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Sample records for analysis infers migration

  1. Logical inferences in discourse analysis

    Institute of Scientific and Technical Information of China (English)

    刘峰廷

    2014-01-01

    Cohesion and coherence are two important characteristics of discourses. Halliday and Hasan have pointed out that cohesion is the basis of coherence and coherence is the premise of forming discourse. The commonly used cohesive devices are: preference, ellipsis, substitution, etc. Discourse coherence is mainly manifested in sentences and paragraphs. However, in real discourse analysis environment, traditional methods on cohesion and coherence are not enough. This article talks about the conception of discourse analysis at the beginning. Then, we list some of the traditional cohesive devices and its uses. Following that, we make corpus analysis. Finally, we explore and find a new device in textual analysis:discourse logical inferences.

  2. Inference of historical changes in migration rate from the lengths of migrant tracts

    DEFF Research Database (Denmark)

    Pool, John E; Nielsen, Rasmus

    2009-01-01

    After migrant chromosomes enter a population, they are progressively sliced into smaller pieces by recombination. Therefore, the length distribution of "migrant tracts" (chromosome segments with recent migrant ancestry) contains information about historical patterns of migration. Here we introduce...... a theoretical framework describing the migrant tract length distribution and propose a likelihood inference method to test demographic hypotheses and estimate parameters related to a historical change in migration rate. Applying this method to data from the hybridizing subspecies Mus musculus domesticus and M...

  3. Bayesian Inference in Statistical Analysis

    CERN Document Server

    Box, George E P

    2011-01-01

    The Wiley Classics Library consists of selected books that have become recognized classics in their respective fields. With these new unabridged and inexpensive editions, Wiley hopes to extend the life of these important works by making them available to future generations of mathematicians and scientists. Currently available in the Series: T. W. Anderson The Statistical Analysis of Time Series T. S. Arthanari & Yadolah Dodge Mathematical Programming in Statistics Emil Artin Geometric Algebra Norman T. J. Bailey The Elements of Stochastic Processes with Applications to the Natural Sciences Rob

  4. Data analysis recipes: Probability calculus for inference

    OpenAIRE

    Hogg, David W.

    2012-01-01

    In this pedagogical text aimed at those wanting to start thinking about or brush up on probabilistic inference, I review the rules by which probability distribution functions can (and cannot) be combined. I connect these rules to the operations performed in probabilistic data analysis. Dimensional analysis is emphasized as a valuable tool for helping to construct non-wrong probabilistic statements. The applications of probability calculus in constructing likelihoods, marginalized likelihoods,...

  5. Data analysis recipes: Probability calculus for inference

    CERN Document Server

    Hogg, David W

    2012-01-01

    In this pedagogical text aimed at those wanting to start thinking about or brush up on probabilistic inference, I review the rules by which probability distribution functions can (and cannot) be combined. I connect these rules to the operations performed in probabilistic data analysis. Dimensional analysis is emphasized as a valuable tool for helping to construct non-wrong probabilistic statements. The applications of probability calculus in constructing likelihoods, marginalized likelihoods, posterior probabilities, and posterior predictions are all discussed.

  6. Inference

    DEFF Research Database (Denmark)

    Møller, Jesper

    .1 with the title ‘Inference'.) This contribution concerns statistical inference for parametric models used in stochastic geometry and based on quick and simple simulation free procedures as well as more comprehensive methods using Markov chain Monte Carlo (MCMC) simulations. Due to space limitations the focus...

  7. Sympatry inference and network analysis in biogeography.

    Science.gov (United States)

    Dos Santos, Daniel A; Fernández, Hugo R; Cuezzo, María Gabriela; Domínguez, Eduardo

    2008-06-01

    A new approach for biogeography to find patterns of sympatry, based on network analysis, is proposed. Biogeographic analysis focuses basically on sympatry patterns of species. Sympatry is a network (= relational) datum, but it has never been analyzed before using relational tools such as Network Analysis. Our approach to biogeographic analysis consists of two parts: first the sympatry inference and second the network analysis method (NAM). The sympatry inference method was designed to propose sympatry hypothesis, constructing a basal sympatry network based on punctual data, independent of a priori distributional area determination. In this way, two or more species are considered sympatric when there is interpenetration and relative proximity among their records of occurrence. In nature, groups of species presenting within-group sympatry and between-group allopatry constitute natural units (units of co-occurrence). These allopatric units are usually connected by intermediary species. The network analysis method (NAM) that we propose here is based on the identification and removal of intermediary species to segregate units of co-occurrence, using the betweenness measure and the clustering coefficient. The species ranges of the units of co-occurrence obtained are transferred to a map, being considered as candidates to areas of endemism. The new approach was implemented on three different real complex data sets (one of them a classic example previously used in biogeography) resulting in (1) independence of predefined spatial units; (2) definition of co-occurrence patterns from the sympatry network structure, not from species range similarities; (3) higher stability in results despite scale changes; (4) identification of candidates to areas of endemism supported by strictly endemic species; (5) identification of intermediary species with particular biological attributes.

  8. Inference

    DEFF Research Database (Denmark)

    Møller, Jesper

    2010-01-01

    Chapter 9: This contribution concerns statistical inference for parametric models used in stochastic geometry and based on quick and simple simulation free procedures as well as more comprehensive methods based on a maximum likelihood or Bayesian approach combined with markov chain Monte Carlo...

  9. Safety Analysis versus Type Inference with Partial Types

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff; Palsberg, Jens

    1992-01-01

    Safety analysis is an algorithm for determining if a term in an untyped lambda calculus with constants is safe, i.e., if it does not cause an error during evaluation. This ambition is also shared by algorithms for type inference. Safety analysis and type inference are based on rather different...... perspectives, however. Safety analysis is global in that it can only analyze a complete program. In contrast, type inference is local in that it can analyze pieces of a program in isolation. In this paper we prove that safety analysis is sound, relative to both a strict and a lazy operational semantics. We...... also prove that safety analysis accepts strictly more safe lambda terms than does type inference for simple types. The latter result demonstrates that global program analysis can be more precise than local ones....

  10. A new isolation with migration model along complete genomes infers very different divergence processes among closely related great ape species.

    Directory of Open Access Journals (Sweden)

    Thomas Mailund

    Full Text Available We present a hidden Markov model (HMM for inferring gradual isolation between two populations during speciation, modelled as a time interval with restricted gene flow. The HMM describes the history of adjacent nucleotides in two genomic sequences, such that the nucleotides can be separated by recombination, can migrate between populations, or can coalesce at variable time points, all dependent on the parameters of the model, which are the effective population sizes, splitting times, recombination rate, and migration rate. We show by extensive simulations that the HMM can accurately infer all parameters except the recombination rate, which is biased downwards. Inference is robust to variation in the mutation rate and the recombination rate over the sequence and also robust to unknown phase of genomes unless they are very closely related. We provide a test for whether divergence is gradual or instantaneous, and we apply the model to three key divergence processes in great apes: (a the bonobo and common chimpanzee, (b the eastern and western gorilla, and (c the Sumatran and Bornean orang-utan. We find that the bonobo and chimpanzee appear to have undergone a clear split, whereas the divergence processes of the gorilla and orang-utan species occurred over several hundred thousands years with gene flow stopping quite recently. We also apply the model to the Homo/Pan speciation event and find that the most likely scenario involves an extended period of gene flow during speciation.

  11. Comparative Analysis of Fuzzy Inference Systems for Air Conditioner

    Directory of Open Access Journals (Sweden)

    Swati R. Chaudhari

    2014-12-01

    Full Text Available In today’s world there is exponential increase in the use of air conditioning devices. The enhancement in utilization of such devices makes it essential for them to work with their full capability and efficiency. The fuzzy inference systems are best suited for the applications requiring easy interpretation, human reasoning, accurate decision making and control. The fuzzy inference systems resemble human decision making and generate precise solutions from approximate information. A comprehensive review of fuzzy inference systems with weighted average and defuzzification is covered in this paper. The objective of the paper is to provide the comparative analysis of fuzzy inference systems. This paper is a quick reference for the researchers in studying the characteristics of fuzzy inference system in air conditioner.

  12. Depth migration and de-migration for 3-D migration velocity analysis; Migration profondeur et demigration pour l'analyse de vitesse de migration 3D

    Energy Technology Data Exchange (ETDEWEB)

    Assouline, F.

    2001-07-01

    3-D seismic imaging of complex geologic structures requires the use of pre-stack imaging techniques, the post-stack ones being unsuitable in that case. Indeed, pre-stack depth migration is a technique which allows to image accurately complex structures provided that we have at our disposal a subsurface velocity model accurate enough. The determination of this velocity model is thus a key element for seismic imaging, and to this end, migration velocity analysis methods have met considerable interest. The SMART method is a specific migration velocity analysis method: the singularity of this method is that it does not rely on any restrictive assumptions on the complexity of the velocity model to determine. The SMART method uses a detour through the pre-stack depth migrated domain for extracting multi-offset kinematic information hardly accessible in the time domain. Once achieved the interpretation of the pre-stack depth migrated seismic data, a kinematic de-migration technique of the interpreted events enables to obtain a consistent kinematic database (i.e. reflection travel-times). Then, the inversion of these travel-times, by means of reflection tomography, allows the determination of an accurate velocity model. To be able to really image geologic structures for which the 3-D feature is predominant, we have studied the implementation of migration velocity analysis in 3-D in the context of the SMART method, and more generally, we have developed techniques allowing to overcome the intrinsic difficulties in the 3-D aspects of seismic imaging. Indeed, although formally the SMART method can be directly applied to the case of 3-D complex structures, the feasibility of its implementation requires to choose well the imaging domain. Once this choice done, it is also necessary to conceive a method allowing, via the associated de-migration, to obtain the reflection travel-times. We first consider the offset domain which constitutes, still today, the strategy most usually used

  13. Tree migration-rates: narrowing the gap between inferred post-glacial rates and projected rates.

    Directory of Open Access Journals (Sweden)

    Angelica Feurdean

    Full Text Available Faster-than-expected post-glacial migration rates of trees have puzzled ecologists for a long time. In Europe, post-glacial migration is assumed to have started from the three southern European peninsulas (southern refugia, where large areas remained free of permafrost and ice at the peak of the last glaciation. However, increasing palaeobotanical evidence for the presence of isolated tree populations in more northerly microrefugia has started to change this perception. Here we use the Northern Eurasian Plant Macrofossil Database and palaeoecological literature to show that post-glacial migration rates for trees may have been substantially lower (60-260 m yr(-1 than those estimated by assuming migration from southern refugia only (115-550 m yr(-1, and that early-successional trees migrated faster than mid- and late-successional trees. Post-glacial migration rates are in good agreement with those recently projected for the future with a population dynamical forest succession and dispersal model, mainly for early-successional trees and under optimal conditions. Although migration estimates presented here may be conservative because of our assumption of uniform dispersal, tree migration-rates clearly need reconsideration. We suggest that small outlier populations may be a key factor in understanding past migration rates and in predicting potential future range-shifts. The importance of outlier populations in the past may have an analogy in the future, as many tree species have been planted beyond their natural ranges, with a more beneficial microclimate than their regional surroundings. Therefore, climate-change-induced range-shifts in the future might well be influenced by such microrefugia.

  14. Radon migration in the soils of the Irno Valley (Southern Italy inferred from radioactive disequilibrium

    Directory of Open Access Journals (Sweden)

    P. Gasparini

    1995-06-01

    Full Text Available Radon migration along vertical profiles in the soils of Irno River alluvial Valley (Southern Italy was studied using radioactive disequilibrium between 226 Ra and 210 Pb. Fractional Radon loss, migration length, diffusion and emanation coefficient and Radon flux density were determined. Our results are in agreement with a migra- tion model by simple diffusion. The migration parameters are within typical values, except the Radon flux density, which is about one order of magnitude higher than the values reported in literature. The values of fractional Radon loss are sensitive to changes in the physical properties of the soil.

  15. Directional migration in the Hindu castes: inferences from mitochondrial, autosomal and Y-chromosomal data.

    Science.gov (United States)

    Wooding, Stephen; Ostler, Christopher; Prasad, B V Ravi; Watkins, W Scott; Sung, Sandy; Bamshad, Mike; Jorde, Lynn B

    2004-08-01

    Genetic, ethnographic, and historical evidence suggests that the Hindu castes have been highly endogamous for several thousand years and that, when movement between castes does occur, it typically consists of females joining castes of higher social status. However, little is known about migration rates in these populations or the extent to which migration occurs between caste groups of low, middle, and high social status. To investigate these aspects of migration, we analyzed the largest collection of genetic markers collected to date in Hindu caste populations. These data included 45 newly typed autosomal short tandem repeat polymorphisms (STRPs), 411 bp of mitochondrial DNA sequence, and 43 Y-chromosomal single-nucleotide polymorphisms that were assayed in more than 200 individuals of known caste status sampled in Andrah Pradesh, in South India. Application of recently developed likelihood-based analyses to this dataset enabled us to obtain genetically derived estimates of intercaste migration rates. STRPs indicated migration rates of 1-2% per generation between high-, middle-, and low-status caste groups. We also found support for the hypothesis that rates of gene flow differ between maternally and paternally inherited genes. Migration rates were substantially higher in maternally than in paternally inherited markers. In addition, while prevailing patterns of migration involved movement between castes of similar rank, paternally inherited markers in the low-status castes were most likely to move into high-status castes. Our findings support earlier evidence that the caste system has been a significant, long-term source of population structuring in South Indian Hindu populations, and that patterns of migration differ between males and females.

  16. Depth migration and de-migration for 3-D migration velocity analysis; Migration profondeur et demigration pour l'analyse de vitesse de migration 3D

    Energy Technology Data Exchange (ETDEWEB)

    Assouline, F.

    2001-07-01

    3-D seismic imaging of complex geologic structures requires the use of pre-stack imaging techniques, the post-stack ones being unsuitable in that case. Indeed, pre-stack depth migration is a technique which allows to image accurately complex structures provided that we have at our disposal a subsurface velocity model accurate enough. The determination of this velocity model is thus a key element for seismic imaging, and to this end, migration velocity analysis methods have met considerable interest. The SMART method is a specific migration velocity analysis method: the singularity of this method is that it does not rely on any restrictive assumptions on the complexity of the velocity model to determine. The SMART method uses a detour through the pre-stack depth migrated domain for extracting multi-offset kinematic information hardly accessible in the time domain. Once achieved the interpretation of the pre-stack depth migrated seismic data, a kinematic de-migration technique of the interpreted events enables to obtain a consistent kinematic database (i.e. reflection travel-times). Then, the inversion of these travel-times, by means of reflection tomography, allows the determination of an accurate velocity model. To be able to really image geologic structures for which the 3-D feature is predominant, we have studied the implementation of migration velocity analysis in 3-D in the context of the SMART method, and more generally, we have developed techniques allowing to overcome the intrinsic difficulties in the 3-D aspects of seismic imaging. Indeed, although formally the SMART method can be directly applied to the case of 3-D complex structures, the feasibility of its implementation requires to choose well the imaging domain. Once this choice done, it is also necessary to conceive a method allowing, via the associated de-migration, to obtain the reflection travel-times. We first consider the offset domain which constitutes, still today, the strategy most usually used

  17. Statistical inference of Minimum Rank Factor Analysis

    NARCIS (Netherlands)

    Shapiro, A; Ten Berge, JMF

    2002-01-01

    For any given number of factors, Minimum Rank Factor Analysis yields optimal communalities for an observed covariance matrix in the sense that the unexplained common variance with that number of factors is minimized, subject to the constraint that both the diagonal matrix of unique variances and the

  18. Inferring Player Experiences Using Facial Expressions Analysis

    NARCIS (Netherlands)

    Tan, C.T.; Bakkes, S.; Pisan, Y.; Blackmore, K.; Nesbitt, K.; Smith, S.P.

    2014-01-01

    Understanding player experiences is central to game design. Video captures of players is a common practice for obtaining rich reviewable data for analysing these experiences. However, not enough has been done in investigating ways of preprocessing the video for a more efficient analysis process. Thi

  19. EMPIRICAL-NUMERICAL ANALYSIS OF HEADCUT MIGRATION

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Headcut migration is studied by using empirical and numerical modeling approaches. Empirical formulas for the headcut migration are established using available measurement data, which consider not only the flow strength but also the properties of soil. Numerical model for the headcut migration is proposed. The influences of dynamic pressure gradient, downward flow, and bed slope on sediment entrainment are considered. The local erosion patterns and migration speeds of headcut calculated by the numerical model agree reasonably well with observed data.

  20. Migration Flows: Measurement, Analysis and Modeling

    NARCIS (Netherlands)

    Willekens, F.J.; White, Michael J.

    2016-01-01

    This chapter is an introduction to the study of migration flows. It starts with a review of major definition and measurement issues. Comparative studies of migration are particularly difficult because different countries define migration differently and measurement methods are not harmonized. Insigh

  1. Inference and contradictory analysis for binary neural networks

    Institute of Scientific and Technical Information of China (English)

    郭宝龙; 郭雷

    1996-01-01

    A weak-inference theory and a contradictory analysis for binary neural networks (BNNs).are presented.The analysis indicates that the essential reason why a neural network is changing its slates is the existence of superior contradiction inside the network,and that the process by which a neural network seeks a solution corresponds to eliminating the superior contradiction.Different from general constraint satisfaction networks,the solutions found by BNNs may contain inferior contradiction but not superior contradiction.

  2. Migration

    NARCIS (Netherlands)

    Gienapp, P.; Candolin, Ulrika; Wong, Bob

    2012-01-01

    This chapter examines how human-induced environmental changes affect migration. It explores how such changes affect conditions along the migration route, as well as the cues that are used in the timing of migration such as the celestial bodies and the planet's magnetic field. It emphasizes the effec

  3. An economic analysis of migration in Mexico.

    Science.gov (United States)

    Greenwood, M J; Ladman, J R

    1978-07-01

    This paper analyzes internal migration in Mexico over the 1960-70 period. A model of the determinants of migration is specified and estimated for aggregated interstate migration flows. Results show that distance serves as a significant deterrent to migration, that higher destination earning levels are attractive to migrants, and that regions with high unemployment rates experience lower rates of inmigration. An unanticipated finding is that regions with higher earning levels have greater rates of outmigration. The data are disaggregated to examine separate migration relationships for each state. The results are that distance is a lesser deterrent for those migrants with more accessible alternatives, that higher earning levels reduce the deterring effects of distance, and that regions with higher earning levels have lower associated elasticities of migration. It is concluded that economic factors have played a crucial role in internal migration and thus in the changing occupational and geographic structure of the Mexican labor force.

  4. Multiwave velocity analysis based on Gaussian beam prestack depth migration

    Institute of Scientific and Technical Information of China (English)

    Han Jian-Guang; Wang Yun; Han Ning; Xing Zhan-Tao; Lu Jun

    2014-01-01

    Prestack depth migration of multicomponent seismic data improves the imaging accuracy of subsurface complex geological structures. An accurate velocityfi eld is critical to accurate imaging. Gaussian beam migration was used to perform multicomponent migration velocity analysis of PP- and PS-waves. First, PP- and PS-wave Gaussian beam prestack depth migration algorithms that operate on common-offset gathers are presented to extract offset-domain common-image gathers of PP- and PS-waves. Second, based on the residual moveout equation, the migration velocity fields of P- and S-waves are updated. Depth matching is used to ensure that the depth of the target layers in the PP- and PS-wave migration profi les are consistent, and high-precision P- and S-wave velocities are obtained. Finally, synthetic andfi eld seismic data suggest that the method can be used effectively in multiwave migration velocity analysis.

  5. Interregional Migration in Spain: A Semiparametric Analysis

    OpenAIRE

    Maza Fernández, Adolfo Jesús; Villaverde Castro, José

    2004-01-01

    This paper analyses the determinants of internal migration in Spain between 1995 and 2002. After a brief descriptive study, we present an analytical model of internal migration flows. Subsequently, we estimate this model by applying semiparametric techniques. The general conclusion that we come to is that net migration rates are influenced mainly by income and climatic condition differentials between the regions of origin and destination; in addition, unemployment and housin...

  6. The NIRS Analysis Package: noise reduction and statistical inference.

    Science.gov (United States)

    Fekete, Tomer; Rubin, Denis; Carlson, Joshua M; Mujica-Parodi, Lilianne R

    2011-01-01

    Near infrared spectroscopy (NIRS) is a non-invasive optical imaging technique that can be used to measure cortical hemodynamic responses to specific stimuli or tasks. While analyses of NIRS data are normally adapted from established fMRI techniques, there are nevertheless substantial differences between the two modalities. Here, we investigate the impact of NIRS-specific noise; e.g., systemic (physiological), motion-related artifacts, and serial autocorrelations, upon the validity of statistical inference within the framework of the general linear model. We present a comprehensive framework for noise reduction and statistical inference, which is custom-tailored to the noise characteristics of NIRS. These methods have been implemented in a public domain Matlab toolbox, the NIRS Analysis Package (NAP). Finally, we validate NAP using both simulated and actual data, showing marked improvement in the detection power and reliability of NIRS.

  7. Inferring Group Processes from Computer-Mediated Affective Text Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schryver, Jack C [ORNL; Begoli, Edmon [ORNL; Jose, Ajith [Missouri University of Science and Technology; Griffin, Christopher [Pennsylvania State University

    2011-02-01

    Political communications in the form of unstructured text convey rich connotative meaning that can reveal underlying group social processes. Previous research has focused on sentiment analysis at the document level, but we extend this analysis to sub-document levels through a detailed analysis of affective relationships between entities extracted from a document. Instead of pure sentiment analysis, which is just positive or negative, we explore nuances of affective meaning in 22 affect categories. Our affect propagation algorithm automatically calculates and displays extracted affective relationships among entities in graphical form in our prototype (TEAMSTER), starting with seed lists of affect terms. Several useful metrics are defined to infer underlying group processes by aggregating affective relationships discovered in a text. Our approach has been validated with annotated documents from the MPQA corpus, achieving a performance gain of 74% over comparable random guessers.

  8. China ASON Network Migration Scenarios and Their Quantitative Analysis

    Institute of Scientific and Technical Information of China (English)

    Soichiro; Araki; Itaru; Nishioka; Yoshihiko; Suemura

    2003-01-01

    This paper proposes two migration scenarios from China ring networks to ASON mesh networks. In our quantitative analysis with ASON/GMPLS simulator, a subnetwork protection scheme achieved best balanced performance in resource utilization and restoration time.

  9. China ASON Network Migration Scenarios and Their Quantitative Analysis

    Institute of Scientific and Technical Information of China (English)

    Guoying Zhang; Soichiro Araki; Itaru Nishioka; Yoshihiko Suemura

    2003-01-01

    This paper proposes two migration scenarios from China rin g networks to ASON mesh networks . In our quantitative analysis with ASON/GMPLS simulator, a subnetwork protection scheme achieved best balanced performance in resource utilization and restoration time.

  10. Nonparametric inference procedures for multistate life table analysis.

    Science.gov (United States)

    Dow, M M

    1985-01-01

    Recent generalizations of the classical single state life table procedures to the multistate case provide the means to analyze simultaneously the mobility and mortality experience of 1 or more cohorts. This paper examines fairly general nonparametric combinatorial matrix procedures, known as quadratic assignment, as an analysis technic of various transitional patterns commonly generated by cohorts over the life cycle course. To some degree, the output from a multistate life table analysis suggests inference procedures. In his discussion of multstate life table construction features, the author focuses on the matrix formulation of the problem. He then presents several examples of the proposed nonparametric procedures. Data for the mobility and life expectancies at birth matrices come from the 458 member Cayo Santiago rhesus monkey colony. The author's matrix combinatorial approach to hypotheses testing may prove to be a useful inferential strategy in several multidimensional demographic areas.

  11. The Analysis of International Migration towards Economic Growth

    Directory of Open Access Journals (Sweden)

    Ferdous Alam

    2011-01-01

    Full Text Available Problem statement: This study discusses the analysis of international migration towards economic growth in Bangladesh. International migration refers to the cross-border movement of people from a mother country to a location outside that mother country, with the purpose of taking up higher income employment, better living conditions, higher education get access to civic amenities and conducting a daily existence there for an extended period of time. The exports of labor, human capital, play a major role to minimize the poverty level in Bangladesh. In the last four decades, Bangladesh exports the huge number of labors abroad for economic growth through remittances. Remittances affect poverty eradication most directly by increasing the income of households which have a family member working abroad. Because income from remittances is usually larger than that which could have been earned by migrants they stayed at home. Approach: The aim of this study is to highlight the policy implications for the maximization of international migration and the analysis of economic growth in Bangladesh. The data for analysis is perceived from the secondary sources. The significant manipulations for acquired data are migration of employment and remittances for economic growth in Bangladesh. Results: Migration contributed for the development of macro and micro level in Bangladesh. Conclusion: There would be potential benefits to world's poor if more international attention were focused on integrating migration policy to within the larger global dialogue economic development and poverty reduction. Strong institutions and good policies will enhance the benefits of human capital migration for Bangladesh.

  12. Bayesian large-scale structure inference and cosmic web analysis

    CERN Document Server

    Leclercq, Florent

    2015-01-01

    Surveys of the cosmic large-scale structure carry opportunities for building and testing cosmological theories about the origin and evolution of the Universe. This endeavor requires appropriate data assimilation tools, for establishing the contact between survey catalogs and models of structure formation. In this thesis, we present an innovative statistical approach for the ab initio simultaneous analysis of the formation history and morphology of the cosmic web: the BORG algorithm infers the primordial density fluctuations and produces physical reconstructions of the dark matter distribution that underlies observed galaxies, by assimilating the survey data into a cosmological structure formation model. The method, based on Bayesian probability theory, provides accurate means of uncertainty quantification. We demonstrate the application of BORG to the Sloan Digital Sky Survey data and describe the primordial and late-time large-scale structure in the observed volume. We show how the approach has led to the fi...

  13. Inference of splicing regulatory activities by sequence neighborhood analysis.

    Directory of Open Access Journals (Sweden)

    Michael B Stadler

    2006-11-01

    Full Text Available Sequence-specific recognition of nucleic-acid motifs is critical to many cellular processes. We have developed a new and general method called Neighborhood Inference (NI that predicts sequences with activity in regulating a biochemical process based on the local density of known sites in sequence space. Applied to the problem of RNA splicing regulation, NI was used to predict hundreds of new exonic splicing enhancer (ESE and silencer (ESS hexanucleotides from known human ESEs and ESSs. These predictions were supported by cross-validation analysis, by analysis of published splicing regulatory activity data, by sequence-conservation analysis, and by measurement of the splicing regulatory activity of 24 novel predicted ESEs, ESSs, and neutral sequences using an in vivo splicing reporter assay. These results demonstrate the ability of NI to accurately predict splicing regulatory activity and show that the scope of exonic splicing regulatory elements is substantially larger than previously anticipated. Analysis of orthologous exons in four mammals showed that the NI score of ESEs, a measure of function, is much more highly conserved above background than ESE primary sequence. This observation indicates a high degree of selection for ESE activity in mammalian exons, with surprisingly frequent interchangeability between ESE sequences.

  14. Evolution and connectivity in the world-wide migration system of the mallard: Inferences from mitochondrial DNA

    Directory of Open Access Journals (Sweden)

    Kraus Robert HS

    2011-11-01

    Full Text Available Abstract Background Main waterfowl migration systems are well understood through ringing activities. However, in mallards (Anas platyrhynchos ringing studies suggest deviations from general migratory trends and traditions in waterfowl. Furthermore, surprisingly little is known about the population genetic structure of mallards, and studying it may yield insight into the spread of diseases such as Avian Influenza, and in management and conservation of wetlands. The study of evolution of genetic diversity and subsequent partitioning thereof during the last glaciation adds to ongoing discussions on the general evolution of waterfowl populations and flyway evolution. Hypothesised mallard flyways are tested explicitly by analysing mitochondrial mallard DNA from the whole northern hemisphere. Results Phylogenetic analyses confirm two mitochondrial mallard clades. Genetic differentiation within Eurasia and North-America is low, on a continental scale, but large differences occur between these two land masses (FST = 0.51. Half the genetic variance lies within sampling locations, and a negligible portion between currently recognised waterfowl flyways, within Eurasia and North-America. Analysis of molecular variance (AMOVA at continent scale, incorporating sampling localities as smallest units, also shows the absence of population structure on the flyway level. Finally, demographic modelling by coalescence simulation proposes a split between Eurasia and North-America 43,000 to 74,000 years ago and strong population growth (~100fold since then and little migration (not statistically different from zero. Conclusions Based on this first complete assessment of the mallard's world-wide population genetic structure we confirm that no more than two mtDNA clades exist. Clade A is characteristic for Eurasia, and clade B for North-America although some representatives of clade A are also found in North-America. We explain this pattern by evaluating competing

  15. Maternal migration and autism risk: systematic analysis.

    Science.gov (United States)

    Crafa, Daina; Warfa, Nasir

    2015-02-01

    Autism (AUT) is one of the most prevalent developmental disorders emerging during childhood, and can be amongst the most incapacitating mental disorders. Some individuals with AUT require a lifetime of supervised care. Autism Speaks reported estimated costs for 2012 at £34 billion in the UK; and $3.2 million-$126 billion in the US, Australia and Canada. Ethnicity and migration experiences appear to increase risks of AUT and relate to underlying biological risk factors. Sociobiological stress factors can affect the uterine environment, or relate to stress-induced epigenetic changes during pregnancy and delivery. Epigenetic risk factors associated with AUT also include poor pregnancy conditions, low birth weight, and congenital malformation. Recent studies report that children from migrant communities are at higher risk of AUT than children born to non-migrant mothers, with the exception of Hispanic children. This paper provides the first systematic review into prevalence and predictors of AUT with a particular focus on maternal migration stressors and epigenetic risk factors. AUT rates appear higher in certain migrant communities, potentially relating to epigenetic changes after stressful experiences. Although AUT remains a rare disorder, failures to recognize its public health urgency and local community needs continue to leave certain cultural groups at a disadvantage.

  16. Bayesian Inference for NASA Probabilistic Risk and Reliability Analysis

    Science.gov (United States)

    Dezfuli, Homayoon; Kelly, Dana; Smith, Curtis; Vedros, Kurt; Galyean, William

    2009-01-01

    This document, Bayesian Inference for NASA Probabilistic Risk and Reliability Analysis, is intended to provide guidelines for the collection and evaluation of risk and reliability-related data. It is aimed at scientists and engineers familiar with risk and reliability methods and provides a hands-on approach to the investigation and application of a variety of risk and reliability data assessment methods, tools, and techniques. This document provides both: A broad perspective on data analysis collection and evaluation issues. A narrow focus on the methods to implement a comprehensive information repository. The topics addressed herein cover the fundamentals of how data and information are to be used in risk and reliability analysis models and their potential role in decision making. Understanding these topics is essential to attaining a risk informed decision making environment that is being sought by NASA requirements and procedures such as 8000.4 (Agency Risk Management Procedural Requirements), NPR 8705.05 (Probabilistic Risk Assessment Procedures for NASA Programs and Projects), and the System Safety requirements of NPR 8715.3 (NASA General Safety Program Requirements).

  17. Migration and diving behavior of Centrophorus squamosus in the NE Atlantic. Combining electronic tagging and Argo hydrography to infer deep ocean trajectories

    Science.gov (United States)

    Rodríguez-Cabello, Cristina; González-Pola, Cesar; Sánchez, Francisco

    2016-09-01

    A total of nine leafscale gulper sharks Centrophorus squamosus (Bonnaterre, 1788), were tagged with pop-up, satellite, archival, transmitting tags (PSAT) in the Marine Protected Area (MPA) of El Cachucho (Le Danois Bank) located in waters to the north of Spain, (NE Atlantic). Tags provided data on time, pressure and temperature that were used to examine movement patterns and diving behavior. Data collected from Argo floats in the study area have been used to devise a simple geolocation algorithm to infer the probable routes followed by this species. Tag release points revealed that C. squamosus moved both to the west (Galician waters) and to the north (Porcupine Bank) from the tagging area, suggesting well defined preferred pathways. The inferred trajectories indicated that sharks alternate periods constrained to specific geographical regions with quick and prompt movements covering large distances. Two sharks made conspicuous diurnal vertical migrations being at shallower depths around midnight and at maximum depths at midday, while other sharks did not make vertical migrations. Vertical movements were done smoothly and independently of the fish swimming long-distances or resting in the area. Overall results confirm that this species is highly migratory, supporting speeds of 20 nautical miles.day-1 and well capable to swim and make vertical migrations well above the abyssal plain.

  18. Modeling and Analysis of Epidemic Diffusion with Population Migration

    Directory of Open Access Journals (Sweden)

    Ming Liu

    2013-01-01

    Full Text Available An improved Susceptible-Infected-Susceptible (SIS epidemic diffusion model with population migration between two cities is modeled. Global stability conditions for both the disease-free equilibrium and the endemic equilibrium are analyzed and proved. The main contribution of this paper is reflected in epidemic modeling and analysis which considers unequal migration rates, and only susceptible individuals can migrate between the two cities. Numerical simulation shows when the epidemic diffusion system is stable, number of infected individuals in one city can reach zero, while the number of infected individuals in the other city is still positive. On the other hand, decreasing population migration in only one city seems not as effective as improving the recovery rate for controlling the epidemic diffusion.

  19. River Channel Migration: A Remote Sensing and GIS Analysis

    Science.gov (United States)

    Islam, Tariqul

    2010-12-01

    Remote sensing and geographic information system provide tools for quantitative and qualitative river morphological analysis. Bangladesh is a riverine, flood prone country and, the Padma and the Jamuna are two of major three rivers in the country. The aim of this research is to monitor the channel migration of the Padma and the Jamuna rivers since 1977 to 2004 using remote sensing and GIS. Four scenes for dry season's cloud free Landsat images were used in this study. Images were processed using PCI Geomatica and ArcGIS 9.3 was used for GIS analysis. The Landsat images were visualized and identified nine locations to investigate the channel migration. The images were classified into two broad categories, i.e. water and nonwater body. ArcGIS 9.3 was used to transfer these classified images into GIS layers. A standard measurement tool of ArcGIS was applied to measure the movement of river channel based on initial river channel in 1977. General trend of the Padma and the Jamuna river channel migration at locations A, B, C, D, F, G, H and I towards north, northeast and southwest eventually, north, northeast, east, east, west and west, respectively. The confluence point of the Padma and Jamuna (at location E) migrated toward southeast with high rate. During 1977-2004, it migrated about 9000m toward southeast. Trend of migration of the confluence point was faster than any other locations in the channel of the Padma river.

  20. Statistical analysis of the migration phenomenon

    Directory of Open Access Journals (Sweden)

    Alina - Andreea CRUCERU

    2010-11-01

    Full Text Available On the basis of economic conditions being devalued in Romania, more and more persons were forced to find a work place – be it temporary or permanent – outside of the country’s borders. This phenomenon of international migration has, as a main effect, the emergence of a special category of persons, respectively that of children left behind under the care of one of the parents or of other people. The situation of these minors is extremely difficult because, lacking the careful supervision of their evolution by their parents, they arefrequently confronted with problems of social adaptation, with learning difficulties and even with situations of willful breaking of legal norms.

  1. Inference of Ancestral Recombination Graphs through Topological Data Analysis.

    Science.gov (United States)

    Cámara, Pablo G; Levine, Arnold J; Rabadán, Raúl

    2016-08-01

    The recent explosion of genomic data has underscored the need for interpretable and comprehensive analyses that can capture complex phylogenetic relationships within and across species. Recombination, reassortment and horizontal gene transfer constitute examples of pervasive biological phenomena that cannot be captured by tree-like representations. Starting from hundreds of genomes, we are interested in the reconstruction of potential evolutionary histories leading to the observed data. Ancestral recombination graphs represent potential histories that explicitly accommodate recombination and mutation events across orthologous genomes. However, they are computationally costly to reconstruct, usually being infeasible for more than few tens of genomes. Recently, Topological Data Analysis (TDA) methods have been proposed as robust and scalable methods that can capture the genetic scale and frequency of recombination. We build upon previous TDA developments for detecting and quantifying recombination, and present a novel framework that can be applied to hundreds of genomes and can be interpreted in terms of minimal histories of mutation and recombination events, quantifying the scales and identifying the genomic locations of recombinations. We implement this framework in a software package, called TARGet, and apply it to several examples, including small migration between different populations, human recombination, and horizontal evolution in finches inhabiting the Galápagos Islands.

  2. [The historical analysis of migration: the pertinence of longitudinal analysis based on retrospective histories].

    Science.gov (United States)

    Piche, V; Gregory, J; Lavoie, J

    1984-01-01

    The appropriateness of longitudinal analysis as a technique for studying migration is considered. Migration in Upper Volta (now Burkina Faso) is used as the example. Data are taken from the 1974-75 National Survey of Migration, in which 36,785 men and 38,987 women were questioned. The authors begin with a theoretical discussion of the biases to be expected in retrospective histories. They next look at the migration data using first longitudinal analysis and then cross-sectional analysis. Results, at least for this example, show that cross-sectional analysis of migration has the advantage over longitudinal analysis of allowing the correlations between changes in migration patterns and particular historical events to be seen more readily.

  3. Ecological Inference

    Science.gov (United States)

    King, Gary; Rosen, Ori; Tanner, Martin A.

    2004-09-01

    This collection of essays brings together a diverse group of scholars to survey the latest strategies for solving ecological inference problems in various fields. The last half-decade has witnessed an explosion of research in ecological inference--the process of trying to infer individual behavior from aggregate data. Although uncertainties and information lost in aggregation make ecological inference one of the most problematic types of research to rely on, these inferences are required in many academic fields, as well as by legislatures and the Courts in redistricting, by business in marketing research, and by governments in policy analysis.

  4. Security Analysis in the Migration to Cloud Environments

    Directory of Open Access Journals (Sweden)

    Eduardo Fernández-Medina

    2012-05-01

    Full Text Available Cloud computing is a new paradigm that combines several computing concepts and technologies of the Internet creating a platform for more agile and cost-effective business applications and IT infrastructure. The adoption of Cloud computing has been increasing for some time and the maturity of the market is steadily growing. Security is the question most consistently raised as consumers look to move their data and applications to the cloud. We justify the importance and motivation of security in the migration of legacy systems and we carry out an analysis of different approaches related to security in migration processes to cloud with the aim of finding the needs, concerns, requirements, aspects, opportunities and benefits of security in the migration process of legacy systems.

  5. Seasonal distributions and migrations of Northwest Atlantic swordfish: inferences from integration of pop-up satellite archival tagging studies.

    Science.gov (United States)

    Neilson, John D; Loefer, Josh; Prince, Eric D; Royer, François; Calmettes, Beatriz; Gaspar, Philippe; Lopez, Rémy; Andrushchenko, Irene

    2014-01-01

    Data sets from three laboratories conducting studies of movements and migrations of Atlantic swordfish (Xiphias gladius) using pop-up satellite archival tags were pooled, and processed using a common methodology. From 78 available deployments, 38 were selected for detailed examination based on deployment duration. The points of deployment ranged from southern Newfoundland to the Straits of Florida. The aggregate data comprise the most comprehensive information describing migrations of swordfish in the Atlantic. Challenges in using data from different tag manufacturers are discussed. The relative utility of geolocations obtained with light is compared with results derived from temperature information for this deep-diving species. The results show that fish tagged off North America remain in the western Atlantic throughout their deployments. This is inconsistent with the model of stock structure used in assessments conducted by the International Commission for the Conservation of Atlantic Tunas, which assumes that fish mix freely throughout the North Atlantic.

  6. Extension of migration velocity analysis to transmitted wavefields

    Science.gov (United States)

    Lameloise, Charles-Antoine; Chauris, Hervé

    2016-10-01

    Migration velocity analysis aims at automatically updating the large-scale components of the velocity model, called macromodel. Extended Common Image Gathers are panels used to evaluate focusing after imaging and are constructed as a function of a spatial shift introduced in the imaging condition. We investigate how transmitted waves can also be used in migration velocity analysis: instead of back-propagating the residuals associated with reflected waves, we propose to back-propagate the full wavefield. The image function, equivalent to the migrated section for reflected data, does not exhibit localized events in space along horizons but is still sensitive to the choice of the background velocity model and can thus be coupled to the same objective function defined in the image domain. In order to enhance the benefits of direct waves, we consider a cross-well configuration. Direct waves provide a large illumination between two vertical wells. Associated Common Image Gathers present different characteristics than the ones associated with reflected waves in surface acquisition. In particular, energy is spread over up to the maximum penetration depth. We invert cross-well seismic data along two lines. In the first case, the input data contain the full wavefield dominated by transmitted waves. It demonstrates the possibility to handle transmitted waves to determine the velocity model. It appears that the misfit in the data domain is largely reduced after inversion. In the second case, we use the same algorithm, but with reflected observed data only, as in a classical approach. Most of velocity updates are localized around the reflectivity, leading to an incorrect final model. This demonstrates the benefit of transmitted waves for migration velocity analysis in a cross-well configuration.

  7. Bayesian inference for inverse problems occurring in uncertainty analysis

    OpenAIRE

    Fu, Shuai; Celeux, Gilles; Bousquet, Nicolas; Couplet, Mathieu

    2012-01-01

    The inverse problem considered here is to estimate the distribution of a non-observed random variable $X$ from some noisy observed data $Y$ linked to $X$ through a time-consuming physical model $H$. Bayesian inference is considered to take into account prior expert knowledge on $X$ in a small sample size setting. A Metropolis-Hastings within Gibbs algorithm is proposed to compute the posterior distribution of the parameters of $X$ through a data augmentation process. Since calls to $H$ are qu...

  8. Unsupervised Transient Light Curve Analysis Via Hierarchical Bayesian Inference

    CERN Document Server

    Sanders, Nathan; Soderberg, Alicia

    2014-01-01

    Historically, light curve studies of supernovae (SNe) and other transient classes have focused on individual objects with copious and high signal-to-noise observations. In the nascent era of wide field transient searches, objects with detailed observations are decreasing as a fraction of the overall known SN population, and this strategy sacrifices the majority of the information contained in the data about the underlying population of transients. A population level modeling approach, simultaneously fitting all available observations of objects in a transient sub-class of interest, fully mines the data to infer the properties of the population and avoids certain systematic biases. We present a novel hierarchical Bayesian statistical model for population level modeling of transient light curves, and discuss its implementation using an efficient Hamiltonian Monte Carlo technique. As a test case, we apply this model to the Type IIP SN sample from the Pan-STARRS1 Medium Deep Survey, consisting of 18,837 photometr...

  9. Possible shallow slow slip events in Hyuga-nada, Nankai subduction zone, inferred from migration of very low frequency earthquakes

    Science.gov (United States)

    Asano, Youichi; Obara, Kazushige; Matsuzawa, Takanori; Hirose, Hitoshi; Ito, Yoshihiro

    2015-01-01

    investigated the spatiotemporal evolution of a shallow very low frequency earthquake (sVLFE) swarm linked to the 2009/2010 long-term slow slip event (SSE) in the Bungo channel, southwestern Japan. Broadband seismograms were analyzed using a cross-correlation technique to detect sVLFEs having similar waveforms to template sVLFEs, and their relative locations were estimated. The sVLFEs exhibit clear migration over a distance of 150 km along the Nankai trough, similar to nonvolcanic tremors and deep very low frequency earthquakes (dVLFEs) accompanied by short-term SSEs on the downward extension of the seismogenic zone. This similarity between sVLFEs and dVLFEs suggests that SSEs occur in both deeper and shallower extensions of the seismogenic zone. The analyzed sVLFEs were likely caused by a shallow SSE that occurred from January to March 2010 following the initiation and acceleration of the long-term SSE. This temporal evolution may be caused by stress interaction between the shallow SSE and the long-term SSE.

  10. IN VITRO ANALYSIS OF MIGRATION ACTIVITY OF ENCEPHALYTOGENIC T CEL

    Directory of Open Access Journals (Sweden)

    M. A. Nosov

    2010-01-01

    Full Text Available Experimental autoimmune encephalomyelitis in an adoptive transfer model is caused by injecting animal with activated T cells specific for a CNS antigen, e.g., basic myelin protein. Development of autimmune inflammation in such a model is connected with changed functional stateof encephalytogenic (EG T cells in the coure of disease progression, as reflected by changes in their activation, proliferation and motility levels. Present work describes an original technique allowing for in vitro analysis of encephalytogenic T cell motility, and studying effects of certain compomemts of extracellular matrix upon migration and functional activities of EG T cells.

  11. Quantitative Analysis on Carbon Migration in Double-Glow Discharge Plasma Surface Alloying Process

    Institute of Scientific and Technical Information of China (English)

    ZHANGZhen-xia; WANGCong-zeng; ZHANGWen-quan; SUXue-kuan

    2004-01-01

    Carbon migration is of great significance in double-glow discharge plasma surface alloying process, but literature of quantitative analysis about carbon migration is relatively scarce. In this paper differential equations of the carbon and metal concentration distribution were established. By means of differential equations carbon migration was described and a numerical solution was acquired. The computational results fit the experiment results quite well.

  12. UNSUPERVISED TRANSIENT LIGHT CURVE ANALYSIS VIA HIERARCHICAL BAYESIAN INFERENCE

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, N. E.; Soderberg, A. M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Betancourt, M., E-mail: nsanders@cfa.harvard.edu [Department of Statistics, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2015-02-10

    Historically, light curve studies of supernovae (SNe) and other transient classes have focused on individual objects with copious and high signal-to-noise observations. In the nascent era of wide field transient searches, objects with detailed observations are decreasing as a fraction of the overall known SN population, and this strategy sacrifices the majority of the information contained in the data about the underlying population of transients. A population level modeling approach, simultaneously fitting all available observations of objects in a transient sub-class of interest, fully mines the data to infer the properties of the population and avoids certain systematic biases. We present a novel hierarchical Bayesian statistical model for population level modeling of transient light curves, and discuss its implementation using an efficient Hamiltonian Monte Carlo technique. As a test case, we apply this model to the Type IIP SN sample from the Pan-STARRS1 Medium Deep Survey, consisting of 18,837 photometric observations of 76 SNe, corresponding to a joint posterior distribution with 9176 parameters under our model. Our hierarchical model fits provide improved constraints on light curve parameters relevant to the physical properties of their progenitor stars relative to modeling individual light curves alone. Moreover, we directly evaluate the probability for occurrence rates of unseen light curve characteristics from the model hyperparameters, addressing observational biases in survey methodology. We view this modeling framework as an unsupervised machine learning technique with the ability to maximize scientific returns from data to be collected by future wide field transient searches like LSST.

  13. Inference of Gene Flow in the Process of Speciation: An Efficient Maximum-Likelihood Method for the Isolation-with-Initial-Migration Model

    Science.gov (United States)

    Costa, Rui J.; Wilkinson-Herbots, Hilde

    2017-01-01

    The isolation-with-migration (IM) model is commonly used to make inferences about gene flow during speciation, using polymorphism data. However, it has been reported that the parameter estimates obtained by fitting the IM model are very sensitive to the model’s assumptions—including the assumption of constant gene flow until the present. This article is concerned with the isolation-with-initial-migration (IIM) model, which drops precisely this assumption. In the IIM model, one ancestral population divides into two descendant subpopulations, between which there is an initial period of gene flow and a subsequent period of isolation. We derive a very fast method of fitting an extended version of the IIM model, which also allows for asymmetric gene flow and unequal population sizes. This is a maximum-likelihood method, applicable to data on the number of segregating sites between pairs of DNA sequences from a large number of independent loci. In addition to obtaining parameter estimates, our method can also be used, by means of likelihood-ratio tests, to distinguish between alternative models representing the following divergence scenarios: (a) divergence with potentially asymmetric gene flow until the present, (b) divergence with potentially asymmetric gene flow until some point in the past and in isolation since then, and (c) divergence in complete isolation. We illustrate the procedure on pairs of Drosophila sequences from ∼30,000 loci. The computing time needed to fit the most complex version of the model to this data set is only a couple of minutes. The R code to fit the IIM model can be found in the supplementary files of this article. PMID:28193727

  14. Inferred vs realized patterns of gene flow: an analysis of population structure in the Andros Island Rock Iguana.

    Directory of Open Access Journals (Sweden)

    Giuliano Colosimo

    Full Text Available Ecological data, the primary source of information on patterns and rates of migration, can be integrated with genetic data to more accurately describe the realized connectivity between geographically isolated demes. In this paper we implement this approach and discuss its implications for managing populations of the endangered Andros Island Rock Iguana, Cyclura cychlura cychlura. This iguana is endemic to Andros, a highly fragmented landmass of large islands and smaller cays. Field observations suggest that geographically isolated demes were panmictic due to high, inferred rates of gene flow. We expand on these observations using 16 polymorphic microsatellites to investigate the genetic structure and rates of gene flow from 188 Andros Iguanas collected across 23 island sites. Bayesian clustering of specimens assigned individuals to three distinct genotypic clusters. An analysis of molecular variance (AMOVA indicates that allele frequency differences are responsible for a significant portion of the genetic variance across the three defined clusters (Fst =  0.117, p<<0.01. These clusters are associated with larger islands and satellite cays isolated by broad water channels with strong currents. These findings imply that broad water channels present greater obstacles to gene flow than was inferred from field observation alone. Additionally, rates of gene flow were indirectly estimated using BAYESASS 3.0. The proportion of individuals originating from within each identified cluster varied from 94.5 to 98.7%, providing further support for local isolation. Our assessment reveals a major disparity between inferred and realized gene flow. We discuss our results in a conservation perspective for species inhabiting highly fragmented landscapes.

  15. Structural Analysis of Labor Market Transitions Using Indirect Inference

    DEFF Research Database (Denmark)

    An, Mark Yuing; Liu, Ming

    1996-01-01

    In the econometric analysis of labor market transitions, the data generating process is often specified as a continuous-time semi-Markovian process with a finite state space. With typically short panel data, analysts have long been concerne d with the initial conditions problem.......In the econometric analysis of labor market transitions, the data generating process is often specified as a continuous-time semi-Markovian process with a finite state space. With typically short panel data, analysts have long been concerne d with the initial conditions problem....

  16. Distribution of Deformation on Cyprus, Inferences from Morphotectonic Analysis

    Science.gov (United States)

    Altinbas, Cevza; Yildirim, Cengiz; Tuysuz, Okan; Melnick, Daniel

    2016-04-01

    Cyprus is located on the subduction zone between African and Anatolian Plates. The topography of the island is a result of distributed deformation associated with the subduction related processes in the south of the Central Anatolian Plateau. Trodos and Kyrenia mountains are major morphotectonic units that integrally tied to plate boundary deformations. To elucidate the mode and pattern of active deformation and possible effects of subduction related processes on topography, we integrated morphometric and topographical analysis across the island. Our regional morphometric analysis rely on topographical swath profiles and topographic residuals to identify regional topographic anomalies, as well as steepness and concavity values of longitudinal river profiles that may reflect ongoing uplift. Accordingly, our swath profiles indicate an assymmetric topography across the Troodos Massif and Kyrenia Range. South of Trodos Massif indicates relatively less disected surfaces that partly associated with marine terraces of Quaternary. Our topographical resudial analysis indicate also strong relief assymmetry on the Troodos Massif that might be related to the Arakapas Fault and lithological contact between Neogene and Pre-Neogene rocks. In the north of the island the Kyrenia Range is characterized by a narrow, steep and long range that is delimited by the Ovgos Fault in the south. Our swath profiles across the range display also strong southward assymmetry. The southern flank is steeper in comparison to northern flank. The steepness index value of the rivers on the southern flank of the Kyrenia Range do not give strong signal along the Ovgos Fault. Neverthess, longitudinal profiles of rivers reveal evident deviations from degraded river profiles in the northern flank. Together with the presence of uplifted marine terraces along the northern flank that might indicate the presence of onshore structure(s) responsible for coastal uplift or regional uplift of the island because of

  17. Proof Validation in Real Analysis: Inferring and Checking Warrants

    Science.gov (United States)

    Alcock, Lara; Weber, Keith

    2005-01-01

    In the study reported here, we investigate the skills needed to validate a proof in real analysis, i.e., to determine whether a proof is valid. We first argue that when one is validating a proof, it is not sufficient to make certain that each statement in the argument is true. One must also check that there is good reason to believe that each…

  18. Analysis of CCR7 mediated T cell transfectant migration using a microfluidic gradient generator.

    Science.gov (United States)

    Wu, Xun; Wu, Jiandong; Li, Hongzhao; Legler, Daniel F; Marshall, Aaron J; Lin, Francis

    2015-04-01

    T lymphocyte migration is crucial for adaptive immunity. Manipulation of signaling molecules controlling cell migration combined with in-vitro cell migration analysis provides a powerful research approach. Microfluidic devices, which can precisely configure chemoattractant gradients and allow quantitative single cell analysis, have been increasingly applied to cell migration and chemotaxis studies. However, there are a very limited number of published studies involving microfluidic migration analysis of genetically manipulated immune cells. In this study, we describe a simple microfluidic method for quantitative analysis of T cells expressing transfected chemokine receptors and other cell migration signaling probes. Using this method, we demonstrated chemotaxis of Jurkat transfectants expressing wild-type or C-terminus mutated CCR7 within a gradient of chemokine CCL19, and characterized the difference in transfectant migration mediated by wild-type and mutant CCR7. The EGFP-tagged CCR7 allows identification of CCR7-expressing transfectants in cell migration analysis and microscopy assessment of CCR7 dynamics. Collectively, our study demonstrated the effective use of the microfluidic method for studying CCR7 mediated T cell transfectant migration. We envision this developed method will provide a useful platform to functionally test various signaling mechanisms at the cell migration level.

  19. An analysis pipeline for the inference of protein-protein interaction networks

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Ronald C.; Singhal, Mudita; Daly, Don S.; Gilmore, Jason M.; Cannon, William R.; Domico, Kelly O.; White, Amanda M.; Auberry, Deanna L.; Auberry, Kenneth J.; Hooker, Brian S.; Hurst, G. B.; McDermott, Jason E.; McDonald, W. H.; Pelletier, Dale A.; Schmoyer, Denise A.; Wiley, H. S.

    2009-12-01

    An analysis pipeline has been created for deployment of a novel algorithm, the Bayesian Estimator of Protein-Protein Association Probabilities (BEPro), for use in the reconstruction of protein-protein interaction networks. We have combined the Software Environment for BIological Network Inference (SEBINI), an interactive environment for the deployment and testing of network inference algorithms that use high-throughput data, and the Collective Analysis of Biological Interaction Networks (CABIN), software that allows integration and analysis of protein-protein interaction and gene-to-gene regulatory evidence obtained from multiple sources, to allow interactions computed by BEPro to be stored, visualized, and further analyzed. Incorporating BEPro into SEBINI and automatically feeding the resulting inferred network into CABIN, we have created a structured workflow for protein-protein network inference and supplemental analysis from sets of mass spectrometry bait-prey experiment data. SEBINI demo site: https://www.emsl.pnl.gov /SEBINI/ Contact: ronald.taylor@pnl.gov. BEPro is available at http://www.pnl.gov/statistics/BEPro3/index.htm. Contact: ds.daly@pnl.gov. CABIN is available at http://www.sysbio.org/dataresources/cabin.stm. Contact: mudita.singhal@pnl.gov.

  20. General Analysis of Type I Planetary Migration with Stochastic Perturbations

    CERN Document Server

    Adams, Fred C

    2009-01-01

    This paper presents a generalized treatment of Type I planetary migration in the presence of stochastic perturbations. In many planet-forming disks, the Type I migration mechanism, driven by asymmetric torques, acts on a short time scale and compromises planet formation. If the disk also supports MHD instabilities, however, the corresponding turbulent fluctuations produce additional stochastic torques that modify the steady inward migration scenario. This work studies the migration of planetary cores in the presence of stochastic fluctuations using complementary methods, including a Fokker-Planck approach and iterative maps. Stochastic torques have two main effects: [1] Through outward diffusion, a small fraction of the planetary cores can survive in the face of Type I inward migration. [2] For a given starting condition, the result of any particular realization of migration is uncertain, so that results must be described in terms of the distributions of outcomes. In addition to exploring different regimes of...

  1. Evaluation of Second-Level Inference in fMRI Analysis

    Directory of Open Access Journals (Sweden)

    Sanne P. Roels

    2016-01-01

    Full Text Available We investigate the impact of decisions in the second-level (i.e., over subjects inferential process in functional magnetic resonance imaging on (1 the balance between false positives and false negatives and on (2 the data-analytical stability, both proxies for the reproducibility of results. Second-level analysis based on a mass univariate approach typically consists of 3 phases. First, one proceeds via a general linear model for a test image that consists of pooled information from different subjects. We evaluate models that take into account first-level (within-subjects variability and models that do not take into account this variability. Second, one proceeds via inference based on parametrical assumptions or via permutation-based inference. Third, we evaluate 3 commonly used procedures to address the multiple testing problem: familywise error rate correction, False Discovery Rate (FDR correction, and a two-step procedure with minimal cluster size. Based on a simulation study and real data we find that the two-step procedure with minimal cluster size results in most stable results, followed by the familywise error rate correction. The FDR results in most variable results, for both permutation-based inference and parametrical inference. Modeling the subject-specific variability yields a better balance between false positives and false negatives when using parametric inference.

  2. A dynamic analysis of net migration and state employment change.

    Science.gov (United States)

    Gruidl, J S; Pulver, G C

    1991-01-01

    "The dynamic relationship of net migration and employment change is examined for ten selected states of the U.S. using a multivariate time series approach--a vector autoregression (VAR) model. Granger causality tests and dynamic multipliers provide information on the dynamic process. The results suggest a state-level process in which employment change occurs first, and net migration follows with a lag. The procedure appears promising in investigating the timing of net migration and regional employment change."

  3. Procrystal Analysis as a Tool for the Visualization of Ion Migration Pathways

    DEFF Research Database (Denmark)

    Filso, Mette O.; Eikeland, Espen; Iversen, Bo B.

    2016-01-01

    The procrystal analysis is presented as a valuable tool for fast, clear visualization of ion migration pathways in solids. The method has been shown to posses great predictive power for ion migration in Li-ion battery materials. Selected results for known Li-ion conductors are presented, including...... a new study of Li2CoPO4F. In addition, examples of visualization of Na-ion and K-ion migration pathways are displayed. A full procrystal analysis includes both visual representation of possible pathways and a ranking of these pathways according to their accessibility to migrating ions. Such an analysis...... can be performed in only a few minutes, making it the fastest choice available for the prediction of ion migration in solids at this time. Further applications include solid oxide fuel cells, and other research fields in which ion migration in crystalline solids plays a significant role....

  4. Study and Preliminary Analysis of Test of Aerosol Migration Mechanism

    Institute of Scientific and Technical Information of China (English)

    CHEN; Lin-lin; SUN; Xue-ting; WEI; Yan-song

    2015-01-01

    TAMM(test of aerosol migration mechanism)is one of the important aspects of Studies on Migration Mechanism of the Source Term under Severe Accident,which is a significant research of the National Large Advanced PWR Research Program.The main task researches the

  5. Analysis of primary cilia in directional cell migration in fibroblasts

    DEFF Research Database (Denmark)

    Christensen, Søren Tvorup; Veland, Iben; Schwab, Albrecht;

    2013-01-01

    Early studies of migrating fibroblasts showed that primary cilia orient in front of the nucleus and point toward the leading edge. Recent work has shown that primary cilia coordinate a series of signaling pathways critical to fibroblast cell migration during development and in wound healing. In p...

  6. Model schedules in Multistate Demographic Analysis: The Case of Migration

    OpenAIRE

    1981-01-01

    This paper draws on the fundamental regularity exhibited by age profiles of migration all over the world to develop a system of hypothetical "synthetic" model miqration schedules that can be used to carry out multiregional population analyses in countries that lack adequate migration data.

  7. Image Analysis of Soil Micromorphology: Feature Extraction, Segmentation, and Quality Inference

    Directory of Open Access Journals (Sweden)

    Petros Maragos

    2004-06-01

    Full Text Available We present an automated system that we have developed for estimation of the bioecological quality of soils using various image analysis methodologies. Its goal is to analyze soilsection images, extract features related to their micromorphology, and relate the visual features to various degrees of soil fertility inferred from biochemical characteristics of the soil. The image methodologies used range from low-level image processing tasks, such as nonlinear enhancement, multiscale analysis, geometric feature detection, and size distributions, to object-oriented analysis, such as segmentation, region texture, and shape analysis.

  8. ANALYSIS OF POPULATION MIGRATION AS A CRIMINOGENIC FACTOR

    Directory of Open Access Journals (Sweden)

    Mariana MITRA-NIŢĂ

    2016-07-01

    Full Text Available Migration is a voluntary movement of population from one geographic location to another. This movement can be of several types, depending on the cause determining the respective migration. Population movements or its mobility is not a new phenomenon but has deep roots in ancient history. We can even say that in the beginning man was migratory, nomadic and later it became steadfast, linked in some way to certain geographic locations. Population migration has multiple consequences, both positive and negative. Among the negative we can mention overpopulation or underpopulation of certain areas, heterogeneity of traditions and cultures of immigrants, inability of migratory population to adapt to the area they migrated to, not finding a job, marginalization, etc. All these are genuine and objective criminological factors that could actually cause committing crimes in the migratory population. We cannot and do not want to stop the mobility of people, but we can be careful to avoid harmful consequences caused by this phenomenon.

  9. Hybrid Origins of Citrus Varieties Inferred from DNA Marker Analysis of Nuclear and Organelle Genomes

    Science.gov (United States)

    Kitajima, Akira; Nonaka, Keisuke; Yoshioka, Terutaka; Ohta, Satoshi; Goto, Shingo; Toyoda, Atsushi; Fujiyama, Asao; Mochizuki, Takako; Nagasaki, Hideki; Kaminuma, Eli; Nakamura, Yasukazu

    2016-01-01

    Most indigenous citrus varieties are assumed to be natural hybrids, but their parentage has so far been determined in only a few cases because of their wide genetic diversity and the low transferability of DNA markers. Here we infer the parentage of indigenous citrus varieties using simple sequence repeat and indel markers developed from various citrus genome sequence resources. Parentage tests with 122 known hybrids using the selected DNA markers certify their transferability among those hybrids. Identity tests confirm that most variant strains are selected mutants, but we find four types of kunenbo (Citrus nobilis) and three types of tachibana (Citrus tachibana) for which we suggest different origins. Structure analysis with DNA markers that are in Hardy–Weinberg equilibrium deduce three basic taxa coinciding with the current understanding of citrus ancestors. Genotyping analysis of 101 indigenous citrus varieties with 123 selected DNA markers infers the parentages of 22 indigenous citrus varieties including Satsuma, Temple, and iyo, and single parents of 45 indigenous citrus varieties, including kunenbo, C. ichangensis, and Ichang lemon by allele-sharing and parentage tests. Genotyping analysis of chloroplast and mitochondrial genomes using 11 DNA markers classifies their cytoplasmic genotypes into 18 categories and deduces the combination of seed and pollen parents. Likelihood ratio analysis verifies the inferred parentages with significant scores. The reconstructed genealogy identifies 12 types of varieties consisting of Kishu, kunenbo, yuzu, koji, sour orange, dancy, kobeni mikan, sweet orange, tachibana, Cleopatra, willowleaf mandarin, and pummelo, which have played pivotal roles in the occurrence of these indigenous varieties. The inferred parentage of the indigenous varieties confirms their hybrid origins, as found by recent studies. PMID:27902727

  10. Coalescent inference for infectious disease: meta-analysis of hepatitis C

    OpenAIRE

    Dearlove, Bethany; Daniel J. Wilson

    2013-01-01

    Genetic analysis of pathogen genomes is a powerful approach to investigating the population dynamics and epidemic history of infectious diseases. However, the theoretical underpinnings of the most widely used, coalescent methods have been questioned, casting doubt on their interpretation. The aim of this study is to develop robust population genetic inference for compartmental models in epidemiology. Using a general approach based on the theory of metapopulations, we derive coalescent models ...

  11. Nonparametric Bayesian Inference for Mean Residual Life Functions in Survival Analysis

    OpenAIRE

    Poynor, Valerie; Kottas, Athanasios

    2014-01-01

    Modeling and inference for survival analysis problems typically revolves around different functions related to the survival distribution. Here, we focus on the mean residual life function which provides the expected remaining lifetime given that a subject has survived (i.e., is event-free) up to a particular time. This function is of direct interest in reliability, medical, and actuarial fields. In addition to its practical interpretation, the mean residual life function characterizes the sur...

  12. Hybrid Origins of Citrus Varieties Inferred from DNA Marker Analysis of Nuclear and Organelle Genomes.

    Science.gov (United States)

    Shimizu, Tokurou; Kitajima, Akira; Nonaka, Keisuke; Yoshioka, Terutaka; Ohta, Satoshi; Goto, Shingo; Toyoda, Atsushi; Fujiyama, Asao; Mochizuki, Takako; Nagasaki, Hideki; Kaminuma, Eli; Nakamura, Yasukazu

    2016-01-01

    Most indigenous citrus varieties are assumed to be natural hybrids, but their parentage has so far been determined in only a few cases because of their wide genetic diversity and the low transferability of DNA markers. Here we infer the parentage of indigenous citrus varieties using simple sequence repeat and indel markers developed from various citrus genome sequence resources. Parentage tests with 122 known hybrids using the selected DNA markers certify their transferability among those hybrids. Identity tests confirm that most variant strains are selected mutants, but we find four types of kunenbo (Citrus nobilis) and three types of tachibana (Citrus tachibana) for which we suggest different origins. Structure analysis with DNA markers that are in Hardy-Weinberg equilibrium deduce three basic taxa coinciding with the current understanding of citrus ancestors. Genotyping analysis of 101 indigenous citrus varieties with 123 selected DNA markers infers the parentages of 22 indigenous citrus varieties including Satsuma, Temple, and iyo, and single parents of 45 indigenous citrus varieties, including kunenbo, C. ichangensis, and Ichang lemon by allele-sharing and parentage tests. Genotyping analysis of chloroplast and mitochondrial genomes using 11 DNA markers classifies their cytoplasmic genotypes into 18 categories and deduces the combination of seed and pollen parents. Likelihood ratio analysis verifies the inferred parentages with significant scores. The reconstructed genealogy identifies 12 types of varieties consisting of Kishu, kunenbo, yuzu, koji, sour orange, dancy, kobeni mikan, sweet orange, tachibana, Cleopatra, willowleaf mandarin, and pummelo, which have played pivotal roles in the occurrence of these indigenous varieties. The inferred parentage of the indigenous varieties confirms their hybrid origins, as found by recent studies.

