Portfolio Selection with Jumps under Regime Switching

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Lin Zhao

2010-01-01

Full Text Available We investigate a continuous-time version of the mean-variance portfolio selection model with jumps under regime switching. The portfolio selection is proposed and analyzed for a market consisting of one bank account and multiple stocks. The random regime switching is assumed to be independent of the underlying Brownian motion and jump processes. A Markov chain modulated diffusion formulation is employed to model the problem.

Loss and gain of function in SERPINB11: an example of a gene under selection on standing variation, with implications for host-pathogen interactions.

Directory of Open Access Journals (Sweden)

Susana Seixas

Full Text Available Serine protease inhibitors (SERPINs are crucial in the regulation of diverse biological processes including inflammation and immune response. SERPINB11, located in the 18q21 gene cluster, is a polymorphic gene/pseudogene coding for a non-inhibitory SERPIN. In a genome-wide scan for recent selection, SERPINB11 was identified as a potential candidate gene for adaptive evolution in Yoruba. The present study sought a better understanding of the evolutionary history of SERPINB11, with special focus on evaluating its selective signature. Through the resequencing of coding and noncoding regions of SERPINB11 in 20 Yorubans and analyzing primate orthologous sequences, we identified a full-length SERPINB11 variant encoding a non-inhibitory SERPIN as the putative candidate of selection--probably driven to higher frequencies by an adaptive response using preexisting variation. In addition, we detected contrasting evolutionary features of SERPINB11 in primates: While primate phylogeny as a whole is under purifying selection, the human lineage shows evidence of positive selection in a few codons, all associated with the active SERPINB11. Comparative modeling studies suggest that positively selected codons reduce SERPINB11's ability to undergo the conformational changes typical of inhibitory SERPINs--suggesting that it is evolving towards a new non-inhibitory function in humans. Significant correlations between SERPINB11 variants and the environmental variables, pastoralism and pathogen richness, have led us to propose a selective advantage through host-pathogen interactions, possibly linked to an adaptive response combating the emergence of infectious diseases in recent human evolution. This work represents the first description of a resurrected gene in humans, and may well exemplify selection on standing variation triggered by drastic ecological shifts.

Molecular interaction of selected phytochemicals under the charged environment of Plasmodium falciparum chloroquine resistance transporter (PfCRT) model.

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Patel, Saumya K; Khedkar, Vijay M; Jha, Prakash C; Jasrai, Yogesh T; Pandya, Himanshu A; George, Linz-Buoy; Highland, Hyacinth N; Skelton, Adam A

2016-01-01

Phytochemicals of Catharanthus roseus Linn. and Tylophora indica have been known for their inhibition of malarial parasite, Plasmodium falciparum in cell culture. Resistance to chloroquine (CQ), a widely used antimalarial drug, is due to the CQ resistance transporter (CRT) system. The present study deals with computational modeling of Plasmodium falciparum chloroquine resistance transporter (PfCRT) protein and development of charged environment to mimic a condition of resistance. The model of PfCRT was developed using Protein homology/analogy engine (PHYRE ver 0.2) and was validated based on the results obtained using PSI-PRED. Subsequently, molecular interactions of selected phytochemicals extracted from C. roseus Linn. and T. indica were studied using multiple-iterated genetic algorithm-based docking protocol in order to investigate the translocation of these legends across the PfCRT protein. Further, molecular dynamics studies exhibiting interaction energy estimates of these compounds within the active site of the protein showed that compounds are more selective toward PfCRT. Clusters of conformations with the free energy of binding were estimated which clearly demonstrated the potential channel and by this means the translocation across the PfCRT is anticipated.

Selection of peptides interfering with protein-protein interaction.

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Gaida, Annette; Hagemann, Urs B; Mattay, Dinah; Räuber, Christina; Müller, Kristian M; Arndt, Katja M

2009-01-01

Cell physiology depends on a fine-tuned network of protein-protein interactions, and misguided interactions are often associated with various diseases. Consequently, peptides, which are able to specifically interfere with such adventitious interactions, are of high interest for analytical as well as medical purposes. One of the most abundant protein interaction domains is the coiled-coil motif, and thus provides a premier target. Coiled coils, which consist of two or more alpha-helices wrapped around each other, have one of the simplest interaction interfaces, yet they are able to confer highly specific homo- and heterotypic interactions involved in virtually any cellular process. While there are several ways to generate interfering peptides, the combination of library design with a powerful selection system seems to be one of the most effective and promising approaches. This chapter guides through all steps of such a process, starting with library options and cloning, detailing suitable selection techniques and ending with purification for further down-stream characterization. Such generated peptides will function as versatile tools to interfere with the natural function of their targets thereby illuminating their down-stream signaling and, in general, promoting understanding of factors leading to specificity and stability in protein-protein interactions. Furthermore, peptides interfering with medically relevant proteins might become important diagnostics and therapeutics.

Genes under positive selection in Escherichia coli

DEFF Research Database (Denmark)

Petersen, Lise; Bollback, Jonathan P; Dimmic, Matt

2007-01-01

We used a comparative genomics approach to identify genes that are under positive selection in six strains of Escherichia coli and Shigella flexneri, including five strains that are human pathogens. We find that positive selection targets a wide range of different functions in the E. coli genome......, including cell surface proteins such as beta barrel porins, presumably because of the involvement of these genes in evolutionary arms races with other bacteria, phages, and/or the host immune system. Structural mapping of positively selected sites on trans-membrane beta barrel porins reveals...... that the residues under positive selection occur almost exclusively in the extracellular region of the proteins that are enriched with sites known to be targets of phages, colicins, or the host immune system. More surprisingly, we also find a number of other categories of genes that show very strong evidence...

Introgression of a Block of Genome Under Infinitesimal Selection.

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Sachdeva, Himani; Barton, Nicholas H

2018-06-12

Adaptive introgression is common in nature and can be driven by selection acting on multiple, linked genes. We explore the effects of polygenic selection on introgression under the infinitesimal model with linkage. This model assumes that the introgressing block has an effectively infinite number of loci, each with an infinitesimal effect on the trait under selection. The block is assumed to introgress under directional selection within a native population that is genetically homogeneous. We use individual-based simulations and a branching process approximation to compute various statistics of the introgressing block, and explore how these depend on parameters such as the map length and initial trait value associated with the introgressing block, the genetic variability along the block, and the strength of selection. Our results show that the introgression dynamics of a block under infinitesimal selection are qualitatively different from the dynamics of neutral introgression. We also find that in the long run, surviving descendant blocks are likely to have intermediate lengths, and clarify how their length is shaped by the interplay between linkage and infinitesimal selection. Our results suggest that it may be difficult to distinguish the long-term introgression of a block of genome with a single strongly selected locus from the introgression of a block with multiple, tightly linked and weakly selected loci. Copyright © 2018, Genetics.

Dynamic interactions between visual working memory and saccade target selection

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Schneegans, Sebastian; Spencer, John P.; Schöner, Gregor; Hwang, Seongmin; Hollingworth, Andrew

2014-01-01

Recent psychophysical experiments have shown that working memory for visual surface features interacts with saccadic motor planning, even in tasks where the saccade target is unambiguously specified by spatial cues. Specifically, a match between a memorized color and the color of either the designated target or a distractor stimulus influences saccade target selection, saccade amplitudes, and latencies in a systematic fashion. To elucidate these effects, we present a dynamic neural field model in combination with new experimental data. The model captures the neural processes underlying visual perception, working memory, and saccade planning relevant to the psychophysical experiment. It consists of a low-level visual sensory representation that interacts with two separate pathways: a spatial pathway implementing spatial attention and saccade generation, and a surface feature pathway implementing color working memory and feature attention. Due to bidirectional coupling between visual working memory and feature attention in the model, the working memory content can indirectly exert an effect on perceptual processing in the low-level sensory representation. This in turn biases saccadic movement planning in the spatial pathway, allowing the model to quantitatively reproduce the observed interaction effects. The continuous coupling between representations in the model also implies that modulation should be bidirectional, and model simulations provide specific predictions for complementary effects of saccade target selection on visual working memory. These predictions were empirically confirmed in a new experiment: Memory for a sample color was biased toward the color of a task-irrelevant saccade target object, demonstrating the bidirectional coupling between visual working memory and perceptual processing. PMID:25228628

Dynamic interactions between visual working memory and saccade target selection.

Science.gov (United States)

Schneegans, Sebastian; Spencer, John P; Schöner, Gregor; Hwang, Seongmin; Hollingworth, Andrew

2014-09-16

Recent psychophysical experiments have shown that working memory for visual surface features interacts with saccadic motor planning, even in tasks where the saccade target is unambiguously specified by spatial cues. Specifically, a match between a memorized color and the color of either the designated target or a distractor stimulus influences saccade target selection, saccade amplitudes, and latencies in a systematic fashion. To elucidate these effects, we present a dynamic neural field model in combination with new experimental data. The model captures the neural processes underlying visual perception, working memory, and saccade planning relevant to the psychophysical experiment. It consists of a low-level visual sensory representation that interacts with two separate pathways: a spatial pathway implementing spatial attention and saccade generation, and a surface feature pathway implementing color working memory and feature attention. Due to bidirectional coupling between visual working memory and feature attention in the model, the working memory content can indirectly exert an effect on perceptual processing in the low-level sensory representation. This in turn biases saccadic movement planning in the spatial pathway, allowing the model to quantitatively reproduce the observed interaction effects. The continuous coupling between representations in the model also implies that modulation should be bidirectional, and model simulations provide specific predictions for complementary effects of saccade target selection on visual working memory. These predictions were empirically confirmed in a new experiment: Memory for a sample color was biased toward the color of a task-irrelevant saccade target object, demonstrating the bidirectional coupling between visual working memory and perceptual processing. © 2014 ARVO.

Social Interactions under Incomplete Information: Games, Equilibria, and Expectations

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Yang, Chao

Interactions under Incomplete Information", is an application of the first chapter to censored outcomes, corresponding to the situation when agents" behaviors are subjected to some binding restrictions. In an interesting empirical analysis for property tax rates set by North Carolina municipal governments, it is found that there is a significant positive correlation among near-by municipalities. Additionally, some private information about its own residents is used by a municipal government to predict others' tax rates, which enriches current empirical work about tax competition. The third chapter, "Social Interactions under Incomplete Information with Multiple Equilibria", extends the first chapter by investigating effective estimation methods when the condition for a unique equilibrium may not be satisfied. With multiple equilibria, the previous model is incomplete due to the unobservable equilibrium selection. Neither conventional likelihoods nor moment conditions can be used to estimate parameters without further specifications. Although there are some solutions to this issue in the current literature, they are based on strong assumptions such as agents with the same observable characteristics play the same strategy. This paper relaxes those assumptions and extends the all-solution method used to estimate discrete choice games to a setting with both discrete and continuous choices, bounded and unbounded outcomes, and a general form of incomplete information, where the existence of a pure strategy equilibrium has been an open question for a long time. By the use of differential topology and functional analysis, it is found that when all exogenous characteristics are public information, there are a finite number of equilibria. With privately known exogenous characteristics, the equilbria can be represented by a compact set in a Banach space and be approximated by a finite set. As a result, a finite-state probability mass function can be used to specify a probability measure

How and when predictability interacts with accentuation in temporally selective attention during speech comprehension.

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Li, Xiaoqing; Lu, Yong; Zhao, Haiyan

2014-11-01

The present study used EEG to investigate how and when top-down prediction interacts with bottom-up acoustic signals in temporally selective attention during speech comprehension. Mandarin Chinese spoken sentences were used as stimuli. We systematically manipulated the predictability and de/accentuation of the critical words in the sentence context. Meanwhile, a linguistic attention probe 'ba' was presented concurrently with the critical words or not. The results showed that, first, words with a linguistic attention probe elicited a larger N1 than those without a probe. The latency of this N1 effect was shortened for accented or lowly predictable words, indicating more attentional resources allocated to these words. Importantly, prediction and accentuation showed a complementary interplay on the latency of this N1 effect, demonstrating that when the words had already attracted attention due to low predictability or due to the presence of pitch accent, the other factor did not modulate attention allocation anymore. Second, relative to the lowly predictable words, the highly predictable words elicited a reduced N400 and enhanced gamma-band power increases, especially under the accented conditions; moreover, under the accented conditions, shorter N1 peak-latency was found to correlate with larger gamma-band power enhancement, which indicates that a close relationship might exist between early selective attention and later semantic integration. Finally, the interaction between top-down selective attention (driven by prediction) and bottom-up selective attention (driven by accentuation) occurred before lexical-semantic processing, namely before the N400 effect evoked by predictability, which was discussed with regard to the language comprehension models. Copyright © 2014 Elsevier Ltd. All rights reserved.

Selecting personnel to work on the interactive graphics system

International Nuclear Information System (INIS)

Norton, F.J.

1979-01-01

The paper established criteria for the selection of personnel to work on the interactive graphics system and mentions some of human behavioral patterns that are created by the implementation of graphic systems. Some of the social and educational problems associated with the interactive graphics system will be discussed. The project also provided for collecting objective data which would be useful in assessing the benefits of interactive graphics systems

Selecting personnel to work on the interactive graphics system

Energy Technology Data Exchange (ETDEWEB)

Norton, F.J.

1979-11-30

The paper established criteria for the selection of personnel to work on the interactive graphics system and mentions some of human behavioral patterns that are created by the implementation of graphic systems. Some of the social and educational problems associated with the interactive graphics system will be discussed. The project also provided for collecting objective data which would be useful in assessing the benefits of interactive graphics systems.

Possible mechanisms underlying bacterial-viral interactions in ...

African Journals Online (AJOL)

Materials and method: For this review, PubMed and Google search engines were used to select about 45 publications on bacterial-viral interactions in respiratory conditions. Studies on animal models were also included in the review. The publications were compared and summarized using a narrative review approach and ...

An Interaction Measure for Control Configuration Selection for Multivariable Bilinear Systems

DEFF Research Database (Denmark)

Shaker, Hamid Reza; Stoustrup, Jakob

2013-01-01

are needed to be controlled, are nonlinear and linear models are insufficient to describe the behavior of the processes. The focus of this paper is on the problem of control configuration selection for a class of nonlinear systems which is known as bilinear systems. A gramian-based interaction measure...... for control configuration selection of MIMO bilinear processes is described. In general, most of the results on the control configuration selection, which have been proposed so far, can only support linear systems. The proposed gramian-based interaction measure not only supports bilinear processes but also...

The temporal distribution of directional gradients under selection for an optimum.

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Chevin, Luis-Miguel; Haller, Benjamin C

2014-12-01

Temporal variation in phenotypic selection is often attributed to environmental change causing movements of the adaptive surface relating traits to fitness, but this connection is rarely established empirically. Fluctuating phenotypic selection can be measured by the variance and autocorrelation of directional selection gradients through time. However, the dynamics of these gradients depend not only on environmental changes altering the fitness surface, but also on evolution of the phenotypic distribution. Therefore, it is unclear to what extent variability in selection gradients can inform us about the underlying drivers of their fluctuations. To investigate this question, we derive the temporal distribution of directional gradients under selection for a phenotypic optimum that is either constant or fluctuates randomly in various ways in a finite population. Our analytical results, combined with population- and individual-based simulations, show that although some characteristic patterns can be distinguished, very different types of change in the optimum (including a constant optimum) can generate similar temporal distributions of selection gradients, making it difficult to infer the processes underlying apparent fluctuating selection. Analyzing changes in phenotype distributions together with changes in selection gradients should prove more useful for inferring the mechanisms underlying estimated fluctuating selection. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

CpG islands undermethylation in human genomic regions under selective pressure.

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Sergio Cocozza

Full Text Available DNA methylation at CpG islands (CGIs is one of the most intensively studied epigenetic mechanisms. It is fundamental for cellular differentiation and control of transcriptional potential. DNA methylation is involved also in several processes that are central to evolutionary biology, including phenotypic plasticity and evolvability. In this study, we explored the relationship between CpG islands methylation and signatures of selective pressure in Homo Sapiens, using a computational biology approach. By analyzing methylation data of 25 cell lines from the Encyclopedia of DNA Elements (ENCODE Consortium, we compared the DNA methylation of CpG islands in genomic regions under selective pressure with the methylation of CpG islands in the remaining part of the genome. To define genomic regions under selective pressure, we used three different methods, each oriented to provide distinct information about selective events. Independently of the method and of the cell type used, we found evidences of undermethylation of CGIs in human genomic regions under selective pressure. Additionally, by analyzing SNP frequency in CpG islands, we demonstrated that CpG islands in regions under selective pressure show lower genetic variation. Our findings suggest that the CpG islands in regions under selective pressure seem to be somehow more "protected" from methylation when compared with other regions of the genome.

Bayesian Model Selection under Time Constraints

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Hoege, M.; Nowak, W.; Illman, W. A.

2017-12-01

Bayesian model selection (BMS) provides a consistent framework for rating and comparing models in multi-model inference. In cases where models of vastly different complexity compete with each other, we also face vastly different computational runtimes of such models. For instance, time series of a quantity of interest can be simulated by an autoregressive process model that takes even less than a second for one run, or by a partial differential equations-based model with runtimes up to several hours or even days. The classical BMS is based on a quantity called Bayesian model evidence (BME). It determines the model weights in the selection process and resembles a trade-off between bias of a model and its complexity. However, in practice, the runtime of models is another weight relevant factor for model selection. Hence, we believe that it should be included, leading to an overall trade-off problem between bias, variance and computing effort. We approach this triple trade-off from the viewpoint of our ability to generate realizations of the models under a given computational budget. One way to obtain BME values is through sampling-based integration techniques. We argue with the fact that more expensive models can be sampled much less under time constraints than faster models (in straight proportion to their runtime). The computed evidence in favor of a more expensive model is statistically less significant than the evidence computed in favor of a faster model, since sampling-based strategies are always subject to statistical sampling error. We present a straightforward way to include this misbalance into the model weights that are the basis for model selection. Our approach follows directly from the idea of insufficient significance. It is based on a computationally cheap bootstrapping error estimate of model evidence and is easy to implement. The approach is illustrated in a small synthetic modeling study.

A competitive interaction theory of attentional selection and decision making in brief, multielement displays.

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Smith, Philip L; Sewell, David K

2013-07-01

We generalize the integrated system model of Smith and Ratcliff (2009) to obtain a new theory of attentional selection in brief, multielement visual displays. The theory proposes that attentional selection occurs via competitive interactions among detectors that signal the presence of task-relevant features at particular display locations. The outcome of the competition, together with attention, determines which stimuli are selected into visual short-term memory (VSTM). Decisions about the contents of VSTM are made by a diffusion-process decision stage. The selection process is modeled by coupled systems of shunting equations, which perform gated where-on-what pathway VSTM selection. The theory provides a computational account of key findings from attention tasks with near-threshold stimuli. These are (a) the success of the MAX model of visual search and spatial cuing, (b) the distractor homogeneity effect, (c) the double-target detection deficit, (d) redundancy costs in the post-stimulus probe task, (e) the joint item and information capacity limits of VSTM, and (f) the object-based nature of attentional selection. We argue that these phenomena are all manifestations of an underlying competitive VSTM selection process, which arise as a natural consequence of our theory. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Control configuration selection for bilinear systems via generalised Hankel interaction index array

DEFF Research Database (Denmark)

Shaker, Hamid Reza; Tahavori, Maryamsadat

2015-01-01

configuration selection. It is well known that a suitable control configuration selection is an important prerequisite for a successful industrial control. In this paper the problem of control configuration selection for multiple-input and multiple-output (MIMO) bilinear processes is addressed. First...... way, an iterative method for solving the generalised Sylvester equation is proposed. The generalised cross-gramian is used to form the generalised Hankel interaction index array. The generalised Hankel interaction index array is used for control configuration selection of MIMO bilinear processes. Most......Decentralised and partially decentralised control strategies are very popular in practice. To come up with a suitable decentralised or partially decentralised control structure, it is important to select the appropriate input and output pairs for control design. This procedure is called control...

Structural Insights into Selective Ligand-Receptor Interactions Leading to Receptor Inactivation Utilizing Selective Melanocortin 3 Receptor Antagonists.

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Cai, Minying; Marelli, Udaya Kiran; Mertz, Blake; Beck, Johannes G; Opperer, Florian; Rechenmacher, Florian; Kessler, Horst; Hruby, Victor J

2017-08-15

Systematic N-methylated derivatives of the melanocortin receptor ligand, SHU9119, lead to multiple binding and functional selectivity toward melanocortin receptors. However, the relationship between N-methylation-induced conformational changes in the peptide backbone and side chains and melanocortin receptor selectivity is still unknown. We conducted comprehensive conformational studies in solution of two selective antagonists of the third isoform of the melanocortin receptor (hMC3R), namely, Ac-Nle-c[Asp-NMe-His 6 -d-Nal(2') 7 -NMe-Arg 8 -Trp 9 -Lys]-NH 2 (15) and Ac-Nle-c[Asp-His 6 -d-Nal(2') 7 -NMe-Arg 8 -NMe-Trp 9 -NMe-Lys]-NH 2 (17). It is known that the pharmacophore (His 6 -DNal 7 -Arg 8 -Trp 9 ) of the SHU-9119 peptides occupies a β II-turn-like region with the turn centered about DNal 7 -Arg 8 . The analogues with hMC3R selectivity showed distinct differences in the spatial arrangement of the Trp 9 side chains. In addition to our NMR studies, we also carried out molecular-level interaction studies of these two peptides at the homology model of hMC3R. Earlier chimeric human melanocortin 3 receptor studies revealed insights regarding the binding and functional sites of hMC3R selectivity. Upon docking of peptides 15 and 17 to the binding pocket of hMC3R, it was revealed that Arg 8 and Trp 9 side chains are involved in a majority of the interactions with the receptor. While Arg 8 forms polar contacts with D154 and D158 of hMC3R, Trp 9 utilizes π-π stacking interactions with F295 and F298, located on the transmembrane domain of hMC3R. It is hypothesized that as the frequency of Trp 9 -hMC3R interactions decrease, antagonistic activity increases. The absence of any interactions of the N-methyl groups with hMC3R suggests that their primary function is to modulate backbone conformations of the ligands.

Improving Classification of Protein Interaction Articles Using Context Similarity-Based Feature Selection.

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Chen, Yifei; Sun, Yuxing; Han, Bing-Qing

2015-01-01

Protein interaction article classification is a text classification task in the biological domain to determine which articles describe protein-protein interactions. Since the feature space in text classification is high-dimensional, feature selection is widely used for reducing the dimensionality of features to speed up computation without sacrificing classification performance. Many existing feature selection methods are based on the statistical measure of document frequency and term frequency. One potential drawback of these methods is that they treat features separately. Hence, first we design a similarity measure between the context information to take word cooccurrences and phrase chunks around the features into account. Then we introduce the similarity of context information to the importance measure of the features to substitute the document and term frequency. Hence we propose new context similarity-based feature selection methods. Their performance is evaluated on two protein interaction article collections and compared against the frequency-based methods. The experimental results reveal that the context similarity-based methods perform better in terms of the F1 measure and the dimension reduction rate. Benefiting from the context information surrounding the features, the proposed methods can select distinctive features effectively for protein interaction article classification.

Plasma–Surface Interactions Under High Heat and Particle Fluxes

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Gregory De Temmerman

2013-01-01

Full Text Available The plasma-surface interactions expected in the divertor of a future fusion reactor are characterized by extreme heat and particle fluxes interacting with the plasma-facing surfaces. Powerful linear plasma generators are used to reproduce the expected plasma conditions and allow plasma-surface interactions studies under those very harsh conditions. While the ion energies on the divertor surfaces of a fusion device are comparable to those used in various plasma-assited deposition and etching techniques, the ion (and energy fluxes are up to four orders of magnitude higher. This large upscale in particle flux maintains the surface under highly non-equilibrium conditions and bring new effects to light, some of which will be described in this paper.

Alleles versus genotypes: Genetic interactions and the dynamics of selection in sexual populations

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Neher, Richard

2010-03-01

Physical interactions between amino-acids are essential for protein structure and activity, while protein-protein interactions and regulatory interactions are central to cellular function. As a consequence of these interactions, the combined effect of two mutations can differ from the sum of the individual effects of the mutations. This phenomenon of genetic interaction is known as epistasis. However, the importance of epistasis and its effects on evolutionary dynamics are poorly understood, especially in sexual populations where recombination breaks up existing combinations of alleles to produce new ones. Here, we present a computational model of selection dynamics involving many epistatic loci in a recombining population. We demonstrate that a large number of polymorphic interacting loci can, despite frequent recombination, exhibit cooperative behavior that locks alleles into favorable genotypes leading to a population consisting of a set of competing clones. As the recombination rate exceeds a certain critical value this ``genotype selection'' phase disappears in an abrupt transition giving way to ``allele selection'' - the phase where different loci are only weakly correlated as expected in sexually reproducing populations. Clustering of interacting sets of genes on a chromosome leads to the emergence of an intermediate regime, where localized blocks of cooperating alleles lock into genetic modules. Large populations attain highest fitness at a recombination rate just below critical, suggesting that natural selection might tune recombination rates to balance the beneficial aspect of exploration of genotype space with the breaking up of synergistic allele combinations.

The interaction between diamond like carbon (DLC coatings and ionic liquids under boundary lubrication conditions

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K. Milewski

2017-01-01

Full Text Available The aim of the study was to analyse antiwear DLC coatings produced by physical vapour deposition. The a-C:H coatings were deposited on steel elements designed to operate under friction conditions. The coating structure was studied by observing the surface topography with a scanning electron microscope (SEM and a profilometer. The friction and wear properties of the coatings were examined using a ball-on-disc tribotester. The lubricants tested were two types of ionic liquids (1-butyl-3-methylimidazolium tetrafluoroborate and trihexyltetradecylphosphonium bis(trifluoromethy-lsulphonyl amide. The experimental data was used to select ionic liquids with the best tribological properties to operate under lubricated friction conditions and interact with DLC coatings.

Tips for Teachers Selecting Toys to Facilitate Social Interaction

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Vail, Cynthia O.; Elmore, Shannon Renee

2011-01-01

Toy selection is an important role for early childhood teachers. This research-to-practice article describes what research tells us about how toys can affect the social interactions and communication of young children including those with developmental delays.

Context-Aware HCI Service Selection

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Yao Shen

2012-01-01

Full Text Available Context-awareness has become a key issue in Human-Computer Interaction(HCI to provide better user experience under multi-device and multi-modal environment. With this intuition, we have proposed a web service based framework, which associates interactions with services, and provided service selection mechanism using context knowledge to achieve smart interaction migration [1]. A fundamental problem of such a service-oriented framework for interaction migration is to design an effective while scalable algorithm for service selection. In this paper, we propose a service selection algorithm considering not only context information and user preferences but also inter-service relations such as relative location. Our algorithm detects interaction hot spots within user active scope and presents the best service combination based on evaluation of interaction effectiveness. We also conduct simulation and the results illustrate that our algorithm is effective and scalable for interaction service selection.

Characterization of selective solar absorber under high vacuum.

Science.gov (United States)

Russo, Roberto; Monti, Matteo; di Giamberardino, Francesco; Palmieri, Vittorio G

2018-05-14

Total absorption and emission coefficients of selective solar absorbers are measured under high vacuum conditions from room temperature up to stagnation temperature. The sample under investigation is illuminated under vacuum @1000W/m 2 and the sample temperature is recorded during heat up, equilibrium and cool down. During stagnation, the absorber temperature exceeds 300°C without concentration. Data analysis allows evaluating the solar absorptance and thermal emittance at different temperatures. These in turn are useful to predict evacuated solar panel performances at operating conditions.

Molecular Dynamics Simulation and Analysis of Interfacial Water at Selected Sulfide Mineral Surfaces under Anaerobic Conditions

Energy Technology Data Exchange (ETDEWEB)

Jin, Jiaqi; Miller, Jan D.; Dang, Liem X.

2014-04-10

In this paper, we report on a molecular dynamics simulation (MDS) study of the behavior of interfacial water at selected sulfide mineral surfaces under anaerobic conditions. The study revealed the interfacial water structure and wetting characteristics of the pyrite (100) surface, galena (100) surface, chalcopyrite (012) surface, sphalerite (110) surface, and molybdenite surfaces (i.e., the face, armchair-edge, and zigzag-edge surfaces), including simulated contact angles, relative number density profiles, water dipole orientations, hydrogen-bonding, and residence times. For force fields of the metal and sulfur atoms in selected sulfide minerals used in the MDS, we used the universal force field (UFF) and another set of force fields optimized by quantum chemical calculations for interactions with interfacial water molecules at selected sulfide mineral surfaces. Simulation results for the structural and dynamic properties of interfacial water molecules indicate the natural hydrophobic character for the selected sulfide mineral surfaces under anaerobic conditions as well as the relatively weak hydrophobicity for the sphalerite (110) surface and two molybdenite edge surfaces. Part of the financial support for this study was provided by the U.S. Department of Energy (DOE) under Basic Science Grant No. DE-FG-03-93ER14315. The Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences (BES), of the DOE, funded work performed by Liem X. Dang. Battelle operates Pacific Northwest National Laboratory for DOE. The calculations were carried out using computer resources provided by BES. The authors are grateful to Professor Tsun-Mei Chang for valuable discussions.

Private selective sweeps identified from next-generation pool-sequencing reveal convergent pathways under selection in two inbred Schistosoma mansoni strains.

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Julie A J Clément

Full Text Available BACKGROUND: The trematode flatworms of the genus Schistosoma, the causative agents of schistosomiasis, are among the most prevalent parasites in humans, affecting more than 200 million people worldwide. In this study, we focused on two well-characterized strains of S. mansoni, to explore signatures of selection. Both strains are highly inbred and exhibit differences in life history traits, in particular in their compatibility with the intermediate host Biomphalaria glabrata. METHODOLOGY/PRINCIPAL FINDINGS: We performed high throughput sequencing of DNA from pools of individuals of each strain using Illumina technology and identified single nucleotide polymorphisms (SNP and copy number variations (CNV. In total, 708,898 SNPs were identified and roughly 2,000 CNVs. The SNPs revealed low nucleotide diversity (π = 2 × 10(-4 within each strain and a high differentiation level (Fst = 0.73 between them. Based on a recently developed in-silico approach, we further detected 12 and 19 private (i.e. specific non-overlapping selective sweeps among the 121 and 151 sweeps found in total for each strain. CONCLUSIONS/SIGNIFICANCE: Functional annotation of transcripts lying in the private selective sweeps revealed specific selection for functions related to parasitic interaction (e.g. cell-cell adhesion or redox reactions. Despite high differentiation between strains, we identified evolutionary convergence of genes related to proteolysis, known as a key virulence factor and a potential target of drug and vaccine development. Our data show that pool-sequencing can be used for the detection of selective sweeps in parasite populations and enables one to identify biological functions under selection.

Some scale-free networks could be robust under selective node attacks

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Zheng, Bojin; Huang, Dan; Li, Deyi; Chen, Guisheng; Lan, Wenfei

2011-04-01

It is a mainstream idea that scale-free network would be fragile under the selective attacks. Internet is a typical scale-free network in the real world, but it never collapses under the selective attacks of computer viruses and hackers. This phenomenon is different from the deduction of the idea above because this idea assumes the same cost to delete an arbitrary node. Hence this paper discusses the behaviors of the scale-free network under the selective node attack with different cost. Through the experiments on five complex networks, we show that the scale-free network is possibly robust under the selective node attacks; furthermore, the more compact the network is, and the larger the average degree is, then the more robust the network is; with the same average degrees, the more compact the network is, the more robust the network is. This result would enrich the theory of the invulnerability of the network, and can be used to build robust social, technological and biological networks, and also has the potential to find the target of drugs.

Category-selective attention interacts with partial awareness processes in a continuous manner: An fMRI study

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Shen Tu

2015-12-01

Full Text Available Recently, our team found that category-selective attention could modulate tool processing at the partial awareness level and unconscious face processing in the middle occipital gyrus (MOG. However, the modulation effects in MOG were in opposite directions across the masked tool and masked face conditions in that study: MOG activation decreased in the masked faces condition but increased in the masked tools condition under the consistent compared with the inconsistent cue-selective-attentional modulation. In the present study, in order to confirm that the opposite effects were due to the changed contours of the tools, using the same tool pictures and fMRI technique, we devised another two conditions: variant mirror tool picture condition and invariant tool picture condition. The results showed that, during the variant mirror tool picture condition, activation in the MOG decreased under tool-selective attention compared with face-selective attention. Interestingly, however, during the invariant tool picture condition, activation in the MOG revealed neither positive nor negative changes. Combined with the result of increased MOG activity in the changed different tool condition, the three different effects demonstrated not only that the unconscious component of partial awareness processing (no knowledge of the identity of the tool could be modulated by the category-selective attention in the earlier visual cortex but also that the modulation effect could further interact with the conscious component of partial awareness processing (consciousness of the changing contour of the tool in a continuous manner.

Assessing the joint effect of population stratification and sample selection in studies of gene-gene (environment interactions

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Cheng KF

2012-01-01

Full Text Available Abstract Background It is well known that the presence of population stratification (PS may cause the usual test in case-control studies to produce spurious gene-disease associations. However, the impact of the PS and sample selection (SS is less known. In this paper, we provide a systematic study of the joint effect of PS and SS under a more general risk model containing genetic and environmental factors. We provide simulation results to show the magnitude of the bias and its impact on type I error rate of the usual chi-square test under a wide range of PS level and selection bias. Results The biases to the estimation of main and interaction effect are quantified and then their bounds derived. The estimated bounds can be used to compute conservative p-values for the association test. If the conservative p-value is smaller than the significance level, we can safely claim that the association test is significant regardless of the presence of PS or not, or if there is any selection bias. We also identify conditions for the null bias. The bias depends on the allele frequencies, exposure rates, gene-environment odds ratios and disease risks across subpopulations and the sampling of the cases and controls. Conclusion Our results show that the bias cannot be ignored even the case and control data were matched in ethnicity. A real example is given to illustrate application of the conservative p-value. These results are useful to the genetic association studies of main and interaction effects.

Selective impairment of decision making under ambiguity in alexithymia.

Science.gov (United States)

Zhang, Lei; Wang, Xue; Zhu, Yu; Li, Hongchen; Zhu, Chunyan; Yu, Fengqiong; Wang, Kai

2017-11-28

Alexithymia is characterised by difficulties identifying and describing emotions. Few studies have investigated how alexithymia influences decision-making under different conditions (ambiguity and risk). This study aimed to examine whether alexithymia contributes to impairment in decision-making. This study included 42 participants with high scores in the Chinese version of Toronto Alexithymia Scale (alexithymia group), and 44 matched subjects with low scores (control group). Decision-making was measured using the Iowa Gambling Task (IGT) and the Game of Dice Task (GDT). The main findings of this study revealed selective deficits in IGT performance for the alexithymia group, while GDT performance was unimpaired when compared with the control group. In IGT, total netscores were lower for the alexithymia group compared to the control group, particularly with regard to block 5. Moreover, the alexithymia individuals selected significantly more adverse cards than the controls, indicating significant decision-making impairments. Alexithymia selectively influences decision-making under ambiguity.

The effect of sexual selection on adaptation and extinction under increasing temperatures.

Science.gov (United States)

Parrett, Jonathan M; Knell, Robert J

2018-04-25

Strong sexual selection has been reported to both enhance and hinder the adaptive capacity and persistence of populations when exposed to novel environments. Consequently, how sexual selection influences population adaption and persistence under stress remains widely debated. Here, we present two empirical investigations of the fitness consequences of sexual selection on populations of the Indian meal moth, Plodia interpunctella, exposed to stable or gradually increasing temperatures. When faced with increasing temperatures, strong sexual selection was associated with both increased fecundity and offspring survival compared with populations experiencing weak sexual selection, suggesting sexual selection acts to drive adaptive evolution by favouring beneficial alleles. Strong sexual selection did not, however, delay extinction when the temperature became excessively high. By manipulating individuals' mating opportunities during fitness assays, we were able to assess the effect of multiple mating independently from the effect of population-level sexual selection, and found that polyandry has a positive effect on both fecundity and offspring survival under increasing temperatures in those populations evolving with weak sexual selection. Within stable temperatures, there were some benefits from strong sexual selection but these were not consistent across the entire experiment, possibly reflecting changing costs and benefits of sexual selection under stabilizing and directional selection. These results indicate that sexual selection can provide a buffer against climate change and increase adaptation rates within a continuously changing environment. These positive effects of sexual selection may, however, be too small to protect populations and delay extinction when environmental changes are relatively rapid. © 2018 The Author(s).

Elaboration of the recently proposed test of Pauli's principle under strong interactions

International Nuclear Information System (INIS)

Ktorides, C.N.; Myung, H.C.; Santilli, R.M.

1980-01-01

The primary objective of this paper is to stimulate the experimental verification of the validity or invalidity of Pauli's principle under strong interactions. We first outline the most relevant steps in the evolution of the notion of particle. The spin as well as other intrinsic characteristics of extended, massive, particles under electromagnetic interactions at large distances might be subjected to a mutation under additional strong interactions at distances smaller than their charge radius. These dynamical effects can apparently be conjectured to account for the nonpointlike nature of the particles, their necessary state of penetration to activate the strong interactions, and the consequential emergence of broader forces which imply the breaking of the SU(2)-spin symmetry. We study a characterization of the mutated value of the spin via the transition from the associative enveloping algebra of SU(2) to a nonassociative Lie-admissible form. The departure from the original associative product then becomes directly representative of the breaking of the SU(2)-spin symmetry, the presence of forces more general than those derivable from a potential, and the mutated value of the spin. In turn, such a departure of the spin from conventional quantum-mechanical values implies the inapplicability of Pauli's exclusion principle under strong interactions, because, according to this hypothesis, particles that are fermions under long-range electromagnetic interactions are no longer fermions under these broader, short-range, forces. In nuclear physics possible deviations from Pauli's exclusion principle can at most be very small. These experimental data establish that, for the nuclei considered, nucleons are in a partial state of penetration of their charge volumes although of small statistical character

Age Differences in Selective Memory of Goal-Relevant Stimuli Under Threat.

