjectivity and restrictions of results. Recently, a computational method, based on the Dempster-Shafer evidence theory and analytic hierarchy process, has been proposed to handle the dependence in human reliability analysis. The model can deal with uncertainty in an analyst's judgment and reduce the subjectivity in the evaluation process. However, the computation is heavy and complicated to some degree. The most important issue is that the existing method is in a positive aspect, which may cause an underestimation of the risk. In this study, a new evidential analytic hierarchy process dependence assessment methodology, based on the improvement of existing methods, has been proposed, which is expected to be easier and more effective.

  2. Comparing population patterns to processes: abundance and survival of a forest salamander following habitat degradation.

    Directory of Open Access Journals (Sweden)

    Clint R V Otto

    Full Text Available Habitat degradation resulting from anthropogenic activities poses immediate and prolonged threats to biodiversity, particularly among declining amphibians. Many studies infer amphibian response to habitat degradation by correlating patterns in species occupancy or abundance with environmental effects, often without regard to the demographic processes underlying these patterns. We evaluated how retention of vertical green trees (CANOPY and coarse woody debris (CWD influenced terrestrial salamander abundance and apparent survival in recently clearcut forests. Estimated abundance of unmarked salamanders was positively related to CANOPY (β Canopy  = 0.21 (0.02-1.19; 95% CI, but not CWD (β CWD  = 0.11 (-0.13-0.35 within 3,600 m2 sites, whereas estimated abundance of unmarked salamanders was not related to CANOPY (β Canopy  = -0.01 (-0.21-0.18 or CWD (β CWD  = -0.02 (-0.23-0.19 for 9 m2 enclosures. In contrast, apparent survival of marked salamanders within our enclosures over 1 month was positively influenced by both CANOPY and CWD retention (β Canopy  = 0.73 (0.27-1.19; 95% CI and β CWD  = 1.01 (0.53-1.50. Our results indicate that environmental correlates to abundance are scale dependent reflecting habitat selection processes and organism movements after a habitat disturbance event. Our study also provides a cautionary example of how scientific inference is conditional on the response variable(s, and scale(s of measure chosen by the investigator, which can have important implications for species conservation and management. Our research highlights the need for joint evaluation of population state variables, such as abundance, and population-level process, such as survival, when assessing anthropogenic impacts on forest biodiversity.

  3. Mathematical Modelling of Bacterial Populations in Bio-remediation Processes

    Science.gov (United States)

    Vasiliadou, Ioanna A.; Vayenas, Dimitris V.; Chrysikopoulos, Constantinos V.

    2011-09-01

    An understanding of bacterial behaviour concerns many field applications, such as the enhancement of water, wastewater and subsurface bio-remediation, the prevention of environmental pollution and the protection of human health. Numerous microorganisms have been identified to be able to degrade chemical pollutants, thus, a variety of bacteria are known that can be used in bio-remediation processes. In this study the development of mathematical models capable of describing bacterial behaviour considered in bio-augmentation plans, such as bacterial growth, consumption of nutrients, removal of pollutants, bacterial transport and attachment in porous media, is presented. The mathematical models may be used as a guide in designing and assessing the conditions under which areas contaminated with pollutants can be better remediated.

  4. Multi-dimensional population balance models of crystallization processes

    DEFF Research Database (Denmark)

    Meisler, Kresten Troelstrup; von Solms, Nicolas

    A generic and model-based framework for batch cooling crystallization operations has been extended to incorporate continuous and fed-batch processes. Modules for the framework have been developed, including a module for reactions, allowing the study of reactive crystallization within the framework....... A kinetic model library together with an ontology for knowledge representation has been developed, in which kinetic models and relations from the literature are stored along with the references and data. The model library connects to the generic modelling framework as well, as models can be retrieved......, analyzed, used for simulation and stored again. The model library facilitates comparison of expressions for kinetic phenomena and is tightly integrated with the model analysis tools of the framework.Through the framework, a model for a crystallization operation may be systematically generated...

  5. Renal microvascular disease in an aging population: a reversible process?

    Science.gov (United States)

    Futrakul, Narisa; Futrakul, Prasit

    2008-01-01

    Renal microvascular disease and tubulointerstitial fibrosis are usually demonstrated in aging in humans and animals. It has recently been proposed that renal microvascular disease is the crucial determinant of tubulointerstitial disease or fibrosis. Enhanced circulating endothelial cell loss is a biomarker that reflects glomerular endothelial injury or renal microvascular disease, and fractional excretion of magnesium (FE Mg) is a sensitive biomarker that reflects an early stage of tubulointerstitial fibrosis. In aging in humans, both of these biomarkers are abnormally elevated. In addition, a glomerular endothelial dysfunction determined by altered hemodynamics associated with peritubular capillary flow reduction is substantiated. A correction of such hemodynamic alteration with vasodilators can effectively improve renal perfusion and restore renal function. Thus, anti-aging therapy can reverse the renal microvascular disease and dysfunction associated with the aging process.

  6. On the A dependence in the process of dilepton production by high-energy nucleons

    International Nuclear Information System (INIS)

    Gevorkyan, S.R.; Zhamkochyan, V.M.

    1978-01-01

    The process of lepton pair production in nucleon-nucleus collisions for high energies is considered. It is shown, that with due regard for the N → π → μ + μ - inelastic transitions the experimentally observed A dependence of the cross section of the NA → μ + μ - X process can be explained in the framework of the multiple scattering theory

  7. Wide sense one-dependent processes with embedded Harris chains and their applications in inventory management

    NARCIS (Netherlands)

    E.M. Bazsa-Oldenkamp; P. den Iseger

    2003-01-01

    textabstractIn this paper we consider stochastic processes with an embedded Harris chain. The embedded Harris chain describes the dependence structure of the stochastic process. That is, all the relevant information of the past is contained in the state of the embedded Harris chain. For these

  8. Personality Disorders, Narcotics, and Stimulants; Relationship in Iranian Male Substance Dependents Population.

    Science.gov (United States)

    Noorbakhsh, Simasadat; Zeinodini, Zahra; Khanjani, Zeynab; Poorsharifi, Hamid; Rajezi Esfahani, Sepideh

    2015-06-01

    Individuals with certain personality disorders, especially the antisocial and borderline personality disorders, are more prone to substance use disorders. Regarding the importance of substance use disorders, this study aimed to explore the association between personality disorders and types of used drugs (narcotics and stimulants) in Iranian male substance users. The current study was a correlation study. We evaluated 285 male substance users and excluded 25 according to exclusion criteria. A total of 130 narcotic users and 130 stimulant users were recruited randomly in several phases from January 2013 to October 2013. All participants were referred to Substance Dependency Treatment Clinics in Tehran, Iran. Data collection process was accomplished by means of clinical interview based on DSM-V criteria for substance use disorders, Iranian version of addiction severity index (ASI), and Millon clinical multi-axial inventory-III (MCMI-III). Data were analyzed by SPSS 21 using Pearson correlation coefficient and regression, the. There was a significant correlation between stimulant use and histrionic personality disorder (P personality disorders (P histrionic, and narcissistic personality disorders (P personality disorders (P personality disorders, and narcotic and stimulants consumption (P personality disorder and narcotics (P personality disorders and types of used drugs were in accordance with the previous studies results. It is necessary to design appropriate treatment plans for medical treatment of those with personality disorders.

  9. Integrating temperature-dependent life table data into a matrix projection model for Drosophila suzukii population estimation.

    Directory of Open Access Journals (Sweden)

    Nik G Wiman

    Full Text Available Temperature-dependent fecundity and survival data was integrated into a matrix population model to describe relative Drosophila suzukii Matsumura (Diptera: Drosophilidae population increase and age structure based on environmental conditions. This novel modification of the classic Leslie matrix population model is presented as a way to examine how insect populations interact with the environment, and has application as a predictor of population density. For D. suzukii, we examined model implications for pest pressure on crops. As case studies, we examined model predictions in three small fruit production regions in the United States (US and one in Italy. These production regions have distinctly different climates. In general, patterns of adult D. suzukii trap activity broadly mimicked seasonal population levels predicted by the model using only temperature data. Age structure of estimated populations suggest that trap and fruit infestation data are of limited value and are insufficient for model validation. Thus, we suggest alternative experiments for validation. The model is advantageous in that it provides stage-specific population estimation, which can potentially guide management strategies and provide unique opportunities to simulate stage-specific management effects such as insecticide applications or the effect of biological control on a specific life-stage. The two factors that drive initiation of the model are suitable temperatures (biofix and availability of a suitable host medium (fruit. Although there are many factors affecting population dynamics of D. suzukii in the field, temperature-dependent survival and reproduction are believed to be the main drivers for D. suzukii populations.

  10. [Prevalence of gene polymorphisms associated with immune-dependent diseases in the populations of North Eurasia].

    Science.gov (United States)

    Cherednichenko, A A; Trifonova, E A; Vagaitseva, K V; Bocharova, A V; Varzari, A M; Radzhabov, M O; Stepanov, V A

    2015-01-01

    The data on distribution of genetic diversity in gene polymorphisms associated with autoimmune and allergic diseases and with regulation of immunoglobulin E and cytokines levels in 26 populations of the Northern Eurasia is presented. Substantial correlation between the values of average expected heterozygosity by 44 gene polymorphisms with climatic and geographical factors has not been revealed. Clustering of population groups in correspondence with their geographic locations is observed. The degree of gene differentiation among populations and the selective neutrality of gene polymorphisms have been assessed. The results of our work evidence the substantial genetic diversity and differentiation of human populations by studied genes.

  11. Population processes with unbounded extinction rate conditioned to non-extinction

    OpenAIRE

    Champagnat, Nicolas; Villemonais, Denis

    2016-01-01

    This article studies the quasi-stationary behaviour of population processes with unbounded absorption rate, including one-dimensional birth and death processes with catastrophes and multi-dimensional birth and death processes, modeling biological populations in interaction. To handle this situation, we develop original non-linear Lyapunov criteria. We obtain the exponential convergence in total variation of the conditional distributions to a unique quasi-stationary distribution, uniformly wit...

  12. Sub-populations of alcohol-dependent patients: differences in psychological functioning between high- and low-frequency alcohol consumers.

    Science.gov (United States)

    Hiltunen, A J; Koechling, U M; Voltaire-Carlsson, A; Borg, S

    1996-07-01

    The purpose of the present study was to examine the processes underlying relapse to drinking using objective biological validation of self-reported recent alcohol consumption, using the ratio of 5-hydroxytryptophol to 5-hydroxyindol-3-ylacetic acid (5-HTOL/5-HIAA), a new biological marker to detect single episodes of drinking, in a sample of 38 male alcohol-dependent patients (DSM-III-R) who were assessed prospectively in terms of their clinical symptomatology over a 6-month treatment period. Results showed that nearly all patients obtained positive 5-HTOL/5-HIAA samples during the course of treatment. However, upon closer inspection, results revealed a bimodal distribution for alcohol intake with high and low frequency of consumption episodes. Results showed that high frequency consumers obtained higher ratings of clinical symptoms as measured by the Comprehensive Psychopathological Rating Scale (CPRS) and by the St Göran's Semi-structured Interview (SGSI) compared to low frequency alcohol consumers on symptoms of inner tension, lack of initiative, risk of relapse (as rated by therapists and as rated by patients themselves), dysphoria, negative craving for alcohol, and positive craving for alcohol. The present results provided evidence for the existence of two sub-populations of alcoholics, those who have frequent lapses and those who have low frequency of sporadic lapses. Further, these two sub-populations were shown to differ with respect to overall psychological functioning, and craving for alcohol. In conclusion, the present findings have important treatment implications in that reliable identification of patients' consumption patterns using biological markers would allow for the design of individually tailored treatment needs.

  13. Validity of the EQ-5D as a generic health outcome instrument in a heroin-dependent population

    NARCIS (Netherlands)

    van der Zanden, Bart P.; Dijkgraaf, Marcel G. W.; Blanken, Peter; de Borgie, Corianne A. J. M.; van Ree, Jan M.; van den Brink, Wim

    2006-01-01

    OBJECTIVE: To evaluate the validity of the EuroQol (EQ-5D) in a population of chronic, treatment-resistant heroin-dependent patients. METHODS: The EQ-5D is studied relative to the Maudsley Addiction Profile (MAP), the Symptom Checklist (SCL-90) and the European Addiction Severity Index (EuropASI)

  14. Alcohol abuse and dependence criteria as predictors of a chronic course of alcohol use disorders in the general population

    NARCIS (Netherlands)

    de Bruijn, Carla; van den Brink, Wim; de Graaf, Ron; Vollebergh, Wilma A. M.

    2005-01-01

    Aims: To investigate whether DSM-IV abuse and dependence criteria and the ICD-10 criterion for craving differentially predict a chronic course of alcohol use disorders (AUD) in the general population. Methods: Data were derived from the Netherlands Mental Health Survey and Incidence Study, a large

  15. Partitioning the sources of demographic variation reveals density-dependent nest predation in an island bird population.

    Science.gov (United States)

    Sofaer, Helen R; Sillett, T Scott; Langin, Kathryn M; Morrison, Scott A; Ghalambor, Cameron K

    2014-07-01

    Ecological factors often shape demography through multiple mechanisms, making it difficult to identify the sources of demographic variation. In particular, conspecific density can influence both the strength of competition and the predation rate, but density-dependent competition has received more attention, particularly among terrestrial vertebrates and in island populations. A better understanding of how both competition and predation contribute to density-dependent variation in fecundity can be gained by partitioning the effects of density on offspring number from its effects on reproductive failure, while also evaluating how biotic and abiotic factors jointly shape demography. We examined the effects of population density and precipitation on fecundity, nest survival, and adult survival in an insular population of orange-crowned warblers (Oreothlypis celata) that breeds at high densities and exhibits a suite of traits suggesting strong intraspecific competition. Breeding density had a negative influence on fecundity, but it acted by increasing the probability of reproductive failure through nest predation, rather than through competition, which was predicted to reduce the number of offspring produced by successful individuals. Our results demonstrate that density-dependent nest predation can underlie the relationship between population density and fecundity even in a high-density, insular population where intraspecific competition should be strong.

  16. Mood disorder, anxiety, and suicide risk among subjects with alcohol abuse and/or dependence: a population-based study

    Directory of Open Access Journals (Sweden)

    Carolina D. Wiener

    2017-06-01

    Full Text Available Objective: To evaluate the prevalence of alcohol abuse and/or dependence in a population-based sample of young adults and assess the prevalence of comorbid mood disorders, anxiety, and suicide risk in this population. Methods: This cross-sectional, population-based study enrolled 1,953 young adults aged 18-35 years. The CAGE questionnaire was used to screen for alcohol abuse and/or dependence, with CAGE scores ≥ 2 considered positive. Psychiatric disorders were investigated through the structured Mini International Neuropsychiatric Interview (MINI. Results: Alcohol abuse and/or dependence was identified in 187 (9.60% individuals (5.10% among women and 15.20% among men. Alcohol abuse and/or dependence were more prevalent among men than women, as well as among those who used tobacco, illicit drugs or presented with anxiety disorder, mood disorder, and suicide risk. Conclusion: These findings suggest that alcohol abuse and/or dependence are consistently associated with a higher prevalence of psychiatric comorbidities, could be considered important predictors of other psychiatric disorders, and deserve greater public heath attention, pointing to the need for alcohol abuse prevention programs.

  17. Mood disorder, anxiety, and suicide risk among subjects with alcohol abuse and/or dependence: a population-based study.

    Science.gov (United States)

    Wiener, Carolina D; Moreira, Fernanda P; Zago, Alethea; Souza, Luciano M; Branco, Jeronimo C; Oliveira, Jacqueline F de; Silva, Ricardo A da; Portela, Luis V; Lara, Diogo R; Jansen, Karen; Oses, Jean P

    2018-01-01

    To evaluate the prevalence of alcohol abuse and/or dependence in a population-based sample of young adults and assess the prevalence of comorbid mood disorders, anxiety, and suicide risk in this population. This cross-sectional, population-based study enrolled 1,953 young adults aged 18-35 years. The CAGE questionnaire was used to screen for alcohol abuse and/or dependence, with CAGE scores ≥ 2 considered positive. Psychiatric disorders were investigated through the structured Mini International Neuropsychiatric Interview (MINI). Alcohol abuse and/or dependence was identified in 187 (9.60%) individuals (5.10% among women and 15.20% among men). Alcohol abuse and/or dependence were more prevalent among men than women, as well as among those who used tobacco, illicit drugs or presented with anxiety disorder, mood disorder, and suicide risk. These findings suggest that alcohol abuse and/or dependence are consistently associated with a higher prevalence of psychiatric comorbidities, could be considered important predictors of other psychiatric disorders, and deserve greater public heath attention, pointing to the need for alcohol abuse prevention programs.

  18. Vascular risk factor burden, atherosclerosis, and functional dependence in old age: a population-based study.

    Science.gov (United States)

    Welmer, Anna-Karin; Liang, Yajun; Angleman, Sara; Santoni, Giola; Yan, Zhongrui; Cai, Chuanzhu; Qiu, Chengxuan

    2014-08-01

    Vascular risk factors such as hypertension and obesity have been associated with physical limitations among older adults. The purpose of this study is to examine whether individual and aggregated vascular risk factors (VRFs) are associated with functional dependence and to what extent carotid atherosclerosis (CAS) or peripheral artery disease (PAD) may mediate the possible associations of aggregated VRFs with functional dependence. This cross-sectional study included 1,451 community-living participants aged ≥60 years in the Confucius Hometown Aging Project of China. Data on demographic features, hypertension, high total cholesterol, obesity, smoking, physical inactivity, diabetes, CAS, PAD, and cardiovascular diseases (CVDs) were collected through an interview, a clinical examination, and laboratory tests. Functional dependence was defined as being dependent in at least one activity in the personal or instrumental activities of daily living. Data were analyzed using multiple logistic models controlling for potential confounders. We used the mediation model to explore the potential mediating effect of CAS and PAD on the associations of aggregated VRFs with functional dependence. Of the 1,451 participants, 222 (15.3%) had functional dependence. The likelihood of functional dependence increased linearly with increasing number of VRFs (hypertension, high total cholesterol, abdominal obesity, and physical inactivity) (p for trend dependence with clustering VRFs was mediated by CAS and PAD. Aggregation of multiple VRFs is associated with an increased likelihood of functional dependence among Chinese older adults; the association is partially mediated by carotid and peripheral artery atherosclerosis independently of CVDs.

  19. Relationship Between Emotional Processing, Drinking Severity and Relapse in Adults Treated for Alcohol Dependence in Poland

    OpenAIRE

    Kopera, Maciej; Jakubczyk, Andrzej; Suszek, Hubert; Glass, Jennifer M.; Klimkiewicz, Anna; Wnorowska, Anna; Brower, Kirk J.; Wojnar, Marcin

    2014-01-01

    Aims: Growing data reveals deficits in perception, understanding and regulation of emotions in alcohol dependence (AD). The study objective was to explore the relationships between emotional processing, drinking history and relapse in a clinical sample of alcohol-dependent patients. Methods: A group of 80 inpatients entering an alcohol treatment program in Warsaw, Poland was recruited and assessed at baseline and follow-up after 12 months. Baseline information about demographics, psychopathol...

  20. Transient Properties of Probability Distribution for a Markov Process with Size-dependent Additive Noise

    Science.gov (United States)

    Yamada, Yuhei; Yamazaki, Yoshihiro

    2018-04-01

    This study considered a stochastic model for cluster growth in a Markov process with a cluster size dependent additive noise. According to this model, the probability distribution of the cluster size transiently becomes an exponential or a log-normal distribution depending on the initial condition of the growth. In this letter, a master equation is obtained for this model, and derivation of the distributions is discussed.

  1. Gaussian process-based Bayesian nonparametric inference of population size trajectories from gene genealogies.

    Science.gov (United States)

    Palacios, Julia A; Minin, Vladimir N

    2013-03-01

    Changes in population size influence genetic diversity of the population and, as a result, leave a signature of these changes in individual genomes in the population. We are interested in the inverse problem of reconstructing past population dynamics from genomic data. We start with a standard framework based on the coalescent, a stochastic process that generates genealogies connecting randomly sampled individuals from the population of interest. These genealogies serve as a glue between the population demographic history and genomic sequences. It turns out that only the times of genealogical lineage coalescences contain information about population size dynamics. Viewing these coalescent times as a point process, estimating population size trajectories is equivalent to estimating a conditional intensity of this point process. Therefore, our inverse problem is similar to estimating an inhomogeneous Poisson process intensity function. We demonstrate how recent advances in Gaussian process-based nonparametric inference for Poisson processes can be extended to Bayesian nonparametric estimation of population size dynamics under the coalescent. We compare our Gaussian process (GP) approach to one of the state-of-the-art Gaussian Markov random field (GMRF) methods for estimating population trajectories. Using simulated data, we demonstrate that our method has better accuracy and precision. Next, we analyze two genealogies reconstructed from real sequences of hepatitis C and human Influenza A viruses. In both cases, we recover more believed aspects of the viral demographic histories than the GMRF approach. We also find that our GP method produces more reasonable uncertainty estimates than the GMRF method. Copyright © 2013, The International Biometric Society.

  2. Dual-memory processes in crack cocaine dependents: The effects of childhood neglect on recall.

    Science.gov (United States)

    Tractenberg, Saulo G; Viola, Thiago W; Gomes, Carlos F A; Wearick-Silva, Luis Eduardo; Kristensen, Christian H; Stein, Lilian M; Grassi-Oliveira, Rodrigo

    2015-01-01

    Exposure to adversities during sensitive periods of neurodevelopment is associated with the subsequent development of substance dependence and exerts harmful, long-lasting effects upon memory functioning. In this study, we investigated the relationship between childhood neglect (CN) and memory using a dual-process model that quantifies recollective and non-recollective retrieval processes in crack cocaine dependents. Eighty-four female crack cocaine-dependent inpatients who did (N = 32) or did not (N = 52) report a history of CN received multiple opportunities to study and recall a short list composed of familiar and concrete words and then received a delayed-recall test. Crack cocaine dependents with a history of CN showed worse performance on free-recall tests than did dependents without a history of CN; this finding was associated with declines in recollective retrieval (direct access) rather than non-recollective retrieval. In addition, we found no evidence of group differences in forgetting rates between immediate- and delayed-recall tests. The results support developmental models of traumatology and suggest that neglect of crack cocaine dependents in early life disrupts the adult memory processes that support the retrieval of detailed representations of events from the past.

  3. Oral health care behavior and frailty-related factors in a care-dependent older population.

    NARCIS (Netherlands)

    Niesten, D.J.M.; Witter, D.J.; Bronkhorst, E.M.; Creugers, N.H.J.

    2017-01-01

    OBJECTIVES: To assess, in older people with different levels of care-dependency 1) which frailty- and non-frailty related predisposing, enabling and need factors are associated with a) dental service use (DSU) frequency, b) changed DSU after the onset of care-dependency, c) brushing frequency, and

  4. Cortical depth dependent population receptive field attraction by spatial attention in human V1

    NARCIS (Netherlands)

    Klein, Barrie P.; Fracasso, Alessio; van Dijk, Jelle A.; Paffen, Chris L.E.; te Pas, Susan F.; Dumoulin, Serge O.

    2018-01-01

    Visual spatial attention concentrates neural resources at the attended location. Recently, we demonstrated that voluntary spatial attention attracts population receptive fields (pRFs) toward its location throughout the visual hierarchy. Theoretically, both a feed forward or feedback mechanism could

  5. On time-dependent diffusion coefficients arising from stochastic processes with memory

    Science.gov (United States)

    Carpio-Bernido, M. Victoria; Barredo, Wilson I.; Bernido, Christopher C.

    2017-08-01

    Time-dependent diffusion coefficients arise from anomalous diffusion encountered in many physical systems such as protein transport in cells. We compare these coefficients with those arising from analysis of stochastic processes with memory that go beyond fractional Brownian motion. Facilitated by the Hida white noise functional integral approach, diffusion propagators or probability density functions (pdf) are obtained and shown to be solutions of modified diffusion equations with time-dependent diffusion coefficients. This should be useful in the study of complex transport processes.

  6. Age and sex dependencies of anxiety and depression in cardiologic patients compared with the general population

    OpenAIRE

    Hinz, A; Kittel, J; Karoff, M; Schwarz, R

    2004-01-01

    Objective: The aim of this study was to test age and sex effects on anxiety and depression using the Hospital Anxiety and Depression Scale HADS. Method: Sample 1 consisted of 2037 subjects of the German general population, and sample 2 comprised 2696 cardiologic patients. Results: In the group of the general population we observed a linear increase of depression and (to a lower extent) of anxiety with age. In contrast to that, the patients reached their anxiety and depression maxima in the ra...

  7. How to design the cost-effectiveness appraisal process of new healthcare technologies to maximise population health: A conceptual framework.

    Science.gov (United States)

    Johannesen, Kasper M; Claxton, Karl; Sculpher, Mark J; Wailoo, Allan J

    2018-02-01

    This paper presents a conceptual framework to analyse the design of the cost-effectiveness appraisal process of new healthcare technologies. The framework characterises the appraisal processes as a diagnostic test aimed at identifying cost-effective (true positive) and non-cost-effective (true negative) technologies. Using the framework, factors that influence the value of operating an appraisal process, in terms of net gain to population health, are identified. The framework is used to gain insight into current policy questions including (a) how rigorous the process should be, (b) who should have the burden of proof, and (c) how optimal design changes when allowing for appeals, price reductions, resubmissions, and re-evaluations. The paper demonstrates that there is no one optimal appraisal process and the process should be adapted over time and to the specific technology under assessment. Optimal design depends on country-specific features of (future) technologies, for example, effect, price, and size of the patient population, which might explain the difference in appraisal processes across countries. It is shown that burden of proof should be placed on the producers and that the impact of price reductions and patient access schemes on the producer's price setting should be considered when designing the appraisal process. Copyright © 2017 John Wiley & Sons, Ltd.

  8. A parametric interpretation of Bayesian Nonparametric Inference from Gene Genealogies: Linking ecological, population genetics and evolutionary processes.

    Science.gov (United States)

    Ponciano, José Miguel

    2017-11-22

    Using a nonparametric Bayesian approach Palacios and Minin (2013) dramatically improved the accuracy, precision of Bayesian inference of population size trajectories from gene genealogies. These authors proposed an extension of a Gaussian Process (GP) nonparametric inferential method for the intensity function of non-homogeneous Poisson processes. They found that not only the statistical properties of the estimators were improved with their method, but also, that key aspects of the demographic histories were recovered. The authors' work represents the first Bayesian nonparametric solution to this inferential problem because they specify a convenient prior belief without a particular functional form on the population trajectory. Their approach works so well and provides such a profound understanding of the biological process, that the question arises as to how truly "biology-free" their approach really is. Using well-known concepts of stochastic population dynamics, here I demonstrate that in fact, Palacios and Minin's GP model can be cast as a parametric population growth model with density dependence and environmental stochasticity. Making this link between population genetics and stochastic population dynamics modeling provides novel insights into eliciting biologically meaningful priors for the trajectory of the effective population size. The results presented here also bring novel understanding of GP as models for the evolution of a trait. Thus, the ecological principles foundation of Palacios and Minin (2013)'s prior adds to the conceptual and scientific value of these authors' inferential approach. I conclude this note by listing a series of insights brought about by this connection with Ecology. Copyright © 2017 The Author. Published by Elsevier Inc. All rights reserved.

  9. Stage-dependent hierarchy of criteria in multiobjective multistage decision processes

    Directory of Open Access Journals (Sweden)

    Tadeusz Trzaskalik

    2017-01-01

    Full Text Available This paper will consider a multiobjective, multistage discrete dynamic process with a changeable, state-dependent hierarchy of stage criteria determined by the decision maker. The goal of this paper is to answer the question of how to control a multistage process while taking into account both the tendency to achieve multiobjective optimization of the entire process and the time-varying hierarchy of stage criteria. We consider in detail possible situations, where the hierarchy of stage criteria changes over time in individual stages and is stage dependent. We present an interactive proposal to solving the problem, where the decision maker actively participates in finding the final realization of the process. The algorithm proposed is illustrated using a numerical example.

  10. Properly quantized history-dependent Parrondo games, Markov processes, and multiplexing circuits

    Energy Technology Data Exchange (ETDEWEB)

    Bleiler, Steven A. [Fariborz Maseeh Department of Mathematics and Statistics, Portland State University, PO Box 751, Portland, OR 97207 (United States); Khan, Faisal Shah, E-mail: faisal.khan@kustar.ac.a [Khalifa University of Science, Technology and Research, PO Box 127788, Abu Dhabi (United Arab Emirates)

    2011-05-09

    Highlights: History-dependent Parrondo games are viewed as Markov processes. Quantum mechanical analogues of these Markov processes are constructed. These quantum analogues restrict to the original process on measurement. Relationship between these analogues and a quantum circuits is exhibited. - Abstract: In the context of quantum information theory, 'quantization' of various mathematical and computational constructions is said to occur upon the replacement, at various points in the construction, of the classical randomization notion of probability distribution with higher order randomization notions from quantum mechanics such as quantum superposition with measurement. For this to be done 'properly', a faithful copy of the original construction is required to exist within the new quantum one, just as is required when a function is extended to a larger domain. Here procedures for extending history-dependent Parrondo games, Markov processes and multiplexing circuits to their quantum versions are analyzed from a game theoretic viewpoint, and from this viewpoint, proper quantizations developed.

  11. 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

  12. Population-Level Density Dependence Influences the Origin and Maintenance of Parental Care.

    Directory of Open Access Journals (Sweden)

    Elijah Reyes

    Full Text Available Parental care is a defining feature of animal breeding systems. We now know that both basic life-history characteristics and ecological factors influence the evolution of care. However, relatively little is known about how these factors interact to influence the origin and maintenance of care. Here, we expand upon previous work and explore the relationship between basic life-history characteristics (stage-specific rates of mortality and maturation and the fitness benefits associated with the origin and the maintenance of parental care for two broad ecological scenarios: the scenario in which egg survival is density dependent and the case in which adult survival is density dependent. Our findings suggest that high offspring need is likely critical in driving the origin, but not the maintenance, of parental care regardless of whether density dependence acts on egg or adult survival. In general, parental care is more likely to result in greater fitness benefits when baseline adult mortality is low if 1 egg survival is density dependent or 2 adult mortality is density dependent and mutant density is relatively high. When density dependence acts on egg mortality, low rates of egg maturation and high egg densities are less likely to lead to strong fitness benefits of care. However, when density dependence acts on adult mortality, high levels of egg maturation and increasing adult densities are less likely to maintain care. Juvenile survival has relatively little, if any, effect on the origin and maintenance of egg-only care. More generally, our results suggest that the evolution of parental care will be influenced by an organism's entire life history characteristics, the stage at which density dependence acts, and whether care is originating or being maintained.

  13. Population-Level Density Dependence Influences the Origin and Maintenance of Parental Care.

    Science.gov (United States)

    Reyes, Elijah; Thrasher, Patsy; Bonsall, Michael B; Klug, Hope

    2016-01-01

    Parental care is a defining feature of animal breeding systems. We now know that both basic life-history characteristics and ecological factors influence the evolution of care. However, relatively little is known about how these factors interact to influence the origin and maintenance of care. Here, we expand upon previous work and explore the relationship between basic life-history characteristics (stage-specific rates of mortality and maturation) and the fitness benefits associated with the origin and the maintenance of parental care for two broad ecological scenarios: the scenario in which egg survival is density dependent and the case in which adult survival is density dependent. Our findings suggest that high offspring need is likely critical in driving the origin, but not the maintenance, of parental care regardless of whether density dependence acts on egg or adult survival. In general, parental care is more likely to result in greater fitness benefits when baseline adult mortality is low if 1) egg survival is density dependent or 2) adult mortality is density dependent and mutant density is relatively high. When density dependence acts on egg mortality, low rates of egg maturation and high egg densities are less likely to lead to strong fitness benefits of care. However, when density dependence acts on adult mortality, high levels of egg maturation and increasing adult densities are less likely to maintain care. Juvenile survival has relatively little, if any, effect on the origin and maintenance of egg-only care. More generally, our results suggest that the evolution of parental care will be influenced by an organism's entire life history characteristics, the stage at which density dependence acts, and whether care is originating or being maintained.

  14. Niche-dependent development of functional neuronal networks from embryonic stem cell-derived neural populations

    Directory of Open Access Journals (Sweden)

    Siebler Mario

    2009-08-01

    Full Text Available Abstract Background The present work was performed to investigate the ability of two different embryonic stem (ES cell-derived neural precursor populations to generate functional neuronal networks in vitro. The first ES cell-derived neural precursor population was cultivated as free-floating neural aggregates which are known to form a developmental niche comprising different types of neural cells, including neural precursor cells (NPCs, progenitor cells and even further matured cells. This niche provides by itself a variety of different growth factors and extracellular matrix proteins that influence the proliferation and differentiation of neural precursor and progenitor cells. The second population was cultivated adherently in monolayer cultures to control most stringently the extracellular environment. This population comprises highly homogeneous NPCs which are supposed to represent an attractive way to provide well-defined neuronal progeny. However, the ability of these different ES cell-derived immature neural cell populations to generate functional neuronal networks has not been assessed so far. Results While both precursor populations were shown to differentiate into sufficient quantities of mature NeuN+ neurons that also express GABA or vesicular-glutamate-transporter-2 (vGlut2, only aggregate-derived neuronal populations exhibited a synchronously oscillating network activity 2–4 weeks after initiating the differentiation as detected by the microelectrode array technology. Neurons derived from homogeneous NPCs within monolayer cultures did merely show uncorrelated spiking activity even when differentiated for up to 12 weeks. We demonstrated that these neurons exhibited sparsely ramified neurites and an embryonic vGlut2 distribution suggesting an inhibited terminal neuronal maturation. In comparison, neurons derived from heterogeneous populations within neural aggregates appeared as fully mature with a dense neurite network and punctuated

  15. Similarity and Difference in Drug Addiction Process Between Heroin- and Methamphetamine-Dependent Users.

    Science.gov (United States)

    Wang, Ziyun; Li, Wei-Xiu; Zhi-Min, Liu

    2017-03-21

    This study aimed to compare the drug addiction process between Chinese heroin- and methamphetamine (MA)-dependent users via a modified 4-stage addiction model (experimentation, occasional use, regular use, and compulsive use). A descriptive study was conducted among 683 eligible participants. In the statistical analysis, we selected 340 heroin- and 295 MA-dependent users without illicit drug use prior to onset of heroin or MA use. The addiction process of heroin-dependent users was shorter than that of MA-dependent users, with shorter transitions from the onset of drug-use to the first drug craving (19.5 vs. 50.0 days), regular use (30.0 vs. 60.0 days), and compulsive use (50.0 vs. 85.0 days). However, no significant differences in the addiction process were observed in frequency of drug administration, except that heroin users reported more administrations of the drug (20.0 vs. 15.0) before progressing to the stage of compulsive drug use. A larger proportion of regular heroin users progressed to use illicit drugs recklessly than did MA users. Most heroin and MA users reported psychological dependence as their primary motivation for compulsive drug use, but more heroin users selected uncomfortable symptoms upon ceasing drug use as further reason to continue. Our results suggest that typical heroin and MA users may experience a similar four-stage addiction process, but MA users might undergo a longer addiction process (in days). More research is necessary to further explore factors influencing the drug addiction process.

  16. Reconstructing Space- and Energy-Dependent Exciton Generation in Solution-Processed Inverted Organic Solar Cells.

    Science.gov (United States)

    Wang, Yuheng; Zhang, Yajie; Lu, Guanghao; Feng, Xiaoshan; Xiao, Tong; Xie, Jing; Liu, Xiaoyan; Ji, Jiahui; Wei, Zhixiang; Bu, Laju

    2018-04-25

    Photon absorption-induced exciton generation plays an important role in determining the photovoltaic properties of donor/acceptor organic solar cells with an inverted architecture. However, the reconstruction of light harvesting and thus exciton generation at different locations within organic inverted device are still not well resolved. Here, we investigate the film depth-dependent light absorption spectra in a small molecule donor/acceptor film. Including depth-dependent spectra into an optical transfer matrix method allows us to reconstruct both film depth- and energy-dependent exciton generation profiles, using which short-circuit current and external quantum efficiency of the inverted device are simulated and compared with the experimental measurements. The film depth-dependent spectroscopy, from which we are able to simultaneously reconstruct light harvesting profile, depth-dependent composition distribution, and vertical energy level variations, provides insights into photovoltaic process. In combination with appropriate material processing methods and device architecture, the method proposed in this work will help optimizing film depth-dependent optical/electronic properties for high-performance solar cells.

  17. Modelling and assessment of dependent performance shaping factors through Analytic Network Process

    International Nuclear Information System (INIS)

    De Ambroggi, Massimiliano; Trucco, Paolo

    2011-01-01

    Despite continuous progresses in research and applications, one of the major weaknesses of current HRA methods dwells in their limited capability of modelling the mutual influences between performance shaping factors (PSFs). Indeed at least two types of dependencies between PSFs can be defined: (i) dependency between the states of the PSFs; (ii) dependency between the influences (impacts) of the PSFs on the human performance. This paper introduces a method, based on Analytic Network Process (ANP), for the quantification of the latter, where the overall contribution of each PSF (weight) to the human error probability (HEP) is eventually returned. The core of the method is the modelling process, articulated into two steps: firstly, a qualitative network of dependencies between PSFs is identified, then, the importance of each PSF is quantitatively assessed using ANP. The model allows to distinguish two components of the PSF influence: direct influence that is the influence that the considered PSF is able to express by itself, notwithstanding the presence of other PSFs and indirect influence that is the incremental influence of the considered PSF through its influence on other PSFs. A case study in Air Traffic Control is presented where the proposed approach is integrated into the cognitive simulator PROCOS. The results demonstrated a significant modification of the influence of PSFs over the operator performance when dependencies are taken into account, underlining the importance of considering not only the possible correlation between the states of PSFs but also their mutual dependency in affecting human performance in complex systems.

  18. The Structure of Social Cognition: In(ter)dependence of Sociocognitive Processes.

    Science.gov (United States)

    Happé, Francesca; Cook, Jennifer L; Bird, Geoffrey

    2017-01-03

    Social cognition is a topic of enormous interest and much research, but we are far from having an agreed taxonomy or factor structure of relevant processes. The aim of this review is to outline briefly what is known about the structure of social cognition and to suggest how further progress can be made to delineate the in(ter)dependence of core sociocognitive processes. We focus in particular on several processes that have been discussed and tested together in typical and atypical (notably autism spectrum disorder) groups: imitation, biological motion, empathy, and theory of mind. We consider the domain specificity/generality of core processes in social learning, reward, and attention, and we highlight the potential relevance of dual-process theories that distinguish systems for fast/automatic and slow/effortful processing. We conclude with methodological and conceptual suggestions for future progress in uncovering the structure of social cognition.

  19. INHOMOGENEITY IN SPATIAL COX POINT PROCESSES – LOCATION DEPENDENT THINNING IS NOT THE ONLY OPTION

    Directory of Open Access Journals (Sweden)

    Michaela Prokešová

    2010-11-01

    Full Text Available In the literature on point processes the by far most popular option for introducing inhomogeneity into a point process model is the location dependent thinning (resulting in a second-order intensity-reweighted stationary point process. This produces a very tractable model and there are several fast estimation procedures available. Nevertheless, this model dilutes the interaction (or the geometrical structure of the original homogeneous model in a special way. When concerning the Markov point processes several alternative inhomogeneous models were suggested and investigated in the literature. But it is not so for the Cox point processes, the canonical models for clustered point patterns. In the contribution we discuss several other options how to define inhomogeneous Cox point process models that result in point patterns with different types of geometric structure. We further investigate the possible parameter estimation procedures for such models.

  20. The structuring process of the macroparasite community of an experimental population of cichlasoma urophthalmus through time

    Science.gov (United States)

    Vidal-Martinez; Kennedy; Aguirre-Macedo

    1998-09-01

    The structuring process of the macroparasite community of caged Cichlasoma urophthalmus was studied over time using sentinel fish. Three thousand uninfected cichlids were stocked in floating cages introduced into a quarry in which a wild population of the same species was present. Caged and wild cichlids were sampled monthly over 6 and 7 months, respectively. Seventeen macroparasite species were found in the wild C. urophthalmus population, ten of which were detected in the caged population after 6 months. Early infections were by those species that were more frequent and abundant in the wild population, while helminths with a low prevalence and abundance in the wild appeared later in the caged fish population. The results suggested that the structuring process of the macroparasite community of caged C. urophthalmus followed a predictable pattern, in which those species that were most frequent and abundant in the wild were the first to establish in sentinel fish.

  1. Cranial computed tomography associated with development of functional dependence in a community-based elderly population

    International Nuclear Information System (INIS)

    Tsukishima, Eri; Shido, Koichi

    2002-01-01

    The purpose of this study was to investigate whether changes at computed tomography (CT) imaging in the ageing brain are associated with future risks for functional dependence. One hundred sixty residents aged 69 years and older at the cranial CT and were independently living in a rural community in Hokkaido, Japan. Cranial CT was performed between 1991 and 1993, graded for ventricular enlargement, sulcal enlargement, white matter change, and small infarction. Functional status was reassessed in 1998 in each participant. Multiple logistic regression analysis was performed to estimate the association of CT changes in the ageing brain with development of functional dependence over six years. Functional dependence was found in 19 residents at the second survey. After adjusting for age, sex, medical conditions, and cognitive functioning, small infarction and ventricular enlargement were significantly associated with development of functional dependence (adjusted odds ratio=9.27 and 4.62). After controlling for age, the age-related changes on cranial CT have significant association on development of functional dependence. (author)

  2. On estimation of time-dependent attributable fraction from population-based case-control studies.

    Science.gov (United States)

    Zhao, Wei; Chen, Ying Qing; Hsu, Li

    2017-09-01

    Population attributable fraction (PAF) is widely used to quantify the disease burden associated with a modifiable exposure in a population. It has been extended to a time-varying measure that provides additional information on when and how the exposure's impact varies over time for cohort studies. However, there is no estimation procedure for PAF using data that are collected from population-based case-control studies, which, because of time and cost efficiency, are commonly used for studying genetic and environmental risk factors of disease incidences. In this article, we show that time-varying PAF is identifiable from a case-control study and develop a novel estimator of PAF. Our estimator combines odds ratio estimates from logistic regression models and density estimates of the risk factor distribution conditional on failure times in cases from a kernel smoother. The proposed estimator is shown to be consistent and asymptotically normal with asymptotic variance that can be estimated empirically from the data. Simulation studies demonstrate that the proposed estimator performs well in finite sample sizes. Finally, the method is illustrated by a population-based case-control study of colorectal cancer. © 2017, The International Biometric Society.

  3. Asian longhorned beetle, over the river and through the woods: habitat-dependent population spread

    Science.gov (United States)

    Alan J. Sawyer; William S. Panagakos; Audra E. Horner; Kevin J. Freeman

    2011-01-01

    The Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), is an introduced pest of hardwood trees in North America. This paper addresses population spread in open landscapes and wooded areas, with emphasis on recent findings from Staten Island, NY, and Worcester, MA.

  4. Are populations of European earwigs, Forficula auricularia, density dependent?

    DEFF Research Database (Denmark)

    Moerkens, R.; Leirs, H; Peusens, G.

    2009-01-01

    Biocontrol using naturally occurring predators is often limited by population parameters of those predators. Earwigs, Forficula auricularia L. (Dermaptera: Forficulidae), are important predators in fruit orchards. They are capable of suppressing outbreaks of pest species, such as pear psyllid and...

  5. Combination of the mutation process with the sensitization and repair processes leading to increased frequencies of mutations in algal populations

    International Nuclear Information System (INIS)

    Necas, J.

    1977-01-01

    The possibility of combining the mutation process with the induction of the repair processes was studied to increase the mutation frequencies in algal populations after UV treatment. The repair process induced by visible light was found to be much more effective than the dark repair processes in the chlorococcal algae used. In these algae, visible light possibly does not induce only those repair processes which affect their DNA, but probably also certain recovery processes which affect their damaged structures and physiological functions. A suitable combination of the sensitization of algae cells by a DNA-base analogue before UV treatment and the induction of the light repair and recovery processes resulted in a rather high increase of viable mutations in chlorococcal algae. These findings may be useful in breeding chlorococcal algae, which have no possibility of hybridization other than somatic. (author)

  6. Spatio-temporal dynamics of a fish predator: Density-dependent and hydrographic effects on Baltic Sea cod population.

    Directory of Open Access Journals (Sweden)

    Valerio Bartolino

    Full Text Available Understanding the mechanisms of spatial population dynamics is crucial for the successful management of exploited species and ecosystems. However, the underlying mechanisms of spatial distribution are generally complex due to the concurrent forcing of both density-dependent species interactions and density-independent environmental factors. Despite the high economic value and central ecological importance of cod in the Baltic Sea, the drivers of its spatio-temporal population dynamics have not been analytically investigated so far. In this paper, we used an extensive trawl survey dataset in combination with environmental data to investigate the spatial dynamics of the distribution of the Eastern Baltic cod during the past three decades using Generalized Additive Models. The results showed that adult cod distribution was mainly affected by cod population size, and to a minor degree by small-scale hydrological factors and the extent of suitable reproductive areas. As population size decreases, the cod population concentrates to the southern part of the Baltic Sea, where the preferred more marine environment conditions are encountered. Using the fitted models, we predicted the Baltic cod distribution back to the 1970s and a temporal index of cod spatial occupation was developed. Our study will contribute to the management and conservation of this important resource and of the ecosystem where it occurs, by showing the forces shaping its spatial distribution and therefore the potential response of the population to future exploitation and environmental changes.

  7. Modeling spiking behavior of neurons with time-dependent Poisson processes.

    Science.gov (United States)

    Shinomoto, S; Tsubo, Y

    2001-10-01

    Three kinds of interval statistics, as represented by the coefficient of variation, the skewness coefficient, and the correlation coefficient of consecutive intervals, are evaluated for three kinds of time-dependent Poisson processes: pulse regulated, sinusoidally regulated, and doubly stochastic. Among these three processes, the sinusoidally regulated and doubly stochastic Poisson processes, in the case when the spike rate varies slowly compared with the mean interval between spikes, are found to be consistent with the three statistical coefficients exhibited by data recorded from neurons in the prefrontal cortex of monkeys.

  8. Pulse-train control of branching processes: Elimination of background and intruder state population

    International Nuclear Information System (INIS)

    Seidl, Markus; Uiberacker, Christoph; Jakubetz, Werner; Etinski, Mihajlo

    2008-01-01

    The authors introduce and describe pulse train control (PTC) of population branching in strongly coupled processes as a novel control tool for the separation of competing multiphoton processes. Control strategies are presented based on the different responses of processes with different photonicities and/or different frequency detunings to the pulse-to-pulse time delay and the pulse-to-pulse phase shift in pulse trains. The control efficiency is further enhanced by the property of pulse trains that complete population transfer can be obtained over an extended frequency range that replaces the resonance frequency of simple pulses. The possibility to freely tune the frequency assists the separation of the competing processes and reduces the number of subpulses required for full control. As a sample application, PTC of leaking multiphoton resonances is demonstrated by numerical simulations. In model systems exhibiting sizable background (intruder) state population if excited with single pulses, PTC leading to complete accumulation of population in the target state and elimination of background population is readily achieved. The analysis of the results reveals different mechanisms of control and provides clues on the mechanisms of the leaking process itself. In an alternative setup, pulse trains can be used as a phase-sensitive tool for level switching. By changing only the pulse-to-pulse phase shift of a train with otherwise unchanged parameters, population can be transferred to any of two different target states in a near-quantitative manner.