  13. District Level Analysis of Urbanization from Rural-to-Urban Migration in the Rajasthan State

    CERN Document Server

    Singh, Jayant; Smarandache, Florentin

    2009-01-01

    Migration has various dimensions; urbanization due to migration is one of them. In Rajasthan State, district level analysis of urbanization due to migrants shows trend invariably for all districts of the state, though the contribution in urbanization by migrants varies from district to district. In some districts the share of migrants moving to urban areas is very impressive, in others it is not that much high. The migrants' contribution is on the raising over the decades. In this paper, the district level migration in the Rajasthan State is examined in relation to total urbanization and urbanization due to migration.

  14. A Macroeconomic Analysis of Regional Migration in Finland, 1975-95

    OpenAIRE

    Sari Pekkala; Jari Ritsila

    1999-01-01

    This study analyzes regional migration in the 85 Finnish subregions during the period 1975-95 using data on net in-migration rates. Both cross-section and panel data methods are employed. The regression analysis reveals that the direction of net in-migration flows can be explained by a set of regionally differing characteristics. Unemployment rates, tax rates, and the share of primary production affect net in-migration negatively, whereas the share of higher education and the growth of region...

  15. Structural influence of gene networks on their inference: analysis of C3NET

    Directory of Open Access Journals (Sweden)

    Emmert-Streib Frank

    2011-06-01

    Full Text Available Abstract Background The availability of large-scale high-throughput data possesses considerable challenges toward their functional analysis. For this reason gene network inference methods gained considerable interest. However, our current knowledge, especially about the influence of the structure of a gene network on its inference, is limited. Results In this paper we present a comprehensive investigation of the structural influence of gene networks on the inferential characteristics of C3NET - a recently introduced gene network inference algorithm. We employ local as well as global performance metrics in combination with an ensemble approach. The results from our numerical study for various biological and synthetic network structures and simulation conditions, also comparing C3NET with other inference algorithms, lead a multitude of theoretical and practical insights into the working behavior of C3NET. In addition, in order to facilitate the practical usage of C3NET we provide an user-friendly R package, called c3net, and describe its functionality. It is available from https://r-forge.r-project.org/projects/c3net and from the CRAN package repository. Conclusions The availability of gene network inference algorithms with known inferential properties opens a new era of large-scale screening experiments that could be equally beneficial for basic biological and biomedical research with auspicious prospects. The availability of our easy to use software package c3net may contribute to the popularization of such methods. Reviewers This article was reviewed by Lev Klebanov, Joel Bader and Yuriy Gusev.

  16. Reframing the Migration Question: An Analysis of Men, Women, and Gender in Mexico.

    Science.gov (United States)

    Kanaiaupuni, Shawn Malia

    2000-01-01

    Analysis of data on approximately 14,000 individuals in 43 Mexican villages examined how gender relations and expectations differentiate male and female patterns of Mexico-to-U.S. migration. Education and migration were related positively for women but negatively for men. Age, marital status, and social networks also had differential effects on…

  17. Development and validation of a Prototype Prakriti Analysis Tool (PPAT): Inferences from a pilot study.

    Science.gov (United States)

    Rastogi, Sanjeev

    2012-04-01

    Prakriti, for its tangible impacts upon decision making in Ayurvedic clinical practice, requires a thorough and fool-proof method of examination. Conventional methods adopted for Prakriti examination are found inconsistent with huge inter- and intra-rater inference variability. By observing the gaps in the field, the present study aims to develop a prototype Prakriti analysis tool and its evaluation on inter-rater validity grounds. The study observes that Vata and Pitta constructs of Prakriti identification in Ayurveda have a significant inter-rater correlation (P ` 0.001 and P ` 0.01), whereas Kapha has less (P ` 0.02) correlation. It is inferred that for less correlated variables like those of Kapha, a better understanding is required to reach a better consensus.

  18. Gas migration through cement slurries analysis: A comparative laboratory study

    Directory of Open Access Journals (Sweden)

    Arian Velayati

    2015-12-01

    Full Text Available Cementing is an essential part of every drilling operation. Protection of the wellbore from formation fluid invasion is one of the primary tasks of a cement job. Failure in this task results in catastrophic events, such as blow outs. Hence, in order to save the well and avoid risky and operationally difficult remedial cementing, slurry must be optimized to be resistant against gas migration phenomenon. In this paper, performances of the conventional slurries facing gas invasion were reviewed and compared with modified slurry containing special gas migration additive by using fluid migration analyzer device. The results of this study reveal the importance of proper additive utilization in slurry formulations. The rate of gas flow through the slurry in neat cement is very high; by using different types of additives, we observe obvious changes in the performance of the cement system. The rate of gas flow in neat class H cement was reported as 36000 ml/hr while the optimized cement formulation with anti-gas migration and thixotropic agents showed a gas flow rate of 13.8 ml/hr.

  19. Design and Analysis of a Service Migration Framework

    DEFF Research Database (Denmark)

    Saeed, Aamir; Olsen, Rasmus Løvenstein; Pedersen, Jens Myrup

    2013-01-01

    Users often use several heterogeneous devices such as mobile phones, PDAs, tablets, handheld devices, PC and laptops to carry out their tasks. These user devices foster a needs for tasks migration from one device to another device at runtime, making it easier for the user to continue his task...

  20. [Migration and health--from deficiency analysis to diversity vision?].

    Science.gov (United States)

    Weber, A; Hörmann, G

    2011-05-01

    In times of globalization the subjects migration and health are gaining more and more in importance. At the same time, one can observe a discrepancy between published opinions, politically intended messages and scientifically proved evidence. With approximately 15.4 million people with a migration background (this is equivalent to approximately 19% of the German population), migrants perform as an important "customer group" for health care and social security. In 2005, the category migrant background was introduced for the first time by the Federal Statistical Office. This category suggests homogeneity, which in fact is not given. Persons with migration background (including active immigrants, their children and grandchildren, repatriates, foreigners), have to be examined in a differentiated way concerning the consequences that the migration process has on health. Apart from potentially pathogenic influences associated with migration (e. g., ethnicity, national origin, cultural/religious characteristics, migration-related stressors), for example, education, social status, life-style and participation in work and society have to be taken into consideration as important "confounders". In this, a recent sociological approach (sinus migrant milieu) could be useful for socio-medical research and practice. Health-relevant information on migrants results on the one hand from scientific studies primarily designed for this purpose and, on the other hand, from routine data from official health reports. In the interpretation of secondary data, the problem arises that the definition of the target group (migrants) is different in the diverse data sources (for example, Germans, non-Germans, foreigners, migration background) and that important confounders (for example, from socio-cultural milieu) are not included. This may result in, among other things, an under- or overestimation of health risks or even incorrect conclusions. In consideration of these limitations, by means of

  1. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    investigated the relationship between the timing of autumn migration and climatic variations at local and spatial scale. The first three papers focused on speciesspecific analysis. In them I described the age-specific patterns in biometrics, phenology and migration strategies as well as trends...... of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I...... also molt their flight feathers at this location and intraspecific interactions are non-aggressive. The second manuscript investigates whether variations in the timing of migration of wader species at a stopover site in southeast Sweden is influence by local or regional climatic variables...

  2. An analysis of interprovincial migration in Vietnam from 1989 to 2009

    Directory of Open Access Journals (Sweden)

    Le Thi Kim Anh

    2012-12-01

    improvements and public service needs in these areas. Analysis of migration can provide useful information for planning health and social services and for policymaking for national economic development.

  3. An analysis of interprovincial migration in Vietnam from 1989 to 2009.

    Science.gov (United States)

    Anh, Le Thi Kim; Hoang Vu, Lan; Bonfoh, Bassirou; Schelling, Esther

    2012-12-31

    public service needs in these areas. Analysis of migration can provide useful information for planning health and social services and for policymaking for national economic development.

  4. Envisioning migration: mathematics in both experimental analysis and modeling of cell behavior.

    Science.gov (United States)

    Zhang, Elizabeth R; Wu, Lani F; Altschuler, Steven J

    2013-10-01

    The complex nature of cell migration highlights the power and challenges of applying mathematics to biological studies. Mathematics may be used to create model equations that recapitulate migration, which can predict phenomena not easily uncovered by experiments or intuition alone. Alternatively, mathematics may be applied to interpreting complex data sets with better resolution--potentially empowering scientists to discern subtle patterns amid the noise and heterogeneity typical of migrating cells. Iteration between these two methods is necessary in order to reveal connections within the cell migration signaling network, as well as to understand the behavior that arises from those connections. Here, we review recent quantitative analysis and mathematical modeling approaches to the cell migration problem.

  5. Analysis on the Changing Spatial Patterns of China's Migration in 1985-2010

    Science.gov (United States)

    Zan, Q.; Bian, Y.

    2014-11-01

    Based on the data of China's fourth, fifth and sixth population census, taking the seven geographical zone as research units, the Changing Spatial Patterns of China's Migration in 1985-2010 is studied by the means of spatial analysis and mathematical statistics. The empirical results show that: (1) The migration population in China was increasing a lot in 1985-2010, and the main part of it is Provincial migration. (2) The total number of migration, immigration and emigration, the relative proportion of inter provincial and provincial migration have been positively correlated to the regional economic development level. (3) The emigrations from Hong Kong, Macao, Taiwan and overseas mainly moved to East and North China. (4) Central and west of China are the main area where people outflowed from, and most migration population moved to south-eastern coastal areas. The migration in Northeast and northwest of China is still relatively small. The main direction of population migration and flowing is from west to east and from north to south.

  6. Delay Analysis and Formulation Inference of Signalized Intersection for Traffic Congestion Conditions

    Institute of Scientific and Technical Information of China (English)

    刘广萍; 丁建梅

    2004-01-01

    Vehicle delay is an important measure to evaluate the signal timings of signalized intersections.When optimization the signal control parameters, delays of vehicles from all approach directions of an intersection should be considered. Based on the analysis of the vehicle delay on an approach of intersection, directed against the typical condition of a congested intersection-over-saturated condition, the paper has analyzed and inferred the intersection delay dynamic formulation, and has established the relation between intersection delay,the signal timings, vehicle arrival rate and the queue lengths, and that provides useful information for understanding vehicle delay of signalized intersection and for establishing performance index function of signal timing optimization.

  7. Agglomeration, migration, and regional growth: A CGE analysis for Uganda

    OpenAIRE

    Dorosh, Paul; Thurlow, James

    2009-01-01

    "Uganda has experienced rapid economic growth and poverty reduction over the past decade but has failed to significantly improve incomes in its northern regions where prolonged conflict has hindered growth. We consider three strategies to close this regional divide: (1) develop a north-south corridor to encourage regional trade, (2) accelerate growth in the southern capital city and encourage north-south migration, and (3) improve agricultural productivity in rural areas. We examine these str...

  8. AN EMPIRICAL ANALYSIS OF MIGRATION PHENOMEN OF ROMANIAN EDUCATION

    Directory of Open Access Journals (Sweden)

    Luminita Claudia CORBU

    2016-02-01

    Full Text Available In a society based on consumption and acquire the best cost-benefit ratio, the time is one of the few resources valuable in money available to an individual in conjunction with the need to redefine priorities and livelihoods against the background of the interminable crisis global financial is becoming increasingly clear that the educational sphere can not remain unchanged. And this is largely due to population migration.

  9. Fully Bayesian inference for structural MRI: application to segmentation and statistical analysis of T2-hypointensities.

    Science.gov (United States)

    Schmidt, Paul; Schmid, Volker J; Gaser, Christian; Buck, Dorothea; Bührlen, Susanne; Förschler, Annette; Mühlau, Mark

    2013-01-01

    Aiming at iron-related T2-hypointensity, which is related to normal aging and neurodegenerative processes, we here present two practicable approaches, based on Bayesian inference, for preprocessing and statistical analysis of a complex set of structural MRI data. In particular, Markov Chain Monte Carlo methods were used to simulate posterior distributions. First, we rendered a segmentation algorithm that uses outlier detection based on model checking techniques within a Bayesian mixture model. Second, we rendered an analytical tool comprising a Bayesian regression model with smoothness priors (in the form of Gaussian Markov random fields) mitigating the necessity to smooth data prior to statistical analysis. For validation, we used simulated data and MRI data of 27 healthy controls (age: [Formula: see text]; range, [Formula: see text]). We first observed robust segmentation of both simulated T2-hypointensities and gray-matter regions known to be T2-hypointense. Second, simulated data and images of segmented T2-hypointensity were analyzed. We found not only robust identification of simulated effects but also a biologically plausible age-related increase of T2-hypointensity primarily within the dentate nucleus but also within the globus pallidus, substantia nigra, and red nucleus. Our results indicate that fully Bayesian inference can successfully be applied for preprocessing and statistical analysis of structural MRI data.

  10. Coalescent inference for infectious disease: meta-analysis of hepatitis C.

    Science.gov (United States)

    Dearlove, Bethany; Wilson, Daniel J

    2013-03-19

    Genetic analysis of pathogen genomes is a powerful approach to investigating the population dynamics and epidemic history of infectious diseases. However, the theoretical underpinnings of the most widely used, coalescent methods have been questioned, casting doubt on their interpretation. The aim of this study is to develop robust population genetic inference for compartmental models in epidemiology. Using a general approach based on the theory of metapopulations, we derive coalescent models under susceptible-infectious (SI), susceptible-infectious-susceptible (SIS) and susceptible-infectious-recovered (SIR) dynamics. We show that exponential and logistic growth models are equivalent to SI and SIS models, respectively, when co-infection is negligible. Implementing SI, SIS and SIR models in BEAST, we conduct a meta-analysis of hepatitis C epidemics, and show that we can directly estimate the basic reproductive number (R(0)) and prevalence under SIR dynamics. We find that differences in genetic diversity between epidemics can be explained by differences in underlying epidemiology (age of the epidemic and local population density) and viral subtype. Model comparison reveals SIR dynamics in three globally restricted epidemics, but most are better fit by the simpler SI dynamics. In summary, metapopulation models provide a general and practical framework for integrating epidemiology and population genetics for the purposes of joint inference.

  11. CFD Analysis of Migration Mechanism of Source Term Under Severe Accident

    Institute of Scientific and Technical Information of China (English)

    CHEN; Lin-lin; SUN; Xue-ting; JI; Song-tao

    2013-01-01

    The analysis of the migration of source term under severe accident is one of the important aspects of‘Studies on Migration Mechanism of the Source Term under Severe Accident’,which is a significant task of the National Large Advanced PWR Research Program.This research aims at building up a method for analyzing fission product behavior in the containment with CFD code.The effect of PCCS(Passive

  12. Analysis of the migration process of Colombian families in Spain

    Directory of Open Access Journals (Sweden)

    Adelina Gimeno Collado

    2014-04-01

    Full Text Available This study analyses migration as a process centred on the transnational family as told by its main characters: migrants – parents and children –¬ and their families in Colombia. The study is based on the systematic model and methodology of the Grounded Theory approach. The migration process is triggered by a combination of push and pull factors. The pioneers, mainly women, have very diverse profiles. We highlight the difficulty of their first experiences, which they overcome via personal tenacity and external support. Despite the difficulties of the acculturation process, the overall outcome is positive, especially regarding their expectations for their children, who wish to stay in Spain having overcome the initial challenges of adaptation. Children experience their own acculturation process, but there is no conflict between children and parents despite their different acculturation levels. Despite hopes that their integration process Spain would have been better, they are thankful for the support received. Decisions are made and adaptation occurs in the private domain, i.e., the family; however, there is a lack of group awareness or joint social action to improve conditions in the country of origin or to improve integration in the host country.

  13. Migration, distribution and population (stock) structure of shallow-water hake (Merluccius capensis) in the Benguela Current Large Marine Ecosystem inferred using a geostatistical population model

    DEFF Research Database (Denmark)

    Jansen, Teunis; Kristensen, Kasper; Kainge, Paulus Inekela

    2016-01-01

    /nursery areas, through the juvenile phase and the adults' migration to the spawning areas outside/upstream of the nursery areas. This revealed some previously unknown migration patterns and indicated natal homing and the existence of three primary population components in the region, namely the Walvis (central...... (stock) structure. We combined data from multiple demersal trawl surveys from the entire distribution area to estimate growth rate, mortality and spatial and temporal patterns of M. capensis. Analyses were conducted using the geostatistical model GeoPop. The complexity of the model and the amount of data...

  14. Analysis of Migration Flows of the Population of the Vologda Oblast Districts

    Directory of Open Access Journals (Sweden)

    Mikhail Mikhailovich Panov

    2015-09-01

    Full Text Available The article presents the research on the main directions and scale of migration in municipal districts of the Vologda Oblast and considers the main types of migration and the specifics of their statistical accounting. The data by Rosstat served as a basis upon which a general analysis of migration dynamics in the Vologda Oblast districts was carried out; and the article presents its periodization. Three main periods are defined: the “migration shock” of 1991–1999 after the collapse of the Soviet Union, the migration stability of 2000–2008 and the post-crisis rural out-migration that began in 2009 and is increasing year by year. At the same time, gross migration indicators have shown high sensitivity to significant socioeconomic change, in particular, to the economic crises of 1999 and 2008. The article describes the main age and gender characteristics of migrants, it has been determined that the most active migrants are girls aged 15–29, who move from rural to urban settlements. In general, it is the young people aged 15–34 who are most likely to migrate. The author has found out that most of the Vologda Oblast districts are characterized by a higher outflow of the population, which is in some places restrained by a relative migration attractiveness of a number of areas. The author has found out that most districts of the Oblast are characterized by a higher outflow of the population, which is sometimes restrained by relative migration attractiveness of some areas. The author highlights the region’s territories with the highest migration attraction; in the long run they can play the role of “growth points” in the region; these territories comprise Velikoustyugsky and Chagodoshchensky districts, as well as several districts of the central part of the Vologda Oblast – Ust-Kubinsky and Vologodsky. The author also points out the territories that suffered the most from out-migration: Kichmengsko-Gorodetsky, Vashkinsky

  15. Order Under Uncertainty: Robust Differential Expression Analysis Using Probabilistic Models for Pseudotime Inference

    Science.gov (United States)

    Campbell, Kieran R.

    2016-01-01

    Single cell gene expression profiling can be used to quantify transcriptional dynamics in temporal processes, such as cell differentiation, using computational methods to label each cell with a ‘pseudotime’ where true time series experimentation is too difficult to perform. However, owing to the high variability in gene expression between individual cells, there is an inherent uncertainty in the precise temporal ordering of the cells. Pre-existing methods for pseudotime estimation have predominantly given point estimates precluding a rigorous analysis of the implications of uncertainty. We use probabilistic modelling techniques to quantify pseudotime uncertainty and propagate this into downstream differential expression analysis. We demonstrate that reliance on a point estimate of pseudotime can lead to inflated false discovery rates and that probabilistic approaches provide greater robustness and measures of the temporal resolution that can be obtained from pseudotime inference. PMID:27870852

  16. Migration of the Pee Dee River system inferred from ancestral paleochannels underlying the South Carolina Grand Strand and Long Bay inner shelf

    Science.gov (United States)

    Baldwin, W.E.; Morton, R.A.; Putney, T.R.; Katuna, M.P.; Harris, M.S.; Gayes, P.T.; Driscoll, N.W.; Denny, J.F.; Schwab, W.C.

    2006-01-01

    Several generations of the ancestral Pee Dee River system have been mapped beneath the South Carolina Grand Strand coastline and adjacent Long Bay inner shelf. Deep boreholes onshore and high-resolution seismic-reflection data offshore allow for reconstruction of these paleochannels, which formed during glacial lowstands, when the Pee Dee River system incised subaerially exposed coastal-plain and continental-shelf strata. Paleochannel groups, representing different generations of the system, decrease in age to the southwest, where the modern Pee Dee River merges with several coastal-plain tributaries at Winyah Bay, the southern terminus of Long Bay. Positions of the successive generational groups record a regional, southwestward migration of the river system that may have initiated during the late Pliocene. The migration was primarily driven by barrier-island deposition, resulting from the interaction of fluvial and shoreline processes during eustatic highstands. Structurally driven, subsurface paleotopography associated with the Mid-Carolina Platform High has also indirectly assisted in forcing this migration. These results provide a better understanding of the evolution of the region and help explain the lack of mobile sediment on the Long Bay inner shelf. Migration of the river system caused a profound change in sediment supply during the late Pleistocene. The abundant fluvial source that once fed sand-rich barrier islands was cut off and replaced with a limited source, supplied by erosion and reworking of former coastal deposits exposed at the shore and on the inner shelf.

  17. Analysis of a South-South International Migration: Chinese Newcomers in Antananarivo and Dakar

    Directory of Open Access Journals (Sweden)

    Julien Rajaoson

    2015-07-01

    Full Text Available South-South dynamic migrations offer the opportunity to some impoverished countries to establish a Diaspora outside their territorial bases in the perspective to address the issues raised by this phenomenon of extreme poverty from abroad. First of all, it is noteworthy that the volume of South-South dynamic migrations rises to more than 61 million people, versus 62 million people in the South-North dynamic migrations. In other words, this increased propensity to mobility, which represents almost one billion people, nowadays concerns parts of the world that face extreme poverty respectively. The analysis of South-South dynamic migrations will focus our attention on one aspect of globalization that studies and expertise tend to avoid by focusing only on trading, goods and capital services. Apart from these various elements that contribute to globalization, it is necessary to include international migration to make the analysis more comprehensive. To paraphrase the words of the analyst Bruno Hérault, there is a new trend emerging in the context of the occurring exchanges between the two countries. However, according to the authors of the report posted by the UNDP in 2009, migration flows can be understood as a major vector for human development. In this regard, the report in question requires States to remove barriers in order to promote human development and allow human mobility.

  18. Migration between home country and diaspora: an economic analysis.

    Science.gov (United States)

    Hercowitz, Z; Pines, D

    1997-07-01

    "This paper investigates the distribution of a population group between a home country and diaspora, given sequential decision-making regarding migration at the individual level. The home country is attractive to the members of the group, yet their presence there requires a fixed amount of public spending (e.g., on defense). The per-capita tax burden depends then on the size of the domestic population, reflecting a case of ¿fiscal externality'. This results in an inefficient distribution of the group between the home country and the diaspora. Encouraging immigration to the home country is an interest not only of those individuals who are currently in the home country but also of those residing in the diaspora. However, only when the burden of public spending in the home country is large enough do the latter volunteer to bear part of it. Even then, in general, this part is smaller than socially optimal."

  19. Insulation Diagnosis of Service Aged XLPE Power Cables Using Statistical Analysis and Fuzzy Inference

    Institute of Scientific and Technical Information of China (English)

    LIU Fei; JIANG Pingkai; LEI Qingquan; ZHANG Li; SU Wenqun

    2013-01-01

    Cables that have been in service for over 20 years in Shanghai,a city with abundant surface water,failed more frequently and induced different cable accidents.This necessitates researches on the insulation aging state of cables working in special circumstances.We performed multi-parameter tests with samples from about 300 cable lines in Shanghai.The tests included water tree investigation,tensile test,dielectric spectroscopy test,thermogravimetric analysis (TGA),fourier transform infrared spectroscopy (FTIR),and electrical aging test.Then,we carried out regression analysis between every two test parameters.Moreover,through two-sample t-Test and analysis of variance (ANOVA) of each test parameter,we analyzed the influences of cable-laying method and sampling section on the degradation of cable insulation respectively.Furthermore,the test parameters which have strong correlation in the regression analysis or significant differences in the t-Test or ANOVA analysis were determined to be the ones identifying the XLPE cable insulation aging state.The thresholds for distinguishing insulation aging states had been also obtained with the aid of statistical analysis and fuzzy clustering.Based on the fuzzy inference,we established a cable insulation aging diagnosis model using the intensity transfer method.The results of regression analysis indicate that the degradation of cable insulation accelerates as the degree of in-service aging increases.This validates the rule that the increase of microscopic imperfections in solid material enhances the dielectric breakdown strength.The results of the two-sample t-Test and the ANOVA indicate that the direct-buried cables are more sensitive to insulation degradation than duct cables.This confirms that the tensile strength and breakdown strength are reliable functional parameters in cable insulation evaluations.A case study further indicates that the proposed diagnosis model based on the fuzzy inference can reflect the comprehensive

  20. Conditional likelihood inference in a case- cohort design: an application to haplotype analysis.

    Science.gov (United States)

    Saarela, Olli; Kulathinal, Sangita

    2007-01-01

    Under the setting of a case-cohort design, covariate values are ascertained for a smaller subgroup of the original study cohort which typically is a representative sample from a population. Individuals with a specific event outcome are selected to the second stage study group as cases and an additional subsample is selected to act as a control group. We carry out analysis of such a design using conditional likelihood where the likelihood expression is conditioned on the ascertainment to the second stage study group. Such likelihood expression involves the probability of ascertainment which need to be expressed in terms of the model parameters. We present examples of conditional likelihoods for models for categorical response and time-to-event response. We show that the conditional likelihood inference leads to valid estimation of population parameters. Our application considers joint estimation of haplotype-event association parameters and population haplotype frequencies based on SNP genotype data collected under a case-cohort design.

  1. On statistical inference in time series analysis of the evolution of road safety.

    Science.gov (United States)

    Commandeur, Jacques J F; Bijleveld, Frits D; Bergel-Hayat, Ruth; Antoniou, Constantinos; Yannis, George; Papadimitriou, Eleonora

    2013-11-01

    Data collected for building a road safety observatory usually include observations made sequentially through time. Examples of such data, called time series data, include annual (or monthly) number of road traffic accidents, traffic fatalities or vehicle kilometers driven in a country, as well as the corresponding values of safety performance indicators (e.g., data on speeding, seat belt use, alcohol use, etc.). Some commonly used statistical techniques imply assumptions that are often violated by the special properties of time series data, namely serial dependency among disturbances associated with the observations. The first objective of this paper is to demonstrate the impact of such violations to the applicability of standard methods of statistical inference, which leads to an under or overestimation of the standard error and consequently may produce erroneous inferences. Moreover, having established the adverse consequences of ignoring serial dependency issues, the paper aims to describe rigorous statistical techniques used to overcome them. In particular, appropriate time series analysis techniques of varying complexity are employed to describe the development over time, relating the accident-occurrences to explanatory factors such as exposure measures or safety performance indicators, and forecasting the development into the near future. Traditional regression models (whether they are linear, generalized linear or nonlinear) are shown not to naturally capture the inherent dependencies in time series data. Dedicated time series analysis techniques, such as the ARMA-type and DRAG approaches are discussed next, followed by structural time series models, which are a subclass of state space methods. The paper concludes with general recommendations and practice guidelines for the use of time series models in road safety research.

  2. LC-MS/MS based proteomic analysis and functional inference of hypothetical proteins in Desulfovibrio vulgaris.

    Science.gov (United States)

    Zhang, Weiwen; Culley, David E; Gritsenko, Marina A; Moore, Ronald J; Nie, Lei; Scholten, Johannes C M; Petritis, Konstantinos; Strittmatter, Eric F; Camp, David G; Smith, Richard D; Brockman, Fred J

    2006-11-03

    High efficiency capillary liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to examine the proteins extracted from Desulfovibrio vulgaris cells across six treatment conditions. While our previous study provided a proteomic overview of the cellular metabolism based on proteins with known functions [W. Zhang, M.A. Gritsenko, R.J. Moore, D.E. Culley, L. Nie, K. Petritis, E.F. Strittmatter, D.G. Camp II, R.D. Smith, F.J. Brockman, A proteomic view of the metabolism in Desulfovibrio vulgaris determined by liquid chromatography coupled with tandem mass spectrometry, Proteomics 6 (2006) 4286-4299], this study describes the global detection and functional inference for hypothetical D. vulgaris proteins. Using criteria that a given peptide of a protein is identified from at least two out of three independent LC-MS/MS measurements and that for any protein at least two different peptides are identified among the three measurements, 129 open reading frames (ORFs) originally annotated as hypothetical proteins were found to encode expressed proteins. Functional inference for the conserved hypothetical proteins was performed by a combination of several non-homology based methods: genomic context analysis, phylogenomic profiling, and analysis of a combination of experimental information, including peptide detection in cells grown under specific culture conditions and cellular location of the proteins. Using this approach we were able to assign possible functions to 20 conserved hypothetical proteins. This study demonstrated that a combination of proteomics and bioinformatics methodologies can provide verification of the expression of hypothetical proteins and improve genome annotation.

  3. A quorum-sensing factor in vegetative Dictyostelium discoideum cells revealed by quantitative migration analysis.

    Directory of Open Access Journals (Sweden)

    Laurent Golé

    Full Text Available BACKGROUND: Many cells communicate through the production of diffusible signaling molecules that accumulate and once a critical concentration has been reached, can activate or repress a number of target genes in a process termed quorum sensing (QS. In the social amoeba Dictyostelium discoideum, QS plays an important role during development. However little is known about its effect on cell migration especially in the growth phase. METHODS AND FINDINGS: To investigate the role of cell density on cell migration in the growth phase, we use multisite timelapse microscopy and automated cell tracking. This analysis reveals a high heterogeneity within a given cell population, and the necessity to use large data sets to draw reliable conclusions on cell motion. In average, motion is persistent for short periods of time (t ≤ 5 min, but normal diffusive behavior is recovered over longer time periods. The persistence times are positively correlated with the migrated distances. Interestingly, the migrated distance decreases as well with cell density. The adaptation of cell migration to cell density highlights the role of a secreted quorum sensing factor (QSF on cell migration. Using a simple model describing the balance between the rate of QSF generation and the rate of QSF dilution, we were able to gather all experimental results into a single master curve, showing a sharp cell transition between high and low motile behaviors with increasing QSF. CONCLUSION: This study unambiguously demonstrates the central role played by QSF on amoeboid motion in the growth phase.

  4. TMA Navigator: Network inference, patient stratification and survival analysis with tissue microarray data.

    Science.gov (United States)

    Lubbock, Alexander L R; Katz, Elad; Harrison, David J; Overton, Ian M

    2013-07-01

    Tissue microarrays (TMAs) allow multiplexed analysis of tissue samples and are frequently used to estimate biomarker protein expression in tumour biopsies. TMA Navigator (www.tmanavigator.org) is an open access web application for analysis of TMA data and related information, accommodating categorical, semi-continuous and continuous expression scores. Non-biological variation, or batch effects, can hinder data analysis and may be mitigated using the ComBat algorithm, which is incorporated with enhancements for automated application to TMA data. Unsupervised grouping of samples (patients) is provided according to Gaussian mixture modelling of marker scores, with cardinality selected by Bayesian information criterion regularization. Kaplan-Meier survival analysis is available, including comparison of groups identified by mixture modelling using the Mantel-Cox log-rank test. TMA Navigator also supports network inference approaches useful for TMA datasets, which often constitute comparatively few markers. Tissue and cell-type specific networks derived from TMA expression data offer insights into the molecular logic underlying pathophenotypes, towards more effective and personalized medicine. Output is interactive, and results may be exported for use with external programs. Private anonymous access is available, and user accounts may be generated for easier data management.

  5. Bayesian Inference for Neural Electromagnetic Source Localization: Analysis of MEG Visual Evoked Activity

    Energy Technology Data Exchange (ETDEWEB)

    George, J.S.; Schmidt, D.M.; Wood, C.C.

    1999-02-01

    We have developed a Bayesian approach to the analysis of neural electromagnetic (MEG/EEG) data that can incorporate or fuse information from other imaging modalities and addresses the ill-posed inverse problem by sarnpliig the many different solutions which could have produced the given data. From these samples one can draw probabilistic inferences about regions of activation. Our source model assumes a variable number of variable size cortical regions of stimulus-correlated activity. An active region consists of locations on the cortical surf ace, within a sphere centered on some location in cortex. The number and radi of active regions can vary to defined maximum values. The goal of the analysis is to determine the posterior probability distribution for the set of parameters that govern the number, location, and extent of active regions. Markov Chain Monte Carlo is used to generate a large sample of sets of parameters distributed according to the posterior distribution. This sample is representative of the many different source distributions that could account for given data, and allows identification of probable (i.e. consistent) features across solutions. Examples of the use of this analysis technique with both simulated and empirical MEG data are presented.

  6. Influence of Changes in Political Barriers and of Geographic Distance on Kinship Inferred from Surnames and Migration Data in Olivenza, Spain, and Surrounding Portuguese Areas.

    Science.gov (United States)

    Román-Busto, J

    2015-04-01

    The existing relationship between human populations is a function of their migratory and genetic exchange, which will be inversely proportional to the distance separating them. The effect of geographic distance on population structure may be estimated by means of isonymic methods that use information on the surnames present in a territory as an approximation to the distribution of allele frequencies. The objective of this study was to analyze whether the 1801 modification of the political border in an area surrounding the town of Olivenza, which experienced a change of sovereignty from Portugal to Spain, has had a noticeable influence on the migration pattern and isolation by distance in that region. For this purpose, data from marriage records of Olivenza and the neighboring Portuguese municipalities of Alandroal, Juromenha, Elvas, Vila Boim (and Terrugem), Terena, Monsaraz, and Vila Viçosa were analyzed. Rates of diversity and inbreeding coefficients were determined to analyze the population structure before (1775-1801) and after (1802-1825) the change of domain. The results show that after the border modification the migration matrices changed differently according to sex, therefore altering the relationship between the various localities of the territory. In Olivenza inbreeding declined slightly and surnames became more heterogeneous. Moreover, after the change of domain the isolation-by-distance models illustrate a temporal reduction in the relative weight of geographical distance on interpopulation kinship. The political border acted as a factor in population differentiation in the Iberian Peninsula (Spain and Portugal).

  7. DESCRIPTIVE ANALYSIS OF THE INTERNATIONAL MIGRATION PHENOMENON IN ROMANIA BETWEEN 1991 AND 2008

    Directory of Open Access Journals (Sweden)

    Bac Dorin Paul

    2011-07-01

    Full Text Available Migration represented and represents a very important phenomenon at global level, taking into consideration besides its demographic implications, its extremely diverse implications such as socio-economic, socio-cultural, territorial, or environmental. This represents, probably, the main reason why the research on migration is interdisciplinary, having strong connections with sociology, political sciences, history, economics, geography, demography, psychology, or low, among others. All these disciplines target different aspects of population migration, and a proper comprehension of the phenomenon implies a contribution from the part of all of them. Although migration represents a phenomenon manifested since ancient times, it has never been such an universal or significant phenomenon from the socio-economical or political perspective, as it is in present times. International migration has both a negative and positive impact on both provider and receiving countries, in general playing a very important role in the structure and dimension of the population of a country. Romania is not an exception to the previously expressed statement; furthermore, after the fall of the communist regime, migration became for Romania one of the most important socio-economical phenomena. The present paper aims at analyzing in a descriptive manner the international migration phenomenon in Romania between 1991 and 2008, from quantitative perspective. Based on data identified in the "Statistical Yearbook of Romania - 2008 and 2009 editions - the analysis revealed the fact that both immigration and emigration flows registered oscillatory evolutions in the analysed period, but the general trend of immigration was of increasing, while the one of emigration was of decreasing. Immigration was dominated by the presence of males, of persons aged between 26 and 40 and of persons coming from the Republic of Moldova. On the other side, in the case of emigration the significant

  8. All Source Analysis System (ASAS): Migration from VAX to Alpha AXP computer systems

    Science.gov (United States)

    Sjoholm-Sierchio, Michael J.; Friedman, Steven Z. (Editor)

    1994-01-01

    The Jet Propulsion Laboratory's (JPL's) experience migrating existing VAX applications to Digital Equipment Corporation's new Alpha AXP processor is covered. The rapid development approach used during the 10-month period required to migrate the All Source Analysis System (ASAS), 1.5 million lines of FORTRAN, C, and Ada code, is also covered. ASAS, an automated tactical intelligence system, was developed by the Jet Propulsion Laboratory for the U. S. Army. Other benefits achieved as a result of the significant performance improvements provided by Alpha AXP platform are also described.

  9. Bayesian analysis of time-series data under case-crossover designs: posterior equivalence and inference.

    Science.gov (United States)

    Li, Shi; Mukherjee, Bhramar; Batterman, Stuart; Ghosh, Malay

    2013-12-01

    Case-crossover designs are widely used to study short-term exposure effects on the risk of acute adverse health events. While the frequentist literature on this topic is vast, there is no Bayesian work in this general area. The contribution of this paper is twofold. First, the paper establishes Bayesian equivalence results that require characterization of the set of priors under which the posterior distributions of the risk ratio parameters based on a case-crossover and time-series analysis are identical. Second, the paper studies inferential issues under case-crossover designs in a Bayesian framework. Traditionally, a conditional logistic regression is used for inference on risk-ratio parameters in case-crossover studies. We consider instead a more general full likelihood-based approach which makes less restrictive assumptions on the risk functions. Formulation of a full likelihood leads to growth in the number of parameters proportional to the sample size. We propose a semi-parametric Bayesian approach using a Dirichlet process prior to handle the random nuisance parameters that appear in a full likelihood formulation. We carry out a simulation study to compare the Bayesian methods based on full and conditional likelihood with the standard frequentist approaches for case-crossover and time-series analysis. The proposed methods are illustrated through the Detroit Asthma Morbidity, Air Quality and Traffic study, which examines the association between acute asthma risk and ambient air pollutant concentrations.

  10. Genetic Mapping by Bulk Segregant Analysis in Drosophila: Experimental Design and Simulation-Based Inference.

    Science.gov (United States)

    Pool, John E

    2016-11-01

    Identifying the genomic regions that underlie complex phenotypic variation is a key challenge in modern biology. Many approaches to quantitative trait locus mapping in animal and plant species suffer from limited power and genomic resolution. Here, I investigate whether bulk segregant analysis (BSA), which has been successfully applied for yeast, may have utility in the genomic era for trait mapping in Drosophila (and other organisms that can be experimentally bred in similar numbers). I perform simulations to investigate the statistical signal of a quantitative trait locus (QTL) in a wide range of BSA and introgression mapping (IM) experiments. BSA consistently provides more accurate mapping signals than IM (in addition to allowing the mapping of multiple traits from the same experimental population). The performance of BSA and IM is maximized by having multiple independent crosses, more generations of interbreeding, larger numbers of breeding individuals, and greater genotyping effort, but is less affected by the proportion of individuals selected for phenotypic extreme pools. I also introduce a prototype analysis method for simulation-based inference for BSA mapping (SIBSAM). This method identifies significant QTL and estimates their genomic confidence intervals and relative effect sizes. Importantly, it also tests whether overlapping peaks should be considered as two distinct QTL. This approach will facilitate improved trait mapping in Drosophila and other species for which hundreds or thousands of offspring (but not millions) can be studied.

  11. Internationalization and migration pressure.

    Science.gov (United States)

    Kultalahti, O

    1994-01-01

    The author first develops the concept of migration pressure, which is defined as the growth in the number of people wishing to migrate and the barriers preventing them from so doing. Both macro- and micro-level factors affecting migration pressure are identified. Historical trends in migration pressure in Finland are then discussed. The author then applies this concept to the analysis of current Finnish migration trends. The primary focus is on international migration.

  12. The Impact of the Great Migration on Mortality of African Americans: Evidence from the Deep South

    Science.gov (United States)

    Black, Dan A.; Sanders, Seth G.; Taylor, Evan J.

    2015-01-01

    The Great Migration—the massive migration of African Americans out of the rural South to largely urban locations in the North, Midwest, and West—was a landmark event in U.S. history. Our paper shows that this migration increased mortality of African Americans born in the early twentieth century South. This inference comes from an analysis that uses proximity of birthplace to railroad lines as an instrument for migration. PMID:26345146

  13. Underlying mechanism of precursory activity from analysis of upward earthquake migration

    Directory of Open Access Journals (Sweden)

    O. A. Molchanov

    2011-01-01

    Full Text Available In this paper we analyse the upward earthquake hypocentral migration in the ten known subduction zones and discuss a possible mechanism of such migration. The total time of the migration appears to range from 2.5 to 10 years. It leads to the estimation of the average velocity Vz~ 60−300 km yr−1. It probably corresponds to the movement of the forcing agent like stress or deformation wave from depths of the upper mantle (600–700 km to the level of the lithosphere with subsequent initiation of fluid migration inside the crust to trigger shallow earthquakes. Averaged over all zones upward migration travel time is about 5 years (< Vz > ≈120 km yr−1 that coincides approximately with the period of characteristic temperature variation (El Nino and crustal seismic periodicity in the Pacific region. These findings are helpful for the study of the seismic precursors and analysis of earthquake triggering.

  14. Inferring domain-domain interactions from protein-protein interactions with formal concept analysis.

    Directory of Open Access Journals (Sweden)

    Susan Khor

    Full Text Available Identifying reliable domain-domain interactions will increase our ability to predict novel protein-protein interactions, to unravel interactions in protein complexes, and thus gain more information about the function and behavior of genes. One of the challenges of identifying reliable domain-domain interactions is domain promiscuity. Promiscuous domains are domains that can occur in many domain architectures and are therefore found in many proteins. This becomes a problem for a method where the score of a domain-pair is the ratio between observed and expected frequencies because the protein-protein interaction network is sparse. As such, many protein-pairs will be non-interacting and domain-pairs with promiscuous domains will be penalized. This domain promiscuity challenge to the problem of inferring reliable domain-domain interactions from protein-protein interactions has been recognized, and a number of work-arounds have been proposed. This paper reports on an application of Formal Concept Analysis to this problem. It is found that the relationship between formal concepts provides a natural way for rare domains to elevate the rank of promiscuous domain-pairs and enrich highly ranked domain-pairs with reliable domain-domain interactions. This piggybacking of promiscuous domain-pairs onto less promiscuous domain-pairs is possible only with concept lattices whose attribute-labels are not reduced and is enhanced by the presence of proteins that comprise both promiscuous and rare domains.

  15. A probabilistic framework for microarray data analysis: fundamental probability models and statistical inference.

    Science.gov (United States)

    Ogunnaike, Babatunde A; Gelmi, Claudio A; Edwards, Jeremy S

    2010-05-21

    Gene expression studies generate large quantities of data with the defining characteristic that the number of genes (whose expression profiles are to be determined) exceed the number of available replicates by several orders of magnitude. Standard spot-by-spot analysis still seeks to extract useful information for each gene on the basis of the number of available replicates, and thus plays to the weakness of microarrays. On the other hand, because of the data volume, treating the entire data set as an ensemble, and developing theoretical distributions for these ensembles provides a framework that plays instead to the strength of microarrays. We present theoretical results that under reasonable assumptions, the distribution of microarray intensities follows the Gamma model, with the biological interpretations of the model parameters emerging naturally. We subsequently establish that for each microarray data set, the fractional intensities can be represented as a mixture of Beta densities, and develop a procedure for using these results to draw statistical inference regarding differential gene expression. We illustrate the results with experimental data from gene expression studies on Deinococcus radiodurans following DNA damage using cDNA microarrays.

  16. Obesity, hypertension, and migration: a meta-analysis of populations of the South Asian diaspora.

    Science.gov (United States)

    Madrigal, Lorena; Brady, Jeffrey; Raxter, Michelle; Ruiz, Ernesto; Otarola, Flory; Blell, Mwenza

    2011-02-01

    The effects of migration on human health have been a topic of interest for demographers and human biologists. Even if migrants to a new region achieve a higher standard of living in their new place of residence, their improved living conditions may not be associated with better health. Part of the difficulty of understanding the health consequences of migration is the complications in trying to control for variables that may affect health, such as gender, age, and urban or rural environment of migrants and nonmigrants. In this paper we report results of a meta-analysis of the body mass index (BMI) and blood pressure (BP) of people of South Asian descent, by comparing nonmigrants who inhabit the subcontinent, with migrants who moved to various places around the globe. Our results indicate that BMI almost always increases to a significant level upon migration and that an increase in BMI is most pronounced in female migrants. Our results also show that BP does not always increase in migrant communities and that it is actually lower in some migrant samples than it is in comparable nonmigrant groups. Therefore, our results show that BP and the BMI do not behave in the same manner following a migration event. We propose that the BMI changes experienced by migrants are likely to reflect different activity levels and diet in the new homeland. However, the BP changes experienced by migrants are likely to reflect stress broadly defined. Such stress may be increased or decreased, depending on the specific migration experience. We propose that the BMI and BP measure two different dimensions of the migration experience.

  17. Vertical Migrating and Cluster Analysis of Soil Mesofauna at Dongying Halophytes Garden in Yellow River Delta

    Institute of Scientific and Technical Information of China (English)

    He Fu-xia; Xie Tong-yin; Xie Gui-lin; Fu Rong-shu

    2014-01-01

    For the first time, we used Tullgren method made a study on vertical migrating and cluster analysis of the soil mesofauna in Dongying Halophytes Garden in the Yellow River Delta (YRD), Shandong Province. The results showed that the soil mesofauna tended to gather on soil surface in most samples at most times, but the vertical migrating greatly varied in different seasons or environment conditions. Acari was the dominant group. The index of diversity of the soil fauna was correlated with the index of evenness. The Acari's number of individuals infected other species and numbers. Dominant group-Acari made greater contribution to the result of cluster analysis, and there were significant differences between communities in different habitats by cluster analysis with both Bray-Curtis and Jaccard similarity coefficient.

  18. Disclosure-Protected Inference with Linked Microdata Using a Remote Analysis Server

    Directory of Open Access Journals (Sweden)

    Chipperfield James O.

    2014-03-01

    Full Text Available Large amounts of microdata are collected by data custodians in the form of censuses and administrative records. Often, data custodians will collect different information on the same individual. Many important questions can be answered by linking microdata collected by different data custodians. For this reason, there is very strong demand from analysts, within government, business, and universities, for linked microdata. However, many data custodians are legally obliged to ensure the risk of disclosing information about a person or organisation is acceptably low. Different authors have considered the problem of how to facilitate reliable statistical inference from analysis of linked microdata while ensuring that the risk of disclosure is acceptably low. This article considers the problem from the perspective of an Integrating Authority that, by definition, is trusted to link the microdata and to facilitate analysts’ access to the linked microdata via a remote server, which allows analysts to fit models and view the statistical output without being able to observe the underlying linked microdata. One disclosure risk that must be managed by an Integrating Authority is that one data custodian may use the microdata it supplied to the Integrating Authority and statistical output released from the remote server to disclose information about a person or organisation that was supplied by the other data custodian. This article considers analysis of only binary variables. The utility and disclosure risk of the proposed method are investigated both in a simulation and using a real example. This article shows that some popular protections against disclosure (dropping records, rounding regression coefficients or imposing restrictions on model selection can be ineffective in the above setting.

  19. Scalable distributed service migration via Complex Networks Analysis

    CERN Document Server

    Pantazopoulos, Panagiotis; Stavrakakis, Ioannis

    2010-01-01

    With social networking sites providing increasingly richer context, User-Centric Service (UCS) creation is expected to explode following a similar success path to User-Generated Content. One of the major challenges in this emerging highly user-centric networking paradigm is how to make these exploding in numbers yet, individually, of vanishing demand services available in a cost-effective manner. Of prime importance to the latter (and focus of this paper) is the determination of the optimal location for hosting a UCS. Taking into account the particular characteristics of UCS, we formulate the problem as a facility location problem and devise a distributed and highly scalable heuristic solution to it. Key to the proposed approach is the introduction of a novel metric drawing on Complex Network Analysis. Given a current location of UCS, this metric helps to a) identify a small subgraph of nodes with high capacity to act as service demand concentrators; b) project on them a reduced yet accurate view of the globa...

  20. Globalization, Development and International Migration: A Cross-National Analysis of Less-Developed Countries, 1970-2000

    Science.gov (United States)

    Sanderson, Matthew R.; Kentor, Jeffrey D.

    2009-01-01

    It is widely argued that globalization and economic development are associated with international migration. However, these relationships have not been tested empirically. We use a cross-national empirical analysis to assess the impact of global and national factors on international migration from less-developed countries. An interdisciplinary…

  1. Labor Migration from Ukraine to the EU: an Analysis of Characteristics and Consequences

    Directory of Open Access Journals (Sweden)

    Bezrukova Nataliya V.

    2016-02-01

    Full Text Available The article is aimed at analyzing characteristics of labor migration from Ukraine to the European Union and evaluating the possible consequences of this process, as well as determining the future development trends in terms of emigration from Ukraine. The main directions of labor migration from Ukraine have been examined. An estimation of the volume of labor migration has been provided. Data about the socio-demographic characteristics of migrants have been presented. It is specified that the process of emigration has both positive and negative consequences for our country. Particular attention is paid to the analysis of employment settings of migrants in the Member States of the European Union. The main causes of emigration from Ukraine, among which both unemployment and low wages, have been allocated. The authors prove that the average monthly salary of Ukrainian migrants in the EU Member States is much higher than in Ukraine. On the basis of the carried out study has been concluded that labor migration from Ukraine to the EU has important socio-economic importance to our State. At the same time, signing of the Association agreement between Ukraine, on the one hand, and the European Union, the European Atomic Energy Community and their Member States, on the other hand, as well as introduction of a visa-free regime, will contribute to an increase in the number of labor migrants.

  2. A Macroscopic Mathematical Model for Cell Migration Assays Using a Real-Time Cell Analysis.

    Science.gov (United States)

    Di Costanzo, Ezio; Ingangi, Vincenzo; Angelini, Claudia; Carfora, Maria Francesca; Carriero, Maria Vincenza; Natalini, Roberto

    Experiments of cell migration and chemotaxis assays have been classically performed in the so-called Boyden Chambers. A recent technology, xCELLigence Real Time Cell Analysis, is now allowing to monitor the cell migration in real time. This technology measures impedance changes caused by the gradual increase of electrode surface occupation by cells during the course of time and provide a Cell Index which is proportional to cellular morphology, spreading, ruffling and adhesion quality as well as cell number. In this paper we propose a macroscopic mathematical model, based on advection-reaction-diffusion partial differential equations, describing the cell migration assay using the real-time technology. We carried out numerical simulations to compare simulated model dynamics with data of observed biological experiments on three different cell lines and in two experimental settings: absence of chemotactic signals (basal migration) and presence of a chemoattractant. Overall we conclude that our minimal mathematical model is able to describe the phenomenon in the real time scale and numerical results show a good agreement with the experimental evidences.

  3. Analysis of aerospace nickel-cadmium battery cells. [cadmium migration as seen by scanning electron microscopy and metallographic analysis

    Science.gov (United States)

    Eliason, R. R.

    1977-01-01

    Various steps followed in analyzing the electrolyte, separator, and electrodes are reviewed. Specific emphasis is given to scanning electron microscopic and metallographic analysis of the plates. Cadmium migration is defined, its effects and causes are examined, and methods for its reduction in cells are suggested.

  4. Application of the Gini correlation coefficient to infer regulatory relationships in transcriptome analysis.

    Science.gov (United States)

    Ma, Chuang; Wang, Xiangfeng

    2012-09-01

    One of the computational challenges in plant systems biology is to accurately infer transcriptional regulation relationships based on correlation analyses of gene expression patterns. Despite several correlation methods that are applied in biology to analyze microarray data, concerns regarding the compatibility of these methods with the gene expression data profiled by high-throughput RNA transcriptome sequencing (RNA-Seq) technology have been raised. These concerns are mainly due to the fact that the distribution of read counts in RNA-Seq experiments is different from that of fluorescence intensities in microarray experiments. Therefore, a comprehensive evaluation of the existing correlation methods and, if necessary, introduction of novel methods into biology is appropriate. In this study, we compared four existing correlation methods used in microarray analysis and one novel method called the Gini correlation coefficient on previously published microarray-based and sequencing-based gene expression data in Arabidopsis (Arabidopsis thaliana) and maize (Zea mays). The comparisons were performed on more than 11,000 regulatory relationships in Arabidopsis, including 8,929 pairs of transcription factors and target genes. Our analyses pinpointed the strengths and weaknesses of each method and indicated that the Gini correlation can compensate for the shortcomings of the Pearson correlation, the Spearman correlation, the Kendall correlation, and the Tukey's biweight correlation. The Gini correlation method, with the other four evaluated methods in this study, was implemented as an R package named rsgcc that can be utilized as an alternative option for biologists to perform clustering analyses of gene expression patterns or transcriptional network analyses.

  5. A preliminary analysis on metaheuristics methods applied to the Haplotype Inference Problem

    CERN Document Server

    Di Gaspero, Luca

    2007-01-01

    Haplotype Inference is a challenging problem in bioinformatics that consists in inferring the basic genetic constitution of diploid organisms on the basis of their genotype. This information allows researchers to perform association studies for the genetic variants involved in diseases and the individual responses to therapeutic agents. A notable approach to the problem is to encode it as a combinatorial problem (under certain hypotheses, such as the pure parsimony criterion) and to solve it using off-the-shelf combinatorial optimization techniques. The main methods applied to Haplotype Inference are either simple greedy heuristic or exact methods (Integer Linear Programming, Semidefinite Programming, SAT encoding) that, at present, are adequate only for moderate size instances. We believe that metaheuristic and hybrid approaches could provide a better scalability. Moreover, metaheuristics can be very easily combined with problem specific heuristics and they can also be integrated with tree-based search techn...

  6. CARRIE web service: automated transcriptional regulatory network inference and interactive analysis.

    Science.gov (United States)

    Haverty, Peter M; Frith, Martin C; Weng, Zhiping

    2004-07-01

    We present an intuitive and interactive web service for CARRIE (Computational Ascertainment of Regulatory Relationships Inferred from Expression). CARRIE is a computational method that analyzes microarray and promoter sequence data to infer a transcriptional regulatory network from the response to a specific stimulus. This service displays an interactive graph of the inferred network and provides easy access to the evidence for the involvement of each gene in the network. We provide functionality to include network data in KEGG XML (KGML) format in this graph. Our service also provides Gene Ontology annotation to aid the user in forming hypotheses about the role of each gene in the cellular response. The CARRIE web service is freely available at http://zlab.bu.edu/CARRIE-web.

  7. Inferring biological tasks using Pareto analysis of high-dimensional data.

    Science.gov (United States)

    Hart, Yuval; Sheftel, Hila; Hausser, Jean; Szekely, Pablo; Ben-Moshe, Noa Bossel; Korem, Yael; Tendler, Avichai; Mayo, Avraham E; Alon, Uri

    2015-03-01

    We present the Pareto task inference method (ParTI; http://www.weizmann.ac.il/mcb/UriAlon/download/ParTI) for inferring biological tasks from high-dimensional biological data. Data are described as a polytope, and features maximally enriched closest to the vertices (or archetypes) allow identification of the tasks the vertices represent. We demonstrate that human breast tumors and mouse tissues are well described by tetrahedrons in gene expression space, with specific tumor types and biological functions enriched at each of the vertices, suggesting four key tasks.

  8. Use of Bayesian Inference in Crystallographic Structure Refinement via Full Diffraction Profile Analysis

    Science.gov (United States)

    Fancher, Chris M.; Han, Zhen; Levin, Igor; Page, Katharine; Reich, Brian J.; Smith, Ralph C.; Wilson, Alyson G.; Jones, Jacob L.

    2016-01-01

    A Bayesian inference method for refining crystallographic structures is presented. The distribution of model parameters is stochastically sampled using Markov chain Monte Carlo. Posterior probability distributions are constructed for all model parameters to properly quantify uncertainty by appropriately modeling the heteroskedasticity and correlation of the error structure. The proposed method is demonstrated by analyzing a National Institute of Standards and Technology silicon standard reference material. The results obtained by Bayesian inference are compared with those determined by Rietveld refinement. Posterior probability distributions of model parameters provide both estimates and uncertainties. The new method better estimates the true uncertainties in the model as compared to the Rietveld method. PMID:27550221

  9. Time-frequency analysis of migrating zooplankton in the Terra Nova Bay polynya (Ross Sea, Antarctica)

    Science.gov (United States)

    Picco, Paola; Schiano, M. Elisabetta; Pensieri, Sara; Bozzano, Roberto

    2017-02-01

    An upward-looking 150 kHz narrow-band Acoustic Doppler Current profiler was operated in Terra Nova Bay (Ross Sea, Antarctica) from 5 February 2000 to 16 January 2001 to monitor marine currents. The instrument sampled the upper 160 m of the water column with a time resolution of 1 h. Although the experimental setup was not specifically designed to assess zooplankton and fish distributions and behaviour, the Acoustic Doppler Current Profiler ancillary data provided useful information regarding the diel vertical migration of these acoustic targets. A time frequency analysis of the mean backscatter strength time series was conducted using a 240 h-wide window with a 1 day step. Assuming that the 24 h period peak is associated with zooplankton diel vertical migration, the amplitude of the power spectral energy on this band was extracted from each spectrum and the time series of amplitudes was analysed. The migration signal was very weak during summer, December to January, but was evident at the beginning and end of the polar night. Interestingly, the results indicated four "migratory blooms," the first at the end of August and the others approximately every three weeks subsequently, ending at the end of October. The daily migration was found to have a good relation with the solar cycle, while it was apparently uncorrelated with the moon phase. Migration patterns in the upper and the lower ocean layers displayed significant differences. Due to the lack of contemporary in-situ net samples, the results are more qualitative than quantitative; nonetheless, they demonstrate the validity of the method to extract relevant information even when applied to data obtained from a non-devoted low-resolution system. This may be of particular interest in polar areas where it is difficult to perform continuous biological monitoring but where a long time series of Acoustic Doppler Current profiler data is available.

  10. Uncertainty Reduction using Bayesian Inference and Sensitivity Analysis: A Sequential Approach to the NASA Langley Uncertainty Quantification Challenge

    Science.gov (United States)

    Sankararaman, Shankar

    2016-01-01

    This paper presents a computational framework for uncertainty characterization and propagation, and sensitivity analysis under the presence of aleatory and epistemic un- certainty, and develops a rigorous methodology for efficient refinement of epistemic un- certainty by identifying important epistemic variables that significantly affect the overall performance of an engineering system. The proposed methodology is illustrated using the NASA Langley Uncertainty Quantification Challenge (NASA-LUQC) problem that deals with uncertainty analysis of a generic transport model (GTM). First, Bayesian inference is used to infer subsystem-level epistemic quantities using the subsystem-level model and corresponding data. Second, tools of variance-based global sensitivity analysis are used to identify four important epistemic variables (this limitation specified in the NASA-LUQC is reflective of practical engineering situations where not all epistemic variables can be refined due to time/budget constraints) that significantly affect system-level performance. The most significant contribution of this paper is the development of the sequential refine- ment methodology, where epistemic variables for refinement are not identified all-at-once. Instead, only one variable is first identified, and then, Bayesian inference and global sensi- tivity calculations are repeated to identify the next important variable. This procedure is continued until all 4 variables are identified and the refinement in the system-level perfor- mance is computed. The advantages of the proposed sequential refinement methodology over the all-at-once uncertainty refinement approach are explained, and then applied to the NASA Langley Uncertainty Quantification Challenge problem.

  11. Inference of Well-Typings for Logic Programs with Application to Termination Analysis

    DEFF Research Database (Denmark)

    Bruynooghe, M.; Gallagher, John Patrick; Humbeeck, W. Van

    2005-01-01

    by the user, or automatically generated monomorphic types describing the success set of predicates. The latter types are less precise and result in weaker termination conditions than those obtained from declared types. Our type inference procedure involves solving set constraints generated from the program...

  12. Hierarchical modeling and inference in ecology: The analysis of data from populations, metapopulations and communities

    Science.gov (United States)

    Royle, J. Andrew; Dorazio, Robert M.

    2008-01-01

    A guide to data collection, modeling and inference strategies for biological survey data using Bayesian and classical statistical methods. This book describes a general and flexible framework for modeling and inference in ecological systems based on hierarchical models, with a strict focus on the use of probability models and parametric inference. Hierarchical models represent a paradigm shift in the application of statistics to ecological inference problems because they combine explicit models of ecological system structure or dynamics with models of how ecological systems are observed. The principles of hierarchical modeling are developed and applied to problems in population, metapopulation, community, and metacommunity systems. The book provides the first synthetic treatment of many recent methodological advances in ecological modeling and unifies disparate methods and procedures. The authors apply principles of hierarchical modeling to ecological problems, including * occurrence or occupancy models for estimating species distribution * abundance models based on many sampling protocols, including distance sampling * capture-recapture models with individual effects * spatial capture-recapture models based on camera trapping and related methods * population and metapopulation dynamic models * models of biodiversity, community structure and dynamics.

  13. Prestack migration velocity analysis based on simplifi ed two-parameter moveout equation

    Institute of Scientific and Technical Information of China (English)

    Chen Hai-Feng; Li Xiang-Yang; Qian Zhong-Ping; Song Jian-Jun; Zhao Gui-Ling

    2016-01-01

    Stacking velocityVC2, vertical velocity ratioγ0, effective velocity ratioγef, and anisotropic parameterχef are correlated in the PS-converted-wave (PS-wave) anisotropic prestack Kirchhoff time migration (PKTM) velocity model and are thus difficult to independently determine. We extended the simplified two-parameter (stacking velocity VC2 and anisotropic parameterkef) moveout equation from stacking velocity analysis to PKTM velocity model updating and formed a new four-parameter (stacking velocityVC2, vertical velocity ratioγ0, effective velocity ratioγef, and anisotropic parameterkef) PS-wave anisotropic PKTM velocity model updating and processfl ow based on the simplifi ed two-parameter moveout equation. In the proposed method, first, the PS-wave two-parameter stacking velocity is analyzed to obtain the anisotropic PKTM initial velocity and anisotropic parameters; then, the velocity and anisotropic parameters are corrected by analyzing the residual moveout on common imaging point gathers after prestack time migration. The vertical velocity ratioγ0 of the prestack time migration velocity model is obtained with an appropriate method utilizing the P- and PS-wave stacked sections after level calibration. The initial effective velocity ratioγef is calculated using the Thomsen (1999) equation in combination with the P-wave velocity analysis; ultimately, the final velocity model of the effective velocity ratioγef is obtained by percentage scanning migration. This method simplifi es the PS-wave parameter estimation in high-quality imaging, reduces the uncertainty of multiparameter estimations, and obtains good imaging results in practice.

  14. Inferring species richness and turnover by statistical multiresolution texture analysis of satellite imagery.

    Directory of Open Access Journals (Sweden)

    Matteo Convertino

    richness, or [Formula: see text] diversity, based on the Shannon entropy of pixel intensity.To test our approach, we specifically use the green band of Landsat images for a water conservation area in the Florida Everglades. We validate our predictions against data of species occurrences for a twenty-eight years long period for both wet and dry seasons. Our method correctly predicts 73% of species richness. For species turnover, the newly proposed KL divergence prediction performance is near 100% accurate. This represents a significant improvement over the more conventional Shannon entropy difference, which provides 85% accuracy. Furthermore, we find that changes in soil and water patterns, as measured by fluctuations of the Shannon entropy for the red and blue bands respectively, are positively correlated with changes in vegetation. The fluctuations are smaller in the wet season when compared to the dry season. CONCLUSIONS/SIGNIFICANCE: Texture-based statistical multiresolution image analysis is a promising method for quantifying interseasonal differences and, consequently, the degree to which vegetation, soil, and water patterns vary. The proposed automated method for quantifying species richness and turnover can also provide analysis at higher spatial and temporal resolution than is currently obtainable from expensive monitoring campaigns, thus enabling more prompt, more cost effective inference and decision making support regarding anomalous variations in biodiversity. Additionally, a matrix-based visualization of the statistical multiresolution analysis is presented to facilitate both insight and quick recognition of anomalous data.

  15. Southern East Siberia PlioceneeQuaternary faults:Database, analysis and inference

    Institute of Scientific and Technical Information of China (English)

    Oksana V. Lunina; Riccardo Caputo; Anton A. Gladkov; Andrey S. Gladkov

    2014-01-01

    This paper presents the first release of an Informational System (IS) devoted to the systematic collection of all available data relating to PlioceneeQuaternary faults in southern East Siberia, their critical analysis and their seismotectonic parameterization. The final goal of this project is to form a new base for improving the assessment of seismic hazard and other natural processes associated with crustal defor-mation. The presented IS has been exploited to create a relational database of active and conditionally active faults in southern East Siberia (between 100º-114º E and 50º-57ºN) whose central sector is characterized by the highly seismic Baikal rift zone. The information within the database for each fault segment is organized as distinct but intercorrelated sections (tables, texts and pictures, etc.) and can be easily visualized as HTML pages in offline browsing. The preliminary version of the database distributed free on disk already highlights the general fault pattern showing that the Holocene and historical activity is quite uniform and dominated by NEeSW and nearly EeW trending faults;the former with a prevailing dip-slip normal kinematics, while the latter structures are left-lateral strike-slip and oblique-slip (with different proportion of left-lateral and normal fault slip components). These faults are mainly concen-trated along the borders of the rift basins and are the main sources of moderate-to-strong (M≧5.5) earthquakes on the southern sectors of East Siberia in recent times. As a whole, based on analyzing the diverse fault kinematics and their variable spatial distribution with respect to the overall pattern of the tectonic structures formed and/or activated during the late PlioceneeQuaternary, we conclude they were generated under a regional stress field mainly characterized by a relatively uniform NWeSE tension, but strongly influenced by the irregular hard boundary of the old Siberian craton. The obtained inferences are in an

  16. Causal inference in cross-lagged panel analysis: a reciprocal causal relationship between cognitive function and depressive symptoms.