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Durbin, Kelly A; Clewett, David; Huang, Ringo; Mather, Mara

2018-02-01

When faced with threat, people often selectively focus on and remember the most pertinent information while simultaneously ignoring any irrelevant information. Filtering distractors under arousal requires inhibitory mechanisms, which take time to recruit and often decline in older age. Despite the adaptive nature of this ability, relatively little research has examined how both threat and time spent preparing these inhibitory mechanisms affect selective memory for goal-relevant information across the life span. In this study, 32 younger and 31 older adults were asked to encode task-relevant scenes, while ignoring transparent task-irrelevant objects superimposed onto them. Threat levels were increased on some trials by threatening participants with monetary deductions if they later forgot scenes that followed threat cues. We also varied the time between threat induction and a to-be-encoded scene (i.e., 2 s, 4 s, 6 s) to determine whether both threat and timing effects on memory selectivity differ by age. We found that age differences in memory selectivity only emerged after participants spent a long time (i.e., 6 s) preparing for selective encoding. Critically, this time-dependent age difference occurred under threatening, but not neutral, conditions. Under threat, longer preparation time led to enhanced memory for task-relevant scenes and greater memory suppression of task-irrelevant objects in younger adults. In contrast, increased preparation time after threat induction had no effect on older adults' scene memory and actually worsened memory suppression of task-irrelevant objects. These findings suggest that increased time to prepare top-down encoding processes benefits younger, but not older, adults' selective memory for goal-relevant information under threat. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Selective CO Methanation on Ru/TiO2 Catalysts: Role and Influence of Metal-Support Interactions

DEFF Research Database (Denmark)

Abdel-Mageed, Ali M.; Widmann, D.; Olesen, Sine Ellemann

2015-01-01

Aiming at a detailed understanding of the role of metal-support interactions in the selective methanation of CO in CO2-rich reformate gases, we have investigated the catalytic performance of a set of Ru/TiO2 catalysts with comparable Ru loading, Ru particle size, and TiO2 phase composition but very...... different surface areas (ranging from 20 to 235 m2 g-1) in this reaction. The activity for CO methanation, under steady-state conditions, was found to strongly depend on the TiO2 support surface area, increasing first with increasing surface area up to a maximum activity for the Ru/TiO2 catalyst...... with a surface area of 121 m2 g-1 and then decreasing for an even higher surface area; however, the selectivity is mainly determined by the Ru particle size, which slightly decreases with increasing support surface area. This goes along with an increase in selectivity for CO methanation, in agreement...

Evolution in response to social selection: the importance of interactive effects of traits on fitness.

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Westneat, David F

2012-03-01

Social interactions have a powerful effect on the evolutionary process. Recent attempts to synthesize models of social selection with equations for indirect genetic effects (McGlothlin et al. 2010) provide a broad theoretical base from which to study selection and evolutionary response in the context of social interactions. However, this framework concludes that social selection will lead to evolution only if the traits carried by social partners are nonrandomly associated. I suggest this conclusion is incomplete, and that traits that do not covary between social partners can nevertheless lead to evolution via interactive effects on fitness. Such effects occur when there are functional interactions between traits, and as an example I use the interplay in water striders (Gerridae) between grasping appendages carried by males and spines by females. Functional interactive effects between traits can be incorporated into both the equations for social selection and the general model of social evolution proposed by McGlothlin et al. These expanded equations would accommodate adaptive coevolution in social interactions, integrate the quantitative genetic approach to social evolution with game theoretical approaches, and stimulate some new questions about the process of social evolution. © 2011 The Author. Evolution© 2011 The Society for the Study of Evolution.

Effect of molecular interactions on retention and selectivity in reversed-phase liquid chromatography.

Science.gov (United States)

Szepesy, László

2002-06-25

The linear solvation energy relationships (LSERs) have been applied in the last years for description and prediction of retention and selectivity in reversed-phase liquid chromatography with good results. Widely different stationary phases have been compared and characterized by LSERs. In recent publications the influence of the type of the organic moderator and the composition of the mobile phase have also been described. However, the influence of the molecular properties of the solutes to be separated has never been discussed. According to the LSER model variation in retention factors (log k) with solute structure can be related to their potential for various intermolecular interactions. The retention factor is given as the sum of the terms of the LSER equation representing various types of molecular interactions. For this reason the influence of the structure and molecular properties of the solutes to be separated can also be investigated using the LSER equation. In this study we shall demonstrate how the specific molecular interactions influence chromatographic retention and selectivity. We intend to show that retention and selectivity depend on all participants of the system. In addition to the structure and properties of the stationary phase and the type and composition of the mobile phase the molecular properties of the solutes, characterized by the solvation parameters, will also influence the type and extent of the various molecular interactions governing retention and selectivity.

Crack Growth Behaviour of P92 Steel Under Creep-fatigue Interaction Conditions

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JING Hong-yang

2017-05-01

Full Text Available Creep-fatigue interaction tests of P92 steel at 630℃ under stress-controlled were carried out, and the crack propagation behaviour of P92 steel was studied. The fracture mechanism of crack growth under creep-fatigue interaction and the transition points in a-N curves were analyzed based on the fracture morphology. The results show that the fracture of P92 steel under creep-fatigue interaction is creep ductile fracture and the (Ctavg parameter is employed to demonstrate the crack growth behaviour; in addition, the fracture morphology shows that the crack growth for P92 steel under creep-fatigue interaction is mainly caused by the nucleation and growth of the creep voids and micro-cracks. Furthermore, the transition point of a-lg(Ni/Nf curve corresponds to the turning point of initial crack growth changed into steady crack growth while the transition point of (da/dN-N curve exhibits the turning point of steady creep crack growth changed into the accelerated crack growth.

The interaction properties of the human Rab GTPase family--comparative analysis reveals determinants of molecular binding selectivity.

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Matthias Stein

Full Text Available Rab GTPases constitute the largest subfamily of the Ras protein superfamily. Rab proteins regulate organelle biogenesis and transport, and display distinct binding preferences for effector and activator proteins, many of which have not been elucidated yet. The underlying molecular recognition motifs, binding partner preferences and selectivities are not well understood.Comparative analysis of the amino acid sequences and the three-dimensional electrostatic and hydrophobic molecular interaction fields of 62 human Rab proteins revealed a wide range of binding properties with large differences between some Rab proteins. This analysis assists the functional annotation of Rab proteins 12, 14, 26, 37 and 41 and provided an explanation for the shared function of Rab3 and 27. Rab7a and 7b have very different electrostatic potentials, indicating that they may bind to different effector proteins and thus, exert different functions. The subfamily V Rab GTPases which are associated with endosome differ subtly in the interaction properties of their switch regions, and this may explain exchange factor specificity and exchange kinetics.We have analysed conservation of sequence and of molecular interaction fields to cluster and annotate the human Rab proteins. The analysis of three dimensional molecular interaction fields provides detailed insight that is not available from a sequence-based approach alone. Based on our results, we predict novel functions for some Rab proteins and provide insights into their divergent functions and the determinants of their binding partner selectivity.

Evolution of molecular phenotypes under stabilizing selection

International Nuclear Information System (INIS)

Nourmohammad, Armita; Schiffels, Stephan; Lässig, Michael

2013-01-01

Molecular phenotypes are important links between genomic information and organismic functions, fitness, and evolution. Complex phenotypes, which are also called quantitative traits, often depend on multiple genomic loci. Their evolution builds on genome evolution in a complicated way, which involves selection, genetic drift, mutations and recombination. Here we develop a coarse-grained evolutionary statistics for phenotypes, which decouples from details of the underlying genotypes. We derive approximate evolution equations for the distribution of phenotype values within and across populations. This dynamics covers evolutionary processes at high and low recombination rates, that is, it applies to sexual and asexual populations. In a fitness landscape with a single optimal phenotype value, the phenotypic diversity within populations and the divergence between populations reach evolutionary equilibria, which describe stabilizing selection. We compute the equilibrium distributions of both quantities analytically and we show that the ratio of mean divergence and diversity depends on the strength of selection in a universal way: it is largely independent of the phenotype’s genomic encoding and of the recombination rate. This establishes a new method for the inference of selection on molecular phenotypes beyond the genome level. We discuss the implications of our findings for the predictability of evolutionary processes. (paper)

Population genetics inference for longitudinally-sampled mutants under strong selection.

Science.gov (United States)

Lacerda, Miguel; Seoighe, Cathal

2014-11-01

Longitudinal allele frequency data are becoming increasingly prevalent. Such samples permit statistical inference of the population genetics parameters that influence the fate of mutant variants. To infer these parameters by maximum likelihood, the mutant frequency is often assumed to evolve according to the Wright-Fisher model. For computational reasons, this discrete model is commonly approximated by a diffusion process that requires the assumption that the forces of natural selection and mutation are weak. This assumption is not always appropriate. For example, mutations that impart drug resistance in pathogens may evolve under strong selective pressure. Here, we present an alternative approximation to the mutant-frequency distribution that does not make any assumptions about the magnitude of selection or mutation and is much more computationally efficient than the standard diffusion approximation. Simulation studies are used to compare the performance of our method to that of the Wright-Fisher and Gaussian diffusion approximations. For large populations, our method is found to provide a much better approximation to the mutant-frequency distribution when selection is strong, while all three methods perform comparably when selection is weak. Importantly, maximum-likelihood estimates of the selection coefficient are severely attenuated when selection is strong under the two diffusion models, but not when our method is used. This is further demonstrated with an application to mutant-frequency data from an experimental study of bacteriophage evolution. We therefore recommend our method for estimating the selection coefficient when the effective population size is too large to utilize the discrete Wright-Fisher model. Copyright © 2014 by the Genetics Society of America.

CLUB-MARTINI: Selecting Favourable Interactions amongst Available Candidates, a Coarse-Grained Simulation Approach to Scoring Docking Decoys.

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Qingzhen Hou

Full Text Available Large-scale identification of native binding orientations is crucial for understanding the role of protein-protein interactions in their biological context. Measuring binding free energy is the method of choice to estimate binding strength and reveal the relevance of particular conformations in which proteins interact. In a recent study, we successfully applied coarse-grained molecular dynamics simulations to measure binding free energy for two protein complexes with similar accuracy to full-atomistic simulation, but 500-fold less time consuming. Here, we investigate the efficacy of this approach as a scoring method to identify stable binding conformations from thousands of docking decoys produced by protein docking programs. To test our method, we first applied it to calculate binding free energies of all protein conformations in a CAPRI (Critical Assessment of PRedicted Interactions benchmark dataset, which included over 19000 protein docking solutions for 15 benchmark targets. Based on the binding free energies, we ranked all docking solutions to select the near-native binding modes under the assumption that the native-solutions have lowest binding free energies. In our top 100 ranked structures, for the 'easy' targets that have many near-native conformations, we obtain a strong enrichment of acceptable or better quality structures; for the 'hard' targets without near-native decoys, our method is still able to retain structures which have native binding contacts. Moreover, in our top 10 selections, CLUB-MARTINI shows a comparable performance when compared with other state-of-the-art docking scoring functions. As a proof of concept, CLUB-MARTINI performs remarkably well for many targets and is able to pinpoint near-native binding modes in the top selections. To the best of our knowledge, this is the first time interaction free energy calculated from MD simulations have been used to rank docking solutions at a large scale.

Molecular Features Underlying Selectivity in Chicken Bitter Taste Receptors

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Antonella Di Pizio

2018-01-01

Full Text Available Chickens sense the bitter taste of structurally different molecules with merely three bitter taste receptors (Gallus gallus taste 2 receptors, ggTas2rs, representing a minimal case of bitter perception. Some bitter compounds like quinine, diphenidol and chlorpheniramine, activate all three ggTas2rs, while others selectively activate one or two of the receptors. We focus on bitter compounds with different selectivity profiles toward the three receptors, to shed light on the molecular recognition complexity in bitter taste. Using homology modeling and induced-fit docking simulations, we investigated the binding modes of ggTas2r agonists. Interestingly, promiscuous compounds are predicted to establish polar interactions with position 6.51 and hydrophobic interactions with positions 3.32 and 5.42 in all ggTas2rs; whereas certain residues are responsible for receptor selectivity. Lys3.29 and Asn3.36 are suggested as ggTas2r1-specificity-conferring residues; Gln6.55 as ggTas2r2-specificity-conferring residue; Ser5.38 and Gln7.42 as ggTas2r7-specificity conferring residues. The selectivity profile of quinine analogs, quinidine, epiquinidine and ethylhydrocupreine, was then characterized by combining calcium-imaging experiments and in silico approaches. ggTas2r models were used to virtually screen BitterDB compounds. ~50% of compounds known to be bitter to human are likely to be bitter to chicken, with 25, 20, 37% predicted to be ggTas2r1, ggTas2r2, ggTas2r7 agonists, respectively. Predicted ggTas2rs agonists can be tested with in vitro and in vivo experiments, contributing to our understanding of bitter taste in chicken and, consequently, to the improvement of chicken feed.

A conserved mammalian protein interaction network.

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Åsa Pérez-Bercoff

Full Text Available Physical interactions between proteins mediate a variety of biological functions, including signal transduction, physical structuring of the cell and regulation. While extensive catalogs of such interactions are known from model organisms, their evolutionary histories are difficult to study given the lack of interaction data from phylogenetic outgroups. Using phylogenomic approaches, we infer a upper bound on the time of origin for a large set of human protein-protein interactions, showing that most such interactions appear relatively ancient, dating no later than the radiation of placental mammals. By analyzing paired alignments of orthologous and putatively interacting protein-coding genes from eight mammals, we find evidence for weak but significant co-evolution, as measured by relative selective constraint, between pairs of genes with interacting proteins. However, we find no strong evidence for shared instances of directional selection within an interacting pair. Finally, we use a network approach to show that the distribution of selective constraint across the protein interaction network is non-random, with a clear tendency for interacting proteins to share similar selective constraints. Collectively, the results suggest that, on the whole, protein interactions in mammals are under selective constraint, presumably due to their functional roles.

Rayleigh scattering under light-atom coherent interaction

OpenAIRE

Takamizawa, Akifumi; Shimoda, Koichi

2012-01-01

Semi-classical calculation of an oscillating dipole induced in a two-level atom indicates that spherical radiation from the dipole under coherent interaction, i.e., Rayleigh scattering, has a power level comparable to that of spontaneous emission resulting from an incoherent process. Whereas spontaneous emission is nearly isotropic and has random polarization generally, Rayleigh scattering is strongly anisotropic and polarized in association with incident light. In the case where Rabi frequen...

Fluorescent Water Soluble Polymers for Isozyme-Selective Interactions with Matrix Metalloproteinase-9

Science.gov (United States)

Dutta, Rinku; Scott, Michael D.; Haldar, Manas K.; Ganguly, Bratati; Srivastava, D. K.; Friesner, Daniel L.; Mallik, Sanku

2011-01-01

Matrix metalloproteinases (MMPs) are overexpressed in various pathological conditions, including various cancers. Although these isozymes have similar active sites, the patterns of exposed amino acids on their surfaces are different. Herein, we report the synthesis and molecular interactions of two water-soluble, fluorescent polymers which demonstrate selective interactions with MMP-9 compared to MMP-7 and -10. PMID:21367603

Considering Interactions among Multiple Criteria for the Server Selection

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Vesna Čančer

2010-06-01

Full Text Available Decision-making about server selection is one of the multi-criteria decision-making (MCDM processes where interactions among criteria should be considered. The paper introduces and develops some solutions for considering interactions among criteria in the MCDM problems. In the frame procedure for MCDM by using the group of methods, based on assigning weights, special attention is given to the synthesis of the local alternatives’ values into the aggregate values where the mutual preferential independence between two criteria is not assumed. Firstly, we delineate how to complete the additive model into the multiplicative one with synergic and redundancy elements in the case that criteria are structured in one level and in two levels. Furthermore, we adapted the concept of the fuzzy Choquet integral to the multi-attribute value theory. Studying and comparing the results of the example case of the server selection obtained by both aggregation approaches, the paper highlights the advantages of the first one since it does not require from decision makers to determine the weights of all possible combinations of the criteria and it enables the further use of the most preferred MCDM methods.

Molecular signature of epistatic selection: interrogating genetic interactions in the sex-ratio meiotic drive of Drosophila simulans.

Science.gov (United States)

Chevin, Luis-Miguel; Bastide, Héloïse; Montchamp-Moreau, Catherine; Hospital, Frédéric

2009-06-01

Fine scale analyses of signatures of selection allow assessing quantitative aspects of a species' evolutionary genetic history, such as the strength of selection on genes. When several selected loci lie in the same genomic region, their epistatic interactions may also be investigated. Here, we study how the neutral polymorphism pattern was shaped by two close recombining loci that cause 'sex-ratio' meiotic drive in Drosophila simulans, as an example of strong selection with potentially strong epistasis. We compare the polymorphism data observed in a natural population with the results of forward stochastic simulations under several contexts of epistasis between the candidate loci for the drive. We compute the likelihood of different possible scenarios, in order to determine which configuration is most consistent with the data. Our results highlight that fine scale analyses of well-chosen candidate genomic regions provide information-rich data that can be used to investigate the genotype-phenotype-fitness map, which can hardly be studied in genome-wide analyses. We also emphasize that initial conditions and time of observation (here, time after the interruption of a partial selective sweep) are crucial parameters in the interpretation of real data, while these are often overlooked in theoretical studies.

Believing versus interacting: Behavioural and neural mechanisms underlying interpersonal coordination

DEFF Research Database (Denmark)

Konvalinka, Ivana; Bauer, Markus; Kilner, James

When two people engage in a bidirectional interaction with each other, they use both bottom-up sensorimotor mechanisms such as monitoring and adapting to the behaviour of the other, as well as top-down cognitive processes, modulating their beliefs and allowing them to make decisions. Most research...... in joint action has investigated only one of these mechanisms at a time – low-level processes underlying joint coordination, or high-level cognitive mechanisms that give insight into how people think about another. In real interactions, interplay between these two mechanisms modulates how we interact...

Genomewide Expression and Functional Interactions of Genes under Drought Stress in Maize

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Nepolean Thirunavukkarasu

2017-01-01

Full Text Available A genomewide transcriptome assay of two subtropical genotypes of maize was used to observe the expression of genes at seedling stage of drought stress. The number of genes expressed differentially was greater in HKI1532 (a drought tolerant genotype than in PC3 (a drought sensitive genotype, indicating primary differences at the transcriptional level in stress tolerance. The global coexpression networks of the two genotypes differed significantly with respect to the number of modules and the coexpression pattern within the modules. A total of 174 drought-responsive genes were selected from HKI1532, and their coexpression network revealed key correlations between different adaptive pathways, each cluster of the network representing a specific biological function. Transcription factors related to ABA-dependent stomatal closure, signalling, and phosphoprotein cascades work in concert to compensate for reduced photosynthesis. Under stress, water balance was maintained by coexpression of the genes involved in osmotic adjustments and transporter proteins. Metabolism was maintained by the coexpression of genes involved in cell wall modification and protein and lipid metabolism. The interaction of genes involved in crucial biological functions during stress was identified and the results will be useful in targeting important gene interactions to understand drought tolerance in greater detail.

Investigation on the interaction of catalase with sodium lauryl sulfonate and the underlying mechanisms.

Science.gov (United States)

Wang, Jing; Jia, Rui; Wang, Jiaxi; Sun, Zhiqiang; Wu, Zitao; Liu, Rutao; Zong, Wansong

2018-02-01

As a classic type of anionic surfactants, sodium lauryl sulfonate (SLS) might change the structure and function of antioxidant enzyme catalase (CAT) through their direct interactions. However, the underlying molecular mechanism is still unknown. This study investigated the direct interaction of SLS with CAT molecule and the underlying mechanisms using multi-spectroscopic methods, isothermal titration calorimetry, and molecular docking studies. No obvious effects were observed on CAT structure and activity under low SLS concentration exposure. The particle size of CAT molecule decreased and CAT activity was slightly inhibited under high SLS concentration exposure. SLS prefers to bind to the interface of CAT mainly via van der Waals' forces and hydrogen bonds. Subsequently, SLS interacts with the amino acid residues around the heme groups of CAT via hydrophobic interactions and might inhibit CAT activity. © 2017 Wiley Periodicals, Inc.

A New Dynamic Multicriteria Decision-Making Approach for Green Supplier Selection in Construction Projects under Time Sequence

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Shi Yin

2017-01-01

Full Text Available Nowadays, due to the lack of natural resources and environment problems which have been appearing increasingly, green building is more and more involved in the construction industry. The evaluation and selection of green supplier are a significant part of the development of green building. In this paper, we propose a new dynamic multicriteria decision-making approach in construction projects under time sequence to deal with these problems. First, the paper establishes 4 main criteria and 17 subcriteria for green supplier selection in construction projects. Then, a method considering interaction between criteria and the influence of constructors subjective preference and objective criteria information is proposed. It uses the interval-valued intuitionistic fuzzy geometric weighted Heronian means (IVIFGWHM operator and multitarget nonlinear programming model to calculate the comprehensive evaluation results of potential green suppliers. The proposed method is much easier for constructors to select green supplier and make the localization of green supplier more practical and accurate in construction projects. Finally, a case study about a green building project is given to verify practicality and effectiveness of the proposed approach.

Numerical Simulation for the Soil-Pile-Structure Interaction under Seismic Loading

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Lifeng Luan

2015-01-01

Full Text Available Piles are widely used as reinforcement structures in geotechnical engineering designs. If the settlement of the soil is greater than the pile, the pile is pulled down by the soil, and negative friction force is produced. Previous studies have mainly focused on the interaction of pile-soil under static condition. However, many pile projects are located in earthquake-prone areas, which indicate the importance of determining the response of the pile-soil structure under seismic load. In this paper, the nonlinear, explicit, and finite difference program FLAC3D, which considers the mechanical behavior of soil-pile interaction, is used to establish an underconsolidated soil-pile mode. The response processes of the pile side friction force, the pile axial force, and the soil response under seismic load are also analyzed.

Interface Pattern Selection in Directional Solidification

Science.gov (United States)

Trivedi, Rohit; Tewari, Surendra N.

2001-01-01

The central focus of this research is to establish key scientific concepts that govern the selection of cellular and dendritic patterns during the directional solidification of alloys. Ground-based studies have established that the conditions under which cellular and dendritic microstructures form are precisely where convection effects are dominant in bulk samples. Thus, experimental data can not be obtained terrestrially under pure diffusive regime. Furthermore, reliable theoretical models are not yet possible which can quantitatively incorporate fluid flow in the pattern selection criterion. Consequently, microgravity experiments on cellular and dendritic growth are designed to obtain benchmark data under diffusive growth conditions that can be quantitatively analyzed and compared with the rigorous theoretical model to establish the fundamental principles that govern the selection of specific microstructure and its length scales. In the cellular structure, different cells in an array are strongly coupled so that the cellular pattern evolution is controlled by complex interactions between thermal diffusion, solute diffusion and interface effects. These interactions give infinity of solutions, and the system selects only a narrow band of solutions. The aim of this investigation is to obtain benchmark data and develop a rigorous theoretical model that will allow us to quantitatively establish the physics of this selection process.

Tribochemical interaction between nanoparticles and surfaces of selective layer during chemical mechanical polishing

International Nuclear Information System (INIS)

Ilie, Filip

2013-01-01

Nanoparticles have been widely used in polish slurries such as those in the chemical mechanical polishing (CMP) process. For understanding the mechanisms of CMP, an atomic force microscope (AFM) is used to characterize polished surfaces of selective layers, after a set of polishing experiments. To optimize the CMP polishing process, one needs to get information on the interaction between the nano-abrasive slurry nanoparticles and the surface of selective layer being polished. The slurry used in CMP process of the solid surfaces is slurry with large nanoparticle size colloidal silica sol nano-abrasives. Silica sol nano-abrasives with large nanoparticle are prepared and characterized by transmission electron microscopy, particles colloidal size, and Zeta potential in this paper. The movement of nanoparticles in liquid and the interaction between nanoparticles and solid surfaces coating with selective layer are very important to obtain an atomic alloy smooth surface in the CMP process. We investigate the nanoparticle adhesion and removal processes during CMP and post-CMP cleaning. The mechanical interaction between nanoparticles and the wafer surface was studied using a microcontact wear model. This model considers the nanoparticle effects between the polishing interfaces during load balancing. Experimental results on polishing and cleaning are compared with numerical analysis. This paper suggests that during post-CMP cleaning, a combined effort in chemical and mechanical interaction (tribochemical interactions) would be effective in removal of small nanoparticles during cleaning. For large nanoparticles, more mechanical forces would be more effective. CMP results show that the removal rate has been improved to 367 nm/min and root mean square (RMS) of roughness has been reduced from 4.4 to 0.80 nm. Also, the results show that the silica sol nano-abrasives about 100 nm are of higher stability (Zeta potential is −65 mV) and narrow distribution of nanoparticle

Directed selective-tunneling of bosons with periodically modulated interaction

International Nuclear Information System (INIS)

Lu, Gengbiao; Fu, Li-Bin; Hai, Wenhua; Zou, Mingliang; Guo, Yu

2015-01-01

We study the tunneling dynamics of bosons with periodically modulated interaction held in a triple-well potential. In high-frequency approximation, we derive a set of reduced coupled equations and the corresponding Floquet solutions are obtained. Based on the analytical results and their numerical correspondence, the directed selective-tunneling effect of a single atom is demonstrated when all bosons are prepared in middle well initially. A scheme for separating a single atom from N bosons is presented, in which the atom can be trapped in right or left well by adjusting the modulation strength. - Highlights: • The Floquet solutions in a modulating triple-well are obtained analytically. • The directed selective-tunneling effect of a single atom is demonstrated. • We present a manipulation scheme for separating a single atom from N bosons

Studies on selected organic-metal interactions of importance in the environment

International Nuclear Information System (INIS)

Mason, Ian.

1995-10-01

This research project investigated the interaction between natural organics acids and selected metal ions. The aims of the project was to provide quantitative data on the speciation of metal ions when placed in systems containing natural organic acids. It was envisaged that such data will assist in the risk assessment of the Drigg low level waste site in Cumbria. The formation and complexing ability of these natural organic acids is discussed and the classing of these acids into high molecular weight organic acids and low molecular weight organic acids. Initial investigations used a potentiometric technique to study the interaction between nickel and europium and selected low molecular weight organic acids which were thought to occur in significant concentrations in soils and groundwaters. These experiments confirmed existing critically assessed literature values, and provided an experimental methodology for further 'in-house' measurement of such values. In addition, studies were also performed on systems containing two competing organic acids. (author)

Strategic interaction in undeveloped credit markets

DEFF Research Database (Denmark)

Andersen, Thomas Barnebeck; Malchow-Møller, Nikolaj

2006-01-01

This paper studies the strategic interaction between informal and formal lenders in undeveloped credit markets. In a model with adverse selection, loan seniority, market power, and differences in the cost of lending, it is shown that under general conditions a co-funding equilibrium will be a Nas...... evidence and the emerging discussion of how to best ensure financial viability and outreach of microfinance institutions......This paper studies the strategic interaction between informal and formal lenders in undeveloped credit markets. In a model with adverse selection, loan seniority, market power, and differences in the cost of lending, it is shown that under general conditions a co-funding equilibrium will be a Nash...

Interactive prostate segmentation using atlas-guided semi-supervised learning and adaptive feature selection.

Science.gov (United States)

Park, Sang Hyun; Gao, Yaozong; Shi, Yinghuan; Shen, Dinggang

2014-11-01

Accurate prostate segmentation is necessary for maximizing the effectiveness of radiation therapy of prostate cancer. However, manual segmentation from 3D CT images is very time-consuming and often causes large intra- and interobserver variations across clinicians. Many segmentation methods have been proposed to automate this labor-intensive process, but tedious manual editing is still required due to the limited performance. In this paper, the authors propose a new interactive segmentation method that can (1) flexibly generate the editing result with a few scribbles or dots provided by a clinician, (2) fast deliver intermediate results to the clinician, and (3) sequentially correct the segmentations from any type of automatic or interactive segmentation methods. The authors formulate the editing problem as a semisupervised learning problem which can utilize a priori knowledge of training data and also the valuable information from user interactions. Specifically, from a region of interest near the given user interactions, the appropriate training labels, which are well matched with the user interactions, can be locally searched from a training set. With voting from the selected training labels, both confident prostate and background voxels, as well as unconfident voxels can be estimated. To reflect informative relationship between voxels, location-adaptive features are selected from the confident voxels by using regression forest and Fisher separation criterion. Then, the manifold configuration computed in the derived feature space is enforced into the semisupervised learning algorithm. The labels of unconfident voxels are then predicted by regularizing semisupervised learning algorithm. The proposed interactive segmentation method was applied to correct automatic segmentation results of 30 challenging CT images. The correction was conducted three times with different user interactions performed at different time periods, in order to evaluate both the efficiency

Object-Based Attention on Social Units: Visual Selection of Hands Performing a Social Interaction.

Science.gov (United States)

Yin, Jun; Xu, Haokui; Duan, Jipeng; Shen, Mowei

2018-05-01

Traditionally, objects of attention are characterized either as full-fledged entities or either as elements grouped by Gestalt principles. Because humans appear to use social groups as units to explain social activities, we proposed that a socially defined group, according to social interaction information, would also be a possible object of attentional selection. This hypothesis was examined using displays with and without handshaking interactions. Results demonstrated that object-based attention, which was measured by an object-specific attentional advantage (i.e., shorter response times to targets on a single object), was extended to two hands performing a handshake but not to hands that did not perform meaningful social interactions, even when they did perform handshake-like actions. This finding cannot be attributed to the familiarity of the frequent co-occurrence of two handshaking hands. Hence, object-based attention can select a grouped object whose parts are connected within a meaningful social interaction. This finding implies that object-based attention is constrained by top-down information.

Plant-insect interactions under bacterial influence: ecological implications and underlying mechanisms.

Science.gov (United States)

Sugio, Akiko; Dubreuil, Géraldine; Giron, David; Simon, Jean-Christophe

2015-02-01

Plants and insects have been co-existing for more than 400 million years, leading to intimate and complex relationships. Throughout their own evolutionary history, plants and insects have also established intricate and very diverse relationships with microbial associates. Studies in recent years have revealed plant- or insect-associated microbes to be instrumental in plant-insect interactions, with important implications for plant defences and plant utilization by insects. Microbial communities associated with plants are rich in diversity, and their structure greatly differs between below- and above-ground levels. Microbial communities associated with insect herbivores generally present a lower diversity and can reside in different body parts of their hosts including bacteriocytes, haemolymph, gut, and salivary glands. Acquisition of microbial communities by vertical or horizontal transmission and possible genetic exchanges through lateral transfer could strongly impact on the host insect or plant fitness by conferring adaptations to new habitats. Recent developments in sequencing technologies and molecular tools have dramatically enhanced opportunities to characterize the microbial diversity associated with plants and insects and have unveiled some of the mechanisms by which symbionts modulate plant-insect interactions. Here, we focus on the diversity and ecological consequences of bacterial communities associated with plants and herbivorous insects. We also highlight the known mechanisms by which these microbes interfere with plant-insect interactions. Revealing such mechanisms in model systems under controlled environments but also in more natural ecological settings will help us to understand the evolution of complex multitrophic interactions in which plants, herbivorous insects, and micro-organisms are inserted. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions

Interactions between coherent twin boundaries and phase transition of iron under dynamic loading and unloading

Science.gov (United States)

Wang, Kun; Chen, Jun; Zhang, Xueyang; Zhu, Wenjun

2017-09-01

Phase transitions and deformation twins are constantly reported in many BCC metals under high pressure, whose interactions are of fundamental importance to understand the strengthening mechanism of these metals under extreme conditions. However, the interactions between twins and phase transition in BCC metals remain largely unexplored. In this work, interactions between coherent twin boundaries and α ↔ ɛ phase transition of iron are investigated using both non-equilibrium molecular dynamics simulations and the nudged elastic band method. Mechanisms of both twin-assisted phase transition and reverse phase transition are studied, and orientation relationships between BCC and HCP phases are found to be ⟨"separators="|11 1 ¯ ⟩ B C C||⟨"separators="|1 ¯2 1 ¯ 0 ⟩ H C P and ⟨"separators="|1 1 ¯ 0 ⟩ B C C||⟨"separators="|0001 ⟩ H C P for both cases. The twin boundary corresponds to {"separators="|10 1 ¯ 0 } H C P after the phase transition. It is amazing that the reverse transition seems to be able to "memorize" and recover the initial BCC twins. The memory would be partly lost when plastic slips take place in the HCP phase before the reverse transition. In the recovered initial BCC twins, three major twin spacings are observed, which are well explained in terms of energy barriers of transition from the HCP phase to the BCC twin. Besides, the variant selection rule of the twin assisted phase transition is also discussed. The results of present work could be expected to give some clues for producing ultra-fine grain structures in materials exhibiting martensitic phase transition.

Influence of Maximum Inbreeding Avoidance under BLUP EBV Selection on Pinzgau Population Diversity

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Radovan Kasarda

2011-05-01

Full Text Available Evaluated was effect of mating (random vs. maximum avoidance of inbreeding under BLUP EBV selection strategy. Existing population structure was under Monte Carlo stochastic simulation analyzed from the point to minimize increase of inbreeding. Maximum avoidance of inbreeding under BLUP selection resulted into comparable increase of inbreeding then random mating in average of 10 generation development. After 10 generations of simulation of mating strategy was observed ΔF= 6,51 % (2 sires, 5,20 % (3 sires, 3,22 % (4 sires resp. 2,94 % (5 sires. With increased number of sires selected, decrease of inbreeding was observed. With use of 4, resp. 5 sires increase of inbreeding was comparable to random mating with phenotypic selection. For saving of genetic diversity and prevention of population loss is important to minimize increase of inbreeding in small populations. Classical approach was based on balancing ratio of sires and dams in mating program. Contrariwise in the most of commercial populations small number of sires was used with high mating ratio.

Oxybiotest project: microorganisms under pressure. Hyperbaric oxygen (HBO and simple pressure interaction on selected bacteria

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Zanon Vincenzo

2012-09-01

Full Text Available Abstract Background HyperBaric Oxygen (HBO therapy involves exposure to pure oxygen in a pressurized room, and it is an already well-established treatment for various conditions, including those originated by serious infections. Starting from the observation of an increased number of patients who were accessing our HBO units for diseases supported from concomitant multidrug-resistant microorganisms, as well as considering the evident clinical benefit and laboratory final outcome of those patients at the end of the treatment, aim of our study was to measure, or better define at least, if there was any interaction between a hyperbaric environment and some selected microorganisms and if those positive results were due to the increased oxygen partial pressure (pO2 value or just to the increased pressure, regardless of the fraction of inspired oxygen (FiO2 applied (21÷100%. Design and methods We applied various increased pO2 values in a hyperbaric environment. Our study design was tailored in four steps to answer four specific questions, ordered in a progressive process: OxyBioTest (OBT-1,2,3, and 4. Specifically, we chose to investigate possible changes in the Minimum Inhibitory Concentration (MIC and in the Minimum Bactericidal Concentration (MBC of multi-resistant microorganisms after a single session of hyperbaric therapy. Results OBT-1 and OBT-2 provide a semi-quantitative confirmation of the bacterio-cidal and cytostatic effects of HBO. HBO is cidal only if the total exposure pressure is elevated, and cidal or cytostatic effect are not always dependent on the pO2 applied. OBT-4 has shown the adjuvant effect of HBO and antimicrobial drug against some selected bacteria. Discussion We seem allowed to hypothesize that only in case of a good approach to a lesion, permitting smaller bacterial loads thanks to surgical debridement and/or eventual antibiotic therapy for example, You can observe the clear effectiveness of the HyperBaric Oxygen (HBO

A Molecular Dynamics Study on Selective Cation Depletion from an Ionic Liquid Droplet under an Electric Field

Science.gov (United States)

Yang, Yudong; Ahn, Myungmo; Im, Dojin; Oh, Jungmin; Kang, Inseok

2017-11-01

General electrohydrodynamic behavior of ionic liquid droplets under an electric field is investigated using MD simulations. Especially, a unique behavior of ion depletion of an ionic liquid droplet under a uniform electric field is studied. Shape deformation due to electric stress and ion distributions inside the droplet are calculated to understand the ionic motion of imidazolium-based ionic liquid droplets with 200 ion pairs of 2 kinds of ionic liquids: EMIM-NTf2 and EMIM-ES. The intermolecular force between cations and anions can be significantly different due to the nature of the structure and charge distribution of the ions. Together with an analytical interpretation of the conducting droplet in an electric field, the MD simulation successfully explains the mechanism of selective ion depletion of an ionic liquid droplet in an electric field. The selective ion depletion phenomenon has been adopted to explain the experimentally observed retreating motion of a droplet in a uniform electric field. The effect of anions on the cation depletion phenomenon can be accounted for from a direct approach to the intermolecular interaction. This research was supproted by the National Research Foundation of Korea (NRF) Grant funded by the Korea government (MSIP) (No. 2017R1D1A1B05035211).

Repeated adaptive introgression at a gene under multiallelic balancing selection.