  9. Fast simulation of reconstructed phylogenies under global time-dependent birth-death processes.

    Science.gov (United States)

    Höhna, Sebastian

    2013-06-01

    Diversification rates and patterns may be inferred from reconstructed phylogenies. Both the time-dependent and the diversity-dependent birth-death process can produce the same observed patterns of diversity over time. To develop and test new models describing the macro-evolutionary process of diversification, generic and fast algorithms to simulate under these models are necessary. Simulations are not only important for testing and developing models but play an influential role in the assessment of model fit. In the present article, I consider as the model a global time-dependent birth-death process where each species has the same rates but rates may vary over time. For this model, I derive the likelihood of the speciation times from a reconstructed phylogenetic tree and show that each speciation event is independent and identically distributed. This fact can be used to simulate efficiently reconstructed phylogenetic trees when conditioning on the number of species, the time of the process or both. I show the usability of the simulation by approximating the posterior predictive distribution of a birth-death process with decreasing diversification rates applied on a published bird phylogeny (family Cettiidae). The methods described in this manuscript are implemented in the R package TESS, available from the repository CRAN (http://cran.r-project.org/web/packages/TESS/). Supplementary data are available at Bioinformatics online.

  10. A test of density-dependent pollination within three populations of endangered Pentachaeta lyonii

    Directory of Open Access Journals (Sweden)

    Jocelyn R. Holt

    2014-02-01

    Full Text Available A major concern with endangered plants is that they might attract insufficient numbers of pollinators, produce low numbers of seeds, and decline towards extinction. We examined effects of density as it varied within populations on the pollination of Pentachaeta lyonii, an endangered species that requires pollinators for seed set. Generalist bee-flies and bees were abundant pollinators at three sites for two years. Per-capita visitation rates did not decline at sparse points or for plants placed on the order of 10 m away from other flowering individuals. Seed production was not pollinator-limited within patches, but seed set was low beyond 10 m from neighbours. Considering prior findings, factors such as habitat loss, competition with alien plants, and poor establishment of new populations likely contribute to the rarity of P. lyonii more than pollination failure.

  11. Local environment and density-dependent feedbacks determine population growth in a forest herb

    DEFF Research Database (Denmark)

    Dahlgren, Johan Petter; Östergård, Hannah; Ehrlén, Johan

    2014-01-01

    Linking spatial variation in environmental factors to variation in demographic rates is essential for a mechanistic understanding of the dynamics of populations. However, we still know relatively little about such links, partly because feedbacks via intraspecific density make them difficult...... to observe in natural populations. We conducted a detailed field study and investigated simultaneous effects of environmental factors and the intraspecific density of individuals on the demography of the herb Lathyrus vernus. In regression models of vital rates we identified effects associated with spring...... shade on survival and growth, while density was negatively correlated with these vital rates. Density was also negatively correlated with average individual size in the study plots, which is consistent with self-thinning. In addition, average plant sizes were larger than predicted by density in plots...

  12. Gender Dependence in Mouth Opening Dimensions in Normal Adult Malaysians Population

    OpenAIRE

    Shaari, Ramizu; Hwa, Teoh Eng; Rahman, Shaifulizan Abdul

    2011-01-01

    While measurement of mouth opening is an important clinica examination in diagnosis and management of oral disease, data on non-Western populations are limited. This study was therefore conducted to determine the range of mouth opening in normal Malaysian male and female adults. A total of 34 dental students of Universiti Sains Malaysia (USM) were chosen randomly and their maximum mouth opening was measured after being asked to open their mouth sufficiently to accommodate three fingers. Measu...

  13. Rate-Independent Processes with Linear Growth Energies and Time-Dependent Boundary Conditions

    Czech Academy of Sciences Publication Activity Database

    Kružík, Martin; Zimmer, J.

    2012-01-01

    Roč. 5, č. 3 (2012), s. 591-604 ISSN 1937-1632 R&D Projects: GA AV ČR IAA100750802 Grant - others:GA ČR(CZ) GAP201/10/0357 Institutional research plan: CEZ:AV0Z10750506 Keywords : concentrations * oscillations * time - dependent boundary conditions * rate-independent evolution Subject RIV: BA - General Mathematics http://library.utia.cas.cz/separaty/2011/MTR/kruzik-rate-independent processes with linear growth energies and time - dependent boundary conditions.pdf

  14. Neural mechanisms of context-dependent processing of CO2 avoidance behavior in fruit flies.

    Science.gov (United States)

    Siju, K P; Bräcker, Lasse B; Grunwald Kadow, I C

    2014-01-01

    The fruit fly, Drosophila melanogaster, innately avoids even low levels of CO2. CO2 is part of the so-called Drosophila stress odor produced by stressed flies, but also a byproduct of fermenting fruit, a main food source, making the strong avoidance behavior somewhat surprising. Therefore, we addressed whether feeding states might influence the fly's behavior and processing of CO2. In a recent report, we showed that this innate behavior is differentially processed and modified according to the feeding state of the fly. Interestingly, we found that hungry flies require the function of the mushroom body, a higher brain center required for olfactory learning and memory, but thought to be dispensable for innate olfactory behaviors. In addition, we anatomically and functionally characterized a novel bilateral projection neuron connecting the CO2 sensory input to the mushroom body. This neuron was essential for processing of CO2 in the starved fly but not in the fed fly. In this Extra View article, we provide evidence for the potential involvement of the neuromodulator dopamine in state-dependent CO2 avoidance behavior. Taken together, our work demonstrates that CO2 avoidance behavior is mediated by alternative neural pathways in a context-dependent manner. Furthermore, it shows that the mushroom body is not only involved in processing of learned olfactory behavior, as previously suggested, but also in context-dependent innate olfaction.

  15. Efficiency of population-dependent sulfite against Brettanomyces bruxellensis in red wine.

    Science.gov (United States)

    Longin, Cédric; Degueurce, Claudine; Julliat, Frédérique; Guilloux-Benatier, Michèle; Rousseaux, Sandrine; Alexandre, Hervé

    2016-11-01

    Brettanomyces bruxellensis is considered as a spoilage yeast encountered mainly in red wine. It is able to reduce vinylphenols from phenolic acids to ethylphenols. These volatiles are responsible for the phenolic "Brett character" described as animal, farm, horse sweat and animal leather odors. Other molecules are responsible for organoleptic deviations described as "mousiness taint". SO 2 is the product most often used by winemakers to prevent B. bruxellensis growth. Usually, the recommended molecular dose of SO 2 (active SO 2 , mSO 2 ) is highly variable, from 0.3 to 0.8mg/L. But these doses do not take into account differences of strain resistance to sulfites or population levels. Moreover, SO 2 is known as a chemical stressor inducing a viable but nonculturable (VBNC) state of B. bruxellensis. These cells, which are non-detectable by plate counting, can lead to new contamination when the amount of sulfite decreases over time. Consequently, we first assessed the effect of SO 2 levels in red wine on two strains with phenotypically different sulfite resistances. Then, we studied the relationship between amounts of SO 2 (0, 0.5, 0.9 and 1.1mg/L active SO 2 ) and population levels (10 3 , 10 4 and 10 5 cells/mL) in red wine. Yeasts were enumerated by both plate counting and flow cytometry over time using viability dye. Our results showed different SO 2 resistances according to the strain used. A relationship between yeast population level and SO 2 resistance was demonstrated: the higher the yeast concentration, the lower the efficiency of SO 2 . Under certain conditions, the VBNC state of B. bruxellensis was highlighted in red wine. Yeasts in this VBNC state did not produce 4-EP. Moreover, cells became culturable again over time. All these results provide new information enabling better management of sulfite addition during wine aging. Copyright © 2016. Published by Elsevier Ltd.

  16. The impact of negative emotions on self-concept abstraction depends on accessible information processing styles.

    Science.gov (United States)

    Isbell, Linda M; Rovenpor, Daniel R; Lair, Elicia C

    2016-10-01

    Research suggests that anger promotes global, abstract processing whereas sadness and fear promote local, concrete processing (see Schwarz & Clore, 2007 for a review). Contrary to a large and influential body of work suggesting that specific affective experiences are tethered to specific cognitive outcomes, the affect-as-cognitive-feedback account maintains that affective experiences confer positive or negative value on currently dominant processing styles, and thus can lead to either global or local processing (Huntsinger, Isbell, & Clore, 2014). The current work extends this theoretical perspective by investigating the impact of discrete negative emotions on the self-concept. By experimentally manipulating information processing styles and discrete negative emotions that vary in appraisals of certainty, we demonstrate that the impact of discrete negative emotions on the spontaneous self-concept depends on accessible processing styles. When global processing was accessible, individuals in angry (negative, high certainty) states generated more abstract statements about themselves than individuals in either sad (Experiment 1) or fearful (Experiment 2; negative, low certainty) states. When local processing was made accessible, however, the opposite pattern emerged, whereby individuals in angry states generated fewer abstract statements than individuals in sad or fearful states. Together these studies provide new insights into the mechanisms through which discrete emotions influence cognition. In contrast to theories assuming a dedicated link between emotions and processing styles, these results suggest that discrete emotions provide feedback about accessible ways of thinking, and are consistent with recent evidence suggesting that the impact of affect on cognition is highly context-dependent. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  17. Polarization dependent dispersion and its impact on optical parametric process in high nonlinear microstructure fibre

    International Nuclear Information System (INIS)

    Xiao Li; Zhang Wei; Huang Yidong; Peng Jiangde

    2008-01-01

    High nonlinear microstructure fibre (HNMF) is preferred in nonlinear fibre optics, especially in the applications of optical parametric effects, due to its high optical nonlinear coefficient. However, polarization dependent dispersion will impact the nonlinear optical parametric process in HNMFs. In this paper, modulation instability (MI) method is used to measure the polarization dependent dispersion of a piece of commercial HNMF, including the group velocity dispersion, the dispersion slope, the fourth-order dispersion and group birefringence. It also experimentally demonstrates the impact of the polarization dependent dispersion on the continuous wave supercontinuum (SC) generation. On one axis MI sidebands with symmetric frequency detunings are generated, while on the other axis with larger MI frequency detuning, SC is generated by soliton self-frequency shift

  18. Going the distance: Memory and control processes in active dependency construction.

    Science.gov (United States)

    Wagers, Matthew W; Phillips, Colin

    2014-01-01

    Filler-gap dependencies make strong demands on working memory in language comprehension because they cannot always be immediately resolved. In a series of three reading-time studies, we test the idea that these demands can be decomposed into active maintenance processes and retrieval events. Results indicate that the fact that a displaced phrase exists and the identity of its basic syntactic category both immediately impact comprehension at potential gap sites. In contrast, specific lexical details of the displaced phrase show an immediate effect only for short dependencies and a much later effect for longer dependencies. We argue that coarse-grained information about the filler is actively maintained and is used to make phrase structure parsing decisions, whereas finer grained information is more quickly released from active maintenance and consequently has to be retrieved at the gap site.

  19. State-dependent sensorimotor processing: gaze and posture stability during simulated flight in birds.

    Science.gov (United States)

    McArthur, Kimberly L; Dickman, J David

    2011-04-01

    Vestibular responses play an important role in maintaining gaze and posture stability during rotational motion. Previous studies suggest that these responses are state dependent, their expression varying with the environmental and locomotor conditions of the animal. In this study, we simulated an ethologically relevant state in the laboratory to study state-dependent vestibular responses in birds. We used frontal airflow to simulate gliding flight and measured pigeons' eye, head, and tail responses to rotational motion in darkness, under both head-fixed and head-free conditions. We show that both eye and head response gains are significantly higher during flight, thus enhancing gaze and head-in-space stability. We also characterize state-specific tail responses to pitch and roll rotation that would help to maintain body-in-space orientation during flight. These results demonstrate that vestibular sensorimotor processing is not fixed but depends instead on the animal's behavioral state.

  20. The Merkel coefficient and its dependence on the temperature position of the cooling tower process

    International Nuclear Information System (INIS)

    Klenke, W.

    1977-01-01

    The Merkel coefficient, or evaporation coefficient, is still being used as a characteristic factor for the cooling tower process. Its dependence on the cooling range or on the warm water temperature of the process is often considered a disadvantage of the theory of evaporation cooling. This is also the reason for the suggestion to change the theory in such a way that the Merkel coefficient becomes independent of the temperature. The present investigation, however, leads to the result that the dependence of the Merkel coefficient on the temperature must be considered as a remarkable confirmation for the evidence of the theory of heat and mass transfer, as the experimental statements agree fully with the results of the theoretical considerations. (orig.) [de

  1. The detrimental effects of emotional process dysregulation on decision making in substance dependence

    Directory of Open Access Journals (Sweden)

    Anna eMurphy

    2012-11-01

    Full Text Available Substance dependence is complex and multifactorial, with many distinct pathways involved in both the development and subsequent maintenance of addictive behaviours. Various cognitive mechanisms have been implicated, including impulsivity, compulsivity and impaired decision-making. These mechanisms are modulated by emotional processes, resulting in increased likelihood of initial drug use, sustained substance dependence, and increased relapse during periods of abstinence. Emotional traits, such as sensation seeking, are risk factors for substance use, and chronic drug use can result in further emotional dysregulation via effects on reward, motivation and stress systems. We will explore theories of hyper and hypo sensitivity of the brain reward systems that may underpin motivational abnormalities and anhedonia. Disturbances in these systems contribute to the biasing of emotional processing toward cues related to drug use at the expense of natural rewards, which serves to maintain addictive behaviour, via enhanced drug craving. We will additionally focus on the sensitization of the brain stress systems that result in negative affect states that continue into protracted abstinence that is may lead to compulsive drug taking. We will explore how these emotional dysregulations impact upon decision-making controlled by goal-directed and habitual action selections systems, and, in combination with a failure of prefrontal inhibitory control, mediate maladaptive decision-making observed in substance dependent individuals such that they continue drug use in spite of negative consequences. An understanding of the emotional impacts on cognition in substance dependent individuals may guide the development of more effective therapeutic interventions.

  2. The detrimental effects of emotional process dysregulation on decision-making in substance dependence

    Science.gov (United States)

    Murphy, Anna; Taylor, Eleanor; Elliott, Rebecca

    2012-01-01

    Substance dependence is complex and multifactorial, with many distinct pathways involved in both the development and subsequent maintenance of addictive behaviors. Various cognitive mechanisms have been implicated, including impulsivity, compulsivity, and impaired decision-making. These mechanisms are modulated by emotional processes, resulting in increased likelihood of initial drug use, sustained substance dependence, and increased relapse during periods of abstinence. Emotional traits, such as sensation-seeking, are risk factors for substance use, and chronic drug use can result in further emotional dysregulation via effects on reward, motivation, and stress systems. We will explore theories of hyper and hypo sensitivity of the brain reward systems that may underpin motivational abnormalities and anhedonia. Disturbances in these systems contribute to the biasing of emotional processing toward cues related to drug use at the expense of natural rewards, which serves to maintain addictive behavior, via enhanced drug craving. We will additionally focus on the sensitization of the brain stress systems that result in negative affect states that continue into protracted abstinence that is may lead to compulsive drug-taking. We will explore how these emotional dysregulations impact upon decision-making controlled by goal-directed and habitual action selections systems, and, in combination with a failure of prefrontal inhibitory control, mediate maladaptive decision-making observed in substance dependent individuals such that they continue drug use in spite of negative consequences. An understanding of the emotional impacts on cognition in substance dependent individuals may guide the development of more effective therapeutic interventions. PMID:23162443

  3. [Geographic Altitude of Residence and Alcohol Dependence in a Peruvian Population].

    Science.gov (United States)

    Quiñones-Laveriano, Dante Manuel; Espinoza-Chiong, César; Scarsi-Mejia, Ottavia; Rojas-Camayo, José; Mejia, Christian Richard

    2016-01-01

    The aim of this study was to determine the association between alcohol dependence and altitude of residence in 11 villages in two high altitude areas of Peru. An analytical cross-sectional study was performed using a survey conducted by physicians in primary health care in 11 villages until 2013, that were divided into low altitude (≤2500m asl (above sea level)), and high altitude (>2500m asl) areas. The CAGE test for alcoholism (cut point, ≥2) was applied to those who responded positively when asked if they consumed alcohol. Statistical associations were obtained with generalised linear models Of the 737 participants, 51% were women and the median age was 36 years [interquartile range, 25-50], 334 (45%) lived at low altitude, and 113 (15%) had alcohol dependence. The highest frequency of alcoholism was positively associated with being a village considered extremely poor (Likelihood Ratio (LP)=2.42; 95%CI, 1.40-4.19), while being female (LP=0.44; 95%CI, 0.23-0.89) and residing at high altitude (LP=0.15; 95%CI, 0.07-0.31) were negatively associated. These were adjusted for nine socio-occupational and pathological variables. According to these data, there is a higher frequency of alcohol dependence in being, male, extremely poor, and residing at low altitude. These results should be taken into account by professionals who work in primary care and those involved in mental health care, because of their implications in society. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  4. Low Variance Couplings for Stochastic Models of Intracellular Processes with Time-Dependent Rate Functions.

    Science.gov (United States)

    Anderson, David F; Yuan, Chaojie

    2018-04-18

    A number of coupling strategies are presented for stochastically modeled biochemical processes with time-dependent parameters. In particular, the stacked coupling is introduced and is shown via a number of examples to provide an exceptionally low variance between the generated paths. This coupling will be useful in the numerical computation of parametric sensitivities and the fast estimation of expectations via multilevel Monte Carlo methods. We provide the requisite estimators in both cases.

  5. An analytical method for determining the temperature dependent moisture diffusivities of pumpkin seeds during drying process

    Energy Technology Data Exchange (ETDEWEB)

    Can, Ahmet [Department of Mechanical Engineering, University of Trakya, 22030 Edirne (Turkey)

    2007-02-15

    This paper presents an analytical method, which determines the moisture diffusion coefficients for the natural and forced convection hot air drying of pumpkin seeds and their temperature dependence. In order to obtain scientific data, the pumpkin seed drying process was investigated under both natural and forced hot air convection regimes. This paper presents the experimental results in which the drying air was heated by solar energy. (author)

  6. Regression Analysis for Multivariate Dependent Count Data Using Convolved Gaussian Processes

    OpenAIRE

    Sofro, A'yunin; Shi, Jian Qing; Cao, Chunzheng

    2017-01-01

    Research on Poisson regression analysis for dependent data has been developed rapidly in the last decade. One of difficult problems in a multivariate case is how to construct a cross-correlation structure and at the meantime make sure that the covariance matrix is positive definite. To address the issue, we propose to use convolved Gaussian process (CGP) in this paper. The approach provides a semi-parametric model and offers a natural framework for modeling common mean structure and covarianc...

  7. Ergodicity breaking, ageing, and confinement in generalized diffusion processes with position and time dependent diffusivity

    International Nuclear Information System (INIS)

    Cherstvy, Andrey G; Metzler, Ralf

    2015-01-01

    We study generalized anomalous diffusion processes whose diffusion coefficient D(x, t) ∼ D 0 |x| α t β depends on both the position x of the test particle and the process time t. This process thus combines the features of scaled Brownian motion and heterogeneous diffusion parent processes. We compute the ensemble and time averaged mean squared displacements of this generalized diffusion process. The scaling exponent of the ensemble averaged mean squared displacement is shown to be the product of the critical exponents of the parent processes, and describes both subdiffusive and superdiffusive systems. We quantify the amplitude fluctuations of the time averaged mean squared displacement as function of the length of the time series and the lag time. In particular, we observe a weak ergodicity breaking of this generalized diffusion process: even in the long time limit the ensemble and time averaged mean squared displacements are strictly disparate. When we start to observe this process some time after its initiation we observe distinct features of ageing. We derive a universal ageing factor for the time averaged mean squared displacement containing all information on the ageing time and the measurement time. External confinement is shown to alter the magnitudes and statistics of the ensemble and time averaged mean squared displacements. (paper)

  8. The right inferior frontal gyrus processes nested non-local dependencies in music.

    Science.gov (United States)

    Cheung, Vincent K M; Meyer, Lars; Friederici, Angela D; Koelsch, Stefan

    2018-02-28

    Complex auditory sequences known as music have often been described as hierarchically structured. This permits the existence of non-local dependencies, which relate elements of a sequence beyond their temporal sequential order. Previous studies in music have reported differential activity in the inferior frontal gyrus (IFG) when comparing regular and irregular chord-transitions based on theories in Western tonal harmony. However, it is unclear if the observed activity reflects the interpretation of hierarchical structure as the effects are confounded by local irregularity. Using functional magnetic resonance imaging (fMRI), we found that violations to non-local dependencies in nested sequences of three-tone musical motifs in musicians elicited increased activity in the right IFG. This is in contrast to similar studies in language which typically report the left IFG in processing grammatical syntax. Effects of increasing auditory working demands are moreover reflected by distributed activity in frontal and parietal regions. Our study therefore demonstrates the role of the right IFG in processing non-local dependencies in music, and suggests that hierarchical processing in different cognitive domains relies on similar mechanisms that are subserved by domain-selective neuronal subpopulations.

  9. Simulation of spatially dependent excitation rates and power deposition in RF discharges for plasma processing

    International Nuclear Information System (INIS)

    Kushner, M.J.; Anderson, H.M.; Hargis, P.J.

    1985-01-01

    In low pressure, radio frequency (RF) discharges of the type used in plasma processing of semiconductor materials, the rate of electron impact excitation and energy transfer processes depends upon both the phase of the RF excitation and position in the discharge. Electron impact collisions create radicals that diffuse or drift to the surfaces of interest where they are adsorbed or otherwise react. To the extent that these radicals have a finite lifetime, their transport time from point of creation to surface of interest is an important parameter. The spatial dependence of the rate of the initial electron impact collisions is therefore also an important parameter. The power that sustains the discharge is coupled into the system by two mechanisms: a high energy e-beam component of the electron distribution resulting from electrons falling through or being accelerated by the sheaths, and by joule heating in the body of the plasma. In this paper, the authors discuss the spatial dependence of excitation rates and the method of power deposition iin RF discharges of the type used for plasma processing

  10. Abnormal thiamine-dependent processes in Alzheimer's Disease. Lessons from diabetes.

    Science.gov (United States)

    Gibson, Gary E; Hirsch, Joseph A; Cirio, Rosanna T; Jordan, Barry D; Fonzetti, Pasquale; Elder, Jessica

    2013-07-01

    Reduced glucose metabolism is an invariant feature of Alzheimer's Disease (AD) and an outstanding biomarker of disease progression. Glucose metabolism may be an attractive therapeutic target, whether the decline initiates AD pathophysiology or is a critical component of a cascade. The cause of cerebral regional glucose hypometabolism remains unclear. Thiamine-dependent processes are critical in glucose metabolism and are diminished in brains of AD patients at autopsy. Further, the reductions in thiamine-dependent processes are highly correlated to the decline in clinical dementia rating scales. In animal models, thiamine deficiency exacerbates plaque formation, promotes phosphorylation of tau and impairs memory. In contrast, treatment of mouse models of AD with the thiamine derivative benfotiamine diminishes plaques, decreases phosphorylation of tau and reverses memory deficits. Diabetes predisposes to AD, which suggests they may share some common mechanisms. Benfotiamine diminishes peripheral neuropathy in diabetic humans and animals. In diabetes, benfotiamine induces key thiamine-dependent enzymes of the pentose shunt to reduce accumulation of toxic metabolites including advanced glycation end products (AGE). Related mechanisms may lead to reversal of plaque formation by benfotiamine in animals. If so, the use of benfotiamine could provide a safe intervention to reverse biological and clinical processes of AD progression. This article is part of a Special Issue entitled 'Mitochondrial function and dysfunction in neurodegeneration'. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Abnormal Thiamine-Dependent Processes in Alzheimer’s Disease. Lessons from Diabetes

    Science.gov (United States)

    Gibson, Gary E.; Hirsch, Joseph A.; Cirio, Rosanna T.; Jordan, Barry D.; Fonzetti, Pasquale; Elder, Jessica

    2013-01-01

    Reduced glucose metabolism is an invariant feature of Alzheimer’s Disease (AD) and an outstanding biomarker of disease progression. Glucose metabolism may be an attractive therapeutic target, whether the decline initiates AD pathophysiology or is a critical component of a cascade. The cause of cerebral regional glucose hypometabolism remains unclear. Thiamine-dependent processes are critical in glucose metabolism and are diminished in brains of AD patients at autopsy. Further, the reductions in thiamine-dependent processes are highly correlated to the decline in clinical dementia rating scales. In animal models, thiamine deficiency exacerbates plaque formation, promotes phosphorylation of tau and impairs memory. In contrast, treatment of mouse models of AD with the thiamine derivative benfotiamine diminishes plaques, decreases phosphorylation of tau and reverses memory deficits. Diabetes predisposes to AD, which suggests they may share some common mechanisms. Benfotiamine diminishes peripheral neuropathy in diabetic humans and animals. In diabetes, benfotiamine induces key thiamine-dependent enzymes of the pentose shunt to reduce accumulation of toxic metabolites including advanced glycation end products (AGE). Related mechanisms may lead to reversal of plaque formation by benfotiamine in animals. If so, the use of benfotiamine could provide a safe intervention to reverse biological and clinical processes of AD progression. PMID:22982063

  12. Density dependence, density independence, and recruitment in the American shad (Alosa sapidissima) population of the Connecticut River

    International Nuclear Information System (INIS)

    Leggett, W.C.

    1977-01-01

    The role of density-dependent and density-independent factors in the regulation of the stock-recruitment relationship of the American shad (Alosa sapidissima) population of the Connecticut River was investigated. Significant reductions in egg-to-adult survival and juvenile growth rates occurred in the Holyoke--Turners Falls region in response to increases in the intensity of spawning in this area. For the Connecticut River population as a whole, egg-to-adult survival was estimated to be 0.00056 percent at replacement levels, and 0.00083 percent at the point of maximum population growth. Density-independent factors result in significant annual deviations from recruitment levels predicted by the density-dependent model. Temperature and flow regimes during spawning and early larval development are involved, but they explain only a small portion (less than 16 percent) of the total variation. In spite of an extensive data base, the accuracy of predictions concerning the potential effects of additional mortality to pre-recruit stages is low. The implications of these findings for environmental impact assessment are discussed

  13. Synchronized mammalian cell culture: part II--population ensemble modeling and analysis for development of reproducible processes.

    Science.gov (United States)

    Jandt, Uwe; Barradas, Oscar Platas; Pörtner, Ralf; Zeng, An-Ping

    2015-01-01

    The consideration of inherent population inhomogeneities of mammalian cell cultures becomes increasingly important for systems biology study and for developing more stable and efficient processes. However, variations of cellular properties belonging to different sub-populations and their potential effects on cellular physiology and kinetics of culture productivity under bioproduction conditions have not yet been much in the focus of research. Culture heterogeneity is strongly determined by the advance of the cell cycle. The assignment of cell-cycle specific cellular variations to large-scale process conditions can be optimally determined based on the combination of (partially) synchronized cultivation under otherwise physiological conditions and subsequent population-resolved model adaptation. The first step has been achieved using the physical selection method of countercurrent flow centrifugal elutriation, recently established in our group for different mammalian cell lines which is presented in Part I of this paper series. In this second part, we demonstrate the successful adaptation and application of a cell-cycle dependent population balance ensemble model to describe and understand synchronized bioreactor cultivations performed with two model mammalian cell lines, AGE1.HNAAT and CHO-K1. Numerical adaptation of the model to experimental data allows for detection of phase-specific parameters and for determination of significant variations between different phases and different cell lines. It shows that special care must be taken with regard to the sampling frequency in such oscillation cultures to minimize phase shift (jitter) artifacts. Based on predictions of long-term oscillation behavior of a culture depending on its start conditions, optimal elutriation setup trade-offs between high cell yields and high synchronization efficiency are proposed. © 2014 American Institute of Chemical Engineers.

  14. Basal serum pancreatic polypeptide is dependent on age and gender in an adult population

    DEFF Research Database (Denmark)

    Brimnes Damholt, M; Rasmussen, B K; Hilsted, L

    1997-01-01

    This study is the first epidemiologically based study of basal levels of serum pancreatic polypeptide (s-PP). The basal level of serum PP has become a field of interest mainly due to the role of PP as an endocrine tumour marker, and as a marker of pancreatic neuroendocrine function after pancreas...... a monospecific radioimmunoassay. Fasting serum pancreatic polypeptide depended on age and gender. The results demonstrated that fasting pancreatic polypeptide levels increase exponentially with age. Fitted separately for each sex, basal serum pancreatic polypeptide was found to increase by approximately 3% per...... reports on the fasting levels of serum pancreatic polypeptide are most likely due to lack of adjustment for age and gender. Thus, variation due to age and gender should be considered in evaluating fasting levels of serum pancreatic polypeptide. Whether similar considerations are important when evaluating...

  15. Reward dependence is related to norepinephrine transporter T-182C gene polymorphism in a Korean population.

    Science.gov (United States)

    Ham, Byung-Joo; Choi, Myoung-Jin; Lee, Heon-Jeong; Kang, Rhee-Hun; Lee, Min-Soo

    2005-06-01

    It is well established that approximately 50% of the variance in personality traits is genetic. The goal of this study was to investigate a relationship between personality traits and the T-182C polymorphism in the norepinephrine transporter gene. The participants included 115 healthy adults with no history of psychiatric disorders and other physical illness during the past 6 months. All participants were tested with the Temperament and Character Inventory and genotyped norepinephrine transporter gene polymorphism. Differences on the Temperament and Character Inventory dimensions among three groups were examined with one-way analysis of variance. Our study suggests that the norepinephrine transporter T-182C gene polymorphism is associated with reward dependence in Koreans, but the small number of study participants and their sex and age heterogeneity limits generalization of our results. Further studies are necessary with a larger number of homogeneous participants to confirm whether the norepinephrine transporter gene is related to personality traits.

  16. Dynamics of radioecological and genetic processes in populations of mammalian model species at contamination of ecosystems

    International Nuclear Information System (INIS)

    Ryabokon', N.I.; Goncharova, R.I.

    2008-01-01

    A short review of data on the time course of radiobiological and genetic processes in natural populations of mammalian model species inhabiting radiocontaminated ecosystems over many generations is presented here. The described time-courses of biological end-points in these populations do not reflect the time course of the whole-body dose rates, but do the outcome of multiple processes, including the direct response to individual irradiation, the transgeneration transmission and accumulation of induced damages and the development of adaptation. (authors)

  17. False recognition depends on depth of prior word processing: a magnetoencephalographic (MEG) study.

    Science.gov (United States)

    Walla, P; Hufnagl, B; Lindinger, G; Deecke, L; Imhof, H; Lang, W

    2001-04-01

    Brain activity was measured with a whole head magnetoencephalograph (MEG) during the test phases of word recognition experiments. Healthy young subjects had to discriminate between previously presented and new words. During prior study phases two different levels of word processing were provided according to two different kinds of instructions (shallow and deep encoding). Event-related fields (ERFs) associated with falsely recognized words (false alarms) were found to depend on the depth of processing during the prior study phase. False alarms elicited higher brain activity (as reflected by dipole strength) in case of prior deep encoding as compared to shallow encoding between 300 and 500 ms after stimulus onset at temporal brain areas. Between 500 and 700 ms we found evidence for differences in the involvement of neural structures related to both conditions of false alarms. Furthermore, the number of false alarms was found to depend on depth of processing. Shallow encoding led to a higher number of false alarms than deep encoding. All data are discussed as strong support for the ideas that a certain level of word processing is performed by a distinct set of neural systems and that the same neural systems which encode information are reactivated during the retrieval.

  18. Association of hypertension and non-insulin-dependent diabetes mellitusin the Saudi population

    International Nuclear Information System (INIS)

    El-Hazmi, Mohsen A.F.; Warsy, Arjumand S.

    2001-01-01

    Saudi Arabia has a high prevalence of diabetes mellitus (DM). Severalstudies have shown that hypertension (HT) occurs frequently in obeseindividuals. This study was conducted to determine the prevalence of HT inSaudi diabetes patients. A total of 13,519 nondiabetic and 1286 diabeticadult subjects diagnosed during the National Program for the Study of DM, inwhich household screening was carried out, were included in the study. Thediagnosis of DM and HT was based on the criteria of World HealthOrganization. From the total group, the prevalence of HT in nondiabetic malesand females was 4.48% and 2.8%, respectively, while it was 11.44% and 15.98%in the diabetic males and females, respectively. The subjects were classifiedaccording to the province to which they belonged, and the prevalence of HTwas calculated in the diabetic and nondiabetic group. In the Central, Easternand Western Provinces, female diabetics had a significantly higher HTprevalence compared to male diabetics, however, the Southern and NorthernProvinces, the prevalence rate was almost the same. In all provinces, theincrease in the prevalence of HT in diabetics was significantly higher in thefemales compared to the males. Since HT prevalence increase significantly indiabetics, and this association leads to several cardiovascularcomplications, it is necessary to adopt measures for the control of DM and HTin the Saudi population. (author)

  19. The risk mortality of the population of azerbaijan from circulatory diseases, depending on the season

    Directory of Open Access Journals (Sweden)

    A. J. Rzayeva

    2015-06-01

    Azerbaijan State Advanced Training Institute for doctors named after A. Aliyev, Baku   ABSTRACT The Objective.  To obtain evidence-based data about the role of seasons of the year in the formation of the population mortality risk from the circulatory system diseases  (CSD in Azerbaijan and its regions with specific climate. Materials of the study. A case of mortality was a unit of statistical observation. The fatalities from all reasons, including CSD have been distributed by the days of every month in the year. Daily average amount of fatalities by months and seasons ( from 20 December to 19 March – winter; from 20 March to 19 June- spring; from 20 June to 16 September; from 20 September to 19 December - autumn have been determined. Results.  In Azerbaijan the risk of general mortality and mortality from CSD is the highest in winter, it decreases in spring but nonuniformly (the general mortality rate is less than that from CSD. That is why the share of CSD increases among mortality reasons. Conclusions. Seasonal change of mortality risks from CSD is multivariant. Winter-spring increase of risk predominates in Azerbaijan. In some regions of Azerbaijan the mortality risk from CSD increases only once either in spring or in summer or winter. Key words: seasonal dynamics, risk of mortality, circulatory system diseases.

  20. Energetic Constraints on H-2-Dependent Terminal Electron Accepting Processes in Anoxic Environments

    DEFF Research Database (Denmark)

    Heimann, Axel Colin; Jakobsen, Rasmus; Blodau, C.

    2010-01-01

    and sulfate reduction are under direct thermodynamic control in soils and sediments and generally approach theoretical minimum energy thresholds. If H-2 concentrations are lowered by thermodynamically more potent TEAPs, these processes are inhibited. This principle is also valid for TEAPS providing more free......Microbially mediated terminal electron accepting processes (TEAPs) to a large extent control the fate of redox reactive elements and associated reactions in anoxic soils, sediments, and aquifers. This review focuses on thermodynamic controls and regulation of H-2-dependent TEAPs, case studies...... illustrating this concept and the quantitative description of thermodynamic controls in modeling. Other electron transfer processes are considered where appropriate. The work reviewed shows that thermodynamics and microbial kinetics are connected near thermodynamic equilibrium. Free energy thresholds...

  1. Point process analyses of variations in smoking rate by setting, mood, gender, and dependence

    Science.gov (United States)

    Shiffman, Saul; Rathbun, Stephen L.

    2010-01-01

    The immediate emotional and situational antecedents of ad libitum smoking are still not well understood. We re-analyzed data from Ecological Momentary Assessment using novel point-process analyses, to assess how craving, mood, and social setting influence smoking rate, as well as assessing the moderating effects of gender and nicotine dependence. 304 smokers recorded craving, mood, and social setting using electronic diaries when smoking and at random nonsmoking times over 16 days of smoking. Point-process analysis, which makes use of the known random sampling scheme for momentary variables, examined main effects of setting and interactions with gender and dependence. Increased craving was associated with higher rates of smoking, particularly among women. Negative affect was not associated with smoking rate, even in interaction with arousal, but restlessness was associated with substantially higher smoking rates. Women's smoking tended to be less affected by negative affect. Nicotine dependence had little moderating effect on situational influences. Smoking rates were higher when smokers were alone or with others smoking, and smoking restrictions reduced smoking rates. However, the presence of others smoking undermined the effects of restrictions. The more sensitive point-process analyses confirmed earlier findings, including the surprising conclusion that negative affect by itself was not related to smoking rates. Contrary to hypothesis, men's and not women's smoking was influenced by negative affect. Both smoking restrictions and the presence of others who are not smoking suppress smoking, but others’ smoking undermines the effects of restrictions. Point-process analyses of EMA data can bring out even small influences on smoking rate. PMID:21480683

  2. Single-cell and population NF-κB dynamic responses depend on lipopolysaccharide preparation.

    Directory of Open Access Journals (Sweden)

    Miriam V Gutschow

    Full Text Available Lipopolysaccharide (LPS, found in the outer membrane of gram-negative bacteria, elicits a strong response from the transcription factor family Nuclear factor (NF-κB via Toll-like receptor (TLR 4. The cellular response to lipopolysaccharide varies depending on the source and preparation of the ligand, however. Our goal was to compare single-cell NF-κB dynamics across multiple sources and concentrations of LPS.Using live-cell fluorescence microscopy, we determined the NF-κB activation dynamics of hundreds of single cells expressing a p65-dsRed fusion protein. We used computational image analysis to measure the nuclear localization of the fusion protein in the cells over time. The concentration range spanned up to nine orders of magnitude for three E. coli LPS preparations. We find that the LPS preparations induce markedly different responses, even accounting for potency differences. We also find that the ability of soluble TNF receptor to affect NF-κB dynamics varies strikingly across the three preparations.Our work strongly suggests that the cellular response to LPS is highly sensitive to the source and preparation of the ligand. We therefore caution that conclusions drawn from experiments using one preparation may not be applicable to LPS in general.

  3. Relationship between emotional processing, drinking severity and relapse in adults treated for alcohol dependence in Poland.

    Science.gov (United States)

    Kopera, Maciej; Jakubczyk, Andrzej; Suszek, Hubert; Glass, Jennifer M; Klimkiewicz, Anna; Wnorowska, Anna; Brower, Kirk J; Wojnar, Marcin

    2015-03-01

    Growing data reveals deficits in perception, understanding and regulation of emotions in alcohol dependence (AD). The study objective was to explore the relationships between emotional processing, drinking history and relapse in a clinical sample of alcohol-dependent patients. A group of 80 inpatients entering an alcohol treatment program in Warsaw, Poland was recruited and assessed at baseline and follow-up after 12 months. Baseline information about demographics, psychopathological symptoms, personality and severity of alcohol problems was obtained. The Schutte Self-Report Emotional Intelligence (EI) Test and Toronto Alexithymia Scale (TAS) were utilized for emotional processing assessment. Follow-up information contained data on drinking alcohol during the last month. At baseline assessment, the duration of alcohol drinking was associated with lower ability to utilize emotions. Patients reporting more difficulties with describing feelings drank more during their last episode of heavy drinking, and had a longer duration of intensive alcohol use. A longer duration of the last episode of heavy drinking was associated with more problems identifying and regulating emotions. Poor utilization of emotions and high severity of depressive symptoms contributed to higher rates of drinking at follow-up. These results underline the importance of systematic identification of discrete emotional problems and dynamics related to AD. This knowledge has implications for treatment. Psychotherapeutic interventions to improve emotional skills could be utilized in treatment of alcohol-dependent patients. © The Author 2014. Medical Council on Alcohol and Oxford University Press. All rights reserved.

  4. Relationship Between Emotional Processing, Drinking Severity and Relapse in Adults Treated for Alcohol Dependence in Poland

    Science.gov (United States)

    Kopera, Maciej; Jakubczyk, Andrzej; Suszek, Hubert; Glass, Jennifer M.; Klimkiewicz, Anna; Wnorowska, Anna; Brower, Kirk J.; Wojnar, Marcin

    2015-01-01

    Aims: Growing data reveals deficits in perception, understanding and regulation of emotions in alcohol dependence (AD). The study objective was to explore the relationships between emotional processing, drinking history and relapse in a clinical sample of alcohol-dependent patients. Methods: A group of 80 inpatients entering an alcohol treatment program in Warsaw, Poland was recruited and assessed at baseline and follow-up after 12 months. Baseline information about demographics, psychopathological symptoms, personality and severity of alcohol problems was obtained. The Schutte Self-Report Emotional Intelligence (EI) Test and Toronto Alexithymia Scale (TAS) were utilized for emotional processing assessment. Follow-up information contained data on drinking alcohol during the last month. Results: At baseline assessment, the duration of alcohol drinking was associated with lower ability to utilize emotions. Patients reporting more difficulties with describing feelings drank more during their last episode of heavy drinking, and had a longer duration of intensive alcohol use. A longer duration of the last episode of heavy drinking was associated with more problems identifying and regulating emotions. Poor utilization of emotions and high severity of depressive symptoms contributed to higher rates of drinking at follow-up. Conclusions: These results underline the importance of systematic identification of discrete emotional problems and dynamics related to AD. This knowledge has implications for treatment. Psychotherapeutic interventions to improve emotional skills could be utilized in treatment of alcohol-dependent patients. PMID:25543129

  5. Scale-Dependence of Processes Structuring Dung Beetle Metacommunities Using Functional Diversity and Community Deconstruction Approaches

    Science.gov (United States)

    da Silva, Pedro Giovâni; Hernández, Malva Isabel Medina

    2015-01-01

    Community structure is driven by mechanisms linked to environmental, spatial and temporal processes, which have been successfully addressed using metacommunity framework. The relative importance of processes shaping community structure can be identified using several different approaches. Two approaches that are increasingly being used are functional diversity and community deconstruction. Functional diversity is measured using various indices that incorporate distinct community attributes. Community deconstruction is a way to disentangle species responses to ecological processes by grouping species with similar traits. We used these two approaches to determine whether they are improvements over traditional measures (e.g., species composition, abundance, biomass) for identification of the main processes driving dung beetle (Scarabaeinae) community structure in a fragmented mainland-island landscape in southern Brazilian Atlantic Forest. We sampled five sites in each of four large forest areas, two on the mainland and two on the island. Sampling was performed in 2012 and 2013. We collected abundance and biomass data from 100 sampling points distributed over 20 sampling sites. We studied environmental, spatial and temporal effects on dung beetle community across three spatial scales, i.e., between sites, between areas and mainland-island. The γ-diversity based on species abundance was mainly attributed to β-diversity as a consequence of the increase in mean α- and β-diversity between areas. Variation partitioning on abundance, biomass and functional diversity showed scale-dependence of processes structuring dung beetle metacommunities. We identified two major groups of responses among 17 functional groups. In general, environmental filters were important at both local and regional scales. Spatial factors were important at the intermediate scale. Our study supports the notion of scale-dependence of environmental, spatial and temporal processes in the distribution

  6. Depth-dependent effects of culling-do mesophotic lionfish populations undermine current management?

    Science.gov (United States)

    Andradi-Brown, Dominic A; Grey, Rachel; Hendrix, Alicia; Hitchner, Drew; Hunt, Christina L; Gress, Erika; Madej, Konrad; Parry, Rachel L; Régnier-McKellar, Catriona; Jones, Owen P; Arteaga, María; Izaguirre, Andrea P; Rogers, Alex D; Exton, Dan A

    2017-05-01

    Invasive lionfish ( Pterois volitans and P. miles ) have spread widely across the western Atlantic and are recognized as a major threat to native marine biodiversity. Although lionfish inhabit both shallow reefs and mesophotic coral ecosystems (MCEs; reefs from 30 to 150 m depth), the primary management response implemented by many countries has been diver-led culling limited to reefs less than 30 m. However, many reef fish undergo ontogenetic migrations, with the largest and therefore most fecund individuals found at greatest depths. Here, we study lionfish density, body size, maturity and dietary patterns across the depth gradient from the surface down to 85 m on heavily culled reefs around Utila, Honduras. We found lionfish at increased densities, body size and weight on MCEs compared with shallow reefs, with MCEs also containing the greatest proportion of actively spawning females, while shallow reefs contained the greatest proportion of immature lionfish. We then compared lionfish behaviour in response to divers on shallow culled and mesophotic unculled Utilan reefs, and on shallow unculled reefs in Tela Bay, on the Honduran mainland. We found that mesophotic lionfish exhibited high alert distances, consistent with individuals previously exposed to culling despite being below the depth limits of removal. In addition, when examining stomach content, we found that fish were the major component of lionfish diets across the depth gradient. Importantly, our results suggest that despite adjacent shallow culling, MCEs retain substantial lionfish populations that may be disproportionately contributing towards continued lionfish recruitment onto the shallow reefs of Utila, potentially undermining current culling-based management.

  7. Depth-dependent effects of culling—do mesophotic lionfish populations undermine current management?

    Science.gov (United States)

    Grey, Rachel; Hendrix, Alicia; Hitchner, Drew; Gress, Erika; Madej, Konrad; Parry, Rachel L.; Régnier-McKellar, Catriona; Jones, Owen P.; Arteaga, María; Izaguirre, Andrea P.; Rogers, Alex D.; Exton, Dan A.

    2017-01-01

    Invasive lionfish (Pterois volitans and P. miles) have spread widely across the western Atlantic and are recognized as a major threat to native marine biodiversity. Although lionfish inhabit both shallow reefs and mesophotic coral ecosystems (MCEs; reefs from 30 to 150 m depth), the primary management response implemented by many countries has been diver-led culling limited to reefs less than 30 m. However, many reef fish undergo ontogenetic migrations, with the largest and therefore most fecund individuals found at greatest depths. Here, we study lionfish density, body size, maturity and dietary patterns across the depth gradient from the surface down to 85 m on heavily culled reefs around Utila, Honduras. We found lionfish at increased densities, body size and weight on MCEs compared with shallow reefs, with MCEs also containing the greatest proportion of actively spawning females, while shallow reefs contained the greatest proportion of immature lionfish. We then compared lionfish behaviour in response to divers on shallow culled and mesophotic unculled Utilan reefs, and on shallow unculled reefs in Tela Bay, on the Honduran mainland. We found that mesophotic lionfish exhibited high alert distances, consistent with individuals previously exposed to culling despite being below the depth limits of removal. In addition, when examining stomach content, we found that fish were the major component of lionfish diets across the depth gradient. Importantly, our results suggest that despite adjacent shallow culling, MCEs retain substantial lionfish populations that may be disproportionately contributing towards continued lionfish recruitment onto the shallow reefs of Utila, potentially undermining current culling-based management. PMID:28573007

  8. Advertising of ultra-processed foods and beverages: children as a vulnerable population

    OpenAIRE

    Mallarino,Christina; Gómez,Luis F; González-Zapata,Laura; Cadena,Yazmín; Parra,Diana C

    2013-01-01

    The rapid nutrition transition occurring in Latin America has resulted in a sharp increase of childhood overweight and obesity. Recent evidence has shown that food and beverage advertising has a great influence on children’s eating behavior. This population has become a key target market for the ultra-processed foods and beverages industry, which is marketing products in an aggressive way. Evidence shows that Latin American countries have poor regulation of ultra-processed foods and bev...

  9. Dynamics of genetic processes in chronically irradiated populations of small mammals

    International Nuclear Information System (INIS)

    Ryabokon', N.I.; Goncharova, R.I.; Smolich, I.I.; Kapitanova, N.P.; Nikitchenko, N.V.