    Science.gov (United States)

    Yoon, Ju Young; Brown, Roger L

    2014-01-01

    Cross-lagged panel analysis (CLPA) is a method of examining one-way or reciprocal causal inference between longitudinally changing variables. It has been used in the social sciences for many years, but not much in nursing research. This article introduces the conceptual and statistical background of CLPA and provides an exemplar of CLPA that examines the reciprocal causal relationship between depression and cognitive function over time in older adults. The 2-year cross-lagged effects of depressive symptoms (T1) on cognitive function (T2) and cognitive function (T1) on depressive symptoms (T2) were significant, which demonstrated a reciprocal causal relationship between cognitive function and depressive mood over time. Although CLPA is a methodologically strong approach to examine the reciprocal causal inferences over time, it is necessary to consider potential sources of spuriousness to lead to false causal relationship and a reasonable time frame to detect the change of the variables.

  17. Algorithms of causal inference for the analysis of effective connectivity among brain regions.

    Science.gov (United States)

    Chicharro, Daniel; Panzeri, Stefano

    2014-01-01

    In recent years, powerful general algorithms of causal inference have been developed. In particular, in the framework of Pearl's causality, algorithms of inductive causation (IC and IC(*)) provide a procedure to determine which causal connections among nodes in a network can be inferred from empirical observations even in the presence of latent variables, indicating the limits of what can be learned without active manipulation of the system. These algorithms can in principle become important complements to established techniques such as Granger causality and Dynamic Causal Modeling (DCM) to analyze causal influences (effective connectivity) among brain regions. However, their application to dynamic processes has not been yet examined. Here we study how to apply these algorithms to time-varying signals such as electrophysiological or neuroimaging signals. We propose a new algorithm which combines the basic principles of the previous algorithms with Granger causality to obtain a representation of the causal relations suited to dynamic processes. Furthermore, we use graphical criteria to predict dynamic statistical dependencies between the signals from the causal structure. We show how some problems for causal inference from neural signals (e.g., measurement noise, hemodynamic responses, and time aggregation) can be understood in a general graphical approach. Focusing on the effect of spatial aggregation, we show that when causal inference is performed at a coarser scale than the one at which the neural sources interact, results strongly depend on the degree of integration of the neural sources aggregated in the signals, and thus characterize more the intra-areal properties than the interactions among regions. We finally discuss how the explicit consideration of latent processes contributes to understand Granger causality and DCM as well as to distinguish functional and effective connectivity.

  18. Algorithms of causal inference for the analysis of effective connectivity among brain regions

    Directory of Open Access Journals (Sweden)

    Daniel eChicharro

    2014-07-01

    Full Text Available In recent years, powerful general algorithms of causal inference have been developed. In particular, in the framework of Pearl’s causality, algorithms of inductive causation (IC and IC* provide a procedure to determine which causal connections among nodes in a network can be inferred from empirical observations even in the presence of latent variables, indicating the limits of what can be learned without active manipulation of the system. These algorithms can in principle become important complements to established techniques such as Granger causality and Dynamic Causal Modeling (DCM to analyze causal influences (effective connectivity among brain regions. However, their application to dynamic processes has not been yet examined. Here we study how to apply these algorithms to time-varying signals such as electrophysiological or neuroimaging signals. We propose a new algorithm which combines the basic principles of the previous algorithms with Granger causality to obtain a representation of the causal relations suited to dynamic processes. Furthermore, we use graphical criteria to predict dynamic statistical dependencies between the signals from the causal structure. We show how some problems for causal inference from neural signals (e.g. measurement noise, hemodynamic responses, and time aggregation can be understood in a general graphical approach. Focusing on the effect of spatial aggregation, we show that when causal inference is performed at a coarser scale than the one at which the neural sources interact, results strongly depend on the degree of integration of the neural sources aggregated in the signals, and thus characterize more the intra-areal properties than the interactions among regions. We finally discuss how the explicit consideration of latent processes contributes to understand Granger causality and DCM as well as to distinguish functional and effective connectivity.

  19. Applying Fractal Dimensions and Energy-Budget Analysis to Characterize Fracturing Processes During Magma Migration and Eruption: 2011-2012 El Hierro (Canary Islands) Submarine Eruption

    Science.gov (United States)

    López, Carmen; Martí, Joan; Abella, Rafael; Tarraga, Marta

    2014-07-01

    The impossibility of observing magma migration inside the crust obliges us to rely on geophysical data and mathematical modelling to interpret precursors and to forecast volcanic eruptions. Of the geophysical signals that may be recorded before and during an eruption, deformation and seismicity are two of the most relevant as they are directly related to its dynamic. The final phase of the unrest episode that preceded the 2011-2012 eruption on El Hierro (Canary Islands) was characterized by local and accelerated deformation and seismic energy release indicating an increasing fracturing and a migration of the magma. Application of time varying fractal analysis to the seismic data and the characterization of the seismicity pattern and the strain and the stress rates allow us to identify different stages in the source mechanism and to infer the geometry of the path used by the magma and associated fluids to reach the Earth's surface. The results obtained illustrate the relevance of such studies to understanding volcanic unrest and the causes that govern the initiation of volcanic eruptions.

  20. CAREFUL NUMERICAL SIMULATION AND ANALYSIS OF MIGRATION-ACCUMULATION OF TANHAI REGION

    Institute of Scientific and Technical Information of China (English)

    YUAN Yi-rang; DU Ning; HAN Yu-ji

    2005-01-01

    Numerical simulation of careful parallel arithmetic of oil resources migration-accumulation of Tanhai Region (three-layer) was done. Careful parallel operator splitting-up implicit iterative scheme, parallel arithmetic program, parallel arithmetic information and alternating-direction mesh subdivision were put forward. Parallel arithmetic and analysis of different CPU combinations were done. This numerical simulation test and the actual conditions are basically coincident. The convergence estimation of the model problem has successfully solved the difficult problem in the fields of permeation fluid mechanics, computational mathematics and petroleum geology.

  1. Computer models and the evidence of anthropogenic climate change: An epistemology of variety-of-evidence inferences and robustness analysis.

    Science.gov (United States)

    Vezér, Martin A

    2016-04-01

    To study climate change, scientists employ computer models, which approximate target systems with various levels of skill. Given the imperfection of climate models, how do scientists use simulations to generate knowledge about the causes of observed climate change? Addressing a similar question in the context of biological modelling, Levins (1966) proposed an account grounded in robustness analysis. Recent philosophical discussions dispute the confirmatory power of robustness, raising the question of how the results of computer modelling studies contribute to the body of evidence supporting hypotheses about climate change. Expanding on Staley's (2004) distinction between evidential strength and security, and Lloyd's (2015) argument connecting variety-of-evidence inferences and robustness analysis, I address this question with respect to recent challenges to the epistemology robustness analysis. Applying this epistemology to case studies of climate change, I argue that, despite imperfections in climate models, and epistemic constraints on variety-of-evidence reasoning and robustness analysis, this framework accounts for the strength and security of evidence supporting climatological inferences, including the finding that global warming is occurring and its primary causes are anthropogenic.

  2. Media deliberation on intra-EU migration. A qualitative approach to framing based on rhetorical analysis

    Directory of Open Access Journals (Sweden)

    Alexandru Cârlan

    2016-04-01

    Full Text Available In this paper we investigate how the model of deliberation proposed by Isabela and Norman Fairclough can be used for a better clarification and understanding of the framing processes in media – especially in opinion articles. We thus aim at integrating theoretical contributions from critical discourse analysis and argumentation theory with standard approaches to framing, originating in media studies. We emphasize how a rhetorical approach to framing can provide analytical insights into framing processes and complement the typical quantitative approaches with qualitative analysis based on textual reconstruction. Starting from an issue-specific approach to framing, we discuss a particular case of framing of intra-EU migration, analyzing four opinion articles selected from a larger corpus of Romanian, British and French media. We highlight, along our analysis, various methodological options and analytical difficulties inherent to such an approach.

  3. Network inference analysis identifies an APRR2-like gene linked to pigment accumulation in tomato and pepper fruits.

    Science.gov (United States)

    Pan, Yu; Bradley, Glyn; Pyke, Kevin; Ball, Graham; Lu, Chungui; Fray, Rupert; Marshall, Alexandra; Jayasuta, Subhalai; Baxter, Charles; van Wijk, Rik; Boyden, Laurie; Cade, Rebecca; Chapman, Natalie H; Fraser, Paul D; Hodgman, Charlie; Seymour, Graham B

    2013-03-01

    Carotenoids represent some of the most important secondary metabolites in the human diet, and tomato (Solanum lycopersicum) is a rich source of these health-promoting compounds. In this work, a novel and fruit-related regulator of pigment accumulation in tomato has been identified by artificial neural network inference analysis and its function validated in transgenic plants. A tomato fruit gene regulatory network was generated using artificial neural network inference analysis and transcription factor gene expression profiles derived from fruits sampled at various points during development and ripening. One of the transcription factor gene expression profiles with a sequence related to an Arabidopsis (Arabidopsis thaliana) ARABIDOPSIS PSEUDO RESPONSE REGULATOR2-LIKE gene (APRR2-Like) was up-regulated at the breaker stage in wild-type tomato fruits and, when overexpressed in transgenic lines, increased plastid number, area, and pigment content, enhancing the levels of chlorophyll in immature unripe fruits and carotenoids in red ripe fruits. Analysis of the transcriptome of transgenic lines overexpressing the tomato APPR2-Like gene revealed up-regulation of several ripening-related genes in the overexpression lines, providing a link between the expression of this tomato gene and the ripening process. A putative ortholog of the tomato APPR2-Like gene in sweet pepper (Capsicum annuum) was associated with pigment accumulation in fruit tissues. We conclude that the function of this gene is conserved across taxa and that it encodes a protein that has an important role in ripening.

  4. Analysis of the GRNs Inference by Using Tsallis Entropy and a Feature Selection Approach

    Science.gov (United States)

    Lopes, Fabrício M.; de Oliveira, Evaldo A.; Cesar, Roberto M.

    An important problem in the bioinformatics field is to understand how genes are regulated and interact through gene networks. This knowledge can be helpful for many applications, such as disease treatment design and drugs creation purposes. For this reason, it is very important to uncover the functional relationship among genes and then to construct the gene regulatory network (GRN) from temporal expression data. However, this task usually involves data with a large number of variables and small number of observations. In this way, there is a strong motivation to use pattern recognition and dimensionality reduction approaches. In particular, feature selection is specially important in order to select the most important predictor genes that can explain some phenomena associated with the target genes. This work presents a first study about the sensibility of entropy methods regarding the entropy functional form, applied to the problem of topology recovery of GRNs. The generalized entropy proposed by Tsallis is used to study this sensibility. The inference process is based on a feature selection approach, which is applied to simulated temporal expression data generated by an artificial gene network (AGN) model. The inferred GRNs are validated in terms of global network measures. Some interesting conclusions can be drawn from the experimental results, as reported for the first time in the present paper.

  5. Comparative analysis of chromosome counts infers three paleopolyploidies in the mollusca.

    Science.gov (United States)

    Hallinan, Nathaniel M; Lindberg, David R

    2011-01-01

    The study of paleopolyploidies requires the comparison of multiple whole genome sequences. If the branches of a phylogeny on which a whole-genome duplication (WGD) occurred could be identified before genome sequencing, taxa could be selected that provided a better assessment of that genome duplication. Here, we describe a likelihood model in which the number of chromosomes in a genome evolves according to a Markov process with one rate of chromosome duplication and loss that is proportional to the number of chromosomes in the genome and another stochastic rate at which every chromosome in the genome could duplicate in a single event. We compare the maximum likelihoods of a model in which the genome duplication rate varies to one in which it is fixed at zero using the Akaike information criterion, to determine if a model with WGDs is a good fit for the data. Once it has been determined that the data does fit the WGD model, we infer the phylogenetic position of paleopolyploidies by calculating the posterior probability that a WGD occurred on each branch of the taxon tree. Here, we apply this model to a molluscan tree represented by 124 taxa and infer three putative WGD events. In the Gastropoda, we identify a single branch within the Hypsogastropoda and one of two branches at the base of the Stylommatophora. We also identify one or two branches near the base of the Cephalopoda.

  6. Bayesian inference analysis of the uncertainty linked to the evaluation of potential flood damage in urban areas.

    Science.gov (United States)

    Fontanazza, C M; Freni, G; Notaro, V

    2012-01-01

    Flood damage in urbanized watersheds may be assessed by combining the flood depth-damage curves and the outputs of urban flood models. The complexity of the physical processes that must be simulated and the limited amount of data available for model calibration may lead to high uncertainty in the model results and consequently in damage estimation. Moreover depth-damage functions are usually affected by significant uncertainty related to the collected data and to the simplified structure of the regression law that is used. The present paper carries out the analysis of the uncertainty connected to the flood damage estimate obtained combining the use of hydraulic models and depth-damage curves. A Bayesian inference analysis was proposed along with a probabilistic approach for the parameters estimating. The analysis demonstrated that the Bayesian approach is very effective considering that the available databases are usually short.

  7. Inference of Global HIV-1 Sequence Patterns and Preliminary Feature Analysis

    Institute of Scientific and Technical Information of China (English)

    Yan Wang; Reda Rawi; Daniel Hoffmann; Binlian Sun; Rongge Yang

    2013-01-01

    The epidemiology of HIV-1 varies in different areas of the world,and it is possible that this complexity may leave unique footprints in the viral genome.Thus,we attempted to find significant patterns in global HIV-1 genome sequences.By applying the rule inference algorithm RIPPER (Repeated Incremental Pruning to Produce Error Reduction) to multiple sequence alignments of Env sequences from four classes of compiled datasets,we generated four sets of signature patterns.We found that these patterns were able to distinguish southeastern Asian from nonsoutheastern Asian sequences with 97.5% accuracy,Chinese from non-Chinese sequences with 98.3% accuracy,African from non-African sequences with 88.4% accuracy,and southern African from non-southern African sequences with 91.2% accuracy.These patterns showed different associations with subtypes and with amino acid positions.In addition,some signature patterns were characteristic of the geographic area from which the sample was taken.Amino acid features corresponding to the phylogenetic clustering of HIV-1 sequences were consistent with some of the deduced patterns.Using a combination of patterns inferred from subtypes B,C,and all subtypes chimeric with CRF01_AE worldwide,we found that signature patterns of subtype C were extremely common in some sampled countries (for example,Zambia in southern Africa),which may hint at the origin of this HIV-1 subtype and the need to pay special attention to this area of Africa.Signature patterns of subtype B sequences were associated with different countries.Even more,there are distinct patterns at single position 21 with glycine,leucine and isoleucine corresponding to subtype C,B and all possible recombination forms chimeric with CRF01_AE,which also indicate distinct geographic features.Our method widens the scope of inference of signature from geographic,genetic,and genomic viewpoints.These findings may provide a valuable reference for epidemiological research or vaccine design.

  8. Characterization of three-dimensional cancer cell migration in mixed collagen-Matrigel scaffolds using microfluidics and image analysis

    Science.gov (United States)

    Maška, Martin; Ederra, Cristina; Peláez, Rafael; Morales, Xabier; Muñoz-Arrieta, Gorka; Mujika, Maite; Kozubek, Michal; Muñoz-Barrutia, Arrate; Rouzaut, Ana; Arana, Sergio; Garcia-Aznar, José Manuel; Ortiz-de-Solorzano, Carlos

    2017-01-01

    Microfluidic devices are becoming mainstream tools to recapitulate in vitro the behavior of cells and tissues. In this study, we use microfluidic devices filled with hydrogels of mixed collagen-Matrigel composition to study the migration of lung cancer cells under different cancer invasion microenvironments. We present the design of the microfluidic device, characterize the hydrogels morphologically and mechanically and use quantitative image analysis to measure the migration of H1299 lung adenocarcinoma cancer cells in different experimental conditions. Our results show the plasticity of lung cancer cell migration, which turns from mesenchymal in collagen only matrices, to lobopodial in collagen-Matrigel matrices that approximate the interface between a disrupted basement membrane and the underlying connective tissue. Our quantification of migration speed confirms a biphasic role of Matrigel. At low concentration, Matrigel facilitates migration, most probably by providing a supportive and growth factor retaining environment. At high concentration, Matrigel slows down migration, possibly due excessive attachment. Finally, we show that antibody-based integrin blockade promotes a change in migration phenotype from mesenchymal or lobopodial to amoeboid and analyze the effect of this change in migration dynamics, in regards to the structure of the matrix. In summary, we describe and characterize a robust microfluidic platform and a set of software tools that can be used to study lung cancer cell migration under different microenvironments and experimental conditions. This platform could be used in future studies, thus benefitting from the advantages introduced by microfluidic devices: precise control of the environment, excellent optical properties, parallelization for high throughput studies and efficient use of therapeutic drugs. PMID:28166248

  9. Methods of quantitative and qualitative analysis of bird migration with a tracking radar

    Science.gov (United States)

    Bruderer, B.; Steidinger, P.

    1972-01-01

    Methods of analyzing bird migration by using tracking radar are discussed. The procedure for assessing the rate of bird passage is described. Three topics are presented concerning the grouping of nocturnal migrants, the velocity of migratory flight, and identification of species by radar echoes. The height and volume of migration under different weather conditions are examined. The methods for studying the directions of migration and the correlation between winds and the height and direction of migrating birds are presented.

  10. Large sample inference for a win ratio analysis of a composite outcome based on prioritized components.

    Science.gov (United States)

    Bebu, Ionut; Lachin, John M

    2016-01-01

    Composite outcomes are common in clinical trials, especially for multiple time-to-event outcomes (endpoints). The standard approach that uses the time to the first outcome event has important limitations. Several alternative approaches have been proposed to compare treatment versus control, including the proportion in favor of treatment and the win ratio. Herein, we construct tests of significance and confidence intervals in the context of composite outcomes based on prioritized components using the large sample distribution of certain multivariate multi-sample U-statistics. This non-parametric approach provides a general inference for both the proportion in favor of treatment and the win ratio, and can be extended to stratified analyses and the comparison of more than two groups. The proposed methods are illustrated with time-to-event outcomes data from a clinical trial.

  11. Improving PWR core simulations by Monte Carlo uncertainty analysis and Bayesian inference

    CERN Document Server

    Castro, Emilio; Buss, Oliver; Garcia-Herranz, Nuria; Hoefer, Axel; Porsch, Dieter

    2016-01-01

    A Monte Carlo-based Bayesian inference model is applied to the prediction of reactor operation parameters of a PWR nuclear power plant. In this non-perturbative framework, high-dimensional covariance information describing the uncertainty of microscopic nuclear data is combined with measured reactor operation data in order to provide statistically sound, well founded uncertainty estimates of integral parameters, such as the boron letdown curve and the burnup-dependent reactor power distribution. The performance of this methodology is assessed in a blind test approach, where we use measurements of a given reactor cycle to improve the prediction of the subsequent cycle. As it turns out, the resulting improvement of the prediction quality is impressive. In particular, the prediction uncertainty of the boron letdown curve, which is of utmost importance for the planning of the reactor cycle length, can be reduced by one order of magnitude by including the boron concentration measurement information of the previous...

  12. Ascariasis in people and pigs: new inferences from DNA analysis of worm populations.

    Science.gov (United States)

    Peng, Weidong; Criscione, Charles D

    2012-03-01

    Ascaris is a large parasitic roundworm (nematode) of the small intestine of humans and pigs. These roundworms cause the socioeconomically important disease, ascariasis. For the past 20 years, molecular markers have been used in studies on Ascaris and ascariasis, and added valuable information to the understanding of these roundworms. Here, we provide a review of these studies on human and pig roundworms. We begin with a summary of studies using molecular phenotypic markers to compare Ascaris from humans and pigs, followed by a synopsis of comparisons using genetic markers. We then draw forth inferences in the aspects of host affiliation and infection success, transmission between and among humans and pigs, evolutionary history of Ascaris. We also highlight additional topics such as mating dynamics, diagnostics, and paleoparasitology where molecular epidemiological approaches have been utilized.

  13. Internal migration in India in the seventies: a demo-economic analysis.

    Science.gov (United States)

    Nair, P S

    1986-01-01

    "This paper is aimed to address mainly the following three aspects of spatial mobility within India during the last inter-censal decade of 1971-1981: (i) Levels of inmigration, outmigration and net migration in the major states (ii) estimates of state-to-state migration flows and (iii) some insights on the socio-economic determinants of internal migration."

  14. Demographic Models for Projecting Population and Migration: Methods for African Historical Analysis

    Directory of Open Access Journals (Sweden)

    Patrick Manning

    2015-08-01

    Full Text Available This study presents methods for projecting population and migration over time in cases were empirical data are missing or undependable. The methods are useful for cases in which the researcher has details of population size and structure for a limited period of time (most obviously, the end point, with scattered evidence on other times. It enables estimation of population size, including its structure in age, sex, and status, either forward or backward in time. The program keeps track of all the details. The calculated data can be reported or sampled and compared to empirical findings at various times and places to expected values based on other procedures of estimation. The application of these general methods that is developed here is the projection of African populations backwards in time from 1950, since 1950 is the first date for which consistently strong demographic estimates are available for national-level populations all over the African continent. The models give particular attention to migration through enslavement, which was highly important in Africa from 1650 to 1900. Details include a sensitivity analysis showing relative significance of input variables and techniques for calibrating various dimensions of the projection with each other. These same methods may be applicable to quite different historical situations, as long as the data conform in structure to those considered here.

  15. Analysis of Phthalate Migration to Food Simulants in Plastic Containers during Microwave Operations

    Directory of Open Access Journals (Sweden)

    Miriany A. Moreira

    2013-12-01

    Full Text Available Phthalates used as plasticizers in the manufacture of household containers can potentially be transferred to foods that are stored or heated in these plastic containers. Phthalates are endocrine disruptor compounds (EDC and are found in very low concentrations in foods, thus, highly sensitive analytical techniques are required for their quantification. This study describes the application of a new method developed for analyzing the migration of dibutylphthalate (DBP and benzylbutylphthalate (BBP from plastic food containers into liquid food simulants. This new method employs the technique of solid phase microextraction cooled with liquid nitrogen. The analysis was conducted by gas chromatography/mass spectrometry (GC/MS using a polyacrylate fiber. Ultrapure water was used as a simulant for liquids foods, and both new and used plastic containers were placed in a domestic microwave oven for different periods of time at different power levels. The limits of detection for DBP and BBP were 0.08 µg/L and 0.31 µg/L, respectively. BBP was not found in the samples that were analyzed. DBP was found in concentrations ranging from migration was observed in containers that were used for a prolonged time, which correlated with increasing heating time.

  16. World Migration Degree Global migration flows in directed networks

    CERN Document Server

    Porat, Idan

    2015-01-01

    In this article we analyze the global flow of migrants from 206 source countries to 145 destination countries (2006-2010) and focus on the differences in the migration network pattern between destination and source counters as represented by its degree and weight distribution. Degree represents the connectivity of a country to the global migration network, and plays an important role in defining migration processes and characteristics. Global analysis of migration degree distribution offers a strong potential contribution to understanding of migration as a global phenomenon. In regard to immigration, we found that it is possible to classify destination countries into three classes: global migration hubs with high connectivity and high migration rate; local migration hubs with low connectivity and high migration rate; and local migration hubs with opposite strategy of high connectivity and low migration rate. The different migration strategies of destination countries are emerging from similar and homogenies p...

  17. Testosterone, migration distance, and migratory timing in song sparrows Melospiza melodia.

    Science.gov (United States)

    Lymburner, Alannah H; Kelly, Tosha R; Hobson, Keith A; MacDougall-Shackleton, Elizabeth A; MacDougall-Shackleton, Scott A

    2016-09-01

    In seasonally migratory animals, migration distance often varies substantially within populations such that individuals breeding at the same site may overwinter different distances from the breeding grounds. Shorter migration may allow earlier return to the breeding grounds, which may be particularly advantageous to males competing to acquire a breeding territory. However, little is known about potential mechanisms that may mediate migration distance. We investigated naturally-occurring variation in androgen levels at the time of arrival to the breeding site and its relationship to overwintering latitude in male and female song sparrows (Melospiza melodia). We used stable isotope analysis of hydrogen (δ(2)H) in winter-grown claw tissue to infer relative overwintering latitude (migration distance), combined with 14years of capture records from a long-term study population to infer the arrival timing of males versus females. Relative to females, males had higher circulating androgen levels, migrated shorter distances, and were more likely to be caught early in the breeding season. Males that migrate short distances may benefit from early arrival at the breeding grounds, allowing them to establish a breeding territory. Even after controlling for sex and date, androgen levels were highest in individuals that migrated shorter distances. Our findings indicate that androgens and migration distance are correlated traits within and between sexes that may reflect individual variation within an integrated phenotype in which testosterone has correlated effects on behavioral traits such as migration.

  18. Thermodynamic analysis of carbon migration in W1-1.0C steel in plasma surface chromizing

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    W1-1.0C steel was chromized at 1173 K with double glow plasma surface alloying process, and the distribution of Fe, Cr,and C contents in the chromized layer was measured using glow discharge spectrum analysis (GDA).The behavior and mechanism of carbon migration during the formation of chromized layer were studied through thermodynamic analysis and calculation.The gradient of carbon chemical potential was regarded as the driving force of carbon migration.An equation was derived to describe the carbon content varying with the chromium content within the carbon-rich region.The calculated results from the equation approximated closely to the experimental ones.

  19. VARIABILITY OF THE ACCRETION DISK OF V926 Sco INFERRED FROM TOMOGRAPHIC ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, S. D. [University of Southampton, Highfield, Southampton, S017 1BJ (United Kingdom); Peris, C. S. [Department of Physics, Northeastern University, Boston, MA 02115 (United States); Vrtilek, S. D., E-mail: sdc1g08@soton.ac.u, E-mail: peris.c@husky.neu.edu, E-mail: cperis@cfa.harvard.edu, E-mail: svrtilek@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2013-11-10

    We present phase-resolved spectroscopic observations of the low-mass X-ray binary V926 Sco (4U 1735-44), covering the orbital period of 0.23 days, obtained with the Walter Baade 6.5 m Magellan Telescope at the Las Campanas Observatory in 2010 June and 2011 June. We use Hα radial velocities to derive a systemic velocity of –109 ± 4 km s{sup –1}. The FWHM of the lines observed in common with previous authors are significantly lower during our observations suggesting much reduced velocities in the system. The equivalent width of the Bowen fluorescence lines with respect to He II λ4686 are factors of two or more lower during our observations in comparison to those previously reported for the system, suggesting reduced irradiation of the secondary. Doppler and modulation tomography of Hα and He II λ4686 show asymmetric emission that can be attributed to a bulge in the accretion disk, as inferred from He II observations by previous authors. The X-ray fluxes from the source at times concurrent with the optical observations are significantly lower during our observations than during optical observations taken in 2003. We suggest that the system is in a lower accretion state compared to earlier observations; this explains both the lower velocities observed from the disk and the reduction of emission due to Bowen fluorescence detected from the secondary.

  20. Geographic population structure analysis of worldwide human populations infers their biogeographical origins

    Science.gov (United States)

    Elhaik, Eran; Tatarinova, Tatiana; Chebotarev, Dmitri; Piras, Ignazio S.; Maria Calò, Carla; De Montis, Antonella; Atzori, Manuela; Marini, Monica; Tofanelli, Sergio; Francalacci, Paolo; Pagani, Luca; Tyler-Smith, Chris; Xue, Yali; Cucca, Francesco; Schurr, Theodore G.; Gaieski, Jill B.; Melendez, Carlalynne; Vilar, Miguel G.; Owings, Amanda C.; Gómez, Rocío; Fujita, Ricardo; Santos, Fabrício R.; Comas, David; Balanovsky, Oleg; Balanovska, Elena; Zalloua, Pierre; Soodyall, Himla; Pitchappan, Ramasamy; GaneshPrasad, ArunKumar; Hammer, Michael; Matisoo-Smith, Lisa; Wells, R. Spencer; Acosta, Oscar; Adhikarla, Syama; Adler, Christina J.; Bertranpetit, Jaume; Clarke, Andrew C.; Cooper, Alan; Der Sarkissian, Clio S. I.; Haak, Wolfgang; Haber, Marc; Jin, Li; Kaplan, Matthew E.; Li, Hui; Li, Shilin; Martínez-Cruz, Begoña; Merchant, Nirav C.; Mitchell, John R.; Parida, Laxmi; Platt, Daniel E.; Quintana-Murci, Lluis; Renfrew, Colin; Lacerda, Daniela R.; Royyuru, Ajay K.; Sandoval, Jose Raul; Santhakumari, Arun Varatharajan; Soria Hernanz, David F.; Swamikrishnan, Pandikumar; Ziegle, Janet S.

    2014-01-01

    The search for a method that utilizes biological information to predict humans’ place of origin has occupied scientists for millennia. Over the past four decades, scientists have employed genetic data in an effort to achieve this goal but with limited success. While biogeographical algorithms using next-generation sequencing data have achieved an accuracy of 700 km in Europe, they were inaccurate elsewhere. Here we describe the Geographic Population Structure (GPS) algorithm and demonstrate its accuracy with three data sets using 40,000–130,000 SNPs. GPS placed 83% of worldwide individuals in their country of origin. Applied to over 200 Sardinians villagers, GPS placed a quarter of them in their villages and most of the rest within 50 km of their villages. GPS’s accuracy and power to infer the biogeography of worldwide individuals down to their country or, in some cases, village, of origin, underscores the promise of admixture-based methods for biogeography and has ramifications for genetic ancestry testing. PMID:24781250

  1. Inference of transcriptional networks in Arabidopsis through conserved noncoding sequence analysis.

    Science.gov (United States)

    Van de Velde, Jan; Heyndrickx, Ken S; Vandepoele, Klaas

    2014-07-01

    Transcriptional regulation plays an important role in establishing gene expression profiles during development or in response to (a)biotic stimuli. Transcription factor binding sites (TFBSs) are the functional elements that determine transcriptional activity, and the identification of individual TFBS in genome sequences is a major goal to inferring regulatory networks. We have developed a phylogenetic footprinting approach for the identification of conserved noncoding sequences (CNSs) across 12 dicot plants. Whereas both alignment and non-alignment-based techniques were applied to identify functional motifs in a multispecies context, our method accounts for incomplete motif conservation as well as high sequence divergence between related species. We identified 69,361 footprints associated with 17,895 genes. Through the integration of known TFBS obtained from the literature and experimental studies, we used the CNSs to compile a gene regulatory network in Arabidopsis thaliana containing 40,758 interactions, of which two-thirds act through binding events located in DNase I hypersensitive sites. This network shows significant enrichment toward in vivo targets of known regulators, and its overall quality was confirmed using five different biological validation metrics. Finally, through the integration of detailed expression and function information, we demonstrate how static CNSs can be converted into condition-dependent regulatory networks, offering opportunities for regulatory gene annotation.

  2. An agent-based model to rural-urban migration analysis

    CERN Document Server

    Silveira, J J; Penna, T J P; Silveira, Jaylson J.; Espindola, Aquino L.

    2005-01-01

    In this paper we analyze the rural-urban migration phenomena as it is usually observed in economies which are in the early stages of industrialization. The analysis is conducted by means of a statistical mechanics approach which builds a computational agent-based model. Agents are placed on a lattice and the connections among them are described via an Ising like model. Simulations on this computational model show some emergent properties that are common in developing economies, such as a transitional dynamics characterized by continuous growth of urban population, followed by the equalization of expected wages between rural and urban sectors (Harris-Todaro equilibrium condition), urban concentration and increasing of per capita income.

  3. Identification of a Putative Quantitative Trait Gene for Resistance to Obesity in Mice Using Transcriptome Analysis and Causal Inference Tests.

    Science.gov (United States)

    Ishikawa, Akira

    2017-01-01

    It is still challenging to identify causal genes governing obesity. Pbwg1.5, a quantitative trait locus (QTL) for resistance to obesity, was previously discovered from wild Mus musculus castaneus mice and was fine-mapped to a 2.1-Mb genomic region of mouse chromosome 2, where no known gene with an effect on white adipose tissue (WAT) has been reported. The aim of this study was to identify a strong candidate gene for Pbwg1.5 by an integration approach of transcriptome analysis (RNA-sequencing followed by real-time PCR analysis) and the causal inference test (CIT), a statistical method to infer causal relationships between diplotypes, gene expression and trait values. Body weight, body composition and biochemical traits were measured in F2 mice obtained from an intercross between the C57BL/6JJcl strain and a congenic strain carrying Pbwg1.5 on the C57BL/6JJcl background. The F2 mice showed significant diplotype differences in 12 traits including body weight, WAT weight and serum cholesterol/triglyceride levels. The transcriptome analysis revealed that Ly75, Pla2r1, Fap and Gca genes were differentially expressed in the liver and that Fap, Ifih1 and Grb14 were differentially expressed in WAT. However, CITs indicated statistical evidence that only the liver Ly75 gene mediated between genotype and WAT. Ly75 expression was negatively associated with WAT weight. The results suggested that Ly75 is a putative quantitative trait gene for the obesity-resistant Pbwg1.5 QTL discovered from the wild M. m. castaneus mouse. The finding provides a novel insight into a better understanding of the genetic basis for prevention of obesity.

  4. Statistical inference

    CERN Document Server

    Rohatgi, Vijay K

    2003-01-01

    Unified treatment of probability and statistics examines and analyzes the relationship between the two fields, exploring inferential issues. Numerous problems, examples, and diagrams--some with solutions--plus clear-cut, highlighted summaries of results. Advanced undergraduate to graduate level. Contents: 1. Introduction. 2. Probability Model. 3. Probability Distributions. 4. Introduction to Statistical Inference. 5. More on Mathematical Expectation. 6. Some Discrete Models. 7. Some Continuous Models. 8. Functions of Random Variables and Random Vectors. 9. Large-Sample Theory. 10. General Meth

  5. Multisensory Bayesian Inference Depends on Synapse Maturation during Training: Theoretical Analysis and Neural Modeling Implementation.

    Science.gov (United States)

    Ursino, Mauro; Cuppini, Cristiano; Magosso, Elisa

    2017-03-01

    Recent theoretical and experimental studies suggest that in multisensory conditions, the brain performs a near-optimal Bayesian estimate of external events, giving more weight to the more reliable stimuli. However, the neural mechanisms responsible for this behavior, and its progressive maturation in a multisensory environment, are still insufficiently understood. The aim of this letter is to analyze this problem with a neural network model of audiovisual integration, based on probabilistic population coding-the idea that a population of neurons can encode probability functions to perform Bayesian inference. The model consists of two chains of unisensory neurons (auditory and visual) topologically organized. They receive the corresponding input through a plastic receptive field and reciprocally exchange plastic cross-modal synapses, which encode the spatial co-occurrence of visual-auditory inputs. A third chain of multisensory neurons performs a simple sum of auditory and visual excitations. The work includes a theoretical part and a computer simulation study. We show how a simple rule for synapse learning (consisting of Hebbian reinforcement and a decay term) can be used during training to shrink the receptive fields and encode the unisensory likelihood functions. Hence, after training, each unisensory area realizes a maximum likelihood estimate of stimulus position (auditory or visual). In cross-modal conditions, the same learning rule can encode information on prior probability into the cross-modal synapses. Computer simulations confirm the theoretical results and show that the proposed network can realize a maximum likelihood estimate of auditory (or visual) positions in unimodal conditions and a Bayesian estimate, with moderate deviations from optimality, in cross-modal conditions. Furthermore, the model explains the ventriloquism illusion and, looking at the activity in the multimodal neurons, explains the automatic reweighting of auditory and visual inputs

  6. Inferring hypotheses on functional relationships of genes: Analysis of the Arabidopsis thaliana subtilase gene family.

    Directory of Open Access Journals (Sweden)

    Carsten Rautengarten

    2005-09-01

    Full Text Available The gene family of subtilisin-like serine proteases (subtilases in Arabidopsis thaliana comprises 56 members, divided into six distinct subfamilies. Whereas the members of five subfamilies are similar to pyrolysins, two genes share stronger similarity to animal kexins. Mutant screens confirmed 144 T-DNA insertion lines with knockouts for 55 out of the 56 subtilases. Apart from SDD1, none of the confirmed homozygous mutants revealed any obvious visible phenotypic alteration during growth under standard conditions. Apart from this specific case, forward genetics gave us no hints about the function of the individual 54 non-characterized subtilase genes. Therefore, the main objective of our work was to overcome the shortcomings of the forward genetic approach and to infer alternative experimental approaches by using an integrative bioinformatics and biological approach. Computational analyses based on transcriptional co-expression and co-response pattern revealed at least two expression networks, suggesting that functional redundancy may exist among subtilases with limited similarity. Furthermore, two hubs were identified, which may be involved in signalling or may represent higher-order regulatory factors involved in responses to environmental cues. A particular enrichment of co-regulated genes with metabolic functions was observed for four subtilases possibly representing late responsive elements of environmental stress. The kexin homologs show stronger associations with genes of transcriptional regulation context. Based on the analyses presented here and in accordance with previously characterized subtilases, we propose three main functions of subtilases: involvement in (i control of development, (ii protein turnover, and (iii action as downstream components of signalling cascades. Supplemental material is available in the Plant Subtilase Database (PSDB (http://csbdb.mpimp-golm.mpg.de/psdb.html, as well as from the CSB.DB (http://csbdb.mpimp-golm.mpg.de.

  7. Inferring Hypotheses on Functional Relationships of Genes: Analysis of the Arabidopsis thaliana Subtilase Gene Family.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available The gene family of subtilisin-like serine proteases (subtilases in Arabidopsis thaliana comprises 56 members, divided into six distinct subfamilies. Whereas the members of five subfamilies are similar to pyrolysins, two genes share stronger similarity to animal kexins. Mutant screens confirmed 144 T-DNA insertion lines with knockouts for 55 out of the 56 subtilases. Apart from SDD1, none of the confirmed homozygous mutants revealed any obvious visible phenotypic alteration during growth under standard conditions. Apart from this specific case, forward genetics gave us no hints about the function of the individual 54 non-characterized subtilase genes. Therefore, the main objective of our work was to overcome the shortcomings of the forward genetic approach and to infer alternative experimental approaches by using an integrative bioinformatics and biological approach. Computational analyses based on transcriptional co-expression and co-response pattern revealed at least two expression networks, suggesting that functional redundancy may exist among subtilases with limited similarity. Furthermore, two hubs were identified, which may be involved in signalling or may represent higher-order regulatory factors involved in responses to environmental cues. A particular enrichment of co-regulated genes with metabolic functions was observed for four subtilases possibly representing late responsive elements of environmental stress. The kexin homologs show stronger associations with genes of transcriptional regulation context. Based on the analyses presented here and in accordance with previously characterized subtilases, we propose three main functions of subtilases: involvement in (i control of development, (ii protein turnover, and (iii action as downstream components of signalling cascades. Supplemental material is available in the Plant Subtilase Database (PSDB (http://csbdb.mpimp-golm.mpg.de/psdb.html , as well as from the CSB.DB (http://csbdb.mpimp-golm.mpg.de.

  8. Comparative analysis of mitochondrial genomes in Diplura (hexapoda, arthropoda): taxon sampling is crucial for phylogenetic inferences.

    Science.gov (United States)

    Chen, Wan-Jun; Koch, Markus; Mallatt, Jon M; Luan, Yun-Xia

    2014-01-01

    Two-pronged bristletails (Diplura) are traditionally classified into three major superfamilies: Campodeoidea, Projapygoidea, and Japygoidea. The interrelationships of these three superfamilies and the monophyly of Diplura have been much debated. Few previous studies included Projapygoidea in their phylogenetic considerations, and its position within Diplura still is a puzzle from both morphological and molecular points of view. Until now, no mitochondrial genome has been sequenced for any projapygoid species. To fill in this gap, we determined and annotated the complete mitochondrial genome of Octostigma sinensis (Octostigmatidae, Projapygoidea), and of three more dipluran species, one each from the Campodeidae, Parajapygidae, and Japygidae. All four newly sequenced dipluran mtDNAs encode the same set of genes in the same gene order as shared by most crustaceans and hexapods. Secondary structure truncations have occurred in trnR, trnC, trnS1, and trnS2, and the reduction of transfer RNA D-arms was found to be taxonomically correlated, with Campodeoidea having experienced the most reduction. Partitioned phylogenetic analyses, based on both amino acids and nucleotides of the protein-coding genes plus the ribosomal RNA genes, retrieve significant support for a monophyletic Diplura within Pancrustacea, with Projapygoidea more closely related to Campodeoidea than to Japygoidea. Another key finding is that monophyly of Diplura cannot be recovered unless Projapygoidea is included in the phylogenetic analyses; this explains the dipluran polyphyly found by past mitogenomic studies. Including Projapygoidea increased the sampling density within Diplura and probably helped by breaking up a long-branch-attraction artifact. This finding provides an example of how proper sampling is significant for phylogenetic inference.

  9. Climate variability since MIS 5 in SW Balkans inferred from multiproxy analysis of Lake Prespa sediments

    Directory of Open Access Journals (Sweden)

    K. Panagiotopoulos

    2013-03-01

    Full Text Available The transboundary Lake Prespa (AL/FYROM/GR has been recognized as a conservation priority wetland. The catchment area has a remarkably diverse flora that points to its refugial properties. A lake sediment core retrieved from a coring location in the northern part of the lake was investigated through geophysical, sedimentological, geochemical, and palynological analyses. Based on tephrochronology, radiocarbon and electron spin resonance (ESR dating, and cross correlation with other Northern Hemisphere records, the age model suggests that the basal part of core Co1215 reaches back to 92 ka cal BP. Here we present the response of this mid-altitude site (849 m a.s.l. to climate oscillations during this interval and assess its sensitivity to millennial-scale variability. Endogenic calcite precipitation occurred in Marine Isotope Stages (MIS 5 and 1 and is synchronous with periods of increased primary production (terrestrial and/or lacustrine. Periods of pronounced phytoplankton blooms (inferred from green algae and dinoflagellate concentrations are recorded in MIS 5 and MIS 1 and suggest that the trophic state and lake levels underwent substantial fluctuations. Three major phases of vegetation development are distinguished: the forested phases of MIS 5 and MIS 1 dominated by deciduous trees with higher temperatures and moisture availability, the open landscapes of MIS 3 with significant presence of temperate trees, and the pine dominated open landscapes of MIS 4 and MIS 2 with lower temperatures and moisture availability. Forest dynamics, cover and density are discussed in an altitudinal context and the existence of temperate tree refugia is examined.

  10. From operations to cognitive tools: new unit of analysis and emergence of the inference-making child

    Directory of Open Access Journals (Sweden)

    HUGO ESCOBAR MELO

    2002-07-01

    Full Text Available This article discusses the passage between the analysis unit used by Piaget in his theory of thinkingoperations, going from the in-action-theories from Inhelder, to the cognitive-scientific tools inside themark of recognizing that the young child uses in a spontaneous way an improving rationality in thecontext of solving problems in an architecture half-end. It stands out the way how questions andepistemic archetypes change in the children studies, unblocking the cognition of a partial and fracturedlook that shadowed it, not letting show out his real functioning, action coordination and the constructionof audacious representations. One resorts is to investigative the landmarks of the Ginebra schooland its later followers post-Inhelderians. The child is thought as a subject that makes inferences whenhe recognizes incongruence and uncongenial completing and improving the reality that his culturalcontext builds.

  11. Analysis of Radionuclide Migration Through a 200-m Vadose Zone Following a 16-Year Infiltration Event

    Energy Technology Data Exchange (ETDEWEB)

    Tompson, A F B; Smith, D K; Hudson, G B

    2002-01-31

    chemical reaction, during transit to the water table. Overall, the long term nature of the experiment, the variety of chemical measurements and isotopic interpretations, and their incorporation into a unified modeling analysis, have contributed to a unique perspective for interpreting radionuclide migration in the unsaturated zone.

  12. Novel migration operators of biogeography-based optimization and Markov analysis

    DEFF Research Database (Denmark)

    Guo, Weian; Wang, Lei; Si, Chenyong;

    2016-01-01

    Biogeography-based optimization (BBO) is a nature-inspired optimization algorithm and has been developed in both theory and practice. In canonical BBO, migration operator is crucial to affect algorithm’s performance. In migration operator, a good solution has a large probability to be selected......, a number of benchmark tests are carried out to empirically assess the performance of the proposed migration operators, on both low-dimensional and high-dimensional numerical optimization problems. The comparison results demonstrate that the proposed migration operators are feasible and effective to enhance...

  13. Migration studies from paper and board food packaging materials. 1. Compositional analysis.

    Science.gov (United States)

    Castle, L; Offen, C P; Baxter, M J; Gilbert, J

    1997-01-01

    A survey of 32 paper and board materials intended for food contact has been undertaken. Sample composition was analysed to identify chemicals with a potential to migrate to foods. Representative materials covering a range of uses such as aqueous and fatty foods, and use at ambient and elevated temperatures, were obtained from industry. The samples were examined in their unfinished state, even where the final form would have included lamination to plastics, printing, or other treatments. A comprehensive and systematic analytical approach was applied which included determination of volatiles by headspace GC-MS, extraction using water, ethanol and chloroform with subsequent analysis by GC-MS and HPLC, and multi-element screening by ICP-MS. The solvent extracts were also weighed to determine the total amount of material available for migration. A large number of volatile substances were identified with alkyl and aryl aldehydes predominating in the majority of samples. Substances identified in solvent extracts included 2,6-di-tert-butyl-4-hydroxytoluene (BHT), di-tert-butylphenol, benzophenone, 4,4'-bis(dimethyl amino) benzophenone (Michler's ketone), triphenyl methane, bicyclohexylphenylphenanthrene carboxylic acid (and its methyl ester) and abietic acid. Levels of these substances were however generally below 1 mg/kg paper. Of the inorganic elements, arsenic and mercury were not detected above the limits of determination of 1.8 and 0.4 mg/kg respectively in any of the 10 samples examined. Cadmium was detected in teabag tissue and in unbleached Kraft paper at 0.3 mg/kg. Chromium was present in seven samples at 1.1-7.8 mg/kg, whilst lead was present in nine of the 10 samples at levels ranging from 0.3 to 5.9 mg/kg.

  14. Migration-Velocity Analysis for Ti and Orthorhombic Background Media Analyse de vitesse par migration dans les cas de milieux environnantsTI et orthorhombiques

    Directory of Open Access Journals (Sweden)

    Ikelle L. T.

    2006-12-01

    Full Text Available A knowledge of the background velocity model is crucial to achieve the accurate reservoir description now expected from imaging and inversion. Conventional methods for reconstructing the background velocity model, like migration-velocity methods, often assume an isotropic subsurface and can yield inaccurate reservoir descriptions when the subsurface contains anisotropic rock formations. Here, we generalize the migration-velocity concept by permitting the background velocity to be transversely isotropic (TI with respect to the vertical axis or othorhombic. The scheme consists of scanning different anisotropic velocity models using a phase-shift migration and of picking anisotropic parameters based on amplitude variations of migrated results (focusing analysis. As the anisotropic background velocity model is generally described by several elastic coefficients, it is important to adopt an efficient scanning procedure. We have chosen to work with common azimuthal sections. For a given common azimuthal section, we sequentially scan two parameters : normal move-out velocity and the anisotropic parameter known as anellipticity. These two scans allow us to reconstruct an azimuthally isotropic velocity model. The procedure is then repeated for different common azimuthal sections; each common azimuthal section leads to a new azimuthally isotropic velocity model if the medium is azimuthally anisotropic. The number of common azimuthal sections, and therefore the number of azimuthally isotropic velocity models, needed to reconstruct an azimuthally anisotropic velocity model is dependent on the type of symmetries. For example, only three common azimuthal sections are needed for an orthorhombic medium. As the contribution of isotropic component of most rock formations is generally more important than the anisotropic one, we have proposed to base the picking of values of anellipticity on the subtraction of the result of isotropic migration from that of TI

  15. Environmental effects of dredging. Preliminary guidelines and conceptual framework for comprehensive analysis of migration pathways (CAMP) of contaminated dredged material. Technical notes

    Energy Technology Data Exchange (ETDEWEB)

    Myers, T.E.

    1990-01-01

    The purpose of this note is to present the conceptual groundwork for the Comprehensive Analysis of Migration Pathways (CAMP). The conceptualization process for CAMP is discussed and available techniques for implementing CAMP are examined. Disposal of contaminated dredged material in a confined disposal facility is used to benchmark conceptual development. Case studies that illustrate analysis of selected migration pathways are also described.

  16. What Drives Human Migration in Sahelian Countries? A Meta-analysis

    NARCIS (Netherlands)

    Neumann, K.; Hermans, Frans

    2015-01-01

    The Sahel region has one of the most mobile populations in the world, with migration serving as a common household strategy to increase livelihood and social resilience. However, the Sahel region's population is extremely heterogeneous, and the processes and factors that contribute to migration are

  17. Analysis of the journalistic treatment given to the migration phenomenon in www.elPaís.com

    Directory of Open Access Journals (Sweden)

    Fernando Sabés Turmo Ph. D.

    2010-01-01

    Full Text Available This article aims to analyze migration-related content incorporated in the portal www.elPaís.com. The paper studies the formal treatment given, the issues and rights incorporated, the valuation made of migration and the migrant subject, and the main actors, among other aspects. The categories that divide the analysis are drawn from a review of the Barcelona Process-Union for the Mediterranean, the European Neighbourhood Policy, and the Alliance of Civilizations. All with the aim of establishing the way in the subject of migration appears in this online newspaper. To this end, we analyze both informative and editorial texts from the perspective of the social construction of reality theory.

  18. Eating or meeting? Cluster analysis reveals intricacies of white shark (Carcharodon carcharias migration and offshore behavior.

    Directory of Open Access Journals (Sweden)

    Salvador J Jorgensen

    Full Text Available Elucidating how mobile ocean predators utilize the pelagic environment is vital to understanding the dynamics of oceanic species and ecosystems. Pop-up archival transmitting (PAT tags have emerged as an important tool to describe animal migrations in oceanic environments where direct observation is not feasible. Available PAT tag data, however, are for the most part limited to geographic position, swimming depth and environmental temperature, making effective behavioral observation challenging. However, novel analysis approaches have the potential to extend the interpretive power of these limited observations. Here we developed an approach based on clustering analysis of PAT daily time-at-depth histogram records to distinguish behavioral modes in white sharks (Carcharodon carcharias. We found four dominant and distinctive behavioral clusters matching previously described behavioral patterns, including two distinctive offshore diving modes. Once validated, we mapped behavior mode occurrence in space and time. Our results demonstrate spatial, temporal and sex-based structure in the diving behavior of white sharks in the northeastern Pacific previously unrecognized including behavioral and migratory patterns resembling those of species with lek mating systems. We discuss our findings, in combination with available life history and environmental data, and propose specific testable hypotheses to distinguish between mating and foraging in northeastern Pacific white sharks that can provide a framework for future work. Our methodology can be applied to similar datasets from other species to further define behaviors during unobservable phases.

  19. Particle migration analysis in iterative classification of cryo-EM single-particle data.

    Science.gov (United States)

    Chen, Bo; Shen, Bingxin; Frank, Joachim

    2014-12-01

    Recently developed classification methods have enabled resolving multiple biological structures from cryo-EM data collected on heterogeneous biological samples. However, there remains the problem of how to base the decisions in the classification on the statistics of the cryo-EM data, to reduce the subjectivity in the process. Here, we propose a quantitative analysis to determine the iteration of convergence and the number of distinguishable classes, based on the statistics of the single particles in an iterative classification scheme. We start the classification with more number of classes than anticipated based on prior knowledge, and then combine the classes that yield similar reconstructions. The classes yielding similar reconstructions can be identified from the migrating particles (jumpers) during consecutive iterations after the iteration of convergence. We therefore termed the method "jumper analysis", and applied it to the output of RELION 3D classification of a benchmark experimental dataset. This work is a step forward toward fully automated single-particle reconstruction and classification of cryo-EM data.

  20. The International Migration in the EU. A Descriptive Analysis Focused on Romania

    Directory of Open Access Journals (Sweden)

    Raluca Mariana Grosu

    2013-08-01

    Full Text Available Migration represents one of the main means humans have chosen for improving their standards of living. Even though it is an important phenomenon manifested since ancient times, migration has never been so much in the attention of scholars and policy makers as it is in present times, especially for its implications in different areas such as demography, economy, sociology, politics, etc. As well, migration is a vital component of the contemporary society and in the same time plays a key role in the development of regions, from various perspectives such as economic, social, or cultural. Taking into consideration the previously outlined framework, the present paper aims at analyzing in a descriptive manner the international migration phenomenon in the European Union (EU countries between 2006 and 2010, in order to highlight the frame in which Romania is placed from the perspective of the quantitative dimension of international migration.

  1. INFERENCES FROM ROSSI TRACES

    Energy Technology Data Exchange (ETDEWEB)

    KENNETH M. HANSON; JANE M. BOOKER

    2000-09-08

    The authors an uncertainty analysis of data taken using the Rossi technique, in which the horizontal oscilloscope sweep is driven sinusoidally in time ,while the vertical axis follows the signal amplitude. The analysis is done within a Bayesian framework. Complete inferences are obtained by tilting the Markov chain Monte Carlo technique, which produces random samples from the posterior probability distribution expressed in terms of the parameters.

  2. The R Package metaLik for Likelihood Inference in Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Annamaria Guolo

    2012-08-01

    Full Text Available Meta-analysis is a statistical method for combining information from different studies about the same issue of interest. Meta-analysis is widely diffuse in medical investigation and more recently it received a growing interest also in social disciplines. Typical applications involve a small number of studies, thus making ordinary inferential methods based on first-order asymptotics unreliable. More accurate results can be obtained by exploiting the theory of higher-order asymptotics. This paper describes the metaLik package which provides an R implementation of higher-order likelihood methods in meta-analysis. The extension to meta-regression is included. Two real data examples are used to illustrate the capabilities of the package.

  3. Evolution of Near-surface Flows Inferred from High-resolution Ring-diagram Analysis

    CERN Document Server

    Bogart, Richard S; Baldner,; Basu, Sarbani

    2015-01-01

    Ring-diagram analysis of acoustic waves observed at the photosphere can provide a relatively robust determination of the sub-surface flows at a particular time under a particular region. The depth of penetration of the waves is related to the size of the region, hence the depth extent of the measured flows is inversely proportional to the spatial resolution. Most ring-diagram analysis has focused on regions of extent ~15{\\deg} (180 Mm) or more in order to provide reasonable mode sets for inversions. HMI data analysis also provides a set of ring fit parameters on a scale three times smaller. These provide flow estimates for the outer 1% (7 Mm) of the Sun only, with very limited depth resolution, but with spatial resolution adequate to map structures potentially associated with the belts and regions of magnetic activity. There are a number of systematic effects affecting the determination of flows from local helioseismic analysis of regions over different parts of the observable disk, not all well understood. I...

  4. Analysis of simulated data for the KArlsruhe TRItium Neutrino experiment using Bayesian inference

    DEFF Research Database (Denmark)

    Riis, Anna Sejersen; Hannestad, Steen; Weinheimer, C.

    2011-01-01

    neutrinos. As an alternative to the frequentist minimization methods used in the analysis of the earlier experiments in Mainz and Troitsk we have been investigating Markov chain Monte Carlo (MCMC) methods which are very well suited for probing multiparameter spaces. We found that implementing the KATRIN χ2...

  5. Return migration.

    Science.gov (United States)

    Gmelch, G

    1980-01-01

    The author reviews the findings of the growing literature on return migration. Topics covered include typologies of return migrants, reasons for return, adaptation and readjustment of returnees, and the impact of return migration on the migrants' home societies. The focus of the study is on international return migration, migration to Northern Europe and northeastern North America, and return migration to the southern and eastern fringes of Europe and the Caribbean

  6. Inferring long memory processes in the climate network via ordinal pattern analysis

    CERN Document Server

    Barreiro, Marcelo; Masoller, Cristina

    2010-01-01

    We use ordinal patterns and symbolic analysis to construct global climate networks and uncover long and short term memory processes. The data analyzed is the monthly averaged surface air temperature (SAT field) and the results suggest that the time variability of the SAT field is determined by patterns of oscillatory behavior that repeat from time to time, with a periodicity related to intraseasonal oscillations and to El Ni\\~{n}o on seasonal-to-interannual time scales.

  7. TMA Navigator: network inference, patient stratification and survival analysis with tissue microarray data

    OpenAIRE

    Lubbock, A. L. R.; Katz, E; Harrison, D J; Overton, I M

    2013-01-01

    Scottish Funding Council (SFC) and the Chief Scientist’s Office (CSO) (to D.H.); Royal Society of Edinburgh Scottish Government Fellowship co-funded by Marie Curie Actions and the UK Medical Research Council (MRC) (to I.O.). Funding for open access charge: Royal Society of Edinburgh. Tissue microarrays (TMAs) allow multiplexed analysis of tissue samples and are frequently used to estimate biomarker protein expression in tumour biopsies. TMA Navigator (www.tmanavigator.org) is an open acces...

  8. Bayesian inference – a way to combine statistical data and semantic analysis meaningfully

    Directory of Open Access Journals (Sweden)

    Eila Lindfors

    2011-11-01

    Full Text Available This article focuses on presenting the possibilities of Bayesian modelling (Finite Mixture Modelling in the semantic analysis of statistically modelled data. The probability of a hypothesis in relation to the data available is an important question in inductive reasoning. Bayesian modelling allows the researcher to use many models at a time and provides tools to evaluate the goodness of different models. The researcher should always be aware that there is no such thing as the exact probability of an exact event. This is the reason for using probabilistic models. Each model presents a different perspective on the phenomenon in focus, and the researcher has to choose the most probable model with a view to previous research and the knowledge available.The idea of Bayesian modelling is illustrated here by presenting two different sets of data, one from craft science research (n=167 and the other (n=63 from educational research (Lindfors, 2007, 2002. The principles of how to build models and how to combine different profiles are described in the light of the research mentioned.Bayesian modelling is an analysis based on calculating probabilities in relation to a specific set of quantitative data. It is a tool for handling data and interpreting it semantically. The reliability of the analysis arises from an argumentation of which model can be selected from the model space as the basis for an interpretation, and on which arguments.Keywords: method, sloyd, Bayesian modelling, student teachersURN:NBN:no-29959

  9. Do Daphnia use metalimnetic organic matter in a north temperate lake? An analysis of vertical migration

    Science.gov (United States)

    Brosseau, Chase Julian; Cline, Timothy J.; Cole, Jonathan J.; Hodgson, James R.; Pace, Michael L.; Weidel, Brian C.

    2012-01-01

    Diel vertical migration of zooplankton is influenced by a variety of factors including predation, food, and temperature. Research has recently shifted from a focus on factors influencing migration to how migration affects nutrient cycling and habitat coupling. Here we evaluate the potential for Daphnia migrations to incorporate metalimnetic productivity in a well-studied northern Wisconsin lake. We use prior studies conducted between 1985 and 1990 and current diel migration data (2008) to compare day and night Daphnia vertical distributions with the depth of the metalimnion (between the thermocline and 1% light depth). Daphnia migrate from a daytime mean residence depth of between about 1.7 and 2.5 m to a nighttime mean residence depth of between 0 and 2.0 m. These migrations are consistent between the prior period and current measurements. Daytime residence depths of Daphnia are rarely deep enough to reach the metalimnion; hence, metalimnetic primary production is unlikely to be an important resource for Daphnia in this system.

  10. Dynamical analysis of seasonal migrating population; the effect of regular hunting to the coexistence

    Science.gov (United States)

    Sambas, T. J. M.; Khaliq, B. F.; Waluyo, D. S. Y. S.; Putra, P. S.; Soewono, E.

    2016-04-01

    Seasonal migration among wild populations is commonly seen especially in the wild life region. The migration takes place during a certain season where logistical condition and the existing territory can no longer support the life of the whole population. In this case portion of the population migrate to the better place as part of their survival, and returning back to the home place when the logistical condition is improved. Here we model the dynamic of North-South annual migration of Impala population in Zimbabwe, where portion of population in the Southern part move to the North in the beginning of the dry season and portion of them return back to the South in the wet season. Here the North area has a better environmental carrying capacity than the South. Different processes take place during the year, partial migration to the south (during the month of December and January), partial migration to the north (during the month of June and July), and birth process (during the month of November and December). We construct a discrete dynamical model for simulating the annual migrating process. It is found that a stable co-existence always occurs when no hunting takes place in all season. When hunting is allowed, the co-existence could be severely affected. We obtain here a threshold condition for co-existence and show numerical simulations for different hunting scenarios.

  11. Analysis of Histone Deacetylase-Dependent Effects on Cell Migration Using the Stripe Assay.

    Science.gov (United States)

    Mertsch, Sonja; Thanos, Solon

    2017-01-01

    For normal embryonic development/morphogenesis, cell migration and homing are well-orchestrated and important events requiring specific cellular mechanisms. In diseases such as cancer deregulated cell migration represents a major problem. Therefore, numerous efforts are under way to understand the molecular mechanisms of tumor cell migration and to generate more efficient tumor therapies. Cell migration assays are one of the most commonly used functional assays. The wound-healing assay or the Boyden chamber assay are variations of these assays. Nearly all of them are two-dimensional assays and the cells can only migrate on one substrate at a time. This is in contrast to the in vivo situation where the cells are faced simultaneously with different surfaces and interact with different cell types. To approach this in vivo situation we used a modified version of the stripe assay designed by Bonhoeffer and colleagues to examine mechanisms of axonal guidance. The design of this assay allows cells to decide between two different substrates offered at the same time. Utilizing alternating neuronal substrates for migration analyses we can partially mimic the complex in vivo situation for brain tumor cells. Here we describe the detailed protocol to perform a modified version of the stripe assay in order to observe substrate-dependent migration effects in vitro, to analyze the effect of Rho-dependent kinases (ROCKS), of histone deacetylases (HDACs) and of other molecules on glioma cells.

  12. Causal inference in econometrics

    CERN Document Server

    Kreinovich, Vladik; Sriboonchitta, Songsak

    2016-01-01

    This book is devoted to the analysis of causal inference which is one of the most difficult tasks in data analysis: when two phenomena are observed to be related, it is often difficult to decide whether one of them causally influences the other one, or whether these two phenomena have a common cause. This analysis is the main focus of this volume. To get a good understanding of the causal inference, it is important to have models of economic phenomena which are as accurate as possible. Because of this need, this volume also contains papers that use non-traditional economic models, such as fuzzy models and models obtained by using neural networks and data mining techniques. It also contains papers that apply different econometric models to analyze real-life economic dependencies.

  13. Inferring phylogenies with incomplete data sets: a 5-gene, 567-taxon analysis of angiosperms

    Directory of Open Access Journals (Sweden)

    Hilu Khidir W

    2009-03-01

    Full Text Available Abstract Background Phylogenetic analyses of angiosperm relationships have used only a small percentage of available sequence data, but phylogenetic data matrices often can be augmented with existing data, especially if one allows missing characters. We explore the effects on phylogenetic analyses of adding 378 matK sequences and 240 26S rDNA sequences to the complete 3-gene, 567-taxon angiosperm phylogenetic matrix of Soltis et al. Results We performed maximum likelihood bootstrap analyses of the complete, 3-gene 567-taxon data matrix and the incomplete, 5-gene 567-taxon data matrix. Although the 5-gene matrix has more missing data (27.5% than the 3-gene data matrix (2.9%, the 5-gene analysis resulted in higher levels of bootstrap support. Within the 567-taxon tree, the increase in support is most evident for relationships among the 170 taxa for which both matK and 26S rDNA sequences were added, and there is little gain in support for relationships among the 119 taxa having neither matK nor 26S rDNA sequences. The 5-gene analysis also places the enigmatic Hydrostachys in Lamiales (BS = 97% rather than in Cornales (BS = 100% in 3-gene analysis. The placement of Hydrostachys in Lamiales is unprecedented in molecular analyses, but it is consistent with embryological and morphological data. Conclusion Adding available, and often incomplete, sets of sequences to existing data sets can be a fast and inexpensive way to increase support for phylogenetic relationships and produce novel and credible new phylogenetic hypotheses.

  14. Gene repertoire evolution of Streptococcus pyogenes inferred from phylogenomic analysis with Streptococcus canis and Streptococcus dysgalactiae.