Directory of Open Access Journals (Sweden)

Vincent Castric

2008-08-01

Full Text Available Recently diverged species typically have incomplete reproductive barriers, allowing introgression of genetic material from one species into the genomic background of the other. The role of natural selection in preventing or promoting introgression remains contentious. Because of genomic co-adaptation, some chromosomal fragments are expected to be selected against in the new background and resist introgression. In contrast, natural selection should favor introgression for alleles at genes evolving under multi-allelic balancing selection, such as the MHC in vertebrates, disease resistance, or self-incompatibility genes in plants. Here, we test the prediction that negative, frequency-dependent selection on alleles at the multi-allelic gene controlling pistil self-incompatibility specificity in two closely related species, Arabidopsis halleri and A. lyrata, caused introgression at this locus at a higher rate than the genomic background. Polymorphism at this gene is largely shared, and we have identified 18 pairs of S-alleles that are only slightly divergent between the two species. For these pairs of S-alleles, divergence at four-fold degenerate sites (K = 0.0193 is about four times lower than the genomic background (K = 0.0743. We demonstrate that this difference cannot be explained by differences in effective population size between the two types of loci. Rather, our data are most consistent with a five-fold increase of introgression rates for S-alleles as compared to the genomic background, making this study the first documented example of adaptive introgression facilitated by balancing selection. We suggest that this process plays an important role in the maintenance of high allelic diversity and divergence at the S-locus in flowering plant families. Because genes under balancing selection are expected to be among the last to stop introgressing, their comparison in closely related species provides a lower-bound estimate of the time since the

Word learning emerges from the interaction of online referent selection and slow associative learning

Science.gov (United States)

McMurray, Bob; Horst, Jessica S.; Samuelson, Larissa K.

2013-01-01

Classic approaches to word learning emphasize the problem of referential ambiguity: in any naming situation the referent of a novel word must be selected from many possible objects, properties, actions, etc. To solve this problem, researchers have posited numerous constraints, and inference strategies, but assume that determining the referent of a novel word is isomorphic to learning. We present an alternative model in which referent selection is an online process that is independent of long-term learning. This two timescale approach creates significant power in the developing system. We illustrate this with a dynamic associative model in which referent selection is simulated as dynamic competition between competing referents, and learning is simulated using associative (Hebbian) learning. This model can account for a range of findings including the delay in expressive vocabulary relative to receptive vocabulary, learning under high degrees of referential ambiguity using cross-situational statistics, accelerating (vocabulary explosion) and decelerating (power-law) learning rates, fast-mapping by mutual exclusivity (and differences in bilinguals), improvements in familiar word recognition with development, and correlations between individual differences in speed of processing and learning. Five theoretical points are illustrated. 1) Word learning does not require specialized processes – general association learning buttressed by dynamic competition can account for much of the literature. 2) The processes of recognizing familiar words are not different than those that support novel words (e.g., fast-mapping). 3) Online competition may allow the network (or child) to leverage information available in the task to augment performance or behavior despite what might be relatively slow learning or poor representations. 4) Even associative learning is more complex than previously thought – a major contributor to performance is the pruning of incorrect associations

Investigating the Nature of GxE Interaction under Different ...

African Journals Online (AJOL)

selection of stress-tolerant genotypes under managed stress conditions. ... breeding and work towards disaggregating it and adjusting parameters for its ... About 51% of trials in 2008 were classified as low yielders, which was high .... flexible and have several benefits, often a maximum of FA(2) is fitted and the Eigen.

Ultrahigh-dimensional variable selection method for whole-genome gene-gene interaction analysis

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Ueki Masao

2012-05-01

Full Text Available Abstract Background Genome-wide gene-gene interaction analysis using single nucleotide polymorphisms (SNPs is an attractive way for identification of genetic components that confers susceptibility of human complex diseases. Individual hypothesis testing for SNP-SNP pairs as in common genome-wide association study (GWAS however involves difficulty in setting overall p-value due to complicated correlation structure, namely, the multiple testing problem that causes unacceptable false negative results. A large number of SNP-SNP pairs than sample size, so-called the large p small n problem, precludes simultaneous analysis using multiple regression. The method that overcomes above issues is thus needed. Results We adopt an up-to-date method for ultrahigh-dimensional variable selection termed the sure independence screening (SIS for appropriate handling of numerous number of SNP-SNP interactions by including them as predictor variables in logistic regression. We propose ranking strategy using promising dummy coding methods and following variable selection procedure in the SIS method suitably modified for gene-gene interaction analysis. We also implemented the procedures in a software program, EPISIS, using the cost-effective GPGPU (General-purpose computing on graphics processing units technology. EPISIS can complete exhaustive search for SNP-SNP interactions in standard GWAS dataset within several hours. The proposed method works successfully in simulation experiments and in application to real WTCCC (Wellcome Trust Case–control Consortium data. Conclusions Based on the machine-learning principle, the proposed method gives powerful and flexible genome-wide search for various patterns of gene-gene interaction.

A selection that reports on protein-protein interactions within a thermophilic bacterium.

Science.gov (United States)

Nguyen, Peter Q; Silberg, Jonathan J

2010-07-01

Many proteins can be split into fragments that exhibit enhanced function upon fusion to interacting proteins. While this strategy has been widely used to create protein-fragment complementation assays (PCAs) for discovering protein-protein interactions within mesophilic organisms, similar assays have not yet been developed for studying natural and engineered protein complexes at the temperatures where thermophilic microbes grow. We describe the development of a selection for protein-protein interactions within Thermus thermophilus that is based upon growth complementation by fragments of Thermotoga neapolitana adenylate kinase (AK(Tn)). Complementation studies with an engineered thermophile (PQN1) that is not viable above 75 degrees C because its adk gene has been replaced by a Geobacillus stearothermophilus ortholog revealed that growth could be restored at 78 degrees C by a vector that coexpresses polypeptides corresponding to residues 1-79 and 80-220 of AK(Tn). In contrast, PQN1 growth was not complemented by AK(Tn) fragments harboring a C156A mutation within the zinc-binding tetracysteine motif unless these fragments were fused to Thermotoga maritima chemotaxis proteins that heterodimerize (CheA and CheY) or homodimerize (CheX). This enhanced complementation is interpreted as arising from chemotaxis protein-protein interactions, since AK(Tn)-C156A fragments having only one polypeptide fused to a chemotaxis protein did not complement PQN1 to the same extent. This selection increases the maximum temperature where a PCA can be used to engineer thermostable protein complexes and to map protein-protein interactions.

Statistical aspects of evolution under natural selection, with implications for the advantage of sexual reproduction.

Science.gov (United States)

Crouch, Daniel J M

2017-10-27

The prevalence of sexual reproduction remains mysterious, as it poses clear evolutionary drawbacks compared to reproducing asexually. Several possible explanations exist, with one of the most likely being that finite population size causes linkage disequilibria to randomly generate and impede the progress of natural selection, and that these are eroded by recombination via sexual reproduction. Previous investigations have either analysed this phenomenon in detail for small numbers of loci, or performed population simulations for many loci. Here we present a quantitative genetic model for fitness, based on the Price Equation, in order to examine the theoretical consequences of randomly generated linkage disequilibria when there are many loci. In addition, most previous work has been concerned with the long-term consequences of deleterious linkage disequilibria for population fitness. The expected change in mean fitness between consecutive generations, a measure of short-term evolutionary success, is shown under random environmental influences to be related to the autocovariance in mean fitness between the generations, capturing the effects of stochastic forces such as genetic drift. Interaction between genetic drift and natural selection, due to randomly generated linkage disequilibria, is demonstrated to be one possible source of mean fitness autocovariance. This suggests a possible role for sexual reproduction in reducing the negative effects of genetic drift, thereby improving the short-term efficacy of natural selection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genomic selection improves response to selection in resilience by exploiting genotype by environment interactions

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Han Mulder

2016-10-01

Full Text Available Genotype by environment interactions (GxE are very common in livestock and hamper genetic improvement. On the other hand, GxE is a source of genetic variation: genetic variation in response to environment, e.g. environmental perturbations such as heat stress or disease. In livestock breeding, there is tendency to ignore GxE because of increased complexity of models for genetic evaluations and lack of accuracy in extreme environments. GxE, however, creates opportunities to increase resilience of animals towards environmental perturbations. The main aim of the paper is to investigate to which extent GxE can be exploited with traditional and genomic selection methods. Furthermore, we investigated the benefit of reaction norm models compared to conventional methods ignoring GxE. The questions were addressed with selection index theory. GxE was modelled according to a linear reaction norm model in which the environmental gradient is the contemporary group mean. Economic values were based on linear and non-linear profit equations.Accuracies of environment-specific (GEBV were highest in intermediate environments and lowest in extreme environments. Reaction norm models had higher accuracies of (GEBV in extreme environments than conventional models ignoring GxE. Genomic selection always resulted in higher response to selection in all environments than sib or progeny testing schemes. The increase in response was with genomic selection between 9% and 140% compared to sib testing and between 11% and 114% compared to progeny testing when the reference population consisted of 1 million animals across all environments. When the aim was to decrease environmental sensitivity, the response in slope of the reaction norm model with genomic selection was between 1.09 and 319 times larger than with sib or progeny testing and in the right direction in contrast to sib and progeny testing that still increased environmental sensitivity. This shows that genomic selection

Interactive prostate segmentation using atlas-guided semi-supervised learning and adaptive feature selection

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Hyun [Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Gao, Yaozong, E-mail: yzgao@cs.unc.edu [Department of Computer Science, Department of Radiology, and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Shi, Yinghuan, E-mail: syh@nju.edu.cn [State Key Laboratory for Novel Software Technology, Nanjing University, Nanjing 210023 (China); Shen, Dinggang, E-mail: dgshen@med.unc.edu [Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 and Department of Brain and Cognitive Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

2014-11-01

Purpose: Accurate prostate segmentation is necessary for maximizing the effectiveness of radiation therapy of prostate cancer. However, manual segmentation from 3D CT images is very time-consuming and often causes large intra- and interobserver variations across clinicians. Many segmentation methods have been proposed to automate this labor-intensive process, but tedious manual editing is still required due to the limited performance. In this paper, the authors propose a new interactive segmentation method that can (1) flexibly generate the editing result with a few scribbles or dots provided by a clinician, (2) fast deliver intermediate results to the clinician, and (3) sequentially correct the segmentations from any type of automatic or interactive segmentation methods. Methods: The authors formulate the editing problem as a semisupervised learning problem which can utilize a priori knowledge of training data and also the valuable information from user interactions. Specifically, from a region of interest near the given user interactions, the appropriate training labels, which are well matched with the user interactions, can be locally searched from a training set. With voting from the selected training labels, both confident prostate and background voxels, as well as unconfident voxels can be estimated. To reflect informative relationship between voxels, location-adaptive features are selected from the confident voxels by using regression forest and Fisher separation criterion. Then, the manifold configuration computed in the derived feature space is enforced into the semisupervised learning algorithm. The labels of unconfident voxels are then predicted by regularizing semisupervised learning algorithm. Results: The proposed interactive segmentation method was applied to correct automatic segmentation results of 30 challenging CT images. The correction was conducted three times with different user interactions performed at different time periods, in order to

Interactive prostate segmentation using atlas-guided semi-supervised learning and adaptive feature selection

International Nuclear Information System (INIS)

Park, Sang Hyun; Gao, Yaozong; Shi, Yinghuan; Shen, Dinggang

2014-01-01

Purpose: Accurate prostate segmentation is necessary for maximizing the effectiveness of radiation therapy of prostate cancer. However, manual segmentation from 3D CT images is very time-consuming and often causes large intra- and interobserver variations across clinicians. Many segmentation methods have been proposed to automate this labor-intensive process, but tedious manual editing is still required due to the limited performance. In this paper, the authors propose a new interactive segmentation method that can (1) flexibly generate the editing result with a few scribbles or dots provided by a clinician, (2) fast deliver intermediate results to the clinician, and (3) sequentially correct the segmentations from any type of automatic or interactive segmentation methods. Methods: The authors formulate the editing problem as a semisupervised learning problem which can utilize a priori knowledge of training data and also the valuable information from user interactions. Specifically, from a region of interest near the given user interactions, the appropriate training labels, which are well matched with the user interactions, can be locally searched from a training set. With voting from the selected training labels, both confident prostate and background voxels, as well as unconfident voxels can be estimated. To reflect informative relationship between voxels, location-adaptive features are selected from the confident voxels by using regression forest and Fisher separation criterion. Then, the manifold configuration computed in the derived feature space is enforced into the semisupervised learning algorithm. The labels of unconfident voxels are then predicted by regularizing semisupervised learning algorithm. Results: The proposed interactive segmentation method was applied to correct automatic segmentation results of 30 challenging CT images. The correction was conducted three times with different user interactions performed at different time periods, in order to

In vitro Selection and Interaction Studies of a DNA Aptamer Targeting Protein A.

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Regina Stoltenburg

Full Text Available A new DNA aptamer targeting Protein A is presented. The aptamer was selected by use of the FluMag-SELEX procedure. The SELEX technology (Systematic Evolution of Ligands by EXponential enrichment is widely applied as an in vitro selection and amplification method to generate target-specific aptamers and exists in various modified variants. FluMag-SELEX is one of them and is characterized by the use of magnetic beads for target immobilization and fluorescently labeled oligonucleotides for monitoring the aptamer selection progress. Structural investigations and sequence truncation experiments of the selected aptamer for Protein A led to the conclusion, that a stem-loop structure at its 5'-end including the 5'-primer binding site is essential for aptamer-target binding. Extensive interaction analyses between aptamer and Protein A were performed by methods like surface plasmon resonance, MicroScale Thermophoresis and bead-based binding assays using fluorescence measurements. The binding of the aptamer to its target was thus investigated in assays with immobilization of one of the binding partners each, and with both binding partners in solution. Affinity constants were determined in the low micromolar to submicromolar range, increasing to the nanomolar range under the assumption of avidity. Protein A provides more than one binding site for the aptamer, which may overlap with the known binding sites for immunoglobulins. The aptamer binds specifically to both native and recombinant Protein A, but not to other immunoglobulin-binding proteins like Protein G and L. Cross specificity to other proteins was not found. The application of the aptamer is directed to Protein A detection or affinity purification. Moreover, whole cells of Staphylococcus aureus, presenting Protein A on the cell surface, could also be bound by the aptamer.

In vitro Selection and Interaction Studies of a DNA Aptamer Targeting Protein A.

Science.gov (United States)

Stoltenburg, Regina; Schubert, Thomas; Strehlitz, Beate

2015-01-01

A new DNA aptamer targeting Protein A is presented. The aptamer was selected by use of the FluMag-SELEX procedure. The SELEX technology (Systematic Evolution of Ligands by EXponential enrichment) is widely applied as an in vitro selection and amplification method to generate target-specific aptamers and exists in various modified variants. FluMag-SELEX is one of them and is characterized by the use of magnetic beads for target immobilization and fluorescently labeled oligonucleotides for monitoring the aptamer selection progress. Structural investigations and sequence truncation experiments of the selected aptamer for Protein A led to the conclusion, that a stem-loop structure at its 5'-end including the 5'-primer binding site is essential for aptamer-target binding. Extensive interaction analyses between aptamer and Protein A were performed by methods like surface plasmon resonance, MicroScale Thermophoresis and bead-based binding assays using fluorescence measurements. The binding of the aptamer to its target was thus investigated in assays with immobilization of one of the binding partners each, and with both binding partners in solution. Affinity constants were determined in the low micromolar to submicromolar range, increasing to the nanomolar range under the assumption of avidity. Protein A provides more than one binding site for the aptamer, which may overlap with the known binding sites for immunoglobulins. The aptamer binds specifically to both native and recombinant Protein A, but not to other immunoglobulin-binding proteins like Protein G and L. Cross specificity to other proteins was not found. The application of the aptamer is directed to Protein A detection or affinity purification. Moreover, whole cells of Staphylococcus aureus, presenting Protein A on the cell surface, could also be bound by the aptamer.

Plant neighbour identity matters to belowground interactions under controlled conditions.

Science.gov (United States)

Armas, Cristina; Pugnaire, Francisco Ignacio

2011-01-01

Root competition is an almost ubiquitous feature of plant communities with profound effects on their structure and composition. Far beyond the traditional view that plants interact mainly through resource depletion (exploitation competition), roots are known to be able to interact with their environment using a large variety of mechanisms that may inhibit or enhance access of other roots to the resource or affect plant growth (contest interactions). However, an extensive analysis on how these contest root interactions may affect species interaction abilities is almost lacking. In a common garden experiment with ten perennial plant species we forced pairs of plants of the same or different species to overlap their roots and analyzed how belowground contest interactions affected plant performance, biomass allocation patterns, and competitive abilities under abundant resource supply. Our results showed that net interaction outcome ranged from negative to positive, affecting total plant mass and allocation patterns. A species could be a strong competitor against one species, weaker against another one, and even facilitator to a third species. This leads to sets of species where competitive hierarchies may be clear but also to groups where such rankings are not, suggesting that intransitive root interactions may be crucial for species coexistence. The outcome of belowground contest interactions is strongly dependent on neighbours' identity. In natural plant communities this conditional outcome may hypothetically help species to interact in non-hierarchical and intransitive networks, which in turn might promote coexistence.

Interspecific Competition Underlying Mutualistic Networks

Science.gov (United States)

Maeng, Seong Eun; Lee, Jae Woo; Lee, Deok-Sun

2012-03-01

Multiple classes of interactions may exist affecting one another in a given system. For the mutualistic networks of plants and pollinating animals, it has been known that the degree distribution is broad but often deviates from power-law form more significantly for plants than animals. To illuminate the origin of such asymmetry, we study a model network in which links are assigned under generalized preferential-selection rules between two groups of nodes and find the sensitive dependence of the resulting connectivity pattern on the model parameters. The nonlinearity of preferential selection can come from interspecific interactions among animals and among plants. The model-based analysis of real-world mutualistic networks suggests that a new animal determines its partners not only by their abundance but also under the competition with existing animal species, which leads to the stretched-exponential degree distributions of plants.

Lines of Descent Under Selection

Science.gov (United States)

Baake, Ellen; Wakolbinger, Anton

2017-11-01

We review recent progress on ancestral processes related to mutation-selection models, both in the deterministic and the stochastic setting. We mainly rely on two concepts, namely, the killed ancestral selection graph and the pruned lookdown ancestral selection graph. The killed ancestral selection graph gives a representation of the type of a random individual from a stationary population, based upon the individual's potential ancestry back until the mutations that define the individual's type. The pruned lookdown ancestral selection graph allows one to trace the ancestry of individuals from a stationary distribution back into the distant past, thus leading to the stationary distribution of ancestral types. We illustrate the results by applying them to a prototype model for the error threshold phenomenon.

Increased prediction accuracy in wheat breeding trials using a marker × environment interaction genomic selection model.

Science.gov (United States)

Lopez-Cruz, Marco; Crossa, Jose; Bonnett, David; Dreisigacker, Susanne; Poland, Jesse; Jannink, Jean-Luc; Singh, Ravi P; Autrique, Enrique; de los Campos, Gustavo

2015-02-06

Genomic selection (GS) models use genome-wide genetic information to predict genetic values of candidates of selection. Originally, these models were developed without considering genotype × environment interaction(G×E). Several authors have proposed extensions of the single-environment GS model that accommodate G×E using either covariance functions or environmental covariates. In this study, we model G×E using a marker × environment interaction (M×E) GS model; the approach is conceptually simple and can be implemented with existing GS software. We discuss how the model can be implemented by using an explicit regression of phenotypes on markers or using co-variance structures (a genomic best linear unbiased prediction-type model). We used the M×E model to analyze three CIMMYT wheat data sets (W1, W2, and W3), where more than 1000 lines were genotyped using genotyping-by-sequencing and evaluated at CIMMYT's research station in Ciudad Obregon, Mexico, under simulated environmental conditions that covered different irrigation levels, sowing dates and planting systems. We compared the M×E model with a stratified (i.e., within-environment) analysis and with a standard (across-environment) GS model that assumes that effects are constant across environments (i.e., ignoring G×E). The prediction accuracy of the M×E model was substantially greater of that of an across-environment analysis that ignores G×E. Depending on the prediction problem, the M×E model had either similar or greater levels of prediction accuracy than the stratified analyses. The M×E model decomposes marker effects and genomic values into components that are stable across environments (main effects) and others that are environment-specific (interactions). Therefore, in principle, the interaction model could shed light over which variants have effects that are stable across environments and which ones are responsible for G×E. The data set and the scripts required to reproduce the analysis are

Social phenotype extended to communities: expanded multilevel social selection analysis reveals fitness consequences of interspecific interactions.

Science.gov (United States)

Campobello, Daniela; Hare, James F; Sarà, Maurizio

2015-04-01

In social species, fitness consequences are associated with both individual and social phenotypes. Social selection analysis has quantified the contribution of conspecific social traits to individual fitness. There has been no attempt, however, to apply a social selection approach to quantify the fitness implications of heterospecific social phenotypes. Here, we propose a novel social selection based approach integrating the role of all social interactions at the community level. We extended multilevel selection analysis by including a term accounting for the group phenotype of heterospecifics. We analyzed nest activity as a model social trait common to two species, the lesser kestrel (Falco naumanni) and jackdaw (Corvus monedula), nesting in either single- or mixed-species colonies. By recording reproductive outcome as a measure of relative fitness, our results reveal an asymmetric system wherein only jackdaw breeding performance was affected by the activity phenotypes of both conspecific and heterospecific neighbors. Our model incorporating heterospecific social phenotypes is applicable to animal communities where interacting species share a common social trait, thus allowing an assessment of the selection pressure imposed by interspecific interactions in nature. Finally, we discuss the potential role of ecological limitations accounting for random or preferential assortments among interspecific social phenotypes, and the implications of such processes to community evolution. © 2015 The Author(s).

Evolution of branched regulatory genetic pathways: directional selection on pleiotropic loci accelerates developmental system drift.

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Johnson, Norman A; Porter, Adam H

2007-01-01

Developmental systems are regulated by a web of interacting loci. One common and useful approach in studying the evolution of development is to focus on classes of interacting elements within these systems. Here, we use individual-based simulations to study the evolution of traits controlled by branched developmental pathways involving three loci, where one locus regulates two different traits. We examined the system under a variety of selective regimes. In the case where one branch was under stabilizing selection and the other under directional selection, we observed "developmental system drift": the trait under stabilizing selection showed little phenotypic change even though the loci underlying that trait showed considerable evolutionary divergence. This occurs because the pleiotropic locus responds to directional selection and compensatory mutants are then favored in the pathway under stabilizing selection. Though developmental system drift may be caused by other mechanisms, it seems likely that it is accelerated by the same underlying genetic mechanism as that producing the Dobzhansky-Muller incompatibilities that lead to speciation in both linear and branched pathways. We also discuss predictions of our model for developmental system drift and how different selective regimes affect probabilities of speciation in the branched pathway system.

The effect of subdivision on variation at multi-allelic loci under balancing selection

DEFF Research Database (Denmark)

Schierup, M H; Vekemans, X; Charlesworth, D

2000-01-01

Simulations are used to investigate the expected pattern of variation at loci under different forms of multi-allelic balancing selection in a finite island model of a subdivided population. The objective is to evaluate the effect of restricted migration among demes on the distribution of polymorp......Simulations are used to investigate the expected pattern of variation at loci under different forms of multi-allelic balancing selection in a finite island model of a subdivided population. The objective is to evaluate the effect of restricted migration among demes on the distribution...

Disgust selectively modulates reciprocal fairness in economic interactions.

Science.gov (United States)

Moretti, Laura; di Pellegrino, Giuseppe

2010-04-01

We report two studies aimed at investigating the effects of distinct negative emotions on pairwise economic interactions. In the ultimatum game, a proposer offers a division of a sum of money to a responder who decides whether to accept the split, or reject and leave both players with nothing. In Experiment 1, we investigated whether induced disgust, as compared to sadness and neutral emotion, specifically influences responders' decisions to reject unfair proposals. In Experiment 2, we assessed whether the effects of disgust were selectively related to social contexts by contrasting interactions with a human partner with those involving a computer. Results showed that relative to being in a sad or neutral mood, induced feelings of disgust significantly increased rejection rates of unfair offers. Moreover, we found that when the partner was not responsible for the fairness violation, such as in the computer-offer condition, the disgust induction failed to affect participants' choices. We conclude by focusing on the hypothesis that disgust and social norm violations may share common computational components, both at a psychological and a neural level. Copyright 2010 APA, all rights reserved.

Selective Attention Enhances Beta-Band Cortical Oscillation to Speech under "Cocktail-Party" Listening Conditions.

Science.gov (United States)

Gao, Yayue; Wang, Qian; Ding, Yu; Wang, Changming; Li, Haifeng; Wu, Xihong; Qu, Tianshu; Li, Liang

2017-01-01

Human listeners are able to selectively attend to target speech in a noisy environment with multiple-people talking. Using recordings of scalp electroencephalogram (EEG), this study investigated how selective attention facilitates the cortical representation of target speech under a simulated "cocktail-party" listening condition with speech-on-speech masking. The result shows that the cortical representation of target-speech signals under the multiple-people talking condition was specifically improved by selective attention relative to the non-selective-attention listening condition, and the beta-band activity was most strongly modulated by selective attention. Moreover, measured with the Granger Causality value, selective attention to the single target speech in the mixed-speech complex enhanced the following four causal connectivities for the beta-band oscillation: the ones (1) from site FT7 to the right motor area, (2) from the left frontal area to the right motor area, (3) from the central frontal area to the right motor area, and (4) from the central frontal area to the right frontal area. However, the selective-attention-induced change in beta-band causal connectivity from the central frontal area to the right motor area, but not other beta-band causal connectivities, was significantly correlated with the selective-attention-induced change in the cortical beta-band representation of target speech. These findings suggest that under the "cocktail-party" listening condition, the beta-band oscillation in EEGs to target speech is specifically facilitated by selective attention to the target speech that is embedded in the mixed-speech complex. The selective attention-induced unmasking of target speech may be associated with the improved beta-band functional connectivity from the central frontal area to the right motor area, suggesting a top-down attentional modulation of the speech-motor process.

Nogo-A couples with Apg-1 through interaction and co-ordinate expression under hypoxic and oxidative stress.

Science.gov (United States)

Kern, Florian; Stanika, Ruslan I; Sarg, Bettina; Offterdinger, Martin; Hess, Daniel; Obermair, Gerald J; Lindner, Herbert; Bandtlow, Christine E; Hengst, Ludger; Schweigreiter, Rüdiger

2013-10-15

Nogo-A is the largest isoform of the Nogo/RTN4 (reticulon 4) proteins and has been characterized as a major myelin-associated inhibitor of regenerative nerve growth in the adult CNS (central nervous system). Apart from the myelin sheath, Nogo-A is expressed at high levels in principal neurons of the CNS. The specificity of Nogo-A resides in its central domain, NiG. We identified Apg-1, a member of the stress-induced Hsp110 (heat-shock protein of 110 kDa) family, as a novel interactor of NiG/Nogo-A. The interaction is selective because Apg-1 interacts with Nogo-A/RTN4-A, but not with RTN1-A, the closest paralogue of Nogo-A. Conversely, Nogo-A binds to Apg-1, but not to Apg-2 or Hsp105, two other members of the Hsp110 family. We characterized the Nogo-A-Apg-1 interaction by affinity precipitation, co-immunoprecipitation and proximity ligation assay, using primary hippocampal neurons derived from Nogo-deficient mice. Under conditions of hypoxic and oxidative stress we found that Nogo-A and Apg-1 were tightly co-regulated in hippocampal neurons. Although both proteins were up-regulated under hypoxic conditions, their expression levels were reduced upon the addition of hydrogen peroxide. Taken together, we suggest that Nogo-A is closely involved in the neuronal response to hypoxic and oxidative stress, an observation that may be of relevance not only in stroke-induced ischaemia, but also in neuroblastoma formation.

Evolutionary dynamics under interactive diversity

Science.gov (United States)

Su, Qi; Li, Aming; Wang, Long

2017-10-01

As evidenced by many cases in human societies, individuals often make different behavior decisions in different interactions, and adaptively adjust their behavior in changeable interactive scenarios. However, up to now, how such diverse interactive behavior affects cooperation dynamics has still remained unknown. Here we develop a general framework of interactive diversity, which models individuals’ separated behavior against distinct opponents and their adaptive adjustment in response to opponents’ strategies, to explore the evolution of cooperation. We find that interactive diversity enables individuals to reciprocate every single opponent, and thus sustains large-scale reciprocal interactions. Our work witnesses an impressive boost of cooperation for a notably extensive range of parameters and for all pairwise games. These results are robust against well-mixed and various networked populations, and against degree-normalized and cumulative payoff patterns. From the perspective of network dynamics, distinguished from individuals competing for nodes in most previous work, in this paper, the system evolves in the form of behavior disseminating along edges. We propose a theoretical method based on evolution of edges, which predicts well both the frequency of cooperation and the compact cooperation clusters. Our thorough investigation clarifies the positive role of interactive diversity in resolving social dilemmas and highlights the significance of understanding evolutionary dynamics from the viewpoint of edge dynamics.

5 CFR 335.106 - Special selection procedures for certain veterans under merit promotion.

Science.gov (United States)

2010-01-01

... veterans under merit promotion. 335.106 Section 335.106 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PROMOTION AND INTERNAL PLACEMENT General Provisions § 335.106 Special selection procedures for certain veterans under merit promotion. Preference eligibles or veterans who have...

Combined modeling of cell aggregation and adhesion mediated by receptor–ligand interactions under shear flow

Directory of Open Access Journals (Sweden)

Yu Du

2015-11-01

Full Text Available Blood cell aggregation and adhesion to endothelial cells under shear flow are crucial to many biological processes such as thrombi formation, inflammatory cascade, and tumor metastasis, in which these cellular interactions are mainly mediated by the underlying receptor–ligand bindings. While theoretical modeling of aggregation dynamics and adhesion kinetics of interacting cells have been well studied separately, how to couple these two processes remains unclear. Here we develop a combined model that couples cellular aggregation dynamics and adhesion kinetics under shear flow. The impacts of shear rate (or shear stress and molecular binding affinity were elucidated. This study provides a unified model where the action of a fluid flow drives cell aggregation and adhesion under the modulations of the mechanical shear flow and receptor–ligand interaction kinetics. It offers an insight into understanding the relevant biological processes and functions.

Training set optimization under population structure in genomic selection.

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Isidro, Julio; Jannink, Jean-Luc; Akdemir, Deniz; Poland, Jesse; Heslot, Nicolas; Sorrells, Mark E

2015-01-01

Population structure must be evaluated before optimization of the training set population. Maximizing the phenotypic variance captured by the training set is important for optimal performance. The optimization of the training set (TRS) in genomic selection has received much interest in both animal and plant breeding, because it is critical to the accuracy of the prediction models. In this study, five different TRS sampling algorithms, stratified sampling, mean of the coefficient of determination (CDmean), mean of predictor error variance (PEVmean), stratified CDmean (StratCDmean) and random sampling, were evaluated for prediction accuracy in the presence of different levels of population structure. In the presence of population structure, the most phenotypic variation captured by a sampling method in the TRS is desirable. The wheat dataset showed mild population structure, and CDmean and stratified CDmean methods showed the highest accuracies for all the traits except for test weight and heading date. The rice dataset had strong population structure and the approach based on stratified sampling showed the highest accuracies for all traits. In general, CDmean minimized the relationship between genotypes in the TRS, maximizing the relationship between TRS and the test set. This makes it suitable as an optimization criterion for long-term selection. Our results indicated that the best selection criterion used to optimize the TRS seems to depend on the interaction of trait architecture and population structure.

Interactive versus passive distraction for acute pain management in young children: the role of selective attention and development.

Science.gov (United States)

Wohlheiter, Karen A; Dahlquist, Lynnda M

2013-03-01

To examine whether age and developmental differences in selective attention influence young children's differential responses to interactive and passive distraction. 65 3- to 6-year-old children underwent three cold-pressor trials while receiving no intervention, playing a video game (interactive distraction), or watching a video game (passive distraction). In addition, children completed a test of selective attention, and parents completed ratings of attention. Consistent with neurocognitive models of pain, children benefited more from interactive distraction than from passive distraction. Although older children demonstrated superior pain tolerance overall, age and selective attention skills did not moderate children's responses to the distraction intervention. These findings suggest that younger preschoolers can benefit from interactive distraction to manage acute pain, provided that the distraction activity is developmentally appropriate. Research is needed to determine whether developmental issues are more important moderators of children's responses to distraction when faced with more challenging task demands.

Expected utility violations evolve under status-based selection mechanisms.

Science.gov (United States)

Dickson, Eric S

2008-10-07

The expected utility theory of decision making under uncertainty, a cornerstone of modern economics, assumes that humans linearly weight "utilities" for different possible outcomes by the probabilities with which these outcomes occur. Despite the theory's intuitive appeal, both from normative and from evolutionary perspectives, many experiments demonstrate systematic, though poorly understood, patterns of deviation from EU predictions. This paper offers a novel theoretical account of such patterns of deviation by demonstrating that EU violations can emerge from evolutionary selection when individual "status" affects inclusive fitness. In humans, battles for resources and social standing involve high-stakes decision making, and assortative mating ensures that status matters for fitness outcomes. The paper therefore proposes grounding the study of decision making under uncertainty in an evolutionary game-theoretic framework.

Selective Interaction of a Cationic Polyfluorene with Model Lipid Membranes: Anionic versus Zwitterionic Lipids

Directory of Open Access Journals (Sweden)

Zehra Kahveci

2014-03-01

Full Text Available This paper explores the interaction mechanism between the conjugated polyelectrolyte {[9,9-bis(6'-N,N,N-trimethylammoniumhexyl]fluorene-phenylene}bromide (HTMA-PFP and model lipid membranes. The study was carried out using different biophysical techniques, mainly fluorescence spectroscopy and microscopy. Results show that despite the preferential interaction of HTMA-PFP with anionic lipids, HTMA-PFP shows affinity for zwitterionic lipids; although the interaction mechanism is different as well as HTMA-PFP’s final membrane location. Whilst the polyelectrolyte is embedded within the lipid bilayer in the anionic membrane, it remains close to the surface, forming aggregates that are sensitive to the physical state of the lipid bilayer in the zwitterionic system. The different interaction mechanism is reflected in the polyelectrolyte fluorescence spectrum, since the maximum shifts to longer wavelengths in the zwitterionic system. The intrinsic fluorescence of HTMA-PFP was used to visualize the interaction between polymer and vesicles via fluorescence microscopy, thanks to its high quantum yield and photostability. This technique allows the selectivity of the polyelectrolyte and higher affinity for anionic membranes to be observed. The results confirmed the appropriateness of using HTMA-PFP as a membrane fluorescent marker and suggest that, given its different behaviour towards anionic and zwitterionic membranes, HTMA-PFP could be used for selective recognition and imaging of bacteria over mammalian cells.

Fixation times in evolutionary games under weak selection

International Nuclear Information System (INIS)

Altrock, Philipp M; Traulsen, Arne

2009-01-01

In evolutionary game dynamics, reproductive success increases with the performance in an evolutionary game. If strategy A performs better than strategy B, strategy A will spread in the population. Under stochastic dynamics, a single mutant will sooner or later take over the entire population or go extinct. We analyze the mean exit times (or average fixation times) associated with this process. We show analytically that these times depend on the payoff matrix of the game in an amazingly simple way under weak selection, i.e. strong stochasticity: the payoff difference Δπ is a linear function of the number of A individuals i, Δπ=u i+v. The unconditional mean exit time depends only on the constant term v. Given that a single A mutant takes over the population, the corresponding conditional mean exit time depends only on the density dependent term u. We demonstrate this finding for two commonly applied microscopic evolutionary processes.

Weighted overlap dominance – a procedure for interactive selection on multidimensional interval data

DEFF Research Database (Denmark)

Hougaard, Jens Leth; Nielsen, Kurt

2011-01-01

We present an outranking procedure that supports selection of alternatives represented by multiple attributes with interval valued data. The procedure is interactive in the sense that the decision maker directs the search for preferred alternatives by providing weights of the different attributes...

Proximity of signallers can maintain sexual signal variation under stabilizing selection

NARCIS (Netherlands)

van Wijk, M.; Heath, J.; Lievers, R.; Schal, C.; Groot, A.T.

2017-01-01

How sexual communication systems can evolve under stabilizing selection is still a paradox in evolutionary biology. In moths, females emit a species-specific sex pheromone, consisting of a blend of biochemically related components, to which males are attracted. Although males appear to exert strong

Diverse effects of arsenic on selected enzyme activities in soil-plant-microbe interactions.

Science.gov (United States)

Lyubun, Yelena V; Pleshakova, Ekaterina V; Mkandawire, Martin; Turkovskaya, Olga V

2013-11-15

Under the influence of pollutants, enzyme activities in plant-microbe-soil systems undergo changes of great importance in predicting soil-plant-microbe interactions, regulation of metal and nutrient uptake, and, ultimately, improvement of soil health and fertility. We evaluated the influence of As on soil enzyme activities and the effectiveness of five field crops for As phytoextraction. The initial As concentration in soil was 50mg As kg(-1) soil; planted clean soil, unplanted polluted soil, and unplanted clean soil served as controls. After 10 weeks, the growth of the plants elevated soil dehydrogenase activity relative to polluted but unplanted control soils by 2.4- and 2.5-fold for sorghum and sunflower (respectively), by 3-fold for ryegrass and sudangrass, and by 5.2-fold for spring rape. Soil peroxidase activity increased by 33% with ryegrass and rape, while soil phosphatase activity was directly correlated with residual As (correlation coefficient R(2)=0.7045). We conclude that soil enzyme activities should be taken into account when selecting plants for phytoremediation. Copyright © 2013 Elsevier B.V. All rights reserved.