    2000-01-01

    The distinctive features of dynamics of mutagenesis in mammalian populations under chronic low-intensive irradiation were first revealed. The main of them is gradual increase in mutability in somatic cells and embryonal lethality during series of irradiated generations of animals (bank vole - Clethrionomys glareolus). The data obtained strongly suggest that there are oppositely directed processes in natural populations after irradiation of more than 20 generations of animals: on the one hand, accumulation of mutations (genetic load of populations) and pre-mutation events which increase genome instability of germ and somatic cells in consecutive generations of animals, and on the other, formation of genetic radio adaptation through better functioning protection systems. In this period of micro evolution in chronically irradiated populations, the frequencies of genetic damages could be higher if the radiation adaptation doesn't form. (authors)

  10. The role of inelastic processes in the temperature dependence of hall induced resistance oscillations

    International Nuclear Information System (INIS)

    Kunold, Alejandro; Torres, Manuel

    2013-01-01

    We develop a model of magnetoresistance oscillations induced by the Hall field in order to study the temperature dependence observed in recent experiments in two dimensional electron systems. The model is based on the solution of the von Neumann equation incorporating the exact dynamics of two-dimensional damped electrons in the presence of arbitrarily strong magnetic and dc electric fields, while the effects of randomly distributed neutral and charged impurities are perturbatively added. Both the effects of elastic impurity scattering as well as those related to inelastic processes play an important role. The theoretical predictions correctly reproduce the experimentally observed oscillations amplitude, provided that the quantum inelastic scattering rate obeys a T 2 temperature dependence, consistent with electron–electron interaction effects

  11. Approximations of time-dependent phenomena in quantum mechanics: adiabatic versus sudden processes

    International Nuclear Information System (INIS)

    Melnichuk, S V; Dijk, W van; Nogami, Y

    2005-01-01

    By means of a one-dimensional model of a particle in an infinite square-well potential with one wall moving at a constant speed, we examine aspects of time-dependent phenomena in quantum mechanics such as adiabatic and sudden processes. The particle is assumed to be initially in the ground state of the potential with its initial width. The time dependence of the wavefunction of the particle in the well is generally more complicated when the potential well is compressed than when it is expanded. We are particularly interested in the case in which the potential well is suddenly compressed. The so-called sudden approximation is not applicable in this case. We also study the energy of the particle in the changing well as a function of time for expansion and contraction as well as for expansion followed by contraction and vice versa

  12. Fluctuations and pseudo long range dependence in network flows: A non-stationary Poisson process model

    International Nuclear Information System (INIS)

    Yu-Dong, Chen; Li, Li; Yi, Zhang; Jian-Ming, Hu

    2009-01-01

    In the study of complex networks (systems), the scaling phenomenon of flow fluctuations refers to a certain power-law between the mean flux (activity) (F i ) of the i-th node and its variance σ i as σ i α (F i ) α . Such scaling laws are found to be prevalent both in natural and man-made network systems, but the understanding of their origins still remains limited. This paper proposes a non-stationary Poisson process model to give an analytical explanation of the non-universal scaling phenomenon: the exponent α varies between 1/2 and 1 depending on the size of sampling time window and the relative strength of the external/internal driven forces of the systems. The crossover behaviour and the relation of fluctuation scaling with pseudo long range dependence are also accounted for by the model. Numerical experiments show that the proposed model can recover the multi-scaling phenomenon. (general)

  13. Characterization of relaxation processes in interacting vortex matter through a time-dependent correlation length

    International Nuclear Information System (INIS)

    Pleimling, Michel; Täuber, Uwe C

    2015-01-01

    Vortex lines in type-II superconductors display complicated relaxation processes due to the intricate competition between their mutual repulsive interactions and pinning to attractive point or extended defects. We perform extensive Monte Carlo simulations for an interacting elastic line model with either point-like or columnar pinning centers. From measurements of the space- and time-dependent height-height correlation function for lateral flux line fluctuations, we extract a characteristic correlation length that we use to investigate different non-equilibrium relaxation regimes. The specific time dependence of this correlation length for different disorder configurations displays characteristic features that provide a novel diagnostic tool to distinguish between point-like pinning centers and extended columnar defects. (paper)

  14. Scalable Bayesian nonparametric measures for exploring pairwise dependence via Dirichlet Process Mixtures.

    Science.gov (United States)

    Filippi, Sarah; Holmes, Chris C; Nieto-Barajas, Luis E

    2016-11-16

    In this article we propose novel Bayesian nonparametric methods using Dirichlet Process Mixture (DPM) models for detecting pairwise dependence between random variables while accounting for uncertainty in the form of the underlying distributions. A key criteria is that the procedures should scale to large data sets. In this regard we find that the formal calculation of the Bayes factor for a dependent-vs.-independent DPM joint probability measure is not feasible computationally. To address this we present Bayesian diagnostic measures for characterising evidence against a "null model" of pairwise independence. In simulation studies, as well as for a real data analysis, we show that our approach provides a useful tool for the exploratory nonparametric Bayesian analysis of large multivariate data sets.

  15. Teaching Population Balances for Chemical Engineering Students: Application to Granulation Processes

    Science.gov (United States)

    Bucala, Veronica; Pina, Juliana

    2007-01-01

    The population balance equation (PBE) is a useful tool to predict particle size distributions in granulation processes. When PBE is taught to advanced chemical engineering students, the internal coordinates (particle properties) are particularly hard to understand. In this paper, the flow of particles along different coordinates is carefully…

  16. Numerical investigation of the recruitment process in open marine population models

    International Nuclear Information System (INIS)

    Angulo, O; López-Marcos, J C; López-Marcos, M A; Martínez-Rodríguez, J

    2011-01-01

    The changes in the dynamics, produced by the recruitment process in an open marine population model, are investigated from a numerical point of view. The numerical method considered, based on the representation of the solution along the characteristic lines, approximates properly the steady states of the model, and is used to analyze the asymptotic behavior of the solutions of the model

  17. Radiation adaptation as one of the factors for microevolution processes in animals populations

    Directory of Open Access Journals (Sweden)

    V. A. Gaychenko

    2013-03-01

    Full Text Available Study of the main directions of response populations of individual species and faunistic complexes provides opportunity to address the relationship of adaptations of animals to radiation press by raising the level of epige-netic variability and features of a survival strategy. It is suggested to increase the level of microevolutionary processes in conditions of radioactive contamination biocenosis.

  18. Jump locations of jump-diffusion processes with state-dependent rates

    International Nuclear Information System (INIS)

    Miles, Christopher E; Keener, James P

    2017-01-01

    We propose a general framework for studying statistics of jump-diffusion systems driven by both Brownian noise (diffusion) and a jump process with state-dependent intensity. Of particular natural interest in many physical systems are the jump locations: the system evaluated at the jump times. As an example, this could be the voltage at which a neuron fires, or the so-called ‘threshold voltage’. However, the state-dependence of the jump rate provides direct coupling between the diffusion and jump components, making it difficult to disentangle the two to study individually. In this work, we provide an iterative map formulation of the sequence of distributions of jump locations. The distributions computed by this map can be used to elucidate other interesting quantities about the process, including statistics of the interjump times. Ultimately, the limit of the map reveals that knowledge of the stationary distribution of the full process is sufficient to recover (but not necessarily equal to) the distribution of jump locations. We propose two biophysical examples to illustrate the use of this framework to provide insight about a system. We find that a sharp threshold voltage emerges robustly in a simple stochastic integrate-and-fire neuronal model. The interplay between the two sources of noise is also investigated in a stepping model of molecular motor in intracellular transport pulling a diffusive cargo. (paper)

  19. Circadian Oscillations within the Hippocampus Support Hippocampus-dependent Memory Processing

    Directory of Open Access Journals (Sweden)

    Kristin Lynn Eckel-Mahan

    2012-04-01

    Full Text Available The ability to sustain memories over long periods of time, sometimes even a lifetime, is one of the most remarkable properties of the brain. Much knowledge has been gained over the past few decades regarding the molecular correlates of memory formation. Once a memory is forged, however, the molecular events that provide permanence are as of yet unclear. Studies in multiple organisms have revealed that circadian rhythmicity is important for the formation, stability, and recall of memories [1]. The neuronal events that provide this link need to be explored further. This article will discuss the findings related to the circadian regulation of memory-dependent processes in the hippocampus. Specifically, the circadian-controlled MAP kinase and cAMP signal transduction pathway plays critical roles in the consolidation of hippocampus-dependent memory. A series of studies have revealed the circadian oscillation of this pathway within the hippocampus, an activity that is absent in memory-deficient, transgenic mice lacking Ca2+-stimulated adenylyl cyclases. Interference with these oscillations proceeding the cellular memory consolidation period impairs the persistence of hippocampus-dependent memory. These data suggest that the persistence of long-term memories may depend upon reactivation of this signal transduction pathway in the hippocampus during the circadian cycle. New data reveals the dependence of hippocampal oscillation in MAPK activity on the SCN, again underscoring the importance of this region in maintaining the circadian physiology of memory. Finally, the downstream ramification of these oscillations in terms of gene expression and epigenetics should be considered, as emerging evidence is pointing strongly to a circadian link between epigenetics and long term synaptic plasticity.

  20. Flat Milling Process Simulation Taking into Consideration a Dependence of Dynamic Characteristics of the Machine

    Directory of Open Access Journals (Sweden)

    D. A. Zavarzin

    2016-01-01

    Full Text Available The milling process inherently is on/off, and therefore inevitably there is vibration excitation in the Machine/Fixture/Tool/Part (MFTP system, which results in a different quality of the treated surface, depending on the machining conditions. The objective is to identify effective operation conditions to cut a part on the 3-way easy class machines when there is no unwanted regenerative self-oscillation, leading to a significant deterioration in the quality of the surface machined. The paper describes vibrations arising during a milling process and their effect on the surface shape and the working tool. To solve this problem we apply a numerical simulation method of cutting dynamics, which consist of 4 modules. The main module is an algorithm of the geometric simulation. The second module is a phenomenological model of the cutting forces. Two remaining modules are responsible for dynamics simulation of the part machined and the cutting tool under time-varying cutting forces. The calculated values are transferred back to the geometric modelling algorithm at each step in time. Thus, the model is closed and allows us to take into account an effect of delay in a dynamic system. A finite element machine model to perform calculation in 3DCUT software has been a selected and compiled. The paper presents geometrical mapping of the machining process and natural frequencies and shapes found for the finite element model. Conducting multivariate calculations allowed us to analyse the dependences of a dynamic behaviour of the system on changing spindle speed. The multivariate modelling results are presented as the Poincare maps for a moving free end of the tool. These Poincare maps allow us to select the operation conditions domains coming both with forced vibration and with self-excited oscillations. On the Poincaré map for two operation conditions of different domains there are graphics of the cutting forces, a thickness of the cutting layer, tool

  1. Processing Incomplete Query Specifications in a Context-Dependent Reasoning Framework

    Directory of Open Access Journals (Sweden)

    Neli P. Zlatareva

    2013-04-01

    Full Text Available Search is the most prominent web service, which is about to change dramatically with the transition to the Semantic Web. Semantic Web applications are expected to deal with complex conjunctive queries, and not always such queries can be completely and precisely defined. Current Semantic Web reasoners built upon Description Logics have limited processing power in such environments. We discuss some of their limitations, and show how an alternative logical framework utilizing context-dependent rules can be extended to handle incomplete or imprecise query specifications.

  2. Salinity- and population-dependent genome regulatory response during osmotic acclimation in the killifish (Fundulus heteroclitus) gill.

    Science.gov (United States)

    Whitehead, Andrew; Roach, Jennifer L; Zhang, Shujun; Galvez, Fernando

    2012-04-15

    The killifish Fundulus heteroclitus is abundant in osmotically dynamic estuaries and it can quickly adjust to extremes in environmental salinity. We performed a comparative osmotic challenge experiment to track the transcriptomic and physiological responses to two salinities throughout a time course of acclimation, and to explore the genome regulatory mechanisms that enable extreme osmotic acclimation. One southern and one northern coastal population, known to differ in their tolerance to hypo-osmotic exposure, were used as our comparative model. Both populations could maintain osmotic homeostasis when transferred from 32 to 0.4 p.p.t., but diverged in their compensatory abilities when challenged down to 0.1 p.p.t., in parallel with divergent transformation of gill morphology. Genes involved in cell volume regulation, nucleosome maintenance, ion transport, energetics, mitochondrion function, transcriptional regulation and apoptosis showed population- and salinity-dependent patterns of expression during acclimation. Network analysis confirmed the role of cytokine and kinase signaling pathways in coordinating the genome regulatory response to osmotic challenge, and also posited the importance of signaling coordinated through the transcription factor HNF-4α. These genome responses support hypotheses of which regulatory mechanisms are particularly relevant for enabling extreme physiological flexibility.

  3. The waterfall paradox: How knickpoints disconnect hillslope and channel processes, isolating salmonid populations in ideal habitats

    Science.gov (United States)

    May, Christine; Roering, Joshua J.; Snow, Kyle; Griswold, Kitty; Gresswell, Robert E.

    2017-01-01

    Waterfalls create barriers to fish migration, yet hundreds of isolated salmonid populations exist above barriers and have persisted for thousands of years in steep mountainous terrain. Ecological theory indicates that small isolated populations in disturbance-prone landscapes are at greatest risk of extirpation because immigration and recolonization are not possible. On the contrary, many above-barrier populations are currently thriving while their downstream counterparts are dwindling. This quandary led us to explore geomorphic knickpoints as a mechanism for disconnecting hillslope and channel processes by limiting channel incision and decreasing the pace of base-level lowering. Using LiDAR from the Oregon Coast Range, we found gentler channel gradients, wider valleys, lower gradient hillslopes, and less shallow landslide potential in an above-barrier catchment compared to a neighboring catchment devoid of persistent knickpoints. Based on this unique geomorphic template, above-barrier channel networks are less prone to debris flows and other episodic sediment fluxes. These above-barrier catchments also have greater resiliency to flooding, owing to wider valleys with greater floodplain connectivity. Habitat preference models further indicate that salmonid habitat is present in greater quantity and quality in these above-barrier networks. Therefore the paradox of the persistence of small isolated fish populations may be facilitated by a geomorphic mechanism that both limits their connectivity to larger fish populations yet dampens the effect of disturbance by decreasing connections between hillslope and channel processes above geomorphic knickpoints.

  4. Generation and monitoring of discrete stable random processes using multiple immigration population models

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, J O; Hopcraft, K I; Jakeman, E [Applied Mathematics Division, School of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD (United Kingdom)

    2003-11-21

    Some properties of classical population processes that comprise births, deaths and multiple immigrations are investigated. The rates at which the immigrants arrive can be tailored to produce a population whose steady state fluctuations are described by a pre-selected distribution. Attention is focused on the class of distributions with a discrete stable law, which have power-law tails and whose moments and autocorrelation function do not exist. The separate problem of monitoring and characterizing the fluctuations is studied, analysing the statistics of individuals that leave the population. The fluctuations in the size of the population are transferred to the times between emigrants that form an intermittent time series of events. The emigrants are counted with a detector of finite dynamic range and response time. This is modelled through clipping the time series or saturating it at an arbitrary but finite level, whereupon its moments and correlation properties become finite. Distributions for the time to the first counted event and for the time between events exhibit power-law regimes that are characteristic of the fluctuations in population size. The processes provide analytical models with which properties of complex discrete random phenomena can be explored, and in addition provide generic means by which random time series encompassing a wide range of intermittent and other discrete random behaviour may be generated.

  5. Generation and monitoring of discrete stable random processes using multiple immigration population models

    International Nuclear Information System (INIS)

    Matthews, J O; Hopcraft, K I; Jakeman, E

    2003-01-01

    Some properties of classical population processes that comprise births, deaths and multiple immigrations are investigated. The rates at which the immigrants arrive can be tailored to produce a population whose steady state fluctuations are described by a pre-selected distribution. Attention is focused on the class of distributions with a discrete stable law, which have power-law tails and whose moments and autocorrelation function do not exist. The separate problem of monitoring and characterizing the fluctuations is studied, analysing the statistics of individuals that leave the population. The fluctuations in the size of the population are transferred to the times between emigrants that form an intermittent time series of events. The emigrants are counted with a detector of finite dynamic range and response time. This is modelled through clipping the time series or saturating it at an arbitrary but finite level, whereupon its moments and correlation properties become finite. Distributions for the time to the first counted event and for the time between events exhibit power-law regimes that are characteristic of the fluctuations in population size. The processes provide analytical models with which properties of complex discrete random phenomena can be explored, and in addition provide generic means by which random time series encompassing a wide range of intermittent and other discrete random behaviour may be generated

  6. Genetic effects at pleiotropic loci are context-dependent with consequences for the maintenance of genetic variation in populations.

    Directory of Open Access Journals (Sweden)

    Heather A Lawson

    2011-09-01

    Full Text Available Context-dependent genetic effects, including genotype-by-environment and genotype-by-sex interactions, are a potential mechanism by which genetic variation of complex traits is maintained in populations. Pleiotropic genetic effects are also thought to play an important role in evolution, reflecting functional and developmental relationships among traits. We examine context-dependent genetic effects at pleiotropic loci associated with normal variation in multiple metabolic syndrome (MetS components (obesity, dyslipidemia, and diabetes-related traits. MetS prevalence is increasing in Western societies and, while environmental in origin, presents substantial variation in individual response. We identify 23 pleiotropic MetS quantitative trait loci (QTL in an F(16 advanced intercross between the LG/J and SM/J inbred mouse strains (Wustl:LG,SM-G16; n = 1002. Half of each family was fed a high-fat diet and half fed a low-fat diet; and additive, dominance, and parent-of-origin imprinting genotypic effects were examined in animals partitioned into sex, diet, and sex-by-diet cohorts. We examine the context-dependency of the underlying additive, dominance, and imprinting genetic effects of the traits associated with these pleiotropic QTL. Further, we examine sequence polymorphisms (SNPs between LG/J and SM/J as well as differential expression of positional candidate genes in these regions. We show that genetic associations are different in different sex, diet, and sex-by-diet settings. We also show that over- or underdominance and ecological cross-over interactions for single phenotypes may not be common, however multidimensional synthetic phenotypes at loci with pleiotropic effects can produce situations that favor the maintenance of genetic variation in populations. Our findings have important implications for evolution and the notion of personalized medicine.

  7. Stage-dependent responses to emergent habitat heterogeneity: consequences for a predatory insect population in a coffee agroecosystem.

    Science.gov (United States)

    Liere, Heidi; Perfecto, Ivette; Vandermeer, John

    2014-08-01

    Interactions among members of biological communities can create spatial patterns that effectively generate habitat heterogeneity for other members in the community, and this heterogeneity might be crucial for their persistence. For example, stage-dependent vulnerability of a predatory lady beetle to aggression of the ant, Azteca instabilis, creates two habitat types that are utilized differently by the immature and adult life stages of the beetle. Due to a mutualistic association between A. instabilis and the hemipteran Coccus viridis - which is A. orbigera main prey in the area - only plants around ant nests have high C. viridis populations. Here, we report on a series of surveys at three different scales aimed at detecting how the presence and clustered distribution of ant nests affect the distribution of the different life stages of this predatory lady beetle in a coffee farm in Chiapas, Mexico. Both beetle adults and larvae were more abundant in areas with ant nests, but adults were restricted to the peripheries of highest ant activity and outside the reach of coffee bushes containing the highest densities of lady beetle larvae. The abundance of adult beetles located around trees with ants increased with the size of the ant nest clusters but the relationship is not significant for larvae. Thus, we suggest that A. orbigera undergoes an ontogenetic niche shift, not through shifting prey species, but through stage-specific vulnerability differences against a competitor that renders areas of abundant prey populations inaccessible for adults but not for larvae. Together with evidence presented elsewhere, this study shows how an important predator is not only dependent on the existence of two qualitatively distinct habitat types, but also on the spatial distribution of these habitats. We suggest that this dependency arises due to the different responses that the predator's life stages have to this emergent spatial pattern.

  8. Generalized Fractional Processes with Long Memory and Time Dependent Volatility Revisited

    Directory of Open Access Journals (Sweden)

    M. Shelton Peiris

    2016-09-01

    Full Text Available In recent years, fractionally-differenced processes have received a great deal of attention due to their flexibility in financial applications with long-memory. This paper revisits the class of generalized fractionally-differenced processes generated by Gegenbauer polynomials and the ARMA structure (GARMA with both the long-memory and time-dependent innovation variance. We establish the existence and uniqueness of second-order solutions. We also extend this family with innovations to follow GARCH and stochastic volatility (SV. Under certain regularity conditions, we give asymptotic results for the approximate maximum likelihood estimator for the GARMA-GARCH model. We discuss a Monte Carlo likelihood method for the GARMA-SV model and investigate finite sample properties via Monte Carlo experiments. Finally, we illustrate the usefulness of this approach using monthly inflation rates for France, Japan and the United States.

  9. Bending behavior of thermoplastic composite sheets viscoelasticity and temperature dependency in the draping process

    CERN Document Server

    Ropers, Steffen

    2017-01-01

    Within the scope of this work, Steffen Ropers evaluates the viscoelastic and temperature-dependent nature of the bending behavior of thermoplastic composite sheets in order to further enhance the predictability of the draping simulation. This simulation is a useful tool for the development of robust large scale processes for continuously fiber-reinforced polymers (CFRP). The bending behavior thereby largely influences the size and position of wrinkles, which are one of the most common processing defects for continuously fiber-reinforced parts. Thus, a better understanding of the bending behavior of thermoplastic composite sheets as well as an appropriate testing method along with corresponding material models contribute to a wide-spread application of CFRPs in large scale production. Contents Thermoplastic Prepregs Draping Simulation of Thermoplastic Prepregs Bending Characterization of Textile Composites Modeling of Bending Behavior Target Groups Researchers and students in the field of polymer, lightweight,...

  10. Manipulating surface wettability and oil absorbency of diatomite depending on processing and ambient conditions

    Science.gov (United States)

    Özen, İlhan; Şimşek, Süleyman; Okyay, Gamze

    2015-03-01

    In this study, a diatomite sample, which is a natural inorganic mineral with inherently high water and oil absorption capacity, was subjected to grinding before surface modification. Afterwards, the diatomite surface was modified via facile methods using a fluorocarbon (FC) chemical and stearic acid (SA) in addition to the sol-gel fluorosilanization (FS) process. The water and oil wettability, and oil absorbency properties of the unmodified and modified diatomites were investigated in addition to diatomite characterizations such as chemical content, surface area, particle size distribution, morphology, and modification efficiency. It was revealed that the wettability was changed completely depending on the surface modification agent and the media used, while the oil absorbency property surprisingly did not change. On the other hand, the oil absorbency was worsened by the grinding process, whereas the wettability was not affected.

  11. [Confirmative study of a French version of the Exercise Dependence Scale-revised with a French population].

    Science.gov (United States)

    Allegre, B; Therme, P

    2008-10-01

    Since the first writings on excessive exercise, there has been an increased interest in exercise dependence. One of the major consequences of this increased interest has been the development of several definitions and measures of exercise dependence. The work of Veale [Does primary exercise dependence really exist? In: Annet J, Cripps B, Steinberg H, editors. Exercise addiction: Motivation for participation in sport and exercise.Leicester, UK: Br Psychol Soc; 1995. p. 1-5.] provides an advance for the definition and measure of exercise dependence. These studies have adapted the DSM-IV criteria for substance dependence to measure exercise dependence. The Exercise Dependence Scale-Revised is based on these diagnostic criteria, which are: tolerance; withdrawal effects; intention effect; lack of control; time; reductions in other activities; continuance. Confirmatory factor analyses of EDS-R provided support to present a measurement model (21 items loaded in seven factors) of EDS-R (Comparative Fit Index=0.97; Root mean Square Error of Approximation=0.05; Tucker-Lewis Index=0.96). The aim of this study was to examine the psychometric properties of a French version of the EDS-R [Factorial validity and psychometric examination of the exercise dependence scale-revised. Meas Phys Educ Exerc Sci 2004;8(4):183-201.] to test the stability of the seven-factor model of the original version with a French population. A total of 516 half-marathoners ranged in age from 17 to 74 years old (Mean age=39.02 years, ET=10.64), with 402 men (77.9%) and 114 women (22.1%) participated in the study. The principal component analysis results in a six-factor structure, which accounts for 68.60% of the total variance. Because principal component analysis presents a six-factor structure differing from the original seven-factor structure, two models were tested, using confirmatory factor analysis. The first model is the seven-factor model of the original version of the EDS-R and the second is the

  12. Momentum-dependent excitation processes in crystalline and amorphous films of conjugated oligomers

    International Nuclear Information System (INIS)

    Zojer, E.; Knupfer, M.; Shuai, Z.; Fink, J.; Bredas, J.L.; Hoerhold, H.-H.; Grimme, J.; Scherf, U.; Benincori, T.; Leising, G.

    2000-01-01

    The electronic structure of periodic materials is usually described on the basis of band-structure models, in which each state is not only characterized by its energy but also by the corresponding electron momentum. In this paper we present investigations of momentum-dependent excitation processes in a number of molecular crystals and amorphous thin films. For our studies we have chosen ladder-type quinquephenyl (5LP), distyrylbenzene (3PV), a substituted quinquephenylenevinylene (5PV), and a bridged quarterthienyl (4TB). These substances are representative for several classes of conjugated organic materials. Their physical properties are dominated by the molecular building blocks. The investigated films, however, also allow us to study differences in the characteristics of crystalline (3PV and 4TB), partly amorphous (5LP) and fully amorphous (5PV) systems. Momentum-dependent excitations are induced by inelastic electron scattering in electron-energy-loss spectroscopy (EELS) experiments. The experimental data are compared to molecule based post-Hartree-Fock quantum-chemical simulations performed with the intermediate neglect of differential overlap (INDO) approach coupled to a configuration interaction (CI) technique applying the proper momentum-dependent transition matrix elements. Our results show that even in relatively small systems the molecular electronic states can be characterized by an associated range in momentum space. In addition, differences between inelastic electron scattering spectra for low values of momentum transfer and the optical data obtained for the crystalline samples underline the strong impact of light propagation on the absorption characteristics of highly anisotropic crystalline materials

  13. Context-dependent motor skill: perceptual processing in memory-based sequence production.

    Science.gov (United States)

    Ruitenberg, Marit F L; Abrahamse, Elger L; De Kleine, Elian; Verwey, Willem B

    2012-10-01

    Previous studies have shown that motor sequencing skill can benefit from the reinstatement of the learning context-even with respect to features that are formally not required for appropriate task performance. The present study explored whether such context-dependence develops when sequence execution is fully memory-based-and thus no longer assisted by stimulus-response translations. Specifically, we aimed to distinguish between preparation and execution processes. Participants performed two keying sequences in a go/no-go version of the discrete sequence production task in which the context consisted of the color in which the target keys of a particular sequence were displayed. In a subsequent test phase, these colors either were the same as during practice, were reversed for the two sequences or were novel. Results showed that, irrespective of the amount of practice, performance across all key presses in the reversed context condition was impaired relative to performance in the same and novel contexts. This suggests that the online preparation and/or execution of single key presses of the sequence is context-dependent. We propose that a cognitive processor is responsible both for these online processes and for advance sequence preparation and that combined findings from the current and previous studies build toward the notion that the cognitive processor is highly sensitive to changes in context across the various roles that it performs.

  14. Hemispheric lateralization for early auditory processing of lexical tones: dependence on pitch level and pitch contour.

    Science.gov (United States)

    Wang, Xiao-Dong; Wang, Ming; Chen, Lin

    2013-09-01

    In Mandarin Chinese, a tonal language, pitch level and pitch contour are two dimensions of lexical tones according to their acoustic features (i.e., pitch patterns). A change in pitch level features a step change whereas that in pitch contour features a continuous variation in voice pitch. Currently, relatively little is known about the hemispheric lateralization for the processing of each dimension. To address this issue, we made whole-head electrical recordings of mismatch negativity in native Chinese speakers in response to the contrast of Chinese lexical tones in each dimension. We found that pre-attentive auditory processing of pitch level was obviously lateralized to the right hemisphere whereas there is a tendency for that of pitch contour to be lateralized to the left. We also found that the brain responded faster to pitch level than to pitch contour at a pre-attentive stage. These results indicate that the hemispheric lateralization for early auditory processing of lexical tones depends on the pitch level and pitch contour, and suggest an underlying inter-hemispheric interactive mechanism for the processing. © 2013 Elsevier Ltd. All rights reserved.

  15. Gender effects in alcohol dependence: an fMRI pilot study examining affective processing.

    Science.gov (United States)

    Padula, Claudia B; Anthenelli, Robert M; Eliassen, James C; Nelson, Erik; Lisdahl, Krista M

    2015-02-01

    Alcohol dependence (AD) has global effects on brain structure and function, including frontolimbic regions regulating affective processing. Preliminary evidence suggests alcohol blunts limbic response to negative affective stimuli and increases activation to positive affective stimuli. Subtle gender differences are also evident during affective processing. Fourteen abstinent AD individuals (8 F, 6 M) and 14 healthy controls (9 F, 5 M), ages 23 to 60, were included in this facial affective processing functional magnetic resonance imaging pilot study. Whole-brain linear regression analyses were performed, and follow-up analyses examined whether AD status significantly predicted depressive symptoms and/or coping. Fearful Condition-The AD group demonstrated reduced activation in the right medial frontal gyrus, compared with controls. Gender moderated the effects of AD in bilateral inferior frontal gyri. Happy Condition-AD individuals had increased activation in the right thalamus. Gender moderated the effects of AD in the left caudate, right middle frontal gyrus, left paracentral lobule, and right lingual gyrus. Interactive AD and gender effects for fearful and happy faces were such that AD men activated more than control men, but AD women activated less than control women. Enhanced coping was associated with greater activation in right medial frontal gyrus during fearful condition in AD individuals. Abnormal affective processing in AD may be a marker of alcoholism risk or a consequence of chronic alcoholism. Subtle gender differences were observed, and gender moderated the effects of AD on neural substrates of affective processing. AD individuals with enhanced coping had brain activation patterns more similar to controls. Results help elucidate the effects of alcohol, gender, and their interaction on affective processing. Copyright © 2015 by the Research Society on Alcoholism.

  16. Decision Making Strategy and the Simultaneous Processing of Syntactic Dependencies in Language and Music.

    Science.gov (United States)

    Roncaglia-Denissen, M P; Bouwer, Fleur L; Honing, Henkjan

    2018-01-01

    Despite differences in their function and domain-specific elements, syntactic processing in music and language is believed to share cognitive resources. This study aims to investigate whether the simultaneous processing of language and music share the use of a common syntactic processor or more general attentional resources. To investigate this matter we tested musicians and non-musicians using visually presented sentences and aurally presented melodies containing syntactic local and long-distance dependencies. Accuracy rates and reaction times of participants' responses were collected. In both sentences and melodies, unexpected syntactic anomalies were introduced. This is the first study to address the processing of local and long-distance dependencies in language and music combined while reducing the effect of sensory memory. Participants were instructed to focus on language (language session), music (music session), or both (dual session). In the language session, musicians and non-musicians performed comparably in terms of accuracy rates and reaction times. As expected, groups' differences appeared in the music session, with musicians being more accurate in their responses than non-musicians and only the latter showing an interaction between the accuracy rates for music and language syntax. In the dual session musicians were overall more accurate than non-musicians. However, both groups showed comparable behavior, by displaying an interaction between the accuracy rates for language and music syntax responses. In our study, accuracy rates seem to better capture the interaction between language and music syntax; and this interaction seems to indicate the use of distinct, however, interacting mechanisms as part of decision making strategy. This interaction seems to be subject of an increase of attentional load and domain proficiency. Our study contributes to the long-lasting debate about the commonalities between language and music by providing evidence for their

  17. Decision Making Strategy and the Simultaneous Processing of Syntactic Dependencies in Language and Music

    Directory of Open Access Journals (Sweden)

    M. P. Roncaglia-Denissen

    2018-01-01

    Full Text Available Despite differences in their function and domain-specific elements, syntactic processing in music and language is believed to share cognitive resources. This study aims to investigate whether the simultaneous processing of language and music share the use of a common syntactic processor or more general attentional resources. To investigate this matter we tested musicians and non-musicians using visually presented sentences and aurally presented melodies containing syntactic local and long-distance dependencies. Accuracy rates and reaction times of participants’ responses were collected. In both sentences and melodies, unexpected syntactic anomalies were introduced. This is the first study to address the processing of local and long-distance dependencies in language and music combined while reducing the effect of sensory memory. Participants were instructed to focus on language (language session, music (music session, or both (dual session. In the language session, musicians and non-musicians performed comparably in terms of accuracy rates and reaction times. As expected, groups’ differences appeared in the music session, with musicians being more accurate in their responses than non-musicians and only the latter showing an interaction between the accuracy rates for music and language syntax. In the dual session musicians were overall more accurate than non-musicians. However, both groups showed comparable behavior, by displaying an interaction between the accuracy rates for language and music syntax responses. In our study, accuracy rates seem to better capture the interaction between language and music syntax; and this interaction seems to indicate the use of distinct, however, interacting mechanisms as part of decision making strategy. This interaction seems to be subject of an increase of attentional load and domain proficiency. Our study contributes to the long-lasting debate about the commonalities between language and music by

  18. Inferring individual-level processes from population-level patterns in cultural evolution

    Science.gov (United States)

    Wilder, Bryan

    2017-01-01

    Our species is characterized by a great degree of cultural variation, both within and between populations. Understanding how group-level patterns of culture emerge from individual-level behaviour is a long-standing question in the biological and social sciences. We develop a simulation model capturing demographic and cultural dynamics relevant to human cultural evolution, focusing on the interface between population-level patterns and individual-level processes. The model tracks the distribution of variants of cultural traits across individuals in a population over time, conditioned on different pathways for the transmission of information between individuals. From these data, we obtain theoretical expectations for a range of statistics commonly used to capture population-level characteristics (e.g. the degree of cultural diversity). Consistent with previous theoretical work, our results show that the patterns observed at the level of groups are rooted in the interplay between the transmission pathways and the age structure of the population. We also explore whether, and under what conditions, the different pathways can be distinguished based on their group-level signatures, in an effort to establish theoretical limits to inference. Our results show that the temporal dynamic of cultural change over time retains a stronger signature than the cultural composition of the population at a specific point in time. Overall, the results suggest a shift in focus from identifying the one individual-level process that likely produced the observed data to excluding those that likely did not. We conclude by discussing the implications for empirical studies of human cultural evolution. PMID:28989786

  19. Inferring individual-level processes from population-level patterns in cultural evolution.

    Science.gov (United States)

    Kandler, Anne; Wilder, Bryan; Fortunato, Laura

    2017-09-01

    Our species is characterized by a great degree of cultural variation, both within and between populations. Understanding how group-level patterns of culture emerge from individual-level behaviour is a long-standing question in the biological and social sciences. We develop a simulation model capturing demographic and cultural dynamics relevant to human cultural evolution, focusing on the interface between population-level patterns and individual-level processes. The model tracks the distribution of variants of cultural traits across individuals in a population over time, conditioned on different pathways for the transmission of information between individuals. From these data, we obtain theoretical expectations for a range of statistics commonly used to capture population-level characteristics (e.g. the degree of cultural diversity). Consistent with previous theoretical work, our results show that the patterns observed at the level of groups are rooted in the interplay between the transmission pathways and the age structure of the population. We also explore whether, and under what conditions, the different pathways can be distinguished based on their group-level signatures, in an effort to establish theoretical limits to inference. Our results show that the temporal dynamic of cultural change over time retains a stronger signature than the cultural composition of the population at a specific point in time. Overall, the results suggest a shift in focus from identifying the one individual-level process that likely produced the observed data to excluding those that likely did not. We conclude by discussing the implications for empirical studies of human cultural evolution.

  20. Fire management strategies to maintain species population processes in a fragmented landscape of fire-interval extremes.

    Science.gov (United States)

    Tulloch, Ayesha I T; Pichancourt, Jean-Baptiste; Gosper, Carl R; Sanders, Angela; Chadès, Iadine

    2016-10-01

    Changed fire regimes have led to declines of fire-regime-adapted species and loss of biodiversity globally. Fire affects population processes of growth, reproduction, and dispersal in different ways, but there is little guidance about the best fire regime(s) to maintain species population processes in fire-prone ecosystems. We use a process-based approach to determine the best range of fire intervals for keystone plant species in a highly modified Mediterranean ecosystem in southwestern Australia where current fire regimes vary. In highly fragmented areas, fires are few due to limited ignitions and active suppression of wildfire on private land, while in highly connected protected areas fires are frequent and extensive. Using matrix population models, we predict population growth of seven Banksia species under different environmental conditions and patch connectivity, and evaluate the sensitivity of species survival to different fire management strategies and burning intervals. We discover that contrasting, complementary patterns of species life-histories with time since fire result in no single best fire regime. All strategies result in the local patch extinction of at least one species. A small number of burning strategies secure complementary species sets depending on connectivity and post-fire growing conditions. A strategy of no fire always leads to fewer species persisting than prescribed fire or random wildfire, while too-frequent or too-rare burning regimes lead to the possible local extinction of all species. In low landscape connectivity, we find a smaller range of suitable fire intervals, and strategies of prescribed or random burning result in a lower number of species with positive growth rates after 100 years on average compared with burning high connectivity patches. Prescribed fire may reduce or increase extinction risk when applied in combination with wildfire depending on patch connectivity. Poor growing conditions result in a significantly

  1. CONTENTS OF LYMPHOCYTE SUB-POPULATIONS IN THE CHILDREN WITH ACUTE LEUKEMIA AND LYMPHOMAS DEPENDENT ON INFECTIOUS COMPLICATION AND NEUTROPENIA

    Directory of Open Access Journals (Sweden)

    M. V. Peshikova

    2005-01-01

    Full Text Available Abstract. The aim of the present work was to evaluate the contents of some lymphocyte sub-populations in peripheral blood of the children with tumors of hematopoietic and lymphoid tissues, depending on infectious complication of cytostatic therapy and neutropenia. In all children undergoing cytostatic therapy for acute lympho-blastic leukemia and non-B cell non-Hodgkinґs lymphomas, we found significant decrease in the numbers of CD95 lymphocytes, absolute amounts of natural killer cells (CD16, CD56-lymphocytes and activated lymphocytes (СD11b, HLA-DR-cells, irrespective of neutrophile numbers in their blood and infectious complications. However, absolute number of CD25- lymphocytes was significantly decreased in the children with neutropenia. Relative contents of CD16, CD56, СD11b, HLA-DR, CD25-lymphocytes did not significantly differ from those in healthy children, or they were found to be significantly increased.

  2. Mesenchymal stem cells induce mature dendritic cells into a novel Jagged-2-dependent regulatory dendritic cell population.

    Science.gov (United States)

    Zhang, Bin; Liu, Rui; Shi, Dan; Liu, Xingxia; Chen, Yuan; Dou, Xiaowei; Zhu, Xishan; Lu, Chunhua; Liang, Wei; Liao, Lianming; Zenke, Martin; Zhao, Robert C H

    2009-01-01

    Mesenchymal stem cells (MSCs), in addition to their multilineage differentiation, exert immunomodulatory effects on immune cells, even dendritic cells (DCs). However, whether they influence the destiny of full mature DCs (maDCs) remains controversial. Here we report that MSCs vigorously promote proliferation of maDCs, significantly reduce their expression of Ia, CD11c, CD80, CD86, and CD40 while increasing CD11b expression. Interestingly, though these phenotypes clearly suggest their skew to immature status, bacterial lipopolysaccharide (LPS) stimulation could not reverse this trend. Moreover, high endocytosic capacity, low immunogenicity, and strong immunoregulatory function of MSC-treated maDCs (MSC-DCs) were also observed. Furthermore we found that MSCs, partly via cell-cell contact, drive maDCs to differentiate into a novel Jagged-2-dependent regulatory DC population and escape their apoptotic fate. These results further support the role of MSCs in preventing rejection in organ transplantation and treatment of autoimmune disease.

  3. Anti-Hebbian Spike Timing Dependent Plasticity and Adaptive Sensory Processing

    Directory of Open Access Journals (Sweden)

    Patrick D Roberts

    2010-12-01

    Full Text Available Adaptive processing influences the central nervous system's interpretation of incoming sensory information. One of the functions of this adaptative sensory processing is to allow the nervous system to ignore predictable sensory information so that it may focus on important new information needed to improve performance of specific tasks. The mechanism of spike timing-dependent plasticity (STDP has proven to be intriguing in this context because of its dual role in long-term memory and ongoing adaptation to maintain optimal tuning of neural responses. Some of the clearest links between STDP and adaptive sensory processing have come from in vitro, in vivo, and modeling studies of the electrosensory systems of fish. Plasticity in such systems is anti-Hebbian, i.e. presynaptic inputs that repeatedly precede and hence could contribute to a postsynaptic neuron’s firing are weakened. The learning dynamics of anti-Hebbian STDP learning rules are stable if the timing relations obey strict constraints. The stability of these learning rules leads to clear predictions of how functional consequences can arise from the detailed structure of the plasticity. Here we review the connection between theoretical predictions and functional consequences of anti-Hebbian STDP, focusing on adaptive processing in the electrosensory system of weakly electric fish. After introducing electrosensory adaptive processing and the dynamics of anti-Hebbian STDP learning rules, we address issues of predictive sensory cancellation and novelty detection, descending control of plasticity, synaptic scaling, and optimal sensory tuning. We conclude with examples in other systems where these principles may apply.

  4. Anti-hebbian spike-timing-dependent plasticity and adaptive sensory processing.

    Science.gov (United States)

    Roberts, Patrick D; Leen, Todd K

    2010-01-01

    Adaptive sensory processing influences the central nervous system's interpretation of incoming sensory information. One of the functions of this adaptive sensory processing is to allow the nervous system to ignore predictable sensory information so that it may focus on important novel information needed to improve performance of specific tasks. The mechanism of spike-timing-dependent plasticity (STDP) has proven to be intriguing in this context because of its dual role in long-term memory and ongoing adaptation to maintain optimal tuning of neural responses. Some of the clearest links between STDP and adaptive sensory processing have come from in vitro, in vivo, and modeling studies of the electrosensory systems of weakly electric fish. Plasticity in these systems is anti-Hebbian, so that presynaptic inputs that repeatedly precede, and possibly could contribute to, a postsynaptic neuron's firing are weakened. The learning dynamics of anti-Hebbian STDP learning rules are stable if the timing relations obey strict constraints. The stability of these learning rules leads to clear predictions of how functional consequences can arise from the detailed structure of the plasticity. Here we review the connection between theoretical predictions and functional consequences of anti-Hebbian STDP, focusing on adaptive processing in the electrosensory system of weakly electric fish. After introducing electrosensory adaptive processing and the dynamics of anti-Hebbian STDP learning rules, we address issues of predictive sensory cancelation and novelty detection, descending control of plasticity, synaptic scaling, and optimal sensory tuning. We conclude with examples in other systems where these principles may apply.

  5. Effects of post-processing handling and packaging on microbial populations

    International Nuclear Information System (INIS)

    Zagory, D.

    1999-01-01

    The type of produce, process conditions, and prior temperature management will all affect the mix of microorganisms found on fresh produce. Normally, fresh produce will be covered by a complex mix of bacteria, fungi and yeasts that are characteristic of that fruit or vegetable. For example, carrots typically have large numbers of Lactobacillus and other lactic acid bacteria while apples may have relatively large numbers of yeasts. Which of these microorganisms will come to dominate the population will be a function of the make-up of the original population on the product in the field, distribution time, distribution temperature and the atmosphere within the package. Another chief determinant of microbial populations will be the physiological condition of the product. Factors that injure or weaken the plant tissues may be expected to encourage microbial growth while conditions that maintain the physiological integrity of the tissues may be expected to discourage microbial growth. Each of these factors can be expected to affect the make-up of the microbial population in characteristic ways but always constrained by the initial condition of original population makeup. This paper describes which microorganisms are favored by given conditions in order to develop a concept of microbial management designed to favor desirable microbes at the expense of undesirable ones. Particular emphasis will be placed on the effects of modified atmospheres on microorganisms, especially human pathogens

  6. Dependency of cardiac rubidium-82 imaging quantitative measures on age, gender, vascular territory, and software in a cardiovascular normal population.

    Science.gov (United States)

    Sunderland, John J; Pan, Xiao-Bo; Declerck, Jerome; Menda, Yusuf

    2015-02-01

    Recent technological improvements to PET imaging equipment combined with the availability of software optimized to calculate regional myocardial blood flow (MBF) and myocardial flow reserve (MFR) create a paradigm shifting opportunity to provide new clinically relevant quantitative information to cardiologists. However, clinical interpretation of the MBF and MFR is entirely dependent upon knowledge of MBF and MFR values in normal populations and subpopulations. This work reports Rb-82-based MBF and MFR measurements for a series of 49 verified cardiovascularly normal subjects as a preliminary baseline for future clinical studies. Forty-nine subjects (24F/25M, ages 41-69) with low probability for coronary artery disease and with normal exercise stress test were included. These subjects underwent rest/dipyridamole stress Rb-82 myocardial perfusion imaging using standard clinical techniques (40 mCi injection, 6-minute acquisition) using a Siemens Biograph 40 PET/CT scanner with high count rate detector option. List mode data was rehistogrammed into 26 dynamic frames (12 × 5 seconds, 6 × 10 seconds, 4 × 20 seconds, 4 × 40 seconds). Cardiac images were processed, and MBF and MFR calculated using Siemens syngo MBF, PMOD, and FlowQuant software using a single compartment Rb-82 model. Global myocardial blood flow under pharmacological stress for the 24 females as measured by PMOD, syngo MBF, and FlowQuant were 3.10 ± 0.72, 2.80 ± 0.66, and 2.60 ± 0.63 mL·minute(-1)·g(-1), and for the 25 males was 2.60 ± 0.84, 2.33 ± 0.75, 2.15 ± 0.62 mL·minute(-1)·g(-1), respectively. Rest flows for PMOD, syngo MBF, and FlowQuant averaged 1.32 ± 0.42, 1.20 ± 0.33, and 1.06 ± 0.38 mL·minute(-1)·g(-1) for the female subjects, and 1.12 ± 0.29, 0.90 ± 0.26, and 0.85 ± 0.24 mL·minute(-1)·g(-1) for the males. Myocardial flow reserves for PMOD, syngo MBF, and FlowQuant for the female normals were calculated to be 2.50 ± 0.80, 2.53 ± 0.67, 2.71 ± 0.90, and 2.50 ± 1.19, 2

  7. Embodied simulation as part of affective evaluation processes: task dependence of valence concordant EMG activity.

    Science.gov (United States)

    Weinreich, André; Funcke, Jakob Maria

    2014-01-01

    Drawing on recent findings, this study examines whether valence concordant electromyography (EMG) responses can be explained as an unconditional effect of mere stimulus processing or as somatosensory simulation driven by task-dependent processing strategies. While facial EMG over the Corrugator supercilii and the Zygomaticus major was measured, each participant performed two tasks with pictures of album covers. One task was an affective evaluation task and the other was to attribute the album covers to one of five decades. The Embodied Emotion Account predicts that valence concordant EMG is more likely to occur if the task necessitates a somatosensory simulation of the evaluative meaning of stimuli. Results support this prediction with regard to Corrugator supercilii in that valence concordant EMG activity was only present in the affective evaluation task but not in the non-evaluative task. Results for the Zygomaticus major were ambiguous. Our findings are in line with the view that EMG activity is an embodied part of the evaluation process and not a mere physical outcome.

  8. Characteristic Changes in the Aroma Profile of Patchouli Depending on Manufacturing Process.

    Science.gov (United States)

    Hasegawa, Toshio; Yoshitome, Kazuma; Fujihara, Takashi; Santoso, Mardi; Aziz, Muhammad Abdul

    2017-08-01

    Patchouli is used as an incense material and essential oil. The characteristic odor of patchouli leaves results from the drying process used in their production; however, there have to date been no reports on the changes in the odor of patchouli leaves during the drying process. We investigated the aroma profile of dried patchouli leaves using the hexane extracts of fresh and dried patchouli leaves. We focused on the presence or absence of the constituents of the fresh and dried extracts, and the differences in the content of the common constituents. Fourteen constituents were identified as characteristic of dried patchouli extract odor by gas chromatography-olfactometry analysis. The structures of seven of the 14 constituents were determined by gas chromatography-mass spectrometry (α-patchoulene, seychellene, humulene, α-bulnesene, isoaromadendrene epoxide, caryophyllene oxide, and patchouli alcohol). The aroma profile of the essential oil obtained from the dried patchouli leaves was clearly different from that of dried patchouli. The aroma profile of the essential oil was investigated by a similar method. We identified 12 compounds as important odor constituents. The structures of nine of the 12 constituents were determined by gas chromatography-mass spectrometry (cis-thujopsene, caryophyllene, α-guaiene, α-patchoulene, seychellene, α-bulnesene, isoaromadendrene epoxide, patchouli alcohol, and corymbolone). Comparing the odors and constituents demonstrated that the aroma profile of patchouli depends on the manufacturing process.

  9. Effects of Lead Exposure, Environmental Conditions, and Metapopulation Processes on Population Dynamics of Spectacled Eiders.

    Science.gov (United States)

    Flint, Paul L.; Grand, James B.; Petersen, Margaret; Rockwell, Robert F.

    2016-01-01

    subpopulation is independent and that future management actions may be improved through a metapopulation framework. For example, management actions could include displacement of breeding females from"sink" areas that reduce the growth potential of the population as a whole. However, this action is contingent upon dispersal among local populations, for which there is limited information. Thus, we recommend that researchers examine dispersal behavior among areas on the Yukon-Kuskokwim Delta in western Alaska. The metapopulation framework could also be applied at the rangewide scale to address the density-dependent limitation of available polynya habitat during winter that may limit the recovery of small subpopulations, such as that on the Yukon-Kuskokwim Delta. Reductions in other subpopulations may be necessary to ensure an increase in the Yukon-Kuskokwim Delta population. Thus, we recommend that managers consider the interpopulation dynamics of spectacled eiders at different spatial scales in future management actions.

