Seeking parsimony in hydrology and water resources technology

Science.gov (United States)

Koutsoyiannis, D.

2009-04-01

The principle of parsimony, also known as the principle of simplicity, the principle of economy and Ockham's razor, advises scientists to prefer the simplest theory among those that fit the data equally well. In this, it is an epistemic principle but reflects an ontological characterization that the universe is ultimately parsimonious. Is this principle useful and can it really be reconciled with, and implemented to, our modelling approaches of complex hydrological systems, whose elements and events are extraordinarily numerous, different and unique? The answer underlying the mainstream hydrological research of the last two decades seems to be negative. Hopes were invested to the power of computers that would enable faithful and detailed representation of the diverse system elements and the hydrological processes, based on merely "first principles" and resulting in "physically-based" models that tend to approach in complexity the real world systems. Today the account of such research endeavour seems not positive, as it did not improve model predictive capacity and processes comprehension. A return to parsimonious modelling seems to be again the promising route. The experience from recent research and from comparisons of parsimonious and complicated models indicates that the former can facilitate insight and comprehension, improve accuracy and predictive capacity, and increase efficiency. In addition - and despite aspiration that "physically based" models will have lower data requirements and, even, they ultimately become "data-free" - parsimonious models require fewer data to achieve the same accuracy with more complicated models. Naturally, the concepts that reconcile the simplicity of parsimonious models with the complexity of hydrological systems are probability theory and statistics. Probability theory provides the theoretical basis for moving from a microscopic to a macroscopic view of phenomena, by mapping sets of diverse elements and events of hydrological

Parsimonious Refraction Interferometry and Tomography

KAUST Repository

Hanafy, Sherif; Schuster, Gerard T.

2017-01-01

We present parsimonious refraction interferometry and tomography where a densely populated refraction data set can be obtained from two reciprocal and several infill shot gathers. The assumptions are that the refraction arrivals are head waves

Direct maximum parsimony phylogeny reconstruction from genotype data

OpenAIRE

Sridhar, Srinath; Lam, Fumei; Blelloch, Guy E; Ravi, R; Schwartz, Russell

2007-01-01

Abstract Background Maximum parsimony phylogenetic tree reconstruction from genetic variation data is a fundamental problem in computational genetics with many practical applications in population genetics, whole genome analysis, and the search for genetic predictors of disease. Efficient methods are available for reconstruction of maximum parsimony trees from haplotype data, but such data are difficult to determine directly for autosomal DNA. Data more commonly is available in the form of ge...

Phylogenetic paleobiogeography of Late Ordovician Laurentian brachiopods

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Jennifer E. Bauer

2014-12-01

Full Text Available Phylogenetic biogeographic analysis of four brachiopod genera was used to uncover large-scale geologic drivers of Late Ordovician biogeographic differentiation in Laurentia. Previously generated phylogenetic hypotheses were converted into area cladograms, ancestral geographic ranges were optimized and speciation events characterized as via dispersal or vicariance, when possible. Area relationships were reconstructed using Lieberman-modified Brooks Parsimony Analysis. The resulting area cladograms indicate tectonic and oceanographic changes were the primary geologic drivers of biogeographic patterns within the focal taxa. The Taconic tectophase contributed to the separation of the Appalachian and Central basins as well as the two midcontinent basins, whereas sea level rise following the Boda Event promoted interbasinal dispersal. Three migration pathways into the Cincinnati Basin were recognized, which supports the multiple pathway hypothesis for the Richmondian Invasion.

Parsimonious Refraction Interferometry and Tomography

KAUST Repository

Hanafy, Sherif

2017-02-04

We present parsimonious refraction interferometry and tomography where a densely populated refraction data set can be obtained from two reciprocal and several infill shot gathers. The assumptions are that the refraction arrivals are head waves, and a pair of reciprocal shot gathers and several infill shot gathers are recorded over the line of interest. Refraction traveltimes from these shot gathers are picked and spawned into O(N2) virtual refraction traveltimes generated by N virtual sources, where N is the number of geophones in the 2D survey. The virtual traveltimes can be inverted to give the velocity tomogram. This enormous increase in the number of traveltime picks and associated rays, compared to the many fewer traveltimes from the reciprocal and infill shot gathers, allows for increased model resolution and a better condition number with the system of normal equations. A significant benefit is that the parsimonious survey and the associated traveltime picking is far less time consuming than that for a standard refraction survey with a dense distribution of sources.

Direct maximum parsimony phylogeny reconstruction from genotype data.

Science.gov (United States)

Sridhar, Srinath; Lam, Fumei; Blelloch, Guy E; Ravi, R; Schwartz, Russell

2007-12-05

Maximum parsimony phylogenetic tree reconstruction from genetic variation data is a fundamental problem in computational genetics with many practical applications in population genetics, whole genome analysis, and the search for genetic predictors of disease. Efficient methods are available for reconstruction of maximum parsimony trees from haplotype data, but such data are difficult to determine directly for autosomal DNA. Data more commonly is available in the form of genotypes, which consist of conflated combinations of pairs of haplotypes from homologous chromosomes. Currently, there are no general algorithms for the direct reconstruction of maximum parsimony phylogenies from genotype data. Hence phylogenetic applications for autosomal data must therefore rely on other methods for first computationally inferring haplotypes from genotypes. In this work, we develop the first practical method for computing maximum parsimony phylogenies directly from genotype data. We show that the standard practice of first inferring haplotypes from genotypes and then reconstructing a phylogeny on the haplotypes often substantially overestimates phylogeny size. As an immediate application, our method can be used to determine the minimum number of mutations required to explain a given set of observed genotypes. Phylogeny reconstruction directly from unphased data is computationally feasible for moderate-sized problem instances and can lead to substantially more accurate tree size inferences than the standard practice of treating phasing and phylogeny construction as two separate analysis stages. The difference between the approaches is particularly important for downstream applications that require a lower-bound on the number of mutations that the genetic region has undergone.

Direct maximum parsimony phylogeny reconstruction from genotype data

Directory of Open Access Journals (Sweden)

Ravi R

2007-12-01

Full Text Available Abstract Background Maximum parsimony phylogenetic tree reconstruction from genetic variation data is a fundamental problem in computational genetics with many practical applications in population genetics, whole genome analysis, and the search for genetic predictors of disease. Efficient methods are available for reconstruction of maximum parsimony trees from haplotype data, but such data are difficult to determine directly for autosomal DNA. Data more commonly is available in the form of genotypes, which consist of conflated combinations of pairs of haplotypes from homologous chromosomes. Currently, there are no general algorithms for the direct reconstruction of maximum parsimony phylogenies from genotype data. Hence phylogenetic applications for autosomal data must therefore rely on other methods for first computationally inferring haplotypes from genotypes. Results In this work, we develop the first practical method for computing maximum parsimony phylogenies directly from genotype data. We show that the standard practice of first inferring haplotypes from genotypes and then reconstructing a phylogeny on the haplotypes often substantially overestimates phylogeny size. As an immediate application, our method can be used to determine the minimum number of mutations required to explain a given set of observed genotypes. Conclusion Phylogeny reconstruction directly from unphased data is computationally feasible for moderate-sized problem instances and can lead to substantially more accurate tree size inferences than the standard practice of treating phasing and phylogeny construction as two separate analysis stages. The difference between the approaches is particularly important for downstream applications that require a lower-bound on the number of mutations that the genetic region has undergone.

The worst case complexity of maximum parsimony.

Science.gov (United States)

Carmel, Amir; Musa-Lempel, Noa; Tsur, Dekel; Ziv-Ukelson, Michal

2014-11-01

One of the core classical problems in computational biology is that of constructing the most parsimonious phylogenetic tree interpreting an input set of sequences from the genomes of evolutionarily related organisms. We reexamine the classical maximum parsimony (MP) optimization problem for the general (asymmetric) scoring matrix case, where rooted phylogenies are implied, and analyze the worst case bounds of three approaches to MP: The approach of Cavalli-Sforza and Edwards, the approach of Hendy and Penny, and a new agglomerative, "bottom-up" approach we present in this article. We show that the second and third approaches are faster than the first one by a factor of Θ(√n) and Θ(n), respectively, where n is the number of species.

Maximum parsimony on subsets of taxa.

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Fischer, Mareike; Thatte, Bhalchandra D

2009-09-21

In this paper we investigate mathematical questions concerning the reliability (reconstruction accuracy) of Fitch's maximum parsimony algorithm for reconstructing the ancestral state given a phylogenetic tree and a character. In particular, we consider the question whether the maximum parsimony method applied to a subset of taxa can reconstruct the ancestral state of the root more accurately than when applied to all taxa, and we give an example showing that this indeed is possible. A surprising feature of our example is that ignoring a taxon closer to the root improves the reliability of the method. On the other hand, in the case of the two-state symmetric substitution model, we answer affirmatively a conjecture of Li, Steel and Zhang which states that under a molecular clock the probability that the state at a single taxon is a correct guess of the ancestral state is a lower bound on the reconstruction accuracy of Fitch's method applied to all taxa.

MPBoot: fast phylogenetic maximum parsimony tree inference and bootstrap approximation.

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Hoang, Diep Thi; Vinh, Le Sy; Flouri, Tomáš; Stamatakis, Alexandros; von Haeseler, Arndt; Minh, Bui Quang

2018-02-02

The nonparametric bootstrap is widely used to measure the branch support of phylogenetic trees. However, bootstrapping is computationally expensive and remains a bottleneck in phylogenetic analyses. Recently, an ultrafast bootstrap approximation (UFBoot) approach was proposed for maximum likelihood analyses. However, such an approach is still missing for maximum parsimony. To close this gap we present MPBoot, an adaptation and extension of UFBoot to compute branch supports under the maximum parsimony principle. MPBoot works for both uniform and non-uniform cost matrices. Our analyses on biological DNA and protein showed that under uniform cost matrices, MPBoot runs on average 4.7 (DNA) to 7 times (protein data) (range: 1.2-20.7) faster than the standard parsimony bootstrap implemented in PAUP*; but 1.6 (DNA) to 4.1 times (protein data) slower than the standard bootstrap with a fast search routine in TNT (fast-TNT). However, for non-uniform cost matrices MPBoot is 5 (DNA) to 13 times (protein data) (range:0.3-63.9) faster than fast-TNT. We note that MPBoot achieves better scores more frequently than PAUP* and fast-TNT. However, this effect is less pronounced if an intensive but slower search in TNT is invoked. Moreover, experiments on large-scale simulated data show that while both PAUP* and TNT bootstrap estimates are too conservative, MPBoot bootstrap estimates appear more unbiased. MPBoot provides an efficient alternative to the standard maximum parsimony bootstrap procedure. It shows favorable performance in terms of run time, the capability of finding a maximum parsimony tree, and high bootstrap accuracy on simulated as well as empirical data sets. MPBoot is easy-to-use, open-source and available at http://www.cibiv.at/software/mpboot .

Fast Construction of Near Parsimonious Hybridization Networks for Multiple Phylogenetic Trees.

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Mirzaei, Sajad; Wu, Yufeng

2016-01-01

Hybridization networks represent plausible evolutionary histories of species that are affected by reticulate evolutionary processes. An established computational problem on hybridization networks is constructing the most parsimonious hybridization network such that each of the given phylogenetic trees (called gene trees) is "displayed" in the network. There have been several previous approaches, including an exact method and several heuristics, for this NP-hard problem. However, the exact method is only applicable to a limited range of data, and heuristic methods can be less accurate and also slow sometimes. In this paper, we develop a new algorithm for constructing near parsimonious networks for multiple binary gene trees. This method is more efficient for large numbers of gene trees than previous heuristics. This new method also produces more parsimonious results on many simulated datasets as well as a real biological dataset than a previous method. We also show that our method produces topologically more accurate networks for many datasets.

Parsimonious refraction interferometry

KAUST Repository

Hanafy, Sherif

2016-09-06

We present parsimonious refraction interferometry where a densely populated refraction data set can be obtained from just two shot gathers. The assumptions are that the first arrivals are comprised of head waves and direct waves, and a pair of reciprocal shot gathers is recorded over the line of interest. The refraction traveltimes from these reciprocal shot gathers can be picked and decomposed into O(N2) refraction traveltimes generated by N virtual sources, where N is the number of geophones in the 2D survey. This enormous increase in the number of virtual traveltime picks and associated rays, compared to the 2N traveltimes from the two reciprocal shot gathers, allows for increased model resolution and better condition numbers in the normal equations. Also, a reciprocal survey is far less time consuming than a standard refraction survey with a dense distribution of sources.

Parsimonious refraction interferometry

KAUST Repository

Hanafy, Sherif; Schuster, Gerard T.

2016-01-01

We present parsimonious refraction interferometry where a densely populated refraction data set can be obtained from just two shot gathers. The assumptions are that the first arrivals are comprised of head waves and direct waves, and a pair of reciprocal shot gathers is recorded over the line of interest. The refraction traveltimes from these reciprocal shot gathers can be picked and decomposed into O(N2) refraction traveltimes generated by N virtual sources, where N is the number of geophones in the 2D survey. This enormous increase in the number of virtual traveltime picks and associated rays, compared to the 2N traveltimes from the two reciprocal shot gathers, allows for increased model resolution and better condition numbers in the normal equations. Also, a reciprocal survey is far less time consuming than a standard refraction survey with a dense distribution of sources.

A simplified parsimonious higher order multivariate Markov chain model

Science.gov (United States)

Wang, Chao; Yang, Chuan-sheng

2017-09-01

In this paper, a simplified parsimonious higher-order multivariate Markov chain model (SPHOMMCM) is presented. Moreover, parameter estimation method of TPHOMMCM is give. Numerical experiments shows the effectiveness of TPHOMMCM.

Efficient parsimony-based methods for phylogenetic network reconstruction.

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Jin, Guohua; Nakhleh, Luay; Snir, Sagi; Tuller, Tamir

2007-01-15

Phylogenies--the evolutionary histories of groups of organisms-play a major role in representing relationships among biological entities. Although many biological processes can be effectively modeled as tree-like relationships, others, such as hybrid speciation and horizontal gene transfer (HGT), result in networks, rather than trees, of relationships. Hybrid speciation is a significant evolutionary mechanism in plants, fish and other groups of species. HGT plays a major role in bacterial genome diversification and is a significant mechanism by which bacteria develop resistance to antibiotics. Maximum parsimony is one of the most commonly used criteria for phylogenetic tree inference. Roughly speaking, inference based on this criterion seeks the tree that minimizes the amount of evolution. In 1990, Jotun Hein proposed using this criterion for inferring the evolution of sequences subject to recombination. Preliminary results on small synthetic datasets. Nakhleh et al. (2005) demonstrated the criterion's application to phylogenetic network reconstruction in general and HGT detection in particular. However, the naive algorithms used by the authors are inapplicable to large datasets due to their demanding computational requirements. Further, no rigorous theoretical analysis of computing the criterion was given, nor was it tested on biological data. In the present work we prove that the problem of scoring the parsimony of a phylogenetic network is NP-hard and provide an improved fixed parameter tractable algorithm for it. Further, we devise efficient heuristics for parsimony-based reconstruction of phylogenetic networks. We test our methods on both synthetic and biological data (rbcL gene in bacteria) and obtain very promising results.

A tridiagonal parsimonious higher order multivariate Markov chain model

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Wang, Chao; Yang, Chuan-sheng

2017-09-01

In this paper, we present a tridiagonal parsimonious higher-order multivariate Markov chain model (TPHOMMCM). Moreover, estimation method of the parameters in TPHOMMCM is give. Numerical experiments illustrate the effectiveness of TPHOMMCM.

Bootstrap-based Support of HGT Inferred by Maximum Parsimony

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Nakhleh Luay

2010-05-01

Full Text Available Abstract Background Maximum parsimony is one of the most commonly used criteria for reconstructing phylogenetic trees. Recently, Nakhleh and co-workers extended this criterion to enable reconstruction of phylogenetic networks, and demonstrated its application to detecting reticulate evolutionary relationships. However, one of the major problems with this extension has been that it favors more complex evolutionary relationships over simpler ones, thus having the potential for overestimating the amount of reticulation in the data. An ad hoc solution to this problem that has been used entails inspecting the improvement in the parsimony length as more reticulation events are added to the model, and stopping when the improvement is below a certain threshold. Results In this paper, we address this problem in a more systematic way, by proposing a nonparametric bootstrap-based measure of support of inferred reticulation events, and using it to determine the number of those events, as well as their placements. A number of samples is generated from the given sequence alignment, and reticulation events are inferred based on each sample. Finally, the support of each reticulation event is quantified based on the inferences made over all samples. Conclusions We have implemented our method in the NEPAL software tool (available publicly at http://bioinfo.cs.rice.edu/, and studied its performance on both biological and simulated data sets. While our studies show very promising results, they also highlight issues that are inherently challenging when applying the maximum parsimony criterion to detect reticulate evolution.

Bootstrap-based support of HGT inferred by maximum parsimony.

Science.gov (United States)

Park, Hyun Jung; Jin, Guohua; Nakhleh, Luay

2010-05-05

Maximum parsimony is one of the most commonly used criteria for reconstructing phylogenetic trees. Recently, Nakhleh and co-workers extended this criterion to enable reconstruction of phylogenetic networks, and demonstrated its application to detecting reticulate evolutionary relationships. However, one of the major problems with this extension has been that it favors more complex evolutionary relationships over simpler ones, thus having the potential for overestimating the amount of reticulation in the data. An ad hoc solution to this problem that has been used entails inspecting the improvement in the parsimony length as more reticulation events are added to the model, and stopping when the improvement is below a certain threshold. In this paper, we address this problem in a more systematic way, by proposing a nonparametric bootstrap-based measure of support of inferred reticulation events, and using it to determine the number of those events, as well as their placements. A number of samples is generated from the given sequence alignment, and reticulation events are inferred based on each sample. Finally, the support of each reticulation event is quantified based on the inferences made over all samples. We have implemented our method in the NEPAL software tool (available publicly at http://bioinfo.cs.rice.edu/), and studied its performance on both biological and simulated data sets. While our studies show very promising results, they also highlight issues that are inherently challenging when applying the maximum parsimony criterion to detect reticulate evolution.

Principle of Parsimony, Fake Science, and Scales

Science.gov (United States)

Yeh, T. C. J.; Wan, L.; Wang, X. S.

2017-12-01

Considering difficulties in predicting exact motions of water molecules, and the scale of our interests (bulk behaviors of many molecules), Fick's law (diffusion concept) has been created to predict solute diffusion process in space and time. G.I. Taylor (1921) demonstrated that random motion of the molecules reach the Fickian regime in less a second if our sampling scale is large enough to reach ergodic condition. Fick's law is widely accepted for describing molecular diffusion as such. This fits the definition of the parsimony principle at the scale of our concern. Similarly, advection-dispersion or convection-dispersion equation (ADE or CDE) has been found quite satisfactory for analysis of concentration breakthroughs of solute transport in uniformly packed soil columns. This is attributed to the solute is often released over the entire cross-section of the column, which has sampled many pore-scale heterogeneities and met the ergodicity assumption. Further, the uniformly packed column contains a large number of stationary pore-size heterogeneity. The solute thus reaches the Fickian regime after traveling a short distance along the column. Moreover, breakthrough curves are concentrations integrated over the column cross-section (the scale of our interest), and they meet the ergodicity assumption embedded in the ADE and CDE. To the contrary, scales of heterogeneity in most groundwater pollution problems evolve as contaminants travel. They are much larger than the scale of our observations and our interests so that the ergodic and the Fickian conditions are difficult. Upscaling the Fick's law for solution dispersion, and deriving universal rules of the dispersion to the field- or basin-scale pollution migrations are merely misuse of the parsimony principle and lead to a fake science ( i.e., the development of theories for predicting processes that can not be observed.) The appropriate principle of parsimony for these situations dictates mapping of large

Parsimonious wave-equation travel-time inversion for refraction waves

KAUST Repository

Fu, Lei; Hanafy, Sherif M.; Schuster, Gerard T.

2017-01-01

We present a parsimonious wave-equation travel-time inversion technique for refraction waves. A dense virtual refraction dataset can be generated from just two reciprocal shot gathers for the sources at the endpoints of the survey line, with N

Análise cladística de Euprepina Hull (Diptera, Bombyliidae, Bombyliinae Cladistic analysis of Euprepina Hull, (Diptera, Bombyliidae, Bombyliinae

Directory of Open Access Journals (Sweden)

Carlos José Einicker Lamas

1999-01-01

Full Text Available A cladistic analysis of Euprepina Hull, 1971 (Diptera, Bombyliidae, Bombyliinae, a Neotropical genus that includes ten species, was made. The cladogram was obtained from eight studied species, based on a data matrix with 21 characters, using the program Hennig86. Character states were polarized following outgroup analysis, and an hypothetical ancestor was included in the analysis in order to root the tree. The options used, "ie*" and "xs w", resulted in four most parsimonious trees with ci = 79, ri = 80 and length 115. The monophiletism of Euprepina was supported by two synapomorphies.

A class representative model for Pure Parsimony Haplotyping under uncertain data.

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Daniele Catanzaro

Full Text Available The Pure Parsimony Haplotyping (PPH problem is a NP-hard combinatorial optimization problem that consists of finding the minimum number of haplotypes necessary to explain a given set of genotypes. PPH has attracted more and more attention in recent years due to its importance in analysis of many fine-scale genetic data. Its application fields range from mapping complex disease genes to inferring population histories, passing through designing drugs, functional genomics and pharmacogenetics. In this article we investigate, for the first time, a recent version of PPH called the Pure Parsimony Haplotype problem under Uncertain Data (PPH-UD. This version mainly arises when the input genotypes are not accurate, i.e., when some single nucleotide polymorphisms are missing or affected by errors. We propose an exact approach to solution of PPH-UD based on an extended version of Catanzaro et al.[1] class representative model for PPH, currently the state-of-the-art integer programming model for PPH. The model is efficient, accurate, compact, polynomial-sized, easy to implement, solvable with any solver for mixed integer programming, and usable in all those cases for which the parsimony criterion is well suited for haplotype estimation.

Ancestral sequence reconstruction with Maximum Parsimony

OpenAIRE

Herbst, Lina; Fischer, Mareike

2017-01-01

One of the main aims in phylogenetics is the estimation of ancestral sequences based on present-day data like, for instance, DNA alignments. One way to estimate the data of the last common ancestor of a given set of species is to first reconstruct a phylogenetic tree with some tree inference method and then to use some method of ancestral state inference based on that tree. One of the best-known methods both for tree inference as well as for ancestral sequence inference is Maximum Parsimony (...

Parsimonious wave-equation travel-time inversion for refraction waves

KAUST Repository

Fu, Lei

2017-02-14

We present a parsimonious wave-equation travel-time inversion technique for refraction waves. A dense virtual refraction dataset can be generated from just two reciprocal shot gathers for the sources at the endpoints of the survey line, with N geophones evenly deployed along the line. These two reciprocal shots contain approximately 2N refraction travel times, which can be spawned into O(N2) refraction travel times by an interferometric transformation. Then, these virtual refraction travel times are used with a source wavelet to create N virtual refraction shot gathers, which are the input data for wave-equation travel-time inversion. Numerical results show that the parsimonious wave-equation travel-time tomogram has about the same accuracy as the tomogram computed by standard wave-equation travel-time inversion. The most significant benefit is that a reciprocal survey is far less time consuming than the standard refraction survey where a source is excited at each geophone location.

Bayesian methods outperform parsimony but at the expense of precision in the estimation of phylogeny from discrete morphological data.

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O'Reilly, Joseph E; Puttick, Mark N; Parry, Luke; Tanner, Alastair R; Tarver, James E; Fleming, James; Pisani, Davide; Donoghue, Philip C J

2016-04-01

Different analytical methods can yield competing interpretations of evolutionary history and, currently, there is no definitive method for phylogenetic reconstruction using morphological data. Parsimony has been the primary method for analysing morphological data, but there has been a resurgence of interest in the likelihood-based Mk-model. Here, we test the performance of the Bayesian implementation of the Mk-model relative to both equal and implied-weight implementations of parsimony. Using simulated morphological data, we demonstrate that the Mk-model outperforms equal-weights parsimony in terms of topological accuracy, and implied-weights performs the most poorly. However, the Mk-model produces phylogenies that have less resolution than parsimony methods. This difference in the accuracy and precision of parsimony and Bayesian approaches to topology estimation needs to be considered when selecting a method for phylogeny reconstruction. © 2016 The Authors.

Phylogenetic analysis using parsimony and likelihood methods.

Science.gov (United States)

Yang, Z

1996-02-01

The assumptions underlying the maximum-parsimony (MP) method of phylogenetic tree reconstruction were intuitively examined by studying the way the method works. Computer simulations were performed to corroborate the intuitive examination. Parsimony appears to involve very stringent assumptions concerning the process of sequence evolution, such as constancy of substitution rates between nucleotides, constancy of rates across nucleotide sites, and equal branch lengths in the tree. For practical data analysis, the requirement of equal branch lengths means similar substitution rates among lineages (the existence of an approximate molecular clock), relatively long interior branches, and also few species in the data. However, a small amount of evolution is neither a necessary nor a sufficient requirement of the method. The difficulties involved in the application of current statistical estimation theory to tree reconstruction were discussed, and it was suggested that the approach proposed by Felsenstein (1981, J. Mol. Evol. 17: 368-376) for topology estimation, as well as its many variations and extensions, differs fundamentally from the maximum likelihood estimation of a conventional statistical parameter. Evidence was presented showing that the Felsenstein approach does not share the asymptotic efficiency of the maximum likelihood estimator of a statistical parameter. Computer simulations were performed to study the probability that MP recovers the true tree under a hierarchy of models of nucleotide substitution; its performance relative to the likelihood method was especially noted. The results appeared to support the intuitive examination of the assumptions underlying MP. When a simple model of nucleotide substitution was assumed to generate data, the probability that MP recovers the true topology could be as high as, or even higher than, that for the likelihood method. When the assumed model became more complex and realistic, e.g., when substitution rates were

Live phylogeny with polytomies: Finding the most compact parsimonious trees.

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Papamichail, D; Huang, A; Kennedy, E; Ott, J-L; Miller, A; Papamichail, G

2017-08-01

Construction of phylogenetic trees has traditionally focused on binary trees where all species appear on leaves, a problem for which numerous efficient solutions have been developed. Certain application domains though, such as viral evolution and transmission, paleontology, linguistics, and phylogenetic stemmatics, often require phylogeny inference that involves placing input species on ancestral tree nodes (live phylogeny), and polytomies. These requirements, despite their prevalence, lead to computationally harder algorithmic solutions and have been sparsely examined in the literature to date. In this article we prove some unique properties of most parsimonious live phylogenetic trees with polytomies, and their mapping to traditional binary phylogenetic trees. We show that our problem reduces to finding the most compact parsimonious tree for n species, and describe a novel efficient algorithm to find such trees without resorting to exhaustive enumeration of all possible tree topologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Approximate maximum parsimony and ancestral maximum likelihood.

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Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

2010-01-01

We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

PTree: pattern-based, stochastic search for maximum parsimony phylogenies

OpenAIRE

Gregor, Ivan; Steinbr?ck, Lars; McHardy, Alice C.

2013-01-01

Phylogenetic reconstruction is vital to analyzing the evolutionary relationship of genes within and across populations of different species. Nowadays, with next generation sequencing technologies producing sets comprising thousands of sequences, robust identification of the tree topology, which is optimal according to standard criteria such as maximum parsimony, maximum likelihood or posterior probability, with phylogenetic inference methods is a computationally very demanding task. Here, we ...

Time-Lapse Monitoring of Subsurface Fluid Flow using Parsimonious Seismic Interferometry

KAUST Repository

Hanafy, Sherif; Li, Jing; Schuster, Gerard T.

2017-01-01

of parsimonious seismic interferometry with the time-lapse mentoring idea with field examples, where we were able to record 30 different data sets within a 2-hour period. The recorded data are then processed to generate 30 snapshots that shows the spread of water

DupTree: a program for large-scale phylogenetic analyses using gene tree parsimony.

Science.gov (United States)

Wehe, André; Bansal, Mukul S; Burleigh, J Gordon; Eulenstein, Oliver

2008-07-01

DupTree is a new software program for inferring rooted species trees from collections of gene trees using the gene tree parsimony approach. The program implements a novel algorithm that significantly improves upon the run time of standard search heuristics for gene tree parsimony, and enables the first truly genome-scale phylogenetic analyses. In addition, DupTree allows users to examine alternate rootings and to weight the reconciliation costs for gene trees. DupTree is an open source project written in C++. DupTree for Mac OS X, Windows, and Linux along with a sample dataset and an on-line manual are available at http://genome.cs.iastate.edu/CBL/DupTree

PTree: pattern-based, stochastic search for maximum parsimony phylogenies

Directory of Open Access Journals (Sweden)

Ivan Gregor

2013-06-01

Full Text Available Phylogenetic reconstruction is vital to analyzing the evolutionary relationship of genes within and across populations of different species. Nowadays, with next generation sequencing technologies producing sets comprising thousands of sequences, robust identification of the tree topology, which is optimal according to standard criteria such as maximum parsimony, maximum likelihood or posterior probability, with phylogenetic inference methods is a computationally very demanding task. Here, we describe a stochastic search method for a maximum parsimony tree, implemented in a software package we named PTree. Our method is based on a new pattern-based technique that enables us to infer intermediate sequences efficiently where the incorporation of these sequences in the current tree topology yields a phylogenetic tree with a lower cost. Evaluation across multiple datasets showed that our method is comparable to the algorithms implemented in PAUP* or TNT, which are widely used by the bioinformatics community, in terms of topological accuracy and runtime. We show that our method can process large-scale datasets of 1,000–8,000 sequences. We believe that our novel pattern-based method enriches the current set of tools and methods for phylogenetic tree inference. The software is available under: http://algbio.cs.uni-duesseldorf.de/webapps/wa-download/.

Mixed integer linear programming for maximum-parsimony phylogeny inference.

Science.gov (United States)

Sridhar, Srinath; Lam, Fumei; Blelloch, Guy E; Ravi, R; Schwartz, Russell

2008-01-01

Reconstruction of phylogenetic trees is a fundamental problem in computational biology. While excellent heuristic methods are available for many variants of this problem, new advances in phylogeny inference will be required if we are to be able to continue to make effective use of the rapidly growing stores of variation data now being gathered. In this paper, we present two integer linear programming (ILP) formulations to find the most parsimonious phylogenetic tree from a set of binary variation data. One method uses a flow-based formulation that can produce exponential numbers of variables and constraints in the worst case. The method has, however, proven extremely efficient in practice on datasets that are well beyond the reach of the available provably efficient methods, solving several large mtDNA and Y-chromosome instances within a few seconds and giving provably optimal results in times competitive with fast heuristics than cannot guarantee optimality. An alternative formulation establishes that the problem can be solved with a polynomial-sized ILP. We further present a web server developed based on the exponential-sized ILP that performs fast maximum parsimony inferences and serves as a front end to a database of precomputed phylogenies spanning the human genome.

PTree: pattern-based, stochastic search for maximum parsimony phylogenies.

Science.gov (United States)

Gregor, Ivan; Steinbrück, Lars; McHardy, Alice C

2013-01-01

Phylogenetic reconstruction is vital to analyzing the evolutionary relationship of genes within and across populations of different species. Nowadays, with next generation sequencing technologies producing sets comprising thousands of sequences, robust identification of the tree topology, which is optimal according to standard criteria such as maximum parsimony, maximum likelihood or posterior probability, with phylogenetic inference methods is a computationally very demanding task. Here, we describe a stochastic search method for a maximum parsimony tree, implemented in a software package we named PTree. Our method is based on a new pattern-based technique that enables us to infer intermediate sequences efficiently where the incorporation of these sequences in the current tree topology yields a phylogenetic tree with a lower cost. Evaluation across multiple datasets showed that our method is comparable to the algorithms implemented in PAUP* or TNT, which are widely used by the bioinformatics community, in terms of topological accuracy and runtime. We show that our method can process large-scale datasets of 1,000-8,000 sequences. We believe that our novel pattern-based method enriches the current set of tools and methods for phylogenetic tree inference. The software is available under: http://algbio.cs.uni-duesseldorf.de/webapps/wa-download/.

Failed refutations: further comments on parsimony and likelihood methods and their relationship to Popper's degree of corroboration.

Science.gov (United States)

de Queiroz, Kevin; Poe, Steven

2003-06-01

Kluge's (2001, Syst. Biol. 50:322-330) continued arguments that phylogenetic methods based on the statistical principle of likelihood are incompatible with the philosophy of science described by Karl Popper are based on false premises related to Kluge's misrepresentations of Popper's philosophy. Contrary to Kluge's conjectures, likelihood methods are not inherently verificationist; they do not treat every instance of a hypothesis as confirmation of that hypothesis. The historical nature of phylogeny does not preclude phylogenetic hypotheses from being evaluated using the probability of evidence. The low absolute probabilities of hypotheses are irrelevant to the correct interpretation of Popper's concept termed degree of corroboration, which is defined entirely in terms of relative probabilities. Popper did not advocate minimizing background knowledge; in any case, the background knowledge of both parsimony and likelihood methods consists of the general assumption of descent with modification and additional assumptions that are deterministic, concerning which tree is considered most highly corroborated. Although parsimony methods do not assume (in the sense of entailing) that homoplasy is rare, they do assume (in the sense of requiring to obtain a correct phylogenetic inference) certain things about patterns of homoplasy. Both parsimony and likelihood methods assume (in the sense of implying by the manner in which they operate) various things about evolutionary processes, although violation of those assumptions does not always cause the methods to yield incorrect phylogenetic inferences. Test severity is increased by sampling additional relevant characters rather than by character reanalysis, although either interpretation is compatible with the use of phylogenetic likelihood methods. Neither parsimony nor likelihood methods assess test severity (critical evidence) when used to identify a most highly corroborated tree(s) based on a single method or model and a

Consequence Valuing as Operation and Process: A Parsimonious Analysis of Motivation

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Whelan, Robert; Barnes-Holmes, Dermot

2010-01-01

The concept of the motivating operation (MO) has been subject to 3 criticisms: (a) the terms and concepts employed do not always overlap with traditional behavior-analytic verbal practices; (b) the dual nature of the MO is unclear; and (c) there is a lack of adequate contact with empirical data. We offer a more parsimonious approach to motivation,…

A simplified parsimonious higher order multivariate Markov chain model with new convergence condition

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Wang, Chao; Yang, Chuan-sheng

2017-09-01

In this paper, we present a simplified parsimonious higher-order multivariate Markov chain model with new convergence condition. (TPHOMMCM-NCC). Moreover, estimation method of the parameters in TPHOMMCM-NCC is give. Numerical experiments illustrate the effectiveness of TPHOMMCM-NCC.

A Parsimonious Bootstrap Method to Model Natural Inflow Energy Series

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Fernando Luiz Cyrino Oliveira

2014-01-01

Full Text Available The Brazilian energy generation and transmission system is quite peculiar in its dimension and characteristics. As such, it can be considered unique in the world. It is a high dimension hydrothermal system with huge participation of hydro plants. Such strong dependency on hydrological regimes implies uncertainties related to the energetic planning, requiring adequate modeling of the hydrological time series. This is carried out via stochastic simulations of monthly inflow series using the family of Periodic Autoregressive models, PAR(p, one for each period (month of the year. In this paper it is shown the problems in fitting these models by the current system, particularly the identification of the autoregressive order “p” and the corresponding parameter estimation. It is followed by a proposal of a new approach to set both the model order and the parameters estimation of the PAR(p models, using a nonparametric computational technique, known as Bootstrap. This technique allows the estimation of reliable confidence intervals for the model parameters. The obtained results using the Parsimonious Bootstrap Method of Moments (PBMOM produced not only more parsimonious model orders but also adherent stochastic scenarios and, in the long range, lead to a better use of water resources in the energy operation planning.

The plunge in German electricity futures prices – Analysis using a parsimonious fundamental model

International Nuclear Information System (INIS)

Kallabis, Thomas; Pape, Christian; Weber, Christoph

2016-01-01

The German market has seen a plunge in wholesale electricity prices from 2007 until 2014, with base futures prices dropping by more than 40%. This is frequently attributed to the unexpected high increase in renewable power generation. Using a parsimonious fundamental model, we determine the respective impact of supply and demand shocks on electricity futures prices. The used methodology is based on a piecewise linear approximation of the supply stack and time-varying price-inelastic demand. This parsimonious model is able to replicate electricity futures prices and discover non-linear dependencies in futures price formation. We show that emission prices have a higher impact on power prices than renewable penetration. Changes in renewables, demand and installed capacities turn out to be similarly important for explaining the decrease in operation margins of conventional power plants. We thus argue for the establishment of an independent authority to stabilize emission prices. - Highlights: •We build a parsimonious fundamental model based on a piecewise linear bid stack. •We use the model to investigate impact factors for the plunge in German futures prices. •Largest impact by CO_2 price developments followed by demand and renewable feed-in. •Power plant operating profits strongly affected by demand and renewables. •We argue that stabilizing CO_2 emission prices could provide better market signals.

Philosophy and phylogenetic inference: a comparison of likelihood and parsimony methods in the context of Karl Popper's writings on corroboration.

Science.gov (United States)

de Queiroz, K; Poe, S

2001-06-01

Advocates of cladistic parsimony methods have invoked the philosophy of Karl Popper in an attempt to argue for the superiority of those methods over phylogenetic methods based on Ronald Fisher's statistical principle of likelihood. We argue that the concept of likelihood in general, and its application to problems of phylogenetic inference in particular, are highly compatible with Popper's philosophy. Examination of Popper's writings reveals that his concept of corroboration is, in fact, based on likelihood. Moreover, because probabilistic assumptions are necessary for calculating the probabilities that define Popper's corroboration, likelihood methods of phylogenetic inference--with their explicit probabilistic basis--are easily reconciled with his concept. In contrast, cladistic parsimony methods, at least as described by certain advocates of those methods, are less easily reconciled with Popper's concept of corroboration. If those methods are interpreted as lacking probabilistic assumptions, then they are incompatible with corroboration. Conversely, if parsimony methods are to be considered compatible with corroboration, then they must be interpreted as carrying implicit probabilistic assumptions. Thus, the non-probabilistic interpretation of cladistic parsimony favored by some advocates of those methods is contradicted by an attempt by the same authors to justify parsimony methods in terms of Popper's concept of corroboration. In addition to being compatible with Popperian corroboration, the likelihood approach to phylogenetic inference permits researchers to test the assumptions of their analytical methods (models) in a way that is consistent with Popper's ideas about the provisional nature of background knowledge.

Quality Assurance Based on Descriptive and Parsimonious Appearance Models

DEFF Research Database (Denmark)

Nielsen, Jannik Boll; Eiríksson, Eyþór Rúnar; Kristensen, Rasmus Lyngby

2015-01-01

In this positional paper, we discuss the potential benefits of using appearance models in additive manufacturing, metal casting, wind turbine blade production, and 3D content acquisition. Current state of the art in acquisition and rendering of appearance cannot easily be used for quality assurance...... in these areas. The common denominator is the need for descriptive and parsimonious appearance models. By ‘parsimonious’ we mean with few parameters so that a model is useful both for fast acquisition, robust fitting, and fast rendering of appearance. The word ‘descriptive’ refers to the fact that a model should...

Vector Autoregressions with Parsimoniously Time Varying Parameters and an Application to Monetary Policy

DEFF Research Database (Denmark)

Callot, Laurent; Kristensen, Johannes Tang

the monetary policy response to inflation and business cycle fluctuations in the US by estimating a parsimoniously time varying parameter Taylor rule.We document substantial changes in the policy response of the Fed in the 1970s and 1980s, and since 2007, but also document the stability of this response...

Hypothesis of the Disappearance of the Limits of Improvidence and Parsimony in the Function of Consumption in an Islamic Economy

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محمد أحمد حسن الأفندي

2018-04-01

Full Text Available There is a rich literature about the analysis of consumption behavior from the perspective of Islamic economy. The focus of such literature has been on the incorporation of the effect of moral values on individuals’ consumption behavior. However, studies on consumption did not pay enough heed to the analysis of the ultimate effect of faith values on the track of consumption behavior over time. This desired track of consumption involves showing certain hypotheses and probabilities. This study suggests a normative statement which includes the gradual disappearance of parsimony and improvidence over time. This disappearance would correct the deviation of actual consumption of society members from the desired moderate consumption level, so as to make households’ consumption behavior at the desired level which is consistent with Islamic Sharia. The study emphasizes the need to develop analysis and research in two integrated directions: i conducting more empirical studies to examine the consistency of the normative statement with evidence from real situations, and ii conducting more analysis to develop a specific measure for the desired consumption levels as well as the limits of parsimony and improvidence. Keywords: Disappearance of improvidence and parsimony limits, Desired moderate consumption level, Actual consumption, Improvidence and parsimony consumption levels, Track of households’ consumption behavior.

On the Quirks of Maximum Parsimony and Likelihood on Phylogenetic Networks

OpenAIRE

Bryant, Christopher; Fischer, Mareike; Linz, Simone; Semple, Charles

2015-01-01

Maximum parsimony is one of the most frequently-discussed tree reconstruction methods in phylogenetic estimation. However, in recent years it has become more and more apparent that phylogenetic trees are often not sufficient to describe evolution accurately. For instance, processes like hybridization or lateral gene transfer that are commonplace in many groups of organisms and result in mosaic patterns of relationships cannot be represented by a single phylogenetic tree. This is why phylogene...

A parsimonious dynamic model for river water quality assessment.

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Mannina, Giorgio; Viviani, Gaspare

2010-01-01

Water quality modelling is of crucial importance for the assessment of physical, chemical, and biological changes in water bodies. Mathematical approaches to water modelling have become more prevalent over recent years. Different model types ranging from detailed physical models to simplified conceptual models are available. Actually, a possible middle ground between detailed and simplified models may be parsimonious models that represent the simplest approach that fits the application. The appropriate modelling approach depends on the research goal as well as on data available for correct model application. When there is inadequate data, it is mandatory to focus on a simple river water quality model rather than detailed ones. The study presents a parsimonious river water quality model to evaluate the propagation of pollutants in natural rivers. The model is made up of two sub-models: a quantity one and a quality one. The model employs a river schematisation that considers different stretches according to the geometric characteristics and to the gradient of the river bed. Each stretch is represented with a conceptual model of a series of linear channels and reservoirs. The channels determine the delay in the pollution wave and the reservoirs cause its dispersion. To assess the river water quality, the model employs four state variables: DO, BOD, NH(4), and NO. The model was applied to the Savena River (Italy), which is the focus of a European-financed project in which quantity and quality data were gathered. A sensitivity analysis of the model output to the model input or parameters was done based on the Generalised Likelihood Uncertainty Estimation methodology. The results demonstrate the suitability of such a model as a tool for river water quality management.

Beyond technology acceptance to effective technology use: a parsimonious and actionable model.

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Holahan, Patricia J; Lesselroth, Blake J; Adams, Kathleen; Wang, Kai; Church, Victoria

2015-05-01

To develop and test a parsimonious and actionable model of effective technology use (ETU). Cross-sectional survey of primary care providers (n = 53) in a large integrated health care organization that recently implemented new medication reconciliation technology. Surveys assessed 5 technology-related perceptions (compatibility with work values, implementation climate, compatibility with work processes, perceived usefulness, and ease of use) and 1 outcome variable, ETU. ETU was measured as both consistency and quality of technology use. Compatibility with work values and implementation climate were found to have differential effects on consistency and quality of use. When implementation climate was strong, consistency of technology use was high. However, quality of technology use was high only when implementation climate was strong and values compatibility was high. This is an important finding and highlights the importance of users' workplace values as a key determinant of quality of use. To extend our effectiveness in implementing new health care information technology, we need parsimonious models that include actionable determinants of ETU and account for the differential effects of these determinants on the multiple dimensions of ETU. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A proteomic approach for studying insect phylogeny: CAPA peptides of ancient insect taxa (Dictyoptera, Blattoptera as a test case

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Gäde Gerd

2009-03-01

Full Text Available Abstract Background Neuropeptide ligands have to fit exactly into their respective receptors and thus the evolution of the coding regions of their genes is constrained and may be strongly conserved. As such, they may be suitable for the reconstruction of phylogenetic relationships within higher taxa. CAPA peptides of major lineages of cockroaches (Blaberidae, Blattellidae, Blattidae, Polyphagidae, Cryptocercidae and of the termite Mastotermes darwiniensis were chosen to test the above hypothesis. The phylogenetic relationships within various groups of the taxon Dictyoptera (praying mantids, termites and cockroaches are still highly disputed. Results Tandem mass spectrometry of neuropeptides from perisympathetic organs was used to obtain sequence data of CAPA peptides from single specimens; the data were analysed by Maximum Parsimony and Bayesian Interference. The resulting cladograms, taking 61 species into account, show a topology which is in general agreement with recent molecular and morphological phylogenetic analyses, including the recent phylogenetic arrangement placing termites within the cockroaches. When sequence data sets from other neuropeptides, viz. adipokinetic hormones and sulfakinins, were included, the general topology of the cladogram did not change but bootstrap values increased considerably. Conclusion This study represents the first comprehensive survey of neuropeptides of insects for solely phylogenetic purposes and concludes that sequences of short neuropeptides are suitable to complement molecular biological and morphological data for the reconstruction of phylogenetic relationships.

FPGA Hardware Acceleration of a Phylogenetic Tree Reconstruction with Maximum Parsimony Algorithm

OpenAIRE

BLOCK, Henry; MARUYAMA, Tsutomu

2017-01-01

In this paper, we present an FPGA hardware implementation for a phylogenetic tree reconstruction with a maximum parsimony algorithm. We base our approach on a particular stochastic local search algorithm that uses the Progressive Neighborhood and the Indirect Calculation of Tree Lengths method. This method is widely used for the acceleration of the phylogenetic tree reconstruction algorithm in software. In our implementation, we define a tree structure and accelerate the search by parallel an...

Ancestral Sequence Reconstruction with Maximum Parsimony.

Science.gov (United States)

Herbst, Lina; Fischer, Mareike

2017-12-01

One of the main aims in phylogenetics is the estimation of ancestral sequences based on present-day data like, for instance, DNA alignments. One way to estimate the data of the last common ancestor of a given set of species is to first reconstruct a phylogenetic tree with some tree inference method and then to use some method of ancestral state inference based on that tree. One of the best-known methods both for tree inference and for ancestral sequence inference is Maximum Parsimony (MP). In this manuscript, we focus on this method and on ancestral state inference for fully bifurcating trees. In particular, we investigate a conjecture published by Charleston and Steel in 1995 concerning the number of species which need to have a particular state, say a, at a particular site in order for MP to unambiguously return a as an estimate for the state of the last common ancestor. We prove the conjecture for all even numbers of character states, which is the most relevant case in biology. We also show that the conjecture does not hold in general for odd numbers of character states, but also present some positive results for this case.

Assessing internet addiction using the parsimonious internet addiction components model—A preliminary study.

OpenAIRE

Kuss, D.J.; Shorter, G.W.; Rooij, A.J. van; Griffiths, M.D.; Schoenmakers, T.M.

2014-01-01

Internet usage has grown exponentially over the last decade. Research indicates that excessive Internet use can lead to symptoms associated with addiction. To date, assessment of potential Internet addiction has varied regarding populations studied and instruments used, making reliable prevalence estimations difficult. To overcome the present problems a preliminary study was conducted testing a parsimonious Internet addiction components model based on Griffiths’ addiction components (Journal ...

Things fall apart: biological species form unconnected parsimony networks.

Science.gov (United States)

Hart, Michael W; Sunday, Jennifer

2007-10-22

The generality of operational species definitions is limited by problematic definitions of between-species divergence. A recent phylogenetic species concept based on a simple objective measure of statistically significant genetic differentiation uses between-species application of statistical parsimony networks that are typically used for population genetic analysis within species. Here we review recent phylogeographic studies and reanalyse several mtDNA barcoding studies using this method. We found that (i) alignments of DNA sequences typically fall apart into a separate subnetwork for each Linnean species (but with a higher rate of true positives for mtDNA data) and (ii) DNA sequences from single species typically stick together in a single haplotype network. Departures from these patterns are usually consistent with hybridization or cryptic species diversity.

A large version of the small parsimony problem

DEFF Research Database (Denmark)

Fredslund, Jakob; Hein, Jotun; Scharling, Tejs

2003-01-01

the most parsimonious assignment of nucleotides. The gaps of the alignment are represented in a so-called gap graph, and through theoretically sound preprocessing the graph is reduced to pave the way for a running time which in all but the most pathological examples is far better than the exponential worst......Given a multiple alignment over $k$ sequences, an evolutionary tree relating the sequences, and a subadditive gap penalty function (e.g. an affine function), we reconstruct the internal nodes of the tree optimally: we find the optimal explanation in terms of indels of the observed gaps and find...... case time. E.g. for a tree with nine leaves and a random alignment of length 10.000 with 60% gaps, the running time is on average around 45 seconds. For a real alignment of length 9868 of nine HIV-1 sequences, the running time is less than one second....

Assessing Internet addiction using the parsimonious Internet addiction components model - a preliminary study [forthcoming

OpenAIRE

Kuss, DJ; Shorter, GW; Van Rooij, AJ; Griffiths, MD; Schoenmakers, T

2014-01-01

Internet usage has grown exponentially over the last decade. Research indicates that excessive Internet use can lead to symptoms associated with addiction. To date, assessment of potential Internet addiction has varied regarding populations studied and instruments used, making reliable prevalence estimations difficult. To overcome the present problems a preliminary study was conducted testing a parsimonious Internet addiction components model based on Griffiths’ addiction components (2005), i...

Seeing the elephant: Parsimony, functionalism, and the emergent design of contempt and other sentiments.

Science.gov (United States)

Gervais, Matthew M; Fessler, Daniel M T

2017-01-01

The target article argues that contempt is a sentiment, and that sentiments are the deep structure of social affect. The 26 commentaries meet these claims with a range of exciting extensions and applications, as well as critiques. Most significantly, we reply that construction and emergence are necessary for, not incompatible with, evolved design, while parsimony requires explanatory adequacy and predictive accuracy, not mere simplicity.

A Parsimonious Instrument for Predicting Students' Intent to Pursue a Sales Career: Scale Development and Validation

Science.gov (United States)

Peltier, James W.; Cummins, Shannon; Pomirleanu, Nadia; Cross, James; Simon, Rob

2014-01-01

Students' desire and intention to pursue a career in sales continue to lag behind industry demand for sales professionals. This article develops and validates a reliable and parsimonious scale for measuring and predicting student intention to pursue a selling career. The instrument advances previous scales in three ways. The instrument is…

Parsimonious Ways to Use Vision for Navigation

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Paul Graham

2012-05-01

Full Text Available The use of visual information for navigation appears to be a universal strategy for sighted animals, amongst which, one particular group of expert navigators are the ants. The broad interest in studies of ant navigation is in part due to their small brains, thus biomimetic engineers expect to be impressed by elegant control solutions, and psychologists might hope for a description of the minimal cognitive requirements for complex spatial behaviours. In this spirit, we have been taking an interdisciplinary approach to the visual guided navigation of ants in their natural habitat. Behavioural experiments and natural image statistics show that visual navigation need not depend on the remembering or recognition of objects. Further modelling work suggests how simple behavioural routines might enable navigation using familiarity detection rather than explicit recall, and we present a proof of concept that visual navigation using familiarity can be achieved without specifying when or what to learn, nor separating routes into sequences of waypoints. We suggest that our current model represents the only detailed and complete model of insect route guidance to date. What's more, we believe the suggested mechanisms represent useful parsimonious hypotheses for the visually guided navigation in larger-brain animals.

The scenario on the origin of translation in the RNA world: in principle of replication parsimony

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Ma Wentao

2010-11-01

Full Text Available Abstract Background It is now believed that in the origin of life, proteins should have been "invented" in an RNA world. However, due to the complexity of a possible RNA-based proto-translation system, this evolving process seems quite complicated and the associated scenario remains very blurry. Considering that RNA can bind amino acids with specificity, it has been reasonably supposed that initial peptides might have been synthesized on "RNA templates" containing multiple amino acid binding sites. This "Direct RNA Template (DRT" mechanism is attractive because it should be the simplest mechanism for RNA to synthesize peptides, thus very likely to have been adopted initially in the RNA world. Then, how this mechanism could develop into a proto-translation system mechanism is an interesting problem. Presentation of the hypothesis Here an explanation to this problem is shown considering the principle of "replication parsimony" --- genetic information tends to be utilized in a parsimonious way under selection pressure, due to its replication cost (e.g., in the RNA world, nucleotides and ribozymes for RNA replication. Because a DRT would be quite long even for a short peptide, its replication cost would be great. Thus the diversity and the length of functional peptides synthesized by the DRT mechanism would be seriously limited. Adaptors (proto-tRNAs would arise to allow a DRT's complementary strand (called "C-DRT" here to direct the synthesis of the same peptide synthesized by the DRT itself. Because the C-DRT is a necessary part in the DRT's replication, fewer turns of the DRT's replication would be needed to synthesize definite copies of the functional peptide, thus saving the replication cost. Acting through adaptors, C-DRTs could transform into much shorter templates (called "proto-mRNAs" here and substitute the role of DRTs, thus significantly saving the replication cost. A proto-rRNA corresponding to the small subunit rRNA would then emerge

A new mathematical modeling for pure parsimony haplotyping problem.

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Feizabadi, R; Bagherian, M; Vaziri, H R; Salahi, M

2016-11-01

Pure parsimony haplotyping (PPH) problem is important in bioinformatics because rational haplotyping inference plays important roles in analysis of genetic data, mapping complex genetic diseases such as Alzheimer's disease, heart disorders and etc. Haplotypes and genotypes are m-length sequences. Although several integer programing models have already been presented for PPH problem, its NP-hardness characteristic resulted in ineffectiveness of those models facing the real instances especially instances with many heterozygous sites. In this paper, we assign a corresponding number to each haplotype and genotype and based on those numbers, we set a mixed integer programing model. Using numbers, instead of sequences, would lead to less complexity of the new model in comparison with previous models in a way that there are neither constraints nor variables corresponding to heterozygous nucleotide sites in it. Experimental results approve the efficiency of the new model in producing better solution in comparison to two state-of-the art haplotyping approaches. Copyright © 2016 Elsevier Inc. All rights reserved.

Hide and vanish: data sets where the most parsimonious tree is known but hard to find, and their implications for tree search methods.

Science.gov (United States)

Goloboff, Pablo A

2014-10-01

Three different types of data sets, for which the uniquely most parsimonious tree can be known exactly but is hard to find with heuristic tree search methods, are studied. Tree searches are complicated more by the shape of the tree landscape (i.e. the distribution of homoplasy on different trees) than by the sheer abundance of homoplasy or character conflict. Data sets of Type 1 are those constructed by Radel et al. (2013). Data sets of Type 2 present a very rugged landscape, with narrow peaks and valleys, but relatively low amounts of homoplasy. For such a tree landscape, subjecting the trees to TBR and saving suboptimal trees produces much better results when the sequence of clipping for the tree branches is randomized instead of fixed. An unexpected finding for data sets of Types 1 and 2 is that starting a search from a random tree instead of a random addition sequence Wagner tree may increase the probability that the search finds the most parsimonious tree; a small artificial example where these probabilities can be calculated exactly is presented. Data sets of Type 3, the most difficult data sets studied here, comprise only congruent characters, and a single island with only one most parsimonious tree. Even if there is a single island, missing entries create a very flat landscape which is difficult to traverse with tree search algorithms because the number of equally parsimonious trees that need to be saved and swapped to effectively move around the plateaus is too large. Minor modifications of the parameters of tree drifting, ratchet, and sectorial searches allow travelling around these plateaus much more efficiently than saving and swapping large numbers of equally parsimonious trees with TBR. For these data sets, two new related criteria for selecting taxon addition sequences in Wagner trees (the "selected" and "informative" addition sequences) produce much better results than the standard random or closest addition sequences. These new methods for Wagner

SEAPODYM-LTL: a parsimonious zooplankton dynamic biomass model

Science.gov (United States)

Conchon, Anna; Lehodey, Patrick; Gehlen, Marion; Titaud, Olivier; Senina, Inna; Séférian, Roland

2017-04-01

Mesozooplankton organisms are of critical importance for the understanding of early life history of most fish stocks, as well as the nutrient cycles in the ocean. Ongoing climate change and the need for improved approaches to the management of living marine resources has driven recent advances in zooplankton modelling. The classical modeling approach tends to describe the whole biogeochemical and plankton cycle with increasing complexity. We propose here a different and parsimonious zooplankton dynamic biomass model (SEAPODYM-LTL) that is cost efficient and can be advantageously coupled with primary production estimated either from satellite derived ocean color data or biogeochemical models. In addition, the adjoint code of the model is developed allowing a robust optimization approach for estimating the few parameters of the model. In this study, we run the first optimization experiments using a global database of climatological zooplankton biomass data and we make a comparative analysis to assess the importance of resolution and primary production inputs on model fit to observations. We also compare SEAPODYM-LTL outputs to those produced by a more complex biogeochemical model (PISCES) but sharing the same physical forcings.

Effects of CO{sub 2} activation on electrochemical performance of microporous carbons derived from poly(vinylidene fluoride)

Energy Technology Data Exchange (ETDEWEB)

Lee, Seul-Yi; Park, Soo-Jin, E-mail: sjpark@inha.ac.kr

2013-11-15

In this work, we have prepared microporous carbons (MPCs) derived from poly(vinylidene fluoride) (PVDF), and the physical activation of MPCs using CO{sub 2} gas is subsequently carried out with various activation temperatures to investigate the electrochemical performance. PVDF is successfully converted into MPCs with a high specific surface area and well-developed micropores. After CO{sub 2} activation, the specific surface areas of MPCs (CA-MPCs) are enhanced by 12% compared with non-activated MPCs. With increasing activation temperature, the micropore size distributions of A-MPCs also become narrower and shift to larger pore size. It is also confirmed that the CO{sub 2} activation had developed the micropores and introduced the oxygen-containing groups to MPCs′ surfaces. From the results, the specific capacitances of the electrodes in electric double layer capacitors (EDLCs) based on CA-MPCs are distinctly improved through CO{sub 2} activation. The highest specific capacitance of the A-MPCs activated at 700 °C is about 125 F/g, an enhancement of 74% in comparison with NA-MPCs, at a discharge current of 2 A/g in a 6 M KOH electrolyte solution. We also found that micropore size of 0.67 nm has a specific impact on the capacitance behaviors, besides the specific surface area of the electrode samples. - Graphical abstract: The A-MPC samples with high specific surface area (ranging from 1030 to 1082 m{sup 2}/g), corresponding to micropore sizes of 0.67 and 0.72 nm, and with the amount of oxygen-containing groups ranging from 3.2% to 4.4% have been evaluated as electrodes for EDLC applications. . Display Omitted - Highlights: • Microporous carbons (MPCs) were synthesized without activation process. • Next, we carried out the CO{sub 2} activation of MPCs with activation temperatures. • It had developed the micropores and introduced the O-functional groups to MPCs. • The highest specific capacitance: 125 F/g, an increase of 74% compared to MPCs.

Effects of CO2 activation on electrochemical performance of microporous carbons derived from poly(vinylidene fluoride)

International Nuclear Information System (INIS)

Lee, Seul-Yi; Park, Soo-Jin

2013-01-01

In this work, we have prepared microporous carbons (MPCs) derived from poly(vinylidene fluoride) (PVDF), and the physical activation of MPCs using CO 2 gas is subsequently carried out with various activation temperatures to investigate the electrochemical performance. PVDF is successfully converted into MPCs with a high specific surface area and well-developed micropores. After CO 2 activation, the specific surface areas of MPCs (CA-MPCs) are enhanced by 12% compared with non-activated MPCs. With increasing activation temperature, the micropore size distributions of A-MPCs also become narrower and shift to larger pore size. It is also confirmed that the CO 2 activation had developed the micropores and introduced the oxygen-containing groups to MPCs′ surfaces. From the results, the specific capacitances of the electrodes in electric double layer capacitors (EDLCs) based on CA-MPCs are distinctly improved through CO 2 activation. The highest specific capacitance of the A-MPCs activated at 700 °C is about 125 F/g, an enhancement of 74% in comparison with NA-MPCs, at a discharge current of 2 A/g in a 6 M KOH electrolyte solution. We also found that micropore size of 0.67 nm has a specific impact on the capacitance behaviors, besides the specific surface area of the electrode samples. - Graphical abstract: The A-MPC samples with high specific surface area (ranging from 1030 to 1082 m 2 /g), corresponding to micropore sizes of 0.67 and 0.72 nm, and with the amount of oxygen-containing groups ranging from 3.2% to 4.4% have been evaluated as electrodes for EDLC applications. . Display Omitted - Highlights: • Microporous carbons (MPCs) were synthesized without activation process. • Next, we carried out the CO 2 activation of MPCs with activation temperatures. • It had developed the micropores and introduced the O-functional groups to MPCs. • The highest specific capacitance: 125 F/g, an increase of 74% compared to MPCs

Bayesian, Maximum Parsimony and UPGMA Models for Inferring the Phylogenies of Antelopes Using Mitochondrial Markers

OpenAIRE

Khan, Haseeb A.; Arif, Ibrahim A.; Bahkali, Ali H.; Al Farhan, Ahmad H.; Al Homaidan, Ali A.

2008-01-01

This investigation was aimed to compare the inference of antelope phylogenies resulting from the 16S rRNA, cytochrome-b (cyt-b) and d-loop segments of mitochondrial DNA using three different computational models including Bayesian (BA), maximum parsimony (MP) and unweighted pair group method with arithmetic mean (UPGMA). The respective nucleotide sequences of three Oryx species (Oryx leucoryx, Oryx dammah and Oryx gazella) and an out-group (Addax nasomaculatus) were aligned and subjected to B...

Mariposas diurnas endémicas de la Región Paleártica occidental: patrones de distribución y su análisis mediante parsimonia (Lepidoptera, Papilionoidea

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García-Barros, Enrique

2003-12-01

Full Text Available The geographic distributions of the butterflies endemic to the Western Palaearctic are used to classify operative area units based on an index of association, and on parsimony analyses, and these results are compared. It is shown that the PAE-PCE method proposed by García-Barros et al. (2002 does not warrant detection of all subsets of area units characterised by endemic elements with identic distributions. However, satisfactory results can be achieved if Wager parsimony is subtituted by a method of cladogram construction that proscibes homoplasy, such as compatibility. When used as a classification procedure, the results of parsimony analysis can be broadly consistent with those derived from other procedures of hyerarchical classification. A distinction should be made between two different usages of parsimony, both of which represent ‘static’ (sensu Rosen, 1988 interpretations of area cladograms: PAE in a strict sense, aimed at detecting putative areas of endemicity. These are potentially overlapping entities, and hence the method may imply potentially multiple solutions. And, cladistic procedures applied as an agglomerative method (ideally with a single, most parsimonious solution. As far as the butterfly faunas are concered, the highest concentration of endemisms occur across the western circum-mediterranean mountain chains, and in the largest Mediterranean islands. The Iberian Peninsula is featured not just by a high concentration of endemic butterflies, but also by the coexistence of several distinc areas of endemism. Broad patterns derived from the endemic fauna fit well to those based on the whole butterfly fauna.

La distribución de las mariposas endémicas del oeste de la Región Paleártica se emplea para producir una clasificación de las unidades de área mediante un coeficiente de asociación y mediante un análisis de parsimonia, y se comparan los resultados. Se demuestra que el procedimiento PAE

Data driven discrete-time parsimonious identification of a nonlinear state-space model for a weakly nonlinear system with short data record

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Relan, Rishi; Tiels, Koen; Marconato, Anna; Dreesen, Philippe; Schoukens, Johan

2018-05-01

Many real world systems exhibit a quasi linear or weakly nonlinear behavior during normal operation, and a hard saturation effect for high peaks of the input signal. In this paper, a methodology to identify a parsimonious discrete-time nonlinear state space model (NLSS) for the nonlinear dynamical system with relatively short data record is proposed. The capability of the NLSS model structure is demonstrated by introducing two different initialisation schemes, one of them using multivariate polynomials. In addition, a method using first-order information of the multivariate polynomials and tensor decomposition is employed to obtain the parsimonious decoupled representation of the set of multivariate real polynomials estimated during the identification of NLSS model. Finally, the experimental verification of the model structure is done on the cascaded water-benchmark identification problem.

Systematics and morphological evolution within the moss family Bryaceae: a comparison between parsimony and Bayesian methods for reconstruction of ancestral character states.