Intensified Arctic warming under greenhouse warming by vegetation–atmosphere–sea ice interaction

International Nuclear Information System (INIS)

Jeong, Jee-Hoon; Kug, Jong-Seong; Linderholm, Hans W; Chen, Deliang; Kim, Baek-Min; Jun, Sang-Yoon

2014-01-01

Observations and modeling studies indicate that enhanced vegetation activities over high latitudes under an elevated CO 2 concentration accelerate surface warming by reducing the surface albedo. In this study, we suggest that vegetation-atmosphere-sea ice interactions over high latitudes can induce an additional amplification of Arctic warming. Our hypothesis is tested by a series of coupled vegetation-climate model simulations under 2xCO 2 environments. The increased vegetation activities over high latitudes under a 2xCO 2 condition induce additional surface warming and turbulent heat fluxes to the atmosphere, which are transported to the Arctic through the atmosphere. This causes additional sea-ice melting and upper-ocean warming during the warm season. As a consequence, the Arctic and high-latitude warming is greatly amplified in the following winter and spring, which further promotes vegetation activities the following year. We conclude that the vegetation-atmosphere-sea ice interaction gives rise to additional positive feedback of the Arctic amplification. (letter)

Production control and supplier selection under demand disruptions

Directory of Open Access Journals (Sweden)

Xianzhe Chen

2010-12-01

Full Text Available This paper investigates the effects of demand disruptions on production control and supplier selection in a three-echelon supply chain system. The customer demand is modeled as a jump-diffusion process in a continuous-time setting. A two-number production-inventory policy is implemented in the production control model for the manufacturer. The objective is to minimize the long-term average total cost consisting of backlog cost, holding cost, switching cost, and ordering cost. The simulated annealing method is applied to search the optimal critical switching values. Furthermore, an improved analytical hierarchy process (AHP is proposed to select the best supplier, based on quantitative factors such as the optimal long-term total cost obtained through the simulated annealing method under demand disruptions and qualitative factors such as quality and service. Numerical studies are conducted to demonstrate the effects of demand disruptions in the face of various risk scenarios. Managerial insights from simulation results are provided as well. Our approaches can be implemented as the “stress test” for companies in front of various supply chain disruption scenarios.

A numerical study of crack interactions under thermo-mechanical load using EFGM

International Nuclear Information System (INIS)

Pant, Mohit; Singh, I. V.; Mishra, B. K.

2011-01-01

In this work, element free Galerkin method (EFGM) has been used to obtain the solution of various edge crack problems under thermo-mechanical loads as it provides a versatile technique to model stationary as well as moving crack problems without re-meshing. Standard diffraction criterion has been modified with multiple crack weight technique to characterize the presence of various cracks in the domain of influence of a particular node. The effect of crack inclination has been studied for single as well as two edge cracks, whereas the cracks interaction has been studied for two edge cracks lying on same as well as opposite edges under plane stress conditions. The values of mode-I and mode-II stress intensity factors have been evaluated by the interaction integral approach

Tuning interionic interaction by rationally controlling solution pH for highly selective colorimetric sensing of arginine.

Science.gov (United States)

Qian, Qin; Hao, Jie; Ma, Wenjie; Yu, Ping; Mao, Lanqun

2016-04-01

Direct selective sensing of arginine in central nervous systems remains very essential to understanding of the molecular basis of some physiological events. This study presents the first demonstration on a simple yet effective method for arginine sensing with gold nanoparticles (Au-NPs) as the signal readout. The rationale for the method is based on the pH-dependent feature of the interionic interaction between cysteine and arginine. At pH 6.0, cysteine can only interact with arginine through the ion-pair interaction and such interaction can lead to the changes in both the solution color and UV-vis spectrum of the cysteine-protected Au-NPs upon the addition of arginine. These changes are further developed into an analytical strategy for effective sensing of arginine by rationally controlling the pH values of Au-NP dispersions with the ratio of the absorbance at 650 nm (A 650) to that at 520 nm (A 520) (A 650/A 520) as a parameter for analysis. The method is responsive to arginine without the interference from other species in the cerebral system; under the optimized conditions, the A 650/A 520 values are linear with the concentration of arginine within a concentration range from 0.80 to 64 μM, yet remain unchanged with the addition of other kinds of amino acids or the species in the central nervous system into the Au-NPs dispersion containing cysteine. The method demonstrated here is reliable and robust and could thus be used for detection of the increase of arginine in central nervous systems.

The Neural Mechanisms Underlying Internally and Externally Guided Task Selection

Science.gov (United States)

Orr, Joseph M.; Banich, Marie T.

2013-01-01

While some prior work suggests that medial prefrontal cortex (MFC) regions mediate freely chosen actions, other work suggests that the lateral frontal pole (LFP) is responsible for control of abstract, internal goals. The present study uses fMRI to determine whether the voluntary selection of a task in pursuit of an overall goal relies on MFC regions or the LFP. To do so, we used a modified voluntary task switching (VTS) paradigm, in which participants choose an individual task to perform on each trial (i.e., a subgoal), under instructions to perform the tasks equally often and in a random order (i.e. the overall goal). In conjunction, we examined patterns of activation in the face of irrelevant, but task-related external stimuli that might nonetheless influence task selection. While there was some evidence that the MFC was involved in voluntary task selection, we found that the LFP and anterior insula (AI) were crucial to task selection in the pursuit of an overall goal. In addition, activation of the LFP and AI increased in the face of environmental stimuli that might serve as an interfering or conflicting external bias on voluntary task choice. These findings suggest that the LFP supports task selection according to abstract, internal goals, and leaves open the possibility that MFC may guide action selection in situations lacking in such top-down biases. As such, the current study represents a critical step towards understanding the neural underpinnings of how tasks are selected voluntarily to enable an overarching goal. PMID:23994316

Impact of selection on maize root traits and rhizosphere interactions

Science.gov (United States)

Schmidt, J. E.; Gaudin, A. C. M.

2017-12-01

Effects of domestication and breeding on maize have been well-characterized aboveground, but impacts on root traits and rhizosphere processes remain unclear. Breeding in high-inorganic-input environments may have negatively affected the ability of modern maize to acquire nutrients through foraging and microbial interactions in marginal and/or organically managed soils. Twelve maize genotypes representing a selection gradient (teosintes, landraces, open-pollinated parents of modern elite germplasm, and modern hybrids released 1934-2015) were grown in three soils varying in intensity of long-term management (unfertilized, organic, conventional) in the greenhouse. Recruitment of rhizosphere microbial communities, nutrient acquisition, and plant productivity were affected by genotype-by-soil interactions. Maize genotypes exhibit significant variation in their ability to obtain nutrients from soils of different management history, indicating the potential for re-integration of beneficial root and rhizosphere traits to increase adaptation to low-input agroecosystems.

The Origin of Mutants Under Selection: How Natural Selection Mimics Mutagenesis (Adaptive Mutation)

Science.gov (United States)

Maisnier-Patin, Sophie; Roth, John R.

2015-01-01

Selection detects mutants but does not cause mutations. Contrary to this dictum, Cairns and Foster plated a leaky lac mutant of Escherichia coli on lactose medium and saw revertant (Lac+) colonies accumulate with time above a nongrowing lawn. This result suggested that bacteria might mutagenize their own genome when growth is blocked. However, this conclusion is suspect in the light of recent evidence that revertant colonies are initiated by preexisting cells with multiple copies the conjugative F′lac plasmid, which carries the lac mutation. Some plated cells have multiple copies of the simple F′lac plasmid. This provides sufficient LacZ activity to support plasmid replication but not cell division. In nongrowing cells, repeated plasmid replication increases the likelihood of a reversion event. Reversion to lac+ triggers exponential cell growth leading to a stable Lac+ revertant colony. In 10% of these plated cells, the high-copy plasmid includes an internal tandem lac duplication, which provides even more LacZ activity—sufficient to support slow growth and formation of an unstable Lac+ colony. Cells with multiple copies of the F′lac plasmid have an increased mutation rate, because the plasmid encodes the error-prone (mutagenic) DNA polymerase, DinB. Without DinB, unstable and stable Lac+ revertant types form in equal numbers and both types arise with no mutagenesis. Amplification and selection are central to behavior of the Cairns–Foster system, whereas mutagenesis is a system-specific side effect or artifact caused by coamplification of dinB with lac. Study of this system has revealed several broadly applicable principles. In all populations, gene duplications are frequent stable genetic polymorphisms, common near-neutral mutant alleles can gain a positive phenotype when amplified under selection, and natural selection can operate without cell division when variability is generated by overreplication of local genome subregions. PMID:26134316

Proposal for selecting an ore sample from mining shaft under Kvanefjeld

International Nuclear Information System (INIS)

Lund Clausen, F.

1979-02-01

Uranium ore recovered from the tunnel under Kvanefjeld (Greenland) will be processed in a pilot plant. Selection of a fully representative ore sample for both the whole area and single local sites is discussed. A FORTRAN program for ore distribution is presented, in order to enable correct sampling. (EG)

Nanopore wall-liquid interaction under scope of molecular dynamics study: Review

Science.gov (United States)

Tsukanov, A. A.; Psakhie, S. G.

2017-12-01

The present review is devoted to the analysis of recent molecular dynamics based on the numerical studies of molecular aspects of solid-fluid interaction in nanoscale channels. Nanopore wall-liquid interaction plays the crucial role in such processes as gas separation, water desalination, liquids decontamination, hydrocarbons and water transport in nano-fractured geological formations. Molecular dynamics simulation is one of the most suitable tools to study molecular level effects occurred in such multicomponent systems. The nanopores are classified by their geometry to four groups: nanopore in nanosheet, nanotube-like pore, slit-shaped nanopore and soft-matter nanopore. The review is focused on the functionalized nanopores in boron nitride nanosheets as novel selective membranes and on the slit-shaped nanopores formed by minerals.

Modeling the Time-Course of Responses for the Border Ownership Selectivity Based on the Integration of Feedforward Signals and Visual Cortical Interactions.

Science.gov (United States)

Wagatsuma, Nobuhiko; Sakai, Ko

2016-01-01

Border ownership (BO) indicates which side of a contour owns a border, and it plays a fundamental role in figure-ground segregation. The majority of neurons in V2 and V4 areas of monkeys exhibit BO selectivity. A physiological work reported that the responses of BO-selective cells show a rapid transition when a presented square is flipped along its classical receptive field (CRF) so that the opposite BO is presented, whereas the transition is significantly slower when a square with a clear BO is replaced by an ambiguous edge, e.g., when the square is enlarged greatly. The rapid transition seemed to reflect the influence of feedforward processing on BO selectivity. Herein, we investigated the role of feedforward signals and cortical interactions for time-courses in BO-selective cells by modeling a visual cortical network comprising V1, V2, and posterior parietal (PP) modules. In our computational model, the recurrent pathways among these modules gradually established the visual progress and the BO assignments. Feedforward inputs mainly determined the activities of these modules. Surrounding suppression/facilitation of early-level areas modulates the activities of V2 cells to provide BO signals. Weak feedback signals from the PP module enhanced the contrast gain extracted in V1, which underlies the attentional modulation of BO signals. Model simulations exhibited time-courses depending on the BO ambiguity, which were caused by the integration delay of V1 and V2 cells and the local inhibition therein given the difference in input stimulus. However, our model did not fully explain the characteristics of crucially slow transition: the responses of BO-selective physiological cells indicated the persistent activation several times longer than that of our model after the replacement with the ambiguous edge. Furthermore, the time-course of BO-selective model cells replicated the attentional modulation of response time in human psychophysical experiments. These attentional

Modeling the Time-Course of Responses for the Border Ownership Selectivity Based on the Integration of Feedforward Signals and Visual Cortical Interactions

Science.gov (United States)

Wagatsuma, Nobuhiko; Sakai, Ko

2017-01-01

Border ownership (BO) indicates which side of a contour owns a border, and it plays a fundamental role in figure-ground segregation. The majority of neurons in V2 and V4 areas of monkeys exhibit BO selectivity. A physiological work reported that the responses of BO-selective cells show a rapid transition when a presented square is flipped along its classical receptive field (CRF) so that the opposite BO is presented, whereas the transition is significantly slower when a square with a clear BO is replaced by an ambiguous edge, e.g., when the square is enlarged greatly. The rapid transition seemed to reflect the influence of feedforward processing on BO selectivity. Herein, we investigated the role of feedforward signals and cortical interactions for time-courses in BO-selective cells by modeling a visual cortical network comprising V1, V2, and posterior parietal (PP) modules. In our computational model, the recurrent pathways among these modules gradually established the visual progress and the BO assignments. Feedforward inputs mainly determined the activities of these modules. Surrounding suppression/facilitation of early-level areas modulates the activities of V2 cells to provide BO signals. Weak feedback signals from the PP module enhanced the contrast gain extracted in V1, which underlies the attentional modulation of BO signals. Model simulations exhibited time-courses depending on the BO ambiguity, which were caused by the integration delay of V1 and V2 cells and the local inhibition therein given the difference in input stimulus. However, our model did not fully explain the characteristics of crucially slow transition: the responses of BO-selective physiological cells indicated the persistent activation several times longer than that of our model after the replacement with the ambiguous edge. Furthermore, the time-course of BO-selective model cells replicated the attentional modulation of response time in human psychophysical experiments. These attentional

Dominance genetic variance for traits under directional selection in Drosophila serrata.

Science.gov (United States)

Sztepanacz, Jacqueline L; Blows, Mark W

2015-05-01

In contrast to our growing understanding of patterns of additive genetic variance in single- and multi-trait combinations, the relative contribution of nonadditive genetic variance, particularly dominance variance, to multivariate phenotypes is largely unknown. While mechanisms for the evolution of dominance genetic variance have been, and to some degree remain, subject to debate, the pervasiveness of dominance is widely recognized and may play a key role in several evolutionary processes. Theoretical and empirical evidence suggests that the contribution of dominance variance to phenotypic variance may increase with the correlation between a trait and fitness; however, direct tests of this hypothesis are few. Using a multigenerational breeding design in an unmanipulated population of Drosophila serrata, we estimated additive and dominance genetic covariance matrices for multivariate wing-shape phenotypes, together with a comprehensive measure of fitness, to determine whether there is an association between directional selection and dominance variance. Fitness, a trait unequivocally under directional selection, had no detectable additive genetic variance, but significant dominance genetic variance contributing 32% of the phenotypic variance. For single and multivariate morphological traits, however, no relationship was observed between trait-fitness correlations and dominance variance. A similar proportion of additive and dominance variance was found to contribute to phenotypic variance for single traits, and double the amount of additive compared to dominance variance was found for the multivariate trait combination under directional selection. These data suggest that for many fitness components a positive association between directional selection and dominance genetic variance may not be expected. Copyright © 2015 by the Genetics Society of America.

Selective Attention Enhances Beta-Band Cortical Oscillation to Speech under “Cocktail-Party” Listening Conditions

Science.gov (United States)

Gao, Yayue; Wang, Qian; Ding, Yu; Wang, Changming; Li, Haifeng; Wu, Xihong; Qu, Tianshu; Li, Liang

2017-01-01

Human listeners are able to selectively attend to target speech in a noisy environment with multiple-people talking. Using recordings of scalp electroencephalogram (EEG), this study investigated how selective attention facilitates the cortical representation of target speech under a simulated “cocktail-party” listening condition with speech-on-speech masking. The result shows that the cortical representation of target-speech signals under the multiple-people talking condition was specifically improved by selective attention relative to the non-selective-attention listening condition, and the beta-band activity was most strongly modulated by selective attention. Moreover, measured with the Granger Causality value, selective attention to the single target speech in the mixed-speech complex enhanced the following four causal connectivities for the beta-band oscillation: the ones (1) from site FT7 to the right motor area, (2) from the left frontal area to the right motor area, (3) from the central frontal area to the right motor area, and (4) from the central frontal area to the right frontal area. However, the selective-attention-induced change in beta-band causal connectivity from the central frontal area to the right motor area, but not other beta-band causal connectivities, was significantly correlated with the selective-attention-induced change in the cortical beta-band representation of target speech. These findings suggest that under the “cocktail-party” listening condition, the beta-band oscillation in EEGs to target speech is specifically facilitated by selective attention to the target speech that is embedded in the mixed-speech complex. The selective attention-induced unmasking of target speech may be associated with the improved beta-band functional connectivity from the central frontal area to the right motor area, suggesting a top-down attentional modulation of the speech-motor process. PMID:28239344

Stress selection indices an acceptable tool to screen superior wheat genotypes under irrigated and rain-fed conditions

International Nuclear Information System (INIS)

Ullah, H.; Alam, M.

2014-01-01

The climate is changing day by day and water scarcity has developed a milieu for the breeder to think accordingly. Twenty-four advanced wheat lines along with four prominent check cultivars were evaluated independently in irrigated (IRE) and rain-fed environments (RFE) for yield related traits at Khyber Pakhtunkhwa, Pakistan during 2010-11, using randomized complete block design with three replications under each test environment. Analysis of variance across the two environments exhibited highly significant variation (p=0.01) among the genotypes for yield and associated traits. Differences among the two test environments (E) were significant for tillers m/sup -2/, 1000-grain weight and harvest index. Genotype * environment interaction (G*E) effects were significant only for 1000-grain weight and grain yield. There was general reduction in 1000-grain weight, biological yield and grain yield of all genotypes under RFE as compared to IRE. Magnitude of heritabilities estimates were greater for tillers m/sup -2/, spikelets spike-1 and grains spike-1 under IRE than RFE. Heritabilities were greater in RFE than IRE for spike length (0.31 vs 0.26), biological yield (0.80 vs 0.22), grain yield (0.94 vs 0.20) and harvest index (0.41 and 0.39). Relative high expected selection response was recorded for all characters under IRE except spike length, grains spike-1 and grain yield. In IRE, highest grain yield was produced by genotypes BRF-7 (5123 kg ha/sup -1/), B-VI(N)16 (5111 kg ha/sup -1/), B-IV(N)1 (5086 kg ha/sup -1/) and B-VI(N)5 (5049 kg ha/sup -1/), while genotypes B-VI(N)5 (4649 kg ha/sup -1/), B-IV(N)1 (4595 kg ha/sup -1/), BRF-7 (4486 kg ha/sup -1/) and B-IV(N)16 (4462 kg ha/sup -1/) were high yielding under RFE. Prominent stress selection indices used in the experiments were mean productivity (MP), tolerance (TOL), stress tolerance index (STI), trait index (TI) and trait stability index (TSI). MP and STI were the efficient and reliable selection indices in both

Selective Impairment of Auditory Selective Attention under Concurrent Cognitive Load

Science.gov (United States)

Dittrich, Kerstin; Stahl, Christoph

2012-01-01

Load theory predicts that concurrent cognitive load impairs selective attention. For visual stimuli, it has been shown that this impairment can be selective: Distraction was specifically increased when the stimulus material used in the cognitive load task matches that of the selective attention task. Here, we report four experiments that…

Sport and Nutrition Education Interaction on Stress

Science.gov (United States)

Ozturk, Mehmet Ertugrul

2015-01-01

The aim of the study was to determine sport and nutrition education interaction on stress. Three groups were selected for the study: control, single treatment and social treatment under nutrition treatment, too. The groups that were under nutrition treatments should have information about the nutrition resources. This experiment was done for two…

Tracer diffusion in colloidal suspensions under dilute and crowded conditions with hydrodynamic interactions

DEFF Research Database (Denmark)

Tomilov, A.; Videcoq, A.; Chartier, T.

2012-01-01

We consider tracer diffusion in colloidal suspensions under solid loading conditions, where hydrodynamic interactions play an important role. To this end, we carry out computer simulations based on the hybrid stochastic rotation dynamics-molecular dynamics (SRD-MD) technique. Many details of the ...... that hydrodynamic interactions are correctly included within the SRD-MD technique. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4731661]...

Automatic selection of reference taxa for protein-protein interaction prediction with phylogenetic profiling

DEFF Research Database (Denmark)

Simonsen, Martin; Maetschke, S.R.; Ragan, M.A.

2012-01-01

Motivation: Phylogenetic profiling methods can achieve good accuracy in predicting protein–protein interactions, especially in prokaryotes. Recent studies have shown that the choice of reference taxa (RT) is critical for accurate prediction, but with more than 2500 fully sequenced taxa publicly......: We present three novel methods for automating the selection of RT, using machine learning based on known protein–protein interaction networks. One of these methods in particular, Tree-Based Search, yields greatly improved prediction accuracies. We further show that different methods for constituting...... phylogenetic profiles often require very different RT sets to support high prediction accuracy....

Graphene-metal interaction and its effect on the interface stability under ambient conditions

Energy Technology Data Exchange (ETDEWEB)

Dong, Aiyi; Fu, Qiang, E-mail: qfu@dicp.ac.cn; Wei, Mingming; Bao, Xinhe

2017-08-01

Highlights: • Graphene (Gr)/transition metal (TM: Fe, Co, Pt, and Au) interfaces form through TM intercalation at Gr/Ru(0001) surface. • Graphene-metal interaction strength follows the order of Ru ≈ Fe ≈ Co > Pt > Au. • Oxygen intercalation occurs at Gr/Fe, Gr/Co, Gr/Pt, and Gr/Ru interfaces but not at Gr/Au interface in air around 100 °C. - Abstract: Interaction between graphene (Gr) and metal plays an important role in physics and chemistry of graphene/metal interfaces. In this work, well-defined interfaces between graphene and transition metals (TMs) including Fe, Co, Pt, and Au were prepared through TM intercalation on Gr/Ru(0001) surface. The Gr-metal interaction was investigated using X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. We found that graphene interacts most strongly with Ru, Fe and Co and most weakly with Au, following the order of Ru ≈ Fe ≈ Co > Pt > Au. The Gr/Fe, Gr/Co, Gr/Pt, and Gr/Ru interfaces can be readily intercalated by oxygen when exposed to air and illuminated by an infrared lamp. In contrast, oxygen intercalation does not happen at the Gr/Au interface under the same condition. It is suggested that both Gr-metal interaction and oxygen adsorption on the underlying metal surface are critical in the oxygen intercalation and the Gr/metal interface stability.

Adaptive scheduling with postexamining user selection under nonidentical fading

KAUST Repository

Gaaloul, Fakhreddine

2012-11-01

This paper investigates an adaptive scheduling algorithm for multiuser environments with statistically independent but nonidentically distributed (i.n.d.) channel conditions. The algorithm aims to reduce feedback load by sequentially and arbitrarily examining the user channels. It also provides improved performance by realizing postexamining best user selection. The first part of the paper presents new formulations for the statistics of the signal-to-noise ratio (SNR) of the scheduled user under i.n.d. channel conditions. The second part capitalizes on the findings in the first part and presents various performance and processing complexity measures for adaptive discrete-time transmission. The results are then extended to investigate the effect of outdated channel estimates on the statistics of the scheduled user SNR, as well as some performance measures. Numerical results are provided to clarify the usefulness of the scheduling algorithm under perfect or outdated channel estimates. © 1967-2012 IEEE.

Product-line selection and pricing with remanufacturing under availability constraints

Science.gov (United States)

Aras, Necati; Esenduran, G.÷k.‡e.; Altinel, I. Kuban

2004-12-01

Product line selection and pricing are two crucial decisions for the profitability of a manufacturing firm. Remanufacturing, on the other hand, may be a profitable strategy that captures the remaining value in used products. In this paper we develop a mixed-integer nonlinear programming model form the perspective of an original equipment manufacturer (OEM). The objective of the OEM is to select products to manufacture and remanufacture among a set of given alternatives and simultaneously determine their prices so as to maximize its profit. It is assumed that the probability a customer selects a product is proportional to its utility and inversely proportional to its price. The utility of a product is an increasing function of its perceived quality. In our base model, products are discriminated by their unit production costs and utilities. We also analyze a case where remanufacturing is limited by the available quantity of collected remanufacturable products. We show that the resulting problem is decomposed into the pricing and product line selection subproblems. Pricing problem is solved by a variant of the simplex search procedure which can also handle constraints, while complete enumeration and a genetic algorithm are used for the solution of the product line selection problem. A number of experiments are carried out to identify conditions under which it is economically viable for the firm to sell remanufactured products. We also determine the optimal utility and unit production cost values of a remanufactured product, which maximizes the total profit of the OEM.

Studies of the interaction of CS@ZnS:Mn with bovine serum albumin under illumination

Energy Technology Data Exchange (ETDEWEB)

Liu, Li, E-mail: 2476625723@qq.com [Institute of Agricultural Quality Standards and Testing Technology Research, Hubei Academy of Agricultural Science, Wuhan 430064 (China); Xiao, Ling [School of Resource and Environmental Science, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430072 (China)

2015-09-15

Highlights: • The interaction and illumination damages of CS@ZnS:Mn D-dots to BSA were studied. • The quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. • The hydrophobic interaction plays a major role; the binding processes are spontaneous. • The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was observed. • The probable mechanism is mainly a photo-induced free radical procedure. - Abstract: In this study, chitosan coated Mn-doped ZnS quantum dots (CS@ZnS:Mn D-dots) were obtained in aqueous media under ambient pressure. The interaction and illumination damages of CS@ZnS:Mn D-dots with bovine serum albumin (BSA) were studied by means of ultraviolet–visible (UV–vis) and fluorescence (FL) spectra. It was found that the FL of BSA was quenched by CS@ZnS:Mn D-dots. The dominating quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. Hydrophobic interaction plays a major role in the CS@ZnS:Mn–BSA interaction; binding processes are spontaneous. Influencing factors such as illumination time and CS@ZnS:Mn D-dots concentrations were considered. The FL quenching effect of BSA by CS@ZnS:Mn D-dots is enhanced with the increase of illumination time and CS@ZnS:Mn D-dots concentration. The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was also observed. It was proved that, the interaction of CS@ZnS:Mn D-dots with BSA under UV illumination is mainly a result of a photo-induced free radical procedure. CS@ZnS:Mn D-dots may be used as photosensitizers in photodynamic therapy.

Studies of the interaction of CS@ZnS:Mn with bovine serum albumin under illumination

International Nuclear Information System (INIS)

Liu, Li; Xiao, Ling

2015-01-01

Highlights: • The interaction and illumination damages of CS@ZnS:Mn D-dots to BSA were studied. • The quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. • The hydrophobic interaction plays a major role; the binding processes are spontaneous. • The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was observed. • The probable mechanism is mainly a photo-induced free radical procedure. - Abstract: In this study, chitosan coated Mn-doped ZnS quantum dots (CS@ZnS:Mn D-dots) were obtained in aqueous media under ambient pressure. The interaction and illumination damages of CS@ZnS:Mn D-dots with bovine serum albumin (BSA) were studied by means of ultraviolet–visible (UV–vis) and fluorescence (FL) spectra. It was found that the FL of BSA was quenched by CS@ZnS:Mn D-dots. The dominating quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. Hydrophobic interaction plays a major role in the CS@ZnS:Mn–BSA interaction; binding processes are spontaneous. Influencing factors such as illumination time and CS@ZnS:Mn D-dots concentrations were considered. The FL quenching effect of BSA by CS@ZnS:Mn D-dots is enhanced with the increase of illumination time and CS@ZnS:Mn D-dots concentration. The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was also observed. It was proved that, the interaction of CS@ZnS:Mn D-dots with BSA under UV illumination is mainly a result of a photo-induced free radical procedure. CS@ZnS:Mn D-dots may be used as photosensitizers in photodynamic therapy

Prospective identification of malaria parasite genes under balancing selection.

Directory of Open Access Journals (Sweden)

Kevin K A Tetteh

Full Text Available Endemic human pathogens are subject to strong immune selection, and interrogation of pathogen genome variation for signatures of balancing selection can identify important target antigens. Several major antigen genes in the malaria parasite Plasmodium falciparum have shown such signatures in polymorphism-versus-divergence indices (comparing with the chimpanzee parasite P. reichenowi, and in allele frequency based indices.To compare methods for prospective identification of genes under balancing selection, 26 additional genes known or predicted to encode surface-exposed proteins of the invasive blood stage merozoite were first sequenced from a panel of 14 independent P. falciparum cultured lines and P. reichenowi. Six genes at the positive extremes of one or both of the Hudson-Kreitman-Aguade (HKA and McDonald-Kreitman (MK indices were identified. Allele frequency based analysis was then performed on a Gambian P. falciparum population sample for these six genes and three others as controls. Tajima's D (TjD index was most highly positive for the msp3/6-like PF10_0348 (TjD = 1.96 as well as the positive control ama1 antigen gene (TjD = 1.22. Across the genes there was a strong correlation between population TjD values and the relative HKA indices (whether derived from the population or the panel of cultured laboratory isolates, but no correlation with the MK indices.Although few individual parasite genes show significant evidence of balancing selection, analysis of population genomic and comparative sequence data with the HKA and TjD indices should discriminate those that do, and thereby identify likely targets of immunity.

Operational decisionmaking and action selection under psychological stress in nuclear power plants

International Nuclear Information System (INIS)

Gertman, D.I.; Haney, L.N.; Jenkins, J.P.; Blackman, H.S.

1985-05-01

An extensive review of literature on individual and group performance and decisionmaking under psychological stress was conducted and summarized. Specific stress-related variables relevant to reactor operation were pinpointed and incorporated in an experiment to assess the performance of reactor operators under psychological stress. The decisionmaking performance of 24 reactor operators under differing levels of workload, conflicting information, and detail of available written procedures was assessed in terms of selecting immediate, subsequent, and nonapplicable actions in response to 12 emergency scenarios resulting from a severe seismic event at a pressurized water reactor. Specific personality characteristics of the operators suggested by the literature to be related to performance under stress were assessed and correlated to decisionmaking under stress. The experimental results were statistically analyzed, and findings indicated that operator decisionmaking under stress was more accurate under lower levels of workload, with the availability of detailed procedures, and in the presence of high conflicting information

Optimizing the allocation of resources for genomic selection in one breeding cycle.

Science.gov (United States)

Riedelsheimer, Christian; Melchinger, Albrecht E

2013-11-01

We developed a universally applicable planning tool for optimizing the allocation of resources for one cycle of genomic selection in a biparental population. The framework combines selection theory with constraint numerical optimization and considers genotype  ×  environment interactions. Genomic selection (GS) is increasingly implemented in plant breeding programs to increase selection gain but little is known how to optimally allocate the resources under a given budget. We investigated this problem with model calculations by combining quantitative genetic selection theory with constraint numerical optimization. We assumed one selection cycle where both the training and prediction sets comprised double haploid (DH) lines from the same biparental population. Grain yield for testcrosses of maize DH lines was used as a model trait but all parameters can be adjusted in a freely available software implementation. An extension of the expected selection accuracy given by Daetwyler et al. (2008) was developed to correctly balance between the number of environments for phenotyping the training set and its population size in the presence of genotype × environment interactions. Under small budget, genotyping costs mainly determine whether GS is superior over phenotypic selection. With increasing budget, flexibility in resource allocation increases greatly but selection gain leveled off quickly requiring balancing the number of populations with the budget spent for each population. The use of an index combining phenotypic and GS predicted values in the training set was especially beneficial under limited resources and large genotype × environment interactions. Once a sufficiently high selection accuracy is achieved in the prediction set, further selection gain can be achieved most efficiently by massively expanding its size. Thus, with increasing budget, reducing the costs for producing a DH line becomes increasingly crucial for successfully exploiting the

Determination of TNT explosive based on its selectively interaction with creatinine-capped CdSe/ZnS quantum dots

International Nuclear Information System (INIS)

Carrillo-Carrión, Carolina; Simonet, Bartolomé M.; Valcárcel, Miguel

2013-01-01

Graphical abstract: -- Highlights: •Creatinine-modified CdSe/ZnS quantum dots fluorescent probe has been prepared. •This modified QDs has been used for sensing 2,4,6,-trinitrotoluene explosive (TNT). •The selectivity of fluorescence quenching of creatinine-QD for TNT has been evaluated. •The potential application of the proposed methodology for the determination of TNT in spiked soils has been demonstrated. -- Abstract: Here, a creatinine-modified CdSe/ZnS quantum dots fluorescent probe has been prepared and used for sensing 2,4,6,-trinitrotoluene explosive (TNT). The proposed method is based on the selective interaction between creatinine and nitroaromatic compounds according to the well-known Jaffé reaction. The procedure for the synthesis of creatinine-CdSe/ZnS reagent is very simple and reproducible and its fluorescent characteristics are reported. We found that the presence of TNT quenches the original fluorescence of creatinine-QD according to the Stern–Volmer model. Under the working conditions, the calibration plot of I o /I versus concentration of TNT was linear in the range 10–300 μg L −1 (R 2 = 0.996). The mechanism interaction is discussed. The selectivity of fluorescence quenching of creatinine-QD for TNT has been evaluated. Finally, the potential application of the proposed methodology for the determination of TNT in spiked soils is demonstrated. For the analysis of soil samples a solid-liquid extraction is carried out and a four-point standard addition protocol is used to correct the matrix effect. The method, which is simple and rapid, allows the detection of 0.057 μg g −1 of TNT in soil samples. This sensor could be a useful tool for environmental studies, a crucial topic for nanotechnology nowadays

Optimal Portfolio Selection Under Concave Price Impact

International Nuclear Information System (INIS)

Ma Jin; Song Qingshuo; Xu Jing; Zhang Jianfeng

2013-01-01

In this paper we study an optimal portfolio selection problem under instantaneous price impact. Based on some empirical analysis in the literature, we model such impact as a concave function of the trading size when the trading size is small. The price impact can be thought of as either a liquidity cost or a transaction cost, but the concavity nature of the cost leads to some fundamental difference from those in the existing literature. We show that the problem can be reduced to an impulse control problem, but without fixed cost, and that the value function is a viscosity solution to a special type of Quasi-Variational Inequality (QVI). We also prove directly (without using the solution to the QVI) that the optimal strategy exists and more importantly, despite the absence of a fixed cost, it is still in a “piecewise constant” form, reflecting a more practical perspective.

Optimal Portfolio Selection Under Concave Price Impact

Energy Technology Data Exchange (ETDEWEB)

Ma Jin, E-mail: jinma@usc.edu [University of Southern California, Department of Mathematics (United States); Song Qingshuo, E-mail: songe.qingshuo@cityu.edu.hk [City University of Hong Kong, Department of Mathematics (Hong Kong); Xu Jing, E-mail: xujing8023@yahoo.com.cn [Chongqing University, School of Economics and Business Administration (China); Zhang Jianfeng, E-mail: jianfenz@usc.edu [University of Southern California, Department of Mathematics (United States)

2013-06-15

In this paper we study an optimal portfolio selection problem under instantaneous price impact. Based on some empirical analysis in the literature, we model such impact as a concave function of the trading size when the trading size is small. The price impact can be thought of as either a liquidity cost or a transaction cost, but the concavity nature of the cost leads to some fundamental difference from those in the existing literature. We show that the problem can be reduced to an impulse control problem, but without fixed cost, and that the value function is a viscosity solution to a special type of Quasi-Variational Inequality (QVI). We also prove directly (without using the solution to the QVI) that the optimal strategy exists and more importantly, despite the absence of a fixed cost, it is still in a 'piecewise constant' form, reflecting a more practical perspective.

The effect of interactions between a bacterial strain isolated from drinking water and a pathogen surrogate on biofilms formation diverged under static vs flow conditions.

Science.gov (United States)

Dai, D; Raskin, L; Xi, C

2017-12-01

Interactions with water bacteria affect the incorporation of pathogens into biofilms and thus pathogen control in drinking water systems. This study was to examine the impact of static vs flow conditions on interactions between a pathogen and a water bacterium on pathogen biofilm formation under laboratory settings. A pathogen surrogate Escherichia coli and a drinking water isolate Stenotrophomonas maltophilia was selected for this study. Biofilm growth was examined under two distinct conditions, in flow cells with continuous medium supply vs in static microtitre plates with batch culture. E. coli biofilm was greatly stimulated (c. 2-1000 times faster) with the presence of S. maltophilia in flow cells, but surprisingly inhibited (c. 65-95% less biomass) in microtitre plates. These divergent effects were explained through various aspects including surface attachment, cellular growth, extracellular signals and autoaggregation. Interactions with the same water bacterium resulted in different effects on E. coli biofilm formation when culture conditions changed from static to flow. This study highlights the complexity of species interactions on biofilm formation and suggests that environmental conditions such as the flow regime can be taken into consideration for the management of microbial contamination in drinking water systems. © 2017 The Society for Applied Microbiology.

Period concatenation underlies interactions between gamma and beta rhythms in neocortex

Directory of Open Access Journals (Sweden)

Anita K Roopun

2008-04-01

Full Text Available The neocortex generates rhythmic electrical activity over a frequency range covering many decades. Specific cognitive and motor states are associated with oscillations in discrete frequency bands within this range, but it is not known whether interactions and transitions between distinct frequencies are of functional importance. When coexpressed rhythms have frequencies that differ by a factor of two or more interactions can be seen in terms of phase synchronization. Larger frequency differences can result in interactions in the form of nesting of faster frequencies within slower ones by a process of amplitude modulation. It is not known how coexpressed rhythms, whose frequencies differ by less than a factor of two may interact. Here we show that two frequencies (gamma – 40 Hz and beta2 – 25 Hz, coexpressed in superficial and deep cortical laminae with low temporal interaction, can combine to generate a third frequency (beta1 – 15 Hz showing strong temporal interaction. The process occurs via period concatenation, with basic rhythm-generating microcircuits underlying gamma and beta2 rhythms forming the building blocks of the beta1 rhythm by a process of addition. The mean ratio of adjacent frequency components was a constant – approximately the golden mean – which served to both minimize temporal interactions, and permit multiple transitions, between frequencies. The resulting temporal landscape may provide a framework for multiplexing – parallel information processing on multiple temporal scales.