  10. Living in the branches: population dynamics and ecological processes in dendritic networks

    Science.gov (United States)

    Grant, E.H.C.; Lowe, W.H.; Fagan, W.F.

    2007-01-01

    Spatial structure regulates and modifies processes at several levels of ecological organization (e.g. individual/genetic, population and community) and is thus a key component of complex systems, where knowledge at a small scale can be insufficient for understanding system behaviour at a larger scale. Recent syntheses outline potential applications of network theory to ecological systems, but do not address the implications of physical structure for network dynamics. There is a specific need to examine how dendritic habitat structure, such as that found in stream, hedgerow and cave networks, influences ecological processes. Although dendritic networks are one type of ecological network, they are distinguished by two fundamental characteristics: (1) both the branches and the nodes serve as habitat, and (2) the specific spatial arrangement and hierarchical organization of these elements interacts with a species' movement behaviour to alter patterns of population distribution and abundance, and community interactions. Here, we summarize existing theory relating to ecological dynamics in dendritic networks, review empirical studies examining the population- and community-level consequences of these networks, and suggest future research integrating spatial pattern and processes in dendritic systems.

  11. Population Dynamics and Temperature-Dependent Development of Chrysomphalus aonidum (L.) to Aid Sustainable Pest Management Decisions.

    Science.gov (United States)

    Campolo, O; Malacrinò, A; Laudani, F; Maione, V; Zappalà, L; Palmeri, V

    2014-10-01

    The increasing worldwide trades progressively led to decreased impact of natural barriers on wild species movement. The exotic scale Chrysomphalus aonidum (L.) (Hemiptera: Diaspididae), recently reported on citrus in southern Italy, may represent a new threat to Mediterranean citriculture. We studied C. aonidum population dynamics under field conditions and documented its development under various temperatures. To enable describing temperature-dependent development through the use of linear and non-linear models, low temperature thresholds and thermal constants for each developmental stage were estimated. Chrysomphalus aonidum was able to perform four generations on green parts (leaves, sprouts) of citrus trees and three on fruits. In addition, an overall higher population density was observed on samples collected in the southern part of the tree canopy. Temperature had a significant effect on the developmental rate; female needed 625 degree days (DD) to complete its development, while male needed 833 DD. The low threshold temperatures, together with data from population dynamics, demonstrated that C. aonidum is able to overwinter as second instar and as an adult. The results obtained, validated by those collected in the field, revealed few differences between predicted and observed dates of first occurrence of each C. aonidum instar in citrus orchards. Data on C. aonidum phenology and the definition of the thermal parameters (lower and upper threshold temperatures, optimum temperature, and the thermal constant) by non-linear models could allow the estimation of the occurrence in the field of each life stage and would be helpful in developing effective integrated control strategies.

  12. Dose-Dependent and Lasting Influences of Intranasal Vasopressin on Face Processing in Men

    Directory of Open Access Journals (Sweden)

    Daniel Price

    2017-09-01

    Full Text Available Arginine vasopressin (AVP and related peptides have diverse effects on social behaviors in vertebrates, sometimes promoting affiliative interactions and sometimes aggressive or antisocial responses. The type of influence, in at least some species, depends on social contexts, including the sex of the individuals in the interaction and/or on the levels of peptide within brain circuits that control the behaviors. To determine if AVP promotes different responses to same- and other-sex faces in men, and if those effects are dose dependent, we measured the effects of two doses of AVP on subjective ratings of male and female faces. We also tested if any influences persist beyond the time of drug delivery. When AVP was administered intranasally on an initial test day, 20 IU was associated with decreased social assessments relative to placebo and 40 IU, and some of the effects persisted beyond the initial drug delivery and appeared to generalize to novel faces on subsequent test days. In single men, those influences were most pronounced, but not exclusive, for male faces, whereas in coupled men they were primarily associated with responses to female faces. Similar influences were not observed if AVP was delivered after placebo on a second test day. In a preliminary analysis, the differences in social assessments observed between men who received 20 and 40 IU, which we suggest primarily reflect lowered social assessments induced by the lower dose, appeared most pronounced in subjects who carry what has been identified as a risk allele for the V1a receptor gene. Together, these results suggest that AVP’s effects on face processing, and possibly other social responses, differ according to dose, depend on relationship status, and may be more prolonged than previously recognized.

  13. On discrete stochastic processes with long-lasting time dependence in the variance

    Science.gov (United States)

    Queirós, S. M. D.

    2008-11-01

    In this manuscript, we analytically and numerically study statistical properties of an heteroskedastic process based on the celebrated ARCH generator of random variables whose variance is defined by a memory of qm-exponencial, form (eqm=1 x=ex). Specifically, we inspect the self-correlation function of squared random variables as well as the kurtosis. In addition, by numerical procedures, we infer the stationary probability density function of both of the heteroskedastic random variables and the variance, the multiscaling properties, the first-passage times distribution, and the dependence degree. Finally, we introduce an asymmetric variance version of the model that enables us to reproduce the so-called leverage effect in financial markets.

  14. A class-based link prediction using Distance Dependent Chinese Restaurant Process

    Science.gov (United States)

    Andalib, Azam; Babamir, Seyed Morteza

    2016-08-01

    One of the important tasks in relational data analysis is link prediction which has been successfully applied on many applications such as bioinformatics, information retrieval, etc. The link prediction is defined as predicting the existence or absence of edges between nodes of a network. In this paper, we propose a novel method for link prediction based on Distance Dependent Chinese Restaurant Process (DDCRP) model which enables us to utilize the information of the topological structure of the network such as shortest path and connectivity of the nodes. We also propose a new Gibbs sampling algorithm for computing the posterior distribution of the hidden variables based on the training data. Experimental results on three real-world datasets show the superiority of the proposed method over other probabilistic models for link prediction problem.

  15. Proteome analysis reveals an energy-dependent central process for Populus×canadensis seed germination.

    Science.gov (United States)

    Zhang, Hong; Zhou, Ke-Xin; Wang, Wei-Qing; Liu, Shu-Jun; Song, Song-Quan

    2017-06-01

    Poplar (Populus×canadensis) seeds rapidly germinated in darkness at 10, 15, and 20°C and reached 50% seed germination after about 22, 4.5, and 3.5h, respectively. Germination of poplar seeds was markedly inhibited by abscisic acid (ABA) at 50μM and cycloheximide (CHX) at 100μM, and these inhibitive roles were temperature-dependent. In the present study, mature poplar seeds were used to investigate the differentially changed proteome of seeds germinating in water, ABA, and CHX. A total of 130 protein spots showed a significant change (1.5-fold increase/decrease, Pgermination of poplar seeds is closely related with the increase in those proteins involved in amino acid and lipid metabolism, the tricarboxylic acid cycle and pentose phosphate pathway, protein synthesis and destination, cell defense and rescue, and degradation of storage proteins. ABA and CHX inhibit the germination of poplar seeds by decreasing the protein abundance associated with protein proteolysis, protein folding, and storage proteins. We conclude that poplar seed germination is an energy-dependent active process, and is accompanied by increasing amino acid activation, protein synthesis and destination, as well as cell defense and rescue, and degradation of storage proteins. Copyright © 2017 Elsevier GmbH. All rights reserved.

  16. Colony Development and Density-Dependent Processes in Breeding Grey Herons

    Directory of Open Access Journals (Sweden)

    Takeshi Shirai

    2013-01-01

    Full Text Available The density-dependent processes that limit the colony size of colonially breeding birds such as herons and egrets remain unclear, because it is difficult to monitor colonies from the first year of their establishment, and the most previous studies have considered mixed-species colonies. In the present study, single-species colonies of the Grey Heron (Ardea cinerea were observed from the first year of their establishment for 16 years in suburban Tokyo. Colony size increased after establishment, illustrating a saturation curve. The breeding duration (days from nest building to fledging by a pair increased, but the number of fledglings per nest decreased, with colony size. The reproductive season in each year began earlier, and there was greater variation in the timing of individual breeding when the colony size was larger. The prolonged duration until nestling feeding by early breeders of the colony suggests that herons at the beginning of the new breeding season exist in an unsteady state with one another, likely owing to interactions with immigrant individuals. Such density-dependent interference may affect reproductive success and limit the colony size of Grey Herons.

  17. Attempts to reduce alcohol intake and treatment needs among people with probable alcohol dependence in England: a general population survey.

    Science.gov (United States)

    Dunne, Jacklyn; Kimergård, Andreas; Brown, Jamie; Beard, Emma; Buykx, Penny; Michie, Susan; Drummond, Colin

    2018-03-25

    To compare the proportion of people in England with probable alcohol dependence [Alcohol Use Disorders Identification Test (AUDIT) score ≥ 20] with those with other drinking patterns (categorized by AUDIT scores) in terms of motivation to reduce drinking and use of alcohol support resources. A combination of random probability and simple quota sampling to conduct monthly cross-sectional household computer-assisted interviews between March 2014 and August 2017. The general population in all nine regions of England. Participants in the Alcohol Toolkit Study (ATS), a monthly household survey of alcohol consumption among people aged 16 years and over in England (n = 69 826). The mean age was 47 years [standard deviation (SD) = 18.78; 95% confidence interval (CI) = 46.8-47] and 51% (n = 35 560) were female. χ 2 tests were used to investigate associations with demographic variables, motivation to quit drinking, attempts to quit drinking, general practitioner (GP) engagement and types of support accessed in the last 12 months across AUDIT risk zones. A total of 0.6% were classified as people with probable alcohol dependence (95% CI = 0.5-0.7). Motivation to quit (χ 2  = 1692.27, P AUDIT risk zone. People with probable dependence were more likely than other ATS participants to have a past-year attempt to cut down or quit (51.8%) and have received a specialist referral from their GP about drinking (13.7%), and less likely to report no motivation to reduce their drinking (26.2%). Those with probable dependence had higher use of self-help books and mobile applications (apps) than other ATS participants; however, 27.7% did not access any resources during their most recent attempt to cut down. Adults in England with probable alcohol dependence, measured through the Alcohol Use Disorders Identification Test, demonstrate higher motivation to quit drinking and greater use of both specialist treatment and self-driven support compared with those in other

  18. Neighbor-dependent Ramachandran probability distributions of amino acids developed from a hierarchical Dirichlet process model.

    Directory of Open Access Journals (Sweden)

    Daniel Ting

    2010-04-01

    Full Text Available Distributions of the backbone dihedral angles of proteins have been studied for over 40 years. While many statistical analyses have been presented, only a handful of probability densities are publicly available for use in structure validation and structure prediction methods. The available distributions differ in a number of important ways, which determine their usefulness for various purposes. These include: 1 input data size and criteria for structure inclusion (resolution, R-factor, etc.; 2 filtering of suspect conformations and outliers using B-factors or other features; 3 secondary structure of input data (e.g., whether helix and sheet are included; whether beta turns are included; 4 the method used for determining probability densities ranging from simple histograms to modern nonparametric density estimation; and 5 whether they include nearest neighbor effects on the distribution of conformations in different regions of the Ramachandran map. In this work, Ramachandran probability distributions are presented for residues in protein loops from a high-resolution data set with filtering based on calculated electron densities. Distributions for all 20 amino acids (with cis and trans proline treated separately have been determined, as well as 420 left-neighbor and 420 right-neighbor dependent distributions. The neighbor-independent and neighbor-dependent probability densities have been accurately estimated using Bayesian nonparametric statistical analysis based on the Dirichlet process. In particular, we used hierarchical Dirichlet process priors, which allow sharing of information between densities for a particular residue type and different neighbor residue types. The resulting distributions are tested in a loop modeling benchmark with the program Rosetta, and are shown to improve protein loop conformation prediction significantly. The distributions are available at http://dunbrack.fccc.edu/hdp.

  19. Generalization of fear inhibition by disrupting hippocampal protein synthesis-dependent reconsolidation process.

    Science.gov (United States)

    Yang, Chih-Hao; Huang, Chiung-Chun; Hsu, Kuei-Sen

    2011-09-01

    Repetitive replay of fear memories may precipitate the occurrence of post-traumatic stress disorder and other anxiety disorders. Hence, the suppression of fear memory retrieval may help prevent and treat these disorders. The formation of fear memories is often linked to multiple environmental cues and these interconnected cues may act as reminders for the recall of traumatic experiences. However, as a convenience, a simple paradigm of one cue pairing with the aversive stimulus is usually used in studies of fear conditioning in animals. Here, we built a more complex fear conditioning model by presenting several environmental stimuli during fear conditioning and characterize the effectiveness of extinction training and the disruption of reconsolidation process on the expression of learned fear responses. We demonstrate that extinction training with a single-paired cue resulted in cue-specific attenuation of fear responses but responses to other cures were unchanged. The cue-specific nature of the extinction persisted despite training sessions combined with D-cycloserine treatment reveals a significant weakness in extinction-based treatment. In contrast, the inhibition of the dorsal hippocampus (DH) but not the basolateral amygdala (BLA)-dependent memory reconsolidation process using either protein synthesis inhibitors or genetic disruption of cAMP-response-element-binding protein-mediated transcription comprehensively disrupted the learned connections between fear responses and all paired environmental cues. These findings emphasize the distinct role of the DH and the BLA in the reconsolidation process of fear memories and further indicate that the disruption of memory reconsolidation process in the DH may result in generalization of fear inhibition.

  20. Metabotropic glutamate receptor 3 is associated with heroin dependence but not depression or schizophrenia in a Chinese population.

    Directory of Open Access Journals (Sweden)

    Wei Jia

    Full Text Available Metabotropic glutamate receptor subtype 3 (mGluR3, encoded by GRM3 plays important roles in the pathophysiology of schizophrenia, depression, and drug dependence. GRM3 polymorphisms were reported to be associated with prefrontal activity, cognitive shifting, and memory capability in healthy subjects, as well as susceptibility to schizophrenia and depression. The goal of this study was to replicate the association of GRM3 with schizophrenia and depression and to explore GRM3's potential association with heroin dependence (HD in a Chinese population. Seventeen SNPs throughout the GRM3 gene were genotyped using MALDI-TOF within the MassARRAY system, and the allele and genotype distributions were compared between 619 healthy controls and 433 patients with schizophrenia, 409 patients with major depression, and 584 unrelated addicts. We found that GRM3 polymorphisms modulate the susceptibility to HD but do not significantly influence the risk for schizophrenia or depression. An increased risk of HD was significantly associated with the minor alleles of two GRM3 SNPs, including the T allele of rs274618 (Odds ratio (OR = 1.631, 95% confidence interval (95%CI: 1.317-2.005, the T allele of rs274622 (OR = 1.652, 95% CI: 1.336-2.036, compared with the major alleles. The addicts carrying the minor allele of rs274618 or rs274622 had a shortened duration for transition from first use to dependence (DTFUD in comparison to homozygote for major allele (P<0.0001 for each SNP using log rank test. Additionally, a 6-SNP haplotype within 5' region of the GRM3 including the minor alleles of the two aforementioned SNPs was significantly associated with an increased risk of HD (P = 0.00001, OR = 1.668, 95% CI: 1.335-2.084. Our data indicated that GRM3 polymorphisms do not contribute to genetic susceptibility to schizophrenia and depression, but they confer an increased risk of HD in a Chinese population.

  1. A Continuous Correlated Beta Process Model for Genetic Ancestry in Admixed Populations.

    Science.gov (United States)

    Gompert, Zachariah

    2016-01-01

    Admixture and recombination create populations and genomes with genetic ancestry from multiple source populations. Analyses of genetic ancestry in admixed populations are relevant for trait and disease mapping, studies of speciation, and conservation efforts. Consequently, many methods have been developed to infer genome-average ancestry and to deconvolute ancestry into continuous local ancestry blocks or tracts within individuals. Current methods for local ancestry inference perform well when admixture occurred recently or hybridization is ongoing, or when admixture occurred in the distant past such that local ancestry blocks have fixed in the admixed population. However, methods to infer local ancestry frequencies in isolated admixed populations still segregating for ancestry do not exist. In the current paper, I develop and test a continuous correlated beta process model to fill this analytical gap. The method explicitly models autocorrelations in ancestry frequencies at the population-level and uses discriminant analysis of SNP windows to take advantage of ancestry blocks within individuals. Analyses of simulated data sets show that the method is generally accurate such that ancestry frequency estimates exhibited low root-mean-square error and were highly correlated with the true values, particularly when large (±10 or ±20) SNP windows were used. Along these lines, the proposed method outperformed post hoc inference of ancestry frequencies from a traditional hidden Markov model (i.e., the linkage model in structure), particularly when admixture occurred more distantly in the past with little on-going gene flow or was followed by natural selection. The reliability and utility of the method was further assessed by analyzing genetic ancestry in an admixed human population (Uyghur) and three populations from a hybrid zone between Mus domesticus and M. musculus. Considerable variation in ancestry frequencies was detected within and among chromosomes in the Uyghur

  2. A Continuous Correlated Beta Process Model for Genetic Ancestry in Admixed Populations.

    Directory of Open Access Journals (Sweden)

    Zachariah Gompert

    Full Text Available Admixture and recombination create populations and genomes with genetic ancestry from multiple source populations. Analyses of genetic ancestry in admixed populations are relevant for trait and disease mapping, studies of speciation, and conservation efforts. Consequently, many methods have been developed to infer genome-average ancestry and to deconvolute ancestry into continuous local ancestry blocks or tracts within individuals. Current methods for local ancestry inference perform well when admixture occurred recently or hybridization is ongoing, or when admixture occurred in the distant past such that local ancestry blocks have fixed in the admixed population. However, methods to infer local ancestry frequencies in isolated admixed populations still segregating for ancestry do not exist. In the current paper, I develop and test a continuous correlated beta process model to fill this analytical gap. The method explicitly models autocorrelations in ancestry frequencies at the population-level and uses discriminant analysis of SNP windows to take advantage of ancestry blocks within individuals. Analyses of simulated data sets show that the method is generally accurate such that ancestry frequency estimates exhibited low root-mean-square error and were highly correlated with the true values, particularly when large (±10 or ±20 SNP windows were used. Along these lines, the proposed method outperformed post hoc inference of ancestry frequencies from a traditional hidden Markov model (i.e., the linkage model in structure, particularly when admixture occurred more distantly in the past with little on-going gene flow or was followed by natural selection. The reliability and utility of the method was further assessed by analyzing genetic ancestry in an admixed human population (Uyghur and three populations from a hybrid zone between Mus domesticus and M. musculus. Considerable variation in ancestry frequencies was detected within and among

  3. A single-rate context-dependent learning process underlies rapid adaptation to familiar object dynamics.

    Science.gov (United States)

    Ingram, James N; Howard, Ian S; Flanagan, J Randall; Wolpert, Daniel M

    2011-09-01

    Motor learning has been extensively studied using dynamic (force-field) perturbations. These induce movement errors that result in adaptive changes to the motor commands. Several state-space models have been developed to explain how trial-by-trial errors drive the progressive adaptation observed in such studies. These models have been applied to adaptation involving novel dynamics, which typically occurs over tens to hundreds of trials, and which appears to be mediated by a dual-rate adaptation process. In contrast, when manipulating objects with familiar dynamics, subjects adapt rapidly within a few trials. Here, we apply state-space models to familiar dynamics, asking whether adaptation is mediated by a single-rate or dual-rate process. Previously, we reported a task in which subjects rotate an object with known dynamics. By presenting the object at different visual orientations, adaptation was shown to be context-specific, with limited generalization to novel orientations. Here we show that a multiple-context state-space model, with a generalization function tuned to visual object orientation, can reproduce the time-course of adaptation and de-adaptation as well as the observed context-dependent behavior. In contrast to the dual-rate process associated with novel dynamics, we show that a single-rate process mediates adaptation to familiar object dynamics. The model predicts that during exposure to the object across multiple orientations, there will be a degree of independence for adaptation and de-adaptation within each context, and that the states associated with all contexts will slowly de-adapt during exposure in one particular context. We confirm these predictions in two new experiments. Results of the current study thus highlight similarities and differences in the processes engaged during exposure to novel versus familiar dynamics. In both cases, adaptation is mediated by multiple context-specific representations. In the case of familiar object dynamics

  4. A single-rate context-dependent learning process underlies rapid adaptation to familiar object dynamics.

    Directory of Open Access Journals (Sweden)

    James N Ingram

    2011-09-01

    Full Text Available Motor learning has been extensively studied using dynamic (force-field perturbations. These induce movement errors that result in adaptive changes to the motor commands. Several state-space models have been developed to explain how trial-by-trial errors drive the progressive adaptation observed in such studies. These models have been applied to adaptation involving novel dynamics, which typically occurs over tens to hundreds of trials, and which appears to be mediated by a dual-rate adaptation process. In contrast, when manipulating objects with familiar dynamics, subjects adapt rapidly within a few trials. Here, we apply state-space models to familiar dynamics, asking whether adaptation is mediated by a single-rate or dual-rate process. Previously, we reported a task in which subjects rotate an object with known dynamics. By presenting the object at different visual orientations, adaptation was shown to be context-specific, with limited generalization to novel orientations. Here we show that a multiple-context state-space model, with a generalization function tuned to visual object orientation, can reproduce the time-course of adaptation and de-adaptation as well as the observed context-dependent behavior. In contrast to the dual-rate process associated with novel dynamics, we show that a single-rate process mediates adaptation to familiar object dynamics. The model predicts that during exposure to the object across multiple orientations, there will be a degree of independence for adaptation and de-adaptation within each context, and that the states associated with all contexts will slowly de-adapt during exposure in one particular context. We confirm these predictions in two new experiments. Results of the current study thus highlight similarities and differences in the processes engaged during exposure to novel versus familiar dynamics. In both cases, adaptation is mediated by multiple context-specific representations. In the case of familiar

  5. Integrating Fisheries Dependent and Independent Approaches to assess Fisheries, Abundance, Diversity, Distribution and Genetic Connectivity of Red Sea Elasmobranch Populations

    KAUST Repository

    Spaet, Julia L.

    2014-05-01

    The Red Sea has long been recognized as a global hotspot of marine biodiversity. Ongoing overfishing, however, is threatening this unique ecosystem, recently leading to the identification of the Red Sea as one of three major hotspots of extinction risk for sharks and rays worldwide. Elasmobranch catches in Saudi Arabian Red Sea waters are unregulated, often misidentified and unrecorded, resulting in a lack of species-specific landings information, which would be vital for the formulation of effective management strategies. Here we employed an integrated approach of fisheries dependent and independent survey methods combined with molecular tools to provide biological, ecological and fisheries data to aid in the assessment of the status of elasmobranch populations in the Red Sea. Over the course of two years, we conducted market surveys at the biggest Saudi Arabian fish market in Jeddah. Market landings were dominated by, mostly immature individuals - implying both recruitment and growth overfishing. Additionally, we employed baited remote underwater video (BRUVS) and longline surveys along almost the entire length of the Red Sea coast of Saudi Arabia as well as at selected reef systems in Sudan. The comparison of catch per unit effort (CPUE) data for Saudi Arabian Red Sea BRUVS and longline surveys to published data originating from non-Red Sea ocean systems revealed CPUE values several orders of magnitude lower for both survey methods in the Red Sea compared to other locations around the world. Finally, we infered the regional population structure of four commercially important shark species between the Red Sea and the Western Indian Ocean.We genotyped nearly 2000 individuals at the mitochondrial control region as well as a total of 20 microsatellite loci. Genetic homogeneity could not be rejected for any of the four species across the spatial comparison. Based on high levels of region-wide exploitation, we suggest that, for management purposes, the population

  6. Diets of differentially processed wheat alter ruminal fermentation parameters and microbial populations in beef cattle.

    Science.gov (United States)

    Jiang, S Z; Yang, Z B; Yang, W R; Li, Z; Zhang, C Y; Liu, X M; Wan, F C

    2015-11-01

    The influences of differently processed wheat products on rumen fermentation, microbial populations, and serum biochemistry profiles in beef cattle were studied. Four ruminally cannulated Limousin × Luxi beef cattle (400 ± 10 kg) were used in the experiment with a 4 × 4 Latin square design. The experimental diets contained (on a DM basis) 60% corn silage as a forage source and 40% concentrate with 4 differently processed wheat products (extruded, pulverized, crushed, and rolled wheat). Concentrations of ruminal NH-N and microbial protein (MCP) in cattle fed crushed and rolled wheat were greater ( Ruminal concentrations of total VFA and acetate and the ratio of acetate to propionate decreased ( 0.05). Our findings suggest that the method of wheat processing could have a significant effect on ruminal fermentation parameters and microbial populations in beef cattle and that crushed and rolled processing is better in terms of ruminal NH-N and MCP content, acetate-to-propionate ratio, and relative abundance of rumen microorganisms.

  7. Emotional bias of sleep-dependent processing shifts from negative to positive with aging.

    Science.gov (United States)

    Jones, Bethany J; Schultz, Kurt S; Adams, Sydney; Baran, Bengi; Spencer, Rebecca M C

    2016-09-01

    Age-related memory decline has been proposed to result partially from impairments in memory consolidation over sleep. However, such decline may reflect a shift toward selective processing of positive information with age rather than impaired sleep-related mechanisms. In the present study, young and older adults viewed negative and neutral pictures or positive and neutral pictures and underwent a recognition test after sleep or wake. Subjective emotional reactivity and affect were also measured. Compared with waking, sleep preserved valence ratings and memory for positive but not negative pictures in older adults and negative but not positive pictures in young adults. In older adults, memory for positive pictures was associated with slow wave sleep. Furthermore, slow wave sleep predicted positive affect in older adults but was inversely related to positive affect in young adults. These relationships were strongest for older adults with high memory for positive pictures and young adults with high memory for negative pictures. Collectively, these results indicate preserved but selective sleep-dependent memory processing with healthy aging that may be biased to enhance emotional well-being. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Viscoelastic characterization of compacted pharmaceutical excipient materials by analysis of frequency-dependent mechanical relaxation processes

    Science.gov (United States)

    Welch, K.; Mousavi, S.; Lundberg, B.; Strømme, M.

    2005-09-01

    A newly developed method for determining the frequency-dependent complex Young's modulus was employed to analyze the mechanical response of compacted microcrystalline cellulose, sorbitol, ethyl cellulose and starch for frequencies up to 20 kHz. A Debye-like relaxation was observed in all the studied pharmaceutical excipient materials and a comparison with corresponding dielectric spectroscopy data was made. The location in frequency of the relaxation peak was shown to correlate to the measured tensile strength of the tablets, and the relaxation was interpreted as the vibrational response of the interparticle hydrogen and van der Waals bindings in the tablets. Further, the measured relaxation strength, holding information about the energy loss involved in the relaxation processes, showed that the weakest material in terms of tensile strength, starch, is the material among the four tested ones that is able to absorb the most energy within its structure when exposed to external perturbations inducing vibrations in the studied frequency range. The results indicate that mechanical relaxation analysis performed over relatively broad frequency ranges should be useful for predicting material properties of importance for the functionality of a material in applications such as, e.g., drug delivery, drug storage and handling, and also for clarifying the origin of hitherto unexplained molecular processes.

  9. The process of adaptation and evolution in irradiated synthetic populations of Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Dislers, V.J.; Rasals, I.D.

    1975-01-01

    Irradiation of synthetic populations of A. thaliana caused an intense process of directed natural selection. As a result, six to eight generations after irradiation, the arithmetic mean of a number of parameters (plant height, stem length, number of internodes) exceeded the arithmetic average for plants in a non-irradiated population. The process of directed selection proceeded more intensely after the plants were irradiated repeatedly than after a single irradiation. The intensity of directed selection when the plants were irradiated with a 10 4 rad dose of fast neutrons was definitely greater than for a dose of 10 3 rad. An intermediate intensity of selection was observed when the plants were irradiated with a 3x10 4 rad dose of gamma radiation. When the plants were subjected to single and repeated 10 4 rad doses of fast neutron radiation, the arithmetic mean of certain features of the best component of the initial population (Enkheim) was exceeded in M 8 and R 6 . (author)

  10. An efficient and reproducible process for transmission electron microscopy (TEM) of rare cell populations

    Science.gov (United States)

    Kumar, Sachin; Ciraolo, Georgianne; Hinge, Ashwini; Filippi, Marie-Dominique

    2014-01-01

    Transmission electron microscopy (TEM) provides ultra-structural details of cells at the sub-organelle level. However, details of the cellular ultrastructure, and the cellular organization and content of various organelles in rare populations, particularly in the suspension, like hematopoietic stem cells (HSCs) remained elusive. This is mainly due to the requirement of millions of cells for TEM studies. Thus, there is a vital requirement of a method that will allow TEM studies with low cell numbers of such rare populations. We describe an alternative and novel approach for TEM studies for rare cell populations. Here we performed TEM study from 10,000 HSC cells with quite ease. In particular, tiny cell pellets were identified by Evans blue staining after PFA-GA fixation. The cell pellet was pre-embedded in agarose in a small microcentrifuge tube and processed for dehydration, infiltration and embedding. Semi-thin and ultra-thin sections identified clusters of numerous cells per sections with well preserved morphology and ultrastructural details of golgi complex and mitochondria. Together, this method provides an efficient, easy and reproducible process to perform qualitative and quantitative TEM analysis from limited biological samples including cells in suspension. PMID:24291346

  11. The inverse Gamma process: A family of continuous stochastic models for describing state-dependent deterioration phenomena

    International Nuclear Information System (INIS)

    Guida, M.; Pulcini, G.

    2013-01-01

    This paper proposes the family of non-stationary inverse Gamma processes for modeling state-dependent deterioration processes with nonlinear trend. The proposed family of processes, which is based on the assumption that the “inverse” time process is Gamma, is mathematically more tractable than previously proposed state-dependent processes, because, unlike the previous models, the inverse Gamma process is a time-continuous and state-continuous model and does not require discretization of time and state. The conditional distribution of the deterioration growth over a generic time interval, the conditional distribution of the residual life and the residual reliability of the unit, given the current state, are provided. Point and interval estimation of the parameters which index the proposed process, as well as of several quantities of interest, are also discussed. Finally, the proposed model is applied to the wear process of the liners of some Diesel engines which was previously analyzed and proved to be a purely state-dependent process. The comparison of the inferential results obtained under the competitor models shows the ability of the Inverse Gamma process to adequately model the observed state-dependent wear process

  12. The Effect of Reversible Abolition of Basolateral Amygdala on Hippocampal Dependent Spatial Memory Processes in Mice

    Directory of Open Access Journals (Sweden)

    A Rashidy-Pour

    2004-04-01

    Full Text Available Introduction: Many evidences have suggested that the Basolateral Amygdala (BLA are probably involved in emotional learning and modulation of spatial memory processes. The aim of this present study was assessment of the effect of reversible abolition of BLA on spatial memory processes in a place avoidance learning model in a stable environment. Methods and Materials: Long-Evans strain rats (280-320 gr. were selected and cannulae aimed at the BLA were surgically implanted bilaterally. The mice were trained to avoid a 60° segment of the arena by punishing with a mild foot shock upon entering the area. The punished sector was defined by room cues during the place avoidance training, which occurred in a single 30-min session and the avoidance memory was assessed during a 30-min extinction trial after 24 hours. The time of the first entry and the number of entrances into the punished sector during extinction were used to measure the place avoidance memory. Bilateral injections of Tetrodotoxin (5ng/0.6ml per side were used to inactivate the BLA 60 min before acquisition, immediately, 60 and 120 min after training, or 60 min before the retrieval test. Control mice were injected saline at the same time. Results : The results indicated that acquisition, consolidation (immediately, 60 min after training and retrieval of spatial memory in stable arena were impaired (p0.05. Conclusion: We conclude that the Basolateral Amygdala (BLA modulate spatial memory processes in place avoidance learning model in stable arena and this effect in regard to consolidation is time dependent.

  13. Attenuated Neural Processing of Risk in Young Adults at Risk for Stimulant Dependence.

    Directory of Open Access Journals (Sweden)

    Martina Reske

    Full Text Available Approximately 10% of young adults report non-medical use of stimulants (cocaine, amphetamine, methylphenidate, which puts them at risk for the development of dependence. This fMRI study investigates whether subjects at early stages of stimulant use show altered decision making processing.158 occasional stimulants users (OSU and 50 comparison subjects (CS performed a "risky gains" decision making task during which they could select safe options (cash in 20 cents or gamble them for double or nothing in two consecutive gambles (win or lose 40 or 80 cents, "risky decisions". The primary analysis focused on risky versus safe decisions. Three secondary analyses were conducted: First, a robust regression examined the effect of lifetime exposure to stimulants and marijuana; second, subgroups of OSU with >1000 (n = 42, or <50 lifetime marijuana uses (n = 32, were compared to CS with <50 lifetime uses (n = 46 to examine potential marijuana effects; third, brain activation associated with behavioral adjustment following monetary losses was probed.There were no behavioral differences between groups. OSU showed attenuated activation across risky and safe decisions in prefrontal cortex, insula, and dorsal striatum, exhibited lower anterior cingulate cortex (ACC and dorsal striatum activation for risky decisions and greater inferior frontal gyrus activation for safe decisions. Those OSU with relatively more stimulant use showed greater dorsal ACC and posterior insula attenuation. In comparison, greater lifetime marijuana use was associated with less neural differentiation between risky and safe decisions. OSU who chose more safe responses after losses exhibited similarities with CS relative to those preferring risky options.Individuals at risk for the development of stimulant use disorders presented less differentiated neural processing of risky and safe options. Specifically, OSU show attenuated brain response in regions critical for performance monitoring

  14. Doubly Nonparametric Sparse Nonnegative Matrix Factorization Based on Dependent Indian Buffet Processes.

    Science.gov (United States)

    Xuan, Junyu; Lu, Jie; Zhang, Guangquan; Xu, Richard Yi Da; Luo, Xiangfeng

    2018-05-01

    Sparse nonnegative matrix factorization (SNMF) aims to factorize a data matrix into two optimized nonnegative sparse factor matrices, which could benefit many tasks, such as document-word co-clustering. However, the traditional SNMF typically assumes the number of latent factors (i.e., dimensionality of the factor matrices) to be fixed. This assumption makes it inflexible in practice. In this paper, we propose a doubly sparse nonparametric NMF framework to mitigate this issue by using dependent Indian buffet processes (dIBP). We apply a correlation function for the generation of two stick weights associated with each column pair of factor matrices while still maintaining their respective marginal distribution specified by IBP. As a consequence, the generation of two factor matrices will be columnwise correlated. Under this framework, two classes of correlation function are proposed: 1) using bivariate Beta distribution and 2) using Copula function. Compared with the single IBP-based NMF, this paper jointly makes two factor matrices nonparametric and sparse, which could be applied to broader scenarios, such as co-clustering. This paper is seen to be much more flexible than Gaussian process-based and hierarchial Beta process-based dIBPs in terms of allowing the two corresponding binary matrix columns to have greater variations in their nonzero entries. Our experiments on synthetic data show the merits of this paper compared with the state-of-the-art models in respect of factorization efficiency, sparsity, and flexibility. Experiments on real-world data sets demonstrate the efficiency of this paper in document-word co-clustering tasks.

  15. The position dependent influence that sensitivity correction processing gives the signal-to-noise ratio measurement in parallel imaging

    International Nuclear Information System (INIS)

    Murakami, Koichi; Yoshida, Koji; Yanagimoto, Shinichi

    2012-01-01

    We studied the position dependent influence that sensitivity correction processing gave the signal-to-noise ratio (SNR) measurement of parallel imaging (PI). Sensitivity correction processing that referred to the sensitivity distribution of the body coil improved regional uniformity more than the sensitivity uniformity correction filter with a fixed correction factor. In addition, the position dependent influence to give the SNR measurement in PI was different from the sensitivity correction processing. Therefore, if we divide SNR of the sensitivity correction processing image by SNR of the original image in each pixel and calculate SNR ratio, we can show the position dependent influence that sensitivity correction processing gives the SNR measurement in PI. It is with an index of the sensitivity correction processing precision. (author)

  16. Assessment of psychological dependence among tobacco users: A survey held among the rural population of India to call for attention of tobacco cessation centers.

    Science.gov (United States)

    Jadhav, Kiran; Singh, Dhanpal

    2013-07-01

    In India most of the tobacco cessation centers are concentrating only on urban population, whereas, literature reveals that it is rural population, which shows high frequency of consumption of tobacco. It is well known that high frequency of tobacco consumption is associated with psychological dependence. This study aimed at identifying, which form of tobacco consumption (smoking or smokeless) is associated with psychological dependence and is associated with which particular age group in rural population. It was a questionnaire based survey where 200 subjects were enrolled. Revised version of standard Fagerstrom Test for Nicotine dependence (FTND) was given to each subject to answer. The collected data was statistically analyzed by using Karl Pearson Correlation (r) test and Student's t-test. Study showed that subjects above 40 years of age are psychologically highly dependent on tobacco smoking as compared to tobacco chewing. Tobacco chewing is more prevalent among the younger population (20-30 years of age) and type of habit does not have any influence over psychological dependence below 40 years of age. A positive correlation was observed between duration of habit and psychological dependence in all age groups irrespective of type of the habit of tobacco consumption. This study attempts at creating a new avenue for the tobacco cessation centers where they can target their efforts towards rural population particularly people above 40 years of age with a tobacco smoking habit so that they can actually reduce the burden of a number of people at risk for developing tobacco associated oral cancer.

  17. Reconstructing the population activity of olfactory output neurons that innervate identifiable processing units

    Directory of Open Access Journals (Sweden)

    Shigehiro Namiki

    2008-06-01

    Full Text Available We investigated the functional organization of the moth antennal lobe (AL, the primary olfactory network, using in vivo electrophysiological recordings and anatomical identification. The moth AL contains about 60 processing units called glomeruli that are identifiable from one animal to another. We were able to monitor the output information of the AL by recording the activity of a population of output neurons, each of which innervated a single glomerulus. Using compiled intracellular recordings and staining data from different animals, we mapped the odor-evoked dynamics on a digital atlas of the AL and geometrically reconstructed the population activity. We examined the quantitative relationship between the similarity of olfactory responses and the anatomical distance between glomeruli. Globally, the olfactory response profile was independent of the anatomical distance, although some local features were present.

  18. Leveraging health information exchange to improve population health reporting processes: lessons in using a collaborative-participatory design process.

    Science.gov (United States)

    Revere, Debra; Dixon, Brian E; Hills, Rebecca; Williams, Jennifer L; Grannis, Shaun J

    2014-01-01

    Surveillance, or the systematic monitoring of disease within a population, is a cornerstone function of public health. Despite significant investment in information technologies (IT) to improve the public's health, health care providers continue to rely on manual, spontaneous reporting processes that can result in incomplete and delayed surveillance activities. Participatory design principles advocate including real users and stakeholders when designing an information system to ensure high ecological validity of the product, incorporate relevance and context into the design, reduce misconceptions designers can make due to insufficient domain expertise, and ultimately reduce barriers to adoption of the system. This paper focuses on the collaborative and informal participatory design process used to develop enhanced, IT-enabled reporting processes that leverage available electronic health records in a health information exchange to prepopulate notifiable-conditions report forms used by public health authorities. Over nine months, public health stakeholders, technical staff, and informatics researchers were engaged in a multiphase participatory design process that included public health stakeholder focus groups, investigator-engineering team meetings, public health survey and census regarding high-priority data elements, and codesign of exploratory prototypes and final form mock-ups. A number of state-mandated report fields that are not highly used or desirable for disease investigation were eliminated, which allowed engineers to repurpose form space for desired and high-priority data elements and improve the usability of the forms. Our participatory design process ensured that IT development was driven by end user expertise and needs, resulting in significant improvements to the layout and functionality of the reporting forms. In addition to informing report form development, engaging with public health end users and stakeholders through the participatory design

  19. Approaching tobacco dependence in youngsters: impact of an interactive smoking cessation program in a population of Romanian adolescents

    Directory of Open Access Journals (Sweden)

    Valentina Esanu

    2010-12-01

    Full Text Available Objectives: The main objective of this study was to investigate the effectiveness of an interactive smoking cessation program when first implemented in a naïve population of Romanian adolescents. The secondary objective was to assess youngsters’ attitudes and beliefs towards tobacco dependence, their compliance to smoking cessation interventions and success rate of a standard smoking cessation pilot program.Materials and methods: A total of 231 subjects 14-19 years old participated in the Adolescent Smoking Cessation (ASC pilot program in Romania in 2005. Subjects were evaluated based on the ASC questionnaire, a validated set of questions about smoking and cessation profile, whether current smoker or not. Smoking status was validated by carbon monoxide determination in exhaled air. Participants were delivered 6 interactive ASC sessions about smoking hazards and methods to quit smoking. A final evaluation was done to assess overall program’s impact and to reward quitters and reducers by prizes.Results: Study population was made of 52.4% every day smokers, 10.4% at least once/week but not every day smokers, 6% less than once/week smokers, 23.4% never smokers and 7.8% ex-smokers. Cessation rate was 12.3% in every day smokers and 16.6 % in at least once a week but not every day smokers. Also, 4.1% every day smokers and 30 % at least once/week not every day smokers reduced number of cigarettes smoked/day. The program registered a high attendance rate/sessions as 85.2 % of subjects were present in all sessions. Also, significant changes occurred in participant’s beliefs about smoking and cessation.Conclusions: Pilot ASC was an efficient program with 12.3% of daily smokers to quit smoking and its positive impact on personal smoking and cessation beliefs in 90 % of participants. J Clin Exp Invest 2010; 1(3: 150-155

  20. Audit diabetes-dependent quality of life questionnaire: usefulness in diabetes self-management education in the Slovak population.

    Science.gov (United States)

    Holmanová, Elena; Ziaková, Katarína

    2009-05-01

    This paper reports a study to test validity and internal consistency of the audit diabetes-dependent quality of life questionnaire in the Slovak population and to evaluate its usefulness in the context of education of people with diabetes. The individualised instruments designed to measure individuals' perceptions of the impact of diabetes on their quality of life may be helpful to identify individuals' preferences, motivational deficits in diabetes management and to tailor individual treatment strategies. Survey. After linguistic validation, the structure of the questionnaire was tested using factor analysis on 104 patients who were recruited from the National Institute of Endocrinology and Diabetology in Lubochna. Internal consistency was evaluated by computing Cronbach's alpha. Clinical variables related to the quality of life were analysed using one-way ANOVA, multifactor ANOVA, Pearson's and Spearman's rank correlation coefficients. A one-dimensional scale structure was supported and internal consistency was high (alpha = 0.93). Variance in impact of diabetes on quality of life was explained by age, presence of late complications and type of insulin regimen. The audit diabetes-dependent quality of life is culturally appropriate, valid and reliable in the sample of Slovak patients attending the educational programme. Our results agreed with previous European and Asian studies supporting its usefulness in the context of diabetes self-management education. Individualised diabetes-specific quality of life measures allow better understanding of patients' treatment preferences and, consequently, more effective prioritizing and targeting of appropriate educational interventions. This instrument may be useful in routine clinical practice and as an outcome measure for international clinical research trials evaluating effectiveness of educational programmes.

  1. Development of a Population Balance Model of a pharmaceutical drying process and testing of solution methods

    DEFF Research Database (Denmark)

    Mortier, Séverine Thérèse F.C.; Gernaey, Krist; De Beer, Thomas

    2013-01-01

    Drying is frequently used in the production of pharmaceutical tablets. Simulation-based control strategy development for such a drying process requires a detailed model. First, the drying of wet granules is modelled using a Population Balance Model. A growth term based on a reduced model was used......, which describes the decrease of the moisture content, to follow the moisture content distribution for a batch of granules. Secondly, different solution methods for solving the PBM are compared. The effect of grid size (discretization methods) is analyzed in terms of accuracy and calculation time. All...

  2. A semigroup approach to the strong ergodic theorem of the multistate stable population process.

    Science.gov (United States)

    Inaba, H

    1988-01-01

    "In this paper we first formulate the dynamics of multistate stable population processes as a partial differential equation. Next, we rewrite this equation as an abstract differential equation in a Banach space, and solve it by using the theory of strongly continuous semigroups of bounded linear operators. Subsequently, we investigate the asymptotic behavior of this semigroup to show the strong ergodic theorem which states that there exists a stable distribution independent of the initial distribution. Finally, we introduce the dual problem in order to obtain a logical definition for the reproductive value and we discuss its applications." (SUMMARY IN FRE) excerpt

  3. Paradox effects of binge drinking on response inhibition processes depending on mental workload.

    Science.gov (United States)

    Stock, Ann-Kathrin; Riegler, Lea; Chmielewski, Witold X; Beste, Christian

    2016-06-01

    Binge drinking is an increasing problem in Western societies, but we are still only beginning to unravel the effects of binge drinking on a cognitive level. While common sense suggests that all cognitive functions are compromised during high-dose ethanol intoxication, several studies suggest that the effects might instead be rather specific. Moreover, some results suggest that the degrees of automaticity and complexity of cognitive operations during response control modulate effects of binge drinking. However, this has not been tested in detail. In the current study, we therefore parametrically modulate cognitive/"mental" workload during response inhibition and examine the effects of high-dose ethanol intoxication (~1.1 ‰) in n = 18 male participants. The results suggest that detrimental effects of high-dose ethanol intoxication strongly depend on the complexity of processes involved in response inhibition. The results revealed strong effects (η (2) = .495) and are in line with findings showing that even high doses of ethanol have very specific effects on a cognitive level. Opposed to common sense, more complex cognitive operations seem to be less affected by a high-dose ethanol intoxication. Complementing this, high-dose ethanol intoxication is increasingly detrimental for action control, as stronger automated response tendencies are in charge and need to be controlled. Binge-like ethanol intoxication may take a heavier toll on cognitive control processes than on automated responses/response tendencies. Therefore, ethanol effects are more pronounced in supposedly "easier" control conditions because those facilitate the formation of automated response tendencies.

  4. Discharge time dependence of a solution plasma process for colloidal copper nanoparticle synthesis and particle characteristics

    International Nuclear Information System (INIS)

    Pootawang, Panuphong; Saito, Nagahiro; Lee, Sang Yul

    2013-01-01

    In this study, we investigate a new synthetic route, termed the solution plasma process, for the synthesis of colloidal copper nanoparticles (CuNPs) in the presence of an amide and acid capping agent. Gelatin and ascorbic acid were selected as the capping agents to protect the particles against coalescence and oxidation side reaction. Using a high voltage power supply, CuNPs were rapidly formed by 1 min after the discharge. The size and shape of the CuNPs were dependent on the discharge time and were clearly influenced by the effect of the capping agents under two characteristics of the discharge medium (pH and temperature). With a long discharge time, the CuNP size tended to decrease with the formation of anisotropic particle morphologies: spherical, cubic, hexagonal, triangular and rod-like shapes. The decrease in CuNP size as a function of discharge time could be explained by the dissolution of CuNPs in a lower pH solution. After 5 min discharge the capping agent evidently allowed the protection of the synthesized CuNPs against oxidation with the presence of anisotropic CuNP shapes. It is demonstrated that the CuNP shape could be tuned from spherical to anisotropic shapes without the undesirable oxidation by adjusting the discharge time of the solution plasma. These advantages are valuable for material engineering to design the properties of Cu-based nanoparticles for the desired applications. (paper)

  5. Proton gradients and proton-dependent transport processes in the chloroplast

    Directory of Open Access Journals (Sweden)

    Ricarda eHöhner

    2016-02-01

    Full Text Available Proton gradients are fundamental to chloroplast function. Across thylakoid membranes, the light induced proton gradient is essential for ATP synthesis. As a result of proton pumping into the thylakoid lumen, an alkaline stromal pH develops, which is required for full activation of pH-dependent Calvin Benson cycle enzymes. This implies that a pH gradient between the cytosol (pH 7 and the stroma (pH 8 is established upon illumination. To maintain this pH gradient chloroplasts actively extrude protons. More than 30 years ago it was already established that these proton fluxes are electrically counterbalanced by Mg2+, K+ or Cl- fluxes, but only recently the first transport systems that regulate the pH gradient were identified. Notably several (Na+,K+/H+ antiporter systems where identified, that play a role in pH gradient regulation, ion homeostasis, osmoregulation, or coupling of secondary active transport. The established pH gradients are important to drive uptake of essential ions and solutes, but not many transporters involved have been identified to date. In this mini review we summarize the current status in the field and the open questions that need to be addressed in order to understand how pH gradients are maintained, how this is interconnected with other transport processes and what this means for chloroplast function.