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Pedersen, Niklas; Holyoak, David T; Newton, Angela E

2007-06-01

The Bryaceae are a large cosmopolitan moss family including genera of significant morphological and taxonomic complexity. Phylogenetic relationships within the Bryaceae were reconstructed based on DNA sequence data from all three genomic compartments. In addition, maximum parsimony and Bayesian inference were employed to reconstruct ancestral character states of 38 morphological plus four habitat characters and eight insertion/deletion events. The recovered phylogenetic patterns are generally in accord with previous phylogenies based on chloroplast DNA sequence data and three major clades are identified. The first clade comprises Bryum bornholmense, B. rubens, B. caespiticium, and Plagiobryum. This corroborates the hypothesis suggested by previous studies that several Bryum species are more closely related to Plagiobryum than to the core Bryum species. The second clade includes Acidodontium, Anomobryum, and Haplodontium, while the third clade contains the core Bryum species plus Imbribryum. Within the latter clade, B. subapiculatum and B. tenuisetum form the sister clade to Imbribryum. Reconstructions of ancestral character states under maximum parsimony and Bayesian inference suggest fourteen morphological synapomorphies for the ingroup and synapomorphies are detected for most clades within the ingroup. Maximum parsimony and Bayesian reconstructions of ancestral character states are mostly congruent although Bayesian inference shows that the posterior probability of ancestral character states may decrease dramatically when node support is taken into account. Bayesian inference also indicates that reconstructions may be ambiguous at internal nodes for highly polymorphic characters.

A Practical pedestrian approach to parsimonious regression with inaccurate inputs

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Seppo Karrila

2014-04-01

Full Text Available A measurement result often dictates an interval containing the correct value. Interval data is also created by roundoff, truncation, and binning. We focus on such common interval uncertainty in data. Inaccuracy in model inputs is typically ignored on model fitting. We provide a practical approach for regression with inaccurate data: the mathematics is easy, and the linear programming formulations simple to use even in a spreadsheet. This self-contained elementary presentation introduces interval linear systems and requires only basic knowledge of algebra. Feature selection is automatic; but can be controlled to find only a few most relevant inputs; and joint feature selection is enabled for multiple modeled outputs. With more features than cases, a novel connection to compressed sensing emerges: robustness against interval errors-in-variables implies model parsimony, and the input inaccuracies determine the regularization term. A small numerical example highlights counterintuitive results and a dramatic difference to total least squares.

Time-Lapse Monitoring of Subsurface Fluid Flow using Parsimonious Seismic Interferometry

KAUST Repository

Hanafy, Sherif

2017-04-21

A typical small-scale seismic survey (such as 240 shot gathers) takes at least 16 working hours to be completed, which is a major obstacle in case of time-lapse monitoring experiments. This is especially true if the subject that needs to be monitored is rapidly changing. In this work, we will discuss how to decrease the recording time from 16 working hours to less than one hour of recording. Here, the virtual data has the same accuracy as the conventional data. We validate the efficacy of parsimonious seismic interferometry with the time-lapse mentoring idea with field examples, where we were able to record 30 different data sets within a 2-hour period. The recorded data are then processed to generate 30 snapshots that shows the spread of water from the ground surface down to a few meters.

Composite scores in comparative effectiveness research: counterbalancing parsimony and dimensionality in patient-reported outcomes.

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Schwartz, Carolyn E; Patrick, Donald L

2014-07-01

When planning a comparative effectiveness study comparing disease-modifying treatments, competing demands influence choice of outcomes. Current practice emphasizes parsimony, although understanding multidimensional treatment impact can help to personalize medical decision-making. We discuss both sides of this 'tug of war'. We discuss the assumptions, advantages and drawbacks of composite scores and multidimensional outcomes. We describe possible solutions to the multiple comparison problem, including conceptual hierarchy distinctions, statistical approaches, 'real-world' benchmarks of effectiveness and subgroup analysis. We conclude that comparative effectiveness research should consider multiple outcome dimensions and compare different approaches that fit the individual context of study objectives.

Maximum parsimony, substitution model, and probability phylogenetic trees.

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Weng, J F; Thomas, D A; Mareels, I

2011-01-01

The problem of inferring phylogenies (phylogenetic trees) is one of the main problems in computational biology. There are three main methods for inferring phylogenies-Maximum Parsimony (MP), Distance Matrix (DM) and Maximum Likelihood (ML), of which the MP method is the most well-studied and popular method. In the MP method the optimization criterion is the number of substitutions of the nucleotides computed by the differences in the investigated nucleotide sequences. However, the MP method is often criticized as it only counts the substitutions observable at the current time and all the unobservable substitutions that really occur in the evolutionary history are omitted. In order to take into account the unobservable substitutions, some substitution models have been established and they are now widely used in the DM and ML methods but these substitution models cannot be used within the classical MP method. Recently the authors proposed a probability representation model for phylogenetic trees and the reconstructed trees in this model are called probability phylogenetic trees. One of the advantages of the probability representation model is that it can include a substitution model to infer phylogenetic trees based on the MP principle. In this paper we explain how to use a substitution model in the reconstruction of probability phylogenetic trees and show the advantage of this approach with examples.

Pengintegrasian Model Leadership Menuju Model yang Lebih Komprhensip dan Parsimoni

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Miswanto Miswanti

2016-06-01

Full Text Available ABTSRACT Through leadership models offered by Locke et. al (1991 we can say that whether good or not the vision of leaders in the organization is highly dependent on whether good or not the motives and traits, knowledge, skill, and abilities owned leaders. Then, good or not the implementation of the vision by the leader depends on whether good or not the motives and traits, knowledge, skills, abilities, and the vision of the leaders. Strategic Leadership written by Davies (1991 states that the implementation of the vision by using strategic leadership, the meaning is much more complete than what has been written by Locke et. al. in the fourth stage of leadership. Thus, aspects of the implementation of the vision by Locke et al (1991 it is not complete implementation of the vision according to Davies (1991. With the considerations mentioned above, this article attempts to combine the leadership model of the Locke et. al and strategic leadership of the Davies. With this modification is expected to be an improvement model of leadership is more comprehensive and parsimony.

A Multi-mission Event-Driven Component-Based System for Support of Flight Software Development, ATLO, and Operations first used by the Mars Science Laboratory (MSL) Project

Science.gov (United States)

Dehghani, Navid; Tankenson, Michael

2006-01-01

This viewgraph presentation reviews the architectural description of the Mission Data Processing and Control System (MPCS). MPCS is an event-driven, multi-mission ground data processing components providing uplink, downlink, and data management capabilities which will support the Mars Science Laboratory (MSL) project as its first target mission. MPCS is designed with these factors (1) Enabling plug and play architecture (2) MPCS has strong inheritance from GDS components that have been developed for other Flight Projects (MER, MRO, DAWN, MSAP), and are currently being used in operations and ATLO, and (3) MPCS components are Java-based, platform independent, and are designed to consume and produce XML-formatted data

Observations and Model Simulations of Orographic Mixed-Phase Clouds at Mountain Range Site

Science.gov (United States)

Lohmann, U.; Henneberg, O. C.; Henneberger, J.

2014-12-01

Aerosol-cloud interactions constitute the highest uncertainties in forcing estimation. Especially uncertainties due to mixed clouds (MPCs) have a large impact on the radiative balance and precipitation prediction. Due to Wegener-Bergeron-Findeisen-process (WBF) which describes glaciation of MPCs due to the lower saturation over ice than over water, MPCs are mostly expected as short lived clouds. In contrast to the theory of the WBF, in-situ measurements have shown that MPCs can persist over longer time. But only a small number of measurements of MPCs is available. In addition modeling studies about MPCs are difficult as their processes of the three-phase-system are on the micro scale and therefore not resolved in models. We present measurements obtained at the high-altitude research station Jungfraujoch (JFJ, 3580 m asl) in the Swiss Alps partly taken during the CLoud-Aerosol Interaction Experiments (CLACE). During the winter season, the JFJ has a high frequency of super-cooled clouds and is considered representative for being in the free troposphere. In-situ measurements of the microstructure of MPCs have been obtained with the digital imager HOLIMO, that delivers phase-resolved size distributions, concentrations, and water contents. The data set of MPCs at JFJ shows that for northerly wind cases partially-glaciated MPCs are more frequently observed than for southerly wind cases. The higher frequency of these intermediate states of MPCs suggests either higher updraft velocities, and therefore higher water-vapor supersaturations, or the absence of sufficiently high IN concentrations to quickly glaciate the MPC. Because of the limitation of in-situ information, i.e. point measurements and missing measurements of vertical velocities at JFJ, the mechanism of the long persistence of MPCs cannot be fully understood. Therefore, in addition to measurements we will investigate the JFJ region with a model study with the non-hydrostatic model COSMO-ART-M7. Combination of km

Singular Spectrum Analysis for Astronomical Time Series: Constructing a Parsimonious Hypothesis Test

Science.gov (United States)

Greco, G.; Kondrashov, D.; Kobayashi, S.; Ghil, M.; Branchesi, M.; Guidorzi, C.; Stratta, G.; Ciszak, M.; Marino, F.; Ortolan, A.

We present a data-adaptive spectral method - Monte Carlo Singular Spectrum Analysis (MC-SSA) - and its modification to tackle astrophysical problems. Through numerical simulations we show the ability of the MC-SSA in dealing with 1/f β power-law noise affected by photon counting statistics. Such noise process is simulated by a first-order autoregressive, AR(1) process corrupted by intrinsic Poisson noise. In doing so, we statistically estimate a basic stochastic variation of the source and the corresponding fluctuations due to the quantum nature of light. In addition, MC-SSA test retains its effectiveness even when a significant percentage of the signal falls below a certain level of detection, e.g., caused by the instrument sensitivity. The parsimonious approach presented here may be broadly applied, from the search for extrasolar planets to the extraction of low-intensity coherent phenomena probably hidden in high energy transients.

On the Accuracy of Ancestral Sequence Reconstruction for Ultrametric Trees with Parsimony.

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Herbst, Lina; Fischer, Mareike

2018-04-01

We examine a mathematical question concerning the reconstruction accuracy of the Fitch algorithm for reconstructing the ancestral sequence of the most recent common ancestor given a phylogenetic tree and sequence data for all taxa under consideration. In particular, for the symmetric four-state substitution model which is also known as Jukes-Cantor model, we answer affirmatively a conjecture of Li, Steel and Zhang which states that for any ultrametric phylogenetic tree and a symmetric model, the Fitch parsimony method using all terminal taxa is more accurate, or at least as accurate, for ancestral state reconstruction than using any particular terminal taxon or any particular pair of taxa. This conjecture had so far only been answered for two-state data by Fischer and Thatte. Here, we focus on answering the biologically more relevant case with four states, which corresponds to ancestral sequence reconstruction from DNA or RNA data.

Patterns and effects of GC3 heterogeneity and parsimony informative sites on the phylogenetic tree of genes.

Science.gov (United States)

Ma, Shuai; Wu, Qi; Hu, Yibo; Wei, Fuwen

2018-05-20

The explosive growth in genomic data has provided novel insights into the conflicting signals hidden in phylogenetic trees. Although some studies have explored the effects of the GC content and parsimony informative sites (PIS) on the phylogenetic tree, the effect of the heterogeneity of the GC content at the first/second/third codon position on parsimony informative sites (GC1/2/3 PIS ) among different species and the effect of PIS on phylogenetic tree construction remain largely unexplored. Here, we used two different mammal genomic datasets to explore the patterns of GC1/2/3 PIS heterogeneity and the effect of PIS on the phylogenetic tree of genes: (i) all GC1/2/3 PIS have obvious heterogeneity between different mammals, and the levels of heterogeneity are GC3 PIS  > GC2 PIS  > GC1 PIS ; (ii) the number of PIS is positively correlated with the metrics of "good" gene tree topologies, and excluding the third codon position (C3) decreases the quality of gene trees by removing too many PIS. These results provide novel insights into the heterogeneity pattern of GC1/2/3 PIS in mammals and the relationship between GC3/PIS and gene trees. Additionally, it is necessary to carefully consider whether to exclude C3 to improve the quality of gene trees, especially in the super-tree method. Copyright © 2018 Elsevier B.V. All rights reserved.

Balancing practicality and hydrologic realism: a parsimonious approach for simulating rapid groundwater recharge via unsaturated-zone preferential flow

Science.gov (United States)

Mirus, Benjamin B.; Nimmo, J.R.

2013-01-01

The impact of preferential flow on recharge and contaminant transport poses a considerable challenge to water-resources management. Typical hydrologic models require extensive site characterization, but can underestimate fluxes when preferential flow is significant. A recently developed source-responsive model incorporates film-flow theory with conservation of mass to estimate unsaturated-zone preferential fluxes with readily available data. The term source-responsive describes the sensitivity of preferential flow in response to water availability at the source of input. We present the first rigorous tests of a parsimonious formulation for simulating water table fluctuations using two case studies, both in arid regions with thick unsaturated zones of fractured volcanic rock. Diffuse flow theory cannot adequately capture the observed water table responses at both sites; the source-responsive model is a viable alternative. We treat the active area fraction of preferential flow paths as a scaled function of water inputs at the land surface then calibrate the macropore density to fit observed water table rises. Unlike previous applications, we allow the characteristic film-flow velocity to vary, reflecting the lag time between source and deep water table responses. Analysis of model performance and parameter sensitivity for the two case studies underscores the importance of identifying thresholds for initiation of film flow in unsaturated rocks, and suggests that this parsimonious approach is potentially of great practical value.

Direct transfer of metallic photonic structures onto end facets of optical fibers

Science.gov (United States)

Zhang, Xinping; Liu, Feifei; Lin, Yuanhai

2016-07-01

We present a flexible approach to transfer metallic photonic crystals (MPCs) onto end facets of optical fibers. The MPCs were initially fabricated on a glass substrate with a spacer layer of indium tin oxide (ITO), which was used as a buffer layer in the transferring process. The fiber ends were firstly welded on the top surface of the MPCs by a drop of polymer solution after the solvent evaporated. The ITO layer was then etched by hydrochloric acid (HCl), so that the MPCs got off the substrate and were transferred to the fiber ends. Alternatively, the MPCs may be also etched off the substrate first by immersing the sample in HCl. The ultra-thin MPC sheet consisting of gold nanolines interlaced with photoresist gratings was then transferred to cap the fiber ends. In the later approach, we can choose which side of the MPCs to be used as the contact with the fiber facet. Such methods enabled convenient nanostructuring on optical fiber tips and achieving miniaturized MPC devices with compact integration, extending significantly applications of MPCs. In particular, the fabrications presented in this manuscript enrich the lab-on-fiber engineering techniques and the resultant devices have potential applications in remote sensing and detection systems.

Direct transfer of metallic photonic structures onto end facets of optical fibers

Directory of Open Access Journals (Sweden)

Xinping Zhang

2016-07-01

Full Text Available We present a flexible approach to transfer metallic photonic crystals (MPCs onto end facets of optical fibers. The MPCs were initially fabricated on a glass substrate with a spacer layer of indium tin oxide (ITO, which was used as a buffer layer in the transferring process. The fiber ends were firstly welded on the top surface of the MPCs by a drop of polymer solution after the solvent evaporated. The ITO layer was then etched by hydrochloric acid (HCl, so that the MPCs got off the substrate and were transferred to the fiber ends. Alternatively, the MPCs may be also etched off the substrate first by immersing the sample in HCl. The ultra-thin MPC sheet consisting of gold nanolines interlaced with photoresist gratings was then transferred to cap the fiber ends. In the later approach, we can choose which side of the MPCs to be used as the contact with the fiber facet. Such methods enabled convenient nanostructuring on optical fiber tips and achieving miniaturized MPC devices with compact integration, extending significantly applications of MPCs. In particular, the fabrications presented in this manuscript enrich the lab-on-fiber engineering techniques and the resultant devices have potential applications in remote sensing and detection systems.

Reading Phylogenetic Trees: The Effects of Tree Orientation and Text Processing on Comprehension

Science.gov (United States)

Novick, Laura R.; Stull, Andrew T.; Catley, Kefyn M.

2012-01-01

Although differently formatted cladograms (hierarchical diagrams depicting evolutionary relationships among taxa) depict the same information, they may not be equally easy to comprehend. Undergraduate biology students attempted to translate cladograms from the diagonal to the rectangular format. The "backbone" line of each diagonal…

More quality measures versus measuring what matters: a call for balance and parsimony.

Science.gov (United States)

Meyer, Gregg S; Nelson, Eugene C; Pryor, David B; James, Brent; Swensen, Stephen J; Kaplan, Gary S; Weissberg, Jed I; Bisognano, Maureen; Yates, Gary R; Hunt, Gordon C

2012-11-01

External groups requiring measures now include public and private payers, regulators, accreditors and others that certify performance levels for consumers, patients and payers. Although benefits have accrued from the growth in quality measurement, the recent explosion in the number of measures threatens to shift resources from improving quality to cover a plethora of quality-performance metrics that may have a limited impact on the things that patients and payers want and need (ie, better outcomes, better care, and lower per capita costs). Here we propose a policy that quality measurement should be: balanced to meet the need of end users to judge quality and cost performance and the need of providers to continuously improve the quality, outcomes and costs of their services; and parsimonious to measure quality, outcomes and costs with appropriate metrics that are selected based on end-user needs.

Controlled assembly and single electron charging of monolayer protected Au144 clusters: an electrochemistry and scanning tunneling spectroscopy study

Science.gov (United States)

Bodappa, Nataraju; Fluch, Ulrike; Fu, Yongchun; Mayor, Marcel; Moreno-García, Pavel; Siegenthaler, Hans; Wandlowski, Thomas

2014-11-01

Single gold particles may serve as room temperature single electron memory units because of their size dependent electronic level spacing. Here, we present a proof-of-concept study by electrochemically controlled scanning probe experiments performed on tailor-made Au particles of narrow dispersity. In particular, the charge transport characteristics through chemically synthesized hexane-1-thiol and 4-pyridylbenzene-1-thiol mixed monolayer protected Au144 clusters (MPCs) by differential pulse voltammetry (DPV) and electrochemical scanning tunneling spectroscopy (EC-STS) are reported. The pyridyl groups exposed by the Au-MPCs enable their immobilization on Pt(111) substrates. By varying the humidity during their deposition, samples coated by stacks of compact monolayers of Au-MPCs or decorated with individual, laterally separated Au-MPCs are obtained. DPV experiments with stacked monolayers of Au144-MPCs and EC-STS experiments with laterally separated individual Au144-MPCs are performed both in aqueous and ionic liquid electrolytes. Lower capacitance values were observed for individual clusters compared to ensemble clusters. This trend remains the same irrespective of the composition of the electrolyte surrounding the Au144-MPC. However, the resolution of the energy level spacing of the single clusters is strongly affected by the proximity of neighboring particles.Single gold particles may serve as room temperature single electron memory units because of their size dependent electronic level spacing. Here, we present a proof-of-concept study by electrochemically controlled scanning probe experiments performed on tailor-made Au particles of narrow dispersity. In particular, the charge transport characteristics through chemically synthesized hexane-1-thiol and 4-pyridylbenzene-1-thiol mixed monolayer protected Au144 clusters (MPCs) by differential pulse voltammetry (DPV) and electrochemical scanning tunneling spectroscopy (EC-STS) are reported. The pyridyl groups

Population-level history of the wrentit (Chamaea fasciata): implications for comparative phylogeography in the California Floristic Province.

Science.gov (United States)

Burns, Kevin J; Barhoum, Dino N

2006-01-01

The phylogeography of a variety of species has been studied within the California Floristic Province; however, few studies have examined genetic variation in bird species across the entire region. This study uses mitochondrial DNA data to investigate the phylogeography of the wrentit (Chamaea fasciata), a sedentary bird native to scrub and chaparral habitats of this region. Analysis of molecular variance shows geographic structure, and maximum likelihood, Bayesian, and parsimony analyses consistently identify six main clades that are each restricted geographically. Nested clade phylogeographic analyses infer an overall range expansion for the entire cladogram, and a range expansion is also inferred from the mismatch distribution. Thus, our results suggest that the wrentit was isolated into southern refugia during the Pleistocene and has undergone a recent range expansion. Southern refugia and a range expansion were also identified in a previous study of the California thrasher (Toxostoma redivivum). The wrentit did not show marked divergence between northern and southern California defined by the Transverse Ranges, a pattern seen in a variety of other taxa within this region, including some birds.

The dynamic effect of exchange-rate volatility on Turkish exports: Parsimonious error-correction model approach

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Demirhan Erdal

2015-01-01

Full Text Available This paper aims to investigate the effect of exchange-rate stability on real export volume in Turkey, using monthly data for the period February 2001 to January 2010. The Johansen multivariate cointegration method and the parsimonious error-correction model are applied to determine long-run and short-run relationships between real export volume and its determinants. In this study, the conditional variance of the GARCH (1, 1 model is taken as a proxy for exchange-rate stability, and generalized impulse-response functions and variance-decomposition analyses are applied to analyze the dynamic effects of variables on real export volume. The empirical findings suggest that exchangerate stability has a significant positive effect on real export volume, both in the short and the long run.

Platelet-Rich Plasma Preparation Types Show Impact on Chondrogenic Differentiation, Migration, and Proliferation of Human Subchondral Mesenchymal Progenitor Cells.

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Kreuz, Peter Cornelius; Krüger, Jan Philipp; Metzlaff, Sebastian; Freymann, Undine; Endres, Michaela; Pruss, Axel; Petersen, Wolf; Kaps, Christian

2015-10-01

To evaluate the chondrogenic potential of platelet concentrates on human subchondral mesenchymal progenitor cells (MPCs) as assessed by histomorphometric analysis of proteoglycans and type II collagen. Furthermore, the migratory and proliferative effect of platelet concentrates were assessed. Platelet-rich plasma (PRP) was prepared using preparation kits (Autologous Conditioned Plasma [ACP] Kit [Arthrex, Naples, FL]; Regen ACR-C Kit [Regen Lab, Le Mont-Sur-Lausanne, Switzerland]; and Dr.PRP Kit [Rmedica, Seoul, Republic of Korea]) by apheresis (PRP-A) and by centrifugation (PRP-C). In contrast to clinical application, freeze-and-thaw cycles were subsequently performed to activate platelets and to prevent medium coagulation by residual fibrinogen in vitro. MPCs were harvested from the cortico-spongious bone of femoral heads. Chondrogenic differentiation of MPCs was induced in high-density pellet cultures and evaluated by histochemical staining of typical cartilage matrix components. Migration of MPCs was assessed using a chemotaxis assay, and proliferation activity was measured by DNA content. MPCs cultured in the presence of 5% ACP, Regen, or Dr.PRP formed fibrous tissue, whereas MPCs stimulated with 5% PRP-A or PRP-C developed compact and dense cartilaginous tissue rich in type II collagen and proteoglycans. All platelet concentrates significantly (ACP, P = .00041; Regen, P = .00029; Dr.PRP, P = .00051; PRP-A, P platelet concentrates but one (Dr.PRP, P = .63) showed a proliferative effect on MPCs, as shown by significant increases (ACP, P = .027; Regen, P = .0029; PRP-A, P = .00021; and PRP-C, P = .00069) in DNA content. Platelet concentrates obtained by different preparation methods exhibit different potentials to stimulate chondrogenic differentiation, migration, and proliferation of MPCs. Platelet concentrates obtained by commercially available preparation kits failed to induce chondrogenic differentiation of MPCs, whereas highly standardized PRP

Anelastic sensitivity kernels with parsimonious storage for adjoint tomography and full waveform inversion

KAUST Repository

Komatitsch, Dimitri; Xie, Zhinan; Bozdağ, Ebru; de Andrade, Elliott Sales; Peter, Daniel; Liu, Qinya; Tromp, Jeroen

2016-01-01

We introduce a technique to compute exact anelastic sensitivity kernels in the time domain using parsimonious disk storage. The method is based on a reordering of the time loop of time-domain forward/adjoint wave propagation solvers combined with the use of a memory buffer. It avoids instabilities that occur when time-reversing dissipative wave propagation simulations. The total number of required time steps is unchanged compared to usual acoustic or elastic approaches. The cost is reduced by a factor of 4/3 compared to the case in which anelasticity is partially accounted for by accommodating the effects of physical dispersion. We validate our technique by performing a test in which we compare the Kα sensitivity kernel to the exact kernel obtained by saving the entire forward calculation. This benchmark confirms that our approach is also exact. We illustrate the importance of including full attenuation in the calculation of sensitivity kernels by showing significant differences with physical-dispersion-only kernels.

Anelastic sensitivity kernels with parsimonious storage for adjoint tomography and full waveform inversion

KAUST Repository

Komatitsch, Dimitri

2016-06-13

We introduce a technique to compute exact anelastic sensitivity kernels in the time domain using parsimonious disk storage. The method is based on a reordering of the time loop of time-domain forward/adjoint wave propagation solvers combined with the use of a memory buffer. It avoids instabilities that occur when time-reversing dissipative wave propagation simulations. The total number of required time steps is unchanged compared to usual acoustic or elastic approaches. The cost is reduced by a factor of 4/3 compared to the case in which anelasticity is partially accounted for by accommodating the effects of physical dispersion. We validate our technique by performing a test in which we compare the Kα sensitivity kernel to the exact kernel obtained by saving the entire forward calculation. This benchmark confirms that our approach is also exact. We illustrate the importance of including full attenuation in the calculation of sensitivity kernels by showing significant differences with physical-dispersion-only kernels.

Anelastic sensitivity kernels with parsimonious storage for adjoint tomography and full waveform inversion

Science.gov (United States)

Komatitsch, Dimitri; Xie, Zhinan; Bozdaǧ, Ebru; Sales de Andrade, Elliott; Peter, Daniel; Liu, Qinya; Tromp, Jeroen

2016-09-01

We introduce a technique to compute exact anelastic sensitivity kernels in the time domain using parsimonious disk storage. The method is based on a reordering of the time loop of time-domain forward/adjoint wave propagation solvers combined with the use of a memory buffer. It avoids instabilities that occur when time-reversing dissipative wave propagation simulations. The total number of required time steps is unchanged compared to usual acoustic or elastic approaches. The cost is reduced by a factor of 4/3 compared to the case in which anelasticity is partially accounted for by accommodating the effects of physical dispersion. We validate our technique by performing a test in which we compare the Kα sensitivity kernel to the exact kernel obtained by saving the entire forward calculation. This benchmark confirms that our approach is also exact. We illustrate the importance of including full attenuation in the calculation of sensitivity kernels by showing significant differences with physical-dispersion-only kernels.

Effect of oxygen tension on bioenergetics and proteostasis in young and old myoblast precursor cells.

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Konigsberg, M; Pérez, V I; Ríos, C; Liu, Y; Lee, S; Shi, Y; Van Remmen, H

2013-01-01

In the majority of studies using primary cultures of myoblasts, the cells are maintained at ambient oxygen tension (21% O2), despite the fact that physiological O2 at the tissue level in vivo is much lower (~1-5% O2). We hypothesized that the cellular response in presence of high oxygen concentration might be particularly important in studies comparing energetic function or oxidative stress in cells isolated from young versus old animals. To test this, we asked whether oxygen tension plays a role in mitochondrial bioenergetics (oxygen consumption, glycolysis and fatty acid oxidation) or oxidative damage to proteins (protein disulfides, carbonyls and aggregates) in myoblast precursor cells (MPCs) isolated from young (3-4 m) and old (29-30 m) C57BL/6 mice. MPCs were grown under physiological (3%) or ambient (21%) O2 for two weeks prior to exposure to an acute oxidative insult (H2O2). Our results show significantly higher basal mitochondrial respiration in young versus old MPCs, an increase in basal respiration in young MPCs maintained at 3% O2 compared to cells maintained at 21% O2, and a shift toward glycolytic metabolism in old MPCs grown at 21% O2. H2O2 treatment significantly reduced respiration in old MPCs grown at 3% O2 but did not further repress respiration at 21% O2 in old MPCs. Oxidative damage to protein was higher in cells maintained at 21% O2 and increased in response to H2O2 in old MPCs. These data underscore the importance of understanding the effect of ambient oxygen tension in cell culture studies, in particular studies measuring oxidative damage and mitochondrial function.

The efficiency of different search strategies in estimating parsimony jackknife, bootstrap, and Bremer support

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Müller Kai F

2005-10-01

Full Text Available Abstract Background For parsimony analyses, the most common way to estimate confidence is by resampling plans (nonparametric bootstrap, jackknife, and Bremer support (Decay indices. The recent literature reveals that parameter settings that are quite commonly employed are not those that are recommended by theoretical considerations and by previous empirical studies. The optimal search strategy to be applied during resampling was previously addressed solely via standard search strategies available in PAUP*. The question of a compromise between search extensiveness and improved support accuracy for Bremer support received even less attention. A set of experiments was conducted on different datasets to find an empirical cut-off point at which increased search extensiveness does not significantly change Bremer support and jackknife or bootstrap proportions any more. Results For the number of replicates needed for accurate estimates of support in resampling plans, a diagram is provided that helps to address the question whether apparently different support values really differ significantly. It is shown that the use of random addition cycles and parsimony ratchet iterations during bootstrapping does not translate into higher support, nor does any extension of the search extensiveness beyond the rather moderate effort of TBR (tree bisection and reconnection branch swapping plus saving one tree per replicate. Instead, in case of very large matrices, saving more than one shortest tree per iteration and using a strict consensus tree of these yields decreased support compared to saving only one tree. This can be interpreted as a small risk of overestimating support but should be more than compensated by other factors that counteract an enhanced type I error. With regard to Bremer support, a rule of thumb can be derived stating that not much is gained relative to the surplus computational effort when searches are extended beyond 20 ratchet iterations per

Macular micropseudocysts in early stages of diabetic retinopathy.

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Tremolada, Gemma; Pierro, Luisa; de Benedetto, Umberto; Margari, Sergio; Gagliardi, Marco; Maestranzi, Gisella; Calori, Giliola; Lorenzi, Mara; Lattanzio, Rosangela

2011-01-01

To identify by noninvasive means early retinal abnormalities that may predict diabetic macular edema. The authors analyzed retrospectively data from consecutive patients with Type 1 (n = 16) or Type 2 (n = 23) diabetes who presented for routine follow-up of early retinopathy, had no clinical signs or symptoms of diabetic macular edema, and were evaluated with spectral-domain optical coherence tomography. Age- and gender-matched nondiabetic subjects provided normative data. Spectral-domain optical coherence tomography revealed in the macular region of diabetic patients small hyporeflective areas (median diameter, 55 μm) contained within discrete retinal layers that we named micropseudocysts (MPCs). Micropseudocysts are associated with vascular leakage. The patients showing MPCs had more frequently systemic hypertension and increased central foveal thickness than those without MPCs. The association with increased central foveal thickness was only in the patients with Type 2 diabetes. Macular MPCs in patients with mild diabetic retinopathy appear to reflect leakage and can precede macular thickening. The association of MPCs with increased central foveal thickness in patients with Type 2 diabetes, but not in patients with Type 1 diabetes, points to a greater tendency to retinal fluid accumulation in patients with Type 2 diabetes. Studies in larger cohorts will determine the usefulness of MPCs in strategies to abort diabetic macular edema.

Retinal micropseudocysts in diabetic retinopathy: prospective functional and anatomic evaluation.

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Forte, Raimondo; Cennamo, Gilda; Finelli, Maria Luisa; Bonavolontà, Paola; Greco, Giovanni Maria; de Crecchio, Giuseppe

2012-01-01

To evaluate the prevalence, progression and functional predictive value of retinal micropseudocysts (MPCs) in diabetic patients. Prospective controlled observational study. From among all the type 2 diabetic patients evaluated during a period of 5 months between September 2009 and January 2010, we enrolled all patients with retinal MPCs at spectral-domain scanning laser ophthalmoscope/optical coherence tomography (SD-SLO/OCT) not previously treated for diabetic retinopathy. Forty diabetic patients without MPCs served as the control group. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), macular sensitivity and stability of fixation at SD-SLO/OCT microperimetry were measured monthly for 12 months. 22/156 patients with type 2 diabetes (14.1%, 32 eyes) met the inclusion criteria. The 95% confidence interval for the prevalence estimate of MPCs was 12.3-16.6%. Mean BCVA, CRT and central retinal sensitivity at baseline were 77.53 ± 2.2 Early Treatment Diabetic Retinopathy Study letters, 242.31 ± 31.0 µm and 15.95 ± 0.61 dB, respectively. Fixation was stable in all cases. Compared to the control group, eyes with MPCs had similar BCVA but greater CRT (p = 0.01) and reduced macular sensitivity (p = 0.001) at baseline and at each follow-up visit. Over time, CRT remained stable in eyes with MPCs, whereas macular sensitivity progressively decreased. MPCs in diabetic retinopathy are associated, temporally or causally, with a progressive reduction of macular sensitivity despite a stable BCVA, CRT and fixation. Copyright © 2011 S. Karger AG, Basel.

Prediction of dissolved reactive phosphorus losses from small agricultural catchments: calibration and validation of a parsimonious model

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C. Hahn

2013-10-01

Full Text Available Eutrophication of surface waters due to diffuse phosphorus (P losses continues to be a severe water quality problem worldwide, causing the loss of ecosystem functions of the respective water bodies. Phosphorus in runoff often originates from a small fraction of a catchment only. Targeting mitigation measures to these critical source areas (CSAs is expected to be most efficient and cost-effective, but requires suitable tools. Here we investigated the capability of the parsimonious Rainfall-Runoff-Phosphorus (RRP model to identify CSAs in grassland-dominated catchments based on readily available soil and topographic data. After simultaneous calibration on runoff data from four small hilly catchments on the Swiss Plateau, the model was validated on a different catchment in the same region without further calibration. The RRP model adequately simulated the discharge and dissolved reactive P (DRP export from the validation catchment. Sensitivity analysis showed that the model predictions were robust with respect to the classification of soils into "poorly drained" and "well drained", based on the available soil map. Comparing spatial hydrological model predictions with field data from the validation catchment provided further evidence that the assumptions underlying the model are valid and that the model adequately accounts for the dominant P export processes in the target region. Thus, the parsimonious RRP model is a valuable tool that can be used to determine CSAs. Despite the considerable predictive uncertainty regarding the spatial extent of CSAs, the RRP can provide guidance for the implementation of mitigation measures. The model helps to identify those parts of a catchment where high DRP losses are expected or can be excluded with high confidence. Legacy P was predicted to be the dominant source for DRP losses and thus, in combination with hydrologic active areas, a high risk for water quality.

Solvent effect on redox properties of hexanethiolate monolayer-protected gold nanoclusters.

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Su, Bin; Zhang, Meiqin; Shao, Yuanhua; Girault, Hubert H

2006-11-02

The capacitance of monolayer-protected gold nanoclusters (MPCs), C(MPC), in solution has been theoretically reconsidered from an electrostatic viewpoint, in which an MPC is considered as an isolated charged sphere within two dielectric layers, the intrinsic coating monolayer, and the bulk solvent. The model predicts that the bulk solvent provides an important contribution to C(MPC) and influences the redox properties of MPCs. This theoretical prediction is then examined experimentally by comparing the redox properties of MPCs in four organic solvents: 1,2-dichloroethane (DCE), dichloromethane (DCM), chlorobenzene (CB), and toluene (TOL), in all of which MPCs have excellent solubility. Furthermore, this set of organic solvents features a dielectric constant in a range from 10.37 (DCE) to 2.38 (TOL), which is wide enough to probe the solvent effect. In these organic solvents, tetrahexylammonium bis(trifluoromethylsulfonyl)imide (THATf2N) is used as the supporting electrolyte. Cyclic and differential pulse voltammetric results provide concrete evidence that, despite the monolayer protection, the solvent plays a significant effect on the properties of MPCs in solution.

Vicariance biogeography of the open-ocean Pacific

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White, Brian N.

The first cladogram to treat oceanic water masses as distinct geographic units presents a ‘hydrotectonic’ history of Pacific surface water masses. It is used to test the idea that the oceanographic subdivision of the surface waters of the Pacific Basin into separate water masses shaped pelagic biogeographic patterns in much the same way that the tectonic fragmentation of Pangea influenced biogeographic patterns on land. The historical water-mass relationships depicted by the surface water-mass cladogram resemble modern pelagic biogeographic regions. The prediction that the cladistic phylogenies of monophyletic groups having allopatric taxa in three or more surface water masses will be consistent with the topology of the surface water-mass cladogram is met by the pelagic fish genera Stomias and Evermanella.

A mixed integer linear programming model to reconstruct phylogenies from single nucleotide polymorphism haplotypes under the maximum parsimony criterion

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2013-01-01

Background Phylogeny estimation from aligned haplotype sequences has attracted more and more attention in the recent years due to its importance in analysis of many fine-scale genetic data. Its application fields range from medical research, to drug discovery, to epidemiology, to population dynamics. The literature on molecular phylogenetics proposes a number of criteria for selecting a phylogeny from among plausible alternatives. Usually, such criteria can be expressed by means of objective functions, and the phylogenies that optimize them are referred to as optimal. One of the most important estimation criteria is the parsimony which states that the optimal phylogeny T∗for a set H of n haplotype sequences over a common set of variable loci is the one that satisfies the following requirements: (i) it has the shortest length and (ii) it is such that, for each pair of distinct haplotypes hi,hj∈H, the sum of the edge weights belonging to the path from hi to hj in T∗ is not smaller than the observed number of changes between hi and hj. Finding the most parsimonious phylogeny for H involves solving an optimization problem, called the Most Parsimonious Phylogeny Estimation Problem (MPPEP), which is NP-hard in many of its versions. Results In this article we investigate a recent version of the MPPEP that arises when input data consist of single nucleotide polymorphism haplotypes extracted from a population of individuals on a common genomic region. Specifically, we explore the prospects for improving on the implicit enumeration strategy of implicit enumeration strategy used in previous work using a novel problem formulation and a series of strengthening valid inequalities and preliminary symmetry breaking constraints to more precisely bound the solution space and accelerate implicit enumeration of possible optimal phylogenies. We present the basic formulation and then introduce a series of provable valid constraints to reduce the solution space. We then prove

An integer programming formulation of the parsimonious loss of heterozygosity problem.

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Catanzaro, Daniele; Labbé, Martine; Halldórsson, Bjarni V

2013-01-01

A loss of heterozygosity (LOH) event occurs when, by the laws of Mendelian inheritance, an individual should be heterozygote at a given site but, due to a deletion polymorphism, is not. Deletions play an important role in human disease and their detection could provide fundamental insights for the development of new diagnostics and treatments. In this paper, we investigate the parsimonious loss of heterozygosity problem (PLOHP), i.e., the problem of partitioning suspected polymorphisms from a set of individuals into a minimum number of deletion areas. Specifically, we generalize Halldórsson et al.'s work by providing a more general formulation of the PLOHP and by showing how one can incorporate different recombination rates and prior knowledge about the locations of deletions. Moreover, we show that the PLOHP can be formulated as a specific version of the clique partition problem in a particular class of graphs called undirected catch-point interval graphs and we prove its general $({\\cal NP})$-hardness. Finally, we provide a state-of-the-art integer programming (IP) formulation and strengthening valid inequalities to exactly solve real instances of the PLOHP containing up to 9,000 individuals and 3,000 SNPs. Our results give perspectives on the mathematics of the PLOHP and suggest new directions on the development of future efficient exact solution approaches.

Synthesis and Dimerization Behavior of Five Metallophthalocyanines in Different Solvents

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Zhenhua Cheng

2014-01-01

Full Text Available Metallophthalocyanine (MPc has become one of the metal organic compounds with the largest production and the most widely application, because of its excellent performance in catalytic oxidation. However, aggregation of the MPc in solution, resulting in decreased solubility, greatly limits the performance of application. Studying the behavior of dimerization of MPcs can provide a theoretical basis for solving the problem of the low solubility. So five metallophthalocyanines (FePc, CoPc, NiPc, CuPc, and ZnPc were prepared with improved method and characterized. Dimerization of the five MPcs was measured by UV-Vis spectroscopy separately in N,N-dimethyl formamide (DMF and dimethylsulfoxide (DMSO. The red-shift of maximum absorption wavelength and deviations from Lambert-Beer law with increasing the concentration were observed for all the five MPcs. The dimerization equilibrium constants (K of the five MPcs in DMF were arranged in order of CoPc > ZnPc > CuPc > FePc > NiPc, while in DMSO they were arranged in order of ZnPc > CoPc > FePc > CuPc > NiPc. The type of the central metal and nature of the solvent affect the dimerization of the MPcs.

Establishing linear solvation energy relationships between VOCs and monolayer-protected gold nanoclusters using quartz crystal microbalance.

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Li, Chi-Lin; Lu, Chia-Jung

2009-08-15

Linear solvation energy relationships (LSERs) have been recognized as a useful model for investigating the chemical forces behind the partition coefficients between vapor molecules and absorbents. This study is the first to determine the solvation properties of monolayer-protected gold nanoclusters (MPCs) with different surface ligands. The ratio of partition coefficients/MPC density (K/rho) of 18 volatile organic compounds (VOCs) for four different MPCs obtained through quartz crystal microbalance (QCM) experiments were used for the LSER model calculations. LSER modeling results indicate that all MPC surfaces showed a statistically significant (pattraction, 4-methoxythiophenol-capped MPCs can also interact with polar organics (s=1.04). Showing a unique preference for the hydrogen bond basicity of vapors (b=1.11), 2-benzothiazolethiol-capped MPCs provide evidence of an intra-molecular, proton-shift mechanism on surface of nano-gold.

Bibliometric analysis of systematics production in Latin America

International Nuclear Information System (INIS)

Michan Aguirre, Layla

2011-01-01

I compare six bibliographic databases with information on Latin American systematics: Biosis, CAB, periodica, SCI, scopus and Zoological record. the databases are characterized and compared considering their content, temporal, typological, geographical, thematical coverage, kind of access and new taxon description, to identify which and how many should be used to be more representative. Of the 1363 journals analyzed, 36.5% are found in more than one database and 63.46% are recorded in a single one. zoological record contains 63421 documents, Biosis 19079, CAB 14363, periodica 11185, SCI 3257 and scopus 916. CAB and ZR are the oldest databases, the average number of articles published per year was 6417 for Biosis, 433 for ZR, 361 for periodica, 145 for CAB, 91 for SCI and 30 for Scopus. According to the network analysis, there are stronger relations between SCI and Biosis, which share at least 16% of titles, CAB and Biosis share 15%, Biosis and ZR 14%, and CAB and ZR 11%. Based on the cladogram obtained from a parsimony analysis on the shared journals, the strongest relation is between Biosis and SCI; periodica has the largest number of exclusive journals with 285. ZR has 72.9% of published articles with descriptions of new taxa and an average of 322 a year, CAB 54.6% with 82, and periodica 24.6% with 90. None of databases meets the characteristics to be used as a single source of information, therefore it would be appropriate to use different combinations according to the aim of the analysis. biosis has the most comprehensive information on any current taxon, zoological record and CAB have a broader temporal coverage and include mainly animals or plants, respectively. SCI has the largest number of documents in mainstream journals, with references, citations and bibliometric indicators. periodica has the largest number of documents and temporal coverage published in the area. The cladogram proved to be an optimal visualization tool to represent the main features of

Innovative Bayesian and Parsimony Phylogeny of Dung Beetles (Coleoptera, Scarabaeidae, Scarabaeinae) Enhanced by Ontology-Based Partitioning of Morphological Characters

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Tarasov, Sergei; Génier, François

2015-01-01

Scarabaeine dung beetles are the dominant dung feeding group of insects and are widely used as model organisms in conservation, ecology and developmental biology. Due to the conflicts among 13 recently published phylogenies dealing with the higher-level relationships of dung beetles, the phylogeny of this lineage remains largely unresolved. In this study, we conduct rigorous phylogenetic analyses of dung beetles, based on an unprecedented taxon sample (110 taxa) and detailed investigation of morphology (205 characters). We provide the description of morphology and thoroughly illustrate the used characters. Along with parsimony, traditionally used in the analysis of morphological data, we also apply the Bayesian method with a novel approach that uses anatomy ontology for matrix partitioning. This approach allows for heterogeneity in evolutionary rates among characters from different anatomical regions. Anatomy ontology generates a number of parameter-partition schemes which we compare using Bayes factor. We also test the effect of inclusion of autapomorphies in the morphological analysis, which hitherto has not been examined. Generally, schemes with more parameters were favored in the Bayesian comparison suggesting that characters located on different body regions evolve at different rates and that partitioning of the data matrix using anatomy ontology is reasonable; however, trees from the parsimony and all the Bayesian analyses were quite consistent. The hypothesized phylogeny reveals many novel clades and provides additional support for some clades recovered in previous analyses. Our results provide a solid basis for a new classification of dung beetles, in which the taxonomic limits of the tribes Dichotomiini, Deltochilini and Coprini are restricted and many new tribes must be described. Based on the consistency of the phylogeny with biogeography, we speculate that dung beetles may have originated in the Mesozoic contrary to the traditional view pointing to a

Purification and ex vivo expansion of postnatal human marrow mesodermal progenitor cells.

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Reyes, M; Lund, T; Lenvik, T; Aguiar, D; Koodie, L; Verfaillie, C M

2001-11-01

It is here reported that mesenchymal stem cells known to give rise to limb-bud mesoderm can, at the single-cell level, also differentiate into cells of visceral mesoderm and can be expanded extensively by means of clinically applicable methods. These cells were named mesodermal progenitor cells (MPCs). MPCs were selected by depleting bone marrow mononuclear cells from more than 30 healthy human donors of CD45(+)/glycophorin-A (GlyA)(+) cells. Cells were cultured on fibronectin with epidermal growth factor and platelet-derived growth factor BB and 2% or less fetal calf serum. It was found that 1/5 x 10(3) CD45(-)GlyA(-) cells, or 1/10(6) bone marrow mononuclear cells, gave rise to clusters of small adherent cells. Cell-doubling time was 48 to 72 hours, and cells have been expanded in culture for more than 60 cell doublings. MPCs are CD34(-), CD44(low), CD45(-), CD117 (cKit)(-), class I-HLA(-), and HLA-DR(-). MPCs differentiated into cells of limb-bud mesoderm (osteoblasts, chondrocytes, adipocytes, stroma cells, and skeletal myoblasts) as well as visceral mesoderm (endothelial cells). Retroviral marking was used to definitively prove that single MPCs can differentiate into cells of limb bud and visceral mesoderm. Thus, MPCs that proliferate without obvious senescence under clinically applicable conditions and differentiate at the single-cell level not only into mesenchymal cells but also cells of visceral mesoderm may be an ideal source of stem cells for treatment of genetic or degenerative disorders affecting cells of mesodermal origin.

Maximum Permissible Concentrations and Negligible Concentrations for pesticides

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Crommentuijn T; Kalf DF; Polder MD; Posthumus R; Plassche EJ van de; CSR

1997-01-01

Maximum Permissible Concentrations (MPCs) and Negligible Concentrations (NCs) derived for a series of pesticides are presented in this report. These MPCs and NCs are used by the Ministry of Housing, Spatial Planning and the Environment (VROM) to set Environmental Quality Objectives. For some of the

An objective and parsimonious approach for classifying natural flow regimes at a continental scale

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Archfield, S. A.; Kennen, J.; Carlisle, D.; Wolock, D.

2013-12-01

Hydroecological stream classification--the process of grouping streams by similar hydrologic responses and, thereby, similar aquatic habitat--has been widely accepted and is often one of the first steps towards developing ecological flow targets. Despite its importance, the last national classification of streamgauges was completed about 20 years ago. A new classification of 1,534 streamgauges in the contiguous United States is presented using a novel and parsimonious approach to understand similarity in ecological streamflow response. This new classification approach uses seven fundamental daily streamflow statistics (FDSS) rather than winnowing down an uncorrelated subset from 200 or more ecologically relevant streamflow statistics (ERSS) commonly used in hydroecological classification studies. The results of this investigation demonstrate that the distributions of 33 tested ERSS are consistently different among the classes derived from the seven FDSS. It is further shown that classification based solely on the 33 ERSS generally does a poorer job in grouping similar streamgauges than the classification based on the seven FDSS. This new classification approach has the additional advantages of overcoming some of the subjectivity associated with the selection of the classification variables and provides a set of robust continental-scale classes of US streamgauges.

Increased Stiffness in Aged Skeletal Muscle Impairs Muscle Progenitor Cell Proliferative Activity.

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Grégory Lacraz

Full Text Available Skeletal muscle aging is associated with a decreased regenerative potential due to the loss of function of endogenous stem cells or myogenic progenitor cells (MPCs. Aged skeletal muscle is characterized by the deposition of extracellular matrix (ECM, which in turn influences the biomechanical properties of myofibers by increasing their stiffness. Since the stiffness of the MPC microenvironment directly impacts MPC function, we hypothesized that the increase in muscle stiffness that occurs with aging impairs the behavior of MPCs, ultimately leading to a decrease in regenerative potential.We showed that freshly isolated individual myofibers from aged mouse muscles contain fewer MPCs overall than myofibers from adult muscles, with fewer quiescent MPCs and more proliferative and differentiating MPCs. We observed alterations in cultured MPC behavior in aged animals, where the proliferation and differentiation of MPCs were lower and higher, respectively. These alterations were not linked to the intrinsic properties of aged myofibers, as shown by the similar values for the cumulative population-doubling values and fusion indexes. However, atomic force microscopy (AFM indentation experiments revealed a nearly 4-fold increase in the stiffness of the MPC microenvironment. We further showed that the increase in stiffness is associated with alterations to muscle ECM, including the accumulation of collagen, which was correlated with higher hydroxyproline and advanced glycation end-product content. Lastly, we recapitulated the impaired MPC behavior observed in aging using a hydrogel substrate that mimics the stiffness of myofibers.These findings provide novel evidence that the low regenerative potential of aged skeletal muscle is independent of intrinsic MPC properties but is related to the increase in the stiffness of the MPC microenvironment.

Magnetophotonic crystals based on yttrium-iron-garnet infiltrated opals: Magnetization-induced second-harmonic generation

Science.gov (United States)

Murzina, T. V.; Kim, E. M.; Kapra, R. V.; Moshnina, I. V.; Aktsipetrov, O. A.; Kurdyukov, D. A.; Kaplan, S. F.; Golubev, V. G.; Bader, M. A.; Marowsky, G.

2006-01-01

Three-dimensional magnetophotonic crystals (MPCs) based on artificial opals infiltrated by yttrium iron garnet (YIG) are fabricated and their structural, optical, and nonlinear optical properties are studied. The formation of the crystalline YIG inside the opal matrix is checked by x-ray analysis. Two templates are used for the infiltration by YIG: bare opals and those covered by a thin platinum film. Optical second-harmonic generation (SHG) technique is used to study the magnetization-induced nonlinear-optical properties of the composed MPCs. A high nonlinear magneto-optical Kerr effect in the SHG intensity is observed at the edge of the photonic band gap of the MPCs.

Speciation on a conveyor belt: sequential colonization of the hawaiian islands by Orsonwelles spiders (Araneae, Linyphiidae).

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Hormiga, Gustavo; Arnedo, Miquel; Gillespie, Rosemary G

2003-02-01

Spiders of the recently described linyphiid genus Orsonwelles (Araneae, Linyphiidae) are one of the most conspicuous groups of terrestrial arthropods of Hawaiian native forests. There are 13 known Orsonwelles species, and all are single- island endemics. This radiation provides an excellent example of insular gigantism. We reconstructed the cladistic relationships of Orsonwelles species using a combination of morphological and molecular characters (both mitochondrial and nuclear sequences) within a parsimony framework. We explored and quantified the contribution of different character partitions and their sensitivity to changes in the traditional parameters (gap, transition, and transversion costs). The character data show a strong phylogenetic signal, robust to parameter changes. The monophyly of the genus Orsonwelles is strongly supported. The parsimony analysis of all character evidence combined recovered a clade with of all the non-Kauai Orsonwelles species; the species from Kauai form a paraphyletic assemblage with respect to the latter former clade. The biogeographic pattern of the Hawaiian Orsonwelles species is consistent with colonization by island progression, but alternative explanations for our data exist. Although the geographic origin of the radiation remains unknown, it appears that the ancestral colonizing species arrived first on Kauai (or an older island). The ambiguity in the area cladogram (i.e., post-Oahu colonization) is not derived from conflicting or unresolved phylogenetic signal among Orsonwelles species but rather from the number of taxa on the youngest islands. Speciation in Orsonwelles occurred more often within islands (8 of the 12 cladogenic events) than between islands. A molecular clock was rejected for the sequence data. Divergence times were estimated by using the nonparametric rate smoothing method of Sanderson (1997, Mol. Biol. Evol. 14:1218-1231) and the available geological data for calibration. The results suggest that the

Inferring phylogenetic networks by the maximum parsimony criterion: a case study.

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Jin, Guohua; Nakhleh, Luay; Snir, Sagi; Tuller, Tamir

2007-01-01

Horizontal gene transfer (HGT) may result in genes whose evolutionary histories disagree with each other, as well as with the species tree. In this case, reconciling the species and gene trees results in a network of relationships, known as the "phylogenetic network" of the set of species. A phylogenetic network that incorporates HGT consists of an underlying species tree that captures vertical inheritance and a set of edges which model the "horizontal" transfer of genetic material. In a series of papers, Nakhleh and colleagues have recently formulated a maximum parsimony (MP) criterion for phylogenetic networks, provided an array of computationally efficient algorithms and heuristics for computing it, and demonstrated its plausibility on simulated data. In this article, we study the performance and robustness of this criterion on biological data. Our findings indicate that MP is very promising when its application is extended to the domain of phylogenetic network reconstruction and HGT detection. In all cases we investigated, the MP criterion detected the correct number of HGT events required to map the evolutionary history of a gene data set onto the species phylogeny. Furthermore, our results indicate that the criterion is robust with respect to both incomplete taxon sampling and the use of different site substitution matrices. Finally, our results show that the MP criterion is very promising in detecting HGT in chimeric genes, whose evolutionary histories are a mix of vertical and horizontal evolution. Besides the performance analysis of MP, our findings offer new insights into the evolution of 4 biological data sets and new possible explanations of HGT scenarios in their evolutionary history.

Stochastic rainfall modeling in West Africa: Parsimonious approaches for domestic rainwater harvesting assessment

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Cowden, Joshua R.; Watkins, David W., Jr.; Mihelcic, James R.

2008-10-01

SummarySeveral parsimonious stochastic rainfall models are developed and compared for application to domestic rainwater harvesting (DRWH) assessment in West Africa. Worldwide, improved water access rates are lowest for Sub-Saharan Africa, including the West African region, and these low rates have important implications on the health and economy of the region. Domestic rainwater harvesting (DRWH) is proposed as a potential mechanism for water supply enhancement, especially for the poor urban households in the region, which is essential for development planning and poverty alleviation initiatives. The stochastic rainfall models examined are Markov models and LARS-WG, selected due to availability and ease of use for water planners in the developing world. A first-order Markov occurrence model with a mixed exponential amount model is selected as the best option for unconditioned Markov models. However, there is no clear advantage in selecting Markov models over the LARS-WG model for DRWH in West Africa, with each model having distinct strengths and weaknesses. A multi-model approach is used in assessing DRWH in the region to illustrate the variability associated with the rainfall models. It is clear DRWH can be successfully used as a water enhancement mechanism in West Africa for certain times of the year. A 200 L drum storage capacity could potentially optimize these simple, small roof area systems for many locations in the region.

Neural differentiation of novel multipotent progenitor cells from cryopreserved human umbilical cord blood

International Nuclear Information System (INIS)

Lee, Myoung Woo; Moon, Young Joon; Yang, Mal Sook; Kim, Sun Kyung; Jang, In Keun; Eom, Young-woo; Park, Joon Seong; Kim, Hugh C.; Song, Kye Yong; Park, Soon Cheol; Lim, Hwan Sub; Kim, Young Jin

2007-01-01

Umbilical cord blood (UCB) is a rich source of hematopoietic stem cells, with practical and ethical advantages. To date, the presence of other stem cells in UCB remains to be established. We investigated whether other stem cells are present in cryopreserved UCB. Seeded mononuclear cells formed adherent colonized cells in optimized culture conditions. Over a 4- to 6-week culture period, colonized cells gradually developed into adherent mono-layer cells, which exhibited homogeneous fibroblast-like morphology and immunophenotypes, and were highly proliferative. Isolated cells were designated 'multipotent progenitor cells (MPCs)'. Under appropriate conditions for 2 weeks, MPCs differentiated into neural tissue-specific cell types, including neuron, astrocyte, and oligodendrocyte. Differentiated cells presented their respective markers, specifically, NF-L and NSE for neurons, GFAP for astrocytes, and myelin/oligodendrocyte for oligodendrocytes. In this study, we successfully isolated MPCs from cryopreserved UCB, which differentiated into the neural tissue-specific cell types. These findings suggest that cryopreserved human UCB is a useful alternative source of neural progenitor cells, such as MPCs, for experimental and therapeutic applications

Sciaenidae fish of the Caeté River estuary, Northern Brazil: mitochondrial DNA suggests explosive radiation for the Western Atlantic assemblage

Directory of Open Access Journals (Sweden)

Christina Vinson

2004-01-01

Full Text Available Sciaenids are fish which are normally abundant in tropical estuaries of the western Atlantic. Studies on the Caeté river estuary in the northern Brazilian state of Pará have revealed that in this area Sciaenidae is the dominant family, comprising almost 50% of all teleosts sampled. In this paper we present the results of the first phylogenetic study on South American estuarine sciaenids, during which we obtained mitochondrial gene 16S sequences from 15 species belonging to eight genera occurring in the Caeté estuary. Intergeneric nucleotide divergences varied from 5 to 15%, Lonchurus and Menticirrhus being the most divergent lineages. Nucleotide divergences were quite variable amongst species of the same genus, ranging from 1.2% (Stellifer microps x Stellifer naso to 8.4% (Menticirrhus americanus x Menticirrhus littoralis. Cladograms based on maximum parsimony, minimum evolution and maximum likelihood depicted an explosive diversification pattern for the western Atlantic sciaenid assemblage. Our analysis further reveals a very close relationship between Bairdiella and Stellifer, a monophyletic clade which emerged during the more recent diversification events of the Sciaenidae family. The phylogenetic reconstruction suggests the need for a revision of the taxonomy and nomenclature of the Bairdiella/Stellifer group.

Parsimonious data: How a single Facebook like predicts voting behavior in multiparty systems.

Directory of Open Access Journals (Sweden)

Jakob Bæk Kristensen

Full Text Available This study shows how liking politicians' public Facebook posts can be used as an accurate measure for predicting present-day voter intention in a multiparty system. We highlight that a few, but selective digital traces produce prediction accuracies that are on par or even greater than most current approaches based upon bigger and broader datasets. Combining the online and offline, we connect a subsample of surveyed respondents to their public Facebook activity and apply machine learning classifiers to explore the link between their political liking behaviour and actual voting intention. Through this work, we show that even a single selective Facebook like can reveal as much about political voter intention as hundreds of heterogeneous likes. Further, by including the entire political like history of the respondents, our model reaches prediction accuracies above previous multiparty studies (60-70%. The main contribution of this paper is to show how public like-activity on Facebook allows political profiling of individual users in a multiparty system with accuracies above previous studies. Beside increased accuracies, the paper shows how such parsimonious measures allows us to generalize our findings to the entire population of a country and even across national borders, to other political multiparty systems. The approach in this study relies on data that are publicly available, and the simple setup we propose can with some limitations, be generalized to millions of users in other multiparty systems.

Using XML Configuration-Driven Development to Create a Customizable Ground Data System

Science.gov (United States)

Nash, Brent; DeMore, Martha

2009-01-01

The Mission data Processing and Control Subsystem (MPCS) is being developed as a multi-mission Ground Data System with the Mars Science Laboratory (MSL) as the first fully supported mission. MPCS is a fully featured, Java-based Ground Data System (GDS) for telecommand and telemetry processing based on Configuration-Driven Development (CDD). The eXtensible Markup Language (XML) is the ideal language for CDD because it is easily readable and editable by all levels of users and is also backed by a World Wide Web Consortium (W3C) standard and numerous powerful processing tools that make it uniquely flexible. The CDD approach adopted by MPCS minimizes changes to compiled code by using XML to create a series of configuration files that provide both coarse and fine grained control over all aspects of GDS operation.

Solvent Effect on Redox Properties of Hexanethiolate Monolayer-Protected Gold Nanoclusters

OpenAIRE

Su, B; Zhang, M; Shao, Y; Girault, HH

2006-01-01

The capacitance of monolayer-protected gold nanoclusters (MPCs), CMPC, in solution has been theoretically reconsidered from an electrostatic viewpoint, in which an MPC is considered as an isolated charged sphere within two dielectric layers, the intrinsic coating monolayer, and the bulk solvent. The model predicts that the bulk solvent provides an important contribution to CMPC and influences the redox properties of MPCs. This theoretical prediction is then examined experimentally by comparin...

Parsimonious model for blood glucose level monitoring in type 2 diabetes patients.

Science.gov (United States)

Zhao, Fang; Ma, Yan Fen; Wen, Jing Xiao; DU, Yan Fang; Li, Chun Lin; Li, Guang Wei

2014-07-01

To establish the parsimonious model for blood glucose monitoring in patients with type 2 diabetes receiving oral hypoglycemic agent treatment. One hundred and fifty-nine adult Chinese type 2 diabetes patients were randomized to receive rapid-acting or sustained-release gliclazide therapy for 12 weeks. Their blood glucose levels were measured at 10 time points in a 24 h period before and after treatment, and the 24 h mean blood glucose levels were measured. Contribution of blood glucose levels to the mean blood glucose level and HbA1c was assessed by multiple regression analysis. The correlation coefficients of blood glucose level measured at 10 time points to the daily MBG were 0.58-0.74 and 0.59-0.79, respectively, before and after treatment (Pblood glucose levels measured at 6 of the 10 time points could explain 95% and 97% of the changes in MBG before and after treatment. The three blood glucose levels, which were measured at fasting, 2 h after breakfast and before dinner, of the 10 time points could explain 84% and 86% of the changes in MBG before and after treatment, but could only explain 36% and 26% of the changes in HbA1c before and after treatment, and they had a poorer correlation with the HbA1c than with the 24 h MBG. The blood glucose levels measured at fasting, 2 h after breakfast and before dinner truly reflected the change 24 h blood glucose level, suggesting that they are appropriate for the self-monitoring of blood glucose levels in diabetes patients receiving oral anti-diabetes therapy. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Taurine Transporter Gene Expression in Mononuclear Blood Cells of Type 1 Diabetes Patients.

Science.gov (United States)

Napoli, Zaleida; Seghieri, Giuseppe; Bianchi, Loria; Anichini, Roberto; De Bellis, Alessandra; Campesi, Ilaria; Carru, Ciriaco; Occhioni, Stefano; Zinellu, Angelo; Franconi, Flavia

2016-01-01

Taurine transporter gene expression (RNA-TauT) has a role in retinal cell function and is modulated in vitro and in vivo by hyperglycemia and/or oxidative stress. This study was aimed at testing whether RNA-TauT gene expression is modified in blood mononuclear peripheral cells (MPCs) of type 1 diabetic patients, is related to plasma markers of oxidative stress or endothelial dysfunction, or, finally, is related to presence of retinopathy. RNA-TauT was measured in MPCs by real-time PCR-analysis in 35 type 1 diabetic patients and in 33 age- and sex-matched controls, additionally measuring plasma and cell taurine and markers of oxidative stress and endothelial dysfunction. RNA-TauT, expressed as 2(-ΔΔCt), was significantly higher in MPCs of type 1 diabetic patients than in controls [median (interquartile range): 1.32(0.31) versus 1.00(0.15); P = 0.01]. In diabetic patients RNA-TauT was related to HbA1c (r = 0.42; P = 0.01) and inversely to plasma homocysteine (r = -0.39; P = 0.02) being additionally significantly higher in MPCs of patients without retinopathy [(n = 22); 1.36(0.34)] compared to those with retinopathy [(n = 13); 1.16(0.20)], independently from HbA1c or diabetes duration. RNA-TauT gene expression is significantly upregulated in MPCs of type 1 diabetes patients and is related to HbA1c levels and inversely to plasma homocysteine. Finally, in diabetes patients, RNA-TauT upregulation seems to be blunted in patients with retinopathy independently of their metabolic control or longer diabetes duration.

Sustained Pulmonary Delivery of a Water-Soluble Antibiotic Without Encapsulating Carriers.