Effect of dataset selection on the topological interpretation of protein interaction networks

Directory of Open Access Journals (Sweden)

Robertson David L

2005-09-01

Full Text Available Abstract Background Studies of the yeast protein interaction network have revealed distinct correlations between the connectivity of individual proteins within the network and the average connectivity of their neighbours. Although a number of biological mechanisms have been proposed to account for these findings, the significance and influence of the specific datasets included in these studies has not been appreciated adequately. Results We show how the use of different interaction data sets, such as those resulting from high-throughput or small-scale studies, and different modelling methodologies for the derivation pair-wise protein interactions, can dramatically change the topology of these networks. Furthermore, we show that some of the previously reported features identified in these networks may simply be the result of experimental or methodological errors and biases. Conclusion When performing network-based studies, it is essential to define what is meant by the term "interaction" and this must be taken into account when interpreting the topologies of the networks generated. Consideration must be given to the type of data included and appropriate controls that take into account the idiosyncrasies of the data must be selected

Selection in spatial working memory is independent of perceptual selective attention, but they interact in a shared spatial priority map.

Science.gov (United States)

Hedge, Craig; Oberauer, Klaus; Leonards, Ute

2015-11-01

We examined the relationship between the attentional selection of perceptual information and of information in working memory (WM) through four experiments, using a spatial WM-updating task. Participants remembered the locations of two objects in a matrix and worked through a sequence of updating operations, each mentally shifting one dot to a new location according to an arrow cue. Repeatedly updating the same object in two successive steps is typically faster than switching to the other object; this object switch cost reflects the shifting of attention in WM. In Experiment 1, the arrows were presented in random peripheral locations, drawing perceptual attention away from the selected object in WM. This manipulation did not eliminate the object switch cost, indicating that the mechanisms of perceptual selection do not underlie selection in WM. Experiments 2a and 2b corroborated the independence of selection observed in Experiment 1, but showed a benefit to reaction times when the placement of the arrow cue was aligned with the locations of relevant objects in WM. Experiment 2c showed that the same benefit also occurs when participants are not able to mark an updating location through eye fixations. Together, these data can be accounted for by a framework in which perceptual selection and selection in WM are separate mechanisms that interact through a shared spatial priority map.

Characteristics of Criteria for Selecting Investment Projects under Uncertainty

Directory of Open Access Journals (Sweden)

Adrian ENCIU

2011-07-01

Full Text Available Within financial theory and practice, there are used five main criteria for selecting investment projects: the net present value (NPV criterion, the internal rate of return (IRR criterion, the return term (RT criterion, the profitability ratio (PR criterion and the supplementary return (SR criterion. The assay will emphasize several new properties of said indexes for investment assessment, having as starting point the hypotheses of (approximately normal repartition of cash-flows generated by an investment project. The obtained results point to the fact that the NPV indexes (the analysis of this criterion was carried out in the article “The NPV Criterion for Valuing Investments under Uncertainty”, Daniel Armeanu, Leonard Lache, Economic Computation and Economic Cybernetics Studies and Research no. 4/2009, pp. 133-143, IRR, PR, RT and SR register normal repartitions, therefore simplifying the investment analysis under economic uncertainty, by the capacity of building confidence intervals and assessing probabilities for the inferior limits of said investment assessment indexes.

PolyUbiquitin chain linkage topology selects the functions from the underlying binding landscape.

Directory of Open Access Journals (Sweden)

Yong Wang

2014-07-01

Full Text Available Ubiquitin (Ub can generate versatile molecular signals and lead to different celluar fates. The functional poly-valence of Ub is believed to be resulted from its ability to form distinct polymerized chains with eight linkage types. To provide a full picture of ubiquitin code, we explore the binding landscape of two free Ub monomers and also the functional landscapes of of all eight linkage types by theoretical modeling. Remarkably, we found that most of the compact structures of covalently connected dimeric Ub chains (diUbs pre-exist on the binding landscape. These compact functional states were subsequently validated by corresponding linkage models. This leads to the proposal that the folding architecture of Ub monomer has encoded all functional states into its binding landscape, which is further selected by different topologies of polymeric Ub chains. Moreover, our results revealed that covalent linkage leads to symmetry breaking of interfacial interactions. We further propose that topological constraint not only limits the conformational space for effective switching between functional states, but also selects the local interactions for realizing the corresponding biological function. Therefore, the topological constraint provides a way for breaking the binding symmetry and reaching the functional specificity. The simulation results also provide several predictions that qualitatively and quantitatively consistent with experiments. Importantly, the K48 linkage model successfully predicted intermediate states. The resulting multi-state energy landscape was further employed to reconcile the seemingly contradictory experimental data on the conformational equilibrium of K48-diUb. Our results further suggest that hydrophobic interactions are dominant in the functional landscapes of K6-, K11-, K33- and K48 diUbs, while electrostatic interactions play a more important role in the functional landscapes of K27, K29, K63 and linear linkages.

PolyUbiquitin chain linkage topology selects the functions from the underlying binding landscape.

Science.gov (United States)

Wang, Yong; Tang, Chun; Wang, Erkang; Wang, Jin

2014-07-01

Ubiquitin (Ub) can generate versatile molecular signals and lead to different celluar fates. The functional poly-valence of Ub is believed to be resulted from its ability to form distinct polymerized chains with eight linkage types. To provide a full picture of ubiquitin code, we explore the binding landscape of two free Ub monomers and also the functional landscapes of of all eight linkage types by theoretical modeling. Remarkably, we found that most of the compact structures of covalently connected dimeric Ub chains (diUbs) pre-exist on the binding landscape. These compact functional states were subsequently validated by corresponding linkage models. This leads to the proposal that the folding architecture of Ub monomer has encoded all functional states into its binding landscape, which is further selected by different topologies of polymeric Ub chains. Moreover, our results revealed that covalent linkage leads to symmetry breaking of interfacial interactions. We further propose that topological constraint not only limits the conformational space for effective switching between functional states, but also selects the local interactions for realizing the corresponding biological function. Therefore, the topological constraint provides a way for breaking the binding symmetry and reaching the functional specificity. The simulation results also provide several predictions that qualitatively and quantitatively consistent with experiments. Importantly, the K48 linkage model successfully predicted intermediate states. The resulting multi-state energy landscape was further employed to reconcile the seemingly contradictory experimental data on the conformational equilibrium of K48-diUb. Our results further suggest that hydrophobic interactions are dominant in the functional landscapes of K6-, K11-, K33- and K48 diUbs, while electrostatic interactions play a more important role in the functional landscapes of K27, K29, K63 and linear linkages.

Selection on crop-derived traits and QTL in sunflower (Helianthus annuus) crop-wild hybrids under water stress.

Science.gov (United States)

Owart, Birkin R; Corbi, Jonathan; Burke, John M; Dechaine, Jennifer M

2014-01-01

Locally relevant conditions, such as water stress in irrigated agricultural regions, should be considered when assessing the risk of crop allele introgression into wild populations following hybridization. Although research in cultivars has suggested that domestication traits may reduce fecundity under water stress as compared to wild-like phenotypes, this has not been investigated in crop-wild hybrids. In this study, we examine phenotypic selection acting on, as well as the genetic architecture of vegetative, reproductive, and physiological characteristics in an experimental population of sunflower crop-wild hybrids grown under wild-like low water conditions. Crop-derived petiole length and head diameter were favored in low and control water environments. The direction of selection differed between environments for leaf size and leaf pressure potential. Interestingly, the additive effect of the crop-derived allele was in the direction favored by selection for approximately half the QTL detected in the low water environment. Selection favoring crop-derived traits and alleles in the low water environment suggests that a subset of these alleles would be likely to spread into wild populations under water stress. Furthermore, differences in selection between environments support the view that risk assessments should be conducted under multiple locally relevant conditions.

Fisher's fundamental theorem of inclusive fitness and the change in fitness due to natural selection when conspecifics interact

NARCIS (Netherlands)

Bijma, P.

2010-01-01

Competition and cooperation is fundamental to evolution by natural selection, both in animals and plants. Here, I investigate the consequences of such interactions for response in fitness due to natural selection. I provide quantitative genetic expressions for heritable variance and response in

A Novel Mechanism for Chemical Sensing Based on Solvent-Fluorophore-Substrate Interaction: Highly Selective Alcohol and Water Sensor with Large Fluorescence Signal Contrast.

Science.gov (United States)

Chung, Kyeongwoon; Yang, Da Seul; Jung, Jaehun; Seo, Deokwon; Kwon, Min Sang; Kim, Jinsang

2016-10-06

Differentiation of solvents having similar physicochemical properties, such as ethanol and methanol, is an important issue of interest. However, without performing chemical analyses, discrimination between methanol and ethanol is highly challenging due to their similarity in chemical structure as well as properties. Here, we present a novel type of alcohol and water sensor based on the subtle differences in interaction among solvent analytes, fluorescent organic molecules, and a mesoporous silica gel substrate. A gradual change in the chemical structure of the fluorescent diketopyrrolopyrrole (DPP) derivatives alters their interaction with the substrate and solvent analyte, which creates a distinct intermolecular aggregation of the DPP derivatives on the silica gel substrate depending on the solvent environment and produces a change in the fluorescence color and intensity as a sensory signal. The devised sensor device, which is fabricated with simple drop-casting of the DPP derivative solutions onto a silica gel substrate, exhibited a completely reversible fluorescence signal change with large fluorescence signal contrast, which allows selective solvent detection by simple optical observation with the naked eye under UV light. Superior selectivity of the alcohol and water sensor system, which can clearly distinguish among ethanol, methanol, ethylene glycol, and water, is demonstrated.

Efficient and selective α-bromination of carbonyl compounds with N-bromosuccinimide under microwave

KAUST Repository

Guan, Xiao-Yu

2014-02-07

A highly efficient method for the synthesis of α-halocarbonyl compounds has been achieved via selective monobromination of aromatic and aliphatic carbonyl compounds with N-bromosuccinimide catalyzed by p-toluenesulfonic acid under microwave irradiation within 30 min.

Efficient and selective α-bromination of carbonyl compounds with N-bromosuccinimide under microwave

KAUST Repository

Guan, Xiao-Yu; Al-Misba'a, Zahra; Huang, Kuo-Wei

2014-01-01

A highly efficient method for the synthesis of α-halocarbonyl compounds has been achieved via selective monobromination of aromatic and aliphatic carbonyl compounds with N-bromosuccinimide catalyzed by p-toluenesulfonic acid under microwave irradiation within 30 min.

Direct chill casting of aluminium alloys under electromagnetic interaction by permanent magnet assembly

Science.gov (United States)

Bojarevičs, Andris; Kaldre, Imants; Milgrāvis, Mikus; Beinerts, Toms

2018-05-01

Direct chill casting is one of the methods used in industry to obtain good microstructure and properties of aluminium alloys. Nevertheless, for some alloys grain structure is not optimal. In this study, we offer the use of electromagnetic interaction to modify melt convection near the solidification interface. Solidification under various electromagnetic interactions has been widely studied, but usually at low solidification velocity and high thermal gradient. This type of interaction may succeed fragmentation of dendrite arms and transport of solidification nuclei thus leading to improved material structure and properties. Realization of experimental small-scale crystallizer and electromagnetic system has been described in this article.

Engineering DNA Backbone Interactions Results in TALE Scaffolds with Enhanced 5-Methylcytosine Selectivity.

Science.gov (United States)

Rathi, Preeti; Witte, Anna; Summerer, Daniel

2017-11-08

Transcription activator-like effectors (TALEs) are DNA major-groove binding proteins widely used for genome targeting. TALEs contain an N-terminal region (NTR) and a central repeat domain (CRD). Repeats of the CRD selectively recognize each one DNA nucleobase, offering programmability. Moreover, repeats with selectivity for 5-methylcytosine (5mC) and its oxidized derivatives can be designed for analytical applications. However, both TALE domains also nonspecifically interact with DNA phosphates via basic amino acids. To enhance the 5mC selectivity of TALEs, we aimed to decrease the nonselective binding energy of TALEs. We substituted basic amino acids with alanine in the NTR and identified TALE mutants with increased selectivity. We then analysed conserved, DNA phosphate-binding KQ diresidues in CRD repeats and identified further improved mutants. Combination of mutations in the NTR and CRD was highly synergetic and resulted in TALE scaffolds with up to 4.3-fold increased selectivity in genomic 5mC analysis via affinity enrichment. Moreover, transcriptional activation in HEK293T cells by a TALE-VP64 construct based on this scaffold design exhibited a 3.5-fold increased 5mC selectivity. This provides perspectives for improved 5mC analysis and for the 5mC-conditional control of TALE-based editing constructs in vivo.

A calix[4]arene derivative and its selective interaction with drugs (clofibric acid, diclofenac and aspirin).

Science.gov (United States)

Danil de Namor, Angela F; Al Nuaim, Maan; Villanueva Salas, Jose A; Bryant, Sophie; Howlin, Brendan

2017-03-30

The synthesis and characterisation of a partially substituted calix[4]arene, namely, 5,11,17,23-tetra-tert-butyl,25,27-bis[aminoethoxy] 26,28-dihydroxycalix[4]arene are reported. Its interaction with commonly used pharmaceuticals (clofibric acid, diclofenac and aspirin) was investigated by spectroscopic ( 1 H NMR and UV), electrochemical (conductance measurements) and thermal (titration calorimetry) techniques. It is concluded on the basis of the experimental work and molecular simulation studies that the receptor interacts selectively with these drugs. Preliminary studies on the selective extraction of these pharmaceuticals from water by the calix receptor are reported and the potential for a carrier mediated sensor based on this ligand for 'on site' monitoring of pharmaceuticals is discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Moral Hazard, Adverse Selection and the Optimal Consumption-Leisure Choice under Equilibrium Price Dispersion

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Sergey Malakhov

2017-09-01

Full Text Available The analysis of the optimal consumption-leisure choice under equilibrium price dispersion discovers the methodological difference between problems of moral hazard and adverse selection. While the phenomenon of moral hazard represents the individual behavioral reaction on the marginal rate of substitution of leisure for consumption proposed by the insurance policy, the adverse selection can take place on any imperfect market under equilibrium price dispersion and it looks like a market phenomenon of a natural selection between consumers with different income and different propensity to search. The analysis of health insurance where the propensity to search takes the form of the propensity to seek healthcare demonstrates that moral hazard takes place when the insurance policy proposes a suboptimal consumption-leisure choice and the increase in consumption of medical services with the reduction of leisure time represents not an unlimited demand for “free goods” but the simple process of the consumption-leisure optimization. The path of consumerism with consumer-directed plans can solve partly the problem of moral hazard because in order to eliminate moral hazard this trend should come to the re-sale of medical services under health vouchers like it takes place in the life settlement.

Criteria for selecting children with special needs for dental treatment under general anaesthesia

OpenAIRE

Nova García, M. Joaquín de; Gallardo López, Nuria E.; Martín Sanjuán, Carmen; Mourelle Martínez, M. Rosa; Alonso García, Yolanda; Carracedo Cabaleiro, Esther

2007-01-01

Objective: To study criteria for helping to select children with special needs for dental treatment under general anaesthesia. Materials and methods: Group of 30 children (aged under 18) examined on the Course at the Universidad Complutense de Madrid (UCM) (Specialisation on holistic dental treatment of children with special needs) and subsequently referred to the Disabled Children’s Oral Health Unit (DCOHU) within Primary Health Care Area 2 of the Madrid Health Service (SERMAS) where dental ...

ZP Domain Proteins in the Abalone Egg Coat Include a Paralog of VERL under Positive Selection That Binds Lysin and 18-kDa Sperm Proteins

Science.gov (United States)

Aagaard, Jan E.; Vacquier, Victor D.; MacCoss, Michael J.; Swanson, Willie J.

2010-01-01

Identifying fertilization molecules is key to our understanding of reproductive biology, yet only a few examples of interacting sperm and egg proteins are known. One of the best characterized comes from the invertebrate archeogastropod abalone (Haliotis spp.), where sperm lysin mediates passage through the protective egg vitelline envelope (VE) by binding to the VE protein vitelline envelope receptor for lysin (VERL). Rapid adaptive divergence of abalone lysin and VERL are an example of positive selection on interacting fertilization proteins contributing to reproductive isolation. Previously, we characterized a subset of the abalone VE proteins that share a structural feature, the zona pellucida (ZP) domain, which is common to VERL and the egg envelopes of vertebrates. Here, we use additional expressed sequence tag sequencing and shotgun proteomics to characterize this family of proteins in the abalone egg VE. We expand 3-fold the number of known ZP domain proteins present within the VE (now 30 in total) and identify a paralog of VERL (vitelline envelope zona pellucida domain protein [VEZP] 14) that contains a putative lysin-binding motif. We find that, like VERL, the divergence of VEZP14 among abalone species is driven by positive selection on the lysin-binding motif alone and that these paralogous egg VE proteins bind a similar set of sperm proteins including a rapidly evolving 18-kDa paralog of lysin, which may mediate sperm–egg fusion. This work identifies an egg coat paralog of VERL under positive selection and the candidate sperm proteins with which it may interact during abalone fertilization. PMID:19767347

Investigation of hydrogen isotopes interaction processes with lithium under neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Zaurbekova, Zhanna, E-mail: zaurbekova@nnc.kz [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Skakov, Mazhyn; Ponkratov, Yuriy; Kulsartov, Timur; Gordienko, Yuriy; Tazhibayeva, Irina; Baklanov, Viktor; Barsukov, Nikolay [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Chikhray, Yevgen [Institute of Experimental and Theoretical Physics of Kazakh National University, Almaty (Kazakhstan)

2016-11-01

Highlights: • The experiments on study of helium and tritium generation and release processes under neutron irradiation from lithium saturated with deuterium are described in paper. ​ • The values of relative tritium and helium yield from lithium sample at different levels of neutron irradiation is calculated. • It was concluded that the main affecting process on tritium release from lithium is its interaction with lithium atoms with formation of lithium tritide. - Abstract: The paper describes the experiments on study of helium and tritium generation and release processes from lithium saturated with deuterium under neutron irradiation (in temperature range from 473 to 773 K). The diagrams of two reactor experiments show the time dependences of helium, DT, T{sub 2}, and tritium water partial pressures changes in experimental chamber with investigated lithium sample. According to experimental results, the values of relative tritium and helium yield from lithium sample at different levels of neutron irradiation were calculated. The time dependences of relative tritium and helium yield from lithium sample were plotted. It was concluded that the main affecting process on tritium release from lithium is its interaction with lithium atoms with formation of lithium tritide.

Natural selection underlies apparent stress-induced mutagenesis in a bacteriophage infection model.

Science.gov (United States)

Yosef, Ido; Edgar, Rotem; Levy, Asaf; Amitai, Gil; Sorek, Rotem; Munitz, Ariel; Qimron, Udi

2016-04-18

The emergence of mutations following growth-limiting conditions underlies bacterial drug resistance, viral escape from the immune system and fundamental evolution-driven events. Intriguingly, whether mutations are induced by growth limitation conditions or are randomly generated during growth and then selected by growth limitation conditions remains an open question(1). Here, we show that bacteriophage T7 undergoes apparent stress-induced mutagenesis when selected for improved recognition of its host's receptor. In our unique experimental set-up, the growth limitation condition is physically and temporally separated from mutagenesis: growth limitation occurs while phage DNA is outside the host, and spontaneous mutations occur during phage DNA replication inside the host. We show that the selected beneficial mutations are not pre-existing and that the initial slow phage growth is enabled by the phage particle's low-efficiency DNA injection into the host. Thus, the phage particle allows phage populations to initially extend their host range without mutagenesis by virtue of residual recognition of the host receptor. Mutations appear during non-selective intracellular replication, and the frequency of mutant phages increases by natural selection acting on free phages, which are not capable of mutagenesis.

Interactions between photodegradation components

Directory of Open Access Journals (Sweden)

Abdollahi Yadollah

2012-09-01

Full Text Available Abstract Background The interactions of p-cresol photocatalytic degradation components were studied by response surface methodology. The study was designed by central composite design using the irradiation time, pH, the amount of photocatalyst and the p-cresol concentration as variables. The design was performed to obtain photodegradation % as actual responses. The actual responses were fitted with linear, two factor interactions, cubic and quadratic model to select an appropriate model. The selected model was validated by analysis of variance which provided evidences such as high F-value (845.09, very low P-value (2 = 0.999, adjusted R-squared (Radj2 = 0.998, predicted R-squared (Rpred2 = 0.994 and the adequate precision (95.94. Results From the validated model demonstrated that the component had interaction with irradiation time under 180 min of the time while the interaction with pH was above pH 9. Moreover, photocatalyst and p-cresol had interaction at minimal amount of photocatalyst (p-cresol. Conclusion These variables are interdependent and should be simultaneously considered during the photodegradation process, which is one of the advantages of the response surface methodology over the traditional laboratory method.

Measurements of Particle Production, Underlying Event and Double Parton Interactions at the LHC

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00439671; The ATLAS collaboration

2016-01-01

The effects of soft, non-pertubative strong interactions (QCD) are an important part of the phenomenology of the events at hadron colliders, as the LHC. In order to constrain the parameters of models of soft QCD, diverse measurements are provided by the ALICE, ATLAS and CMS collaborations. Measurements of particle production, underlying event and double parton interactions are presented. In general, reasonable agreement between the measured data and the models is found, but discrepancies hint at the need for a better description.

Coevolution between positive reciprocity, punishment, and partner switching in repeated interactions.

Science.gov (United States)

Wubs, Matthias; Bshary, Redouan; Lehmann, Laurent

2016-06-15

Cooperation based on mutual investments can occur between unrelated individuals when they are engaged in repeated interactions. Individuals then need to use a conditional strategy to deter their interaction partners from defecting. Responding to defection such that the future payoff of a defector is reduced relative to cooperating with it is called a partner control mechanism. Three main partner control mechanisms are (i) to switch from cooperation to defection when being defected ('positive reciprocity'), (ii) to actively reduce the payoff of a defecting partner ('punishment'), or (iii) to stop interacting and switch partner ('partner switching'). However, such mechanisms to stabilize cooperation are often studied in isolation from each other. In order to better understand the conditions under which each partner control mechanism tends to be favoured by selection, we here analyse by way of individual-based simulations the coevolution between positive reciprocity, punishment, and partner switching. We show that random interactions in an unstructured population and a high number of rounds increase the likelihood that selection favours partner switching. In contrast, interactions localized in small groups (without genetic structure) increase the likelihood that selection favours punishment and/or positive reciprocity. This study thus highlights the importance of comparing different control mechanisms for cooperation under different conditions. © 2016 The Author(s).

Stakeholder-driven multi-attribute analysis for energy project selection under uncertainty

International Nuclear Information System (INIS)

Read, Laura; Madani, Kaveh; Mokhtari, Soroush; Hanks, Catherine

2017-01-01

In practice, selecting an energy project for development requires balancing criteria and competing stakeholder priorities to identify the best alternative. Energy source selection can be modeled as multi-criteria decision-maker problems to provide quantitative support to reconcile technical, economic, environmental, social, and political factors with respect to the stakeholders' interests. Decision making among these complex interactions should also account for the uncertainty present in the input data. In response, this work develops a stochastic decision analysis framework to evaluate alternatives by involving stakeholders to identify both quantitative and qualitative selection criteria and performance metrics which carry uncertainties. The developed framework is illustrated using a case study from Fairbanks, Alaska, where decision makers and residents must decide on a new source of energy for heating and electricity. We approach this problem in a five step methodology: (1) engaging experts (role players) to develop criteria of project performance; (2) collecting a range of quantitative and qualitative input information to determine the performance of each proposed solution according to the selected criteria; (3) performing a Monte-Carlo analysis to capture uncertainties given in the inputs; (4) applying multi-criteria decision-making, social choice (voting), and fallback bargaining methods to account for three different levels of cooperation among the stakeholders; and (5) computing an aggregate performance index (API) score for each alternative based on its performance across criteria and cooperation levels. API scores communicate relative performance between alternatives. In this way, our methodology maps uncertainty from the input data to reflect risk in the decision and incorporates varying degrees of cooperation into the analysis to identify an optimal and practical alternative. - Highlights: • We develop an applicable stakeholder-driven framework for

Selective layer-free blood serum ionogram based on ion-specific interactions with a nanotransistor

Science.gov (United States)

Sivakumarasamy, R.; Hartkamp, R.; Siboulet, B.; Dufrêche, J.-F.; Nishiguchi, K.; Fujiwara, A.; Clément, N.

2018-05-01

Despite being ubiquitous in the fields of chemistry and biology, the ion-specific effects of electrolytes pose major challenges for researchers. A lack of understanding about ion-specific surface interactions has hampered the development and application of materials for (bio-)chemical sensor applications. Here, we show that scaling a silicon nanotransistor sensor down to 25 nm provides a unique opportunity to understand and exploit ion-specific surface interactions, yielding a surface that is highly sensitive to cations and inert to pH. The unprecedented sensitivity of these devices to Na+ and divalent ions can be attributed to an overscreening effect via molecular dynamics. The surface potential of multi-ion solutions is well described by the sum of the electrochemical potentials of each cation, enabling selective measurements of a target ion concentration without requiring a selective organic layer. We use these features to construct a blood serum ionogram for Na+, K+, Ca2+ and Mg2+, in an important step towards the development of a versatile, durable and mobile chemical or blood diagnostic tool.

Bayes Empirical Bayes Inference of Amino Acid Sites Under Positive Selection

DEFF Research Database (Denmark)

Yang, Ziheng; Wong, Wendy Shuk Wan; Nielsen, Rasmus

2005-01-01

, with > 1 indicating positive selection. Statistical distributions are used to model the variation in among sites, allowing a subset of sites to have > 1 while the rest of the sequence may be under purifying selection with ... probabilities that a site comes from the site class with > 1. Current implementations, however, use the naive EB (NEB) approach and fail to account for sampling errors in maximum likelihood estimates of model parameters, such as the proportions and ratios for the site classes. In small data sets lacking...... information, this approach may lead to unreliable posterior probability calculations. In this paper, we develop a Bayes empirical Bayes (BEB) approach to the problem, which assigns a prior to the model parameters and integrates over their uncertainties. We compare the new and old methods on real and simulated...

Deciphering peculiar protein-protein interacting modules in Deinococcus radiodurans

Directory of Open Access Journals (Sweden)

Barkallah Insaf

2009-04-01

Full Text Available Abstract Interactomes of proteins under positive selection from ionizing-radiation-resistant bacteria (IRRB might be a part of the answer to the question as to how IRRB, particularly Deinococcus radiodurans R1 (Deira, resist ionizing radiation. Here, using the Database of Interacting Proteins (DIP and the Protein Structural Interactome (PSI-base server for PSI map, we have predicted novel interactions of orthologs of the 58 proteins under positive selection in Deira and other IRRB, but which are absent in IRSB. Among these, 18 domains and their interactomes have been identified in DNA checkpoint and repair; kinases pathways; energy and nucleotide metabolisms were the important biological processes that were found to be involved. This finding provides new clues to the cellular pathways that can to be important for ionizing-radiation resistance in Deira.

Mechanisms underlying the attachment and spreading of human osteoblasts: from transient interactions to focal adhesions on vitronectin-grafted bioactive surfaces.

Science.gov (United States)

Brun, Paola; Scorzeto, Michele; Vassanelli, Stefano; Castagliuolo, Ignazio; Palù, Giorgio; Ghezzo, Francesca; Messina, Grazia M L; Iucci, Giovanna; Battaglia, Valentina; Sivolella, Stefano; Bagno, Andrea; Polzonetti, Giovanni; Marletta, Giovanni; Dettin, Monica

2013-04-01

The features of implant devices and the reactions of bone-derived cells to foreign surfaces determine implant success during osseointegration. In an attempt to better understand the mechanisms underlying osteoblasts attachment and spreading, in this study adhesive peptides containing the fibronectin sequence motif for integrin binding (Arg-Gly-Asp, RGD) or mapping the human vitronectin protein (HVP) were grafted on glass and titanium surfaces with or without chemically induced controlled immobilization. As shown by total internal reflection fluorescence microscopy, human osteoblasts develop adhesion patches only on specifically immobilized peptides. Indeed, cells quickly develop focal adhesions on RGD-grafted surfaces, while HVP peptide promotes filopodia, structures involved in cellular spreading. As indicated by immunocytochemistry and quantitative polymerase chain reaction, focal adhesions kinase activation is delayed on HVP peptides with respect to RGD while an osteogenic phenotypic response appears within 24h on osteoblasts cultured on both peptides. Cellular pathways underlying osteoblasts attachment are, however, different. As demonstrated by adhesion blocking assays, integrins are mainly involved in osteoblast adhesion to RGD peptide, while HVP selects osteoblasts for attachment through proteoglycan-mediated interactions. Thus an interfacial layer of an endosseous device grafted with specifically immobilized HVP peptide not only selects the attachment and supports differentiation of osteoblasts but also promotes cellular migration. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Demographically-Based Evaluation of Genomic Regions under Selection in Domestic Dogs.

Directory of Open Access Journals (Sweden)

Adam H Freedman

2016-03-01

Full Text Available Controlling for background demographic effects is important for accurately identifying loci that have recently undergone positive selection. To date, the effects of demography have not yet been explicitly considered when identifying loci under selection during dog domestication. To investigate positive selection on the dog lineage early in the domestication, we examined patterns of polymorphism in six canid genomes that were previously used to infer a demographic model of dog domestication. Using an inferred demographic model, we computed false discovery rates (FDR and identified 349 outlier regions consistent with positive selection at a low FDR. The signals in the top 100 regions were frequently centered on candidate genes related to brain function and behavior, including LHFPL3, CADM2, GRIK3, SH3GL2, MBP, PDE7B, NTAN1, and GLRA1. These regions contained significant enrichments in behavioral ontology categories. The 3rd top hit, CCRN4L, plays a major role in lipid metabolism, that is supported by additional metabolism related candidates revealed in our scan, including SCP2D1 and PDXC1. Comparing our method to an empirical outlier approach that does not directly account for demography, we found only modest overlaps between the two methods, with 60% of empirical outliers having no overlap with our demography-based outlier detection approach. Demography-aware approaches have lower-rates of false discovery. Our top candidates for selection, in addition to expanding the set of neurobehavioral candidate genes, include genes related to lipid metabolism, suggesting a dietary target of selection that was important during the period when proto-dogs hunted and fed alongside hunter-gatherers.

Stapled Voltage-Gated Calcium Channel (CaV) α-Interaction Domain (AID) Peptides Act As Selective Protein-Protein Interaction Inhibitors of CaV Function.

Science.gov (United States)

Findeisen, Felix; Campiglio, Marta; Jo, Hyunil; Abderemane-Ali, Fayal; Rumpf, Christine H; Pope, Lianne; Rossen, Nathan D; Flucher, Bernhard E; DeGrado, William F; Minor, Daniel L

2017-06-21

For many voltage-gated ion channels (VGICs), creation of a properly functioning ion channel requires the formation of specific protein-protein interactions between the transmembrane pore-forming subunits and cystoplasmic accessory subunits. Despite the importance of such protein-protein interactions in VGIC function and assembly, their potential as sites for VGIC modulator development has been largely overlooked. Here, we develop meta-xylyl (m-xylyl) stapled peptides that target a prototypic VGIC high affinity protein-protein interaction, the interaction between the voltage-gated calcium channel (Ca V ) pore-forming subunit α-interaction domain (AID) and cytoplasmic β-subunit (Ca V β). We show using circular dichroism spectroscopy, X-ray crystallography, and isothermal titration calorimetry that the m-xylyl staples enhance AID helix formation are structurally compatible with native-like AID:Ca V β interactions and reduce the entropic penalty associated with AID binding to Ca V β. Importantly, electrophysiological studies reveal that stapled AID peptides act as effective inhibitors of the Ca V α 1 :Ca V β interaction that modulate Ca V function in an Ca V β isoform-selective manner. Together, our studies provide a proof-of-concept demonstration of the use of protein-protein interaction inhibitors to control VGIC function and point to strategies for improved AID-based Ca V modulator design.

Source-sink interaction: a century old concept under the light of modern molecular systems biology.

Science.gov (United States)

Chang, Tian-Gen; Zhu, Xin-Guang; Raines, Christine

2017-07-20

Many approaches to engineer source strength have been proposed to enhance crop yield potential. However, a well-co-ordinated source-sink relationship is required finally to realize the promised increase in crop yield potential in the farmer's field. Source-sink interaction has been intensively studied for decades, and a vast amount of knowledge about the interaction in different crops and under different environments has been accumulated. In this review, we first introduce the basic concepts of source, sink and their interactions, then summarize current understanding of how source and sink can be manipulated through both environmental control and genetic manipulations. We show that the source-sink interaction underlies the diverse responses of crops to the same perturbations and argue that development of a molecular systems model of source-sink interaction is required towards a rational manipulation of the source-sink relationship for increased yield. We finally discuss both bottom-up and top-down routes to develop such a model and emphasize that a community effort is needed for development of this model. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Behaviors of Polymer Additives Under EHL and Influences of Interactions Between Additives on Friction Modification

Science.gov (United States)

Sakurai, T.

1984-01-01

Polymer additives have become requisite for the formulation of multigrade engine oils. The behavior of polymethacrylate (PMA)-thickened oils as lubricants in concentrated contacts under nominal rolling and pure sliding conditions was investigated by conventional optical interferometry. The PMA thickened oils behaved differently from the base oil in the formation of elastohydrodynamic (EHL) films. The higher the elastohydrodynamic molecular weight of the PMA contained in the lubricant, the thinner was the oil film under EHL conditions. The film thickness of shear-degraded PMA-thickened oils was also investigated. The behavior of graphite particles dispersed in both the base oil and the PMA-thickened oil was studied under pure sliding by taking photomicrographs. Many kinds of additives are contained in lubricating oil and the interactions between additives are considered. The interactions of zinc-organodithiophosphates (ZDP) with other additives is discussed.

Robust portfolio selection under norm uncertainty

Directory of Open Access Journals (Sweden)

Lei Wang

2016-06-01

Full Text Available Abstract In this paper, we consider the robust portfolio selection problem which has a data uncertainty described by the ( p , w $(p,w$ -norm in the objective function. We show that the robust formulation of this problem is equivalent to a linear optimization problem. Moreover, we present some numerical results concerning our robust portfolio selection problem.

Mechanisms underlying selecting objects for action

Directory of Open Access Journals (Sweden)

Melanie eWulff

2015-04-01

Full Text Available We assessed the factors which affect the selection of objects for action, focusing on the role of action knowledge and its modulation by distracters. 14 neuropsychological patients and 10 healthy aged-matched controls selected pairs of objects commonly used together among distracters in two contexts: with real objects and with pictures of the same objects presented sequentially on a computer screen. Across both tasks, semantically related distracters led to slower responses and more errors than unrelated distracters and the object actively used for action was selected prior to the object that would be passively held during the action. We identified a sub-group of patients (N=6 whose accuracy was 2SD below the controls performances in the real object task. Interestingly, these impaired patients were more affected by the presence of unrelated distracters during both tasks than intact patients and healthy controls. Note the impaired had lesions to left parietal, right anterior temporal and bilateral pre-motor regions. We conclude that: (1 motor procedures guide object selection for action, (2 semantic knowledge affects action-based selection, (3 impaired action decision is associated with the inability to ignore distracting information and (4 lesions to either the dorsal or ventral visual stream can lead to deficits in making action decisions. Overall, the data indicate that impairments in everyday tasks can be evaluated using a simulated computer task. The implications for rehabilitation are discussed.

Mapping Haplotype-haplotype Interactions with Adaptive LASSO

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Li Ming

2010-08-01

Full Text Available Abstract Background The genetic etiology of complex diseases in human has been commonly viewed as a complex process involving both genetic and environmental factors functioning in a complicated manner. Quite often the interactions among genetic variants play major roles in determining the susceptibility of an individual to a particular disease. Statistical methods for modeling interactions underlying complex diseases between single genetic variants (e.g. single nucleotide polymorphisms or SNPs have been extensively studied. Recently, haplotype-based analysis has gained its popularity among genetic association studies. When multiple sequence or haplotype interactions are involved in determining an individual's susceptibility to a disease, it presents daunting challenges in statistical modeling and testing of the interaction effects, largely due to the complicated higher order epistatic complexity. Results In this article, we propose a new strategy in modeling haplotype-haplotype interactions under the penalized logistic regression framework with adaptive L1-penalty. We consider interactions of sequence variants between haplotype blocks. The adaptive L1-penalty allows simultaneous effect estimation and variable selection in a single model. We propose a new parameter estimation method which estimates and selects parameters by the modified Gauss-Seidel method nested within the EM algorithm. Simulation studies show that it has low false positive rate and reasonable power in detecting haplotype interactions. The method is applied to test haplotype interactions involved in mother and offspring genome in a small for gestational age (SGA neonates data set, and significant interactions between different genomes are detected. Conclusions As demonstrated by the simulation studies and real data analysis, the approach developed provides an efficient tool for the modeling and testing of haplotype interactions. The implementation of the method in R codes can be

Selection of tomato mutants (lycopersicon esculentum mill) under conditions of drought stress

International Nuclear Information System (INIS)

Gonzalez, Maria Caridad; Mansoor, Ali; Suarez, Lorenzo; Mukandama, Jean P.; Rodriguez, Yanet

2001-01-01

At the National Institute of Agricultural Sciences were evaluated under conditions of drought estres an M5 population obtained starting from the irradiation of seeds of the Amalia and INCA 9-1varieties with dose of 300 and 500 Gy of rays gamma of 60 Co. The number of clusters for plant, mass average of the fruits, number of fruits for plant and yield for plant, the content of total soluble solids and the acidity of the fruits was evaluated observing differ highly significant among the different ones lines and the respective donating studied. Promissory genotipos of high productive potential was selected under this condition

High-Arctic Plant-Herbivore Interactions under Climate Influence

DEFF Research Database (Denmark)

Berg, Thomas B.; Schmidt, Niels M.; Høye, Toke Thomas

production upon which the herbivores depend, and snow may be the most important climatic factor affecting the different trophic levels and the interactions between them. Hence, the spatio-temporal distribution of snow, as well as thawing events during winter, may have considerable effects on the herbivores...... by both the timing of onset and the duration of winter snow-cover. Musk oxen significantly reduced the productivity of arctic willow, while high densities of collared lemmings during winter reduced the production of mountain averts flowers in the following summer. Under a deep snow-layer scenario, climate...... and the previous year's density of musk oxen had a negative effect on the present year's production of arctic willow. Previous year's primary production of arctic willow, in turn, significantly affected the present year's density of musk oxen positively. Climatic factors that affect primary production of plants...