    Science.gov (United States)

    Lefébure, Tristan; Richards, Vince P; Lang, Ping; Pavinski-Bitar, Paulina; Stanhope, Michael J

    2012-01-01

    Streptococcus pyogenes, is an important human pathogen classified within the pyogenic group of streptococci, exclusively adapted to the human host. Our goal was to employ a comparative evolutionary approach to better understand the genomic events concomitant with S. pyogenes human adaptation. As part of ascertaining these events, we sequenced the genome of one of the potential sister species, the agricultural pathogen S. canis, and combined it in a comparative genomics reconciliation analysis with two other closely related species, Streptococcus dysgalactiae and Streptococcus equi, to determine the genes that were gained and lost during S. pyogenes evolution. Genome wide phylogenetic analyses involving 15 Streptococcus species provided convincing support for a clade of S. equi, S. pyogenes, S. dysgalactiae, and S. canis and suggested that the most likely S. pyogenes sister species was S. dysgalactiae. The reconciliation analysis identified 113 genes that were gained on the lineage leading to S. pyogenes. Almost half (46%) of these gained genes were phage associated and 14 showed significant matches to experimentally verified bacteria virulence factors. Subsequent to the origin of S. pyogenes, over half of the phage associated genes were involved in 90 different LGT events, mostly involving different strains of S. pyogenes, but with a high proportion involving the horse specific pathogen S. equi subsp. equi, with the directionality almost exclusively (86%) in the S. pyogenes to S. equi direction. Streptococcus agalactiae appears to have played an important role in the evolution of S. pyogenes with a high proportion of LGTs originating from this species. Overall the analysis suggests that S. pyogenes adaptation to the human host was achieved in part by (i) the integration of new virulence factors (e.g. speB, and the sal locus) and (ii) the construction of new regulation networks (e.g. rgg, and to some extent speB).

  15. Phylogenetic relationships of some Microsporum and Arthroderma species inferred from mitochondrial DNA analysis.

    Science.gov (United States)

    Kawasaki, M; Aoki, M; Ishizaki, H

    1995-01-01

    Thirty-eight strains of 12 Microsporum and 10 Arthroderma (Nannizzia) species were investigated by analysis of mitochondrial DNA with 6 restriction enzymes, and classified into 13 genetic groups. The phylogenetic tree of the 13 groups thus established was constructed. On the tree, M. audouinii, M. langeronii, M. rivalieri, M. distortum, M. equinum, M. ferrugineum and A. otae comprise one genetic group and are suggested to be the same species. A. gypseum, A. fulvum, M. duboisii, M. ripariae, A. incurvatum, A. persicolor and A. obtusum are clustered on one of five boughs of the tree indicating their close relation. A. racemosum and A. cajetani are also closely related.

  16. Applying comparative fractal analysis to infer origin and process in channels on Earth and Mars

    Science.gov (United States)

    Balakrishnan, A.; Rice-Snow, S.; Hampton, B. A.

    2010-12-01

    Recently there has been a large amount of interest in identifying the nature of channels on (extra terrestrial) bodies. These studies are closely linked to the search for water (and ultimately signs of life) and are unarguably important. Current efforts in this direction rely on identifying geomorphic characteristics of these channels through painstaking analysis of multiple high resolution images. Here we present a new and simple technique that shows significant potential in its ability to distinguish between lava and water channels. Channels formed by water or lava on earth (as depicted in map view) display sinuosity over a large scale of range. Their geometries often point to the fluid dynamics, channel gradient, type of sediments in the river channels and for lava channels, it has been suggested that they are indicative of the thermal characteristics of the flow. The degree of this sinuosity in geometry can be measured using the divider method, and represented by fractal dimension (D) values. The higher D value corresponds to higher degree of sinuosity and channel irregularity and vice versa. Here we apply this fractal analysis to compare channels on Earth and Mars using D values extracted from satellite images. The fractal dimensions computed in this work for terrestrial river channels range from 1.04 - 1.38, terrestrial lava channels range from 1.01-1.10 and Martian channels range from 1.01 - 1.18. For terrestrial channels, preliminary results from river networks attain a fractal dimension greater than or equal to 1.1 while lava channels have fractal dimension less than or equal to 1.1. This analysis demonstrates the higher degree of irregularity present in rivers as opposed to lava channels and ratifies the utility of using fractal dimension to identify the source of channels on earth, and by extension, extra terrestrial bodies. Initial estimates of the fractal dimension from Mars fall within the same ranges as the lava channels on Earth. Based on what has

  17. Portuguese migration to the Canary Islands: an analysis based on surnames.

    Science.gov (United States)

    Román-Busto, J; Fuster, V; Colantonio, S E

    2012-01-01

    As a part of a wider analysis of population and genetic exchange between Spain and Portugal, the long-term pattern of Portuguese immigration to the Canary Islands was studied by means of the frequency of Portuguese surnames. A database of 1,995,833 individuals was obtained from the Spanish National Statistics Institute (2006). Among the 826 most frequent surnames to appear, 79 surnames of Portuguese origin were selected. The distribution of these surnames by municipalities and islands, the Fisher index of diversity, and the Lasker inter-population relationship coefficients R(ij) were considered. These coefficients were inter-correlated and correlated with other variables that could have influenced the distribution of surnames. From the observed distribution of the frequency of surnames, a non-random migration pattern conditioned by economic factors was found. The greatest diversity of surnames existed in cane cultivating areas after the first arrival of Portuguese immigrants. A later dispersion of surnames among islands was correlated with the inter-island geographic distances. In some islands the arrival of new immigrants continued due to their strategic location within the Canary archipelago. The Canary Islands reveal a high frequency and diversity of Portuguese surnames. The results also prove a heterogeneous distribution of these surnames throughout the archipelago. In contrast to the Portuguese archipelagos, some Canary localities have received immigrants continuously because of their economic importance in sugar cane cultivation and strategic geographic location on the maritime routes to Africa and America.

  18. Conflicting modes of reasoning in the Assisted Migration debate: a concept mapping analysis

    Science.gov (United States)

    Klenk, N. L.; Larson, B.

    2011-12-01

    A growing body of literature in biodiversity conservation and forestry has developed around the risks and benefits of the Assisted Migration (AM) of species, including recommendations for planning and management. However, despite years of academic debate, general consensus has yet to be reached between the proponents and the opponents of AM as a policy option. We hypothesize that the continued impasse arises out of fundamentally conflicting value judgments. Using a concept mapping technique, we analyzed reasons for and against AM, including the use of scientific evidence and the nature of the values and ethical norms that shape the modes of reasoning in the debate. Our results indicate the presence of a diversity of ethical arguments in addition to the standard precautionary argument and pragmatic reasoning. We further discovered that different kinds of scientific arguments are used by proponents versus opponents of AM: the former rely mostly on detailed biological and ecological facts about species most-at-risk under climate change, while the latter focus on broader ecological theories. Our analysis suggests little dispute over the scientific foundations of the debate. Instead, we suggest that the main barrier to consensus is the advocacy of fundamental values, which are a matter of personal choice, and thus not likely to be changed. One way out of this impasse is a pragmatic mode of reasoning, which eschews the debate on fundamental values and evaluates the means and ends of AM in a case-by-case approach.

  19. Functional analysis of all aminotransferase proteins inferred from the genome sequence of Corynebacterium glutamicum.

    Science.gov (United States)

    Marienhagen, Jan; Kennerknecht, Nicole; Sahm, Hermann; Eggeling, Lothar

    2005-11-01

    Twenty putative aminotransferase (AT) proteins of Corynebacterium glutamicum, or rather pyridoxal-5'-phosphate (PLP)-dependent enzymes, were isolated and assayed among others with L-glutamate, L-aspartate, and L-alanine as amino donors and a number of 2-oxo-acids as amino acceptors. One outstanding AT identified is AlaT, which has a broad amino donor specificity utilizing (in the order of preference) L-glutamate > 2-aminobutyrate > L-aspartate with pyruvate as acceptor. Another AT is AvtA, which utilizes L-alanine to aminate 2-oxo-isovalerate, the L-valine precursor, and 2-oxo-butyrate. A second AT active with the L-valine precursor and that of the other two branched-chain amino acids, too, is IlvE, and both enzyme activities overlap partially in vivo, as demonstrated by the analysis of deletion mutants. Also identified was AroT, the aromatic AT, and this and IlvE were shown to have comparable activities with phenylpyruvate, thus demonstrating the relevance of both ATs for L-phenylalanine synthesis. We also assessed the activity of two PLP-containing cysteine desulfurases, supplying a persulfide intermediate. One of them is SufS, which assists in the sulfur transfer pathway for the Fe-S cluster assembly. Together with the identification of further ATs and the additional analysis of deletion mutants, this results in an overview of the ATs within an organism that may not have been achieved thus far.

  20. Knowledge Representation and Inference for Analysis and Design of Database and Tabular Rule-Based Systems

    Directory of Open Access Journals (Sweden)

    Antoni Ligeza

    2001-01-01

    Full Text Available Rulebased systems constitute a powerful tool for specification of knowledge in design and implementation of knowledge based systems. They provide also a universal programming paradigm for domains such as intelligent control, decision support, situation classification and operational knowledge encoding. In order to assure safe and reliable performance, such system should satisfy certain formal requirements, including completeness and consistency. This paper addresses the issue of analysis and verification of selected properties of a class of such system in a systematic way. A uniform, tabular scheme of single-level rule-based systems is considered. Such systems can be applied as a generalized form of databases for specification of data pattern (unconditional knowledge, or can be used for defining attributive decision tables (conditional knowledge in form of rules. They can also serve as lower-level components of a hierarchical multi-level control and decision support knowledge-based systems. An algebraic knowledge representation paradigm using extended tabular representation, similar to relational database tables is presented and algebraic bases for system analysis, verification and design support are outlined.

  1. A meta-frontier approach for causal inference in productivity analysis

    DEFF Research Database (Denmark)

    Henningsen, Arne; Mpeta, Daniel F.; Adem, Anwar S.;

    (2012) and create a meta-frontier in order to estimate the effects of participation on the farms’ meta-technology ratio, their group technical efficiency, and their meta-technology technical efficiency. The empirical analysis uses a cross-sectional data set from sunflower farmers in Tanzania, where some...... of the farmers participate in contract farming while others do not. We find a significant selection bias, which justifies the use of the sample selection framework. Our preliminary results indicate that contract farming significantly increases the yield potential (meta-technology ratio) but lowers the group...... technical efficiency. As the first effect is slightly larger than the second, we find a small positive effect of contract farming on productivity (meta-technology technical efficiency). The positive effects on the yield potential and the (average) productivity can be (at least partly) explained...

  2. The origin of modern metabolic networks inferred from phylogenomic analysis of protein architecture.

    Science.gov (United States)

    Caetano-Anollés, Gustavo; Kim, Hee Shin; Mittenthal, Jay E

    2007-05-29

    Metabolism represents a complex collection of enzymatic reactions and transport processes that convert metabolites into molecules capable of supporting cellular life. Here we explore the origins and evolution of modern metabolism. Using phylogenomic information linked to the structure of metabolic enzymes, we sort out recruitment processes and discover that most enzymatic activities were associated with the nine most ancient and widely distributed protein fold architectures. An analysis of newly discovered functions showed enzymatic diversification occurred early, during the onset of the modern protein world. Most importantly, phylogenetic reconstruction exercises and other evidence suggest strongly that metabolism originated in enzymes with the P-loop hydrolase fold in nucleotide metabolism, probably in pathways linked to the purine metabolic subnetwork. Consequently, the first enzymatic takeover of an ancient biochemistry or prebiotic chemistry was related to the synthesis of nucleotides for the RNA world.

  3. Does Migration Raise Agricultural Investment? An Empirical Analysis for Rural Mexico

    OpenAIRE

    Böhme, Marcus

    2013-01-01

    The effect of remittances on capital accumulation remains a contested topic. This paper uses a panel data set from rural Mexico to investigate the impact of remittances on agriculture and livestock investments. After controlling for the endogeneity of migration through an instrumental variable estimation our empirical results show that international migration has a significantly positive effect on the accumulated agricultural assets but not on livestock capital. This suggests that households ...

  4. Topographic factor analysis: a Bayesian model for inferring brain networks from neural data.

    Directory of Open Access Journals (Sweden)

    Jeremy R Manning

    Full Text Available The neural patterns recorded during a neuroscientific experiment reflect complex interactions between many brain regions, each comprising millions of neurons. However, the measurements themselves are typically abstracted from that underlying structure. For example, functional magnetic resonance imaging (fMRI datasets comprise a time series of three-dimensional images, where each voxel in an image (roughly reflects the activity of the brain structure(s-located at the corresponding point in space-at the time the image was collected. FMRI data often exhibit strong spatial correlations, whereby nearby voxels behave similarly over time as the underlying brain structure modulates its activity. Here we develop topographic factor analysis (TFA, a technique that exploits spatial correlations in fMRI data to recover the underlying structure that the images reflect. Specifically, TFA casts each brain image as a weighted sum of spatial functions. The parameters of those spatial functions, which may be learned by applying TFA to an fMRI dataset, reveal the locations and sizes of the brain structures activated while the data were collected, as well as the interactions between those structures.

  5. Variation in winter diet of southern Beaufort Sea polar bears inferred from stable isotope analysis

    Science.gov (United States)

    Bentzen, T.W.; Follmann, E.H.; Amstrup, Steven C.; York, G.S.; Wooller, M.J.; O'Hara, T. M.

    2007-01-01

    Ringed seals (Phoca hispida Schreber, 1775 = Pusa hispida (Schreber, 1775)) and bearded seals (Erignathus barbatus (Erxleben, 1777)) represent the majority of the polar bear (Ursus maritimus Phipps, 1774) annual diet. However, remains of lower trophic level bowhead whales (Balaena mysticetus L., 1758) are available in the southern Beaufort Sea and their dietary contribution to polar bears has been unknown. We used stable isotope (13C/12C, δ13C, 15N/14N, and δ15N) analysis to determine the diet composition of polar bears sampled along Alaska’s Beaufort Sea coast in March and April 2003 and 2004. The mean δ15N values of polar bear blood cells were 19.5‰ (SD = 0.7‰) in 2003 and 19.9‰ (SD = 0.7‰) in 2004. Mixing models indicated bowhead whales composed 11%–26% (95% CI) of the diets of sampled polar bears in 2003, and 0%–14% (95% CI) in 2004. This suggests significant variability in the proportion of lower trophic level prey in polar bear diets among individuals and between years. Polar bears depend on sea ice for hunting seals, and the temporal and spatial availabilities of sea ice are projected to decline. Consumption of low trophic level foods documented here suggests bears may increasingly scavenge such foods in the future.

  6. Genetic variation and population structure of the mushroom Pleurotusferulae in China inferred from nuclear DNA analysis

    Institute of Scientific and Technical Information of China (English)

    ZHAO Meng-ran; HUANG Chen-yang; WU Xiang-li; CHEN Qiang; QU Ji-bin; LI Yan-chun; GAO Wei; ZHANG Jin-xia

    2016-01-01

    To investigate the genetic diversity of an edible fungusPleurotus ferulae, a total of 89 wild samples colected from six geographical locations in the Xinjiang Uygur Autonomous Region of China and two geographical locations in Italy, were analyzed using three DNA fragments including the translation elongation factor (EF1α), the second largest subunit of the RNA polymerase II (RPB2) and the largest subunit of the RNA polymerase II (RPB1). The results indicated relatively abundant genetic variability in the wild resources ofP.ferulae.The analysis of molecular variance (AMOVA) showed that the vast majority of the genetic variation was found within geographical populations. Both the Chinese populations and the Italian populations ofP. ferulaedisplayed a limited genetic differentiation. The degree of differentiation between the Chinese populations and the Italian populations was obviously higher than that between the populations from the same region, and moreover the genetic differentiation among al the tested populations was correlated to the geographical dis-tance. The phylogeny analyses conifrmed that samples from China and Italy belonged to another genetic group separated fromPleurotus eryngi. They were closely related to each other but were clustered according to their geographical origins, which implied the Chinese populations were highly differentiated from the Italian populations because of distance isolation, and the two populations from different regions might be stil in the process of alopatric divergence.

  7. Phylogenetic inferences in Avena based on analysis of FL intron2 sequences.

    Science.gov (United States)

    Peng, Yuan-Ying; Wei, Yu-Ming; Baum, Bernard R; Yan, Ze-Hong; Lan, Xiu-Jin; Dai, Shou-Fen; Zheng, You-Liang

    2010-09-01

    The development and application of molecular methods in oats has been relatively slow compared with other crops. Results from the previous analyses have left many questions concerning species evolutionary relationships unanswered, especially regarding the origins of the B and D genomes, which are only known to be present in polyploid oat species. To investigate the species and genome relationships in genus Avena, among 13 diploid (A and C genomes), we used the second intron of the nuclear gene FLORICAULA/LEAFY (FL int2) in seven tetraploid (AB and AC genomes), and five hexaploid (ACD genome) species. The Avena FL int2 is rather long, and high levels of variation in length and sequence composition were found. Evidence for more than one copy of the FL int2 sequence was obtained for both the A and C genome groups, and the degree of divergence of the A genome copies was greater than that observed within the C genome sequences. Phylogenetic analysis of the FL int2 sequences resulted in topologies that contained four major groups; these groups reemphasize the major genomic divergence between the A and C genomes, and the close relationship among the A, B, and D genomes. However, the D genome in hexaploids more likely originated from a C genome diploid rather than the generally believed A genome, and the C genome diploid A. clauda may have played an important role in the origination of both the C and D genome in polyploids.

  8. Historical metal pollution in natural gudgeon populations: Inferences from allozyme, microsatellite and condition factor analysis

    Energy Technology Data Exchange (ETDEWEB)

    Knapen, Dries, E-mail: dries.knapen@ua.ac.be [University of Antwerp, Department of Biology, Ecophysiology, Biochemistry and Toxicology Research Group, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); De Wolf, Hans [University of Antwerp, Department of Biology, Ecophysiology, Biochemistry and Toxicology Research Group, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Knaepkens, Guy [University of Antwerp, Department of Biology, Ethology Research Group, Universiteitsplein 1, 2610 Wilrijk (Belgium); Bervoets, Lieven [University of Antwerp, Department of Biology, Ecophysiology, Biochemistry and Toxicology Research Group, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Eens, Marcel [University of Antwerp, Department of Biology, Ethology Research Group, Universiteitsplein 1, 2610 Wilrijk (Belgium); Blust, Ronny [University of Antwerp, Department of Biology, Ecophysiology, Biochemistry and Toxicology Research Group, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Verheyen, Erik [Royal Belgian Institute of Natural Sciences, Department of Vertebrates, Molecular Laboratory, Vautierstraat 29, 1000 Brussel (Belgium)

    2009-10-19

    This study presents the results of a microsatellite and allozyme analysis on natural populations of the gudgeon (Gobio gobio) located in a pollution gradient of cadmium and zinc. Differences among contaminated and reference populations were observed at 2 allozyme loci, as well as a relationship between the fish condition factor and glucose-6-phosphate dehydrogenase genotypes, the locus that showed the largest difference in allele frequencies. The microsatellite data partly confirmed the differentiation pattern that was revealed by the allozyme survey. Our data further suggest that at least 2 microsatellite loci may be affected by natural selection. We thus illustrate that both microsatellite and allozyme loci do not necessarily behave as selectively neutral markers in polluted populations. Estimates of population differentiation can therefore be significantly different depending on which loci are being studied. Finally, these results are discussed in the light of the conservation unit concept, because microsatellites are often used to assess genetic variation in endangered natural populations and to propose measures for conservation or management.

  9. Stochastic processes inference theory

    CERN Document Server

    Rao, Malempati M

    2014-01-01

    This is the revised and enlarged 2nd edition of the authors’ original text, which was intended to be a modest complement to Grenander's fundamental memoir on stochastic processes and related inference theory. The present volume gives a substantial account of regression analysis, both for stochastic processes and measures, and includes recent material on Ridge regression with some unexpected applications, for example in econometrics. The first three chapters can be used for a quarter or semester graduate course on inference on stochastic processes. The remaining chapters provide more advanced material on stochastic analysis suitable for graduate seminars and discussions, leading to dissertation or research work. In general, the book will be of interest to researchers in probability theory, mathematical statistics and electrical and information theory.

  10. A method of spherical harmonic analysis in the geosciences via hierarchical Bayesian inference

    Science.gov (United States)

    Muir, J. B.; Tkalčić, H.

    2015-11-01

    The problem of decomposing irregular data on the sphere into a set of spherical harmonics is common in many fields of geosciences where it is necessary to build a quantitative understanding of a globally varying field. For example, in global seismology, a compressional or shear wave speed that emerges from tomographic images is used to interpret current state and composition of the mantle, and in geomagnetism, secular variation of magnetic field intensity measured at the surface is studied to better understand the changes in the Earth's core. Optimization methods are widely used for spherical harmonic analysis of irregular data, but they typically do not treat the dependence of the uncertainty estimates on the imposed regularization. This can cause significant difficulties in interpretation, especially when the best-fit model requires more variables as a result of underestimating data noise. Here, with the above limitations in mind, the problem of spherical harmonic expansion of irregular data is treated within the hierarchical Bayesian framework. The hierarchical approach significantly simplifies the problem by removing the need for regularization terms and user-supplied noise estimates. The use of the corrected Akaike Information Criterion for picking the optimal maximum degree of spherical harmonic expansion and the resulting spherical harmonic analyses are first illustrated on a noisy synthetic data set. Subsequently, the method is applied to two global data sets sensitive to the Earth's inner core and lowermost mantle, consisting of PKPab-df and PcP-P differential traveltime residuals relative to a spherically symmetric Earth model. The posterior probability distributions for each spherical harmonic coefficient are calculated via Markov Chain Monte Carlo sampling; the uncertainty obtained for the coefficients thus reflects the noise present in the real data and the imperfections in the spherical harmonic expansion.

  11. Nematode Diversity of Qingdao Coast Inferred from the 18S Ribosomal RNA Gene Sequence Analysis

    Institute of Scientific and Technical Information of China (English)

    SHEN Xiquan; YANG Guanpin; LIU Yongjian

    2007-01-01

    The 18S ribosomal DNA gene (18S rDNA) sequences (approximately 1300 bp in length) were amplified from the DNA extracted from the free-living marine nematodes collected from the inter-tidal sediment of Qingdao coast in bulk with nematode specific primers. The PCR products were cloned, re-amplified, digested with Rsa I and Hin6Ⅰ restriction endonucleases and separated in agarose gel. Among 17 restriction fragment length types, types 1, 2 and 6 covered 61.2%, 14.4% and 9.3% of the clones analyzed, respectively, while the remaining 14 only covered 21 clones, which accounted for 15.1% of the total. Twenty-four representative clones were sequenced and phylogenetically analyzed by referring to those currently available in RDP and GenBank databases. Although it was hard to assign these sequences to known species or genera due to the lack of the 18S rDNA sequence data of known marine free-living nematodes, the obtained sequences were assigned to the nematodes of Adenophorea. Among them, twelve sequences were close to Pontonema vulgare and Adoncholaimus sp., four to Daptonemaprocerus and two (identical) to Enoplus brevis. Our results showed that free-living marine nematode diversities could be determined by PCR retrieving and analysis of the 18S rDNA sequences and an 18S rDNA sequence could be assigned to a species or a genus only if the 18S rDNA sequences of the free-living marine nematodes were accumulated to some extent.

  12. Maternal inheritance in polyploid fish inferred from mitochondrial ATPase genes analysis

    Institute of Scientific and Technical Information of China (English)

    Jinpeng Yan; Xinhong Guo; Shaojun Liu; Jun Xiao; Zhen Liu; Yubao Chen; Yun Liu

    2009-01-01

    The sequences of the ATPase8/6 genes for the triploid, tetraploid and pentaploid hybrids as well as for their male parent blunt snout bream were determined. In order to examine mitochondrial maternal inheritance, the sequences were subjected to a comparative sequence analysis with the homologous sequences of red crucian carp, their female parent, and zebrafish as the outgroup. Base compo-sition and variation as well as the divergences based on nucleotide sequences and deduced amino acid sequences were calculated. Phy-logenetic trees were also constructed with maximum parsimony (MP), minimum evolution (ME), neighbor joining (NJ) and the unweighted pair group method with arithmetic mean (UPGMA) algorithms in MEGA 3.1. The results showed that most nucleotide sub-stitutions occurred at the third codon position of the two genes and thus represented synonymous mutations. The nucleotide sequence divergences of the ATPase8/6 genes ranged from 0.0% to 21.6% among ingroup samples (three types of polyploids and their parents), and 27.0-28.2% between their ingroup and the outgroup samples. All the polyploids were considerably closer in sequence relationship to the female parent red crucian carp (0.0-3.3%) compared to their male parent blunt snout bream (21.0-21.6%). The phylogenetic trees also showed a similar result. In conclusion, the mitochondrial ATPase8/6 genes of artificial polyploid fish stringently indicated maternal inheritance. Our results also suggested that the ATPase8/6 genes are valuable genetic markers to track genealogies and variations in the progenies of the hybrids.

  13. Analysis of the population structure of Uruguayan Creole cattle as inferred from milk major gene polymorphisms

    Directory of Open Access Journals (Sweden)

    Gonzalo Rincón

    2006-01-01

    Full Text Available The ancestors of Uruguayan Creole cattle were introduced by the Spanish conquerors in the XVII century, following which the population grew extensively and became semi-feral before the introduction of selected breeds. Today the Uruguayan Creole cattle genetic reserve consists of 575 animals. We used the tetra primer amplification refractory mutation system polymerase chain reaction (ARMS-PCR to analyze the kappa-casein, beta-casein, alphaS1-casein and alpha-lactoalbumin gene polymorphisms and restriction fragment length polymorphism PCR (RFLP-PCR for the beta-lactoglobulin and the acylCoA:diacyl glycerol acyltransferase 1 (DGAT1 genes. The kappa-casein and beta-lactoglobulin genes presented very similar A and B allele frequencies, while the alphas1-casein and alpha-lactoalbumin gene B alleles showed much higher frequencies than the corresponding A alleles. The beta-casein B allele was not found in the population sampled. There was a very high frequency of the DGAT1 gene A allele which is associated with low milk fat content and high milk yield. All loci were in Hardy-Weinberg equilibrium and the level of heterozygosity agreed with the high genetic diversity observed in a previous analysis of this population. Preservation of the allelic richness observed in the Uruguayan Creole cattle should be considered for future dairy management and livestock genetic improvement. The results also emphasize the value of the tetra primers ARMS-PCR technique as a rapid, easy and economical way of genotyping cattle breeds for milk gene single nucleotide polymorphisms.

  14. Global sensitivity analysis and Bayesian parameter inference for solute transport in porous media colonized by biofilms

    Science.gov (United States)

    Younes, A.; Delay, F.; Fajraoui, N.; Fahs, M.; Mara, T. A.

    2016-08-01

    The concept of dual flowing continuum is a promising approach for modeling solute transport in porous media that includes biofilm phases. The highly dispersed transit time distributions often generated by these media are taken into consideration by simply stipulating that advection-dispersion transport occurs through both the porous and the biofilm phases. Both phases are coupled but assigned with contrasting hydrodynamic properties. However, the dual flowing continuum suffers from intrinsic equifinality in the sense that the outlet solute concentration can be the result of several parameter sets of the two flowing phases. To assess the applicability of the dual flowing continuum, we investigate how the model behaves with respect to its parameters. For the purpose of this study, a Global Sensitivity Analysis (GSA) and a Statistical Calibration (SC) of model parameters are performed for two transport scenarios that differ by the strength of interaction between the flowing phases. The GSA is shown to be a valuable tool to understand how the complex system behaves. The results indicate that the rate of mass transfer between the two phases is a key parameter of the model behavior and influences the identifiability of the other parameters. For weak mass exchanges, the output concentration is mainly controlled by the velocity in the porous medium and by the porosity of both flowing phases. In the case of large mass exchanges, the kinetics of this exchange also controls the output concentration. The SC results show that transport with large mass exchange between the flowing phases is more likely affected by equifinality than transport with weak exchange. The SC also indicates that weakly sensitive parameters, such as the dispersion in each phase, can be accurately identified. Removing them from calibration procedures is not recommended because it might result in biased estimations of the highly sensitive parameters.

  15. Genetic characterization and evolutionary inference of TNF-α through computational analysis

    Directory of Open Access Journals (Sweden)

    Gauri Awasthi

    2008-10-01

    Full Text Available TNF-α is an important human cytokine that imparts dualism in malaria pathogenicity. At high dosages, TNF-α is believed to provoke pathogenicity in cerebral malaria; while at lower dosages TNF-α is protective against severe human malaria. In order to understand the human TNF-α gene and to ascertain evolutionary aspects of its dualistic nature for malaria pathogenicity, we characterized this gene in detail in six different mammalian taxa. The avian taxon, Gallus gallus was included in our study, as TNF-α is not present in birds; therefore, a tandemly placed duplicate of TNF-α (LT-α or TNF-β was included. A comparative study was made of nucleotide length variations, intron and exon sizes and number variations, differential compositions of coding to non-coding bases, etc., to look for similarities/dissimilarities in the TNF-α gene across all seven taxa. A phylogenetic analysis revealed the pattern found in other genes, as humans, chimpanzees and rhesus monkeys were placed in a single clade, and rats and mice in another; the chicken was in a clearly separate branch. We further focused on these three taxa and aligned the amino acid sequences; there were small differences between humans and chimpanzees; both were more different from the rhesus monkey. Further, comparison of coding and non-coding nucleotide length variations and coding to non-coding nucleotide ratio between TNF-α and TNF-β among these three mammalian taxa provided a first-hand indication of the role of the TNF-α gene, but not of TNF-β in the dualistic nature of TNF-α in malaria pathogenicity.

  16. Global developmental gene expression and pathway analysis of normal brain development and mouse models of human neuronal migration defects.

    Science.gov (United States)

    Pramparo, Tiziano; Libiger, Ondrej; Jain, Sonia; Li, Hong; Youn, Yong Ha; Hirotsune, Shinji; Schork, Nicholas J; Wynshaw-Boris, Anthony

    2011-03-01

    Heterozygous LIS1 mutations are the most common cause of human lissencephaly, a human neuronal migration defect, and DCX mutations are the most common cause of X-linked lissencephaly. LIS1 is part of a protein complex including NDEL1 and 14-3-3ε that regulates dynein motor function and microtubule dynamics, while DCX stabilizes microtubules and cooperates with LIS1 during neuronal migration and neurogenesis. Targeted gene mutations of Lis1, Dcx, Ywhae (coding for 14-3-3ε), and Ndel1 lead to neuronal migration defects in mouse and provide models of human lissencephaly, as well as aid the study of related neuro-developmental diseases. Here we investigated the developing brain of these four mutants and wild-type mice using expression microarrays, bioinformatic analyses, and in vivo/in vitro experiments to address whether mutations in different members of the LIS1 neuronal migration complex lead to similar and/or distinct global gene expression alterations. Consistent with the overall successful development of the mutant brains, unsupervised clustering and co-expression analysis suggested that cell cycle and synaptogenesis genes are similarly expressed and co-regulated in WT and mutant brains in a time-dependent fashion. By contrast, focused co-expression analysis in the Lis1 and Ndel1 mutants uncovered substantial differences in the correlation among pathways. Differential expression analysis revealed that cell cycle, cell adhesion, and cytoskeleton organization pathways are commonly altered in all mutants, while synaptogenesis, cell morphology, and inflammation/immune response are specifically altered in one or more mutants. We found several commonly dysregulated genes located within pathogenic deletion/duplication regions, which represent novel candidates of human mental retardation and neurocognitive disabilities. Our analysis suggests that gene expression and pathway analysis in mouse models of a similar disorder or within a common pathway can be used to define

  17. Wavelet phase analysis of two velocity components to infer the structure of interscale transfers in a turbulent boundary-layer

    Energy Technology Data Exchange (ETDEWEB)

    Keylock, Christopher J [Sheffield Fluid Mechanics Group and Department of Civil and Structural Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD (United Kingdom); Nishimura, Kouichi, E-mail: c.keylock@sheffield.ac.uk [Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)

    2016-04-15

    Scale-dependent phase analysis of velocity time series measured in a zero pressure gradient boundary layer shows that phase coupling between longitudinal and vertical velocity components is strong at both large and small scales, but minimal in the middle of the inertial regime. The same general pattern is observed at all vertical positions studied, but there is stronger phase coherence as the vertical coordinate, y, increases. The phase difference histograms evolve from a unimodal shape at small scales to the development of significant bimodality at the integral scale and above. The asymmetry in the off-diagonal couplings changes sign at the midpoint of the inertial regime, with the small scale relation consistent with intense ejections followed by a more prolonged sweep motion. These results may be interpreted in a manner that is consistent with the action of low speed streaks and hairpin vortices near the wall, with large scale motions further from the wall, the effect of which penetrates to smaller scales. Hence, a measure of phase coupling, when combined with a scale-by-scale decomposition of perpendicular velocity components, is a useful tool for investigating boundary-layer structure and inferring process from single-point measurements. (paper)

  18. EXTERNAL MIGRATION AS HAVING ROMANIA AS A COUNTRY ORIGIN – A FEW STRUCTURAL ANALYSIS ELEMENTS AND IMPACT ON LABOUR

    Directory of Open Access Journals (Sweden)

    Eduard Andrei CIOCĂNESCU

    2011-09-01

    Full Text Available The main purpose of the following article is to present, based on the Eurostat and INS research, the structure of the Romanian immigrants according to age and sex. The second objective of this article is to show the impact that the external migration phenomenon has on labour market at national level.The approaches are quantitative and specific elements of the descriptive statistics and more advanced procedures of the analysis of the bounds between variables are being used.

  19. Global migration topology analysis and modeling of bilateral flow network 2006-2010

    Science.gov (United States)

    Porat, I.; Benguigui, L.

    2016-07-01

    Migration is one of the most dramatic and vast human processes in modern times. Migration is defined as people that leave their home and home-land and move to a new country. In this research we address the pattern of this massive human movement with the tools of network theory. The undirected global flow migration network (2006-2010) was identified as an exclusive disassortative network which combines two types of defined groups of large- and small-degree (D) countries with betweeness (Be) of Be˜D 3. This structure was modeled and simulated with synthetic networks of similar characteristics as the global flow migration network, and the results suggest that small-degree nodes have the topology of random networks, but the dominant part of the large-degree hubs controls this topology and shapes the network into an ultra-small world. This exclusive topology and the difference of the global flow migration network from scale-free and from Erdös-Rényi networks may be a result of two defined and different topologies of large- and small-degree countries.

  20. Analysis and migration of phthalates in infant food packed in recycled paperboard.

    Science.gov (United States)

    Gärtner, Sonja; Balski, Matthias; Koch, Matthias; Nehls, Irene

    2009-11-25

    The contamination of infant food with substances from its packaging due to migration processes is still a problem. Most recently, great attention was paid to the migration of epoxidized soybean oil (ESBO) and phthalates from twist-off closures into baby food packed in glass jars. Besides, packaging made of recycled fiber materials such as paper and paperboard were found to be the source of contaminants in dry and powdery foodstuffs such as sugar, rice, and maize flour. In this study 20 infant food samples packed in recycled paperboard containers were tested for phthalates and diisopropyl naphthalenes (DIPN), known incorporated substances in recycled paper. Furthermore, the barrier function of different secondary packaging materials (paper and aluminum-coated foil) was investigated. The highest contents of phthalates (mainly diisobutyl phthalate, DiBP) and DIPN in infant food samples were found for those foods packed in inner bags made of paper. Migration experiments were performed under authentic conditions to evaluate possible transfer mechanism (gas phase, direct contact) of phthalate esters into foodstuff. It is shown that paper does not provide an appropriate barrier against migration of semipolar compounds such as phthalates. The air space itself otherwise effectively prevents migration of the less volatile phthalates under the applied conditions.

  1. Analysis of saturated and aromatic hydrocarbons migrating from a polyolefin-based hot-melt adhesive into food.

    Science.gov (United States)

    Lommatzsch, Martin; Biedermann, Maurus; Grob, Koni; Simat, Thomas J

    2016-01-01

    Hot-melt adhesives are widely utilised to glue cardboard boxes used as food packaging material. They have to comply with the requirements of Article 3 of the European Framework Regulation for food contact materials (1935/2004). The hot melt raw materials analysed mainly consisted of paraffinic waxes, hydrocarbon resins and polyolefins. The hydrocarbon resins, functioning as tackifiers, were the predominant source of hydrocarbons of sufficient volatility to migrate into dry foods: the 18 hydrocarbon resins analysed contained 8.2-118 g kg(-1) saturated and up to 59 g kg(-1) aromatic hydrocarbons eluted from GC between n-C16 and n-C24, substantially more than the paraffinic waxes and the polyolefins. These tackfier resins, especially the oligomers ≤ C24, have been characterised structurally by GC×GC-MS and (1)H-NMR spectroscopy. Migration into food was estimated using a simulating system with polenta as food simulant, which was verified by the analysis of a commercial risotto rice sample packed in a virgin fibre folding box sealed with a hot melt. About 0.5-1.5% of the potentially migrating substances (between n-C16 and n-C24) of a hot melt were found to be transferred into food under storage conditions, which can result in a food contamination in the order of 1 mg kg(-1) food (depending on the amount of potentially migrating substances from the hot melt, the hot melt surface, amount of food, contact time etc.). Migrates from hot melts are easily mistaken for mineral oil hydrocarbons from recycled cardboard.

  2. Kinship Paths To and From the New Europe: A Unified Analysis of Peruvian Adoption and Migration

    Science.gov (United States)

    Leinaweaver, Jessaca B.

    2013-01-01

    This article compares migrants and adoptees of Peruvian origin residing in Europe by focusing on their respective movements out of and return to the sending country of Peru. First, it analyzes family-based reunifications by drawing on a framework from studies of adoption and kinship. Juxtaposing the experiences of adoptees with those of migrants reveals how migration, too, may be steeped in concerns about kin ties. Next, it analyzes returns of adult adoptees using a template modeled on migrant returns, focusing on the centrality of the notion of contribution. The article shows how migrants and adoptees contest the constraints of European nation-state definitions of kinship intended to limit migration. It is based on recent research with Peruvian migrants and adoptees in Spain, as well as longer-term research in Peru on migration and adoption. PMID:24443664

  3. PERFORMANCE ANALYSIS OF TRANSPORT PROTOCOL DURING LIVE MIGRATION OF VIRTUAL MACHINES

    Directory of Open Access Journals (Sweden)

    Prakash H R

    2011-10-01

    Full Text Available The Physical servers used in IT are under-utilized. The better utilization of these servers can be achieved using virtualization technology. Virtualization techniques create multiple partitions whichare isolated with each other called virtual machines. Each virtual machine (guest runs their own operating system. The resource allocated for these VMs may fail to execute an application because ofresource conflict or un availability of resources. This motivates towards live migration of virtual machines. The live migration copies the running VM from source host to destination host seamlesslyusing TCP as transport protocol.This paper evaluates performance of TCP in live migration of KVM based virtual machines. The flexibility in UDP which drives the concentration can also be used for thismigration.

  4. Comparative analysis of dynamic cell viability, migration and invasion assessments by novel real-time technology and classic endpoint assays.

    Directory of Open Access Journals (Sweden)

    Ridha Limame

    Full Text Available BACKGROUND: Cell viability and motility comprise ubiquitous mechanisms involved in a variety of (pathobiological processes including cancer. We report a technical comparative analysis of the novel impedance-based xCELLigence Real-Time Cell Analysis detection platform, with conventional label-based endpoint methods, hereby indicating performance characteristics and correlating dynamic observations of cell proliferation, cytotoxicity, migration and invasion on cancer cells in highly standardized experimental conditions. METHODOLOGY/PRINCIPAL FINDINGS: Dynamic high-resolution assessments of proliferation, cytotoxicity and migration were performed using xCELLigence technology on the MDA-MB-231 (breast cancer and A549 (lung cancer cell lines. Proliferation kinetics were compared with the Sulforhodamine B (SRB assay in a series of four cell concentrations, yielding fair to good correlations (Spearman's Rho 0.688 to 0.964. Cytotoxic action by paclitaxel (0-100 nM correlated well with SRB (Rho>0.95 with similar IC(50 values. Reference cell migration experiments were performed using Transwell plates and correlated by pixel area calculation of crystal violet-stained membranes (Rho 0.90 and optical density (OD measurement of extracted dye (Rho>0.95. Invasion was observed on MDA-MB-231 cells alone using Matrigel-coated Transwells as standard reference method and correlated by OD reading for two Matrigel densities (Rho>0.95. Variance component analysis revealed increased variances associated with impedance-based detection of migration and invasion, potentially caused by the sensitive nature of this method. CONCLUSIONS/SIGNIFICANCE: The xCELLigence RTCA technology provides an accurate platform for non-invasive detection of cell viability and motility. The strong correlations with conventional methods imply a similar observation of cell behavior and interchangeability with other systems, illustrated by the highly correlating kinetic invasion profiles on

  5. Russell and Humean Inferences

    Directory of Open Access Journals (Sweden)

    João Paulo Monteiro

    2001-12-01

    Full Text Available Russell's The Problems of Philosophy tries to establish a new theory of induction, at the same time that Hume is there accused of an irrational/ scepticism about induction". But a careful analysis of the theory of knowledge explicitly acknowledged by Hume reveals that, contrary to the standard interpretation in the XXth century, possibly influenced by Russell, Hume deals exclusively with causal inference (which he never classifies as "causal induction", although now we are entitled to do so, never with inductive inference in general, mainly generalizations about sensible qualities of objects ( whether, e.g., "all crows are black" or not is not among Hume's concerns. Russell's theories are thus only false alternatives to Hume's, in (1912 or in his (1948.

  6. Drought prediction using co-active neuro-fuzzy inference system, validation, and uncertainty analysis (case study: Birjand, Iran)

    Science.gov (United States)

    Memarian, Hadi; Pourreza Bilondi, Mohsen; Rezaei, Majid

    2016-08-01

    This work aims to assess the capability of co-active neuro-fuzzy inference system (CANFIS) for drought forecasting of Birjand, Iran through the combination of global climatic signals with rainfall and lagged values of Standardized Precipitation Index (SPI) index. Using stepwise regression and correlation analyses, the signals NINO 1 + 2, NINO 3, Multivariate Enso Index, Tropical Southern Atlantic index, Atlantic Multi-decadal Oscillation index, and NINO 3.4 were recognized as the effective signals on the drought event in Birjand. Based on the results from stepwise regression analysis and regarding the processor limitations, eight models were extracted for further processing by CANFIS. The metrics P-factor and D-factor were utilized for uncertainty analysis, based on the sequential uncertainty fitting algorithm. Sensitivity analysis showed that for all models, NINO indices and rainfall variable had the largest impact on network performance. In model 4 (as the model with the lowest error during training and testing processes), NINO 1 + 2(t-5) with an average sensitivity of 0.7 showed the highest impact on network performance. Next, the variables rainfall, NINO 1 + 2(t), and NINO 3(t-6) with the average sensitivity of 0.59, 0.28, and 0.28, respectively, could have the highest effect on network performance. The findings based on network performance metrics indicated that the global indices with a time lag represented a better correlation with El Niño Southern Oscillation (ENSO). Uncertainty analysis of the model 4 demonstrated that 68 % of the observed data were bracketed by the 95PPU and D-Factor value (0.79) was also within a reasonable range. Therefore, the fourth model with a combination of the input variables NINO 1 + 2 (with 5 months of lag and without any lag), monthly rainfall, and NINO 3 (with 6 months of lag) and correlation coefficient of 0.903 (between observed and simulated SPI) was selected as the most accurate model for drought forecasting using CANFIS

  7. In-depth analysis of protein inference algorithms using multiple search engines and well-defined metrics.

    Science.gov (United States)

    Audain, Enrique; Uszkoreit, Julian; Sachsenberg, Timo; Pfeuffer, Julianus; Liang, Xiao; Hermjakob, Henning; Sanchez, Aniel; Eisenacher, Martin; Reinert, Knut; Tabb, David L; Kohlbacher, Oliver; Perez-Riverol, Yasset

    2017-01-06

    In mass spectrometry-based shotgun proteomics, protein identifications are usually the desired result. However, most of the analytical methods are based on the identification of reliable peptides and not the direct identification of intact proteins. Thus, assembling peptides identified from tandem mass spectra into a list of proteins, referred to as protein inference, is a critical step in proteomics research. Currently, different protein inference algorithms and tools are available for the proteomics community. Here, we evaluated five software tools for protein inference (PIA, ProteinProphet, Fido, ProteinLP, MSBayesPro) using three popular database search engines: Mascot, X!Tandem, and MS-GF+. All the algorithms were evaluated using a highly customizable KNIME workflow using four different public datasets with varying complexities (different sample preparation, species and analytical instruments). We defined a set of quality control metrics to evaluate the performance of each combination of search engines, protein inference algorithm, and parameters on each dataset. We show that the results for complex samples vary not only regarding the actual numbers of reported protein groups but also concerning the actual composition of groups. Furthermore, the robustness of reported proteins when using databases of differing complexities is strongly dependant on the applied inference algorithm. Finally, merging the identifications of multiple search engines does not necessarily increase the number of reported proteins, but does increase the number of peptides per protein and thus can generally be recommended.

  8. Kinetic Analysis of Dynamic Positron Emission Tomography Data using Open-Source Image Processing and Statistical Inference Tools.

    Science.gov (United States)

    Hawe, David; Hernández Fernández, Francisco R; O'Suilleabháin, Liam; Huang, Jian; Wolsztynski, Eric; O'Sullivan, Finbarr

    2012-05-01

    In dynamic mode, positron emission tomography (PET) can be used to track the evolution of injected radio-labelled molecules in living tissue. This is a powerful diagnostic imaging technique that provides a unique opportunity to probe the status of healthy and pathological tissue by examining how it processes substrates. The spatial aspect of PET is well established in the computational statistics literature. This article focuses on its temporal aspect. The interpretation of PET time-course data is complicated because the measured signal is a combination of vascular delivery and tissue retention effects. If the arterial time-course is known, the tissue time-course can typically be expressed in terms of a linear convolution between the arterial time-course and the tissue residue. In statistical terms, the residue function is essentially a survival function - a familiar life-time data construct. Kinetic analysis of PET data is concerned with estimation of the residue and associated functionals such as flow, flux, volume of distribution and transit time summaries. This review emphasises a nonparametric approach to the estimation of the residue based on a piecewise linear form. Rapid implementation of this by quadratic programming is described. The approach provides a reference for statistical assessment of widely used one- and two-compartmental model forms. We illustrate the method with data from two of the most well-established PET radiotracers, (15)O-H(2)O and (18)F-fluorodeoxyglucose, used for assessment of blood perfusion and glucose metabolism respectively. The presentation illustrates the use of two open-source tools, AMIDE and R, for PET scan manipulation and model inference.

  9. Data partitions, Bayesian analysis and phylogeny of the zygomycetous fungal family Mortierellaceae, inferred from nuclear ribosomal DNA sequences.

    Directory of Open Access Journals (Sweden)

    Tamás Petkovits

    Full Text Available Although the fungal order Mortierellales constitutes one of the largest classical groups of Zygomycota, its phylogeny is poorly understood and no modern taxonomic revision is currently available. In the present study, 90 type and reference strains were used to infer a comprehensive phylogeny of Mortierellales from the sequence data of the complete ITS region and the LSU and SSU genes with a special attention to the monophyly of the genus Mortierella. Out of 15 alternative partitioning strategies compared on the basis of Bayes factors, the one with the highest number of partitions was found optimal (with mixture models yielding the best likelihood and tree length values, implying a higher complexity of evolutionary patterns in the ribosomal genes than generally recognized. Modeling the ITS1, 5.8S, and ITS2, loci separately improved model fit significantly as compared to treating all as one and the same partition. Further, within-partition mixture models suggests that not only the SSU, LSU and ITS regions evolve under qualitatively and/or quantitatively different constraints, but that significant heterogeneity can be found within these loci also. The phylogenetic analysis indicated that the genus Mortierella is paraphyletic with respect to the genera Dissophora, Gamsiella and Lobosporangium and the resulting phylogeny contradict previous, morphology-based sectional classification of Mortierella. Based on tree structure and phenotypic traits, we recognize 12 major clades, for which we attempt to summarize phenotypic similarities. M. longicollis is closely related to the outgroup taxon Rhizopus oryzae, suggesting that it belongs to the Mucorales. Our results demonstrate that traits used in previous classifications of the Mortierellales are highly homoplastic and that the Mortierellales is in a need of a reclassification, where new, phylogenetically informative phenotypic traits should be identified, with molecular phylogenies playing a decisive role.

  10. Black Return Migration to a Southern State: An Analysis of Motives and Parental Support.

    Science.gov (United States)

    Uzzell, Odell

    1984-01-01

    Research into return migration of Blacks to four urban communities in North Carolina suggests that differences in motivation existed between older, female and younger, male return migrants. The former returned for personal social reasons mainly, the latter for economic reasons. (RDN)

  11. Meta-Analysis of mitochondrial DNA reveals several population bottlenecks during worldwide migrations of cattle

    NARCIS (Netherlands)

    Lenstra, Johannes A.; Ajmone-Marsan, Paolo; Beja-Pereira, Albano; Bollongino, Ruth; Bradley, Daniel G.; Colli, Licia; De Gaetano, Anna; Edwards, Ceiridwen J.; Felius, Marleen; Ferretti, Luca; Ginja, Catarina; Hristov, Peter; Kantanen, Juha; Lirón, Juan Pedro; Magee, David A.; Negrini, Riccardo; Radoslavov, Georgi A.

    2014-01-01

    Several studies have investigated the differentiation of mitochondrial DNA in Eurasian, African and American cattle as well as archaeological bovine material. A global survey of these studies shows that haplogroup distributions are more stable in time than in space. All major migrations of cattle ha

  12. An Analysis of Rural Manpower Migration Patterns in the South Plains Region of Texas.

    Science.gov (United States)

    Stapleton, Richard C.

    Because of declining prices for sorghum and cotton, increased operating costs, and reduction in the underground water level, opportunities for male high school graduates in the Southern Plains region have declined in recent years. The study collected data on migration patterns of males who graduated during the 1953-63 period by surveying high…

  13. World Migration Degree Global migration flows in directed networks

    OpenAIRE

    2015-01-01

    In this article we analyze the global flow of migrants from 206 source countries to 145 destination countries (2006-2010) and focus on the differences in the migration network pattern between destination and source counters as represented by its degree and weight distribution. Degree represents the connectivity of a country to the global migration network, and plays an important role in defining migration processes and characteristics. Global analysis of migration degree distribution offers a...

  14. Multi-component pre-stack time-imaging and migration-based velocity analysis in transversely isotropic media; Imagerie sismique multicomposante et analyse de vitesse de migration en milieu transverse isotrope

    Energy Technology Data Exchange (ETDEWEB)

    Gerea, C.V.

    2001-06-01

    Complementary to the recording of compressional (P-) waves, the observation of P-S converted waves has recently been receiving specific attention. This is mainly due to their tremendous potential as a tool for fracture and lithology characterization, imaging sediments in gas saturated rocks, and imaging shallow sediments with higher resolution than conventional P-P data. In a conventional marine seismic survey, we cannot record P-to-S converted-wave energy since the fluids cannot support shear-wave strain. Thus, to capture the converted-wave energy, we need to record it at the water-bottom casing an ocean-bottom cable (OBC). The S-waves recorded at the seabed are mainly converted from P to S (i.e., PS-waves or C-waves) at the subsurface reflectors. The most accurate way to image seismic data is pre-stack depth migration. In this thesis, I develop a numerically efficient 2.5-D true-amplitude elastic Kirchhoff pre-stack migration algorithm designed to handle OBC data gathered along a single line. All the kinematic and dynamic elastic Green's functions required in the computation of true-amplitude weight term of Kirchhoff summation, are based on the non-hyperbolic explicit approximations of P- and SV-wave travel-times in layered transversely isotropic (VTI) media. Hence, this elastic imaging algorithm is very well-suited for migration-based velocity analysis techniques, for which fast, robust and iterative pre-stack migration is desired. In this thesis, I approach also the topic of anisotropic velocity model building for elastic pre-stack time-imaging. and propose an original methodology for joint PP-PS migration-based velocity analysis (MVA) in layered VTI anisotropic media. Tests on elastic synthetic and real OBC seismic data ascertain the validity of the pre-stack migration algorithm and velocity analysis methodology. (author)

  15. A Brief Discussion and Evaluation of the Approaches to the Teaching of Grammar Inferred from Contrastive Analysis, Krashen's Monitor Theory and Universal Grammar

    Institute of Scientific and Technical Information of China (English)

    刘艳

    2008-01-01

    As Richards and Rodgers (1996) pointed out each method and approach had its own underlying theories of language and language learning.Different theories of language and language learning will influence what method or approach will be focused.Based on the description and evaluation of each approach inferred from Contrastive Analy-sis (CA),Krashen's Monitor theory,and Universal Grammar (UG),an integrated approach will be proposed.

  16. CHARACTERISTICS OF MIGRATION IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Daniela DĂNĂCICĂ

    2010-06-01

    Full Text Available The aim of this research is to study the patterns of migration in Romania. Labor migration in Romania has seen major growth after 1989. Permanent migration rapidly increased in the early years after the revolution, decreasing rapidly thereafter, due to difficulties of obtaining long term residence and work permit in the host countries. However, temporary migration has been found to evolve very dynamically, requiring economic analysis of potential externalities, whether positive or the negative of this phenomenon.

  17. CHARACTERISTICS OF MIGRATION IN ROMANIA

    OpenAIRE

    Daniela DĂNĂCICĂ

    2010-01-01

    The aim of this research is to study the patterns of migration in Romania. Labor migration in Romania has seen major growth after 1989. Permanent migration rapidly increased in the early years after the revolution, decreasing rapidly thereafter, due to difficulties of obtaining long term residence and work permit in the host countries. However, temporary migration has been found to evolve very dynamically, requiring economic analysis of potential externalities, whet...

  18. Stories of HERMES: An Analysis of the Issues Faced by Young European Researchers in Migration and Ethnic Studies

    Directory of Open Access Journals (Sweden)

    Maren Borkert

    2006-05-01

    Full Text Available This article introduces contemporary migration research from the perspective of a cross-section of itinerant European academics at the early stages of their research career. Specifically, it examines self-reflexivity as an effective tool to support qualitative data analysis in light of the multiple dimensions of migration and ethnic research in Europe. As part of this reflexivity, the paper considers the complex relations and relationships that shape researcher-participant interaction. It shows how these are made even more intricate and confusing by research conducted outside ones home country and/ or with national communities to which one does not "naturally" belong. Over recent years, the European Commission has sought to foster inter-academic exchange, especially amongst new European researchers. Emphasis has been placed on the need to build up effective international and inter-disciplinary research networks but, we argue, very little attention has been directed towards how the processes of up-rooting and re-grouping facilitate and/ or restrict the research experience. Using self-reflexivity, and in light of the particular complexities of carrying out international migration research, the paper will review these issues and seek to increase our understanding of how young European academics become successful transnational researchers. URN: urn:nbn:de:0114-fqs060397

  19. Quantitative magnetic resonance analysis and a morphometric predictive model reveal lean body mass changes in migrating Nearctic-Neotropical passerines.

    Science.gov (United States)

    Seewagen, Chad L; Guglielmo, Christopher G

    2011-04-01

    Most studies of lean mass dynamics in free-living passerine birds have focused on Old World species at geographical barriers where they are challenged to make the longest non-stop flight of their migration. We examined lean mass variation in New World passerines in an area where the distribution of stopover habitat does not require flights to exceed more than a few hours and most migrants stop flying well before fat stores near exhaustion. We used either quantitative magnetic resonance (QMR) analysis or a morphometric model to measure or estimate, respectively, the fat and lean body mass of migrants during stopovers in New York, USA. With these data, we examined (1) variance in total body mass explained by lean body mass, (2) hourly rates of fat and lean body mass change in single-capture birds, and (3) net changes in fat and lean mass in recaptured birds. Lean mass contributed to 50% of the variation in total body mass among white-throated sparrows Zonotrichia albicollis and hermit thrushes Catharus guttatus. Lean mass of refueling gray catbirds Dumetella carolinensis and white-throated sparrows, respectively, increased 1.123 and 0.320 g h(-1). Lean mass of ovenbirds Seiurus aurocapillus accounted for an estimated 33-40% of hourly gains in total body mass. On average 35% of the total mass gained among recaptured birds was lean mass. Substantial changes in passerine lean mass are not limited to times when birds are forced to make long, non-stop flights across barriers. Protein usage during migration is common across broad taxonomic groups, migration systems, and migration strategies.

  20. Analysis of the Research Status and Topics on the Radionuclide Migration and Retardation in Natural Barriers

    Energy Technology Data Exchange (ETDEWEB)

    Baik, Min Hoon; Park, Chung Kyun; Kim, Seung Soo; Lee, Seung Yeop; Lee, Jae Kwang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-12-15

    In this report, recent research status for major developed countries in the high-level radioactive waste disposal including international organizations was investigated and analyzed in research topics for the radionuclide migration and retardation in natural barriers. Besides, recent research trends and future prospects were investigated for selected major 10 topics about the radionuclide migration and retardation processes. Based upon these investigations and analyses, future research goals and topics to be concentrated were presented. This report will be helpful for understanding our current research status and technical position and establishing future research direction and topics by analyzing domestic and foreign research status and trends. The results will also be utilized as basic information for establishing future policy and plans of the government for the high-level radioactive waste disposal.

  1. ANALYSIS OF THE MIGRATION THROUGH SURVEYS. ADVANTAGES, DISADVANTAGES, AND CHALLENGES TO SOLVE

    Directory of Open Access Journals (Sweden)

    Juan Gabino González Becerril

    2014-07-01

    Full Text Available In order to provide quantitative elements useful for the design of an update on the migration situation in the State of Mexico diagnosis, this paper analyzes the Survey on Migration to the United States of Mexico State (EMMEU that was designed and implemented with to quantify and characterize migrants moving to the United States and within the country to identify the impact of this movement in their homes of origin. Concepts and ordinarily resident household who are regularly employed in population censuses and demographic surveys conducted by the National Institute of Geography of Mexico are used. Analytical dimension, design and survey sample is explained and concludes with the scope and limitations of EMMEU 2009.

  2. Association analysis of schizophrenia on 18 genes involved in neuronal migration

    DEFF Research Database (Denmark)

    Kähler, Anna K; Djurovic, Srdjan; Kulle, Bettina;

    2008-01-01

    Several lines of evidence support the theory of schizophrenia (SZ) being a neurodevelopmental disorder. The structural, cytoarchitectural and functional brain abnormalities reported in patients with SZ, might be due to aberrant neuronal migration, since the final position of neurons affects...... neuronal function, morphology, and formation of synaptic connections. We have investigated the putative association between SZ and gene variants engaged in the neuronal migration process, by performing an association study on 839 cases and 1,473 controls of Scandinavian origin. Using a gene-wide approach......, tagSNPs in 18 candidate genes have been genotyped, with gene products involved in the neuron-to-glial cell adhesion, interactions with the DISC1 protein and/or rearrangements of the cytoskeleton. Of the 289 markers tested, 19 markers located in genes MDGA1, RELN, ITGA3, DLX1, SPARCL1, and ASTN1...

  3. Global identification of caspase substrates using PROTOMAP (protein topography and migration analysis platform).

    Science.gov (United States)

    Dix, Melissa M; Simon, Gabriel M; Cravatt, Benjamin F

    2014-01-01

    Delineation of the natural substrate scope of proteases is important for understanding the functions of proteolytic pathways in physiology and disease. Herein we describe the protocol for PROTOMAP, a technique that combines SDS-PAGE with tandem mass spectrometry to globally identify shifts in protein migration indicative of proteolytic processing. When applied to cells undergoing apoptosis, this unbiased global method provides a snapshot of the topography and magnitude of proteolytic events associated with programmed cell death.

  4. Compilation of data for the analysis of radionuclide migration from SFL 3-5

    Energy Technology Data Exchange (ETDEWEB)

    Skagius, K.; Pettersson, Michael; Wiborgh, M. [Kemakta Konsult AB, Stockholm (Sweden); Albinsson, Yngve; Holgersson, Stellan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry

    1999-12-01

    A preliminary safety assessment of the deep repository for long-lived, low and intermediate level waste, SFL 3-5, has been made. This report contains a compilation of data selected for the calculations of the migration of radionuclides and toxic metals from the waste to the biosphere. It also contains the data needed for the next step, which is to calculate dose to man from the far-field release figures. In the preliminary safety assessment it is assumed that SFL 3-5 is located in connection to the deep repository for spent fuel. This makes it possible to utilise site-specific information derived within the safety assessment of the deep repository for spent fuel, SR 97, for the sites Aberg, Beberg and Ceberg. When information from SR 97 is utilised, the values selected are as far as possible those proposed as a 'reasonable estimate' for the migration calculations in SR 97. The selection of values for parameters specific for the calculation of migration from the SFL 3-5 repository is in general on the pessimistic side. The uncertainty in the selected values is discussed and if possible also quantified.

  5. A simulation analysis of the migration and transformation of pollutants contained in landfill leachate

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-qi; TIAN Kai-ming; QI Yong-qiang; CHEN Jia-jun; WANG Ya-nan

    2003-01-01

    A dynamic composite model for a soil-water system that can be used to simulate the movement of leachate from a landfill. The composite model includes nine sub-models that trace water movement and the migration and transformation of five pollutants(organic N, NH4- ,NO3- , NO2- , and Cl- ) in saturated and unsaturated soil. The model to simulate the movement of leachate from a landfill in Laogang Town,Shanghai City was used. In this application, the values for the model parameters were obtained by performing a laboratory simulation experiment of water movement and pollutant migration and transformation in soil colunms. Soil and leachate obtained from the landfill site and its vicinity were used in the laboratory experiments. The model was then used to simulate leachate movement and pollutant activity during the ten-year period when the landfill was in operation and in the twenty-year period following its closure. The simulation results revealed that the leachate migrated into the groundwater at the rate of 90-100 meters per year. This model can be applied in the design of future landfills in China for the purpose of assessing and forecasting leachate plumes.

  6. Geography of European Migration

    Directory of Open Access Journals (Sweden)

    Zhitin Dmitry V.

    2016-08-01

    Full Text Available In recent decades, the role of international migration has increased dramatically in most European countries. The growth in migration has made some authors proclaim the beginning of a second Migration Period that could transform the social and cultural identity of Europe. The article presents an analysis of international migration geography in Europe in the last twenty-five years. The authors identify the main trends in migration, provide migration profiles of European countries, and propose a classification based on the recent changes in the migrant stock. Changes in the migrant stock (total emigration and immigration reflect the level of involvement in international and global processes. They can serve as an indicator of a country’s attractiveness for both foreigners and the country’s citizens. The study shows that European countries are increasingly split into ‘immigrant’ and ‘emigrant’ states. The authors describe spatial patterns of migration. The volume and localisation of migration flows in Europe are affected not only by cultural and historical circumstance, such as a colonial past or a common language. The scale of immigrant influx often does not depend on a donor country’s demographic potential or the level of its socio-economic development. The links between the place of origin and destination are often more complex than it might initially seem. The authors stress the importance of a differentiated immigration policy taking into account ethnic and cultural features of host societies.

  7. Migration without migraines

    Energy Technology Data Exchange (ETDEWEB)

    Lines, L.; Burton, A.; Lu, H.X. [Memorial Univ. of Newfoundland, St. John`s (Canada)

    1994-12-31

    Accurate velocity models are a necessity for reliable migration results. Velocity analysis generally involves the use of methods such as normal moveout analysis (NMO), seismic traveltime tomography, or iterative prestack migration. These techniques can be effective, and each has its own advantage or disadvantage. Conventional NMO methods are relatively inexpensive but basically require simplifying assumptions about geology. Tomography is a more general method but requires traveltime interpretation of prestack data. Iterative prestack depth migration is very general but is computationally expensive. In some cases, there is the opportunity to estimate vertical velocities by use of well information. The well information can be used to optimize poststack migrations, thereby eliminating some of the time and expense of iterative prestack migration. The optimized poststack migration procedure defined here computes the velocity model which minimizes the depth differences between seismic images and formation depths at the well by using a least squares inversion method. The optimization methods described in this paper will hopefully produce ``migrations without migraines.``

  8. Ecomorphological analysis of the astragalo-calcaneal complex in rodents and inferences of locomotor behaviours in extinct rodent species

    OpenAIRE

    Ginot, Samuel; Hautier, Lionel; Marivaux, Laurent; Vianey-Liaud, Monique

    2016-01-01

    Studies linking postcranial morphology with locomotion in mammals are common. However, such studies are mostly restricted to caviomorphs in rodents. We present here data from various families, belonging to the three main groups of rodents (Sciuroidea, Myodonta, and Ctenohystrica). The aim of this study is to define morphological indicators for the astragalus and calcaneus, which allow for inferences to be made about the locomotor behaviours in rodents. Several specimens were dissected and des...

  9. Ecomorphological analysis of the astragalo-calcaneal complex in rodents and inferences of locomotor behaviours in extinct rodent species.

    Science.gov (United States)

    Ginot, Samuel; Hautier, Lionel; Marivaux, Laurent; Vianey-Liaud, Monique

    2016-01-01

    Studies linking postcranial morphology with locomotion in mammals are common. However, such studies are mostly restricted to caviomorphs in rodents. We present here data from various families, belonging to the three main groups of rodents (Sciuroidea, Myodonta, and Ctenohystrica). The aim of this study is to define morphological indicators for the astragalus and calcaneus, which allow for inferences to be made about the locomotor behaviours in rodents. Several specimens were dissected and described to bridge the myology of the leg with the morphology of the bones of interest. Osteological characters were described, compared, mechanically interpreted, and correlated with a "functional sequence" comprising six categories linked to the lifestyle and locomotion (jumping, cursorial, generalist, fossorial, climber and semi-aquatic). Some character states are typical of some of these categories, especially arboreal climbers, fossorial and "cursorial-jumping" taxa. Such reliable characters might be used to infer locomotor behaviours in extinct species. Linear discriminant analyses (LDAs) were used on a wider sample of species and show that astragalar and calcaneal characters can be used to discriminate the categories among extant species whereas a posteriori inferences on extinct species should be examined with caution.