Science.gov (United States)

Ong, Winston; Nowak, Pawel; Cu, Yen; Schopf, Lisa; Bourassa, James; Enlow, Elizabeth; Moskowitz, Samuel M; Chen, Hongming

2016-03-01

Traditional polymeric nanoparticle formulations for prolonged local action during inhalation therapy are highly susceptible to muco-ciliary clearance. In addition, polymeric carriers are typically administered in high doses due to finite drug loading. For toxicological reasons, these carriers and their degradation byproducts are undesirable for inhalation therapy, particularly for chronic use, due to potential lung accumulation. We synthesized a novel, insoluble prodrug (MRPD) of a time-dependent β-lactam, meropenem, and formulated MRPD into mucus-penetrating crystals (MRPD-MPCs). After characterizing their mucus mobility (in vitro) and stability, we evaluated the lung pharmacokinetics of intratracheally-instilled MRPD-MPCs and a meropenem solution in guinea pigs. Meropenem levels rapidly declined in the lungs of guinea pigs receiving meropenem solution compared to those given MRPD-MPCs. At 9 h after dosing, drug levels in the lungs of animals that received meropenem solution dropped to 12 ng/mL, whereas those that received MRPD-MPCs maintained an average drug level of ≥1,065 ng/mL over a 12-h period. This work demonstrated that the combination of prodrug chemistry and mucus-penetrating platform created nanoparticles that produced sustained levels of meropenem in guinea pig lungs. This strategy represents a novel approach for sustained local drug delivery to the lung without using encapsulating matrices.

Graphene oxide as a dual-function conductive binder for PEEK-derived microporous carbons in high performance supercapacitors

Science.gov (United States)

Kim, Christine H. J.; Zhang, Hongbo; Liu, Jie

2015-06-01

Microporous carbons (MPCs) are promising electrode materials for supercapacitors because of their high surface area and accessible pores. However, their low electrical conductivity and mechanical instability result in limited power density and poor cycle life. This work proposes a unique two-layered film made of polyetheretherketone-derived MPCs and reduced graphene oxide (rGO) as an electrode for supercapacitors. Electrochemical characterizations of films show that such a layered structure is more effective in increasing the accessibility of ions to the hydrophilic MPCs and establishing conductive paths through the rGO network than a simple mixed composite film. The two-layered structure increases the capacitance by ˜124% (237 F g-1) with excellent cycling stability (˜93% after 6000 cycles). More importantly, we demonstrate that such performance improvements result from an optimal balance between electrical conductivity and ion accessibility, which maximizes the synergistic effects of MPC and rGO. The MPCs, which are exposed to the surface, provide a highly accessible surface area for ion adsorption. The rGO serves a dual function as a conductive filler to increase the electrical conductivity and as a binder to interconnect individual MPC particles into a robust and flexible film. These findings provide a rational basis for the design of MPC-based electrodes in high performance supercapacitors.

Three-dimensional magnetophotonic crystals based on artificial opals

Science.gov (United States)

Baryshev, A. V.; Kodama, T.; Nishimura, K.; Uchida, H.; Inoue, M.

2004-06-01

We fabricated and experimentally investigated three-dimensional magnetophotonic crystals (3D MPCs) based on artificial opals. Opal samples with three-dimensional dielectric lattices were impregnated with different types of magnetic material. Magnetic and structural properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. We have shown that magnetic materials synthesized in voids of opal lattices and the composites obtained have typical magnetic properties.

Three-dimensional magnetophotonic crystals based on artificial opals

International Nuclear Information System (INIS)

Baryshev, A.V.; Kodama, T.; Nishimura, K.; Uchida, H.; Inoue, M.

2004-01-01

We fabricated and experimentally investigated three-dimensional magnetophotonic crystals (3D MPCs) based on artificial opals. Opal samples with three-dimensional dielectric lattices were impregnated with different types of magnetic material. Magnetic and structural properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. We have shown that magnetic materials synthesized in voids of opal lattices and the composites obtained have typical magnetic properties

Adult Stem Cell-Based Enhancement of Nerve Conduit for Peripheral Nerve Repair

Science.gov (United States)

2017-10-01

neurotrophically activated cell types and conditioned media (via RT-PCR and ELISA of neurotrophic factors), followed by cell storage Specific objective 9...Mesenchymal Progenitor Cells (NI-MiMPCs) and Mesenchymal Stem Cells (MSCs), quantified via ELISA . MiMPCs and MSCs were cultured in neurotrophic induction...LIF, (E) osteonectin, and (F) clusterin. All ELISA results are expressed in pg/ml or ng/ml produced per million cells. Medium taken from NI-MiMPC

Modeling the isotopic evolution of snowpack and snowmelt: Testing a spatially distributed parsimonious approach.

Science.gov (United States)

Ala-Aho, Pertti; Tetzlaff, Doerthe; McNamara, James P; Laudon, Hjalmar; Kormos, Patrick; Soulsby, Chris

2017-07-01

Use of stable water isotopes has become increasingly popular in quantifying water flow paths and travel times in hydrological systems using tracer-aided modeling. In snow-influenced catchments, snowmelt produces a traceable isotopic signal, which differs from original snowfall isotopic composition because of isotopic fractionation in the snowpack. These fractionation processes in snow are relatively well understood, but representing their spatiotemporal variability in tracer-aided studies remains a challenge. We present a novel, parsimonious modeling method to account for the snowpack isotope fractionation and estimate isotope ratios in snowmelt water in a fully spatially distributed manner. Our model introduces two calibration parameters that alone account for the isotopic fractionation caused by sublimation from interception and ground snow storage, and snowmelt fractionation progressively enriching the snowmelt runoff. The isotope routines are linked to a generic process-based snow interception-accumulation-melt model facilitating simulation of spatially distributed snowmelt runoff. We use a synthetic modeling experiment to demonstrate the functionality of the model algorithms in different landscape locations and under different canopy characteristics. We also provide a proof-of-concept model test and successfully reproduce isotopic ratios in snowmelt runoff sampled with snowmelt lysimeters in two long-term experimental catchment with contrasting winter conditions. To our knowledge, the method is the first such tool to allow estimation of the spatially distributed nature of isotopic fractionation in snowpacks and the resulting isotope ratios in snowmelt runoff. The method can thus provide a useful tool for tracer-aided modeling to better understand the integrated nature of flow, mixing, and transport processes in snow-influenced catchments.

Differentiation and carcinogenesis: an integrated multilevel study of mechanisms from molecules to man. Progress report

International Nuclear Information System (INIS)

1985-01-01

This study sought to identify and characterize mesenchymal progenitor cells (MPCs) in vitro, to identify the in vivo equivalent of the in vitro MPCs, and to determine the relationship between the presence or response of these cells both in vitro and eventually in vivo to altered proliferative capacity (in vitro cellular senescence, in vivo organismal aging) and altered susceptibility to carcinogenesis (frequency of in vitro neoplastic transformation and age-related frequency of in vivo cancer incidence). 16 refs

Crosstalk between Wnt/β-catenin and estrogen receptor signaling synergistically promotes osteogenic differentiation of mesenchymal progenitor cells.

Directory of Open Access Journals (Sweden)

Yanhong Gao

Full Text Available Osteogenic differentiation from mesenchymal progenitor cells (MPCs are initiated and regulated by a cascade of signaling events. Either Wnt/β-catenin or estrogen signaling pathway has been shown to play an important role in regulating skeletal development and maintaining adult tissue homeostasis. Here, we investigate the potential crosstalk and synergy of these two signaling pathways in regulating osteogenic differentiation of MPCs. We find that the activation of estrogen receptor (ER signaling by estradiol (E2 or exogenously expressed ERα in MPCs synergistically enhances Wnt3A-induced early and late osteogenic markers, as well as matrix mineralization. The E2 or ERα-mediated synergy can be effectively blocked by ERα antagonist tamoxifen. E2 stimulation can enhance endochondral ossification of Wnt3A-transduced mouse fetal limb explants. Furthermore, exogenously expressed ERα significantly enhances the maturity and mineralization of Wnt3A-induced subcutaneous and intramuscular ectopic bone formation. Mechanistically, we demonstrate that E2 does not exert any detectable effect on β-catenin/Tcf reporter activity. However, ERα expression is up-regulated within the first 48h in AdWnt3A-transduced MPCs, whereas ERβ expression is significantly inhibited within 24h. Moreover, the key enzyme for the biosynthesis of estrogens aromatase is modulated by Wnt3A in a biphasic manner, up-regulated at 24h but reduced after 48h. Our results demonstrate that, while ER signaling acts synergistically with Wnt3A in promoting osteogenic differentiation, Wnt3A may crosstalk with ER signaling by up-regulating ERα expression and down-regulating ERβ expression in MPCs. Thus, the signaling crosstalk and synergy between these two pathways should be further explored as a potential therapeutic approach to combating bone and skeletal disorders, such as fracture healing and osteoporosis.

Graphene oxide as a dual-function conductive binder for PEEK-derived microporous carbons in high performance supercapacitors

International Nuclear Information System (INIS)

Kim, Christine H J; Zhang, Hongbo; Liu, Jie

2015-01-01

Microporous carbons (MPCs) are promising electrode materials for supercapacitors because of their high surface area and accessible pores. However, their low electrical conductivity and mechanical instability result in limited power density and poor cycle life. This work proposes a unique two-layered film made of polyetheretherketone-derived MPCs and reduced graphene oxide (rGO) as an electrode for supercapacitors. Electrochemical characterizations of films show that such a layered structure is more effective in increasing the accessibility of ions to the hydrophilic MPCs and establishing conductive paths through the rGO network than a simple mixed composite film. The two-layered structure increases the capacitance by ∼124% (237 F g −1 ) with excellent cycling stability (∼93% after 6000 cycles). More importantly, we demonstrate that such performance improvements result from an optimal balance between electrical conductivity and ion accessibility, which maximizes the synergistic effects of MPC and rGO. The MPCs, which are exposed to the surface, provide a highly accessible surface area for ion adsorption. The rGO serves a dual function as a conductive filler to increase the electrical conductivity and as a binder to interconnect individual MPC particles into a robust and flexible film. These findings provide a rational basis for the design of MPC-based electrodes in high performance supercapacitors. (paper)

Data regarding association between serum osteoprotegerin level, numerous of circulating endothelial-derived and mononuclear-derived progenitor cells in patients with metabolic syndrome

Directory of Open Access Journals (Sweden)

Alexander E. Berezin

2016-09-01

Full Text Available Metabolic syndrome (MetS is defined as cluster of multiple metabolic and cardiovascular (CV abnormalities included abdominal obesity, high-normal blood pressure, dyslipidaemia, and impaired fasting glucose tolerance that exhibits has a growing prevalence worldwide. We investigated whether an elevated level of osteoprotegerin (OPG predicts imbalance between different phenotypes of circulating endothelial (EPCs and mononuclear (MPCs progenitor cells in MetS patients. We have analyzed data regarding dysmetabolic disorder subjects without known CV disease, as well as with known type two diabetes mellitus. All patients have given their informed written consent for participation in the study. This article contains data on the independent predictors of depletion in numerous of circulating EPCs and MPCs in MetS patients. The data are supplemental to our original research article describing detailed associations of elevated OPG level in MetS patients with numerous of EPCs and MPCs beyond traditional CV risk factors. Keywords: Metabolic syndrome, Osteoprotegerin, Circulating endothelial derived progenitor cells, Mononuclear-derived progenitor cells

Myogenic Progenitor Cells Control Extracellular Matrix Production by Fibroblasts during Skeletal Muscle Hypertrophy.

Science.gov (United States)

Fry, Christopher S; Kirby, Tyler J; Kosmac, Kate; McCarthy, John J; Peterson, Charlotte A

2017-01-05

Satellite cells, the predominant stem cell population in adult skeletal muscle, are activated in response to hypertrophic stimuli and give rise to myogenic progenitor cells (MPCs) within the extracellular matrix (ECM) that surrounds myofibers. This ECM is composed largely of collagens secreted by interstitial fibrogenic cells, which influence satellite cell activity and muscle repair during hypertrophy and aging. Here we show that MPCs interact with interstitial fibrogenic cells to ensure proper ECM deposition and optimal muscle remodeling in response to hypertrophic stimuli. MPC-dependent ECM remodeling during the first week of a growth stimulus is sufficient to ensure long-term myofiber hypertrophy. MPCs secrete exosomes containing miR-206, which represses Rrbp1, a master regulator of collagen biosynthesis, in fibrogenic cells to prevent excessive ECM deposition. These findings provide insights into how skeletal stem and progenitor cells interact with other cell types to actively regulate their extracellular environments for tissue maintenance and adaptation. Copyright © 2017 Elsevier Inc. All rights reserved.

Design, Synthesis, and Characterization of Novel Thiol-Derivatized Ibuprofen Monolayer Protected Gold Clusters

International Nuclear Information System (INIS)

Lee, K.H.; Lee, K.H.; Lin, Y.Sh.; Huang, P.J.

2013-01-01

A series of new thiol-derivatized ibuprofen monolayer protected gold clusters have been prepared by amidation of ibuprofen with alkyl alcohol or aminophenol affording the carboxamide, N-hydroxyalkyl amide 2, and N-hydroxyphenyl amide 6, which were then tosylate with p-toluenesulfonyl chloride at hydroxyl group to give 3 and 7. Reactions of 3 and 7 with NaSH afforded the mercapto derivatives 4 and 8. Conducting Brust’s reaction with a 3:1 mole ratio of thiolate ibuprofen/ AuCl 4 - yielded polydisperse thiol-derivatized ibuprofen-MPCs 5 and 9. All compounds have been identified by NMR, MS, UV, and IR spectroscopies. Compounds 4 and 8 and the MPCs 5 and 9 have been investigated by using the method of 1 H NMR spectroscopy. The broadening of the signals from 0.8 to 2.0 ppm in 1 H NMR spectrum of MPCs 5 and 9 confirmed the success of the conjugation of thiol-containing derivatives with nano gold cluster.

Where and why hyporheic exchange is important: Inferences from a parsimonious, physically-based river network model

Science.gov (United States)

Gomez-Velez, J. D.; Harvey, J. W.

2014-12-01

Hyporheic exchange has been hypothesized to have basin-scale consequences; however, predictions throughout river networks are limited by available geomorphic and hydrogeologic data as well as models that can analyze and aggregate hyporheic exchange flows across large spatial scales. We developed a parsimonious but physically-based model of hyporheic flow for application in large river basins: Networks with EXchange and Subsurface Storage (NEXSS). At the core of NEXSS is a characterization of the channel geometry, geomorphic features, and related hydraulic drivers based on scaling equations from the literature and readily accessible information such as river discharge, bankfull width, median grain size, sinuosity, channel slope, and regional groundwater gradients. Multi-scale hyporheic flow is computed based on combining simple but powerful analytical and numerical expressions that have been previously published. We applied NEXSS across a broad range of geomorphic diversity in river reaches and synthetic river networks. NEXSS demonstrates that vertical exchange beneath submerged bedforms dominates hyporheic fluxes and turnover rates along the river corridor. Moreover, the hyporheic zone's potential for biogeochemical transformations is comparable across stream orders, but the abundance of lower-order channels results in a considerably higher cumulative effect for low-order streams. Thus, vertical exchange beneath submerged bedforms has more potential for biogeochemical transformations than lateral exchange beneath banks, although lateral exchange through meanders may be important in large rivers. These results have implications for predicting outcomes of river and basin management practices.

* Tissue-Specific Extracellular Matrix Enhances Skeletal Muscle Precursor Cell Expansion and Differentiation for Potential Application in Cell Therapy.

Science.gov (United States)

Zhang, Deying; Zhang, Yong; Zhang, Yuanyuan; Yi, Hualin; Wang, Zhan; Wu, Rongpei; He, Dawei; Wei, Guanghui; Wei, Shicheng; Hu, Yun; Deng, Junhong; Criswell, Tracy; Yoo, James; Zhou, Yu; Atala, Anthony

2017-08-01

Skeletal muscle precursor cells (MPCs) are considered a key candidate for cell therapy in the treatment of skeletal muscle dysfunction due to injury, disease, or age. However, expansion of a sufficient number of functional skeletal muscle cells in vitro from a small tissue biopsy has been challenging due to changes in phenotypic expression of these cells under traditional culture conditions. Thus, the aim of the study was to develop a better culture system for the expansion and myo-differentiation of MPCs that could further be used for therapy. For this purpose, we developed an ideal method of tissue decellularization and compared the ability of different matrices to support MPC growth and differentiation. Porcine-derived skeletal muscle and liver and kidney extracellular matrix (ECM) were generated by decellularization methods consisting of distilled water, 0.2 mg/mL DNase, or 5% fetal bovine serum. Acellular matrices were further homogenized, dissolved, and combined with a hyaluronic acid-based hydrogel decorated with heparin (ECM-HA-HP). The cell proliferation and myogenic differentiation capacity of human MPCs were assessed when grown on gel alone, ECM, or each ECM-HA-HP substrate. Human MPC proliferation was significantly enhanced when cultured on the ECM-HA-HP substrates compared to the other substrates tested, with the greatest proliferation on the muscle ECM-HA-HP (mECM-HA-HP) substrate. The number of differentiated myotubes was significantly increased on the mECM-HA-HP substrate compared to the other gel-ECM substrates, as well as the numbers of MPCs expressing specific myogenic cell markers (i.e., myosin, desmin, myoD, and myf5). In conclusion, skeletal mECM-HA-HP as a culture substrate provided an optimal culture microenvironment potentially due to its similarity to the in vivo environment. These data suggest a potential use of skeletal muscle-derived ECM gel for the expansion and differentiation of human MPCs for cell-based therapy for skeletal muscle

Bayesian, maximum parsimony and UPGMA models for inferring the phylogenies of antelopes using mitochondrial markers.

Science.gov (United States)

Khan, Haseeb A; Arif, Ibrahim A; Bahkali, Ali H; Al Farhan, Ahmad H; Al Homaidan, Ali A

2008-10-06

This investigation was aimed to compare the inference of antelope phylogenies resulting from the 16S rRNA, cytochrome-b (cyt-b) and d-loop segments of mitochondrial DNA using three different computational models including Bayesian (BA), maximum parsimony (MP) and unweighted pair group method with arithmetic mean (UPGMA). The respective nucleotide sequences of three Oryx species (Oryx leucoryx, Oryx dammah and Oryx gazella) and an out-group (Addax nasomaculatus) were aligned and subjected to BA, MP and UPGMA models for comparing the topologies of respective phylogenetic trees. The 16S rRNA region possessed the highest frequency of conserved sequences (97.65%) followed by cyt-b (94.22%) and d-loop (87.29%). There were few transitions (2.35%) and none transversions in 16S rRNA as compared to cyt-b (5.61% transitions and 0.17% transversions) and d-loop (11.57% transitions and 1.14% transversions) while comparing the four taxa. All the three mitochondrial segments clearly differentiated the genus Addax from Oryx using the BA or UPGMA models. The topologies of all the gamma-corrected Bayesian trees were identical irrespective of the marker type. The UPGMA trees resulting from 16S rRNA and d-loop sequences were also identical (Oryx dammah grouped with Oryx leucoryx) to Bayesian trees except that the UPGMA tree based on cyt-b showed a slightly different phylogeny (Oryx dammah grouped with Oryx gazella) with a low bootstrap support. However, the MP model failed to differentiate the genus Addax from Oryx. These findings demonstrate the efficiency and robustness of BA and UPGMA methods for phylogenetic analysis of antelopes using mitochondrial markers.

Brain, calvarium, cladistics: A new approach to an old question, who are modern humans and Neandertals?

Science.gov (United States)

Mounier, Aurélien; Balzeau, Antoine; Caparros, Miguel; Grimaud-Hervé, Dominique

2016-03-01

The evolutionary history of the genus Homo is the focus of major research efforts in palaeoanthropology. However, the use of palaeoneurology to infer phylogenies of our genus is rare. Here we use cladistics to test the importance of the brain in differentiating and defining Neandertals and modern humans. The analysis is based on morphological data from the calvarium and endocast of Pleistocene fossils and results in a single most parsimonious cladogram. We demonstrate that the joint use of endocranial and calvarial features with cladistics provides a unique means to understand the evolution of the genus Homo. The main results of this study indicate that: (i) the endocranial features are more phylogenetically informative than the characters from the calvarium; (ii) the specific differentiation of Neandertals and modern humans is mostly supported by well-known calvarial autapomorphies; (iii) the endocranial anatomy of modern humans and Neandertals show strong similarities, which appeared in the fossil record with the last common ancestor of both species; and (iv) apart from encephalisation, human endocranial anatomy changed tremendously during the end of the Middle Pleistocene. This may be linked to major cultural and technological novelties that had happened by the end of the Middle Pleistocene (e.g., expansion of the Middle Stone Age (MSA) in Africa and Mousterian in Europe). The combined study of endocranial and exocranial anatomy offers opportunities to further understand human evolution and the implication for the phylogeny of our genus. Copyright © 2015 Elsevier Ltd. All rights reserved.

An efficient one-step condensation and activation strategy to synthesize porous carbons with optimal micropore sizes for highly selective CO₂ adsorption.

Science.gov (United States)

Wang, Jiacheng; Liu, Qian

2014-04-21

A series of microporous carbons (MPCs) were successfully prepared by an efficient one-step condensation and activation strategy using commercially available dialdehyde and diamine as carbon sources. The resulting MPCs have large surface areas (up to 1881 m(2) g(-1)), micropore volumes (up to 0.78 cm(3) g(-1)), and narrow micropore size distributions (0.7-1.1 nm). The CO₂ uptakes of the MPCs prepared at high temperatures (700-750 °C) are higher than those prepared under mild conditions (600-650 °C), because the former samples possess optimal micropore sizes (0.7-0.8 nm) that are highly suitable for CO₂ capture due to enhanced adsorbate-adsorbent interactions. At 1 bar, MPC-750 prepared at 750 °C demonstrates the best CO₂ capture performance and can efficiently adsorb CO₂ molecules at 2.86 mmol g(-1) and 4.92 mmol g(-1) at 25 and 0 °C, respectively. In particular, the MPCs with optimal micropore sizes (0.7-0.8 nm) have extremely high CO₂/N₂ adsorption ratios (47 and 52 at 25 and 0 °C, respectively) at 1 bar, and initial CO₂/N₂ adsorption selectivities of up to 81 and 119 at 25 °C and 0 °C, respectively, which are far superior to previously reported values for various porous solids. These excellent results, combined with good adsorption capacities and efficient regeneration/recyclability, make these carbons amongst the most promising sorbents reported so far for selective CO₂ adsorption in practical applications.

The Mediterranean Solar Plan: Project proposals for renewable energy in the Mediterranean Partner Countries region

International Nuclear Information System (INIS)

Jablonski, Sophie; Tarhini, Mohamad; Touati, Manaf; Gonzalez Garcia, David; Alario, Juan

2012-01-01

This paper presents a first assessment of the renewable energy projects, proposed by the nine Mediterranean Partner Countries (MPCs) under the Mediterranean Solar Plan (MSP) and the associated potential economic impacts. As one of the priority projects of the Union for the Mediterranean (UfM), the MSP's objective which attracted most attention until now is the intention to deploy an additional 20 GW of renewable electrical capacity in the Southern and Eastern Mediterranean region (covering the MPCs plus Turkey) by 2020. The main findings of this research are: (1) as of February 2010, a total of 10.3 GW of renewable project proposals were identified in the MPCs, corresponding to about half of the 20 GW target; (2) investment needs for the identified projects could amount to EUR 21 billion by 2020, which represents about five times the amount invested by the region in conventional electricity generation in the last decade; and (3) the difference between the cost of renewable electricity generation and the economic cost of its fossil fuel alternatives could amount to EUR 1.2 billion. Insights stemming from the results of this research can generate useful regional messages for energy policy leaders in the MPCs to accelerate the development of renewable energy projects. - Highlights: ► We conducted a systematic survey of renewable energy projects in the Mediterranean. ► The identified projects correspond to half the MSP 20 GW target. ► Maturity assessment is used to classify the advancement of the projects. ► We estimated the investment needs and required subsidies in the region by 2020.

Parsimonious Hydrologic and Nitrate Response Models For Silver Springs, Florida

Science.gov (United States)

Klammler, Harald; Yaquian-Luna, Jose Antonio; Jawitz, James W.; Annable, Michael D.; Hatfield, Kirk

2014-05-01

Silver Springs with an approximate discharge of 25 m3/sec is one of Florida's first magnitude springs and among the largest springs worldwide. Its 2500-km2 springshed overlies the mostly unconfined Upper Floridan Aquifer. The aquifer is approximately 100 m thick and predominantly consists of porous, fractured and cavernous limestone, which leads to excellent surface drainage properties (no major stream network other than Silver Springs run) and complex groundwater flow patterns through both rock matrix and fast conduits. Over the past few decades, discharge from Silver Springs has been observed to slowly but continuously decline, while nitrate concentrations in the spring water have enormously increased from a background level of 0.05 mg/l to over 1 mg/l. In combination with concurrent increases in algae growth and turbidity, for example, and despite an otherwise relatively stable water quality, this has given rise to concerns about the ecological equilibrium in and near the spring run as well as possible impacts on tourism. The purpose of the present work is to elaborate parsimonious lumped parameter models that may be used by resource managers for evaluating the springshed's hydrologic and nitrate transport responses. Instead of attempting to explicitly consider the complex hydrogeologic features of the aquifer in a typically numerical and / or stochastic approach, we use a transfer function approach wherein input signals (i.e., time series of groundwater recharge and nitrate loading) are transformed into output signals (i.e., time series of spring discharge and spring nitrate concentrations) by some linear and time-invariant law. The dynamic response types and parameters are inferred from comparing input and output time series in frequency domain (e.g., after Fourier transformation). Results are converted into impulse (or step) response functions, which describe at what time and to what magnitude a unitary change in input manifests at the output. For the

Using genes as characters and a parsimony analysis to explore the phylogenetic position of turtles.

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Bin Lu

Full Text Available The phylogenetic position of turtles within the vertebrate tree of life remains controversial. Conflicting conclusions from different studies are likely a consequence of systematic error in the tree construction process, rather than random error from small amounts of data. Using genomic data, we evaluate the phylogenetic position of turtles with both conventional concatenated data analysis and a "genes as characters" approach. Two datasets were constructed, one with seven species (human, opossum, zebra finch, chicken, green anole, Chinese pond turtle, and western clawed frog and 4584 orthologous genes, and the second with four additional species (soft-shelled turtle, Nile crocodile, royal python, and tuatara but only 1638 genes. Our concatenated data analysis strongly supported turtle as the sister-group to archosaurs (the archosaur hypothesis, similar to several recent genomic data based studies using similar methods. When using genes as characters and gene trees as character-state trees with equal weighting for each gene, however, our parsimony analysis suggested that turtles are possibly sister-group to diapsids, archosaurs, or lepidosaurs. None of these resolutions were strongly supported by bootstraps. Furthermore, our incongruence analysis clearly demonstrated that there is a large amount of inconsistency among genes and most of the conflict relates to the placement of turtles. We conclude that the uncertain placement of turtles is a reflection of the true state of nature. Concatenated data analysis of large and heterogeneous datasets likely suffers from systematic error and over-estimates of confidence as a consequence of a large number of characters. Using genes as characters offers an alternative for phylogenomic analysis. It has potential to reduce systematic error, such as data heterogeneity and long-branch attraction, and it can also avoid problems associated with computation time and model selection. Finally, treating genes as

Using Genes as Characters and a Parsimony Analysis to Explore the Phylogenetic Position of Turtles

Science.gov (United States)

Lu, Bin; Yang, Weizhao; Dai, Qiang; Fu, Jinzhong

2013-01-01

The phylogenetic position of turtles within the vertebrate tree of life remains controversial. Conflicting conclusions from different studies are likely a consequence of systematic error in the tree construction process, rather than random error from small amounts of data. Using genomic data, we evaluate the phylogenetic position of turtles with both conventional concatenated data analysis and a “genes as characters” approach. Two datasets were constructed, one with seven species (human, opossum, zebra finch, chicken, green anole, Chinese pond turtle, and western clawed frog) and 4584 orthologous genes, and the second with four additional species (soft-shelled turtle, Nile crocodile, royal python, and tuatara) but only 1638 genes. Our concatenated data analysis strongly supported turtle as the sister-group to archosaurs (the archosaur hypothesis), similar to several recent genomic data based studies using similar methods. When using genes as characters and gene trees as character-state trees with equal weighting for each gene, however, our parsimony analysis suggested that turtles are possibly sister-group to diapsids, archosaurs, or lepidosaurs. None of these resolutions were strongly supported by bootstraps. Furthermore, our incongruence analysis clearly demonstrated that there is a large amount of inconsistency among genes and most of the conflict relates to the placement of turtles. We conclude that the uncertain placement of turtles is a reflection of the true state of nature. Concatenated data analysis of large and heterogeneous datasets likely suffers from systematic error and over-estimates of confidence as a consequence of a large number of characters. Using genes as characters offers an alternative for phylogenomic analysis. It has potential to reduce systematic error, such as data heterogeneity and long-branch attraction, and it can also avoid problems associated with computation time and model selection. Finally, treating genes as characters

Algorithms for computing parsimonious evolutionary scenarios for genome evolution, the last universal common ancestor and dominance of horizontal gene transfer in the evolution of prokaryotes

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Galperin Michael Y

2003-01-01

Full Text Available Abstract Background Comparative analysis of sequenced genomes reveals numerous instances of apparent horizontal gene transfer (HGT, at least in prokaryotes, and indicates that lineage-specific gene loss might have been even more common in evolution. This complicates the notion of a species tree, which needs to be re-interpreted as a prevailing evolutionary trend, rather than the full depiction of evolution, and makes reconstruction of ancestral genomes a non-trivial task. Results We addressed the problem of constructing parsimonious scenarios for individual sets of orthologous genes given a species tree. The orthologous sets were taken from the database of Clusters of Orthologous Groups of proteins (COGs. We show that the phyletic patterns (patterns of presence-absence in completely sequenced genomes of almost 90% of the COGs are inconsistent with the hypothetical species tree. Algorithms were developed to reconcile the phyletic patterns with the species tree by postulating gene loss, COG emergence and HGT (the latter two classes of events were collectively treated as gene gains. We prove that each of these algorithms produces a parsimonious evolutionary scenario, which can be represented as mapping of loss and gain events on the species tree. The distribution of the evolutionary events among the tree nodes substantially depends on the underlying assumptions of the reconciliation algorithm, e.g. whether or not independent gene gains (gain after loss after gain are permitted. Biological considerations suggest that, on average, gene loss might be a more likely event than gene gain. Therefore different gain penalties were used and the resulting series of reconstructed gene sets for the last universal common ancestor (LUCA of the extant life forms were analysed. The number of genes in the reconstructed LUCA gene sets grows as the gain penalty increases. However, qualitative examination of the LUCA versions reconstructed with different gain penalties

Urban micro-scale flood risk estimation with parsimonious hydraulic modelling and census data

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C. Arrighi

2013-05-01

Full Text Available The adoption of 2007/60/EC Directive requires European countries to implement flood hazard and flood risk maps by the end of 2013. Flood risk is the product of flood hazard, vulnerability and exposure, all three to be estimated with comparable level of accuracy. The route to flood risk assessment is consequently much more than hydraulic modelling of inundation, that is hazard mapping. While hazard maps have already been implemented in many countries, quantitative damage and risk maps are still at a preliminary level. A parsimonious quasi-2-D hydraulic model is here adopted, having many advantages in terms of easy set-up. It is here evaluated as being accurate in flood depth estimation in urban areas with a high-resolution and up-to-date Digital Surface Model (DSM. The accuracy, estimated by comparison with marble-plate records of a historic flood in the city of Florence, is characterized in the downtown's most flooded area by a bias of a very few centimetres and a determination coefficient of 0.73. The average risk is found to be about 14 € m−2 yr−1, corresponding to about 8.3% of residents' income. The spatial distribution of estimated risk highlights a complex interaction between the flood pattern and the building characteristics. As a final example application, the estimated risk values have been used to compare different retrofitting measures. Proceeding through the risk estimation steps, a new micro-scale potential damage assessment method is proposed. This is based on the georeferenced census system as the optimal compromise between spatial detail and open availability of socio-economic data. The results of flood risk assessment at the census section scale resolve most of the risk spatial variability, and they can be easily aggregated to whatever upper scale is needed given that they are geographically defined as contiguous polygons. Damage is calculated through stage–damage curves, starting from census data on building type and

Electrocatalytic behavior of carbon paste electrode modified with metal phthalocyanines nanoparticles toward the hydrogen evolution

International Nuclear Information System (INIS)

Abbaspour, Abdolkarim; Norouz-sarvestani, Fatemeh; Mirahmadi, Ehsan

2012-01-01

Highlights: ► The new construction of a carbon paste electrode impregnated with nanoparticles of Zn and Ni phthalocyanine (nano ZnPc and nano NiPc). ► The decrease overpotential and higher current value obtained in nano ZnPc and nano NiPc compared to bulky ZnPc and bulky NiPc, respectively. ► Types of the catalyst and pH of the solution affect the electro catalytic proton reduction reaction considerably. - Abstract: This paper describes the construction of a carbon paste electrode (CPE) impregnated with nanoparticles of Zn and Ni phthalocyanine (nano ZnPc and nano NiPc). These new electrodes (nano ZnPc-CPE and nano NiPc-CPE) reveal interesting electrocatalytic behavior toward hydrogen evolution reaction (HER). Voltammetric characteristics indicated that the proposed electrodes display better electrocatalytic activity compared to their corresponding bulky modified metal phthalocyanines (MPcs) in minimizing overpotential and increasing the reduction current of HER. Electrocatalytic activities irregularly change with the pH of the solution. However by increasing the pH while nano MPcs are still active, bulky MPcs are almost inactive, and their corresponding ΔE increase by increasing the pH.

Block Copolymer Micelles for Photonic Fluids and Crystals.

Science.gov (United States)

Poutanen, Mikko; Guidetti, Giulia; Gröschel, Tina I; Borisov, Oleg V; Vignolini, Silvia; Ikkala, Olli; Gröschel, Andre H

2018-03-15

Block copolymer micelles (BCMs) are self-assembled nanoparticles in solution with a collapsed core and a brush-like stabilizing corona typically in the size range of tens of nanometers. Despite being widely studied in various fields of science and technology, their ability to form structural colors at visible wavelength has not received attention, mainly due to the stringent length requirements of photonic lattices. Here, we describe the precision assembly of BCMs with superstretched corona, yet with narrow size distribution to qualify as building blocks for tunable and reversible micellar photonic fluids (MPFs) and micellar photonic crystals (MPCs). The BCMs form free-flowing MPFs with an average interparticle distance of 150-300 nm as defined by electrosteric repulsion arising from the highly charged and stretched corona. Under quiescent conditions, millimeter-sized MPCs with classical FCC lattice grow within the photonic fluid-medium upon refinement of the positional order of the BCMs. We discuss the generic properties of MPCs with special emphasis on surprisingly narrow reflected wavelengths with full width at half-maximum (fwhm) as small as 1 nm. We expect this concept to open a generic and facile way for self-assembled tunable micellar photonic structures.

Nonreciprocal optical tunnelling through evanescently coupled Tamm states in magnetophotonic crystals

Energy Technology Data Exchange (ETDEWEB)

Fang, Yun-Tuan [Jiangsu Univ., Zhenjiang (China). School of Computer Science and Telecommunication Engineering; Han, Ling [The Second Military Medical Univ., Shanghai (China). Dept. of Radiation Medicine; Gao, Yong-Feng [Jiangsu Univ., Zhenjiang (China). School of Mechanical Engineering

2015-07-01

Evanescently coupled Tamm states are achieved through two magnetophotonic crystals (MPCs) with a pair of coupling prisms. At the wavelengths of coupled Tamm states, a double of nonreciprocal optical tunnelling channels is found through the transmission spectra obtained from a developed transfer matrix method. The nonreciprocal tunnelling wavelength and the interval between two nonreciprocal channels can be adjusted depending on the width of the air gap between two MPCs or the scale invariant of a PC. The nonreciprocal tunnelling is demonstrated through electromagnetic field distribution simulations based on finite element software. Such theoretical results may provide a new method to design tunable optical isolators with a double of channels.

Classificação de Muscidae (Diptera: uma proposta através da análise cladístical

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Cláudio José Barros de Carvalho

1989-01-01

Full Text Available A cladistic analysis for 27 muscid genera is given, running the PAUP program (SWOFFORD, 1985. The 35 characters used in this study are polarized based on three outgroups of related families. A cladogram showing hypothetical phylogenetic relationships among genera and a discussion of the characters enable to propose a sequencial phylogenetic classification of Muscidae at tribal level. The following seven subfamilies and eight tribes are included: Achanthipterinae; Atherigoninae; Muscinae, with Muscini and Stomoxiini; Azeliinae, with Azeliini and Reinwardtiini; Phaoniinae; Mydaeinae, with Graphomyiini and Mydaeini and Coenosiinae, with Coenosiini and Limnophorini. Helina Robineau-Desvoidy, 1830 has not a defined position in the obtained cladogram to the considered levels. The neotropical species of Phaonia (aut. must be separated in a new genus. The proposed classification is compared with contemporaneous classifications. The greatest congruence is found with that of SKIDMORE (1985.

Parsimonious data

DEFF Research Database (Denmark)

Kristensen, Jakob Baek; Albrechtsen, Thomas; Dahl-Nielsen, Emil

2017-01-01

This study shows how liking politicians’ public Facebook posts can be used as an accurate measure for predicting present-day voter intention in a multiparty system. We highlight that a few, but selective digital traces produce prediction accuracies that are on par or even greater than most curren...

The Use of Parsimonious Questionnaires in Occupational Health Surveillance: Psychometric Properties of the Short Italian Version of the Effort/Reward Imbalance Questionnaire

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Nicola Magnavita

2012-01-01

Full Text Available Purpose. To perform a parsimonious measurement of workplace psychosocial stress in routine occupational health surveillance, this study tests the psychometric properties of a short version of the original Italian effort-reward imbalance (ERI questionnaire. Methods. 1,803 employees (63 percent women from 19 service companies in the Italian region of Latium participated in a cross-sectional survey containing the short version of the ERI questionnaire (16 items and questions related to self-reported health, musculoskeletal complaints and job satisfaction. Exploratory factor analysis, internal consistency of scales and criterion validity were utilized. Results. The internal consistency of scales was satisfactory. Principal component analysis enabled to identify the model’s main factors. Significant associations with health and job satisfaction in the majority of cases support the notion of criterion validity. A high score on the effort-reward ratio was associated with an elevated odds ratio (OR = 2.71; 95% CI 1.86–3.95 of musculoskeletal complaints in the upper arm. Conclusions. The short form of the Italian ERI questionnaire provides a psychometrically useful tool for routine occupational health surveillance, although further validation is recommended.

Patrones biogeográficos de la avifauna de la Sierra Madre del Sur Biogeographic patterns of the avifauna of the Sierra Madre del Sur

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Epifanio Blancas-Calva

2010-08-01

Full Text Available Analizamos la avifauna de 26 subcuencas de la provincia biótica de la Sierra Madre del Sur y sus relaciones biogeográficas utilizando el análisis de parsimonia de endemismos (PAE. A partir de información distributional de las especies obtenida de la base de datos del Atlas de las aves de México y de la literatura disponible, construimos una matriz de datos para 26 subcuencas y 437 especies. Se obtuvo un cladograma que sugiere la existencia de 3 grupos de subcuencas: el primero agrupa subcuencas de climas áridos, ubicadas geográficamente de norte a sureste en el estado de Oaxaca; el segundo, otras subcuencas de ambientes climáticos subhúmedos, y el tercero, las restantes subcuencas de ambientes climáticos húmedos de mayor complejidad ambiental.We analyzed the avifauna of 26 sub-basins of the Sierra Madre del Sur biotic province and their biogeographical relationships applying a parsimony analysis of endemicity (PAE. Based on the distributional information of the species obtained from the Atlas de las aves de México and published literature, we built a data matrix for 26 sub-basins and 437 species. The single cladogram obtained suggests the existence of three groups of sub-basins:the first with 5 sub-basins from arid environments, geographically located in north-southeastern Oaxaca; the second with another 5 sub-basins form subhumid environments; and the third one with the remaining sub-basins, from humid and environmentally more complex habitats.

Studies in the Arundinelleae (Gramineae) VIII. The Phylogeny — A Hypothesis

NARCIS (Netherlands)

Phipps, J.B.

1967-01-01

This study considers the 163 species accepted as belonging to the tribe Arundinelleae (Gramineae) and arranges them into a putative cladogram. A discussion of the rationale is presented, 38 characters are studied for advanced versus primitive states, advancement indices calculated, and trends of

When Relationships Depicted Diagrammatically Conflict with Prior Knowledge: An Investigation of Students' Interpretations of Evolutionary Trees

Science.gov (United States)

Novick, Laura R.; Catley, Kefyn M.

2014-01-01

Science is an important domain for investigating students' responses to information that contradicts their prior knowledge. In previous studies of this topic, this information was communicated verbally. The present research used diagrams, specifically trees (cladograms) depicting evolutionary relationships among taxa. Effects of college…

Sparing of extraocular muscle in aging and muscular dystrophies: A myogenic precursor cell hypothesis

Energy Technology Data Exchange (ETDEWEB)

Kallestad, Kristen M.; Hebert, Sadie L.; McDonald, Abby A.; Daniel, Mark L.; Cu, Sharon R.; McLoon, Linda K., E-mail: mcloo001@tc.umn.edu

2011-04-01

The extraocular muscles (EOM) are spared from pathology in aging and many forms of muscular dystrophy. Despite many studies, this sparing remains an enigma. The EOM have a distinct embryonic lineage compared to somite-derived muscles, and we have shown that they continuously remodel throughout life, maintaining a population of activated satellite cells even in aging. These data suggested the hypothesis that there is a population of myogenic precursor cells (mpcs) in EOM that is different from those in limb, with either elevated numbers of stem cells and/or mpcs with superior proliferative capacity compared to mpcs in limb. Using flow cytometry, EOM and limb muscle mononuclear cells were compared, and a number of differences were seen. Using two different cell isolation methods, EOM have significantly more mpcs per mg muscle than limb skeletal muscle. One specific subpopulation significantly increased in EOM compared to limb was positive for CD34 and negative for Sca-1, M-cadherin, CD31, and CD45. We named these the EOMCD34 cells. Similar percentages of EOMCD34 cells were present in both newborn EOM and limb muscle. They were retained in aged EOM, whereas the population decreased significantly in adult limb muscle and were extremely scarce in aged limb muscle. Most importantly, the percentage of EOMCD34 cells was elevated in the EOM from both the mdx and the mdx/utrophin{sup -/-} (DKO) mouse models of DMD and extremely scarce in the limb muscles of these mice. In vitro, the EOMCD34 cells had myogenic potential, forming myotubes in differentiation media. After determining a media better able to induce proliferation in these cells, a fusion index was calculated. The cells isolated from EOM had a 40% higher fusion index compared to the same cells isolated from limb muscle. The EOMCD34 cells were resistant to both oxidative stress and mechanical injury. These data support our hypothesis that the EOM may be spared in aging and in muscular dystrophies due to a

Sparing of extraocular muscle in aging and muscular dystrophies: A myogenic precursor cell hypothesis

International Nuclear Information System (INIS)

Kallestad, Kristen M.; Hebert, Sadie L.; McDonald, Abby A.; Daniel, Mark L.; Cu, Sharon R.; McLoon, Linda K.

2011-01-01

The extraocular muscles (EOM) are spared from pathology in aging and many forms of muscular dystrophy. Despite many studies, this sparing remains an enigma. The EOM have a distinct embryonic lineage compared to somite-derived muscles, and we have shown that they continuously remodel throughout life, maintaining a population of activated satellite cells even in aging. These data suggested the hypothesis that there is a population of myogenic precursor cells (mpcs) in EOM that is different from those in limb, with either elevated numbers of stem cells and/or mpcs with superior proliferative capacity compared to mpcs in limb. Using flow cytometry, EOM and limb muscle mononuclear cells were compared, and a number of differences were seen. Using two different cell isolation methods, EOM have significantly more mpcs per mg muscle than limb skeletal muscle. One specific subpopulation significantly increased in EOM compared to limb was positive for CD34 and negative for Sca-1, M-cadherin, CD31, and CD45. We named these the EOMCD34 cells. Similar percentages of EOMCD34 cells were present in both newborn EOM and limb muscle. They were retained in aged EOM, whereas the population decreased significantly in adult limb muscle and were extremely scarce in aged limb muscle. Most importantly, the percentage of EOMCD34 cells was elevated in the EOM from both the mdx and the mdx/utrophin -/- (DKO) mouse models of DMD and extremely scarce in the limb muscles of these mice. In vitro, the EOMCD34 cells had myogenic potential, forming myotubes in differentiation media. After determining a media better able to induce proliferation in these cells, a fusion index was calculated. The cells isolated from EOM had a 40% higher fusion index compared to the same cells isolated from limb muscle. The EOMCD34 cells were resistant to both oxidative stress and mechanical injury. These data support our hypothesis that the EOM may be spared in aging and in muscular dystrophies due to a subpopulation of

Reasoning about Evolution's Grand Patterns: College Students' Understanding of the Tree of Life

Science.gov (United States)

Novick, Laura R.; Catley, Kefyn M.

2013-01-01

Tree thinking involves using cladograms, hierarchical diagrams depicting the evolutionary history of a set of taxa, to reason about evolutionary relationships and support inferences. Tree thinking is indispensable in modern science. College students' tree-thinking skills were investigated using tree (much more common in professional biology) and…

Biogeographic congruence in the south Pacific

DEFF Research Database (Denmark)

Seberg, Ole

1991-01-01

Ever since J. D. Hooker's famous 'Introductory Essay' to Flora NOVE-Zelandise, a classical problem in biogeography has been to give a casual explanation of southern hemisphere distribution patterns. An attempt is made to see whether the cladograms for the circum-Pacific areas (South America, New ...

Neotropical Monogenoidea. 24. Rhinoxenus bulbovaginatus n. sp. (Dactylogyridae, Ancyrocephalinae from the nasal cavity of Salminus maxillosus (Osteichthyes, Characidae from the Rio Paraná, Paraná, Brazil

Directory of Open Access Journals (Sweden)

Walter A. Boeger

1995-12-01

Full Text Available Rhinoxenus bulbovaginatus n. sp. is described from the nose of Salminus maxillosus (Characidae collected in the basin of the rio Paraná, near the city of Porto Rico, state of Paraná, Brazil. The new species can be differentiated from the other three species in the genus by the morphology of the copulatory complex, vagina, and ventral anchor. The sister group relationship of the known species of Rhinoxenus was determined using techniques of Phylogenetic Systematics (Cladism. The resulting cladogram (C.I.=100% indicates that the new species is most closely related to R. piranhus Kritsky, Boeger and Thatcher, 1988. The other two species of the genus, R. arietinus Kritsky, Boeger and Thatcher, 1988 and R. nyttus Kritsky, Boeger and Thatcher, 1988, both parasites of Anostomidae fishes, have a paraphyletic position in the cladogram, suggesting that the origin of at least one of them can not be associated to cospeciation.

Can Children Read Evolutionary Trees?

Science.gov (United States)

Ainsworth, Shaaron; Saffer, Jessica

2013-01-01

Representations of the "tree of life" such as cladograms show the history of lineages and their relationships. They are increasingly found in formal and informal learning settings. Unfortunately, there is evidence that these representations can be challenging to interpret correctly. This study explored the question of whether children…

Highly ordered three-dimensional macroporous carbon spheres for determination of heavy metal ions

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yuxiao; Zhang, Jianming [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Liu, Yang, E-mail: yangl@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Huang, Hui [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China); Kang, Zhenhui, E-mail: zhkang@suda.edu.cn [Institute of Functional Nano and Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123 (China)

2012-04-15

Highlights: Black-Right-Pointing-Pointer Highly ordered three dimensional macroporous carbon spheres (MPCSs) were prepared. Black-Right-Pointing-Pointer MPCS was covalently modified by cysteine (MPCS-CO-Cys). Black-Right-Pointing-Pointer MPCS-CO-Cys was first time used in electrochemical detection of heavy metal ions. Black-Right-Pointing-Pointer Heavy metal ions such as Pb{sup 2+} and Cd{sup 2+} can be simultaneously determined. -- Abstract: An effective voltammetric method for detection of trace heavy metal ions using chemically modified highly ordered three dimensional macroporous carbon spheres electrode surfaces is described. The highly ordered three dimensional macroporous carbon spheres were prepared by carbonization of glucose in silica crystal bead template, followed by removal of the template. The highly ordered three dimensional macroporous carbon spheres were covalently modified by cysteine, an amino acid with high affinities towards some heavy metals. The materials were characterized by physical adsorption of nitrogen, scanning electron microscopy, and transmission electron microscopy techniques. While the Fourier-transform infrared spectroscopy was used to characterize the functional groups on the surface of carbon spheres. High sensitivity was exhibited when this material was used in electrochemical detection (square wave anodic stripping voltammetry) of heavy metal ions due to the porous structure. And the potential application for simultaneous detection of heavy metal ions was also investigated.

Vertical distribution of microphysical properties of Arctic springtime low-level mixed-phase clouds over the Greenland and Norwegian seas

Science.gov (United States)

Mioche, Guillaume; Jourdan, Olivier; Delanoë, Julien; Gourbeyre, Christophe; Febvre, Guy; Dupuy, Régis; Monier, Marie; Szczap, Frédéric; Schwarzenboeck, Alfons; Gayet, Jean-François

2017-10-01

This study aims to characterize the microphysical and optical properties of ice crystals and supercooled liquid droplets within low-level Arctic mixed-phase clouds (MPCs). We compiled and analyzed cloud in situ measurements from four airborne spring campaigns (representing 18 flights and 71 vertical profiles in MPCs) over the Greenland and Norwegian seas mainly in the vicinity of the Svalbard archipelago. Cloud phase discrimination and representative vertical profiles of the number, size, mass and shape of ice crystals and liquid droplets are established. The results show that the liquid phase dominates the upper part of the MPCs. High concentrations (120 cm-3 on average) of small droplets (mean values of 15 µm), with an averaged liquid water content (LWC) of 0.2 g m-3 are measured at cloud top. The ice phase dominates the microphysical properties in the lower part of the cloud and beneath it in the precipitation region (mean values of 100 µm, 3 L-1 and 0.025 g m-3 for diameter, particle concentration and ice water content (IWC), respectively). The analysis of the ice crystal morphology shows that the majority of ice particles are irregularly shaped or rimed particles; the prevailing regular habits found are stellars and plates. We hypothesize that riming and diffusional growth processes, including the Wegener-Bergeron-Findeisen (WBF) mechanism, are the main growth mechanisms involved in the observed MPCs. The impact of larger-scale meteorological conditions on the vertical profiles of MPC properties was also investigated. Large values of LWC and high concentration of smaller droplets are possibly linked to polluted situations and air mass origins from the south, which can lead to very low values of ice crystal size and IWC. On the contrary, clean situations with low temperatures exhibit larger values of ice crystal size and IWC. Several parameterizations relevant for remote sensing or modeling studies are also determined, such as IWC (and LWC) - extinction

Vertical distribution of microphysical properties of Arctic springtime low-level mixed-phase clouds over the Greenland and Norwegian seas

Directory of Open Access Journals (Sweden)

G. Mioche

2017-10-01

Full Text Available This study aims to characterize the microphysical and optical properties of ice crystals and supercooled liquid droplets within low-level Arctic mixed-phase clouds (MPCs. We compiled and analyzed cloud in situ measurements from four airborne spring campaigns (representing 18 flights and 71 vertical profiles in MPCs over the Greenland and Norwegian seas mainly in the vicinity of the Svalbard archipelago. Cloud phase discrimination and representative vertical profiles of the number, size, mass and shape of ice crystals and liquid droplets are established. The results show that the liquid phase dominates the upper part of the MPCs. High concentrations (120 cm−3 on average of small droplets (mean values of 15 µm, with an averaged liquid water content (LWC of 0.2 g m−3 are measured at cloud top. The ice phase dominates the microphysical properties in the lower part of the cloud and beneath it in the precipitation region (mean values of 100 µm, 3 L−1 and 0.025 g m−3 for diameter, particle concentration and ice water content (IWC, respectively. The analysis of the ice crystal morphology shows that the majority of ice particles are irregularly shaped or rimed particles; the prevailing regular habits found are stellars and plates. We hypothesize that riming and diffusional growth processes, including the Wegener–Bergeron–Findeisen (WBF mechanism, are the main growth mechanisms involved in the observed MPCs. The impact of larger-scale meteorological conditions on the vertical profiles of MPC properties was also investigated. Large values of LWC and high concentration of smaller droplets are possibly linked to polluted situations and air mass origins from the south, which can lead to very low values of ice crystal size and IWC. On the contrary, clean situations with low temperatures exhibit larger values of ice crystal size and IWC. Several parameterizations relevant for remote sensing or modeling studies are also determined

Safeguards considerations related to the use of multi-purpose canisters in the Civilian Radioactive Waste Management system

International Nuclear Information System (INIS)

Floyd, W.C.

1995-01-01

The US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) is responsible for disposing of the nation's high-level radioactive waste. Currently, DOE is considering the use of Multi-Purpose Canisters (MPCs) to containerize commercial spent nuclear fuel (SNF) to be handled by the system. To achieve its safeguards and security objectives, OCRWM plans to institute a US Regulatory Commission (NRC)-approved safeguards program. Since the Mined Geologic Disposal System (MGDS) facility and a possible Monitored Retrievable Storage (MRS) facility may be subject to selection for International Atomic Energy Agency (IAEA) inspections, the safeguards program for MPCs may not preclude compliance with the requirements of the IAEA's Annex D, Special Criteria for Difficult-to-Access Fuel Items. MPC safeguards are based on three principles: Verification, Material Control and Accounting, and Physical Protection

A Multi-mission Event-Driven Component-Based System for Support of Flight Software Development, ATLO, and Operations first used by the Mars Science Laboratory (MSL) Project

Science.gov (United States)

Dehghani, Navid; Tankenson, Michael

2006-01-01

This paper details an architectural description of the Mission Data Processing and Control System (MPCS), an event-driven, multi-mission ground data processing components providing uplink, downlink, and data management capabilities which will support the Mars Science Laboratory (MSL) project as its first target mission. MPCS is developed based on a set of small reusable components, implemented in Java, each designed with a specific function and well-defined interfaces. An industry standard messaging bus is used to transfer information among system components. Components generate standard messages which are used to capture system information, as well as triggers to support the event-driven architecture of the system. Event-driven systems are highly desirable for processing high-rate telemetry (science and engineering) data, and for supporting automation for many mission operations processes.

Salvage and storage of infectious disease protein targets in the SSGCID high-throughput crystallization pathway using microfluidics

International Nuclear Information System (INIS)

Christensen, Jeff; Gerdts, Cory J.; Clifton, Mathew C.; Stewart, Lance

2011-01-01

SSGCID protein crystals were salvaged and stored using the MPCS Plug Maker and CrystalCards when high-throughput traditional sitting-drop vapor diffusion initially failed. The MPCS Plug Maker is a microcapillary-based protein-crystallization system for generating diffraction-ready crystals from nanovolumes of protein. Crystallization screening using the Plug Maker was used as a salvage pathway for proteins that failed to crystallize during the initial observation period using the traditional sitting-drop vapor-diffusion method. Furthermore, the CrystalCards used to store the crystallization experiments set up by the Plug Maker are shown be a viable container for long-term storage of protein crystals without a discernable loss of diffraction quality with time. Use of the Plug Maker with SSGCID proteins is demonstrated to be an effective crystal-salvage and storage method

Catchment legacies and time lags: a parsimonious watershed model to predict the effects of legacy storage on nitrogen export.

Directory of Open Access Journals (Sweden)

Kimberly J Van Meter

Full Text Available Nutrient legacies in anthropogenic landscapes, accumulated over decades of fertilizer application, lead to time lags between implementation of conservation measures and improvements in water quality. Quantification of such time lags has remained difficult, however, due to an incomplete understanding of controls on nutrient depletion trajectories after changes in land-use or management practices. In this study, we have developed a parsimonious watershed model for quantifying catchment-scale time lags based on both soil nutrient accumulations (biogeochemical legacy and groundwater travel time distributions (hydrologic legacy. The model accurately predicted the time lags observed in an Iowa watershed that had undergone a 41% conversion of area from row crop to native prairie. We explored the time scales of change for stream nutrient concentrations as a function of both natural and anthropogenic controls, from topography to spatial patterns of land-use change. Our results demonstrate that the existence of biogeochemical nutrient legacies increases time lags beyond those due to hydrologic legacy alone. In addition, we show that the maximum concentration reduction benefits vary according to the spatial pattern of intervention, with preferential conversion of land parcels having the shortest catchment-scale travel times providing proportionally greater concentration reductions as well as faster response times. In contrast, a random pattern of conversion results in a 1:1 relationship between percent land conversion and percent concentration reduction, irrespective of denitrification rates within the landscape. Our modeling framework allows for the quantification of tradeoffs between costs associated with implementation of conservation measures and the time needed to see the desired concentration reductions, making it of great value to decision makers regarding optimal implementation of watershed conservation measures.

The transboundary non-renewable Nubian Aquifer System of Chad, Egypt, Libya and Sudan: classical groundwater questions and parsimonious hydrogeologic analysis and modeling

Science.gov (United States)

Voss, Clifford I.; Soliman, Safaa M.

2014-03-01

Parsimonious groundwater modeling provides insight into hydrogeologic functioning of the Nubian Aquifer System (NAS), the world's largest non-renewable groundwater system (belonging to Chad, Egypt, Libya, and Sudan). Classical groundwater-resource issues exist (magnitude and lateral extent of drawdown near pumping centers) with joint international management questions regarding transboundary drawdown. Much of NAS is thick, containing a large volume of high-quality groundwater, but receives insignificant recharge, so water-resource availability is time-limited. Informative aquifer data are lacking regarding large-scale response, providing only local-scale information near pumps. Proxy data provide primary underpinning for understanding regional response: Holocene water-table decline from the previous pluvial period, after thousands of years, results in current oasis/sabkha locations where the water table still intersects the ground. Depletion is found to be controlled by two regional parameters, hydraulic diffusivity and vertical anisotropy of permeability. Secondary data that provide insight are drawdowns near pumps and isotope-groundwater ages (million-year-old groundwaters in Egypt). The resultant strong simply structured three-dimensional model representation captures the essence of NAS regional groundwater-flow behavior. Model forecasts inform resource management that transboundary drawdown will likely be minimal—a nonissue—whereas drawdown within pumping centers may become excessive, requiring alternative extraction schemes; correspondingly, significant water-table drawdown may occur in pumping centers co-located with oases, causing oasis loss and environmental impacts.

Parsimonious classification of binary lacunarity data computed from food surface images using kernel principal component analysis and artificial neural networks.

Science.gov (United States)

Iqbal, Abdullah; Valous, Nektarios A; Sun, Da-Wen; Allen, Paul

2011-02-01

Lacunarity is about quantifying the degree of spatial heterogeneity in the visual texture of imagery through the identification of the relationships between patterns and their spatial configurations in a two-dimensional setting. The computed lacunarity data can designate a mathematical index of spatial heterogeneity, therefore the corresponding feature vectors should possess the necessary inter-class statistical properties that would enable them to be used for pattern recognition purposes. The objectives of this study is to construct a supervised parsimonious classification model of binary lacunarity data-computed by Valous et al. (2009)-from pork ham slice surface images, with the aid of kernel principal component analysis (KPCA) and artificial neural networks (ANNs), using a portion of informative salient features. At first, the dimension of the initial space (510 features) was reduced by 90% in order to avoid any noise effects in the subsequent classification. Then, using KPCA, the first nineteen kernel principal components (99.04% of total variance) were extracted from the reduced feature space, and were used as input in the ANN. An adaptive feedforward multilayer perceptron (MLP) classifier was employed to obtain a suitable mapping from the input dataset. The correct classification percentages for the training, test and validation sets were 86.7%, 86.7%, and 85.0%, respectively. The results confirm that the classification performance was satisfactory. The binary lacunarity spatial metric captured relevant information that provided a good level of differentiation among pork ham slice images. Copyright © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

Blood Lead Toxicity Analysis of Multipurpose Canines and Military Working Dogs.

Science.gov (United States)

Reid, Paul; George, Clinton; Byrd, Christopher M; Miller, Laura; Lee, Stephen J; Motsinger-Reif, Alison; Breen, Matthew; Hayduk, Daniel W

Special Operations Forces and their accompanying tactical multipurpose canines (MPCs) who are involved in repeated live-fire exercises and military operations have the potential for increased blood lead levels and toxicity due to aerosolized and environmental lead debris. Clinical lead-toxicity symptoms can mimic other medical disorders, rendering accurate diagnosis more challenging. The objective of this study was to examine baseline lead levels of MPCs exposed to indoor firing ranges compared with those of nontactical military working dogs (MWDs) with limited or no exposure to the same environment. In the second part of the study, results of a commercially available, human-blood lead testing system were compared with those of a benchtop inductively coupled plasma-mass spectrometry (ICP-MS) analysis technique. Blood samples from 18 MPCs were tested during routine clinical blood draws, and six samples from a canine group with limited exposure to environmental lead (nontactical MWDs) were tested for comparison. There was a high correlation between results of the commercial blood-testing system compared with ICP-MS when blood lead levels were higher than 4.0µg/dL. Both testing methods recorded higher blood lead levels in the MPC blood samples than in those of the nontactical MWDs, although none of the MPC samples tested contained lead levels approaching those at which symptoms of lead toxicity have previously been reported in animals (i.e., 35µg/dL). 2018.

A Parsimonious Model of the Rabbit Action Potential Elucidates the Minimal Physiological Requirements for Alternans and Spiral Wave Breakup.

Science.gov (United States)

Gray, Richard A; Pathmanathan, Pras

2016-10-01

Elucidating the underlying mechanisms of fatal cardiac arrhythmias requires a tight integration of electrophysiological experiments, models, and theory. Existing models of transmembrane action potential (AP) are complex (resulting in over parameterization) and varied (leading to dissimilar predictions). Thus, simpler models are needed to elucidate the "minimal physiological requirements" to reproduce significant observable phenomena using as few parameters as possible. Moreover, models have been derived from experimental studies from a variety of species under a range of environmental conditions (for example, all existing rabbit AP models incorporate a formulation of the rapid sodium current, INa, based on 30 year old data from chick embryo cell aggregates). Here we develop a simple "parsimonious" rabbit AP model that is mathematically identifiable (i.e., not over parameterized) by combining a novel Hodgkin-Huxley formulation of INa with a phenomenological model of repolarization similar to the voltage dependent, time-independent rectifying outward potassium current (IK). The model was calibrated using the following experimental data sets measured from the same species (rabbit) under physiological conditions: dynamic current-voltage (I-V) relationships during the AP upstroke; rapid recovery of AP excitability during the relative refractory period; and steady-state INa inactivation via voltage clamp. Simulations reproduced several important "emergent" phenomena including cellular alternans at rates > 250 bpm as observed in rabbit myocytes, reentrant spiral waves as observed on the surface of the rabbit heart, and spiral wave breakup. Model variants were studied which elucidated the minimal requirements for alternans and spiral wave break up, namely the kinetics of INa inactivation and the non-linear rectification of IK.The simplicity of the model, and the fact that its parameters have physiological meaning, make it ideal for engendering generalizable mechanistic

Marginal Propensity to Consume in Hungary: The long-term versus Short-term Challenges to Policy Makers

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Keith Write

2017-11-01

Full Text Available This study uses Hungarian quarterly data from the International Monetary Fund to estimate a distributed lag model whose coefficients allow derivation of the short-run and long-run marginal propensities to consume.  MPCs are main factors determining the consumption, investment, government spending, and export and import multipliers of the economy.  Hungary's economy has stagnated and its policy makers are exploring new ways to manage its economy.  Our model reveals that the numerical value of Hungarian short-run marginal propensity to consume (MPC is 0.4081181655 and the long-run MPC is 0.9458619.  These results are consistent with the corresponding figures in emerging and advanced economies.  These derived MPCs suggest that Hungarian economic policy makers should use fiscal instruments to bring these macroeconomic variables back to their long-term trend effectively

Are our dynamic water quality models too complex? A comparison of a new parsimonious phosphorus model, SimplyP, and INCA-P

Science.gov (United States)

Jackson-Blake, L. A.; Sample, J. E.; Wade, A. J.; Helliwell, R. C.; Skeffington, R. A.