Optimal processing pathway selection for microalgae-based biorefinery under uncertainty

DEFF Research Database (Denmark)

Rizwan, Muhammad; Zaman, Muhammad; Lee, Jay H.

2015-01-01

We propose a systematic framework for the selection of optimal processing pathways for a microalgaebased biorefinery under techno-economic uncertainty. The proposed framework promotes robust decision making by taking into account the uncertainties that arise due to inconsistencies among...... and shortage in the available technical information. A stochastic mixed integer nonlinear programming (sMINLP) problem is formulated for determining the optimal biorefinery configurations based on a superstructure model where parameter uncertainties are modeled and included as sampled scenarios. The solution...... the accounting of uncertainty are compared with respect to different objectives. (C) 2015 Elsevier Ltd. All rights reserved....

Numerical Simulation of Interactions between Corrosion Pits on Stainless Steel under Loading Conditions

International Nuclear Information System (INIS)

Wang, Haitao; Han, En-Hou

2017-01-01

The interactions between corrosion pits on stainless steel under loading conditions are studied by using a cellular automata model coupled with finite element method at a mesoscopic scale. The cellular automata model focuses on a metal/film/electrolyte system, including anodic dissolution, passivation, diffusion of hydrogen ions and salt film hydrolysis. The Chopard block algorithm is used to improve the diffusion simulation efficiency. The finite element method is used to calculate the stress concentration on the pit surface during pit growth, and the effect of local stress and strain on anodic current is obtained by using the Gutman model, which is used as the boundary conditions of the cellular automata model. The transient current characteristics of the interactions between corrosion pits under different simulation factors including the breakdown of the passive film at the pit mouth and the diffusion of hydrogen ions are analyzed. The analysis of the pit stability product shows that the simulation results are close to the experimental conclusions.

Numerical Simulation of Interactions between Corrosion Pits on Stainless Steel under Loading Conditions

Energy Technology Data Exchange (ETDEWEB)

Wang, Haitao; Han, En-Hou [Chinese Academy of Sciences, Shenyang (China)

2017-04-15

The interactions between corrosion pits on stainless steel under loading conditions are studied by using a cellular automata model coupled with finite element method at a mesoscopic scale. The cellular automata model focuses on a metal/film/electrolyte system, including anodic dissolution, passivation, diffusion of hydrogen ions and salt film hydrolysis. The Chopard block algorithm is used to improve the diffusion simulation efficiency. The finite element method is used to calculate the stress concentration on the pit surface during pit growth, and the effect of local stress and strain on anodic current is obtained by using the Gutman model, which is used as the boundary conditions of the cellular automata model. The transient current characteristics of the interactions between corrosion pits under different simulation factors including the breakdown of the passive film at the pit mouth and the diffusion of hydrogen ions are analyzed. The analysis of the pit stability product shows that the simulation results are close to the experimental conclusions.

Natural selection interacts with recombination to shape the evolution of hybrid genomes.

Science.gov (United States)

Schumer, Molly; Xu, Chenling; Powell, Daniel L; Durvasula, Arun; Skov, Laurits; Holland, Chris; Blazier, John C; Sankararaman, Sriram; Andolfatto, Peter; Rosenthal, Gil G; Przeworski, Molly

2018-05-11

To investigate the consequences of hybridization between species, we studied three replicate hybrid populations that formed naturally between two swordtail fish species, estimating their fine-scale genetic map and inferring ancestry along the genomes of 690 individuals. In all three populations, ancestry from the "minor" parental species is more common in regions of high recombination and where there is linkage to fewer putative targets of selection. The same patterns are apparent in a reanalysis of human and archaic admixture. These results support models in which ancestry from the minor parental species is more likely to persist when rapidly uncoupled from alleles that are deleterious in hybrids. Our analyses further indicate that selection on swordtail hybrids stems predominantly from deleterious combinations of epistatically interacting alleles. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Analyses of crystal field and exchange interaction of Dy3Ga5O12 under extreme conditions

International Nuclear Information System (INIS)

Wang Wei; Qi Xin; Yue Yuan

2011-01-01

This paper theoretically investigates the effects of crystal field and exchange interaction field on magnetic properties in dysprosium gallium garnet under extreme conditions (low temperatures and high magnetic fields) based on quantum theory. Here, five sets of crystal field parameters are discussed and compared. It demonstrates that, only considering the crystal field effect, the experiments can not be successfully explained. Thus, referring to the molecular field theory, an effective exchange field associated with the Dy—Dy exchange interaction is further taken into account. Under special consideration of crystal field and the exchange interaction field, it obtains an excellent agreement between the theoretical results and experiments, and further confirms that the exchange interaction field between rare-earth ions has great importance to magnetic properties in paramagnetic rare-earth gallium garnets. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Interhemispheric interaction expands attentional capacity in an auditory selective attention task.

Science.gov (United States)

Scalf, Paige E; Banich, Marie T; Erickson, Andrew B

2009-04-01

Previous work from our laboratory indicates that interhemispheric interaction (IHI) functionally increases the attentional capacity available to support performance on visual tasks (Banich in The asymmetrical brain, pp 261-302, 2003). Because manipulations of both computational complexity and selection demand alter the benefits of IHI to task performance, we argue that IHI may be a general strategy for meeting increases in attentional demand. Other researchers, however, have suggested that the apparent benefits of IHI to attentional capacity are an epiphenomenon of the organization of the visual system (Fecteau and Enns in Neuropsychologia 43:1412-1428, 2005; Marsolek et al. in Neuropsychologia 40:1983-1999, 2002). In the current experiment, we investigate whether IHI increases attentional capacity outside the visual system by manipulating the selection demands of an auditory temporal pattern-matching task. We find that IHI expands attentional capacity in the auditory system. This suggests that the benefits of requiring IHI derive from a functional increase in attentional capacity rather than the organization of a specific sensory modality.

Selection of Representative Models for Decision Analysis Under Uncertainty

Science.gov (United States)

Meira, Luis A. A.; Coelho, Guilherme P.; Santos, Antonio Alberto S.; Schiozer, Denis J.

2016-03-01

The decision-making process in oil fields includes a step of risk analysis associated with the uncertainties present in the variables of the problem. Such uncertainties lead to hundreds, even thousands, of possible scenarios that are supposed to be analyzed so an effective production strategy can be selected. Given this high number of scenarios, a technique to reduce this set to a smaller, feasible subset of representative scenarios is imperative. The selected scenarios must be representative of the original set and also free of optimistic and pessimistic bias. This paper is devoted to propose an assisted methodology to identify representative models in oil fields. To do so, first a mathematical function was developed to model the representativeness of a subset of models with respect to the full set that characterizes the problem. Then, an optimization tool was implemented to identify the representative models of any problem, considering not only the cross-plots of the main output variables, but also the risk curves and the probability distribution of the attribute-levels of the problem. The proposed technique was applied to two benchmark cases and the results, evaluated by experts in the field, indicate that the obtained solutions are richer than those identified by previously adopted manual approaches. The program bytecode is available under request.

Genome-wide characterization of genetic variants and putative regions under selection in meat and egg-type chicken lines.

Science.gov (United States)

Boschiero, Clarissa; Moreira, Gabriel Costa Monteiro; Gheyas, Almas Ara; Godoy, Thaís Fernanda; Gasparin, Gustavo; Mariani, Pilar Drummond Sampaio Corrêa; Paduan, Marcela; Cesar, Aline Silva Mello; Ledur, Mônica Corrêa; Coutinho, Luiz Lehmann

2018-01-25

Meat and egg-type chickens have been selected for several generations for different traits. Artificial and natural selection for different phenotypes can change frequency of genetic variants, leaving particular genomic footprints throghtout the genome. Thus, the aims of this study were to sequence 28 chickens from two Brazilian lines (meat and white egg-type) and use this information to characterize genome-wide genetic variations, identify putative regions under selection using Fst method, and find putative pathways under selection. A total of 13.93 million SNPs and 1.36 million INDELs were identified, with more variants detected from the broiler (meat-type) line. Although most were located in non-coding regions, we identified 7255 intolerant non-synonymous SNPs, 512 stopgain/loss SNPs, 1381 frameshift and 1094 non-frameshift INDELs that may alter protein functions. Genes harboring intolerant non-synonymous SNPs affected metabolic pathways related mainly to reproduction and endocrine systems in the white-egg layer line, and lipid metabolism and metabolic diseases in the broiler line. Fst analysis in sliding windows, using SNPs and INDELs separately, identified over 300 putative regions of selection overlapping with more than 250 genes. For the first time in chicken, INDEL variants were considered for selection signature analysis, showing high level of correlation in results between SNP and INDEL data. The putative regions of selection signatures revealed interesting candidate genes and pathways related to important phenotypic traits in chicken, such as lipid metabolism, growth, reproduction, and cardiac development. In this study, Fst method was applied to identify high confidence putative regions under selection, providing novel insights into selection footprints that can help elucidate the functional mechanisms underlying different phenotypic traits relevant to meat and egg-type chicken lines. In addition, we generated a large catalog of line-specific and common

Selection of efficient salt-tolerant bacteria containing ACC deaminase for promotion of tomato growth under salinity stress

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Kannika Chookietwattana* and Kedsukon Maneewan

2012-05-01

Full Text Available For successful application of plant growth promoting bacteria (PGPB in salt-affected soil, bioinoculant with salt-tolerant property is required in order to provide better survival and perform well in the field. The present study aimed to select the most efficient salt-tolerant bacterium containing 1-aminocyclopropane-1-carboxylic acid (ACC deaminase from eighty four bacterial strains and to investigate the effects of the selected bacterium on the germination and growth of tomato (Licopersicon esculentum Mill. cv. Seeda under saline conditions. The Bacillus licheniformis B2r was selected for its ability to utilize ACC as a sole nitrogen source under salinity stress. It also showed a high ACC deaminase activity at 0.6 M NaCl salinity. Tomato plants inoculated with the selected bacterium under various saline conditions (0, 30, 60, 90 and 120 mM NaCl revealed a significant increase in the germination percentage, germination index, root length, and seedling dry weight especially at salinity levels ranging from 30-90 mM NaCl. The work described in this report is an important step in developing an efficient salt-tolerant bioinoculant to facilitate plant growth in saline soil.

Geographical patterns of adaptation within a species' range : Interactions between drift and gene flow

NARCIS (Netherlands)

Alleaume-Benharira, M; Pen, IR; Ronce, O

We use individual-based stochastic simulations and analytical deterministic predictions to investigate the interaction between drift, natural selection and gene flow on the patterns of local adaptation across a fragmented species' range under clinally varying selection. Migration between populations

Decision framework of photovoltaic module selection under interval-valued intuitionistic fuzzy environment

International Nuclear Information System (INIS)

Long, Shengping; Geng, Shuai

2015-01-01

Highlights: • The evaluation index system is set by the engineering and supply chain perspectives. • The interval-valued intuitionistic fuzzy set (IVIFS) to express the performances. • The IVIFS entropy weight method is applied to improve the objectivity of weights. - Abstract: The selection of appropriate photovoltaic module is of extremely high importance for the solar power station project; however the comprehensive problem of evaluation index system, the information loss problem and the lack-objectivity problem in the selection process will decrease the reasonability of the selection result. The innovation points of this paper are as follows: first, the comprehensive evaluation index system of photovoltaic module is established from the engineering management and supply chain management perspectives to solve the comprehensive problem; second, the interval-valued intuitionistic fuzzy set (IVIFS) are introduced into the photovoltaic modules selection process to express the alternatives’ performances to solve the information loss problem; third, the IVIFS entropy weight method is applied to improve the objectivity of the criteria’s weights. According to the aforementioned solutions, the decision framework of photovoltaic module selection under interval-valued intuitionistic fuzzy environment are established and used in a case study to demonstrate its effectiveness. Therefore, from the theoretical modeling and empirical demonstration, the decision framework proposed in this paper can effectively handle such a complicated problem and lead to an outstanding result.

Biophysical parameters of erythrocyte membranes and mechanisms of interaction with non-opioid analgesics under acute pain syndrome

Directory of Open Access Journals (Sweden)

Yu. I. Gubskyi

2014-06-01

Full Text Available Methods of fluorescent probing, spectrophotometry and microcalorimetry were applied to investigate the alterations in biophysical parameters of erythrocytes membranes, and specifically microviscosity, surface charge, molecular organization of lipid bilayer and lipid-protein interactions under conditions of acute pain syndrome produced by experimental chemical lesion. The distinctive features of non-opiod analgesics interactions and binding to the erythrocytes membranes of rats subjected to acute nociceptive pain accompanied with oxidative stress development were investigated. The abilities of analgesics under research, and namely paracetamol, aspirin, phenazone, ketorolac, pyrodazole, ketoprofenum, natrium mefenaminate, indometacin, nimesulide to make up physico-chemical complexes with lipoperoxidation modified erythrocytes surface and protein-lipid bilayer showed marked changes. The significance of oxidative damage of biophase under conditions of acute pain syndrome for analgesics effective pharmacodynamics and pharmacokinetics realization is under consideration.

The Interaction of Selective Attention and Cognitive Development on Achievement in Nigerian Secondary School Genetics

Science.gov (United States)

Okoye, Namdi N. S.

2009-01-01

The study tried to examine the interaction between two independent variables of selective attention and cognitive development on Achievement in Genetics at the Secondary School level. In looking at the problem of this study three null hypotheses were generated for testing at 0.05 level of significance. Factorial Analysis of Variance design with…

Interactivity effects in social media marketing on brand engagement: an investigation of underlying mechanisms

NARCIS (Netherlands)

Antheunis, M.L.; van Noort, G.; Eisend, M.; Langner, T.

2011-01-01

Although, SNS advertising spending increases, research on SNS campaigning is still underexposed. First, this study aims to investigate the effect of SNS campaign interactivity on the receivers brand engagement, taking four underlying mechanisms into account (brand identification, campaign

Green supplier development program selection using NGT and VIKOR under fuzzy environment

DEFF Research Database (Denmark)

Awasthi, Anjali; Govindan, Kannan

2016-01-01

Developing environmental performance of suppliers is critical for green supply chain management. Organizations are nowadays investing in various green supplier development programs to enhance their supplier performances. The decision to select the right program for green supplier development...... is often a challenging decision due to lack of prior experience, limited quantitative information, specific context of the organization, and varying supplier backgrounds. This paper addresses the problem of evaluating green supplier development programs and proposes a fuzzy NGT (Nominal Group Technique......)-VIKOR (VlseKriterijumska Optimizacija I Kompromisno Resenje) based solution approach. NGT is used to identify criteria for evaluating green supplier development programs. Fuzzy theory is used to address qualitative (linguistic) ratings for the alternatives and the selected criteria used under lack...

Histological Architecture Underlying Brain-Immune Cell-Cell Interactions and the Cerebral Response to Systemic Inflammation.

Science.gov (United States)

Shimada, Atsuyoshi; Hasegawa-Ishii, Sanae

2017-01-01

Although the brain is now known to actively interact with the immune system under non-inflammatory conditions, the site of cell-cell interactions between brain parenchymal cells and immune cells has been an open question until recently. Studies by our and other groups have indicated that brain structures such as the leptomeninges, choroid plexus stroma and epithelium, attachments of choroid plexus, vascular endothelial cells, cells of the perivascular space, circumventricular organs, and astrocytic endfeet construct the histological architecture that provides a location for intercellular interactions between bone marrow-derived myeloid lineage cells and brain parenchymal cells under non-inflammatory conditions. This architecture also functions as the interface between the brain and the immune system, through which systemic inflammation-induced molecular events can be relayed to the brain parenchyma at early stages of systemic inflammation during which the blood-brain barrier is relatively preserved. Although brain microglia are well known to be activated by systemic inflammation, the mechanism by which systemic inflammatory challenge and microglial activation are connected has not been well documented. Perturbed brain-immune interaction underlies a wide variety of neurological and psychiatric disorders including ischemic brain injury, status epilepticus, repeated social defeat, and neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Proinflammatory status associated with cytokine imbalance is involved in autism spectrum disorders, schizophrenia, and depression. In this article, we propose a mechanism connecting systemic inflammation, brain-immune interface cells, and brain parenchymal cells and discuss the relevance of basic studies of the mechanism to neurological disorders with a special emphasis on sepsis-associated encephalopathy and preterm brain injury.

Self-Consistent Monte Carlo Study of the Coulomb Interaction under Nano-Scale Device Structures

Science.gov (United States)

Sano, Nobuyuki

2011-03-01

It has been pointed that the Coulomb interaction between the electrons is expected to be of crucial importance to predict reliable device characteristics. In particular, the device performance is greatly degraded due to the plasmon excitation represented by dynamical potential fluctuations in high-doped source and drain regions by the channel electrons. We employ the self-consistent 3D Monte Carlo (MC) simulations, which could reproduce both the correct mobility under various electron concentrations and the collective plasma waves, to study the physical impact of dynamical potential fluctuations on device performance under the Double-gate MOSFETs. The average force experienced by an electron due to the Coulomb interaction inside the device is evaluated by performing the self-consistent MC simulations and the fixed-potential MC simulations without the Coulomb interaction. Also, the band-tailing associated with the local potential fluctuations in high-doped source region is quantitatively evaluated and it is found that the band-tailing becomes strongly dependent of position in real space even inside the uniform source region. This work was partially supported by Grants-in-Aid for Scientific Research B (No. 2160160) from the Ministry of Education, Culture, Sports, Science and Technology in Japan.

Interactions between selected bile salts and Triton X-100 or sodium lauryl ether sulfate

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Ćirin Dejan M

2011-12-01

Full Text Available Abstract Background In order to develop colloidal drug carriers with desired properties, it is important to determine physico-chemical characteristics of these systems. Bile salt mixed micelles are extensively studied as novel drug delivery systems. The objective of the present investigation is to develop and characterize mixed micelles of nonionic (Triton X-100 or anionic (sodium lauryl ether sulfate surfactant having oxyethylene groups in the polar head and following bile salts: cholate, deoxycholate and 7-oxodeoxycholate. Results The micellization behaviour of binary anionic-nonionic and anionic-anionic surfactant mixtures was investigated by conductivity and surface tension measurements. The results of the study have been analyzed using Clint's, Rubingh's, and Motomura's theories for mixed binary systems. The negative values of the interaction parameter indicate synergism between micelle building units. It was noticed that Triton X-100 and sodium lauryl ether sulfate generate the weakest synergistic interactions with sodium deoxycholate, while 7-oxodeoxycholate creates the strongest attractive interaction with investigated co-surfactants. Conclusion It was concluded that increased synergistic interactions can be attributed to the larger number of hydrophilic groups at α side of the bile salts. Additionally, 7-oxo group of 7-oxodeoxycholate enhance attractive interactions with selected co-surfactants more than 7-hydroxyl group of sodium cholate.

Interactions between selected bile salts and Triton X-100 or sodium lauryl ether sulfate.

Science.gov (United States)

Cirin, Dejan M; Poša, Mihalj M; Krstonošić, Veljko S

2011-12-29

In order to develop colloidal drug carriers with desired properties, it is important to determine physico-chemical characteristics of these systems. Bile salt mixed micelles are extensively studied as novel drug delivery systems. The objective of the present investigation is to develop and characterize mixed micelles of nonionic (Triton X-100) or anionic (sodium lauryl ether sulfate) surfactant having oxyethylene groups in the polar head and following bile salts: cholate, deoxycholate and 7-oxodeoxycholate. The micellization behaviour of binary anionic-nonionic and anionic-anionic surfactant mixtures was investigated by conductivity and surface tension measurements. The results of the study have been analyzed using Clint's, Rubingh's, and Motomura's theories for mixed binary systems. The negative values of the interaction parameter indicate synergism between micelle building units. It was noticed that Triton X-100 and sodium lauryl ether sulfate generate the weakest synergistic interactions with sodium deoxycholate, while 7-oxodeoxycholate creates the strongest attractive interaction with investigated co-surfactants. It was concluded that increased synergistic interactions can be attributed to the larger number of hydrophilic groups at α side of the bile salts. Additionally, 7-oxo group of 7-oxodeoxycholate enhance attractive interactions with selected co-surfactants more than 7-hydroxyl group of sodium cholate.

A Bioinspired Organocatalytic Cascade for the Selective Oxidation of Amines under Air.

Science.gov (United States)

Largeron, Martine; Fleury, Maurice-Bernard

2017-05-17

A bioinspired organocatalytic cascade reaction for the selective aerobic oxidative cross-coupling of primary amines to imines is described. This approach takes advantages of commercially available pyrogallol monomeric precursor to deliver low loadings of natural purpurogallin in situ, under air. This is further engaged in a catalytic process with the amine substrate affording, under single turnover, the active biomimetic quinonoid organocatalyst and the homocoupled imine intermediate, which is then converted into cross-coupled imine after dynamic transimination. This organocatalytic cascade inspired by both purpurogallin biosynthesis and copper amine oxidases allows the aerobic oxidation of non-activated primary amines that non-enzymatic organocatalysts were not able to accomplish alone. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The selective interaction between silica nanoparticles and enzymes from molecular dynamics simulations.

Directory of Open Access Journals (Sweden)

Xiaotian Sun

Full Text Available Nanoscale particles have become promising materials in many fields, such as cancer therapeutics, diagnosis, imaging, drug delivery, catalysis, as well as biosensors. In order to stimulate and facilitate these applications, there is an urgent need for the understanding of the interaction mode between the nano-particles and proteins. In this study, we investigate the orientation and adsorption between several enzymes (cytochrome c, RNase A, lysozyme and 4 nm/11 nm silica nanoparticles (SNPs by using molecular dynamics (MD simulation. Our results show that three enzymes are adsorbed onto the surfaces of both 4 nm and 11 nm SNPs during our MD simulations and the small SNPs induce greater structural stabilization. The active site of cytochrome c is far away from the surface of 4 nm SNPs, while it is adsorbed onto the surface of 11 nm SNPs. We also explore the influences of different groups (-OH, -COOH, -NH2 and CH3 coated onto silica nanoparticles, which show significantly different impacts. Our molecular dynamics results indicate the selective interaction between silicon nanoparticles and enzymes, which is consistent with experimental results. Our study provides useful guides for designing/modifying nanomaterials to interact with proteins for their bio-applications.

Taxation and regulation of petroleum companies under asymmetric information; a monograph

Energy Technology Data Exchange (ETDEWEB)

Osmundsen, P

1994-12-01

The report relates to the taxation and regulation of petroleum companies. The main topics of this report are as follow: Taxation and regulation of petroleum companies under asymmetric information. A discussion of incentive problems and the principles for applying principal-agent analysis; taxation and regulation of petroleum companies under asymmetric information. A static adverse selection model; Petroleum Taxation with adverse selection. Interactions of dynamics in costs and information; Adverse selection and moral hazard in the petroleum industry, repeated auctions of incentive contracts; Petroleum taxation and regulation. Policy implications from principal-agent theory, and a comparison with the current Norwegian system. 54 refs., 7 figs.

Taxation and regulation of petroleum companies under asymmetric information; a monograph

International Nuclear Information System (INIS)

Osmundsen, P.

1994-12-01

The report relates to the taxation and regulation of petroleum companies. The main topics of this report are as follow: Taxation and regulation of petroleum companies under asymmetric information. A discussion of incentive problems and the principles for applying principal-agent analysis; taxation and regulation of petroleum companies under asymmetric information. A static adverse selection model; Petroleum Taxation with adverse selection. Interactions of dynamics in costs and information; Adverse selection and moral hazard in the petroleum industry, repeated auctions of incentive contracts; Petroleum taxation and regulation. Policy implications from principal-agent theory, and a comparison with the current Norwegian system. 54 refs., 7 figs

Formation of imines by selective gold-catalysed aerobic oxidative coupling of alcohols and amines under ambient conditions

DEFF Research Database (Denmark)

Kegnæs, Søren; Mielby, Jerrik Jørgen; Mentzel, Uffe Vie

2010-01-01

with excellent selectivity (above 98%) at moderate conversion under optimized conditions. The effect of catalytic amounts of different bases was studied, along with reaction temperature and time. Utilisation of a selective catalyst system that uses dioxygen as an oxidant and only produces water as by...

UO2 - Zr chemical interaction of PHWR fuel pins under high temperature

International Nuclear Information System (INIS)

Majumdar, P.; Mukhopadhyay, D.; Gupta, S.K.

2001-01-01

At high temperature Zircaloy clad interacts with the UO 2 fuel as well as with the steam to produce oxide layer of a-Zr(O) and ZrO 2 . This layer formation significantly reduces the structural strength of the clad. A computer code SFDCPA/MOD1 has been developed to simulate the interaction and predict the oxide layer thickness for any accidental transient condition. It is well validated with published experimental data on the isothermal and transient temperature condition. The program is applied to Indian Pressurized Heavy Water Reactor (PHWR) fuel pin under certain severe transient condition where it experiences temperature above 1000 C. The study gives an idea of the un-oxidized thickness of Zircaloy, which is an important criterion for fuel integrity. (author)

Introduction to the modified TROI test facility for fuel coolant interaction under a submerged reactor vessel

International Nuclear Information System (INIS)

Na, Young Su; Hong, Seong-Wan; Song, Jin Ho; Hong, Seong-Ho

2014-01-01

The molten Fuel-Coolant Interaction (FCI) can threaten the integrity of the reactor cavity under a severe accident. A steam explosion can be occurred by the rapid energy transfer in the high-temperature corium melt jet penetrating into water, which makes the dynamic load applying to the surrounding structure. Before a steam explosion, the corium melt jet breaks into small-sized particles, and the steam is generated continuously by the film boiling on the hot surface of the melt contacting with water. The premixing phase consisting of the corium melt, water, and steam can determine the intensity of the steam explosion. Unfortunately, the previous experimental studies on the FCI phenomena have carried out under a free fall of the corium melt jet in a gas phase before interacting with water. The previous TROI (Test for Real cOrium Interaction with water) test facility, that is a well-known test facility for the FCI phenomena in the world, has observed a steam explosion under a free fall of a corium melt jet in a gas phase before contacting a coolant since 2000, which is changing to simulate the FCI phenomena under a submerged reactor vessel. This study introduces the modified TROI test facility as shown in Fig. 1 and the considerations for the experiment with success. The previous TROI test facility, that has observed the molten Fuel-Coolant Interaction (FCI) with a free fall of the prototypic corium melt in a gas phase before contacting a coolant, was modified to simulate the FCI phenomena under a submerged reactor vessel for the assessment of the In-Vessel Retention (IVR) concept, i.e., without a free-fall distance of the corium melt before contacting water. The superheated prototypic corium melt created by the cold crucible melting method moves on a releasing valve newly installed just above the water level in the interaction vessel. The corium melt will stay on a releasing valve in less than 0.2 seconds to reduce heat loss for preventing the solidification, and

Selective interaction of heparin with the variable region 3 within surface glycoprotein of laboratory-adapted feline immunodeficiency virus.

Directory of Open Access Journals (Sweden)

Qiong-Ying Hu

Full Text Available Heparan sulfate proteoglycans (HSPG can act as binding receptors for certain laboratory-adapted (TCA strains of feline immunodeficiency virus (FIV and human immunodeficiency virus (HIV. Heparin, a soluble heparin sulfate (HS, can inhibit TCA HIV and FIV entry mediated by HSPG interaction in vitro. In the present study, we further determined the selective interaction of heparin with the V3 loop of TCA of FIV. Our current results indicate that heparin selectively inhibits infection by TCA strains, but not for field isolates (FS. Heparin also specifically interferes with TCA surface glycoprotein (SU binding to CXCR4, by interactions with HSPG binding sites on the V3 loop of the FIV envelope protein. Peptides representing either the N- or C-terminal side of the V3 loop and containing HSPG binding sites were able to compete away the heparin block of TCA SU binding to CXCR4. Heparin does not interfere with the interaction of SU with anti-V3 antibodies that target the CXCR4 binding region or with the interaction between FS FIV and anti-V3 antibodies since FS SU has no HSPG binding sites within the HSPG binding region. Our data show that heparin blocks TCA FIV infection or entry not only through its competition of HSPG on the cell surface interaction with SU, but also by its interference with CXCR4 binding to SU. These studies aid in the design and development of heparin derivatives or analogues that can inhibit steps in virus infection and are informative regarding the HSPG/SU interaction.

A drought resistance-promoting microbiome is selected by root system under desert farming.

Directory of Open Access Journals (Sweden)

Ramona Marasco

Full Text Available BACKGROUND: Traditional agro-systems in arid areas are a bulwark for preserving soil stability and fertility, in the sight of "reverse desertification". Nevertheless, the impact of desert farming practices on the diversity and abundance of the plant associated microbiome is poorly characterized, including its functional role in supporting plant development under drought stress. METHODOLOGY/PRINCIPAL FINDINGS: We assessed the structure of the microbiome associated to the drought-sensitive pepper plant (Capsicum annuum L. cultivated in a traditional Egyptian farm, focusing on microbe contribution to a crucial ecosystem service, i.e. plant growth under water deficit. The root system was dissected by sampling root/soil with a different degree of association to the plant: the endosphere, the rhizosphere and the root surrounding soil that were compared to the uncultivated soil. Bacterial community structure and diversity, determined by using Denaturing Gradient Gel Electrophoresis, differed according to the microhabitat, indicating a selective pressure determined by the plant activity. Similarly, culturable bacteria genera showed different distribution in the three root system fractions. Bacillus spp. (68% of the isolates were mainly recovered from the endosphere, while rhizosphere and the root surrounding soil fractions were dominated by Klebsiella spp. (61% and 44% respectively. Most of the isolates (95% presented in vitro multiple plant growth promoting (PGP activities and stress resistance capabilities, but their distribution was different among the root system fractions analyzed, with enhanced abilities for Bacillus and the rhizobacteria strains. We show that the C. annuum rhizosphere under desert farming enriched populations of PGP bacteria capable of enhancing plant photosynthetic activity and biomass synthesis (up to 40% under drought stress. CONCLUSIONS/SIGNIFICANCE: Crop cultivation provides critical ecosystem services in arid lands with the

Extrapolating Weak Selection in Evolutionary Games

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Wu, Bin; García, Julián; Hauert, Christoph; Traulsen, Arne

2013-01-01

In evolutionary games, reproductive success is determined by payoffs. Weak selection means that even large differences in game outcomes translate into small fitness differences. Many results have been derived using weak selection approximations, in which perturbation analysis facilitates the derivation of analytical results. Here, we ask whether results derived under weak selection are also qualitatively valid for intermediate and strong selection. By “qualitatively valid” we mean that the ranking of strategies induced by an evolutionary process does not change when the intensity of selection increases. For two-strategy games, we show that the ranking obtained under weak selection cannot be carried over to higher selection intensity if the number of players exceeds two. For games with three (or more) strategies, previous examples for multiplayer games have shown that the ranking of strategies can change with the intensity of selection. In particular, rank changes imply that the most abundant strategy at one intensity of selection can become the least abundant for another. We show that this applies already to pairwise interactions for a broad class of evolutionary processes. Even when both weak and strong selection limits lead to consistent predictions, rank changes can occur for intermediate intensities of selection. To analyze how common such games are, we show numerically that for randomly drawn two-player games with three or more strategies, rank changes frequently occur and their likelihood increases rapidly with the number of strategies . In particular, rank changes are almost certain for , which jeopardizes the predictive power of results derived for weak selection. PMID:24339769

Behavior of uranium under conditions of interaction of rocks and ores with subsurface water

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Omel'Yanenko, B. I.; Petrov, V. A.; Poluektov, V. V.

2007-10-01

The behavior of uranium during interaction of subsurface water with crystalline rocks and uranium ores is considered in connection with the problem of safe underground insulation of spent nuclear fuel (SNF). Since subsurface water interacts with crystalline rocks formed at a high temperature, the mineral composition of these rocks and uranium species therein are thermodynamically unstable. Therefore, reactions directed toward the establishment of equilibrium proceed in the water-rock system. At great depths that are characterized by hindered water exchange, where subsurface water acquires near-neutral and reducing properties, the interaction is extremely sluggish and is expressed in the formation of micro- and nanoparticles of secondary minerals. Under such conditions, the slow diffusion redistribution of uranium with enrichment in absorbed forms relative to all other uranium species is realized as well. The products of secondary alteration of Fe- and Ti-bearing minerals serve as the main sorbents of uranium. The rate of alteration of minerals and conversion of uranium species into absorbed forms is slow, and the results of these processes are insignificant, so that the rocks and uranium species therein may be regarded as unaltered. Under reducing conditions, subsurface water is always saturated with uranium. Whether water interacts with rock or uranium ore, the equilibrium uranium concentration in water is only ≤10-8 mol/l. Uraninite ore under such conditions always remains stable irrespective of its age. The stability conditions of uranium ore are quite suitable for safe insulation of SNF, which consists of 95% uraninite (UO2) and is a confinement matrix for all other radionuclides. The disposal of SNF in massifs of crystalline rocks at depths below 500 m, where reducing conditions are predominant, is a reliable guarantee of high SNF stability. Under oxidizing conditions of the upper hydrodynamic zone, the rate of interaction of rocks with subsurface water

Under multilevel selection: "when shall you be neither spiteful nor envious?".

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Garay, József; Csiszár, Villő; Móri, Tamás F

2014-01-07

In this paper, we study the egalitarianism-game in multilevel selection situation. The individuals form reproductive groups. In each group, an egalitarianism-game determines the number of juveniles of different phenotypes (spiteful, envious, neutral and donator). Before the juveniles form the next reproductive group, they have to survive either predators' attacks or a fight between two groups. We adopt the ESS definition of Maynard Smith to multilevel selection. Based on the "group size advantage" assumption (which claims that each juvenile's survival rate depends on the size of his own group, supposing that either the survival rate under predators' attacks is higher in larger groups, or in inter-group aggression usually the larger group wins) we found that when the survival probability has a massive effect on the average fitness, then "group fitness maximizing behavior" (in our case, either neutral or donator) has evolutionary advantage over "competitive behavior" (in our case, either spiteful or envious). © 2013 Elsevier Ltd. All rights reserved.

Anatomy and computational modeling of networks underlying cognitive-emotional interaction

Directory of Open Access Journals (Sweden)

Yohan Joshua John

2013-04-01

Full Text Available The classical dichotomy between cognition and emotion equated the first with rationality or logic and the second with irrational behaviors. The idea that cognition and emotion are separable, antagonistic forces competing for dominance of mind has been hard to displace despite abundant evidence to the contrary. For instance, it is now known that a pathological absence of emotion leads to profound impairment of decision making. Behavioral observations of this kind are corroborated at the mechanistic level: neuroanatomical studies reveal that brain areas typically described as underlying either cognitive or emotional processes are linked in ways that imply complex interactions that do not resemble a simple mutual antagonism. Instead, physiological studies and network simulations suggest that top-down signals from prefrontal cortex realize ``cognitive control'' in part by either suppressing or promoting emotional responses controlled by the amygdala, in a way that facilitates adaptation to changing task demands. Behavioral, anatomical, and physiological data suggest that emotion and cognition are equal partners in enabling a continuum or matrix of flexible behaviors that are subserved by multiple brain regions acting in concert. Here we focus on neuroanatomical data that highlight circuitry that structures cognitive-emotional interactions by directly or indirectly linking prefrontal areas with the amygdala. We also present an initial computational circuit model, based on anatomical, physiological and behavioral data to explicitly frame the learning and performance mechanisms by which cognition and emotion interact to achieve flexible behavior.

Anatomy and computational modeling of networks underlying cognitive-emotional interaction.

Science.gov (United States)

John, Yohan J; Bullock, Daniel; Zikopoulos, Basilis; Barbas, Helen

2013-01-01

The classical dichotomy between cognition and emotion equated the first with rationality or logic and the second with irrational behaviors. The idea that cognition and emotion are separable, antagonistic forces competing for dominance of mind has been hard to displace despite abundant evidence to the contrary. For instance, it is now known that a pathological absence of emotion leads to profound impairment of decision making. Behavioral observations of this kind are corroborated at the mechanistic level: neuroanatomical studies reveal that brain areas typically described as underlying either cognitive or emotional processes are linked in ways that imply complex interactions that do not resemble a simple mutual antagonism. Instead, physiological studies and network simulations suggest that top-down signals from prefrontal cortex realize "cognitive control" in part by either suppressing or promoting emotional responses controlled by the amygdala, in a way that facilitates adaptation to changing task demands. Behavioral, anatomical, and physiological data suggest that emotion and cognition are equal partners in enabling a continuum or matrix of flexible behaviors that are subserved by multiple brain regions acting in concert. Here we focus on neuroanatomical data that highlight circuitry that structures cognitive-emotional interactions by directly or indirectly linking prefrontal areas with the amygdala. We also present an initial computational circuit model, based on anatomical, physiological, and behavioral data to explicitly frame the learning and performance mechanisms by which cognition and emotion interact to achieve flexible behavior.

Thalamic control of sensory selection in divided attention.