  10. Ecomorphological analysis of the astragalo-calcaneal complex in rodents and inferences of locomotor behaviours in extinct rodent species

    Directory of Open Access Journals (Sweden)

    Samuel Ginot

    2016-10-01

    Full Text Available Studies linking postcranial morphology with locomotion in mammals are common. However, such studies are mostly restricted to caviomorphs in rodents. We present here data from various families, belonging to the three main groups of rodents (Sciuroidea, Myodonta, and Ctenohystrica. The aim of this study is to define morphological indicators for the astragalus and calcaneus, which allow for inferences to be made about the locomotor behaviours in rodents. Several specimens were dissected and described to bridge the myology of the leg with the morphology of the bones of interest. Osteological characters were described, compared, mechanically interpreted, and correlated with a “functional sequence” comprising six categories linked to the lifestyle and locomotion (jumping, cursorial, generalist, fossorial, climber and semi-aquatic. Some character states are typical of some of these categories, especially arboreal climbers, fossorial and “cursorial-jumping” taxa. Such reliable characters might be used to infer locomotor behaviours in extinct species. Linear discriminant analyses (LDAs were used on a wider sample of species and show that astragalar and calcaneal characters can be used to discriminate the categories among extant species whereas a posteriori inferences on extinct species should be examined with caution.

  11. Ecomorphological analysis of the astragalo-calcaneal complex in rodents and inferences of locomotor behaviours in extinct rodent species

    Science.gov (United States)

    Hautier, Lionel; Marivaux, Laurent; Vianey-Liaud, Monique

    2016-01-01

    Studies linking postcranial morphology with locomotion in mammals are common. However, such studies are mostly restricted to caviomorphs in rodents. We present here data from various families, belonging to the three main groups of rodents (Sciuroidea, Myodonta, and Ctenohystrica). The aim of this study is to define morphological indicators for the astragalus and calcaneus, which allow for inferences to be made about the locomotor behaviours in rodents. Several specimens were dissected and described to bridge the myology of the leg with the morphology of the bones of interest. Osteological characters were described, compared, mechanically interpreted, and correlated with a “functional sequence” comprising six categories linked to the lifestyle and locomotion (jumping, cursorial, generalist, fossorial, climber and semi-aquatic). Some character states are typical of some of these categories, especially arboreal climbers, fossorial and “cursorial-jumping” taxa. Such reliable characters might be used to infer locomotor behaviours in extinct species. Linear discriminant analyses (LDAs) were used on a wider sample of species and show that astragalar and calcaneal characters can be used to discriminate the categories among extant species whereas a posteriori inferences on extinct species should be examined with caution. PMID:27761303

  12. Gene regulatory network inference and validation using relative change ratio analysis and time-delayed dynamic Bayesian network.

    Science.gov (United States)

    Li, Peng; Gong, Ping; Li, Haoni; Perkins, Edward J; Wang, Nan; Zhang, Chaoyang

    2014-12-01

    The Dialogue for Reverse Engineering Assessments and Methods (DREAM) project was initiated in 2006 as a community-wide effort for the development of network inference challenges for rigorous assessment of reverse engineering methods for biological networks. We participated in the in silico network inference challenge of DREAM3 in 2008. Here we report the details of our approach and its performance on the synthetic challenge datasets. In our methodology, we first developed a model called relative change ratio (RCR), which took advantage of the heterozygous knockdown data and null-mutant knockout data provided by the challenge, in order to identify the potential regulators for the genes. With this information, a time-delayed dynamic Bayesian network (TDBN) approach was then used to infer gene regulatory networks from time series trajectory datasets. Our approach considerably reduced the searching space of TDBN; hence, it gained a much higher efficiency and accuracy. The networks predicted using our approach were evaluated comparatively along with 29 other submissions by two metrics (area under the ROC curve and area under the precision-recall curve). The overall performance of our approach ranked the second among all participating teams.

  13. Bank Credit Risk Management and Rating Migration Analysis on the Business Cycle

    Directory of Open Access Journals (Sweden)

    Dimitris Gavalas

    2014-03-01

    Full Text Available Credit risk measurement remains a critical field of top priority in banking finance, directly implicated in the recent global financial crisis. This paper examines the dynamic linkages between credit risk migration due to rating shifts and prevailing macroeconomic conditions, reflected in alternative business cycle states. An innovative empirical methodology applies to bank internal rating data, under different economic scenarios and investigates the implications of credit risk quality shifts for risk rating transition matrices. The empirical findings are useful and critical for banks to align to Basel guidelines in relation to core capital requirements and risk-weighted assets in the underlying loan portfolio.

  14. A general equilibrium analysis of rural-urban migration under uncertainty.

    Science.gov (United States)

    Beladi, H; Ingene, C A

    1994-02-01

    "This paper analyzes the implications of an exogenous shift in relative prices for an economy that suffers from urban unemployment, as well as uncertainty in the agricultural sector. Among other things, we show that with agricultural uncertainty, an exogenous shift in relative prices will lower agricultural profit. This result is in sharp contrast with the conventional case of risk-neutrality or certainty where agricultural profit is unaffected by changes in the terms of trade." The consequences for rural-urban migration in developing countries are implied.

  15. Statistical inferences in phylogeography

    DEFF Research Database (Denmark)

    Nielsen, Rasmus; Beaumont, Mark A

    2009-01-01

    In conventional phylogeographic studies, historical demographic processes are elucidated from the geographical distribution of individuals represented on an inferred gene tree. However, the interpretation of gene trees in this context can be difficult as the same demographic/geographical process ...... may also be challenged by computational problems or poor model choice. In this review, we will describe the development of statistical methods in phylogeographic analysis, and discuss some of the challenges facing these methods....... can randomly lead to multiple different genealogies. Likewise, the same gene trees can arise under different demographic models. This problem has led to the emergence of many statistical methods for making phylogeographic inferences. A popular phylogeographic approach based on nested clade analysis...... is challenged by the fact that a certain amount of the interpretation of the data is left to the subjective choices of the user, and it has been argued that the method performs poorly in simulation studies. More rigorous statistical methods based on coalescence theory have been developed. However, these methods...

  16. Population genetic analysis of the intertidal limpet Lottia scabra and inference of the causes and mechanisms of range limits

    OpenAIRE

    Lehman, Joan

    2010-01-01

    Range limits have been described for many species, and the interest in range limits has increased in the wake of climate change, but few researchers attempt to document the causes and mechanisms of these limits and empirical tests of range limit theory remain sparse. Three principle mechanisms have been proposed to limit species’ range in models incorporating environmental heterogeneity and evolution: genetic impoverishment, migration load, or a physical barrier to dispersal. O...

  17. Quantitative Analysis of the Migration and Accumulation of Bacillus subtilis in Asparagus officinalis.

    Science.gov (United States)

    Hao, Bian-Qing; Ma, Li-Ping; Qiao, Xiong-Wu

    2015-09-01

    Bacillus subtilis B96-II is a broad-spectrum biological control strain. It effectively suppresses soil-borne fungal diseases in vegetables. A green fluorescence protein (GFP) was expressed in B96-II to detect migration of B96-II into the root and stem of asparagus. The GFP-tagged B96-II (B96-II-GFP) strain exhibited bright green fluorescence under a fluorescence microscope. GFP was stable and had no apparent effects on the growth of the strain. Asparagus plants were planted in the soil inoculated with B96-II-GFP. Our results showed that B96-II-GFP was detected in both the root and stem 15, 30, and 45 days after the asparagus seedlings were planted. B96-II-GFP was also detected in leaves but at a lower concentration. The highest concentration was detected in 15 days, and the number of bacteria decreased subsequently irrespective of duration of growth or sampling period. The highest concentration of B96-II-GFP was present in the root base suggesting that the root base served as the hub of bacterial migration from the soil to the stem.

  18. Preparation and analysis of styrene oligomers containing migrates from various polystyrenes used in food packaging.

    Science.gov (United States)

    Klärner, P; Klenz, R; Eder, R; Volz, W E; Schnell, H W; Leyendecker, D; Güntner, A; Niessner, N; Morris, C R; Christian, M S

    1998-01-01

    An oligostyrene-like product (F2L5250) was reported to have estrogen-like activity (statistically significant increases in means for absolute uterine weight and the ratios of the uterine weight to terminal body weight) in juvenile female rats provided a dietary concentration of 100 ppm F2L5250 for four consecutive days. The highest no-effect-level (NOEL) for estrogenic activity was 80 ppm in the diet, corresponding to a daily intake of 13.3 mg F2L5250/kg. Although it is unlikely that such estrogenic tetramers would occur in commercial polystyrene, the Styrene Steering Committee (SSC) of the European Chemical Industry Council (CEFIC) sponsored the current extensive project to address any concern that human consumption of styrene oligomers migrating from polystyrene containers into food, e.g., from packaged yoghurt, or from the use of EPS coffee cups and related products, might affect human health. To ensure confidentiality and compliance with the highest scientific and regulatory standards, the entire project was conducted without knowledge of the oligomer migrates tested, and all activities were managed and audited under a contract between the SSC and a third party, Argus International. This paper describes the preparation and analyses of the 23 representative polystyrenes [9 general purpose polystyrenes (GPPS), 8 high impact polystyrenes (HIPS) and 6 expandable polystyrenes (EPS)] evaluated for estrogenicity in an in vivo uterotrophic assay in immature female rats. The polystyrene samples were chosen to represent food packaging applications. They were obtained from participating European Polystyrene Manufacturers, coded at the TNO Nutrition and Food Research Institute, Utrecht, The Netherlands (TNO) and sent to BASF, Ludwigshafen, Germany for preparation of test bars (GPPS and HIPS) or test foam parts (EPS). The prepared polystyrene test bars or test foam parts were submitted to elution with 50% aqueous (v/v) ethanol for 10 days at 40 degrees C, a procedure which

  19. Gender and migration from Albania.

    Science.gov (United States)

    Stecklov, Guy; Carletto, Calogero; Azzarri, Carlo; Davis, Benjamin

    2010-11-01

    This article examines the dynamics and causes of the shift in the gender composition of migration, and more particularly, in women's access to migration opportunities and decision-making. Our analysis focuses on Albania, a natural laboratory for studying international migration where out-migration was essentially nonexistent from the end of World War II to the end of the 1980s. Interest in the Albanian case is heightened because of the complex layers of inequality existing at the time when migration began: relatively low levels of inequality within the labor market and educational system-a product of the Communist era-while household relations remained heavily steeped in tradition and patriarchy. We use micro-level data from the Albania 2005 Living Standards Measurement Study, including migration histories for family members since migration began. Based on discrete-time hazard models, the analysis shows a dramatic increase in male migration and a gradual and uneven expansion of the female proportion of this international migration. Female migration, which is shown to be strongly associated with education, wealth, and social capital, appears responsive to economic incentives and constraints. Using information on the dependency of female migration to the household demographic structure as well as the sensitivity of female migration to household-level shocks, we show how household-level constraints and incentives affect male and female migration differently. Throughout this period, however, women's migration behavior appears more directly aligned with household-level factors, and there is little evidence to suggest that increased female migration signals rising behavioral independence among Albanian women.

  20. Analysis of trunk neural crest cell migration using a modified Zigmond chamber assay.

    Science.gov (United States)

    Walheim, Christopher C; Zanin, Juan Pablo; de Bellard, Maria Elena

    2012-01-19

    Neural crest cells (NCCs) are a transient population of cells present in vertebrate development that emigrate from the dorsal neural tube (NT) after undergoing an epithelial-mesenchymal transition. Following EMT, NCCs migrate large distances along stereotypic pathways until they reach their targets. NCCs differentiate into a vast array of cell types including neurons, glia, melanocytes, and chromaffin cells. The ability of NCCs to reach and recognize their proper target locations is foundational for the appropriate formation of all structures containing trunk NCC-derived components. Elucidating the mechanisms of guidance for trunk NCC migration has therefore been a matter of great significance. Numerous molecules have been demonstrated to guide NCC migration. For instance, trunk NCCs are known to be repelled by negative guidance cues such as Semaphorin, Ephrin, and Slit ligands. However, not until recently have any chemoattractants of trunk NCCs been identified. Conventional in vitro approaches to studying the chemotactic behavior of adherent cells work best with immortalized, homogenously distributed cells, but are more challenging to apply to certain primary stem cell cultures that initially lack a homogenous distribution and rapidly differentiate (such as NCCs). One approach to homogenize the distribution of trunk NCCs for chemotaxis studies is to isolate trunk NCCs from primary NT explant cultures, then lift and replate them to be almost 100% confluent. However, this plating approach requires substantial amounts of time and effort to explant enough cells, is harsh, and distributes trunk NCCs in a dissimilar manner to that found in in vivo conditions. Here, we report an in vitro approach that is able to evaluate chemotaxis and other migratory responses of trunk NCCs without requiring a homogenous cell distribution. This technique utilizes time-lapse imaging of primary, unperturbed trunk NCCs inside a modified Zigmond chamber (a standard Zigmond chamber is

  1. The Statistical Analysis of Migration of Strong Earthquakes-Taking the North China Region as an Example

    Institute of Scientific and Technical Information of China (English)

    Qin Chengzhi; Zhou Chenghu; Pei Tao; Li Quanlin

    2004-01-01

    The migration of strong earthquakes is an important research topic because the migration phenomena reflect partly the seismic mechanism and involve the prediction of tendency of seismic activity. Research on migration of strong earthquakes has mostly focused on finding the phenomena. Some attempts on getting regularity were comparatively subjective. This paper suggests that there should be indices of migration in earthquake dataset and the indexes should have statistical meaning if there is regularity in the migration of strong earthquakes. In this study, three derivative attributes of migration, i.e., migration orientation, migration distance and migration time interval, were statistically analyzed. Results in the North China region show that the migration of strong earthquakes has statistical meaning. There is a dominant migration orientation (W by S to E by N), a dominant distance ( ≤ 100km and on the confines of 300 ~ 700km), and a dominant time interval ( ≤ 1 a and on the confines of 3 ~ 4a). The results also show that the migration will differ slightly with different magnitude range or earthquake activity phase.

  2. Meta-Analysis of Mitochondrial DNA Reveals Several Population Bottlenecks during Worldwide Migrations of Cattle

    Directory of Open Access Journals (Sweden)

    Johannes A. Lenstra

    2014-03-01

    Full Text Available Several studies have investigated the differentiation of mitochondrial DNA in Eurasian, African and American cattle as well as archaeological bovine material. A global survey of these studies shows that haplogroup distributions are more stable in time than in space. All major migrations of cattle have shifted the haplogroup distributions considerably with a reduction of the number of haplogroups and/or an expansion of haplotypes that are rare or absent in the ancestral populations. The most extreme case is the almost exclusive colonization of Africa by the T1 haplogroup, which is rare in Southwest Asian cattle. In contrast, ancient samples invariably show continuity with present-day cattle from the same location. These findings indicate strong maternal founder effects followed by limited maternal gene flow when new territories are colonized. However, effects of adaptation to new environments may also play a role.

  3. SEBINI-CABIN: An Analysis Pipeline for Biological Network Inference, with a Case Study in Protein-Protein Interaction Network Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Ronald C.; Singhal, Mudita; Daly, Don S.; Domico, Kelly O.; White, Amanda M.; Auberry, Deanna L.; Auberry, Kenneth J.; Hooker, Brian S.; Hurst, G. B.; McDermott, Jason E.; McDonald, W. Hayes; Pelletier, Dale A.; Schmoyer, Denise D.; Cannon, William R.

    2007-12-01

    One of the core tasks of the emerging discipline of systems biology is the reconstruction of the various biological networks in an organism. The importance of understanding such regulatory, interaction, and signaling networks has fueled the development by bioinformatics researchers of many inference algorithms for determining their structure. The Software Environment for BIological Network Inference (SEBINI) has been created to provide an interactive environment for the deployment, testing, and improvement of algorithms used to reconstruct the structures of regulatory and interaction networks from high-throughput expression data. Networks inferred from the SEBINI software platform can be further analyzed using the Collective Analysis of Biological Interaction Networks (CABIN) tool, a software package for exploratory data analysis that allows basic integration and analysis of protein-protein interaction and gene-to-gene regulatory evidence obtained from multiple sources. Thus, the combined SEBINI–CABIN platform aids in the more accurate determination of biological networks, in less time, with less effort. In this paper, we present a case study demonstrating the use of the SEBINI and CABIN tools for protein-protein interaction network reconstruction. Incorporating the Bayesian Estimator of Protein-Protein Association Probabilities (BEPro) algorithm into the SEBINI toolkit, we have created a pipeline for structural inference and supplemental analysis of protein-protein interaction networks from sets of mass spectrometry bait-prey experiment data. To the best of our knowledge the pipeline so designed is the first to be publicly available for such use. A demonstration web site for SEBINI can be accessed from https://www.emsl.pnl.gov/NIT/NIT.html. Source code and PostgreSQL database schema are available under open source license. Contact: ronald.taylor@pnl.gov. For commercial use, some algorithms included in SEBINI require licensing from the original developers. The

  4. Analysing immune cell migration.

    Science.gov (United States)

    Beltman, Joost B; Marée, Athanasius F M; de Boer, Rob J

    2009-11-01

    The visualization of the dynamic behaviour of and interactions between immune cells using time-lapse video microscopy has an important role in modern immunology. To draw robust conclusions, quantification of such cell migration is required. However, imaging experiments are associated with various artefacts that can affect the estimated positions of the immune cells under analysis, which form the basis of any subsequent analysis. Here, we describe potential artefacts that could affect the interpretation of data sets on immune cell migration. We propose how these errors can be recognized and corrected, and suggest ways to prevent the data analysis itself leading to biased results.

  5. MicroRNA-Target Network Inference and Local Network Enrichment Analysis Identify Two microRNA Clusters with Distinct Functions in Head and Neck Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Steffen Sass

    2015-12-01

    Full Text Available MicroRNAs represent ~22 nt long endogenous small RNA molecules that have been experimentally shown to regulate gene expression post-transcriptionally. One main interest in miRNA research is the investigation of their functional roles, which can typically be accomplished by identification of mi-/mRNA interactions and functional annotation of target gene sets. We here present a novel method “miRlastic”, which infers miRNA-target interactions using transcriptomic data as well as prior knowledge and performs functional annotation of target genes by exploiting the local structure of the inferred network. For the network inference, we applied linear regression modeling with elastic net regularization on matched microRNA and messenger RNA expression profiling data to perform feature selection on prior knowledge from sequence-based target prediction resources. The novelty of miRlastic inference originates in predicting data-driven intra-transcriptome regulatory relationships through feature selection. With synthetic data, we showed that miRlastic outperformed commonly used methods and was suitable even for low sample sizes. To gain insight into the functional role of miRNAs and to determine joint functional properties of miRNA clusters, we introduced a local enrichment analysis procedure. The principle of this procedure lies in identifying regions of high functional similarity by evaluating the shortest paths between genes in the network. We can finally assign functional roles to the miRNAs by taking their regulatory relationships into account. We thoroughly evaluated miRlastic on a cohort of head and neck cancer (HNSCC patients provided by The Cancer Genome Atlas. We inferred an mi-/mRNA regulatory network for human papilloma virus (HPV-associated miRNAs in HNSCC. The resulting network best enriched for experimentally validated miRNA-target interaction, when compared to common methods. Finally, the local enrichment step identified two functional

  6. [Internal migration].

    Science.gov (United States)

    Borisovna, L

    1991-06-01

    Very few studies have been conducted that truly permit explanation of internal migration and it repercussions on social and economic structure. It is clear however that a profound knowledge of the determinants and consequences of internal migration will be required as a basis for economic policy decisions that advance the goal of improving the level of living of the population. the basic supposition of most studies of the relationship of population and development is that socioeconomic development conditions demographic dynamics. The process of development in Mexico, which can be characterized by great heterogeneity, consequently produces great regional disparities. At the national level various studies have estimated the volume of internal migration in Mexico, but they have usually been limited to interstate migration because the main source of data, the census, is classified by states. But given the great heterogeneity within states in all the elements related to internal migration, it is clear that studies of internal migration within states are also needed. Such studies are almost nonexistent because of their technical difficulty. National level studies show that interstate migration increased significantly between 1940-80. The proportion of Mexicans living outside their states of birth increased by 558% in those years, compared to the 342% increase in the total Mexican population. Although Puebla has a high rate of increase, migration has kept it below Mexico's national growth rate. Migration between Puebla and other states and within Puebla has led to an increasing unevenness of spatial distribution. Between 1970-80, 57 of Puebla's municipios had growth rates above the state average of 2.8%/year, 6 had growth rates equal to the average, and 129 had growth rates that were below the average but not negative. 25 states with negative growth rates that were considered strongly expulsive. In 1980, 51.7% of the population was concentrated in the 57 municipios

  7. Evidence for Patterns of Selective Urban Migration in the Greater Indus Valley (2600-1900 BC: A Lead and Strontium Isotope Mortuary Analysis.

    Directory of Open Access Journals (Sweden)

    Benjamin Valentine

    Full Text Available Just as modern nation-states struggle to manage the cultural and economic impacts of migration, ancient civilizations dealt with similar external pressures and set policies to regulate people's movements. In one of the earliest urban societies, the Indus Civilization, mechanisms linking city populations to hinterland groups remain enigmatic in the absence of written documents. However, isotopic data from human tooth enamel associated with Harappa Phase (2600-1900 BC cemetery burials at Harappa (Pakistan and Farmana (India provide individual biogeochemical life histories of migration. Strontium and lead isotope ratios allow us to reinterpret the Indus tradition of cemetery inhumation as part of a specific and highly regulated institution of migration. Intra-individual isotopic shifts are consistent with immigration from resource-rich hinterlands during childhood. Furthermore, mortuary populations formed over hundreds of years and composed almost entirely of first-generation immigrants suggest that inhumation was the final step in a process linking certain urban Indus communities to diverse hinterland groups. Additional multi disciplinary analyses are warranted to confirm inferred patterns of Indus mobility, but the available isotopic data suggest that efforts to classify and regulate human movement in the ancient Indus region likely helped structure socioeconomic integration across an ethnically diverse landscape.

  8. Evidence for Patterns of Selective Urban Migration in the Greater Indus Valley (2600-1900 BC): A Lead and Strontium Isotope Mortuary Analysis

    Science.gov (United States)

    Valentine, Benjamin; Kamenov, George D.; Kenoyer, Jonathan Mark; Shinde, Vasant; Mushrif-Tripathy, Veena; Otarola-Castillo, Erik; Krigbaum, John

    2015-01-01

    Just as modern nation-states struggle to manage the cultural and economic impacts of migration, ancient civilizations dealt with similar external pressures and set policies to regulate people’s movements. In one of the earliest urban societies, the Indus Civilization, mechanisms linking city populations to hinterland groups remain enigmatic in the absence of written documents. However, isotopic data from human tooth enamel associated with Harappa Phase (2600-1900 BC) cemetery burials at Harappa (Pakistan) and Farmana (India) provide individual biogeochemical life histories of migration. Strontium and lead isotope ratios allow us to reinterpret the Indus tradition of cemetery inhumation as part of a specific and highly regulated institution of migration. Intra-individual isotopic shifts are consistent with immigration from resource-rich hinterlands during childhood. Furthermore, mortuary populations formed over hundreds of years and composed almost entirely of first-generation immigrants suggest that inhumation was the final step in a process linking certain urban Indus communities to diverse hinterland groups. Additional multi disciplinary analyses are warranted to confirm inferred patterns of Indus mobility, but the available isotopic data suggest that efforts to classify and regulate human movement in the ancient Indus region likely helped structure socioeconomic integration across an ethnically diverse landscape. PMID:25923705

  9. Analysis of the Ecological Migration Pattern in Ethnic Minority Areas——A Case Study of Ningxia Hui Autonomous Region

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    By taking Ningxia Hui Autonomous Region as an example,this paper analyzes the ecological migration pattern in ethnic minority areas.The basic patterns of development for poverty relief in Ningxia are in-situ migration and new area development pattern.The new area development pattern includes three types,namely small town development pattern around urban radiation districts,urban labor migration pattern,and large-scale ecological migration pattern.Finally,successful experience of ecological migration in Ningxia is summarized.First,scientific industrial planning shall be made on the basis of proper selection of ecological migration location in immigrant settlement regions.Second,scientific and comprehensive ecological migration policies should be formulated.

  10. Inferring deterministic causal relations

    CERN Document Server

    Daniusis, Povilas; Mooij, Joris; Zscheischler, Jakob; Steudel, Bastian; Zhang, Kun; Schoelkopf, Bernhard

    2012-01-01

    We consider two variables that are related to each other by an invertible function. While it has previously been shown that the dependence structure of the noise can provide hints to determine which of the two variables is the cause, we presently show that even in the deterministic (noise-free) case, there are asymmetries that can be exploited for causal inference. Our method is based on the idea that if the function and the probability density of the cause are chosen independently, then the distribution of the effect will, in a certain sense, depend on the function. We provide a theoretical analysis of this method, showing that it also works in the low noise regime, and link it to information geometry. We report strong empirical results on various real-world data sets from different domains.

  11. Inferring the eccentricity distribution

    CERN Document Server

    Hogg, David W; Bovy, Jo

    2010-01-01

    Standard maximum-likelihood estimators for binary-star and exoplanet eccentricities are biased high, in the sense that the estimated eccentricity tends to be larger than the true eccentricity. As with most non-trivial observables, a simple histogram of estimated eccentricities is not a good estimate of the true eccentricity distribution. Here we develop and test a hierarchical probabilistic method for performing the relevant meta-analysis, that is, inferring the true eccentricity distribution, taking as input the likelihood functions for the individual-star eccentricities, or samplings of the posterior probability distributions for the eccentricities (under a given, uninformative prior). The method is a simple implementation of a hierarchical Bayesian model; it can also be seen as a kind of heteroscedastic deconvolution. It can be applied to any quantity measured with finite precision--other orbital parameters, or indeed any astronomical measurements of any kind, including magnitudes, parallaxes, or photometr...

  12. International migration in Serbia: Facts and policies

    OpenAIRE

    Bobić Mirjana; Babović Marija

    2013-01-01

    In the absence of comprehensive, systematic and precize data on international migration in Serbia, and consequently the analysis of migration trends, their drivers and outcomes, the objective of this paper is to offer the review of contemporary migration flows in Serbia. International migration flows are observed in the context of semi-peripheral position of Serbia in the global system, and hindered transformation and development. Migrations are analyzed at the macro level, according to...

  13. Analysis prediction of Indonesian banks (BCA, BNI, MANDIRI) using adaptive neuro-fuzzy inference system (ANFIS) and investment strategies

    Science.gov (United States)

    Trianto, Andriantama Budi; Hadi, I. M.; Liong, The Houw; Purqon, Acep

    2015-09-01

    Indonesian economical development is growing well. It has effect for their invesment in Banks and the stock market. In this study, we perform prediction for the three blue chips of Indonesian bank i.e. BCA, BNI, and MANDIRI by using the method of Adaptive Neuro-Fuzzy Inference System (ANFIS) with Takagi-Sugeno rules and Generalized bell (Gbell) as the membership function. Our results show that ANFIS perform good prediction with RMSE for BCA of 27, BNI of 5.29, and MANDIRI of 13.41, respectively. Furthermore, we develop an active strategy to gain more benefit. We compare between passive strategy versus active strategy. Our results shows that for the passive strategy gains 13 million rupiah, while for the active strategy gains 47 million rupiah in one year. The active investment strategy significantly shows gaining multiple benefit than the passive one.

  14. Comparing wind directions inferred from Martian dust devil tracks analysis with those predicted by the Mars Climate Database

    Science.gov (United States)

    Statella, T.; Pina, P.; Silva, E. A.; Nervis Frigeri, Ary Vinicius; Neto, Frederico Gallon

    2016-10-01

    We have calculated the prevailing dust devil tracks direction as a means of verifying the Mars Climate Database (MCD) predicted wind directions accuracy. For that purpose we have applied an automatic method based on morphological openings for inferring the prevailing tracks direction in a dataset comprising 200 Mars Orbiter Camera (MOC) Narrow Angle (NA) and High Resolution Imaging Science Experiment (HiRISE) images of the Martian surface, depicting regions in the Aeolis, Eridania, Noachis, Argyre and Hellas quadrangles. The prevailing local wind directions were calculated from the MCD predicted speeds for the WE and SN wind components. The results showed that the MCD may not be able to predict accurately the locally dominant wind direction near the surface. In adittion, we confirm that the surface wind stress alone cannot produce dust lifting in the studied sites, since it never exceeds the threshold value of 0.0225 Nm-2 in the MCD.

  15. Migration velocity analysis using a transversely isotropic medium with tilt normal to the reflector dip

    KAUST Repository

    Alkhalifah, T.

    2010-06-13

    A transversely isotropic model in which the tilt is constrained to be normal to the dip (DTI model) allows for simplifications in the imaging and velocity model building efforts as compared to a general TTI model. Though this model, in some cases, can not be represented physically like in the case of conflicting dips, it handles all dips with the assumption of symmetry axis normal to the dip. It provides a process in which areas that meet this feature is handled properly. We use efficient downward continuation algorithms that utilizes the reflection features of such a model. For lateral inhomogeneity, phase shift migration can be easily extended to approximately handle lateral inhomogeneity, because unlike the general TTI case the DTI model reduces to VTI for zero dip. We also equip these continuation algorithms with tools that expose inaccuracies in the velocity. We test this model on synthetic data of general TTI nature and show its resilience even couping with complex models like the recently released anisotropic BP model.

  16. Barriers to accessing substance abuse treatment in Mexico: national comparative analysis by migration status

    Science.gov (United States)

    2014-01-01

    Background We examined Mexican migrants’ perceived barriers to entering substance abuse treatment and potential differences by gender. Methods This study analyzed a subset of household data collected in Mexico in 2011 via the Encuesta Nacional de Adicciones (National Survey of Addictions). A sample of 1,143 individuals who reported using illicit drugs was analyzed using multivariate negative binomial models to determine direct and moderated relationships of gender, migrant status, and drug dependence with perceived barriers to accessing treatment. Results Significant findings included disparities in drug dependence by migrant status. Compared with non-migrant men, women who have traveled to the United States was associated with fewer (1.3) barriers to access treatment. Fewer barriers to access care were associated with individuals residing in other regions of the country, compared to those living in Mexico City. Conclusions Drug dependence, gender, migration status and regional location are factors associated with access to needed treatment. Implications for health care policy to develop treatment services infrastructure and for future research are discussed in the context of ongoing drug policy reform in Mexico. PMID:25074067

  17. Migration distance-based platelet function analysis in a microfluidic system.

    Science.gov (United States)

    Song, Suk-Heung; Lim, Chae-Seung; Shin, Sehyun

    2013-01-01

    Aggregation and adhesion of platelets to the vascular wall are shear-dependent processes that play critical roles in hemostasis and thrombosis at vascular injury sites. In this study, we designed a simple and rapid assay of platelet aggregation and adhesion in a microfluidic system. A shearing mechanism using a rotating stirrer provided adjustable shear rate and shearing time and induced platelet activation. When sheared blood was driven through the microchannel under vacuum pressure, shear-activated platelets adhered to a collagen-coated surface, causing blood flow to significantly slow and eventually stop. To measure platelet adhesion and aggregation, the migration distance (MD) of blood through the microchannel was monitored. As the microstirrer speed increased, MD initially decreased exponentially but then increased beyond a critical rpm. For platelet-excluded blood samples, there were no changes in MD with increasing stirrer speed. These findings imply that the stirrer provided sufficiently high shear to activate platelets and that blood MD is a potentially valuable index for measuring the shear-dependence of platelet activation. Our microfluidic system is quick and simple, while providing a precise assay to measure the effects of shear on platelet aggregation and adhesion.

  18. Causal inference in economics and marketing.

    Science.gov (United States)

    Varian, Hal R

    2016-07-05

    This is an elementary introduction to causal inference in economics written for readers familiar with machine learning methods. The critical step in any causal analysis is estimating the counterfactual-a prediction of what would have happened in the absence of the treatment. The powerful techniques used in machine learning may be useful for developing better estimates of the counterfactual, potentially improving causal inference.

  19. Gender and Migration from Albania

    OpenAIRE

    2010-01-01

    This article examines the dynamics and causes of the shift in the gender composition of migration, and more particularly, in women's access to migration opportunities and decision-making. Our analysis focuses on Albania, a natural laboratory for studying international migration where outmigration was essentially nonexistent from the end of World War II to the end of the 1980s. Interest in the Albanian case is heightened because of the complex layers of inequality existing at the time when mig...

  20. A comparative analysis of clustering algorithms: O2 migration in truncated hemoglobin I from transition networks

    Science.gov (United States)

    Cazade, Pierre-André; Zheng, Wenwei; Prada-Gracia, Diego; Berezovska, Ganna; Rao, Francesco; Clementi, Cecilia; Meuwly, Markus

    2015-01-01

    The ligand migration network for O2-diffusion in truncated Hemoglobin N is analyzed based on three different clustering schemes. For coordinate-based clustering, the conventional k-means and the kinetics-based Markov Clustering (MCL) methods are employed, whereas the locally scaled diffusion map (LSDMap) method is a collective-variable-based approach. It is found that all three methods agree well in their geometrical definition of the most important docking site, and all experimentally known docking sites are recovered by all three methods. Also, for most of the states, their population coincides quite favourably, whereas the kinetics of and between the states differs. One of the major differences between k-means and MCL clustering on the one hand and LSDMap on the other is that the latter finds one large primary cluster containing the Xe1a, IS1, and ENT states. This is related to the fact that the motion within the state occurs on similar time scales, whereas structurally the state is found to be quite diverse. In agreement with previous explicit atomistic simulations, the Xe3 pocket is found to be a highly dynamical site which points to its potential role as a hub in the network. This is also highlighted in the fact that LSDMap cannot identify this state. First passage time distributions from MCL clusterings using a one- (ligand-position) and two-dimensional (ligand-position and protein-structure) descriptor suggest that ligand- and protein-motions are coupled. The benefits and drawbacks of the three methods are discussed in a comparative fashion and highlight that depending on the questions at hand the best-performing method for a particular data set may differ.

  1. SEMANTIC PATCH INFERENCE

    DEFF Research Database (Denmark)

    Andersen, Jesper

    2009-01-01

    Collateral evolution the problem of updating several library-using programs in response to API changes in the used library. In this dissertation we address the issue of understanding collateral evolutions by automatically inferring a high-level specification of the changes evident in a given set ...... specifications inferred by spdiff in Linux are shown. We find that the inferred specifications concisely capture the actual collateral evolution performed in the examples....

  2. Human migration: Climate and the peopling of the world

    Science.gov (United States)

    Demenocal, Peter B.; Stringer, Chris

    2016-10-01

    The human dispersal out of Africa that populated the world was probably paced by climate changes. This is the inference drawn from computer modelling of climate variability during the time of early human migration. See Letter p.92

  3. The Determinants of Actual Migration and the Role of Wages and Unemployment in Albania: an Empirical Analysis

    Directory of Open Access Journals (Sweden)

    Cristina Cattaneo

    2008-06-01

    Full Text Available The paper explores the determinants of internal migration in Albania, adopting the Harris-Todaro approach to migration: an internal migration function is estimated using district wage and unemployment rate differentials. The aggregate level wages and unemployment, included in the migration equation, are retrieved from a first stage wage and unemployment equations, estimated controlling for personal characteristics. Moreover, in order to test the predictions of the human capital model of migration, the difference between migrants and non-migrants is emphasized in the estimation. The data source is the "Living Standard Measurement Survey for Albania" (2002, undertaken by the national Institute of Statistics and the World Bank jointly. The results reveal that both wage and unemployment differentials are important determinants of the propensity to migrate in Albania. This conclusion is further emphasized by noting that migrants gain substantially in terms of higher returns to individual characteristics after emigration.

  4. Daily newspaper reporting on elderly care in Sweden and Finland: a quantitative content analysis of ethnicity- and migration-related issues

    Directory of Open Access Journals (Sweden)

    Sandra Torres

    2014-11-01

    Full Text Available Media representations are important sources of information especially about contexts that people have limited access to (such as the one we address here, that is, elderly care. Representations of this also give us an insight into how ethnicity-, culture-, and migration-related issues are regarded. This article aims to shed light on media representations related to the nexus of elderly care, ethnicity, and migration in Sweden and Finland, given that the two countries have similar elderly care regimes but different migration regimes. The study uses quantitative content analysis to analyze all of the daily newspaper articles on elderly care that have touched upon these issues and have been published in one major newspaper in each country between 1995 and 2011 (N=347. In this article, we present the topics that these newspaper articles discuss; the elderly care actors that the articles focus on (i.e. whether the focus has been on elderly care recipients, elderly care providers or informal caregivers; the ethnic backgrounds of those who expressed themselves in the articles (i.e. whether the focus has been on the ethnic majority or on ethnic minorities; and the type of explanatory frameworks used in the daily press reporting in question. The article problematizes the media representations of ethnicity- and migration-related issues within the Swedish and Finnish elderly care sectors that the analysis has unveiled in relation to the debate on the challenges that the globalization of international migration poses to the elderly care sector.

  5. Network Dependency in Migration Flows – A Space-time Analysis for Germany since Re-unification

    DEFF Research Database (Denmark)

    Mitze, Timo

    The contribution of this paper is to analyse the role of network interdependencies in a dynamic panel data model for German internal migration fl ows since re-unification. So far, a capacious account of spatial patterns in German migration data is still missing in the empirical literature....... In the context of this paper, network dependencies are associated with correlations of migration flows strictly attributable to proximate flows in geographic space. Using the neoclassical migration model, we start from its aspatial specification and show by means of residual testing that network dependency eff...

  6. Using stable isotope analysis to understand the migration and trophic ecology of northeastern Pacific white sharks (Carcharodon carcharias).

    Science.gov (United States)

    Carlisle, Aaron B; Kim, Sora L; Semmens, Brice X; Madigan, Daniel J; Jorgensen, Salvador J; Perle, Christopher R; Anderson, Scot D; Chapple, Taylor K; Kanive, Paul E; Block, Barbara A

    2012-01-01

    The white shark (Carcharodon carcharias) is a wide-ranging apex predator in the northeastern Pacific (NEP). Electronic tagging has demonstrated that white sharks exhibit a regular migratory pattern, occurring at coastal sites during the late summer, autumn and early winter and moving offshore to oceanic habitats during the remainder of the year, although the purpose of these migrations remains unclear. The purpose of this study was to use stable isotope analysis (SIA) to provide insight into the trophic ecology and migratory behaviors of white sharks in the NEP. Between 2006 and 2009, 53 white sharks were biopsied in central California to obtain dermal and muscle tissues, which were analyzed for stable isotope values of carbon (δ(13)C) and nitrogen (δ(15)N). We developed a mixing model that directly incorporates movement data and tissue incorporation (turnover) rates to better estimate the relative importance of different focal areas to white shark diet and elucidate their migratory behavior. Mixing model results for muscle showed a relatively equal dietary contribution from coastal and offshore regions, indicating that white sharks forage in both areas. However, model results indicated that sharks foraged at a higher relative rate in coastal habitats. There was a negative relationship between shark length and muscle δ(13)C and δ(15)N values, which may indicate ontogenetic changes in habitat use related to onset of maturity. The isotopic composition of dermal tissue was consistent with a more rapid incorporation rate than muscle and may represent more recent foraging. Low offshore consumption rates suggest that it is unlikely that foraging is the primary purpose of the offshore migrations. These results demonstrate how SIA can provide insight into the trophic ecology and migratory behavior of marine predators, especially when coupled with electronic tagging data.

  7. Probing membrane protein interactions with their lipid raft environment using single-molecule tracking and Bayesian inference analysis.

    Directory of Open Access Journals (Sweden)

    Silvan Türkcan

    Full Text Available The statistical properties of membrane protein random walks reveal information on the interactions between the proteins and their environments. These interactions can be included in an overdamped Langevin equation framework where they are injected in either or both the friction field and the potential field. Using a Bayesian inference scheme, both the friction and potential fields acting on the ε-toxin receptor in its lipid raft have been measured. Two types of events were used to probe these interactions. First, active events, the removal of cholesterol and sphingolipid molecules, were used to measure the time evolution of confining potentials and diffusion fields. Second, passive rare events, de-confinement of the receptors from one raft and transition to an adjacent one, were used to measure hopping energies. Lipid interactions with the ε-toxin receptor are found to be an essential source of confinement. ε-toxin receptor confinement is due to both the friction and potential field induced by cholesterol and sphingolipids. Finally, the statistics of hopping energies reveal sub-structures of potentials in the rafts, characterized by small hopping energies, and the difference of solubilization energy between the inner and outer raft area, characterized by higher hopping energies.

  8. Comparative analysis of an evaporative condenser using artificial neural network and adaptive neuro-fuzzy inference system

    Energy Technology Data Exchange (ETDEWEB)

    Metin Ertunc, H. [Department of Mechatronics Engineering, Kocaeli University, Umuttepe, 41380 Kocaeli (Turkey); Hosoz, Murat [Department of Mechanical Education, Kocaeli University, Umuttepe, 41380 Kocaeli (Turkey)

    2008-12-15

    This study deals with predicting the performance of an evaporative condenser using both artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) techniques. For this aim, an experimental evaporative condenser consisting of a copper tube condensing coil along with air and water circuit elements was developed and equipped with instruments used for temperature, pressure and flow rate measurements. After the condenser was connected to an R134a vapour-compression refrigeration circuit, it was operated at steady state conditions, while varying both dry and wet bulb temperatures of the air stream entering the condenser, air and water flow rates as well as pressure, temperature and flow rate of the entering refrigerant. Using some of the experimental data for training, ANN and ANFIS models for the evaporative condenser were developed. These models were used for predicting the condenser heat rejection rate, refrigerant temperature leaving the condenser along with dry and wet bulb temperatures of the leaving air stream. Although it was observed that both ANN and ANFIS models yielded a good statistical prediction performance in terms of correlation coefficient, mean relative error, root mean square error and absolute fraction of variance, the accuracies of ANFIS predictions were usually slightly better than those of ANN predictions. This study reveals that, having an extended prediction capability compared to ANN, the ANFIS technique can also be used for predicting the performance of evaporative condensers. (author)

  9. A Nuclear Ribosomal DNA Phylogeny of Acer Inferred with Maximum Likelihood, Splits Graphs, and Motif Analysis of 606 Sequences

    Directory of Open Access Journals (Sweden)

    Guido W. Grimm

    2006-01-01

    Full Text Available The multi-copy internal transcribed spacer (ITS region of nuclear ribosomal DNA is widely used to infer phylogenetic relationships among closely related taxa. Here we use maximum likelihood (ML and splits graph analyses to extract phylogenetic information from ~ 600 mostly cloned ITS sequences, representing 81 species and subspecies of Acer, and both species of its sister Dipteronia. Additional analyses compared sequence motifs in Acer and several hundred Anacardiaceae, Burseraceae, Meliaceae, Rutaceae, and Sapindaceae ITS sequences in GenBank. We also assessed the effects of using smaller data sets of consensus sequences with ambiguity coding (accounting for within-species variation instead of the full (partly redundant original sequences. Neighbor-nets and bipartition networks were used to visualize conflict among character state patterns. Species clusters observed in the trees and networks largely agree with morphology-based classifications; of de Jong’s (1994 16 sections, nine are supported in neighbor-net and bipartition networks, and ten by sequence motifs and the ML tree; of his 19 series, 14 are supported in networks, motifs, and the ML tree. Most nodes had higher bootstrap support with matrices of 105 or 40 consensus sequences than with the original matrix. Within-taxon ITS divergence did not differ between diploid and polyploid Acer, and there was little evidence of differentiated parental ITS haplotypes, suggesting that concerted evolution in Acer acts rapidly.

  10. Gradient Matching Methods for Computational Inference in Mechanistic Models for Systems Biology: A Review and Comparative Analysis.

    Science.gov (United States)

    Macdonald, Benn; Husmeier, Dirk

    2015-01-01

    Parameter inference in mathematical models of biological pathways, expressed as coupled ordinary differential equations (ODEs), is a challenging problem in contemporary systems biology. Conventional methods involve repeatedly solving the ODEs by numerical integration, which is computationally onerous and does not scale up to complex systems. Aimed at reducing the computational costs, new concepts based on gradient matching have recently been proposed in the computational statistics and machine learning literature. In a preliminary smoothing step, the time series data are interpolated; then, in a second step, the parameters of the ODEs are optimized, so as to minimize some metric measuring the difference between the slopes of the tangents to the interpolants, and the time derivatives from the ODEs. In this way, the ODEs never have to be solved explicitly. This review provides a concise methodological overview of the current state-of-the-art methods for gradient matching in ODEs, followed by an empirical comparative evaluation based on a set of widely used and representative benchmark data.

  11. Statistical inference on residual life

    CERN Document Server

    Jeong, Jong-Hyeon

    2014-01-01

    This is a monograph on the concept of residual life, which is an alternative summary measure of time-to-event data, or survival data. The mean residual life has been used for many years under the name of life expectancy, so it is a natural concept for summarizing survival or reliability data. It is also more interpretable than the popular hazard function, especially for communications between patients and physicians regarding the efficacy of a new drug in the medical field. This book reviews existing statistical methods to infer the residual life distribution. The review and comparison includes existing inference methods for mean and median, or quantile, residual life analysis through medical data examples. The concept of the residual life is also extended to competing risks analysis. The targeted audience includes biostatisticians, graduate students, and PhD (bio)statisticians. Knowledge in survival analysis at an introductory graduate level is advisable prior to reading this book.

  12. Calibration of crash risk models on freeways with limited real-time traffic data using Bayesian meta-analysis and Bayesian inference approach.

    Science.gov (United States)

    Xu, Chengcheng; Wang, Wei; Liu, Pan; Li, Zhibin

    2015-12-01

    This study aimed to develop a real-time crash risk model with limited data in China by using Bayesian meta-analysis and Bayesian inference approach. A systematic review was first conducted by using three different Bayesian meta-analyses, including the fixed effect meta-analysis, the random effect meta-analysis, and the meta-regression. The meta-analyses provided a numerical summary of the effects of traffic variables on crash risks by quantitatively synthesizing results from previous studies. The random effect meta-analysis and the meta-regression produced a more conservative estimate for the effects of traffic variables compared with the fixed effect meta-analysis. Then, the meta-analyses results were used as informative priors for developing crash risk models with limited data. Three different meta-analyses significantly affect model fit and prediction accuracy. The model based on meta-regression can increase the prediction accuracy by about 15% as compared to the model that was directly developed with limited data. Finally, the Bayesian predictive densities analysis was used to identify the outliers in the limited data. It can further improve the prediction accuracy by 5.0%.

  13. Gender and Migration from Albania

    OpenAIRE

    2010-01-01

    This article examines the dynamics and causes of the shift in the gender composition of migration, and more particularly, in women’s access to migration opportunities and decision-making. Our analysis focuses on Albania, a natural laboratory for studying international migration where out-migration was essentially nonexistent from the end of World War II to the end of the 1980s. Interest in the Albanian case is heightened because of the complex layers of inequality existing at the time when mi...

  14. Inference in `poor` languages

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, S.

    1996-10-01

    Languages with a solvable implication problem but without complete and consistent systems of inference rules (`poor` languages) are considered. The problem of existence of finite complete and consistent inference rule system for a ``poor`` language is stated independently of the language or rules syntax. Several properties of the problem arc proved. An application of results to the language of join dependencies is given.

  15. Africa: Setting for Human Migration

    Science.gov (United States)

    Buuba, Babacar Diop

    2007-01-01

    Analysis of African migrations can help to understand prehistoric, historical, ancient modern and contemporaneous migrations. Movements of populations were and continue to be so intense that, for some analysts, they constitute one of the dominant trends of the history and destiny of the very old continent. African and non-African states, whether…

  16. Migration of styrene and ethylbenzene from virgin and recycled expanded polystyrene containers and discrimination of these two kinds of polystyrene by principal component analysis.

    Science.gov (United States)

    Lin, Qin-Bao; Song, Xue-Chao; Fang, Hong; Wu, Yu-Mei; Wang, Zhi-Wei

    2017-01-01

    The migration of styrene and ethylbenzene from virgin and recycled expanded polystyrene (EPS) containers into isooctane was investigated using gas chromatography-mass spectrometry (GC-MS). EPS containers were in two-sided contact with isooctane at temperatures of 25 and 40°C. It was shown that recycled EPS gave greater migration ratios compared with virgin EPS, which indicated that styrene and ethylbenzene migrated more easily from recycled EPS. In addition, an analytical method to distinguish between virgin and recycled EPS containers was established by GC-MS followed by principal component analysis (PCA). The relative peak area of the identified compounds was used as input data for PCA. Distinct separation between virgin and recycled EPS was achieved on a score plot. Extension of this method to other plastics may be of great interest for recycled plastics identification.

  17. Origin and diversification of major clades in parmelioid lichens (Parmeliaceae, Ascomycota) during the Paleogene inferred by Bayesian analysis.

    Science.gov (United States)

    Amo de Paz, Guillermo; Cubas, Paloma; Divakar, Pradeep K; Lumbsch, H Thorsten; Crespo, Ana

    2011-01-01

    There is a long-standing debate on the extent of vicariance and long-distance dispersal events to explain the current distribution of organisms, especially in those with small diaspores potentially prone to long-distance dispersal. Age estimates of clades play a crucial role in evaluating the impact of these processes. The aim of this study is to understand the evolutionary history of the largest clade of macrolichens, the parmelioid lichens (Parmeliaceae, Lecanoromycetes, Ascomycota) by dating the origin of the group and its major lineages. They have a worldwide distribution with centers of distribution in the Neo- and Paleotropics, and semi-arid subtropical regions of the Southern Hemisphere. Phylogenetic analyses were performed using DNA sequences of nuLSU and mtSSU rDNA, and the protein-coding RPB1 gene. The three DNA regions had different evolutionary rates: RPB1 gave a rate two to four times higher than nuLSU and mtSSU. Divergence times of the major clades were estimated with partitioned BEAST analyses allowing different rates for each DNA region and using a relaxed clock model. Three calibrations points were used to date the tree: an inferred age at the stem of Lecanoromycetes, and two dated fossils: Parmelia in the parmelioid group, and Alectoria. Palaeoclimatic conditions and the palaeogeological area cladogram were compared to the dated phylogeny of parmelioid. The parmelioid group diversified around the K/T boundary, and the major clades diverged during the Eocene and Oligocene. The radiation of the genera occurred through globally changing climatic condition of the early Oligocene, Miocene and early Pliocene. The estimated divergence times are consistent with long-distance dispersal events being the major factor to explain the biogeographical distribution patterns of Southern Hemisphere parmelioids, especially for Africa-Australia disjunctions, because the sequential break-up of Gondwana started much earlier than the origin of these clades. However, our

  18. Determinants of Mexico-U.S. Outward and Return Migration Flows: A State-Level Panel Data Analysis.

    Science.gov (United States)

    Chort, Isabelle; de la Rupelle, Maëlys

    2016-10-01

    Using a unique panel data set of state-to-state outward and return migration flows between Mexico and the United States from 1995 to 2012, this study is the first to analyze Mexico-U.S. migration at the state level and explore simultaneously the effect of economic, environmental, and social factors in Mexico over two decades. Pairing origin and destination states and controlling for a rich structure of fixed effects, we find that income positively impacts migration outflows, especially for Mexican states of origin with a recent migration history and for low-educated migrant flows, suggesting the existence of credit constraints. We find evidence that drought causes more out-migration, while other climatic shocks have no effect. Violence is found to increase out-migration flows from border states and to decrease migration from other Mexican states, especially where violence is directed at migrants. Last, return flows are larger when income growth at destination is lower, consistent with the accumulation of savings as a primary motivation of migrants. Exploring the impact of the crisis, we find evidence of significant changes in the geography of migration flows. Traditional flows are drying up, and new migration corridors are rising, with implications on the composition of the Mexican population in the United States. Although the effect of income on flows in both directions is unchanged by the crisis, the negative effect of violence on out-migration tends to reverse at the end of the period. Overall, this study emphasizes the interest of analyzing disaggregated flows at the infra-country level.

  19. An introduction to causal inference.

    Science.gov (United States)

    Pearl, Judea

    2010-02-26

    This paper summarizes recent advances in causal inference and underscores the paradigmatic shifts that must be undertaken in moving from traditional statistical analysis to causal analysis of multivariate data. Special emphasis is placed on the assumptions that underlie all causal inferences, the languages used in formulating those assumptions, the conditional nature of all causal and counterfactual claims, and the methods that have been developed for the assessment of such claims. These advances are illustrated using a general theory of causation based on the Structural Causal Model (SCM) described in Pearl (2000a), which subsumes and unifies other approaches to causation, and provides a coherent mathematical foundation for the analysis of causes and counterfactuals. In particular, the paper surveys the development of mathematical tools for inferring (from a combination of data and assumptions) answers to three types of causal queries: those about (1) the effects of potential interventions, (2) probabilities of counterfactuals, and (3) direct and indirect effects (also known as "mediation"). Finally, the paper defines the formal and conceptual relationships between the structural and potential-outcome frameworks and presents tools for a symbiotic analysis that uses the strong features of both. The tools are demonstrated in the analyses of mediation, causes of effects, and probabilities of causation.

  20. Media deliberation on intra-EU migration. A qualitative approach to framing based on rhetorical analysis

    OpenAIRE

    Alexandru Cârlan; Mălina Ciocea

    2016-01-01

    In this paper we investigate how the model of deliberation proposed by Isabela and Norman Fairclough can be used for a better clarification and understanding of the framing processes in media – especially in opinion articles. We thus aim at integrating theoretical contributions from critical discourse analysis and argumentation theory with standard approaches to framing, originating in media studies. We emphasize how a rhetorical approach to framing can provide analytical insights into framin...

  1. Identification of Fold Hinge Migration in Natural Deformation: A New Technique Using Grain Shape Fabric Analysis

    OpenAIRE

    Rose, Kelly Kathleen

    1999-01-01

    Partitioning of finite strains in different domains within the limb and hinge regions of a fold can be used to understand the deformation processes operative during fold formation. Samples taken from the limb and hinge regions of a gently plunging, asymmetric, tight, mesoscale fold in the Erwin formation of the Blue Ridge in North Carolina were analyzed to determine the deformation mechanisms and strains associated with the folding event. Rf/phi grain shape fabric analysis was conducted for...

  2. Juvenile magma recognition and eruptive dynamics inferred from the analysis of ash time series: The 2015 reawakening of Cotopaxi volcano

    Science.gov (United States)

    Gaunt, H. Elizabeth; Bernard, Benjamin; Hidalgo, Silvana; Proaño, Antonio; Wright, Heather; Mothes, Patricia; Criollo, Evelyn; Kueppers, Ulrich

    2016-12-01

    Forecasting future activity and performing hazard assessments during the reactivation of volcanoes remain great challenges for the volcanological community. On August 14, 2015 Cotopaxi volcano erupted for the first time in 73 years after approximately four months of precursory activity, which included an increase in seismicity, gas emissions, and minor ground deformation. Here we discuss the use of near real-time petrological monitoring of ash samples as a complementary aid to geophysical monitoring, in order to infer eruption dynamics and evaluate possible future eruptive activity at Cotopaxi. Twenty ash samples were collected between August 14 and November 23, 2015 from a monitoring site on the west flank of the volcano. These samples contain a range of grain types that we classified as: hydrothermal/altered, lithic, juvenile, and free crystals. The relative proportions of theses grains evolved as the eruption progressed, with increasing amounts of juvenile material and a decrease in hydrothermally altered material. In samples from the initial explosion, juvenile grains are glassy, microlite-poor and contain hydrothermal minerals (opal and alunite). The rising magma came in contact with the hydrothermal system under confinement, causing hydro-magmatic explosions that cleared the upper part of the plumbing system. Subsequently, the magmatic column produced a thermal aureole in the conduit and dried out the hydrothermal system, allowing for dry eruptions. Magma ascent rates were low enough to allow for efficient outgassing and microlite growth. Constant supply of magma from below caused quasi-continuous disruption of the uppermost magma volume through a combination of shear-deformation and gas expansion. The combination of increasing crystallinity of juvenile grains, and high measured SO2 flux indicate decreasing integrated magma ascent rates and clearing of the hydrothermal system along transport pathways in a system open to gas loss. The near real-time monitoring

  3. Juvenile magma recognition and eruptive dynamics inferred from the analysis of ash time series: The 2015 reawakening of Cotopaxi volcano

    Science.gov (United States)

    Gaunt, H. Elizabeth; Bernard, Benjamin; Hidalgo, Silvana; Proano, Antonio; Wright, Heather M.; Mothes, Patricia; Criollo, Evelyn; Kueppers, Ulrich

    2016-01-01

    Forecasting future activity and performing hazard assessments during the reactivation of volcanoes remain great challenges for the volcanological community. On August 14, 2015 Cotopaxi volcano erupted for the first time in 73 years after approximately four months of precursory activity, which included an increase in seismicity, gas emissions, and minor ground deformation. Here we discuss the use of near real-time petrological monitoring of ash samples as a complementary aid to geophysical monitoring, in order to infer eruption dynamics and evaluate possible future eruptive activity at Cotopaxi. Twenty ash samples were collected between August 14 and November 23, 2015 from a monitoring site on the west flank of the volcano. These samples contain a range of grain types that we classified as: hydrothermal/altered, lithic, juvenile, and free crystals. The relative proportions of theses grains evolved as the eruption progressed, with increasing amounts of juvenile material and a decrease in hydrothermally altered material. In samples from the initial explosion, juvenile grains are glassy, microlite-poor and contain hydrothermal minerals (opal and alunite). The rising magma came in contact with the hydrothermal system under confinement, causing hydro-magmatic explosions that cleared the upper part of the plumbing system. Subsequently, the magmatic column produced a thermal aureole in the conduit and dried out the hydrothermal system, allowing for dry eruptions. Magma ascent rates were low enough to allow for efficient outgassing and microlite growth. Constant supply of magma from below caused quasi-continuous disruption of the uppermost magma volume through a combination of shear-deformation and gas expansion. The combination of increasing crystallinity of juvenile grains, and high measured SO2 flux indicate decreasing integrated magma ascent rates and clearing of the hydrothermal system along transport pathways in a system open to gas loss. The near real

  4. Bayesian Inference Methods for Sparse Channel Estimation

    DEFF Research Database (Denmark)

    Pedersen, Niels Lovmand

    2013-01-01

    This thesis deals with sparse Bayesian learning (SBL) with application to radio channel estimation. As opposed to the classical approach for sparse signal representation, we focus on the problem of inferring complex signals. Our investigations within SBL constitute the basis for the development...... of Bayesian inference algorithms for sparse channel estimation. Sparse inference methods aim at finding the sparse representation of a signal given in some overcomplete dictionary of basis vectors. Within this context, one of our main contributions to the field of SBL is a hierarchical representation...... analysis of the complex prior representation, where we show that the ability to induce sparse estimates of a given prior heavily depends on the inference method used and, interestingly, whether real or complex variables are inferred. We also show that the Bayesian estimators derived from the proposed...

  5. A preference for migration

    OpenAIRE

    Stark, Oded

    2007-01-01

    At least to some extent migration behavior is the outcome of a preference for migration. The pattern of migration as an outcome of a preference for migration depends on two key factors: imitation technology and migration feasibility. We show that these factors jointly determine the outcome of a preference for migration and we provide examples that illustrate how the prevalence and transmission of a migration-forming preference yield distinct migration patterns. In particular, the imitation of...

  6. Applied statistical inference with MINITAB

    CERN Document Server

    Lesik, Sally

    2009-01-01

    Through clear, step-by-step mathematical calculations, Applied Statistical Inference with MINITAB enables students to gain a solid understanding of how to apply statistical techniques using a statistical software program. It focuses on the concepts of confidence intervals, hypothesis testing, validating model assumptions, and power analysis.Illustrates the techniques and methods using MINITABAfter introducing some common terminology, the author explains how to create simple graphs using MINITAB and how to calculate descriptive statistics using both traditional hand computations and MINITAB. Sh

  7. Phylogeographical analyses reveal global migration patterns of the barley scald pathogen Rhynchosporium secalis.

    Science.gov (United States)

    Zaffarano, Pascal L; McDonald, Bruce A; Linde, Celeste C

    2009-01-01

    A phylogeographical analysis of the scald pathogen Rhynchosporium secalis was conducted using nuclear DNA sequences from two neutral restriction fragment length polymorphism loci and the mating-type idiomorphs. Approximately 500 isolates sampled from more than 60 field populations from five continents were analysed to infer migration patterns and the demographic history of the fungus. Migration rates among continents were generally low, consistent with earlier reports of significant population subdivision among continents. Northern Europe was mainly a source population for global migration. We hypothesize that the pathogen only recently moved out of its centre of origin, resulting in founder populations that are reproductively isolated due to the contemporary absence of long-distance gene flow.

  8. Knowledge and inference

    CERN Document Server

    Nagao, Makoto

    1990-01-01

    Knowledge and Inference discusses an important problem for software systems: How do we treat knowledge and ideas on a computer and how do we use inference to solve problems on a computer? The book talks about the problems of knowledge and inference for the purpose of merging artificial intelligence and library science. The book begins by clarifying the concept of """"knowledge"""" from many points of view, followed by a chapter on the current state of library science and the place of artificial intelligence in library science. Subsequent chapters cover central topics in the artificial intellig

  9. TPM可迁移密钥安全性分析与研究%Security Analysis and Research on TPM Migratable Key

    Institute of Scientific and Technical Information of China (English)

    张倩颖; 赵世军; 冯登国

    2012-01-01

    TPM key migration mechanism put keys into two categories in accordance with the migration characteristics. This paper gives a deep security analysis of TPM migratable keys, and points out some security flaws about TPM key migration. First, by key migration mechanism, the TPM owner can export a migratable key in the form of migration blob, decrypt the blob, and get the plaintext of the TPM private key. Second, a TPM user can use TPM key migration mechanism to import a non-TPM generated key blob into TPM. Third, a TPM user can construct a loadable blob of a non-TPM generated key, and then load it into TPM by the TPM key loading command. On the basis of analyzing the TPM specification theoretically, we give an attack in technical view, and propose a solution to one of the security problems. The analysis indicates that the TPM key migration mechanism, in spite of improving key interoperability between TPMs, reduces the security strength of the migratable key. Therefore, TPM users must think over the security weaknesses when using migratable keys, and do not use migratable keys in security critical operation as far as possible.%TPM密钥迁移机制使密钥按照迁移特性分为了可迁移密钥和不可迁移密钥两类,本文深入分析可迁移密钥的安全性,指出可迁移密钥存在的安全问题.首先,利用密钥迁移机制,TPM所有者能将TPM内部可迁移密钥以迁移块的形式导出,解密迁移块能获得可迁移密钥私钥.其次,TPM用户能通过密钥迁移机制将非TPM产生的用户可控密钥构造成迁移块,作为迁移密钥导入到TPM内部.此外,用户使用TPM密钥加载命令能将非TPM产生的用户可控密钥作为TPM产生的可迁移密钥加载到TPM中.在对TPM规范理论分析的基础上,本文从技术角度给出了攻击可迁移密钥安全性的实现方法,并对部分安全问题提出了解决方案.通过分析,本文指出TPM提供密钥迁移机制的同时,也降低了可迁移密钥的安

  10. Remotely Sensed Trajectory Analysis of Channel Migration in Lower Jingjiang Reach during the Period of 1983–2013

    Directory of Open Access Journals (Sweden)

    Chao Yang

    2015-12-01

    Full Text Available In China, the Lower Jingjiang Reach (LJR of the Yangtze River could be one of the most complicated areas in terms of channel migration. The river had undergone many channel changes in the reach since the 18th century. Intensive human activities in recent decades, such as the construction of upstream dams and revetments, had directly affected the channel migration characteristics. The revetment would significantly diminish migration, whereas the reduced sediment caused by dams would increase bank erosion and bank failure risks. Satellite imageries of Landsat Multi Spectral Scanner (MSS, Thematic Mapper (TM, Enhanced Thematic Mapper Plus (ETM+ and Operational Land Imager (OLI were employed to quantify the planform migration of the reach from 1983 to 2013 and to investigate the possible effect of human activities on the LJR channel evolution. Apart from the commonly used planform morphometric parameters, the migration direction was introduced to predict the future migration trends. Results showed that the LJR was gradually changing to a straighter channel, with sinuosity reducing from 2.09 to 1.9 and river length decreasing from 125.32 km to 113.31 km in the past 30 years. Planform morphometric parameters, such as migration rate of the channel centerline and erosion and deposition areas and rates, also decreased drastically in the past 30 years. The migration rate of the channel centerline decreased from 31.05 m·year−1 in 1983–1988 to 11.62 m·year−1 in 2009–2013. The lateral erosion and deposition areas decreased from 21.32 and 25.73 km2 in 1983–1988 to 4.83 and 5.83 km2 in 2009–2013. All of these findings indicate that the LJR tended to be in a steady state from 1983 to 2013 and was totally controlled by the bank revetments. However, the undercutting was strengthened because of the restrictive effect of revetments on lateral migration in the LJR. Moreover, the channel migrated to the left bank with a visible tendency as the total

  11. Ethnological Analysis of the Process of the Post-War Migration of Slovaks from Hungary to Czechoslovakia in the Years 1946-1948

    Directory of Open Access Journals (Sweden)

    Paríková Magdaléna

    2014-12-01

    Full Text Available The article focuses on the application of the possibilities of collecting narratives and their analysis in the reconstruction process of migration of people to the new country - in Slovakia. The analysis of the particular data gained by fieldwork research using the oral history method comparative with the historical and statistic dates. These facts offer not only relevant information documenting the real process of the migration, but also create the network of microprobes (case study on the basis of specific experienced events of the direct participants of migration, as well as the reflection in memory of the resettled. Fieldwork research was in the region of South Slovakia - around Nové Zámky and Komárno cities. The aim of this approach is to interpret individually experience “small history” of the context of “big history”, specifically, one post-war phase of migration, which occurred in this area of Central Europe in the period from 1946 to 1948.