2017-07-01

Catchment-scale water quality models are increasingly popular tools for exploring the potential effects of land management, land use change and climate change on water quality. However, the dynamic, catchment-scale nutrient models in common usage are complex, with many uncertain parameters requiring calibration, limiting their usability and robustness. A key question is whether this complexity is justified. To explore this, we developed a parsimonious phosphorus model, SimplyP, incorporating a rainfall-runoff model and a biogeochemical model able to simulate daily streamflow, suspended sediment, and particulate and dissolved phosphorus dynamics. The model's complexity was compared to one popular nutrient model, INCA-P, and the performance of the two models was compared in a small rural catchment in northeast Scotland. For three land use classes, less than six SimplyP parameters must be determined through calibration, the rest may be based on measurements, while INCA-P has around 40 unmeasurable parameters. Despite substantially simpler process-representation, SimplyP performed comparably to INCA-P in both calibration and validation and produced similar long-term projections in response to changes in land management. Results support the hypothesis that INCA-P is overly complex for the study catchment. We hope our findings will help prompt wider model comparison exercises, as well as debate among the water quality modeling community as to whether today's models are fit for purpose. Simpler models such as SimplyP have the potential to be useful management and research tools, building blocks for future model development (prototype code is freely available), or benchmarks against which more complex models could be evaluated.

Maximum permissible concentrations and negligible concentrations for phthalates (dibutylphthalate and di(2-ethylhexyl)phthlate), with emphasis on endocrine disruptive properties

NARCIS (Netherlands)

Wezel AP van; Posthumus R; Vlaardingen P van; Crommentuijn T; Plassche EJ van de; CSR

This report presents maximal permissible concentrations (MPCs) and negligible concentrations (NCs) are derived for di-n-butylphthalate (DBP) and di(2-ethylhexyl)phthalate (DEHP). Phthalates are often mentioned as suspected endocrine disrupters. Data with endpoints related to the endocrine or

Rethinking Heat Injury in the SOF Multipurpose Canine: A Critical Review.

Science.gov (United States)

Baker, Janice L; Hollier, Paul J; Miller, Laura; Lacy, Ward A

2012-01-01

Heat injury is a significant concern of the Special Operations Forces Multipurpose Canine (SOF MPC). The unique athletic abilities and working environment of the SOF MPC differ from that of companion dogs or even conventional military working dogs. This should be considered in the prevention, diagnosis, and treatment of heat injury of the SOF MPC. A critical review of the literature on canine heat injury as it pertains to working dogs demonstrates limited scientific evidence on best practices for immediate clinical management of heat injury in SOF MPCs. A majority of management guidelines for heat injury in veterinary reference books and journals are based on review articles or professional opinion of the author vs. evidence from original research. In addition, guidelines are written primarily for companion animal populations vs. SOF MPCs and focus on measures to be undertaken in a clinical setting vs. point of injury. The phenomenon of ?circular referencing? is also prevalent in the heat injury literature. Current guidelines supported by review articles and textbooks often provide no citation or cite other review articles for clinical standards such as normal temperature ranges, treatment methods, and recurrence of heat injury. This ?circular referencing? phenomenon misrepresents anecdotal evidence and professional opinion as scientifically validated, reinforcing concepts and recommendations that are not truly supported by the evidence. Further study is needed to fully understand heat injury in SOF MPCs and how this applies to prevention, diagnosis and treatment guidelines. In order to provide SOF canine programs with best clinical advice and care, SOF Veterinarians must make clinical judgments based on evaluation of the most accurate and valid information possible. Clinical guidelines are fluid and should be reviewed regularly for relevance to the defined population in question. Clinical Guidelines should also be utilized as guiding principles in conjunction with

Hyainailourine and teratodontine cranial material from the late Eocene of Egypt and the application of parsimony and Bayesian methods to the phylogeny and biogeography of Hyaenodonta (Placentalia, Mammalia).

Science.gov (United States)

Borths, Matthew R; Holroyd, Patricia A; Seiffert, Erik R

2016-01-01

recovered from each phylogenetic method, we reconstructed the biogeographic history of Hyaenodonta using parsimony optimization (PO), likelihood optimization (LO), and Bayesian Binary Markov chain Monte Carlo (MCMC) to examine support for the Afro-Arabian origin of Hyaenodonta. Across all analyses, we found that Hyaenodonta most likely originated in Europe, rather than Afro-Arabia. The clade is estimated by tip-dating analysis to have undergone a rapid radiation in the Late Cretaceous and Paleocene; a radiation currently not documented by fossil evidence. During the Paleocene, lineages are reconstructed as dispersing to Asia, Afro-Arabia, and North America. The place of origin of Hyainailouroidea is likely Afro-Arabia according to the Bayesian topologies but it is ambiguous using parsimony. All topologies support the constituent clades-Hyainailourinae, Apterodontinae, and Teratodontinae-as Afro-Arabian and tip-dating estimates that each clade is established in Afro-Arabia by the middle Eocene.

Análise filogenética e implicações sistemáticas e evolutivas nos Cuculiformes (Aves com base na osteologia, comportamento e ecologia Phylogenetic analysis of Cuculiformes (Aves based on osteology, behavior and ecology: systematics and evolutionary implications

Directory of Open Access Journals (Sweden)

Sérgio R. Posso

2006-09-01

Full Text Available Têm-se notado vários estudos recentes em filogenia com os Cuculiformes, no entanto nestes trabalhos ainda há divergências. Apresenta-se aqui uma nova e ampla análise filogenética para os Cuculiformes com base em 250 caracteres da osteologia, comportamento e ecologia. Esta análise resultou em 18 cladogramas igualmente parcimoniosos (768 passos, IC = 0.4779, IR = 0.8080 e ICR = 0.3861. De acordo com o cladograma de consenso estrito se pode observar: a o monofiletismo dos Cuculiformes; b a ordem dividida em dois grupos: a Coua/Carpococcyx e; b demais cucos (Neomorphidae, (Crotophagidae, (Tapera/Dromoccoccyx, (Cuculidae, no entanto a posição sistemática de Centropus é ambígua entre estes dois grandes grupos; c os cucos terrestres basais e parafiléticos e os cucos arbóreos derivados e monofiléticos. Ainda, propõe-se que o comportamento de parasitar ninho tenha surgido duas vezes independentemente (uma em Tapera/Dromoccoccyx e outra dentro de Cuculidae.Despite of many recent cladistic studies the classification of the order Cuculiformes is still controversial. Thus, we performed the most extensive cladistic analysis of the cuckoos, inferred based on 250 characters of the osteology, behavior and ecology. The resulting analysis provided 18 equally parsimonious trees (768 steps, CI = 0.4779, RI = 0.8080 and CRI = 0.3861. According to the topology of the strict consensus cladogram: a the monophyly of Cuculiformes order is corroborated; b the order is divided in two groups: a Coua/Carpococcyx and b others cuckoos (Neomorphidae, (Crotophagidae, (Tapera/Dromoccoccyx, (Cuculidae, being the systematic position of Centropus ambiguous between these two groups; c the terrestrial cuckoos are considered basal and a paraphyletic group and the arboreal cuckoos are derived and monophyletic; d brood parasitism evolved twice in the cuckoos (in Tapera/Dromoccoccyx and in Cuculidae.

Phylogeny, evolutionary trends and classification of the Spathelia-Ptaeroxylon clade: morphological and molecular insights.

Science.gov (United States)

Appelhans, M S; Smets, E; Razafimandimbison, S G; Haevermans, T; van Marle, E J; Couloux, A; Rabarison, H; Randrianarivelojosia, M; Kessler, P J A

2011-06-01

The Spathelia-Ptaeroxylon clade is a group of morphologically diverse plants that have been classified together as a result of molecular phylogenetic studies. The clade is currently included in Rutaceae and recognized at a subfamilial level (Spathelioideae) despite the fact that most of its genera have traditionally been associated with other families and that there are no obvious morphological synapomorphies for the clade. The aim of the present study is to construct phylogenetic trees for the Spathelia-Ptaeroxylon clade and to investigate anatomical characters in order to decide whether it should be kept in Rutaceae or recognized at the familial level. Anatomical characters were plotted on a cladogram to help explain character evolution within the group. Moreover, phylogenetic relationships and generic limits within the clade are also addressed. A species-level phylogenetic analysis of the Spathelia-Ptaeroxylon clade based on five plastid DNA regions (rbcL, atpB, trnL-trnF, rps16 and psbA-trnH) was conducted using Bayesian, maximum parsimony and maximum likelihood methods. Leaf and seed anatomical characters of all genera were (re)investigated by light and scanning electron microscopy. With the exception of Spathelia, all genera of the Spathelila-Ptaeroxylon clade are monophyletic. The typical leaf and seed anatomical characters of Rutaceae were found. Further, the presence of oil cells in the leaves provides a possible synapomorphy for the clade. The Spathelia-Ptaeroxylon clade is well placed in Rutaceae and it is reasonable to unite the genera into one subfamily (Spathelioideae). We propose a new tribal classification of Spathelioideae. A narrow circumscription of Spathelia is established to make the genus monophyletic, and Sohnreyia is resurrected to accommodate the South American species of Spathelia. The most recent common ancestor of Spathelioideae probably had leaves with secretory cavities and oil cells, haplostemonous flowers with appendaged staminal

Germline large genomic alterations on 7q in patients with multiple primary cancers

DEFF Research Database (Denmark)

Villacis, Rolando A R; Basso, Tatiane R; Canto, Luisa M

2017-01-01

Patients with multiple primary cancers (MPCs) are suspected to have a hereditary cancer syndrome. However, only a small proportion may be explained by mutations in high-penetrance genes. We investigate two unrelated MPC patients that met Hereditary Breast and Ovaria Cancer criteria, both presenti...

Secondary poisoning of cadmium, copper and mercury: implications for the Maximum Permissible Concentrations and Negligible Concentrations in water, sediment and soil

NARCIS (Netherlands)

Smit CE; Wezel AP van; Jager T; Traas TP; CSR

2000-01-01

The impact of secondary poisoning on the Maximum Permissible Concentrations (MPCs) and Negligible Concentrations (NCs) of cadmium, copper and mercury in water, sediment and soil have been evaluated. Field data on accumulation of these elements by fish, mussels and earthworms were used to derive

Computational tasks in robotics and factory automation

NARCIS (Netherlands)

Biemans, Frank P.; Vissers, C.A.

1988-01-01

The design of Manufacturing Planning and Control Systems (MPCSs) — systems that negotiate with Customers and Suppliers to exchange products in return for money in order to generate profit, is discussed. The computational task of MPCS components are systematically specified as a starting point for

Trace element patterns in Dutch coastal dunes after 50 years of artificial recharge with Rhine River water

NARCIS (Netherlands)

Stuijfzand, P.J.

2014-01-01

Trace elements (TEs) are important in water quality monitoring of managed aquifer recharge (MAR) systems, because they need to be tested against maximum permissible concentrations (MPCs), and some can be used as a tracer of either infiltration water, pollution or geochemical processes. The behavior

Do fly parasites of bats and their hosts coevolve?speciation in Trichobius phyllostomae group (Diptera, Streblidae and their hosts (Chiroptera, Phyllostomidae suggests that they do not

Directory of Open Access Journals (Sweden)

Gustavo Graciolli

2012-12-01

Full Text Available We examined whether, like many parasite-host systems of coevolution, a group of obligate parasitic bat flies (Trichobius phyllostomae Kessel and related species cospeciate with their hosts. We first did a cladistic analysis of the T. phyllostomae group and combined that analysis with a phylogenetic hypothesis from the literature for the Stenodermatinae bats. The cladistic analysis included, as outgroups, one species from each morphological group and complex of Trichobius Gervais, and one species from the following genera: Paratrichobius Miranda-Ribeiro, Megistopoda Macquart, Megistapophysys Dick & Wenzel, Neotrichobius Wenzel & Aitken, Speiseria Kessel and Strebla Wiedemann. The cladogram was rooted with a species of Strebla in the subfamily Streblinae. One cladogram was obtained and which found Trichobius to be polyphyletic. The phylogenetic hypothesis as follows: (Paratrichobius, (Neotrichobius, (Megistopoda, Megistapophysis is the sister-group of the phyllostomae group and the following relationships within the ingroup, (((T. vampyropis Wenzel, Trichobius sp. 2 ((T. hispidus Wenzel, T. petersoni Wenzel ((Trichobius sp. 1 (T. phyllostomae, T. brennani Wenzel. When we compared phylogenies through historical association analyses, cospeciation was uncommon, while host-switching was more common and better explained the association between the phyllostomae group and their bat hosts.

Flood modelling with a distributed event-based parsimonious rainfall-runoff model: case of the karstic Lez river catchment

Directory of Open Access Journals (Sweden)

M. Coustau

2012-04-01

Full Text Available Rainfall-runoff models are crucial tools for the statistical prediction of flash floods and real-time forecasting. This paper focuses on a karstic basin in the South of France and proposes a distributed parsimonious event-based rainfall-runoff model, coherent with the poor knowledge of both evaporative and underground fluxes. The model combines a SCS runoff model and a Lag and Route routing model for each cell of a regular grid mesh. The efficiency of the model is discussed not only to satisfactorily simulate floods but also to get powerful relationships between the initial condition of the model and various predictors of the initial wetness state of the basin, such as the base flow, the Hu2 index from the Meteo-France SIM model and the piezometric levels of the aquifer. The advantage of using meteorological radar rainfall in flood modelling is also assessed. Model calibration proved to be satisfactory by using an hourly time step with Nash criterion values, ranging between 0.66 and 0.94 for eighteen of the twenty-one selected events. The radar rainfall inputs significantly improved the simulations or the assessment of the initial condition of the model for 5 events at the beginning of autumn, mostly in September–October (mean improvement of Nash is 0.09; correction in the initial condition ranges from −205 to 124 mm, but were less efficient for the events at the end of autumn. In this period, the weak vertical extension of the precipitation system and the low altitude of the 0 °C isotherm could affect the efficiency of radar measurements due to the distance between the basin and the radar (~60 km. The model initial condition S is correlated with the three tested predictors (R² > 0.6. The interpretation of the model suggests that groundwater does not affect the first peaks of the flood, but can strongly impact subsequent peaks in the case of a multi-storm event. Because this kind of model is based on a limited

Production and Characterization of a Novel, Electrospun, Tri-Layer Polycaprolactone Membrane for the Segregated Co-Culture of Bone and Soft Tissue

Directory of Open Access Journals (Sweden)

Sasima Puwanun

2016-06-01

Full Text Available Composite tissue-engineered constructs combining bone and soft tissue have applications in regenerative medicine, particularly dentistry. This study generated a tri-layer, electrospun, poly-ε-caprolactone membrane, with two microfiber layers separated by a layer of nanofibers, for the spatially segregated culture of mesenchymal progenitor cells (MPCs and fibroblasts. The two cell types were seeded on either side, and cell proliferation and spatial organization were investigated over several weeks. Calcium deposition by MPCs was detected using xylenol orange (XO and the separation between fibroblasts and the calcified matrix was visualized by confocal laser scanning microscopy. SEM confirmed that the scaffold consisted of two layers of micron-diameter fibers with a thin layer of nano-diameter fibers in-between. Complete separation of cell types was maintained and calcified matrix was observed on only one side of the membrane. This novel tri-layer membrane is capable of supporting the formation of a bilayer of calcified and non-calcified connective tissue.

The Shell Structure Effect on the Vapor Selectivity of Monolayer-Protected Gold Nanoparticle Sensors

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Rui-Xuan Huang

2014-02-01

Full Text Available Four types of monolayer-protected gold nanoclusters (MPCs were synthesized and characterized as active layers of vapor sensors. An interdigitated microelectrode (IDE and quartz crystal microbalance (QCM were used to measure the electrical resistance and mass loading changes of MPC films during vapor sorption. The vapor sensing selectivity was influenced by the ligand structure of the monolayer on the surface of gold nanoparticles. The responses of MPC-coated QCM were mainly determined according to the affinity between the vapors and surface ligands of MPCs. The responses to the resistance changes of the MPC films were due to the effectiveness of the swelling when vapor was absorbed. It was observed that resistive sensitivity to polar organics could be greatly enhanced when the MPC contained ligands that contain interior polar functional groups with exterior nonpolar groups. This finding reveals that reducing interparticle attraction by using non-polar exterior groups could increase effective swelling and therefore enhance the sensitivity of MPC-coated chemiresistors.

Temporal coupled mode analysis of one-dimensional magneto-photonic crystals with cavity structures

Energy Technology Data Exchange (ETDEWEB)

Saghirzadeh Darki, Behnam, E-mail: b.saghirzadeh@ec.iut.ac.ir; Zeidaabadi Nezhad, Abolghasem; Firouzeh, Zaker Hossein

2016-12-01

In this paper, we propose the time-dependent coupled mode analysis of one-dimensional magneto-photonic crystals including one, two or multiple defect layers. The performance of the structures, namely the total transmission, Faraday rotation and ellipticity, is obtained using the proposed method. The results of the developed analytic approach are verified by comparing them to the results of the exact numerical transfer matrix method. Unlike the widely used numerical method, our proposed analytic method seems promising for the synthesis as well as the analysis purposes. Moreover, the proposed method has not the restrictions of the previously examined analytic methods. - Highlights: • A time-dependent coupled mode analysis is proposed for the cavity-type 1D MPCs. • Analytical formalism is presented for the single, double and multiple-defect MPCs. • Transmission, Faraday rotation and ellipticity are gained using the proposed method. • The proposed analytic method has advantages over the previously examined methods.

Human Migratory Meniscus Progenitor Cells Are Controlled via the TGF-β Pathway

Science.gov (United States)

Muhammad, Hayat; Schminke, Boris; Bode, Christa; Roth, Moritz; Albert, Julius; von der Heyde, Silvia; Rosen, Vicki; Miosge, Nicolai

2014-01-01

Summary Degeneration of the knee joint during osteoarthritis often begins with meniscal lesions. Meniscectomy, previously performed extensively after meniscal injury, is now obsolete because of the inevitable osteoarthritis that occurs following this procedure. Clinically, meniscus self-renewal is well documented as long as the outer, vascularized meniscal ring remains intact. In contrast, regeneration of the inner, avascular meniscus does not occur. Here, we show that cartilage tissue harvested from the avascular inner human meniscus during the late stages of osteoarthritis harbors a unique progenitor cell population. These meniscus progenitor cells (MPCs) are clonogenic and multipotent and exhibit migratory activity. We also determined that MPCs are likely to be controlled by canonical transforming growth factor β (TGF-β) signaling that leads to an increase in SOX9 and a decrease in RUNX2, thereby enhancing the chondrogenic potential of MPC. Therefore, our work is relevant for the development of novel cell biological, regenerative therapies for meniscus repair. PMID:25418724

Osteología craneal del género Philodryas (Serpentes: Colubridae

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Lobo, Fernando

1994-01-01

Full Text Available We studied the skulls of eleven species of Philodryas. The skull of Philodryas patagoniensis is described, and some characters that show interspecific variation are recognized. These characters are used for phylogenetic inferences. We obtained three trees using Hennig86. The pair of sister species wich is presented in the three cladograms is P. mattogrossensis - P. varius: in only ene tree: P. buroni - P. burmeisteri.

Cooperative function of Pdx1 and Oc1 in multipotent pancreatic progenitors impacts postnatal islet maturation and adaptability.

Science.gov (United States)

Kropp, Peter A; Dunn, Jennifer C; Carboneau, Bethany A; Stoffers, Doris A; Gannon, Maureen

2018-04-01

The transcription factors pancreatic and duodenal homeobox 1 (Pdx1) and onecut1 (Oc1) are coexpressed in multipotent pancreatic progenitors (MPCs), but their expression patterns diverge in hormone-expressing cells, with Oc1 expression being extinguished in the endocrine lineage and Pdx1 being maintained at high levels in β-cells. We previously demonstrated that cooperative function of these two factors in MPCs is necessary for proper specification and differentiation of pancreatic endocrine cells. In those studies, we observed a persistent decrease in expression of the β-cell maturity factor MafA. We therefore hypothesized that Pdx1 and Oc1 cooperativity in MPCs impacts postnatal β-cell maturation and function. Here our model of Pdx1-Oc1 double heterozygosity was used to investigate the impact of haploinsufficiency for both of these factors on postnatal β-cell maturation, function, and adaptability. Examining mice at postnatal day (P) 14, we observed alterations in pancreatic insulin content in both Pdx1 heterozygotes and double heterozygotes. Gene expression analysis at this age revealed significantly decreased expression of many genes important for glucose-stimulated insulin secretion (e.g., Glut2, Pcsk1/2, Abcc8) exclusively in double heterozygotes. Analysis of P14 islets revealed an increase in the number of mixed islets in double heterozygotes. We predicted that double-heterozygous β-cells would have an impaired ability to respond to stress. Indeed, we observed that β-cell proliferation fails to increase in double heterozygotes in response to either high-fat diet or placental lactogen. We thus report here the importance of cooperation between regulatory factors early in development for postnatal islet maturation and adaptability.

phthalocyanine-catalyzed synthesis of 2-nitro-4

Indian Academy of Sciences (India)

CHENG HUANG

2017-09-22

Sep 22, 2017 ... Through optimization of the reaction parameters, the highest yield of NMSBA and conversion ... developed by Syngenta company. It is widely ... and co-authors12 reported a method for oxidation of ... excellent performance in catalytic oxidation by oxygen .... tion: It is necessary to measure the effect of MPcs.

32 CFR 635.20 - Military Police Codes (MPC).

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Military Police Codes (MPC). 635.20 Section 635.20 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS LAW ENFORCEMENT REPORTING Offense Reporting § 635.20 Military Police Codes (MPC). (a) MPCs identify individual Provos...

Revision, cladistic analysis and biogeography of Typhochlaena C. L. Koch, 1850, Pachistopelma Pocock, 1901 and Iridopelma Pocock, 1901 (Araneae, Theraphosidae, Aviculariinae).

Science.gov (United States)

Bertani, Rogério

2012-01-01

Three aviculariine genera endemic to Brazil are revised. Typhochlaena C. L. Koch, 1850 is resurrected, including five species; Pachistopelma Pocock, 1901 includes two species; and Iridopelma Pocock, 1901, six species. Nine species are newly described: Typhochlaena ammasp. n., Typhochlaena costaesp. n., Typhochlaena curumimsp. n., Typhochlaena paschoalisp. n., Pachistopelma bromelicolasp. n., Iridopelma katiaesp. n., Iridopelma marcoisp. n., Iridopelma oliveiraisp. n. and Iridopelma vaninisp. n. Three new synonymies are established: Avicularia pulchra Mello-Leitão, 1933 and Avicularia recifiensis Struchen & Brändle, 1996 are junior synonyms of Pachistopelma rufonigrum Pocock, 1901 syn. n., and Avicularia palmicola Mello-Leitão, 1945 is a junior synonym of Iridopelma hirsutum Pocock, 1901 syn. n.Pachistopelma concolor Caporiacco, 1947 is transferred to Tapinauchenius Ausserer, 1871, making the new combination Tapinauchenius concolor (Caporiacco, 1947)comb. n. Lectotypes are newly designed for Pachistopelma rufonigrum Pocock, 1901 , Iridopelma hirsutum Pocock, 1901 and Pachistopelma concolor Caporiacco, 1947. Cladistic analyses using both equal and implied weights were carried out with a matrix comprising 62 characters and 38 terminal taxa. The chosen cladogram found with X-Pee-Wee and concavity 6 suggests they are monophyletic. All species are keyed and mapped and information on species habitat and area cladograms are presented. Discussion on biogeography and conservation is provided.

Suitability of cuticular pores and sensilla for harpacticoid copepod species delineation and phylogenetic reconstruction.

Science.gov (United States)

Karanovic, Tomislav; Kim, Kichoon

2014-11-01

Cuticular organs have not been described systematically in harpacticoids until recently, and they haven ever been used as characters for reconstructing phylogenetic relationships in any crustacean group. We survey cuticular pores and sensilla on somites in ten Miraciidae species, belonging to six genera, from Korea, Australia, and Russia. Nine species belong to the subfamily Stenheliinae, while the outgroup belongs to the subfamily Diosaccinae. We aim to compare phylogenetic trees reconstructed for these harpactioids based on: 1) cuticular organs (with 76 characters scored, 71% of them phylogenetically informative); 2) traditionally used macro-morphological characters (66 scored, 77% of them informative);and 3) mtCOI DNA data. All analyses suggest that cuticular organs are useful characters for harpacticoid species delineation, although not as sensitive as some fast-evolving molecular markers. Reconstructed cladograms based on all three datasets show very high bootstrap values for clades representing distinct genera, suggesting that cuticular organs are suitable characters for studying phylogenetic relationships. Bootstrap values for the more basal nodes differ among the different cladograms,as do the sister-group relationships they suggest, indicating that cuticular organs probably have different evolutionary constraints from macro-morphological characters. Cuticular organs could be quite useful in the study of old museum specimens and fossil crustaceans.

Improvement of diffraction efficiency of three-dimensional magneto-optic spatial light modulator with magnetophotonic crystal

Energy Technology Data Exchange (ETDEWEB)

Nakamura, K.; Takagi, H., E-mail: takagi@ee.tut.ac.jp; Lim, P. B.; Inoue, M., E-mail: inoue@tut.ac.jp [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441 8580 (Japan); Goto, Taichi [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441 8580 (Japan); JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Horimai, H. [HolyMine Corporation, Atsugi, Kanagawa 243 0813 (Japan); Yoshikawa, H. [Department of Computer Engineering, College of Science and Technology, Nihon University, Funabashi, Chiba 274 8501 (Japan); Bove, V. M. [MIT Media Lab, Cambridge, Massachusetts 02139 (United States)

2016-01-11

We have developed three-dimensional magneto-optic spatial light modulators (3D-MOSLMs) that use magnetic domains as submicron scale pixels to represent holograms. Our display system uses a submicron-scale magnetic pixel array on an amorphous TbFe film to create a wide viewing angle hologram. However, in previous work the reconstructed images had a low intensity and a low optical contrast; brightness of the reconstructed image was 4.4 × 10{sup −2 }cd/m{sup 2} with 532 nm illumination light at 10.8 mW/cm{sup 2}, while display standard ISO13406 recommends 100 cd/m{sup 2} or more. In this paper, we describe our development of a 3D-MOSLM composed of an artificial magnetic lattice structure of magnetophotonic crystals (MPCs). The MPCs enhance the diffraction efficiency of reconstructed 3D images and reduce the power consumption for controlling the magnetic pixels by a light localization effect. We demonstrate reconstructed 3D images using the MPC and show significant brightness improvement.

The Role of Endothelial Cells in Myofiber Differentiation and the Vascularization and Innervation of Bioengineered Muscle Tissue in vivo

Science.gov (United States)

2012-10-08

muscle in vitro. MPCs, ECs and PCs were co-cultured together on either Matrigel-coated dishes (A, B) or on the BAM scaffold (C, D) and live cell imaging was...differentiated in DM (D) were visualized using live cell imaging . Arrows (C) indicate branched vessel-like structures. Scale bars: 65 mm (E) EC content on the BAM

Análise biogeográfica da avifauna da região oeste do baixo Rio Negro, amazônia brasileira Biogeographical analysis of the avifauna in the lower western Rio Negro region in the Brazilian Amazon

Directory of Open Access Journals (Sweden)

Sérgio H. Borges

2007-12-01

Full Text Available Neste estudo é realizada uma análise biogeográfica detalhada da avifauna da Amazônia Central a oeste do Rio Negro, região onde está localizado o Parque Nacional do Jaú (PNJ. As distribuições geográficas de 383 táxons (espécies e subespécies de aves registradas no PNJ foram analisadas através de métodos biogeográficos qualitativos e quantitativos (análise de agrupamento e análise de parcimônia de endemismo. A avifauna do PNJ é fortemente influenciada pelas regiões noroeste e oeste da bacia amazônica. Foram identificadas três unidades biogeográficas e o PNJ se agrupa com sítios localizados no alto Rio Orinoco e na Guiana. De modo similar, o PNJ se agrupa com o sítio do alto Rio Orinoco tendo a Guiana como grupo-irmão no cladograma de área com maior suporte. Diferentes sub-grupos de espécies revelaram cladogramas de áreas com variadas topologias, sugerindo complexos cenários de diversificação da avifauna amazônica. Estes cenários biogeográficos podem ter sido influenciados por eventos geológicos ocorridos durante o Mioceno e Pleistoceno. Neste estudo foi identificada uma área de endemismo não descrita para a Amazônia - a área de endemismo Rio Negro. A avifauna da região do PNJ, além de ser representativa dos setores noroeste e oeste da Amazônia, possui táxons de distribuição restrita à região central da Amazônia, reforçando ainda mais sua importância na proteção da biodiversidade amazônica.This study makes a detailed biogeographical analysis of Central Amazon avifauna west of the Rio Negro, where Parque Nacional do Jaú (PNJ is located. The geographical distribution of 383 bird taxa (species or subspecies recorded in PNJ was analyzed through qualitative and quantitative biogeographic methods (cluster analysis and parsimony analysis of endemicity. Results showed that the avifauna of PNJ is strongly influenced by the northwestern and western regions of the Amazon Basin. Three biogeographic units

Fries' goby, a European oddity

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Peter J Miller

2015-12-01

Full Text Available Fries' Goby, Lesueurigobius friesii (Malm, 1874 is common on softer grounds of the more offshore eastern Atlantic continental shelf from Norway to Mauritania, and in the Mediterranean to the Sea of Marmora. The several species of the genus are unique among Lusitanian/Boreal gobiine gobies in coloration and caudal morphology as well as in the 'longitudinal' pattern of infraorbital free neuromast-organs and the lack of head lateral-line canals. A new classification of Old World longitudinal gobiines, based on these free neuromast patterns of both infraorbital and hyomandibular innervation, places Lesueurigobius as the Atlantic sister group to the other longitudinal gobiines, which are all Indo/West Pacific in distribution. The proposed cladogram, the first for the group, is based on synapomorphies in features of rostral mandibular line neuromast series f, the rows of the cheek, and vertebral number. Species of Lesueurigobius show an apparently apomorphic reduction in infraorbital row cp that is shared with three Indo-West Pacific genera (Silhouettea, Heteroplopomus and Platygobiopsis but, in Lesueurigobius , this is now believed to be plesiomorphic. Morphological character states were used to construct a cladogram which was discussed in relation to molecular findings that support Lesueurigobius as an outgroup to the Indo/West Pacific genera. The importance of the latter as tools for testing morphological phylogenies, rather than as conflicting classification, is strongly emphasised.

Phylogeny, evolutionary trends and classification of the Spathelia–Ptaeroxylon clade: morphological and molecular insights

Science.gov (United States)

Appelhans, M. S.; Smets, E.; Razafimandimbison, S. G.; Haevermans, T.; van Marle, E. J.; Couloux, A.; Rabarison, H.; Randrianarivelojosia, M.; Keßler, P. J. A.

2011-01-01

Background and Aims The Spathelia–Ptaeroxylon clade is a group of morphologically diverse plants that have been classified together as a result of molecular phylogenetic studies. The clade is currently included in Rutaceae and recognized at a subfamilial level (Spathelioideae) despite the fact that most of its genera have traditionally been associated with other families and that there are no obvious morphological synapomorphies for the clade. The aim of the present study is to construct phylogenetic trees for the Spathelia–Ptaeroxylon clade and to investigate anatomical characters in order to decide whether it should be kept in Rutaceae or recognized at the familial level. Anatomical characters were plotted on a cladogram to help explain character evolution within the group. Moreover, phylogenetic relationships and generic limits within the clade are also addressed. Methods A species-level phylogenetic analysis of the Spathelia–Ptaeroxylon clade based on five plastid DNA regions (rbcL, atpB, trnL–trnF, rps16 and psbA–trnH) was conducted using Bayesian, maximum parsimony and maximum likelihood methods. Leaf and seed anatomical characters of all genera were (re)investigated by light and scanning electron microscopy. Key Results With the exception of Spathelia, all genera of the Spathelila–Ptaeroxylon clade are monophyletic. The typical leaf and seed anatomical characters of Rutaceae were found. Further, the presence of oil cells in the leaves provides a possible synapomorphy for the clade. Conclusions The Spathelia–Ptaeroxylon clade is well placed in Rutaceae and it is reasonable to unite the genera into one subfamily (Spathelioideae). We propose a new tribal classification of Spathelioideae. A narrow circumscription of Spathelia is established to make the genus monophyletic, and Sohnreyia is resurrected to accommodate the South American species of Spathelia. The most recent common ancestor of Spathelioideae probably had leaves with secretory cavities

Supplementary cranial description of the types of Edmontosaurus regalis (Ornithischia: Hadrosauridae, with comments on the phylogenetics and biogeography of Hadrosaurinae.

Directory of Open Access Journals (Sweden)

Hai Xing

Full Text Available The cranial anatomy of the flat-skulled hadrosaurine Edmontosaurus regalis (Ornithischia: Hadrosauridae is extensively described here, based on the holotype and paratype collected from the middle part of the Horseshoe Canyon Formation in southern Alberta. Focus is given to previously undocumented features of ontogenetic and phylogenetic importance. This description facilitates overall osteological comparisons between E. regalis and other hadrosaurids (especially E. annectens, and revises the diagnosis of E. regalis, to which a new autapomorphy (the dorsal half of the jugal anterior process bearing a sharp posterolateral projection into the orbit is added. We consider the recently named Ugrunaaluk kuukpikensis from the upper Campanian/lower Maastrichtian of Alaska a nomen dubium, and conservatively regard the Alaskan material as belonging to Edmontosaurus sp.. A phylogenetic analysis of Hadrosauroidea using maximum parsimony further corroborates the sister-taxon relationship between E. regalis and E. annectens. In the strict consensus tree, Hadrosaurus foulkii occurs firmly within the clade comprising all non-lambeosaurine hadrosaurids, supporting the taxonomic scheme that divides Hadrosauridae into Hadrosaurinae and Lambeosaurinae. Within Edmontosaurini, Kerberosaurus is posited as the sister taxon to the clade of Shantungosaurus + Edmontosaurus. The biogeographic reconstruction of Hadrosaurinae in light of the time-calibrated cladogram and probability calculation of ancestral areas for all internal nodes reveals a significantly high probability for the North American origin of the clade. However, the Laramidia-Appalachia dispersals around the Santonian-Campanian boundary, inferred from the biogeographic scenario for the North American origin of Hadrosaurinae, are in conflict with currently accepted paleogeographic models. By contrast, the Asian origin of Hadrosaurinae with its relatively low probability resulting from the biogeographic analysis

Supplementary cranial description of the types of Edmontosaurus regalis (Ornithischia: Hadrosauridae), with comments on the phylogenetics and biogeography of Hadrosaurinae.

Science.gov (United States)

Xing, Hai; Mallon, Jordan C; Currie, Margaret L

2017-01-01

The cranial anatomy of the flat-skulled hadrosaurine Edmontosaurus regalis (Ornithischia: Hadrosauridae) is extensively described here, based on the holotype and paratype collected from the middle part of the Horseshoe Canyon Formation in southern Alberta. Focus is given to previously undocumented features of ontogenetic and phylogenetic importance. This description facilitates overall osteological comparisons between E. regalis and other hadrosaurids (especially E. annectens), and revises the diagnosis of E. regalis, to which a new autapomorphy (the dorsal half of the jugal anterior process bearing a sharp posterolateral projection into the orbit) is added. We consider the recently named Ugrunaaluk kuukpikensis from the upper Campanian/lower Maastrichtian of Alaska a nomen dubium, and conservatively regard the Alaskan material as belonging to Edmontosaurus sp.. A phylogenetic analysis of Hadrosauroidea using maximum parsimony further corroborates the sister-taxon relationship between E. regalis and E. annectens. In the strict consensus tree, Hadrosaurus foulkii occurs firmly within the clade comprising all non-lambeosaurine hadrosaurids, supporting the taxonomic scheme that divides Hadrosauridae into Hadrosaurinae and Lambeosaurinae. Within Edmontosaurini, Kerberosaurus is posited as the sister taxon to the clade of Shantungosaurus + Edmontosaurus. The biogeographic reconstruction of Hadrosaurinae in light of the time-calibrated cladogram and probability calculation of ancestral areas for all internal nodes reveals a significantly high probability for the North American origin of the clade. However, the Laramidia-Appalachia dispersals around the Santonian-Campanian boundary, inferred from the biogeographic scenario for the North American origin of Hadrosaurinae, are in conflict with currently accepted paleogeographic models. By contrast, the Asian origin of Hadrosaurinae with its relatively low probability resulting from the biogeographic analysis is worth

The percolation effect and optimization of soft magnetic properties of FeSiAl magnetic powder cores

Energy Technology Data Exchange (ETDEWEB)

Bai, Ruru [College of Material Science and Engineering, Nanchang University, Nanchang 330031, Jiangxi (China); Zhu, Zhenghou, E-mail: z00708@sina.com [College of Material Science and Engineering, Nanchang University, Nanchang 330031, Jiangxi (China); Zhao, Hui, E-mail: candyzhaohui@126.com [College of Material Science and Engineering, Nanchang University, Nanchang 330031, Jiangxi (China); Institute of Space Science and Technology, Nanchang University, Nanchang 330031, Jiangxi (China); Mao, Shenghua [Jiangxi Aite magnetic materials Co. Ltd., Yichun 336000, Jiangxi (China); Zhong, Qi [College of Material Science and Engineering, Nanchang University, Nanchang 330031, Jiangxi (China)

2017-07-01

Highlights: • A new magnetic percolation phenomenon of ρ-μe in MPCs was discovered. • The soft magnetic properties of FeSiAl MPCs were studied. • The comprehensive magnetic properties of MPCs were optimized. • The formation mechanism of magnetic conductive path was explained. - Abstract: In this paper, a new magnetic percolation phenomenon between the green compact density ρ and effective permeability μe in FeSi{sub 9.6}Al{sub 6.5} magnetic powder cores, was discovered. The Magnetic Percolation Area of ρ is the range of 5.6 g/cm{sup 3} ∼ 5.78 g/cm{sup 3}, and the percolation threshold is 5.78 g/cm{sup 3}. As a result of the guidance of the percolation theory, the best comprehensive magnetic properties have been optimized through adjusting the distribution of powders. The special distribution of the magnetic powder cores with the best comprehensive magnetic properties was as follows: the content 60% with the particle size distribution of 100–200 mesh, the content 20% with the particle size distribution of 200–325 mesh and the content 20% with the particle size distribution of ≥400 mesh. When the green compact density ρ of cores was 5.79 g/cm{sup 3}, and the frequency was in the range of 1 kHz ∼ 100 kHz, the best comprehensive magnetic properties were as follows: μe = 91, ∆μ = 0.61%, μe(H80 Oe) = 43, μe(H100 Oe) = 33, μe(H120 Oe) = 26, Pc(50 mT/20 kHz) = 30.58 kW/m{sup 3}, Pc(50 mT/50 kHz) = 76.85 kW/m{sup 3}, Pc(50 mT/100 kHz) = 178 kW/m{sup 3}. Not only have those cores the excellent constant magnetic properties with frequency, the excellent DC superposition characteristic and the lower loss at high frequency, but also the effective permeability outstandingly goes up, which has important significance for the miniaturization of inductance components.

Origin and spread of the 1278insTATC mutation causing Tay-Sachs disease in Ashkenazi Jews: genetic drift as a robust and parsimonious hypothesis.

Science.gov (United States)

Frisch, Amos; Colombo, Roberto; Michaelovsky, Elena; Karpati, Mazal; Goldman, Boleslaw; Peleg, Leah

2004-03-01

The 1278insTATC is the most prevalent beta-hexosaminidase A ( HEXA) gene mutation causing Tay-Sachs disease (TSD), one of the four lysosomal storage diseases (LSDs) occurring at elevated frequencies among Ashkenazi Jews (AJs). To investigate the genetic history of this mutation in the AJ population, a conserved haplotype (D15S981:175-D15S131:240-D15S1050:284-D15S197:144-D15S188:418) was identified in 1278insTATC chromosomes from 55 unrelated AJ individuals (15 homozygotes and 40 heterozygotes for the TSD mutation), suggesting the occurrence of a common founder. When two methods were used for analysis of linkage disequilibrium (LD) between flanking polymorphic markers and the disease locus and for the study of the decay of LD over time, the estimated age of the insertion was found to be 40+/-12 generations (95% confidence interval: 30-50 generations), so that the most recent common ancestor of the mutation-bearing chromosomes would date to the 8th-9th century. This corresponds with the demographic expansion of AJs in central Europe, following the founding of the Ashkenaz settlement in the early Middle Ages. The results are consistent with the geographic distribution of the main TSD mutation, 1278insTATC being more common in central Europe, and with the coalescent times of mutations causing two other LSDs, Gaucher disease and mucolipidosis type IV. Evidence for the absence of a determinant positive selection (heterozygote advantage) over the mutation is provided by a comparison between the estimated age of 1278insTATC and the probability of the current AJ frequency of the mutant allele as a function of its age, calculated by use of a branching-process model. Therefore, the founder effect in a rapidly expanding population arising from a bottleneck provides a robust parsimonious hypothesis explaining the spread of 1278insTATC-linked TSD in AJ individuals.

Software Architecture Evolution

Science.gov (United States)

2013-12-01

system’s major components occurring via a Java Message Service message bus [69]. This architecture was designed to promote loose coupling of soft- ware...play reconfiguration of the system. The components were Java -based and platform-independent; the interfaces by which they communicated were based on...The MPCS database, a MySQL database used for storing telemetry as well as some other information, such as logs and commanding data [68]. This

Distribution, Seasonal Variations and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Foliar Dust of Nanjing, China.

Science.gov (United States)

Zha, Yan; Zhang, Yinlong; Ma, Zilong; Tang, Jie; Sun, Kai

2018-04-01

Polycyclic aromatic hydrocarbons (PAHs) are of concern for both ecosystem and human health due to their potential teratogenic, carcinogenic, and mutagenic properties. The concentration of ∑ 16 PAHs in foliar dust ranged from 49.4 to 19,018.1 µg kg -1 , with a mean value of 7074.5 µg kg -1 . There were significant seasonal variations in the concentration of ∑ 16 PAHs, with the concentration in winter being almost twice as high as in summer. Similarly, the differences between PAH profiles in different seasons indicated that they had common sources, which were attributed to the combined effect of regional transport and local emissions. The diagnostic ratios of indicator compounds indicated that PAHs detected in foliar dust originated from a mixture of gasoline vehicle emissions, biomass, and coal combustion in Nanjing. According to the ecological risk classification of ∑ 16 PAHs, the ecological risk caused by PAHs was high since the value of RQ ∑16PAHs(MPCs) was ≥ 1 and RQ ∑16PAHs(NCs) were ≥ 800. The mean values for RQ∑ 16 PAHs (MPCs) and RQ∑ 16 PAHs (NCs) were 14.8 and 2368.9, which indicated a relatively high ecological risks of PAHs in foliar dust in Nanjing.

Derived limits for radiological protection against ionizing radiation based on ICRP-60 recommendations

International Nuclear Information System (INIS)

Jang, Si Young; Lee, Byung Soo

2000-01-01

In Korea the dose limits are reduced and are set at the ICRP-60 limits. However, derived limits tabulated as MPC in air and water are sill specified in Notice Nol 98-12. There are some discrepancies between the primary dose limits and MPCs in air and water. Therefore, in order to accept ICRP-60 recommendations fully, derived limits such as ALI, DAC, ECL for radiological protection against ionizing radiation based on ICRP-60 recommendations were calculated using modified methods of those of 10 CFR part 20, dose limits and committed effective dose coefficients of the Basic Safety Standards of the IAEA. The derived limits in this study were also compared with those prescribed in 10 CFR part 20 as well as MPCs of Notice No.98-12 in order to analyze the impact of implementing derived limits on nuclear facilities. ECLs in air and water for the control of radioactive discharge into the environment in this study are shown to have lower values (i.e. more conservative), for most part, than those in Notice No. 98-12. Especially, for uranium elements, ECLs in water are approximately a magnitude in the order of two lower than those in Notice No. 98-12. (author)

Regulation of the muscle fiber microenvironment by activated satellite cells during hypertrophy

Science.gov (United States)

Fry, Christopher S.; Lee, Jonah D.; Jackson, Janna R.; Kirby, Tyler J.; Stasko, Shawn A.; Liu, Honglu; Dupont-Versteegden, Esther E.; McCarthy, John J.; Peterson, Charlotte A.

2014-01-01

Our aim in the current study was to determine the necessity of satellite cells for long-term muscle growth and maintenance. We utilized a transgenic Pax7-DTA mouse model, allowing for the conditional depletion of > 90% of satellite cells with tamoxifen treatment. Synergist ablation surgery, where removal of synergist muscles places functional overload on the plantaris, was used to stimulate robust hypertrophy. Following 8 wk of overload, satellite cell-depleted muscle demonstrated an accumulation of extracellular matrix (ECM) and fibroblast expansion that resulted in reduced specific force of the plantaris. Although the early growth response was normal, an attenuation of hypertrophy measured by both muscle wet weight and fiber cross-sectional area occurred in satellite cell-depleted muscle. Isolated primary myogenic progenitor cells (MPCs) negatively regulated fibroblast ECM mRNA expression in vitro, suggesting a novel role for activated satellite cells/MPCs in muscle adaptation. These results provide evidence that satellite cells regulate the muscle environment during growth.—Fry, C. S., Lee, J. D., Jackson, J. R., Kirby, T. J., Stasko, S. A., Liu, H., Dupont-Versteegden, E. E., McCarthy, J. J., Peterson, C. A. Regulation of the muscle fiber microenvironment by activated satellite cells during hypertrophy. PMID:24376025

Plethodontid salamander mitochondrial genomics: A parsimonyevaluation of character conflict and implications for historicalbiogeography

Energy Technology Data Exchange (ETDEWEB)

Macey, J. Robert

2005-01-19

A new parsimony analysis of 27 complete mitochondrial genomic sequences is conducted to investigate the phylogenetic relationships of plethodontid salamanders. This analysis focuses on the amount of character conflict between phylogenetic trees recovered from newly conducted parsimony searches and the Bayesian and maximum likelihood topology reported by Mueller et al. (2004, PNAS, 101, 13820-13825). Strong support for Hemidactylium as the sister taxon to all other plethodontids is recovered from parsimony analyses. Plotting area relationships on the most parsimonious phylogenetic tree suggests that eastern North America is the origin of the family Plethodontidae supporting the ''Out of Appalachia'' hypothesis. A new taxonomy that recognizes clades recovered from phylogenetic analyses is proposed.

Optical and Electrical Properties of TTF-MPcs (M = Cu, Zn Interfaces for Optoelectronic Applications

Directory of Open Access Journals (Sweden)

María Elena Sánchez-Vergara

2015-11-01

Full Text Available Sandwich structures were fabricated by a vacuum deposition method using MPc (M = Cu, Zn, with a Tetrathiafulvalene (TTF derivative, and Indium Tin Oxide (ITO and aluminum electrodes. The structure and morphology of the deposited films were studied by IR spectroscopy, scanning electron microscopy (SEM and energy dispersive spectroscopy (EDS. The absorption spectra of TTF derivative-MPc (M = Cu, Zn thin films deposited at room temperature were recorded in the spectral range 200–1000 nm. The optical band gap of the thin films was determined from the (αhν1/2 vs. hν plot. The direct-current (DC electrical properties of the glass/ITO/TTFderiv-MPc (M = Cu, Zn/Al structures were also investigated. Changes in conductivity of the derivative-TTF-enriched Pc compounds suggest the formation of alternative paths for carrier conduction. At low voltages, forward current density obeys an ohmic I-V relationship; at higher voltages, conduction is mostly due to a space-charge-limited conduction (SCLC mechanism.

Parsimony in personality: predicting sexual prejudice.

Science.gov (United States)

Miller, Audrey K; Wagner, Maverick M; Hunt, Amy N

2012-01-01

Extant research has established numerous demographic, personal-history, attitudinal, and ideological correlates of sexual prejudice, also known as homophobia. The present study investigated whether Five-Factor Model (FFM) personality domains, particularly Openness, and FFM facets, particularly Openness to Values, contribute independent and incremental variance to the prediction of sexual prejudice beyond these established correlates. Participants were 117 college students who completed a comprehensive FFM measure, measures of sexual prejudice, and a demographics, personal-history, and attitudes-and-ideologies questionnaire. Results of stepwise multiple regression analyses demonstrated that, whereas Openness domain score predicted only marginal incremental variance in sexual prejudice, Openness facet scores (particularly Openness to Values) predicted independent and substantial incremental variance beyond numerous other zero-order correlates of sexual prejudice. The importance of integrating FFM personality variables, especially facet-level variables, into conceptualizations of sexual prejudice is highlighted. Study strengths and weaknesses are discussed as are potential implications for prejudice-reduction interventions.

Categorizing ideas about trees: a tree of trees.

Science.gov (United States)

Fisler, Marie; Lecointre, Guillaume

2013-01-01

The aim of this study is to explore whether matrices and MP trees used to produce systematic categories of organisms could be useful to produce categories of ideas in history of science. We study the history of the use of trees in systematics to represent the diversity of life from 1766 to 1991. We apply to those ideas a method inspired from coding homologous parts of organisms. We discretize conceptual parts of ideas, writings and drawings about trees contained in 41 main writings; we detect shared parts among authors and code them into a 91-characters matrix and use a tree representation to show who shares what with whom. In other words, we propose a hierarchical representation of the shared ideas about trees among authors: this produces a "tree of trees." Then, we categorize schools of tree-representations. Classical schools like "cladists" and "pheneticists" are recovered but others are not: "gradists" are separated into two blocks, one of them being called here "grade theoreticians." We propose new interesting categories like the "buffonian school," the "metaphoricians," and those using "strictly genealogical classifications." We consider that networks are not useful to represent shared ideas at the present step of the study. A cladogram is made for showing who is sharing what with whom, but also heterobathmy and homoplasy of characters. The present cladogram is not modelling processes of transmission of ideas about trees, and here it is mostly used to test for proximity of ideas of the same age and for categorization.

Properties of magnetic photonic crystals in the visible spectral region and their performance limitations

Science.gov (United States)

Kotov, V. A.; Shavrov, V. G.; Vasiliev, M.; Alameh, K.; Nur-E-Alam, M.; Balabanov, D. E.

2018-02-01

We report on the results of computer modelling and performance analysis of the optical and magneto-optical (MO) characteristics of one-dimensional magnetic photonic crystals (MPC) of several classic design types (having either a single structure defect, or a number of these), designed for applications in the visible spectral region. The calculations are performed accounting for the real levels of optical absorption achievable in existing MO materials which currently demonstrate the best MO quality (bismuth-substituted ferrite garnets). We consider Bi2Dy1Fe4Ga1O12 as the base material for use within quarter-wave thick MO layers of MPC; silica is used for the non-magnetic transparent quarter-wave layers. The achieved results can be used to clarify the nature of the differences that exist between the expected practical potential of MPCs in integrated photonics, and the actual attained experimental results. Our results show that in MPCs optimized for light intensity modulation applications, in the red spectral region (near 650 nm), the achievable levels of optical transmission are limited to about 30%. This coincides spectrally with the peaks of Faraday rotation reaching their maxima at about 25°, with further transmission increases possible in the near-infrared region. Larger Faraday rotation angles are only achievable currently in structures or single film layers with reduced transmission.

The prospective usage of the multi-purpose canister and impacts on the waste management and disposal system

International Nuclear Information System (INIS)

McLeod, N.B.

1993-01-01

The Multi-Purpose Canister (MPC) is designed to be loaded with spent fuel and sealed at reactors and then serve the functions of transport, storage and disposal without reopening. It can be either self-shielded or unshielded, thus requiring compatible overpacks for transport, storage and disposal. The MPC is not a new concept but it may now be viable because of the particular characteristics at Yucca Mountain: larger MPCs are possible because of ramp access to the repository horizon, and the less difficult temperature limits because of in-drift emplacement, rather than borehole emplacement. This paper describes the advantages and disadvantages of adopting the MPC as the principal technology to be employed in the US program. Use of the MPC permits integration of the utility and DOE portions of the system as well as among the elements within the DOE portion. Paradoxically, the principal disadvantage of the MPC is a direct consequence of its merit as an integrating technology. Full integration includes disposability without reopening, and requires that disposability design decisions be made and implemented well in advance of when waste package licensing uncertainties are resolved. There is, therefore, a risk that MPCs loaded prior to waste package licensing will have to be opened. This risk is discussed in terms of probability and consequences and various alternatives for mitigating this risk are discussed

Comparative study of the mutant prevention concentrations of moxifloxacin, levofloxacin, and gemifloxacin against pneumococci.

Science.gov (United States)

Credito, Kim; Kosowska-Shick, Klaudia; McGhee, Pamela; Pankuch, Glenn A; Appelbaum, Peter C

2010-02-01

We tested the propensity of three quinolones to select for resistant Streptococcus pneumoniae mutants by determining the mutant prevention concentration (MPC) against 100 clinical strains, some of which harbored mutations in type II topoisomerases. Compared with levofloxacin and gemifloxacin, moxifloxacin had the lowest number of strains with MPCs above the susceptibility breakpoint (P<0.001), thus representing a lower selective pressure for proliferation of resistant mutants. Only moxifloxacin gave a 50% MPC (MPC50) value (1 microg/ml) within the susceptible range.

Multi-purpose canister project overview

International Nuclear Information System (INIS)

Williams, J.

1995-01-01

In this presentation, the author lists the approved and proposed dry storage technologies. He discusses the compatibility of dry storage systems with waste management systems. Historical aspects, recent history, key features of the program approach, benefits, specifications, acquisition and potential utility use of the multi-purpose canister (MPC) are covered. The MPCs provide standardization in the waste management system and a cost savings to utilities and government. MPC will be developed to the same level as existing dry storage systems

Comparative Study of the Mutant Prevention Concentrations of Moxifloxacin, Levofloxacin, and Gemifloxacin against Pneumococci▿ †

Science.gov (United States)

Credito, Kim; Kosowska-Shick, Klaudia; McGhee, Pamela; Pankuch, Glenn A.; Appelbaum, Peter C.

2010-01-01

We tested the propensity of three quinolones to select for resistant Streptococcus pneumoniae mutants by determining the mutant prevention concentration (MPC) against 100 clinical strains, some of which harbored mutations in type II topoisomerases. Compared with levofloxacin and gemifloxacin, moxifloxacin had the lowest number of strains with MPCs above the susceptibility breakpoint (P < 0.001), thus representing a lower selective pressure for proliferation of resistant mutants. Only moxifloxacin gave a 50% MPC (MPC50) value (1 μg/ml) within the susceptible range. PMID:20008781

Morphological support for the phylogenetic positioning of Pentastomida and related fossils

Directory of Open Access Journals (Sweden)

Elaine Christine Costa Eloy

2008-09-01

Full Text Available Pentastomida is a group of parasites that infects the respiratory tracts of vertebrates. They have a mixture of annelid and arthropod characteristics. For that reason, the phylogenetic relationships of the pentastomids have been controversial in proposals of metazoan phylogeny. Forty-seven characters were selected for the analyses of the taxa Annelida, Arthropoda, Kinorhyncha, Loricifera, Nematoda, Nematomorpha, Onychophora, Pentastomida, Priapulida and Tardigrada. The analyses with PAUP resulted in a single shortest cladogram (length 89, ci 0.78, ri 0.86. Our results indicate that Pentastomida is a transitional group between the Arthropoda and some of the Nemathelminth groups such as Nematoda and Nematomorpha.

Seed protein variations of Salicornia L. and allied taxa in Turkey.

Science.gov (United States)

Yaprak, A E; Yurdakulol, E

2007-06-01

Electrophoretic seed protein patterns of a number of accessions of Salicornia europaea L. sl., S. prostrata Palas, S. fragilis P.W. Ball and Tutin, Sarcocornia fruticosa (L.) A. J. Scott, Sarcocornia perennis (Miller.) A. J. Scott, Arthrocnemum glaucum (Del.) Ung.-Sternb., Microcnemum coralloides (Loscos and Pardo) subsp. anatolicum Wagenitz and Halocnemum strobilaceum (Pall.) Bieb. were electrophoretically analysed on SDS-PAGE. In total 48 different bands were identified. The obtained data have been treated numerically using the cluster analysis method of unweighted pair group (UPGMA). Finally it was determined that all species separated according to seed protein profiles. And the cladogram obtained studied taxa have been given.

Parsimonious Charge Deconvolution for Native Mass Spectrometry

Science.gov (United States)

2018-01-01

Charge deconvolution infers the mass from mass over charge (m/z) measurements in electrospray ionization mass spectra. When applied over a wide input m/z or broad target mass range, charge-deconvolution algorithms can produce artifacts, such as false masses at one-half or one-third of the correct mass. Indeed, a maximum entropy term in the objective function of MaxEnt, the most commonly used charge deconvolution algorithm, favors a deconvolved spectrum with many peaks over one with fewer peaks. Here we describe a new “parsimonious” charge deconvolution algorithm that produces fewer artifacts. The algorithm is especially well-suited to high-resolution native mass spectrometry of intact glycoproteins and protein complexes. Deconvolution of native mass spectra poses special challenges due to salt and small molecule adducts, multimers, wide mass ranges, and fewer and lower charge states. We demonstrate the performance of the new deconvolution algorithm on a range of samples. On the heavily glycosylated plasma properdin glycoprotein, the new algorithm could deconvolve monomer and dimer simultaneously and, when focused on the m/z range of the monomer, gave accurate and interpretable masses for glycoforms that had previously been analyzed manually using m/z peaks rather than deconvolved masses. On therapeutic antibodies, the new algorithm facilitated the analysis of extensions, truncations, and Fab glycosylation. The algorithm facilitates the use of native mass spectrometry for the qualitative and quantitative analysis of protein and protein assemblies. PMID:29376659

Incoming editorial: bigger, purple, pragmatic, and parsimony.

Science.gov (United States)

Hilsenroth, Mark J

2011-03-01

It is with great excitement and enthusiasm that I write to you regarding several updates, new initiatives and changes with our journal. As you may have already noticed, this includes the change to a larger format, and a return to the color purple that helped define this journal from the early 1980s through the turn of the century, as well as to the original title "Psychotherapy." The change in format will allow us to benefit from the standard American Psychological Association (APA) journal design and layout, leading to more efficient processing and arrangement within their electronic journal system. I have found this first year as the Incoming Editor of Psychotherapy to be as challenging, rewarding, and intellectually stimulating as I imagined it would be, and I remain quite excited and enthusiastic about the work ahead. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

ANÁLISIS BIBLIOMÉTRICO DE LA PRODUCCIÓN TAXONÓMICA EN AMÉRICA LATINA

Directory of Open Access Journals (Sweden)

Layla Michán Aguirre

2011-05-01

ódica cuenta con la mayor cantidad de documentos y cobertura temporal más amplia sobre lo publicado en América Latina. El cladograma obtenido por el análisis de parsimonia resultó ser una herramienta de visualización ideal para representar las características principales de cada una. Palabras clave: Bibliometría, revistas, artículos, análisis de parsimonia, análisis de redes ABSTRACT I compare six bibliographic databases with information on Latin American systematics: Biosis, CAB, Periódica, SCI, Scopus and Zoological Record. The databases are characterized and compared considering their content, temporal, typological, geographical, thematical coverage, kind of access and new taxa description, to identify which and how many should be used to be more representative. Of the 1 363 journals analyzed, 36.5% is found in more than one database and 63.46% is recorded in a single. Zoologial Record contains 63 421 documents, Biosis 19 079, CAB 14 363, Periódica 11 185, SCI 3257 and Scopus 916. CAB and ZR are the oldest, the average number of articles published per year was 6 417 for Biosis, 433 for ZR, 361 for Periódica, 145 for CAB, 91 for SCI and 30 for Scopus. According to the network analysis there are stronger relations between SCI and Biosis, which share at least 16% of titles, CAB and Biosis share 15%, Biosis and ZR 14%, and CAB and ZR 11%. Based on the cladogram obtained from a parsimony analysis based on the shared journals, the strong relation is between Biosis and SCI, Periódica has the largest number of exclusive journals with 285. ZR has 72.9% of published articles with descriptions of new taxa and an average of 322 a year, CAB 54.6% with 82, and Periódica 24.6% with 90. None of databases meets the characteristics enough to be used as the single source of information, it would be appropriate to use different combinations according to the object of analysis. Biosis has the most comprehensive information on any current taxa, Zoological Record and CAB have a

Mutant prevention concentrations of four carbapenems against gram-negative rods.

Science.gov (United States)

Credito, Kim; Kosowska-Shick, Klaudia; Appelbaum, Peter C

2010-06-01

We tested the propensities of four carbapenems to select for resistant Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii mutants by determining the mutant prevention concentrations (MPCs) for 100 clinical strains with various ss-lactam phenotypes. Among the members of the Enterobacteriaceae family and A. baumannii strains, the MPC/MIC ratios were mostly 2 to 4. In contrast, for P. aeruginosa the MPC/MIC ratios were 4 to > or =16. The MPC/MIC ratios for beta-lactamase-positive K. pneumoniae and E. coli isolates were much higher (range, 4 to >16 microg/ml) than those for ss-lactamase-negative strains.

Preparation and magnetic properties of magnetic photonic crystal by using monodisperse polystyrene covered Fe3O4 nanoparticles onto glass substrate

Science.gov (United States)

Azizi, Zahra Sadat; Tehranchi, Mohammad Mehdi; Vakili, Seyed Hamed; Pourmahdian, Saeed

2018-05-01

Engineering approach towards combined photonic band gap properties and magnetic/polymer composite particles, attract considerable attention of researchers due to their unique properties. In this research, two different magnetic particles were prepared by nearly monodisperse polystyrene spheres as bead with two concentrations of Fe3O4 nanoparticles to prepare magnetic photonic crystals (MPCs). The crystal surfaces and particles morphology were investigated employing scanning electron microscopy and transmission electron microscopy. The volume fraction of magnetic material embedded into colloidal spheres and their morphology was found to be a key parameter in the optical and magneto-optical properties of transparent MPC.

Biogeografía histórica de la familia Curculionidae (Coleoptera en las subregiones Subantártica y Chilena Central Historical biogeography of family Curculionidae (Coleoptera on Subantarctic and Central Chilean subregions

Directory of Open Access Journals (Sweden)

Paula Posadas

2003-07-01

Full Text Available El análisis de los patrones de distribución y la información filogenética de 71 especies de Curculionidae, distribuidas en las subregiones Subantártica y Chilena Central, aplicando los métodos biogeográficos de los árboles reconciliados y análisis de parsimonia de Brooks (BPA, resulta en un único cladograma general de áreas: ((Chile Central (Maule, Bosque Valdiviano (Islas Malvinas (Páramo Magallánico, Bosque Magallánico. La aplicación del análisis de dispersión-vicarianza (DIVA muestra que el evento vicariante más frecuente es el que separa las Islas Malvinas de las otras dos provincias subantárticas meridionales. Por otra parte, de acuerdo con los resultados del DIVA, se evidencia que las relaciones entre el Maule, Bosque Valdiviano y Chile Central no se deberían a eventos de vicarianza sino a eventos de dispersión, ya que el 61% del total de los eventos de dispersión implica a estas tres áreas. Aún más, los eventos de dispersión más frecuentes implican al Maule, ya sea en relación con Chile Central o con el Bosque Valdiviano, por lo que se deduce que la aparente complejidad de las relaciones biogeográficas del Maule podría estar relacionada con dichos eventos de dispersión.The application of the historical biogeographic techniques of reconciled trees and Brooks parsimony analysis (BPA to the distributional and phylogenetic information of 71 species of Curculionidae ranged in the Subantarctic and Central Chilean subregions results in a single general area cladogram: ((Central Chile (Maule, Valdivian Forest (Malvinas Islands (Magellanic Moorland, Magellanic Forest. The application of dispersal-vicariance analysis (DIVA to the same data set shows as the most frequent vicariant event the split of Islas Malvinas from the two southern Subantarctic provinces. In addition, DIVA results evidenced that the relationship among Maule, Valdivian Forest, and Central Chile did not arise from vicariance events (common history

A parsimonious model for the proportional control valve

OpenAIRE

Elmer, KF; Gentle, CR

2001-01-01

A generic non-linear dynamic model of a direct-acting electrohydraulic proportional solenoid valve is presented. The valve consists of two subsystems-s-a spool assembly and one or two unidirectional proportional solenoids. These two subsystems are modelled separately. The solenoid is modelled as a non-linear resistor-inductor combination, with inductance parameters that change with current. An innovative modelling method has been used to represent these components. The spool assembly is model...

A parsimonious approach to modeling animal movement data.