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Wimmer, Ralf D; Schmitt, L Ian; Davidson, Thomas J; Nakajima, Miho; Deisseroth, Karl; Halassa, Michael M

2015-10-29

How the brain selects appropriate sensory inputs and suppresses distractors is unknown. Given the well-established role of the prefrontal cortex (PFC) in executive function, its interactions with sensory cortical areas during attention have been hypothesized to control sensory selection. To test this idea and, more generally, dissect the circuits underlying sensory selection, we developed a cross-modal divided-attention task in mice that allowed genetic access to this cognitive process. By optogenetically perturbing PFC function in a temporally precise window, the ability of mice to select appropriately between conflicting visual and auditory stimuli was diminished. Equivalent sensory thalamocortical manipulations showed that behaviour was causally dependent on PFC interactions with the sensory thalamus, not sensory cortex. Consistent with this notion, we found neurons of the visual thalamic reticular nucleus (visTRN) to exhibit PFC-dependent changes in firing rate predictive of the modality selected. visTRN activity was causal to performance as confirmed by bidirectional optogenetic manipulations of this subnetwork. Using a combination of electrophysiology and intracellular chloride photometry, we demonstrated that visTRN dynamically controls visual thalamic gain through feedforward inhibition. Our experiments introduce a new subcortical model of sensory selection, in which the PFC biases thalamic reticular subnetworks to control thalamic sensory gain, selecting appropriate inputs for further processing.

Element-specific density profiles in interacting biomembrane models

International Nuclear Information System (INIS)

Schneck, Emanuel; Rodriguez-Loureiro, Ignacio; Bertinetti, Luca; Gochev, Georgi; Marin, Egor; Novikov, Dmitri; Konovalov, Oleg

2017-01-01

Surface interactions involving biomembranes, such as cell–cell interactions or membrane contacts inside cells play important roles in numerous biological processes. Structural insight into the interacting surfaces is a prerequisite to understand the interaction characteristics as well as the underlying physical mechanisms. Here, we work with simplified planar experimental models of membrane surfaces, composed of lipids and lipopolymers. Their interaction is quantified in terms of pressure–distance curves using ellipsometry at controlled dehydrating (interaction) pressures. For selected pressures, their internal structure is investigated by standing-wave x-ray fluorescence (SWXF). This technique yields specific density profiles of the chemical elements P and S belonging to lipid headgroups and polymer chains, as well as counter-ion profiles for charged surfaces. (paper)

Effective interactions approach to phase stability in alloys under irradiation

International Nuclear Information System (INIS)

Enrique, R.A.; Bellon, P.

1999-01-01

Phase stability in alloys under irradiation is studied considering effective thermodynamic potentials. A simple kinetic model of a binary alloy with phase separation is investigated. Time evolution in the alloy results form two competing dynamics: thermal diffusion, and irradiation induced ballistic exchanges. The dynamical (steady state) phase diagram is evaluated exactly performing Kinetic Monte Carlo simulations. The solution is then compared to two theoretical frameworks: the effective quasi-interactions model as proposed by Vaks and Kamishenko, and the effective free energy model as proposed by Martin. New developments of these models are proposed to allow for quantitative comparisons. Both theoretical frameworks yield fairly good approximations to the dynamical phase diagram

Effective interactions approach to phase stability in alloys under irradiation

International Nuclear Information System (INIS)

Enrique, R.A.; Bellon, P.

1999-01-01

Phase stability in alloys under irradiation is studied considering effective thermodynamic potentials. A simple kinetic model of a binary alloy with phase separation is investigated. Time evolution in the alloy results from two competing dynamics: thermal diffusion, and irradiation induced ballistic exchanges The dynamical (steady state) phase diagram is evaluated exactly performing Kinetic Monte Carlo simulations. The solution is then compared to two theoretical frameworks: the effective quasi-interactions model as proposed by Vaks and Kamishenko, and the effective free energy model as proposed by Martin. New developments of these models are proposed to allow for quantitative comparisons. Both theoretical frameworks yield fairly good approximations to the dynamical phase diagram

Frontal and parietal cortical interactions with distributed visual representations during selective attention and action selection.

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Nelissen, Natalie; Stokes, Mark; Nobre, Anna C; Rushworth, Matthew F S

2013-10-16

Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity.

Frontal and Parietal Cortical Interactions with Distributed Visual Representations during Selective Attention and Action Selection

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Stokes, Mark; Nobre, Anna C.; Rushworth, Matthew F. S.

2013-01-01

Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity. PMID:24133250

[Change of character of intersystemic interactions in newborn rat pups under conditions of a decrease of central influences (urethane anesthesia)].

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Kuznetsov, S V; Sizonov, V A; Dmitrieva, L E

2014-01-01

On newborn rat pups, for the first day after birth, there was studied the character of mutual influences between the slow-wave rhythmical components of the cardiac, respiratory, and motor activities reflecting interactions between the main functional systems of the developing organism. The study was carried out in norm and after pharmacological depression of the spontaneous periodical motor activity (SPMA) performed by narcotization of rat pups with urethane at low (0.5 g/kg, i/p) and maximal (1 g/kg, i/p) doses. Based on the complex of our obtained data, it is possible to conclude that after birth in rat pups the intersystemic interactions are realized mainly by the slow-wave oscillations of the near- and manyminute diapason. The correlational interactions mediated by rhythms of the decasecond diapason do not play essential role in integrative processes. Injection to the animals of urethane producing selective suppression of reaction of consciousness, but not affecting activating influences of reticular formation on cerebral cortex does not cause marked changes of autonomous parameters, but modulates structure and expression of spontaneous periodical motor activity. There occurs an essential decrease of mutual influences between motor and cardiovascular systems. In the case of preservation of motor activity bursts, a tendency for enhancement of correlational relations between the modulating rhythms of motor and somatomotor systems is observed. The cardiorespiratory interactions, more pronounced in intact rat pups in the near- and many-minute modulation diapason, under conditions of urethane, somewhat decrease, whereas the rhythmical components of the decasecond diapason--are weakly enhanced.

Probing the Selectivity and Protein•Protein Interactions of a Non-Reducing Fungal Polyketide Synthase Using Mechanism-Based Crosslinkers

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Bruegger, Joel; Haushalter, Bob; Vagstad, Anna; Shakya, Gaurav; Mih, Nathan; Townsend, Craig A.; Burkart, Michael D.; Tsai, Shiou-Chuan

2013-01-01

SUMMARY Protein•protein interactions, which often involve interactions between an acyl carrier protein (ACP) and its partner enzymes, are important for coordinating polyketide biosynthesis. However, the nature of such interactions is not well understood, especially in the fungal non-reducing polyketide synthases (NR-PKSs) that biosynthesize toxic and pharmaceutically important polyketides. Here, we employ a mechanism-based crosslinker to successfully probe ACP and ketosynthase (KS) domain interactions in NR-PKSs. We found that crosslinking efficiency is closely correlated with the strength of ACP•KS interactions, and that KS demonstrates strong starter unit selectivity. We further identified positively charged surface residues by KS mutagenesis, which mediate key interactions with the negatively-charged ACP surface. Such complementary/matching contact pairs can serve as “adapter surfaces” for future efforts to generate new polyketides using NR-PKSs. PMID:23993461

Identification of a domain within human TAF(I)48, a subunit of Selectivity Factor 1, that interacts with helix 2 of TBP.

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Xu, Shuping; Hori, Roderick T

2004-09-01

RNA polymerase I transcription in human cells requires Selectivity Factor 1, a multisubunit complex composed of the TATA-box-binding protein (TBP) and three TBP-associated factors (TAFs) called TAF(I)48, TAF(I)63 and TAF(I)110. Each of the Selectivity Factor 1 subunits binds directly to the other three components, but these interactions have not been characterized. This study is the initial identification and analysis of a TBP-binding domain within a Selectivity Factor 1 TAF. The interaction between human TBP and human TAF(I)48 was initially examined using the yeast two-hybrid assay, and a TBP-binding domain was identified in the carboxyl-terminus of human (h)TAF(I)48. Consistent with this result, the hTAF(I)48 carboxyl-terminus was able to bind directly to TBP in protein-protein interaction assays. When mutations were introduced into the hTAF(I)48 carboxyl-terminus, we identified changes in uncharged and positive residues that affect its interaction with TBP. By examining TBP mutants, residues within and adjacent to helix 2 of TBP, previously demonstrated to interact with subunits of other TBP-containing complexes [Transcription Factor IID (TFIID) and TFIIIB] were also found to diminish its affinity for the carboxyl-terminus of hTAF(I)48. The regions of hTAF(I)48 and TBP that interact are compared to those identified within other complexes containing TBP.

Automated Hydrophobic Interaction Chromatography Column Selection for Use in Protein Purification

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Murphy, Patrick J. M.; Stone, Orrin J.; Anderson, Michelle E.

2011-01-01

In contrast to other chromatographic methods for purifying proteins (e.g. gel filtration, affinity, and ion exchange), hydrophobic interaction chromatography (HIC) commonly requires experimental determination (referred to as screening or "scouting") in order to select the most suitable chromatographic medium for purifying a given protein 1. The method presented here describes an automated approach to scouting for an optimal HIC media to be used in protein purification. HIC separates proteins and other biomolecules from a crude lysate based on differences in hydrophobicity. Similar to affinity chromatography (AC) and ion exchange chromatography (IEX), HIC is capable of concentrating the protein of interest as it progresses through the chromatographic process. Proteins best suited for purification by HIC include those with hydrophobic surface regions and able to withstand exposure to salt concentrations in excess of 2 M ammonium sulfate ((NH4)2SO4). HIC is often chosen as a purification method for proteins lacking an affinity tag, and thus unsuitable for AC, and when IEX fails to provide adequate purification. Hydrophobic moieties on the protein surface temporarily bind to a nonpolar ligand coupled to an inert, immobile matrix. The interaction between protein and ligand are highly dependent on the salt concentration of the buffer flowing through the chromatography column, with high ionic concentrations strengthening the protein-ligand interaction and making the protein immobile (i.e. bound inside the column) 2. As salt concentrations decrease, the protein-ligand interaction dissipates, the protein again becomes mobile and elutes from the column. Several HIC media are commercially available in pre-packed columns, each containing one of several hydrophobic ligands (e.g. S-butyl, butyl, octyl, and phenyl) cross-linked at varying densities to agarose beads of a specific diameter 3. Automated column scouting allows for an efficient approach for determining which HIC media

Selecting rice mutants with good agronomic performance under conditions of low water supplies

International Nuclear Information System (INIS)

González Cepero, María C.; Martínez Romero, Anirebis

2016-01-01

The present work is part of the researches that are carried out in the Regional Project of the International Organization of Atomic Energy (IAEA) Mutation Breeding of Alimentary Cultivations in Latin America where Cuba participates. The aim of this project is to obtain new rice varieties tolerant to drought using nuclear techniques, for that which is necessary to determine indicators for early selection of tolerant genotypes and to identify somaclones and/or mutants of good behavior under low water supply. For this study were used, 13 mutants obtained in the National Institute of Agricultural Sciences (INCA) as well as the rice varieties Amistad-82 and J-104. The response to the hydric stress under field conditions was determined, using irrigation during the first 45 days, interrupting later for the plant cycle, were determined: I) the height of the plant, II) weigh of 1000 grains, III) length of panicle, IV) number of full grains, V) vain grains, VI) number of panicle for lineal meter and VII) yield for square meter. Likewise in vitro the answers to the drought with a concentration of 5 g L-1 of PEG-6000 to simulate the hydric stress and the Relative Tolerance Index of root and of height were evaluated. Some indicators for early selection of tolerant genotypes starting from the existent correlation among the characters evaluated in the field in vivo and in vitro were also determined. The INCA genotypes LP-10 and 8552 showed a better behavior under conditions of low supplies of water and INCA LP 16 genotypes and mutant 8553 were the most susceptible because they could not panicular under the same conditions. (author)

Stock selection of high-dose-irradiation-resistant materials for filter press under high-dose irradiation operation

International Nuclear Information System (INIS)

Ishiyama, Shintaro; Minami, Mamoru; Hara, Kouji; Yamashita, Manabu

2015-01-01

In a volume reduction process for the decontamination of contained soil, the performance degradation of a filter press is expected owing to material deterioration under high-dose irradiation. Eleven-stock selection of candidate materials including polymers, fibers and rubbers for the filter press was conducted to achieve a high performance of volume reduction of contaminated soil and the following results were derived. Crude rubber and nylon were selected as prime candidates for packing, diaphragm and filter plate materials. Polyethylene was also selected as a prime candidate for the filter cloth material. (author)

The relationship between visual working memory and attention: retention of precise colour information in the absence of effects on perceptual selection.

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Hollingworth, Andrew; Hwang, Seongmin

2013-10-19

We examined the conditions under which a feature value in visual working memory (VWM) recruits visual attention to matching stimuli. Previous work has suggested that VWM supports two qualitatively different states of representation: an active state that interacts with perceptual selection and a passive (or accessory) state that does not. An alternative hypothesis is that VWM supports a single form of representation, with the precision of feature memory controlling whether or not the representation interacts with perceptual selection. The results of three experiments supported the dual-state hypothesis. We established conditions under which participants retained a relatively precise representation of a parcticular colour. If the colour was immediately task relevant, it reliably recruited attention to matching stimuli. However, if the colour was not immediately task relevant, it failed to interact with perceptual selection. Feature maintenance in VWM is not necessarily equivalent with feature-based attentional selection.

The theory of the interaction of atmospheric aerosol with underlying surface

International Nuclear Information System (INIS)

Buikov, M.V.

1993-01-01

The interaction of wind with underlying surfaces through resuspension makes a great contribution to the total amount of atmospheric aerosols. The dry deposition process results in cleaning of the atmosphere and contamination of near-surface air layers of soil and vegetation. This paper examines the theory leading to an exact solution of the problem of turbulent transportation of pollution taking into account resuspension and dry-deposition. This may be useful for the interpretation of observational data and for the improvement of calculation methods to describe aerosol exchange at surfaces in air. (author)

Fluid-structure interaction dynamic simulation of spring-loaded pressure relief valves under seismic wave

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Lv, Dongwei; Zhang, Jian; Yu, Xinhai

2018-05-01

In this paper, a fluid-structure interaction dynamic simulation method of spring-loaded pressure relief valve was established. The dynamic performances of the fluid regions and the stress and strain of the structure regions were calculated at the same time by accurately setting up the contact pairs between the solid parts and the coupling surfaces between the fluid regions and the structure regions. A two way fluid-structure interaction dynamic simulation of a simplified pressure relief valve model was carried out. The influence of vertical sinusoidal seismic waves on the performance of the pressure relief valve was preliminarily investigated by loading sine waves. Under vertical seismic waves, the pressure relief valve will flutter, and the reseating pressure was affected by the amplitude and frequency of the seismic waves. This simulation method of the pressure relief valve under vertical seismic waves can provide effective means for investigating the seismic performances of the valves, and make up for the shortcomings of the experiment.

A Study of Power Relations in Doctor-Patient Interactions in Selected Hospitals in Lagos State, Nigeria

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Adam, Qasim

2014-01-01

This paper explores power relations in clinical interactions in Nigeria. It seeks to investigate the use of power between doctors and patients during consultations on patient-centred approach to medicine in selected public and private hospitals in Lagos State, Nigeria. The objective is to establish how doctors' projection of power, using the…

A Vietnamese man with selective mutism: the relevance of multiple interacting 'cultures' in clinical psychiatry.

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Hollifield, Michael; Geppert, Cynthia; Johnson, Yuam; Fryer, Carol

2003-09-01

Multiple cultural variables have effects on the psychobiology and behavioral manifestations of illness, as do patient and physician perceptions of illness. The interaction among these variables is at the heart of clinical psychiatry. This case of a Vietnamese man with selective mutism underscores the relevance of the 'cultures' of medicine, psychiatry, and war and trauma on the manifestations of illness and illness perceptions by patient and physician. The discussion focuses on how these cultures interact and play a crucial role in formulating diagnosis and treatment planning. Suggestions are given for shifts in medical education that will encourage relevant cultural paradigms to make their way into educational and clinical systems, which in turn should improve cultural competence in clinical psychiatry.

Selective adsorption of thiophenic compounds from fuel over TiO{sub 2}/SiO{sub 2} under UV-irradiation

Energy Technology Data Exchange (ETDEWEB)

Miao, Guang [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640 (China); Ye, Feiyan [Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education South China University of Technology, Guangzhou 510640 (China); Wu, Luoming; Ren, Xiaoling [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640 (China); Xiao, Jing, E-mail: cejingxiao@scut.edu.cn [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640 (China); Li, Zhong, E-mail: cezhli@scut.edu.cn [Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education South China University of Technology, Guangzhou 510640 (China); Wang, Haihui [Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education South China University of Technology, Guangzhou 510640 (China)

2015-12-30

Highlights: • TiO{sub 2}/SiO{sub 2} was developed for selective adsorption of DBTs under UV irradiation. • Remarkable adsorption uptake and selectivity were achieved for deep desulfurization. • Introduction of TiO{sub 2} into SiO{sub 2} enhanced its adsorption for DBTO{sub 2}. • Adsorption mechanism using TiO{sub 2}/SiO{sub 2} under UV irradiation was elucidated. - Abstract: This study investigates selective adsorption of thiophenic compounds from fuel over TiO{sub 2}/SiO{sub 2} under UV-irradiation. The TiO{sub 2}/SiO{sub 2} adsorbents were prepared and then characterized by N{sub 2} adsorption, X-ray diffraction and X-ray photoelectron spectroscopy. Adsorption isotherms, selectivity and kinetics of TiO{sub 2}/SiO{sub 2} were measured in a UV built-in batch reactor. It was concluded that (a) with the employment of UV-irradiation, high organosulfur uptake of 5.12 mg/g was achieved on the optimized 0.3TiO{sub 2}/0.7SiO{sub 2} adsorbent at low sulfur concentration of 15 ppmw-S, and its adsorption selectivity over naphthalene was up to 325.5; (b) highly dispersed TiO{sub 2} served as the photocatalytic sites for DBT oxidation, while SiO{sub 2} acted as the selective adsorption sites for the corresponding oxidized DBT using TiO{sub 2} as a promoter, the two types of active sites worked cooperatively to achieve the high adsorption selectivity of TiO{sub 2}/SiO{sub 2}; (c) The kinetic rate-determining step for the UV photocatalysis-assisted adsorptive desulfurization (PADS) over TiO{sub 2}/SiO{sub 2} was DBT oxidation; (d) consecutive adsorption-regeneration cycles suggested that the 0.3TiO{sub 2}/0.7SiO{sub 2} adsorbent can be regenerated by acetonitrile washing followed with oxidative air treatment. This work demonstrated an effective PADS approach to greatly enhance adsorption capacity and selectivity of thiophenic compounds at low concentrations for deep desulfurization under ambient conditions.

Selective N-alkylation of amines using nitriles under hydrogenation conditions: facile synthesis of secondary and tertiary amines.

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Ikawa, Takashi; Fujita, Yuki; Mizusaki, Tomoteru; Betsuin, Sae; Takamatsu, Haruki; Maegawa, Tomohiro; Monguchi, Yasunari; Sajiki, Hironao

2012-01-14

Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH(4)OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.

Genomic regions under selection in crop-wild hybrids of lettuce: implications for crop breeding and environmental risk assessment

NARCIS (Netherlands)

Hartman, Y.

2012-01-01

The results of this thesis show that the probability of introgression of a putative transgene to wild relatives indeed depends strongly on the insertion location of the transgene. The study of genomic selection patterns can identify crop genomic regions under negative selection in multiple

Study of the pluronic-silica interaction in synthesis of mesoporous silica under mild acidic conditions.

Science.gov (United States)

Sundblom, Andreas; Palmqvist, Anders E C; Holmberg, Krister

2010-02-02

The interaction between silica and poly(ethylene oxide) (PEO) in water may appear trivial and it is generally stated that hydrogen bonding is responsible for the attraction. However, a literature search shows that there is not a consensus with respect to the mechanism behind the attractive interaction. Several papers claim that only hydrogen bonding is not sufficient to explain the binding. The silica-PEO interaction is interesting from an academic perspective and it is also exploited in the preparation of mesoporous silica, a material of considerable current interest. This study concerns the very early stage of synthesis of mesoporous silica under mild acidic conditions, pH 2-5, and the aim is to shed light on the interaction between silica and the PEO-containing structure directing agent. The synthesis comprises two steps. An organic silica source, tetraethylorthosilicate (TEOS), is first hydrolyzed and Pluronic P123, a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymer, is subsequently added at different time periods following the hydrolysis of TEOS. It is shown that the interaction between the silica and the Pluronic is dependent both on the temperature and on the time between onset of TEOS hydrolysis and addition of the copolymer. The results show that the interaction is mainly driven by entropy. The effect of the synthesis temperature and of the time between hydrolysis and addition of the copolymer on the final material is also studied. The material with the highest degree of mesoorder was obtained when the reaction was performed at 20 degrees C and the copolymer was added 40 h after the start of TEOS hydrolysis. It is claimed that the reason for the good ordering of the silica is that whereas particle formation under these conditions is fast, the rate of silica condensation is relatively low.

76 FR 73521 - Statutory Bar to Appointment of Persons Who Fail To Register Under Selective Service Law

Science.gov (United States)

2011-11-29

... 3206-AM06 Statutory Bar to Appointment of Persons Who Fail To Register Under Selective Service Law... statutory bar on employment in an Executive agency of an individual who was required to register with the... as follows: Subpart G--Statutory Bar to Appointment of Persons Who Fail To Register Under the...

Fourier transform IR studies on the interaction of selected chemicals with isolated cuticles

International Nuclear Information System (INIS)

Luque, P.; Ramirez, F.J.; Heredia, A.; Bukovac, M.J.

1994-01-01

It is known that the plant cuticle represents the first barrier that must be overcome by any chemical reaching the plant surface from the atmosphere before entering the plant. Because of the importance of the cuticle as a barrier to penetration of a wide variety of compounds, its morphology, chemistry, and permeability have been extensively studied. However, only limited information is available on the nature of functional chemical groups present and their interaction and role during the penetration process. The usefulness of in situ Fourier transform infrared spectroscopy studies in identifying functional groups present in isolated cuticles is described and their relationships to the structure of the cuticular membrane are discussed. Applications of infrared spectroscopy on the presence and role of phenolics in the cuticle structure and during the cuticle development, nitrogen oxide binding to isolated cuticles, and the interactions between selected chemical probes during sorption by the cuticle are also described. (orig.)

Reactive Oxygen Species Generation-Scavenging and Signaling during Plant-Arbuscular Mycorrhizal and Piriformospora indica Interaction under Stress Condition.

Science.gov (United States)

Nath, Manoj; Bhatt, Deepesh; Prasad, Ram; Gill, Sarvajeet S; Anjum, Naser A; Tuteja, Narendra

2016-01-01

A defined balance between the generation and scavenging of reactive oxygen species (ROS) is essential to utilize ROS as an adaptive defense response of plants under biotic and abiotic stress conditions. Moreover, ROS are not only a major determinant of stress response but also act as signaling molecule that regulates various cellular processes including plant-microbe interaction. In particular, rhizosphere constitutes the biologically dynamic zone for plant-microbe interactions which forms a mutual link leading to reciprocal signaling in both the partners. Among plant-microbe interactions, symbiotic associations of arbuscular mycorrhizal fungi (AMF) and arbuscular mycorrhizal-like fungus especially Piriformospora indica with plants are well known to improve plant growth by alleviating the stress-impacts and consequently enhance the plant fitness. AMF and P. indica colonization mainly enhances ROS-metabolism, maintains ROS-homeostasis, and thereby averts higher ROS-level accrued inhibition in plant cellular processes and plant growth and survival under stressful environments. This article summarizes the major outcomes of the recent reports on the ROS-generation, scavenging and signaling in biotic-abiotic stressed plants with AMF and P. indica colonization. Overall, a detailed exploration of ROS-signature kinetics during plant-AMF/ P. indica interaction can help in designing innovative strategies for improving plant health and productivity under stress conditions.

Investigating category- and shape-selective neural processing in ventral and dorsal visual stream under interocular suppression.

Science.gov (United States)

Ludwig, Karin; Kathmann, Norbert; Sterzer, Philipp; Hesselmann, Guido

2015-01-01

Recent behavioral and neuroimaging studies using continuous flash suppression (CFS) have suggested that action-related processing in the dorsal visual stream might be independent of perceptual awareness, in line with the "vision-for-perception" versus "vision-for-action" distinction of the influential dual-stream theory. It remains controversial if evidence suggesting exclusive dorsal stream processing of tool stimuli under CFS can be explained by their elongated shape alone or by action-relevant category representations in dorsal visual cortex. To approach this question, we investigated category- and shape-selective functional magnetic resonance imaging-blood-oxygen level-dependent responses in both visual streams using images of faces and tools. Multivariate pattern analysis showed enhanced decoding of elongated relative to non-elongated tools, both in the ventral and dorsal visual stream. The second aim of our study was to investigate whether the depth of interocular suppression might differentially affect processing in dorsal and ventral areas. However, parametric modulation of suppression depth by varying the CFS mask contrast did not yield any evidence for differential modulation of category-selective activity. Together, our data provide evidence for shape-selective processing under CFS in both dorsal and ventral stream areas and, therefore, do not support the notion that dorsal "vision-for-action" processing is exclusively preserved under interocular suppression. © 2014 Wiley Periodicals, Inc.

Competitive interactions between native and invasive exotic plant species are altered under elevated carbon dioxide.

Science.gov (United States)

Manea, Anthony; Leishman, Michelle R

2011-03-01

We hypothesized that the greater competitive ability of invasive exotic plants relative to native plants would increase under elevated CO(2) because they typically have traits that confer the ability for fast growth when resources are not limiting and thus are likely to be more responsive to elevated CO(2). A series of competition experiments under ambient and elevated CO(2) glasshouse conditions were conducted to determine an index of relative competition intensity for 14 native-invasive exotic species-pairs. Traits including specific leaf area, leaf mass ratio, leaf area ratio, relative growth rate, net assimilation rate and root weight ratio were measured. Competitive rankings within species-pairs were not affected by CO(2) concentration: invasive exotic species were more competitive in 9 of the 14 species-pairs and native species were more competitive in the remaining 5 species-pairs, regardless of CO(2) concentration. However, there was a significant interaction between plant type and CO(2) treatment due to reduced competitive response of native species under elevated compared with ambient CO(2) conditions. Native species had significantly lower specific leaf area and leaf area ratio under elevated compared with ambient CO(2). We also compared traits of more-competitive with less-competitive species, regardless of plant type, under both CO(2) treatments. More-competitive species had smaller leaf weight ratio and leaf area ratio, and larger relative growth rate and net assimilation rate under both ambient and elevated CO(2) conditions. These results suggest that growth and allocation traits can be useful predictors of the outcome of competitive interactions under both ambient and elevated CO(2) conditions. Under predicted future atmospheric CO(2) conditions, competitive rankings among species may not change substantially, but the relative success of invasive exotic species may be increased. Thus, under future atmospheric CO(2) conditions, the ecological and

Institutional interactions in developing a transportation system under the Nuclear Waste Policy Act

International Nuclear Information System (INIS)

Denny, S.H.

1986-01-01

The Department of Energy (DOE) recognizes that the success of its efforts to develop and operate a system for transporting nuclear waste under the provisions of the Nuclear Waste Policy Act of 1982 (NWPA) depends in large measure on the effectiveness of Departmental interactions with the affected parties. To ensure the necessary network of communication, the DOE is establishing lines of contact with those who are potential participants in the task of developing the policies and procedures for the NWPA transportation system. In addition, a number of measures have been initiated to reinforce broad-based involvement in program development. The Transportation Institutional Plan provides a preliminary road map of DOE's projected interactions over the next decade and is discussed in this paper

Interaction between two subducting plates under Tokyo and its possible effects on seismic hazards

Science.gov (United States)

Wu, Francis; Okaya, David; Sato, Hiroshi; Hirata, Naoshi

2007-09-01

Underneath metropolitan Tokyo the Philippine Sea plate (PHS) subducts to the north on top of the westward subducting Pacific plate (PAC). New, relatively high-resolution tomography images the PHS as a well-defined subduction zone under western Kanto Plain. As PAC shoals under eastern Kanto, the PHS lithosphere is being thrusted into an increasingly tighter space of the PAC-Eurasian mantle wedge. As a result, zones of enhanced seismicity appear under eastern Kanto at the top of PHS, internal to PHS and also at its contact with PAC. These zones are located at depths greater than the causative fault of the disastrous 1923 Great Tokyo ``megathrust'' earthquake, in the vicinity of several well-located historical, damaging (M6 and M7) earthquakes. Thus a rather unique interaction between subducting plates under Tokyo may account for additional seismic hazards in metropolitan Tokyo.

Flame-vortex interaction and mixing behaviors of turbulent non-premixed jet flames under acoustic forcing

Energy Technology Data Exchange (ETDEWEB)

Kim, Munki; Choi, Youngil; Oh, Jeongseog; Yoon, Youngbin [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea)

2009-12-15

This study examines the effect of acoustic excitation using forced coaxial air on the flame characteristics of turbulent hydrogen non-premixed flames. A resonance frequency was selected to acoustically excite the coaxial air jet due to its ability to effectively amplify the acoustic amplitude and reduce flame length and NO{sub x} emissions. Acoustic excitation causes the flame length to decrease by 15% and consequently, a 25% reduction in EINO{sub x} is achieved, compared to coaxial air flames without acoustic excitation at the same coaxial air to fuel velocity ratio. Moreover, acoustic excitation induces periodical fluctuation of the coaxial air velocity, thus resulting in slight fluctuation of the fuel velocity. From phase-lock PIV and OH PLIF measurement, the local flow properties at the flame surface were investigated under acoustic forcing. During flame-vortex interaction in the near field region, the entrainment velocity and the flame surface area increased locally near the vortex. This increase in flame surface area and entrainment velocity is believed to be a crucial factor in reducing flame length and NO{sub x} emission in coaxial jet flames with acoustic excitation. Local flame extinction occurred frequently when subjected to an excessive strain rate, indicating that intense mass transfer of fuel and air occurs radially inward at the flame surface. (author)

High selection pressure promotes increase in cumulative adaptive culture.

Directory of Open Access Journals (Sweden)

Carolin Vegvari

Full Text Available The evolution of cumulative adaptive culture has received widespread interest in recent years, especially the factors promoting its occurrence. Current evolutionary models suggest that an increase in population size may lead to an increase in cultural complexity via a higher rate of cultural transmission and innovation. However, relatively little attention has been paid to the role of natural selection in the evolution of cultural complexity. Here we use an agent-based simulation model to demonstrate that high selection pressure in the form of resource pressure promotes the accumulation of adaptive culture in spite of small population sizes and high innovation costs. We argue that the interaction of demography and selection is important, and that neither can be considered in isolation. We predict that an increase in cultural complexity is most likely to occur under conditions of population pressure relative to resource availability. Our model may help to explain why culture change can occur without major environmental change. We suggest that understanding the interaction between shifting selective pressures and demography is essential for explaining the evolution of cultural complexity.

Genome Sequencing Reveals Loci under Artificial Selection that Underlie Disease Phenotypes in the Laboratory Rat

NARCIS (Netherlands)

Atanur, Santosh S.; Diaz, Ana Garcia; Maratou, Klio; Sarkis, Allison; Rotival, Maxime; Game, Laurence; Tschannen, Michael R.; Kaisaki, Pamela J.; Otto, Georg W.; Ma, Man Chun John; Keane, Thomas M.; Hummel, Oliver; Saar, Kathrin; Chen, Wei; Guryev, Victor; Gopalakrishnan, Kathirvel; Garrett, Michael R.; Joe, Bina; Citterio, Lorena; Bianchi, Giuseppe; McBride, Martin; Dominiczak, Anna; Adams, David J.; Serikawa, Tadao; Flicek, Paul; Cuppen, Edwin; Hubner, Norbert; Petretto, Enrico; Gauguier, Dominique; Kwitek, Anne; Jacob, Howard; Aitman, Timothy J.

2013-01-01

Large numbers of inbred laboratory rat strains have been developed for a range of complex disease phenotypes. To gain insights into the evolutionary pressures underlying selection for these phenotypes, we sequenced the genomes of 27 rat strains, including 11 models of hypertension, diabetes, and

Genes under positive selection in a model plant pathogenic fungus, Botrytis.

Science.gov (United States)

Aguileta, Gabriela; Lengelle, Juliette; Chiapello, Hélène; Giraud, Tatiana; Viaud, Muriel; Fournier, Elisabeth; Rodolphe, François; Marthey, Sylvain; Ducasse, Aurélie; Gendrault, Annie; Poulain, Julie; Wincker, Patrick; Gout, Lilian

2012-07-01

The rapid evolution of particular genes is essential for the adaptation of pathogens to new hosts and new environments. Powerful methods have been developed for detecting targets of selection in the genome. Here we used divergence data to compare genes among four closely related fungal pathogens adapted to different hosts to elucidate the functions putatively involved in adaptive processes. For this goal, ESTs were sequenced in the specialist fungal pathogens Botrytis tulipae and Botrytis ficariarum, and compared with genome sequences of Botrytis cinerea and Sclerotinia sclerotiorum, responsible for diseases on over 200 plant species. A maximum likelihood-based analysis of 642 predicted orthologs detected 21 genes showing footprints of positive selection. These results were validated by resequencing nine of these genes in additional Botrytis species, showing they have also been rapidly evolving in other related species. Twenty of the 21 genes had not previously been identified as pathogenicity factors in B. cinerea, but some had functions related to plant-fungus interactions. The putative functions were involved in respiratory and energy metabolism, protein and RNA metabolism, signal transduction or virulence, similarly to what was detected in previous studies using the same approach in other pathogens. Mutants of B. cinerea were generated for four of these genes as a first attempt to elucidate their functions. Copyright © 2012 Elsevier B.V. All rights reserved.

Experimental study of the molten glass/water thermal interaction under free and forced conditions

International Nuclear Information System (INIS)

Arakeri, V.H.; Catton, I.; Kastenberg, W.E.

1978-01-01

Molten glass interacts explosively with water under certain contact mode conditions. The contact mode found explosive is as follows: Molten glass enters the water bath in the film boiling regime (as predicted by Dhir's correlation), and soon after entry the vapor film is perturbed sufficiently by an external pressure pulse. The ensuing reaction proceeds basically along the same lines as energetic tin/water interactions observed by several investigators. In the absence of this pressure pulse, the event is nonenergetic. The present findings are for a combination in which the hot material has a very low thermal diffusivity and the calculated interface temperature is significantly (approximately 180 K) below its melting temperature. This is similar to the characteristics of the UO 2 /sodium or UO 2 /water combinations. The observed explosive glass/water interactions show growth times on the order of a few milliseconds. The particulate size distribution from the present tests was coarser than the particulate size distribution from some in-pile and out-of-pile UO 2 /sodium interaction tests

Selection rules for the dematerialization of a particle into two photons

International Nuclear Information System (INIS)

Yang, C.N.

1983-01-01

Selection rules governing the disintegration of a particle into two photons are derived from the general principle of invariance under rotation and inversion. The polarization state of the photons is completely fixed by the selection rules for initial particles with spin less than 2. These results which are independent of any specific assumption about the interactions may possibly offer a method of deciding the symmetry nature of mesons which decay into two photons. 4 tables

Species as Stressors: Heterospecific Interactions and the Cellular Stress Response under Global Change.

Science.gov (United States)

Gunderson, Alex R; King, Emily E; Boyer, Kirsten; Tsukimura, Brian; Stillman, Jonathon H

2017-07-01

Anthropogenic global change is predicted to increase the physiological stress of organisms through changes in abiotic conditions such as temperature, pH, and pollution. However, organisms can also experience physiological stress through interactions with other species, especially parasites, predators, and competitors. The stress of species interactions could be an important driver of species' responses to global change as the composition of biological communities change through factors such as distributional and phenological shifts. Interactions between biotic and abiotic stressors could also induce non-linear physiological stress responses under global change. One of the primary means by which organisms deal with physiological stress is through the cellular stress response (CSR), which is broadly the upregulation of a conserved set of genes that facilitate the removal and repair of damaged macromolecules. Here, we present data on behavioral interactions and CSR gene expression for two competing species of intertidal zone porcelain crab (Petrolisthes cinctipes and Petrolisthes manimaculis). We found that P. cinctipes and P. manimaculis engage in more agonistic behaviors when interacting with heterospecifics than conspecifics; however, we found no evidence that heterospecific interactions induced a CSR in these species. In addition to our new data, we review the literature with respect to CSR induction via species interactions, focusing on predator-prey systems and heterospecific competition. We find extensive evidence for predators to induce cellular stress and aspects of the CSR in prey, even in the absence of direct physical contact between species. Effects of heterospecific competition on the CSR have been studied far less, but we do find evidence that agonistic interactions with heterospecifics can induce components of the CSR. Across all published studies, there is clear evidence that species interactions can lead to cellular stress and induction of the CSR

A Scientific Decision Framework for Supplier Selection under Interval Valued Intuitionistic Fuzzy Environment

Directory of Open Access Journals (Sweden)

R. Krishankumar

2017-01-01

Full Text Available This paper proposes a new scientific decision framework (SDF under interval valued intuitionistic fuzzy (IVIF environment for supplier selection (SS. The framework consists of two phases, where, in the first phase, criteria weights are estimated in a sensible manner using newly proposed IVIF based statistical variance (SV method and, in the second phase, the suitable supplier is selected using ELECTRE (ELimination and Choice Expressing REality ranking method under IVIF environment. This method involves three categories of outranking, namely, strong, moderate, and weak. Previous studies on ELECTRE ranking reveal that scholars have only used two categories of outranking, namely, strong and weak, in the formulation of IVIF based ELECTRE, which eventually aggravates fuzziness and vagueness in decision making process due to the potential loss of information. Motivated by this challenge, third outranking category, called moderate, is proposed, which considerably reduces the loss of information by improving checks to the concordance and discordance matrices. Thus, in this paper, IVIF-ELECTRE (IVIFE method is presented and popular TOPSIS method is integrated with IVIFE for obtaining a linear ranking. Finally, the practicality of the proposed framework is demonstrated using SS example and the strength of proposed SDF is realized by comparing the framework with other similar methods.