  6. Experimentally testing the dependence of momentum transport on second derivatives using Gaussian process regression

    Science.gov (United States)

    Chilenski, M. A.; Greenwald, M. J.; Hubbard, A. E.; Hughes, J. W.; Lee, J. P.; Marzouk, Y. M.; Rice, J. E.; White, A. E.

    2017-12-01

    It remains an open question to explain the dramatic change in intrinsic rotation induced by slight changes in electron density (White et al 2013 Phys. Plasmas 20 056106). One proposed explanation is that momentum transport is sensitive to the second derivatives of the temperature and density profiles (Lee et al 2015 Plasma Phys. Control. Fusion 57 125006), but it is widely considered to be impossible to measure these higher derivatives. In this paper, we show that it is possible to estimate second derivatives of electron density and temperature using a nonparametric regression technique known as Gaussian process regression. This technique avoids over-constraining the fit by not assuming an explicit functional form for the fitted curve. The uncertainties, obtained rigorously using Markov chain Monte Carlo sampling, are small enough that it is reasonable to explore hypotheses which depend on second derivatives. It is found that the differences in the second derivatives of n{e} and T{e} between the peaked and hollow rotation cases are rather small, suggesting that changes in the second derivatives are not likely to explain the experimental results.

  7. Crossmodal processing of emotions in alcohol-dependence and Korsakoff syndrome.

    Science.gov (United States)

    Brion, Mélanie; D'Hondt, Fabien; Lannoy, Séverine; Pitel, Anne-Lise; Davidoff, Donald A; Maurage, Pierre

    2017-09-01

    Decoding emotional information from faces and voices is crucial for efficient interpersonal communication. Emotional decoding deficits have been found in alcohol-dependence (ALC), particularly in crossmodal situations (with simultaneous stimulations from different modalities), but are still underexplored in Korsakoff syndrome (KS). The aim of this study is to determine whether the continuity hypothesis, postulating a gradual worsening of cognitive and brain impairments from ALC to KS, is valid for emotional crossmodal processing. Sixteen KS, 17 ALC and 19 matched healthy controls (CP) had to detect the emotion (anger or happiness) displayed by auditory, visual or crossmodal auditory-visual stimuli. Crossmodal stimuli were either emotionally congruent (leading to a facilitation effect, i.e. enhanced performance for crossmodal condition compared to unimodal ones) or incongruent (leading to an interference effect, i.e. decreased performance for crossmodal condition due to discordant information across modalities). Reaction times and accuracy were recorded. Crossmodal integration for congruent information was dampened only in ALC, while both ALC and KS demonstrated, compared to CP, decreased performance for decoding emotional facial expressions in the incongruent condition. The crossmodal integration appears impaired in ALC but preserved in KS. Both alcohol-related disorders present an increased interference effect. These results show the interest of more ecological designs, using crossmodal stimuli, to explore emotional decoding in alcohol-related disorders. They also suggest that the continuum hypothesis cannot be generalised to emotional decoding abilities.

  8. Hippocampal Theta-Gamma Coupling Reflects State-Dependent Information Processing in Decision Making.

    Science.gov (United States)

    Amemiya, Seiichiro; Redish, A David

    2018-03-20

    During decision making, hippocampal activity encodes information sometimes about present and sometimes about potential future plans. The mechanisms underlying this transition remain unknown. Building on the evidence that gamma oscillations at different frequencies (low gamma [LG], 30-55 Hz; high gamma [HG], 60-90 Hz; and epsilon, 100-140 Hz) reflect inputs from different circuits, we identified how changes in those frequencies reflect different information-processing states. Using a unique noradrenergic manipulation by clonidine, which shifted both neural representations and gamma states, we found that future representations depended on gamma components. These changes were identifiable on each cycle of theta as asymmetries in the theta cycle, which arose from changes within the ratio of LG and HG power and the underlying phases of those gamma rhythms within the theta cycle. These changes in asymmetry of the theta cycle reflected changes in representations of present and future on each theta cycle. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  9. Expression-dependent susceptibility to face distortions in processing of facial expressions of emotion.

    Science.gov (United States)

    Guo, Kun; Soornack, Yoshi; Settle, Rebecca

    2018-03-05

    Our capability of recognizing facial expressions of emotion under different viewing conditions implies the existence of an invariant expression representation. As natural visual signals are often distorted and our perceptual strategy changes with external noise level, it is essential to understand how expression perception is susceptible to face distortion and whether the same facial cues are used to process high- and low-quality face images. We systematically manipulated face image resolution (experiment 1) and blur (experiment 2), and measured participants' expression categorization accuracy, perceived expression intensity and associated gaze patterns. Our analysis revealed a reasonable tolerance to face distortion in expression perception. Reducing image resolution up to 48 × 64 pixels or increasing image blur up to 15 cycles/image had little impact on expression assessment and associated gaze behaviour. Further distortion led to decreased expression categorization accuracy and intensity rating, increased reaction time and fixation duration, and stronger central fixation bias which was not driven by distortion-induced changes in local image saliency. Interestingly, the observed distortion effects were expression-dependent with less deterioration impact on happy and surprise expressions, suggesting this distortion-invariant facial expression perception might be achieved through the categorical model involving a non-linear configural combination of local facial features. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Anatomic Variation in Morphometry of Human Coracoid Process among Asian Population

    Directory of Open Access Journals (Sweden)

    Manal Fathi

    2017-01-01

    Full Text Available Ethnic origin plays an important role in bone morphometry. Studies examining the influence of coracoid process have focused primarily on adults and have not included people from diverse Asian ethnic backgrounds. Our goal was to explore ethnic differences in morphometry of coracoid among Asian population. We performed morphometric measurements of coracoid process on cadaveric shoulders and shoulder CT scans from 118 specimens. The cadaveric sample included Indian (46%, Chinese (27%, and Myanmarese (27% subjects, while the CT scans sample included Chinese (67% and Malay (33% subjects. The morphometric measurements were performed using digital caliper and software developed at Golden Horses Health Sanctuary (GHHS. In the Indian cadaveric shoulders, the coracoid process is better developed than the other groups with the exception of the tip width of coracoid process. There are significant differences in almost all measurements (P<0.05 between the ethnic groups. On the other hand, the morphometry of coracoid process from CT scans data is bigger in Chinese than Malay subjects when stratified by sex (P<0.05. Moreover, in all morphometric measurements, the females had smaller measurements than males (P<0.05. Understanding such differences is important in anatomy, forensic and biological identity, and orthopaedic and shoulder surgeries.

  11. Advertising of ultra-processed foods and beverages: children as a vulnerable population

    Directory of Open Access Journals (Sweden)

    Christina Mallarino

    2013-10-01

    Full Text Available The rapid nutrition transition occurring in Latin America has resulted in a sharp increase of childhood overweight and obesity. Recent evidence has shown that food and beverage advertising has a great influence on children’s eating behavior. This population has become a key target market for the ultra-processed foods and beverages industry, which is marketing products in an aggressive way. Evidence shows that Latin American countries have poor regulation of ultra-processed foods and beverages advertising, where the discourse of self-regulation still prevails over statutory regulations. The following commentary explores how advertising might play an important role in developing unhealthy dietary patterns and obesity in Latin American children, as well as the urgent need for government action and the involvement of civil society to tackle this public health issue.

  12. Advertising of ultra-processed foods and beverages: children as a vulnerable population.

    Science.gov (United States)

    Mallarino, Christina; Gómez, Luis F; González-Zapata, Laura; Cadena, Yazmín; Parra, Diana C

    2013-10-01

    The rapid nutrition transition occurring in Latin America has resulted in a sharp increase of childhood overweight and obesity. Recent evidence has shown that food and beverage advertising has a great influence on children's eating behavior. This population has become a key target market for the ultra-processed foods and beverages industry, which is marketing products in an aggressive way. Evidence shows that Latin American countries have poor regulation of ultra-processed foods and beverages advertising, where the discourse of self-regulation still prevails over statutory regulations. The following commentary explores how advertising might play an important role in developing unhealthy dietary patterns and obesity in Latin American children, as well as the urgent need for government action and the involvement of civil society to tackle this public health issue.

  13. Linking individual phenotype to density-dependent population growth: the influence of body size on the population dynamics of malaria vectors

    NARCIS (Netherlands)

    Russell, T.L.; Lwetoijera, D.W.; Knols, B.G.J.; Takken, W.; Killeen, G.F.; Ferguson, H.M.

    2011-01-01

    Understanding the endogenous factors that drive the population dynamics of malaria mosquitoes will facilitate more accurate predictions about vector control effectiveness and our ability to destabilize the growth of either low- or high-density insect populations. We assessed whether variation in

  14. Linking individual phenotype to density-dependent population growth: the influence of body size on the population dynamics of malaria vectors

    NARCIS (Netherlands)

    Russell, T.L.; Lwetoijera, D.W.; Knols, B.G.J.; Takken, W.; Killeen, G.F.; Ferguson, H.M.

    2011-01-01

    Understanding the endogenous factors that drive the population dynamics of malaria mosquitoes will facilitate more accurate predictions about vector control effectiveness and our ability to destabilize the growth of either low-or high-density insect populations. We assessed whether variation in

  15. The impact of media type on shared decision processes in third-age populations.

    Science.gov (United States)

    Reychav, Iris; Najami, Inam; Raban, Daphne Ruth; McHaney, Roger; Azuri, Joseph

    2018-04-01

    To examine the relationship between the media, through which medical information was made available (e.g. digital versus printed), and the patients' desire to play an active part in a medical decision in an SDM or an ISDM-based process. The goal of this research was to expand knowledge concerning social and personal factors that affect and explain patients' willingness to participate in the process. A questionnaire was distributed in this empirical study of 103 third-age participants. A theoretical model formed the basis for the study and utilized a variety of factors from technology acceptance, as well as personal and environmental influences to investigate the likelihood of subjects preferring a certain decision-making approach. The research population included men and women aged 65 or older who resided in five assisted living facilities in Israel. The sample was split randomly into 2 groups. One group used digital information and the other print. A path analysis was conducted, using Structural Equation Modelling (SEM) in AMOS SPSS, to determine the influence of the information mode of presentation on the patient's choice of the SDM or ISDM model. When digital media was accessible, the information's perceived usefulness (PU) led participants to choose an ISDM-based process; this was not true with printed information. When information was available online, higher self-efficacy (SE) led participants to prefer an SDM-based process. When the information was available in print, a direct positive influence was found on the participant's choice of SDM, while a direct negative influence was found on their choice of an ISDM-based process. PU was found to be affected by external peer influences, particularly when resources were made available in print. This meant that digital resources tended to be accepted at face value more readily. Cognitive absorption had a positive effect on the research variables only when the information was available digitally. The findings suggest

  16. Consolidating birth-death and death-birth processes in structured populations.

    Directory of Open Access Journals (Sweden)

    Joshua Zukewich

    Full Text Available Network models extend evolutionary game theory to settings with spatial or social structure and have provided key insights on the mechanisms underlying the evolution of cooperation. However, network models have also proven sensitive to seemingly small details of the model architecture. Here we investigate two popular biologically motivated models of evolution in finite populations: Death-Birth (DB and Birth-Death (BD processes. In both cases reproduction is proportional to fitness and death is random; the only difference is the order of the two events at each time step. Although superficially similar, under DB cooperation may be favoured in structured populations, while under BD it never is. This is especially troubling as natural populations do not follow a strict one birth then one death regimen (or vice versa; such constraints are introduced to make models more tractable. Whether structure can promote the evolution of cooperation should not hinge on a simplifying assumption. Here, we propose a mixed rule where in each time step DB is used with probability δ and BD is used with probability 1-δ. We derive the conditions for selection favouring cooperation under the mixed rule for all social dilemmas. We find that the only qualitatively different outcome occurs when using just BD (δ = 0. This case admits a natural interpretation in terms of kin competition counterbalancing the effect of kin selection. Finally we show that, for any mixed BD-DB update and under weak selection, cooperation is never inhibited by population structure for any social dilemma, including the Snowdrift Game.

  17. Convergent processing of both positive and negative motivational signals by the VTA dopamine neuronal populations.

    Directory of Open Access Journals (Sweden)

    Dong V Wang

    2011-02-01

    Full Text Available Dopamine neurons in the ventral tegmental area (VTA have been traditionally studied for their roles in reward-related motivation or drug addiction. Here we study how the VTA dopamine neuron population may process fearful and negative experiences as well as reward information in freely behaving mice. Using multi-tetrode recording, we find that up to 89% of the putative dopamine neurons in the VTA exhibit significant activation in response to the conditioned tone that predict food reward, while the same dopamine neuron population also respond to the fearful experiences such as free fall and shake events. The majority of these VTA putative dopamine neurons exhibit suppression and offset-rebound excitation, whereas ∼25% of the recorded putative dopamine neurons show excitation by the fearful events. Importantly, VTA putative dopamine neurons exhibit parametric encoding properties: their firing change durations are proportional to the fearful event durations. In addition, we demonstrate that the contextual information is crucial for these neurons to respectively elicit positive or negative motivational responses by the same conditioned tone. Taken together, our findings suggest that VTA dopamine neurons may employ the convergent encoding strategy for processing both positive and negative experiences, intimately integrating with cues and environmental context.

  18. Population-Based Analysis of Histologically Confirmed Melanocytic Proliferations Using Natural Language Processing.

    Science.gov (United States)

    Lott, Jason P; Boudreau, Denise M; Barnhill, Ray L; Weinstock, Martin A; Knopp, Eleanor; Piepkorn, Michael W; Elder, David E; Knezevich, Steven R; Baer, Andrew; Tosteson, Anna N A; Elmore, Joann G

    2018-01-01

    Population-based information on the distribution of histologic diagnoses associated with skin biopsies is unknown. Electronic medical records (EMRs) enable automated extraction of pathology report data to improve our epidemiologic understanding of skin biopsy outcomes, specifically those of melanocytic origin. To determine population-based frequencies and distribution of histologically confirmed melanocytic lesions. A natural language processing (NLP)-based analysis of EMR pathology reports of adult patients who underwent skin biopsies at a large integrated health care delivery system in the US Pacific Northwest from January 1, 2007, through December 31, 2012. Skin biopsy procedure. The primary outcome was histopathologic diagnosis, obtained using an NLP-based system to process EMR pathology reports. We determined the percentage of diagnoses classified as melanocytic vs nonmelanocytic lesions. Diagnoses classified as melanocytic were further subclassified using the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis (MPATH-Dx) reporting schema into the following categories: class I (nevi and other benign proliferations such as mildly dysplastic lesions typically requiring no further treatment), class II (moderately dysplastic and other low-risk lesions that may merit narrow reexcision with skin biopsies, performed on 47 529 patients, were examined. Nearly 1 in 4 skin biopsies were of melanocytic lesions (23%; n = 18 715), which were distributed according to MPATH-Dx categories as follows: class I, 83.1% (n = 15 558); class II, 8.3% (n = 1548); class III, 4.5% (n = 842); class IV, 2.2% (n = 405); and class V, 1.9% (n = 362). Approximately one-quarter of skin biopsies resulted in diagnoses of melanocytic proliferations. These data provide the first population-based estimates across the spectrum of melanocytic lesions ranging from benign through dysplastic to malignant. These results may serve as a foundation for future

  19. Validating the extract, transform, load process used to populate a large clinical research database.

    Science.gov (United States)

    Denney, Michael J; Long, Dustin M; Armistead, Matthew G; Anderson, Jamie L; Conway, Baqiyyah N

    2016-10-01

    Informaticians at any institution that are developing clinical research support infrastructure are tasked with populating research databases with data extracted and transformed from their institution's operational databases, such as electronic health records (EHRs). These data must be properly extracted from these source systems, transformed into a standard data structure, and then loaded into the data warehouse while maintaining the integrity of these data. We validated the correctness of the extract, load, and transform (ETL) process of the extracted data of West Virginia Clinical and Translational Science Institute's Integrated Data Repository, a clinical data warehouse that includes data extracted from two EHR systems. Four hundred ninety-eight observations were randomly selected from the integrated data repository and compared with the two source EHR systems. Of the 498 observations, there were 479 concordant and 19 discordant observations. The discordant observations fell into three general categories: a) design decision differences between the IDR and source EHRs, b) timing differences, and c) user interface settings. After resolving apparent discordances, our integrated data repository was found to be 100% accurate relative to its source EHR systems. Any institution that uses a clinical data warehouse that is developed based on extraction processes from operational databases, such as EHRs, employs some form of an ETL process. As secondary use of EHR data begins to transform the research landscape, the importance of the basic validation of the extracted EHR data cannot be underestimated and should start with the validation of the extraction process itself. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Anatomic Variation in Morphometry of Human Coracoid Process among Asian Population.

    Science.gov (United States)

    Fathi, Manal; Cheah, Pike-See; Ahmad, Umar; Nasir, M Nizlan; San, Aye Aye; Abdul Rahim, Ezamin; Hussin, Paisal; Mahmud, Rozi; Othman, Fauziah

    2017-01-01

    Ethnic origin plays an important role in bone morphometry. Studies examining the influence of coracoid process have focused primarily on adults and have not included people from diverse Asian ethnic backgrounds. Our goal was to explore ethnic differences in morphometry of coracoid among Asian population. We performed morphometric measurements of coracoid process on cadaveric shoulders and shoulder CT scans from 118 specimens. The cadaveric sample included Indian (46%), Chinese (27%), and Myanmarese (27%) subjects, while the CT scans sample included Chinese (67%) and Malay (33%) subjects. The morphometric measurements were performed using digital caliper and software developed at Golden Horses Health Sanctuary (GHHS). In the Indian cadaveric shoulders, the coracoid process is better developed than the other groups with the exception of the tip width of coracoid process. There are significant differences in almost all measurements ( P Chinese than Malay subjects when stratified by sex ( P < 0.05). Moreover, in all morphometric measurements, the females had smaller measurements than males ( P < 0.05). Understanding such differences is important in anatomy, forensic and biological identity, and orthopaedic and shoulder surgeries.

  1. Match or mismatch: the influence of phenology on size-dependent life history and divergence in population structure

    Science.gov (United States)

    Borcherding, Jost; Beeck, Peter; DeAngelis, Donald L.; Scharf, Werner R.

    2010-01-01

    age cohort of the predator. 6. The results demonstrate that the switch between competitive interactions and a predator-prey relationship depended on phenology. This resulted in pronounced size differences in the YOY age cohort, which had far-reaching consequences for the entire predator population.

  2. Temperature dependent development parameters and population life table of beet armyworm, Spodoptera exigua (Hübner (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    HonQing Dai

    2017-12-01

    Full Text Available Beet armyworm, Spodoptera exigua (Hübner, is an important insect pest fed on many crops. Temperature and host plant dependent development, survival, and population parameters of S. exigua were studied in present article. The results showed that the generation duration of S. exigua at temperatures 20, 25, 27, 30, and 35 ℃ were 37.61, 30.78, 22.40, 18.57, and 13.74 days, respectively. S. exigua could not survive at 38 ℃. The generation duration of S. exigua, feeding on Lactuca sativa, Lactuca Sativa L., Raphanus sativus L., and Allium fistulosum at 27 ℃, were 18.86, 20.10, 22.67, and 22.50 days respectively. And the generation survivorship was 30.91, 29.00, 22.00, and 27.50% respectively, far less than observed 81.91% feeding on artificial diet. S. exigua feeding on L. sativa showed the highest net reproduction rate (216.29, intrinsic rate for increase (0.34, population trend index (76.59, finite rate for increase (1.33, and fecundity (606.5 eggs, while these values were the lowest when it fed on A. fistulosum. Relationship between development rate and temperature was fitted with three models, the linear model, Logistic model and Wang model, and Wang model produced the best fitting goodness. Wang model showed that for the egg, the 1st-5th instar larvae, pupa and adult of S. exigua, the upper limit temperatures for development are 45, 44.5, 44.4, 40.3, 43.6, 38.9, 38, and 38 ℃, resepctively; the lower limit temperatures for development are 7.5, 7.2, 13.4, 7.3, 6.6, 5.3, 5.6, and 5.6 ℃, respectively, and the optimum temperatures for development are 21.9, 28.9, 25.5, 24.5, 26, 31.6, 30.6, and 29.1 ℃, respectively. The upper limit, lower limit and optimum temperatures for development of the entire generation are 38, 5.7 and 30 ℃, resepctively.

  3. Ocular allergy modulation to hi-dose antigen sensitization is a Treg-dependent process.

    Science.gov (United States)

    Lee, Hyun Soo; Schlereth, Simona; Khandelwal, Payal; Saban, Daniel R

    2013-01-01

    A reproducible method to inhibit allergic immune responses is accomplished with hi-dose Ag sensitization, via intraperitoneal (IP) injection. However, the role of CD4+ CD25+ FoxP3+ T regulatory cells (Treg) in this process is unknown, as is whether such modulation extends to ocular allergy. We therefore determined herein whether hi-dose sensitization modulates ocular allergy, and whether CD4+ CD25+ FoxP3+ Treg are involved. C57BL/6 mice were IP sensitized via low-dose (100 µg) versus hi-dose (1000 µg) ovalbumin (OVA), in aluminum hydroxide (1 mg) and pertussis-toxin (300 ng). Other mice received anti-CD25 Ab (PC61) to ablate Treg during sensitization. In another experiment, Treg from hi-dose sensitized mice were adoptively transferred into low-dose sensitized mice. Once daily OVA challenges were administered. Clinical signs, IgE, T cell cytokines, and eosinophils were assessed. Data revealed that hi-dose, but not low-dose, sensitization led to allergy modulation, indicated by decreased clinical signs, serum IgE levels, Th2 recall responses, and eosinophil recruitment. T cells from hi-dose sensitized mice showed a robust increase in TGF-b production, and Treg from these mice were able to efficiently suppress effector T cell proliferation in vitro. In addition, in vivo Treg ablation in hi-dose sensitized mice revoked allergy modulation. Lastly, Treg from hi-dose sensitized mice were able to adoptively transfer allergy modulation to their low-dose sensitized counterparts. Collectively, these findings indicate that modulation to hi-dose sensitization, which is extended to ocular allergy, occurs in a Treg-dependent manner. In addition, our data suggest that hi-dose sensitization may henceforth facilitate the further examination of CD4+ CD25+ FoxP3+ Treg in allergic disease.

  4. The impact on environment and population of the sands with radioactive heavy minerals processing activity

    International Nuclear Information System (INIS)

    Aurelian, F.; Popescu, M.; Georgescu, D.

    2006-01-01

    The paper presents a case study concerning the impact on environment and population of a Pilot Station, which was used between 1970 and 1996 to obtain mono-mineral concentrates (ilmenite, zircon, garnet, rutile, monazite) by processing alluvial and seashore sands. The processing technological flow sheet was constituted only of physical separation processes, where were operating equipments such as shaking tables, electric and magnetic separators, attrition equipments, etc. The paper is structured on three levels and presents: - A brief description of the Pilot Station activity, sand types processed and its physical, chemical and mineralogic characteristics. The obtained products were: garnets with 10 ppm uranium and 60 ppm thorium, ilmenite with 10 ppm uranium and 20 ppm thorium, zircon with 450 ppm uranium and 750 ppm thorium and monazite with 3,000 ppm uranium and 20,000 ppm thorium. The sterile accumulated during the Pilot Station functioning time is also characterized. - The impact of the Pilot Station activity on environment (soil, air). The contamination sources are identified and characterized. The only one contamination pathway is represented by 'radioactive dust' resulted from the sands processing activity. The contamination processes are explained and justified. The contaminated soil surface was investigated through: gamma rate doses determination (at the surface and on a depth o f up to 40 cm), measurement of Rn 222 + Rn 220 concentration at one meter distance from the surface and for 40 cm soil depth, analysis of uranium, radium and thorium for samples collected from a soil depth ranging between 10 and 40 cm. There were elaborated maps showing gamma rate doses distribution and the specific activity for the surface as well as for the different soil depths. It was established the contamination level and its value was compared to the ones stipulated by Romanian Nuclear Authority norms, namely 0.2 Bq/g for the specific activity (Ra 226 + Th 232) and 0.3

  5. An epidemiological model of viral infections in a Varroa-infested bee colony: the case of a bee-dependent mite population size

    OpenAIRE

    Bernardi, Sara; Venturino, Ezio

    2016-01-01

    In recent years the spread of the ectoparasitic mite Varroa destructor has become the most serious threat to worldwide apiculture. In the model presented here we extend the bee population dynamics with mite viral epidemiology examined in an earlier paper by allowing a bee-dependent mite population size. The results of the analysis match field observations well and give a clear explanation of how Varroa affects the epidemiology of certain naturally occurring bee viruses, causing considerable d...

  6. CCR6 is expressed on an IL-10-producing, autoreactive memory T cell population with context-dependent regulatory function.

    Science.gov (United States)

    Rivino, Laura; Gruarin, Paola; Häringer, Barbara; Steinfelder, Svenja; Lozza, Laura; Steckel, Bodo; Weick, Anja; Sugliano, Elisa; Jarrossay, David; Kühl, Anja A; Loddenkemper, Christoph; Abrignani, Sergio; Sallusto, Federica; Lanzavecchia, Antonio; Geginat, Jens

    2010-03-15

    Interleukin (IL)-10 produced by regulatory T cell subsets is important for the prevention of autoimmunity and immunopathology, but little is known about the phenotype and function of IL-10-producing memory T cells. Human CD4(+)CCR6(+) memory T cells contained comparable numbers of IL-17- and IL-10-producing cells, and CCR6 was induced under both Th17-promoting conditions and upon tolerogenic T cell priming with transforming growth factor (TGF)-beta. In normal human spleens, the majority of CCR6(+) memory T cells were in the close vicinity of CCR6(+) myeloid dendritic cells (mDCs), and strikingly, some of them were secreting IL-10 in situ. Furthermore, CCR6(+) memory T cells produced suppressive IL-10 but not IL-2 upon stimulation with autologous immature mDCs ex vivo, and secreted IL-10 efficiently in response to suboptimal T cell receptor (TCR) stimulation with anti-CD3 antibodies. However, optimal TCR stimulation of CCR6(+) T cells induced expression of IL-2, interferon-gamma, CCL20, and CD40L, and autoreactive CCR6(+) T cell lines responded to various recall antigens. Notably, we isolated autoreactive CCR6(+) T cell clones with context-dependent behavior that produced IL-10 with autologous mDCs alone, but that secreted IL-2 and proliferated upon stimulation with tetanus toxoid. We propose the novel concept that a population of memory T cells, which is fully equipped to participate in secondary immune responses upon recognition of a relevant recall antigen, contributes to the maintenance of tolerance under steady-state conditions.

  7. Identification and medical utilization of incident cases of alcohol dependence: A population-based case-control study.

    Science.gov (United States)

    Pan, Chun-Hung; Li, Min-Shan; Yang, Tien-Wey; Huang, Ming-Chyi; Su, Sheng-Shiang; Hung, Yen-Ni; Chen, Chiao-Chicy; Kuo, Chian-Jue

    2018-05-05

    Patients with alcohol dependence (AD) often seek help from medical professionals due to alcohol-related diseases, but the overall distribution of medical specialties identifying new AD cases is unclear. We investigated how such cases were identified and how medical resources were utilized before the identification of AD in a nationwide cohort. We enrolled a population-based cohort (N = 1,000,000) using the National Health Insurance Research Database of Taiwan; 8181 cases with incident AD were retrieved between January 1, 2000, and December 31, 2010. For this nested case-control study, four controls were matched for age and sex with each case based on risk-set sampling. We measured various dimensions of medical utilization before AD was diagnosed, including department visited, physical comorbidity, and medication used. Conditional logistic regression was used for estimating the variables associated with AD. Patients living in less urbanized areas who were unemployed were more likely to develop AD. The highest proportions (34.2%) of AD cases were identified in the internal medicine department, followed by the emergency (22.3%) and psychiatry (18.7%) departments. AD patients had a higher risk of comorbid chronic hepatic disease (adjusted RR = 2.72, p identification of AD than controls. AD patients also had greater numbers of hospital admissions than controls, including non-psychiatric and psychiatric hospitalizations. Outpatient visit numbers were similar for AD patients and controls. The findings indicate that clinicians providing care in diverse medical settings should be prepared to screen for unhealthy alcohol use and to mitigate its detrimental effects. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Error Processing and Gender-Shared and -Specific Neural Predictors of Relapse in Cocaine Dependence

    Science.gov (United States)

    Luo, Xi; Zhang, Sheng; Hu, Sien; Bednarski, Sarah R.; Erdman, Emily; Farr, Olivia M.; Hong, Kwang-Ik; Sinha, Rajita; Mazure, Carolyn M.; Li, Chiang-shan R.

    2013-01-01

    Deficits in cognitive control are implicated in cocaine dependence. Previously, combining functional magnetic resonance imaging and a stop signal task, we demonstrated altered cognitive control in cocaine-dependent individuals. However, the clinical implications of these cross-sectional findings and, in particular, whether the changes were…

  9. Changes in population of S. enterica serotype Enteritidis in experimentally contaminated milk depending on temperature and acidity

    Directory of Open Access Journals (Sweden)

    Rajić-Savić Nataša

    2009-01-01

    Full Text Available Salmonella bacteria are among the most frequent causes of food poisoning, and milk and milk products are food items through which these bacteria can be transmitted. More recent data indicate that the infective dose of Salmonella is very small - up to 101/g/ml food. The preservation of Salmonella in milk depends on the acidity, temperature and the duration of storage. The objective of the work was to examine the survival of Salmonella in milk depending on the changes of the total number of bacteria, pH and temperature. In the study, 0.1 ml of 24-hour bouillon culture of S. enteritidis was inoculated in raw collective milk (104 cfu/ml and in marketed pasteurized milk (102 cfu/ml each. The examined milk samples were maintained at room temperature and at a temperature of 7oC. At the beginning of the examinations, after 24h, 48h, 72h, after 7, 14 and 21 days, decimal solutions were made from the milk, and, following incubation, the number of S. enteritidis was determined (Rambach agar, the total number of bacteria (base for total number of bacteria by multiplying the number of grown colonies and the corresponding solution, and the milk pH was measured. There was a bigger reduction of S. enteritidis at room temperature because the pH value dropped more swiftly. The lowest pH at which S. enteritidis was isolated from experimentally contaminated milk was 3.88. The results of the examinations show that Salmonella can adapt to biochemical processes during milk acid fermentation of soft cheeses. No Salmonella bacteria were isolated from experimentally contaminated pasterurized milk at both maintenance temperatures after seven days of investigations.

  10. pH-Dependent spin state population and 19F NMR chemical shift via remote ligand protonation in an iron(ii) complex.

    Science.gov (United States)

    Gaudette, Alexandra I; Thorarinsdottir, Agnes E; Harris, T David

    2017-11-30

    An Fe II complex that features a pH-dependent spin state population, by virtue of a variable ligand protonation state, is described. This behavior leads to a highly pH-dependent 19 F NMR chemical shift with a sensitivity of 13.9(5) ppm per pH unit at 37 °C, thereby demonstrating the potential utility of the complex as a 19 F chemical shift-based pH sensor.

  11. Cyclic AMP (cAMP)-mediated stimulation of adipocyte differentiation requires the synergistic action of Epac- and cAMP-dependent protein kinase-dependent processes

    DEFF Research Database (Denmark)

    Petersen, Rasmus Koefoed; Madsen, Lise; Pedersen, Lone Møller

    2008-01-01

    AMP-dependent stimulation of adipocyte differentiation. Epac, working via Rap, acted synergistically with cAMP-dependent protein kinase (protein kinase A [PKA]) to promote adipogenesis. The major role of PKA was to down-regulate Rho and Rho-kinase activity, rather than to enhance CREB phosphorylation. Suppression of Rho......-kinase impaired proadipogenic insulin/insulin-like growth factor 1 signaling, which was restored by activation of Epac. This interplay between PKA and Epac-mediated processes not only provides novel insight into the initiation and tuning of adipocyte differentiation, but also demonstrates a new mechanism of c......AMP signaling whereby cAMP uses both PKA and Epac to achieve an appropriate cellular response....

  12. Genome-Enabled Modeling of Biogeochemical Processes Predicts Metabolic Dependencies that Connect the Relative Fitness of Microbial Functional Guilds

    Science.gov (United States)

    Brodie, E.; King, E.; Molins, S.; Karaoz, U.; Steefel, C. I.; Banfield, J. F.; Beller, H. R.; Anantharaman, K.; Ligocki, T. J.; Trebotich, D.

    2015-12-01

    Pore-scale processes mediated by microorganisms underlie a range of critical ecosystem services, regulating carbon stability, nutrient flux, and the purification of water. Advances in cultivation-independent approaches now provide us with the ability to reconstruct thousands of genomes from microbial populations from which functional roles may be assigned. With this capability to reveal microbial metabolic potential, the next step is to put these microbes back where they belong to interact with their natural environment, i.e. the pore scale. At this scale, microorganisms communicate, cooperate and compete across their fitness landscapes with communities emerging that feedback on the physical and chemical properties of their environment, ultimately altering the fitness landscape and selecting for new microbial communities with new properties and so on. We have developed a trait-based model of microbial activity that simulates coupled functional guilds that are parameterized with unique combinations of traits that govern fitness under dynamic conditions. Using a reactive transport framework, we simulate the thermodynamics of coupled electron donor-acceptor reactions to predict energy available for cellular maintenance, respiration, biomass development, and enzyme production. From metagenomics, we directly estimate some trait values related to growth and identify the linkage of key traits associated with respiration and fermentation, macromolecule depolymerizing enzymes, and other key functions such as nitrogen fixation. Our simulations were carried out to explore abiotic controls on community emergence such as seasonally fluctuating water table regimes across floodplain organic matter hotspots. Simulations and metagenomic/metatranscriptomic observations highlighted the many dependencies connecting the relative fitness of functional guilds and the importance of chemolithoautotrophic lifestyles. Using an X-Ray microCT-derived soil microaggregate physical model combined

  13. A New Population of Parvocellular Oxytocin Neurons Controlling Magnocellular Neuron Activity and Inflammatory Pain Processing.

    Science.gov (United States)

    Eliava, Marina; Melchior, Meggane; Knobloch-Bollmann, H Sophie; Wahis, Jérôme; da Silva Gouveia, Miriam; Tang, Yan; Ciobanu, Alexandru Cristian; Triana Del Rio, Rodrigo; Roth, Lena C; Althammer, Ferdinand; Chavant, Virginie; Goumon, Yannick; Gruber, Tim; Petit-Demoulière, Nathalie; Busnelli, Marta; Chini, Bice; Tan, Linette L; Mitre, Mariela; Froemke, Robert C; Chao, Moses V; Giese, Günter; Sprengel, Rolf; Kuner, Rohini; Poisbeau, Pierrick; Seeburg, Peter H; Stoop, Ron; Charlet, Alexandre; Grinevich, Valery

    2016-03-16

    Oxytocin (OT) is a neuropeptide elaborated by the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. Magnocellular OT neurons of these nuclei innervate numerous forebrain regions and release OT into the blood from the posterior pituitary. The PVN also harbors parvocellular OT cells that project to the brainstem and spinal cord, but their function has not been directly assessed. Here, we identified a subset of approximately 30 parvocellular OT neurons, with collateral projections onto magnocellular OT neurons and neurons of deep layers of the spinal cord. Evoked OT release from these OT neurons suppresses nociception and promotes analgesia in an animal model of inflammatory pain. Our findings identify a new population of OT neurons that modulates nociception in a two tier process: (1) directly by release of OT from axons onto sensory spinal cord neurons and inhibiting their activity and (2) indirectly by stimulating OT release from SON neurons into the periphery. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Assessment of psychological dependence among tobacco users: A survey held among the rural population of India to call for attention of tobacco cessation centers

    Directory of Open Access Journals (Sweden)

    Kiran Jadhav

    2013-01-01

    Full Text Available Background: In India most of the tobacco cessation centers are concentrating only on urban population, whereas, literature reveals that it is rural population, which shows high frequency of consumption of tobacco. It is well known that high frequency of tobacco consumption is associated with psychological dependence. This study aimed at identifying, which form of tobacco consumption (smoking or smokeless is associated with psychological dependence and is associated with which particular age group in rural population. Materials and Methods: It was a questionnaire based survey where 200 subjects were enrolled. Revised version of standard Fagerstrom Test for Nicotine dependence (FTND was given to each subject to answer. The collected data was statistically analyzed by using Karl Pearson Correlation (r test and Student′s t-test. Results: Study showed that subjects above 40 years of age are psychologically highly dependent on tobacco smoking as compared to tobacco chewing. Tobacco chewing is more prevalent among the younger population (20-30 years of age and type of habit does not have any influence over psychological dependence below 40 years of age. A positive correlation was observed between duration of habit and psychological dependence in all age groups irrespective of type of the habit of tobacco consumption. Conclusion: This study attempts at creating a new avenue for the tobacco cessation centers where they can target their efforts towards rural population particularly people above 40 years of age with a tobacco smoking habit so that they can actually reduce the burden of a number of people at risk for developing tobacco associated oral cancer.

  15. Reference serving sizes for the Brazilian population: An analysis of processed food labels

    Directory of Open Access Journals (Sweden)

    Nathalie Kliemann

    2014-06-01

    Full Text Available OBJECTIVE: To compare serving sizes reported on processed food labels with reference serving sizes according to nutrition labeling legislation and the "Food Guide for the Brazilian Population". METHODS: This cross-sectional study analyzed the labels of 2,072 processed foods in a supermarket of Florianópolis, Santa Caratina, Brazil. The foods were classified according to the Brazilian food labeling legislation. Central tendency and variability values were calculated for the serving sizes and energy values reported on the labels, as well as the ratio between the reported and reference energy value. The Spearman correlation test was performed between the reference serving size and the reference energy density, and also between the reference serving size and energy density of each study food. RESULTS: Nutrition labeling and the Food Guide presented reference servings with different sizes and energy values. The serving sizes reported on the labels did not follow either of the references and presented heterogeneous values, with a maximum range of 55-240 g among ready and semi-ready pre-prepared dishes. The reported energy values were between 0.1 times smaller and 2.4 times larger than the reference values. The reference serving sizes presented a highly inverse correlation with the reference energy density (Spearman coefficient= 0.9 and a very low inverse correlation with the energy density of the foods analyzed (Spearman coefficient= 0.2. CONCLUSION: This study showed the need for standardizing reference serving size information for the Brazilian population as well as reviewing nutrition labeling legislation in order to standardize the serving sizes reported on labels and to update the reference energy density used to calculate serving sizes.

  16. Population-level impacts of pesticide-induced chronic effects on individuals depend more on ecology than toxicology

    DEFF Research Database (Denmark)

    Dalkvist, Trine; Topping, Christopher John; Forbes, Valery, E.

    2009-01-01

    at the population-level. Here we demonstrate how, using ABM modelling, assessments at the population-level can be obtained even for a pesticide with complex long-term effects such as epigenetic transmission of reproductive depression. By objectively fitting nonlinear models to the simulation outputs it was possible...... to compare population depression and recovery rates for a range of scenarios in which toxicity and exposure factors were varied. The system was differentially sensitive to the various factors, but vole ecology and behaviour were at least as important predictors of population-level effects as toxicology...

  17. Neurophysiological evidence for abnormal cognitive processing of drug cues in heroin dependence

    NARCIS (Netherlands)

    Franken, Ingmar H. A.; Stam, Cornelis J.; Hendriks, Vincent M.; van den Brink, Wim

    2003-01-01

    Rationale. Recent studies provide evidence for specific aspects of cue processing in addictive disorders. Objective. The present study employs event related potentials (ERPs) to investigate heroin related visual information processing Methods. Neutral and heroin related pictures were presented to 19

  18. An ongoing process: a qualitative study of how the alcohol-dependent free themselves of addiction through progressive abstinence.

    Science.gov (United States)

    Yeh, Mei-Yu; Che, Hui-Lian; Wu, Shu-Mei

    2009-11-24

    Most people being treated for alcoholism are unable to successfully quit drinking within their treatment programs. In few cases do we know the full picture of how abstinence is achieved in Taiwan. We tracked processes of abstinence in alcohol-dependency disorders, based on study evidence and results. This research explores the process of recovery from the viewpoint of the alcohol-dependent. Semi-structured interviews were conducted in two different settings, using purpose sampling, during 2003-2004. The data were analyzed using content analysis. Participants were 32 adults, purposefully selected from an Alcoholics Anonymous group and a psychiatric hospital in North Taiwan. We found that the abstinence process is an ongoing process, in which the alcohol-dependent free themselves of addiction progressively. This process never ends or resolves in complete recovery. We have identified three stages in the struggle against alcoholism: the Indulgence, Ambivalence and Attempt (IAA) cycle, in which the sufferer is trapped in a cycle of attempting to give up and failing; the Turning Point, in which a Personal Nadir is reached, and the Ongoing Process of abstinence, in which a constant effort is made to remain sober through willpower and with the help of support groups. We also discuss Influencing Factors that can derail abstinence attempts, pushing the sufferer back into the IAA cycle. This study provides important points of reference for alcohol and drug service workers and community healthcare professionals in Taiwan, casting light on the abstinence process and providing a basis for intervention or rehabilitation services.

  19. DIAGNOSTICS OF MOTOR ABILITY AS A BASE OF CORRECTION PLANNING OF TRANSFORMATION PROCESSES IN SPECIAL POPULATIONS

    Directory of Open Access Journals (Sweden)

    Kosta Goranović

    2011-08-01

    Full Text Available In the research, at sample of 80 tested, employees in the special police force, as representatives of police population age from 20 to 25, diagnostics of motor potential in transitive period of annual macrostructure was done. The aim of the research was doing potential correction in planning and programming of transformation process in the next cycles of sports preparation on the base of diagnosed quantitative value of motor abilities. Besides analyses of achieved values, the difference was established between two leading teams in the space of measuring potential. The research results indicated to statistically important differences between two groups of tested people, as well as to unacceptable level of development in some abilities. The achieved results are, from aspect of training process’ control, the indicator to instructors’ team on the need of correction of transformation process’ content, with aim of improving bad segments. Diagnostics of motor abilities with measuring instruments in terrain conditions is one of methods, which can be in function of valorising transformation process of the special police force, taking into account specifics of their professional manifestation.

  20. Experiments to populate and validate a processing model for polyurethane foam. BKC 44306 PMDI-10

    Energy Technology Data Exchange (ETDEWEB)

    Mondy, Lisa Ann [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rao, Rekha Ranjana [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shelden, Bion [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Soehnel, Melissa Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); O' Hern, Timothy J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grillet, Anne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Celina, Mathias C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wyatt, Nicholas B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Russick, Edward Mark [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bauer, Stephen J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hileman, Michael Bryan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Urquhart, Alexander [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Thompson, Kyle Richard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Smith, David Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-03-01

    We are developing computational models to elucidate the expansion and dynamic filling process of a polyurethane foam, PMDI. The polyurethane of interest is chemically blown, where carbon dioxide is produced via the reaction of water, the blowing agent, and isocyanate. The isocyanate also reacts with polyol in a competing reaction, which produces the polymer. Here we detail the experiments needed to populate a processing model and provide parameters for the model based on these experiments. The model entails solving the conservation equations, including the equations of motion, an energy balance, and two rate equations for the polymerization and foaming reactions, following a simplified mathematical formalism that decouples these two reactions. Parameters for the polymerization kinetics model are reported based on infrared spectrophotometry. Parameters describing the gas generating reaction are reported based on measurements of volume, temperature and pressure evolution with time. A foam rheology model is proposed and parameters determined through steady-shear and oscillatory tests. Heat of reaction and heat capacity are determined through differential scanning calorimetry. Thermal conductivity of the foam as a function of density is measured using a transient method based on the theory of the transient plane source technique. Finally, density variations of the resulting solid foam in several simple geometries are directly measured by sectioning and sampling mass, as well as through x-ray computed tomography. These density measurements will be useful for model validation once the complete model is implemented in an engineering code.

  1. Mechanosensory organ regeneration in zebrafish depends on a population of multipotent progenitor cells kept latent by Schwann cells.

    Science.gov (United States)

    Sánchez, Mario; Ceci, Maria Laura; Gutiérrez, Daniela; Anguita-Salinas, Consuelo; Allende, Miguel L

    2016-04-07

    Regenerating damaged tissue is a complex process, requiring progenitor cells that must be stimulated to undergo proliferation, differentiation and, often, migratory behaviors and morphological changes. Multiple cell types, both resident within the damaged tissue and recruited to the lesion site, have been shown to participate. However, the cellular and molecular mechanisms involved in the activation of progenitor cell proliferation and differentiation after injury, and their regulation by different cells types, are not fully understood. The zebrafish lateral line is a suitable system to study regeneration because most of its components are fully restored after damage. The posterior lateral line (PLL) is a mechanosensory system that develops embryonically and is initially composed of seven to eight neuromasts distributed along the trunk and tail, connected by a continuous stripe of interneuromastic cells (INCs). The INCs remain in a quiescent state owing to the presence of underlying Schwann cells. They become activated during development to form intercalary neuromasts. However, no studies have described if INCs can participate in a regenerative event, for example, after the total loss of a neuromast. We used electroablation in transgenic larvae expressing fluorescent proteins in PLL components to completely ablate single neuromasts in larvae and adult fish. This injury results in discontinuity of the INCs, Schwann cells, and the PLL nerve. In vivo imaging showed that the INCs fill the gap left after the injury and can regenerate a new neuromast in the injury zone. Further, a single INC is able to divide and form all cell types in a regenerated neuromast and, during this process, it transiently expresses the sox2 gene, a neural progenitor cell marker. We demonstrate a critical role for Schwann cells as negative regulators of INC proliferation and neuromast regeneration, and that this inhibitory property is completely dependent on active ErbB signaling. The potential

  2. Temperature dependent investigation on optically active process of higher-order bands in irradiated silicon

    International Nuclear Information System (INIS)

    Shi Yi; Nanjing Univ., JS; Wu Fengmei; Nanjing Univ., JS; Zheng Youdou; Nanjing Univ., JS; Suezawa, M.; Imai, M.; Sumino, K.

    1996-01-01

    Optically active processes of the higher-order bands (HOB) are investigated at different temperatures in fast neutron irradiated silicon using Fourier transform infrared absorption measurement. It is shown that the optically active process is nearly temperature independent below 80 K, the slow decay process remains up to a heating temperature of 180 K. The observations are analyzed in terms of the relaxation behavior of photoexcited carriers governed by fast neutron radiation induced defect clusters. (orig.)

  3. Filling Predictable and Unpredictable Gaps, with and without Similarity-Based Interference: Evidence for LIFG Effects of Dependency Processing.

    Science.gov (United States)

    Leiken, Kimberly; McElree, Brian; Pylkkänen, Liina

    2015-01-01

    One of the most replicated findings in neurolinguistic literature on syntax is the increase of hemodynamic activity in the left inferior frontal gyrus (LIFG) in response to object relative (OR) clauses compared to subject relative clauses. However, behavioral studies have shown that ORs are primarily only costly when similarity-based interference is involved and recently, Leiken and Pylkkänen (2014) showed with magnetoencephalography (MEG) that an LIFG increase at an OR gap is also dependent on such interference. However, since ORs always involve a cue indicating an upcoming dependency formation, OR dependencies could be processed already prior to the gap-site and thus show no sheer dependency effects at the gap itself. To investigate the role of gap predictability in LIFG dependency effects, this MEG study compared ORs to verb phrase ellipsis (VPE), which was used as an example of a non-predictable dependency. Additionally, we explored LIFG sensitivity to filler-gap order by including right node raising structures, in which the order of filler and gap is reverse to that of ORs and VPE. Half of the stimuli invoked similarity-based interference and half did not. Our results demonstrate that LIFG effects of dependency can be elicited regardless of whether the dependency is predictable, the stimulus materials evoke similarity-based interference, or the filler precedes the gap. Thus, contrary to our own prior data, the current findings suggest a highly general role for the LIFG in dependency interpretation that is not limited to environments involving similarity-based interference. Additionally, the millisecond time-resolution of MEG allowed for a detailed characterization of the temporal profiles of LIFG dependency effects across our three constructions, revealing that the timing of these effects is somewhat construction-specific.