Directory of Open Access Journals (Sweden)

Yann Tremblay

Full Text Available Animal tracking is a growing field in ecology and previous work has shown that simple speed filtering of tracking data is not sufficient and that improvement of tracking location estimates are possible. To date, this has required methods that are complicated and often time-consuming (state-space models, resulting in limited application of this technique and the potential for analysis errors due to poor understanding of the fundamental framework behind the approach. We describe and test an alternative and intuitive approach consisting of bootstrapping random walks biased by forward particles. The model uses recorded data accuracy estimates, and can assimilate other sources of data such as sea-surface temperature, bathymetry and/or physical boundaries. We tested our model using ARGOS and geolocation tracks of elephant seals that also carried GPS tags in addition to PTTs, enabling true validation. Among pinnipeds, elephant seals are extreme divers that spend little time at the surface, which considerably impact the quality of both ARGOS and light-based geolocation tracks. Despite such low overall quality tracks, our model provided location estimates within 4.0, 5.5 and 12.0 km of true location 50% of the time, and within 9, 10.5 and 20.0 km 90% of the time, for above, equal or below average elephant seal ARGOS track qualities, respectively. With geolocation data, 50% of errors were less than 104.8 km (<0.94 degrees, and 90% were less than 199.8 km (<1.80 degrees. Larger errors were due to lack of sea-surface temperature gradients. In addition we show that our model is flexible enough to solve the obstacle avoidance problem by assimilating high resolution coastline data. This reduced the number of invalid on-land location by almost an order of magnitude. The method is intuitive, flexible and efficient, promising extensive utilization in future research.

Carbon-nitrogen-water interactions: is model parsimony fruitful?

Science.gov (United States)

Puertes, Cristina; González-Sanchis, María; Lidón, Antonio; Bautista, Inmaculada; Lull, Cristina; Francés, Félix

2017-04-01

It is well known that carbon and nitrogen cycles are highly intertwined and both should be explained through the water balance. In fact, in water-controlled ecosystems nutrient deficit is related to this water scarcity. For this reason, the present study compares the capability of three models in reproducing the interaction between the carbon and nitrogen cycles and the water cycle. The models are BIOME-BGCMuSo, LEACHM and a simple carbon-nitrogen model coupled to the hydrological model TETIS. Biome-BGCMuSo and LEACHM are two widely used models that reproduce the carbon and nitrogen cycles adequately. However, their main limitation is that these models are quite complex and can be too detailed for watershed studies. On the contrary, the TETIS nutrient sub-model is a conceptual model with a vertical tank distribution over the active soil depth, dividing it in two layers. Only the input of the added litter and the losses due to soil respiration, denitrification, leaching and plant uptake are considered as external fluxes. Other fluxes have been neglected. The three models have been implemented in an experimental plot of a semi-arid catchment (La Hunde, East of Spain), mostly covered by holm oak (Quercus ilex). Plant transpiration, soil moisture and runoff have been monitored daily during nearly two years (26/10/2012 to 30/09/2014). For the same period, soil samples were collected every two months and taken to the lab in order to obtain the concentrations of dissolved organic carbon, microbial biomass carbon, ammonium and nitrate. In addition, between field trips soil samples were placed in PVC tubes with resin traps and were left incubating (in situ buried cores). Thus, mineralization and nitrification accumulated fluxes for two months, were obtained. The ammonium and nitrate leaching accumulated for two months were measured using ion-exchange resin cores. Soil respiration was also measured every field trip. Finally, water samples deriving from runoff, were collected to obtain the concentrations of dissolved organic carbon, dissolved organic nitrogen, ammonium and nitrate. The comparison shows a better performance of the complex models reproducing carbon and nitrogen cycles. However, the TETIS nutrient sub-model, even simpler than BIOME-BGCMuSo and LEACHM, reproduces the water balance adequately and it obtains a suitable representation of the carbon and nitrogen cycles.

A Multi-Criterion Evolutionary Approach Applied to Phylogenetic Reconstruction

OpenAIRE

Cancino, W.; Delbem, A.C.B.

2010-01-01

In this paper, we proposed an MOEA approach, called PhyloMOEA which solves the phylogenetic inference problem using maximum parsimony and maximum likelihood criteria. The PhyloMOEA's development was motivated by several studies in the literature (Huelsenbeck, 1995; Jin & Nei, 1990; Kuhner & Felsenstein, 1994; Tateno et al., 1994), which point out that various phylogenetic inference methods lead to inconsistent solutions. Techniques using parsimony and likelihood criteria yield to different tr...

Dynamical minimalism: why less is more in psychology.

Science.gov (United States)

Nowak, Andrzej

2004-01-01

The principle of parsimony, embraced in all areas of science, states that simple explanations are preferable to complex explanations in theory construction. Parsimony, however, can necessitate a trade-off with depth and richness in understanding. The approach of dynamical minimalism avoids this trade-off. The goal of this approach is to identify the simplest mechanisms and fewest variables capable of producing the phenomenon in question. A dynamical model in which change is produced by simple rules repetitively interacting with each other can exhibit unexpected and complex properties. It is thus possible to explain complex psychological and social phenomena with very simple models if these models are dynamic. In dynamical minimalist theories, then, the principle of parsimony can be followed without sacrificing depth in understanding. Computer simulations have proven especially useful for investigating the emergent properties of simple models.

A Microwave Photonic Interference Canceller: Architectures, Systems, and Integration

Science.gov (United States)

Chang, Matthew P.

This thesis is a comprehensive portfolio of work on a Microwave Photonic Self-Interference Canceller (MPC), a specialized optical system designed to eliminate interference from radio-frequency (RF) receivers. The novelty and value of the microwave photonic system lies in its ability to operate over bandwidths and frequencies that are orders of magnitude larger than what is possible using existing RF technology. The work begins, in 2012, with a discrete fiber-optic microwave photonic canceller, which prior work had demonstrated as a proof-of-concept, and culminates, in 2017, with the first ever monolithically integrated microwave photonic canceller. With an eye towards practical implementation, the thesis establishes novelty through three major project thrusts. (Fig. 1): (1) Extensive RF and system analysis to develop a full understanding of how, and through what mechanisms, MPCs affect an RF receiver. The first investigations of how a microwave photonic canceller performs in an actual wireless environment and a digital radio are also presented. (2) New architectures to improve the performance and functionality of MPCs, based on the analysis performed in Thrust 1. A novel balanced microwave photonic canceller architecture is developed and experimentally demonstrated. The balanced architecture shows significant improvements in link gain, noise figure, and dynamic range. Its main advantage is its ability to suppress common-mode noise and reduce noise figure by increasing the optical power. (3) Monolithic integration of the microwave photonic canceller into a photonic integrated circuit. This thrust presents the progression of integrating individual discrete devices into their semiconductor equivalent, as well as a full functional and RF analysis of the first ever integrated microwave photonic canceller.

Molecular systematics of terraranas (Anura: Brachycephaloidea) with an assessment of the effects of alignment and optimality criteria.

Science.gov (United States)

Padial, José M; Grant, Taran; Frost, Darrel R

2014-06-26

Brachycephaloidea is a monophyletic group of frogs with more than 1000 species distributed throughout the New World tropics, subtropics, and Andean regions. Recently, the group has been the target of multiple molecular phylogenetic analyses, resulting in extensive changes in its taxonomy. Here, we test previous hypotheses of phylogenetic relationships for the group by combining available molecular evidence (sequences of 22 genes representing 431 ingroup and 25 outgroup terminals) and performing a tree-alignment analysis under the parsimony optimality criterion using the program POY. To elucidate the effects of alignment and optimality criterion on phylogenetic inferences, we also used the program MAFFT to obtain a similarity-alignment for analysis under both parsimony and maximum likelihood using the programs TNT and GARLI, respectively. Although all three analytical approaches agreed on numerous points, there was also extensive disagreement. Tree-alignment under parsimony supported the monophyly of the ingroup and the sister group relationship of the monophyletic marsupial frogs (Hemiphractidae), while maximum likelihood and parsimony analyses of the MAFFT similarity-alignment did not. All three methods differed with respect to the position of Ceuthomantis smaragdinus (Ceuthomantidae), with tree-alignment using parsimony recovering this species as the sister of Pristimantis + Yunganastes. All analyses rejected the monophyly of Strabomantidae and Strabomantinae as originally defined, and the tree-alignment analysis under parsimony further rejected the recently redefined Craugastoridae and Pristimantinae. Despite the greater emphasis in the systematics literature placed on the choice of optimality criterion for evaluating trees than on the choice of method for aligning DNA sequences, we found that the topological differences attributable to the alignment method were as great as those caused by the optimality criterion. Further, the optimal tree-alignment indicates

Mutant Prevention Concentrations of Four Carbapenems against Gram-Negative Rods▿ †

Science.gov (United States)

Credito, Kim; Kosowska-Shick, Klaudia; Appelbaum, Peter C.

2010-01-01

We tested the propensities of four carbapenems to select for resistant Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii mutants by determining the mutant prevention concentrations (MPCs) for 100 clinical strains with various ß-lactam phenotypes. Among the members of the Enterobacteriaceae family and A. baumannii strains, the MPC/MIC ratios were mostly 2 to 4. In contrast, for P. aeruginosa the MPC/MIC ratios were 4 to ≥16. The MPC/MIC ratios for β-lactamase-positive K. pneumoniae and E. coli isolates were much higher (range, 4 to >16 μg/ml) than those for ß-lactamase-negative strains. PMID:20308376

A fast method for calculating reliable event supports in tree reconciliations via Pareto optimality.

Science.gov (United States)

To, Thu-Hien; Jacox, Edwin; Ranwez, Vincent; Scornavacca, Celine

2015-11-14

Given a gene and a species tree, reconciliation methods attempt to retrieve the macro-evolutionary events that best explain the discrepancies between the two tree topologies. The DTL parsimonious approach searches for a most parsimonious reconciliation between a gene tree and a (dated) species tree, considering four possible macro-evolutionary events (speciation, duplication, transfer, and loss) with specific costs. Unfortunately, many events are erroneously predicted due to errors in the input trees, inappropriate input cost values or because of the existence of several equally parsimonious scenarios. It is thus crucial to provide a measure of the reliability for predicted events. It has been recently proposed that the reliability of an event can be estimated via its frequency in the set of most parsimonious reconciliations obtained using a variety of reasonable input cost vectors. To compute such a support, a straightforward but time-consuming approach is to generate the costs slightly departing from the original ones, independently compute the set of all most parsimonious reconciliations for each vector, and combine these sets a posteriori. Another proposed approach uses Pareto-optimality to partition cost values into regions which induce reconciliations with the same number of DTL events. The support of an event is then defined as its frequency in the set of regions. However, often, the number of regions is not large enough to provide reliable supports. We present here a method to compute efficiently event supports via a polynomial-sized graph, which can represent all reconciliations for several different costs. Moreover, two methods are proposed to take into account alternative input costs: either explicitly providing an input cost range or allowing a tolerance for the over cost of a reconciliation. Our methods are faster than the region based method, substantially faster than the sampling-costs approach, and have a higher event-prediction accuracy on

Characterization of a mutation commonly associated with persistent stuttering: evidence for a founder mutation

Science.gov (United States)

Fedyna, Alison; Drayna, Dennis; Kang, Changsoo

2010-01-01

Stuttering is a disorder which affects the fluency of speech. It has been shown to have high heritability, and has recently been linked to mutations in the GNPTAB gene. One such mutation, Glu1200Lys, has been repeatedly observed in unrelated families and individual cases. Eight unrelated individuals carrying this mutation were analyzed in an effort to distinguish whether these arise from repeated mutation at the same site, or whether they represent a founder mutation with a single origin. Results show that all 12 chromosomes carrying this mutation share a common haplotype in this region, indicating it is a founder mutation. Further analysis estimated the age of this allele to be ~572 generations. Construction of a cladogram tracing the mutation through our study sample also supports the founder mutation hypothesis. PMID:20944643

A phylogenetic analysis of the monogenomic Triticeae (Poaceae) based on morphology

DEFF Research Database (Denmark)

Seberg, Ole; Frederiksen, Signe Elisabeth

2001-01-01

not traditionally included in Aegilops s.J. Most of the 33 characters used in the analysis are coded as binary. The only four multistate characters in the matrix are treated as unordered. Three diploid species of Bromus are used as outgroup. The number of equally parsimonious trees found is very large (approx....... 170000; length = 107, ci = 0.36, ri = 0.75) and the strict consensus tree has an expectedly low level of resolution. However, most of the equally parsimonious trees owe their existence to an unresolved Aegilops clade. If this clade is replaced by its hypothetical ancestor, the number of equally...... parsimonious trees drops dramatically (48; length = 78, ci = 0.45, ri = 0.76). When trees for which more highly resolved compatible trees exist are excluded, only two trees remain. Bremer support is used as a measure of branch support. The trees based on morphology and on molecular data are largely incongruent....

A probabilistic model for deriving soil quality criteria based on secondary poisoning of top predators. I. Model description and uncertainty analysis.

Science.gov (United States)

Traas, T P; Luttik, R; Jongbloed, R H

1996-08-01

In previous studies, the risk of toxicant accumulation in food chains was used to calculate quality criteria for surface water and soil. A simple algorithm was used to calculate maximum permissable concentrations [MPC = no-observed-effect concentration/bioconcentration factor(NOEC/BCF)]. These studies were limited to simple food chains. This study presents a method to calculate MPCs for more complex food webs of predators. The previous method is expanded. First, toxicity data (NOECs) for several compounds were corrected for differences between laboratory animals and animals in the wild. Second, for each compound, it was assumed these NOECs were a sample of a log-logistic distribution of mammalian and avian NOECs. Third, bioaccumulation factors (BAFs) for major food items of predators were collected and were assumed to derive from different log-logistic distributions of BAFs. Fourth, MPCs for each compound were calculated using Monte Carlo sampling from NOEC and BAF distributions. An uncertainty analysis for cadmium was performed to identify the most uncertain parameters of the model. Model analysis indicated that most of the prediction uncertainty of the model can be ascribed to uncertainty of species sensitivity as expressed by NOECs. A very small proportion of model uncertainty is contributed by BAFs from food webs. Correction factors for the conversion of NOECs from laboratory conditions to the field have some influence on the final value of MPC5, but the total prediction uncertainty of the MPC is quite large. It is concluded that the uncertainty in species sensitivity is quite large. To avoid unethical toxicity testing with mammalian or avian predators, it cannot be avoided to use this uncertainty in the method proposed to calculate MPC distributions. The fifth percentile of the MPC is suggested as a safe value for top predators.

EUROSUNMED. Euro-Mediterranean cooperation on research and training in sun based renewable energies

International Nuclear Information System (INIS)

Slaoui, Abdelilah

2013-01-01

Here we present the different aspects of the EUROSUNMED project. The scientific targets of EUROSUNMED are the development of new technologies in three energy field areas, namely photovoltaics (PV), concentrated solar power (CSP) and grid integration (GI), in strong collaboration with research institutes, universities and SMSs from Europe in the north side of the Mediterranean sea and from Morocco and Egypt from the south of the sea. the focus in PV will be on thin film (Si, CZTS) based solar cells and modules while the goal in CSP field is to design and test new heliostats as well as novel solutions for energy storage compatible with these technologies. The project aims at producing components that will be tested under specific conditions of MPC (hot climate, absence of water, etc.). Such investigations are complemented with studies on grid integration of energy sources from PV and CSP in Morocco and Egypt context. Additionally, the consortium envisages training PhD students and post-docs in these interdisciplinary fields (chemistry, physics, materials science) in a close and fruitful collaboration between academic institutions and industry from EU and MPCs. The consortium is well placed around leading academic groups in materials science and engineering devices and equipments for the development of PV and CSP, and also in the promotion of the renewable energies in general. Moreover, technology transfer and research infrastructure development in the targeted areas will be provided. Disseminating the results of the projects will be done through the organization of summer schools and stakeholders involved in the 3 selected energy area and beyond. Another outreach of the project will be the proposal for a roadmap on the technological aspects (research, industry, implementation) of the PV, CSP and grid area as well as on the best practice for the continuation of strong collaboration between the EU and MPCS partners and beyond for mutual interest. (author)

The nuclear hormone receptor family member NR5A2 controls aspects of multipotent progenitor cell formation and acinar differentiation during pancreatic organogenesis.

Science.gov (United States)

Hale, Michael A; Swift, Galvin H; Hoang, Chinh Q; Deering, Tye G; Masui, Toshi; Lee, Youn-Kyoung; Xue, Jumin; MacDonald, Raymond J

2014-08-01

The orphan nuclear receptor NR5A2 is necessary for the stem-like properties of the epiblast of the pre-gastrulation embryo and for cellular and physiological homeostasis of endoderm-derived organs postnatally. Using conditional gene inactivation, we show that Nr5a2 also plays crucial regulatory roles during organogenesis. During the formation of the pancreas, Nr5a2 is necessary for the expansion of the nascent pancreatic epithelium, for the subsequent formation of the multipotent progenitor cell (MPC) population that gives rise to pre-acinar cells and bipotent cells with ductal and islet endocrine potential, and for the formation and differentiation of acinar cells. At birth, the NR5A2-deficient pancreas has defects in all three epithelial tissues: a partial loss of endocrine cells, a disrupted ductal tree and a >90% deficit of acini. The acinar defects are due to a combination of fewer MPCs, deficient allocation of those MPCs to pre-acinar fate, disruption of acinar morphogenesis and incomplete acinar cell differentiation. NR5A2 controls these developmental processes directly as well as through regulatory interactions with other pancreatic transcriptional regulators, including PTF1A, MYC, GATA4, FOXA2, RBPJL and MIST1 (BHLHA15). In particular, Nr5a2 and Ptf1a establish mutually reinforcing regulatory interactions and collaborate to control developmentally regulated pancreatic genes by binding to shared transcriptional regulatory regions. At the final stage of acinar cell development, the absence of NR5A2 affects the expression of Ptf1a and its acinar specific partner Rbpjl, so that the few acinar cells that form do not complete differentiation. Nr5a2 controls several temporally distinct stages of pancreatic development that involve regulatory mechanisms relevant to pancreatic oncogenesis and the maintenance of the exocrine phenotype. © 2014. Published by The Company of Biologists Ltd.

Life-cycle cost implications of a system using bare SNF transfer

International Nuclear Information System (INIS)

Rose, M.

1995-01-01

The U.S. Department of Energy (DOE) is planning the use of the Multi-Purpose Canister (MPC) to handle transportation, storage, and disposal of civilian spent nuclear fuel. This canister, which would be loaded and sealed at the utility site, would remain sealed through waste emplacement in a Mined Geologic Disposal System (MGDS). Two sizes of MPCs are now being considered: large and small rail. The large rail canister has design requirements to be compatible with a 125 ton hook weight crane when fully loaded in the pool with fuel assemblies, water, transportation overpack, and the lifting yoke. The small rail canister under the same conditions weighs less than 75 tons. At present, it is estimated that between four and seventeen reactors will not be able to accommodate either canister. One method of accommodating MPCs at all reactors is the use of Bare Spent nuclear fuel Transfer (BST). In this concept, a small transfer cask is used to move small numbers of assemblies from the spent fuel pool to an external transfer station where a large MPC is loaded. After several of these transfers, the MPC is sealed and either stored on-site, transported to a central storage site, or transported to the MGDS. This paper addresses the total system cost implications of use of BST at 20 sites (31 reactors) which are currently projected to be unable to use the large rail MPC. Results are presented parametrically as a function of the BST capital cost and the time required to load a MPC. This analysis indicates use of BST may be economically favorable if the combination of MPC load times and capital expenditures can be kept to a reasonable level

Space micropropulsion systems for Cubesats and small satellites: From proximate targets to furthermost frontiers

Science.gov (United States)

Levchenko, Igor; Bazaka, Kateryna; Ding, Yongjie; Raitses, Yevgeny; Mazouffre, Stéphane; Henning, Torsten; Klar, Peter J.; Shinohara, Shunjiro; Schein, Jochen; Garrigues, Laurent; Kim, Minkwan; Lev, Dan; Taccogna, Francesco; Boswell, Rod W.; Charles, Christine; Koizumi, Hiroyuki; Shen, Yan; Scharlemann, Carsten; Keidar, Michael; Xu, Shuyan

2018-03-01

Rapid evolution of miniaturized, automatic, robotized, function-centered devices has redefined space technology, bringing closer the realization of most ambitious interplanetary missions and intense near-Earth space exploration. Small unmanned satellites and probes are now being launched in hundreds at a time, resurrecting a dream of satellite constellations, i.e., wide, all-covering networks of small satellites capable of forming universal multifunctional, intelligent platforms for global communication, navigation, ubiquitous data mining, Earth observation, and many other functions, which was once doomed by the extraordinary cost of such systems. The ingression of novel nanostructured materials provided a solid base that enabled the advancement of these affordable systems in aspects of power, instrumentation, and communication. However, absence of efficient and reliable thrust systems with the capacity to support precise maneuvering of small satellites and CubeSats over long periods of deployment remains a real stumbling block both for the deployment of large satellite systems and for further exploration of deep space using a new generation of spacecraft. The last few years have seen tremendous global efforts to develop various miniaturized space thrusters, with great success stories. Yet, there are critical challenges that still face the space technology. These have been outlined at an inaugural International Workshop on Micropropulsion and Cubesats, MPCS-2017, a joint effort between Plasma Sources and Application Centre/Space Propulsion Centre (Singapore) and the Micropropulsion and Nanotechnology Lab, the G. Washington University (USA) devoted to miniaturized space propulsion systems, and hosted by CNR-Nanotec—P.Las.M.I. lab in Bari, Italy. This focused review aims to highlight the most promising developments reported at MPCS-2017 by leading world-reputed experts in miniaturized space propulsion systems. Recent advances in several major types of small

Effects of Microencapsulated Phase Change Material (MPCM) on Critical Heat Flux in Pool Boiling

International Nuclear Information System (INIS)

Park, Sung Dae; Kim, Seong Man; Kang, Sarah; Lee, Seung Won; Seo, Han; Bang, In Cheol

2011-01-01

Thermal power is limited by critical heat flux (CHF) in the nuclear power plant. And the in-vessel retention by external reactor vessel cooling (IVR-ERVC) is applied in some nuclear power plants; AP600, AP1000, Loviisa and APR1400. The heat removal capacity of IVR-ERVC is also restricted by CHF. So, it is essential to get CHF margin to improve an economics and a safety of the plant. There are some typical approaches to enhance CHF: vibrating the heater or fluid, coating with porous media on the heater surface, applying an electric field. The recent study related to the CHF is focus on using the nanofluid. In this paper, the new approach was investigated by using the microencapsulated phase change material (MPCM). MPCM is the particles whose diameter is from 0.1μm to 1000μm. The MPCM consists of the core material and the shell material. The core material can be solid, liquid, gas or even the mixture. The solid paraffin is the best candidate as the core material due to its stable chemical and thermal properties. And the shell material is generally synthesized polymer of about several micrometers in thickness. The most interesting feature of the MPCM is that the latent heat associated with the solid-liquid phase change is related to the heat transfer. When the MPCM is dispersed into the carrier fluid, a kind of suspension named as microencapsulated phase change slurry (MPCS) is formed. The study on the MPCS was conducted in field of both the heat transfer fluids and energy storage media. It is inspired by the fact that the latent heat can serve distribution to the additional CHF margin. The purpose of this work is to confirm whether or not the CHF is enhanced

Application of parsimonious learning feedforward control to mechatronic systems

NARCIS (Netherlands)

de Vries, Theodorus J.A.; Velthuis, W.J.R.; Idema, L.J.

2001-01-01

For motion control, learning feedforward controllers (LFFCs) should be applied when accurate process modelling is difficult. When controlling such processes with LFFCs in the form of multidimensional B-spline networks, large network sizes and a poor generalising ability may result, known as the

A Parsimonious and Universal Description of Turbulent Velocity Increments

DEFF Research Database (Denmark)

Barndorff-Nielsen, O.E.; Blæsild, P.; Schmiegel, J.

boundary layer experiment with Taylor-Reynolds numbers Rλ = 80,190,17000, respectively. The application of a time change in terms of the scale parameter δ of the normal inverse Gaussian distribution reveals some universal features that are inherent to the pdf of all three data sets....

Parsimonious evaluation of concentric-tube continuum robot equilibrium conformation.

Science.gov (United States)

Rucker, Daniel Caleb; Webster Iii, Robert J

2009-09-01

Dexterous at small diameters, continuum robots consisting of precurved concentric tubes are well-suited for minimally invasive surgery. These active cannulas are actuated by relative translations and rotations applied at the tube bases, which create bending via elastic tube interaction. An accurate kinematic model of cannula shape is required for applications in surgical and other settings. Previous models are limited to circular tube precurvatures, and neglect torsional deformation in curved sections. Recent generalizations account for arbitrary tube preshaping and bending and torsion throughout the cannula, providing differential equations that define cannula shape. In this paper, we show how to simplify these equations using Frenet-Serret frames. An advantage of this approach is the interpretation of torsional components of the preset tube shapes as "forcing functions" on the cannula's differential equations. We also elucidate a process for numerically solving the differential equations, and use it to produce simulations illustrating the implications of torsional deformation and helical tube shapes.

Timing of birth: Parsimony favors strategic over dysregulated parturition.

Science.gov (United States)

Catalano, Ralph; Goodman, Julia; Margerison-Zilko, Claire; Falconi, April; Gemmill, Alison; Karasek, Deborah; Anderson, Elizabeth

2016-01-01

The "dysregulated parturition" narrative posits that the human stress response includes a cascade of hormones that "dysregulates" and accelerates parturition but provides questionable utility as a guide to understand or prevent preterm birth. We offer and test a "strategic parturition" narrative that not only predicts the excess preterm births that dysregulated parturition predicts but also makes testable, sex-specific predictions of the effect of stressful environments on the timing of birth among term pregnancies. We use interrupted time-series modeling of cohorts conceived over 101 months to test for lengthening of early term male gestations in stressed population. We use an event widely reported to have stressed Americans and to have increased the incidence of low birth weight and fetal death across the country-the terrorist attacks of September 2001. We tested the hypothesis that the odds of male infants conceived in December 2000 (i.e., at term in September 2001) being born early as opposed to full term fell below the value expected from those conceived in the 50 prior and 50 following months. We found that term male gestations exposed to the terrorist attacks exhibited 4% lower likelihood of early, as opposed to full or late, term birth. Strategic parturition explains observed data for which the dysregulated parturition narrative offers no prediction-the timing of birth among gestations stressed at term. Our narrative may help explain why findings from studies examining associations between population- and/or individual-level stressors and preterm birth are generally mixed. © 2015 Wiley Periodicals, Inc.

HOW TO FIND YOUNG MASSIVE CLUSTER PROGENITORS

Energy Technology Data Exchange (ETDEWEB)

Bressert, E.; Longmore, S.; Testi, L. [European Southern Observatory, Karl Schwarzschild Str. 2, D-85748 Garching bei Muenchen (Germany); Ginsburg, A.; Bally, J.; Battersby, C. [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States)

2012-10-20

We propose that bound, young massive stellar clusters form from dense clouds that have escape speeds greater than the sound speed in photo-ionized gas. In these clumps, radiative feedback in the form of gas ionization is bottled up, enabling star formation to proceed to sufficiently high efficiency so that the resulting star cluster remains bound even after gas removal. We estimate the observable properties of the massive proto-clusters (MPCs) for existing Galactic plane surveys and suggest how they may be sought in recent and upcoming extragalactic observations. These surveys will potentially provide a significant sample of MPC candidates that will allow us to better understand extreme star-formation and massive cluster formation in the Local Universe.

Towards improving searches for optimal phylogenies.

Science.gov (United States)

Ford, Eric; St John, Katherine; Wheeler, Ward C

2015-01-01

Finding the optimal evolutionary history for a set of taxa is a challenging computational problem, even when restricting possible solutions to be "tree-like" and focusing on the maximum-parsimony optimality criterion. This has led to much work on using heuristic tree searches to find approximate solutions. We present an approach for finding exact optimal solutions that employs and complements the current heuristic methods for finding optimal trees. Given a set of taxa and a set of aligned sequences of characters, there may be subsets of characters that are compatible, and for each such subset there is an associated (possibly partially resolved) phylogeny with edges corresponding to each character state change. These perfect phylogenies serve as anchor trees for our constrained search space. We show that, for sequences with compatible sites, the parsimony score of any tree [Formula: see text] is at least the parsimony score of the anchor trees plus the number of inferred changes between [Formula: see text] and the anchor trees. As the maximum-parsimony optimality score is additive, the sum of the lower bounds on compatible character partitions provides a lower bound on the complete alignment of characters. This yields a region in the space of trees within which the best tree is guaranteed to be found; limiting the search for the optimal tree to this region can significantly reduce the number of trees that must be examined in a search of the space of trees. We analyze this method empirically using four different biological data sets as well as surveying 400 data sets from the TreeBASE repository, demonstrating the effectiveness of our technique in reducing the number of steps in exact heuristic searches for trees under the maximum-parsimony optimality criterion. © The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Relaciones filogenéticas del género Anomala (Coleoptera: Melolonthidae: Rutelinae Phylogenetic relationships of the genus Anomala (Coleoptera: Melolonthidae: Rutelinae

Directory of Open Access Journals (Sweden)

Andrés Ramírez-Ponce

2009-08-01

Full Text Available Se presenta un análisis filogenético basado en caracteres morfológicos de adultos de varios géneros de la tribu Anomalini para redefinir al género Anomala Samouelle, 1819 y evaluar su situación filogenética. El análisis de parsimonia, que incluyó 46 especies de 18 géneros procedentes de varias partes del mundo, permitió poner a prueba la monofilia de algunos géneros y evaluar su posición taxonómica, además de revelar que los límites de algunos géneros no son claros. Con base en el cladograma de consenso estricto existen evidencias suficientes para considerar las especies americanas hasta ahora incluidas en Anomala como un género diferente, al que corresponde nombrar Paranomala Casey, 1915, stat. rev. También se comprobó que algunas especies americanas incluidas en el género Callistethus Blanchard, 1851 deben incorporarse al género Paranomala, con excepción de C. viduus (Newman, la cual fundamenta la revalidación del género Pachystethus Blanchard, 1851, stat. rev. También se sinonimiza el género Anomalacra Casey, 1915 con Paranomala, y se transfiere Anomala carlsoni Hardy, 1976 a Leptohoplia Saylor, 1935. Se actualizan las descripciones y diagnosis de los géneros Anomala, Paranomala, Callistethus y Pachystethus y se incluye una clave de los géneros americanos de Anomalini que incorpora las definiciones y cambios nomenclaturales propuestos.A phylogenetic analysis based on adult morphology that includes some genera included in the tribe Anomalini is presented, to redefine the genus Anomala Samouelle, 1819, and evaluate its phylogenetic situation. The parsimony analysis, based on 46 species of 18 genera from several areas of the world, allowed us to test the monophyly of some genera and evaluate their taxonomic position, and to reveal that the generic limits are not clear. On the basis of the strict consensus cladogram there is reason to consider the American species heretofore included in Anomala as members of a

Simulation Modeling by Classification of Problems: A Case of Cellular Manufacturing

International Nuclear Information System (INIS)

Afiqah, K N; Mahayuddin, Z R

2016-01-01

Cellular manufacturing provides good solution approach to manufacturing area by applying Group Technology concept. The evolution of cellular manufacturing can enhance performance of the cell and to increase the quality of the product manufactured but it triggers other problem. Generally, this paper highlights factors and problems which emerge commonly in cellular manufacturing. The aim of the research is to develop a thorough understanding of common problems in cellular manufacturing. A part from that, in order to find a solution to the problems exist using simulation technique, this classification framework is very useful to be adapted during model building. Biology evolution tool was used in the research in order to classify the problems emerge. The result reveals 22 problems and 25 factors using cladistic technique. In this research, the expected result is the cladogram established based on the problems in cellular manufacturing gathered. (paper)

Possible sister groups and phylogenetic relationships among selected North Pacific and North Atlantic Rhodophyta

Science.gov (United States)

Lindstrom, Sandra C.

1987-09-01

Although the cool temperate (boreal) waters of the N. Pacific and N. Atlantic share many similar if not identical species, there have been few studies to test the identity of these species pairs. Whereas such tests are important from a taxonomic perspective, they tell us little if anything about biogeographic relationships. A more useful approach is one employing phylogenetic systematics (cladistics). The interpretation of phylogenetic diagrams (cladograms) in terms of biogeographic area relationships is explained. It is argued that cladistic analyses of taxa occurring in the cool temperate waters of the northern oceans can provide biogeographic tracks, which in turn can suggest the origins and migrations of species and possibly even floras. A number of cool temperate taxa that appear particularly amenable to this approach are discussed, including genera in the Palmariaceae, Corallinaceae, Dumontiaceae, Solieriaceae, Petrocelidaceae, Ceramiaceae and Rhodomelaceae.

The phylogeny and evolutionary history of tyrannosauroid dinosaurs

Science.gov (United States)

Brusatte, Stephen L.; Carr, Thomas D.

2016-02-01

Tyrannosauroids—the group of carnivores including Tyrannosaurs rex—are some of the most familiar dinosaurs of all. A surge of recent discoveries has helped clarify some aspects of their evolution, but competing phylogenetic hypotheses raise questions about their relationships, biogeography, and fossil record quality. We present a new phylogenetic dataset, which merges published datasets and incorporates recently discovered taxa. We analyze it with parsimony and, for the first time for a tyrannosauroid dataset, Bayesian techniques. The parsimony and Bayesian results are highly congruent, and provide a framework for interpreting the biogeography and evolutionary history of tyrannosauroids. Our phylogenies illustrate that the body plan of the colossal species evolved piecemeal, imply no clear division between northern and southern species in western North America as had been argued, and suggest that T. rex may have been an Asian migrant to North America. Over-reliance on cranial shape characters may explain why published parsimony studies have diverged and filling three major gaps in the fossil record holds the most promise for future work.

The phylogeny and evolutionary history of tyrannosauroid dinosaurs.

Science.gov (United States)

Brusatte, Stephen L; Carr, Thomas D

2016-02-02

Tyrannosauroids--the group of carnivores including Tyrannosaurs rex--are some of the most familiar dinosaurs of all. A surge of recent discoveries has helped clarify some aspects of their evolution, but competing phylogenetic hypotheses raise questions about their relationships, biogeography, and fossil record quality. We present a new phylogenetic dataset, which merges published datasets and incorporates recently discovered taxa. We analyze it with parsimony and, for the first time for a tyrannosauroid dataset, Bayesian techniques. The parsimony and Bayesian results are highly congruent, and provide a framework for interpreting the biogeography and evolutionary history of tyrannosauroids. Our phylogenies illustrate that the body plan of the colossal species evolved piecemeal, imply no clear division between northern and southern species in western North America as had been argued, and suggest that T. rex may have been an Asian migrant to North America. Over-reliance on cranial shape characters may explain why published parsimony studies have diverged and filling three major gaps in the fossil record holds the most promise for future work.

A Pareto-optimal moving average multigene genetic programming model for daily streamflow prediction

Science.gov (United States)

Danandeh Mehr, Ali; Kahya, Ercan

2017-06-01

Genetic programming (GP) is able to systematically explore alternative model structures of different accuracy and complexity from observed input and output data. The effectiveness of GP in hydrological system identification has been recognized in recent studies. However, selecting a parsimonious (accurate and simple) model from such alternatives still remains a question. This paper proposes a Pareto-optimal moving average multigene genetic programming (MA-MGGP) approach to develop a parsimonious model for single-station streamflow prediction. The three main components of the approach that take us from observed data to a validated model are: (1) data pre-processing, (2) system identification and (3) system simplification. The data pre-processing ingredient uses a simple moving average filter to diminish the lagged prediction effect of stand-alone data-driven models. The multigene ingredient of the model tends to identify the underlying nonlinear system with expressions simpler than classical monolithic GP and, eventually simplification component exploits Pareto front plot to select a parsimonious model through an interactive complexity-efficiency trade-off. The approach was tested using the daily streamflow records from a station on Senoz Stream, Turkey. Comparing to the efficiency results of stand-alone GP, MGGP, and conventional multi linear regression prediction models as benchmarks, the proposed Pareto-optimal MA-MGGP model put forward a parsimonious solution, which has a noteworthy importance of being applied in practice. In addition, the approach allows the user to enter human insight into the problem to examine evolved models and pick the best performing programs out for further analysis.

Analysis and synthesis of one-dimensional magneto-photonic crystals using coupled mode theory

Energy Technology Data Exchange (ETDEWEB)

Saghirzadeh Darki, Behnam, E-mail: b.saghirzadeh@ec.iut.ac.ir; Nezhad, Abolghasem Zeidaabadi; Firouzeh, Zaker Hossein

2017-03-15

We utilize our previously developed temporal coupled mode approach to investigate the performance of one-dimensional magneto-photonic crystals (MPCs). We analytically demonstrate that a double-defect MPC provides adequate degrees of freedom to design a structure for arbitrary transmittance and Faraday rotation. By using our developed analytic approach along with the numerical transfer matrix method, we present a procedure for the synthesis of an MPC to generate any desired transmittance and Faraday rotation in possible ranges. However it is seen that only discrete values of transmittance and Faraday rotation are practically obtainable. To remedy this problem along with having short structures, we introduce a class of MPC heterostructures which are combinations of stacks with high and low optical contrast ratios.

Differentially activated macrophages orchestrate myogenic precursor cell fate during human skeletal muscle regeneration

DEFF Research Database (Denmark)

Saclier, Marielle; Yacoub-Youssef, Houda; Mackey, Abigail

2013-01-01

, we explored both in vitro and in vivo, in human, the interactions of differentially activated MPs with myogenic precursor cells (MPCs) during adult myogenesis and skeletal muscle regeneration. We showed in vitro that through the differential secretion of cytokines and growth factors, proinflammatory...... anti-inflammatory markers. These data demonstrate for the first time in human that MPs sequentially orchestrate adult myogenesis during regeneration of damaged skeletal muscle. These results support the emerging concept that inflammation, through MP activation, controls stem cell fate and coordinates......Macrophages (MPs) exert either beneficial or deleterious effects on tissue repair, depending on their activation/polarization state. They are crucial for adult skeletal muscle repair, notably by acting on myogenic precursor cells. However, these interactions have not been fully characterized. Here...

Measuring Stratigraphic Congruence Across Trees, Higher Taxa, and Time.

Science.gov (United States)

O'Connor, Anne; Wills, Matthew A

2016-09-01

The congruence between the order of cladistic branching and the first appearance dates of fossil lineages can be quantified using a variety of indices. Good matching is a prerequisite for the accurate time calibration of trees, while the distribution of congruence indices across large samples of cladograms has underpinned claims about temporal and taxonomic patterns of completeness in the fossil record. The most widely used stratigraphic congruence indices are the stratigraphic consistency index (SCI), the modified Manhattan stratigraphic measure (MSM*), and the gap excess ratio (GER) (plus its derivatives; the topological GER and the modified GER). Many factors are believed to variously bias these indices, with several empirical and simulation studies addressing some subset of the putative interactions. This study combines both approaches to quantify the effects (on all five indices) of eight variables reasoned to constrain the distribution of possible values (the number of taxa, tree balance, tree resolution, range of first occurrence (FO) dates, center of gravity of FO dates, the variability of FO dates, percentage of extant taxa, and percentage of taxa with no fossil record). Our empirical data set comprised 647 published animal and plant cladograms spanning the entire Phanerozoic, and for these data we also modeled the effects of mean age of FOs (as a proxy for clade age), the taxonomic rank of the clade, and the higher taxonomic group to which it belonged. The center of gravity of FO dates had not been investigated hitherto, and this was found to correlate most strongly with some measures of stratigraphic congruence in our empirical study (top-heavy clades had better congruence). The modified GER was the index least susceptible to bias. We found significant differences across higher taxa for all indices; arthropods had lower congruence and tetrapods higher congruence. Stratigraphic congruence-however measured-also varied throughout the Phanerozoic, reflecting

Light wavelength dependency of mating activity in the drosophila melanogaster species subgroup

International Nuclear Information System (INIS)

Sakai, Takaomi; Tomaru, Masatoshi; Oguma, Yuzuru; Isono, Kunio; Fukatami, Akishi

2002-01-01

The action spectra of mating activity among the six species of the Drosophila melanogaster species subgroup were compared to understand how light wavelength affects mating activity. The species fell into three groups with respect to the action spectrum of mating activity. We chose one representative species from each of the three types for detailed study: D. melanogaster, D. sechellia and D. yakuba. The mating activities were investigated under three different light intensities of three monochromatic lights stimulus. Each species showed a unique spectral and intensity response. To know the evolutionary meaning of the light wavelength dependency of mating activity, we superimposed the type of action spectrum of mating activity in these six species on a cladogram. Mating inhibition under UV was conserved in evolution among these species. Furthermore we clarified that D. melanogaster showed low mating activity under UV because males courted less under UV. (author)

Ancestral sequence alignment under optimal conditions

Directory of Open Access Journals (Sweden)

Brown Daniel G

2005-11-01

Full Text Available Abstract Background Multiple genome alignment is an important problem in bioinformatics. An important subproblem used by many multiple alignment approaches is that of aligning two multiple alignments. Many popular alignment algorithms for DNA use the sum-of-pairs heuristic, where the score of a multiple alignment is the sum of its induced pairwise alignment scores. However, the biological meaning of the sum-of-pairs of pairs heuristic is not obvious. Additionally, many algorithms based on the sum-of-pairs heuristic are complicated and slow, compared to pairwise alignment algorithms. An alternative approach to aligning alignments is to first infer ancestral sequences for each alignment, and then align the two ancestral sequences. In addition to being fast, this method has a clear biological basis that takes into account the evolution implied by an underlying phylogenetic tree. In this study we explore the accuracy of aligning alignments by ancestral sequence alignment. We examine the use of both maximum likelihood and parsimony to infer ancestral sequences. Additionally, we investigate the effect on accuracy of allowing ambiguity in our ancestral sequences. Results We use synthetic sequence data that we generate by simulating evolution on a phylogenetic tree. We use two different types of phylogenetic trees: trees with a period of rapid growth followed by a period of slow growth, and trees with a period of slow growth followed by a period of rapid growth. We examine the alignment accuracy of four ancestral sequence reconstruction and alignment methods: parsimony, maximum likelihood, ambiguous parsimony, and ambiguous maximum likelihood. Additionally, we compare against the alignment accuracy of two sum-of-pairs algorithms: ClustalW and the heuristic of Ma, Zhang, and Wang. Conclusion We find that allowing ambiguity in ancestral sequences does not lead to better multiple alignments. Regardless of whether we use parsimony or maximum likelihood, the

On defining a unique phylogenetic tree with homoplastic characters.

Science.gov (United States)

Goloboff, Pablo A; Wilkinson, Mark

2018-05-01

This paper discusses the problem of whether creating a matrix with all the character state combinations that have a fixed number of steps (or extra steps) on a given tree T, produces the same tree T when analyzed with maximum parsimony or maximum likelihood. Exhaustive enumeration of cases up to 20 taxa for binary characters, and up to 12 taxa for 4-state characters, shows that the same tree is recovered (as unique most likely or most parsimonious tree) as long as the number of extra steps is within 1/4 of the number of taxa. This dependence, 1/4 of the number of taxa, is discussed with a general argumentation, in terms of the spread of the character changes on the tree used to select character state distributions. The present finding allows creating matrices which have as much homoplasy as possible for the most parsimonious or likely tree to be predictable, and examination of these matrices with hill-climbing search algorithms provides additional evidence on the (lack of a) necessary relationship between homoplasy and the ability of search methods to find optimal trees. Copyright © 2018 Elsevier Inc. All rights reserved.

A Basic Bivariate Structure of Personality Attributes Evident Across Nine Languages.

Science.gov (United States)

Saucier, Gerard; Thalmayer, Amber Gayle; Payne, Doris L; Carlson, Robert; Sanogo, Lamine; Ole-Kotikash, Leonard; Church, A Timothy; Katigbak, Marcia S; Somer, Oya; Szarota, Piotr; Szirmák, Zsofia; Zhou, Xinyue

2014-02-01

Here, two studies seek to characterize a parsimonious common-denominator personality structure with optimal cross-cultural replicability. Personality differences are observed in all human populations and cultures, but lexicons for personality attributes contain so many distinctions that parsimony is lacking. Models stipulating the most important attributes have been formulated by experts or by empirical studies drawing on experience in a very limited range of cultures. Factor analyses of personality lexicons of nine languages of diverse provenance (Chinese, Korean, Filipino, Turkish, Greek, Polish, Hungarian, Maasai, and Senoufo) were examined, and their common structure was compared to that of several prominent models in psychology. A parsimonious bivariate model showed evidence of substantial convergence and ubiquity across cultures. Analyses involving key markers of these dimensions in English indicate that they are broad dimensions involving the overlapping content of the interpersonal circumplex, models of communion and agency, and morality/warmth and competence. These "Big Two" dimensions-Social Self-Regulation and Dynamism-provide a common-denominator model involving the two most crucial axes of personality variation, ubiquitous across cultures. The Big Two might serve as an umbrella model serving to link diverse theoretical models and associated research literatures. © 2013 Wiley Periodicals, Inc.

Compactness in the Euler-lattice: A parsimonious pitch spelling model

NARCIS (Netherlands)

Honingh, A.K.

2009-01-01

Compactness and convexity have been shown to represent important principles in music, reflecting a notion of consonance in scales and chords, and have been successfully applied to well-known problems from music research. In this paper, the notion of compactness is applied to the problem of pitch

Large-scale runoff generation - parsimonious parameterisation using high-resolution topography

Science.gov (United States)

Gong, L.; Halldin, S.; Xu, C.-Y.

2011-08-01

World water resources have primarily been analysed by global-scale hydrological models in the last decades. Runoff generation in many of these models are based on process formulations developed at catchments scales. The division between slow runoff (baseflow) and fast runoff is primarily governed by slope and spatial distribution of effective water storage capacity, both acting at very small scales. Many hydrological models, e.g. VIC, account for the spatial storage variability in terms of statistical distributions; such models are generally proven to perform well. The statistical approaches, however, use the same runoff-generation parameters everywhere in a basin. The TOPMODEL concept, on the other hand, links the effective maximum storage capacity with real-world topography. Recent availability of global high-quality, high-resolution topographic data makes TOPMODEL attractive as a basis for a physically-based runoff-generation algorithm at large scales, even if its assumptions are not valid in flat terrain or for deep groundwater systems. We present a new runoff-generation algorithm for large-scale hydrology based on TOPMODEL concepts intended to overcome these problems. The TRG (topography-derived runoff generation) algorithm relaxes the TOPMODEL equilibrium assumption so baseflow generation is not tied to topography. TRG only uses the topographic index to distribute average storage to each topographic index class. The maximum storage capacity is proportional to the range of topographic index and is scaled by one parameter. The distribution of storage capacity within large-scale grid cells is obtained numerically through topographic analysis. The new topography-derived distribution function is then inserted into a runoff-generation framework similar VIC's. Different basin parts are parameterised by different storage capacities, and different shapes of the storage-distribution curves depend on their topographic characteristics. The TRG algorithm is driven by the HydroSHEDS dataset with a resolution of 3" (around 90 m at the equator). The TRG algorithm was validated against the VIC algorithm in a common model framework in 3 river basins in different climates. The TRG algorithm performed equally well or marginally better than the VIC algorithm with one less parameter to be calibrated. The TRG algorithm also lacked equifinality problems and offered a realistic spatial pattern for runoff generation and evaporation.

Towards a parsimonious program theory of return to work intervention.

Science.gov (United States)

Claudi Jensen, Anne Grete

2013-01-01

Presentation of a salutogenic theory of return to work (RTW). The study group include 118 unskilled Danish public employees and privately employed house-cleaners on sick leave due to musculoskeletal and/or common mental illnesses. Theory of RTW is discussed from a theoretical and empirical viewpoint, using baseline-data from an intervention study in a longitudinal, non-randomized study design with follow-up after one year. High work ability, strong social support from colleagues and over-commitment are the most important prognostic factors for RTW. An active coping style, high self-efficacy and Sense of Coherence (SOC) are found to increase RTW and high hostility and over-commitment to decrease RTW. Besides health elements in work ability are SOC, self-efficacy, social support and physical activity. Work ability and active coping mediate positive associations between RTW and health, and a negative association with stress. Work ability seems to express the intention to work decisive for RTW, reflecting the interpretation of the work/health situation based on comprehensibility, meaningfulness and manageability. It is influenced by the personal view of life, attitudes and interaction with the workplace. An ecological theory, integrating health promotion is proposed. A later paper will present the intervention study and further validation of the theory.

Regularized Estimation of Structural Instability in Factor Models: The US Macroeconomy and the Great Moderation

DEFF Research Database (Denmark)

Callot, Laurent; Kristensen, Johannes Tang

This paper shows that the parsimoniously time-varying methodology of Callot and Kristensen (2015) can be applied to factor models.We apply this method to study macroeconomic instability in the US from 1959:1 to 2006:4 with a particular focus on the Great Moderation. Models with parsimoniously time...... that the parameters of both models exhibit a higher degree of instability in the period from 1970:1 to 1984:4 relative to the following 15 years. In our setting the Great Moderation appears as the gradual ending of a period of high structural instability that took place in the 1970s and early 1980s....

Assessing the potential of group 13 and 14 metal/metalloid phthalocyanines as hole transport layers in organic light emitting diodes

Science.gov (United States)

Plint, Trevor; Lessard, Benoît H.; Bender, Timothy P.

2016-04-01

In this study, we have assessed the potential application of group 13 and 14 metal and metalloid phthalocyanines ((X)n-MPcs) and their axially substituted derivatives as hole-transporting layers in organic light emitting diodes (OLEDs). OLEDs studied herein have the generic structure of glass/ITO/(N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB) or (X)n-MPc)(50 nm)/Alq3 (60 nm)/LiF (1 nm)/Al (80 nm), where X is an axial substituent group. OLEDs using chloro aluminum phthalocyanine (Cl-AlPc) showed good peak luminance values of 2620 ± 113 cd/m2 at 11 V. To our knowledge, Cl-AlPc has not previously been shown to work as a hole transport material (HTL) in OLEDs. Conversely, the di-chlorides of silicon, germanium, and tin phthalocyanine (Cl2-SiPc, Cl2-GePc, and Cl2-SnPc, respectively) showed poor performance compared to Cl-AlPc, having peak luminances of only 38 ± 4 cd/m2 (12 V), 23 ± 1 cd/m2 (8.5 V), and 59 ± 5 cd/m2 (13.5 V), respectively. However, by performing a simple axial substitution of the chloride groups of Cl2-SiPc with pentafluorophenoxy groups, the resulting bis(pentafluorophenoxy) silicon phthalocyanine (F10-SiPc) containing OLED had a peak luminance of 5141 ± 941 cd/m2 (10 V), a two order of magnitude increase over its chlorinated precursor. This material showed OLED characteristics approaching those of a baseline OLED based on the well-studied triarylamine NPB. Attempts to attach the pentafluorophenoxy axial group to both SnPc and GePc were hindered by synthetic difficulties and low thermal stability, respectively. In light of the performance improvements observed by simple axial substitution of SiPc in OLEDs, the use of axially substituted MPcs in organic electronic devices remains of continuing interest to us and potentially the field in general.

Heterogeneity of Prognostic Profiles in Non-small Cell Lung Cancer: Too Many Variables but a Few Relevant

International Nuclear Information System (INIS)

Camara, Agustin Gomez de la; Lopez-Encuentra, Angel; Ferrando, Paloma

2005-01-01

Objective: Many prognostic factors, exceeding 150, for non-small cell lung cancer (NSCLC) are mentioned in the literature. The different statistical weight of the some variables at issue, their heterogeneity and their clinical uselessness is reviewed. Study design and setting: Survival analysis of a cohort of NSCLC operated (n = 1730, 1993-1997) was carried out utilizing different statistical approaches: Cox proportional hazard analysis (CPHA), logistic regression (LRA), and recursive partitioning (CART). Results: CPHA identified 13 prognostic variables and 11 LRA. Of the 17 possible variables, 10 are coincident. CART provided five different diagnostic groups but only three differentiated survival levels. Parsimonious models were constructed including only T and N cancer staging variables. Areas under the ROC curve of 0.68 and 0.68 were found for CPHA and LGA parsimonious models respectively, and 0.72 and 0.71 for complete models. Conclusion: Variables with a minimal impact on the respective models and thus with little or scarce predictive clinical repercussion were identified. Differences in the prognostic profile of survival can be caused by the different methodological approaches used. No relevant differences were found between the parsimonious and complete models. Although the amount of information managed is considerable, there continues to be a large predictive gap yet to be explained

Intraspecific relationship within the genus convolvulus l. inferred by rbcl gene using different phylogenetic approaches

International Nuclear Information System (INIS)

Kausar, S.; Qamarunnisa, S.

2016-01-01

A molecular systematics analysis was conducted using sequence data of chloroplast rbcL gene for the genus Convolvulus L., by distance and character based phylogenetic methods. Fifteen representative members from genus Convolvulus L., were included as in group whereas two members from a sister family Solanaceae were taken as out group to root the tree. Intraspecific relationships within Convolvulus were inferred by distance matrix, maximum parsimony and bayesian analysis. Transition/transversion ratio was also calculated and it was revealed that in the investigated Convolvulus species, transitional changes were more prevalent in rbcL gene. The nature of rbcL gene in the present study was observed to be conserved, as it does not show major variations between examined species. Distance matrix represented the minimal genetic variations between some species (C. glomeratus and C. pyrrhotrichus), thus exhibiting them as close relatives. The result of parsimonious and bayesian analysis revealed almost similar clades however maximum parsimony based tree was unable to establish relationship between some Convolvulus species. The bayesian inference method was found to be the method of choice for establishing intraspecific associations between Convolvulus species using rbcL data as it clearly defined the connections supported by posterior probability values. (author)

Molecular Phylogeny of the Bamboo Sharks (Chiloscyllium spp.

Directory of Open Access Journals (Sweden)

Noor Haslina Masstor

2014-01-01

Full Text Available Chiloscyllium, commonly called bamboo shark, can be found inhabiting the waters of the Indo-West Pacific around East Asian countries such as Malaysia, Myanmar, Thailand, Singapore, and Indonesia. The International Union for Conservation of Nature (IUCN Red List has categorized them as nearly threatened sharks out of their declining population status due to overexploitation. A molecular study was carried out to portray the systematic relationships within Chiloscyllium species using 12S rRNA and cytochrome b gene sequences. Maximum parsimony and Bayesian were used to reconstruct their phylogeny trees. A total of 381 bp sequences’ lengths were successfully aligned in the 12S rRNA region, with 41 bp sites being parsimony-informative. In the cytochrome b region, a total of 1120 bp sites were aligned, with 352 parsimony-informative characters. All analyses yield phylogeny trees on which C. indicum has close relationships with C. plagiosum. C. punctatum is sister taxon to both C. indicum and C. plagiosum while C. griseum and C. hasseltii formed their own clade as sister taxa. These Chiloscyllium classifications can be supported by some morphological characters (lateral dermal ridges on the body, coloring patterns, and appearance of hypobranchials and basibranchial plate that can clearly be used to differentiate each species.

Model structure selection in convolutive mixtures

DEFF Research Database (Denmark)

Dyrholm, Mads; Makeig, S.; Hansen, Lars Kai

2006-01-01

The CICAAR algorithm (convolutive independent component analysis with an auto-regressive inverse model) allows separation of white (i.i.d) source signals from convolutive mixtures. We introduce a source color model as a simple extension to the CICAAR which allows for a more parsimonious represent......The CICAAR algorithm (convolutive independent component analysis with an auto-regressive inverse model) allows separation of white (i.i.d) source signals from convolutive mixtures. We introduce a source color model as a simple extension to the CICAAR which allows for a more parsimonious...... representation in many practical mixtures. The new filter-CICAAR allows Bayesian model selection and can help answer questions like: ’Are we actually dealing with a convolutive mixture?’. We try to answer this question for EEG data....

Large-scale runoff generation – parsimonious parameterisation using high-resolution topography

OpenAIRE

L. Gong; S. Halldin; C.-Y. Xu

2010-01-01

World water resources have primarily been analysed by global-scale hydrological models in the last decades. Runoff generation in many of these models are based on process formulations developed at catchments scales. The division between slow runoff (baseflow) and fast runoff is primarily governed by slope and spatial distribution of effective water storage capacity, both acting a very small scales. Many hydrological models, e.g. VIC, account for the spatial storage variability in terms...

Large-scale runoff generation – parsimonious parameterisation using high-resolution topography

Directory of Open Access Journals (Sweden)

L. Gong

2011-08-01

Full Text Available World water resources have primarily been analysed by global-scale hydrological models in the last decades. Runoff generation in many of these models are based on process formulations developed at catchments scales. The division between slow runoff (baseflow and fast runoff is primarily governed by slope and spatial distribution of effective water storage capacity, both acting at very small scales. Many hydrological models, e.g. VIC, account for the spatial storage variability in terms of statistical distributions; such models are generally proven to perform well. The statistical approaches, however, use the same runoff-generation parameters everywhere in a basin. The TOPMODEL concept, on the other hand, links the effective maximum storage capacity with real-world topography. Recent availability of global high-quality, high-resolution topographic data makes TOPMODEL attractive as a basis for a physically-based runoff-generation algorithm at large scales, even if its assumptions are not valid in flat terrain or for deep groundwater systems. We present a new runoff-generation algorithm for large-scale hydrology based on TOPMODEL concepts intended to overcome these problems. The TRG (topography-derived runoff generation algorithm relaxes the TOPMODEL equilibrium assumption so baseflow generation is not tied to topography. TRG only uses the topographic index to distribute average storage to each topographic index class. The maximum storage capacity is proportional to the range of topographic index and is scaled by one parameter. The distribution of storage capacity within large-scale grid cells is obtained numerically through topographic analysis. The new topography-derived distribution function is then inserted into a runoff-generation framework similar VIC's. Different basin parts are parameterised by different storage capacities, and different shapes of the storage-distribution curves depend on their topographic characteristics. The TRG algorithm is driven by the HydroSHEDS dataset with a resolution of 3" (around 90 m at the equator. The TRG algorithm was validated against the VIC algorithm in a common model framework in 3 river basins in different climates. The TRG algorithm performed equally well or marginally better than the VIC algorithm with one less parameter to be calibrated. The TRG algorithm also lacked equifinality problems and offered a realistic spatial pattern for runoff generation and evaporation.

Theorizing Strategic Communication in Parsimony from the U.S. Government Perspective

Directory of Open Access Journals (Sweden)

Young Joon Lim

2015-06-01

Full Text Available Although the term Strategic Communication seems to be a rising topic in communication studies, it is obvious that the term has been hardly visualized and explained from the U.S. government perspective in academic work. This paper theoretically visualizes strategic communication processes. The Department of State and the Department of Defense streamlined the use of strategic communication in different terms but they both focus on using soft power over hard power to gain support from foreign audiences through communication. Both departments especially after the 9/11attacks have developed programs to win hearts and minds of the target audience. This paper shows the salient process of strategic communication programs and conceptualizes principles of strategic communication from their perspectives. This paper after all illustrates the processes for theorizing strategic communication.

Desktop Modeling and Simulation: Parsimonious, yet Effective Discrete-Event Simulation Analysis

Science.gov (United States)

Bradley, James R.

2012-01-01

This paper evaluates how quickly students can be trained to construct useful discrete-event simulation models using Excel The typical supply chain used by many large national retailers is described, and an Excel-based simulation model is constructed of it The set of programming and simulation skills required for development of that model are then determined we conclude that six hours of training are required to teach the skills to MBA students . The simulation presented here contains all fundamental functionallty of a simulation model, and so our result holds for any discrete-event simulation model. We argue therefore that Industry workers with the same technical skill set as students having completed one year in an MBA program can be quickly trained to construct simulation models. This result gives credence to the efficacy of Desktop Modeling and Simulation whereby simulation analyses can be quickly developed, run, and analyzed with widely available software, namely Excel.

A parsimonious model to forecast financial distress, based on audit evidence

Directory of Open Access Journals (Sweden)

Carlos Piñeiro Sánchez

2013-01-01

Full Text Available Este artículo proporciona evidencia de que los informes de auditoría contienen evidencias relevantes para inferir la existencia de disfunciones financieras latentes. A diferencia de trabajos previos, que han estudiado el fallo financiero en grandes empresas cotizadas, fundamentalmente de EE.UU., nuestro trabajo se centra en Pymes españolas sometidas a tensiones financieras latentes. Nuestros resultados indican que la auditoría de las Pymes financieramente desequilibradas posee varias características distintivas: una tasa mayor de rotación de auditores, más informes con salvedades e incumplimientos de los plazos legales para aprobar y registrar las cuentas anuales. Empleamos estas evidencias para construir y verificar un modelo simple, o parsimonioso, capaz de anticipar eficazmente esas disfunciones. Se discuten las implicaciones para la independencia del auditor, la calidad de la información, y el pronóstico del fallo.

Community gardening: a parsimonious path to individual, community, and environmental resilience.

Science.gov (United States)

Okvat, Heather A; Zautra, Alex J

2011-06-01

The goal of this paper is to introduce community gardening as a promising method of furthering well-being and resilience on multiple levels: individual, social group, and natural environment. We examine empirical evidence for the benefits of gardening, and we advocate the development and testing of social ecological models of community resilience through examination of the impact of community gardens, especially in urban areas. The definition of community is extended beyond human social ties to include connections with other species and the earth itself, what Berry (1988) has called an Earth community. We discuss the potential contribution of an extensive network of community gardens to easing the global climate change crisis and address the role of community psychologists in community gardening research and policy-oriented action.

Influenza epidemics, seasonality, and the effects of cold weather on cardiac mortality

Science.gov (United States)

2012-01-01

Background More people die in the winter from cardiac disease, and there are competing hypotheses to explain this. The authors conducted a study in 48 US cities to determine how much of the seasonal pattern in cardiac deaths could be explained by influenza epidemics, whether that allowed a more parsimonious control for season than traditional spline models, and whether such control changed the short term association with temperature. Methods The authors obtained counts of daily cardiac deaths and of emergency hospital admissions of the elderly for influenza during 1992–2000. Quasi-Poisson regression models were conducted estimating the association between daily cardiac mortality, and temperature. Results Controlling for influenza admissions provided a more parsimonious model with better Generalized Cross-Validation, lower residual serial correlation, and better captured Winter peaks. The temperature-response function was not greatly affected by adjusting for influenza. The pooled estimated increase in risk for a temperature decrease from 0 to −5°C was 1.6% (95% confidence interval (CI) 1.1-2.1%). Influenza accounted for 2.3% of cardiac deaths over this period. Conclusions The results suggest that including epidemic data explained most of the irregular seasonal pattern (about 18% of the total seasonal variation), allowing more parsimonious models than when adjusting for seasonality only with smooth functions of time. The effect of cold temperature is not confounded by epidemics. PMID:23025494

Combining epidemiologic and biostatistical tools to enhance variable selection in HIV cohort analyses.

Directory of Open Access Journals (Sweden)

Christopher Rentsch

Full Text Available BACKGROUND: Variable selection is an important step in building a multivariate regression model for which several methods and statistical packages are available. A comprehensive approach for variable selection in complex multivariate regression analyses within HIV cohorts is explored by utilizing both epidemiological and biostatistical procedures. METHODS: Three different methods for variable selection were illustrated in a study comparing survival time between subjects in the Department of Defense's National History Study and the Atlanta Veterans Affairs Medical Center's HIV Atlanta VA Cohort Study. The first two methods were stepwise selection procedures, based either on significance tests (Score test, or on information theory (Akaike Information Criterion, while the third method employed a Bayesian argument (Bayesian Model Averaging. RESULTS: All three methods resulted in a similar parsimonious survival model. Three of the covariates previously used in the multivariate model were not included in the final model suggested by the three approaches. When comparing the parsimonious model to the previously published model, there was evidence of less variance in the main survival estimates. CONCLUSIONS: The variable selection approaches considered in this study allowed building a model based on significance tests, on an information criterion, and on averaging models using their posterior probabilities. A parsimonious model that balanced these three approaches was found to provide a better fit than the previously reported model.