  12. OperationalAmplifier Analysis when Migrating from 0.18 µm to 65 µm CMOS Technology

    Directory of Open Access Journals (Sweden)

    Karolis Kiela

    2013-05-01

    Full Text Available The article offers the analysis of operational amplifier parameter changes, when circuits are scaled from 0.18 μm to 65 nm CMOS technology. Two two-stage operational amplifiers were designed for this purpose: first uses n-MOS input differential pair; second uses cascaded active loads structure and p-MOS type input differential pair. The operational amplifiers were designed in 0.18 μm CMOS technology and scaled to 65 nm CMOS. Other scaling methods were also analysed when redesigning circuits from one IC technology to another. Results of the original and scaled operational amplifier parameters are presented and analysed.Article in Lithuanian

  13. Forced bachelors, migration and HIV transmission risk in the context of China's gender imbalance: a meta-analysis.

    Science.gov (United States)

    Liu, Huijun; Li, Shuzhuo; Feldman, M W

    2012-01-01

    China has experienced continual increase in the sex ratio at birth (SRB) since the 1980s, which has led to a serious gender imbalance. To identify whether the future forced bachelors, especially those who migrate to cities, will increase the risk of HIV spread, a systematic review was carried out of studies published since 2000 that include the sexual risks of male migrants of China. Five studies comparing risk differences between migrants and non-migrants showed male migrants had greater risk of having multiple sexual partners and engaging in commercial sex. Ten studies concerning the relationship between sexual risks and socio-demographic characteristics showed that unmarried male migrants were more likely to engage in commercial sex and be infected with STDs than married migrants, while male migrants with higher income were more likely to have multiple sexual partners and be infected with STDs. In an analysis stratified by sample characteristics, the association between marriage and sexual risk was greater among samples with lower mean age, higher average income and education. In addition, the risk selection on education and income disappeared in the samples of migrants of whom more than half were unmarried.

  14. MARFA version 3.2.2 user's manual: migration analysis of radionuclides in the far field

    Energy Technology Data Exchange (ETDEWEB)

    Painter, Scott; Mancillas, James (Center for Nuclear Waste Regulatory Analyses, Southwest Research Inst., San Antonio, TX (United States))

    2009-12-15

    The computer code Migration Analysis of Radionuclides in the Far Field (MARFA) uses a particle-based Monte Carlo method to simulate the transport of radionuclides in a sparsely fractured geological medium. Transport in sparsely fractured rock is of interest because this medium may serve as a barrier to migration of radionuclides to the accessible environment. The physical processes represented in MARFA include advection, longitudinal dispersion, Fickian diffusion into an infinite or finite rock matrix, equilibrium sorption, decay, and in-growth. Multiple non-branching decay chains of arbitrary length are supported. This document describes the technical basis and input requirements for MARFA Version 3.2.2. MARFA Version 3.2 included new capabilities to accommodate transient flow velocities and sorption parameters, which are assumed to be piecewise constant in time. Version 3.2.1 was a minor change from Version 3.2 to allow a more convenient input format for sorption information. New capabilities in Version 3.2.2 include an option to specify a non-zero start time for the simulation, an optional input parameter that decreases the amount of retention within a single fracture because of flow channeling, and an alternative method for sampling the radionuclide source. MARFA uses the particle on random streamline segment algorithm/Painter et al. 2006/, a Monte Carlo algorithm combining time-domain random walk methods with pathway stochastic simulation. The algorithm uses non-interacting particles to represent packets of radionuclide mass. These particles are moved through the system according to rules that mimic the underlying physical transport and retention processes. The set of times required for particles to pass through the geological barrier are then used to reconstruct discharge rates (mass or activity basis). Because the algorithm uses non-interacting particles, the transport and retention processes are limited to those that depend linearly on radionuclide

  15. Source inference of exogenous gamma-hydroxybutyric acid (GHB) administered to humans by means of carbon isotopic ratio analysis: novel perspectives regarding forensic investigation and intelligence issues.

    Science.gov (United States)

    Marclay, François; Saudan, Christophe; Vienne, Julie; Tafti, Mehdi; Saugy, Martial

    2011-05-01

    γ-Hydroxybutyric acid (GHB) is an endogenous short-chain fatty acid popular as a recreational drug due to sedative and euphoric effects, but also often implicated in drug-facilitated sexual assaults owing to disinhibition and amnesic properties. Whilst discrimination between endogenous and exogenous GHB as required in intoxication cases may be achieved by the determination of the carbon isotope content, such information has not yet been exploited to answer source inference questions of forensic investigation and intelligence interests. However, potential isotopic fractionation effects occurring through the whole metabolism of GHB may be a major concern in this regard. Thus, urine specimens from six healthy male volunteers who ingested prescription GHB sodium salt, marketed as Xyrem(®), were analysed by means of gas chromatography/combustion/isotope ratio mass spectrometry to assess this particular topic. A very narrow range of δ(13)C values, spreading from -24.81‰ to -25.06‰, was observed, whilst mean δ(13)C value of Xyrem(®) corresponded to -24.99‰. Since urine samples and prescription drug could not be distinguished by means of statistical analysis, carbon isotopic effects and subsequent influence on δ(13)C values through GHB metabolism as a whole could be ruled out. Thus, a link between GHB as a raw matrix and found in a biological fluid may be established, bringing relevant information regarding source inference evaluation. Therefore, this study supports a diversified scope of exploitation for stable isotopes characterized in biological matrices from investigations on intoxication cases to drug intelligence programmes.

  16. Probability and Statistical Inference

    OpenAIRE

    Prosper, Harrison B.

    2006-01-01

    These lectures introduce key concepts in probability and statistical inference at a level suitable for graduate students in particle physics. Our goal is to paint as vivid a picture as possible of the concepts covered.

  17. Angle-domain Migration Velocity Analysis using Wave-equation Reflection Traveltime Inversion

    KAUST Repository

    Zhang, Sanzong

    2012-11-04

    The main difficulty with an iterative waveform inversion is that it tends to get stuck in a local minima associated with the waveform misfit function. This is because the waveform misfit function is highly non-linear with respect to changes in the velocity model. To reduce this nonlinearity, we present a reflection traveltime tomography method based on the wave equation which enjoys a more quasi-linear relationship between the model and the data. A local crosscorrelation of the windowed downgoing direct wave and the upgoing reflection wave at the image point yields the lag time that maximizes the correlation. This lag time represents the reflection traveltime residual that is back-projected into the earth model to update the velocity in the same way as wave-equation transmission traveltime inversion. The residual movemout analysis in the angle-domain common image gathers provides a robust estimate of the depth residual which is converted to the reflection traveltime residual for the velocity inversion. We present numerical examples to demonstrate its efficiency in inverting seismic data for complex velocity model.

  18. Introductory statistical inference

    CERN Document Server

    Mukhopadhyay, Nitis

    2014-01-01

    This gracefully organized text reveals the rigorous theory of probability and statistical inference in the style of a tutorial, using worked examples, exercises, figures, tables, and computer simulations to develop and illustrate concepts. Drills and boxed summaries emphasize and reinforce important ideas and special techniques.Beginning with a review of the basic concepts and methods in probability theory, moments, and moment generating functions, the author moves to more intricate topics. Introductory Statistical Inference studies multivariate random variables, exponential families of dist

  19. 角度域弹性波Kirchhoff叠前深度偏移速度分析方法%Angle-domain migration velocity analysis based on elastic-wave Kirchhoff prestack depth migration

    Institute of Scientific and Technical Information of China (English)

    杜启振; 李芳; 侯; 秦童; 毕丽飞

    2011-01-01

    为提高地震成像结果的准确性并真实反映实际地震波场在介质中的传播特性,应该充分利用多分量地震数据的矢量特征进行弹性波成像,其中,最为棘手的问题是纵横波偏移速度场的确定,为此,本文提出了直接利用多分量地震数据进行弹性波角度域偏移速度分析的方法.基于空移成像条件的弹性波Kirchhoff偏移方程提取了弹性波局部偏移距域共成像点道集,通过Fourier域角度分解求得以纵波入射角为参数的弹性波角度域共成像点道集.利用提出的反射纵波和转换横波成像深度一致性准则,依据导出的弹性波角度域共成像点道集剩余时差方程分别对纵波、横波偏移速度进行了更新.在此基础上,实现了弹性波Kirchhoff叠前深度偏移速度分析.实例表明,本文提出的弹性波偏移速度分析方法具有可行性和可应用性.%To improve the accuracy of seismic imaging and describe the propagation of seismic wavefield more exactly, we need to take full advantage of the vectorial multicomponent seismic data to conduct the elastic wave imaging. However, the great challenge of elastic wave imaging is the determination migration velocity of P- and S waves. Based on multicomponent seismic data angle-domain common-image gathers (ADCIGs), elastic wave migration velocity analysis is proposed in this paper. Firstly, according to the elastic Kirchhoff migration equation which is based on space shift imaging condition, P- and PS converted waves subsurface offset-domaincommon-image gathers (SODCIGs) are extracted and transformed into P-incidence angle-domaincommon-image gathers (P-ADCIGs) for P- and PS converted waves through the angledecomposition in the Fourier domain, respectively. Secondly, P- and PS converted wave residualmovement equations were derived, and velocity analysis criteria of image depth consistency for P-and PS converted waves at the same reflector were proposed. We iteratively

  20. Using a Simple Binomial Model to Assess Improvement in Predictive Capability: Sequential Bayesian Inference, Hypothesis Testing, and Power Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sigeti, David E. [Los Alamos National Laboratory; Pelak, Robert A. [Los Alamos National Laboratory

    2012-09-11

    We present a Bayesian statistical methodology for identifying improvement in predictive simulations, including an analysis of the number of (presumably expensive) simulations that will need to be made in order to establish with a given level of confidence that an improvement has been observed. Our analysis assumes the ability to predict (or postdict) the same experiments with legacy and new simulation codes and uses a simple binomial model for the probability, {theta}, that, in an experiment chosen at random, the new code will provide a better prediction than the old. This model makes it possible to do statistical analysis with an absolute minimum of assumptions about the statistics of the quantities involved, at the price of discarding some potentially important information in the data. In particular, the analysis depends only on whether or not the new code predicts better than the old in any given experiment, and not on the magnitude of the improvement. We show how the posterior distribution for {theta} may be used, in a kind of Bayesian hypothesis testing, both to decide if an improvement has been observed and to quantify our confidence in that decision. We quantify the predictive probability that should be assigned, prior to taking any data, to the possibility of achieving a given level of confidence, as a function of sample size. We show how this predictive probability depends on the true value of {theta} and, in particular, how there will always be a region around {theta} = 1/2 where it is highly improbable that we will be able to identify an improvement in predictive capability, although the width of this region will shrink to zero as the sample size goes to infinity. We show how the posterior standard deviation may be used, as a kind of 'plan B metric' in the case that the analysis shows that {theta} is close to 1/2 and argue that such a plan B should generally be part of hypothesis testing. All the analysis presented in the paper is done with a

  1. Temporal profiling of cytokine-induced genes in pancreatic β-cells by meta-analysis and network inference

    DEFF Research Database (Denmark)

    Lopes, Miguel; Kutlu, Burak; Miani, Michela;

    2014-01-01

    Type 1 Diabetes (T1D) is an autoimmune disease where local release of cytokines such as IL-1β and IFN-γ contributes to β-cell apoptosis. To identify relevant genes regulating this process we performed a meta-analysis of 8 datasets of β-cell gene expression after exposure to IL-1β and IFN-γ. Two o...

  2. Migration background and juvenile mental health: a descriptive retrospective analysis of diagnostic rates of psychiatric disorders in young people

    Directory of Open Access Journals (Sweden)

    Tilman Jakob Gaber

    2013-06-01

    Full Text Available Introduction: This article presents diagnostic rates for specific mental disorders in a German pediatric inpatient population over a period of 20 years with respect to migration background and socioeconomic status (SES. Methods: Diagnostic data were obtained over a period of 20 years from 8,904 patients who visited a child and adolescent psychiatry mental health service in Germany. Data from 5,985 diagnosed patients (ICD-9 and ICD-10 criteria were included with respect to gender, migration background, and SES. Results:Migration- and gender-specific effects were found for both periods of assessment. The group of boys with a migration background showed significantly higher rates of reactions to severe stress, adjustment disorders, and posttraumatic stress disorder compared to their male, non-migrant counterparts. Conversely, boys without a migration background showed a significantly higher percentage rate of hyperkinetic disorders than male migrants. Similar results were found for female migrants in the latter assessment period (ICD-10. In addition, female migrants showed lower rates of emotional disorders whose onset occurs in childhood compared to their non-migrant counterparts. Conclusions: Data from this investigation provide preliminary evidence that the prevalence of various psychiatric disorders in children and adolescents is influenced by migration background and SES.

  3. Nonparametric Bayesian inference in biostatistics

    CERN Document Server

    Müller, Peter

    2015-01-01

    As chapters in this book demonstrate, BNP has important uses in clinical sciences and inference for issues like unknown partitions in genomics. Nonparametric Bayesian approaches (BNP) play an ever expanding role in biostatistical inference from use in proteomics to clinical trials. Many research problems involve an abundance of data and require flexible and complex probability models beyond the traditional parametric approaches. As this book's expert contributors show, BNP approaches can be the answer. Survival Analysis, in particular survival regression, has traditionally used BNP, but BNP's potential is now very broad. This applies to important tasks like arrangement of patients into clinically meaningful subpopulations and segmenting the genome into functionally distinct regions. This book is designed to both review and introduce application areas for BNP. While existing books provide theoretical foundations, this book connects theory to practice through engaging examples and research questions. Chapters c...

  4. Statistical learning and selective inference.

    Science.gov (United States)

    Taylor, Jonathan; Tibshirani, Robert J

    2015-06-23

    We describe the problem of "selective inference." This addresses the following challenge: Having mined a set of data to find potential associations, how do we properly assess the strength of these associations? The fact that we have "cherry-picked"--searched for the strongest associations--means that we must set a higher bar for declaring significant the associations that we see. This challenge becomes more important in the era of big data and complex statistical modeling. The cherry tree (dataset) can be very large and the tools for cherry picking (statistical learning methods) are now very sophisticated. We describe some recent new developments in selective inference and illustrate their use in forward stepwise regression, the lasso, and principal components analysis.

  5. Evolution of the Near-surface Flows Inferred from High-resolution Ring-diagram Analysis of HMI Data

    Science.gov (United States)

    Bogart, Richard S.; Baldner, Charles; Basu, Sarbani

    2014-06-01

    Ring-diagram analysis of acoustic waves observed at the photosphere provides in principle a relatively robust determination of the sub-surface flows at a particular time under a particular region. The depth of penetration of the waves is related to the size of the region, hence the depth extent of the measured flows is inversely proportional to the spatial resolution. Most ring-analysis has focused on regions of extent ~15 deg (200 Mm) or more in order to provide reasonable mode sets for inversions. The HMI analysis pipeline however also provides a set of ring fit parameters on a scale three times smaller. These provide flow estimates for the outer 1% (7 Mm) of the Sun only, with very limited depth resolution, but with spatial resolution adequate to map structures.potentially associated with the belts and regions of magnetic activity. There are a number of systematic effects affecting the determination of flows from local helioseismic analysis of regions over different parts of the observable disc, not all well-understood. In this study we characterize those systematic effects with higher spatial resolution. This enable us to remove them more effectively as we map the temporal and spatial evolution of the flows, leaving open the question of their mean structure which is most affected by the systematics. We present results for the ring-diagram determination of the flow anomalies corresponding to the torsional oscillation pattern in differential rotation and analogous patterns in the meridional cell structure over the early part of the current solar cycle observed by HMI.

  6. [Variability and phylogenetic relationships of the Cucumis sativus L. species inferred from NBS profiling and RAPD analysis].

    Science.gov (United States)

    Goriunova, S V; Gashkova, I V; Kosareva, G A

    2011-08-01

    Genetic variability of the Cucumis sativus species and its phylogenetic relationsips with other species of the genus were studied on the basis of RAPD marking and analysis of intra- and interspecific polymorphism of the nucleotide sequences of the NBS-LRR gene family in species of the genus Cucumis with the use of the NBS profiling method. According to RAPD analysis, cucumber cultivars from different geographic regions are highly similar, except for accessions k-3835 and k-3833 from Afghanistan. NBS profiling analysis revealed phylogenetically most distinct accessions expected to be characterized by specificity of resistance: k-3845 from Uzbekistan, k-3851 from Kyrgyzstan, line 701, k-3835 and k-3833 from Afghanistan, k-2757 and k-3079 from Netherlands, vr.k. 908 from Canada, k-2926 from Bulgaria, Russian cultivars Monastyrskii, Izyashchnyi, and Lel'. Three essentially different groups of species were distinguished, and the C. sativus species (subgenus Cucumis) was found to be distant from the species belonging to the subgenus Melo.

  7. A meta-analysis of caloric restriction gene expression profiles to infer common signatures and regulatory mechanisms.

    Science.gov (United States)

    Plank, Michael; Wuttke, Daniel; van Dam, Sipko; Clarke, Susan A; de Magalhães, João Pedro

    2012-04-01

    Caloric restriction, a reduction in calorie intake without malnutrition, retards age-related degeneration and extends lifespan in several organisms. CR induces multiple changes, yet its underlying mechanisms remain poorly understood. In this work, we first performed a meta-analysis of microarray CR studies in mammals and identified genes and processes robustly altered due to CR. Our results reveal a complex array of CR-induced changes and we re-identified several genes and processes previously associated with CR, such as growth hormone signalling, lipid metabolism and immune response. Moreover, our results highlight novel associations with CR, such as retinol metabolism and copper ion detoxification, as well as hint of a strong effect of CR on circadian rhythms that in turn may contribute to metabolic changes. Analyses of our signatures by integrating co-expression data, information on genetic mutants, and transcription factor binding site analysis revealed candidate regulators of transcriptional modules in CR. Our results hint at a transcriptional module involved in sterol metabolism regulated by Srebf1. A putative regulatory role of Ppara was also identified. Overall, our conserved molecular signatures of CR provide a comprehensive picture of CR-induced changes and help understand its regulatory mechanisms.

  8. Metabolomic Dynamic Analysis of Hypoxia in MDA-MB-231 and the Comparison with Inferred Metabolites from Transcriptomics Data

    Directory of Open Access Journals (Sweden)

    Yufeng Jane Tseng

    2013-05-01

    Full Text Available Hypoxia affects the tumor microenvironment and is considered important to metastasis progression and therapy resistance. Thus far, the majority of global analyses of tumor hypoxia responses have been limited to just a single omics level. Combining multiple omics data can broaden our understanding of tumor hypoxia. Here, we investigate the temporal change of the metabolite composition with gene expression data from literature to provide a more comprehensive insight into the system level in response to hypoxia. Nuclear magnetic resonance spectroscopy was used to perform metabolomic profiling on the MDA-MB-231 breast cancer cell line under hypoxic conditions. Multivariate statistical analysis revealed that the metabolic difference between hypoxia and normoxia was similar over 24 h, but became distinct over 48 h. Time dependent microarray data from the same cell line in the literature displayed different gene expressions under hypoxic and normoxic conditions mostly at 12 h or earlier. The direct metabolomic profiles show a large overlap with theoretical metabolic profiles deduced from previous transcriptomic studies. Consistent pathways are glycolysis/gluconeogenesis, pyruvate, purine and arginine and proline metabolism. Ten metabolic pathways revealed by metabolomics were not covered by the downstream of the known transcriptomic profiles, suggesting new metabolic phenotypes. These results confirm previous transcriptomics understanding and expand the knowledge from existing models on correlation and co-regulation between transcriptomic and metabolomics profiles, which demonstrates the power of integrated omics analysis.

  9. Diet of yellow-billed loons (Gavia adamsii) in Arctic lakes during the nesting season inferred from fatty acid analysis

    Science.gov (United States)

    Haynes, T B; Schmutz, Joel A.; Bromaghin, Jeffrey; Iverson, S J; Padula, V. M.; Rosenberger, A E

    2015-01-01

    Understanding the dietary habits of yellow-billed loons (Gavia adamsii) can give important insights into their ecology, however, studying the diet of loons is difficult when direct observation or specimen collection is impractical. We investigate the diet of yellow-billed loons nesting on the Arctic Coastal Plain of Alaska using quantitative fatty acid signature analysis. Tissue analysis from 26 yellow-billed loons and eleven prey groups (nine fish species and two invertebrate groups) from Arctic lakes suggests that yellow-billed loons are eating high proportions of Alaska blackfish (Dallia pectoralis), broad whitefish (Coregonus nasus) and three-spined stickleback (Gasterosteus aculeatus) during late spring and early summer. The prominence of blackfish in diets highlights the widespread availability of blackfish during the early stages of loon nesting, soon after spring thaw. The high proportions of broad whitefish and three-spined stickleback may reflect a residual signal from the coastal staging period prior to establishing nesting territories on lakes, when loons are more likely to encounter these species. Our analyses were sensitive to the choice of calibration coefficient based on data from three different species, indicating the need for development of loon-specific coefficients for future study and confirmation of our results. Regardless, fish that are coastally distributed and that successfully overwinter in lakes are likely key food items for yellow-billed loons early in the nesting season.

  10. Patterns of human genetic variation inferred from comparative analysis of allelic mutations in blood group antigen genes.

    Science.gov (United States)

    Patnaik, Santosh Kumar; Blumenfeld, Olga O

    2011-03-01

    Comparative analysis of allelic variation of a gene sheds light on the pattern and process of its diversification at the population level. Gene families for which a large number of allelic forms have been verified by sequencing provide a useful resource for such studies. In this regard, human blood group-encoding genes are unique in that differences of cell surface traits among individuals and populations can be readily detected by serological screening, and correlation between the variant cell surface phenotype and the genotype is, in most cases, unequivocal. Here, we perform a comprehensive analysis of allelic forms, compiled in the Blood Group Antigen Gene Mutation database, of ABO, RHD/CE, GYPA/B/E and FUT1/2 gene families that encode the ABO, RH, MNS, and H/h blood group system antigens, respectively. These genes are excellent illustrative examples showing distinct mutational patterns among the alleles, and leading to speculation on how their origin may have been driven by recurrent but different molecular mechanisms. We illustrate how alignment of alleles of a gene may provide an additional insight into the DNA variation process and its pathways, and how this approach may serve to catalog alleles of a gene, simplifying the task and content of mutation databases.

  11. Causal inference in economics and marketing

    Science.gov (United States)

    Varian, Hal R.

    2016-01-01

    This is an elementary introduction to causal inference in economics written for readers familiar with machine learning methods. The critical step in any causal analysis is estimating the counterfactual—a prediction of what would have happened in the absence of the treatment. The powerful techniques used in machine learning may be useful for developing better estimates of the counterfactual, potentially improving causal inference. PMID:27382144

  12. Molecular characterization, tissue distribution and functional analysis of macrophage migration inhibitory factor protein (MIF) in Chinese giant salamanders Andrias davidianus.

    Science.gov (United States)

    Wang, Lixin; Yang, Hui; Li, Fenggang; Zhang, Yingying; Yang, Zhaoxia; Li, Yang; Liu, Xiaolin

    2013-03-01

    The macrophage migration inhibitory factor (MIF) produced in numerous cell types is a multi-functional cytokine mediating both innate and adaptive immune responses. To obtain a better understanding of the innate immune ability of Andrias davidianus and their defensive mechanisms, we identify the A. davidianus MIF (AdMIF) cDNA sequence from a skin cDNA library. The full-length cDNA of AdMIF was of 661bp, consisting of 134bp 5'-terminal UTR, 348bp open reading frame and 179bp 3'-terminal UTR. The deduced protein was composed of 115 amino acids, with an estimated molecular mass of 12.53kDa and a predicted pI of 6.07. AdMIF primary structure is as conserved as the other known sequences. Real time quantitative PCR (qRT-PCR) analysis indicated that AdMIF gene was ubiquitously expressed in selected tissues, with the highest level in liver, moderate level in spleen, intestine, stomach, and the lowest level in heart and skin. The cDNA fragment encoding mature peptide of AdMIF was recombined and expressed in Escherichia coli BL21 (DE3). By means of Ni(2+)-chelating chromatography, the recombinant protein of AdMIF (rAdMIF) was purified successfully. The rAdMIF protein was proved to have enzymatic redox and tautomerase activity in vitro. This study represents the first report for characterization of A. davidianus MIF, demonstrating the successful isolation of MIF from Chinese giant salamanders, and the purified rAdMIF protein is important to produce the monoclonal antibodies and provides a foundation for further investigation of the physiological function of AdMIF.

  13. Radionuclide migration through fractured rock for arbitrary-length decay chain: Analytical solution and global sensitivity analysis

    Science.gov (United States)

    Shahkarami, Pirouz; Liu, Longcheng; Moreno, Luis; Neretnieks, Ivars

    2015-01-01

    This study presents an analytical approach to simulate nuclide migration through a channel in a fracture accounting for an arbitrary-length decay chain. The nuclides are retarded as they diffuse in the porous rock matrix and stagnant zones in the fracture. The Laplace transform and similarity transform techniques are applied to solve the model. The analytical solution to the nuclide concentrations at the fracture outlet is governed by nine parameters representing different mechanisms acting on nuclide transport through a fracture, including diffusion into the rock matrices, diffusion into the stagnant water zone, chain decay and hydrodynamic dispersion. Furthermore, to assess how sensitive the results are to parameter uncertainties, the Sobol method is applied in variance-based global sensitivity analyses of the model output. The Sobol indices show how uncertainty in the model output is apportioned to the uncertainty in the model input. This method takes into account both direct effects and interaction effects between input parameters. The simulation results suggest that in the case of pulse injections, ignoring the effect of a stagnant water zone can lead to significant errors in the time of first arrival and the peak value of the nuclides. Likewise, neglecting the parent and modeling its daughter as a single stable species can result in a significant overestimation of the peak value of the daughter nuclide. It is also found that as the dispersion increases, the early arrival time and the peak time of the daughter decrease while the peak value increases. More importantly, the global sensitivity analysis reveals that for time periods greater than a few thousand years, the uncertainty of the model output is more sensitive to the values of the individual parameters than to the interaction between them. Moreover, if one tries to evaluate the true values of the input parameters at the same cost and effort, the determination of priorities should follow a certain

  14. Inferring time-variable effects of nutrient enrichment on marine ecosystems using inverse modelling and ecological network analysis.

    Science.gov (United States)

    Luong, Anh D; De Laender, Frederik; Olsen, Yngvar; Vadstein, Olav; Dewulf, Jo; Janssen, Colin R

    2014-09-15

    We combined data from an outdoor mesocosm experiment with carbon budget modelling and an ecological network analysis to assess the effects of continuous nutrient additions on the structural and functional dynamics of a marine planktonic ecosystem. The food web receiving no nutrient additions was fuelled by detritus, as zooplankton consumed 7.2 times more detritus than they consumed algae. Nutrient supply instantly promoted herbivory so that it was comparable to detritivory at the highest nutrient addition rate. Nutrient-induced food web restructuring reduced carbon cycling and decreased the average number of compartments a unit flow of carbon crosses before dissipation. Also, the efficiency of copepod production, the link to higher trophic levels harvestable by man, was lowered up to 35 times by nutrient addition, but showed signs of recovery after 9 to 11 days. The dependency of the food web on exogenous input was not changed by the nutrient additions.

  15. Neolithic and Eneolithic activities inferred from organic residue analysis of pottery from Mala Triglavca, Moverna vas and Ajdovska jama, Slovenia

    Directory of Open Access Journals (Sweden)

    Lucija Šoberl

    2014-12-01

    Full Text Available The research discussed in this paper focused on the analysis and identification of organic residues either preserved as visible or absorbed organic remains on Neolithic and Eneolithic pottery from various archaeological and geographical contexts. These are connected with various food preparation strategies and past human activities, i.e. cave burials in Ajdovska jama (food as a grave good/offering, the rock shelter at Mala Triglavca (meat and dairy animal husbandry practices and Moverna vas, which had a long occupation sequence (complex farming and animal management. The preservation of biomarkers mirrored past human activities and different pottery uses at various types of sites. The carbon stable isotope ratios of primary fatty acids in lipid pottery extracts confirmed the presence of adipose and dairy fats as well as biomarkers of plant fats, beeswax and birch bark tar.

  16. Phylogenetic Relationships of Sorghum and Related Species Inferred from Sequence Analysis of the nrDNA ITS Region

    Institute of Scientific and Technical Information of China (English)

    GUO Qiong-xia; HUANG Ke-hui; YU Yun; HUANG Zhen; WU Zhen-quan

    2006-01-01

    Analysis of phylogenetic and evolution in six species of Sorghum was based on internal transcribed spacer (ITS) sequences in nuclear ribosomal DNA. Results showed that the length of the ITS regions among the six species ranged from 588 to 589bp and the contents of G + C in ITS (ITS 1 + 5.8S + ITS2) regions ranged from 60.27 to 61.05%; the length of ITS 1 ranged from 207 to 208 bp and the contents of G+C in the ITS1 regions ranged from 53.91 to 61.54%. The length of the 5.8S rDNA and ITS2 regions in the six species was 164 and 217 bp respectively, and the contents of G+C ranged from 56.10 to 58.54% in the 5.8S rDNA region and 66.36 to 67.28% in the ITS2 region. Among regions of ITS, ITS1, ITS2, and 5.8S, the best sequence for genetic relationship analysis in the six species was the ITS region. On the basis of the Jaccard coefficient and phylogentic tree, S. sp. was more related to S. propinguum than to other species. This was consistent with the fact that S.sp. is derived from S. propinguum. From the phylogenetic tree based on ITS 1, S. halepense, silk sorghum and S. sudanense,are identical in the ITS1 sequence, whereas the phylogenetic tree based one shows that S. sudanense has a closer genetic association with S. almum rather than with S. halepense and silk sorghum.

  17. Time-lapse analysis reveals different modes of primordial germ cell migration in the medaka Oryzias latipes.

    Science.gov (United States)

    Kurokawa, Hiromi; Aoki, Yumiko; Nakamura, Shuhei; Ebe, Youko; Kobayashi, Daisuke; Tanaka, Minoru

    2006-04-01

    Previous studies have shown that medaka primordial germ cells (PGC) are first distinguishable by olvas expression during late gastrulation, and that they migrate to the gonadal region through the lateral plate mesoderm. Here, we demonstrate that medaka nanos expression marks the germ line at early gastrulation stage. By marking the germ line with green fluorescent protein (GFP) fused to the nanos 3' untranslated region, we were able to visualize the behavior of PGC using time-lapse imaging. We show that there are three distinct modes of PGC migration that function at different stages of development. At early gastrulation stage, PGC actively migrate towards the marginal zone, a process that requires the function of a chemokine receptor, CXCR4. However, at late gastrulation stage, PGC change the mode and direction of their movement, as they are carried towards the midline along with somatic cells undergoing convergent movements. After aligning bilaterally, PGC actively migrate to the posterior end of the lateral plate mesoderm. This posterior movement depends on the activity of both HMGCoAR and a ligand of CXCR4, SDF-1a. These results demonstrate that PGC undergo different modes of migration to reach the prospective gonadal region of the embryo.

  18. Linguistic Markers of Inference Generation While Reading.

    Science.gov (United States)

    Clinton, Virginia; Carlson, Sarah E; Seipel, Ben

    2016-06-01

    Words can be informative linguistic markers of psychological constructs. The purpose of this study is to examine associations between word use and the process of making meaningful connections to a text while reading (i.e., inference generation). To achieve this purpose, think-aloud data from third-fifth grade students ([Formula: see text]) reading narrative texts were hand-coded for inferences. These data were also processed with a computer text analysis tool, Linguistic Inquiry and Word Count, for percentages of word use in the following categories: cognitive mechanism words, nonfluencies, and nine types of function words. Findings indicate that cognitive mechanisms were an independent, positive predictor of connections to background knowledge (i.e., elaborative inference generation) and nonfluencies were an independent, negative predictor of connections within the text (i.e., bridging inference generation). Function words did not provide unique variance towards predicting inference generation. These findings are discussed in the context of a cognitive reflection model and the differences between bridging and elaborative inference generation. In addition, potential practical implications for intelligent tutoring systems and computer-based methods of inference identification are presented.

  19. Dispersal and migration

    Directory of Open Access Journals (Sweden)

    Schwarz, C.

    2004-06-01

    Full Text Available Ringing of birds unveiled many aspects of avian migration and dispersal movements. However, there is even much more to be explored by the use of ringing and other marks. Dispersal is crucial in understanding the initial phase of migration in migrating birds as it is to understand patterns and processes of distribution and gene flow. So far, the analysis of migration was largely based on analysing spatial and temporal patters of recoveries of ringed birds. However, there are considerable biases and pitfalls in using recoveries due to spatial and temporal variation in reporting probabilities. Novel methods are required for future studies separating the confounding effects of spatial and temporal heterogeneity of recovery data and heterogeneity of the landscape as well. These novel approaches should aim a more intensive and novel use of the existing recovery data by taking advantage of, for instance, dynamic and multistate modeling, should elaborate schemes for future studies, and should also include other marks that allow a more rapid data collection, like telemetry, geolocation and global positioning systems, and chemical and molecular markers. The latter appear to be very useful in the delineating origin of birds and connectivity between breeding and non–breeding grounds. Many studies of migration are purely descriptive. However, King and Brooks (King & Brooks, 2004 examine if movement patterns of dolphins change after the introduction of a gillnet ban. Bayesian methods are an interesting approach to this problem as they provide a meaningful measure of the probability that such a change occurred rather than simple yes/no response that is often the result of classical statistical methods. However, the key difficulty of a general implementation of Bayesian methods is the complexity of the modelling —there is no general userfriendly package that is easily accessible to most scientists. Drake and Alisauskas (Drake & Alisauskas, 2004 examine the

  20. Evaluation of energy expenditure in adult spring Chinook salmon migrating upstream in the Columbia River Basin: an assessment based on sequential proximate analysis

    Science.gov (United States)

    Mesa, M.G.; Magie, C.D.

    2006-01-01

    The upstream migration of adult anadromous salmonids in the Columbia River Basin (CRB) has been dramatically altered and fish may be experiencing energetically costly delays at dams. To explore this notion, we estimated the energetic costs of migration and reproduction of Yakima River-bound spring Chinook salmon Oncorhynchus tshawytscha using a sequential analysis of their proximate composition (i.e., percent water, fat, protein, and ash). Tissues (muscle, viscera, and gonad) were sampled from fish near the start of their migration (Bonneville Dam), at a mid point (Roza Dam, 510 km upstream from Bonneville Dam) and from fresh carcasses on the spawning grounds (about 100 km above Roza Dam). At Bonneville Dam, the energy reserves of these fish were remarkably high, primarily due to the high percentage of fat in the muscle (18-20%; energy content over 11 kJ g-1). The median travel time for fish from Bonneville to Roza Dam was 27 d and ranged from 18 to 42 d. Fish lost from 6 to 17% of their energy density in muscle, depending on travel time. On average, fish taking a relatively long time for migration between dams used from 5 to 8% more energy from the muscle than faster fish. From the time they passed Bonneville Dam to death, these fish, depending on gender, used 95-99% of their muscle and 73-86% of their viscera lipid stores. Also, both sexes used about 32% of their muscular and very little of their visceral protein stores. However, we were unable to relate energy use and reproductive success to migration history. Our results suggest a possible influence of the CRB hydroelectric system on adult salmonid energetics.

  1. Crustal structure of Tolfa domes complex (northern Latium - Italy) inferred from receiver functions analysis: an interplay between tectonics and magmatism

    Science.gov (United States)

    Buttinelli, M.; Bianchi, I.; Anselmi, M.; Chiarabba, C.; de Rita, D.; Quattrocchi, F.

    2010-12-01

    The Tolfa-Cerite volcanic district developed along the Tyrrhenian passive margin of central Italy, as part of magmatic processes started during the middle Pliocene. In this area the uncertainties on the deep crustal structures and the definition of the intrusive bodies geometry are focal issues that still need to be addressed. After the onset of the spreading of the Tyrrhenian sea during the Late Miocene, the emplacement of the intrusive bodies of the Tolfa complex (TDC), in a general back-arc geodynamical regime, generally occurred in a low stretching rate, in correspondence of the junctions between major lithospheric discontinuities. Normal faults, located at the edge of Mio-Pliocene basins, were used as preferential pathways for the rising of magmatic masses from the mantle to the surface. We used teleseismic recordings at the TOLF and MAON broad band station of the INGV seismic network (located between the Argentario promontory and Tolfa-Ceriti dome complexes -TDC-) to image the principal seismic velocity discontinuities by receiver function analysis (RF's). Together with RF’s velocity models of the area computed using the teleseismic events recorded by a temporary network of eight stations deployed around the TDC, we achieve a general crustal model of this area. The geometry of the seismic network has been defined to focus on the crustal structure beneath the TDC, trying to define the main velocity changes attributable to the intrusive bodies, the calcareous basal complex, the deep metamorphic basement, the lower crust and the Moho. The analysis of these data show the Moho at a depth of 23 km in the TDC area and 20 km in the Argentario area. Crustal models also show an unexpected velocity decrease between 12 and 18 km, consistent with a slight dropdown of the Vp/Vs ratio, imputable to a regional mid-crustal shear zone inherited from the previous alpine orogenesis, re-activated in extensional tectonic by the early opening phases of the Tyrrhenian sea. Above

  2. EU Migration Policy

    OpenAIRE

    Kleinschmidt, Harald

    2004-01-01

    I shall confine myself in this paper to international migration as migration across international borders.I do so despite the fact that,still today,international migration accounts only for a small share of migration at large.Likewise,I shall deal widh voluntary migration and shall thus exclude,deportation ...

  3. Significant population genetic structure detected in the rock bream Oplegnathus fasciatus (Temminck & Schlegel, 1844) inferred from fluorescent-AFLP analysis

    Science.gov (United States)

    Xiao, Yongshuang; Ma, Daoyuan; Xu, Shihong; Liu, Qinghua; Wang, Yanfeng; Xiao, Zhizhong; Li, Jun

    2016-05-01

    Oplegnathus fasciatus (rock bream) is a commercial rocky reef fish species in East Asia that has been considered for aquaculture. We estimated the population genetic diversity and population structure of the species along the coastal waters of China using fluorescent-amplified fragment length polymorphisms technology. Using 53 individuals from three populations and four pairs of selective primers, we amplified 1 264 bands, 98.73% of which were polymorphic. The Zhoushan population showed the highest Nei's genetic diversity and Shannon genetic diversity. The results of analysis of molecular variance (AMOVA) showed that 59.55% of genetic variation existed among populations and 40.45% occurred within populations, which indicated that a significant population genetic structure existed in the species. The pairwise fixation index F st ranged from 0.20 to 0.63 and were significant after sequential Bonferroni correction. The topology of an unweighted pair group method with arithmetic mean tree showed two significant genealogical branches corresponding to the sampling locations of North and South China. The AMOVA and STRUCTURE analyses suggested that the O. fasciatus populations examined should comprise two stocks.

  4. Statistical analysis and decoding of neural activity in the rodent geniculate ganglion using a metric-based inference system.

    Directory of Open Access Journals (Sweden)

    Wei Wu

    Full Text Available We analyzed the spike discharge patterns of two types of neurons in the rodent peripheral gustatory system, Na specialists (NS and acid generalists (AG to lingual stimulation with NaCl, acetic acid, and mixtures of the two stimuli. Previous computational investigations found that both spike rate and spike timing contribute to taste quality coding. These studies used commonly accepted computational methods, but they do not provide a consistent statistical evaluation of spike trains. In this paper, we adopted a new computational framework that treated each spike train as an individual data point for computing summary statistics such as mean and variance in the spike train space. We found that these statistical summaries properly characterized the firing patterns (e. g. template and variability and quantified the differences between NS and AG neurons. The same framework was also used to assess the discrimination performance of NS and AG neurons and to remove spontaneous background activity or "noise" from the spike train responses. The results indicated that the new metric system provided the desired decoding performance and noise-removal improved stimulus classification accuracy, especially of neurons with high spontaneous rates. In summary, this new method naturally conducts statistical analysis and neural decoding under one consistent framework, and the results demonstrated that individual peripheral-gustatory neurons generate a unique and reliable firing pattern during sensory stimulation and that this pattern can be reliably decoded.

  5. Statistical analysis and decoding of neural activity in the rodent geniculate ganglion using a metric-based inference system.

    Science.gov (United States)

    Wu, Wei; Mast, Thomas G; Ziembko, Christopher; Breza, Joseph M; Contreras, Robert J

    2013-01-01

    We analyzed the spike discharge patterns of two types of neurons in the rodent peripheral gustatory system, Na specialists (NS) and acid generalists (AG) to lingual stimulation with NaCl, acetic acid, and mixtures of the two stimuli. Previous computational investigations found that both spike rate and spike timing contribute to taste quality coding. These studies used commonly accepted computational methods, but they do not provide a consistent statistical evaluation of spike trains. In this paper, we adopted a new computational framework that treated each spike train as an individual data point for computing summary statistics such as mean and variance in the spike train space. We found that these statistical summaries properly characterized the firing patterns (e. g. template and variability) and quantified the differences between NS and AG neurons. The same framework was also used to assess the discrimination performance of NS and AG neurons and to remove spontaneous background activity or "noise" from the spike train responses. The results indicated that the new metric system provided the desired decoding performance and noise-removal improved stimulus classification accuracy, especially of neurons with high spontaneous rates. In summary, this new method naturally conducts statistical analysis and neural decoding under one consistent framework, and the results demonstrated that individual peripheral-gustatory neurons generate a unique and reliable firing pattern during sensory stimulation and that this pattern can be reliably decoded.

  6. A hybrid swarm population of Pinus densiflora × P. sylvestris inferred from sequence analysis of chloroplast DNA and morphological characters

    Institute of Scientific and Technical Information of China (English)

    Young Hee Joung; Jerry L.Hill; Jung Oh Hyun; Ding Mu; Juchun Luo; Do Hyung Lee; Takayuki Kawahara; Jeung Keun Suh; Mark S.Roh

    2013-01-01

    To confirm a hybrid swarm population ofPinus densiflora × P.sylvestris in Jilin,China,we used needles and seeds from P.densiflora,P.sylvestris,and P.densiflora × P.sylvestris collected from natural stands or experimental stations to study whether shoot apex morphology of 4-year old seedlings can be correlated with the sequence of a chloroplast DNA simple sequence repeat marker (cpDNA SSRs).Total genomic DNA was extracted and subjected to sequence analysis of the pine cpDNA SSR marker Pt15169.Results show that morphological characters from 4-year old seedlings did not correlate with sequence variants of this marker.Marker haplotypes from all P.sylvestris trees had a CTAT element that was absent from all sampled P.densiflora trees.However,both haplotype classes involving this insertion/deletion element were found in a P.densiflora × P.sylvestris population and its seedling progeny.It was concluded that the P.densiflora × P.sylvestris accessions sampled from Jilin,China resulted from bi-directional crosses,as evidenced by both species' cpDNA haplotypes within the hybrid swarm population.

  7. Genetic divergence between Mexican Opuntia accessions inferred by polymerase chain reaction-restriction fragment length polymorphism analysis.

    Science.gov (United States)

    Samah, S; Valadez-Moctezuma, E; Peláez-Luna, K S; Morales-Manzano, S; Meza-Carrera, P; Cid-Contreras, R C

    2016-06-03

    Molecular methods are powerful tools in characterizing and determining relationships between plants. The aim of this study was to study genetic divergence between 103 accessions of Mexican Opuntia. To accomplish this, polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis of three chloroplast intergenic spacers (atpB-rbcL, trnL-trnF, and psbA-trnH), one chloroplast gene (ycf1), two nuclear genes (ppc and PhyC), and one mitochondrial gene (cox3) was conducted. The amplified products from all the samples had very similar molecular sizes, and there were only very small differences between the undigested PCR amplicons for all regions, with the exception of ppc. We obtained 5850 bp from the seven regions, and 136 fragments were detected with eight enzymes, 37 of which (27.2%) were polymorphic. We found that 40% of the fragments from the chloroplast regions were polymorphic, 9.8% of the bands detected in the nuclear genes were polymorphic, and 20% of the bands in the mitochondrial locus were polymorphic. trnL-trnF and psbA-trnH were the most variable regions. The Nei and Li/Dice distance was very short, and ranged from 0 to 0.12; indeed, 77 of the 103 genotypes had the same genetic profile. All the xoconostle accessions (acidic fruits) were grouped together without being separated from three genotypes of prickly pear (sweet fruits). We assume that the genetic divergence between prickly pears and xoconostles is very low, and question the number of Opuntia species currently considered in Mexico.

  8. Molecular analysis allows inference into HIV transmission among young men who have sex with men in the United States

    Science.gov (United States)

    WHITESIDE, Y. Omar; SONG, Ruiguang; WERTHEIM, Joel O.; OSTER, Alexandra M.

    2016-01-01

    Objective To understand the spread of HIV among and between age and racial/ethnic groups of men who engage in male-to-male sexual contact (men who have sex with men, MSM) in the United States. Design Analysis of HIV-1 pol sequences for MSM collected through the U.S. National HIV Surveillance System (NHSS) during 2001–2012. Methods Pairwise genetic distance was calculated to determine potential transmission partners (those with very closely related nucleotide sequences, i.e., distance ≤1.5%). We described race/ethnicity and age of potential transmission partners of MSM. Results Of 23,048 MSM with HIV sequences submitted to NHSS during 2000–2012, we identified potential transmission partners for 8,880 (39%). Most potential transmission partners were of the same race/ethnicity (78% for blacks/African Americans, 64% for whites, and 49% for Hispanics/Latinos). This assortative mixing was even more pronounced in the youngest age groups. Significantly fewer young black/African American and Hispanic/Latino MSM had older potential transmission partners compared with young white MSM. Conclusion Black/African American MSM, who are more profoundly affected by HIV, were more likely to have potential HIV transmission partners who were of the same race/ethnicity and similar in age, suggesting that disparities in HIV infections are in large part not due to age-disassortative relationships. Concerted efforts to increase access to pre-exposure prophylaxis, quality HIV care, and effective treatment are needed to interrupt transmission chains among young, black/African American MSM. PMID:26558547

  9. Inferring genome-wide patterns of admixture in Qataris using fifty-five ancestral populations

    Directory of Open Access Journals (Sweden)

    Omberg Larsson

    2012-06-01

    Full Text Available Abstract Background Populations of the Arabian Peninsula have a complex genetic structure that reflects waves of migrations including the earliest human migrations from Africa and eastern Asia, migrations along ancient civilization trading routes and colonization history of recent centuries. Results Here, we present a study of genome-wide admixture in this region, using 156 genotyped individuals from Qatar, a country located at the crossroads of these migration patterns. Since haplotypes of these individuals could have originated from many different populations across the world, we have developed a machine learning method "SupportMix" to infer loci-specific genomic ancestry when simultaneously analyzing many possible ancestral populations. Simulations show that SupportMix is not only more accurate than other popular admixture discovery tools but is the first admixture inference method that can efficiently scale for simultaneous analysis of 50-100 putative ancestral populations while being independent of prior demographic information. Conclusions By simultaneously using the 55 world populations from the Human Genome Diversity Panel, SupportMix was able to extract the fine-scale ancestry of the Qatar population, providing many new observations concerning the ancestry of the region. For example, as well as recapitulating the three major sub-populations in Qatar, composed of mainly Arabic, Persian, and African ancestry, SupportMix additionally identifies the specific ancestry of the Persian group to populations sampled in Greater Persia rather than from China and the ancestry of the African group to sub-Saharan origin and not Southern African Bantu origin as previously thought.

  10. A well-sampled phylogenetic analysis of the polystichoid ferns (Dryopteridaceae) suggests a complex biogeographical history involving both boreotropical migrations and recent transoceanic dispersals.

    Science.gov (United States)

    Le Péchon, Timothée; Zhang, Liang; He, Hai; Zhou, Xin-Mao; Bytebier, Benny; Gao, Xin-Fen; Zhang, Li-Bing

    2016-05-01

    Intercontinental disjunctions in ferns have often been considered as the result of long-distance dispersal (LDD) events rather than of vicariance. However, in many leptosporangiate groups, both processes appear to have played a major role in shaping current geographical distribution. In this study, we reconstructed the phylogenetic relationships and inferred the ancestral distribution areas of the polystichoid ferns (Cyrtomium, Phanerophlebia, and Polystichum), to evaluate the relative impact of vicariance and LDD on the biogeography of this group. We used a molecular dataset including 3346 characters from five plastid loci. With 190 accessions our taxon coverage was about three times as large as any previous worldwide sampling. Biogeographical analyses were performed using S-DIVA and S-DEC and divergence times were estimated by integrating fossil and secondary calibrations. The polystichoid ferns are a monophyletic clade that may have originated in East Asia during the Eocene, an age much younger than previously estimated. Three transoceanic disjunctions between East Asia and New World were identified in the Paleogene: one for Phanerophlebia during late Eocene (34Ma, 19-51Ma), and two in Polystichum at the Eocene-Oligocene boundary (30Ma, 18-43Ma; 28Ma, 19-39Ma respectively). During the Neogene, further range expansions took place from Asia to Africa, Hawaii, and the Southwestern Indian Ocean region. Our results indicate that early transfers between the Old and the New World are compatible with a boreotropical migration scenario. After evolving in Asia during the Eocene, the polystichoid ferns reached the New World in independent migrations at the Eocene-Oligocene boundary through the boreotropical belt. However, although less likely, the alternative hypothesis of independent transoceanic dispersals from the Old to the New World cannot be ruled out. Further range expansion during the Neogene was most likely the result of long-distance dispersal (LDD).

  11. Making Type Inference Practical

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff; Oxhøj, Nicholas; Palsberg, Jens

    1992-01-01

    We present the implementation of a type inference algorithm for untyped object-oriented programs with inheritance, assignments, and late binding. The algorithm significantly improves our previous one, presented at OOPSLA'91, since it can handle collection classes, such as List, in a useful way. Abo....... Experiments indicate that the implementation type checks as much as 100 lines pr. second. This results in a mature product, on which a number of tools can be based, for example a safety tool, an image compression tool, a code optimization tool, and an annotation tool. This may make type inference for object...

  12. Foundations of Inference

    CERN Document Server

    Knuth, Kevin H

    2010-01-01

    We present a foundation for inference that unites and significantly extends the approaches of Kolmogorov and Cox. Our approach is based on quantifying finite lattices of logical statements in a way that satisfies general lattice symmetries. With other applications in mind, our derivations assume minimal symmetries, relying on neither complementarity nor continuity or differentiability. Each relevant symmetry corresponds to an axiom of quantification, and these axioms are used to derive a unique set of rules governing quantification of the lattice. These rules form the familiar probability calculus. We also derive a unique quantification of divergence and information. Taken together these results form a simple and clear foundation for the quantification of inference.

  13. The Bayes Inference Engine

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, K.M.; Cunningham, G.S.

    1996-04-01

    The authors are developing a computer application, called the Bayes Inference Engine, to provide the means to make inferences about models of physical reality within a Bayesian framework. The construction of complex nonlinear models is achieved by a fully object-oriented design. The models are represented by a data-flow diagram that may be manipulated by the analyst through a graphical programming environment. Maximum a posteriori solutions are achieved using a general, gradient-based optimization algorithm. The application incorporates a new technique of estimating and visualizing the uncertainties in specific aspects of the model.

  14. Titan's organic aerosols: Molecular composition and structure of laboratory analogues inferred from pyrolysis gas chromatography mass spectrometry analysis

    Science.gov (United States)

    Morisson, Marietta; Szopa, Cyril; Carrasco, Nathalie; Buch, Arnaud; Gautier, Thomas

    2016-10-01

    Analogues of Titan's aerosols are of primary interest in the understanding of Titan's atmospheric chemistry and climate, and in the development of in situ instrumentation for future space missions. Numerous studies have been carried out to characterize laboratory analogues of Titan aerosols (tholins), but their molecular composition and structure are still poorly known. If pyrolysis gas chromatography mass spectrometry (pyr-GCMS) has been used for years to give clues about their chemical composition, highly disparate results were obtained with this technique. They can be attributed to the variety of analytical conditions used for pyr-GCMS analyses, and/or to differences in the nature of the analogues analyzed, that were produced with different laboratory set-ups under various operating conditions. In order to have a better description of Titan's tholin's molecular composition by pyr-GCMS, we carried out a systematic study with two major objectives: (i) exploring the pyr-GCMS analytical parameters to find the optimal ones for the detection of a wide range of chemical products allowing a characterization of the tholins composition as comprehensive as possible, and (ii) highlighting the role of the CH4 ratio in the gaseous reactive medium on the tholin's molecular structure. We used a radio-frequency plasma discharge to synthetize tholins with different concentrations of CH4 diluted in N2. The samples were pyrolyzed at temperatures covering the 200-700°C range. The extracted gases were then analyzed by GCMS for their molecular identification. The optimal pyrolysis temperature for characterizing the molecular composition of our tholins by GCMS analysis is found to be 600°C. This temperature choice results from the best compromise between the number of compounds released, the quality of the signal and the appearance of pyrolysis artifacts. About a hundred molecules are identified as pyrolysates. A common major chromatographic pattern appears clearly for all the

  15. Holocene evolution of a montane lake catchment inferred from multiproxy sediment analysis : climatic and anthropic impacts in french prealps

    Science.gov (United States)

    Bajard, Manon; Sabatier, Pierre; Poulenard, Jérôme; David, Fernand; Arnaud, Fabien; Develle, Anne-Lise; Reyss, Jean-Louis; Fanget, Bernard; Malet, Emmanuel; Crouzet, Christian

    2015-04-01

    Lake La Thuile in the Massif des Bauges (874 m a.s.l. French Alps) provides a 18 meters sedimentary sequence. Due to its mid-altitude position, this lake is one of the first to be formed through the glacial retreat and documents the evolution of its catchment since the Late Glacial Maximum. The first 6 meters of the core cover the last 12 000 years, and allowed to study human/climate/environment interactions in a carbonated environment. This study is the first one to investigate a mid-altitude lake in the French Alps for paleoenvironment reconstruction from lake sediment archive. Its altitudinal position presents the advantage to be very accessible to human activities and allows more developed agriculture than in higher altitude. This study aims to determined how and when is expressed the erosive response of such an environment to human settlement. High resolution multiproxy analysis of the first 6 meters including sedimentological, palynological and geochemical data associated to a well-constrained chronology over the Holocene period allows us to understand the respective impacts of both climate and human on the evolution of Lake La Thuile environment. Five major phases of evolution have been highlighted over this period. From 12 000 to 10 000 yr cal. BP, the vegetation is developing with the onset of hardwood species and the disappearance of Pinus. From 10 000 to 4500 yr cal. BP the warmer climatic conditions of the middle of the Holocene allows the forest to densify and the very low sedimentation rate indicates that the forest stabilizes slopes and prevents from the erosion on the watershed. The climate cooling of the Neoglacial period triggers a first erosive phase with a decreasing of the forest around 3300 cal. BP. Human settlements are suggested at La Thuile from 2500 yr cal. BP by palynological evidence of anthropic taxa. The triggered clearing is accompanied by a second erosive phase related to anthropic activities during the Roman period. Erosion

  16. Linking predators to seasonality of upwelling: Using food web indicators and path analysis to infer trophic connections

    Science.gov (United States)

    Thompson, Sarah Ann; Sydeman, William J.; Santora, Jarrod A.; Black, Bryan A.; Suryan, Robert M.; Calambokidis, John; Peterson, William T.; Bograd, Steven J.

    2012-08-01

    Upwelling in eastern boundary current systems is a primary driver of ecosystem productivity. Typically, peak upwelling occurs during spring and summer, but winter upwelling may also be important to ecosystem functions. In this study, we investigated the hypothesis that winter and spring/summer upwelling, operating through indirect trophic interactions, are important to a suite of top predators in the California Current. To test this hypothesis, we collated information on upwelling, chlorophyll-a concentrations, zooplankton and forage fish, and related these to predator responses including rockfish growth, salmon abundance, seabird productivity and phenology (timing of egg-laying), and whale abundance. Seabird diets served in part as food web indicators. We modeled pathways of response using path analysis and tested for significance of the dominant paths with multiple regression. We found support for the hypothesis that relationships between upwelling and top predator variables were mediated primarily by intermediate trophic levels. Both winter and summer upwelling were important in path models, as were intermediate lower and mid trophic level functional groups represented by chlorophyll-a, zooplankton, and forage fish. Significant pathways of response explained from 50% to 80% of the variation of seabird (Cassin's auklet (Ptychoramphus aleuticus) and common murre (Uria aalge)), humpback whale (Megaptera novaeangliae) and Chinook salmon (Oncorhynchus tshawytscha) dependent variables, whereas splitnose rockfish (Sebastes diploproa) showed no significant response pathways. Upwelling and trophic responses for salmon were established for both the year of ocean entry and the year of return, with zooplankton important in the year of ocean entry and forage fish important in the year of return. This study provides one of the first comparative investigations between upwelling and predators, from fish to marine mammals and birds within a geographically restricted area

  17. Adaptive Neuro-Fuzzy Inference system analysis on adsorption studies of Reactive Red 198 from aqueous solution by SBA-15/CTAB composite

    Science.gov (United States)

    Aghajani, Khadijeh; Tayebi, Habib-Allah

    2017-01-01

    In this study, the Mesoporous material SBA-15 were synthesized and then, the surface was modified by the surfactant Cetyltrimethylammoniumbromide (CTAB). Finally, the obtained adsorbent was used in order to remove Reactive Red 198 (RR 198) from aqueous solution. Transmission electron microscope (TEM), Fourier transform infra-red spectroscopy (FTIR), Thermogravimetric analysis (TGA), X-ray diffraction (XRD), and BET were utilized for the purpose of examining the structural characteristics of obtained adsorbent. Parameters affecting the removal of RR 198 such as pH, the amount of adsorbent, and contact time were investigated at various temperatures and were also optimized. The obtained optimized condition is as follows: pH = 2, time = 60 min and adsorbent dose = 1 g/l. Moreover, a predictive model based on ANFIS for predicting the adsorption amount according to the input variables is presented. The presented model can be used for predicting the adsorption rate based on the input variables include temperature, pH, time, dosage, concentration. The error between actual and approximated output confirm the high accuracy of the proposed model in the prediction process. This fact results in cost reduction because prediction can be done without resorting to costly experimental efforts. SBA-15, CTAB, Reactive Red 198, adsorption study, Adaptive Neuro-Fuzzy Inference systems (ANFIS).

  18. Research on Protocol Migration

    Institute of Scientific and Technical Information of China (English)

    汪芸; 顾冠群; 等

    1996-01-01

    This paper elaborates the concept and model of protocol migration in network interconnection.Migration strategies and principles are discussed and several cases are studied in detail which show the basic procedure and techniques used in protocol migration.

  19. Migration of birds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the migration of birds. Topics covered include why birds migrate, when birds migrate, speed, altitude, courses, distance, major flyways and...

  20. State transition analysis of spontaneous branch migration of the Holliday junction by photon-based single-molecule fluorescence resonance energy transfer.

    Science.gov (United States)

    Okamoto, Kenji; Sako, Yasushi

    2016-02-01

    Branch migration of Holliday junction (HJ) DNA in solution is a spontaneous conformational change between multiple discrete states. We applied single-molecule fluorescence resonance energy transfer (smFRET) measurement to three-state branch migration. The photon-based variational Bayes-hidden Markov model (VB-HMM) method was applied to fluorescence signals to reproduce the state transition trajectories and evaluate the transition parameters, such as transition rate. The upper limit of time resolution suggested in simulation was nearly achieved for the state dynamics with relatively small FRET changes, and the distinctions in the populations of different states were successfully retrieved. We also discuss the suitability of the HJ as a standard sample for smFRET dynamics measurements and data analysis.

  1. Analysis of the migration characteristics of tracers in a heterogeneous flow field through a natural fracture of a domestic granite

    Energy Technology Data Exchange (ETDEWEB)

    Kum, Y. S.; Park, J. K.; Han, P. S. [KAERI, Taejon (Korea, Republic of)

    2001-05-01

    Tracers migration experiment was performed in a natural fracture of a domestic granite. The scale of rock fracture was 100x60x40(cm). In order to observe the migration characteristics, two kinds of nonsorbing tracers were used; as high molecular organic dyes, Eosine, and NaLS, and as anions, Bromide and Chloride. Tracers was injected in a borehole as a band funtion and collected at the opposite borehole. A variable aperture channel model with particle tracking method was used to characterize the aperture width of the fracture and to simulate solute transport. The heterogeneous flow field was modeled by a variable aperture channel model after characterizing aperture distribution by hydraulic tests through boreholes. The particle tracking method applied effectively in simulating tracers transport through a heterogeneous flow field in the rock fracture. Simulated results show that tracers do not migrate through the shortest straight line between inlet and outlet, but migrate through the paths having lowest flow resistance. that is channeling flow.

  2. Inference as Prediction

    Science.gov (United States)

    Watson, Jane

    2007-01-01

    Inference, or decision making, is seen in curriculum documents as the final step in a statistical investigation. For a formal statistical enquiry this may be associated with sophisticated tests involving probability distributions. For young students without the mathematical background to perform such tests, it is still possible to draw informal…

  3. Universum Inference and Corpus Homogeneity

    Science.gov (United States)

    Vogel, Carl; Lynch, Gerard; Janssen, Jerom

    Universum Inference is re-interpreted for assessment of corpus homogeneity in computational stylometry. Recent stylometric research quantifies strength of characterization within dramatic works by assessing the homogeneity of corpora associated with dramatic personas. A methodological advance is suggested to mitigate the potential for the assessment of homogeneity to be achieved by chance. Baseline comparison analysis is constructed for contributions to debates by nonfictional participants: the corpus analyzed consists of transcripts of US Presidential and Vice-Presidential debates from the 2000 election cycle. The corpus is also analyzed in translation to Italian, Spanish and Portuguese. Adding randomized categories makes assessments of homogeneity more conservative.

  4. National and international graduate migration flows.

    Science.gov (United States)

    Mosca, Irene; Wright, Robert E

    2010-01-01

    This article examines the nature of national and international graduate migration flows in the UK. Migration equations are estimated with microdata from a matched dataset of Students and Destinations of Leavers from Higher Education, information collected by the Higher Education Statistical Agency. The probability of migrating is related to a set of observable characteristics using multinomial logit regression. The analysis suggests that migration is a selective process with graduates with certain characteristics having considerably higher probabilities of migrating, both to other regions of the UK and abroad.

  5. Inferring polymorphism-induced regulatory gene networks active in human lymphocyte cell lines by weighted linear mixed model analysis of multiple RNA-Seq datasets.

    Directory of Open Access Journals (Sweden)

    Wensheng Zhang

    Full Text Available Single-nucleotide polymorphisms (SNPs contribute to the between-individual expression variation of many genes. A regulatory (trait-associated SNP is usually located near or within a (host gene, possibly influencing the gene's transcription or/and post-transcriptional modification. But its targets may also include genes that are physically farther away from it. A heuristic explanation of such multiple-target interferences is that the host gene transfers the SNP genotypic effects to the distant gene(s by a transcriptional or signaling cascade. These connections between the host genes (regulators and the distant genes (targets make the genetic analysis of gene expression traits a promising approach for identifying unknown regulatory relationships. In this study, through a mixed model analysis of multi-source digital expression profiling for 140 human lymphocyte cell lines (LCLs and the genotypes distributed by the international HapMap project, we identified 45 thousands of potential SNP-induced regulatory relationships among genes (the significance level for the underlying associations between expression traits and SNP genotypes was set at FDR < 0.01. We grouped the identified relationships into four classes (paradigms according to the two different mechanisms by which the regulatory SNPs affect their cis- and trans- regulated genes, modifying mRNA level or altering transcript splicing patterns. We further organized the relationships in each class into a set of network modules with the cis- regulated genes as hubs. We found that the target genes in a network module were often characterized by significant functional similarity, and the distributions of the target genes in three out of the four networks roughly resemble a power-law, a typical pattern of gene networks obtained from mutation experiments. By two case studies, we also demonstrated that significant biological insights can be inferred from the identified network modules.

  6. InSAR Analysis of the 2011 Hawthorne (Nevada) Earthquake Swarm: Implications of Earthquake Migration and Stress Transfer

    Science.gov (United States)

    Zha, X.; Dai, Z.; Lu, Z.