  4. All for one : Factors for alignment of inter-dependent business processes at KLM and Schiphol

    NARCIS (Netherlands)

    Perié, R.P.

    2008-01-01

    As airline and hub competition becomes fiercer, airline-airport co-operation becomes a necessary option for both main carrier airlines and hub airports to face this competition together. The inter-dependency between airlines and airports in producing air-transport services is tight, i.e. their

  5. Dependability and Survivability Evaluation of a Water Distribution Process with Arcade

    NARCIS (Netherlands)

    Roolvink, S.; Remke, Anne Katharina Ingrid; Stoelinga, Mariëlle Ida Antoinette

    2009-01-01

    Among others, drinking water belongs to the socalled critical infrastructures. To ensure that the water production meets current and future societal needs, a systematic and rigorous analysis is needed. In this paper, we report our ��?rst experience with dependability analysis of the last phase of a

  6. Take control : Developing and testing novel treatments of substance dependence by targeting underlying neurocognitive processes

    NARCIS (Netherlands)

    Schulte, M.H.J.

    2018-01-01

    In this PhD project we investigated the effect of N-acetylcysteine (NAC) and working memory (WM) training on substance use, and associated changes in neural correlates of substance dependence. N-acetylcysteine is a glutamatergic agent that reduces craving by restoring the imbalance in the brain

  7. Context-dependent motor skill: perceptual processing in memory-based sequence production

    NARCIS (Netherlands)

    Ruitenberg, M.F.L.; Abrahamse, E.L.; de Kleine, Elian; Verwey, Willem B.

    2012-01-01

    Previous studies have shown that motor sequencing skill can benefit from the reinstatement of the learning context—even with respect to features that are formally not required for appropriate task performance. The present study explored whether such context-dependence develops when sequence

  8. Internet Dependence in an Undergraduate Population: The Roles of Coping with Stress, Self-Efficacy Beliefs, and Sex Role Orientation

    Science.gov (United States)

    Odaci, Hatice; Çelik, Çigdem B.

    2017-01-01

    This study examined the relationship between Internet dependence in university students and forms of coping with stress and self-efficacy and investigated whether Internet dependence varies according to such variables as sex roles, gender, and duration of Internet use. The study was performed with 632 university students. The Internet Addiction…

  9. Decision Making Strategy and the Simultaneous Processing of Syntactic Dependencies in Language and Music

    NARCIS (Netherlands)

    Roncaglia-Denissen, M.P.; Bouwer, F.L.; Honing, H.

    2018-01-01

    Despite differences in their function and domain-specific elements, syntactic processing in music and language is believed to share cognitive resources. This study aims to investigate whether the simultaneous processing of language and music share the use of a common syntactic processor or more

  10. Families of birth-death processes with similar time-dependent behaviour

    NARCIS (Netherlands)

    Lenin, R.B.; Parthasarathy, P.R.; Scheinhardt, Willem R.W.; van Doorn, Erik A.

    1999-01-01

    We consider birth-death processes taking values in ${\\cal N} \\equiv \\{0,1,\\ldots\\}$, but allow the death rate in state $0$ to be positive, so that escape from ${\\cal N}$ is possible. Two such processes with transition functions $\\{p_{ij}(t)\\}$ and $\\{{\\tilde p}_{ij}(t)\\}$ are said to be {\\it

  11. Families of birth-death processes with similar time-dependent behaviour.

    NARCIS (Netherlands)

    Lenin, R.B.; Parthasarathy, P.R.; Scheinhardt, Willem R.W.; van Doorn, Erik A.

    2000-01-01

    We consider birth-death processes taking values in N ≡ {0,1,... }, but allow the death rate in state 0 to be positive, so that escape from N is possible. Two such processes with transition functions { pij(t) } and { ̃pij(t) } are said to be similar if, for all i, j ∈ N, there are constants cij such

  12. A condition-based maintenance of a dependent degradation-threshold-shock model in a system with multiple degradation processes

    International Nuclear Information System (INIS)

    Caballé, N.C.; Castro, I.T.; Pérez, C.J.; Lanza-Gutiérrez, J.M.

    2015-01-01

    This paper proposes a condition-based maintenance strategy for a system subject to two dependent causes of failure: degradation and sudden shocks. The internal degradation is reflected by the presence of multiple degradation processes in the system. Degradation processes start at random times following a Non-homogeneous Poisson process and their growths are modelled by using a gamma process. When the deterioration level of a degradation process exceeds a predetermined value, we assume that a degradation failure occurs. Furthermore, the system is subject to sudden shocks that arrive at the system following a Doubly Stochastic Poisson Process. A sudden shock provokes the total breakdown of the system. Thus, the state of the system is evaluated at inspection times and different maintenance tasks can be carried out. If the system is still working at an inspection time, a preventive maintenance task is performed if the deterioration level of a degradation process exceeds a certain threshold. A corrective maintenance task is performed if the system is down at an inspection time. A preventive (corrective) maintenance task implies the replacement of the system by a new one. Under this maintenance strategy, the expected cost rate function is obtained. A numerical example illustrates the analytical results. - Highlights: • A condition-based maintenance model is proposed. • Two dependent causes of failure are considered: deterioration and external shocks. • Deterioration is given by multiple degradation processes growing by a gamma process. • The initiation of degradation processes follows a Non-homogeneous Poisson process. • External shocks arrive at the system by using a Doubly Stochastic Poisson Process

  13. Analysis of amyotrophic lateral sclerosis as a multistep process: a population-based modelling study.

    Science.gov (United States)

    Al-Chalabi, Ammar; Calvo, Andrea; Chio, Adriano; Colville, Shuna; Ellis, Cathy M; Hardiman, Orla; Heverin, Mark; Howard, Robin S; Huisman, Mark H B; Keren, Noa; Leigh, P Nigel; Mazzini, Letizia; Mora, Gabriele; Orrell, Richard W; Rooney, James; Scott, Kirsten M; Scotton, William J; Seelen, Meinie; Shaw, Christopher E; Sidle, Katie S; Swingler, Robert; Tsuda, Miho; Veldink, Jan H; Visser, Anne E; van den Berg, Leonard H; Pearce, Neil

    2014-11-01

    Amyotrophic lateral sclerosis shares characteristics with some cancers, such as onset being more common in later life, progression usually being rapid, the disease affecting a particular cell type, and showing complex inheritance. We used a model originally applied to cancer epidemiology to investigate the hypothesis that amyotrophic lateral sclerosis is a multistep process. We generated incidence data by age and sex from amyotrophic lateral sclerosis population registers in Ireland (registration dates 1995-2012), the Netherlands (2006-12), Italy (1995-2004), Scotland (1989-98), and England (2002-09), and calculated age and sex-adjusted incidences for each register. We regressed the log of age-specific incidence against the log of age with least squares regression. We did the analyses within each register, and also did a combined analysis, adjusting for register. We identified 6274 cases of amyotrophic lateral sclerosis from a catchment population of about 34 million people. We noted a linear relationship between log incidence and log age in all five registers: England r(2)=0·95, Ireland r(2)=0·99, Italy r(2)=0·95, the Netherlands r(2)=0·99, and Scotland r(2)=0·97; overall r(2)=0·99. All five registers gave similar estimates of the linear slope ranging from 4·5 to 5·1, with overlapping confidence intervals. The combination of all five registers gave an overall slope of 4·8 (95% CI 4·5-5·0), with similar estimates for men (4·6, 4·3-4·9) and women (5·0, 4·5-5·5). A linear relationship between the log incidence and log age of onset of amyotrophic lateral sclerosis is consistent with a multistage model of disease. The slope estimate suggests that amyotrophic lateral sclerosis is a six-step process. Identification of these steps could lead to preventive and therapeutic avenues. UK Medical Research Council; UK Economic and Social Research Council; Ireland Health Research Board; The Netherlands Organisation for Health Research and Development (ZonMw); the

  14. Two-Agent Single-Machine Scheduling of Jobs with Time-Dependent Processing Times and Ready Times

    Directory of Open Access Journals (Sweden)

    Jan-Yee Kung

    2013-01-01

    Full Text Available Scheduling involving jobs with time-dependent processing times has recently attracted much research attention. However, multiagent scheduling with simultaneous considerations of jobs with time-dependent processing times and ready times is relatively unexplored. Inspired by this observation, we study a two-agent single-machine scheduling problem in which the jobs have both time-dependent processing times and ready times. We consider the model in which the actual processing time of a job of the first agent is a decreasing function of its scheduled position while the actual processing time of a job of the second agent is an increasing function of its scheduled position. In addition, each job has a different ready time. The objective is to minimize the total completion time of the jobs of the first agent with the restriction that no tardy job is allowed for the second agent. We propose a branch-and-bound and several genetic algorithms to obtain optimal and near-optimal solutions for the problem, respectively. We also conduct extensive computational results to test the proposed algorithms and examine the impacts of different problem parameters on their performance.

  15. Relaxation of Isolated Ventricular Cardiomyocytes by a Voltage-Dependent Process

    Science.gov (United States)

    Bridge, John H. B.; Spitzer, Kenneth W.; Ershler, Philip R.

    1988-08-01

    Cell contraction and relaxation were measured in single voltage-clamped guinea pig cardiomyocytes to investigate the contribution of sarcolemmal Na+-Ca2+ exchange to mechanical relaxation. Cells clamped from -80 to 0 millivolts displayed initial phasic and subsequent tonic contractions; caffeine reduced or abolished the phasic and enlarged the tonic contraction. The rate of relaxation from tonic contractions was steeply voltage-dependent and was significantly slowed in the absence of a sarcolemmal Na+ gradient. Tonic contractions elicited in the absence of a Na+ gradient promptly relaxed when external Na+ was applied, reflecting activation of Na+-Ca2+ exchange. It appears that a voltage-dependent Na+-Ca2+ exchange can rapidly mechanically relax mammalian heart muscle.

  16. Temperature and driving field dependence of fatigue processes in PZT bulk ceramics

    International Nuclear Information System (INIS)

    Glaum, Julia; Granzow, Torsten; Schmitt, Ljubomira Ana; Kleebe, Hans-Joachim; Roedel, Juergen

    2011-01-01

    The temperature- and field-dependent degradation properties of bulk Pb(Zr,Ti)O 3 material (PZT) under a unipolar electric field were investigated. Unipolar cycling leads to the build-up of an internal bias field based on the agglomeration of charges at grain boundaries. A simple model was developed which describes the general dynamics of unipolar fatigue and its dependence on temperature and driving field. Comparing the large and small signal permittivity before and after fatigue led to the conclusion that domain walls became clamped by the agglomerated charges. This clamping effect could be visualized by transmission electron microscopy (TEM). Additionally, the TEM investigations revealed that unipolar fatigue leads to a weakening of the microstructure and to the development of microcracks.

  17. Process dependence of H passivation and doping in H-implanted ZnO

    International Nuclear Information System (INIS)

    Zhang, Z; Brillson, L J; Look, D C; Schifano, R; Johansen, K M; Svensson, B G

    2013-01-01

    We used depth-resolved cathodoluminescence spectroscopy (DRCLS), photoluminescence (PL) spectroscopy and temperature-dependent Hall-effect (TDHE) measurements to describe the strong dependence of H passivation and doping in H-implanted ZnO on thermal treatment. Increasing H implantation dose increases passivation of Zn and oxygen vacancy-related defects, while reducing deep level emissions. Over annealing temperatures of 100-400 °C at different times, 1 h annealing at 200 °C yielded the lowest DRCLS deep level emissions, highest TDHE carrier mobility, and highest near band-edge PL emission. These results describe the systematics of dopant implantation and thermal activation on H incorporation in ZnO and their effects on its electrical properties.

  18. Combining shallow and deep processing for a robust, fast, deep-linguistic dependency parser

    OpenAIRE

    Schneider, G

    2004-01-01

    This paper describes Pro3Gres, a fast, robust, broad-coverage parser that delivers deep-linguistic grammatical relation structures as output, which are closer to predicate-argument structures and more informative than pure constituency structures. The parser stays as shallow as is possible for each task, combining shallow and deep-linguistic methods by integrating chunking and by expressing the majority of long-distance dependencies in a context-free way. It combines statistical and rule-base...

  19. Transverse momentum dependent quark distributions and polarized Drell-Yan processes

    OpenAIRE

    Zhou, Jian; Yuan, Feng; Liang, Zuo-Tang

    2009-01-01

    We study the spin-dependent quark distributions at large transverse momentum. We derive their transverse momentum behaviors in the collinear factorization approach in this region. We further calculate the angular distribution of the Drell-Yan lepton pair production with polarized beams and present the results in terms of the collinear twist-three quark-gluon correlation functions. In the intermediate transverse momentum region, we find that the two pproaches: the collinear factorization and t...

  20. Litter processing and population food intake of the mangrove crab Ucides cordatus in a high intertidal forest in northern Brazil

    Science.gov (United States)

    Nordhaus, Inga; Wolff, Matthias; Diele, Karen

    2006-03-01

    This study provides the first quantification of the population food intake of the litter-consuming mangrove crab Ucides cordatus (Ocypodidae, L. 1763) in a New World mangrove forest. Diet, feeding periodicity, gastric evacuation rates and size-dependent consumption were determined for this intensively exploited semi-terrestrial crab in different types of mangrove forest. Unlike many other crabs Ucides cordatus is a continuous feeder, as shown by gastrointestinal contents over a day's cycle. Starvation experiments revealed that most gastric evacuation occurs during the first 12 h after feeding, following an exponential decay function. Evacuation rates (0.35 h -1 and 0.31 h -1) for small (carapace width CW 2.5-3.5 cm) and large (CW 6.5-7.5 cm) crabs, respectively, and the mean daily gastrointestinal contents were used to calculate the daily food intake (DFI) of U. cordatus for both sexes and different size classes. DFI was strongly correlated to body size and ranged from 19.8 to 6.0% of body dry weight in small and large crabs, respectively. The daily energy intake of U. cordatus (37.6 kJ for a 65 g wet weight specimen) was high when compared to other leaf-eating crabs. Litter fall and propagule production were calculated as 16.38 t ha -1 y -1, corresponding to a daily mean of 4.49 g m -2 in a high intertidal Rhizophora mangle forest stand. The estimated population food intake of Ucides cordatus (4.1 g dw m -2 d -1) corresponds to 81.3% of this production. This high litter removal rate, a low litter quantity in burrows and high consumption rates during field experiments suggest that the local crab population is food-limited in many parts of the study area. The very efficient coupling of forest litter production and crab litter consumption is possible due to the high crab density and the low inundation frequency of the mangrove forests, allowing for prolonged foraging periods. By processing the major part of the litter, U. cordatus helps to retain nutrients and energy

  1. Ultraviolet Laser Damage Dependence on Contamination Concentration in Fused Silica Optics during Reactive Ion Etching Process

    Directory of Open Access Journals (Sweden)

    Laixi Sun

    2018-04-01

    Full Text Available The reactive ion etching (RIE process of fused silica is often accompanied by surface contamination, which seriously degrades the ultraviolet laser damage performance of the optics. In this study, we find that the contamination behavior on the fused silica surface is very sensitive to the RIE process which can be significantly optimized by changing the plasma generating conditions such as discharge mode, etchant gas and electrode material. Additionally, an optimized RIE process is proposed to thoroughly remove polishing-introduced contamination and efficiently prevent the introduction of other contamination during the etching process. The research demonstrates the feasibility of improving the damage performance of fused silica optics by using the RIE technique.

  2. Identifying significant uncertainties in thermally dependent processes for repository performance analysis

    International Nuclear Information System (INIS)

    Gansemer, J.D.; Lamont, A.

    1994-01-01

    In order to study the performance of the potential Yucca Mountain Nuclear Waste Repository, scientific investigations are being conducted to reduce the uncertainty about process models and system parameters. This paper is intended to demonstrate a method for determining a strategy for the cost effective management of these investigations. It is not meant to be a complete study of all processes and interactions, but does outline a method which can be applied to more in-depth investigations

  3. Decision Making Strategy and the Simultaneous Processing of Syntactic Dependencies in Language and Music

    OpenAIRE

    Roncaglia-Denissen, M. P.; Bouwer, Fleur L.; Honing, Henkjan

    2018-01-01

    Despite differences in their function and domain-specific elements, syntactic processing in music and language is believed to share cognitive resources. This study aims to investigate whether the simultaneous processing of language and music share the use of a common syntactic processor or more general attentional resources. To investigate this matter we tested musicians and non-musicians using visually presented sentences and aurally presented melodies containing syntactic local and long-dis...

  4. Modeling the Population-Level Processes of Biodiversity Gain and Loss at Geological Timescales.

    Science.gov (United States)

    Fortelius, Mikael; Geritz, Stefan; Gyllenberg, Mats; Raia, Pasquale; Toivonen, Jaakko

    2015-12-01

    The path of species diversification is commonly observed by inspecting the fossil record. Yet, how species diversity changes at geological timescales relate to lower-level processes remains poorly understood. Here we use mathematical models of spatially structured populations to show that natural selection and gradual environmental change give rise to discontinuous phenotype changes that can be connected to speciation and extinction at the macroevolutionary level. In our model, new phenotypes arise in the middle of the environmental gradient, while newly appearing environments are filled by existing phenotypes shifting their adaptive optima. Slow environmental change leads to loss of phenotypes in the middle of the extant environmental range, whereas fast change causes extinction at one extreme of the environmental range. We compared our model predictions against a well-known yet partially unexplained pattern of intense hoofed mammal diversification associated with grassland expansion during the Late Miocene. We additionally used the model outcomes to cast new insight into Cope's law of the unspecialized. Our general finding is that the rate of environmental change determines where generation and loss of diversity occur in the phenotypic and physical spaces.

  5. Development of Yeast Populations during Processing and Ripening of Blue Veined Cheese

    Directory of Open Access Journals (Sweden)

    Alison M. Knox

    2003-01-01

    Full Text Available Varieties of blue veined cheese were analyzed regularly during different stages of manufacturing and ripening to determine the origin of contaminating the yeasts present in them, their population diversity and development until the end of the storage. Yeast diversity and development in the inner and outer core of the cheeses during ripening were also compared. Air samples revealed few if any yeasts whereas the samples in contact with the equipment and the surroundings revealed high number of yeasts, implicating it as the possible main source of post-pasteurization contamination, as very few yeasts were isolated from the milk and cheese making process itself. Samples from the inner and outer core of the maturing cheeses had typical survival curves. The number of yeasts on the outer core was about a 100-fold more than of those in the inner core. The most abundant yeasts isolated from the environment and ripening cheeses were identified as Debaryomyces hansenii, Saccharomyces cerevisiae, Torulaspora delbrueckii, Trichosporon beigelii, Candida versatilis and Cryptococcus albidus, while the yeasts Candida zeylanoides and Dekkera anomala were additionally isolated from the environment. Yeasts were present in high number, making their occurrence in blue-veined cheeses meaningful.

  6. Employing Young Talent from Underserved Populations: Designing a Flexible Organizational Process for Assimilation and Productivity

    Directory of Open Access Journals (Sweden)

    Arthur Mark Langer

    2013-04-01

    Full Text Available This article describes an ongoing 13-year-old program designed to improve the ability of organizations to assimilate young talent from underserved populations, mostly students who have recently graduated from high school. Although many firms have internship and orientation programs, few have well-tested organizational approaches for assimilating 17-20 year-olds into their organizations in an efficient and productive manner. The objective of this study is to describe and evaluate the solution introduced by Workforce Opportunity Services (WOS, a non-profit agency that provides organizations with well-trained talent from underserved local communities. The WOS model is a systemic design involving a lead agency (WOS, corporate clients, training partnerships with local colleges and universities, and underutilized human capital. Over 290 students have completed the WOS program and obtained long-term employment, mostly in IT jobs that normally are outsourced. The results of the study show that companies have success employing young talent when they follow the WOS organizational process. Companies need to have patience with WOS student employees, but within six months most members of the WOS program make positive contributions to their sponsoring firm and have a strong likelihood of becoming permanently employed. Implications of the WOS model for organization design are discussed.

  7. [Changes in the consumption of dairy products, sugary drinks and processed juices in the Chilean population].

    Science.gov (United States)

    Crovetto, Mirta M; Uauy, Ricardo

    2014-12-01

    Nowadays, Chilean population tends to replace or eat a lower amount of food with health protective properties and a higher proportion of unhealthy foodstuff. To describe and compare the intake of dairy products, sugary drinks and processed juices among Chileans. An analysis of data compiled from the Survey on Household Budget and Expenses carried out by the Chilean National Institute of Statistics (INE), using a representative sample of households. The sample was surveyed between 1987 and 2007. The analysis was performed for all households surveyed and for households belonging to the second (highest incomes) and fifth quintile (lowest incomes). The Chilean Food Guide and the international recommendations of the Institute of Medicine of the United States and the American Heart Association (in the case of sugars) were used as reference. Even though the intake of dairy products increased during the period of the survey, it was lower than the intake of sugary drinks and juices, which increased. Also, calcium recommendations were not covered. On the other hand, the intake of added sugars increased to figures over current recommendations. The intake of dairy products and calcium is below the recommended amounts established by international organisms, and added sugars intake is greater than the advisable levels recommended by international organisms.

  8. Genetic determinants of PAM-dependent DNA targeting and pre-crRNA processing in Sulfolobus islandicus

    DEFF Research Database (Denmark)

    Peng, Wenfang; Li, Huan; Hallstrøm, Søren

    2013-01-01

    -adjacent motif (PAM)-dependent DNA targeting activity and mature CRISPR RNA (crRNA) production in this organism, mutants deleting individual genes of the type IA system or removing each of other Cas modules were constructed. Characterization of these mutants revealed that Cas7, Cas5, Cas6, Cas3' and Cas3......" are essential for PAM-dependent DNA targeting activity, whereas Csa5, along with all other Cas modules, is dispensable for the targeting in the crenarchaeon. Cas6 is implicated as the only enzyme for pre-crRNA processing and the crRNA maturation is independent of the DNA targeting activity. Importantly, we show...

  9. Uncertainty in Population Estimates for Endangered Animals and Improving the Recovery Process

    Directory of Open Access Journals (Sweden)

    Janet L. Rachlow

    2013-08-01

    Full Text Available United States recovery plans contain biological information for a species listed under the Endangered Species Act and specify recovery criteria to provide basis for species recovery. The objective of our study was to evaluate whether recovery plans provide uncertainty (e.g., variance with estimates of population size. We reviewed all finalized recovery plans for listed terrestrial vertebrate species to record the following data: (1 if a current population size was given, (2 if a measure of uncertainty or variance was associated with current estimates of population size and (3 if population size was stipulated for recovery. We found that 59% of completed recovery plans specified a current population size, 14.5% specified a variance for the current population size estimate and 43% specified population size as a recovery criterion. More recent recovery plans reported more estimates of current population size, uncertainty and population size as a recovery criterion. Also, bird and mammal recovery plans reported more estimates of population size and uncertainty compared to reptiles and amphibians. We suggest the use of calculating minimum detectable differences to improve confidence when delisting endangered animals and we identified incentives for individuals to get involved in recovery planning to improve access to quantitative data.

  10. Protein kinase C interaction with calcium: a phospholipid-dependent process.

    LENUS (Irish Health Repository)

    Bazzi, M D

    1990-08-21

    The calcium-binding properties of calcium- and phospholipid-dependent protein kinase C (PKC) were investigated by equilibrium dialysis in the presence and the absence of phospholipids. Calcium binding to PKC displayed striking and unexpected behavior; the free proteins bound virtually no calcium at intracellular calcium concentrations and bound limited calcium (about 1 mol\\/mol of PKC) at 200 microM calcium. However, in the presence of membranes containing acidic phospholipids, PKC bound at least eight calcium ions per protein. The presence of 1 microM phorbol dibutyrate (PDBu) in the dialysis buffer had little effect on these calcium-binding properties. Analysis of PKC-calcium binding by gel filtration under equilibrium conditions gave similar results; only membrane-associated PKC bound significant amounts of calcium. Consequently, PKC is a member of what may be a large group of proteins that bind calcium in a phospholipid-dependent manner. The calcium concentrations needed to induce PKC-membrane binding were similar to those needed for calcium binding (about 40 microM calcium at the midpoint). However, the calcium concentration required for PKC-membrane binding was strongly influenced by the phosphatidylserine composition of the membranes. Membranes with higher percentages of phosphatidylserine required lower concentrations of calcium. These properties suggested that the calcium sites may be generated at the interface between PKC and the membrane. Calcium may function as a bridge between PKC and phospholipids. These studies also suggested that calcium-dependent PKC-membrane binding and PKC function could be regulated by a number of factors in addition to calcium levels and diacylglycerol content of the membrane.

  11. Ultrasonic testing of austenitic welds and its dependency on the welding process

    International Nuclear Information System (INIS)

    Tabatabaeipour, S.M.; Honarvar, F.

    2009-01-01

    This paper describes the ultrasonic testing of austenitic welds prepared by two different welding processes. The tests were carried out by the ultrasonic Time-of-Flight Diffraction (ToFD) technique. Shielded Metal Arc Welding (SMAW) and Gas Tungsten Arc Welding (GTAW) are the welding processes used for preparing the specimens. Identical artificial defects were implanted in both welds during the welding process. Both specimens were examined by the ToFD technique under similar conditions. Metallographic images were also obtained from the cross sectional plane of both the SMA and GTA welds. These images show that the grain orientation in the two welded specimens are different. D-scan images obtained by the ToFD technique from these welds indicates that inspecting the specimens prepared by the SMAW process is easier than the one made by the GTAW process. The results also show that the D-scan images cannot reveal the small vertical drilled holes implanted in the specimens. (author)

  12. Spatial dependence and origin of the ambient doce due to neutron activation processes in linear accelerators

    International Nuclear Information System (INIS)

    Ruiz Egea, E.; Sanchez Carrascal, M.; Torres Pozas, S.; Monja Ray, P. de la; Perez Molina, J. L.; Madan Rodriguez, C.; Luque Japon, L.; Morera Molina, A.; Hernandez Perez, A.; Barquero Bravo, Y.; Morengo Pedagna, I.; Oliva Gordillo, M. C.; Martin Olivar, R.

    2011-01-01

    In order to try to determine the high dose in the bunker of a Linear Accelerator clinical use trying to measure the spatial dependence of the sane f ron the isocenter to tite gateway to the Board ceeking to establich the origin of it. This doce measurements performed with an ionization charober at different locations incide the bunker after an irradiation of 400 Monitor Units verifying the doce rate per minute for an hour, and accumulating the doce received during that period of time.

  13. Exact Time-Dependent Exchange-Correlation Potential in Electron Scattering Processes

    Science.gov (United States)

    Suzuki, Yasumitsu; Lacombe, Lionel; Watanabe, Kazuyuki; Maitra, Neepa T.

    2017-12-01

    We identify peak and valley structures in the exact exchange-correlation potential of time-dependent density functional theory that are crucial for time-resolved electron scattering in a model one-dimensional system. These structures are completely missed by adiabatic approximations that, consequently, significantly underestimate the scattering probability. A recently proposed nonadiabatic approximation is shown to correctly capture the approach of the electron to the target when the initial Kohn-Sham state is chosen judiciously, and it is more accurate than standard adiabatic functionals but ultimately fails to accurately capture reflection. These results may explain the underestimation of scattering probabilities in some recent studies on molecules and surfaces.

  14. An ongoing process: A qualitative study of how the alcohol-dependent free themselves of addiction through progressive abstinence

    Directory of Open Access Journals (Sweden)

    Che Hui-Lian

    2009-11-01

    Full Text Available Abstract Background Most people being treated for alcoholism are unable to successfully quit drinking within their treatment programs. In few cases do we know the full picture of how abstinence is achieved in Taiwan. We tracked processes of abstinence in alcohol-dependency disorders, based on study evidence and results. This research explores the process of recovery from the viewpoint of the alcohol-dependent. Methods Semi-structured interviews were conducted in two different settings, using purpose sampling, during 2003-2004. The data were analyzed using content analysis. Participants were 32 adults, purposefully selected from an Alcoholics Anonymous group and a psychiatric hospital in North Taiwan. Results We found that the abstinence process is an ongoing process, in which the alcohol-dependent free themselves of addiction progressively. This process never ends or resolves in complete recovery. We have identified three stages in the struggle against alcoholism: the Indulgence, Ambivalence and Attempt (IAA cycle, in which the sufferer is trapped in a cycle of attempting to give up and failing; the Turning Point, in which a Personal Nadir is reached, and the Ongoing Process of abstinence, in which a constant effort is made to remain sober through willpower and with the help of support groups. We also discuss Influencing Factors that can derail abstinence attempts, pushing the sufferer back into the IAA cycle. Conclusion This study provides important points of reference for alcohol and drug service workers and community healthcare professionals in Taiwan, casting light on the abstinence process and providing a basis for intervention or rehabilitation services.

  15. Experimental evolution of an RNA virus in wild birds: evidence for host-dependent impacts on population structure and competitive fitness.

    Directory of Open Access Journals (Sweden)

    Nathan D Grubaugh

    2015-05-01

    Full Text Available Within hosts, RNA viruses form populations that are genetically and phenotypically complex. Heterogeneity in RNA virus genomes arises due to error-prone replication and is reduced by stochastic and selective mechanisms that are incompletely understood. Defining how natural selection shapes RNA virus populations is critical because it can inform treatment paradigms and enhance control efforts. We allowed West Nile virus (WNV to replicate in wild-caught American crows, house sparrows and American robins to assess how natural selection shapes RNA virus populations in ecologically relevant hosts that differ in susceptibility to virus-induced mortality. After five sequential passages in each bird species, we examined the phenotype and population diversity of WNV through fitness competition assays and next generation sequencing. We demonstrate that fitness gains occur in a species-specific manner, with the greatest replicative fitness gains in robin-passaged WNV and the least in WNV passaged in crows. Sequencing data revealed that intrahost WNV populations were strongly influenced by purifying selection and the overall complexity of the viral populations was similar among passaged hosts. However, the selective pressures that control WNV populations seem to be bird species-dependent. Specifically, crow-passaged WNV populations contained the most unique mutations (~1.7× more than sparrows, ~3.4× more than robins and defective genomes (~1.4× greater than sparrows, ~2.7× greater than robins, but the lowest average mutation frequency (about equal to sparrows, ~2.6× lower than robins. Therefore, our data suggest that WNV replication in the most disease-susceptible bird species is positively associated with virus mutational tolerance, likely via complementation, and negatively associated with the strength of selection. These differences in genetic composition most likely have distinct phenotypic consequences for the virus populations. Taken together

  16. Magnetic field-dependent molecular and chemical processes in biochemistry, genetics and medicine

    International Nuclear Information System (INIS)

    Buchachenko, A L

    2014-01-01

    The molecular concept (paradigm) in magnetobiology seems to be most substantiated and significant for explaining the biomedical effects of electromagnetic fields, for the new medical technology of transcranial magnetic stimulation of cognitive activity, for the nuclear magnetic control of biochemical processes and for the search of new magnetic effects in biology and medicine. The key structural element of the concept is a radical ion pair as the receiver of magnetic fields and the source of magnetic effects. The existence of such pairs was recently detected in the two life-supporting processes of paramount importance — in enzymatic ATP and DNA syntheses. The bibliography includes 80 references

  17. Pheromones enhance somatosensory processing in newt brains through a vasotocin-dependent mechanism.

    Science.gov (United States)

    Thompson, R R; Dickinson, P S; Rose, J D; Dakin, K A; Civiello, G M; Segerdahl, A; Bartlett, R

    2008-07-22

    We tested whether the sex pheromones that stimulate courtship clasping in male roughskin newts do so, at least in part, by amplifying the somatosensory signals that directly trigger the motor pattern associated with clasping and, if so, whether that amplification is dependent on endogenous vasotocin (VT). Female olfactory stimuli increased the number of action potentials recorded in the medulla of males in response to tactile stimulation of the cloaca, which triggers the clasp motor reflex, as well as to tactile stimulation of the snout and hindlimb. That enhancement was blocked by exposing the medulla to a V1a receptor antagonist before pheromone exposure. However, the antagonist did not affect medullary responses to tactile stimuli in the absence of pheromone exposure, suggesting that pheromones amplify somatosensory signals by inducing endogenous VT release. The ability of VT to couple sensory systems together in response to social stimulation could allow this peptide to induce variable behavioural outcomes, depending on the immediate context of the social interaction and thus on the nature of the associated stimuli that are amplified. If widespread in vertebrates, this mechanism could account for some of the behavioural variability associated with this and related peptides both within and across species.

  18. Energy-dependent imaging in digital radiography: a review on acquisition, processing and display technique

    International Nuclear Information System (INIS)

    Coppini, G.; Maltinti, G.; Valli, G.; Baroni, M.; Buchignan, M.; Valli, G.

    1986-01-01

    The capabilities of energy-dependent imaging in digital radiography are analyzed paying particular attention to digital video systems. The main techniques developed in recent years for selective energy imaging are reviewed following a unified approach. Discussion about advantages and limits of energy methods is carried out by a comparative analysis of computer simulated data and experimental results as obtained by standard x-ray equipments coupled to a digital video unit. Geometric phantoms are used as test object, as also images of a chest phantom are produced. Since signal-to-noise ratio degradation is one of the major problems when dealing with selective imaging, a particular effort is made to investigate noise effects. In this perspective, an original colour encoding display of energy sequences is presented. By mapping the various energy measurements on different colour bands (typically those of an RGB TV-monitor), an increased image conspicuity is obtained without a significant noise degradation: this is ensured by the energy dependence of attenuation coefficients and by the integrating characteristics of the display device

  19. Childhood trajectories of inattention, hyperactivity and oppositional behaviors and prediction of substance abuse/dependence: a 15-year longitudinal population-based study.

    Science.gov (United States)

    Pingault, J-B; Côté, S M; Galéra, C; Genolini, C; Falissard, B; Vitaro, F; Tremblay, R E

    2013-07-01

    Numerous prospective studies have shown that children diagnosed with attention deficit/hyperactivity disorder (ADHD) are at higher risk of long-term substance abuse/dependence. However, there are three important limits to these studies: (a) most did not differentiate the role of hyperactivity and inattention; (b) most did not control for associated behavioral problems; and (c) most did not consider females. Our aim was to clarify the unique and interactive contributions of childhood inattention and hyperactivity symptoms to early adulthood substance abuse/dependence. Behavioral problems of 1803 participants (814 males) in a population-based longitudinal study were assessed yearly between 6 and 12 years by mothers and teachers. The prevalence of substance abuse/dependence at age 21 years was 30.7% for nicotine, 13.4% for alcohol, 9.1% for cannabis and 2.0% for cocaine. The significant predictors of nicotine dependence were inattention (odds ratio (OR): 2.25; 95% confidence interval (CI): 1.63-3.11) and opposition (OR: 1.65; 95%: 1.20-2.28). Only opposition contributed to the prediction of cannabis dependence (OR: 2.33; 95% CI: 1.40-3.87) and cocaine dependence (OR: 2.97; 95% CI: 1.06-8.57). The best behavioral predictor of alcohol abuse/dependence (opposition) was only marginally significant (OR: 1.38; 95% CI: 0.98-1.95). Frequent oppositional behaviors during elementary school were clearly the most pervasive predictors of substance abuse/dependence in early adulthood. The association of childhood ADHD with substance abuse/dependence is largely attributable to its association with opposition problems during childhood. However, inattention remained an important predictor of nicotine dependence, in line with genetic and molecular commonalities between the two phenotypes suggested in the literature.

  20. Inferences on the population structure and colonization process of the invasive oriental fruit fly, Bactrocera dorsalis (Hendel).

    Science.gov (United States)

    Aketarawong, N; Bonizzoni, M; Thanaphum, S; Gomulski, L M; Gasperi, G; Malacrida, A R; Gugliemino, C R

    2007-09-01

    The phytophagous insects of the Tephritidae family offer different case histories of successful invasions. An example is Bactrocera dorsalis sensu stricto, the oriental fruit fly which has been recognized as a key pest of Asia and the Pacific. It is known to have the potential to establish adventive populations in various tropical and subtropical areas. Despite the economic risk associated with a putative stable presence of this fly, the genetic aspects of its invasion process have remained relatively unexplored. Using microsatellite markers we have investigated the population structure and genetic variability in 14 geographical populations across the four areas of the actual species range: Far East Asia, South Asia, Southeast Asia and the Pacific Area. Results of clustering and admixture, associated with phylogenetic and migration analyses, were used to evaluate the changes in population genetic structure that this species underwent during its invasion process and establishment in the different areas. The colonization process of this fly is associated with a relatively stable population demographic structure, especially in an unfragmented habitat, rich in intensive cultivation such as in Southeast Asia. In this area, the results suggest a lively demographic history, characterized by evolutionary recent demographic expansions and no recent bottlenecks. Cases of genetic isolation attributable to geographical factors, fragmented habitats and/or fruit trade restrictions were observed in Bangladesh, Myanmar and Hawaii. Regarding the pattern of invasion, the overall genetic profile of the considered populations suggests a western orientated migration route from China to the West.

  1. Stone crayfish in the Czech Republic: how does its population density depend on basic chemical and physical properties of water?

    Directory of Open Access Journals (Sweden)

    Vlach P.

    2013-03-01

    Full Text Available The stone crayfish (Austropotamobius torrentium Schrank is one of the two native crayfish species in the Czech Republic. The populations as well as physical and chemical parameters of water (pH, conductivity, dissolved oxygen, undissolved particles, NH3, NH4+, NO2−, NO3−, phosphorus, Ca2+ and SO42 −  of 33 streams were examined to find the ecological plasticity of this crayfish and some relations between these parameters and population densities. The mentioned parameters often significantly varied at the sites. Two approaches were applied to find relations between these parameters and observed abundance. At first, the observed streams were compared using RDA (streams  ×  physical-chemical parameters. No significance was found while testing relationship between the streams grouped along the 1st axis of model and the observed abundances of stone crayfish. However, some correlations between abundance and conductivity, calcium, nitrates and sulphates were found using polynomial regression. These relationships are explicable in terms of mutual correlations, underlying geology and other factors which affect abundances. In conclusion, A. torrentium is able to inhabit waters with a large range of physical and chemical parameters of the water without any fundamental influence on population densities. Water properties play an indisputable role as limiting ecological factors at uncommon concentrations, but population densities are probably influenced much more by the types of habitats, habitat features, predation and other ecological factors.

  2. Dopamine-dependent social information processing in non-human primates.

    Science.gov (United States)

    Lee, Young-A; Lionnet, Sarah; Kato, Akemi; Goto, Yukiori

    2018-04-01

    Dopamine (DA) is a neurotransmitter whose roles have been suggested in various aspects of brain functions. Recent studies in rodents have reported its roles in social function. However, how DA is involved in social information processing in primates has largely remained unclear. We investigated prefrontal cortical (PFC) activities associated with social vs. nonsocial visual stimulus processing. Near-infrared spectroscopy (NIRS) was applied to Japanese macaques, along with pharmacological manipulations of DA transmission, while they were gazing at social and nonsocial visual stimuli. Oxygenated (oxy-Hb) and deoxygenated (deoxy-Hb) hemoglobin changes as well as functional connectivity based on such Hb changes within the PFC network which were distinct between social and nonsocial stimuli were observed. Administration of both D1 and D2 receptor antagonists affected the Hb changes associated with social stimuli, whereas D1, but not D2, receptor antagonist affected the Hb changes associated with nonsocial stimuli. These results suggest that mesocortical DA transmission in the PFC plays significant roles in social information processing, which involves both D1 and D2 receptor activation, in nonhuman primates. However, D1 and D2 receptor signaling in the PFC mediates different aspects of social vs. nonsocial information processing.

  3. Microglia kill amyloid-beta1-42 damaged neurons by a CD14-dependent process

    NARCIS (Netherlands)

    Bate, Clive; Veerhuis, Robert; Eikelenboom, Piet; Williams, Alun

    2004-01-01

    Activated microglia are closely associated with neuronal damage in Alzheimer's disease. In the present study, neurons exposed to low concentrations of amyloid-beta1-42, a toxic fragment of the amyloid-beta protein, were killed by microglia in a process that required cell-cell contact. Pre-treating

  4. Levels of Processing and the Cue-Dependent Nature of Recollection

    Science.gov (United States)

    Mulligan, Neil W.; Picklesimer, Milton

    2012-01-01

    Dual-process models differentiate between two bases of memory, recollection and familiarity. It is routinely claimed that deeper, semantic encoding enhances recollection relative to shallow, non-semantic encoding, and that recollection is largely a product of semantic, elaborative rehearsal. The present experiments show that this is not always the…

  5. Deep Processing of Long-Distance Dependencies in L2 English: The Case of Anaphora

    Science.gov (United States)

    Wang, Yi-Ting

    2012-01-01

    Since the seminal work of Alan Juffs, second language (L2) sentence processing has become a central research topic in the field of L2 acquisition. Beyond a general hunger for new data offered by new experimental techniques and designs, intellectual concerns with system-wide understanding of first-language (L1)-L2 differences extended to the…

  6. Making Women Count: Gender-Typing, Technology and Path Dependencies in Dutch Statistical Data Processing

    NARCIS (Netherlands)

    van den Ende, Jan; van Oost, Elizabeth C.J.

    2001-01-01

    This article is a longitudinal analysis of the relation between gendered labour divisions and new data processing technologies at the Dutch Central Bureau of Statistics (CBS). Following social-constructivist and evolutionary economic approaches, the authors hold that the relation between technology

  7. Radiation exposure of the Bulgarian population exceeding the background as a result of mining and processing of uranium ores

    International Nuclear Information System (INIS)

    Yonchev, L.; Vasilev, G.

    1999-01-01

    The nearly 50-year-long history of researches, mining and processing and closure of uranium industry of researches, mining and processing and the closure of uranium industry sites in the country as well necessitate reassessment of the radiation exposure of the human population in the regions nearby such projects. Proceeding from the available data from expert examination reports the radiation exposure of the Bulgarian population in excess of the background as a result of mining and processing of uranium ores is analysed. The study covers about 135000 persons. The mean value of exposure above the background, attributable to the technologically increased background amounts to 3.04 mSv/a at effective background dose about 2.3 mSv/a. The collective effective dose is 410 mSv/a and represents about 5 per cent of the overall radiation exposure of the Bulgarian population

  8. Theoretical methodical aspects of forming skills of swimming among the different groups of population in the process of physical education and sport taking into account gender differences

    Directory of Open Access Journals (Sweden)

    Hanchar А.І.

    2012-03-01

    Full Text Available Research purpose: to expose theoretical and practical bases of effective methods of forming of skills of swimming at the different groups of population taking into account the gender differences of student in the process of physical education and sport. The dominant aspects of forming skills of swimming for different age-dependent groups are set. The negative phenomena of organizational character, which does not allow in good time and reliably to form for a man vitally important skills of safe movement on water, are selected. 5 basic aspects of forming of skills are recommended swimming which characterize high-quality realization of educational in detail, professionally-applied, health-improvement-hygienical, medical prophylactic and sporting-pedagogical influences of facilities of swimming on a population.

  9. Assessment of variability in the hydrological cycle of the Loess Plateau, China: examining dependence structures of hydrological processes

    Science.gov (United States)

    Guo, A.; Wang, Y.

    2017-12-01

    Investigating variability in dependence structures of hydrological processes is of critical importance for developing an understanding of mechanisms of hydrological cycles in changing environments. In focusing on this topic, present work involves the following: (1) identifying and eliminating serial correlation and conditional heteroscedasticity in monthly streamflow (Q), precipitation (P) and potential evapotranspiration (PE) series using the ARMA-GARCH model (ARMA: autoregressive moving average; GARCH: generalized autoregressive conditional heteroscedasticity); (2) describing dependence structures of hydrological processes using partial copula coupled with the ARMA-GARCH model and identifying their variability via copula-based likelihood-ratio test method; and (3) determining conditional probability of annual Q under different climate scenarios on account of above results. This framework enables us to depict hydrological variables in the presence of conditional heteroscedasticity and to examine dependence structures of hydrological processes while excluding the influence of covariates by using partial copula-based ARMA-GARCH model. Eight major catchments across the Loess Plateau (LP) are used as study regions. Results indicate that (1) The occurrence of change points in dependence structures of Q and P (PE) varies across the LP. Change points of P-PE dependence structures in all regions almost fully correspond to the initiation of global warming, i.e., the early 1980s. (3) Conditional probabilities of annual Q under various P and PE scenarios are estimated from the 3-dimensional joint distribution of (Q, P and PE) based on the above change points. These findings shed light on mechanisms of the hydrological cycle and can guide water supply planning and management, particularly in changing environments.

  10. Contribution to the stochastically studies of space-time dependable hydrological processes

    International Nuclear Information System (INIS)

    Kjaevski, Ivancho

    2002-12-01

    One of the fundaments of today's planning and water economy is Science of Hydrology. Science of Hydrology through the history had followed the development of the water management systems. Water management systems, during the time from single-approach evolved to complex and multi purpose systems. The dynamic and development of the today's society contributed for increasing the demand of clean water, and in the same time, the resources of clean water in the nature are reduced. In this kind of conditions, water management systems should resolve problems that are more complicated during managing of water sources. Solving the problems in water management, enable development and applying new methods and technologies in planning and management with water resources and water management systems like: systematical analyses, operational research, hierarchy decisions, expert systems, computer technology etc. Planning and management of water sources needs historical measured data for hydro metrological processes. In our country there are data of hydro metrological processes in period of 50-70, but in some Europe countries there are data more than 100 years. Water economy trends follow the hydro metrological trend research. The basic statistic techniques like sampling, probability distribution function, correlation and regression, are used about one intended and simple water management problems. Solving new problems about water management needs using of space-time stochastic technique, modem mathematical and statistical techniques during simulation and optimization of complex water systems. We need tree phases of development of the techniques to get secure hydrological models: i) Estimate the quality of hydro meteorological data, analyzing of their consistency, and homogeneous; ii) Structural analyze of hydro meteorological processes; iii) Mathematical models for modeling hydro meteorological processes. Very often, the third phase is applied for analyzing and modeling of hydro

  11. Tailoring of motional states in double-well potentials by time-dependent processes

    International Nuclear Information System (INIS)

    Haerkoenen, Kari; Kaerki, Ollijuhani; Suominen, Kalle-Antti

    2006-01-01

    We show that the vibrational state tailoring method developed for molecular systems can be applied for cold atoms in optical lattices. The original method is based on a three-level model interacting with two strong laser pulses in a counterintuitive sequence [M. Rodriguez et al., Phys. Rev. A 62, 053413 (2000)]. Here we outline the conditions for achieving similar dynamics with single time-dependent potential surfaces. It is shown that guided switching between diabatic and adiabatic evolution has an essential role in this system. We also show that efficient and precise tailoring of motional states in optical lattices can be achieved, for instance, simply by superimposing two lattices and moving them with respect to each other

  12. Minimizing the effect of process mismatch in a neuromorphic system using spike-timing-dependent adaptation.

    Science.gov (United States)

    Cameron, Katherine; Murray, Alan

    2008-05-01

    This paper investigates whether spike-timing-dependent plasticity (STDP) can minimize the effect of mismatch within the context of a depth-from-motion algorithm. To improve noise rejection, this algorithm contains a spike prediction element, whose performance is degraded by analog very large scale integration (VLSI) mismatch. The error between the actual spike arrival time and the prediction is used as the input to an STDP circuit, to improve future predictions. Before STDP adaptation, the error reflects the degree of mismatch within the prediction circuitry. After STDP adaptation, the error indicates to what extent the adaptive circuitry can minimize the effect of transistor mismatch. The circuitry is tested with static and varying prediction times and chip results are presented. The effect of noisy spikes is also investigated. Under all conditions the STDP adaptation is shown to improve performance.

  13. Spin-dependent recombination processes in wide band gap II-Mn-VI compounds

    International Nuclear Information System (INIS)

    Godlewski, M.; Yatsunenko, S.; Khachapuridze, A.; Ivanov, V.Yu.