Molecular phylogeny of the neritidae (Gastropoda: Neritimorpha) based on the mitochondrial genes cytochrome oxidase I (COI) and 16S rRNA

International Nuclear Information System (INIS)

Quintero Galvis, Julian Fernando; Castro, Lyda Raquel

2013-01-01

The family Neritidae has representatives in tropical and subtropical regions that occur in a variety of environments, and its known fossil record dates back to the late Cretaceous. However there have been few studies of molecular phylogeny in this family. We performed a phylogenetic reconstruction of the family Neritidae using the COI (722 bp) and the 16S rRNA (559 bp) regions of the mitochondrial genome. Neighbor-joining, maximum parsimony and Bayesian inference were performed. The best phylogenetic reconstruction was obtained using the COI region, and we consider it an appropriate marker for phylogenetic studies within the group. Consensus analysis (COI +16S rRNA) generally obtained the same tree topologies and confirmed that the genus Nerita is monophyletic. The consensus analysis using parsimony recovered a monophyletic group consisting of the genera Neritina, Septaria, Theodoxus, Puperita, and Clithon, while in the Bayesian analyses Theodoxus is separated from the other genera. The phylogenetic status of the species from the genus Nerita from the Colombian Caribbean generated in this study was consistent with that reported for the genus in previous studies. In the resulting consensus tree obtained using maximum parsimony, we included information on habitat type for each species, to map the evolution by habitat. Species of the family Neritidae possibly have their origin in marine environments, which is consistent with conclusions from previous reports based on anatomical studies.

The relative importance of imaging markers for the prediction of Alzheimer's disease dementia in mild cognitive impairment — Beyond classical regression

Directory of Open Access Journals (Sweden)

Stefan J. Teipel

2015-01-01

Penalized regression yielded more parsimonious models than unpenalized stepwise regression for the integration of multiregional and multimodal imaging information. The advantage of penalized regression was particularly strong with a high number of collinear predictors.

Data Mining Methods Applied to Flight Operations Quality Assurance Data: A Comparison to Standard Statistical Methods

Science.gov (United States)

Stolzer, Alan J.; Halford, Carl

2007-01-01

In a previous study, multiple regression techniques were applied to Flight Operations Quality Assurance-derived data to develop parsimonious model(s) for fuel consumption on the Boeing 757 airplane. The present study examined several data mining algorithms, including neural networks, on the fuel consumption problem and compared them to the multiple regression results obtained earlier. Using regression methods, parsimonious models were obtained that explained approximately 85% of the variation in fuel flow. In general data mining methods were more effective in predicting fuel consumption. Classification and Regression Tree methods reported correlation coefficients of .91 to .92, and General Linear Models and Multilayer Perceptron neural networks reported correlation coefficients of about .99. These data mining models show great promise for use in further examining large FOQA databases for operational and safety improvements.

Assessing the potential of group 13 and 14 metal/metalloid phthalocyanines as hole transport layers in organic light emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Plint, Trevor; Lessard, Benoît H. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5 (Canada); Bender, Timothy P. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5 (Canada); Department of Materials Science and Engineering, University of Toronto, 184 College Street, Toronto, Ontario M5S 3E4 (Canada); Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 (Canada)

2016-04-14

In this study, we have assessed the potential application of group 13 and 14 metal and metalloid phthalocyanines ((X){sub n}-MPcs) and their axially substituted derivatives as hole-transporting layers in organic light emitting diodes (OLEDs). OLEDs studied herein have the generic structure of glass/ITO/(N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) or (X){sub n}-MPc)(50 nm)/Alq{sub 3} (60 nm)/LiF (1 nm)/Al (80 nm), where X is an axial substituent group. OLEDs using chloro aluminum phthalocyanine (Cl-AlPc) showed good peak luminance values of 2620 ± 113 cd/m{sup 2} at 11 V. To our knowledge, Cl-AlPc has not previously been shown to work as a hole transport material (HTL) in OLEDs. Conversely, the di-chlorides of silicon, germanium, and tin phthalocyanine (Cl{sub 2}-SiPc, Cl{sub 2}-GePc, and Cl{sub 2}-SnPc, respectively) showed poor performance compared to Cl-AlPc, having peak luminances of only 38 ± 4 cd/m{sup 2} (12 V), 23 ± 1 cd/m{sup 2} (8.5 V), and 59 ± 5 cd/m{sup 2} (13.5 V), respectively. However, by performing a simple axial substitution of the chloride groups of Cl{sub 2}-SiPc with pentafluorophenoxy groups, the resulting bis(pentafluorophenoxy) silicon phthalocyanine (F{sub 10}-SiPc) containing OLED had a peak luminance of 5141 ± 941 cd/m{sup 2} (10 V), a two order of magnitude increase over its chlorinated precursor. This material showed OLED characteristics approaching those of a baseline OLED based on the well-studied triarylamine NPB. Attempts to attach the pentafluorophenoxy axial group to both SnPc and GePc were hindered by synthetic difficulties and low thermal stability, respectively. In light of the performance improvements observed by simple axial substitution of SiPc in OLEDs, the use of axially substituted MPcs in organic electronic devices remains of continuing interest to us and potentially the field in general.

Modeling Smart Energy Systems for Model Predictive Control

DEFF Research Database (Denmark)

Halvgaard, Rasmus; Poulsen, Niels Kjølstad; Madsen, Henrik

2012-01-01

as it is produced requires a very exible and controllable power consumption. Examples of controllable electric loads are heat pumps in buildings and Electric Vehicles (EVs) that are expected to play a large role in the future danish energy system. These units in a smart energy system can potentially oer exibility...... on a time scale ranging from seconds to several days by moving power consumption, exploiting thermal inertia or battery storage capacity, respectively. Using advanced control algorithms these systems are able to reduce their own electricity costs by planning ahead and moving consumption to periods...... future price should also be available in order for the individual units to plan ahead in the most feasible way. This is necessary since Economic MPCs do not respond to the absolute cost of electricity, but to variations of the price over the prediction horizon. Economic MPC is ideal for price responsive...

Multi-purpose canister system evaluation: A systems engineering approach

International Nuclear Information System (INIS)

1994-09-01

This report summarizes Department of Energy (DOE) efforts to investigate various container systems for handling, transporting, storing, and disposing of spent nuclear fuel (SNF) assemblies in the Civilian Radioactive Waste Management System (CRWMS). The primary goal of DOE's investigations was to select a container technology that could handle the vast majority of commercial SNF at a reasonable cost, while ensuring the safety of the public and protecting the environment. Several alternative cask and canister concepts were evaluated for SNF assembly packaging to determine the most suitable concept. Of these alternatives, the multi-purpose canister (MPC) system was determined to be the most suitable. Based on the results of these evaluations, the decision was made to proceed with design and certification of the MPC system. A decision to fabricate and deploy MPCs will be made after further studies and preparation of an environmental impact statement

RISC-type microprocessors may revolutionize aerospace simulation

Science.gov (United States)

Jackson, Albert S.

The author explores the application of RISC (reduced instruction set computer) processors in massively parallel computer (MPC) designs for aerospace simulation. The MPC approach is shown to be well adapted to the needs of aerospace simulation. It is shown that any of the three common types of interconnection schemes used with MPCs are effective for general-purpose simulation, although the bus-or switch-oriented machines are somewhat easier to use. For partial differential equation models, the hypercube approach at first glance appears more efficient because the nearest-neighbor connections required for three-dimensional models are hardwired in a hypercube machine. However, the data broadcast ability of a bus system, combined with the fact that data can be transmitted over a bus as soon as it has been updated, makes the bus approach very competitive with the hypercube approach even for these types of models.

Robust estimation of the correlation matrix of longitudinal data

KAUST Repository

Maadooliat, Mehdi; Pourahmadi, Mohsen; Huang, Jianhua Z.

2011-01-01

,D) are modeled parsimoniously using covariates. We compare our results with those based on the modified Cholesky decomposition of the form LD2L⊤ using simulations and a real dataset. © 2011 Springer Science+Business Media, LLC.

Population structure and genetic diversity of Sinibrama macrops from Ou River and Ling River based on mtDNA D-loop region analysis, China.

Science.gov (United States)

Zhao, Liangjie; Chenoweth, Erica L; Liu, Qigen

2018-03-01

In order to understand the influence of human activities such as habitat fragmentation on freshwater fish population evolution, we investigated and compared the genetic diversity and phylogeography of Sinibrama macrops populations in the Oujiang River and Ling River. Mitochondrial control region sequences (D-loop region) of 131 specimens from six populations were obtained and analyzed. The diversity of main stream in the Ou River was lower than that in Ling River. Changtan population showed the lowest diversity (H = 0.646 ± 0.077; π = 0.00060 ± 0.00820). Pairwise F ST , gene flow (Nm), and genetic distance (Da) indicated that Longquan and Changtan significantly differentiate from other populations. Nested clade phylogeographical analysis (NCPA) showed some clades and total cladogram experienced isolation by distance. In conclusion, the populations from severely fragmented Ou River have the lower diversity and more intense differentiation than that from the mainstream of Ling River, Changtan population present the lowest diversity and were isolated by the dam construction.

Homeopathy and systematics: a systematic analysis of the therapeutic effects of the plant species used in homeopathy.

Science.gov (United States)

Bharatan, V

2008-07-01

The therapeutic effects of the plant species used in homeopathy have never been subjected to systematic analysis. A survey of the various Materiae Medicae shows that over 800 plant species are the source of medicines in homeopathy. As these medicines are considered related to one another with respect to their therapeutic effects for treating similar symptoms, the aim is to classify and map them using the concept of homology. This involves placing the discipline of homeopathy into a comparative framework using these plant medicines as taxa, therapeutic effects as characters, and contemporary cladistic techniques to analyse these relationships. The results are compared using cladograms based on different data sets used in biology (e.g. morphological characters and DNA sequences) to test whether similar cladistic patterns exist among these medicines. By classifying the therapeutic actions, genuine homologies can be distinguished from homoplasies. As this is a comparative study it has been necessary first to update the existing nomenclature of the plant species in the homeopathic literature in line with the current International Code of Botanical Nomenclature.

Multigene phylogeny of land plants with special reference to bryophytes and the earliest land plants.

Science.gov (United States)

Nickrent, D L; Parkinson, C L; Palmer, J D; Duff, R J

2000-12-01

A widely held view of land plant relationships places liverworts as the first branch of the land plant tree, whereas some molecular analyses and a cladistic study of morphological characters indicate that hornworts are the earliest land plants. To help resolve this conflict, we used parsimony and likelihood methods to analyze a 6, 095-character data set composed of four genes (chloroplast rbcL and small-subunit rDNA from all three plant genomes) from all major land plant lineages. In all analyses, significant support was obtained for the monophyly of vascular plants, lycophytes, ferns (including PSILOTUM: and EQUISETUM:), seed plants, and angiosperms. Relationships among the three bryophyte lineages were unresolved in parsimony analyses in which all positions were included and weighted equally. However, in parsimony and likelihood analyses in which rbcL third-codon-position transitions were either excluded or downweighted (due to apparent saturation), hornworts were placed as sister to all other land plants, with mosses and liverworts jointly forming the second deepest lineage. Decay analyses and Kishino-Hasegawa tests of the third-position-excluded data set showed significant support for the hornwort-basal topology over several alternative topologies, including the commonly cited liverwort-basal topology. Among the four genes used, mitochondrial small-subunit rDNA showed the lowest homoplasy and alone recovered essentially the same topology as the multigene tree. This molecular phylogeny presents new opportunities to assess paleontological evidence and morphological innovations that occurred during the early evolution of terrestrial plants.

Making sense: duty hours, work flow, and waste in graduate medical education.

Science.gov (United States)

Bush, Roger W; Philibert, Ingrid

2009-12-01

Parsimony, and not industry, is the immediate cause of the increase of capital. Industry, indeed, provides the subject which parsimony accumulates. But whatever industry might acquire, if parsimony did not save and store up, the capital would never be the greater.Adam Smith, The Wealth of Nations, book 2, chapter 31In 2003, the Accreditation Council for Graduate Medical Education implemented resident duty hour limits that included a weekly limit and limits on continuous hours. Recent recommendations for added reductions in resident duty hours have produced concern about concomitant reductions in future graduates' preparedness for independent practice. The current debate about resident hours largely does not consider whether all hours residents spend in the educational and clinical-care environment contribute meaningfully either to residents' learning or to effective patient care. This may distract the community from waste in the current clinical-education model. We propose that use of "lean production" and quality improvement methods may assist teaching institutions in attaining a deeper understanding of work flow and waste. These methods can be used to assign value to patient- and learner-centered activities and outputs and to optimize the competing and synergistic aspects of all desired outcomes to produce the care the Institute of Medicine recommends: safe, effective, efficient, patient-centered, timely, and equitable. Finally, engagement of senior clinical faculty in determining the culture of the care and education system will contribute to an advanced social-learning and care network.

Assessing the accuracy of ancestral protein reconstruction methods.

Directory of Open Access Journals (Sweden)

Paul D Williams

2006-06-01

Full Text Available The phylogenetic inference of ancestral protein sequences is a powerful technique for the study of molecular evolution, but any conclusions drawn from such studies are only as good as the accuracy of the reconstruction method. Every inference method leads to errors in the ancestral protein sequence, resulting in potentially misleading estimates of the ancestral protein's properties. To assess the accuracy of ancestral protein reconstruction methods, we performed computational population evolution simulations featuring near-neutral evolution under purifying selection, speciation, and divergence using an off-lattice protein model where fitness depends on the ability to be stable in a specified target structure. We were thus able to compare the thermodynamic properties of the true ancestral sequences with the properties of "ancestral sequences" inferred by maximum parsimony, maximum likelihood, and Bayesian methods. Surprisingly, we found that methods such as maximum parsimony and maximum likelihood that reconstruct a "best guess" amino acid at each position overestimate thermostability, while a Bayesian method that sometimes chooses less-probable residues from the posterior probability distribution does not. Maximum likelihood and maximum parsimony apparently tend to eliminate variants at a position that are slightly detrimental to structural stability simply because such detrimental variants are less frequent. Other properties of ancestral proteins might be similarly overestimated. This suggests that ancestral reconstruction studies require greater care to come to credible conclusions regarding functional evolution. Inferred functional patterns that mimic reconstruction bias should be reevaluated.

The performance of phylogenetic algorithms in estimating haplotype genealogies with migration.

Science.gov (United States)

Salzburger, Walter; Ewing, Greg B; Von Haeseler, Arndt

2011-05-01

Genealogies estimated from haplotypic genetic data play a prominent role in various biological disciplines in general and in phylogenetics, population genetics and phylogeography in particular. Several software packages have specifically been developed for the purpose of reconstructing genealogies from closely related, and hence, highly similar haplotype sequence data. Here, we use simulated data sets to test the performance of traditional phylogenetic algorithms, neighbour-joining, maximum parsimony and maximum likelihood in estimating genealogies from nonrecombining haplotypic genetic data. We demonstrate that these methods are suitable for constructing genealogies from sets of closely related DNA sequences with or without migration. As genealogies based on phylogenetic reconstructions are fully resolved, but not necessarily bifurcating, and without reticulations, these approaches outperform widespread 'network' constructing methods. In our simulations of coalescent scenarios involving panmictic, symmetric and asymmetric migration, we found that phylogenetic reconstruction methods performed well, while the statistical parsimony approach as implemented in TCS performed poorly. Overall, parsimony as implemented in the PHYLIP package performed slightly better than other methods. We further point out that we are not making the case that widespread 'network' constructing methods are bad, but that traditional phylogenetic tree finding methods are applicable to haplotypic data and exhibit reasonable performance with respect to accuracy and robustness. We also discuss some of the problems of converting a tree to a haplotype genealogy, in particular that it is nonunique. © 2011 Blackwell Publishing Ltd.

Assessing the accuracy of ancestral protein reconstruction methods.

Science.gov (United States)

Williams, Paul D; Pollock, David D; Blackburne, Benjamin P; Goldstein, Richard A

2006-06-23

The phylogenetic inference of ancestral protein sequences is a powerful technique for the study of molecular evolution, but any conclusions drawn from such studies are only as good as the accuracy of the reconstruction method. Every inference method leads to errors in the ancestral protein sequence, resulting in potentially misleading estimates of the ancestral protein's properties. To assess the accuracy of ancestral protein reconstruction methods, we performed computational population evolution simulations featuring near-neutral evolution under purifying selection, speciation, and divergence using an off-lattice protein model where fitness depends on the ability to be stable in a specified target structure. We were thus able to compare the thermodynamic properties of the true ancestral sequences with the properties of "ancestral sequences" inferred by maximum parsimony, maximum likelihood, and Bayesian methods. Surprisingly, we found that methods such as maximum parsimony and maximum likelihood that reconstruct a "best guess" amino acid at each position overestimate thermostability, while a Bayesian method that sometimes chooses less-probable residues from the posterior probability distribution does not. Maximum likelihood and maximum parsimony apparently tend to eliminate variants at a position that are slightly detrimental to structural stability simply because such detrimental variants are less frequent. Other properties of ancestral proteins might be similarly overestimated. This suggests that ancestral reconstruction studies require greater care to come to credible conclusions regarding functional evolution. Inferred functional patterns that mimic reconstruction bias should be reevaluated.

West African Journal of Industrial and Academic Research ...

African Journals Online (AJOL)

Prof. Osuagwwu

like Nigeria depend so much on trade taxes and the sluggishness of ... between Malaysian actual demand for imports and the composition of final .... principles of parsimony using the AIC ..... is paramount. It is a standard practice to incorporate.

The impact of positive, negative and topical relevance feedback

NARCIS (Netherlands)

Kaptein, Rianne; Kamps, Jaap; Hiemstra, Djoerd

2008-01-01

This document contains a description of experiments for the 2008 Relevance Feedback track. We experiment with different amounts of feedback, including negative relevance feedback. Feedback is implemented using massive weighted query expansion. Parsimonious query expansion using only relevant

Experiments with positive, negative and topical relevance feedback

NARCIS (Netherlands)

Kaptein, R.; Kamps, J.; Li, R.; Hiemstra, D.

2008-01-01

This document contains a description of experiments for the 2008 Relevance Feedback track. We experiment with different amounts of feedback, including negative relevance feedback. Feedback is implemented using massive weighted query expansion. Parsimonious query expansion using Dirichlet smoothing

Ockham's razors a user's manual

CERN Document Server

Sober, Elliott

2015-01-01

Ockham's razor, the principle of parsimony, states that simpler theories are better than theories that are more complex. It has a history dating back to Aristotle and it plays an important role in current physics, biology, and psychology. The razor also gets used outside of science – in everyday life and in philosophy. This book evaluates the principle and discusses its many applications. Fascinating examples from different domains provide a rich basis for contemplating the principle's promises and perils. It is obvious that simpler theories are beautiful and easy to understand; the hard problem is to figure out why the simplicity of a theory should be relevant to saying what the world is like. In this book, the ABCs of probability theory are succinctly developed and put to work to describe two 'parsimony paradigms' within which this problem can be solved.

Phylogenetic analyses of RPB1 and RPB2 support a middle Cretaceous origin for a clade comprising all agriculturally and medically important fusaria

DEFF Research Database (Denmark)

O’Donnell, Kerry; Rooney, Alejandro P.; Proctor, Robert H.

2013-01-01

Fusarium (Hypocreales, Nectriaceae) is one of the most economically important and systematically challenging groups of mycotoxigenic phytopathogens and emergent human pathogens. We conducted maximum likelihood (ML), maximum parsimony (MP) and Bayesian (B) analyses on partial DNA-directed RNA poly...

A Danish Twin Study of Schizophrenia Liability

DEFF Research Database (Denmark)

Kläning, Ulla; Trumbetta, Susan L; Gottesman, Irving I

2016-01-01

whether variance in schizophrenia liability attributable to environmental factors may have decreased with successive cohorts exposed to improvements in public health. ICD-10 diagnoses were determined by clinical interview. Although the best-fitting, most parsimonious biometric model of schizophrenia...

Measurement bias detection with Kronecker product restricted models for multivariate longitudinal data : An illustration with health-related quality of life data from thirteen measurement occasions

NARCIS (Netherlands)

Verdam, M.G.E.; Oort, F.J.

2014-01-01

Highlights: - Application of Kronecker product to construct parsimonious structural equation models for multivariate longitudinal data. - A method for the investigation of measurement bias with Kronecker product restricted models. - Application of these methods to health-related quality of life data

*Corresponding Author Sensitivity Analysis of a Physiochemical ...

African Journals Online (AJOL)

Michael Horsfall

The numerical method of sensitivity or the principle of parsimony ... analysis is a widely applied numerical method often being used in the .... Chemical Engineering Journal 128(2-3), 85-93. Amod S ... coupled 3-PG and soil organic matter.

Shared Agency on Gilbert and deep continuity

Directory of Open Access Journals (Sweden)

Smith Thomas H.

2015-01-01

Full Text Available I compare Bratman’s theory with Gilbert’s. I draw attention to their ­similarities, query Bratman’s claim that his theory is the more parsimonious, and point to one theoretical advantage of Gilbert’s theory.

Spatial Statistical Network Models for Stream and River Temperatures in the Chesapeake Bay Watershed

Science.gov (United States)

Numerous metrics have been proposed to describe stream/river thermal regimes, and researchers are still struggling with the need to describe thermal regimes in a parsimonious fashion. Regional temperature models are needed for characterizing and mapping current stream thermal re...

Systematic Methodology for Reproducible Optimizing Batch Operation

DEFF Research Database (Denmark)

Bonné, Dennis; Jørgensen, Sten Bay

2006-01-01

This contribution presents a systematic methodology for rapid acquirement of discrete-time state space model representations of batch processes based on their historical operation data. These state space models are parsimoniously parameterized as a set of local, interdependent models. The present...

Measurement bias detection with Kronecker product restricted models for multivariate longitudinal data: an illustration with health-related quality of life data from thirteen measurement occasions

NARCIS (Netherlands)

Verdam, Mathilde G. E.; Oort, Frans J.

2014-01-01

Application of Kronecker product to construct parsimonious structural equation models for multivariate longitudinal data. A method for the investigation of measurement bias with Kronecker product restricted models. Application of these methods to health-related quality of life data from bone

Distributional patterns of the American Peiratinae (Heteroptera: Reduviidae)

NARCIS (Netherlands)

Morrone, J.J.; Coscarón, del C M.

1996-01-01

Based on distributional data of 40 species of Peiratinae, historical relationships of five Amazonian areas (Paranaense, Atlantic, Pacific, Amazonian, and Cerrado) and two Chacoan areas (Chaco and Caatinga), were investigated through a parsimony analysis of endemicity (PAE). The resulting area

The Role of Family Background for Earnings in Rural China

DEFF Research Database (Denmark)

Eriksson, Tor Viking; Qiang, Zhang Ying

This paper provides estimates of brother income correlations for rural China. Brother correlations are a parsimonious measure of the importance of family and community background as determinants of individuals' economic status. We find internationally high levels of income similarity for brothers...

Bayesian inference of the metazoan phylogeny

DEFF Research Database (Denmark)

Glenner, Henrik; Hansen, Anders J; Sørensen, Martin V

2004-01-01

Metazoan phylogeny remains one of evolutionary biology's major unsolved problems. Molecular and morphological data, as well as different analytical approaches, have produced highly conflicting results due to homoplasy resulting from more than 570 million years of evolution. To date, parsimony has...

A physically-based parsimonious hydrological model for flash floods in Mediterranean catchments

Directory of Open Access Journals (Sweden)

H. Roux

2011-09-01

Full Text Available A spatially distributed hydrological model, dedicated to flood simulation, is developed on the basis of physical process representation (infiltration, overland flow, channel routing. Estimation of model parameters requires data concerning topography, soil properties, vegetation and land use. Four parameters are calibrated for the entire catchment using one flood event. Model sensitivity to individual parameters is assessed using Monte-Carlo simulations. Results of this sensitivity analysis with a criterion based on the Nash efficiency coefficient and the error of peak time and runoff are used to calibrate the model. This procedure is tested on the Gardon d'Anduze catchment, located in the Mediterranean zone of southern France. A first validation is conducted using three flood events with different hydrometeorological characteristics. This sensitivity analysis along with validation tests illustrates the predictive capability of the model and points out the possible improvements on the model's structure and parameterization for flash flood forecasting, especially in ungauged basins. Concerning the model structure, results show that water transfer through the subsurface zone also contributes to the hydrograph response to an extreme event, especially during the recession period. Maps of soil saturation emphasize the impact of rainfall and soil properties variability on these dynamics. Adding a subsurface flow component in the simulation also greatly impacts the spatial distribution of soil saturation and shows the importance of the drainage network. Measures of such distributed variables would help discriminating between different possible model structures.

Evapotranspiration estimation using a parameter-parsimonious energy partition model over Amazon basin

Science.gov (United States)

Xu, D.; Agee, E.; Wang, J.; Ivanov, V. Y.

2017-12-01

The increased frequency and severity of droughts in the Amazon region have emphasized the potential vulnerability of the rainforests to heat and drought-induced stresses, highlighting the need to reduce the uncertainty in estimates of regional evapotranspiration (ET) and quantify resilience of the forest. Ground-based observations for estimating ET are resource intensive, making methods based on remotely sensed observations an attractive alternative. Several methodologies have been developed to estimate ET from satellite data, but challenges remained in model parameterization and satellite limited coverage reducing their utility for monitoring biodiverse regions. In this work, we apply a novel surface energy partition method (Maximum Entropy Production; MEP) based on Bayesian probability theory and nonequilibrium thermodynamics to derive ET time series using satellite data for Amazon basin. For a large, sparsely monitored region such as the Amazon, this approach has the advantage methods of only using single level measurements of net radiation, temperature, and specific humidity data. Furthermore, it is not sensitive to the uncertainty of the input data and model parameters. In this first application of MEP theory for a tropical forest biome, we assess its performance at various spatiotemporal scales against a diverse field data sets. Specifically, the objective of this work is to test this method using eddy flux data for several locations across the Amazonia at sub-daily, monthly, and annual scales and compare the new estimates with those using traditional methods. Analyses of the derived ET time series will contribute to reducing the current knowledge gap surrounding the much debated response of the Amazon Basin region to droughts and offer a template for monitoring the long-term changes in global hydrologic cycle due to anthropogenic and natural causes.

Hydrologic behaviour of the Lake of Monate (Italy): a parsimonious modelling strategy

Science.gov (United States)

Tomesani, Giulia; Soligno, Irene; Castellarin, Attilio; Baratti, Emanuele; Cervi, Federico; Montanari, Alberto

2016-04-01

The Lake of Monate (province of Varese, Northern Italy), is a unique example of ecosystem in equilibrium. The lake water quality is deemed excellent notwithstanding the intensive agricultural cultivation, industrial assets and mining activities characterising the surrounding areas. The lake has a true touristic vocation and is the only swimmable water body of the province of Varese, which counts several natural lakes. Lake of Monate has no tributary and its overall watershed area is equal to c.a. 6.6 km2 including the lake surface (i.e. 2.6 km2), of which 3.3 out of c.a. 4.0 km2 belong to the topographical watershed, while the remaining 0.7 km2 belong to the underground watershed. The latter is larger than the topographical watershed due to the presence of moraine formations on top of the limestone bedrock. The local administration recently promoted an intensive environmental monitoring campaign that aims to reach a better understanding of the hydrology of the lake and the subsurface water fluxes. The monitoring campaign started in October 2013 and, as a result, several meteoclimatic and hydrologic data have been collected up to now at daily and hourly timescales. Our study focuses on a preliminary representation of the hydrological behaviour of the lake through a modified version of HyMOD, a conceptual 5-parameter lumped rainfall-runoff model based on the probability-distributed soil storage capacity. The modified model is a semi-distributed application of HyMOD that uses the same five parameters of the original version and simulates the rainfall-runoff transformation for the whole lake watershed at daily time scale in terms of: direct precipitation on, and evaporation from, the lake surface; overall lake inflow, by separating the runoff component (topographic watershed) from the groundwater component (overall watershed); lake water-level oscillation; streamflow at the lake outlet. We used the first year of hydrometeorological observations as calibration data and the second year as validation data and we compared two calibration strategies which maximize two different objective functions: (1) Nash-Sutcliffe efficiency of simulated daily water-level fluctuations, NSE, and (2) linear correlation coefficient between daily series of simulated groundwater inflow and observed water table elevation multiplied by NSE. The validation exercise seems to point out the value of incorporating groundwater measurements for improving the reliability and robustness of the conceptual model.

Perils of parsimony: properties of reduced-rank estimates of genetic covariance matrices.

Science.gov (United States)

Meyer, Karin; Kirkpatrick, Mark

2008-10-01

Eigenvalues and eigenvectors of covariance matrices are important statistics for multivariate problems in many applications, including quantitative genetics. Estimates of these quantities are subject to different types of bias. This article reviews and extends the existing theory on these biases, considering a balanced one-way classification and restricted maximum-likelihood estimation. Biases are due to the spread of sample roots and arise from ignoring selected principal components when imposing constraints on the parameter space, to ensure positive semidefinite estimates or to estimate covariance matrices of chosen, reduced rank. In addition, it is shown that reduced-rank estimators that consider only the leading eigenvalues and -vectors of the "between-group" covariance matrix may be biased due to selecting the wrong subset of principal components. In a genetic context, with groups representing families, this bias is inverse proportional to the degree of genetic relationship among family members, but is independent of sample size. Theoretical results are supplemented by a simulation study, demonstrating close agreement between predicted and observed bias for large samples. It is emphasized that the rank of the genetic covariance matrix should be chosen sufficiently large to accommodate all important genetic principal components, even though, paradoxically, this may require including a number of components with negligible eigenvalues. A strategy for rank selection in practical analyses is outlined.

Between Complexity and Parsimony: Can Agent-Based Modelling Resolve the Trade-off

DEFF Research Database (Denmark)

Nielsen, Helle Ørsted; Malawska, Anna Katarzyna

2013-01-01

to BR- based policy studies would be to couple research on bounded ra-tionality with agent-based modeling. Agent-based models (ABMs) are computational models for simulating the behavior and interactions of any number of decision makers in a dynamic system. Agent-based models are better suited than...... are general equilibrium models for capturing behavior patterns of complex systems. ABMs may have the potential to represent complex systems without oversimplifying them. At the same time, research in bounded rationality and behavioral economics has already yielded many insights that could inform the modeling......While Herbert Simon espoused development of general models of behavior, he also strongly advo-cated that these models be based on realistic assumptions about humans and therefore reflect the complexity of human cognition and social systems (Simon 1997). Hence, the model of bounded rationality...

Introduction to the special issue: parsimony and redundancy in models of language.

Science.gov (United States)

Wiechmann, Daniel; Kerz, Elma; Snider, Neal; Jaeger, T Florian

2013-09-01

One of the most fundamental goals in linguistic theory is to understand the nature of linguistic knowledge, that is, the representations and mechanisms that figure in a cognitively plausible model of human language-processing. The past 50 years have witnessed the development and refinement of various theories about what kind of 'stuff' human knowledge of language consists of, and technological advances now permit the development of increasingly sophisticated computational models implementing key assumptions of different theories from both rationalist and empiricist perspectives. The present special issue does not aim to present or discuss the arguments for and against the two epistemological stances or discuss evidence that supports either of them (cf. Bod, Hay, & Jannedy, 2003; Christiansen & Chater, 2008; Hauser, Chomsky, & Fitch, 2002; Oaksford & Chater, 2007; O'Donnell, Hauser, & Fitch, 2005). Rather, the research presented in this issue, which we label usage-based here, conceives of linguistic knowledge as being induced from experience. According to the strongest of such accounts, the acquisition and processing of language can be explained with reference to general cognitive mechanisms alone (rather than with reference to innate language-specific mechanisms). Defined in these terms, usage-based approaches encompass approaches referred to as experience-based, performance-based and/or emergentist approaches (Amrnon & Snider, 2010; Bannard, Lieven, & Tomasello, 2009; Bannard & Matthews, 2008; Chater & Manning, 2006; Clark & Lappin, 2010; Gerken, Wilson, & Lewis, 2005; Gomez, 2002;

A Maximum Parsimony Model to Reconstruct Phylogenetic Network in Honey Bee Evolution

OpenAIRE

Usha Chouhan; K. R. Pardasani

2007-01-01

Phylogenies ; The evolutionary histories of groups of species are one of the most widely used tools throughout the life sciences, as well as objects of research with in systematic, evolutionary biology. In every phylogenetic analysis reconstruction produces trees. These trees represent the evolutionary histories of many groups of organisms, bacteria due to horizontal gene transfer and plants due to process of hybridization. The process of gene transfer in bacteria and hyb...

Dynamics of pesticide uptake into plants: From system functioning to parsimonious modeling

DEFF Research Database (Denmark)

Fantke, Peter; Wieland, Peter; Wannaz, Cedric

2013-01-01

Dynamic plant uptake models are suitable for assessing environmental fate and behavior of toxic chemicals in food crops. However, existing tools mostly lack in-depth analysis of system dynamics. Furthermore, no existing model is available as parameterized version that is easily applicable for use...

Ancestral sequence reconstruction in primate mitochondrial DNA: compositional bias and effect on functional inference.

Science.gov (United States)

Krishnan, Neeraja M; Seligmann, Hervé; Stewart, Caro-Beth; De Koning, A P Jason; Pollock, David D

2004-10-01

Reconstruction of ancestral DNA and amino acid sequences is an important means of inferring information about past evolutionary events. Such reconstructions suggest changes in molecular function and evolutionary processes over the course of evolution and are used to infer adaptation and convergence. Maximum likelihood (ML) is generally thought to provide relatively accurate reconstructed sequences compared to parsimony, but both methods lead to the inference of multiple directional changes in nucleotide frequencies in primate mitochondrial DNA (mtDNA). To better understand this surprising result, as well as to better understand how parsimony and ML differ, we constructed a series of computationally simple "conditional pathway" methods that differed in the number of substitutions allowed per site along each branch, and we also evaluated the entire Bayesian posterior frequency distribution of reconstructed ancestral states. We analyzed primate mitochondrial cytochrome b (Cyt-b) and cytochrome oxidase subunit I (COI) genes and found that ML reconstructs ancestral frequencies that are often more different from tip sequences than are parsimony reconstructions. In contrast, frequency reconstructions based on the posterior ensemble more closely resemble extant nucleotide frequencies. Simulations indicate that these differences in ancestral sequence inference are probably due to deterministic bias caused by high uncertainty in the optimization-based ancestral reconstruction methods (parsimony, ML, Bayesian maximum a posteriori). In contrast, ancestral nucleotide frequencies based on an average of the Bayesian set of credible ancestral sequences are much less biased. The methods involving simpler conditional pathway calculations have slightly reduced likelihood values compared to full likelihood calculations, but they can provide fairly unbiased nucleotide reconstructions and may be useful in more complex phylogenetic analyses than considered here due to their speed and

Predicting consumer behavior with two emotion appraisal dimensions: Emotion valence and agency in gift giving

NARCIS (Netherlands)

Hooge, de I.E.

2014-01-01

Decades of emotion research have demonstrated the unique influences of many specific emotions on consumer behaviors. These countless numbers of emotion effects can make it difficult to understand the role of emotions in consumer behavior. The current research introduces a parsimonious framework that

Advanced language modeling approaches, case study: Expert search

NARCIS (Netherlands)

Hiemstra, Djoerd

2008-01-01

This tutorial gives a clear and detailed overview of advanced language modeling approaches and tools, including the use of document priors, translation models, relevance models, parsimonious models and expectation maximization training. Expert search will be used as a case study to explain the

Evaluating two model reduction approaches for large scale hedonic models sensitive to omitted variables and multicollinearity

DEFF Research Database (Denmark)

Panduro, Toke Emil; Thorsen, Bo Jellesmark

2014-01-01

Hedonic models in environmental valuation studies have grown in terms of number of transactions and number of explanatory variables. We focus on the practical challenge of model reduction, when aiming for reliable parsimonious models, sensitive to omitted variable bias and multicollinearity. We...

TESTING TREE-CLASSIFIER VARIANTS AND ALTERNATE MODELING METHODOLOGIES IN THE EAST GREAT BASIN MAPPING UNIT OF THE SOUTHWEST REGIONAL GAP ANALYSIS PROJECT (SW REGAP)

Science.gov (United States)

We tested two methods for dataset generation and model construction, and three tree-classifier variants to identify the most parsimonious and thematically accurate mapping methodology for the SW ReGAP project. Competing methodologies were tested in the East Great Basin mapping un...

Identifying the important factors in simulation models with many factors

NARCIS (Netherlands)

Bettonvil, B.; Kleijnen, J.P.C.

1994-01-01

Simulation models may have many parameters and input variables (together called factors), while only a few factors are really important (parsimony principle). For such models this paper presents an effective and efficient screening technique to identify and estimate those important factors. The

Mortgage Risk and the Yield Curve

DEFF Research Database (Denmark)

Malkhozov, Aytek; Mueller, Philippe; Vedolin, Andrea

2016-01-01

We study feedback from the risk of outstanding mortgage-backed securities (MBS) on the level and volatility of interest rates. We incorporate supply shocks resulting from changes in MBS duration into a parsimonious equilibrium dynamic term structure model and derive three predictions...

A statistical method for 2D facial landmarking

NARCIS (Netherlands)

Dibeklioğlu, H.; Salah, A.A.; Gevers, T.

2012-01-01

Many facial-analysis approaches rely on robust and accurate automatic facial landmarking to correctly function. In this paper, we describe a statistical method for automatic facial-landmark localization. Our landmarking relies on a parsimonious mixture model of Gabor wavelet features, computed in

Morphological character evolution of Amorphophallus (Araceae) based on a combined phylogenetic analysis of trnL, rbcL, and LEAFY second intron sequences

NARCIS (Netherlands)

Sedayu, A.; Eurlings, M.C.M.; Gravendeel, B.; Hetterscheid, W.L.A.

2010-01-01

Sequences of three different genes in 69 taxa of Amorphophallus were combined to reconstruct the molecular phylogeny of this species-rich Aroid genus. The data set was analyzed by three different methods, Maximum Parsimony, Maximum Likelihood and Bayesian analysis, producing slightly different tree

Assessing uncertainties in global cropland futures using a conditional probabilistic modelling framework

NARCIS (Netherlands)

Engström, Kerstin; Olin, Stefan; Rounsevell, Mark D A; Brogaard, Sara; Van Vuuren, Detlef P.; Alexander, Peter; Murray-Rust, Dave; Arneth, Almut

2016-01-01

We present a modelling framework to simulate probabilistic futures of global cropland areas that are conditional on the SSP (shared socio-economic pathway) scenarios. Simulations are based on the Parsimonious Land Use Model (PLUM) linked with the global dynamic vegetation model LPJ-GUESS

The spatial representation of market information

NARCIS (Netherlands)

DeSarbo, WS; Degeratu, AM; Wedel, M; Saxton, MK

2001-01-01

To be used effectively, market knowledge and information must be structured and represented in ways that are parsimonious and conducive to efficient managerial decision making. This manuscript proposes a new latent structure spatial model for the representation of market information that meets this

Comparison among cognitive diagnostic models for the TIMSS 2007 fourth grade mathematics assessment.

Science.gov (United States)

Yamaguchi, Kazuhiro; Okada, Kensuke

2018-01-01

A variety of cognitive diagnostic models (CDMs) have been developed in recent years to help with the diagnostic assessment and evaluation of students. Each model makes different assumptions about the relationship between students' achievement and skills, which makes it important to empirically investigate which CDMs better fit the actual data. In this study, we examined this question by comparatively fitting representative CDMs to the Trends in International Mathematics and Science Study (TIMSS) 2007 assessment data across seven countries. The following two major findings emerged. First, in accordance with former studies, CDMs had a better fit than did the item response theory models. Second, main effects models generally had a better fit than other parsimonious or the saturated models. Related to the second finding, the fit of the traditional parsimonious models such as the DINA and DINO models were not optimal. The empirical educational implications of these findings are discussed.

Analyzing Oil Futures with a Dynamic Nelson-Siegel Model

DEFF Research Database (Denmark)

Hansen, Niels Strange; Lunde, Asger

In this paper we are interested in the term structure of futures contracts on oil. The objective is to specify a relatively parsimonious model which explains data well and performs well in a real time out of sample forecasting. The dynamic Nelson-Siegel model is normally used to analyze and forec......In this paper we are interested in the term structure of futures contracts on oil. The objective is to specify a relatively parsimonious model which explains data well and performs well in a real time out of sample forecasting. The dynamic Nelson-Siegel model is normally used to analyze...... and forecast interest rates of different maturities. The structure of oil futures resembles the structure of interest rates and this motivates the use of this model for our purposes. The data set is vast and the dynamic Nelson-Siegel model allows for a significant dimension reduction by introducing three...

Phylogenetic relationships of click beetles (Coleoptera: Elateridae) inferred from 28S ribosomal DNA: insights into the evolution of bioluminescence in Elateridae.

Science.gov (United States)

Sagegami-Oba, Reiko; Oba, Yuichi; Ohira, Hitoo

2007-02-01

Although the taxonomy of click beetles (family Elateridae) has been studied extensively, inconsistencies remain. We examine here the relationships between species of Elateridae based on partial sequences of nuclear 28S ribosomal DNA. Specimens were collected primarily from Japan, while luminous click beetles were also sampled from Central and South America to investigate the origins of bioluminescence in Elateridae. Neighbor-joining, maximum-parsimony, and maximum-likelihood analyses produced a consistent basal topology with high statistical support that is partially congruent with the results of previous investigations based on the morphological characteristics of larvae and adults. The most parsimonious reconstruction of the "luminous" and "nonluminous" states, based on the present molecular phylogeny, indicates that the ancestral state of Elateridae was nonluminous. This suggests that the bioluminescence in click beetle evolved independent of that of other luminous beetles, such as Lampyridae, despite their common mechanisms of bioluminescence.

Mechanisms responsible for imipenem resistance among Pseudomonas aeruginosa clinical isolates exposed to imipenem concentrations within the mutant selection window.

Science.gov (United States)

Vassilara, Foula; Galani, Irene; Souli, Maria; Papanikolaou, Konstantinos; Giamarellou, Helen; Papadopoulos, Antonios

2017-07-01

The aim of this study was to determine the propensities of imipenem to select for resistant Pseudomonas aeruginosa mutants by determining the mutant prevention concentrations (MPCs) for 9 unrelated clinical isolates and the accession of any relationship with mechanisms of resistance development. The MPC/MIC ratios ranged from 4 to 16. Detection of resistance mechanisms in the mutant derivatives of the nine isolates mainly revealed inactivating mutations in the gene coding for outer membrane protein OprD. Point mutations leading to premature stop codons or amino acid substitution S278P, ≥1bp deletion leading to frameshift mutations and interruption of the oprD by an insertion sequence, were observed. MPC and mutant selection window (MSW) are unique parameters that may guide the implementation of antimicrobial treatment, providing useful information about the necessary imipenem concentration needed in the infection area, in order to avoid the emergence of resistance, especially in clinical situations with high bacterial load. Copyright © 2017 Elsevier Inc. All rights reserved.

Engineered materials characterization report for the Yucca Mountain Site Characterization Project. Volume 2, Design data

International Nuclear Information System (INIS)

Konynenburg, R.A.; McCright, R.D.; Roy, A.K.; Jones, D.A.

1995-08-01

This is Volume 2 of the Engineered Materials Characterization Report which presents the design data for candidate materials needed in fabricating different components for both large and medium multi-purpose canister (MPC) disposal containers, waste packages for containing uncanistered spent fuel (UCF), and defense high-level waste (HLW) glass disposal containers. The UCF waste package consists of a disposal container with a basket therein. It is assumed that the waste packages will incorporate all-metallic multibarrier disposal containers to accommodate medium and large MPCs, ULCF, and HLW glass canisters. Unless otherwise specified, the disposal container designs incorporate an outer corrosion-allowance metal barrier over an inner corrosion-resistant metal barrier. The corrosion-allowance barrier, which will be thicker than the inner corrosion-resistant barrier, is designed to undergo corrosion-induced degradation at a very low rate, thus providing the inner barrier protection from the near-field environment for a prolonged service period

Mosasauroid phylogeny under multiple phylogenetic methods provides new insights on the evolution of aquatic adaptations in the group.

Directory of Open Access Journals (Sweden)

Tiago R Simões

Full Text Available Mosasauroids were a successful lineage of squamate reptiles (lizards and snakes that radiated during the Late Cretaceous (95-66 million years ago. They can be considered one of the few lineages in the evolutionary history of tetrapods to have acquired a fully aquatic lifestyle, similarly to whales, ichthyosaurs and plesiosaurs. Despite a long history of research on this group, their phylogenetic relationships have only been tested so far using traditional (unweighted maximum parsimony. However, hypotheses of mosasauroid relationships and the recently proposed multiple origins of aquatically adapted pelvic and pedal features in this group can be more thoroughly tested by methods that take into account variation in branch lengths and evolutionary rates. In this study, we present the first mosasauroid phylogenetic analysis performed under different analytical methods, including maximum likelihood, Bayesian inference, and implied weighting maximum parsimony. The results indicate a lack of congruence in the topological position of halisaurines and Dallasaurus. Additionally, the genus Prognathodon is paraphyletic under all hypotheses. Interestingly, a number of traditional mosasauroid clades become weakly supported, or unresolved, under Bayesian analyses. The reduced resolutions in some consensus trees create ambiguities concerning the evolution of fully aquatic pelvic/pedal conditions under many analyses. However, when enough resolution was obtained, reversals of the pelvic/pedal conditions were favoured by parsimony and likelihood ancestral state reconstructions instead of independent origins of aquatic features in mosasauroids. It is concluded that most of the observed discrepancies among the results can be associated with different analytical procedures, but also due to limited postcranial data on halisaurines, yaguarasaurines and Dallasaurus.

Mosasauroid phylogeny under multiple phylogenetic methods provides new insights on the evolution of aquatic adaptations in the group

Science.gov (United States)

Vernygora, Oksana; Paparella, Ilaria; Jimenez-Huidobro, Paulina; Caldwell, Michael W.

2017-01-01

Mosasauroids were a successful lineage of squamate reptiles (lizards and snakes) that radiated during the Late Cretaceous (95–66 million years ago). They can be considered one of the few lineages in the evolutionary history of tetrapods to have acquired a fully aquatic lifestyle, similarly to whales, ichthyosaurs and plesiosaurs. Despite a long history of research on this group, their phylogenetic relationships have only been tested so far using traditional (unweighted) maximum parsimony. However, hypotheses of mosasauroid relationships and the recently proposed multiple origins of aquatically adapted pelvic and pedal features in this group can be more thoroughly tested by methods that take into account variation in branch lengths and evolutionary rates. In this study, we present the first mosasauroid phylogenetic analysis performed under different analytical methods, including maximum likelihood, Bayesian inference, and implied weighting maximum parsimony. The results indicate a lack of congruence in the topological position of halisaurines and Dallasaurus. Additionally, the genus Prognathodon is paraphyletic under all hypotheses. Interestingly, a number of traditional mosasauroid clades become weakly supported, or unresolved, under Bayesian analyses. The reduced resolutions in some consensus trees create ambiguities concerning the evolution of fully aquatic pelvic/pedal conditions under many analyses. However, when enough resolution was obtained, reversals of the pelvic/pedal conditions were favoured by parsimony and likelihood ancestral state reconstructions instead of independent origins of aquatic features in mosasauroids. It is concluded that most of the observed discrepancies among the results can be associated with different analytical procedures, but also due to limited postcranial data on halisaurines, yaguarasaurines and Dallasaurus. PMID:28467456

Molecular phylogenetics of emydine turtles: taxonomic revision and the evolution of shell kinesis.

Science.gov (United States)

Feldman, Chris R; Parham, James Ford

2002-03-01

The 10 extant species of emydine turtles represent an array of morphological and ecological forms recognizable and popular among scientists and hobbyists. Nevertheless, the phylogenetic affinities of most emydines remain contentious. Here, we examine the evolutionary relationships of emydine turtles using 2092 bp of DNA encoding the mitochondrial genes cyt b, ND4, and adjacent tRNAs. These data contain 339 parsimony informative characters that we use to erect hypotheses of relationships for the Emydinae. Both maximum parsimony and maximum likelihood methods yield a monophyletic Emydinae in which all but three nodes are well resolved. Emys orbicularis, Emydoidea blandingii, and Clemmys marmorata form a monophyletic clade, as do the species of Terrapene. Clemmys muhlenbergii and Clemmys insculpta form a third monophyletic group that may be sister to all other emydines. Clemmys guttata is problematic and probably related to Terrapene. Based on this phylogeny, and previous molecular work on the group, we suggest the following taxonomic revisions: (1) Clemmys should be restricted to a single species, C. guttata. (2) Calemys should be resurrected for C. muhlenbergii and C. insculpta. (3) Emys should be expanded to include three species: E. orbicularis, E. blandingii, and E. marmorata. Furthermore, our analyses show that neither kinetic-shelled nor akinetic-shelled emydines form monophyletic groups. Therefore, shell kinesis was either independently gained in Emys and Terrapene or secondarily lost in E. marmorata and C. guttata. Parsimony, paleontological evidence, and the multiple origins of shell kinesis in related turtle lineages (especially geoemydines) support the independent origin of plastral kinesis.

Summarization of meetings using word clouds

NARCIS (Netherlands)

de Hollander, G.; Marx, M.

2011-01-01

In this study parsimonious language models were used to construct word clouds of the proceedings of the European Parliament. Multiple design choices had to be made and are discussed. Important features are stemming during tokenization, including bigrams into the word cloud and multilingualism. Also,

Emotions in advice taking: the roles of agency and valence

NARCIS (Netherlands)

de Hooge, I.E.; Verlegh, P.W.J.; Tzioti, S.C.

2014-01-01

Recently, advice taking has received attention in decision-making research, and some studies suggest that emotions may play a role in this process. Yet a clear account of how emotions influence advice taking is lacking. The current research introduces a parsimonious explanation by suggesting that

Low Endogenous Neural Noise in Autism

Science.gov (United States)

Davis, Greg; Plaisted-Grant, Kate

2015-01-01

"Heuristic" theories of autism postulate that a single mechanism or process underpins the diverse psychological features of autism spectrum disorder. Although no such theory can offer a comprehensive account, the parsimonious descriptions they provide are powerful catalysts to autism research. One recent proposal holds that…

Modeling Unobserved Consideration Sets for Household Panel Data

NARCIS (Netherlands)

J.E.M. van Nierop; R. Paap (Richard); B. Bronnenberg; Ph.H.B.F. Franses (Philip Hans)

2000-01-01

textabstractWe propose a new method to model consumers' consideration and choice processes. We develop a parsimonious probit type model for consideration and a multinomial probit model for choice, given consideration. Unlike earlier models of consideration ours is not prone to the curse of

Phylogenetic relationships of Chaetomium isolates based on the ...

African Journals Online (AJOL)

Biotech Unit

2013-02-27

Feb 27, 2013 ... Phylogenetic analysis of Chaetomium species. The evolutionary history was inferred using the maximum parsimony method. The bootstrap consensus tree inferred from. 1000 replicates is taken to represent the evolutionary history of the taxa analyzed (Felsenstein, 1985). The MP tree was obtained using.

Modelling asymmetric persistence over the business cycle

NARCIS (Netherlands)

Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard)

1998-01-01

textabstractWe address the issue of time varying persistence of shocks to macroeconomic time series variables by proposing a new and parsimonious time series model. Our model assumes that this time varying persistence depends on a linear combination of lagged explanatory variables, where this

Tourism Ethnocentrism and its Effects on Tourist and Resident Behavior

DEFF Research Database (Denmark)

Kock, Florian; Josiassen, Alexander; Assaf, A. George

2018-01-01

that captures tourists’ and residents’ motivation to support the domestic tourism economy. The research reported herein develops the parsimonious, reliable, and valid TE scale, and provides an empirical test thereof. The results show that TE is an important means to investigate both tourists’ and residents...

Sources of Conflict among Nigerian Workers | Mogaji | IFE ...

African Journals Online (AJOL)

The parsimonious model of the multiple regression analysis revealed that 9 out of 27 interpersonal, intergroup and organizational climate variables, significantly predicted the occurrence of conflict in the organization. The variables including: standard, warmth, risk and organizational support were significant at p<.01 ...

Montessori Elementary Philosophy Reflects Current Motivation Theories

Science.gov (United States)

Murray, Angela

2011-01-01

Montessori's theories, developed more than 100 years ago, certainly resonate with current psychological research on improving education. Autonomy, interest, competence, and relatedness form the foundation for three contemporary efforts to organize the vast literature on motivation into a parsimonious theory. These four elements also comprise…

Sojourn times in finite-capacity processor-sharing queues

NARCIS (Netherlands)

Borst, S.C.; Boxma, O.J.; Hegde, N.

2005-01-01

Motivated by the need to develop simple parsimonious models for evaluating the performance of wireless data systems, we consider finite-capacity processor-sharing systems. For such systems, we analyze the sojourn time distribution, which presents a useful measure for the transfer delay of documents

Integration of transport concepts for risk assessment of pesticide erosion

NARCIS (Netherlands)

Yang, Xiaomei; Zee, van der Sjoerd E.A.T.M.; Gai, Lingtong; Wesseling, Jan G.; Ritsema, Coen J.; Geissen, Violette

2016-01-01

Environmental contamination by agrochemicals has been a large problem for decades. Pesticides are transported in runoff and remain attached to eroded soil particles, posing a risk to water and soil quality and human health. We have developed a parsimonious integrative model of pesticide

Assessing Credit with Equity : A CEV Model with Jump to Default

NARCIS (Netherlands)

Campi, L.; Polbennikov, S.Y.; Sbuelz, A.

2005-01-01

Unlike in structural and reduced-form models, we use equity as a liquid and observable primitive to analytically value corporate bonds and credit default swaps.Restrictive assumptions on the .rm.s capital structure are avoided.Default is parsimoniously represented by equity value hitting the zero

Emotions in Advice Taking: The Roles of Agency and Valence

NARCIS (Netherlands)

Hooge, de I.E.; Verlegh, P.W.J.; Tzioti, S.C.

2014-01-01

Recently, advice taking has received attention in decision-making research, and some studies suggest that emotions may play a role in this process. Yet a clear account of how emotions influence advice taking is lacking. The current research introduces a parsimonious explanation by suggesting that

A Range-Based Multivariate Model for Exchange Rate Volatility

NARCIS (Netherlands)

B. Tims (Ben); R.J. Mahieu (Ronald)

2003-01-01

textabstractIn this paper we present a parsimonious multivariate model for exchange rate volatilities based on logarithmic high-low ranges of daily exchange rates. The multivariate stochastic volatility model divides the log range of each exchange rate into two independent latent factors, which are

Historical explanation of the origin of the herpetofauna of Mexico Explicación histórica del origen de la herpetofauna de México

Directory of Open Access Journals (Sweden)

Oscar Flores-Villela

2009-12-01

Full Text Available A hypothesis of historical area relationships for Mexico, Central, and South America was investigated by a cladistic biogographic analysis using 10 taxon cladograms of the herpetofauna of Mexico. A hypothesis is presented based on previous narrative biogeographic scenarios and compared with the general area cladograms (GACs obtained using reconciled trees of COMPONENT 2.0 and Brooks Parsimony Analysis (BPA. For tree reconciliation, 1 000 trees were saved after the analysis. BPA yielded 18 GACs (CI = 0.805, RI= 0.549. The GAC derived from tree reconciliation is more or less pectinate and has only 3 groups of 2 areas each. These groups consist of the Chihuahuan and Sonoran deserts as sister areas on the one hand (DCHI, DSON, and the Sierra Madre Oriental and Occidental as sister areas on the other (SMOR, SMOC. This latter clade is sister to the Chihuahuan and Sonoran desert clade. The third group has the Transvolcanic Belt and Sierra Madre del Sur as sister areas (TVA, SMEX. The GAC obtained by BPA showed 4 main groups of areas: the first is comprised of the Pacific coast of Mexico and the Balsas Depression (PCBAL, the Sierra Madre del Sur (SMEX, and the Transvolcanic Belt (TVA; the second group includes the Sierra Madre Oriental (SMOR, Sierra Madre Occidental (SMOC, Sonoran (DSON and Chihuahuan deserts (DCHI; the third comprised the Highlands of Chiapas and Guatemala (CHIG, the Eastern Lowlands, on the Atlantic coast (ELL and the Semiarid Lands of Tamaulipas-Texas (TAMS; the fourth group contains the Western Lowlands, in the Pacific coast (WLL and northern South America (SA; the Talamanca Ridge (TALA is isolated at the base of the 3 first groups. The GAC from narrative biogeography contains 3 groups: the first has areas of northern Mexico (DSON, DCHI, TAMPS, the second has areas from central Mexico (PCBAL, SMOR, SMOC, TV A, and third has areas from southern Mexico and Central America (SMEX, CHIG, TALA, WLL, ELL, SA. In general, the GAC from the

Finding patterns of distribution for freshwater phytoplankton, zooplankton and fish, by means of parsimony analysis of endemicity Encontrando patrones de distribución para fitoplancton, zooplancton y peces dulceacuícolas por medio de análisis de parsimonia de endemismos

Directory of Open Access Journals (Sweden)

J. PABLO OYANEDEL

2008-06-01

Full Text Available During the last decades, limnological studies on Chilean systems have contributed to know the species composition and main environmental variables of many water bodies distributed over a wide latitudinal interval, from 18º to 53º S. However, we still lack of a comprehensive view about the structure and functioning of regional freshwaters. In this work we review the available information about pelagic biota from Chilean basins, in order to reveal patterns of species distribution and their possible association with environmental variables. We built presence-absence matrices for phytoplankton, zooplankton and fish over lakes and basins. From this database, we performed parsimony analysis of endemicity as a tool for determining fundamental distribution patterns of freshwater biota. Also, we assessed the relationship between species occurrences and some available site-related variables. Our results indicated that latitude exerted the strongest influence on species distribution, although altitude, longitude, and area also exerted significant effects for some groups. On the other hand, our results suggest a relationship between the degree of vagility of the groups and the degree of metacommunity structuring, related to the number of endemicity areas.Durante las últimas décadas, los estudios limnológicos en sistemas chilenos han contribuido al conocimiento de la composición de especies y de las principales variables ambientales de muchos cuerpos de agua distribuidos sobre un amplio intervalo latitudinal, desde los 18º a los 53º S. Asimismo, aún carecemos de una visión comprensiva acerca de la estructura y funcionamiento de las aguas dulces regionales. En este trabajo revisamos la información sobre la biota pelágica de las cuencas de Chile, con el propósito de revelar patrones de distribución de especies y su posible asociación con variables ambientales. Construimos matrices de presencia-ausencia para fitoplancton, zooplancton y peces en

Ancient DNA and the rewriting of human history: be sparing with Occam's razor.

Science.gov (United States)

Haber, Marc; Mezzavilla, Massimo; Xue, Yali; Tyler-Smith, Chris

2016-01-11

Ancient DNA research is revealing a human history far more complex than that inferred from parsimonious models based on modern DNA. Here, we review some of the key events in the peopling of the world in the light of the findings of work on ancient DNA.

IRT Item Parameter Recovery with Marginal Maximum Likelihood Estimation Using Loglinear Smoothing Models

Science.gov (United States)

Casabianca, Jodi M.; Lewis, Charles

2015-01-01

Loglinear smoothing (LLS) estimates the latent trait distribution while making fewer assumptions about its form and maintaining parsimony, thus leading to more precise item response theory (IRT) item parameter estimates than standard marginal maximum likelihood (MML). This article provides the expectation-maximization algorithm for MML estimation…

Interpreting treatment x environment interaction in agronomy trials

NARCIS (Netherlands)

Vargas, M.; Crossa, J.; Eeuwijk, van F.A.; Sayre, K.; Reynolds, M.P.

2001-01-01

Multienvironment trials are important in agronomy because the effects of agronomic treatments can change differentially in relation to environmental changes, producing a treatment × environment interaction (T × E). The aim of this study was to find a parsimonious description of the T × E existing in

Continuous-Time Semi-Markov Models in Health Economic Decision Making : An Illustrative Example in Heart Failure Disease Management

NARCIS (Netherlands)

Cao, Qi; Buskens, Erik; Feenstra, Talitha; Jaarsma, Tiny; Hillege, Hans; Postmus, Douwe

Continuous-time state transition models may end up having large unwieldy structures when trying to represent all relevant stages of clinical disease processes by means of a standard Markov model. In such situations, a more parsimonious, and therefore easier-to-grasp, model of a patient's disease

The Effect of Error Correlation on Interfactor Correlation in Psychometric Measurement

Science.gov (United States)

Westfall, Peter H.; Henning, Kevin S. S.; Howell, Roy D.

2012-01-01

This article shows how interfactor correlation is affected by error correlations. Theoretical and practical justifications for error correlations are given, and a new equivalence class of models is presented to explain the relationship between interfactor correlation and error correlations. The class allows simple, parsimonious modeling of error…

An ITS phylogeny of Leccinum and an analysis of the evolution of minisatellite-like sequences within ITS1

NARCIS (Netherlands)

Bakker, den H.C.; Gravendeel, B.; Kuyper, T.W.

2004-01-01

Phylogenetic relationships of the European species of Leccinum (Boletales, Boletaceae) were investigated by maximum parsimony, Bayesian and likelihood analyses of nrITS1-5.8S-ITS2 and 28S sequences. The separate gene trees inferred were largely concordant, and their combined analysis indicates that

A composite view of well-being since 1820

NARCIS (Netherlands)

Rijpma, Auke

2014-01-01

This chapter provides a parsimonious overview of the trends in various well-being dimensions covered in the previous chapters by constructing a composite index of well-being. It discusses the crucial problem of choosing a set of weights to calculate such a composite index. Related problems include

DNA barcodes identify Central Asian Colias butterflies (Lepidoptera, Pieridae).

Science.gov (United States)

Laiho, Juha; Ståhls, Gunilla

2013-12-30

A majority of the known Colias species (Lepidoptera: Pieridae, Coliadinae) occur in the mountainous regions of Central-Asia, vast areas that are hard to access, rendering the knowledge of many species limited due to the lack of extensive sampling. Two gene regions, the mitochondrial COI 'barcode' region and the nuclear ribosomal protein RpS2 gene region were used for exploring the utility of these DNA markers for species identification. A comprehensive sampling of COI barcodes for Central Asian Colias butterflies showed that the barcodes facilitated identification of most of the included species. Phylogenetic reconstruction based on parsimony and Neighbour-Joining recovered most species as monophyletic entities. For the RpS2 gene region species-specific sequences were registered for some of the included Colias spp. Nevertheless, this gene region was not deemed useful as additional molecular 'barcode'. A parsimony analysis of the combined COI and RpS2 data did not support the current subgeneric classification based on morphological characteristics.

Convergence among cave catfishes: long-branch attraction and a Bayesian relative rates test.

Science.gov (United States)

Wilcox, T P; García de León, F J; Hendrickson, D A; Hillis, D M

2004-06-01

Convergence has long been of interest to evolutionary biologists. Cave organisms appear to be ideal candidates for studying convergence in morphological, physiological, and developmental traits. Here we report apparent convergence in two cave-catfishes that were described on morphological grounds as congeners: Prietella phreatophila and Prietella lundbergi. We collected mitochondrial DNA sequence data from 10 species of catfishes, representing five of the seven genera in Ictaluridae, as well as seven species from a broad range of siluriform outgroups. Analysis of the sequence data under parsimony supports a monophyletic Prietella. However, both maximum-likelihood and Bayesian analyses support polyphyly of the genus, with P. lundbergi sister to Ictalurus and P. phreatophila sister to Ameiurus. The topological difference between parsimony and the other methods appears to result from long-branch attraction between the Prietella species. Similarly, the sequence data do not support several other relationships within Ictaluridae supported by morphology. We develop a new Bayesian method for examining variation in molecular rates of evolution across a phylogeny.

Molecular phylogenetic trees - On the validity of the Goodman-Moore augmentation algorithm

Science.gov (United States)

Holmquist, R.

1979-01-01

A response is made to the reply of Nei and Tateno (1979) to the letter of Holmquist (1978) supporting the validity of the augmentation algorithm of Moore (1977) in reconstructions of nucleotide substitutions by means of the maximum parsimony principle. It is argued that the overestimation of the augmented numbers of nucleotide substitutions (augmented distances) found by Tateno and Nei (1978) is due to an unrepresentative data sample and that it is only necessary that evolution be stochastically uniform in different regions of the phylogenetic network for the augmentation method to be useful. The importance of the average value of the true distance over all links is explained, and the relative variances of the true and augmented distances are calculated to be almost identical. The effects of topological changes in the phylogenetic tree on the augmented distance and the question of the correctness of ancestral sequences inferred by the method of parsimony are also clarified.

Comparison among cognitive diagnostic models for the TIMSS 2007 fourth grade mathematics assessment.

Directory of Open Access Journals (Sweden)

Kazuhiro Yamaguchi

Full Text Available A variety of cognitive diagnostic models (CDMs have been developed in recent years to help with the diagnostic assessment and evaluation of students. Each model makes different assumptions about the relationship between students' achievement and skills, which makes it important to empirically investigate which CDMs better fit the actual data. In this study, we examined this question by comparatively fitting representative CDMs to the Trends in International Mathematics and Science Study (TIMSS 2007 assessment data across seven countries. The following two major findings emerged. First, in accordance with former studies, CDMs had a better fit than did the item response theory models. Second, main effects models generally had a better fit than other parsimonious or the saturated models. Related to the second finding, the fit of the traditional parsimonious models such as the DINA and DINO models were not optimal. The empirical educational implications of these findings are discussed.