    2015-12-01

    The 2011 Hawthorne earthquake swarm occurred in the central Walker Lane zone, neighboring the border between California and Nevada. The swarm included an Mw 4.4 on April 13, Mw 4.6 on April 17, and Mw 3.9 on April 27. Due to the lack of the near-field seismic instrument, it is difficult to get the accurate source information from the seismic data for these moderate-magnitude events. ENVISAT InSAR observations captured the deformation mainly caused by three events during the 2011 Hawthorne earthquake swarm. The surface traces of three seismogenic sources could be identified according to the local topography and interferogram phase discontinuities. The epicenters could be determined using the interferograms and the relocated earthquake distribution. An apparent earthquake migration is revealed by InSAR observations and the earthquake distribution. Analysis and modeling of InSAR data show that three moderate magnitude earthquakes were produced by slip on three previously unrecognized faults in the central Walker Lane. Two seismogenic sources are northwest striking, right-lateral strike-slip faults with some thrust-slip components, and the other source is a northeast striking, thrust-slip fault with some strike-slip components. The former two faults are roughly parallel to each other, and almost perpendicular to the latter one. This special spatial correlation between three seismogenic faults and nature of seismogenic faults suggest the central Walker Lane has been undergoing southeast-northwest horizontal compressive deformation, consistent with the region crustal movement revealed by GPS measurement. The Coulomb failure stresses on the fault planes were calculated using the preferred slip model and the Coulomb 3.4 software package. For the Mw4.6 earthquake, the Coulomb stress change caused by the Mw4.4 event increased by ~0.1 bar. For the Mw3.9 event, the Coulomb stress change caused by the Mw4.6 earthquake increased by ~1.0 bar. This indicates that the preceding

  7. MIGRATION IMPACT ON ECONOMICAL SITUATION

    Directory of Open Access Journals (Sweden)

    Virginia COJOCARU

    2016-01-01

    Full Text Available This paper presents recent trends and flows of labor migration and its impact on economic and social life. Main aim of this research sets up the influence of the migration on the European economics and its competitiveness. Methods of research are: method of comparison, analysis method, method of deduction, method of statistics, modeling method. The economic impact of migration has been intensively studied but is still often driven by ill-informed perceptions, which, in turn, can lead to public antagonism towards migration. These negative views risk jeopardising efforts to adapt migration policies to the new economic and demographic challenges facing many countries. Migration Policy looks at the evidence for how immigrants affect the economy in three main areas: The labour market, public purse and economic growth. In Europe, the scope of labour mobility greatly increased within the EU/EFTA zones following the EU enlargements of 2004, 2007 and 2014-2015. This added to labour markets’ adjustment capacity. Recent estimates suggest that as much as a quarter of the asymmetric labour market shock – that is occurring at different times and with different intensities across countries – may have been absorbed by migration within a year.

  8. Model selection as a tool for phylogeographic inference: an example from the willow Salix melanopsis.

    Science.gov (United States)

    Carstens, Bryan C; Brennan, Reid S; Chua, Vivien; Duffie, Caroline V; Harvey, Michael G; Koch, Rachel A; McMahan, Caleb D; Nelson, Bradley J; Newman, Catherine E; Satler, Jordan D; Seeholzer, Glenn; Posbic, Karine; Tank, David C; Sullivan, Jack

    2013-08-01

    Phylogeographic inference has typically relied on analyses of data from one or a few genes to provide estimates of demography and population histories. While much has been learned from these studies, all phylogeographic analysis is conditioned on the data, and thus, inferences derived from data that represent a small sample of the genome are unavoidably tenuous. Here, we demonstrate one approach for moving beyond classic phylogeographic research. We use sequence capture probes and Illumina sequencing to generate data from >400 loci in order to infer the phylogeographic history of Salix melanopsis, a riparian willow with a disjunct distribution in coastal and the inland Pacific Northwest. We evaluate a priori phylogeographic hypotheses using coalescent models for parameter estimation, and the results support earlier findings that identified post-Pleistocene dispersal as the cause of the disjunction in S. melanopsis. We also conduct a series of model selection exercises using IMa2, Migrate-n and ∂a∂i. The resulting ranking of models indicates that refugial dynamics were complex, with multiple regions in the inland regions serving as the source for postglacial colonization. Our results demonstrate that new sources of data and new approaches to data analysis can rejuvenate phylogeographic research by allowing for the identification of complex models that enable researchers to both identify and estimate the most relevant parameters for a given system.

  9. Haplotype-Based Regression Analysis and Inference of Case–Control Studies with Unphased Genotypes and Measurement Errors in Environmental Exposures

    Science.gov (United States)

    Lobach, Iryna; Carroll, Raymond J.; Spinka, Christine; Gail, Mitchell H.; Chatterjee, Nilanjan

    2009-01-01

    Summary. It is widely believed that risks of many complex diseases are determined by genetic susceptibilities, environmental exposures, and their interaction. Chatterjee and Carroll (2005, Biometrika 92, 399–418) developed an efficient retrospective maximum-likelihood method for analysis of case–control studies that exploits an assumption of gene–environment independence and leaves the distribution of the environmental covariates to be completely nonparametric. Spinka, Carroll, and Chatterjee (2005, Genetic Epidemiology 29, 108–127) extended this approach to studies where certain types of genetic information, such as haplotype phases, may be missing on some subjects. We further extend this approach to situations when some of the environmental exposures are measured with error. Using a polychotomous logistic regression model, we allow disease status to have K + 1 levels. We propose use of a pseudolikelihood and a related EM algorithm for parameter estimation. We prove consistency and derive the resulting asymptotic covariance matrix of parameter estimates when the variance of the measurement error is known and when it is estimated using replications. Inferences with measurement error corrections are complicated by the fact that the Wald test often behaves poorly in the presence of large amounts of measurement error. The likelihood-ratio (LR) techniques are known to be a good alternative. However, the LR tests are not technically correct in this setting because the likelihood function is based on an incorrect model, i.e., a prospective model in a retrospective sampling scheme. We corrected standard asymptotic results to account for the fact that the LR test is based on a likelihood-type function. The performance of the proposed method is illustrated using simulation studies emphasizing the case when genetic information is in the form of haplotypes and missing data arises from haplotype-phase ambiguity. An application of our method is illustrated using a

  10. Social Physics and China's Population Migration

    Science.gov (United States)

    Wang, Yun-Lin; Li, Ding

    Based on the social physics theory, this paper analyzes the economic disparities between different regions in China, and contributes a conceptual model of population migration among eastern, central, western and north-eastern regions. The national 1% population sample investigation data is adopted to build a network of inter-provincial population migration, and the population migration network is analyzed with social network analysis. The results are shown that there is a very strong correlation between migrant population and economy disparity in China, and the migration with obviously geographical characteristics. The eastern region is the main areas for migration-inflow; the central region is the main areas of migration-outflow; the western region is relatively “locked-up”, with a little of population flow; and the migration of the northeast is mainly within its own regional territory.

  11. [A study on feeding ecology and migration patterns of Dosidicus gigas off Peru using stable isotope analysis].

    Science.gov (United States)

    Gong, Yi; Chen, Xin-jun; Li, Yun-kai; Han, Meng-jie

    2015-09-01

    As a pelagic cephalopod and one of the main target species of Chinese distant water fishery, jumbo squids (Dosidicus gigas) play a major role in the marine ecosystems of the eastern Pacific. Understanding the feeding ecology and migration patterns of jumbo squids is of importance for better utilizing the resources. The isotopic signatures of gladius, have been proved to be a powerful tool to reveal high resolution and ontogenic variations in individual foraging strategies of squids; which is an archival tissue with no elemental turnover after formation. In this study, the growth equation of gladius proostracum was established based on the age information determined by statolith. Gladius was cut successionally by the growth curve of gladius proostracum, the stable isotopic values of the gladius profiles were determined, and the feeding ecology and migration patterns of jumbo squids during its growth process were investigated. Results showed that the jumbo squids began to migrate after 180 days of postnatal, and their trophic levels tended to decrease throughout the life span. These results demonstrated the feasibility of using continuous sampling hard tissue to study the feeding ecology and habitat transfer of jumbo squids.

  12. Child-street migration among HIV-affected families in Kenya: a mediation analysis from cross-sectional data

    Science.gov (United States)

    Goodman, Michael L.; Mutambudzi, Miriam S.; Gitari, Stanley; Keiser, Philip H.; Seidel, Sarah E.

    2016-01-01

    ABSTRACT Within Kenya, an estimated quarter of a million children live on the streets, and 1.8 million children are orphaned. In this study, we analyze how HIV contributes to the phenomenon of child-street migration. We interviewed a random community sample of caregiving women (n = 1974) in Meru County, Kenya, using a structured questionnaire in summer 2015. Items included reported HIV prevalence of respondent and her partner, social support, overall health, school enrollment of biologically related children and whether the respondent has a child currently living on the streets. Controlling for alcohol use, education, wealth, age and household size, we found a positive-graded association between the number of partners living with HIV and the probability that a child lives on the street. There was little difference in the odds of a child living on the street between maternally affected and paternally affected households. Lower maternal social support, overall health and school enrollment of biologically related children mediated 14% of the association between HIV-affected households and reporting child-street migration. Street-migration of children is strongly associated with household HIV, but the small percentage of mediated effect presents a greater need to focus on interactions between household and community factors in the context of HIV. Programs and policies responding to these findings will involve targeting parents and children in HIV-affected households, and coordinate care between clinical providers, social service providers and schools. PMID:27392012

  13. Continuous Integrated Invariant Inference Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project will develop a new technique for invariant inference and embed this and other current invariant inference and checking techniques in an...

  14. Probabilistic Inferences in Bayesian Networks

    OpenAIRE

    Ding, Jianguo

    2010-01-01

    This chapter summarizes the popular inferences methods in Bayesian networks. The results demonstrates that the evidence can propagated across the Bayesian networks by any links, whatever it is forward or backward or intercausal style. The belief updating of Bayesian networks can be obtained by various available inference techniques. Theoretically, exact inferences in Bayesian networks is feasible and manageable. However, the computing and inference is NP-hard. That means, in applications, in ...

  15. Comparative feeding ecology of bull sharks (Carcharhinus leucas) in the coastal waters of the southwest Indian Ocean inferred from stable isotope analysis.

    Science.gov (United States)

    Daly, Ryan; Froneman, Pierre W; Smale, Malcolm J

    2013-01-01

    As apex predators, sharks play an important role shaping their respective marine communities through predation and associated risk effects. Understanding the predatory dynamics of sharks within communities is, therefore, necessary to establish effective ecologically based conservation strategies. We employed non-lethal sampling methods to investigate the feeding ecology of bull sharks (Carcharhinus leucas) using stable isotope analysis within a subtropical marine community in the southwest Indian Ocean. The main objectives of this study were to investigate and compare the predatory role that sub-adult and adult bull sharks play within a top predatory teleost fish community. Bull sharks had significantly broader niche widths compared to top predatory teleost assemblages with a wide and relatively enriched range of δ(13)C values relative to the local marine community. This suggests that bull sharks forage from a more diverse range of δ(13)C sources over a wider geographical range than the predatory teleost community. Adult bull sharks appeared to exhibit a shift towards consistently higher trophic level prey from an expanded foraging range compared to sub-adults, possibly due to increased mobility linked with size. Although predatory teleost fish are also capable of substantial migrations, bull sharks may have the ability to exploit a more diverse range of habitats and appeared to prey on a wider diversity of larger prey. This suggests that bull sharks play an important predatory role within their respective marine communities and adult sharks in particular may shape and link ecological processes of a variety of marine communities over a broad range.

  16. Multimodel inference and adaptive management

    Science.gov (United States)

    Rehme, S.E.; Powell, L.A.; Allen, C.R.

    2011-01-01

    Ecology is an inherently complex science coping with correlated variables, nonlinear interactions and multiple scales of pattern and process, making it difficult for experiments to result in clear, strong inference. Natural resource managers, policy makers, and stakeholders rely on science to provide timely and accurate management recommendations. However, the time necessary to untangle the complexities of interactions within ecosystems is often far greater than the time available to make management decisions. One method of coping with this problem is multimodel inference. Multimodel inference assesses uncertainty by calculating likelihoods among multiple competing hypotheses, but multimodel inference results are often equivocal. Despite this, there may be pressure for ecologists to provide management recommendations regardless of the strength of their study’s inference. We reviewed papers in the Journal of Wildlife Management (JWM) and the journal Conservation Biology (CB) to quantify the prevalence of multimodel inference approaches, the resulting inference (weak versus strong), and how authors dealt with the uncertainty. Thirty-eight percent and 14%, respectively, of articles in the JWM and CB used multimodel inference approaches. Strong inference was rarely observed, with only 7% of JWM and 20% of CB articles resulting in strong inference. We found the majority of weak inference papers in both journals (59%) gave specific management recommendations. Model selection uncertainty was ignored in most recommendations for management. We suggest that adaptive management is an ideal method to resolve uncertainty when research results in weak inference.

  17. Fertility, Migration, and Altruism

    OpenAIRE

    2000-01-01

    Consider migration to a higher income region as a human capital investment in which parents bear migration costs and children share returns. Migrants from a population with heterogeneous intergenerational discount rates will be self-selected on intergenerational altruism. Thus, immigrants may be self-selected on fertility. Soviet Jews who migrate to Israel despite high migration costs have significantly more children than members of the same birth cohort who migrate later when costs are low. ...

  18. Governing Global Migration

    OpenAIRE

    2008-01-01

    This study explores the global regulative function of migration politics. Its main aim is to rethink migration politics through an engagement with the Foucauldian governmentality perspective, which focuses on the relation between government and thought. A secondary aim is to use this perspective to explore the global description of migration and migration politics which is emerging with the currently evolving global governance of migration. Doing so, it wishes to contribute both to the study ...

  19. SICK: THE SPECTROSCOPIC INFERENCE CRANK

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Andrew R., E-mail: arc@ast.cam.ac.uk [Institute of Astronomy, University of Cambridge, Madingley Road, Cambdridge, CB3 0HA (United Kingdom)

    2016-03-15

    There exists an inordinate amount of spectral data in both public and private astronomical archives that remain severely under-utilized. The lack of reliable open-source tools for analyzing large volumes of spectra contributes to this situation, which is poised to worsen as large surveys successively release orders of magnitude more spectra. In this article I introduce sick, the spectroscopic inference crank, a flexible and fast Bayesian tool for inferring astrophysical parameters from spectra. sick is agnostic to the wavelength coverage, resolving power, or general data format, allowing any user to easily construct a generative model for their data, regardless of its source. sick can be used to provide a nearest-neighbor estimate of model parameters, a numerically optimized point estimate, or full Markov Chain Monte Carlo sampling of the posterior probability distributions. This generality empowers any astronomer to capitalize on the plethora of published synthetic and observed spectra, and make precise inferences for a host of astrophysical (and nuisance) quantities. Model intensities can be reliably approximated from existing grids of synthetic or observed spectra using linear multi-dimensional interpolation, or a Cannon-based model. Additional phenomena that transform the data (e.g., redshift, rotational broadening, continuum, spectral resolution) are incorporated as free parameters and can be marginalized away. Outlier pixels (e.g., cosmic rays or poorly modeled regimes) can be treated with a Gaussian mixture model, and a noise model is included to account for systematically underestimated variance. Combining these phenomena into a scalar-justified, quantitative model permits precise inferences with credible uncertainties on noisy data. I describe the common model features, the implementation details, and the default behavior, which is balanced to be suitable for most astronomical applications. Using a forward model on low-resolution, high signal

  20. European Integration and Labour Migration

    Directory of Open Access Journals (Sweden)

    Julda Kielyte

    2010-11-01

    Full Text Available The present paper studies how European integration might affect the migration of workers in the enlarged EU. Unlike the reduced-form migration models, we base our empirical analysis on the theory of economic geography à la Krugman (1991, which provides an alternative modelling of migration pull and push factors. Parameters of the theoretical model are estimated econometrically using historical migration data. Our empirical findings suggest that European integration would trigger selective migration between the countries in the enlarged EU. In the Baltics, Lithuania would gain about 7.25% of the total work force. In the Visegrád Four, the share of the mobile labour force would increase the most in Hungary, 8.35%, compared to the pre-integration state. Our predictions for the East-West migration are moderate and lower than those of reduced-form models: between 5.44% (from the Baltics and 3.61% (from the Visegrád Four would emigrate to the EU North. Because migrants not only follow market potential, but also shape the region’s market potential, the long-run agglomeration forces are sufficiently weak to make a swift emergence of a core-periphery pattern in the enlarged EU very unlikely.

  1. Generic patch inference

    DEFF Research Database (Denmark)

    Andersen, Jesper; Lawall, Julia

    2010-01-01

    A key issue in maintaining Linux device drivers is the need to keep them up to date with respect to evolutions in Linux internal libraries. Currently, there is little tool support for performing and documenting such changes. In this paper we present a tool, spdiff, that identifies common changes...... developers can use it to extract an abstract representation of the set of changes that others have made. Our experiments on recent changes in Linux show that the inferred generic patches are more concise than the corresponding patches found in commits to the Linux source tree while being safe with respect...

  2. Nonparametric statistical inference

    CERN Document Server

    Gibbons, Jean Dickinson

    2010-01-01

    Overall, this remains a very fine book suitable for a graduate-level course in nonparametric statistics. I recommend it for all people interested in learning the basic ideas of nonparametric statistical inference.-Eugenia Stoimenova, Journal of Applied Statistics, June 2012… one of the best books available for a graduate (or advanced undergraduate) text for a theory course on nonparametric statistics. … a very well-written and organized book on nonparametric statistics, especially useful and recommended for teachers and graduate students.-Biometrics, 67, September 2011This excellently presente

  3. Foundations of Inference

    Directory of Open Access Journals (Sweden)

    Kevin H. Knuth

    2012-06-01

    Full Text Available We present a simple and clear foundation for finite inference that unites and significantly extends the approaches of Kolmogorov and Cox. Our approach is based on quantifying lattices of logical statements in a way that satisfies general lattice symmetries. With other applications such as measure theory in mind, our derivations assume minimal symmetries, relying on neither negation nor continuity nor differentiability. Each relevant symmetry corresponds to an axiom of quantification, and these axioms are used to derive a unique set of quantifying rules that form the familiar probability calculus. We also derive a unique quantification of divergence, entropy and information.

  4. Inference of Isoforms from Short Sequence Reads

    Science.gov (United States)

    Feng, Jianxing; Li, Wei; Jiang, Tao

    Due to alternative splicing events in eukaryotic species, the identification of mRNA isoforms (or splicing variants) is a difficult problem. Traditional experimental methods for this purpose are time consuming and cost ineffective. The emerging RNA-Seq technology provides a possible effective method to address this problem. Although the advantages of RNA-Seq over traditional methods in transcriptome analysis have been confirmed by many studies, the inference of isoforms from millions of short sequence reads (e.g., Illumina/Solexa reads) has remained computationally challenging. In this work, we propose a method to calculate the expression levels of isoforms and infer isoforms from short RNA-Seq reads using exon-intron boundary, transcription start site (TSS) and poly-A site (PAS) information. We first formulate the relationship among exons, isoforms, and single-end reads as a convex quadratic program, and then use an efficient algorithm (called IsoInfer) to search for isoforms. IsoInfer can calculate the expression levels of isoforms accurately if all the isoforms are known and infer novel isoforms from scratch. Our experimental tests on known mouse isoforms with both simulated expression levels and reads demonstrate that IsoInfer is able to calculate the expression levels of isoforms with an accuracy comparable to the state-of-the-art statistical method and a 60 times faster speed. Moreover, our tests on both simulated and real reads show that it achieves a good precision and sensitivity in inferring isoforms when given accurate exon-intron boundary, TSS and PAS information, especially for isoforms whose expression levels are significantly high.

  5. 跆拳道腿法技术训练中迁移途径的分析%Analysis of the Migration Ways of Taekwondo Leg Technology Training

    Institute of Scientific and Technical Information of China (English)

    孟强

    2012-01-01

    文章运用观察法、文献资料法和分析归纳法等研究方法,从跆拳道腿法的技术属性、动作结构等方面下手,结合跆拳道技术教学训练实践,运用迁移理论分析了跆拳道腿法技术之间产生迁移的条件和途径,以期为跆拳道的技能教学训练提供参考。%Through the observation,literature research and analysis methods,from Taekwondo technical attributes,motion structure aspects,combined with the teaching practice of Taekwondo techniques,with the use of migration theory,the paper does the analysis of Taekwondo leg technology between produce migration conditions and ways,in order to provide references for teaching and training of Taekwondo skills.

  6. A dynamic real time in vivo and static ex vivo analysis of granulomonocytic cell migration in the collagen-induced arthritis model.

    Directory of Open Access Journals (Sweden)

    Ruth Byrne

    Full Text Available Neutrophilic granulocytes and monocytes (granulomonocytic cells; GMC drive the inflammatory process at the earliest stages of rheumatoid arthritis (RA. The migratory behavior and functional properties of GMC within the synovial tissue are, however, only incompletely characterized. Here we have analyzed GMC in the murine collagen-induced arthritis (CIA model of RA using multi-photon real time in vivo microscopy together with ex vivo analysis of GMC in tissue sections.GMC were abundant as soon as clinical arthritis was apparent. GMC were motile and migrated randomly through the synovial tissue. In addition, we observed the frequent formation of cell clusters consisting of both neutrophilic granulocytes and monocytes that actively contributed to the inflammatory process of arthritis. Treatment of animals with a single dose of prednisolone reduced the mean velocity of cell migration and diminished the overall immigration of GMC.In summary, our study shows that the combined application of real time in vivo microscopy together with elaborate static post-mortem analysis of GMC enables the description of dynamic migratory characteristics of GMC together with their precise location in a complex anatomical environment. Moreover, this approach is sensitive enough to detect subtle therapeutic effects within a very short period of time.

  7. A proposed method for accurate 3D analysis of cochlear implant migration using fusion of cone beam CT

    Directory of Open Access Journals (Sweden)

    Guido eDees

    2016-01-01

    Full Text Available IntroductionThe goal of this investigation was to compare fusion of sequential cone beam CT volumes to the gold standard (fiducial registration in order to be able to analyze clinical CI migration with high accuracy in three dimensions. Materials and MethodsPaired time-lapsed cone beam CT volumes were performed on five human cadaver temporal bones and one human subject. These volumes were fused using 3D Slicer 4 and BRAINSFit software. Using a gold standard fiducial technique, the accuracy, robustness and performance time of the fusion process were assessed.Results This proposed fusion protocol achieves a sub voxel mean Euclidean distance of 0.05 millimeter in human cadaver temporal bones and 0.16 millimeter when applied to the described in vivo human synthetic data set in over 95% of all fusions. Performance times are less than two minutes.ConclusionHere a new and validated method based on existing techniques is described which could be used to accurately quantify migration of cochlear implant electrodes.

  8. Moment inference from tomograms

    Science.gov (United States)

    Day-Lewis, F. D.; Chen, Y.; Singha, K.

    2007-01-01

    Time-lapse geophysical tomography can provide valuable qualitative insights into hydrologic transport phenomena associated with aquifer dynamics, tracer experiments, and engineered remediation. Increasingly, tomograms are used to infer the spatial and/or temporal moments of solute plumes; these moments provide quantitative information about transport processes (e.g., advection, dispersion, and rate-limited mass transfer) and controlling parameters (e.g., permeability, dispersivity, and rate coefficients). The reliability of moments calculated from tomograms is, however, poorly understood because classic approaches to image appraisal (e.g., the model resolution matrix) are not directly applicable to moment inference. Here, we present a semi-analytical approach to construct a moment resolution matrix based on (1) the classic model resolution matrix and (2) image reconstruction from orthogonal moments. Numerical results for radar and electrical-resistivity imaging of solute plumes demonstrate that moment values calculated from tomograms depend strongly on plume location within the tomogram, survey geometry, regularization criteria, and measurement error. Copyright 2007 by the American Geophysical Union.

  9. Elevated uptake of CO2 over Europe inferred from GOSAT XCO2 retrievals: a real phenomenon or an artefact of the analysis?

    Directory of Open Access Journals (Sweden)

    L. Feng

    2015-01-01

    Full Text Available Estimates of the natural CO2 flux over Europe inferred from in situ measurements of atmospheric CO2 mole fraction have been used previously to check top-down flux estimates inferred from space-borne dry-air CO2 column (XCO2 retrievals. Recent work has shown that CO2 fluxes inferred from XCO2 data from the Japanese Greenhouse gases Observing SATellite (GOSAT have a larger seasonal amplitude and a more negative annual net CO2 balance than those inferred from the in situ data. The causes of this enhanced European CO2 uptake have since become the focus of recent studies. We show this elevated uptake over Europe could largely be explained by mis-fitting data due to regional biases. We establish a reference in situ inversion that uses an Ensemble Kalman Filter (EnKF to assimilate surface flask data and the XCO2 data from the surface-based Total Carbon Column Observing Network (TCCON. The same EnKF system is also used to assimilate two, independent versions of GOSAT XCO2 data. We find that the GOSAT-inferred European terrestrial biosphere uptake peaks during the summer, similar to the reference inversion, but the net annual flux is 1.18 ± 0.1 GtC a−1 compared to a value of 0.56 ± 0.1 GtC a−1 for our control inversion that uses only in situ data. To reconcile these two estimates, we have performed a series of numerical experiments that assimilate observations with biases or assimilate synthetic observations for which part or all of the GOSAT XCO2 data are replaced with model data. We find that 50–80% of the elevated European uptake in 2010 inferred from GOSAT data is due to retrievals outside the immediate European region, while most of the remainder can be explained by a sub-ppm retrieval bias over Europe. We have used data assimilation techniques to estimate monthly GOSAT XCO2 biases from the joint assimilation of in situ observations and GOSAT XCO2 retrievals. We find a monthly varying bias of up to 0.5 ppm can explain an overestimate of the

  10. Deep Learning for Population Genetic Inference.

    Science.gov (United States)

    Sheehan, Sara; Song, Yun S

    2016-03-01

    Given genomic variation data from multiple individuals, computing the likelihood of complex population genetic models is often infeasible. To circumvent this problem, we introduce a novel likelihood-free inference framework by applying deep learning, a powerful modern technique in machine learning. Deep learning makes use of multilayer neural networks to learn a feature-based function from the input (e.g., hundreds of correlated summary statistics of data) to the output (e.g., population genetic parameters of interest). We demonstrate that deep learning can be effectively employed for population genetic inference and learning informative features of data. As a concrete application, we focus on the challenging problem of jointly inferring natural selection and demography (in the form of a population size change history). Our method is able to separate the global nature of demography from the local nature of selection, without sequential steps for these two factors. Studying demography and selection jointly is motivated by Drosophila, where pervasive selection confounds demographic analysis. We apply our method to 197 African Drosophila melanogaster genomes from Zambia to infer both their overall demography, and regions of their genome under selection. We find many regions of the genome that have experienced hard sweeps, and fewer under selection on standing variation (soft sweep) or balancing selection. Interestingly, we find that soft sweeps and balancing selection occur more frequently closer to the centromere of each chromosome. In addition, our demographic inference suggests that previously estimated bottlenecks for African Drosophila melanogaster are too extreme.

  11. Deep Learning for Population Genetic Inference.

    Directory of Open Access Journals (Sweden)

    Sara Sheehan

    2016-03-01

    Full Text Available Given genomic variation data from multiple individuals, computing the likelihood of complex population genetic models is often infeasible. To circumvent this problem, we introduce a novel likelihood-free inference framework by applying deep learning, a powerful modern technique in machine learning. Deep learning makes use of multilayer neural networks to learn a feature-based function from the input (e.g., hundreds of correlated summary statistics of data to the output (e.g., population genetic parameters of interest. We demonstrate that deep learning can be effectively employed for population genetic inference and learning informative features of data. As a concrete application, we focus on the challenging problem of jointly inferring natural selection and demography (in the form of a population size change history. Our method is able to separate the global nature of demography from the local nature of selection, without sequential steps for these two factors. Studying demography and selection jointly is motivated by Drosophila, where pervasive selection confounds demographic analysis. We apply our method to 197 African Drosophila melanogaster genomes from Zambia to infer both their overall demography, and regions of their genome under selection. We find many regions of the genome that have experienced hard sweeps, and fewer under selection on standing variation (soft sweep or balancing selection. Interestingly, we find that soft sweeps and balancing selection occur more frequently closer to the centromere of each chromosome. In addition, our demographic inference suggests that previously estimated bottlenecks for African Drosophila melanogaster are too extreme.

  12. Return migration to Italy and labour migration.

    Science.gov (United States)

    Calvaruso, C

    1983-01-01

    The problems caused by large-scale return migration to Italy in recent years are considered. The importance of the additional skills and capital acquired by these migrants while abroad is stressed. Extensive data on the volume of return migration in the 1970s are included.

  13. Multipolar migration: the third mode of radial neuronal migration in the developing cerebral cortex.

    Science.gov (United States)

    Tabata, Hidenori; Nakajima, Kazunori

    2003-11-05

    Two distinct modes of radial neuronal migration, locomotion and somal translocation, have been reported in the developing cerebral cortex. Although these two modes of migration have been well documented, the cortical intermediate zone contains abundant multipolar cells, and they do not resemble the cells migrating by locomotion or somal translocation. Here, we report that these multipolar cells express neuronal markers and extend multiple thin processes in various directions independently of the radial glial fibers. Time-lapse analysis of living slices revealed that the multipolar cells do not have any fixed cell polarity, and that they very dynamically extend and retract multiple processes as their cell bodies slowly move. They do not usually move straight toward the pial surface during their radial migration, but instead frequently change migration direction and rate; sometimes they even remain in almost the same position, especially when they are in the subventricular zone. Occasionally, the multipolar cells jump tangentially during their radial migration. Because the migration modality of these cells clearly differs from locomotion or somal translocation, we refer to their novel type of migration as "multipolar migration." In view of the high proportion of cells exhibiting multipolar migration, this third mode of radial migration must be an important type of migration in the developing cortex.

  14. Statistical inference based on divergence measures

    CERN Document Server

    Pardo, Leandro

    2005-01-01

    The idea of using functionals of Information Theory, such as entropies or divergences, in statistical inference is not new. However, in spite of the fact that divergence statistics have become a very good alternative to the classical likelihood ratio test and the Pearson-type statistic in discrete models, many statisticians remain unaware of this powerful approach.Statistical Inference Based on Divergence Measures explores classical problems of statistical inference, such as estimation and hypothesis testing, on the basis of measures of entropy and divergence. The first two chapters form an overview, from a statistical perspective, of the most important measures of entropy and divergence and study their properties. The author then examines the statistical analysis of discrete multivariate data with emphasis is on problems in contingency tables and loglinear models using phi-divergence test statistics as well as minimum phi-divergence estimators. The final chapter looks at testing in general populations, prese...

  15. Meta-learning framework applied in bioinformatics inference system design.

    Science.gov (United States)

    Arredondo, Tomás; Ormazábal, Wladimir

    2015-01-01

    This paper describes a meta-learner inference system development framework which is applied and tested in the implementation of bioinformatic inference systems. These inference systems are used for the systematic classification of the best candidates for inclusion in bacterial metabolic pathway maps. This meta-learner-based approach utilises a workflow where the user provides feedback with final classification decisions which are stored in conjunction with analysed genetic sequences for periodic inference system training. The inference systems were trained and tested with three different data sets related to the bacterial degradation of aromatic compounds. The analysis of the meta-learner-based framework involved contrasting several different optimisation methods with various different parameters. The obtained inference systems were also contrasted with other standard classification methods with accurate prediction capabilities observed.

  16. Target and non-target analysis of migrants from PVC-coated cans using UHPLC-Q-Orbitrap MS: evaluation of long-term migration testing.

    Science.gov (United States)

    Vaclavikova, Marta; Paseiro-Cerrato, Rafael; Vaclavik, Lukas; Noonan, Gregory O; DeVries, Jonathan; Begley, Timothy H

    2016-01-01

    A simple, rapid and sensitive method for analyzing multi-target and non-target additives in polyvinyl chloride (PVC) food can coatings using ultra-high-performance liquid chromatography coupled to quadrupole-orbital ion-trap mass spectrometry was developed. This procedure was used to study the behaviour of a cross-linking agent, benzoguanamine (BGA), two slip agents, oleamide and erucamide, and 18 other commonly used plasticisers including phthalates, adipates, sebacates, acetyl tributyl citrate and epoxidised soybean or linseed oils. This optimised method was used to detect these analytes in food simulants (water and 3% acetic acid) in a long-term migration test of PVC-coated food cans for a period ranging from 1 day to 1.5 years at 40°C. Although very low detection limits (5 ng ml(-1)) were obtained for the majority of compounds, none of the monitored plasticisers and slip agents was detected in simulants extracted from cans over the period of the test. However, the presence of BGA in both aqueous food simulants was confirmed based on high-resolution mass spectrometry, product ion spectra and analysis of a reference standard. The BGA concentration in both simulants continued to increase with storage time: after 1.5 years storage in aqueous food simulants at 40°C, BGA was detected at concentrations up to 84 µg dm(-2). We believe this is the first study describing the long-term migration capacity of BGA from any vinyl coating material intended for use in PVC-coated food cans. Our results may have implications for migration test protocols for food cans that will be stored for extended time periods.

  17. Polynomial Regressions and Nonsense Inference

    Directory of Open Access Journals (Sweden)

    Daniel Ventosa-Santaulària

    2013-11-01

    Full Text Available Polynomial specifications are widely used, not only in applied economics, but also in epidemiology, physics, political analysis and psychology, just to mention a few examples. In many cases, the data employed to estimate such specifications are time series that may exhibit stochastic nonstationary behavior. We extend Phillips’ results (Phillips, P. Understanding spurious regressions in econometrics. J. Econom. 1986, 33, 311–340. by proving that an inference drawn from polynomial specifications, under stochastic nonstationarity, is misleading unless the variables cointegrate. We use a generalized polynomial specification as a vehicle to study its asymptotic and finite-sample properties. Our results, therefore, lead to a call to be cautious whenever practitioners estimate polynomial regressions.

  18. Statistical inference for financial engineering

    CERN Document Server

    Taniguchi, Masanobu; Ogata, Hiroaki; Taniai, Hiroyuki

    2014-01-01

    This monograph provides the fundamentals of statistical inference for financial engineering and covers some selected methods suitable for analyzing financial time series data. In order to describe the actual financial data, various stochastic processes, e.g. non-Gaussian linear processes, non-linear processes, long-memory processes, locally stationary processes etc. are introduced and their optimal estimation is considered as well. This book also includes several statistical approaches, e.g., discriminant analysis, the empirical likelihood method, control variate method, quantile regression, realized volatility etc., which have been recently developed and are considered to be powerful tools for analyzing the financial data, establishing a new bridge between time series and financial engineering. This book is well suited as a professional reference book on finance, statistics and statistical financial engineering. Readers are expected to have an undergraduate-level knowledge of statistics.

  19. Policy review: Japan-Philippines Economic Partnership Agreement (JPEPA)--analysis of a failed nurse migration policy.

    Science.gov (United States)

    Yagi, Nozomi; Mackey, Tim K; Liang, Bryan A; Gerlt, Lorna

    2014-02-01

    In 2008, the bilateral Japan-Philippines Economic Partnership Agreement took effect. Contained within this regional free trade agreement are unique provisions allowing exchange of Filipino nurses and healthcare workers to work abroad in Japan. Japan's increasing need for healthcare workers due to its aging demographic and the Philippines need for economic development could have led to shared benefits under the Japan-Philippines Economic Partnership Agreement. However, 4 years following program implementation, results have been disappointing, e.g., only 7% of candidates passing the programs requirements since 2009. These disappointing results represent a policy failure within the current Japan-Philippines Economic Partnership Agreement framework, and point to the need for reform. Hence, amending the current Japan-Philippines Economic Partnership Agreement structure by potentially adopting a USA based approach to licensure examinations and implementing necessary institutional and governance reform measures may be necessary to ensure beneficial healthcare worker migration for both countries.

  20. Population, migration and urbanization.

    Science.gov (United States)

    1982-06-01

    Despite recent estimates that natural increase is becoming a more important component of urban growth than rural urban transfer (excess of inmigrants over outmigrants), the share of migration in the total population growth has been consistently increasing in both developed and developing countries. From a demographic perspective, the migration process involves 3 elements: an area of origin which the mover leaves and where he or she is considered an outmigrant; the destination or place of inmigration; and the period over which migration is measured. The 2 basic types of migration are internal and international. Internal migration consists of rural to urban migration, urban to urban migration, rural to rural migration, and urban to rural migration. Among these 4 types of migration various patterns or processes are followed. Migration may be direct when the migrant moves directly from the village to the city and stays there permanently. It can be circular migration, meaning that the migrant moves to the city when it is not planting season and returns to the village when he is needed on the farm. In stage migration the migrant makes a series of moves, each to a city closer to the largest or fastest growing city. Temporary migration may be 1 time or cyclical. The most dominant pattern of internal migration is rural urban. The contribution of migration to urbanization is evident. For example, the rapid urbanization and increase in urban growth from 1960-70 in the Republic of Korea can be attributed to net migration. In Asia the largest component of the population movement consists of individuals and groups moving from 1 rural location to another. Recently, because urban centers could no longer absorb the growing number of migrants from other places, there has been increased interest in the urban to rural population redistribution. This reverse migration also has come about due to slower rates of employment growth in the urban centers and improved economic opportunities

  1. Skilled Migration: Australia. Working Paper No. 63

    Science.gov (United States)

    Shah, Chandra; Burke, Gerald

    2005-01-01

    Migration patterns to and from Australia are becoming complex with migration programmes increasingly targeted towards meeting the needs of the labour market and regional development. This paper provides an analysis of the permanent and temporary movements of people to and from Australia in the last three years and their impact on the skilled…

  2. Kinematics of shot-geophone migration

    NARCIS (Netherlands)

    C.C. Stolk; M.V. de Hoop; W.W. Symes

    2009-01-01

    Recent analysis and synthetic examples have shown that many prestack depth migration methods produce nonflat image gathers containing spurious events, even when provided with a kinematically correct migration velocity field, if this velocity field is highly refractive. This pathology occurs in all m

  3. Review Fair migration : Setting an ILO agenda

    NARCIS (Netherlands)

    Cremers, Jan

    2014-01-01

    The ILO-report Fair migration is intended to offer an opportunity for tripartite global debate on the migration issue. In his review Jan Cremers admits that the analysis is correct. However, he questions how to make these ideas concrete as workers exploited in a foreign constituency live and work fa

  4. Bayesian inference in geomagnetism

    Science.gov (United States)

    Backus, George E.

    1988-01-01

    The inverse problem in empirical geomagnetic modeling is investigated, with critical examination of recently published studies. Particular attention is given to the use of Bayesian inference (BI) to select the damping parameter lambda in the uniqueness portion of the inverse problem. The mathematical bases of BI and stochastic inversion are explored, with consideration of bound-softening problems and resolution in linear Gaussian BI. The problem of estimating the radial magnetic field B(r) at the earth core-mantle boundary from surface and satellite measurements is then analyzed in detail, with specific attention to the selection of lambda in the studies of Gubbins (1983) and Gubbins and Bloxham (1985). It is argued that the selection method is inappropriate and leads to lambda values much larger than those that would result if a reasonable bound on the heat flow at the CMB were assumed.

  5. Inferring attitudes from mindwandering.

    Science.gov (United States)

    Critcher, Clayton R; Gilovich, Thomas

    2010-09-01

    Self-perception theory posits that people understand their own attitudes and preferences much as they understand others', by interpreting the meaning of their behavior in light of the context in which it occurs. Four studies tested whether people also rely on unobservable "behavior," their mindwandering, when making such inferences. It is proposed here that people rely on the content of their mindwandering to decide whether it reflects boredom with an ongoing task or a reverie's irresistible pull. Having the mind wander to positive events, to concurrent as opposed to past activities, and to many events rather than just one tends to be attributed to boredom and therefore leads to perceived dissatisfaction with an ongoing task. Participants appeared to rely spontaneously on the content of their wandering minds as a cue to their attitudes, but not when an alternative cause for their mindwandering was made salient.

  6. International migration: a global challenge.

    Science.gov (United States)

    Martin, P; Widgren, J

    1996-04-01

    Trends in international migration are presented in this multiregional analysis. Seven of the world's wealthiest countries have about 33% of the world's migrant population, but under 16% of the total world population. Population growth in these countries is substantially affected by the migrant population. The migration challenge is external and internal. The external challenge is to balance the need for foreign labor and the commitment to human rights for those migrants seeking economic opportunity and political freedom. The internal challenge is to assure the social adjustment of immigrants and their children and to integrate them into society as citizens and future leaders. Why people cross national borders and how migration flows are likely to evolve over the next decades are explained. This report also presents some ways that countries can manage migration or reduce the pressures which force people to migrate. It is recommended that receiving nations control immigration by accelerating global economic growth and reducing wars and human rights violations. This report examines the impact of immigration on international trade, aid, and direct intervention policies. Although migration is one of the most important international economic issues, it is not coordinated by an international group. The European experience indicates that it is not easy to secure international cooperation on issues that affect national sovereignty. It is suggested that countries desiring control of their borders should remember that most people never cross national borders to live or work in another country, that 50% of the world's migrants move among developing countries, and that countries can shift from being emigration to immigration countries. The author suggests that sustained reductions in migration pressure are a better alternative than the "quick fixes" that may invite the very much feared mass and unpredictable movements.

  7. Multiresidual LC-MS analysis of plasticizers used in PVC gaskets of lids and assessment of their migration into food sauces.

    Science.gov (United States)

    Lambertini, F; Catellani, D; Vindigni, M; Suman, M

    2016-09-01

    Plasticizers may migrate from polyvinyl chloride (PVC) gaskets into the foodstuffs mainly by direct contact during the packaging and sterilization procedure, but also by means of occasional contacts occurring during shipment and storage. The present work reports a reliable liquid chromatography-mass spectrometry (LC-MS) method able to quantify the main plasticizers used in the PVC closure gaskets for metal lids to verify their compliance in both food contact materials and foodstuffs. The atmospheric pressure chemical ionization in the positive ion mode resulted the best performing interface for the multiresidual detection of the plasticizers taken into account, followed by selected/multiple reaction monitoring, selected ion monitoring or full scan experiments, depending on the compounds to detect. The method was single-laboratory validated, demonstrating to reach a good sensitivity, thus making possible to perform analysis without any preliminary sample purification or concentration step. It proved to be effectively applicable not only for the determination of plasticizers in PVC gaskets but also in complex food matrices. In particular, it was applied for monitoring plasticizer migration into sauces placed in contact with the lids in worst storage conditions, observing therefore their trend during the shelf-life. Copyright © 2016 John Wiley & Sons, Ltd.

  8. A CUSUM analysis of discharge patterns by a hydroelectric dam and discussion of potential effects on the upstream migration of American eel elvers

    Energy Technology Data Exchange (ETDEWEB)

    Jessop, B.M.; Harvie, C.J. [Department of Fisheries and Oceans, Dartmouth, NS (Canada). Bedford Inst. of Oceanography

    2003-07-01

    American eel elvers are among the diadromous fishes native to the Saint John River in New Brunswick that have been affected by the construction of hydroelectric dams. Before 1980, large numbers of elvers were observed entering the fishway of the Mactaquac Dam in May and June for upstream migration, but their presence abruptly ceased after 1980. A study was conducted to determine why they disappeared at the Mactaquac Dam. A cumulative sum (CUSUM) analysis was performed to determine the variability in magnitude, duration, timing, frequency, and rate of change in the daily and seasonal average level of water discharge associated with the installation of the last two of six turbines in late 1979 and early 1980. It is believed that the rapid, short-term fluctuations in water discharge which is characteristic of peaking hydroelectric dam operations, could seriously affect life cycle transitions of diadromous fishes. Upstream and downstream migration of the elvers may be affected along with their abundance, diversity and productivity. Young fish in particular are at higher risk of mortality during high flows, depending on the species. 40 refs., 3 tabs., 10 figs.

  9. More Myths of Migration.

    Science.gov (United States)

    Basch, Linda; Lerner, Gail

    1986-01-01

    Challenges "myths" about women and migration, including (1) the causes of migration are economic, not racism; (2) migrant women receive support from feminist groups and trade unions; (3) transnational corporations are positive forces in developing nations; (4) migration today has little impact on family life; and (5) most migrants cluster in…

  10. Migration and Adult Education

    Science.gov (United States)

    Gois, William

    2007-01-01

    The objective of this paper is to highlight the role of adult education as a tool in addressing labour migration issues, specifically those concerning the protection of migrant workers' rights and the transformation of the impact of migration into positive holistic developmental gains. The view of labour migration as a means to forge the economic…

  11. Migration and Literature

    DEFF Research Database (Denmark)

    Frank, Søren

    We live in an age of migration and more and more authors have migrant backgrounds. Migration and Literature offers a thorough and thought provoking examination of the thematic and formal role of migration in four contemporary and canonized novelists, Günter Grass, Milan Kundera, Salman Rushdie...

  12. Admissibility of logical inference rules

    CERN Document Server

    Rybakov, VV

    1997-01-01

    The aim of this book is to present the fundamental theoretical results concerning inference rules in deductive formal systems. Primary attention is focused on: admissible or permissible inference rules the derivability of the admissible inference rules the structural completeness of logics the bases for admissible and valid inference rules. There is particular emphasis on propositional non-standard logics (primary, superintuitionistic and modal logics) but general logical consequence relations and classical first-order theories are also considered. The book is basically self-contained and

  13. Cell migration in confined environments.

    Science.gov (United States)

    Irimia, Daniel

    2014-01-01

    We describe a protocol for measuring the speed of human neutrophils migrating through small channels, in conditions of mechanical confinement comparable to those experienced by neutrophils migrating through tissues. In such conditions, we find that neutrophils move persistently, at constant speed for tens of minutes, enabling precise measurements at single cells resolution, for large number of cells. The protocol relies on microfluidic devices with small channels in which a solution of chemoattractant and a suspension of isolated neutrophils are loaded in sequence. The migration of neutrophils can be observed for several hours, starting within minutes after loading the neutrophils in the devices. The protocol is divided into four main steps: the fabrication of the microfluidic devices, the separation of neutrophils from whole blood, the preparation of the assay and cell loading, and the analysis of data. We discuss the practical steps for the implementation of the migration assays in biology labs, the adaptation of the protocols to various cell types, including cancer cells, and the supplementary device features required for precise measurements of directionality and persistence during migration.

  14. Double jeopardy in inferring cognitive processes.

    Science.gov (United States)

    Fific, Mario

    2014-01-01

    Inferences we make about underlying cognitive processes can be jeopardized in two ways due to problematic forms of aggregation. First, averaging across individuals is typically considered a very useful tool for removing random variability. The threat is that averaging across subjects leads to averaging across different cognitive strategies, thus harming our inferences. The second threat comes from the construction of inadequate research designs possessing a low diagnostic accuracy of cognitive processes. For that reason we introduced the systems factorial technology (SFT), which has primarily been designed to make inferences about underlying processing order (serial, parallel, coactive), stopping rule (terminating, exhaustive), and process dependency. SFT proposes that the minimal research design complexity to learn about n number of cognitive processes should be equal to 2 (n) . In addition, SFT proposes that (a) each cognitive process should be controlled by a separate experimental factor, and (b) The saliency levels of all factors should be combined in a full factorial design. In the current study, the author cross combined the levels of jeopardies in a 2 × 2 analysis, leading to four different analysis conditions. The results indicate a decline in the diagnostic accuracy of inferences made about cognitive processes due to the presence of each jeopardy in isolation and when combined. The results warrant the development of more individual subject analyses and the utilization of full-factorial (SFT) experimental designs.

  15. The mixed effects of migration: community-level migration and birthweight in Mexico.

    Science.gov (United States)

    Hamilton, Erin R; Choi, Kate H

    2015-05-01

    Research on the relationship between migration and infant health in Mexico finds that migration has mixed impacts on the risk of low birthweight (LBW). Whereas the departure and absence of household and community members are harmful, remittances are beneficial. We extend this work by considering a different measure of infant health in addition to LBW: macrosomia (i.e., heavy birthweight), which is associated with infant, child, and maternal morbidities but has a different social risk profile from LBW. We link the 2008 and 2009 Mexican birth certificates with community data from the 2000 Mexican census to analyze the association between various dimensions of community-level migration (i.e., rates of out-migration, receipt of remittances, and return migration) and the risk of LBW and macrosomia. We examine this association using two sets of models which differ in the extent to which they account for endogeneity. We find that the health impacts of migration differ depending not only on the dimension of migration, but also on the measure of health, and that they are robust to potential sources of endogeneity. Whereas community remittances and return migration are associated with lower risk of LBW, they are associated with increased risk of macrosomia. By contrast, out-migration is associated with increased risk of LBW and lower risk of macrosomia. Our analysis of endogeneity suggests that bias resulting from unmeasured differences between communities with different levels of migration may result in an underestimate of the impacts of community migration on birthweight.

  16. Migration and fate of ethanol-enhanced gasoline in groundwater: a modelling analysis of a field experiment.

    Science.gov (United States)

    Freitas, Juliana G; Mocanu, Marian T; Zoby, José Luiz G; Molson, John W; Barker, James F

    2011-01-25

    Ethanol use as a gasoline additive is increasing, as are the chances of groundwater contamination caused by gasoline releases involving ethanol. To evaluate the impact of ethanol on dissolved hydrocarbon plumes, a field test was performed in which three gasoline residual sources with different ethanol fractions (E0: no ethanol, E10: 10% ethanol and E95: 95% ethanol) were emplaced below the water table. Using the numerical model BIONAPL/3D, the mass discharge rates of benzene, toluene, ethylbenzene, xylenes, trimethylbenzenes and naphthalene were simulated and results compared to those obtained from sampling transects of multilevel samplers. It was shown that ethanol dissolved rapidly and migrated downgradient as a short slug. Mass discharge of the hydrocarbons from the E0 and E10 sources suggested similar first-order hydrocarbon decay rates, indicating that ethanol from E10 had no impact on hydrocarbon degradation. In contrast, the estimated hydrocarbon decay rates were significantly lower when the source was E95. For the E0 and E10 cases, the aquifer did not have enough oxygen to support complete mineralization of the hydrocarbon compounds to the extent suggested by the field-based mass discharge. Introducing a heterogeneous distribution of hydraulic conductivity did little to overcome this discrepancy. A better match between the numerical model and the field data was obtained assuming partial degradation of the hydrocarbons to intermediate compounds. Besides depending on the ethanol concentration, the impact of ethanol on hydrocarbon degradation appears to be highly dependent on the availability of electron acceptors.

  17. The health of irregular and illegal immigrants: analysis of day-hospital admissions in a department of migration medicine.

    Science.gov (United States)

    Affronti, Mario; Affronti, Andrea; Pagano, Salvatore; Soresi, Maurizio; Giannitrapani, Lydia; Valenti, Miriam; La Spada, Emanuele; Montalto, Giuseppe

    2013-10-01

    It is difficult to trace full details of the path which irregular or illegal immigrants follow when seeking assistance in the network of the various hospital departments and health structures. The aim of this work was to analyze the health needs of immigrant people by reviewing the types of treatment given to them in the day-hospital of our Department of Migration Medicine. Our study analyzed day-hospital admissions between 2003 and 2009. The patient charts used for managing day-hospital activity were adopted in 2002 in conformity with the "OSI project". From these it is possible to draw up a scale picture of the distribution of each pathology in the immigrant population. The sample population consisted of 1,758 subjects, representing 7.4% of potential users. More than half came from Africa, followed by Asia, and then Europe. Gastroenterological diseases ranked first, with dyspeptic syndromes most frequently diagnosed. Infections and parasitic diseases ranked second, and the most frequent diagnoses were sexually transmitted diseases. Third were diseases of the genitourinary system. Metabolic disorders ranked fourth, among them, more than half of the cases were of diabetes mellitus, in patients from south-east Asia. Diseases of the circulatory system were sixth, with hypertension the most frequent pathology. Our data confirm a marked persistence of the phenomenon known as the "healthy immigrant effect" in these types of patients, as well as the prominent role played by "social determinants" in conditioning the health of immigrants, particularly in the case of some infectious diseases.

  18. A high-throughput three-dimensional cell migration assay for toxicity screening with mobile device-based macroscopic image analysis

    Science.gov (United States)

    Timm, David M.; Chen, Jianbo; Sing, David; Gage, Jacob A.; Haisler, William L.; Neeley, Shane K.; Raphael, Robert M.; Dehghani, Mehdi; Rosenblatt, Kevin P.; Killian, T. C.; Tseng, Hubert; Souza, Glauco R.

    2013-10-01

    There is a growing demand for in vitro assays for toxicity screening in three-dimensional (3D) environments. In this study, 3D cell culture using magnetic levitation was used to create an assay in which cells were patterned into 3D rings that close over time. The rate of closure was determined from time-lapse images taken with a mobile device and related to drug concentration. Rings of human embryonic kidney cells (HEK293) and tracheal smooth muscle cells (SMCs) were tested with ibuprofen and sodium dodecyl sulfate (SDS). Ring closure correlated with the viability and migration of cells in two dimensions (2D). Images taken using a mobile device were similar in analysis to images taken with a microscope. Ring closure may serve as a promising label-free and quantitative assay for high-throughput in vivo toxicity in 3D cultures.

  19. Migration processes in SCO member states

    Directory of Open Access Journals (Sweden)

    Valentina Sergeevna Antonyuk

    2012-12-01

    Full Text Available The article concerns modern state and development of migration processes in SCO member states. As a main method of research statistical analysis was applied. The article shows that migration streams between SCO member states are rather intensive, and the problem of labor migration becomes more and more urgent. The countries of consuming and supplying of labour force are clearly differentiated in the region. For some countries, labor export is the key sector of economy. At the same time, interstate relations between SCO member states sometimes are rather disputed. The most urgent factors causing the development of migration processes in the region were determined. Among them, thefactor of growing outflows from China isespecially noted. It is noted that migration processes are discussed by SCO member states nowadays in terms of illegal migration and international criminality connected with it. It means that the question of labor migration is a real problem. It is indicated that the creation of a specific joint commission on migration policy affiliated with the Council of Foreign Ministers of SCO member states is the necessary condition of effective interaction in migration questions within the framework of Shanghai Cooperation Organization.

  20. Migration Flows in Europe: Space and Time Transformation

    Directory of Open Access Journals (Sweden)

    Zhitin Dmitry

    2016-06-01

    Full Text Available One of the key manifestations of globalisation is an increase in the spatial mobility of population involving growing numbers of people into international migration processes. This article is an attempt to assess the density of migration connections between European states based on the 1990—2015 quantitative data. An analysis of migration flows and relevant net migration and net migration and migration localisation at the national and regional levels makes it possible to identify key trends in the spatial and temporal transformation of this phenomenon on the European continent. Calculations suggest that an increase in migration has not narrowed the gap between source and recipient countries but, on the contrary, it has made it more pronounced over the recent decades. The article presents an attempt at classifying European countries by the direction and intensity of migration connections and stresses the impact of international migration on the demographic and sociocultural situation in different European states.

  1. An Inference Language for Imaging

    DEFF Research Database (Denmark)

    Pedemonte, Stefano; Catana, Ciprian; Van Leemput, Koen

    2014-01-01

    We introduce iLang, a language and software framework for probabilistic inference. The iLang framework enables the definition of directed and undirected probabilistic graphical models and the automated synthesis of high performance inference algorithms for imaging applications. The iLang framework...

  2. Causal Inference and Developmental Psychology

    Science.gov (United States)

    Foster, E. Michael

    2010-01-01

    Causal inference is of central importance to developmental psychology. Many key questions in the field revolve around improving the lives of children and their families. These include identifying risk factors that if manipulated in some way would foster child development. Such a task inherently involves causal inference: One wants to know whether…

  3. Variational Program Inference

    CERN Document Server

    Harik, Georges

    2010-01-01

    We introduce a framework for representing a variety of interesting problems as inference over the execution of probabilistic model programs. We represent a "solution" to such a problem as a guide program which runs alongside the model program and influences the model program's random choices, leading the model program to sample from a different distribution than from its priors. Ideally the guide program influences the model program to sample from the posteriors given the evidence. We show how the KL- divergence between the true posterior distribution and the distribution induced by the guided model program can be efficiently estimated (up to an additive constant) by sampling multiple executions of the guided model program. In addition, we show how to use the guide program as a proposal distribution in importance sampling to statistically prove lower bounds on the probability of the evidence and on the probability of a hypothesis and the evidence. We can use the quotient of these two bounds as an estimate of ...

  4. Statistical Inference and String Theory

    CERN Document Server

    Heckman, Jonathan J

    2013-01-01

    In this note we expose some surprising connections between string theory and statistical inference. We consider a large collective of agents sweeping out a family of nearby statistical models for an M-dimensional manifold of statistical fitting parameters. When the agents making nearby inferences align along a d-dimensional grid, we find that the pooled probability that the collective reaches a correct inference is the partition function of a non-linear sigma model in d dimensions. Stability under perturbations to the original inference scheme requires the agents of the collective to distribute along two dimensions. Conformal invariance of the sigma model corresponds to the condition of a stable inference scheme, directly leading to the Einstein field equations for classical gravity. By summing over all possible arrangements of the agents in the collective, we reach a string theory. We also use this perspective to quantify how much an observer can hope to learn about the internal geometry of a superstring com...

  5. TYBO/BENHAM: Model Analysis of Groundwater Flow and Radionuclide Migration from Underground Nuclear Tests in Southwestern Pahute Mesa, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Wolfsberg; Lee Glascoe; Guoping Lu; Alyssa Olson; Peter Lichtner; Maureen McGraw; Terry Cherry; Guy Roemer

    2002-09-01

    Recent field studies have led to the discovery of trace quantities of plutonium originating from the BENHAM underground nuclear test in two groundwater observation wells on Pahute Mesa at the Nevada Test Site. These observation wells are located 1.3 km from the BENHAM underground nuclear test and approximately 300 m from the TYBO underground nuclear test. In addition to plutonium, several other conservative (e.g. tritium) and reactive (e.g. cesium) radionuclides were found in both observation wells. The highest radionuclide concentrations were found in a well sampling a welded tuff aquifer more than 500m above the BENHAM emplacement depth. These measurements have prompted additional investigations to ascertain the mechanisms, processes, and conditions affecting subsurface radionuclide transport in Pahute Mesa groundwater. This report describes an integrated modeling approach used to simulate groundwater flow, radionuclide source release, and radionuclide transport near the BENHAM and TYBO underground nuclear tests on Pahute Mesa. The components of the model include a flow model at a scale large enough to encompass many wells for calibration, a source-term model capable of predicting radionuclide releases to aquifers following complex processes associated with nonisothermal flow and glass dissolution, and site-scale transport models that consider migration of solutes and colloids in fractured volcanic rock. Although multiple modeling components contribute to the methodology presented in this report, they are coupled and yield results consistent with laboratory and field observations. Additionally, sensitivity analyses are conducted to provide insight into the relative importance of uncertainty ranges in the transport parameters.

  6. Tracking human migrations by the analysis of the distribution of HLA alleles, lineages and haplotypes in closed and open populations.

    Science.gov (United States)

    Fernandez Vina, Marcelo A; Hollenbach, Jill A; Lyke, Kirsten E; Sztein, Marcelo B; Maiers, Martin; Klitz, William; Cano, Pedro; Mack, Steven; Single, Richard; Brautbar, Chaim; Israel, Shosahna; Raimondi, Eduardo; Khoriaty, Evelyne; Inati, Adlette; Andreani, Marco; Testi, Manuela; Moraes, Maria Elisa; Thomson, Glenys; Stastny, Peter; Cao, Kai

    2012-03-19

    The human leucocyte antigen (HLA) system shows extensive variation in the number and function of loci and the number of alleles present at any one locus. Allele distribution has been analysed in many populations through the course of several decades, and the implementation of molecular typing has significantly increased the level of diversity revealing that many serotypes have multiple functional variants. While the degree of diversity in many populations is equivalent and may result from functional polymorphism(s) in peptide presentation, homogeneous and heterogeneous populations present contrasting numbers of alleles and lineages at the loci with high-density expression products. In spite of these differences, the homozygosity levels are comparable in almost all of them. The balanced distribution of HLA alleles is consistent with overdominant selection. The genetic distances between outbred populations correlate with their geographical locations; the formal genetic distance measurements are larger than expected between inbred populations in the same region. The latter present many unique alleles grouped in a few lineages consistent with limited founder polymorphism in which any novel allele may have been positively selected to enlarge the communal peptide-binding repertoire of a given population. On the other hand, it has been observed that some alleles are found in multiple populations with distinctive haplotypic associations suggesting that convergent evolution events may have taken place as well. It appears that the HLA system has been under strong selection, probably owing to its fundamental role in varying immune responses. Therefore, allelic diversity in HLA should be analysed in conjunction with other genetic markers to accurately track the migrations of modern humans.

  7. Cost-benefit analysis of the mechanisms that enable migrating cells to sustain motility upon changes in matrix environments.

    Science.gov (United States)

    Tozluoglu, Melda; Mao, Yanlan; Bates, Paul A; Sahai, Erik

    2015-05-06

    Cells can move through extracellular environments with varying geometries and adhesive properties. Adaptation to these differences is achieved by switching between different modes of motility, including lamellipod-driven and blebbing motility. Further, cells can modulate their level of adhesion to the extracellular matrix (ECM) depending on both the level of force applied to the adhesions and cell intrinsic biochemical properties. We have constructed a computational model of cell motility to investigate how motile cells transition between extracellular environments with varying surface continuity, confinement and adhesion. Changes in migration strategy are an emergent property of cells as the ECM geometry and adhesion changes. The transition into confined environments with discontinuous ECM fibres is sufficient to induce shifts from lamellipod-based to blebbing motility, while changes in confinement alone within a continuous geometry are not. The geometry of the ECM facilitates plasticity, by inducing shifts where the cell has high marginal gain from a mode change, and conserving persistency where the cell can continue movement regardless of the motility mode. This regulation of cell motility is independent of global changes in cytoskeletal properties, but requires locally higher linkage between the actin network and the plasma membrane at the cell rear, and changes in internal cell pressure. In addition to matrix geometry, we consider how cells might transition between ECM of different adhesiveness. We find that this requires positive feedback between the forces cells apply on the adhesion points, and the strength of the cell-ECM adhesions on those sites. This positive feedback leads to the emergence of a small number of highly adhesive cores, similar to focal adhesions. While the range of ECM adhesion levels the cell can invade is expanded with this feedback mechanism; the velocities are lowered for conditions where the positive feedback is not vital. Thus

  8. Cost–benefit analysis of the mechanisms that enable migrating cells to sustain motility upon changes in matrix environments

    Science.gov (United States)

    Tozluoglu, Melda; Mao, Yanlan; Bates, Paul A.; Sahai, Erik

    2015-01-01

    Cells can move through extracellular environments with varying geometries and adhesive properties. Adaptation to these differences is achieved by switching between different modes of motility, including lamellipod-driven and blebbing motility. Further, cells can modulate their level of adhesion to the extracellular matrix (ECM) depending on both the level of force applied to the adhesions and cell intrinsic biochemical properties. We have constructed a computational model of cell motility to investigate how motile cells transition between extracellular environments with varying surface continuity, confinement and adhesion. Changes in migration strategy are an emergent property of cells as the ECM geometry and adhesion changes. The transition into confined environments with discontinuous ECM fibres is sufficient to induce shifts from lamellipod-based to blebbing motility, while changes in confinement alone within a continuous geometry are not. The geometry of the ECM facilitates plasticity, by inducing shifts where the cell has high marginal gain from a mode change, and conserving persistency where the cell can continue movement regardless of the motility mode. This regulation of cell motility is independent of global changes in cytoskeletal properties, but requires locally higher linkage between the actin network and the plasma membrane at the cell rear, and changes in internal cell pressure. In addition to matrix geometry, we consider how cells might transition between ECM of different adhesiveness. We find that this requires positive feedback between the forces cells apply on the adhesion points, and the strength of the cell–ECM adhesions on those sites. This positive feedback leads to the emergence of a small number of highly adhesive cores, similar to focal adhesions. While the range of ECM adhesion levels the cell can invade is expanded with this feedback mechanism; the velocities are lowered for conditions where the positive feedback is not vital. Thus

  9. A comparative analysis of clustering algorithms: O{sub 2} migration in truncated hemoglobin I from transition networks

    Energy Technology Data Exchange (ETDEWEB)

    Cazade, Pierre-André; Berezovska, Ganna; Meuwly, Markus, E-mail: m.meuwly@unibas.ch [Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel (Switzerland); Zheng, Wenwei; Clementi, Cecilia [Department of Chemistry, Rice University, 6100 Main St., Houston, Texas 77005 (United States); Prada-Gracia, Diego; Rao, Francesco [School of Soft Matter Research, Freiburg Institute for Advanced Studies, Albertstrasse 19, 79104 Freiburg im Breisgau (Germany)

    2015-01-14

    The ligand migration network for O{sub 2}–diffusion in truncated Hemoglobin N is analyzed based on three different clustering schemes. For coordinate-based clustering, the conventional k–means and the kinetics-based Markov Clustering (MCL) methods are employed, whereas the locally scaled diffusion map (LSDMap) method is a collective-variable-based approach. It is found that all three methods agree well in their geometrical definition of the most important docking site, and all experimentally known docking sites are recovered by all three methods. Also, for most of the states, their population coincides quite favourably, whereas the kinetics of and between the states differs. One of the major differences between k–means and MCL clustering on the one hand and LSDMap on the other is that the latter finds one large primary cluster containing the Xe1a, IS1, and ENT states. This is related to the fact that the motion within the state occurs on similar time scales, whereas structurally the state is found to be quite diverse. In agreement with previous explicit atomistic simulations, the Xe3 pocket is found to be a highly dynamical site which points to its potential role as a hub in the network. This is also highlighted in the fact that LSDMap cannot identify this state. First passage time distributions from MCL clusterings using a one- (ligand-position) and two-dimensional (ligand-position and protein-structure) descriptor suggest that ligand- and protein-motions are coupled. The benefits and drawbacks of the three methods are discussed in a comparative fashion and highlight that depending on the questions at hand the best-performing method for a particular data set may differ.