    2004-01-01

    Mechanisms of optical detection of magnetic resonance in wide band gap II-Mn-VI diluted magnetic semiconductor (DMS) are discussed based on the results of photoluminescence (PL), PL kinetics, electron spin resonance (ESR) and optically detected magnetic resonance (ODMR) and optically detected cyclotron resonance (ODCR) investigations. Spin-dependent interactions between localized spins of Mn 2+ ions and spins/magnetic moments of free, localized or bound carriers are responsible for the observed ODMR signals. We conclude that these interactions are responsible for the observed rapid shortening of the PL decay time of 4 T 1 → 6 A 1 intra-shell emission of Mn 2+ ions and also for the observed delocalization of excitons in low dimensional structures

  14. New learning while consolidating memory during sleep is actively blocked by a protein synthesis dependent process.

    Science.gov (United States)

    Levy, Roi; Levitan, David; Susswein, Abraham J

    2016-12-06

    Brief experiences while a memory is consolidated may capture the consolidation, perhaps producing a maladaptive memory, or may interrupt the consolidation. Since consolidation occurs during sleep, even fleeting experiences when animals are awakened may produce maladaptive long-term memory, or may interrupt consolidation. In a learning paradigm affecting Aplysia feeding, when animals were trained after being awakened from sleep, interactions between new experiences and consolidation were prevented by blocking long-term memory arising from the new experiences. Inhibiting protein synthesis eliminated the block and allowed even a brief, generally ineffective training to produce long-term memory. Memory formation depended on consolidative proteins already expressed before training. After effective training, long term memory required subsequent transcription and translation. Memory formation during the sleep phase was correlated with increased CREB1 transcription, but not CREB2 transcription. Increased C/EBP transcription was a correlate of both effective and ineffective training and of treatments not producing memory.

  15. Muonium spin exchange as a Poisson process: magnetic field dependence in transverse fields

    International Nuclear Information System (INIS)

    Senba, Masayoshi; British Columbia Univ., Vancouver, BC

    1993-01-01

    The muonium spin exchange has been investigated as a function of transverse magnetic field strength, where the Poisson nature of collisions is exploited to simplify the calculation. In intermediate fields where the so-called two-frequency muonium signal is observed, the muonium relaxation due to spin exchange is 1.5 times faster than in low fields. In even higher fields, the observed relaxation rate drops back to the low field value. Since the relaxation rate due to a chemical reaction is field independent, such a distinct field dependence in spin exchange can be used in distinguishing experimentally spin exchange from chemical reactions. The time evolution of the muon spin polarization in the presence of muonium spin exchange has been expressed in a simple analytical closed form. (author)

  16. The influence of wavelength-dependent radiation in simulation of lamp-heated rapid thermal processing systems

    Energy Technology Data Exchange (ETDEWEB)

    Ting, A. [Sandia National Labs., Livermore, CA (United States). Computational Mechanics Dept.

    1994-08-01

    Understanding the thermal response of lamp-heated rapid thermal processing (RTP) systems requires understanding relatively complex radiation exchange among opaque and partially transmitting surfaces and materials. The objective of this paper is to investigate the influence of wavelength-dependent radiative properties. The examples used for the analysis consider axisymmetric systems of the kind that were developed by Texas Instruments (TI) for the Microelectronics Manufacturing Science and Technology (MMST) Program and illustrate a number of wavelength-dependent (spectral) effects. The models execute quickly on workstation class computing flatforms, and thus permit rapid comparison of alternative reactor designs and physical models. The fast execution may also permit the incorporation of these models into real-time model-based process control algorithms.

  17. PRO-Elicere: A Study for Create a New Process of Dependability Analysis of Space Computer Systems

    Science.gov (United States)

    da Silva, Glauco; Netto Lahoz, Carlos Henrique

    2013-09-01

    This paper presents the new approach to the computer system dependability analysis, called PRO-ELICERE, which introduces data mining concepts and intelligent mechanisms to decision support to analyze the potential hazards and failures of a critical computer system. Also, are presented some techniques and tools that support the traditional dependability analysis and briefly discusses the concept of knowledge discovery and intelligent databases for critical computer systems. After that, introduces the PRO-ELICERE process, an intelligent approach to automate the ELICERE, a process created to extract non-functional requirements for critical computer systems. The PRO-ELICERE can be used in the V&V activities in the projects of Institute of Aeronautics and Space, such as the Brazilian Satellite Launcher (VLS-1).

  18. Surface conductivity dependent dynamic behaviour of an ultrafine atmospheric pressure plasma jet for microscale surface processing

    Energy Technology Data Exchange (ETDEWEB)

    Abuzairi, Tomy [Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561 (Japan); Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Depok 16424 (Indonesia); Okada, Mitsuru [Department of Engineering, Shizuoka University, Hamamatsu 432-8561 (Japan); Bhattacharjee, Sudeep [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India); Nagatsu, Masaaki, E-mail: nagatsu.masaaki@shizuoka.ac.jp [Graduate School of Science and Technology, Shizuoka University, Hamamatsu 432-8561 (Japan); Department of Engineering, Shizuoka University, Hamamatsu 432-8561 (Japan); Research Institute of Electronics, Shizuoka University, Hamamatsu 432-8561 (Japan)

    2016-12-30

    Highlights: • Spatio-temporal behaviors of capillary APPJs are studied for various substrates. • Plasma irradiation area depended on the substrate conductivity and permittivity. • Surface irradiation area was significantly broadened in polymer-like substrate. • Effect of applying a substrate bias on the APPJ irradiation area was investigated. - Abstract: An experimental study on the dynamic behaviour of microcapillary atmospheric pressure plasma jets (APPJs) with 5 μm tip size for surfaces of different conductivity is reported. Electrical and spatio-temporal characteristics of the APPJs are monitored using high voltage probe, current monitor and high speed intensified charge couple device camera. From these experimental results, we presented a simple model to understand the electrical discharge characteristics of the capillary APPJs with double electrodes, and estimated the velocity of the ionization fronts in the jet and the electron density to be 3.5–4.2 km/s and 2–7 × 10{sup 17} m{sup −3}. By analyzing the dynamics of the microcapillary APPJs for different substrate materials, it was found that the surface irradiation area strongly depended on the substrate conductivity and permittivity, especially in the case of polymer-like substrate, surface irradiation area was significantly broadened probably due to the repelling behaviour of the plasma jets from the accumulated electrical charges on the polymer surface. The effect of applying a substrate bias in the range from −900 V to +900 V on the plasma irradiation onto the substrates was also investigated. From the knowledge of the present results, it is helpful for choosing the substrate materials for microscale surface modification.

  19. Surface conductivity dependent dynamic behaviour of an ultrafine atmospheric pressure plasma jet for microscale surface processing

    International Nuclear Information System (INIS)

    Abuzairi, Tomy; Okada, Mitsuru; Bhattacharjee, Sudeep; Nagatsu, Masaaki

    2016-01-01

    Highlights: • Spatio-temporal behaviors of capillary APPJs are studied for various substrates. • Plasma irradiation area depended on the substrate conductivity and permittivity. • Surface irradiation area was significantly broadened in polymer-like substrate. • Effect of applying a substrate bias on the APPJ irradiation area was investigated. - Abstract: An experimental study on the dynamic behaviour of microcapillary atmospheric pressure plasma jets (APPJs) with 5 μm tip size for surfaces of different conductivity is reported. Electrical and spatio-temporal characteristics of the APPJs are monitored using high voltage probe, current monitor and high speed intensified charge couple device camera. From these experimental results, we presented a simple model to understand the electrical discharge characteristics of the capillary APPJs with double electrodes, and estimated the velocity of the ionization fronts in the jet and the electron density to be 3.5–4.2 km/s and 2–7 × 10"1"7 m"−"3. By analyzing the dynamics of the microcapillary APPJs for different substrate materials, it was found that the surface irradiation area strongly depended on the substrate conductivity and permittivity, especially in the case of polymer-like substrate, surface irradiation area was significantly broadened probably due to the repelling behaviour of the plasma jets from the accumulated electrical charges on the polymer surface. The effect of applying a substrate bias in the range from −900 V to +900 V on the plasma irradiation onto the substrates was also investigated. From the knowledge of the present results, it is helpful for choosing the substrate materials for microscale surface modification.

  20. Testing effort dependent software reliability model for imperfect debugging process considering both detection and correction

    International Nuclear Information System (INIS)

    Peng, R.; Li, Y.F.; Zhang, W.J.; Hu, Q.P.

    2014-01-01

    This paper studies the fault detection process (FDP) and fault correction process (FCP) with the incorporation of testing effort function and imperfect debugging. In order to ensure high reliability, it is essential for software to undergo a testing phase, during which faults can be detected and corrected by debuggers. The testing resource allocation during this phase, which is usually depicted by the testing effort function, considerably influences not only the fault detection rate but also the time to correct a detected fault. In addition, testing is usually far from perfect such that new faults may be introduced. In this paper, we first show how to incorporate testing effort function and fault introduction into FDP and then develop FCP as delayed FDP with a correction effort. Various specific paired FDP and FCP models are obtained based on different assumptions of fault introduction and correction effort. An illustrative example is presented. The optimal release policy under different criteria is also discussed

  1. Stereotype Strength and Attentional Bias: Preference for Confirming versus Disconfirming Information Depends on Processing Capacity

    Science.gov (United States)

    Allen, Thomas J.; Sherman, Jeffrey W.; Conrey, Frederica R.; Stroessner, Steven J.

    2009-01-01

    In two experiments, we investigated the relationships among stereotype strength, processing capacity, and the allocation of attention to stereotype-consistent versus stereotype-inconsistent information describing a target person. The results of both experiments showed that, with full capacity, greater stereotype strength was associated with increased attention toward stereotype-consistent versus stereotype-inconsistent information. However, when capacity was diminished, greater stereotype strength was associated with increased attention toward inconsistent versus consistent information. Thus, strong stereotypes may act as self-confirming filters when processing capacity is plentiful, but as efficient information gathering devices that maximize the acquisition of novel (disconfirming) information when capacity is depleted. Implications for models of stereotyping and stereotype change are discussed. PMID:20161043

  2. Building on prior knowledge: schema-dependent encoding processes relate to academic performance.

    Science.gov (United States)

    van Kesteren, Marlieke T R; Rijpkema, Mark; Ruiter, Dirk J; Morris, Richard G M; Fernández, Guillén

    2014-10-01

    The acquisition and retention of conceptual knowledge is more effective in well-structured curricula that provide an optimal conceptual framework for learning new material. However, the neural mechanisms by which preexisting conceptual schemas facilitate learning are not yet well understood despite their fundamental importance. A preexisting schema has been shown to enhance memory by influencing the balance between activity within the medial-temporal lobe and the medial pFC during mnemonic processes such as encoding, consolidation, and retrieval. Specifically, correctly encoding and retrieving information that is related to preexisting schemas appears rather related to medial prefrontal processing, whereas information unrelated or inconsistent with preexisting schemas rather relates to enhanced medial temporal processing and enhanced interaction between these structures. To further investigate interactions between these regions during conceptual encoding in a real-world university setting, we probed human brain activity and connectivity using fMRI during educationally relevant conceptual encoding carefully embedded within two course programs. Early second-year undergraduate biology and education students were scanned while encoding new facts that were either related or unrelated to the preexisting conceptual knowledge they had acquired during their first year of study. Subsequently, they were tested on their knowledge of these facts 24 hr later. Memory scores were better for course-related information, and this enhancement was associated with larger medial-prefrontal, but smaller medial-temporal subsequent memory effects. These activity differences went along with decreased functional interactions between these regions. Furthermore, schema-related medial-prefrontal subsequent memory effects measured during this experiment were found to be predictive of second-year course performance. These results, obtained in a real-world university setting, reveal brain

  3. Age-Dependent Positivity-Bias in Children’s Processing of Emotion Terms

    Science.gov (United States)

    Bahn, Daniela; Vesker, Michael; García Alanis, José C.; Schwarzer, Gudrun; Kauschke, Christina

    2017-01-01

    Emotions play an important role in human communication, and the daily-life interactions of young children often include situations that require the verbalization of emotional states with verbal means, e.g., with emotion terms. Through them, one can express own emotional states and those of others. Thus, the acquisition of emotion terms allows children to participate more intensively in social contexts – a basic requirement for learning new words and for elaborating socio-emotional skills. However, little is known about how children acquire and process this specific word category, which is positioned between concrete and abstract words. In particular, the influence of valence on emotion word processing during childhood has not been sufficiently investigated. Previous research points to an advantage of positive words over negative and neutral words in word processing. While previous studies found valence effects to be influenced by factors such as arousal, frequency, concreteness, and task, it is still unclear if and how valence effects are also modified by age. The present study compares the performance of children aged from 5 to 12 years and adults in two experimental tasks: lexical decision (word or pseudoword) and emotional categorization (positive or negative). Stimuli consisted of 48 German emotion terms (24 positive and 24 negative) matched for arousal, concreteness, age of acquisition, word class, word length, morphological complexity, frequency, and neighborhood density. Results from both tasks reveal two developmental trends: First, with increasing age children responded faster and more correctly, suggesting that emotion vocabulary gradually becomes more stable and differentiated during middle childhood. Second, the influence of valence varied with age: younger children (5- and 6-year-olds) showed significantly higher performance levels for positive emotion terms compared to negative emotion terms, whereas older children and adults did not. This age

  4. Disambiguating past events: Accurate source memory for time and context depends on different retrieval processes.

    Science.gov (United States)

    Persson, Bjorn M; Ainge, James A; O'Connor, Akira R

    2016-07-01

    Current animal models of episodic memory are usually based on demonstrating integrated memory for what happened, where it happened, and when an event took place. These models aim to capture the testable features of the definition of human episodic memory which stresses the temporal component of the memory as a unique piece of source information that allows us to disambiguate one memory from another. Recently though, it has been suggested that a more accurate model of human episodic memory would include contextual rather than temporal source information, as humans' memory for time is relatively poor. Here, two experiments were carried out investigating human memory for temporal and contextual source information, along with the underlying dual process retrieval processes, using an immersive virtual environment paired with a 'Remember-Know' memory task. Experiment 1 (n=28) showed that contextual information could only be retrieved accurately using recollection, while temporal information could be retrieved using either recollection or familiarity. Experiment 2 (n=24), which used a more difficult task, resulting in reduced item recognition rates and therefore less potential for contamination by ceiling effects, replicated the pattern of results from Experiment 1. Dual process theory predicts that it should only be possible to retrieve source context from an event using recollection, and our results are consistent with this prediction. That temporal information can be retrieved using familiarity alone suggests that it may be incorrect to view temporal context as analogous to other typically used source contexts. This latter finding supports the alternative proposal that time since presentation may simply be reflected in the strength of memory trace at retrieval - a measure ideally suited to trace strength interrogation using familiarity, as is typically conceptualised within the dual process framework. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. A decision dependent stochastic process model for repairable systems with applications

    Directory of Open Access Journals (Sweden)

    Paul F. Zantek

    2015-12-01

    This paper mathematically formalizes the notion of how management actions impact the functioning of a repairable system over time by developing a new stochastic process model for such systems. The proposed model is illustrated using both simulated and real data. The proposed model compares favorably to other models for well-known data on Boeing airplanes. The model is further illustrated and compared to other models on failure time and maintenance data stemming from the South Texas Project nuclear power plant.

  6. Age-Dependent Positivity-Bias in Children’s Processing of Emotion Terms

    Directory of Open Access Journals (Sweden)

    Daniela Bahn

    2017-07-01

    Full Text Available Emotions play an important role in human communication, and the daily-life interactions of young children often include situations that require the verbalization of emotional states with verbal means, e.g., with emotion terms. Through them, one can express own emotional states and those of others. Thus, the acquisition of emotion terms allows children to participate more intensively in social contexts – a basic requirement for learning new words and for elaborating socio-emotional skills. However, little is known about how children acquire and process this specific word category, which is positioned between concrete and abstract words. In particular, the influence of valence on emotion word processing during childhood has not been sufficiently investigated. Previous research points to an advantage of positive words over negative and neutral words in word processing. While previous studies found valence effects to be influenced by factors such as arousal, frequency, concreteness, and task, it is still unclear if and how valence effects are also modified by age. The present study compares the performance of children aged from 5 to 12 years and adults in two experimental tasks: lexical decision (word or pseudoword and emotional categorization (positive or negative. Stimuli consisted of 48 German emotion terms (24 positive and 24 negative matched for arousal, concreteness, age of acquisition, word class, word length, morphological complexity, frequency, and neighborhood density. Results from both tasks reveal two developmental trends: First, with increasing age children responded faster and more correctly, suggesting that emotion vocabulary gradually becomes more stable and differentiated during middle childhood. Second, the influence of valence varied with age: younger children (5- and 6-year-olds showed significantly higher performance levels for positive emotion terms compared to negative emotion terms, whereas older children and adults did not

  7. Frequency-Dependent Social Transmission and the Interethnic Transfer of Female Genital Modification in the African Diaspora and Indigenous Populations of Colombia.

    Science.gov (United States)

    Ross, Cody T; Campiño, Patricia Joyas; Winterhalder, Bruce

    2015-12-01

    We present a quantitative account based on ethnographic and documentary research of the prevalence of female genital modification (FGMo) in the African diaspora and indigenous populations of Colombia. We use these data to test hypotheses concerning the cultural evolutionary drivers of costly trait persistence, attenuation, and intergroup transmission. The uptake of FGMo by indigenous populations in Colombia is consistent with frequency-dependent hypotheses for the social transmission of the FGMo trait from the African diaspora population in the period following the era of slavery in Colombia. The prevalence and severity of practices related to FGMo decline with level of sociocultural integration into mainstream Colombian culture. Our results provide empirical support for the cultural evolutionary models proposed by Ross et al. (2015) to describe the transmission dynamics of FGMo and other costly traits. Analysis of costly trait dynamics contributes knowledge useful to applied anthropology and may be of interest in policy design and human rights monitoring in Colombia and elsewhere.

  8. Age-dependent impairment of auditory processing under spatially focused and divided attention: an electrophysiological study.

    Science.gov (United States)

    Wild-Wall, Nele; Falkenstein, Michael

    2010-01-01

    By using event-related potentials (ERPs) the present study examines if age-related differences in preparation and processing especially emerge during divided attention. Binaurally presented auditory cues called for focused (valid and invalid) or divided attention to one or both ears. Responses were required to subsequent monaurally presented valid targets (vowels), but had to be suppressed to non-target vowels or invalidly cued vowels. Middle-aged participants were more impaired under divided attention than young ones, likely due to an age-related decline in preparatory attention following cues as was reflected in a decreased CNV. Under divided attention, target processing was increased in the middle-aged, likely reflecting compensatory effort to fulfill task requirements in the difficult condition. Additionally, middle-aged participants processed invalidly cued stimuli more intensely as was reflected by stimulus ERPs. The results suggest an age-related impairment in attentional preparation after auditory cues especially under divided attention and latent difficulties to suppress irrelevant information.

  9. Analysis of Filling and Stresses in the Hot Forging Process Depending on Flange Die Shapes

    International Nuclear Information System (INIS)

    Kim, Jun Hyoung; Kim, Cheol

    2010-01-01

    Hot closed-forging process and the die used for forming an automotive flange were analyzed from the viewpoints of heat transfer, grain-flow lines, and stresses to obtain a forged product without defects such as surface cracks, laps, cold shots, and partial filling. The forging process including up-set, pre-forging, final forging and pressing forces was investigated using finite element analysis. The influence of the preform die and the ratio of the heights of the upper die to lower die on the forging process and die were investigated and a die shape (10 .deg. for the preform die, and 1.5:1 ratio for the final die) suitable to achieve successful forging was determined on the basis of a parametric study. All parametric design requirements such as strength, full filling, and a load limit of 13,000 KN were satisfied for this newly developed flange die. New dies and flanges were fabricated and investigated. Defects such as partial filling and surface cracks were not observed

  10. Determination of solvent concentration-dependent dispersion in the vapor extraction (VAPEX) process

    Energy Technology Data Exchange (ETDEWEB)

    Abukhalifeh, H.; Lohi, A.; Upreti, S. [Ryerson Polytechnic Univ., Toronto, ON (Canada)

    2008-07-01

    This paper presented the results of a computational algorithm that revealed the optimal conditions required for vapor extraction (VAPEX) for a solvent gas-heavy oil system. VAPEX is a promising recovery process because it requires low energy use and emits fewer greenhouse gases to the atmosphere compared to other enhanced oil recovery methods. The process is governed by the dispersion of solvent gases into heavy oil and bitumen. As such, it is essential to accurately determine solvent dispersion in VAPEX in order to effectively predict the amount and time scale of oil recovery, and to optimize field operations. VAPEX experiments were conducted in this study to determined the dispersion coefficient of a solvent as a function of its concentration in heavy oil and bitumen. The principles of variational calculus were used together with a mass transfer model of the experimental process. It was concluded that the oil production determined by the model should agree with its experimental counterpart, given the optimal gas dispersion versus concentration function.

  11. Lipolysis and lipid oxidation in fermented sausages depending on different processing conditions and different antioxidants.

    Science.gov (United States)

    Zanardi, Emanuela; Ghidini, Sergio; Battaglia, Alessandra; Chizzolini, Roberto

    2004-02-01

    Lipolysis and lipid oxidation in Mediterranean and North Europe type sausages were studied in relation to raw material, processing conditions and additives. In particular the effect of ascorbic acid, nitrites and spices was evaluated. Lipolysis was measured by the determination of total and free fatty acids of fresh minces and matured products and lipid oxidation was evaluated by thiobarbituric acid reactive substances and cholesterol oxidation products. The increase of free fatty acids during maturation appears to be independent from processing conditions and the differences in polyunsaturated fatty acids increment found among the formulations appear to be due to inherent variations of raw materials. The presence of ascorbic acid and/or nitrite seems important for cholesterol protection and, as a consequence, for the safety of fermented meat products while spices at doses up to 0.1% do not seem to have a remarkable effect. The effect on fatty acid oxidation of the same additives and of the different processing technologies is not significantly different and the variations linked to raw material may play the greatest role.

  12. Culture-Dependent and -Independent Methods to Investigate the Predominant Microorganisms Associated with Wet Processed Coffee.

    Science.gov (United States)

    Feng, Xiaomin; Dong, Honghong; Yang, Pan; Yang, Ruijuan; Lu, Jun; Lv, Jie; Sheng, Jun

    2016-08-01

    The fermentation process of Yunnan arabica coffee is a typical wet fermentation. Its excellent quality is closely related to microbes in the process of fermentation. The purpose of this study was to isolate and identify the microorganisms in the wet method of coffee processing in Yunnan Province, China. Microbial community structure and dominant bacterial species were evaluated by traditional cultivated separation method and PCR-DGGE technology, and were further analyzed in combination with the changes of organic acid content, activity of pectinase, and physical parameters (pH and temperature). A large number of microorganisms which can produce pectinase were found. Among them, Enterobacter cowanii, Pantoea agglomerans, Enterobacteriaceae bacterium, and Rahnella aquatilis were the predominant gram-negative bacteria, Bacillus cereus was the predominant gram-positive bacterium, Pichia kluyveri, Hanseniaspora uvarum, and Pichia fermentans were the predominant yeasts, and all those are pectinase-producing microorganisms. As for the contents of organic acids, oxalic was the highest, followed by acetic and lactic acids. Butyrate and propionate, which were unfavorable during the fermentation period, were barely discovered.

  13. Cas4-Dependent Prespacer Processing Ensures High-Fidelity Programming of CRISPR Arrays.

    Science.gov (United States)

    Lee, Hayun; Zhou, Yi; Taylor, David W; Sashital, Dipali G

    2018-04-05

    CRISPR-Cas immune systems integrate short segments of foreign DNA as spacers into the host CRISPR locus to provide molecular memory of infection. Cas4 proteins are widespread in CRISPR-Cas systems and are thought to participate in spacer acquisition, although their exact function remains unknown. Here we show that Bacillus halodurans type I-C Cas4 is required for efficient prespacer processing prior to Cas1-Cas2-mediated integration. Cas4 interacts tightly with the Cas1 integrase, forming a heterohexameric complex containing two Cas1 dimers and two Cas4 subunits. In the presence of Cas1 and Cas2, Cas4 processes double-stranded substrates with long 3' overhangs through site-specific endonucleolytic cleavage. Cas4 recognizes PAM sequences within the prespacer and prevents integration of unprocessed prespacers, ensuring that only functional spacers will be integrated into the CRISPR array. Our results reveal the critical role of Cas4 in maintaining fidelity during CRISPR adaptation, providing a structural and mechanistic model for prespacer processing and integration. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Differential dependence of Pavlovian incentive motivation and instrumental incentive learning processes on dopamine signaling

    Science.gov (United States)

    Wassum, Kate M.; Ostlund, Sean B.; Balleine, Bernard W.; Maidment, Nigel T.

    2011-01-01

    Here we attempted to clarify the role of dopamine signaling in reward seeking. In Experiment 1, we assessed the effects of the dopamine D1/D2 receptor antagonist flupenthixol (0.5 mg/kg i.p.) on Pavlovian incentive motivation and found that flupenthixol blocked the ability of a conditioned stimulus to enhance both goal approach and instrumental performance (Pavlovian-to-instrumental transfer). In Experiment 2 we assessed the effects of flupenthixol on reward palatability during post-training noncontingent re-exposure to the sucrose reward in either a control 3-h or novel 23-h food-deprived state. Flupenthixol, although effective in blocking the Pavlovian goal approach, was without effect on palatability or the increase in reward palatability induced by the upshift in motivational state. This noncontingent re-exposure provided an opportunity for instrumental incentive learning, the process by which rats encode the value of a reward for use in updating reward-seeking actions. Flupenthixol administered prior to the instrumental incentive learning opportunity did not affect the increase in subsequent off-drug reward-seeking actions induced by that experience. These data suggest that although dopamine signaling is necessary for Pavlovian incentive motivation, it is not necessary for changes in reward experience, or for the instrumental incentive learning process that translates this experience into the incentive value used to drive reward-seeking actions, and provide further evidence that Pavlovian and instrumental incentive learning processes are dissociable. PMID:21693635

  15. Matrix Model for Methamphetamine Dependence Among Iranian Female Methadone Patients: The First Report From the Most Populated Persian Gulf Country

    Directory of Open Access Journals (Sweden)

    Omid Massah

    2017-09-01

    Discussion: The results indicated that the Matrix Model is effective for treating MA dependence. However, the long length of the treatment, lack of cost-effectiveness, and intensive staff training are significant problems associated with providing MA treatment. Further studies are suggested to evaluate the role of brief interventions in reducing these problems in methadone treatment services.

  16. Do we have to choose between feeding the human population and conserving nature? Modelling the global dependence of people on ecosystem services.

    Science.gov (United States)

    Cazalis, Victor; Loreau, Michel; Henderson, Kirsten

    2018-09-01

    The ability of the human population to continue growing depends strongly on the ecosystem services provided by nature. Nature, however, is becoming more and more degraded as the number of individuals increases, which could potentially threaten the future well-being of the human population. We use a dynamic model to conceptualise links between the global proportion of natural habitats and human demography, through four categories of ecosystem services (provisioning, regulating, cultural recreational and informational) to investigate the common future of nature and humanity in terms of size and well-being. Our model shows that there is generally a trade-off between the quality of life and human population size and identifies four short-term scenarios, corresponding to three long-term steady states of the model. First, human population could experience declines if nature becomes too degraded and regulating services diminish; second the majority of the population could be in a famine state, where the population continues to grow with minimal food provision. Between these scenarios, a desirable future scenario emerges from the model. It occurs if humans convert enough land to feed all the population, while maintaining biodiversity and ecosystem services. Finally, we find a fourth scenario, which combines famine and a decline in the population because of an overexploitation of land leading to a decrease in food production. Human demography is embedded in natural dynamics; the two factors should be considered together if we are to identify a desirable future for both nature and humans. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Collision velocity dependence of double capture processes in N7+ and Ne8+ + He systems (v = 0.18 to 0.61 au)

    International Nuclear Information System (INIS)

    Moretto-Capelle, P.; Benoit-Cattin, P.; Bordenave-Montesquieu, A.; Gleizes, A.

    1991-01-01

    Double capture processes depend on the collision velocity in the complicated way which is different for N 7+ and Ne 8+ + He collisional systems. Some examples of energy dependence for differential and total cross sections are given. (orig.)

  18. Heterogeneity of breast cancer stem cells as evidenced with Notch-dependent and Notch-independent populations

    International Nuclear Information System (INIS)

    Wong, Nelson K Y; Fuller, Megan; Sung, Sandy; Wong, Fred; Karsan, Aly

    2012-01-01

    Studies have suggested the potential importance of Notch signaling to the cancer stem cell population in some tumors, but it is not known whether all cells in the cancer stem cell fraction require Notch activity. To address this issue, we blocked Notch activity in MCF-7 cells by expressing a dominant-negative MAML-GFP (dnMAML) construct, which inhibits signaling through all Notch receptors, and quantified the effect on tumor-initiating activity. Inhibition of Notch signaling reduced primary tumor sphere formation and side population. Functional quantification of tumor-initiating cell numbers in vivo showed a significant decrease, but not a complete abrogation, of these cells in dnMAML-expressing cells. Interestingly, when assessed in secondary assays in vitro or in vivo, there was no difference in tumor-initiating activity between the dnMAML-expressing cells and control cells. The fact that a subpopulation of dnMAML-expressing cells was capable of forming primary and secondary tumors indicates that there are Notch-independent tumor-initiating cells in the breast cancer cell line MCF-7. Our findings thus provide direct evidence for a heterogeneous cancer stem cell pool, which will require combination therapies against multiple oncogenic pathways to eliminate the tumor-initiating cell population

  19. Application of Finite Element Method to Analyze the Influences of Process Parameters on the Cut Surface in Fine Blanking Processes by Using Clearance-Dependent Critical Fracture Criteria

    Directory of Open Access Journals (Sweden)

    Phyo Wai Myint

    2018-04-01

    Full Text Available The correct choice of process parameters is important in predicting the cut surface and obtaining a fully-fine sheared surface in the fine blanking process. The researchers used the value of the critical fracture criterion obtained by long duration experiments to predict the conditions of cut surfaces in the fine blanking process. In this study, the clearance-dependent critical ductile fracture criteria obtained by the Cockcroft-Latham and Oyane criteria were used to reduce the time and cost of experiments to obtain the value of the critical fracture criterion. The Finite Element Method (FEM was applied to fine blanking processes to study the influences of process parameters such as the initial compression, the punch and die corner radii and the shape and size of the V-ring indenter on the length of the sheared surface. The effects of stress triaxiality and punch diameters on the cut surface produced by the fine blanking process are also discussed. The verified process parameters and tool geometry for obtaining a fully-fine sheared SPCC surface are described. The results showed that the accurate and stable prediction of ductile fracture initiation can be achieved using the Oyane criterion.

  20. Solution-processed organic thermoelectric materials exhibiting doping-concentration-dependent polarity.

    Science.gov (United States)

    Hwang, Sunbin; Potscavage, William J; Yang, Yu Seok; Park, In Seob; Matsushima, Toshinori; Adachi, Chihaya

    2016-10-26

    Recent progress in conducting polymer-based organic thermoelectric generators (OTEGs) has resulted in high performance due to high Seebeck coefficient, high electrical conductivity (σ), and low thermal conductivity obtained by chemically controlling the materials's redox levels. In addition to improving the properties of individual OTEGs to obtain high performance, the development of solution processes for the fabrication of OTEG modules is necessary to realize large thermoelectric voltage and low-cost mass production. However, the scarcity of good candidates for soluble organic n-type materials limits the use of π-leg module structures consisting of complementary elements of p- and n-type materials because of unbalanced transport coefficients that lead to power losses. In particular, the extremely low σ of n-type materials compared with that of p-type materials is a serious challenge. In this study, poly(pyridinium phenylene) (P(PymPh)) was tested as an n-type semiconductor in solution-processed OTEGs, and the carrier density was controlled by a solution-based chemical doping process using the dopant sodium naphthalenide, a well-known reductant. The electronic structures and doping mechanism of P(PymPh) were explored based on the changes in UV-Vis-IR absorption, ultraviolet photoelectron, and X-ray photoelectron spectra. By controlling the dopant concentration, we demonstrate a maximum n-type power factor of 0.81 μW m -1 K -2 with high σ, and at higher doping concentrations, a switch from n-type to p-type TE operation. This is one of the first cases of a switch in polarity just by increasing the concentration of the reductant and may open a new route for simplified fabrication of complementary organic layers.

  1. New learning while consolidating memory during sleep is actively blocked by a protein synthesis dependent process

    Science.gov (United States)

    Levy, Roi; Levitan, David; Susswein, Abraham J

    2016-01-01

    Brief experiences while a memory is consolidated may capture the consolidation, perhaps producing a maladaptive memory, or may interrupt the consolidation. Since consolidation occurs during sleep, even fleeting experiences when animals are awakened may produce maladaptive long-term memory, or may interrupt consolidation. In a learning paradigm affecting Aplysia feeding, when animals were trained after being awakened from sleep, interactions between new experiences and consolidation were prevented by blocking long-term memory arising from the new experiences. Inhibiting protein synthesis eliminated the block and allowed even a brief, generally ineffective training to produce long-term memory. Memory formation depended on consolidative proteins already expressed before training. After effective training, long term memory required subsequent transcription and translation. Memory formation during the sleep phase was correlated with increased CREB1 transcription, but not CREB2 transcription. Increased C/EBP transcription was a correlate of both effective and ineffective training and of treatments not producing memory. DOI: http://dx.doi.org/10.7554/eLife.17769.001 PMID:27919318

  2. The optimal production-run time for a stock-dependent imperfect production process

    Directory of Open Access Journals (Sweden)

    Jain Divya

    2013-01-01

    Full Text Available This paper develops an inventory model for a hypothesized volume flexible manufacturing system in which the production rate is stock-dependent and the system produces both perfect and imperfect quality items. The demand rate of perfect quality items is known and constant, whereas the demand rate of imperfect (non-conforming to specifications quality items is a function of discount offered in the selling price. In this paper, we determine an optimal production-run time and the optimal discount that should be offered in the selling price to influence the sale of imperfect quality items produced by the manufacturing system. The considered model aims to maximize the net profit obtained through the sales of both perfect and imperfect quality items subject to certain constraints of the system. The solution procedure suggests the use of ‘Interior Penalty Function Method’ to solve the associated constrained maximization problem. Finally, a numerical example demonstrating the applicability of proposed model has been included.

  3. Dependence of radon emanation of red mud bauxite processing wastes on heat treatment

    International Nuclear Information System (INIS)

    Jobbagy, V.; Somlai, J.; Kovacs, J.; Szeiler, G.; Kovacs, T.

    2009-01-01

    Natural radioactivity content, radon emanation and some other physical characteristics of red mud were investigated, so that to identify the possibilities of the safe utilization of such material as a building material additive. Based on the radionuclide concentration, red mud is not permitted to be used directly as a building material, however, mixing of a maximum 20% red mud and 80% clay meets the requirements. The main aim of this work was to determine the dependence of the emanation factor of red mud firing temperature and some other parameters. The relevant experimental procedure was carried out in two different ways: without any additional material, and by adding a known amount of sawdust (5-35 wt%) then firing the sample at a given temperature (100-1000 deg. C). The average emanation factor of the untreated dry red mud was estimated to 20%, which decreased to about 5% at a certain heat treatment. Even lower values were found using semi-reductive atmosphere. It has been concluded that all emanation measurements results correlate well to the firing temperature, the specific surface and the pore volume.

  4. Transverse momentum dependence of the angular distribution of the Drell-Yan process

    International Nuclear Information System (INIS)

    Berger, Edmond L.; Qiu Jianwei; Rodriguez-Pedraza, Ricardo A.

    2007-01-01

    We calculate the transverse momentum Q perpendicular dependence of the helicity structure functions for the hadroproduction of a massive pair of leptons with pair invariant mass Q. These structure functions determine the angular distribution of the leptons in the pair rest frame. Unphysical behavior in the region Q perpendicular →0 is seen in the results of calculations done at fixed order in QCD perturbation theory. We use current conservation to demonstrate that the unphysical inverse-power and ln(Q/Q perpendicular ) logarithmic divergences in three of the four independent helicity structure functions share the same origin as the divergent terms in fixed-order calculations of the angular-integrated cross section. We show that the resummation of these divergences to all orders in the strong coupling strength α s can be reduced to the solved problem of the resummation of the divergences in the angular-integrated cross section, resulting in well-behaved predictions in the small Q perpendicular region. Among other results, we show the resummed part of the helicity structure functions preserves the Lam-Tung relation between the longitudinal and double spin-flip structure functions as a function of Q perpendicular to all orders in α s

  5. Dose dependent oxidation kinetics of lipids in fish during irradiation processing

    International Nuclear Information System (INIS)

    Tukenmez, I.; Ersen, M.S.; Bakioglu, A.T.; Bicer, A.; Pamuk, V.

    1997-01-01

    Kinetic aspects of the development of lipid oxidation in complex foods as fish in the course of irradiation were analyzed with respect to the associated formation of malonaldehyde (MA) through the reactions modified so as to be consistent with those in complex foods as fish. Air-packed anchovy (Engraulis encrasicholus) samples in polyethylene pouches were irradiated at the doses of 1, 2, 5, 10, 15,20 and 25 kGy at 20 o C in a Cs-137 gamma irradiator of 1.806 kGy/h dose rate. Immediately after each irradiation, MA contents of irradiated and unirradiated samples were determined by thiobarbituric acid test. Based on the MA formation, a kinetic model to simulate the apparent oxidation of lipid in fish as a function of irradiation dose was derived from the rate equations consistent with modified reactions. Kinetic parameters and simulation were related to conditions of lipid oxidation, and associated rancidity state of fish with respect to the doses applied in different irradiation-preservation processes. Numerical values of kinetic parameters based on the MA formation were found as a threshold dose of 0.375 kGy, an apparent yield of 1.871 μmol/kg kGy, and a maximum attainable concentration of 15.853 μmol/kg which may be used for process control and dosimetry. (author)

  6. Following the time course of face gender and expression processing: a task-dependent ERP study.

    Science.gov (United States)

    Valdés-Conroy, Berenice; Aguado, Luis; Fernández-Cahill, María; Romero-Ferreiro, Verónica; Diéguez-Risco, Teresa

    2014-05-01

    The effects of task demands and the interaction between gender and expression in face perception were studied using event-related potentials (ERPs). Participants performed three different tasks with male and female faces that were emotionally inexpressive or that showed happy or angry expressions. In two of the tasks (gender and expression categorization) facial properties were task-relevant while in a third task (symbol discrimination) facial information was irrelevant. Effects of expression were observed on the visual P100 component under all task conditions, suggesting the operation of an automatic process that is not influenced by task demands. The earliest interaction between expression and gender was observed later in the face-sensitive N170 component. This component showed differential modulations by specific combinations of gender and expression (e.g., angry male vs. angry female faces). Main effects of expression and task were observed in a later occipito-temporal component peaking around 230 ms post-stimulus onset (EPN or early posterior negativity). Less positive amplitudes in the presence of angry faces and during performance of the gender and expression tasks were observed. Finally, task demands also modulated a positive component peaking around 400 ms (LPC, or late positive complex) that showed enhanced amplitude for the gender task. The pattern of results obtained here adds new evidence about the sequence of operations involved in face processing and the interaction of facial properties (gender and expression) in response to different task demands. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Mood-dependent integration in discourse comprehension: happy and sad moods affect consistency processing via different brain networks.

    Science.gov (United States)

    Egidi, Giovanna; Caramazza, Alfonso

    2014-12-01

    According to recent research on language comprehension, the semantic features of a text are not the only determinants of whether incoming information is understood as consistent. Listeners' pre-existing affective states play a crucial role as well. The current fMRI experiment examines the effects of happy and sad moods during comprehension of consistent and inconsistent story endings, focusing on brain regions previously linked to two integration processes: inconsistency detection, evident in stronger responses to inconsistent endings, and fluent processing (accumulation), evident in stronger responses to consistent endings. The analysis evaluated whether differences in the BOLD response for consistent and inconsistent story endings correlated with self-reported mood scores after a mood induction procedure. Mood strongly affected regions previously associated with inconsistency detection. Happy mood increased sensitivity to inconsistency in regions specific for inconsistency detection (e.g., left IFG, left STS), whereas sad mood increased sensitivity to inconsistency in regions less specific for language processing (e.g., right med FG, right SFG). Mood affected more weakly regions involved in accumulation of information. These results show that mood can influence activity in areas mediating well-defined language processes, and highlight that integration is the result of context-dependent mechanisms. The finding that language comprehension can involve different networks depending on people's mood highlights the brain's ability to reorganize its functions. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Attention-dependent allocation of auditory processing resources as measured by mismatch negativity.

    Science.gov (United States)

    Dittmann-Balcar, A; Thienel, R; Schall, U

    1999-12-16

    Mismatch negativity (MMN) is a pre-attentive event-related potential measure of echoic memory. However, recent studies suggest attention-related modulation of MMN. This study investigates duration-elicited MMN in healthy subjects (n = 12) who were performing a visual discrimination task and, subsequently, an auditory discrimination task in a series of increasing task difficulty. MMN amplitude was found to be maximal at centro-frontal electrode sites without hemispheric differences. Comparison of both attend conditions (visual vs. auditory), revealed larger MMN amplitudes at Fz in the visual task without differences across task difficulty. However, significantly smaller MMN in the most demanding auditory condition supports the notion of limited processing capacity whose resources are modulated by attention in response to task requirements.

  9. Safety of parsley intended for processing depending on the cultivation technology and storage

    Directory of Open Access Journals (Sweden)

    Pobereżny Jarosław

    2016-09-01

    Full Text Available The factors that affect the value of parsley for consumption include its taste, flavour and dietary utility (vitamins C and E, β-carotene, potassium, calcium, phosphorus and iron, raw fibre, proteins as well as the content of hazardous substances, especially nitrogen compounds. A study was carried out in 2013–2015 to determine the effect of the cultivation technology and storage on the safety of parsley intended for processing. The study material was taken from an experiment where the following fertilisers were applied to the ground: nitrogen (0, 40, 80, 120 kg N∙ha−1 and magnesium (0; 30 kg Mg∙ha−1. Parsley roots were stored for six months in a storage room at +1°C and RH 95%. The content of nitrates (V and (III was determined by the ion selective method immediately after the harvest and after storage in parsley roots.

  10. Simulation of electrorefining process using time-dependent multi-component electrochemical model: REFIN

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byung Gi; Hwang, Il Soon [Seoul National Univ., Seoul (Korea, Republic of)

    1999-10-01

    REFIN model is applied to analyze a series of experiments that had been conducted by Tomczuk, et al. at Argonne National Laboratory (ANL) in the U.S.A.. Predicted results from REFIN model for the electrorefining experiment are compared with the published experimental results. It is demonstrated that REFIN model can predict faradic current of each element and electrochemical potential as a function of time over the entire campaign of the electrorefining experiment. The elemental concentration changes agree with the experimental results well. Elemental concentration changes during an open-circuit equilibration period are revealed to suggest that the electrorefining process could not be adequately described by the equilibrium model often applied for an electrode surface. Surface potential drop is changed according to equilibrium potential of chemical species with high activity in liquid metal.

  11. Processing-dependent thermal stability of a prototypical amorphous metal oxide

    Science.gov (United States)

    Zeng, Li; Moghadam, Mahyar M.; Buchholz, D. Bruce; Li, Ran; Keane, Denis T.; Dravid, Vinayak P.; Chang, Robert P. H.; Voorhees, Peter W.; Marks, Tobin J.; Bedzyk, Michael J.

    2018-05-01

    Amorphous metal oxides (AMOs) are important candidate materials for fabricating next-generation thin-film transistors. While much attention has been directed toward the synthesis and electrical properties of AMOs, less is known about growth conditions that allow AMOs to retain their desirable amorphous state when subjected to high operating temperatures. Using in situ x-ray scattering and level-set simulations, we explore the time evolution of the crystallization process for a set of amorphous I n2O3 thin films synthesized by pulsed-laser deposition at deposition temperatures (Td) of -50, -25, and 0 °C. The films were annealed isothermally and the degree of crystallinity was determined by a quantitative analysis of the time-evolved x-ray scattering patterns. As expected, for films grown at the same Td, an increase in the annealing temperature TA led to a shorter delay prior to the onset of crystallization, and a faster crystallization rate. Moreover, when lowering the deposition temperature by 25 °C, a 40 °C increase in annealing temperature is needed to achieve the same time interval for the crystals to grow from 10 to 90% volume fraction of the sample. Films grown at Td=0 ∘C exhibited strong cubic texture after crystallization. A level-set method was employed to quantitatively model the texture that develops in the microstructures and to determine key parameters, such as the interface growth velocity, the nucleation density, and the activation energy. The differences observed in the crystallization processes are attributed to the changes in the atomic structure of the oxide and possible nanocrystalline inclusions that formed during the deposition of the amorphous phase.

  12. Capability-oriented agent theory and its applications in dependable systems and process engineering

    Energy Technology Data Exchange (ETDEWEB)

    Thunem, Atoosa P-J.

    2004-04-15

    During the rapid growth of computerised systems in the past 15 years, the variety of services and their efficiency have been the strongest deciding factors in design and development of the systems within various industrial branches. At the same time, the introduction and popularity of emerging design and development techniques seems to have forced the industry to include these in their product development process. Unfortunately, too many examples of lack of use or erroneous use of these techniques within industries such as telecommunications, telemedicine, aerospace and indeed the energy sector indicate that a common understanding of and belief in the rationale behind the techniques and their solution domains has not been obtained. At the same time, a tremendous increase in the number of emerging techniques has made such an understanding difficult to gain, especially when the techniques share the same application field, but differ in few yet important issues. Finally, the lack of knowledge about system aspects and the integration of various abstraction levels to describe them have added even more to the confusion on how to use different techniques. The work resulting in the Capability-Oriented Agent Theory began while trying to find more descriptive system models, taking into account a wider selection of system aspects. Although related to object-oriented and agent-oriented principles, the theory differs from such principles in many respects. Among others, its focal point is on a category of system aspects neither addressed nor recognised within such principles before. Additionally, the theory opposes the well-established idea of distinct separation between requirement, design, implementation and test specifications, but suggests a systematic integration of the related activities, hence to increase their traceability and intercommunication in both a top-down and a bottom-up manner along the development process. (Author)

  13. Monarch butterfly population decline in North America: identifying the threatening processes

    Science.gov (United States)

    Thogmartin, Wayne E.; Wiederholt, Ruscena; Oberhauser, Karen; Drum, Ryan G.; Diffendorfer, Jay E.; Altizer, Sonia; Taylor, Orley R.; Pleasants, John M.; Semmens, Darius J.; Semmens, Brice X.; Erickson, Richard A.; Libby, Kaitlin; Lopez-Hoffman, Laura

    2017-01-01

    The monarch butterfly (Danaus plexippus) population in North America has sharply declined over the last two decades. Despite rising concern over the monarch butterfly's status, no comprehensive study of the factors driving this decline has been conducted. Using partial least-squares regressions and time-series analysis, we investigated climatic and habitat-related factors influencing monarch population size from 1993 to 2014. Potential threats included climatic factors, habitat loss (milkweed and overwinter forest), disease and agricultural insecticide use (neonicotinoids). While climatic factors, principally breeding season temperature, were important determinants of annual variation in abundance, our results indicated strong negative relationships between population size and habitat loss variables, principally glyphosate use, but also weaker negative effects from the loss of overwinter forest and breeding season use of neonicotinoids. Further declines in population size because of glyphosate application are not expected. Thus, if remaining threats to habitat are mitigated we expect climate-induced stochastic variation of the eastern migratory population of monarch butterfly around a relatively stationary population size.