The Leipzig Ice Nucleation chamber Comparison (LINC): An overview of ice nucleation measurements observed with four on-line ice nucleation devices

Science.gov (United States)

Kohn, Monika; Wex, Heike; Grawe, Sarah; Hartmann, Susan; Hellner, Lisa; Herenz, Paul; Welti, André; Stratmann, Frank; Lohmann, Ulrike; Kanji, Zamin A.

2016-04-01

Mixed-phase clouds (MPCs) are found to be the most relevant cloud type leading to precipitation in mid-latitudes. The formation of ice crystals in MPCs is not completely understood. To estimate the effect of aerosol particles on the radiative properties of clouds and to describe ice nucleation in models, the specific properties of aerosol particles acting as ice nucleating particles (INPs) still need to be identified. A number of devices are able to measure INPs in the lab and in the field. However, methods can be very different and need to be tested under controlled conditions with respect to aerosol generation and properties in order to standardize measurement and data analysis approaches for subsequent ambient measurements. Here, we present an overview of the LINC campaign hosted at TROPOS in September 2015. We compare four ice nucleation devices: PINC (Portable Ice Nucleation Chamber, Chou et al., 2011) and SPIN (SPectrometer for Ice Nuclei) are operated in deposition nucleation and condensation freezing mode. LACIS (Leipzig Aerosol Cloud Interaction Simulator, Hartmann et al., 2011) and PIMCA (Portable Immersion Mode Cooling chamber) measure in the immersion freezing mode. PIMCA is used as a vertical extension to PINC and allows activation and droplet growth prior to exposure to the investigated ice nucleation temperature. Size-resolved measurements of multiple aerosol types were performed including pure mineral dust (K-feldspar, kaolinite) and biological particles (Birch pollen washing waters) as well as some of them after treatment with sulfuric or nitric acid prior to experiments. LACIS and PIMCA-PINC operated in the immersion freezing mode showed very good agreement in the measured frozen fraction (FF). For the comparison between PINC and SPIN, which were scanning relative humidity from below to above water vapor saturation, an agreement was found for the obtained INP concentration. However, some differences were observed, which may result from ice

Redefining the WISC-R: Implications for Professional Practice and Public Policy.

Science.gov (United States)

Macmann, Gregg M.; Barnett, David W.

1992-01-01

The factor structure of the Wechsler Intelligence Scale for Children (Revised) was examined in the standardization sample using new methods of factor analysis. The substantial overlap across factors was most parsimoniously represented by a single general factor. Implications for public policy regarding the purposes and outcomes of special…

Sparse estimation of polynomial dynamical models

NARCIS (Netherlands)

Toth, R.; Hjalmarsson, H.; Rojas, C.R.; Kinnaert, M.

2012-01-01

In many practical situations, it is highly desirable to estimate an accurate mathematical model of a real system using as few parameters as possible. This can be motivated either from appealing to a parsimony principle (Occam's razor) or from the view point of the utilization complexity in terms of

Language, Perception, and the Schematic Representation of Spatial Relations

Science.gov (United States)

Amorapanth, Prin; Kranjec, Alexander; Bromberger, Bianca; Lehet, Matthew; Widick, Page; Woods, Adam J.; Kimberg, Daniel Y.; Chatterjee, Anjan

2012-01-01

Schemas are abstract nonverbal representations that parsimoniously depict spatial relations. Despite their ubiquitous use in maps and diagrams, little is known about their neural instantiation. We sought to determine the extent to which schematic representations are neurally distinguished from language on the one hand, and from rich perceptual…

Code-switching among chiShona-English bilinguals in courtroom ...

African Journals Online (AJOL)

As has become the norm in bilingual situations, code-switching in both formal and informal contexts has increased recognition as a verbal mode of communication. This article presents a parsimonious exegesis of the patterns and functions of code-switching in the courtroom discourse of chiShona-English bilinguals.

Fall Risk Assessment Tools for Elderly Living in the Community: Can We Do Better?

Science.gov (United States)

Palumbo, Pierpaolo; Palmerini, Luca; Bandinelli, Stefania; Chiari, Lorenzo

2015-01-01

Falls are a common, serious threat to the health and self-confidence of the elderly. Assessment of fall risk is an important aspect of effective fall prevention programs. In order to test whether it is possible to outperform current prognostic tools for falls, we analyzed 1010 variables pertaining to mobility collected from 976 elderly subjects (InCHIANTI study). We trained and validated a data-driven model that issues probabilistic predictions about future falls. We benchmarked the model against other fall risk indicators: history of falls, gait speed, Short Physical Performance Battery (Guralnik et al. 1994), and the literature-based fall risk assessment tool FRAT-up (Cattelani et al. 2015). Parsimony in the number of variables included in a tool is often considered a proxy for ease of administration. We studied how constraints on the number of variables affect predictive accuracy. The proposed model and FRAT-up both attained the same discriminative ability; the area under the Receiver Operating Characteristic (ROC) curve (AUC) for multiple falls was 0.71. They outperformed the other risk scores, which reported AUCs for multiple falls between 0.64 and 0.65. Thus, it appears that both data-driven and literature-based approaches are better at estimating fall risk than commonly used fall risk indicators. The accuracy-parsimony analysis revealed that tools with a small number of predictors (~1-5) were suboptimal. Increasing the number of variables improved the predictive accuracy, reaching a plateau at ~20-30, which we can consider as the best trade-off between accuracy and parsimony. Obtaining the values of these ~20-30 variables does not compromise usability, since they are usually available in comprehensive geriatric assessments.

Using tree diversity to compare phylogenetic heuristics.

Science.gov (United States)

Sul, Seung-Jin; Matthews, Suzanne; Williams, Tiffani L

2009-04-29

Evolutionary trees are family trees that represent the relationships between a group of organisms. Phylogenetic heuristics are used to search stochastically for the best-scoring trees in tree space. Given that better tree scores are believed to be better approximations of the true phylogeny, traditional evaluation techniques have used tree scores to determine the heuristics that find the best scores in the fastest time. We develop new techniques to evaluate phylogenetic heuristics based on both tree scores and topologies to compare Pauprat and Rec-I-DCM3, two popular Maximum Parsimony search algorithms. Our results show that although Pauprat and Rec-I-DCM3 find the trees with the same best scores, topologically these trees are quite different. Furthermore, the Rec-I-DCM3 trees cluster distinctly from the Pauprat trees. In addition to our heatmap visualizations of using parsimony scores and the Robinson-Foulds distance to compare best-scoring trees found by the two heuristics, we also develop entropy-based methods to show the diversity of the trees found. Overall, Pauprat identifies more diverse trees than Rec-I-DCM3. Overall, our work shows that there is value to comparing heuristics beyond the parsimony scores that they find. Pauprat is a slower heuristic than Rec-I-DCM3. However, our work shows that there is tremendous value in using Pauprat to reconstruct trees-especially since it finds identical scoring but topologically distinct trees. Hence, instead of discounting Pauprat, effort should go in improving its implementation. Ultimately, improved performance measures lead to better phylogenetic heuristics and will result in better approximations of the true evolutionary history of the organisms of interest.

Prediction of long-term absence due to sickness in employees: development and validation of a multifactorial risk score in two cohort studies.

Science.gov (United States)

Airaksinen, Jaakko; Jokela, Markus; Virtanen, Marianna; Oksanen, Tuula; Koskenvuo, Markku; Pentti, Jaana; Vahtera, Jussi; Kivimäki, Mika

2018-01-24

Objectives This study aimed to develop and validate a risk prediction model for long-term sickness absence. Methods Survey responses on work- and lifestyle-related questions from 65 775 public-sector employees were linked to sickness absence records to develop a prediction score for medically-certified sickness absence lasting >9 days and ≥90 days. The score was externally validated using data from an independent population-based cohort of 13 527 employees. For both sickness absence outcomes, a full model including 46 candidate predictors was reduced to a parsimonious model using least-absolute-shrinkage-and-selection-operator (LASSO) regression. Predictive performance of the model was evaluated using C-index and calibration plots. Results Variance explained in ≥90-day sickness absence by the full model was 12.5%. In the parsimonious model, the predictors included self-rated health (linear and quadratic term), depression, sex, age (linear and quadratic), socioeconomic position, previous sickness absences, number of chronic diseases, smoking, shift work, working night shift, and quadratic terms for body mass index and Jenkins sleep scale. The discriminative ability of the score was good (C-index 0.74 in internal and 0.73 in external validation). Calibration plots confirmed high correspondence between the predicted and observed risk. In >9-day sickness absence, the full model explained 15.2% of the variance explained, but the C-index of the parsimonious model was poor (<0.65). Conclusions Individuals' risk of a long-term sickness absence that lasts ≥90 days can be estimated using a brief risk score. The predictive performance of this score is comparable to those for established multifactorial risk algorithms for cardiovascular disease, such as the Framingham risk score.

Fall Risk Assessment Tools for Elderly Living in the Community: Can We Do Better?

Directory of Open Access Journals (Sweden)

Pierpaolo Palumbo

Full Text Available Falls are a common, serious threat to the health and self-confidence of the elderly. Assessment of fall risk is an important aspect of effective fall prevention programs.In order to test whether it is possible to outperform current prognostic tools for falls, we analyzed 1010 variables pertaining to mobility collected from 976 elderly subjects (InCHIANTI study. We trained and validated a data-driven model that issues probabilistic predictions about future falls. We benchmarked the model against other fall risk indicators: history of falls, gait speed, Short Physical Performance Battery (Guralnik et al. 1994, and the literature-based fall risk assessment tool FRAT-up (Cattelani et al. 2015. Parsimony in the number of variables included in a tool is often considered a proxy for ease of administration. We studied how constraints on the number of variables affect predictive accuracy.The proposed model and FRAT-up both attained the same discriminative ability; the area under the Receiver Operating Characteristic (ROC curve (AUC for multiple falls was 0.71. They outperformed the other risk scores, which reported AUCs for multiple falls between 0.64 and 0.65. Thus, it appears that both data-driven and literature-based approaches are better at estimating fall risk than commonly used fall risk indicators. The accuracy-parsimony analysis revealed that tools with a small number of predictors (~1-5 were suboptimal. Increasing the number of variables improved the predictive accuracy, reaching a plateau at ~20-30, which we can consider as the best trade-off between accuracy and parsimony. Obtaining the values of these ~20-30 variables does not compromise usability, since they are usually available in comprehensive geriatric assessments.

PHYLOGENETIC ANALYSIS WHITHIN THE PRISTIMANTIS UNISTRIGATUS (ANURA, CRAUGASTORIDAE GROUP BASED ON MORPHOLOGICAL CHARACTERS

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JULIO MARIO HOYOS

2014-06-01

Full Text Available We present a phylogenetic analysis within the Pristimantis unistrigatus group (Anura, Craugastoridae of Colombia . Characters from the superficial muscles of the hands and feet as well as external characters were taken for analysis. Most of the muscle characters were observed directly, and some were taken from the literature. Similarly, the external ones were taken mostly from the original descriptions and others from the literature as well. Two matrices were constructed, as the species belonging to this group have changed in recent years with respect to the initially proposed when the group was defined. The results lead us to conclude that the group is not monophyletic, although there are some relationships that are worth to survey because they are kept in the very last cladograms obtained for both proposals. It is suggested that these last relationships should be explored in particular, and the overall group in general, increasing the number of characters and taxa that belong to P. unistrigatus. An open question we left is whether actually is worth to keep these informal taxonomic hierarchy called group within the genera of anurans.

Arthropod phylogeny based on eight molecular loci and morphology

Science.gov (United States)

Giribet, G.; Edgecombe, G. D.; Wheeler, W. C.

2001-01-01

The interrelationships of major clades within the Arthropoda remain one of the most contentious issues in systematics, which has traditionally been the domain of morphologists. A growing body of DNA sequences and other types of molecular data has revitalized study of arthropod phylogeny and has inspired new considerations of character evolution. Novel hypotheses such as a crustacean-hexapod affinity were based on analyses of single or few genes and limited taxon sampling, but have received recent support from mitochondrial gene order, and eye and brain ultrastructure and neurogenesis. Here we assess relationships within Arthropoda based on a synthesis of all well sampled molecular loci together with a comprehensive data set of morphological, developmental, ultrastructural and gene-order characters. The molecular data include sequences of three nuclear ribosomal genes, three nuclear protein-coding genes, and two mitochondrial genes (one protein coding, one ribosomal). We devised new optimization procedures and constructed a parallel computer cluster with 256 central processing units to analyse molecular data on a scale not previously possible. The optimal 'total evidence' cladogram supports the crustacean-hexapod clade, recognizes pycnogonids as sister to other euarthropods, and indicates monophyly of Myriapoda and Mandibulata.

A parsimonious characterization of change in global age-specific and total fertility rates

Science.gov (United States)

2018-01-01

This study aims to understand trends in global fertility from 1950-2010 though the analysis of age-specific fertility rates. This approach incorporates both the overall level, as when the total fertility rate is modeled, and different patterns of age-specific fertility to examine the relationship between changes in age-specific fertility and fertility decline. Singular value decomposition is used to capture the variation in age-specific fertility curves while reducing the number of dimensions, allowing curves to be described nearly fully with three parameters. Regional patterns and trends over time are evident in parameter values, suggesting this method provides a useful tool for considering fertility decline globally. The second and third parameters were analyzed using model-based clustering to examine patterns of age-specific fertility over time and place; four clusters were obtained. A country’s demographic transition can be traced through time by membership in the different clusters, and regional patterns in the trajectories through time and with fertility decline are identified. PMID:29377899

Cross-National Applicability of a Parsimonious Measure of Acculturation to Global Consumer Culture.

Science.gov (United States)

Gupta, Nitin

2016-04-01

Durvasula and Lysonski's paper presented a shorter version of the Acculturation to Global Consumer Culture Scale (hereafter AGCC), which was developed by Cleveland and Laroche to address scarcity of measurements that determined how individuals acquired and became a part of the emerging global consumer culture. The following critique discusses a few concerns and three major shortcomings of the paper, including skewed sample frame and incorrect choice of countries for assessing cross-national applicability of the scale, not discussing the differences in the means of the seven distinct dimensions of AGCC across the four nations studied by the authors, and absence of any critical review of existing consumer acculturation scales vis-à-vis AGCC. © The Author(s) 2016.

Assessing internet addiction using the parsimonious internet addiction components model—A preliminary study.

NARCIS (Netherlands)

Kuss, D.J.; Shorter, G.W.; Rooij, A.J. van; Griffiths, M.D.; Schoenmakers, T.M.

2014-01-01

Internet usage has grown exponentially over the last decade. Research indicates that excessive Internet use can lead to symptoms associated with addiction. To date, assessment of potential Internet addiction has varied regarding populations studied and instruments used, making reliable prevalence

Charge-Neutral Constant pH Molecular Dynamics Simulations Using a Parsimonious Proton Buffer.

Science.gov (United States)

Donnini, Serena; Ullmann, R Thomas; Groenhof, Gerrit; Grubmüller, Helmut

2016-03-08

In constant pH molecular dynamics simulations, the protonation states of titratable sites can respond to changes of the pH and of their electrostatic environment. Consequently, the number of protons bound to the biomolecule, and therefore the overall charge of the system, fluctuates during the simulation. To avoid artifacts associated with a non-neutral simulation system, we introduce an approach to maintain neutrality of the simulation box in constant pH molecular dynamics simulations, while maintaining an accurate description of all protonation fluctuations. Specifically, we introduce a proton buffer that, like a buffer in experiment, can exchange protons with the biomolecule enabling its charge to fluctuate. To keep the total charge of the system constant, the uptake and release of protons by the buffer are coupled to the titration of the biomolecule with a constraint. We find that, because the fluctuation of the total charge (number of protons) of a typical biomolecule is much smaller than the number of titratable sites of the biomolecule, the number of buffer sites required to maintain overall charge neutrality without compromising the charge fluctuations of the biomolecule, is typically much smaller than the number of titratable sites, implying markedly enhanced simulation and sampling efficiency.

Further Examining Berry's Model: The Applicability of Latent Profile Analysis to Acculturation

Science.gov (United States)

Fox, Rina S.; Merz, Erin L.; Solórzano, Martha T.; Roesch, Scott C.

2013-01-01

This study used latent profile analysis (LPA) to identify acculturation profiles. A three-profile solution fit the data best, and comparisons on demographic and psychosocial outcomes as a function of profile yielded expected results. The findings support using LPA as a parsimonious way to model acculturation without anticipating profiles in…

Diversification in insular plants: Inferring the phylogenetic relationship in Aeonium (Crassulaceae) using ITS sequences of nuclear ribosomal DNA

DEFF Research Database (Denmark)

Jorgensen, T.H.; Frydenberg, J.

1999-01-01

The ITS regions of nuclear ribosomal DNA were sequenced in 37 species of the genus Aeonium. A phylogeny obtained through the use of parsimony agrees to some extent with the sectional division of the genus and confirms the position of two newly described species. It also suggests the potential imp...

Author Reply: The Unbearable Heaviness of Feeling

OpenAIRE

Scherer, Klaus R.; Ellsworth, Phoebe C.

2013-01-01

The comments by Brosch and Sander, de Sousa, Frijda, Kuppens, and Parkinson admirably complement the four main articles, adding layers of complexity, but perhaps at the expense of theoretical parsimony and stringency. Their suggestions are inspiring and heuristic, but we must not forget that science is about testing concrete predictions.

Measuring Financial Cycles in a Model-Based Analysis: Empirical Evidence for the United States and the Euro Area

NARCIS (Netherlands)

Galati, E.B.G.; Hindrayanto, A.I.W.; Koopman, S.J.; Vlekke, M.

2016-01-01

We adopt an unobserved components time series model to extract financial cycles for the United States and the five largest euro area countries over the period 1970-2014. We find that financial cycles can parsimoniously be estimated by house prices and total credit or the credit-to-GDP ratio. We show

Role of Family Background, Student Behaviors, and School-Related Beliefs in Predicting High School Dropout

Science.gov (United States)

Parr, Alyssa K.; Bonitz, Verena S.

2015-01-01

The authors' purpose was to test a parsimonious model derived from social cognitive career theory (R. W. Lent, S. D. Brown, & G. Hackett, 1994) and expectancy value theory (J. S. Eccles & A. Wigfield, 2002) that integrates groups of variables (demographic background, student behaviors, and school-related beliefs) with the goal of…

Reality-Based Genre Preferences Do Not Direct Personal Involvement

Science.gov (United States)

Konijn, Elly A.; Hoorn, Johan F.

2004-01-01

Although it seems plausible that people who prefer a particular genre would appreciate characters from that category more than those from other genres, this appears not to be the case. We devised a parsimonious reality-based genre taxonomy that differentiates nonfiction, realism, fantasy, and humor. In Study 1, evidence from film viewers' genre…

Linking Metatraits of the Big Five to Well-Being and Ill-Being: Do Basic Psychological Needs Matter?

Science.gov (United States)

Simsek, Omer Faruk; Koydemir, Selda

2013-01-01

There is considerable evidence that two higher order factors underlie the Big-Five dimensions and that these two factors provide a parsimonious taxonomy. However, not much empirical evidence has been documented as to the extent to which these traits relate to certain psychological constructs. In this study, we tested a structural model to…

Do fly parasites of bats and their hosts coevolve?speciation in Trichobius phyllostomae group (Diptera, Streblidae and their hosts (Chiroptera, Phyllostomidae suggests that they do not Moscas parasitas de morcegos e seus hospedeiros co-evoluem?especiação do grupo Trichobius phyllostomae (Diptera, Streblidae e seus hospedeiros (Chiroptera, Phyllostomidae sugere que eles não fazem

Directory of Open Access Journals (Sweden)

Gustavo Graciolli

2012-12-01

Full Text Available We examined whether, like many parasite-host systems of coevolution, a group of obligate parasitic bat flies (Trichobius phyllostomae Kessel and related species cospeciate with their hosts. We first did a cladistic analysis of the T. phyllostomae group and combined that analysis with a phylogenetic hypothesis from the literature for the Stenodermatinae bats. The cladistic analysis included, as outgroups, one species from each morphological group and complex of Trichobius Gervais, and one species from the following genera: Paratrichobius Miranda-Ribeiro, Megistopoda Macquart, Megistapophysys Dick & Wenzel, Neotrichobius Wenzel & Aitken, Speiseria Kessel and Strebla Wiedemann. The cladogram was rooted with a species of Strebla in the subfamily Streblinae. One cladogram was obtained and which found Trichobius to be polyphyletic. The phylogenetic hypothesis as follows: (Paratrichobius, (Neotrichobius, (Megistopoda, Megistapophysis is the sister-group of the phyllostomae group and the following relationships within the ingroup, (((T. vampyropis Wenzel, Trichobius sp. 2 ((T. hispidus Wenzel, T. petersoni Wenzel ((Trichobius sp. 1 (T. phyllostomae, T. brennani Wenzel. When we compared phylogenies through historical association analyses, cospeciation was uncommon, while host-switching was more common and better explained the association between the phyllostomae group and their bat hosts.Nós examinamos, como em muitos sistemas parasito-hospedeiro de coevolução, se um grupo de moscas parasitas obrigatórias de morcegos (Trichobius phyllostomae Kessel e espécies relacionadas coespecia com seus hospedeiros. Primeiro, nós fizemos uma análise cladística do grupo T. phyllostomae e combinamos a análise com a hipótese filogenética da literatura para os morcegos da subfamília Stenodermatinae. A análise cladística incluiu, como grupo-externo, uma espécie de cada grupo morfológico de Trichobius Gervais, e uma espécie dos seguintes g

Productivity, embryo and eggshell characteristics, and contaminants in bald eagles from the Great Lakes, USA, 1986 to 2000

Science.gov (United States)

Best, David A.; Elliott, Kyle; Bowerman, William; Shieldcastle, Mark C.; Postupalsky, Sergej; Kubiak, Timothy J.; Tillitt, Donald E.; Elliott, John E.

2010-01-01

Chlorinated hydrocarbon concentrations in eggs of fish-eating birds from contaminated environments such as the Great Lakes of North America tend to be highly intercorrelated, making it difficult to elucidate mechanisms causing reproductive impairment, and to ascribe cause to specific chemicals. An information- theoretic approach was used on data from 197 salvaged bald eagle (Haliaeetus leucocephalus) eggs (159 clutches) that failed to hatch in Michigan and Ohio, USA (1986–2000). Contaminant levels declined over time while eggshell thickness increased, and by 2000 was at pre-1946 levels. The number of occupied territories and productivity increased during 1981 to 2004. For both the entire dataset and a subset of nests along the Great Lakes shoreline, polychlorinated biphenyls (ΣPCBs, fresh wet wt) were generally included in the most parsimonious models (lowest-Akaike's information criterion [AICs]) describing productivity, with significant declines in productivity observed above 26 µg/g ΣPCBs (fresh wet wt). Of 73 eggs with a visible embryo, eight (11%) were abnormal, including three with skewed bills, but they were not associated with known teratogens, including ΣPCBs. Eggs with visible embryos had greater concentrations of all measured contaminants than eggs without visible embryos; the most parsimonious models describing the presence of visible embryos incorporated dieldrin equivalents and dichlorodiphenyldichloroethylene (DDE). There were significant negative correlations between eggshell thickness and all contaminants, with ΣPCBs included in the most parsimonious models. There were, however, no relationships between productivity and eggshell thickness or Ratcliffe's index. The ΣPCBs and DDE were negatively associated with nest success of bald eagles in the Great Lakes watersheds, but the mechanism does not appear to be via shell quality effects, at least at current contaminant levels, while it is not clear what other mechanisms were involved.

Multivariate Prediction Equations for HbA1c Lowering, Weight Change, and Hypoglycemic Events Associated with Insulin Rescue Medication in Type 2 Diabetes Mellitus: Informing Economic Modeling.

Science.gov (United States)

Willis, Michael; Asseburg, Christian; Nilsson, Andreas; Johnsson, Kristina; Kartman, Bernt

2017-03-01

Type 2 diabetes mellitus (T2DM) is chronic and progressive and the cost-effectiveness of new treatment interventions must be established over long time horizons. Given the limited durability of drugs, assumptions regarding downstream rescue medication can drive results. Especially for insulin, for which treatment effects and adverse events are known to depend on patient characteristics, this can be problematic for health economic evaluation involving modeling. To estimate parsimonious multivariate equations of treatment effects and hypoglycemic event risks for use in parameterizing insulin rescue therapy in model-based cost-effectiveness analysis. Clinical evidence for insulin use in T2DM was identified in PubMed and from published reviews and meta-analyses. Study and patient characteristics and treatment effects and adverse event rates were extracted and the data used to estimate parsimonious treatment effect and hypoglycemic event risk equations using multivariate regression analysis. Data from 91 studies featuring 171 usable study arms were identified, mostly for premix and basal insulin types. Multivariate prediction equations for glycated hemoglobin A 1c lowering and weight change were estimated separately for insulin-naive and insulin-experienced patients. Goodness of fit (R 2 ) for both outcomes were generally good, ranging from 0.44 to 0.84. Multivariate prediction equations for symptomatic, nocturnal, and severe hypoglycemic events were also estimated, though considerable heterogeneity in definitions limits their usefulness. Parsimonious and robust multivariate prediction equations were estimated for glycated hemoglobin A 1c and weight change, separately for insulin-naive and insulin-experienced patients. Using these in economic simulation modeling in T2DM can improve realism and flexibility in modeling insulin rescue medication. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All

Potential Predictors of Injury Among Pre-Professional Ballet and Contemporary Dancers.

Science.gov (United States)

Yau, Rebecca K; Golightly, Yvonne M; Richardson, David B; Runfola, Cristin D; Waller, Anna E; Marshall, Stephen W

2017-06-15

Injuries occur frequently among ballet and contemporary dancers. However, limited literature exists on injuries to pre-professional dancers in the USA. The goals of this study were to 1. provide a descriptive epidemiology of the incidence of musculoskeletal injuries in an adolescent and young adult dance population and 2. identify parsimonious regression models that could be potentially used to predict injury incidence. The study was based at the University of North Carolina School of the Arts (UNCSA) from Fall 2009 to Spring 2015. An injury was defined as any event that caused a dancer to be seen at the UNCSA Student Health Services and caused the dancer to modify or curtail dance activity for at least 1 day. Injury rate ratios (IRRs) were calculated using negative binomial generalized estimating equations. Models predicting injury rates were built using forward selection, stratified by sex. Among 480 dancers, 1,014 injuries were sustained. Most injuries were to the lower extremity and the result of overuse. There were differences in upper extremity, lower extremity, and traumatic injury rates by demographic subgroups. Among females, the most parsimonious predictive model for injury rates included a self-reported history of depression, age at time of injury, and number of injuries sustained at UNCSA prior to the semester of current injury. Among males, the most parsimonious model was a univariate model with family history of alcohol or drug problems. Strategies for traumatic injury prevention among dancers should be both sex- and style-specific. No differences were observed in overuse injury rates by sex or style, suggesting that generic overuse prevention strategies may not need to be guided by these factors. It is concluded that strategies can be implemented to reduce and mitigate the consequences of injuries if not the injuries themselves.

Analysis of Acorus calamus chloroplast genome and its phylogenetic implications.

Science.gov (United States)

Goremykin, Vadim V; Holland, Barbara; Hirsch-Ernst, Karen I; Hellwig, Frank H

2005-09-01

Determining the phylogenetic relationships among the major lines of angiosperms is a long-standing problem, yet the uncertainty as to the phylogenetic affinity of these lines persists. While a number of studies have suggested that the ANITA (Amborella-Nymphaeales-Illiciales-Trimeniales-Aristolochiales) grade is basal within angiosperms, studies of complete chloroplast genome sequences also suggested an alternative tree, wherein the line leading to the grasses branches first among the angiosperms. To improve taxon sampling in the existing chloroplast genome data, we sequenced the chloroplast genome of the monocot Acorus calamus. We generated a concatenated alignment (89,436 positions for 15 taxa), encompassing almost all sequences usable for phylogeny reconstruction within spermatophytes. The data still contain support for both the ANITA-basal and grasses-basal hypotheses. Using simulations we can show that were the ANITA-basal hypothesis true, parsimony (and distance-based methods with many models) would be expected to fail to recover it. The self-evident explanation for this failure appears to be a long-branch attraction (LBA) between the clade of grasses and the out-group. However, this LBA cannot explain the discrepancies observed between tree topology recovered using the maximum likelihood (ML) method and the topologies recovered using the parsimony and distance-based methods when grasses are deleted. Furthermore, the fact that neither maximum parsimony nor distance methods consistently recover the ML tree, when according to the simulations they would be expected to, when the out-group (Pinus) is deleted, suggests that either the generating tree is not correct or the best symmetric model is misspecified (or both). We demonstrate that the tree recovered under ML is extremely sensitive to model specification and that the best symmetric model is misspecified. Hence, we remain agnostic regarding phylogenetic relationships among basal angiosperm lineages.

Phylogeny and infrageneric delimitation in Spiraea (Rosaceae) inferred from AFLP markers and a comparison with morphology

Czech Academy of Sciences Publication Activity Database

Záveská Drábková, Lenka; Pospíšková, M.; Businský, R.

2017-01-01

Roč. 185, č. 4 (2017), s. 525-541 ISSN 0024-4074 R&D Projects: GA ČR(CZ) GA16-14649S Institutional support: RVO:61389030 Keywords : classification * spiraeoideae * networks * aflp * Bayesian analysis * maximum parsimony * neighbour network * taxonomy Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 2.277, year: 2016

Affinity for Quantitative Tools: Undergraduate Marketing Students Moving beyond Quantitative Anxiety

Science.gov (United States)

Tarasi, Crina O.; Wilson, J. Holton; Puri, Cheenu; Divine, Richard L.

2013-01-01

Marketing students are known as less likely to have an affinity for the quantitative aspects of the marketing discipline. In this article, we study the reasons why this might be true and develop a parsimonious 20-item scale for measuring quantitative affinity in undergraduate marketing students. The scale was administered to a sample of business…

Molecular phylogeny and larval morphological diversity of the lanternfish genus Hygophum (Teleostei: Myctophidae).

Science.gov (United States)

Yamaguchi, M; Miya, M; Okiyama, M; Nishida, M

2000-04-01

Larvae of the deep-sea lanternfish genus Hygophum (Myctophidae) exhibit a remarkable morphological diversity that is quite unexpected, considering their homogeneous adult morphology. In an attempt to elucidate the evolutionary patterns of such larval morphological diversity, nucleotide sequences of a portion of the mitochondrially encoded 16S ribosomal RNA gene were determined for seven Hygophum species and three outgroup taxa. Secondary structure-based alignment resulted in a character matrix consisting of 1172 bp of unambiguously aligned sequences, which were subjected to phylogenetic analyses using maximum-parsimony, maximum-likelihood, and neighbor-joining methods. The resultant tree topologies from the three methods were congruent, with most nodes, including that of the genus Hygophum, being strongly supported by various tree statistics. The most parsimonious reconstruction of the three previously recognized, distinct larval morphs onto the molecular phylogeny revealed that one of the morphs had originated as the common ancestor of the genus, the other two having diversified separately in two subsequent major clades. The patterns of such diversification are discussed in terms of the unusual larval eye morphology and geographic distribution. Copyright 2000 Academic Press.

A taxonomic monograph of Nearctic Scolytus Geoffroy (Coleoptera, Curculionidae, Scolytinae).

Science.gov (United States)

Smith, Sarah M; Cognato, Anthony I

2014-01-01

The Nearctic bark beetle genus Scolytus Geoffroy was revised based in part on a molecular and morphological phylogeny. Monophyly of the native species was tested using mitochondrial (COI) and nuclear (28S, CAD, ArgK) genes and 43 morphological characters in parsimony and Bayesian phylogenetic analyses. Parsimony analyses of molecular and combined datasets provided mixed results while Bayesian analysis recovered most nodes with posterior probabilities >90%. Native hardwood- and conifer-feeding Scolytus species were recovered as paraphyletic. Native Nearctic species were recovered as paraphyletic with hardwood-feeding species sister to Palearctic hardwood-feeding species rather than to native conifer-feeding species. The Nearctic conifer-feeding species were monophyletic. Twenty-five species were recognized. Four new synonyms were discovered: Scolytuspraeceps LeConte, 1868 (= Scolytusabietis Blackman, 1934; = Scolytusopacus Blackman, 1934), Scolytusreflexus Blackman, 1934 (= Scolytusvirgatus Bright, 1972; = Scolytuswickhami Blackman, 1934). Two species were reinstated: Scolytusfiskei Blackman, 1934 and Scolytussilvaticus Bright, 1972. A diagnosis, description, distribution, host records and images were provided for each species and a key is presented to all species.

[Simplified indicator of socioeconomic status in short surveys: a proposal based on assets and services].

Science.gov (United States)

Díaz-Acosta, Rodrigo; Shiba-Matsumoto, Andrey Ryo; Gutiérrez, Juan Pablo

2015-01-01

To develop a socioeconomic index for brief surveys that allows a classification in relation to a reference population with a parsimonious approach. A socioeconomic index was created using assets and use of services indicators to predict income level within a national representative survey of income (ENIGH, National Survey of Households Income and Expenditures) and then tested with data from a survey among key populations (men who have sex with men/transvestite, transgender, transsexual/female sex workers) and compared to an already published indicator. The concordance for quintiles 1, 2, 3, 4, and 5 between the two indexes were 94, 94, 82, 83, and 89%, respectively. The Spearman's rank correlation coefficient was 0.85. The proposed parsimonious index captures the socioeconomic level heterogeneity in the MSM/TTT/FSW survey. The use of this index is suggested for short surveys because of the next advantages: a) it uses dichotomic variables; b) the variables used do not imply the fulfillment of any statistical assumption; c) it is easily calculated; d) it can be used for comparing groups.

Phylogenetic reconstruction of the family Acrypteridae (Orthoptera: Acridoidea) based on mitochondrial cytochrome B gene.

Science.gov (United States)

Huo, Guangming; Jiang, Guofang; Sun, Zhengli; Liu, Dianfeng; Zhang, Yalin; Lu, Lin

2007-04-01

Sequences from the mitochondrial cytochrome b gene (Cyt b) were determined for 25 species from the superfamily Acridoidae and the homologous sequences of 19 species of grasshoppers were downloaded from the GenBank data library. The purpose was to develop a molecular phylogeny of the Acrypteridae, and to interpret the phylogenetic position of the family within the superfamily Acridoidea. Phylogeny was reconstructed by Maximum-parsimony (MP) and Bayesian criteria using Yunnanites coriacea and Tagasta marginella as outgroups. The alignment length of the fragments was 384 bp after excluding ambiguous sites, including 167 parsimony informative sites. In the fragments, the percentages of A + T and G + C were 70.7% and 29.3%, respectively. The monophyly of Arcypteridae is not supported by phylogenetic trees. Within the Arcypteridae, neither Arcypterinae nor Ceracrinae is supported as a monophyletic group. The current genus Chorthippus is not a monophyletic group, and should be a polyphyletic group. The present results are significantly different from the classification scheme of Arcypteridae, which is based on morphology.

Mined Geologic Disposal System Requirements Document

International Nuclear Information System (INIS)

1994-03-01

This Mined Geologic Disposal System Requirements Document (MGDS-RD) describes the functions to be performed by, and the requirements for, a Mined Geologic Disposal System (MGDS) for the permanent disposal of spent nuclear fuel (SNF) (including SNF loaded in multi-purpose canisters (MPCs)) and commercial and defense high-level radioactive waste (HLW) in support of the Civilian Radioactive Waste Management System (CRWMS). The purpose of the MGDS-RD is to define the program-level requirements for the design of the Repository, the Exploratory Studies Facility (ESF), and Surface Based Testing Facilities (SBTF). These requirements include design, operation, and decommissioning requirements to the extent they impact on the physical development of the MGDS. The document also presents an overall description of the MGDS, its functions (derived using the functional analysis documented by the Physical System Requirements (PSR) documents as a starting point), its segments as described in Section 3.1.3, and the requirements allocated to the segments. In addition, the program-level interfaces of the MGDS are identified. As such, the MGDS-RD provides the technical baseline for the design of the MGDS

Scaffold-cell bone engineering in a validated preclinical animal model: precursors vs differentiated cell source.

Science.gov (United States)

Berner, A; Henkel, J; Woodruff, M A; Saifzadeh, S; Kirby, G; Zaiss, S; Gohlke, J; Reichert, J C; Nerlich, M; Schuetz, M A; Hutmacher, D W

2017-07-01

The properties of osteoblasts (OBs) isolated from the axial skeleton (tOBs) differ from OBs of the orofacial skeleton (mOBs) due to the different embryological origins of the bones. The aim of the study was to assess and compare the regenerative potential of allogenic bone marrow-derived mesenchymal progenitor cells with allogenic tOBs and allogenic mOBs in combination with a mPCL-TCP scaffold in critical-sized segmental bone defects in sheep tibiae. After 6 months, the tibiae were explanted and underwent biomechanical testing, micro-computed tomography (microCT) and histological and immunohistochemical analyses. Allogenic MPCs demonstrated a trend towards a better outcome in biomechanical testing and the mean values of newly formed bone. Biomechanical, microCT and histological analysis showed no significant differences in the bone regeneration potential of tOBs and mOBs in our in vitro study, as well as in the bone regeneration potential of different cell types in vivo. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Value Chain Dynamics of Agri-Food Exports from Southern Mediterranean to the European Union: End-Market Perspective

Directory of Open Access Journals (Sweden)

Samir Mili

2016-08-01

Full Text Available This contribution explores the buyer side of the value chains of the main agricultural products exported from the Mediterranean Partner Countries (MPCs to the EU, taking Spain as an explorative case study in the broader European context. It draws on the Global Value Chain (GVC approach to provide new survey-based evidence for better profiling the opportunities and constraints for EU trade for orange, strawberry, tomato and olive oil imported from Morocco, Tunisia, Egypt and Turkey. The approach used complements inquiries using quantitative trade models usually based on aggregate sectoral level. Results show differences depending on the product and the country studied. There are in all cases multiple challenges to be solved at the origin of the value chain including better chain organization, further transparency and security, improvement in infrastructure and logistics, keeping transaction costs manageable at the same time. Consumer preferences in buyer markets when sourcing must be taken on the first place. The findings can have relevant policy implications in terms of prospective Euro-Mediterranean Partnership Agreements on agriculture and food.

White Paper: Multi-purpose canister (MPC) for DOE-owned spent nuclear fuel (SNF)

International Nuclear Information System (INIS)

Knecht, D.A.

1994-04-01

The paper examines the issue, What are the advantages, disadvantages, and other considerations for using the MPC concept as part of the strategy for interim storage and disposal of DOE-owned SNF? The paper is based in part on the results of an evaluation made for the DOE National Spent Fuel Program by the Waste Form Barrier/Canister Team, which is composed of knowledgeable DOE and DOE-contractor personnel. The paper reviews the MPC and DOE SNF status, provides criteria and other considerations applicable to the issue, and presents an evaluation, conclusions, and recommendations. The primary conclusion is that while most of DOE SNF is not currently sufficiently characterized to be sealed into an MPC, the advantages of standardized packages in handling, reduced radiation exposure, and improved human factors should be considered in DOE SNF program planning. While the design of MPCs for DOE SNF are likely premature at this time, the use of canisters should be considered which are consistent with interim storage options and the MPC design envelope

Interpersonal Tension: A Two-Factor Approach to the POX Situation.

Science.gov (United States)

Gupta, Mahesh

1985-01-01

A theoretical explanation, in terms of a two-factor approach to a Person-Other-Issue (POX) Situation is offered, in an attempt to fill the void that exists in the face of the Heider-Newcomb controversy about POX balance. Validity and parsimony is demonstrated by applying it to some of the POX data reported in earlier studies. (Author/BL)

Quality of Life of Family Caregivers of Children with Autism: The Mother's Perspective

Science.gov (United States)

Shu, Bih-Ching

2009-01-01

The purpose of this study was to explore the relationship between the quality of life (QOL) and feeling of mothers of a child with autism. The QOL instrument was also used. A total of 104 participants completed all questionnaires, which included the Taiwan version of the WHOQOL-BREF. A final robust parsimonious structural model showed a positive…

A robust and well-resolved phylogeny of Bactridinae (Arecaceae) based on plastid and nuclear DNA sequences

DEFF Research Database (Denmark)

Eiserhardt, Wolf L.; Pintaud, Jean-Christophe; Asmussen-Lange, Conny

as well as most of the currently accepted infrageneric taxa and recently proposed informal groups. Analyses are based on five plastid DNA regions (matK, trnQ-rps16, rps16 intron, trnD-trnT, trnL-trnF) and three nuclear markers (PRK, RPB2, ITS). A combined dataset was analysed with likelihood and parsimony...

Neonatal imitation and an epigenetic account of mirror neuron development.

Science.gov (United States)

Simpson, Elizabeth A; Fox, Nathan A; Tramacere, Antonella; Ferrari, Pier F

2014-04-01

Neonatal imitation should not exclusively be considered at the population-level; instead, we propose that inconsistent findings regarding its occurrence result from important individual differences in imitative responses. We also highlight what we consider to be a false dichotomy of genetic versus learning accounts of the development of mirror neurons, and instead suggest a more parsimonious epigenetic perspective.

A short proof that phylogenetic tree reconstruction by maximum likelihood is hard.

Science.gov (United States)

Roch, Sebastien

2006-01-01

Maximum likelihood is one of the most widely used techniques to infer evolutionary histories. Although it is thought to be intractable, a proof of its hardness has been lacking. Here, we give a short proof that computing the maximum likelihood tree is NP-hard by exploiting a connection between likelihood and parsimony observed by Tuffley and Steel.

A Short Proof that Phylogenetic Tree Reconstruction by Maximum Likelihood is Hard

OpenAIRE

Roch, S.

2005-01-01

Maximum likelihood is one of the most widely used techniques to infer evolutionary histories. Although it is thought to be intractable, a proof of its hardness has been lacking. Here, we give a short proof that computing the maximum likelihood tree is NP-hard by exploiting a connection between likelihood and parsimony observed by Tuffley and Steel.

Human skeletal muscle fibroblasts stimulate in vitro myogenesis and in vivo muscle regeneration.

Science.gov (United States)

Mackey, Abigail L; Magnan, Mélanie; Chazaud, Bénédicte; Kjaer, Michael

2017-08-01

Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. The extent of cross-talk between fibroblasts, as the source of matrix protein, and satellite cells in humans is unknown. We studied this in human muscle biopsies and cell-culture studies. We observed a strong stimulation of myogenesis by human fibroblasts in cell culture. In biopsies collected 30 days after a muscle injury protocol, fibroblast number increased to four times control levels, where fibroblasts were found to be preferentially located immediately surrounding regenerating muscle fibres. These novel findings indicate an important role for fibroblasts in supporting the regeneration of muscle fibres, potentially through direct stimulation of satellite cell differentiation and fusion, and contribute to understanding of cell-cell cross-talk during physiological and pathological muscle remodelling. Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. In addition to the indispensable role satellite cells play in muscle regeneration, there is emerging evidence in rodents for a regulatory influence on fibroblast activity. However, the influence of fibroblasts on satellite cells and muscle regeneration in humans is unknown. The purpose of this study was to investigate this in vitro and during in vivo regeneration in humans. Following a muscle injury protocol in young healthy men (n = 7), the number of fibroblasts (TCF7L2+), satellite cells (Pax7+), differentiating myogenic cells (myogenin+) and regenerating fibres (neonatal/embryonic myosin+) was determined from biopsy cross-sections. Fibroblasts and myogenic precursor cells (MPCs) were also isolated from human skeletal muscle (n = 4) and co-cultured using different cell ratios, with the two cell populations either in direct contact with each other or separated by a permeable

Genetic characterization of Neotropical Jabiru Storks: Insights for conservation

Science.gov (United States)

Lopes, I.F.; Haig, S.M.; Lama, S.N.D.

2010-01-01

Jabiru Stork (Jabiru mycteria is listed under Appendix I of CITES and considered threatened in Central America. The first population genetic analysis of Jabiru Storks was carried out using mitochondrial DNA (mtDNA) control region sequences (520 bp) and five heterologous microsatellite loci. Samples were collected from the field (N = 49) and museum skins (N = 22) in Central (mainly Belize, Nicaragua and Costa Rica) and South America (Colombia, Venezuela, Peru and Brazil). A decline of mtDNA diversity was observed in comparisons between past (N = 20) and present (N = 40) samples collected in Central America and northern South America. Similar levels of microsatellite loci diversity were observed among contemporary samples. Lower levels of mtDNA variability were observed in samples from Central America and northern South America when compared to the Brazilian Pantanal region. Significant levels of genetic differentiation were found between contemporary locations sampled, whereas non-significant results were observed for historic samples. The non-geographic association of haplotypes observed at the cladograms and the recent divergence times estimated between locations are indicative of an evolutionary history of a large population size with limited population structure. Reconnection of populations via increased gene flow, particularly in Central America, is recommended if genetic structure and status are to be restored.

Molecular systematics of Dendrobium (Orchidaceae, Dendrobieae) from mainland Asia based on plastid and nuclear sequences.

Science.gov (United States)

Xiang, Xiao-Guo; Schuiteman, André; Li, De-Zhu; Huang, Wei-Chang; Chung, Shih-Wen; Li, Jian-Wu; Zhou, Hai-Lang; Jin, Wei-Tao; Lai, Yang-Jun; Li, Zhen-Yu; Jin, Xiao-Hua

2013-12-01

Dendrobium is one of the three largest genera and presents some of the most intricate taxonomic problems in the family Orchidaceae. Based on five DNA markers and a broad sampling of Dendrobium and its relatives from mainland Asia (109 species), our results indicate that mainland Asia Dendrobium is divided into eight clades (with two unplaced species) that form polytomies along the spine of the cladogram. Both Dendrobium and Epigeneium are well supported as monophyletic, whereas sect. Dendrobium, sect. Densiflora, sect. Breviflores, sect. Holochrysa, are paraphyletic/polyphyletic. Many ignored phylogenetic relationships, such as the one of major clades formed by D. jenkinsii and D. lindleyi (two members of sect. Densiflora), the Aphyllum group, the Devonianum group, the Catenatum group, the Crepidatum group, and the Dendrobium moniliforme complex are well supported by both molecular and morphological evidence. Based on our data, we propose to broaden sect. Dendrobium to include sect. Stuposa, sect. Breviflores, and sect. Holochrysa and to establish a new section to accommodate D. jenkinsii and D. lindleyi. Our results indicated that it is preferable to use a broad generic concept of Dendrobium and to pursue an improved infrageneric classification at sectional level, taking into account both morphology and current molecular findings. Copyright © 2013 Elsevier Inc. All rights reserved.

The feeding practices and structure questionnaire: construction and initial validation in a sample of Australian first-time mothers and their 2-year olds

OpenAIRE

Jansen, Elena; Mallan, Kimberley M; Nicholson, Jan M; Daniels, Lynne A

2014-01-01

Background Early feeding practices lay the foundation for children’s eating habits and weight gain. Questionnaires are available to assess parental feeding but overlapping and inconsistent items, subscales and terminology limit conceptual clarity and between study comparisons. Our aim was to consolidate a range of existing items into a parsimonious and conceptually robust questionnaire for assessing feeding practices with very young children (

Phylogeny of Salsoleae s.l. (Chenopodiaceae) based on DNA sequence data from ITS, psbB-psbH, and rbcL, with emphasis on taxa of northwestern China

Science.gov (United States)

Zhi-Bin Wen; Ming-Li Zhang; Ge-Lin Zhu; Stewart C. Sanderson

2010-01-01

To reconstruct phylogeny and verify the monophyly of major subgroups, a total of 52 species representing almost all species of Salsoleae s.l. in China were sampled, with analysis based on three molecular markers (nrDNA ITS, cpDNA psbB-psbH and rbcL), using maximum parsimony, maximum likelihood, and Bayesian inference methods. Our molecular evidence provides strong...

Quantitative Phylogenetic Analysis in the 21st Century Análisis Filogenéticos Cuantitativos en el siglo XXI

Directory of Open Access Journals (Sweden)

Daniel R Brooks

2007-12-01

Full Text Available We review Hennigian phylogenetics and compare it with Maximum parsimony, Maximum likelihood, and Bayesian likelihood approaches. All methods use the principle of parsimony in some form. Hennigian-based approaches are justified ontologically by the Darwinian concepts of phylogenetic conservatism and cohesion of homologies, embodied in Hennig's Auxiliary Principle, and applied by outgroup comparisons. Parsimony is used as an epistemological tool, applied a posteriori to choose the most robust hypothesis when there are conflicting data. Quantitative methods use parsimony as an ontological criterion: Maximum parsimony analysis uses unweighted parsimony, Maximum likelihood weight all characters equally that explain the data, and Bayesian likelihood relying on weighting each character partition that explains the data. Different results most often stem from insufficient data, in which case each quantitative method treats ambiguities differently. All quantitative methods produce networks. The networks can be converted into trees by rooting them. If the rooting is done in accordance with Hennig's Auxiliary Principle, using outgroup comparisons, the resulting tree can then be interpreted as a phylogenetic hypothesis. As the size of the data set increases, likelihood methods select models that allow an increasingly greater number of a priori possibilities, converging on the Hennigian perspective that nothing is prohibited a priori. Thus, all methods produce similar results, regardless of data type, especially when their networks are rooted using outgroups. Appeals to Popperian philosophy cannot justify any kind of phylogenetic analysis, because they argue from effect to cause rather than from cause to effect. Nor can particular methods be justified on the basis of statistical consistency, because all may be consistent or inconsistent depending on the data. If analyses using different types of data and/or different methods of phylogeny reconstruction do not

Per Aspera ad Astra: Through Complex Population Modeling to Predictive Theory.

Science.gov (United States)

Topping, Christopher J; Alrøe, Hugo Fjelsted; Farrell, Katharine N; Grimm, Volker

2015-11-01

Population models in ecology are often not good at predictions, even if they are complex and seem to be realistic enough. The reason for this might be that Occam's razor, which is key for minimal models exploring ideas and concepts, has been too uncritically adopted for more realistic models of systems. This can tie models too closely to certain situations, thereby preventing them from predicting the response to new conditions. We therefore advocate a new kind of parsimony to improve the application of Occam's razor. This new parsimony balances two contrasting strategies for avoiding errors in modeling: avoiding inclusion of nonessential factors (false inclusions) and avoiding exclusion of sometimes-important factors (false exclusions). It involves a synthesis of traditional modeling and analysis, used to describe the essentials of mechanistic relationships, with elements that are included in a model because they have been reported to be or can arguably be assumed to be important under certain conditions. The resulting models should be able to reflect how the internal organization of populations change and thereby generate representations of the novel behavior necessary for complex predictions, including regime shifts.

BOX & JENKINS METHODOLOGY: AN APLICATION IN RAW MILK DATA FROM THE STATE OF MINAS GERAIS

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Eduardo Campana Barbosa

2014-04-01

Full Text Available The Box & Jenkins methodology was used to obtain a statistical model for estimate the production in liters of milk of the 6 first months of 2013 in Minas Gerais state, adjusting SARIMA (p, d, q x (P, D, Qs models, where d and D are the number of differences to remove the trend and seasonality of time series, p and q are the order of the autoregressive and moving average operators, P and Q are the order of the autoregressive and moving average seasonal operators and s is the seasonal periodicity. The Akaike Criterion Information (AIC procedure was used to select the 6 most parsimonious models and to find the best one the error indicators Mean Squared Error (EQM and Mean Absolute Percent Error (MAPE were analyzed, in addition to the assumptions of residues white noise. The Seasonal Autoregressive Integrated Moving Average SARIMA (3,1,2 x (0,1,212 was upper, view of the principle of parsimony and with more precise estimates. The forecast was more adjusted to the real values of milk production in Minas Gerais state and the model had smaller error indicators. The residues estimated were by this model white noise.

Contrasting phylogeographic patterns in Sphagnum fimbriatum and Sphagnum squarrosum (Bryophyta, Sphagnopsida) in Europe.

Science.gov (United States)

Szövényi, Péter; Hock, Zsófia; Urmi, Edwin; Schneller, Jakob J

2006-01-01

The chloroplast phylogeography of two peat mosses (Sphagnum fimbriatum and Sphagnum squarrosum) with similar distributions but different life history characteristics was investigated in Europe. Our main aim was to test whether similar distributions reflect similar phylogeographic and phylodemographic processes. Accessions covering the European distributions of the species were collected and approx. 2000 bp of the chloroplast genome of each species was sequenced. Maximum parsimony, statistical parsimony and phylodemographic analyses were used to address the question of whether these species with similar distributions show evidence of similar phylogeographic and phylodemographic processes. The chloroplast haplotypes of the currently spreading species S. fimbriatum showed strong geographic structure, whereas those of S. squarrosum, which has stable historical population sizes, showed only very weak geographic affinity and were widely distributed. We hypothesize that S. fimbriatum survived the last glaciations along the Atlantic coast of Europe, whereas S. squarrosum had numerous, scattered refugia in Europe. The dominance of one haplotype of S. fimbriatum across almost all of Europe suggests rapid colonization after the last glacial maximum. We hypothesize that high colonizing ability is an inherent characteristic of the species and its recent expansion in Europe is a response to climate change.

Successful child psychotherapy of attention deficit/hyperactive disorder: an agitated depression explanation.

Science.gov (United States)

Seitler, Burton Norman

2008-09-01

Science tries to explain phenomena in ways that are demonstrable and replicable to develop logical, coherent, parsimonious, and predictive theoretical systems. Yet hyperactive children are given stimulants to "calm" them down, despite the fact that science would predict stimulants would increase hyperactivity. Bradley (1937, 1950) observed that half of the behavior-problem children to whom he administered a stimulant for one week became subdued. He called this finding paradoxical, speculating that inhibitory centers of the central nervous system were stimulated. While Bradley's assertion of a paradoxical reverse effect in children may be an empirical observation, it is not an explanation. The Attention Deficit/Hyperactive Disorder (ADHD) is inferred to exist from hyperactive behavior, which in turn, is inferred to be neurological in origin, a circular argument. An inevitable consequence of the belief in the hypothetical neurological etiology of ADHD is that children are typically given stimulants. Using the case of a seven-year old child, described as experiencing ADHD, who was treated successfully without medication as an illustration, the author provides an alternative, more parsimonious explanation of the etiology, suggesting that ADHD is related to agitated depression.

The Evolutionary Logic of the Obsessive Trait Complex: Obsessive Compulsive Personality Disorder as a Complementary Behavioral Syndrome

Directory of Open Access Journals (Sweden)

Steven Charles Hertler

2015-04-01

Full Text Available Freud noted that the obsessive traits of orderliness, parsimony, and obstinacy incontestably belonged together. This observation has been unfailingly justified, but unsatisfactorily explained. Being a highly heritable pattern essentially unaffected by parental influence, it is counterfactual to continue to explain the obsessive trait constellation as a pathological signature of harsh, authoritarian parenting. Alternatively, the present paper, building upon a previously promulgated evolutionary etiological model, describes how obsessive traits work in unison to enable survival within harsh northerly climates. What appears to be a loosely federated inventory of pathology, after the application of evolutionary reasoning, becomes a coherent behavioral package, adaptive suite, or behavioral syndrome. All three of these terms, taken from behavioral biology, suggest that traits strategically covary, such that the adaptive value of each trait is enhanced by the presence of the others. In this vein, the union of anxious tension and conscientiousness drives the obsessive personality to labor incessantly. The fruits of obsessive labor are then conserved through parsimoniousness, hoarding, vigilance, and niggardliness. And so, obsessive personality is a coherent behavioral package in that the drive to work towards the acquisition of necessities is paired with the drive to conserve and defend them.

Reconstruction of ancestral RNA sequences under multiple structural constraints.

Science.gov (United States)

Tremblay-Savard, Olivier; Reinharz, Vladimir; Waldispühl, Jérôme

2016-11-11

Secondary structures form the scaffold of multiple sequence alignment of non-coding RNA (ncRNA) families. An accurate reconstruction of ancestral ncRNAs must use this structural signal. However, the inference of ancestors of a single ncRNA family with a single consensus structure may bias the results towards sequences with high affinity to this structure, which are far from the true ancestors. In this paper, we introduce achARNement, a maximum parsimony approach that, given two alignments of homologous ncRNA families with consensus secondary structures and a phylogenetic tree, simultaneously calculates ancestral RNA sequences for these two families. We test our methodology on simulated data sets, and show that achARNement outperforms classical maximum parsimony approaches in terms of accuracy, but also reduces by several orders of magnitude the number of candidate sequences. To conclude this study, we apply our algorithms on the Glm clan and the FinP-traJ clan from the Rfam database. Our results show that our methods reconstruct small sets of high-quality candidate ancestors with better agreement to the two target structures than with classical approaches. Our program is freely available at: http://csb.cs.mcgill.ca/acharnement .

Multi-Trait analysis of growth traits: fitting reduced rank models using principal components for Simmental beef cattle

Directory of Open Access Journals (Sweden)

Rodrigo Reis Mota

2016-09-01

Full Text Available ABSTRACT: The aim of this research was to evaluate the dimensional reduction of additive direct genetic covariance matrices in genetic evaluations of growth traits (range 100-730 days in Simmental cattle using principal components, as well as to estimate (covariance components and genetic parameters. Principal component analyses were conducted for five different models-one full and four reduced-rank models. Models were compared using Akaike information (AIC and Bayesian information (BIC criteria. Variance components and genetic parameters were estimated by restricted maximum likelihood (REML. The AIC and BIC values were similar among models. This indicated that parsimonious models could be used in genetic evaluations in Simmental cattle. The first principal component explained more than 96% of total variance in both models. Heritability estimates were higher for advanced ages and varied from 0.05 (100 days to 0.30 (730 days. Genetic correlation estimates were similar in both models regardless of magnitude and number of principal components. The first principal component was sufficient to explain almost all genetic variance. Furthermore, genetic parameter similarities and lower computational requirements allowed for parsimonious models in genetic evaluations of growth traits in Simmental cattle.

Molecular Taxonomy of Anopheles (Nyssorhynchus) benarrochi (Diptera: Culicidae) and Malaria Epidemiology in Southern Amazonian Peru

Science.gov (United States)

Conn, Jan E.; Moreno, Marta; Saavedra, Marlon; Bickersmith, Sara A.; Knoll, Elisabeth; Fernandez, Roberto; Vera, Hubert; Burrus, Roxanne G.; Lescano, Andres G.; Sanchez, Juan Francisco; Rivera, Esteban; Vinetz, Joseph M.

2013-01-01

Anopheline specimens were collected in 2011 by human landing catch, Shannon and CDC traps from the malaria endemic localities of Santa Rosa and San Pedro in Madre de Dios Department, Peru. Most specimens were either Anopheles (Nyssorhynchus) benarrochi B or An. (Nys.) rangeli, confirmed by polymerase chain reaction-restriction fragment length polymorphism-internal transcribed spacer 2 (PCR-RFLP-ITS2) and, for selected individuals, ITS2 sequences. A few specimens from Lupuna, Loreto Department, northern Amazonian Peru, were also identified as An. benarrochi B. A statistical parsimony network using ITS2 sequences confirmed that all Peruvian An. benarrochi B analyzed were identical to those in GenBank from Putumayo, southern Colombia. Sequences of the mtDNA COI BOLD region of specimens from all three Peruvian localities were connected using a statistical parsimony network, although there were multiple mutation steps between northern and southern Peruvian sequences. A Bayesian inference of concatenated Peruvian sequences of ITS2+COI detected a single clade with very high support for all An. benarrochi B except one individual from Lupuna that was excluded. No samples were positive for Plasmodium by CytB-PCR. PMID:23243107

Spatiotemporal Dynamics and Reliable Computations in Recurrent Spiking Neural Networks

Science.gov (United States)

Pyle, Ryan; Rosenbaum, Robert

2017-01-01

Randomly connected networks of excitatory and inhibitory spiking neurons provide a parsimonious model of neural variability, but are notoriously unreliable for performing computations. We show that this difficulty is overcome by incorporating the well-documented dependence of connection probability on distance. Spatially extended spiking networks exhibit symmetry-breaking bifurcations and generate spatiotemporal patterns that can be trained to perform dynamical computations under a reservoir computing framework.

Spatiotemporal Dynamics and Reliable Computations in Recurrent Spiking Neural Networks.

Science.gov (United States)

Pyle, Ryan; Rosenbaum, Robert

2017-01-06

Randomly connected networks of excitatory and inhibitory spiking neurons provide a parsimonious model of neural variability, but are notoriously unreliable for performing computations. We show that this difficulty is overcome by incorporating the well-documented dependence of connection probability on distance. Spatially extended spiking networks exhibit symmetry-breaking bifurcations and generate spatiotemporal patterns that can be trained to perform dynamical computations under a reservoir computing framework.

Phylogenetic relationships among populations of Pristurus rupestris Blanford,1874 (Sauria: Sphaerodactylidae) in southern Iran

OpenAIRE

YOUSOFI, SUGOL; POUYANI, ESKANDAR RASTEGAR; HOJATI, VIDA

2015-01-01

We examined intraspecific relationships of the subspecies Pristurus rupestris iranicus from the northern Persian Gulf area (Hormozgan, Bushehr, and Sistan and Baluchestan provinces). Phylogenetic relationships among these samples were estimated based on the mitochondrial cytochrome b gene. We used three methods of phylogenetic tree reconstruction (maximum likelihood, maximum parsimony, and Bayesian inference). The sampled populations were divided into 5 clades but exhibit little genetic diver...

Consequences of Collective-Focused Leadership and Differentiated Individual-Focused Leadership : Development and Testing of an Organizational-Level Model

OpenAIRE

Kunze, Florian; de Jong, Simon Barend; Bruch, Heike

2016-01-01

Recent advances in leadership research suggest that collective-focused leadership climate and differentiated individual-focused leadership might simultaneously, yet oppositely, affect collective outcomes. The present study extends this literature by addressing open questions regarding theory, methods, statistics, and level of analysis. Therefore, a new and more parsimonious theoretical model is developed on the organizational-level of analysis. Drawing on the commitment literature, we argue f...

The Effect of Multiple Interventions on Environmental Attitudes and Behaviors

Science.gov (United States)

2012-03-22

influences such as television advertisements or state-run programs could not be controlled for; therefore, it was assumed that no other external factors...already exists in a certain area (Brown et al., 2010). Social proofs broadcast on television have also had beneficial effects on energy reduction...still acceptable in many circumstances ( McDonald & Ho, 2002). Parsimony-based fit measures discourage the use of unnecessary or excess parameters

Phylogeny of Marsileaceous Ferns and Relationships of the Fossil Hydropteris pinnata Reconsidered.

Science.gov (United States)

Pryer

1999-09-01

Recent phylogenetic studies have provided compelling evidence that confirms the once disputed hypothesis of monophyly for heterosporous leptosporangiate ferns (Marsileaceae and Salviniaceae). Hypotheses for relationships among the three genera of Marsileaceae (Marsilea, Regnellidium, and Pilularia), however, have continued to be in conflict. The phylogeny of Marsileaceae is investigated here using information from morphology and rbcL sequence data. In addition, relationships among all heterosporous ferns, including the whole-plant fossil Hydropteris pinnata are reconsidered. Data sets of 71 morphological and 1239 rbcL characters for 23 leptosporangiate ferns, including eight heterosporous ingroup taxa and 15 homosporous outgroup taxa, were subjected to maximum parsimony analysis. Morphological analyses were carried out both with and without the fossil Hydropteris, and it was excluded from all analyses with rbcL data. An annotated list of the 71 morphological characters is provided in the appendix. For comparative purposes, the Rothwell and Stockey (1994) data set was also reanalyzed here. The best estimate of phylogenetic relationships for Marsileaceae in all analyses is that Pilularia and Regnellidium are sister taxa and Marsilea is sister to that clade. Morphological synapomorphies for various nodes are discussed. Analyses that included Hydropteris resulted in two most-parsimonious trees that differ only in the placement of the fossil. One topology is identical to the relationship found by Rothwell and Stockey (1994), placing the fossil sister to the Azolla plus Salvinia clade. The alternative topology places Hydropteris as the most basal member of the heterosporous fern clade. Equivocal interpretations for character evolution in heterosporous ferns are discussed in the context of these two most-parsimonious trees. Because of the observed degree of character ambiguity, the phylogenetic placement of Hydropteris is best viewed as unresolved, and recognition of the

Type I STS markers are more informative than cytochrome B in phylogenetic reconstruction of the Mustelidae (Mammalia: Carnivora).