  10. Redshift data and statistical inference

    Science.gov (United States)

    Newman, William I.; Haynes, Martha P.; Terzian, Yervant

    1994-01-01

    Frequency histograms and the 'power spectrum analysis' (PSA) method, the latter developed by Yu & Peebles (1969), have been widely employed as techniques for establishing the existence of periodicities. We provide a formal analysis of these two classes of methods, including controlled numerical experiments, to better understand their proper use and application. In particular, we note that typical published applications of frequency histograms commonly employ far greater numbers of class intervals or bins than is advisable by statistical theory sometimes giving rise to the appearance of spurious patterns. The PSA method generates a sequence of random numbers from observational data which, it is claimed, is exponentially distributed with unit mean and variance, essentially independent of the distribution of the original data. We show that the derived random processes is nonstationary and produces a small but systematic bias in the usual estimate of the mean and variance. Although the derived variable may be reasonably described by an exponential distribution, the tail of the distribution is far removed from that of an exponential, thereby rendering statistical inference and confidence testing based on the tail of the distribution completely unreliable. Finally, we examine a number of astronomical examples wherein these methods have been used giving rise to widespread acceptance of statistically unconfirmed conclusions.

  11. Inferring Patterns in Network Traffic: Time Scales and Variations

    Science.gov (United States)

    2014-10-21

    2014 Carnegie Mellon University Inferring Patterns in Network Traffic : Time Scales and Variation Soumyo Moitra smoitra@sei.cmu.edu...number. 1. REPORT DATE 21 OCT 2014 2. REPORT TYPE N/A 3. DATES COVERED 4. TITLE AND SUBTITLE Inferring Patterns in Network Traffic : Time...method and metrics for Situational Awareness • SA  Monitoring trends and changes in traffic • Analysis over time  Time series data analysis • Metrics

  12. Migration, remittances and poverty in Ecuador

    OpenAIRE

    2015-01-01

    Etudes & documents; We analyse the influence of the recent wave of migration on the incidence of poverty among stayers in Ecuador. We draw our data from a survey that provides detailed information on migrants. The analysis reveals a significant negative effect of migration on poverty among migrant households. This effect is substantially smaller than the one that we find focusing on recipient households. We explore the factors that account for this divergence. Our analysis entails that the ex...

  13. Data migration scheme of die & mould enterprises and evaluation analysis%模具企业数据迁移方案及评价分析

    Institute of Scientific and Technical Information of China (English)

    何伟; 洪福; 黎展滔

    2014-01-01

    针对以订单生产型的模具企业数据库中数据迁移后导致当前业务数据库数据不完整而影响数据库数据抽取的问题,提出了增量式、覆盖式的抽取方案,并对2种方案进行优缺点分析。针对2种方案的特点建立了一套评价指标,设计试验对2种方案的各项指标进行了对比分析,为具有商业智能信息系统的模具企业数据迁移提供一种理论指导。%In die & mould manufacturing enterprises of taking order-driven production as fea-tures, the data extraction from database may have problem due to the migration of data and cause incompletion of existing business database. To solve the problem, both incremen-tal and coverage type of extraction method was proposed. The advantages and disadvantag-es of two solutions based on the two extraction methods were analyzed. Then a set of evaluation index was established based on the two solutions characteristics; and experi-ment was designed to make comparative analysis on every indicator of the two solutions. This application can be a theory guide to the data migration of die & mould enterprises with business intelligent information system.

  14. Statistical causal inferences and their applications in public health research

    CERN Document Server

    Wu, Pan; Chen, Ding-Geng

    2016-01-01

    This book compiles and presents new developments in statistical causal inference. The accompanying data and computer programs are publicly available so readers may replicate the model development and data analysis presented in each chapter. In this way, methodology is taught so that readers may implement it directly. The book brings together experts engaged in causal inference research to present and discuss recent issues in causal inference methodological development. This is also a timely look at causal inference applied to scenarios that range from clinical trials to mediation and public health research more broadly. In an academic setting, this book will serve as a reference and guide to a course in causal inference at the graduate level (Master's or Doctorate). It is particularly relevant for students pursuing degrees in Statistics, Biostatistics and Computational Biology. Researchers and data analysts in public health and biomedical research will also find this book to be an important reference.

  15. Malaysia and forced migration

    OpenAIRE

    Arzura Idris

    2012-01-01

    This paper analyzes the phenomenon of “forced migration” in Malaysia. It examines the nature of forced migration, the challenges faced by Malaysia, the policy responses and their impact on the country and upon the forced migrants. It considers forced migration as an event hosting multifaceted issues related and relevant to forced migrants and suggests that Malaysia has been preoccupied with the issue of forced migration movements. This is largely seen in various responses invoked from Malaysi...

  16. Union Dissolution and Migration

    OpenAIRE

    Cooke, Thomas; Mulder, Clara H.; Thomas, Michael

    2016-01-01

    BACKGROUND While there is a limited body of research regarding residential mobility and migration following union dissolution, there is a particular dearth of studies that go into detail about the factors that shape how union dissolution may result in long-distance migration. OBJECTIVE This research isolates and identifies the processes that influence inter-state migration in the period immediately following the dissolution of a marital union. METHODS Multilevel logit models of the probabilit...

  17. Characterizing the International Migration Barriers with a Probabilistic Multilateral Migration Model

    Science.gov (United States)

    Li, Xiaomeng; Xu, Hongzhong; Chen, Jiawei; Chen, Qinghua; Zhang, Jiang; di, Zengru

    2016-09-01

    Human migration is responsible for forming modern civilization and has had an important influence on the development of various countries. There are many issues worth researching, and “the reason to move” is the most basic one. The concept of migration cost in the classical self-selection theory, which was introduced by Roy and Borjas, is useful. However, migration cost cannot address global migration because of the limitations of deterministic and bilateral choice. Following the idea of migration cost, this paper developed a new probabilistic multilateral migration model by introducing the Boltzmann factor from statistical physics. After characterizing the underlying mechanism or driving force of human mobility, we reveal some interesting facts that have provided a deeper understanding of international migration, such as the negative correlation between migration costs for emigrants and immigrants and a global classification with clear regional and economic characteristics, based on clustering of migration cost vectors. In addition, we deconstruct the migration barriers using regression analysis and find that the influencing factors are complicated but can be partly (12.5%) described by several macro indexes, such as the GDP growth of the destination country, the GNI per capita and the HDI of both the source and destination countries.

  18. Characterizing the International Migration Barriers with a Probabilistic Multilateral Migration Model

    Science.gov (United States)

    Li, Xiaomeng; Xu, Hongzhong; Chen, Jiawei; Chen, Qinghua; Zhang, Jiang; Di, Zengru

    2016-01-01

    Human migration is responsible for forming modern civilization and has had an important influence on the development of various countries. There are many issues worth researching, and “the reason to move” is the most basic one. The concept of migration cost in the classical self-selection theory, which was introduced by Roy and Borjas, is useful. However, migration cost cannot address global migration because of the limitations of deterministic and bilateral choice. Following the idea of migration cost, this paper developed a new probabilistic multilateral migration model by introducing the Boltzmann factor from statistical physics. After characterizing the underlying mechanism or driving force of human mobility, we reveal some interesting facts that have provided a deeper understanding of international migration, such as the negative correlation between migration costs for emigrants and immigrants and a global classification with clear regional and economic characteristics, based on clustering of migration cost vectors. In addition, we deconstruct the migration barriers using regression analysis and find that the influencing factors are complicated but can be partly (12.5%) described by several macro indexes, such as the GDP growth of the destination country, the GNI per capita and the HDI of both the source and destination countries. PMID:27597319

  19. Characterizing the International Migration Barriers with a Probabilistic Multilateral Migration Model.

    Science.gov (United States)

    Li, Xiaomeng; Xu, Hongzhong; Chen, Jiawei; Chen, Qinghua; Zhang, Jiang; Di, Zengru

    2016-09-06

    Human migration is responsible for forming modern civilization and has had an important influence on the development of various countries. There are many issues worth researching, and "the reason to move" is the most basic one. The concept of migration cost in the classical self-selection theory, which was introduced by Roy and Borjas, is useful. However, migration cost cannot address global migration because of the limitations of deterministic and bilateral choice. Following the idea of migration cost, this paper developed a new probabilistic multilateral migration model by introducing the Boltzmann factor from statistical physics. After characterizing the underlying mechanism or driving force of human mobility, we reveal some interesting facts that have provided a deeper understanding of international migration, such as the negative correlation between migration costs for emigrants and immigrants and a global classification with clear regional and economic characteristics, based on clustering of migration cost vectors. In addition, we deconstruct the migration barriers using regression analysis and find that the influencing factors are complicated but can be partly (12.5%) described by several macro indexes, such as the GDP growth of the destination country, the GNI per capita and the HDI of both the source and destination countries.

  20. Regional Redistribution and Migration

    DEFF Research Database (Denmark)

    Manasse, Paolo; Schultz, Christian

    We study a model with free migration between a rich and a poor region. Since there is congestion, the rich region has an incentive to give the poor region a transfer in order to reduce immigration. Faced with free migration, the rich region voluntarily chooses a transfer, which turns out...... to be equal to that a social planner would choose. Provided migration occurs in equilibrium, this conclusion holds even in the presence of moderate mobility costs. However, large migration costs will lead to suboptimal transfers in the market solution...

  1. Internal migration in Mexico and its determinants

    Directory of Open Access Journals (Sweden)

    Rogelio Varela Llamas

    2016-12-01

    Full Text Available This paper presents an analysis of internal migration in Mexico. Using micro data from the National Survey on Occupation and Employment (enoe, we estimate a multinomial logit model for the case of intrastate and interstate migration. We also conduct estimations for municipalities of different sizes. The results suggest that the probability of migrating increases with the number of weeks spent searching for a job, regardless of whether the search is conducted while the individual is employed or unemployed. In addition, we find that as the number of hours of work per week increases, the probability of migrating rises. The search process does not increase the probability of migrating in rural communities as it does in urban centers.

  2. Optimization methods for logical inference

    CERN Document Server

    Chandru, Vijay

    2011-01-01

    Merging logic and mathematics in deductive inference-an innovative, cutting-edge approach. Optimization methods for logical inference? Absolutely, say Vijay Chandru and John Hooker, two major contributors to this rapidly expanding field. And even though ""solving logical inference problems with optimization methods may seem a bit like eating sauerkraut with chopsticks. . . it is the mathematical structure of a problem that determines whether an optimization model can help solve it, not the context in which the problem occurs."" Presenting powerful, proven optimization techniques for logic in

  3. The Movement Analysis of Ions in the FAIMS Migration Tube and the Structures Design of Migration Tube%FAIMS迁移管中离子运动分析及迁移管结构的初步设计

    Institute of Scientific and Technical Information of China (English)

    吴福民; 钟其水; 杨敏; 何柳

    2011-01-01

    According to Newton's second law, the force and movement situation of ions in the migration tube of high-field asymmetric waveform ion mobility spectrometry (FAIMS)were analyzed. The motion of ions in the migration tube was only relevant to the very nature of ions themselves under a certain electric field and its duty ratio, while , the ions would do movement of trochoidal curve under the electric and magnetic fields if there were magnetic disturbances around the migration tube of FAIMS. The ions would drift in the electric field, whereas the movement of ions became complicated due to the magnetic disturbances which have greatly reduced the reliability and stability of FAIMS. In order to reduce the impact produced by magnetic field on the movement of ions in the migration tube, the structure of migration tube for shielding electromagnetic interference is put forward.%根据牛顿第二定律,分析了离子在高场不对称波形离子迁移谱(High-Field Asymmetric Waveform Ion Mobility Spectrometry,FAIMS)迁移管中的受力及运动情况.当作用的电场大小和占空比一定时,离子在迁移管中的运动仅仅与其本身的性质有关,而当FAIMS迁移管周围存在磁场干扰时,离子处于电场和磁场的复合作用下而作余摆线运动.电场的作用使离子定向漂移,而磁场的干扰使离子的运动变得复杂,从而大大降低了FAIMS的可靠性和稳定性.为了降低磁场对迁移管中离子运动的干扰,提出了具有屏蔽电磁干扰的FAIMS迁移管结构.

  4. The Legal Effect of Best-Interests-of-the-Child Reports in Judicial Migration Proceedings : A Qualitative Analysis of Five Cases

    NARCIS (Netherlands)

    Beltman, Daan; Kalverboer, Margrite; Zijlstra, Elianne; van Os, Carla; Zevulun, Daniëlle; Liefaard, Ton; Sloth-Nielsen, Julia

    2016-01-01

    In 2006 the Study Centre for Children, Migration and Law began research on a method for diagnostic assessments of, and reporting on, the best interests of the child in migration law cases. The reports, which are based on the Best Interests of the Child Model of Kalverboer and Zijlstra (2006) and whi

  5. International Migration and Human Development in Destination Countries: A Cross-National Analysis of Less-Developed Countries, 1970-2005

    Science.gov (United States)

    Sanderson, Matthew

    2010-01-01

    Contemporary levels of international migration in less-developed countries are raising new and important questions regarding the consequences of immigration for human welfare and well-being. However, there is little systematic cross-national evidence of how international migration affects human development levels in migrant-receiving countries in…

  6. Statistical inference via fiducial methods

    NARCIS (Netherlands)

    Salomé, Diemer

    1998-01-01

    In this thesis the attention is restricted to inductive reasoning using a mathematical probability model. A statistical procedure prescribes, for every theoretically possible set of data, the inference about the unknown of interest. ... Zie: Summary

  7. On principles of inductive inference

    OpenAIRE

    Kostecki, Ryszard Paweł

    2011-01-01

    We propose an intersubjective epistemic approach to foundations of probability theory and statistical inference, based on relative entropy and category theory, and aimed to bypass the mathematical and conceptual problems of existing foundational approaches.

  8. Type Inference for Guarded Recursive Data Types

    OpenAIRE

    Stuckey, Peter J.; Sulzmann, Martin

    2005-01-01

    We consider type inference for guarded recursive data types (GRDTs) -- a recent generalization of algebraic data types. We reduce type inference for GRDTs to unification under a mixed prefix. Thus, we obtain efficient type inference. Inference is incomplete because the set of type constraints allowed to appear in the type system is only a subset of those type constraints generated by type inference. Hence, inference only succeeds if the program is sufficiently type annotated. We present refin...

  9. Bayesian Inference: with ecological applications

    Science.gov (United States)

    Link, William A.; Barker, Richard J.

    2010-01-01

    This text provides a mathematically rigorous yet accessible and engaging introduction to Bayesian inference with relevant examples that will be of interest to biologists working in the fields of ecology, wildlife management and environmental studies as well as students in advanced undergraduate statistics.. This text opens the door to Bayesian inference, taking advantage of modern computational efficiencies and easily accessible software to evaluate complex hierarchical models.

  10. An Inference Language for Imaging

    DEFF Research Database (Denmark)

    Pedemonte, Stefano; Catana, Ciprian; Van Leemput, Koen

    2014-01-01

    We introduce iLang, a language and software framework for probabilistic inference. The iLang framework enables the definition of directed and undirected probabilistic graphical models and the automated synthesis of high performance inference algorithms for imaging applications. The iLang framewor......-accelerated primitives specializes iLang to the spatial data-structures that arise in imaging applications. We illustrate the framework through a challenging application: spatio-temporal tomographic reconstruction with compressive sensing....

  11. Statistical Inference: The Big Picture.

    Science.gov (United States)

    Kass, Robert E

    2011-02-01

    Statistics has moved beyond the frequentist-Bayesian controversies of the past. Where does this leave our ability to interpret results? I suggest that a philosophy compatible with statistical practice, labelled here statistical pragmatism, serves as a foundation for inference. Statistical pragmatism is inclusive and emphasizes the assumptions that connect statistical models with observed data. I argue that introductory courses often mis-characterize the process of statistical inference and I propose an alternative "big picture" depiction.

  12. Statistical Inference in Graphical Models

    Science.gov (United States)

    2008-06-17

    Probabilistic Network Library ( PNL ). While not fully mature, PNL does provide the most commonly-used algorithms for inference and learning with the efficiency...of C++, and also offers interfaces for calling the library from MATLAB and R 1361. Notably, both BNT and PNL provide learning and inference algorithms...mature and has been used for research purposes for several years, it is written in MATLAB and thus is not suitable to be used in real-time settings. PNL

  13. International Migration of Couples

    DEFF Research Database (Denmark)

    Junge, Martin; Munk, Martin D.; Poutvaara, Panu

    2017-01-01

    Migrant self-selection is important to both origin and destination countries. We develop a theoretical model regarding the migration of dual-earner couples and test it in the context of international migration, using population-wide administrative data from Denmark. Our model predicts...

  14. Migrating Art History

    DEFF Research Database (Denmark)

    Ørum, Tania

    2012-01-01

    Review of Hiroko Ikegami, The Great Migrator. Robert Rauschenberg and the Global Rise of American Art. Cambridge Mass., The MIT Press, 2010. 277 pages. ISBN 978-0-262-01425-0.......Review of Hiroko Ikegami, The Great Migrator. Robert Rauschenberg and the Global Rise of American Art. Cambridge Mass., The MIT Press, 2010. 277 pages. ISBN 978-0-262-01425-0....

  15. Migration, klima og sundhed

    DEFF Research Database (Denmark)

    Tellier, Siri; Carballo, Manuel

    2009-01-01

    Many tentative connections have been postulated between migration and climate. This article points to rural-urban migration, particularly into low elevation urban slums prone to flooding as an issue needing urgent attention by health professionals. It also notes the no-man's land in which...

  16. Migration in Burkina Faso

    NARCIS (Netherlands)

    Wouterse, F.S.

    2007-01-01

    Migration plays an important role in development and as a strategy for poverty reduction. A recent World Bank investigation finds a significant positive relationship between international migration and poverty reduction at the country level (Adams and Page 2003). Burkina Faso, whose conditions for a

  17. Model Migration Schedules

    OpenAIRE

    1981-01-01

    This report draws on the fundamental regularity exhibited by age profiles of migration all over the world to develop a system of hypothetical model schedules that can be used in multiregional population analyses carried out in countries that lack adequate migration data.

  18. Samtidskunst og migration

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2010-01-01

    "Samtidskunst og migration. En oversigt over faglitteraturen" er en forskningsoversigt der gør status over hvad der hidtil er skrevet inden for det kunsthistoriske område om vor tids billedkunst og migration som politisk, socialt og kulturelt fænomen, primært i forbindelse med immigration til...

  19. Quasi-Monte Carlo based global uncertainty and sensitivity analysis in modeling free product migration and recovery from petroleum-contaminated aquifers.

    Science.gov (United States)

    He, Li; Huang, Gordon; Lu, Hongwei; Wang, Shuo; Xu, Yi

    2012-06-15

    This paper presents a global uncertainty and sensitivity analysis (GUSA) framework based on global sensitivity analysis (GSA) and generalized likelihood uncertainty estimation (GLUE) methods. Quasi-Monte Carlo (QMC) is employed by GUSA to obtain realizations of uncertain parameters, which are then input to the simulation model for analysis. Compared to GLUE, GUSA can not only evaluate global sensitivity and uncertainty of modeling parameter sets, but also quantify the uncertainty in modeling prediction sets. Moreover, GUSA's another advantage lies in alleviation of computational effort, since those globally-insensitive parameters can be identified and removed from the uncertain-parameter set. GUSA is applied to a practical petroleum-contaminated site in Canada to investigate free product migration and recovery processes under aquifer remediation operations. Results from global sensitivity analysis show that (1) initial free product thickness has the most significant impact on total recovery volume but least impact on residual free product thickness and recovery rate; (2) total recovery volume and recovery rate are sensitive to residual LNAPL phase saturations and soil porosity. Results from uncertainty predictions reveal that the residual thickness would remain high and almost unchanged after about half-year of skimmer-well scheme; the rather high residual thickness (0.73-1.56 m 20 years later) indicates that natural attenuation would not be suitable for the remediation. The largest total recovery volume would be from water pumping, followed by vacuum pumping, and then skimmer. The recovery rates of the three schemes would rapidly decrease after 2 years (less than 0.05 m(3)/day), thus short-term remediation is not suggested.

  20. Trafficking and cell migration.

    Science.gov (United States)

    Ulrich, Florian; Heisenberg, Carl-Philipp

    2009-07-01

    The migration of single cells and epithelial sheets is of great importance for gastrulation and organ formation in developing embryos and, if misregulated, can have dire consequences e.g. during cancer metastasis. A keystone of cell migration is the regulation of adhesive contacts, which are dynamically assembled and disassembled via endocytosis. Here, we discuss some of the basic concepts about the function of endocytic trafficking during cell migration: transport of integrins from the cell rear to the leading edge in fibroblasts; confinement of signalling to the front of single cells by endocytic transport of growth factors; regulation of movement coherence in multicellular sheets by cadherin turnover; and shaping of extracellular chemokine gradients. Taken together, endocytosis enables migrating cells and tissues to dynamically modulate their adhesion and signalling, allowing them to efficiently migrate through their extracellular environment.

  1. Malaysia and forced migration

    Directory of Open Access Journals (Sweden)

    Arzura Idris

    2012-06-01

    Full Text Available This paper analyzes the phenomenon of “forced migration” in Malaysia. It examines the nature of forced migration, the challenges faced by Malaysia, the policy responses and their impact on the country and upon the forced migrants. It considers forced migration as an event hosting multifaceted issues related and relevant to forced migrants and suggests that Malaysia has been preoccupied with the issue of forced migration movements. This is largely seen in various responses invoked from Malaysia due to “south-south forced migration movements.” These responses are, however, inadequate in terms of commitment to the international refugee regime. While Malaysia did respond to economic and migration challenges, the paper asserts that such efforts are futile if she ignores issues critical to forced migrants.

  2. Human collective intelligence as distributed Bayesian inference

    CERN Document Server

    Krafft, Peter M; Pan, Wei; Della Penna, Nicolás; Altshuler, Yaniv; Shmueli, Erez; Tenenbaum, Joshua B; Pentland, Alex

    2016-01-01

    Collective intelligence is believed to underly the remarkable success of human society. The formation of accurate shared beliefs is one of the key components of human collective intelligence. How are accurate shared beliefs formed in groups of fallible individuals? Answering this question requires a multiscale analysis. We must understand both the individual decision mechanisms people use, and the properties and dynamics of those mechanisms in the aggregate. As of yet, mathematical tools for such an approach have been lacking. To address this gap, we introduce a new analytical framework: We propose that groups arrive at accurate shared beliefs via distributed Bayesian inference. Distributed inference occurs through information processing at the individual level, and yields rational belief formation at the group level. We instantiate this framework in a new model of human social decision-making, which we validate using a dataset we collected of over 50,000 users of an online social trading platform where inves...

  3. On marriage and migration.

    Science.gov (United States)

    Stark, O

    1988-09-01

    Marriage, migration, and related phenomena such as marital stability, fertility, and investment in human capital may be better explained by studying marriage and migration jointly. This paper examines the role of migration in obtaining joint labor market and marriage market equilibrium. When broadly interpreted, marriage and migration share a number of common features. Both involve search and its resolution (pairing of mates in the former and matching of labor and firms in the latter). In both cases, success in finding a partner is sensitive to the availability of partners and to the distribution of their endowments and traits. Almost always, and along with separation and divorce, marriage mandates spatial relocation which may translate into migration. Both involve a movement that is associated with adjustment costs from 1 state into another. The decisions to enter marriage and undertake employment or the decisions to divorce and quit a job depend on exogenous parameters, some of which are determined by the marriage market and the labor market. Since both marriage and divorce take place in the context of broadly defined markets, they may and often are analyzed applying market concepts, theorems, and solutions. Yet the authors could not pinpoint 1 single, systematic attempt that checks through the interactions between marriage and migration, so this paper attempts to rectify this state of research. Essentially, this paper 1) discusses individual decision making pending possible migration prior to or following marriage, 2) examines whether it is easier for a married couple or a single person to migrate, and 3) considers whether marriage dissolution could cause migration when marriage is the only reason that has kept a spouse from moving. This integrated research agenda for both marriage and migration can delineate interesting new implications to examine.

  4. Nonparametric statistical inference

    CERN Document Server

    Gibbons, Jean Dickinson

    2014-01-01

    Thoroughly revised and reorganized, the fourth edition presents in-depth coverage of the theory and methods of the most widely used nonparametric procedures in statistical analysis and offers example applications appropriate for all areas of the social, behavioral, and life sciences. The book presents new material on the quantiles, the calculation of exact and simulated power, multiple comparisons, additional goodness-of-fit tests, methods of analysis of count data, and modern computer applications using MINITAB, SAS, and STATXACT. It includes tabular guides for simplified applications of tests and finding P values and confidence interval estimates.

  5. A Brief Analysis of Hot Testing Item in NMT-Ion Inference%高考热点试题--离子推断题浅析

    Institute of Scientific and Technical Information of China (English)

    寸智

    2012-01-01

    Ion inference is one of the main topic ion reactions and a kind of item students are easy to lose scores. Because it is of wide knowledge scope, strong comprehension and large thinking capacity, comprehensive applying ability and inferential capability, it gains more popularity. This paper it can check students' problem-solving strategies and analyzes some typical items in NMT.%离子推断题是离子反应的主要题型之一,也是学生失分比较严重的一种题型。因其涉及知识面广、知识综合强、思维容量大.能较好地考查出学生对知识的综合运用水平和推理能力,从而备受高考命题者的青睐。本文对此类试题的解题策略做了简单归纳,并分析了此类高考试题的经典题型。

  6. Analysis of cytoskeleton dynamics and cell migration in drosophila ovaries using GFP-actin and E-cadherin-GFP fusion molecules

    Science.gov (United States)

    Verkhusha, Vladyslav V.; Tsukita, Shoichiro; Oda, Hiroki

    1999-06-01

    Coordination of cell migration and adhesion is essential for movement of tissues during morphogenesis. During Drosophila oogenesis so called border cells (BCs) break from an anterior epithelium of egg chamber, acquire a mesenchymal-like morphology, and migrate posteriorly between nurse cells to oocyte. The confocal microscopic observation of BCs has revealed well-developed forepart lamellipodium stained with Drosophila E-cadherin (DE-cadherin), PS2 integrin, cytoplasmic myosin and F-actin. To investigate mechanism of BC migration in vivo we have constructed a DE-cadherin-GFP and a GFP-actin fusion proteins and induced their expression BCs utilizing the UAS/GAL4 system. The DE-cadherin-GFP signal as well as immunostaining of PS2 integrin visualized a track of migrating BCs providing an evidence that adhesive molecules are pulled out and left behind on the surface of nurse cells. Our data suggest that two distinct adhesive systems, DE-cadherins and PS2 integrins simultaneously mediate the migration of BCs. Release of adhesive contacts in the tail region is a rate- limited event in BC migration. The spatial-temporal sequence of actin-based events visualized by the GFP-actin suggest a treadmilling model for actin behavior in BC lamellipodium. BC migration can be considered as simultaneous reiterating processes of lamellipodium extension and adhesive attachment, cytoskeletal contraction, and rear detachment.

  7. Migration matrices and surnames in populations with different isolation patterns: Val di Lima (Italian Apennines), Val di Sole (Italian Alps), and La Cabrera (Spain).

    Science.gov (United States)

    Boattini, Alessio; Calboli, Federico C F; Blanco Villegas, Maria José; Gueresi, Paola; Franceschi, Marcello G; Paoli, Giorgio; Cavicchi, Sandro; Pettener, Davide

    2006-01-01

    Biodemographic methods are widely used to infer the genetic structure of human populations. In this study, we revise and standardize the procedures required by the migration matrix model of Malécot ([1950] Ann Univ Lyon Sci [A] 13:37-60), testing it in large historical-demographic databases of 85 populations from three mountain valleys with different degrees of isolation: Val di Lima (Italian Apennines, 21 parishes), Val di Sole, (Italian Alps, 27 parishes), and La Cabrera (Spain, 37 parishes). An add-on package (Biodem) for the R program is proposed to perform all calculations. Results from migration matrices are compared with those obtained from isonymic relationships. Migration and isonymy matrices are derived from 22,781 marriage records. Matrices are analyzed using a nonlinear isolation-by-distance (IBD) model and multivariate techniques (multidimensional scaling, Procrustes rotation, and cluster analysis). Microdifferentiation levels (F(ST)) from the migration data agree with the observed inbreeding values: higher values are found in La Cabrera (F(ST) = 0.0082), the most isolated population; Val di Lima (F(ST) = 0.0015) and Val di Sole (F(ST) = 0.0012) have lower values due to the larger parish population sizes and greater mobility. Temporal changes of F(ST) and IBD are analyzed using the migration matrix approach. The populations show a marked decline in F(ST) values in time, together with increased population mobility and emigration rates. In all three valleys, marital migration and isonymy yield similar results, suggesting that geographic distance is the most important factor structuring the populations. However, isonymy shows a lower correlation with geographic distance than migration matrices do. This difference can be attributed to the differing sensitivity of the methods for past migration events, and to genetic drift.

  8. Global migration can lead to stronger spatial selection than local migration.

    Science.gov (United States)

    Fu, Feng; Nowaks, Martin A

    2013-05-01

    The outcome of evolutionary processes depends on population structure. It is well known that mobility plays an important role in affecting evolutionary dynamics in group structured populations. But it is largely unknown whether global or local migration leads to stronger spatial selection and would therefore favor to a larger extent the evolution of cooperation. To address this issue, we quantify the impacts of these two migration patterns on the evolutionary competition of two strategies in a finite island model. Global migration means that individuals can migrate from any one island to any other island. Local migration means that individuals can only migrate between islands that are nearest neighbors; we study a simple geometry where islands are arranged on a one-dimensional, regular cycle. We derive general results for weak selection and large population size. Our key parameters are: the number of islands, the migration rate and the mutation rate. Surprisingly, our comparative analysis reveals that global migration can lead to stronger spatial selection than local migration for a wide range of parameter conditions. Our work provides useful insights into understanding how different mobility patterns affect evolutionary processes.

  9. Global ice volume during MIS 3 inferred from a sea-level analysis of sedimentary core records in the Yellow River Delta

    Science.gov (United States)

    Pico, Tamara; Mitrovica, Jerry X.; Ferrier, Ken L.; Braun, Jean

    2016-11-01

    Estimates of global ice volume during the glacial phase of the most recent ice age cycle are characterized by significant uncertainty, reflecting the relative paucity of geological constraints on sea level relevant to this time interval. For example, during the middle stages of Marine Isotope Stage 3, published estimates of peak global mean sea level (GMSL) relative to the present range from -25 m to -87 m. The large uncertainty in GMSL at MIS 3 has significant implications for estimates of the rate of ice growth in the period leading to the Last Glacial Maximum (∼26 ka). We refine estimates of global ice volume during MIS 3 by employing sediment cores in the Bohai and Yellow Sea that record a migration of the paleoshoreline at ∼50-37 ka through a transition from marine to brackish conditions. In particular, we correct relative sea level at these sites for contamination due to glacial isostatic adjustment using a sea-level calculation that includes a gravitationally self-consistent treatment of sediment redistribution and compaction, and estimate a peak global mean sea level of -38 ± 7 m during the interval 50-37 ka. With suitable sedimentary core records, the approach described herein can be extended to refine existing constraints on global ice volume across the entire glacial period.

  10. African return migration: past, present, and future.

    Science.gov (United States)

    Gregory, J W; Piche, V

    1983-01-01

    The various forms of return migration in Africa in the twentieth century are first examined, and the factors affecting them are discussed. The authors then consider the value of the household, rather than the individual, as the unit of analysis. Return migration is also analyzed in terms of the linking role it plays between Africa's capitalist and non-capitalist countries. Finally, alternative future trends in the circulatory flow of African labor are considered.

  11. INFERENCE OF THE MARKET VALUE OF URBAN LOTS FROM THE PERSPECTIVE OF SURVIVAL ANALYSIS. CASE STUDY: CITY OF SÃO CARLOS, SÃO PAULO, BRAZIL

    Directory of Open Access Journals (Sweden)

    Guilherme Moraes Ferraudo

    Full Text Available ABSTRACT The survival analysis was originally proposed for data analysis related to time before the occurrence of a specific event of interest and has been widely used in studies of biomedical data (survival analysis, industrial research (reliability analysis and financial data (credit scoring. In this study, we presented a new approach to modeling the market value of urban lots based on survival analysis considering the left censoring mechanism, which allows estimating the probability for sale and the hazard associated with sales at the lot market value. The modeling is made from the survival analysis that introduces greater flexibility when compared to the usual linear models as it allows including the effectively traded lots (not censored and lots in negotiation (censored into the process, however, it is not enough to affirm the effective improvement of models based on the survival analysis.

  12. Water quality analysis in rivers with non-parametric probability distributions and fuzzy inference systems: application to the Cauca River, Colombia.

    Science.gov (United States)

    Ocampo-Duque, William; Osorio, Carolina; Piamba, Christian; Schuhmacher, Marta; Domingo, José L

    2013-02-01

    The integration of water quality monitoring variables is essential in environmental decision making. Nowadays, advanced techniques to manage subjectivity, imprecision, uncertainty, vagueness, and variability are required in such complex evaluation process. We here propose a probabilistic fuzzy hybrid model to assess river water quality. Fuzzy logic reasoning has been used to compute a water quality integrative index. By applying a Monte Carlo technique, based on non-parametric probability distributions, the randomness of model inputs was estimated. Annual histograms of nine water quality variables were built with monitoring data systematically collected in the Colombian Cauca River, and probability density estimations using the kernel smoothing method were applied to fit data. Several years were assessed, and river sectors upstream and downstream the city of Santiago de Cali, a big city with basic wastewater treatment and high industrial activity, were analyzed. The probabilistic fuzzy water quality index was able to explain the reduction in water quality, as the river receives a larger number of agriculture, domestic, and industrial effluents. The results of the hybrid model were compared to traditional water quality indexes. The main advantage of the proposed method is that it considers flexible boundaries between the linguistic qualifiers used to define the water status, being the belongingness of water quality to the diverse output fuzzy sets or classes provided with percentiles and histograms, which allows classify better the real water condition. The results of this study show that fuzzy inference systems integrated to stochastic non-parametric techniques may be used as complementary tools in water quality indexing methodologies.

  13. "Celtic migrations": fact or fiction? Strontium and oxygen isotope analysis of the Czech cemeteries of Radovesice and Kutná Hora in Bohemia.

    Science.gov (United States)

    Scheeres, Mirjam; Knipper, Corina; Hauschild, Maya; Schönfelder, Martin; Siebel, Wolfgang; Pare, Christopher; Alt, Kurt W

    2014-12-01

    Strontium and oxygen isotope analysis of human remains from the early La Tène (fourth/third century BC) Czech cemeteries of Radovesice I (RAD I), Radovesice II (RAD II), and Kutná Hora were conducted to investigate the importance of residential changes during the period of the historic "Celtic migrations". In the initial phases (LT A/B), the grave goods of these cemeteries are typical for the core area of the La Tène culture, while around 300 BC (LT B2) an alteration occurs and typical Bohemian styles arise, and connections to Moravia and the Danubian region become visible. The strontium isotope ratios are highly varied with (87) Sr/(86) Sr values between 0.7062 and 0.7153 in Radovesice, and between 0.7082 and 0.7147 in Kutná Hora. The oxygen isotope data are more homogeneous and yield δ(18) Op ratios from 14.8‰ to 17.2‰ [mean: 16.2‰ ± 0.5 (1σ)] in Radovesice, and from 14.9‰ to 17.3‰ [mean: 16.5‰ ± 0.6 (1σ)] in Kutná Hora. Because the geological properties of the landscapes around the sites are variable and complex, most of the observed variations among the strontium isotope ratios may have been caused by agricultural practices, such as regularly changing farming land. Nevertheless, there are some individuals who differ completely from the regional isotopic baseline values. This suggests that at least a small part of the community migrated, which does not seem to be correlated with any particular phase of the La Tène period. Remarkably, it is mainly males who seem to be of nonlocal origin, and particularly those who were buried as warriors. Females, on the other hand, appear to have been more closely bonded to the Bohemian region. Whether the "foreign" individuals with differing isotopic compositions came from Moravia or the Danubian region remains debatable.

  14. Goliath catfish spawning in the far western Amazon confirmed by the distribution of mature adults, drifting larvae and migrating juveniles.

    Science.gov (United States)

    Barthem, Ronaldo B; Goulding, Michael; Leite, Rosseval G; Cañas, Carlos; Forsberg, Bruce; Venticinque, Eduardo; Petry, Paulo; Ribeiro, Mauro L de B; Chuctaya, Junior; Mercado, Armando

    2017-02-06

    We mapped the inferred long-distance migrations of four species of Amazonian goliath catfishes (Brachyplatystoma rousseauxii, B. platynemum, B. juruense and B. vaillantii) based on the presence of individuals with mature gonads and conducted statistical analysis of the expected long-distance downstream migrations of their larvae and juveniles. By linking the distribution of larval, juvenile and mature adult size classes across the Amazon, the results showed: (i) that the main spawning regions of these goliath catfish species are in the western Amazon; (ii) at least three species-B. rousseauxii, B. platynemum, and B. juruense-spawn partially or mainly as far upstream as the Andes; (iii) the main spawning area of B. rousseauxii is in or near the Andes; and (iv) the life history migration distances of B. rousseauxii are the longest strictly freshwater fish migrations in the world. These results provide an empirical baseline for tagging experiments, life histories extrapolated from otolith microchemistry interpretations and other methods to establish goliath catfish migratory routes, their seasonal timing and possible return (homing) to western headwater tributaries where they were born.

  15. Goliath catfish spawning in the far western Amazon confirmed by the distribution of mature adults, drifting larvae and migrating juveniles

    Science.gov (United States)

    Barthem, Ronaldo B.; Goulding, Michael; Leite, Rosseval G.; Cañas, Carlos; Forsberg, Bruce; Venticinque, Eduardo; Petry, Paulo; Ribeiro, Mauro L. de B.; Chuctaya, Junior; Mercado, Armando

    2017-01-01

    We mapped the inferred long-distance migrations of four species of Amazonian goliath catfishes (Brachyplatystoma rousseauxii, B. platynemum, B. juruense and B. vaillantii) based on the presence of individuals with mature gonads and conducted statistical analysis of the expected long-distance downstream migrations of their larvae and juveniles. By linking the distribution of larval, juvenile and mature adult size classes across the Amazon, the results showed: (i) that the main spawning regions of these goliath catfish species are in the western Amazon; (ii) at least three species—B. rousseauxii, B. platynemum, and B. juruense—spawn partially or mainly as far upstream as the Andes; (iii) the main spawning area of B. rousseauxii is in or near the Andes; and (iv) the life history migration distances of B. rousseauxii are the longest strictly freshwater fish migrations in the world. These results provide an empirical baseline for tagging experiments, life histories extrapolated from otolith microchemistry interpretations and other methods to establish goliath catfish migratory routes, their seasonal timing and possible return (homing) to western headwater tributaries where they were born. PMID:28165499

  16. Active inference and robot control: a case study.

    Science.gov (United States)

    Pio-Lopez, Léo; Nizard, Ange; Friston, Karl; Pezzulo, Giovanni

    2016-09-01

    Active inference is a general framework for perception and action that is gaining prominence in computational and systems neuroscience but is less known outside these fields. Here, we discuss a proof-of-principle implementation of the active inference scheme for the control or the 7-DoF arm of a (simulated) PR2 robot. By manipulating visual and proprioceptive noise levels, we show under which conditions robot control under the active inference scheme is accurate. Besides accurate control, our analysis of the internal system dynamics (e.g. the dynamics of the hidden states that are inferred during the inference) sheds light on key aspects of the framework such as the quintessentially multimodal nature of control and the differential roles of proprioception and vision. In the discussion, we consider the potential importance of being able to implement active inference in robots. In particular, we briefly review the opportunities for modelling psychophysiological phenomena such as sensory attenuation and related failures of gain control, of the sort seen in Parkinson's disease. We also consider the fundamental difference between active inference and optimal control formulations, showing that in the former the heavy lifting shifts from solving a dynamical inverse problem to creating deep forward or generative models with dynamics, whose attracting sets prescribe desired behaviours.

  17. Active inference and robot control: a case study

    Science.gov (United States)

    Nizard, Ange; Friston, Karl; Pezzulo, Giovanni

    2016-01-01

    Active inference is a general framework for perception and action that is gaining prominence in computational and systems neuroscience but is less known outside these fields. Here, we discuss a proof-of-principle implementation of the active inference scheme for the control or the 7-DoF arm of a (simulated) PR2 robot. By manipulating visual and proprioceptive noise levels, we show under which conditions robot control under the active inference scheme is accurate. Besides accurate control, our analysis of the internal system dynamics (e.g. the dynamics of the hidden states that are inferred during the inference) sheds light on key aspects of the framework such as the quintessentially multimodal nature of control and the differential roles of proprioception and vision. In the discussion, we consider the potential importance of being able to implement active inference in robots. In particular, we briefly review the opportunities for modelling psychophysiological phenomena such as sensory attenuation and related failures of gain control, of the sort seen in Parkinson's disease. We also consider the fundamental difference between active inference and optimal control formulations, showing that in the former the heavy lifting shifts from solving a dynamical inverse problem to creating deep forward or generative models with dynamics, whose attracting sets prescribe desired behaviours. PMID:27683002

  18. Angle-domain common-image gathers from anisotropic Gaussian beam migration and its application to anisotropy-induced imaging errors analysis

    Indian Academy of Sciences (India)

    Jianguang Han; Yun Wang; Changqing Yu; Peng Chen

    2017-02-01

    An approach for extracting angle-domain common-image gathers (ADCIGs) from anisotropic Gaussian beam prestack depth migration (GB-PSDM) is presented in this paper. The propagation angle is calculated in the process of migration using the real-value traveltime information of Gaussian beam. Based on the above, we further investigate the effects of anisotropy on GB-PSDM, where the corresponding ADCIGs are extracted to assess the quality of migration images. The test results of the VTI syncline model and the TTI thrust sheet model show that anisotropic parameters ε, δ, and tilt angle θ, have a great influence on the accuracy of the migrated image in anisotropic media, and ignoring any one of them will cause obvious imaging errors. The anisotropic GB-PSDM with the true anisotropic parameters can obtain more accurate seismic images of subsurface structures in anisotropic media.

  19. Angle-domain common-image gathers from anisotropic Gaussian beam migration and its application to anisotropy-induced imaging errors analysis

    Science.gov (United States)

    Han, Jianguang; Wang, Yun; Yu, Changqing; Chen, Peng

    2017-02-01

    An approach for extracting angle-domain common-image gathers (ADCIGs) from anisotropic Gaussian beam prestack depth migration (GB-PSDM) is presented in this paper. The propagation angle is calculated in the process of migration using the real-value traveltime information of Gaussian beam. Based on the above, we further investigate the effects of anisotropy on GB-PSDM, where the corresponding ADCIGs are extracted to assess the quality of migration images. The test results of the VTI syncline model and the TTI thrust sheet model show that anisotropic parameters ɛ, δ, and tilt angle 𝜃, have a great influence on the accuracy of the migrated image in anisotropic media, and ignoring any one of them will cause obvious imaging errors. The anisotropic GB-PSDM with the true anisotropic parameters can obtain more accurate seismic images of subsurface structures in anisotropic media.

  20. Computational Analysis of mRNA Expression Profiles Identifies the ITG Family and PIK3R3 as Crucial Genes for Regulating Triple Negative Breast Cancer Cell Migration

    Directory of Open Access Journals (Sweden)

    Sukhontip Klahan

    2014-01-01

    Full Text Available Triple-negative breast cancer (TNBC is an aggressive type of breast cancer that does not express estrogen receptor (ER, progesterone receptor (PR, and human epidermal growth factor receptor (Her2/neu. TNBC has worse clinical outcomes than other breast cancer subtypes. However, the key molecules and mechanisms of TNBC migration remain unclear. In this study, we compared two normalized microarray datasets from GEO database between Asian (GSE33926 and non-Asian populations (GSE46581 to determine the molecules and common pathways in TNBC migration. We demonstrated that 16 genes in non-Asian samples and 9 genes in Asian samples are related to TNBC migration. In addition, our analytic results showed that 4 genes, PIK3R3, ITGB1, ITGAL, and ITGA6, were involved in the regulation of actin cytoskeleton. Our results indicated potential genes that link to TNBC migration. This study may help identify novel therapeutic targets for drug development in cancer therapy.

  1. Inference of magnetic fields in inhomogeneous prominences

    Science.gov (United States)

    Milić, I.; Faurobert, M.; Atanacković, O.

    2017-01-01

    Context. Most of the quantitative information about the magnetic field vector in solar prominences comes from the analysis of the Hanle effect acting on lines formed by scattering. As these lines can be of non-negligible optical thickness, it is of interest to study the line formation process further. Aims: We investigate the multidimensional effects on the interpretation of spectropolarimetric observations, particularly on the inference of the magnetic field vector. We do this by analyzing the differences between multidimensional models, which involve fully self-consistent radiative transfer computations in the presence of spatial inhomogeneities and velocity fields, and those which rely on simple one-dimensional geometry. Methods: We study the formation of a prototype line in ad hoc inhomogeneous, isothermal 2D prominence models. We solve the NLTE polarized line formation problem in the presence of a large-scale oriented magnetic field. The resulting polarized line profiles are then interpreted (i.e. inverted) assuming a simple 1D slab model. Results: We find that differences between input and the inferred magnetic field vector are non-negligible. Namely, we almost universally find that the inferred field is weaker and more horizontal than the input field. Conclusions: Spatial inhomogeneities and radiative transfer have a strong effect on scattering line polarization in the optically thick lines. In real-life situations, ignoring these effects could lead to a serious misinterpretation of spectropolarimetric observations of chromospheric objects such as prominences.

  2. Inferring sparse networks for noisy transient processes

    Science.gov (United States)

    Tran, Hoang M.; Bukkapatnam, Satish T. S.

    2016-02-01

    Inferring causal structures of real world complex networks from measured time series signals remains an open issue. The current approaches are inadequate to discern between direct versus indirect influences (i.e., the presence or absence of a directed arc connecting two nodes) in the presence of noise, sparse interactions, as well as nonlinear and transient dynamics of real world processes. We report a sparse regression (referred to as the -min) approach with theoretical bounds on the constraints on the allowable perturbation to recover the network structure that guarantees sparsity and robustness to noise. We also introduce averaging and perturbation procedures to further enhance prediction scores (i.e., reduce inference errors), and the numerical stability of -min approach. Extensive investigations have been conducted with multiple benchmark simulated genetic regulatory network and Michaelis-Menten dynamics, as well as real world data sets from DREAM5 challenge. These investigations suggest that our approach can significantly improve, oftentimes by 5 orders of magnitude over the methods reported previously for inferring the structure of dynamic networks, such as Bayesian network, network deconvolution, silencing and modular response analysis methods based on optimizing for sparsity, transients, noise and high dimensionality issues.

  3. Patterns of Avian Migration in California: An Analysis and Comparison of Results from NEXRAD Doppler Weather Radar and Multiple Mist-net Stations

    Science.gov (United States)

    2008-02-01

    KMAX Medford, OR KBHX Eureka, CA KRGX Nixon, NV KBBX Sacramento, CA KDAX Davis, CA KMUX Los Gatos , CA KHNX Hanford, CA KESX Las Vegas, NV...The stations at Medford, OR (KMAX) and Los Gatos , CA (KMUX) both had the highest number of high-level migration densities (3 nights...additionally the Los Gatos station also detected the highest number of medium-level migration densities (26 nights). The Nixon, NV (KRXG) station

  4. Locative inferences in medical texts.

    Science.gov (United States)

    Mayer, P S; Bailey, G H; Mayer, R J; Hillis, A; Dvoracek, J E

    1987-06-01

    Medical research relies on epidemiological studies conducted on a large set of clinical records that have been collected from physicians recording individual patient observations. These clinical records are recorded for the purpose of individual care of the patient with little consideration for their use by a biostatistician interested in studying a disease over a large population. Natural language processing of clinical records for epidemiological studies must deal with temporal, locative, and conceptual issues. This makes text understanding and data extraction of clinical records an excellent area for applied research. While much has been done in making temporal or conceptual inferences in medical texts, parallel work in locative inferences has not been done. This paper examines the locative inferences as well as the integration of temporal, locative, and conceptual issues in the clinical record understanding domain by presenting an application that utilizes two key concepts in its parsing strategy--a knowledge-based parsing strategy and a minimal lexicon.

  5. Sick, the spectroscopic inference crank

    CERN Document Server

    Casey, Andrew R

    2016-01-01

    There exists an inordinate amount of spectral data in both public and private astronomical archives which remain severely under-utilised. The lack of reliable open-source tools for analysing large volumes of spectra contributes to this situation, which is poised to worsen as large surveys successively release orders of magnitude more spectra. In this Article I introduce sick, the spectroscopic inference crank, a flexible and fast Bayesian tool for inferring astrophysical parameters from spectra. sick can be used to provide a nearest-neighbour estimate of model parameters, a numerically optimised point estimate, or full Markov Chain Monte Carlo sampling of the posterior probability distributions. This generality empowers any astronomer to capitalise on the plethora of published synthetic and observed spectra, and make precise inferences for a host of astrophysical (and nuisance) quantities. Model intensities can be reliably approximated from existing grids of synthetic or observed spectra using linear multi-di...

  6. Analysis of oil migration in one and two-stage heat pumps; Analyse de la migration d'huile dans les pompes a chaleur mono- et bi-etagees

    Energy Technology Data Exchange (ETDEWEB)

    Zehnder, M.; Favrat, D.

    2003-07-01

    This final report for the Swiss Federal Office of Energy SFOE describes work done at the Swiss Federal Institute of Technology in Lausanne, Switzerland, as part of the Swiss Retrofit Heat Pump project that examines ways of replacing traditional oil-fired domestic heating systems with heat pumps. The apparatus used to investigate the migration of oil within the refrigeration circuit of a purpose-built air-water heat pump is described. The construction of the heat pump, which could be operated in single or two-stage mode, is described and the results obtained from the investigations are presented. The properties of lubricants used in heat pumps are discussed and the techniques used to measure the oil concentration in the various parts of the refrigeration cycle, which include the use of an infra-red spectrometer, are described.

  7. Do estrogenic compounds in drinking water migrating from plastic pipe distribution system pose adverse effects to human? An analysis of scientific literature.

    Science.gov (United States)

    Liu, Ze-Hua; Yin, Hua; Dang, Zhi

    2017-01-01

    With the widespread application of plastic pipes in drinking water distribution system, the effects of various leachable organic chemicals have been investigated and their occurrence in drinking water supplies is monitored. Most studies focus on the odor problems these substances may cause. This study investigates the potential endocrine disrupting effects of the migrating compound 2,4-di-tert-butylphenol (2,4-d-t-BP). The summarized results show that the migration of 2,4-d-t-BP from plastic pipes could result in chronic exposure and the migration levels varied greatly among different plastic pipe materials and manufacturing brands. Based on estrogen equivalent (EEQ), the migrating levels of the leachable compound 2,4-d-t-BP in most plastic pipes were relative low. However, the EEQ levels in drinking water migrating from four out of 15 pipes may pose significant adverse effects. With the increasingly strict requirements on regulation of drinking water quality, these results indicate that some drinking water transported with plastic pipes may not be safe for human consumption due to the occurrence of 2,4-d-t-BP. Moreover, 2,4-d-t-BP is not the only plastic pipe-migrating estrogenic compound, other compounds such as 2-tert-butylphenol (2-t-BP), 4-tert-butylphenol (4-t-BP), and others may also be leachable from plastic pipes.

  8. Determinants on Rural-Urban Labor Migration in China: Empirical Analysis on the Effect of Rural Cooperate Medical Insurance based on Cross-Sectional and Longitudinal Data%Determinants on Rural-Urban Labor Migration in China: Empirical Analysis on the Effect of Rural Cooperate Medical Insurance based on Cross-Sectional and Longitudinal Data

    Institute of Scientific and Technical Information of China (English)

    Jiang Yong; Hart Xiangyang; Wang Shumei; Jiang Huayun; Wang Shanshan

    2012-01-01

    This paper studies factors influencing rural-urban la- bor migration in China, particularly the implementation of rural cooperative medical insurance (RCMI) in the year 2003. With the support of data analysis from the year 2000, 2004 and 2006, clear linear correlations are found between gender, income, health con- dition and rural-urban labor flow, whereas the impact of education and employment status are more complicated. More importantly, results from regression show that the establishment of RCMI in countryside of China not only inhibits rural residents from seeking employment outside the village, but also pulls back rural people who have already worked in cities. When regional dimension is concerned, the pure composite effect of RCMI on rural labor flow is less significant in coastal areas with better economic perfor- mance and medical service.

  9. Inference of population splits and mixtures from genome-wide allele frequency data.

    Directory of Open Access Journals (Sweden)

    Joseph K Pickrell

    Full Text Available Many aspects of the historical relationships between populations in a species are reflected in genetic data. Inferring these relationships from genetic data, however, remains a challenging task. In this paper, we present a statistical model for inferring the patterns of population splits and mixtures in multiple populations. In our model, the sampled populations in a species are related to their common ancestor through a graph of ancestral populations. Using genome-wide allele frequency data and a Gaussian approximation to genetic drift, we infer the structure of this graph. We applied this method to a set of 55 human populations and a set of 82 dog breeds and wild canids. In both species, we show that a simple bifurcating tree does not fully describe the data; in contrast, we infer many migration events. While some of the migration events that we find have been detected previously, many have not. For example, in the human data, we infer that Cambodians trace approximately 16% of their ancestry to a population ancestral to other extant East Asian populations. In the dog data, we infer that both the boxer and basenji trace a considerable fraction of their ancestry (9% and 25%, respectively to wolves subsequent to domestication and that East Asian toy breeds (the Shih Tzu and the Pekingese result from admixture between modern toy breeds and "ancient" Asian breeds. Software implementing the model described here, called TreeMix, is available at http://treemix.googlecode.com.

  10. Migration og etnicitet

    DEFF Research Database (Denmark)

    Christiansen, Connie Carøe

    2004-01-01

    Migration og etnicitet er aktuelle og forbundne fænomener, idet migration øger berøringsfladerne mellem befolkningsgrupper. Etniciteter formes i takt med at grænser drages imellem disse grupper. Imod moderniserings-teoriernes forventning forsvandt etnicitet ikke som en traditionel eller oprindelig...... måde at skabe tilhørsforhold på; globalt set fremstår vor tid istedet som en "migrationens tidsalder", der tilsyneladende også er en tidsalder, hvor kulturelle særtræk, i form af etnicitet, udgør vigtige linjer, hvorefter grupper skilller sig ud fra hinanden. Både migration og etnicitet bringer fokus...... den finder sted i modtagerlandet, men nyere perspektiver på migration, som begreber om medborgerskab, transnationalisme og diaspora er eksponenter for, søger udover den nationalstatslige ramme og inddrager konsekvenserne af migrationen for afsenderlande....

  11. Global Governance of Migration

    OpenAIRE

    2011-01-01

    The aim of this thesis is to analyze the recently formed global governance of migration, which has got an unprecedented trans-boundary nature due to the impacts og globalization in the post Cold War era. 

  12. Translucent titanium coating altered the composition of focal adhesions and promoted migration of osteoblast-like MG-63 cells on glass.

    Science.gov (United States)

    Ho, Yi; Kok, Sang-Heng; Wang, Juo-Song; Lin, Li-Deh

    2014-04-01

    "TiGlass" was designed and was known to promote initial adhesion and increase migration of rat calvarial osteoblats. In this article, migration study and a series of epifluorescence microscopic studies were conducted to find out the composition of focal adhesion on titanium surface. The translucent titanium surface was applied in random migration analysis and immunofluorescence cell staining. In the immunofluorescent double staining, phosphorylated focal adhesion kinase was tested with vinculin. Various integrin subunits were then tested with vinculin to study the composition of activated focal adhesions. Integrin subunit α5 and αV were tested against β3; integrin subunits α5, αV, β3, and αVβ3 were tested with F-actin, respectively. The MG-63 cells began migration earlier and migrated faster on "TiGlass." Immunofluorescent double staining revealed that all focal adhesion kinase in the focal adhesions were activated on both the surfaces. The osteoblast was inferred to made adhesion to titanium and glass through integrins. The focal adhesions on glass were found to be composed of integrin subunits αV and β3. However, on "TiGlass," integrin subunits α5 might have supplemented the adhesion to titanium. Results from double staining of integrin subunits α5, αV, β3, and αVβ3 with F-actin also supported integrin subunits α5 might have involved in adhesion of titanium.

  13. Sensitivity analysis of the potential impact of discrepancies in stratosphere–troposphere exchange on inferred sources and sinks of CO2

    Directory of Open Access Journals (Sweden)

    F. Deng

    2015-04-01

    Full Text Available The upper troposphere and lower stratosphere (UTLS represents a transition region between the more dynamically active troposphere and more stably stratified stratosphere. The region is characterized by strong gradients in the distribution of long-lived tracers, which are sensitive to discrepancies in transport in models. We evaluate the GEOS-Chem model in the UTLS using carbon dioxide (CO2 and ozone (O3 observations from the HIAPER (The High-Performance Instrumented Airborne Platform for Environmental Research Pole-to-Pole Observations (HIPPO campaign in March 2010. GEOS-Chem CO2 / O3 correlation suggests that there is a discrepancy in mixing across the tropopause in the model, which results in an overestimate of CO2 and an underestimate of O3 in the Arctic lower stratosphere. We assimilate stratospheric O3 data from OSIRIS and used the assimilated O3 fields together with the HIPPO CO2 / O3 correlations to obtain a correction to the modeled CO2 profile in the Arctic UTLS (primarily between the 320 and 360 K isentropic surfaces. The HIPPO-derived correction corresponds to a sink of 0.13 Pg C month−1 in the Arctic. Imposing this sink during March–August 2010 results in a reduction in the CO2 sinks inferred from GOSAT observations for temperate North America, Europe, and tropical Asia of 20, 12, and 50%, respectively. Conversely, the inversion increased the source of CO2 from tropical South America by 20%. We found that the model also underestimated CO2 in the upper tropical and subtropical troposphere, which may be linked by mixing across the subtropical tropopause. Correcting for the bias relative to HIPPO in the tropical upper troposphere, by imposing a source of 0.33 Pg C, led to a reduction in the source from tropical South America by 44%, and produced a flux estimate for tropical Asia that was in agreement with the standard inversion (without the imposed source and sink. However, the seasonal transition from a source to a sink of CO2 for

  14. Perception, illusions and Bayesian inference.

    Science.gov (United States)

    Nour, Matthew M; Nour, Joseph M

    2015-01-01

    Descriptive psychopathology makes a distinction between veridical perception and illusory perception. In both cases a perception is tied to a sensory stimulus, but in illusions the perception is of a false object. This article re-examines this distinction in light of new work in theoretical and computational neurobiology, which views all perception as a form of Bayesian statistical inference that combines sensory signals with prior expectations. Bayesian perceptual inference can solve the 'inverse optics' problem of veridical perception and provides a biologically plausible account of a number of illusory phenomena, suggesting that veridical and illusory perceptions are generated by precisely the same inferential mechanisms.

  15. Automatic Inference of DATR Theories

    CERN Document Server

    Barg, P

    1996-01-01

    This paper presents an approach for the automatic acquisition of linguistic knowledge from unstructured data. The acquired knowledge is represented in the lexical knowledge representation language DATR. A set of transformation rules that establish inheritance relationships and a default-inference algorithm make up the basis components of the system. Since the overall approach is not restricted to a special domain, the heuristic inference strategy uses criteria to evaluate the quality of a DATR theory, where different domains may require different criteria. The system is applied to the linguistic learning task of German noun inflection.

  16. Indonesia's migration transition.

    Science.gov (United States)

    Hugo, G

    1995-01-01

    This article describes population movements in Indonesia in the context of rapid and marked social and economic change. Foreign investment in Indonesia is increasing, and global mass media is available to many households. Agriculture is being commercialized, and structural shifts are occurring in the economy. Educational levels are increasing, and women's role and status are shifting. Population migration has increased over the decades, both short and long distance, permanent and temporary, legal and illegal, and migration to and between urban areas. This article focuses specifically on rural-to-urban migration and international migration. Population settlements are dense in the agriculturally rich inner areas of Java, Bali, and Madura. Although the rate of growth of the gross domestic product was 6.8% annually during 1969-94, the World Bank ranked Indonesia as a low-income economy in 1992 because of the large population size. Income per capita is US $670. Indonesia is becoming a large exporter of labor to the Middle East, particularly women. The predominance of women as overseas contract workers is changing women's role and status in the family and is controversial due to the cases of mistreatment. Malaysia's high economic growth rate of over 8% per year means an additional 1.3 million foreign workers and technicians are needed. During the 1980s urban growth increased at a very rapid rate. Urban growth tended to occur along corridors and major transportation routes around urban areas. It is posited that most of the urban growth is due to rural-to-urban migration. Data limitations prevent an exact determination of the extent of rural-to-urban migration. More women are estimated to be involved in movements to cities during the 1980s compared to the 1970s. Recruiters and middlemen have played an important role in rural-to-urban migration and international migration.

  17. Astrocytes in Migration.

    Science.gov (United States)

    Zhan, Jiang Shan; Gao, Kai; Chai, Rui Chao; Jia, Xi Hua; Luo, Dao Peng; Ge, Guo; Jiang, Yu Wu; Fung, Yin-Wan Wendy; Li, Lina; Yu, Albert Cheung Hoi

    2017-01-01

    Cell migration is a fundamental phenomenon that underlies tissue morphogenesis, wound healing, immune response, and cancer metastasis. Great progresses have been made in research methodologies, with cell migration identified as a highly orchestrated process. Brain is considered the most complex organ in the human body, containing many types of neural cells with astrocytes playing crucial roles in monitoring normal functions of the central nervous system. Astrocytes are mostly quiescent under normal physiological conditions in the adult brain but become migratory after injury. Under most known pathological conditions in the brain, spinal cord and retina, astrocytes are activated and become hypertrophic, hyperplastic, and up-regulating GFAP based on the grades of severity. These three observations are the hallmark in glia scar formation-astrogliosis. The reactivation process is initiated with structural changes involving cell process migration and ended with cell migration. Detailed mechanisms in astrocyte migration have not been studied extensively and remain largely unknown. Here, we therefore attempt to review the mechanisms in migration of astrocytes.

  18. Migration of the model HCR to the SAIC/TRC in the analysis of human reliability of the APS de CN Vandellos II; Migracion del modelo HCR al SAIC/TRC en el analisis de fiabilidad humana del APS de CN Vandellos II

    Energy Technology Data Exchange (ETDEWEB)

    Nos, V.; Rosa, J. C. de la; Hernandez, H.

    2011-07-01

    This paper describes the systematics of adaptation and conversion of models, to migrate the detailed analysis of human actions from the APS (in operation at power) of NPP Vandellos, which uses the HCR to SAIC-CRT model. Are offered the results achieved after the migration and the main conclusions.

  19. Migration in Vulnerable Deltas: A Research Strategy

    Science.gov (United States)

    Hutton, C.; Nicholls, R. J.; Allan, A.

    2015-12-01

    C. Hutton1, & R. J. Nicholls1, , 1 University of Southampton, University Road, Southampton, Hampshire, United Kingdom, SO17 1BJ. cwh@geodata. soton.ac.ukAbstractGlobally, deltas contain 500 million people and with rising sea levels often linked to large number of forced migrants are expected in the coming century. However, migration is already a major process in deltas, such as the growth of major cities such as Dhaka and Kolkata. Climate and environmental change interacts with a range of catchment and delta level drivers, which encompass a nexus of sea-level rise, storms, freshwater and sediment supply from the catchment, land degradation, subsidence, agricultural loss and socio-economic stresses. DECCMA (Deltas, Vulnerability and Climate Change: Migration and Adaptation/CARRIA) is investigating migration in the Ganges-Brahmaputra-Meghna (GBM), Mahanadi and Volta Deltas, including the influence of climate change. The research will explore migration from a range of perspectives including governance and stakeholder analysis, demographic analysis, household surveys of sending and receiving areas, macro-economic analysis, and hazards and hotspot analysis both historically and into the future. Migration under climate change will depend on other adaptation in the deltas and this will be examined. Collectively, integrated analysis will be developed to examine migration, other adaptation and development pathways with a particular focus on the implications for the poorest. This will require the development of input scenarios, including expert-derived exogenous scenarios (e.g., climate change) and endogenous scenarios of the delta developed in a participatory manner. This applied research will facilitate decision support methods for the development of deltas under climate change, with a focus on migration and other adaptation strategies.

  20. Service Migration Protocol for NFC Links

    DEFF Research Database (Denmark)

    Nickelsen, Anders; Schwefel, Hans-Peter; Martin, Miquel

    2010-01-01

    of use while preserving state. This paper focuses on the scenario of migration between two devices in which the actual migration procedure is executed over near-field communication (NFC) ad-hoc links. The NFC link is interesting as it gives the user the perception of trust and enables service continuity...... in cases where mid- or long-range wireless connectivity is unavailable. Based on an experimental performance analysis of a specific NFC platform, the paper presents a migration orchestration protocol with low overhead and low delays to be used with NFC links. Experimental results allow to conclude...... on the sizes of application state that can be expected to be feasible for such ad-hoc NFC migration....