  14. BACTERIAL POPULATION DYNAMICS IN WASTE OILY EMULSIONS FROM THE METAL-PROCESSING INDUSTRY

    Directory of Open Access Journals (Sweden)

    Paweł Kaszycki

    2014-07-01

    Full Text Available Oil-containing wastewaters are regarded as main industrial pollutants of soil and water environments. They can occur as free-floating oil, unstable or stable oil-in-water (O/W emulsions, and in the case of extreme organic load, as water-in-oil (W/O emulsions. In this study two types of oily effluents, a typical O/W emulsion marked as E1 and a W/O emulsion E2, both discharged by local metal processing plants were examined to test their toxicity to microbial communities and the ability to serve as nutrient sources for bacterial growth. The organic contaminant load of the samples was evaluated on the basis of chemical oxygen demand (COD parameter values and was equal to 48 200 mg O2·dm-3 and >300 000 mg O2·dm-3 for E1 and E2, respectively.Both emulsions proved to be non toxic to bacterial communities and were shown to contain biodiverse autochthonous microflora consisting of several bacterial strains adapted to the presence of xenobiotics (the total of 1.36 · 106 CFU·cm-3 and 1.72 · 105 CFU·cm-3 was determined for E1 and E2, respectively. These indigenous bacteria as well as exogenously inoculated specialized allochthonous microorganisms were biostimulated so as to proliferate within the wastewater environment whose organic content served as the only source of carbon. The most favorable cultivation conditions were determined as fully aerobic growth at the temperature of 25 ºC. In 9 to 18 day-tests, autochthonous as well as bioaugmented allochthonous bacterial population dynamics were monitored. For both emulsions tested there was a dramatic increase (up to three orders of magnitude in bacterial frequency, as compared to the respective initial values. The resultant high biomass densities suggest that the effluents are susceptible to bioremediation. A preliminary xenobiotic biodegradation test confirmed that mixed auto- and allochthonous bacterial consortia obtained upon inoculation of the samples with microbiocenoses preselected for efficient

  15. EPR pilot study on the population of Stepnogorsk city living in the vicinity of a uranium processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Zhumadilov, Kassym; Akilbekov, Abdirash; Morzabayev, Aidar [L.N. Gumilyov Eurasian National University, Astana (Kazakhstan); Ivannikov, Alexander; Stepanenko, Valeriy [Medical Radiological Research Center, Obninsk (Russian Federation); Abralina, Sholpan; Sadvokasova, Lyazzat; Rakhypbekov, Tolebay [Semey State Medical University, Semey (Kazakhstan); Hoshi, Masaharu [Hiroshima University, Research Institute for Radiation Biology and Medicine, Hiroshima (Japan)

    2015-03-15

    The aim of this pilot study was to evaluate possible doses in teeth received by workers of a uranium processing plant, in excess to the natural background dose. For this, the electron paramagnetic resonance dosimetry method was applied. Absorbed doses in teeth from the workers were compared with those measured in teeth from the Stepnogorsk city population and a control pool population from Astana city. The measured tooth samples were extracted according to medical indications. In total, 32 tooth enamel samples were analyzed, 5 from Astana city, Kazakhstan (control population), 21 from the residents of Stepnogorsk city (180 km from Astana city), and 6 from the workers of a uranium processing plant. The estimated doses in tooth enamel from the uranium processing plant workers were not significantly different to those measured in enamel from the control population. In teeth from the workers, the maximum dose in excess to background dose was 33 mGy. In two teeth from residents of Stepnogorsk city, however, somewhat larger doses were measured. The results of this pilot study encourage further investigations in an effort to receiving a final conclusion on the exposure situation of the uranium processing plant workers and the residents of Stepnogorsk city. (orig.)

  16. Process-Oriented Guided-Inquiry Learning in an Introductory Anatomy and Physiology Course with a Diverse Student Population

    Science.gov (United States)

    Brown, Patrick J. P.

    2010-01-01

    Process-oriented guided-inquiry learning (POGIL), a pedagogical technique initially developed for college chemistry courses, has been implemented for 2 yr in a freshman-level anatomy and physiology course at a small private college. The course is populated with students with backgrounds ranging from no previous college-level science to junior and…

  17. Progressive Recruitment of Mesenchymal Progenitors Reveals a Time-Dependent Process of Cell Fate Acquisition in Mouse and Human Nephrogenesis.

    Science.gov (United States)

    Lindström, Nils O; De Sena Brandine, Guilherme; Tran, Tracy; Ransick, Andrew; Suh, Gio; Guo, Jinjin; Kim, Albert D; Parvez, Riana K; Ruffins, Seth W; Rutledge, Elisabeth A; Thornton, Matthew E; Grubbs, Brendan; McMahon, Jill A; Smith, Andrew D; McMahon, Andrew P

    2018-06-04

    Mammalian nephrons arise from a limited nephron progenitor pool through a reiterative inductive process extending over days (mouse) or weeks (human) of kidney development. Here, we present evidence that human nephron patterning reflects a time-dependent process of recruitment of mesenchymal progenitors into an epithelial nephron precursor. Progressive recruitment predicted from high-resolution image analysis and three-dimensional reconstruction of human nephrogenesis was confirmed through direct visualization and cell fate analysis of mouse kidney organ cultures. Single-cell RNA sequencing of the human nephrogenic niche provided molecular insights into these early patterning processes and predicted developmental trajectories adopted by nephron progenitor cells in forming segment-specific domains of the human nephron. The temporal-recruitment model for nephron polarity and patterning suggested by direct analysis of human kidney development provides a framework for integrating signaling pathways driving mammalian nephrogenesis. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Chromosomal aberrations and DNA damage in human populations exposed to the processing of electronics waste.

    Science.gov (United States)

    Liu, Qiang; Cao, Jia; Li, Ke Qiu; Miao, Xu Hong; Li, Guang; Fan, Fei Yue; Zhao, Yong Cheng

    2009-05-01

    were significantly higher than in the control group (P = 0.000). The percentage of DNA in the comet tail, tail moment, and Olive tail moment detected by comet assay showed that there was a significant difference in DNA damage in the exposure group (P = 0.000). The chromosome aberration, micronucleus rate, and DNA damage observed in women were significantly higher than those in men. Chromosome aberration and micronuclear rates of both smokers and non-smokers in the exposure group are obviously higher than that in the control group (P = 0.000). The use of outdated (and unsafe) ways to deal with E-wastes can lead to exposure to a variety of substances harmful to human health. The components of pollution may enter the human body through the air, drinking water, and food chain to damage human genetic material, resulting in genomic instability. The rates of chromosomal aberration, micronucleus formation, and the degree of DNA damage in women in the group exposed to electronic waste were significantly higher than in men. The reason for this may be concerned with the traditional lifestyle of the local residents or the difference of sensitivity to the exposure to E-wastes or any others. Further investigations are needed to provide evidence to demonstrate this. Here, we report the obviously cytogenetic toxicity to the exposure population by the E-waste pollution for the first time. E-waste pollution may be a potential agent of genetic mutation, and may induce cytogenetic damage within the general population exposed to the pollution. These findings need to be considered, and steps should be taken to protect the current population and future generations from the effects of pollution with E-wastes. The above results remind us that the impact of E-waste recycling on environmental quality of Jinghai should be evaluated soon. Moreover, it is urgent for the government to prohibit E-waste import and its processing by outdated ways. The future studies such as pollutant details of

  19. Charge dependence of one and two electron processes in collisions between hydrogen molecules and fast projectiles

    International Nuclear Information System (INIS)

    Wells, E.; Ben-Itzhak, I.; Carnes, K.D.; Krishnamurthi, V.

    1996-01-01

    The ratio of double- to single-ionization (DI/SI) as well as the ratio of ionization-excitation to single-ionization (IE/SI) in hydrogen molecules was studied by examining the effect of the projectile charge on these processes. The DI/SI and IE/SI ratios were measured using the coincidence time of flight technique at a fixed velocity (1 MeV/amu) over a range of projectile charge states (q = 1-9,14,20). Preliminary results indicate that for a highly charged F 9+ projectile the DI/SI and IE/SI ratios are 6.8% and 24.7%, respectively, a large increase from the ratios of 0.13% and 1.95%, respectively, for H + projectiles. For low charge states, the DI/SI is negligible relative to the IE/SI ratio, while for more highly charged projectiles the DI/SI ratio becomes comparable to the IE/SI ratio. This indicates that double-ionization increases much more rapidly with projectile charge than ionization-excitation

  20. Cation binding to 15-TBA quadruplex DNA is a multiple-pathway cation-dependent process.

    Science.gov (United States)

    Reshetnikov, Roman V; Sponer, Jiri; Rassokhina, Olga I; Kopylov, Alexei M; Tsvetkov, Philipp O; Makarov, Alexander A; Golovin, Andrey V

    2011-12-01

    A combination of explicit solvent molecular dynamics simulation (30 simulations reaching 4 µs in total), hybrid quantum mechanics/molecular mechanics approach and isothermal titration calorimetry was used to investigate the atomistic picture of ion binding to 15-mer thrombin-binding quadruplex DNA (G-DNA) aptamer. Binding of ions to G-DNA is complex multiple pathway process, which is strongly affected by the type of the cation. The individual ion-binding events are substantially modulated by the connecting loops of the aptamer, which play several roles. They stabilize the molecule during time periods when the bound ions are not present, they modulate the route of the ion into the stem and they also stabilize the internal ions by closing the gates through which the ions enter the quadruplex. Using our extensive simulations, we for the first time observed full spontaneous exchange of internal cation between quadruplex molecule and bulk solvent at atomistic resolution. The simulation suggests that expulsion of the internally bound ion is correlated with initial binding of the incoming ion. The incoming ion then readily replaces the bound ion while minimizing any destabilization of the solute molecule during the exchange. © The Author(s) 2011. Published by Oxford University Press.

  1. Cation binding to 15-TBA quadruplex DNA is a multiple-pathway cation-dependent process

    Science.gov (United States)

    Reshetnikov, Roman V.; Sponer, Jiri; Rassokhina, Olga I.; Kopylov, Alexei M.; Tsvetkov, Philipp O.; Makarov, Alexander A.; Golovin, Andrey V.

    2011-01-01

    A combination of explicit solvent molecular dynamics simulation (30 simulations reaching 4 µs in total), hybrid quantum mechanics/molecular mechanics approach and isothermal titration calorimetry was used to investigate the atomistic picture of ion binding to 15-mer thrombin-binding quadruplex DNA (G-DNA) aptamer. Binding of ions to G-DNA is complex multiple pathway process, which is strongly affected by the type of the cation. The individual ion-binding events are substantially modulated by the connecting loops of the aptamer, which play several roles. They stabilize the molecule during time periods when the bound ions are not present, they modulate the route of the ion into the stem and they also stabilize the internal ions by closing the gates through which the ions enter the quadruplex. Using our extensive simulations, we for the first time observed full spontaneous exchange of internal cation between quadruplex molecule and bulk solvent at atomistic resolution. The simulation suggests that expulsion of the internally bound ion is correlated with initial binding of the incoming ion. The incoming ion then readily replaces the bound ion while minimizing any destabilization of the solute molecule during the exchange. PMID:21893589

  2. Early childhood experiences, parenting and the process of drug dependency among young people in Tehran, Iran.

    Science.gov (United States)

    Mirlashari, Jila; Demirkol, Apo; Salsali, Mahvash; Rafiey, Hassan; Jahanbani, Jahanfar

    2012-06-01

    Substance abuse has become a major public health problem in Iran. The process of developing an addiction is complex and multifaceted. Early childhood experiences are thought to be one of the important determinants of addictive behaviour. The aim of this qualitative study is to explore the early childhood experiences, especially the experiences within the immediate family, of current substance-using young adults in Iran. The study is qualitative in nature. In-depth interviews were conducted with 15 young men and women who were either in treatment for their addiction or were active drug users at the time of the interviews. Moreover, four interviews have been conducted with family members of participants. The majority of the participants experienced traumatic events during childhood and came from dysfunctional families. There appears to be a significant disconnect between these individuals and their families. An obedience-instilling parenting style and parents' knowledge and attitude toward drug using and prevention were also identified as important determinants of substance use. The results of this research point out the need for early interventions for at-risk families as well as at-risk individuals. © 2011 Australasian Professional Society on Alcohol and other Drugs.

  3. Parallel processing for a 1-D time-dependent solution to impurity rate equations for fusion plasma simulations

    International Nuclear Information System (INIS)

    Veerasingam, R.

    1990-01-01

    In fusion plasmas impurities such as carbon, oxygen or nickel can contaminate the plasma and cause degradation of the performance of a fusion device through radiation. However, impurities can also be used as diagnostics to obtain information about a plasma through spectroscopic experiments which can then be used in plasma modeling and simulations. In the past, serial algorithms have been described for either the time dependent or steady state problem. In this paper, we describe a parallel procedure adopted to solve the time-dependent problem. It can be shown that for the steady state problem a parallel procedure would not be a useful application of parallelization because a few seconds of the Central Processing Unit time on a CRAY-XMP or IBM 3090/600S would suffice to obtain the solution, while this is not the case for the time-dependent problem. In order to study the effects of low Z and high Z impurities on the final state of a plasma, time-dependent solutions are necessary. For purposes of diagnostics and comparisons with experiments, a fast turn around time of the simulations would be advantageous. We have implemented a parallel algorithm on and IBM 3090/600S and tested its performance for a typical set of fusion plasma parameters. 4 refs., 1 tab

  4. Experimental population dynamics of Rhabdias bufonis (Nematoda) in toads (Bufo bufo): density-dependence in the primary infection

    OpenAIRE

    Goater, C. P.

    2017-01-01

    Density-dependence in worm establishment, numbers, biomass and larval production were examined in primary infections of 0, 10, 40, 80 and 160 larvae of the lung nematode, Rhabdias bufonis in the common toad, Bufo bufo. The infection procedure established 4 non-overlapping levels of infection which persisted until 6 weeks post-infection (p.i.), after which there was an overall decline up to 12 weeks p.i. Worm numbers had no direct effect on adult worm survival but temporal changes in worm weig...

  5. The patient's vulnerability, dependence and exposed situation in the discharge process: experiences of district nurses, geriatric nurses and social workers.

    Science.gov (United States)

    Rydeman, IngBritt; Törnkvist, Lena

    2006-10-01

    The aim of the study was to obtain a deeper understanding of the experiences of the discharge process among different professionals. An optimal discharge process for hospitalized elderly to other forms of care is of crucial importance, especially since health and medical policies encourages shorter hospital stays and increased healthcare service in outpatient care. Nurses and social workers from inpatient care, outpatient care, municipal care and social services were interviewed. Eight focus-group interviews with a total of 31 persons were conducted. The subsequent analyses followed a phenomenological approach. The findings revealed three themes, Framework, Basic Values and Patient Resources, which influenced the professionals' actions in the discharge process. The overall emerging structure comprised the patient's vulnerability, dependence and exposed situation in the discharge process. In conclusion some factors are of special importance for the co-operation and the actions of professionals involved in the discharge process. Firstly, a distinct and common framework, with conscious and organizationally based values. Secondly the need to take the patient resources into consideration. Together these factors could contribute to secure the patients involvement in the discharge process and to design an optimal, safe and good care. Collaborative approaches among a range of professionals within a variety of organizations are common, especially in the care of the elderly. The role and support of both the organizations and the educational units are decisive factors in this area.

  6. Basal ganglia-dependent processes in recalling learned visual-motor adaptations.

    Science.gov (United States)

    Bédard, Patrick; Sanes, Jerome N

    2011-03-01

    Humans learn and remember motor skills to permit adaptation to a changing environment. During adaptation, the brain develops new sensory-motor relationships that become stored in an internal model (IM) that may be retained for extended periods. How the brain learns new IMs and transforms them into long-term memory remains incompletely understood since prior work has mostly focused on the learning process. A current model suggests that basal ganglia, cerebellum, and their neocortical targets actively participate in forming new IMs but that a cerebellar cortical network would mediate automatization. However, a recent study (Marinelli et al. 2009) reported that patients with Parkinson's disease (PD), who have basal ganglia dysfunction, had similar adaptation rates as controls but demonstrated no savings at recall tests (24 and 48 h). Here, we assessed whether a longer training session, a feature known to increase long-term retention of IM in healthy individuals, could allow PD patients to demonstrate savings. We recruited PD patients and age-matched healthy adults and used a visual-motor adaptation paradigm similar to the study by Marinelli et al. (2009), doubling the number of training trials and assessed recall after a short and a 24-h delay. We hypothesized that a longer training session would allow PD patients to develop an enhanced representation of the IM as demonstrated by savings at the recall tests. Our results showed that PD patients had similar adaptation rates as controls but did not demonstrate savings at both recall tests. We interpret these results as evidence that fronto-striatal networks have involvement in the early to late phase of motor memory formation, but not during initial learning.

  7. Accuracy of Genomic Prediction in Synthetic Populations Depending on the Number of Parents, Relatedness, and Ancestral Linkage Disequilibrium.

    Science.gov (United States)

    Schopp, Pascal; Müller, Dominik; Technow, Frank; Melchinger, Albrecht E

    2017-01-01

    Synthetics play an important role in quantitative genetic research and plant breeding, but few studies have investigated the application of genomic prediction (GP) to these populations. Synthetics are generated by intermating a small number of parents ([Formula: see text] and thereby possess unique genetic properties, which make them especially suited for systematic investigations of factors contributing to the accuracy of GP. We generated synthetics in silico from [Formula: see text]2 to 32 maize (Zea mays L.) lines taken from an ancestral population with either short- or long-range linkage disequilibrium (LD). In eight scenarios differing in relatedness of the training and prediction sets and in the types of data used to calculate the relationship matrix (QTL, SNPs, tag markers, and pedigree), we investigated the prediction accuracy (PA) of Genomic best linear unbiased prediction (GBLUP) and analyzed contributions from pedigree relationships captured by SNP markers, as well as from cosegregation and ancestral LD between QTL and SNPs. The effects of training set size [Formula: see text] and marker density were also studied. Sampling few parents ([Formula: see text]) generates substantial sample LD that carries over into synthetics through cosegregation of alleles at linked loci. For fixed [Formula: see text], [Formula: see text] influences PA most strongly. If the training and prediction set are related, using [Formula: see text] parents yields high PA regardless of ancestral LD because SNPs capture pedigree relationships and Mendelian sampling through cosegregation. As [Formula: see text] increases, ancestral LD contributes more information, while other factors contribute less due to lower frequencies of closely related individuals. For unrelated prediction sets, only ancestral LD contributes information and accuracies were poor and highly variable for [Formula: see text] due to large sample LD. For large [Formula: see text], achieving moderate accuracy requires

  8. Population inversion of two atoms under the phase decoherence in the multiphoton process

    International Nuclear Information System (INIS)

    Zhang Dongxia; Sa Chuerfu; Mu Qier

    2011-01-01

    By means of the quantum theory, the population inversion of two atoms in the system of two two-level atoms coupled to a light field in the Binomial Optical Field are investigated in the presence of phase decoherence in the multiphoton Tavis-Cumming Model. The influences of the phase decoherence coefficient, the parameters η of the binomial optical field, the maximum number of photons and the number of the transitional photons on the properties of the population inversion of two atoms have been discussed. The results show that the phase decoherence reduced the oscillation amplitude of the population inversion of two atoms and destroyed the atomic quantum characteristic. Changing the number of the transitional photons, evolved cycle and evolved intensity the population inversion of two atoms can be changed. The phenomena of collapse and revival disappear as photon number increase. When the binomial optical state changes from a coherent state to a Fock state, the oscillation frequency of the atomic population reduces gradually, the phenomena of collapse and revival vanishes gradually. (authors)

  9. Using a laboratory-based growth model to estimate mass- and temperature-dependent growth parameters across populations of juvenile Chinook Salmon

    Science.gov (United States)

    Perry, Russell W.; Plumb, John M.; Huntington, Charles

    2015-01-01

    To estimate the parameters that govern mass- and temperature-dependent growth, we conducted a meta-analysis of existing growth data from juvenile Chinook Salmon Oncorhynchus tshawytscha that were fed an ad libitum ration of a pelleted diet. Although the growth of juvenile Chinook Salmon has been well studied, research has focused on a single population, a narrow range of fish sizes, or a narrow range of temperatures. Therefore, we incorporated the Ratkowsky model for temperature-dependent growth into an allometric growth model; this model was then fitted to growth data from 11 data sources representing nine populations of juvenile Chinook Salmon. The model fit the growth data well, explaining 98% of the variation in final mass. The estimated allometric mass exponent (b) was 0.338 (SE = 0.025), similar to estimates reported for other salmonids. This estimate of b will be particularly useful for estimating mass-standardized growth rates of juvenile Chinook Salmon. In addition, the lower thermal limit, optimal temperature, and upper thermal limit for growth were estimated to be 1.8°C (SE = 0.63°C), 19.0°C (SE = 0.27°C), and 24.9°C (SE = 0.02°C), respectively. By taking a meta-analytical approach, we were able to provide a growth model that is applicable across populations of juvenile Chinook Salmon receiving an ad libitum ration of a pelleted diet.

  10. Prohormone convertase 1/3 is essential for processing of the glucose-dependent insulinotropic polypeptide precursor

    DEFF Research Database (Denmark)

    Ugleholdt, Randi; Poulsen, Marie-Louise H; Holst, Peter J

    2006-01-01

    The physiology of the incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), and their role in type 2 diabetes currently attract great interest. Recently we reported an essential role for prohormone convertase (PC) 1/3 in the cleavage of intesti......The physiology of the incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), and their role in type 2 diabetes currently attract great interest. Recently we reported an essential role for prohormone convertase (PC) 1/3 in the cleavage....../3 is essential and sufficient for the production of the intestinal incretin hormone GIP, whereas PC2, although capable of cleaving proGIP, does not participate in intestinal proGIP processing and is not found in intestinal GIP-expressing cells....

  11. Multivariate dependencies between difficult childhood, temperament and antisocial personality disorder in a population of French male prisoners.

    Science.gov (United States)

    Pousset, M; Tremblay, R E; Falissard, B

    2011-06-01

    The aim of this study was to contribute to clarification of the relations between antisocial personality disorder (APD) and its potential risk factors in a population of 560 French male prisoners. Adverse childhood was assessed as a latent variable determined by several traumatic events. APD (MINI), character and temperament (Cloninger's model), WAIS®-III similarities subtest and psychosocial characteristics were assessed by two clinicians. The WAIS®-III subtest accounts for verbal and cognitive performance. We used a structural model to determine the weight of the different pathways between adverse childhood and APD. Study confirmed the major and direct role of adverse childhood (standardized coefficient=0.48). An intermediate effect mediated by character (considered as a global variable) and novelty-seeking was also shown, confirming previous results from the literature. This study emphasizes the role of adverse childhood in APD, suggesting the potential benefit of early intervention in the prevention of antisocial behaviours. Copyright © 2011. Published by Elsevier Masson SAS.

  12. Temperature-dependent elimination efficiency on Phaeocystis globosa by different initial population sizes of rotifer Brachionus plicatilis.

    Science.gov (United States)

    Sun, Yunfei; Wang, Yuanyuan; Lei, Jin; Qian, Chenchen; Zhu, Xuexia; Akbar, Siddiq; Huang, Yuan; Yang, Zhou

    2018-07-01

    Due to sea water eutrophication and global warming, the harmful Phaeocystis blooms outbreak frequently in coastal waters, which cause a serious threat to marine ecosystem. The application of rotifer to control the harmful alga is a promising way. To investigate the influence of initial rotifer density and temperature on the ability of rotifer Brachionus plicatilis to eliminate Phaeocystis globosa population, we cultured P. globosa with different initial rotifer densities (1, 3, 5 inds mL -1 ) at 19, 22, 25, 28, and 31 °C for 9-16 d. Results showed that the population of rotifer feeding on Phaeocystis increased rapidly and higher temperatures favored the growth of P. globosa and B. plicatilis. With increased initial rotifer density and temperature, both the clearance rate of rotifer and the reduction rate of P. globosa increased, and thus P. globosa were eliminated earlier. Both temperature and initial rotifer density had significant effects on clearance rate of rotifer and the time to Phaeocystis extinction, and there was a significant interaction between the two factors on the two parameters, i.e., the effect of initial rotifer density on eliminating Phaeocystis decreased with increasing temperature. The rotifer in 5 inds mL -1 at 28 °C eliminated P. globosa in 4 d, whereas the rotifer in 1 ind mL -1 at 19 °C spent about 16 d on eliminating P. globosa. In conclusion, higher temperature and bigger initial rotifer density promote rotifer to eliminate the harmful P. globosa, and the optimal temperature for rotifer to clear P. globosa is 28 °C. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Apolipoprotein A-I configuration and cell cholesterol efflux activity of discoidal lipoproteins depend on the reconstitution process.

    Science.gov (United States)

    Cuellar, Luz Ángela; Prieto, Eduardo Daniel; Cabaleiro, Laura Virginia; Garda, Horacio Alberto

    2014-01-01

    Discoidal high-density lipoproteins (D-HDL) are critical intermediates in reverse cholesterol transport. Most of the present knowledge of D-HDL is based on studies with reconstituted lipoprotein complexes of apolipoprotein A-I (apoA-I) obtained by cholate dialysis (CD). D-HDL can also be generated by the direct microsolubilization (DM) of phospholipid vesicles at the gel/fluid phase transition temperature, a process mechanistically similar to the "in vivo" apoAI lipidation via ABCA1. We compared the apoA-I configuration in D-HDL reconstituted with dimyristoylphosphatidylcholine by both procedures using fluorescence resonance energy transfer measurements with apoA-I tryptophan mutants and fluorescently labeled cysteine mutants. Results indicate that apoA-I configuration in D-HDL depends on the reconstitution process and are consistent with a "double belt" molecular arrangement with different helix registry. As reported by others, a configuration with juxtaposition of helices 5 of each apoAI monomer (5/5 registry) predominates in D-HDL obtained by CD. However, a configuration with helix 5 of one monomer juxtaposed with helix 2 of the other (5/2 registry) would predominate in D-HDL generated by DM. Moreover, we also show that the kinetics of cholesterol efflux from macrophage cultures depends on the reconstitution process, suggesting that apoAI configuration is important for this HDL function. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Determining individual variation in growth and its implication for life-history and population processes using the empirical Bayes method.

    Directory of Open Access Journals (Sweden)

    Simone Vincenzi

    2014-09-01

    Full Text Available The differences in demographic and life-history processes between organisms living in the same population have important consequences for ecological and evolutionary dynamics. Modern statistical and computational methods allow the investigation of individual and shared (among homogeneous groups determinants of the observed variation in growth. We use an Empirical Bayes approach to estimate individual and shared variation in somatic growth using a von Bertalanffy growth model with random effects. To illustrate the power and generality of the method, we consider two populations of marble trout Salmo marmoratus living in Slovenian streams, where individually tagged fish have been sampled for more than 15 years. We use year-of-birth cohort, population density during the first year of life, and individual random effects as potential predictors of the von Bertalanffy growth function's parameters k (rate of growth and L∞ (asymptotic size. Our results showed that size ranks were largely maintained throughout marble trout lifetime in both populations. According to the Akaike Information Criterion (AIC, the best models showed different growth patterns for year-of-birth cohorts as well as the existence of substantial individual variation in growth trajectories after accounting for the cohort effect. For both populations, models including density during the first year of life showed that growth tended to decrease with increasing population density early in life. Model validation showed that predictions of individual growth trajectories using the random-effects model were more accurate than predictions based on mean size-at-age of fish.

  15. Determining individual variation in growth and its implication for life-history and population processes using the empirical Bayes method.

    Science.gov (United States)

    Vincenzi, Simone; Mangel, Marc; Crivelli, Alain J; Munch, Stephan; Skaug, Hans J

    2014-09-01

    The differences in demographic and life-history processes between organisms living in the same population have important consequences for ecological and evolutionary dynamics. Modern statistical and computational methods allow the investigation of individual and shared (among homogeneous groups) determinants of the observed variation in growth. We use an Empirical Bayes approach to estimate individual and shared variation in somatic growth using a von Bertalanffy growth model with random effects. To illustrate the power and generality of the method, we consider two populations of marble trout Salmo marmoratus living in Slovenian streams, where individually tagged fish have been sampled for more than 15 years. We use year-of-birth cohort, population density during the first year of life, and individual random effects as potential predictors of the von Bertalanffy growth function's parameters k (rate of growth) and L∞ (asymptotic size). Our results showed that size ranks were largely maintained throughout marble trout lifetime in both populations. According to the Akaike Information Criterion (AIC), the best models showed different growth patterns for year-of-birth cohorts as well as the existence of substantial individual variation in growth trajectories after accounting for the cohort effect. For both populations, models including density during the first year of life showed that growth tended to decrease with increasing population density early in life. Model validation showed that predictions of individual growth trajectories using the random-effects model were more accurate than predictions based on mean size-at-age of fish.

  16. Fuel pellets from biomass: The importance of the pelletizing pressure and its dependency on the processing conditions

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Holm, Jens K.; Sanadi, Anand R.

    2011-01-01

    The aim of the present study was to identify the key factors affecting the pelletizing pressure in biomass pelletization processes. The impact of raw material type, pellet length, temperature, moisture content and particle size on the pressure build up in the press channel of a pellet mill...... act as lubricants, lowering the friction between the biomass and the press channel walls. The effect of moisture content on the pelletizing pressure was dependent on the raw material species. Different particle size fractions, from below 0.5 mm up to 2.8 mm diameter, were tested, and it was shown...

  17. Linguistic Diversity in a Deaf Prison Population: Implications for Due Process

    Science.gov (United States)

    Miller, Katrina R.

    2004-01-01

    The entire deaf prison population in the state of Texas formed the basis for this research. The linguistic skills of prison inmates were assessed using the following measures: (1) Kannapell's categories of bilingualism, (2) adaptation of the diagnostic criteria for Primitive Personality Disorder, (3) reading scores on the Test of Adult Basic…

  18. Syncope prevalence in the ED compared to general practice and population: a strong selection process

    NARCIS (Netherlands)

    Olde Nordkamp, Louise R. A.; van Dijk, Nynke; Ganzeboom, Karin S.; Reitsma, Johannes B.; Luitse, Jan S. K.; Dekker, Lukas R. C.; Shen, Win-Kuang; Wieling, Wouter

    2009-01-01

    Objective: We assessed the prevalence and distribution of the different causes of transient loss of consciousness (TLOC) in the emergency department (ED) and chest pain unit (CPU) and estimated the proportion of persons with syncope in the general population who seek medical attention from either

  19. Voltage-Dependent Rhythmogenic Property of Respiratory Pre-Bötzinger Complex Glutamatergic, Dbx1-Derived, and Somatostatin-Expressing Neuron Populations Revealed by Graded Optogenetic Inhibition.

    Science.gov (United States)

    Koizumi, Hidehiko; Mosher, Bryan; Tariq, Mohammad F; Zhang, Ruli; Koshiya, Naohiro; Smith, Jeffrey C

    2016-01-01

    The rhythm of breathing in mammals, originating within the brainstem pre-Bötzinger complex (pre-BötC), is presumed to be generated by glutamatergic neurons, but this has not been directly demonstrated. Additionally, developmental expression of the transcription factor Dbx1 or expression of the neuropeptide somatostatin (Sst), has been proposed as a marker for the rhythmogenic pre-BötC glutamatergic neurons, but it is unknown whether these other two phenotypically defined neuronal populations are functionally equivalent to glutamatergic neurons with regard to rhythm generation. To address these problems, we comparatively investigated, by optogenetic approaches, the roles of pre-BötC glutamatergic, Dbx1-derived, and Sst-expressing neurons in respiratory rhythm generation in neonatal transgenic mouse medullary slices in vitro and also more intact adult perfused brainstem-spinal cord preparations in situ. We established three different triple-transgenic mouse lines with Cre-driven Archaerhodopsin-3 (Arch) expression selectively in glutamatergic, Dbx1-derived, or Sst-expressing neurons for targeted photoinhibition. In each line, we identified subpopulations of rhythmically active, Arch-expressing pre-BötC inspiratory neurons by whole-cell recordings in medullary slice preparations in vitro, and established that Arch-mediated hyperpolarization of these inspiratory neurons was laser power dependent with equal efficacy. By site- and population-specific graded photoinhibition, we then demonstrated that inspiratory frequency was reduced by each population with the same neuronal voltage-dependent frequency control mechanism in each state of the respiratory network examined. We infer that enough of the rhythmogenic pre-BötC glutamatergic neurons also have the Dbx1 and Sst expression phenotypes, and thus all three phenotypes share the same voltage-dependent frequency control property.

  20. Voltage-Dependent Rhythmogenic Property of Respiratory Pre-Bötzinger Complex Glutamatergic, Dbx1-Derived, and Somatostatin-Expressing Neuron Populations Revealed by Graded Optogenetic Inhibition123

    Science.gov (United States)

    Koizumi, Hidehiko; Mosher, Bryan; Tariq, Mohammad F.; Zhang, Ruli

    2016-01-01

    Abstract The rhythm of breathing in mammals, originating within the brainstem pre-Bötzinger complex (pre-BötC), is presumed to be generated by glutamatergic neurons, but this has not been directly demonstrated. Additionally, developmental expression of the transcription factor Dbx1 or expression of the neuropeptide somatostatin (Sst), has been proposed as a marker for the rhythmogenic pre-BötC glutamatergic neurons, but it is unknown whether these other two phenotypically defined neuronal populations are functionally equivalent to glutamatergic neurons with regard to rhythm generation. To address these problems, we comparatively investigated, by optogenetic approaches, the roles of pre-BötC glutamatergic, Dbx1-derived, and Sst-expressing neurons in respiratory rhythm generation in neonatal transgenic mouse medullary slices in vitro and also more intact adult perfused brainstem-spinal cord preparations in situ. We established three different triple-transgenic mouse lines with Cre-driven Archaerhodopsin-3 (Arch) expression selectively in glutamatergic, Dbx1-derived, or Sst-expressing neurons for targeted photoinhibition. In each line, we identified subpopulations of rhythmically active, Arch-expressing pre-BötC inspiratory neurons by whole-cell recordings in medullary slice preparations in vitro, and established that Arch-mediated hyperpolarization of these inspiratory neurons was laser power dependent with equal efficacy. By site- and population-specific graded photoinhibition, we then demonstrated that inspiratory frequency was reduced by each population with the same neuronal voltage-dependent frequency control mechanism in each state of the respiratory network examined. We infer that enough of the rhythmogenic pre-BötC glutamatergic neurons also have the Dbx1 and Sst expression phenotypes, and thus all three phenotypes share the same voltage-dependent frequency control property. PMID:27275007

  1. Demographic processes underlying subtle patterns of population structure in the scalloped hammerhead shark, Sphyrna lewini.

    Directory of Open Access Journals (Sweden)

    Holly A Nance

    Full Text Available Genetic diversity (θ, effective population size (N(e, and contemporary levels of gene flow are important parameters to estimate for species of conservation concern, such as the globally endangered scalloped hammerhead shark, Sphyrna lewini. Therefore, we have reconstructed the demographic history of S. lewini across its Eastern Pacific (EP range by applying classical and coalescent population genetic methods to a combination of 15 microsatellite loci and mtDNA control region sequences. In addition to significant population genetic structure and isolation-by-distance among seven coastal sites between central Mexico and Ecuador, the analyses revealed that all populations have experienced a bottleneck and that all current values of θ are at least an order of magnitude smaller than ancestral θ, indicating large decreases in N(e (θ = 4N(eμ, where μ is the mutation rate. Application of the isolation-with-migration (IM model showed modest but significant genetic connectivity between most sampled sites (point estimates of Nm = 0.1-16.7, with divergence times (t among all populations significantly greater than zero. Using a conservative (i.e., slow fossil-based taxon-specific phylogenetic calibration for mtDNA mutation rates, posterior probability distributions (PPDs for the onset of the decline in N(e predate modern fishing in this region. The cause of decline over the last several thousand years is unknown but is highly atypical as a post-glacial demographic history. Regardless of the cause, our data and analyses suggest that S. lewini was far more abundant throughout the EP in the past than at present.

  2. Six-month trial of bupropion with contingency management for cocaine dependence in a methadone-maintained population.

    Science.gov (United States)

    Poling, James; Oliveto, Alison; Petry, Nancy; Sofuoglu, Mehmet; Gonsai, Kishorchandra; Gonzalez, Gerardo; Martell, Bridget; Kosten, Thomas R

    2006-02-01

    No effective pharmacotherapies exist for cocaine dependence, although contingency management (CM) has demonstrated efficacy. To compare the efficacy of bupropion hydrochloride and CM for reducing cocaine use in methadone hydrochloride-maintained individuals. This 25-week, placebo-controlled, double-blind trial randomly assigned participants to 1 of 4 treatment conditions: CM and placebo (CMP), CM and 300 mg/d of bupropion hydrochloride (CMB), voucher control and placebo (VCP), or voucher control and bupropion (VCB). Outpatient clinic at the Veterans Affairs Connecticut Healthcare System. A total of 106 opiate-dependent, cocaine-abusing individuals. All study participants received methadone hydrochloride (range, 60-120 mg). Participants receiving bupropion hydrochloride were given 300 mg/d beginning at week 3. In the CM conditions, each urine sample negative for both opioids and cocaine resulted in a monetary-based voucher that increased for consecutively drug-free urine samples during weeks 1 to 13. Completion of abstinence-related activities also resulted in a voucher. During weeks 14 to 25, only completion of activities was reinforced in the CM group, regardless of sample results. The voucher control groups received vouchers for submitting urine samples, regardless of results, throughout the study. Thrice-weekly urine toxicologic test results for cocaine and heroin. Groups did not differ in baseline characteristics or retention rates. Opiate use decreased significantly, with all treatment groups attaining equivalent amounts of opiate use at the end of the study. In the CMB group, the proportion of cocaine-positive samples significantly decreased during weeks 3 to 13 (P<.001) relative to week 3 and remained low during weeks 14 to 25. In the CMP group, cocaine use significantly increased during weeks 3 to 13 (P<.001) relative to week 3, but then cocaine use significantly decreased relative to the initial slope during weeks 14 to 25 (P<.001). In contrast, by

  3. Are Drinking Motives Universal? Characteristics of Motive Types in Alcohol-Dependent Men from Two Diverse Populations

    Directory of Open Access Journals (Sweden)

    Verena Ertl

    2018-02-01

    Full Text Available Background and AimsSince alcohol use disorders are among the most prevalent and destructive mental disorders, it is critical to address factors contributing to their development and maintenance. Drinking motives are relevant driving factors for consumption. Identifying groups of drinkers with similar motivations may help to specialize intervention components and make treatment more effective and efficient. We aimed to identify and describe distinct motive types of drinkers in dependent males from two diverse cultures (Uganda and Germany and to explore potential differences and similarities in addiction-related measures. Moreover, we investigated specific links between motive types and childhood maltreatment, traumatic experiences, and symptoms of comorbid psychopathologies.MethodsTo determine distinct drinking motive types, we conducted latent class analyses concerning drinking motives (Drinking Motive Scale in samples of treatment-seeking alcohol-dependent men (N = 75. Subsequently we compared the identified motive types concerning their alcohol consumption and alcohol-related symptoms (Alcohol Use Disorders Identification Test, history of childhood maltreatment (Childhood Trauma Questionnaire, trauma exposure (Violence, War and Abduction Exposure Scale, psychopathology (Posttraumatic Stress Diagnostic Scale, Depression-section of the Hopkins Symptom Checklist, and Brief Symptom Inventory and deficits in emotion regulation (Difficulties in Emotion Regulation Scale.ResultsWe found two congruent drinking motive types in both contexts. Reward-oriented drinking motives like the generation of positive feelings and enhancing performance were endorsed almost equally by both motive types, whereas high relief motive endorsement characterized one group, but not the other. The relief motive type drank to overcome aversive feelings, withdrawal, and daily hassles and was characterized by higher adversity in general. Emotional maltreatment in childhood

  4. The microbial fermentation characteristics depend on both carbohydrate source and heat processing: a model experiment with ileo-cannulated pigs

    DEFF Research Database (Denmark)

    Nielsen, Tina Skau; Jørgensen, Henry Johs. Høgh; Knudsen, Knud Erik Bach

    2017-01-01

    The effects of carbohydrate (CHO) source and processing (extrusion cooking) on large intestinal fermentation products were studied in ileo-cannulated pigs as a model for humans. Pigs were fed diets containing barley, pea or a mixture of potato starch:wheat bran (PSWB) either raw or extrusion cooked....... Extrusion cooking reduced the amount of starch fermented in the large intestine by 52–96% depending on the CHO source and the total pool of butyrate in the distal small intestine + large intestine by on average 60% across diets. Overall, extrusion cooking caused a shift in the composition of short......-chain fatty acids (SCFA) produced towards more acetate and less propionate and butyrate. The CHO source and processing highly affected the fermentation characteristics and extrusion cooking generally reduced large intestinal fermentation and resulted in a less desirable composition of the fermentation...

  5. Using a spatially structured life cycle model to assess the influence of multiple stressors on an exploited coastal-nursery-dependent population

    Science.gov (United States)

    Archambault, B.; Rivot, E.; Savina, M.; Le Pape, O.

    2018-02-01

    Exploited coastal-nursery-dependent fish species are subject to various stressors occurring at specific stages of the life cycle: climate-driven variability in hydrography determines the success of the first eggs/larvae stages; coastal nursery habitat suitability controls juvenile growth and survival; and fisheries target mostly adults. A life cycle approach was used to quantify the relative influence of these stressors on the Eastern English Channel (EEC) population of the common sole (Solea solea), a coastal-nursery-dependent flatfish population which sustains important fisheries. The common sole has a complex life cycle: after eggs hatch, larvae spend several weeks drifting in open water. Survivors go on to metamorphose into benthic fish. Juveniles spend the first two years of their life in coastal and estuarine nurseries. Close to maturation, they migrate to deeper areas, where different subpopulations supplied by different nurseries reproduce and are exploited by fisheries. A spatially structured age-and stage-based hierarchical Bayesian model integrating various aspects of ecological knowledge, data sources and expert knowledge was built to quantitatively describe this complex life cycle. The model included the low connectivity among three subpopulations in the EEC, the influence of hydrographic variability, the availability of suitable juvenile habitat and fisheries. Scenarios were designed to quantify the effects of interacting stressors on population renewal. Results emphasized the importance of coastal nursery habitat availability and quality for the population renewal. Realistic restoration scenarios of the highly degraded Seine estuary produced a two-third increase in catch potential for the adjacent subpopulation. Fisheries, however, remained the main source of population depletion. Setting fishing mortality to the maximum sustainable yield led to substantial increases in biomass (+100%) and catch (+33%) at the EEC scale. The approach also showed how

  6. Rare gas dependence of vibration--vibration energy transfer processes: A diagnostic technique. Applications to CH2D2 and CH3F

    International Nuclear Information System (INIS)

    Apkarian, V.A.; Weitz, E.

    1979-01-01

    The rare gas dependence of V--V rates can be used as a diagnostic technique to identify different mechanisms of vibrational energy transfer and determine the rate constants for individual kinetic steps. The method is especially useful for the identification and measurement of rates of resonant vibrational energy transfer processes. Analytical and numerical solutions of pertinent model equations are presented and their range of applicability is discussed. The technique is applied to CH 2 D 2 and CH 3 F. In CH 2 D 2 results of studies on ν 9 , [ν 1 , ν 6 ] and states in the 2000 cm -1 region are presented where the application of the technique has made it possible to identify the pathways leading to population of these states and to assign rate constants to some of the steps involved. In CH 3 F, by studying the Ar dependence of the V--V rates of the [ν 2 , ν 5 ] and [ν 1 , ν 4 ] states it has been possible to construct a complete map of energy transfer pathways which can explain all experimental observations for this system, to date. The general applicability of the technique and its potential application to other systems is also considered

  7. Age-dependent transition from cell-level to population-level control in murine intestinal homeostasis revealed by coalescence analysis.

    Directory of Open Access Journals (Sweden)

    Zheng Hu

    Full Text Available In multi-cellular organisms, tissue homeostasis is maintained by an exquisite balance between stem cell proliferation and differentiation. This equilibrium can be achieved either at the single cell level (a.k.a. cell asymmetry, where stem cells follow strict asymmetric divisions, or the population level (a.k.a. population asymmetry, where gains and losses in individual stem cell lineages are randomly distributed, but the net effect is homeostasis. In the mature mouse intestinal crypt, previous evidence has revealed a pattern of population asymmetry through predominantly symmetric divisions of stem cells. In this work, using population genetic theory together with previously published crypt single-cell data obtained at different mouse life stages, we reveal a strikingly dynamic pattern of stem cell homeostatic control. We find that single-cell asymmetric divisions are gradually replaced by stochastic population-level asymmetry as the mouse matures to adulthood. This lifelong process has important developmental and evolutionary implications in understanding how adult tissues maintain their homeostasis integrating the trade-off between intrinsic and extrinsic regulations.

  8. A Preclinical Population Pharmacokinetic Model for Anti-CD20/CD3 T-Cell-Dependent Bispecific Antibodies.

    Science.gov (United States)

    Ferl, Gregory Z; Reyes, Arthur; Sun, Liping L; Cheu, Melissa; Oldendorp, Amy; Ramanujan, Saroja; Stefanich, Eric G

    2018-05-01

    CD20 is a cell-surface receptor expressed by healthy and neoplastic B cells and is a well-established target for biologics used to treat B-cell malignancies. Pharmacokinetic (PK) and pharmacodynamic (PD) data for the anti-CD20/CD3 T-cell-dependent bispecific antibody BTCT4465A were collected in transgenic mouse and nonhuman primate (NHP) studies. Pronounced nonlinearity in drug elimination was observed in the murine studies, and time-varying, nonlinear PK was observed in NHPs, where three empirical drug elimination terms were identified using a mixed-effects modeling approach: i) a constant nonsaturable linear clearance term (7 mL/day/kg); ii) a rapidly decaying time-varying, linear clearance term (t ½  = 1.6 h); and iii) a slowly decaying time-varying, nonlinear clearance term (t ½  = 4.8 days). The two time-varying drug elimination terms approximately track with time scales of B-cell depletion and T-cell migration/expansion within the central blood compartment. The mixed-effects NHP model was scaled to human and prospective clinical simulations were generated. © 2018 The Authors. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

  9. Effects of long-term voluntary exercise on learning and memory processes: dependency of the task and level of exercise.

    Science.gov (United States)

    García-Capdevila, Sílvia; Portell-Cortés, Isabel; Torras-Garcia, Meritxell; Coll-Andreu, Margalida; Costa-Miserachs, David

    2009-09-14

    The effect of long-term voluntary exercise (running wheel) on anxiety-like behaviour (plus maze and open field) and learning and memory processes (object recognition and two-way active avoidance) was examined on Wistar rats. Because major individual differences in running wheel behaviour were observed, the data were analysed considering the exercising animals both as a whole and grouped according to the time spent in the running wheel (low, high, and very-high running). Although some variables related to anxiety-like behaviour seem to reflect an anxiogenic compatible effect, the view of the complete set of variables could be interpreted as an enhancement of defensive and risk assessment behaviours in exercised animals, without major differences depending on the exercise level. Effects on learning and memory processes were dependent on task and level of exercise. Two-way avoidance was not affected either in the acquisition or in the retention session, while the retention of object recognition task was affected. In this latter task, an enhancement in low running subjects and impairment in high and very-high running animals were observed.

  10. Pipe-dependent ventral processing of Easter by Snake is the defining step in Drosophila embryo DV axis formation.

    Science.gov (United States)

    Cho, Yong Suk; Stevens, Leslie M; Stein, David

    2010-06-22

    The establishment of Drosophila embryonic dorsal-ventral (DV) polarity relies on serine proteolytic activity in the perivitelline space between the embryonic membrane and the eggshell. Gastrulation Defective cleaves and activates Snake, which processes and activates Easter, which cleaves Spätzle to form the activating ligand for the Toll receptor. Ventral restriction of ligand formation depends on the Pipe sulfotransferase, which is expressed in ventral cells of the follicular epithelium surrounding the developing oocyte. Pipe modifies components of the developing eggshell to produce a ventral cue embedded in the vitelline membrane. This ventral cue is believed to promote one or more of the proteolysis steps in the perivitelline space. By examining the processing of transgenic, tagged versions of the perivitelline proteins during DV patterning, we find that the proteolysis of Easter by Snake is the first Pipe-dependent step and therefore the key ventrally restricted event in the protease cascade. We also find that Snake and Easter associate together in a complex in both wild-type and pipe mutant-derived embryos. This observation suggests a mechanism in which the sulfated target of Pipe promotes a productive interaction between Snake and Easter, perhaps by facilitating conformational changes in a complex containing the two proteins. Copyright 2010 Elsevier Ltd. All