Science.gov (United States)

Koepfli, Klaus-Peter; Wayne, Robert K

2003-10-01

We compared the utility of five nuclear gene segments amplified with type I sequence-tagged site (STS) primers versus the complete mitochondrial cytochrome b (cyt b) gene in resolving phylogenetic relationships within the Mustelidae, a large and ecomorphologically diverse family of mammalian carnivores. Maximum parsimony and likelihood analyses of separate and combined data sets were used to address questions regarding the levels of homoplasy, incongruence, and information content within and among loci. All loci showed limited resolution in the separate analyses because of either a low amount of informative variation (nuclear genes) or high levels of homoplasy (cyt b). Individually or combined, the nuclear gene sequences had less homoplasy, retained more signal, and were more decisive, even though cyt b contained more potentially informative variation than all the nuclear sequences combined. We obtained a well-resolved and supported phylogeny when the nuclear sequences were combined. Maximum likelihood and Bayesian phylogenetic analyses of the total combined data (nuclear and mitochondrial DNA sequences) were able to better accommodate the high levels of homoplasy in the cyt b data than was an equally weighted maximum parsimony analysis. Furthermore, partition Bremer support analyses of the total combined tree showed that the relative support of the nuclear and mitochondrial genes differed according to whether or not the homoplasy in the cyt b gene was downweighted. Although the cyt b gene contributed phylogenetic signal for most major groupings, the nuclear gene sequences were more effective in reconstructing the deeper nodes of the combined tree in the equally weighted parsimony analysis, as judged by the variable-length bootstrap method. The total combined data supported the monophyly of the Lutrinae (otters), whereas the Melinae (badgers) and Mustelinae (weasels, martens) were both paraphyletic. The American badger, Taxidea taxus (Taxidiinae), was the most

Effect of solution composition on determination of uranium (6) microquantities by laser-induced luminescence method

International Nuclear Information System (INIS)

Romanovskaya, G.I.; Zakharova, G.V.; Chibisova, A.K.

1984-01-01

The effect of cation and anion composition of natural waters (sea water, ground water, etc.) on the uranium (6) determination in the form of uranyl complexes with Na 2 O3SiO 2 using the laser-induced luminescence method with the determination limit 2x10 -11 g/ml, has been studied. The dependence of the luminescence intensity of uranyl polysilicate complexes on the inorganic ion concentration has been measured. The measurement results permitted to determine the maximum permissible concentrations (MAC) of ions, the values of which are presented. The results reproducibility is characterized by a relative standard deveation within 0.01-0.05. It follows from the data analysis that the MPC of impurities vary from 10 -8 to 10 -2 g/ml. The MPCs of uranium as determined in the form of polysilicate complexes, are shown to be close to the values obtained during uranium determination in the form of complexes with fluoran for the CO 3 2- , Ni, Cu ions and they are by an order higher for the Na, K, Cl - , SO 4 2- , HPO 4 2- , Mn ions

Progenitor Epithelium

Science.gov (United States)

Marty-Santos, Leilani

2015-01-01

Insulin-producing β cells within the vertebrate fetal pancreas acquire their fate in a step-wise manner. Whereas the intrinsic factors dictating the transcriptional or epigenetic status of pancreatic lineages have been intensely examined, less is known about cell–cell interactions that might constitute a niche for the developing β cell lineage. It is becoming increasingly clear that understanding and recapitulating these steps may instruct in vitro differentiation of embryonic stem cells and/or therapeutic regeneration. Indeed, directed differentiation techniques have improved since transitioning from 2D to 3D cultures, suggesting that the 3D microenvironment in which β cells are born is critical. However, to date, it remains unknown whether the changing architecture of the pancreatic epithelium impacts the fate of cells therein. An emerging challenge in the field is to elucidate how progenitors are allocated during key events, such as the stratification and subsequent resolution of the pre-pancreatic epithelium, as well as the formation of lumens and branches. Here, we assess the progenitor epithelium and examine how it might influence the emergence of pancreatic multipotent progenitors (MPCs), which give rise to β cells and other pancreatic lineages. PMID:26216134

Mars Science Laboratory Flight Software Internal Testing

Science.gov (United States)

Jones, Justin D.; Lam, Danny

2011-01-01

The Mars Science Laboratory (MSL) team is sending the rover, Curiosity, to Mars, and therefore is physically and technically complex. During my stay, I have assisted the MSL Flight Software (FSW) team in implementing functional test scripts to ensure that the FSW performs to the best of its abilities. There are a large number of FSW requirements that have been written up for implementation; however I have only been assigned a few sections of these requirements. There are many stages within testing; one of the early stages is FSW Internal Testing (FIT). The FIT team can accomplish this with simulation software and the MSL Test Automation Kit (MTAK). MTAK has the ability to integrate with the Software Simulation Equipment (SSE) and the Mission Processing and Control System (MPCS) software which makes it a powerful tool within the MSL FSW development process. The MSL team must ensure that the rover accomplishes all stages of the mission successfully. Due to the natural complexity of this project there is a strong emphasis on testing, as failure is not an option. The entire mission could be jeopardized if something is overlooked.

Peracetic Acid Depolymerization of Biorefinery Lignin for Production of Selective Monomeric Phenolic Compounds

Energy Technology Data Exchange (ETDEWEB)

Ma, Ruoshui [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Guo, Mond [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Lin, Kuan-ting [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Hebert, Vincent R. [Food and Environmental Laboratory, Washington State, University-TriCities, 2710 Crimson Way Richland WA 99354 USA; Zhang, Jinwen [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Wolcott, Michael P. [Wood Materials and Engineering Laboratory, Washington State University, Pullman WA 99164 USA; Quintero, Melissa [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA; Ramasamy, Karthikeyan K. [Chemical and Biological Process Development Group, Pacific Northwest National Laboratory, Richland WA 99354 USA; Chen, Xiaowen [National Bioenergy Center, National Renewable Energy Lab, 1617 Cole Blvd Golden CO 80127 USA; Zhang, Xiao [Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science & Engineering Laboratory, Washington State University, 2710 Crimson Way Richland WA 99354 USA

2016-07-04

Lignin is the largest source of renewable material with an aromatic skeleton. However, due to the recalcitrant and heterogeneous nature of the lignin polymer as well as its complex side chain structures, it has been a challenge to effectively depolymerize lignin and produce high value chemicals with high selectivity. In this study, a highly efficient lignin-to-monomeric phenolic compounds (MPC) conversion method based on peracetic acid (PAA) treatment was reported. PAA treatment of two biorefinery lignin samples, diluted acid pretreated corn stover lignin (DACSL) and steam exploded spruce lignin (SESPL), led to complete solubilization and production of selective hydroxylated monomeric phenolic compounds (MPC-H) and monomeric phenolic acid compounds (MPC-A) inclduing 4-hydroxy-2-methoxyphenol, p-hydroxybenzoic acid, vanillic acid, syringic acid, and 3,4-dihydroxybenzoic acid. The maximized MPCs yields obtained were 18% and 22% based on the initial weight of the lignin in SESPL and DACSL respectively. However, we found that the addition of niobium pentoxide catalyst to PAA treatment of lignin can significantly improve the MPC yields up to 47%. The key reaction steps and main mechanisms involved in this new lignin-to-MPC valorization pathway were investigated and elucidated.

A bFGF-releasing silk/PLGA-based biohybrid scaffold for ligament/tendon tissue engineering using mesenchymal progenitor cells.

Science.gov (United States)

Sahoo, Sambit; Toh, Siew Lok; Goh, James C H

2010-04-01

An ideal scaffold that provides a combination of suitable mechanical properties along with biological signals is required for successful ligament/tendon regeneration in mesenchymal stem cell-based tissue engineering strategies. Among the various fibre-based scaffolds that have been used, hybrid fibrous scaffolds comprising both microfibres and nanofibres have been recently shown to be particularly promising. This study developed a biohybrid fibrous scaffold system by coating bioactive bFGF-releasing ultrafine PLGA fibres over mechanically robust slowly-degrading degummed knitted microfibrous silk scaffolds. On the ECM-like biomimetic architecture of ultrafine fibres, sustained release of bFGF mimicked the ECM in function, initially stimulating mesenchymal progenitor cell (MPC) proliferation, and subsequently, their tenogeneic differentiation. The biohybrid scaffold system not only facilitated MPC attachment and promoted cell proliferation, with cells growing both on ultrafine PLGA fibres and silk microfibres, but also stimulated tenogeneic differentiation of seeded MPCs. Upregulated gene expression of ligament/tendon-specific ECM proteins and increased collagen production likely contributed to enhancing mechanical properties of the constructs, generating a ligament/tendon analogue that has the potential to be used to repair injured ligaments/tendons. Copyright 2010 Elsevier Ltd. All rights reserved.

Impacts of the proposed program approach on waste stream characteristics

International Nuclear Information System (INIS)

King, J.F.; Fleming, M.E.

1995-01-01

The evolution of the U.S. Department of Energy's Civilian Radioactive Waste Management System (CRWMS) over the past few years has led to significant changes in key system scenario assumption. This paper describes the effects of two recent changes on waste stream characteristics focusing primarily on repository impacts. First, the multi-purpose canister (MPC) concept has been included in the Program baseline. The change from a bare fuel system to one including an MPC-based system forces the fuel assemblies initially loaded together in MPCs to remain together throughout the system. Second, current system analyses also assume a system without a monitored retrievable storage (MRS), with the understanding that an MRS would be reincorporated if a site becomes available. Together these two changes have significant impacts on waste stream characteristics. Those two changes create a class of scenarios referred to generally as Program Approach (PA) scenarios. Scenarios based on the previously assumed system, bare fuel with an MRS, are referred to here as the Previous Reference (PR) system scenarios. The analysis compares scenarios with otherwise consistent assumptions and presents summary comparisons. The number of disposal containers and the waste heat output are determined for eight PA and PR scenarios

Phylogeny of the Aplousobranchia (Tunicata: Ascidiacea Filogenia de Aplousobranchia (Tunicata: Ascidiacea

Directory of Open Access Journals (Sweden)

Tatiane R. Moreno

2008-06-01

Full Text Available The phylogenetic relationships of genera and families of Aplousobranchia Lahille (Tunicata, Ascidiacea is reconstructed based on morphological characters - the first comprehensive morphology-based phylogenetic analysis for the Aplousobranchia. Monophyly of Aplousobranchia and its families were tested with samples of 14 families. The final character matrix comprised 47 characters and 41 genera as terminal taxa. Nine equally most parsimonious trees (length 161, CI = 0.5031, RI = 0.7922 were found. Characters describing replication, colony system formation, and branchial walls were the more important in phylogenetic reconstruction. These characters were more useful than others more traditionally used in ascidian taxonomy, such as: body division, position of the heart, gonads and epicardium. Characters not frequently used in phylogenetic analysis, such as body wall muscles, muscles associated with transversal blood vessels and arrangement of the larval papillae, also have phylogenetic information. Results supported monophyly of the Aplousobranchia sensu Lahille, 1887 including only Polycitoridae, Polyclinidae, and Didemnidae. On the other hand, Aplousobranchia including also Cionidae and Diazonidae is not monophyletic since Perophora and Ecteinascidia were included as ingroups in the cladogram, Ciona (now closer to Ascidia was no longer included in Aplousobranchia and the position of Rhopalaea and Diazona is not resolved. We propose a revised classification based on this phylogenetic analysis, in which Aplousobranchia, with three new families and an indeterminate taxon, now has 15 families.O relacionamento filogenéticos de gêneros e famílias de de Aplousobranchia Lahille (Tunicata, Ascidiacea foi reconstruída com base em caracteres morfológicos - esta constitui a primeira análise filogenética morfológica abrangente para Aplousobranchia. A monofilia de Aplousobranchia e suas famílias foi testada com espécies de 14 famílias. A matriz final

Distribución geográfica del género Gyriosomus Guérin-Méneville, 1834 (Coleoptera: Tenebrionidae: una aproximación biogeográfica Geographical distribution of the genus Gyriosomus Guérin-Méneville, 1834 (Coleoptera: Tenebrionidae: a biogeographic approach

Directory of Open Access Journals (Sweden)

JAIME PIZARRO-ARAYA

2004-09-01

Full Text Available Se realizó un análisis de parsimonia de endemismo para el género Gyriosomus, taxón monofilético, erémico y endémico del norte de Chile. En este trabajo se evalúa (i si los patrones de distribución de las especies de Gyriosomus están determinados por la heterogeneidad del hábitat y (ii si que las discontinuidades distribucionales de los taxa reflejan áreas de endemismo. Para ello se determinaron áreas de endemismo para las especies de Gyriosomus, se relacionaron con formaciones vegetacionales, y se establecieron las relaciones biogeográficas entre los distintos ecosistemas descritos para el norte de Chile. El área de estudio correspondió a la distribución del género y fue dividida en cuadrículas de un cuarto de grado de latitud y medio grado de longitud; los datos de presencia o ausencia de las especies se registraron en una matriz, la que se analizó mediante los programas NONA 2.0 y Winclada. Un árbol de consenso estricto permitió establecer para Gyriosomus, un patrón de áreas anidadas, donde se reconocieron dos áreas de endemismo en los ecosistemas costeros de Paposo y Carrizal Bajo. Los ecosistemas de desierto costero de Huasco y Matorral estepario costero presentaron la mayor riqueza de especies de Gyriosomus. Un cladograma reveló una divergencia en el componente faunístico en dos unidades biogeográficas, el desierto costero y matorral estepario. Los resultados de este trabajo complementados con una reconstrucción filogenética del género podrían ser utilizados para entender los eventos vicariantes que explicarían las divergencias evolutivas de GyriosomusA parsimony analysis of areas of endemism for the monophyletic genus Gyriosomus, an eremic and endemic element of the northern coast of Chile, was performed. We tested that: (i distributional patterns of Gyriosomus species are determined by environmental heterogeneity, and that (ii discontinuities in the distribution of Gyriosomus species will reflect areas of

MEGA5: Molecular Evolutionary Genetics Analysis Using Maximum Likelihood, Evolutionary Distance, and Maximum Parsimony Methods

Science.gov (United States)

Tamura, Koichiro; Peterson, Daniel; Peterson, Nicholas; Stecher, Glen; Nei, Masatoshi; Kumar, Sudhir

2011-01-01

Comparative analysis of molecular sequence data is essential for reconstructing the evolutionary histories of species and inferring the nature and extent of selective forces shaping the evolution of genes and species. Here, we announce the release of Molecular Evolutionary Genetics Analysis version 5 (MEGA5), which is a user-friendly software for mining online databases, building sequence alignments and phylogenetic trees, and using methods of evolutionary bioinformatics in basic biology, biomedicine, and evolution. The newest addition in MEGA5 is a collection of maximum likelihood (ML) analyses for inferring evolutionary trees, selecting best-fit substitution models (nucleotide or amino acid), inferring ancestral states and sequences (along with probabilities), and estimating evolutionary rates site-by-site. In computer simulation analyses, ML tree inference algorithms in MEGA5 compared favorably with other software packages in terms of computational efficiency and the accuracy of the estimates of phylogenetic trees, substitution parameters, and rate variation among sites. The MEGA user interface has now been enhanced to be activity driven to make it easier for the use of both beginners and experienced scientists. This version of MEGA is intended for the Windows platform, and it has been configured for effective use on Mac OS X and Linux desktops. It is available free of charge from http://www.megasoftware.net. PMID:21546353

Enhancement of a parsimonious water balance model to simulate surface hydrology in a glacierized watershed

Science.gov (United States)

Valentin, Melissa M.; Viger, Roland J.; Van Beusekom, Ashley E.; Hay, Lauren E.; Hogue, Terri S.; Foks, Nathan Leon

2018-01-01

The U.S. Geological Survey monthly water balance model (MWBM) was enhanced with the capability to simulate glaciers in order to make it more suitable for simulating cold region hydrology. The new model, MWBMglacier, is demonstrated in the heavily glacierized and ecologically important Copper River watershed in Southcentral Alaska. Simulated water budget components compared well to satellite‐based observations and ground measurements of streamflow, evapotranspiration, snow extent, and total water storage, with differences ranging from 0.2% to 7% of the precipitation flux. Nash Sutcliffe efficiency for simulated and observed streamflow was greater than 0.8 for six of eight stream gages. Snow extent matched satellite‐based observations with Nash Sutcliffe efficiency values of greater than 0.89 in the four Copper River ecoregions represented. During the simulation period 1949 to 2009, glacier ice melt contributed 25% of total runoff, ranging from 12% to 45% in different tributaries, and glacierized area was reduced by 6%. Statistically significant (p < 0.05) decreasing and increasing trends in annual glacier mass balance occurred during the multidecade cool and warm phases of the Pacific Decadal Oscillation, respectively, reinforcing the link between climate perturbations and glacier mass balance change. The simulations of glaciers and total runoff for a large, remote region of Alaska provide useful data to evaluate hydrologic, cryospheric, ecologic, and climatic trends. MWBM glacier is a valuable tool to understand when, and to what extent, streamflow may increase or decrease as glaciers respond to a changing climate.

Motion adaptation leads to parsimonious encoding of natural optic flow by blowfly motion vision system

NARCIS (Netherlands)

Heitwerth, J.; Kern, R.; Hateren, J.H. van; Egelhaaf, M.

Neurons sensitive to visual motion change their response properties during prolonged motion stimulation. These changes have been interpreted as adaptive and were concluded, for instance, to adjust the sensitivity of the visual motion pathway to velocity changes or to increase the reliability of

A quantum theory of the mind-brain interface

Energy Technology Data Exchange (ETDEWEB)

Stapp, H.P.

1990-07-30

The Heisenberg quantum mechanical conception of nature is extended and applied to the brain. Strict adherence to the principle of parsimony, and to quantum thinking, produces naturally, on the basis of an overview of brain operation compatible with the information provided by the brain sciences, a unified description of the physical and mental aspects of nature that can account in principle for the full content of felt human experience. 33 refs.

House price responsiveness of housing investments across major European economies

OpenAIRE

Gattini, Luca; Ganoulis, Ioannis

2012-01-01

In comparison with the large literature on house prices, housing investments have been studied far less. This paper investigates the behaviour of private residential investments for the six largest European economies, namely: Germany, France, Italy, Spain, the Netherlands and the United Kingdom. It employs a common modelling structure based on an error correction approach and country specific models. First, co-integration among the parsimoniously specified set of fundamental variables is dete...

Fake It Until You Make It

DEFF Research Database (Denmark)

Mattsson, Jan; Standing, Craig

2016-01-01

have difficulty explaining their business model components we identified that critical features in our simplicity framework include three main modules, transaction/matching, marketing and back-office components, and simplicity in terms of value proposition, conceptualization approach and usability....... This research proposes that a parsimonious view of digital business models, aligned with the lean start-up idea, makes sense for theory development and in terms of usefulness for entrepreneurs....

Models of Thinking, Learning, and Teaching in Games

OpenAIRE

Colin Camerer; Teck Ho; Kuan Chong

2003-01-01

Noncooperative game theory combines strategic thinking, best-response, and mutual consistency of beliefs and choices (equilibrium). Hundreds of experiments show that in actual behavior these three forces are limited, even when subjects are highly motivated and analytically skilled (Camerer, 2003). The challenge is to create models that are as general, precise, and parsimonious as equilibrium, but which also use cognitive details to explain experimental evidence more accurately and to predict ...

A quantum theory of the mind-brain interface

International Nuclear Information System (INIS)

Stapp, H.P.

1990-01-01

The Heisenberg quantum mechanical conception of nature is extended and applied to the brain. Strict adherence to the principle of parsimony, and to quantum thinking, produces naturally, on the basis of an overview of brain operation compatible with the information provided by the brain sciences, a unified description of the physical and mental aspects of nature that can account in principle for the full content of felt human experience. 33 refs

Calculating the probability of multitaxon evolutionary trees: bootstrappers Gambit.

OpenAIRE

Lake, J A

1995-01-01

The reconstruction of multitaxon trees from molecular sequences is confounded by the variety of algorithms and criteria used to evaluate trees, making it difficult to compare the results of different analyses. A global method of multitaxon phylogenetic reconstruction described here, Bootstrappers Gambit, can be used with any four-taxon algorithm, including distance, maximum likelihood, and parsimony methods. It incorporates a Bayesian-Jeffreys'-bootstrap analysis to provide a uniform probabil...

Méthodes avancées pour la résolution du problème de maximum parcimonie

OpenAIRE

Vazquez Ortiz , Karla Esmeralda

2016-01-01

Phylogenetic reconstruction is considered a central underpinning of diverse fields like ecology, molecular biology and physiology where genealogical relationships of species or gene sequences represented as trees can provide the most meaningful insights into biology. Maximum Parsimony (MP) is an important approach to solve the phylogenetic reconstruction based on an optimality criterion under which the tree that minimizes the total number of genetic transformations is preferred. In this thesi...

A Range-Based Multivariate Model for Exchange Rate Volatility

OpenAIRE

Tims, Ben; Mahieu, Ronald

2003-01-01

textabstractIn this paper we present a parsimonious multivariate model for exchange rate volatilities based on logarithmic high-low ranges of daily exchange rates. The multivariate stochastic volatility model divides the log range of each exchange rate into two independent latent factors, which are interpreted as the underlying currency specific components. Due to the normality of logarithmic volatilities the model can be estimated conveniently with standard Kalman filter techniques. Our resu...

Predictive accuracy of the PanCan lung cancer risk prediction model - external validation based on CT from the Danish Lung Cancer Screening Trial

International Nuclear Information System (INIS)

Winkler Wille, Mathilde M.; Dirksen, Asger; Riel, Sarah J. van; Jacobs, Colin; Scholten, Ernst T.; Ginneken, Bram van; Saghir, Zaigham; Pedersen, Jesper Holst; Hohwue Thomsen, Laura; Skovgaard, Lene T.

2015-01-01

Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. From the DLCST database, 1,152 nodules from 718 participants were included. Parsimonious and full PanCan risk prediction models were applied to DLCST data, and also coefficients of the model were recalculated using DLCST data. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were used to evaluate risk discrimination. AUCs of 0.826-0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer; in fact opposing effects of sex were observed in the two cohorts. Thus, female sex appeared to lower the risk (p = 0.047 and p = 0.040) in the DLCST. High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were significant predictors and could be included in the parsimonious model. Sex appears to be a less useful predictor. (orig.)

A Biologically Inspired Computational Model of Basal Ganglia in Action Selection.

Science.gov (United States)

Baston, Chiara; Ursino, Mauro

2015-01-01

The basal ganglia (BG) are a subcortical structure implicated in action selection. The aim of this work is to present a new cognitive neuroscience model of the BG, which aspires to represent a parsimonious balance between simplicity and completeness. The model includes the 3 main pathways operating in the BG circuitry, that is, the direct (Go), indirect (NoGo), and hyperdirect pathways. The main original aspects, compared with previous models, are the use of a two-term Hebb rule to train synapses in the striatum, based exclusively on neuronal activity changes caused by dopamine peaks or dips, and the role of the cholinergic interneurons (affected by dopamine themselves) during learning. Some examples are displayed, concerning a few paradigmatic cases: action selection in basal conditions, action selection in the presence of a strong conflict (where the role of the hyperdirect pathway emerges), synapse changes induced by phasic dopamine, and learning new actions based on a previous history of rewards and punishments. Finally, some simulations show model working in conditions of altered dopamine levels, to illustrate pathological cases (dopamine depletion in parkinsonian subjects or dopamine hypermedication). Due to its parsimonious approach, the model may represent a straightforward tool to analyze BG functionality in behavioral experiments.

A Biologically Inspired Computational Model of Basal Ganglia in Action Selection

Directory of Open Access Journals (Sweden)

Chiara Baston

2015-01-01

Full Text Available The basal ganglia (BG are a subcortical structure implicated in action selection. The aim of this work is to present a new cognitive neuroscience model of the BG, which aspires to represent a parsimonious balance between simplicity and completeness. The model includes the 3 main pathways operating in the BG circuitry, that is, the direct (Go, indirect (NoGo, and hyperdirect pathways. The main original aspects, compared with previous models, are the use of a two-term Hebb rule to train synapses in the striatum, based exclusively on neuronal activity changes caused by dopamine peaks or dips, and the role of the cholinergic interneurons (affected by dopamine themselves during learning. Some examples are displayed, concerning a few paradigmatic cases: action selection in basal conditions, action selection in the presence of a strong conflict (where the role of the hyperdirect pathway emerges, synapse changes induced by phasic dopamine, and learning new actions based on a previous history of rewards and punishments. Finally, some simulations show model working in conditions of altered dopamine levels, to illustrate pathological cases (dopamine depletion in parkinsonian subjects or dopamine hypermedication. Due to its parsimonious approach, the model may represent a straightforward tool to analyze BG functionality in behavioral experiments.

Inferring Phylogenetic Networks Using PhyloNet.

Science.gov (United States)

Wen, Dingqiao; Yu, Yun; Zhu, Jiafan; Nakhleh, Luay

2018-07-01

PhyloNet was released in 2008 as a software package for representing and analyzing phylogenetic networks. At the time of its release, the main functionalities in PhyloNet consisted of measures for comparing network topologies and a single heuristic for reconciling gene trees with a species tree. Since then, PhyloNet has grown significantly. The software package now includes a wide array of methods for inferring phylogenetic networks from data sets of unlinked loci while accounting for both reticulation (e.g., hybridization) and incomplete lineage sorting. In particular, PhyloNet now allows for maximum parsimony, maximum likelihood, and Bayesian inference of phylogenetic networks from gene tree estimates. Furthermore, Bayesian inference directly from sequence data (sequence alignments or biallelic markers) is implemented. Maximum parsimony is based on an extension of the "minimizing deep coalescences" criterion to phylogenetic networks, whereas maximum likelihood and Bayesian inference are based on the multispecies network coalescent. All methods allow for multiple individuals per species. As computing the likelihood of a phylogenetic network is computationally hard, PhyloNet allows for evaluation and inference of networks using a pseudolikelihood measure. PhyloNet summarizes the results of the various analyzes and generates phylogenetic networks in the extended Newick format that is readily viewable by existing visualization software.

Genetic Diversity in Passiflora Species Assessed by Morphological and ITS Sequence Analysis

Directory of Open Access Journals (Sweden)

Shiamala Devi Ramaiya

2014-01-01

Full Text Available This study used morphological characterization and phylogenetic analysis of the internal transcribed spacer (ITS region of nuclear ribosomal DNA to investigate the phylogeny of Passiflora species. The samples were collected from various regions of East Malaysia, and discriminant function analysis based on linear combinations of morphological variables was used to classify the Passiflora species. The biplots generated five distinct groups discriminated by morphological variables. The group consisted of cultivars of P. edulis with high levels of genetic similarity; in contrast, P. foetida was highly divergent from other species in the morphological biplots. The final dataset of aligned sequences from nine studied Passiflora accessions and 30 other individuals obtained from GenBank database (NCBI yielded one most parsimonious tree with two strongly supported clades. Maximum parsimony (MP tree showed the phylogenetic relationships within this subgenus Passiflora support the classification at the series level. The constructed phylogenic tree also confirmed the divergence of P. foetida from all other species and the closeness of wild and cultivated species. The phylogenetic relationships were consistent with results of morphological assessments. The results of this study indicate that ITS region analysis represents a useful tool for evaluating genetic diversity in Passiflora at the species level.

Reconstruction of ancestral RNA sequences under multiple structural constraints

Directory of Open Access Journals (Sweden)

Olivier Tremblay-Savard

2016-11-01

Full Text Available Abstract Background Secondary structures form the scaffold of multiple sequence alignment of non-coding RNA (ncRNA families. An accurate reconstruction of ancestral ncRNAs must use this structural signal. However, the inference of ancestors of a single ncRNA family with a single consensus structure may bias the results towards sequences with high affinity to this structure, which are far from the true ancestors. Methods In this paper, we introduce achARNement, a maximum parsimony approach that, given two alignments of homologous ncRNA families with consensus secondary structures and a phylogenetic tree, simultaneously calculates ancestral RNA sequences for these two families. Results We test our methodology on simulated data sets, and show that achARNement outperforms classical maximum parsimony approaches in terms of accuracy, but also reduces by several orders of magnitude the number of candidate sequences. To conclude this study, we apply our algorithms on the Glm clan and the FinP-traJ clan from the Rfam database. Conclusions Our results show that our methods reconstruct small sets of high-quality candidate ancestors with better agreement to the two target structures than with classical approaches. Our program is freely available at: http://csb.cs.mcgill.ca/acharnement .

Replicate phylogenies and post-glacial range expansion of the pitcher-plant mosquito, Wyeomyia smithii, in North America.

Directory of Open Access Journals (Sweden)

Clayton Merz

Full Text Available Herein we tested the repeatability of phylogenetic inference based on high throughput sequencing by increased taxon sampling using our previously published techniques in the pitcher-plant mosquito, Wyeomyia smithii in North America. We sampled 25 natural populations drawn from different localities nearby 21 previous collection localities and used these new data to construct a second, independent phylogeny, expressly to test the reproducibility of phylogenetic patterns. Comparison of trees between the two data sets based on both maximum parsimony and maximum likelihood with Bayesian posterior probabilities showed close correspondence in the grouping of the most southern populations into clear clades. However, discrepancies emerged, particularly in the middle of W. smithii's current range near the previous maximum extent of the Laurentide Ice Sheet, especially concerning the most recent common ancestor to mountain and northern populations. Combining all 46 populations from both studies into a single maximum parsimony tree and taking into account the post-glacial historical biogeography of associated flora provided an improved picture of W. smithii's range expansion in North America. In a more general sense, we propose that extensive taxon sampling, especially in areas of known geological disruption is key to a comprehensive approach to phylogenetics that leads to biologically meaningful phylogenetic inference.

Nonparametric Fine Tuning of Mixtures: Application to Non-Life Insurance Claims Distribution Estimation

Science.gov (United States)

Sardet, Laure; Patilea, Valentin

When pricing a specific insurance premium, actuary needs to evaluate the claims cost distribution for the warranty. Traditional actuarial methods use parametric specifications to model claims distribution, like lognormal, Weibull and Pareto laws. Mixtures of such distributions allow to improve the flexibility of the parametric approach and seem to be quite well-adapted to capture the skewness, the long tails as well as the unobserved heterogeneity among the claims. In this paper, instead of looking for a finely tuned mixture with many components, we choose a parsimonious mixture modeling, typically a two or three-component mixture. Next, we use the mixture cumulative distribution function (CDF) to transform data into the unit interval where we apply a beta-kernel smoothing procedure. A bandwidth rule adapted to our methodology is proposed. Finally, the beta-kernel density estimate is back-transformed to recover an estimate of the original claims density. The beta-kernel smoothing provides an automatic fine-tuning of the parsimonious mixture and thus avoids inference in more complex mixture models with many parameters. We investigate the empirical performance of the new method in the estimation of the quantiles with simulated nonnegative data and the quantiles of the individual claims distribution in a non-life insurance application.

Cohesion, team mental models, and collective efficacy: towards an integrated framework of team dynamics in sport.

Science.gov (United States)

Filho, Edson; Tenenbaum, Gershon; Yang, Yanyun

2015-01-01

A nomological network on team dynamics in sports consisting of a multiframework perspective is introduced and tested. The aim was to explore the interrelationship among cohesion, team mental models (TMMs), collective efficacy (CE) and perceived performance potential (PPP). Three hundred and forty college-aged soccer players representing 17 different teams (8 female and 9 male) participated in the study. They responded to surveys on team cohesion, TMMs, CE and PPP. Results are congruent with the theoretical conceptualisation of a parsimonious view of team dynamics in sports. Specifically, cohesion was found to be an exogenous variable predicting both TMMs and CE beliefs. TMMs and CE were correlated and predicted PPP, which in turn accounted for 59% of the variance of objective performance scores as measured by teams' season record. From a theoretical standpoint, findings resulted in a parsimonious view of team dynamics, which may represent an initial step towards clarifying the epistemological roots and nomological network of various team-level properties. From an applied standpoint, results suggest that team expertise starts with the establishment of team cohesion. Following the establishment of cohesiveness, teammates are able to advance team-related schemas and a collective sense of confidence. Limitations and key directions for future research are outlined.

Predictive accuracy of the PanCan lung cancer risk prediction model - external validation based on CT from the Danish Lung Cancer Screening Trial

Energy Technology Data Exchange (ETDEWEB)

Winkler Wille, Mathilde M.; Dirksen, Asger [Gentofte Hospital, Department of Respiratory Medicine, Hellerup (Denmark); Riel, Sarah J. van; Jacobs, Colin; Scholten, Ernst T.; Ginneken, Bram van [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Saghir, Zaigham [Herlev Hospital, Department of Respiratory Medicine, Herlev (Denmark); Pedersen, Jesper Holst [Copenhagen University Hospital, Department of Thoracic Surgery, Rigshospitalet, Koebenhavn Oe (Denmark); Hohwue Thomsen, Laura [Hvidovre Hospital, Department of Respiratory Medicine, Hvidovre (Denmark); Skovgaard, Lene T. [University of Copenhagen, Department of Biostatistics, Koebenhavn Oe (Denmark)

2015-10-15

Lung cancer risk models should be externally validated to test generalizability and clinical usefulness. The Danish Lung Cancer Screening Trial (DLCST) is a population-based prospective cohort study, used to assess the discriminative performances of the PanCan models. From the DLCST database, 1,152 nodules from 718 participants were included. Parsimonious and full PanCan risk prediction models were applied to DLCST data, and also coefficients of the model were recalculated using DLCST data. Receiver operating characteristics (ROC) curves and area under the curve (AUC) were used to evaluate risk discrimination. AUCs of 0.826-0.870 were found for DLCST data based on PanCan risk prediction models. In the DLCST, age and family history were significant predictors (p = 0.001 and p = 0.013). Female sex was not confirmed to be associated with higher risk of lung cancer; in fact opposing effects of sex were observed in the two cohorts. Thus, female sex appeared to lower the risk (p = 0.047 and p = 0.040) in the DLCST. High risk discrimination was validated in the DLCST cohort, mainly determined by nodule size. Age and family history of lung cancer were significant predictors and could be included in the parsimonious model. Sex appears to be a less useful predictor. (orig.)

Intraspecific variations in Cyt b and D-loop sequences of Testudine species, Lissemys punctata from south Karnataka

Directory of Open Access Journals (Sweden)

R. Lalitha

2018-01-01

Full Text Available The freshwater Testudine species have gained importance in recent years, as most of their population is threatened due to exploitation for delicacy and pet trade. In this regard, Lissemys punctata, a freshwater terrapin, predominantly distributed in Asian countries has gained its significance for the study. A pilot study report on mitochondrial markers (Cyt b and D-loop conducted on L. punctata species from southern Karnataka, India was presented in this investigation. A complete region spanning 1.14 kb and ∼1 kb was amplified by HotStart PCR and sequenced by Sanger sequencing. The Cyt b sequence revealed 85 substitution sites, no indels and 17 parsimony informative sites, whereas D-loop showed 189 variable sites, 51 parsimony informative sites with 5′ functional domains TAS, CSB-F, CSBs (1, 2, 3 preceding tandem repeat at 3′ end. Current data highlights the intraspecific variations in these target regions and variations validated using suitable evolutionary models points out that the overall point mutations observed in the region are transitions leading to no structural and functional alterations. The mitochondrial data generated uncover the genetic diversity within species and conservationist can utilize the data to estimate the effective population size or for forensic identification of animal or its seizures during unlawful trade activities.

Population genetics of four heavily exploited shark species around the Arabian Peninsula

KAUST Repository

Spaet, Julia L.Y.

2015-05-01

The northwestern Indian Ocean harbors a number of larger marine vertebrate taxa that warrant the investigation of genetic population structure given remarkable spatial heterogeneity in biological characteristics such as distribution, behavior, and morphology. Here, we investigate the genetic population structure of four commercially exploited shark species with different biological characteristics (Carcharhinus limbatus, Carcharhinus sorrah, Rhizoprionodon acutus, and Sphyrna lewini) between the Red Sea and all other water bodies surrounding the Arabian Peninsula. To assess intraspecific patterns of connectivity, we constructed statistical parsimony networks among haplotypes and estimated (1) population structure; and (2) time of most recent population expansion, based on mitochondrial control region DNA and a total of 20 microsatellites. Our analysis indicates that, even in smaller, less vagile shark species, there are no contemporary barriers to gene flow across the study region, while historical events, for example, Pleistocene glacial cycles, may have affected connectivity in C. sorrah and R. acutus. A parsimony network analysis provided evidence that Arabian S. lewini may represent a population segment that is distinct from other known stocks in the Indian Ocean, raising a new layer of conservation concern. Our results call for urgent regional cooperation to ensure the sustainable exploitation of sharks in the Arabian region.

Revision of the cicada genus Dilobopyga (Hemiptera, Cicadidae) from Sulawesi and the Moluccas.

Science.gov (United States)

Duffels, J P

2018-04-13

This revision of the cicadas of the genus Dilobopyga provides a diagnosis of the genus and descriptions, illustrations and distribution maps for 48 species. The following 33 species described here are new to science: D. angulata, angustata, bifida, curvispina, fasciata, hayashii, hollowayi, johani, knighti, langeraki, laterocurvata, latifascia, luwukensis, macrocerata, maleo, mamasa, mediolobata, nebulosa, operculata, palopoensis, pelengensis, platyacantha, quadrimaculata, rantemario, recurvata, rozendaali, sangihensis, sarasinorum, splendida, tambusisi, toraja, vantoli and watuwila. The key presented is designed for the identification of males of Dilobopyga to the species level. The subdivision of the genus in five species groups viz., opercularis group (17 species), nebulosa group (1 species), chlorogaster group (16 species), minahassae group (6 species) and watuwila group (8 species), is sustained by a phylogenetic analysis of morphological characters of all species described.        The cicadas of the genus Dilobopyga are found in Sulawesi, neighbouring islands and southern Moluccas. Of the 48 species of Dilobopyga 43 species are endemic to Sulawesi. Most of these Sulawesi species are restricted to either one peninsula or to a part of Central Sulawesi. The remaining five species are endemic to either the Sangihe Islands, Banggai Islands or the southern Moluccas. A taxon-area cladogram for the species of Dilobopyga provides a basis for a discussion on the historic biogeography of the genus.

Pollen morphology of some asiatic species of genus salsola (chenopodiaceae) and its taxonomic relationships

International Nuclear Information System (INIS)

Toderich, K.N.; Shuyskaya, E.V.; Ozturk, M

2010-01-01

Comparative studies on the pollen grain morphology of 27 Asiatic species of the genus Salsola were conducted by using scanning electron microscope (SEM analysis) in order to assess the taxonomic value of pollen traits. The pollen are radially symmetrical isopolar, pantopolyporate, spherical or subspheroid. The pollen characters like size, pore number, chord (C/D ratio), pore diameter, exine thickness, level of sinking of pore, convexness of mesoporial exine, spinule and minute-hole densities and number of spines on pore membrane appeared to be useful characters in distinguishing the species. Interesting intraspecific variations in pollen grain morphology were recorded for the C/D ratio. This parameter is highly specific, supporting the delimitation of Salsola species, and appears to be more conservative than some flower and fruit characters. The numerical value of form index comprising the ratio between the length of polar axis and diameter (P/E) also was an informative trait for delimitation of the species investigated here. Three pollen types were recognized. Euclidean distance was used to compute the dissimilarity matrix and a cladogram prepared. The quantitative characters of pollen morphology allowed clustering of groups and ordination analyses of species from different sections/subsections within genus Salsola. These features indicated that overall pollen traits reflect the current taxonomic boundaries, except for the Salsola species allocated to Climacoptera and Halothamnus, which should be accepted as separate genera. (author)

Bayesian accounts and black swans: Questioning the erotetic theory of delusional thinking.

Science.gov (United States)

McKay, Ryan

2015-01-01

Parrott and Koralus argue that a particular cognitive factor--"impaired endogenous question raising"--offers a parsimonious account of three delusion-related phenomena: (1) the development of the Capgras delusion; (2) evidence that patients with schizophrenia outperform healthy control participants on a conditional reasoning task; and (3) evidence that deluded individuals "jump to conclusions". In this response, I assess these claims, and raise my own questions about the "erotetic" theory of delusional thinking.

Cointegrating MiDaS Regressions and a MiDaS Test

OpenAIRE

J. Isaac Miller

2011-01-01

This paper introduces cointegrating mixed data sampling (CoMiDaS) regressions, generalizing nonlinear MiDaS regressions in the extant literature. Under a linear mixed-frequency data-generating process, MiDaS regressions provide a parsimoniously parameterized nonlinear alternative when the linear forecasting model is over-parameterized and may be infeasible. In spite of potential correlation of the error term both serially and with the regressors, I find that nonlinear least squares consistent...

Job durations and the job search model : a two-country, multi-sample analysis

OpenAIRE

Bagger, Jesper; Henningsen, Morten

2008-01-01

Abstract: This paper assesses whether a parsimonious partial equilibrium job search model with on-the-job search can reproduce observed job durations and transitions to other jobs and to nonemployment. We allow for unobserved heterogeneity across individuals in key structural parameters. Observed heterogeneity and life cycle effects are accounted for by estimating separate models for flow samples of labor market entrants and stock samples of “mature” workers with 10-11 years of...

A Molecular Phylogeny of Anopheles Annulipes (Diptera: Culicidae) sensu lato: The Most Species-Rich Anopheline Complex

Science.gov (United States)

2006-09-27

Maximum parsimony; Sibling species; Species complex; Myxomatosis ; DNA barcoding; Australia; Papua New Guinea; ITS2; COI; COII; EF-11. Introduction... myxomatosis to con- trol rabbits (Fenner and RatcliVe, 1965). Chris Green used data from cross-matings and the band- ing pattern of polytene chromosomes to... myxomatosis based on distribution but more sam- pling is required to conWrm this. Many of the sampling locations in this study and the allozyme study of

Modélisation en bosses pour l'analyse de motifs oscillatoires reproductibles dans l'activité de populations neuronales: applications à l'apprentissage olfactif chez l'animal et à la détection précoce de la maladie d'Alzheimer

OpenAIRE

Vialatte , François Benoît

2005-01-01

The method presented here, namely « bump modeling », provides a simple representation of time-frequency maps obtained by wavelet transformation of signals; the representation is parsimonious in terms of number of parameters. Time-frequency features can be extracted from the resulting models, which allows (i) a statistical analysis of large sets of signal recordings, and (ii) the detection of reproducible time-frequency patterns. We apply that method to the analysis of electrophysiological sig...

Phylogenetic Analysis of a ?Jewel Orchid? Genus Goodyera (Orchidaceae) Based on DNA Sequence Data from Nuclear and Plastid Regions

OpenAIRE

Hu, Chao; Tian, Huaizhen; Li, Hongqing; Hu, Aiqun; Xing, Fuwu; Bhattacharjee, Avishek; Hsu, Tianchuan; Kumar, Pankaj; Chung, Shihwen

2016-01-01

A molecular phylogeny of Asiatic species of Goodyera (Orchidaceae, Cranichideae, Goodyerinae) based on the nuclear ribosomal internal transcribed spacer (ITS) region and two chloroplast loci (matK and trnL-F) was presented. Thirty-five species represented by 132 samples of Goodyera were analyzed, along with other 27 genera/48 species, using Pterostylis longifolia and Chloraea gaudichaudii as outgroups. Bayesian inference, maximum parsimony and maximum likelihood methods were used to reveal th...

Phylogenetic inferences of Nepenthes species in Peninsular Malaysia revealed by chloroplast (trnL intron) and nuclear (ITS) DNA sequences

OpenAIRE

Bunawan, Hamidun; Yen, Choong Chee; Yaakop, Salmah; Noor, Normah Mohd

2017-01-01

Background The chloroplastic trnL intron and the nuclear internal transcribed spacer (ITS) region were sequenced for 11 Nepenthes species recorded in Peninsular Malaysia to examine their phylogenetic relationship and to evaluate the usage of trnL intron and ITS sequences for phylogenetic reconstruction of this genus. Results Phylogeny reconstruction was carried out using neighbor-joining, maximum parsimony and Bayesian analyses. All the trees revealed two major clusters, a lowland group consi...

Inferring species trees from incongruent multi-copy gene trees using the Robinson-Foulds distance

Science.gov (United States)

2013-01-01

Background Constructing species trees from multi-copy gene trees remains a challenging problem in phylogenetics. One difficulty is that the underlying genes can be incongruent due to evolutionary processes such as gene duplication and loss, deep coalescence, or lateral gene transfer. Gene tree estimation errors may further exacerbate the difficulties of species tree estimation. Results We present a new approach for inferring species trees from incongruent multi-copy gene trees that is based on a generalization of the Robinson-Foulds (RF) distance measure to multi-labeled trees (mul-trees). We prove that it is NP-hard to compute the RF distance between two mul-trees; however, it is easy to calculate this distance between a mul-tree and a singly-labeled species tree. Motivated by this, we formulate the RF problem for mul-trees (MulRF) as follows: Given a collection of multi-copy gene trees, find a singly-labeled species tree that minimizes the total RF distance from the input mul-trees. We develop and implement a fast SPR-based heuristic algorithm for the NP-hard MulRF problem. We compare the performance of the MulRF method (available at http://genome.cs.iastate.edu/CBL/MulRF/) with several gene tree parsimony approaches using gene tree simulations that incorporate gene tree error, gene duplications and losses, and/or lateral transfer. The MulRF method produces more accurate species trees than gene tree parsimony approaches. We also demonstrate that the MulRF method infers in minutes a credible plant species tree from a collection of nearly 2,000 gene trees. Conclusions Our new phylogenetic inference method, based on a generalized RF distance, makes it possible to quickly estimate species trees from large genomic data sets. Since the MulRF method, unlike gene tree parsimony, is based on a generic tree distance measure, it is appealing for analyses of genomic data sets, in which many processes such as deep coalescence, recombination, gene duplication and losses as

A supermatrix analysis of genomic, morphological, and paleontological data from crown Cetacea

Directory of Open Access Journals (Sweden)

Yang Guang

2011-04-01

Full Text Available Abstract Background Cetacea (dolphins, porpoises, and whales is a clade of aquatic species that includes the most massive, deepest diving, and largest brained mammals. Understanding the temporal pattern of diversification in the group as well as the evolution of cetacean anatomy and behavior requires a robust and well-resolved phylogenetic hypothesis. Although a large body of molecular data has accumulated over the past 20 years, DNA sequences of cetaceans have not been directly integrated with the rich, cetacean fossil record to reconcile discrepancies among molecular and morphological characters. Results We combined new nuclear DNA sequences, including segments of six genes (~2800 basepairs from the functionally extinct Yangtze River dolphin, with an expanded morphological matrix and published genomic data. Diverse analyses of these data resolved the relationships of 74 taxa that represent all extant families and 11 extinct families of Cetacea. The resulting supermatrix (61,155 characters and its sub-partitions were analyzed using parsimony methods. Bayesian and maximum likelihood (ML searches were conducted on the molecular partition, and a molecular scaffold obtained from these searches was used to constrain a parsimony search of the morphological partition. Based on analysis of the supermatrix and model-based analyses of the molecular partition, we found overwhelming support for 15 extant clades. When extinct taxa are included, we recovered trees that are significantly correlated with the fossil record. These trees were used to reconstruct the timing of cetacean diversification and the evolution of characters shared by "river dolphins," a non-monophyletic set of species according to all of our phylogenetic analyses. Conclusions The parsimony analysis of the supermatrix and the analysis of morphology constrained to fit the ML/Bayesian molecular tree yielded broadly congruent phylogenetic hypotheses. In trees from both analyses, all Oligocene

A supermatrix analysis of genomic, morphological, and paleontological data from crown Cetacea

Science.gov (United States)

2011-01-01

Background Cetacea (dolphins, porpoises, and whales) is a clade of aquatic species that includes the most massive, deepest diving, and largest brained mammals. Understanding the temporal pattern of diversification in the group as well as the evolution of cetacean anatomy and behavior requires a robust and well-resolved phylogenetic hypothesis. Although a large body of molecular data has accumulated over the past 20 years, DNA sequences of cetaceans have not been directly integrated with the rich, cetacean fossil record to reconcile discrepancies among molecular and morphological characters. Results We combined new nuclear DNA sequences, including segments of six genes (~2800 basepairs) from the functionally extinct Yangtze River dolphin, with an expanded morphological matrix and published genomic data. Diverse analyses of these data resolved the relationships of 74 taxa that represent all extant families and 11 extinct families of Cetacea. The resulting supermatrix (61,155 characters) and its sub-partitions were analyzed using parsimony methods. Bayesian and maximum likelihood (ML) searches were conducted on the molecular partition, and a molecular scaffold obtained from these searches was used to constrain a parsimony search of the morphological partition. Based on analysis of the supermatrix and model-based analyses of the molecular partition, we found overwhelming support for 15 extant clades. When extinct taxa are included, we recovered trees that are significantly correlated with the fossil record. These trees were used to reconstruct the timing of cetacean diversification and the evolution of characters shared by "river dolphins," a non-monophyletic set of species according to all of our phylogenetic analyses. Conclusions The parsimony analysis of the supermatrix and the analysis of morphology constrained to fit the ML/Bayesian molecular tree yielded broadly congruent phylogenetic hypotheses. In trees from both analyses, all Oligocene taxa included in our

Sequencing of whole plastid genomes and nuclear ribosomal DNA of Diospyros species (Ebenaceae) endemic to New Caledonia: many species, little divergence.

Science.gov (United States)

Turner, Barbara; Paun, Ovidiu; Munzinger, Jérôme; Chase, Mark W; Samuel, Rosabelle

2016-06-01

Some plant groups, especially on islands, have been shaped by strong ancestral bottlenecks and rapid, recent radiation of phenotypic characters. Single molecular markers are often not informative enough for phylogenetic reconstruction in such plant groups. Whole plastid genomes and nuclear ribosomal DNA (nrDNA) are viewed by many researchers as sources of information for phylogenetic reconstruction of groups in which expected levels of divergence in standard markers are low. Here we evaluate the usefulness of these data types to resolve phylogenetic relationships among closely related Diospyros species. Twenty-two closely related Diospyros species from New Caledonia were investigated using whole plastid genomes and nrDNA data from low-coverage next-generation sequencing (NGS). Phylogenetic trees were inferred using maximum parsimony, maximum likelihood and Bayesian inference on separate plastid and nrDNA and combined matrices. The plastid and nrDNA sequences were, singly and together, unable to provide well supported phylogenetic relationships among the closely related New Caledonian Diospyros species. In the nrDNA, a 6-fold greater percentage of parsimony-informative characters compared with plastid DNA was found, but the total number of informative sites was greater for the much larger plastid DNA genomes. Combining the plastid and nuclear data improved resolution. Plastid results showed a trend towards geographical clustering of accessions rather than following taxonomic species. In plant groups in which multiple plastid markers are not sufficiently informative, an investigation at the level of the entire plastid genome may also not be sufficient for detailed phylogenetic reconstruction. Sequencing of complete plastid genomes and nrDNA repeats seems to clarify some relationships among the New Caledonian Diospyros species, but the higher percentage of parsimony-informative characters in nrDNA compared with plastid DNA did not help to resolve the phylogenetic tree

Perceptual interaction between carrier periodicity and amplitude modulation in broadband stimuli: A comparison of the autocorrelation and modulation-filterbank model

DEFF Research Database (Denmark)

Stein, A.; Ewert, Stephan; Wiegrebe, L.

2005-01-01

, autocorrelation is applied. Considering the large overlap in pitch and modulation perception, this is not parsimonious. Two experiments are presented to investigate the interaction between carrier periodicity, which produces strong pitch sensations, and envelope periodicity using broadband stimuli. Results show......Recent temporal models of pitch and amplitude modulation perception converge on a relatively realistic implementation of cochlear processing followed by a temporal analysis of periodicity. However, for modulation perception, a modulation filterbank is applied whereas for pitch perception...

Molecular phylogeny of ateline new world monkeys (Platyrrhini, atelinae) based on gamma-globin gene sequences: evidence that brachyteles is the sister group of lagothrix.

Science.gov (United States)

Meireles, C M; Czelusniak, J; Schneider, M P; Muniz, J A; Brigido, M C; Ferreira, H S; Goodman, M

1999-06-01

Nucleotide sequences, each spanning approximately 7 kb of the contiguous gamma1 and gamma2 globin genomic loci, were determined for seven species representing all extant genera (Ateles, Lagothrix, Brachyteles, and Alouatta) of the New World monkey subfamily Atelinae. After aligning these seven ateline sequences with outgroup sequences from several other primate (non-ateline) genera, they were analyzed by maximum parsimony, maximum likelihood, and neighbor-joining algorithms. All three analyzes estimated the same phylogenetic relationships: [Alouatta [Ateles (Brachyteles, Lagothrix)

Possibility of dying as a unified explanation of why we discount the future, get weaker with age, and display risk-aversion.

Science.gov (United States)

Chowdhry, Bhagwan

2011-01-01

I formulate a simple and parsimonious evolutionary model that shows that because most species face a possibility of dying because of external factors, called extrinsic mortality in the biology literature, it can simultaneously explain (a) why we discount the future, (b) get weaker with age, and (c) display risk-aversion. The paper suggests that testable restrictions—across species, across time, or across genders—among time preference, aging, and risk-aversion could be analyzed in a simple framework .

A Rational Model of the Closed-End Fund Discount

OpenAIRE

Jonathan Berk; Richard Stanton

2004-01-01

The discount on closed-end funds is widely accepted as proof of investor irrationality. We show,however, that a parsimonious rational model can generate a discount that exhibits many of the characteristics observed in practice. The only required features of the model are that managers have (imperfectly observable) ability to generate excess returns; they sign long-term contracts guaranteeing them a fee each year equal to a fixed fraction of assets under management; and they can leave to earn ...

A state-dependent model for inflation forecasting

OpenAIRE

Andrea Stella; James H. Stock

2012-01-01

We develop a parsimonious bivariate model of inflation and unemployment that allows for persistent variation in trend inflation and the NAIRU. The model, which consists of five unobserved components (including the trends) with stochastic volatility, implies a time-varying VAR for changes in the rates of inflation and unemployment. The implied backwards-looking Phillips curve has a time-varying slope that is steeper in the 1970s than in the 1990s. Pseudo out-of-sample forecasting experiments i...

MassSieve: Panning MS/MS peptide data for proteins

OpenAIRE

Slotta, Douglas J.; McFarland, Melinda A.; Markey, Sanford P.

2010-01-01

We present MassSieve, a Java-based platform for visualization and parsimony analysis of single and comparative LC-MS/MS database search engine results. The success of mass spectrometric peptide sequence assignment algorithms has led to the need for a tool to merge and evaluate the increasing data set sizes that result from LC-MS/MS-based shotgun proteomic experiments. MassSieve supports reports from multiple search engines with differing search characteristics, which can increase peptide sequ...

The health hump

OpenAIRE

Strulik, Holger

2015-01-01

In this paper, I suggest a novel explanation for a hump-shaped ageconsumption profile, based on human aging. The model integrates health in the utility function and utilizes recent estimates on the effects of health on the marginal utility of consumption. The parsimonious model has a closed-form solution for the age of peak consumption and the consumption level at that age relative to initial consumption. A calibration of the model with data from gerontology produces an empirically plausible ...

an empirical investigation of the drivers of international strategic alliance formation

OpenAIRE

Nielsen, Bo B.

2003-01-01

Using data from a web-survey of Danish partner firms engaged in international strategic alliances, this study explores the factors that drive alliance formation between two specific firms across national borders. The relative importance of a set of partner selection criteria is identified and related to extant theory. By means of exploratory factor analysis, a more parsimonious set of selection criteria is provided and their relationships to a number of characteristics of the sample – prior i...

[Reconstruction of the phylogenetic position of larch (Larix sukaczewii Dylis) by sequencing data for the trnK intron of chloroplast DNA].

Science.gov (United States)

Bashalkhanov, S I; Konstantinov, Iu M; Verbitskiĭ, D S; Kobzev, V F

2003-10-01

To reconstruct the systematic relationships of larch Larix sukaczewii, we used the chloroplast trnK intron sequences of L. decidua, L. sukaczewii, L. sibirica, L. czekanovskii, and L. gmelinii. Analysis of phylogenetic trees constructed using the maximum parsimony and maximum likelihood methods showed a clear divergence of the trnK intron sequences between L. sukaczewii and L. sibirica. This divergence reaches intraspecific level, which supports a previously published hypothesis on the taxonomic isolation of L. sukaczewii.

Reconstruction of ancestral RNA sequences under multiple structural constraints

OpenAIRE

Tremblay-Savard, Olivier; Reinharz, Vladimir; Waldisp?hl, J?r?me

2016-01-01

Background Secondary structures form the scaffold of multiple sequence alignment of non-coding RNA (ncRNA) families. An accurate reconstruction of ancestral ncRNAs must use this structural signal. However, the inference of ancestors of a single ncRNA family with a single consensus structure may bias the results towards sequences with high affinity to this structure, which are far from the true ancestors. Methods In this paper, we introduce achARNement, a maximum parsimony approach that, given...

Big data to optimise product strategy in electronic industry

OpenAIRE

Khan, Nawaz; Lakshmi Sabih, Vijay; Georgiadou, Elli; Repanovich, Angela

2016-01-01

This research identifies the success factors for new product development and competitive advantage as well as argues how big data can expedite the process of launching a new product initiative. By combining the research findings and the patterns of background theories, an inquisitive framework for the new product development and competitive advantage is proposed. This model and framework is a prototype, which with the aid of scenario recommends the parsimonious and an unified way to elucidate...

Ultra Fast and Parsimonious Materials Screening for Polymer Solar Cells Using Differentially Pumped Slot-Die Coating

DEFF Research Database (Denmark)

Alstrup, Jan; Jørgensen, Mikkel; Medford, Andrew James

2010-01-01

and materials usage by variation of the layer thickness in small steps of 1.5−4 nm. Contrary to expectation we did not find oscillatory variation of the device performance with device thickness because of optical interference. We ascribe this to the nature of the solar cell type explored in this example...

Parsimonious Structural Equation Models for Repeated Measures Data, with Application to the Study of Consumer Preferences

Science.gov (United States)

Elrod, Terry; Haubl, Gerald; Tipps, Steven W.

2012-01-01

Recent research reflects a growing awareness of the value of using structural equation models to analyze repeated measures data. However, such data, particularly in the presence of covariates, often lead to models that either fit the data poorly, are exceedingly general and hard to interpret, or are specified in a manner that is highly data…

Energy Utilization for Survival and Fertilization-Parsimonious Quiescent Sperm Turn Extravagant on Motility Activation in Rat.

Science.gov (United States)

Kumar, Lokesh; Yadav, Santosh K; Kushwaha, Bhavana; Pandey, Aastha; Sharma, Vikas; Verma, Vikas; Maikhuri, Jagdamba P; Rajender, Singh; Sharma, Vishnu L; Gupta, Gopal

2016-04-01

Quiescent sperm survive in cauda epididymis for long periods of time under extreme crowding conditions and with a very limited energy substrate, while after ejaculation, motile sperm live for a much shorter period with an unlimited energy resource and without crowding. Thus, the energy metabolism in relation to the energy requirement of the two may be quite different. A simple physiological technique was evolved to collect viable quiescent sperm from rat cauda epididymis to compare its energy metabolism with motile sperm. Quiescent sperm exhibited 40%-60% higher activities of mitochondrial electron transport chain complexes I-IV and ATP synthase in comparison to motile sperm and accumulated Ca(2+) in the midpiece mitochondria to enhance oxidative phosphorylation (OxPhos). In contrast, motile sperm displayed up to 75% higher activities of key glycolytic enzymes and secreted more than two times the lactate than quiescent sperm. Quiescent sperm phosphorylated AMPK and MAPK-p38, while motile sperm phosphorylated AKT and MAPK/ERK. Glycolytic inhibitor iodoacetamide prevented motility activation of quiescent rat sperm and inhibited conception in rabbits more effectively than OxPhos uncoupler 2,4-dinitrophenol. Apparently, quiescent sperm employ the most energy efficient OxPhos to survive for extended periods of time under extreme conditions of nutrition and crowding. However, on motility initiation, sperm switch predominantly to glycolysis to cater to their high- and quick-energy requirement of much shorter periods. This study also presents a proof of concept for targeting sperm energy metabolism for contraception. © 2016 by the Society for the Study of Reproduction, Inc.

A Model Predictive Control-Based Power Converter System for Oscillating Water Column Wave Energy Converters

Directory of Open Access Journals (Sweden)

Gimara Rajapakse

2017-10-01

Full Text Available Despite the predictability and availability at large scale, wave energy conversion (WEC has still not become a mainstream renewable energy technology. One of the main reasons is the large variations in the extracted power which could lead to instabilities in the power grid. In addition, maintaining the speed of the turbine within optimal range under changing wave conditions is another control challenge, especially in oscillating water column (OWC type WEC systems. As a solution to the first issue, this paper proposes the direct connection of a battery bank into the dc-link of the back-to-back power converter system, thereby smoothening the power delivered to the grid. For the second issue, model predictive controllers (MPCs are developed for the rectifier and the inverter of the back-to-back converter system aiming to maintain the turbine speed within its optimum range. In addition, MPC controllers are designed to control the battery current as well, in both charging and discharging conditions. Operations of the proposed battery direct integration scheme and control solutions are verified through computer simulations. Simulation results show that the proposed integrated energy storage and control solutions are capable of delivering smooth power to the grid while maintaining the turbine speed within its optimum range under varying wave conditions.

Highly ordered three-dimensional macroporous carbon spheres for determination of heavy metal ions

International Nuclear Information System (INIS)

Zhang, Yuxiao; Zhang, Jianming; Liu, Yang; Huang, Hui; Kang, Zhenhui

2012-01-01

Highlights: ► Highly ordered three dimensional macroporous carbon spheres (MPCSs) were prepared. ► MPCS was covalently modified by cysteine (MPCS–CO–Cys). ► MPCS–CO–Cys was first time used in electrochemical detection of heavy metal ions. ► Heavy metal ions such as Pb 2+ and Cd 2+ can be simultaneously determined. -- Abstract: An effective voltammetric method for detection of trace heavy metal ions using chemically modified highly ordered three dimensional macroporous carbon spheres electrode surfaces is described. The highly ordered three dimensional macroporous carbon spheres were prepared by carbonization of glucose in silica crystal bead template, followed by removal of the template. The highly ordered three dimensional macroporous carbon spheres were covalently modified by cysteine, an amino acid with high affinities towards some heavy metals. The materials were characterized by physical adsorption of nitrogen, scanning electron microscopy, and transmission electron microscopy techniques. While the Fourier-transform infrared spectroscopy was used to characterize the functional groups on the surface of carbon spheres. High sensitivity was exhibited when this material was used in electrochemical detection (square wave anodic stripping voltammetry) of heavy metal ions due to the porous structure. And the potential application for simultaneous detection of heavy metal ions was also investigated.

Genetic optimization of magneto-optic Kerr effect in lossy cavity-type magnetophotonic crystals

Energy Technology Data Exchange (ETDEWEB)

Ghanaatshoar, M., E-mail: m-ghanaat@cc.sbu.ac.i [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Evin 1983963113, Tehran (Iran, Islamic Republic of); Alisafaee, H. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Evin 1983963113, Tehran (Iran, Islamic Republic of)

2011-07-15

We have demonstrated an optimization approach in order to obtain desired magnetophotonic crystals (MPCs) composed of a lossy magnetic layer (TbFeCo) placed within a multilayer structure. The approach is an amalgamation between a 4x4 transfer matrix method and a genetic algorithm. Our objective is to enhance the magneto-optic Kerr effect of TbFeCo at short visible wavelength of 405 nm. Through the optimization approach, MPC structures are found meeting definite criteria on the amount of reflectivity and Kerr rotation. The resulting structures are fitted more than 99.9% to optimization criteria. Computation of the internal electric field distribution shows energy localization in the vicinity of the magnetic layer, which is responsible for increased light-matter interaction and consequent enhanced magneto-optic Kerr effect. Versatility of our approach is also exhibited by examining and optimizing several MPC structures. - Research highlights: Structures comprising a highly absorptive TbFeCo layer are designed to work for data storage applications at 405 nm. Optimization algorithm resulted in structures fitted 99.9% to design criteria. More than 10 structures are found exhibiting magneto-optical response of about 1{sup o} rotation and 20% reflection. The ratio of the Kerr rotation to the Kerr ellipticity is enhanced by a factor of 30.