Estimation of the ancestral effective population sizes of African great apes under different selection regimes.

Science.gov (United States)

Schrago, Carlos G

2014-08-01

Reliable estimates of ancestral effective population sizes are necessary to unveil the population-level phenomena that shaped the phylogeny and molecular evolution of the African great apes. Although several methods have previously been applied to infer ancestral effective population sizes, an analysis of the influence of the selective regime on the estimates of ancestral demography has not been thoroughly conducted. In this study, three independent data sets under different selective regimes were used were composed to tackle this issue. The results showed that selection had a significant impact on the estimates of ancestral effective population sizes of the African great apes. The inference of the ancestral demography of African great apes was affected by the selection regime. The effects, however, were not homogeneous along the ancestral populations of great apes. The effective population size of the ancestor of humans and chimpanzees was more impacted by the selection regime when compared to the same parameter in the ancestor of humans, chimpanzees and gorillas. Because the selection regime influenced the estimates of ancestral effective population size, it is reasonable to assume that a portion of the discrepancy found in previous studies that inferred the ancestral effective population size may be attributable to the differential action of selection on the genes sampled.

Project selection problem under uncertainty: An application of utility theory and chance constrained programming to a real case

Directory of Open Access Journals (Sweden)

Reza Hosnavi Atashgah

2013-06-01

Full Text Available Selecting from a pool of interdependent projects under certainty, when faced with resource constraints, has been studied well in the literature of project selection problem. After briefly reviewing and discussing popular modeling approaches for dealing with uncertainty, this paper proposes an approach based on chance constrained programming and utility theory for a certain range of problems and under some practical assumptions. Expected Utility Programming, as the proposed modeling approach, will be compared with other well-known methods and its meaningfulness and usefulness will be illustrated via two numerical examples and one real case.

Category-selective attention modulates unconscious processes in the middle occipital gyrus.

Science.gov (United States)

Tu, Shen; Qiu, Jiang; Martens, Ulla; Zhang, Qinglin

2013-06-01

Many studies have revealed the top-down modulation (spatial attention, attentional load, etc.) on unconscious processing. However, there is little research about how category-selective attention could modulate the unconscious processing. In the present study, using functional magnetic resonance imaging (fMRI), the results showed that category-selective attention modulated unconscious face/tool processing in the middle occipital gyrus (MOG). Interestingly, MOG effects were of opposed direction for face and tool processes. During unconscious face processing, activation in MOG decreased under the face-selective attention compared with tool-selective attention. This result was in line with the predictive coding theory. During unconscious tool processing, however, activation in MOG increased under the tool-selective attention compared with face-selective attention. The different effects might be ascribed to an interaction between top-down category-selective processes and bottom-up processes in the partial awareness level as proposed by Kouider, De Gardelle, Sackur, and Dupoux (2010). Specifically, we suppose an "excessive activation" hypothesis. Copyright © 2013 Elsevier Inc. All rights reserved.

Relation between motility, accelerated aging and gene expression in selected Drosophila strains under hypergravity conditions

NARCIS (Netherlands)

Serrano, P.; van Loon, J.J.W.A.; Javier Medina, F.; Herranz, R.

2013-01-01

Motility and aging in Drosophila have proven to be highly modified under altered gravity conditions (both in space and ground simulation facilities). In order to find out how closely connected they are, five strains with altered geotactic response or survival rates were selected and exposed to an

An opinion formation based binary optimization approach for feature selection

Science.gov (United States)

Hamedmoghadam, Homayoun; Jalili, Mahdi; Yu, Xinghuo

2018-02-01

This paper proposed a novel optimization method based on opinion formation in complex network systems. The proposed optimization technique mimics human-human interaction mechanism based on a mathematical model derived from social sciences. Our method encodes a subset of selected features to the opinion of an artificial agent and simulates the opinion formation process among a population of agents to solve the feature selection problem. The agents interact using an underlying interaction network structure and get into consensus in their opinions, while finding better solutions to the problem. A number of mechanisms are employed to avoid getting trapped in local minima. We compare the performance of the proposed method with a number of classical population-based optimization methods and a state-of-the-art opinion formation based method. Our experiments on a number of high dimensional datasets reveal outperformance of the proposed algorithm over others.

Selection of the important performance influencing factors for the assessment of human error under accident management situations in nuclear power plants

International Nuclear Information System (INIS)

Kim, J. H.; Jung, W. J.

1999-01-01

This paper introduces the process and final results of selection of the important Performance Influencing Factors (PIFs) under emergency operation and accident management situations in nuclear power plants for use in the assessment of human errors. We collected two types of PIF taxonomies, one is the full set PIF list mainly developed for human error analysis, and the other is the PIFs for human reliability analysis (HRA) in probabilistic safety assessment (PSA). 5 PIF taxonomies among the full set PIF list and 10 PIF taxonomies among HRA methodologies (CREAM, SLIM, INTENT, were collected in this research. By reviewing and analyzing PIFs selected for HRA methodologies, the criterion could be established for the selection of appropriate PIFs under emergency operation and accident management situations. Based on this selection criteria, a new PIF taxonomy was proposed for the assessment of human error under emergency operation and accident management situations in nuclear power plants

Annotating long intergenic non-coding RNAs under artificial selection during chicken domestication.

Science.gov (United States)

Wang, Yun-Mei; Xu, Hai-Bo; Wang, Ming-Shan; Otecko, Newton Otieno; Ye, Ling-Qun; Wu, Dong-Dong; Zhang, Ya-Ping

2017-08-15

Numerous biological functions of long intergenic non-coding RNAs (lincRNAs) have been identified. However, the contribution of lincRNAs to the domestication process has remained elusive. Following domestication from their wild ancestors, animals display substantial changes in many phenotypic traits. Therefore, it is possible that diverse molecular drivers play important roles in this process. We analyzed 821 transcriptomes in this study and annotated 4754 lincRNA genes in the chicken genome. Our population genomic analysis indicates that 419 lincRNAs potentially evolved during artificial selection related to the domestication of chicken, while a comparative transcriptomic analysis identified 68 lincRNAs that were differentially expressed under different conditions. We also found 47 lincRNAs linked to special phenotypes. Our study provides a comprehensive view of the genome-wide landscape of lincRNAs in chicken. This will promote a better understanding of the roles of lincRNAs in domestication, and the genetic mechanisms associated with the artificial selection of domestic animals.

[BMIM][PF6] Incorporation Doubles CO2 Selectivity of ZIF-8: Elucidation of Interactions and Their Consequences on Performance.

Science.gov (United States)

Kinik, F Pelin; Altintas, Cigdem; Balci, Volkan; Koyuturk, Burak; Uzun, Alper; Keskin, Seda

2016-11-16

Experiments were combined with atomically detailed simulations and density functional theory (DFT) calculations to understand the effect of incorporation of an ionic liquid (IL), 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF 6 ]), into a metal organic framework (MOF with a zeolitic imidazolate framework), ZIF-8, on the CO 2 separation performance. The interactions between [BMIM][PF 6 ] and ZIF-8 were examined in deep detail, and their consequences on CO 2 /CH 4 , CO 2 /N 2 , and CH 4 /N 2 separation have been elucidated by using experimental measurements complemented by DFT calculations and atomically detailed simulations. Results suggest that IL-MOF interactions strongly affect the gas affinity of materials at low pressure, whereas available pore volume plays a key role for gas adsorption at high pressures. Direct interactions between IL and MOF lead to at least a doubling of CO 2 /CH 4 and CO 2 /N 2 selectivities of ZIF-8. These results provide opportunities for rational design and development of IL-incorporated MOFs with exceptional selectivity for target gas separation applications.

Convergence in Multispecies Interactions.

Science.gov (United States)

Bittleston, Leonora S; Pierce, Naomi E; Ellison, Aaron M; Pringle, Anne

2016-04-01

The concepts of convergent evolution and community convergence highlight how selective pressures can shape unrelated organisms or communities in similar ways. We propose a related concept, convergent interactions, to describe the independent evolution of multispecies interactions with similar physiological or ecological functions. A focus on convergent interactions clarifies how natural selection repeatedly favors particular kinds of associations among species. Characterizing convergent interactions in a comparative context is likely to facilitate prediction of the ecological roles of organisms (including microbes) in multispecies interactions and selective pressures acting in poorly understood or newly discovered multispecies systems. We illustrate the concept of convergent interactions with examples: vertebrates and their gut bacteria; ectomycorrhizae; insect-fungal-bacterial interactions; pitcher-plant food webs; and ants and ant-plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dual-EEG of joint finger tapping: what can two interacting brains teach us about social interaction?

DEFF Research Database (Denmark)

Konvalinka, Ivana

-frequency analysis revealed a left-motor and right-frontal suppression at 10 Hz during task execution, when carrying the task out interactively in contrast with the uncoupled computer-driven task. We used machine-learning approaches to identify the brain signals driving the interaction. The raw-power at 10 Hz during...... tapping emanating from electrodes of member one and member two were used as features. We combined data from both participants in each pair, and applied logistic regression using feature selection in order to classify the two conditions. The first seven (frontal) electrodes consistently emerged as good...... classifiers, with 85-99% accuracy. There was a tendency for one member’s frontal electrodes to drive the classifier over the other’s, which predicted the leader of the interaction in 8/9 pairs. This study reveals new neural mechanisms underlying two-person interactions. It also shows how analyzing two...

Evaluation of inelastic constitutive models under plasticity-creep interaction for 2 1/4 Cr-1 Mo steel: Results of joint work (A)

International Nuclear Information System (INIS)

Inoue, T.; Ohno, N.; Suzuki, A.; Igari, T.

1987-01-01

The authorization of constitutive models under plasticity-creep condition and life estimation methods in fatigue-creep regime is expected to be achieved from the viewpoint of design purposes of high temperature components of reactor structures. The present Subcommittee has performed the cooperative project consisting of the following two parts: (A) To review and evaluate inelastic constitutive models relevant to the material response under plasticity-creep interaction and (B) to recommend some adequate methods to estimate material life under fatigue-creep interaction by taking account of the effect of plasticity-creep interaction on the stress-strain hysteresis loops. The material treated is normalized and tempered 2 1/4 Cr-1Mo steel at 600 0 C. The part (A) plays a preliminary role for the part (B), since the constitutive models examined in the part (A) were used to describe the stress-strain hysteresis loops necessary to predict analytically the lives under fatigue-creep interaction. In the part (A), thererfore, it is important to check how accurately the constitutive models simulate the stress-strain hysteresis loops especially by taking account of the effect of plasticity-creep interaction. (orig./GL)

Partial QoS-Aware Opportunistic Relay Selection Over Two-Hop Channels: End-to-End Performance Under Spectrum-Sharing Requirements

KAUST Repository

Yuli Yang,

2014-10-01

In this paper, we propose a partial quality-of-service (QoS)-oriented relay selection scheme with a decode-and-forward (DF) relaying protocol, to reduce the feedback amount required for relay selection. In the proposed scheme, the activated relay is the one with the maximum signal-to-noise power ratio (SNR) in the second hop among those whose packet loss rates (PLRs) in the first hop achieve a predetermined QoS level. For the purpose of evaluating the performance of the proposed scheme, we exploit it with transmission constraints imposed on the transmit power budget and interference to other users. By analyzing the statistics of received SNRs in the first and second hops, we obtain the end-to-end PLR of this scheme in closed form under the considered scenario. Moreover, to compare the proposed scheme with popular relay selection schemes, we also derive the closed-form PLR expressions for partial relay selection (PRS) and opportunistic relay selection (ORS) criteria in the same scenario under study. Illustrative numerical results demonstrate the accuracy of our derivations and substantiate that the proposed relay selection scheme is a promising alternative with respect to the tradeoff between performance and complexity.

Estimation of a multivariate mean under model selection uncertainty

Directory of Open Access Journals (Sweden)

Georges Nguefack-Tsague

2014-05-01

Full Text Available Model selection uncertainty would occur if we selected a model based on one data set and subsequently applied it for statistical inferences, because the "correct" model would not be selected with certainty.  When the selection and inference are based on the same dataset, some additional problems arise due to the correlation of the two stages (selection and inference. In this paper model selection uncertainty is considered and model averaging is proposed. The proposal is related to the theory of James and Stein of estimating more than three parameters from independent normal observations. We suggest that a model averaging scheme taking into account the selection procedure could be more appropriate than model selection alone. Some properties of this model averaging estimator are investigated; in particular we show using Stein's results that it is a minimax estimator and can outperform Stein-type estimators.

Optimal Contracting under Adverse Selection

DEFF Research Database (Denmark)

Lenells, Jonatan; Stea, Diego; Foss, Nicolai Juul

2015-01-01

We study a model of adverse selection, hard and soft information, and mentalizing ability--the human capacity to represent others' intentions, knowledge, and beliefs. By allowing for a continuous range of different information types, as well as for different means of acquiring information, we dev...... of that information. This strategy affects the properties of the optimal contract, which grows closer to the first best. This research provides insights into the implications of mentalizing for agency theory....

Prediction of Effective Drug Combinations by Chemical Interaction, Protein Interaction and Target Enrichment of KEGG Pathways

Directory of Open Access Journals (Sweden)

Lei Chen

2013-01-01

Full Text Available Drug combinatorial therapy could be more effective in treating some complex diseases than single agents due to better efficacy and reduced side effects. Although some drug combinations are being used, their underlying molecular mechanisms are still poorly understood. Therefore, it is of great interest to deduce a novel drug combination by their molecular mechanisms in a robust and rigorous way. This paper attempts to predict effective drug combinations by a combined consideration of: (1 chemical interaction between drugs, (2 protein interactions between drugs’ targets, and (3 target enrichment of KEGG pathways. A benchmark dataset was constructed, consisting of 121 confirmed effective combinations and 605 random combinations. Each drug combination was represented by 465 features derived from the aforementioned three properties. Some feature selection techniques, including Minimum Redundancy Maximum Relevance and Incremental Feature Selection, were adopted to extract the key features. Random forest model was built with its performance evaluated by 5-fold cross-validation. As a result, 55 key features providing the best prediction result were selected. These important features may help to gain insights into the mechanisms of drug combinations, and the proposed prediction model could become a useful tool for screening possible drug combinations.

Selective oxidation of n-butane to maleic anhydride under oxygen-deficient conditions over V-P-O mixed oxides

NARCIS (Netherlands)

Bosch, H.; Bruggink, A.A.; Ross, J.R.H.

1987-01-01

The selective oxidation of n-butane to maleic anhydride over V-P-O mixed oxides was studied under oxygen deficient conditions. The mixed oxides were prepared with P/V atomic ratios ranging from 0.7 to 1.0. Catalysts with P/V <1.0 did not show any selectivity to maleic anhydride formation, regardless

PSP: rapid identification of orthologous coding genes under positive selection across multiple closely related prokaryotic genomes.

Science.gov (United States)

Su, Fei; Ou, Hong-Yu; Tao, Fei; Tang, Hongzhi; Xu, Ping

2013-12-27

With genomic sequences of many closely related bacterial strains made available by deep sequencing, it is now possible to investigate trends in prokaryotic microevolution. Positive selection is a sub-process of microevolution, in which a particular mutation is favored, causing the allele frequency to continuously shift in one direction. Wide scanning of prokaryotic genomes has shown that positive selection at the molecular level is much more frequent than expected. Genes with significant positive selection may play key roles in bacterial adaption to different environmental pressures. However, selection pressure analyses are computationally intensive and awkward to configure. Here we describe an open access web server, which is designated as PSP (Positive Selection analysis for Prokaryotic genomes) for performing evolutionary analysis on orthologous coding genes, specially designed for rapid comparison of dozens of closely related prokaryotic genomes. Remarkably, PSP facilitates functional exploration at the multiple levels by assignments and enrichments of KO, GO or COG terms. To illustrate this user-friendly tool, we analyzed Escherichia coli and Bacillus cereus genomes and found that several genes, which play key roles in human infection and antibiotic resistance, show significant evidence of positive selection. PSP is freely available to all users without any login requirement at: http://db-mml.sjtu.edu.cn/PSP/. PSP ultimately allows researchers to do genome-scale analysis for evolutionary selection across multiple prokaryotic genomes rapidly and easily, and identify the genes undergoing positive selection, which may play key roles in the interactions of host-pathogen and/or environmental adaptation.

Selection of Amino Acid Chirality via Neutrino Interactions with 14N in Crossed Electric and Magnetic Fields

Science.gov (United States)

Boyd, Richard N.; Kajino, Toshitaka; Onaka, Takashi

2018-01-01

Abstract Previous work has suggested that the chirality of the amino acids could be established in the magnetic field of a nascent neutron star from a core-collapse supernova or massive collapsar. The magnetic field would orient the 14N nuclei, and the alignment of its nuclear spin with respect to those of the electron antineutrinos emitted from the collapsing star would determine the probability of destruction of the 14N nuclei by interactions with the antineutrinos. Subsequent work estimated the bulk polarization of the 14N nuclei in large rotating meteoroids in such an environment. The present work adds a crucial piece of this model by describing the details by which the selective 14N nuclear destruction would produce molecular chiral selectivity. The effects of the neutrino-induced interactions on the 14N nuclei bound in amino acids polarized in strong magnetic fields are studied. It is shown that electric fields in the reference frame of the nuclei modify the magnetic field at the nucleus, creating nuclear magnetizations that are asymmetric in chirality. The antineutrino cross sections depend on this magnetization, creating a selective destructive effect. The environmental conditions and sites in which such a selection mechanism could occur are discussed. Selective destruction of D-enantiomers results in enantiomeric excesses which may be sufficient to drive subsequent autocatalysis necessary to produce the few-percent enantiomeric excesses found in meteorites and subsequent homochirality. Molecular quantum chemical calculations were performed for alanine, and the chirality-dependent effects studied were included. A preference for left-handed molecules was found, and enantiomeric excesses as high as 0.02% were estimated for molecules in the electromagnetic conditions expected from a core-collapse supernova. Key Words: Amino acids—Supernovae—Antineutrinos—Enantiomeric excess—Chirality. Astrobiology 18, 190–206. PMID:29160728

Exploring Selective Exposure and Confirmation Bias as Processes Underlying Employee Work Happiness: An Intervention Study.

Science.gov (United States)

Williams, Paige; Kern, Margaret L; Waters, Lea

2016-01-01

Employee psychological capital (PsyCap), perceptions of organizational virtue (OV), and work happiness have been shown to be associated within and over time. This study examines selective exposure and confirmation bias as potential processes underlying PsyCap, OV, and work happiness associations. As part of a quasi-experimental study design, school staff (N = 69) completed surveys at three time points. After the first assessment, some staff (n = 51) completed a positive psychology training intervention. Results of descriptive statistics, correlation, and regression analyses on the intervention group provide some support for selective exposure and confirmation bias as explanatory mechanisms. In focusing on the processes through which employee attitudes may influence work happiness this study advances theoretical understanding, specifically of selective exposure and confirmation bias in a field study context.

Modulations of the processing of line discontinuities under selective attention conditions?

Science.gov (United States)

Giersch, Anne; Fahle, Manfred

2002-01-01

We examined whether the processing of discontinuities involved in figure-ground segmentation, like line ends, can be modulated under selective attention conditions. Subjects decided whether a gap in collinear or parallel lines was located to the right or left. Two stimuli were displayed in immediate succession. When the gaps were on the same side, reaction times (RTs) for the second stimulus increased when collinear lines followed parallel lines, or the reverse, but only when the two stimuli shared the same orientation and location. The effect did not depend on the global form of the stimuli or on the relative orientation of the gaps. A frame drawn around collinear elements affected the results, suggesting a crucial role of the "amodal" orthogonal lines produced when line ends are aligned. Including several gaps in the first stimulus also eliminated RT variations. By contrast, RT variations remained stable across several experimental blocks and were significant for interstimulus intervals from 50 to 600 msec between the two stimuli. These results are interpreted in terms of a modulation of the processing of line ends or the production of amodal lines, arising when attention is selectively drawn to a gap.

Low-temperature synthesis of allyl dimethylamine by selective heating under microwave irradiation used for water treatment

International Nuclear Information System (INIS)

Tian Binghui; Luan Zhaokun; Li Mingming

2005-01-01

Low-temperature synthesis of allyl dimethylamine (ADA) by selective heating under microwave irradiation (MI) used for water treatment is investigated. The effect of MI, ultrasound irradiation (UI) and conventional heating on yield of ADA, reaction time and the flocculation efficiency of polydiallyl dimethylammunion chloride (PDADMAC) prepared form ADA were studied. The results show that by selective heating at low temperature, MI not only increases yield of ADA and reduces reaction time, but also greatly enhances the flocculation efficiency of PDADMAC

Selective anodic dissolution of cerium from aluminium alloys under potentiostatic conditions

International Nuclear Information System (INIS)

Gol'dshtejn, S.L.; Raspopin, S.P.; Seleznev, V.D.; Tunin, A.V.; Fedorov, V.A.

1975-01-01

A study was made of selective anodic dissolution of aluminum alloys containing cerium in concentrations from 0.5 to 10% by mass. The electropurification was carried out with the aid of a potentiostatic setup at 700 deg C in atmosphere of purified argon. Liquid aluminum served as the cathode, with chlorine half-cell as reference electrode and the melt of equimolar KCl-NaCl mixture as the electrolyte. The ''current-time'' plots are presented for selective ionization of cerium from aluminum alloys at preset potential values on the installation. For PHIsub(preset)=-2.04 v the current of potentiostatic electrolysis fades out to that of the supporting electrolyte, and the process itself proceeds at a rate that provides maximal extraction of cerium from the alloy (csub9finite)approximately equal to 0.002% by mass) at minimal ionization of the metalsolvent (Δ Msub(Al)approximately equal to 0.2). Alloys containing not less then 1% by mass of Ce exhibit a characteristic abrupt change of the attenuation coefficient apparently owing to nonlinear dependence of unbalance (ΔE) of signals at the input of the potentiostat. The ''ΔE-c'' function for Al alloy containing 0.5% by mass of Ce can be approximated by linear function. In this case the current of potentiostatic electrolysis approaches the value of the limiting diffusion current. To obtain the relationship between the magnitude of the limiting current of Ce ionization and the initial composition of the dissolving alloy, measurements were made under potentiodynamic conditions at a scanning rate of approximately equal to 500 mv/min. The results indicate that isub(intermediate) is directly proportional to csub(initial). It was shown that under the conditions employed, practically complete (csub(finite)<=0.004% by mass) extraction of the electronegative component is possible without noticeable ionization of the metal-solvent

Theoretical study of chlordecone and surface groups interaction in an activated carbon model under acidic and neutral conditions.

Science.gov (United States)

Gamboa-Carballo, Juan José; Melchor-Rodríguez, Kenia; Hernández-Valdés, Daniel; Enriquez-Victorero, Carlos; Montero-Alejo, Ana Lilian; Gaspard, Sarra; Jáuregui-Haza, Ulises Javier

2016-04-01

Activated carbons (ACs) are widely used in the purification of drinking water without almost any knowledge about the adsorption mechanisms of the persistent organic pollutants. Chlordecone (CLD, Kepone) is an organochlorinated synthetic compound that has been used mainly as agricultural insecticide. CLD has been identified and listed as a persistent organic pollutant by the Stockholm Convention. The selection of the best suited AC for this type of contaminants is mainly an empirical and costly process. A theoretical study of the influence of AC surface groups (SGs) on CLD adsorption is done in order to help understanding the process. This may provide a first selection criteria for the preparation of AC with suitable surface properties. A model of AC consisting of a seven membered ring graphene sheet (coronene) with a functional group on the edge was used to evaluate the influence of the SGs over the adsorption. Multiple Minima Hypersurface methodology (MMH) coupled with PM7 semiempirical Hamiltonian was employed in order to study the interactions of the chlordecone with SGs (hydroxyl and carboxyl) at acidic and neutral pH and different hydration conditions. Selected structures were re-optimized using CAM-B3LYP to achieve a well-defined electron density to characterize the interactions by the Quantum Theory of Atoms in Molecules approach. The deprotonated form of surface carboxyl and hydroxyl groups of AC models show the strongest interactions, suggesting a chemical adsorption. An increase in carboxylic SGs content is proposed to enhance CLD adsorption onto AC at neutral pH conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Selective updating of working memory content modulates meso-cortico-striatal activity.

Science.gov (United States)

Murty, Vishnu P; Sambataro, Fabio; Radulescu, Eugenia; Altamura, Mario; Iudicello, Jennifer; Zoltick, Bradley; Weinberger, Daniel R; Goldberg, Terry E; Mattay, Venkata S

2011-08-01

Accumulating evidence from non-human primates and computational modeling suggests that dopaminergic signals arising from the midbrain (substantia nigra/ventral tegmental area) mediate striatal gating of the prefrontal cortex during the selective updating of working memory. Using event-related functional magnetic resonance imaging, we explored the neural mechanisms underlying the selective updating of information stored in working memory. Participants were scanned during a novel working memory task that parses the neurophysiology underlying working memory maintenance, overwriting, and selective updating. Analyses revealed a functionally coupled network consisting of a midbrain region encompassing the substantia nigra/ventral tegmental area, caudate, and dorsolateral prefrontal cortex that was selectively engaged during working memory updating compared to the overwriting and maintenance of working memory content. Further analysis revealed differential midbrain-dorsolateral prefrontal interactions during selective updating between low-performing and high-performing individuals. These findings highlight the role of this meso-cortico-striatal circuitry during the selective updating of working memory in humans, which complements previous research in behavioral neuroscience and computational modeling. Published by Elsevier Inc.

Collaborative filtering for brain-computer interaction using transfer learning and active class selection.

Science.gov (United States)

Wu, Dongrui; Lance, Brent J; Parsons, Thomas D

2013-01-01

Brain-computer interaction (BCI) and physiological computing are terms that refer to using processed neural or physiological signals to influence human interaction with computers, environment, and each other. A major challenge in developing these systems arises from the large individual differences typically seen in the neural/physiological responses. As a result, many researchers use individually-trained recognition algorithms to process this data. In order to minimize time, cost, and barriers to use, there is a need to minimize the amount of individual training data required, or equivalently, to increase the recognition accuracy without increasing the number of user-specific training samples. One promising method for achieving this is collaborative filtering, which combines training data from the individual subject with additional training data from other, similar subjects. This paper describes a successful application of a collaborative filtering approach intended for a BCI system. This approach is based on transfer learning (TL), active class selection (ACS), and a mean squared difference user-similarity heuristic. The resulting BCI system uses neural and physiological signals for automatic task difficulty recognition. TL improves the learning performance by combining a small number of user-specific training samples with a large number of auxiliary training samples from other similar subjects. ACS optimally selects the classes to generate user-specific training samples. Experimental results on 18 subjects, using both k nearest neighbors and support vector machine classifiers, demonstrate that the proposed approach can significantly reduce the number of user-specific training data samples. This collaborative filtering approach will also be generalizable to handling individual differences in many other applications that involve human neural or physiological data, such as affective computing.

Collaborative filtering for brain-computer interaction using transfer learning and active class selection.

Directory of Open Access Journals (Sweden)

Dongrui Wu

Full Text Available Brain-computer interaction (BCI and physiological computing are terms that refer to using processed neural or physiological signals to influence human interaction with computers, environment, and each other. A major challenge in developing these systems arises from the large individual differences typically seen in the neural/physiological responses. As a result, many researchers use individually-trained recognition algorithms to process this data. In order to minimize time, cost, and barriers to use, there is a need to minimize the amount of individual training data required, or equivalently, to increase the recognition accuracy without increasing the number of user-specific training samples. One promising method for achieving this is collaborative filtering, which combines training data from the individual subject with additional training data from other, similar subjects. This paper describes a successful application of a collaborative filtering approach intended for a BCI system. This approach is based on transfer learning (TL, active class selection (ACS, and a mean squared difference user-similarity heuristic. The resulting BCI system uses neural and physiological signals for automatic task difficulty recognition. TL improves the learning performance by combining a small number of user-specific training samples with a large number of auxiliary training samples from other similar subjects. ACS optimally selects the classes to generate user-specific training samples. Experimental results on 18 subjects, using both k nearest neighbors and support vector machine classifiers, demonstrate that the proposed approach can significantly reduce the number of user-specific training data samples. This collaborative filtering approach will also be generalizable to handling individual differences in many other applications that involve human neural or physiological data, such as affective computing.

Predictability of Genetic Interactions from Functional Gene Modules

Directory of Open Access Journals (Sweden)

Jonathan H. Young

2017-02-01

Full Text Available Characterizing genetic interactions is crucial to understanding cellular and organismal response to gene-level perturbations. Such knowledge can inform the selection of candidate disease therapy targets, yet experimentally determining whether genes interact is technically nontrivial and time-consuming. High-fidelity prediction of different classes of genetic interactions in multiple organisms would substantially alleviate this experimental burden. Under the hypothesis that functionally related genes tend to share common genetic interaction partners, we evaluate a computational approach to predict genetic interactions in Homo sapiens, Drosophila melanogaster, and Saccharomyces cerevisiae. By leveraging knowledge of functional relationships between genes, we cross-validate predictions on known genetic interactions and observe high predictive power of multiple classes of genetic interactions in all three organisms. Additionally, our method suggests high-confidence candidate interaction pairs that can be directly experimentally tested. A web application is provided for users to query genes for predicted novel genetic interaction partners. Finally, by subsampling the known yeast genetic interaction network, we found that novel genetic interactions are predictable even when knowledge of currently known interactions is minimal.

Optimal tariff design under consumer self-selection

Energy Technology Data Exchange (ETDEWEB)

Raesaenen, M.; Ruusunen, J.; Haemaelaeinen, R.

1995-12-31

This report considers the design of electricity tariffs which guides an individual consumer to select the tariff designed for his consumption pattern. In the model the utility maximizes the weighted sum of individual consumers` benefits of electricity consumption subject to the utility`s revenue requirement constraints. The consumers` free choice of tariffs is ensured with the so-called self-selection constraints. The relationship between the consumers` optimal choice of tariffs and the weights in the aggregated consumers` benefit function is analyzed. If such weights exist, they will guarantee both the consumers` optimal choice of tariffs and the efficient consumption patterns. Also the welfare effects are analyzed by using demand parameters estimated from a Finnish dynamic pricing experiment. The results indicate that it is possible to design an efficient tariff menu with the welfare losses caused by the self-selection constraints being small compared with the costs created when some consumers choose tariffs other than assigned for them. (author)

Relation Between Motility, Accelerated Aging and Gene Expression in Selected Drosophila Strains under Hypergravity Conditions

Science.gov (United States)

Serrano, Paloma; van Loon, Jack J. W. A.; Medina, F. Javier; Herranz, Raúl

2013-02-01

Motility and aging in Drosophila have proven to be highly modified under altered gravity conditions (both in space and ground simulation facilities). In order to find out how closely connected they are, five strains with altered geotactic response or survival rates were selected and exposed to an altered gravity environment of 2 g. By analysing the different motile and behavioural patterns and the median survival rates, we show that altered gravity leads to changes in motility, which will have a negative impact on the flies' survival. Previous results show a differential gene expression between sessile samples and adults and confirm that environmentally-conditioned behavioural patterns constrain flies' gene expression and life span. Therefore, hypergravity is considered an environmental stress factor and strains that do not respond to this new environment experience an increment in motility, which is the major cause for the observed increased mortality also under microgravity conditions. The neutral-geotaxis selected strain (strain M) showed the most severe phenotype, unable to respond to variations in the gravitational field. Alternatively, the opposite phenotype was observed in positive-geotaxis and long-life selected flies (strains B and L, respectively), suggesting that these populations are less sensitive to alterations in the gravitational load. We conclude that the behavioural response has a greater contribution to aging than the modified energy consumption in altered gravity environments.

Natural selection and family X location interaction in the common (dry bean plant

Directory of Open Access Journals (Sweden)

Luís Henrique Pirola

2002-01-01

Full Text Available Natural selection takes place while advancing generations of segregant populations of self pollinating species by the population (bulk method. There is evidence that it maintains the individuals with greater grain yield. The question arises whether natural selection preserves the individuals which are more adapted only to the environment where the generation advance occurred, that is, if it contributes to increasing the genotype x environment interaction in the family assessment. This study was carried out to check this hypothesis in the common bean plant using families derived from a segregating population from a cross between the Carioca MG x ESAL 686 cultivars. The segregating populations increase in homozygosity was obtained by the population (bulk method until the F14 generation, in three distinct locations in Minas Gerais state: Lavras, Lambari and Patos de Minas. Forty-seven F14:15 families were randomly taken from the population in each location and later multiplied to obtain F14:16 families. These families were jointly assessed with three controls using a triple 12 x 12 lattice design in the three locations of generation advance in the wet season of 1998/1999. All the estimated parameters showed that while advancing segregant populations by the population (bulk method, natural selection acted to preserve the individuals which are more adapted to the environment in which they were advanced.

Quantum computer based on activated dielectric nanoparticles selectively interacting with short optical pulses

International Nuclear Information System (INIS)

Gadomskii, Oleg N; Kharitonov, Yu Ya

2004-01-01

The operation principle of a quantum computer is proposed based on a system of dielectric nanoparticles activated with two-level atoms - cubits, in which electric dipole transitions are excited by short intense optical pulses. It is proved that the logical operation (logical operator) CNOT (controlled NOT) is performed by means of time-dependent transfer of quantum information over 'long' (of the order of 10 4 nm) distances between spherical nanoparticles owing to the delayed interaction between them in the optical radiation field. It is shown that one-cubit and two-cubit logical operators required for quantum calculations can be realised by selectively exciting dielectric particles with short optical pulses. (quantum calculations)

Conformational transitions and interactions underlying the function of membrane embedded receptor protein kinases.

Science.gov (United States)

Bocharov, Eduard V; Sharonov, Georgy V; Bocharova, Olga V; Pavlov, Konstantin V

2017-09-01

Among membrane receptors, the single-span receptor protein kinases occupy a broad but specific functional niche determined by distinctive features of the underlying transmembrane signaling mechanisms that are briefly overviewed on the basis of some of the most representative examples, followed by a more detailed discussion of several hierarchical levels of organization and interactions involved. All these levels, including single-molecule interactions (e.g., dimerization, liganding, chemical modifications), local processes (e.g. lipid membrane perturbations, cytoskeletal interactions), and larger scale phenomena (e.g., effects of membrane surface shape or electrochemical potential gradients) appear to be closely integrated to achieve the observed diversity of the receptor functioning. Different species of receptor protein kinases meet their specific functional demands through different structural features defining their responses to stimulation, but certain common patterns exist. Signaling by receptor protein kinases is typically associated with the receptor dimerization and clustering, ligand-induced rearrangements of receptor domains through allosteric conformational transitions with involvement of lipids, release of the sequestered lipids, restriction of receptor diffusion, cytoskeleton and membrane shape remodeling. Understanding of complexity and continuity of the signaling processes can help identifying currently neglected opportunities for influencing the receptor signaling with potential therapeutic implications. This article is part of a Special Issue entitled: Interactions between membrane receptors in cellular membranes edited by Kalina Hristova. Copyright © 2017 Elsevier B.V. All rights reserved.

Mitochondrial Biogenesis in Diverse Cauliflower Cultivars under Mild and Severe Drought. Impaired Coordination of Selected Transcript and Proteomic Responses, and Regulation of Various Multifunctional Proteins

Directory of Open Access Journals (Sweden)

Michał Rurek

2018-04-01

Full Text Available Mitochondrial responses under drought within Brassica genus are poorly understood. The main goal of this study was to investigate mitochondrial biogenesis of three cauliflower (Brassica oleracea var. botrytis cultivars with varying drought tolerance. Diverse quantitative changes (decreases in abundance mostly in the mitochondrial proteome were assessed by two-dimensional gel electrophoresis (2D PAGE coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS. Respiratory (e.g., complex II, IV (CII, CIV and ATP synthase subunits, transporter (including diverse porin isoforms and matrix multifunctional proteins (e.g., components of RNA editing machinery were diversely affected in their abundance under two drought levels. Western immunoassays showed additional cultivar-specific responses of selected mitochondrial proteins. Dehydrin-related tryptic peptides (found in several 2D spots immunopositive with dehydrin-specific antisera highlighted the relevance of mitochondrial dehydrin-like proteins for the drought response. The abundance of selected mRNAs participating in drought response was also determined. We conclude that mitochondrial biogenesis was strongly, but diversely affected in various cauliflower cultivars, and associated with drought tolerance at the proteomic and functional levels. However, discussed alternative oxidase (AOX regulation at the RNA and protein level were largely uncoordinated due to the altered availability of transcripts for translation, mRNA/ribosome interactions, and/or miRNA impact on transcript abundance and translation.

Mitochondrial Biogenesis in Diverse Cauliflower Cultivars under Mild and Severe Drought. Impaired Coordination of Selected Transcript and Proteomic Responses, and Regulation of Various Multifunctional Proteins

Science.gov (United States)

Rurek, Michał; Czołpińska, Magdalena; Staszak, Aleksandra Maria; Nowak, Witold; Krzesiński, Włodzimierz; Spiżewski, Tomasz

2018-01-01

Mitochondrial responses under drought within Brassica genus are poorly understood. The main goal of this study was to investigate mitochondrial biogenesis of three cauliflower (Brassica oleracea var. botrytis) cultivars with varying drought tolerance. Diverse quantitative changes (decreases in abundance mostly) in the mitochondrial proteome were assessed by two-dimensional gel electrophoresis (2D PAGE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Respiratory (e.g., complex II, IV (CII, CIV) and ATP synthase subunits), transporter (including diverse porin isoforms) and matrix multifunctional proteins (e.g., components of RNA editing machinery) were diversely affected in their abundance under two drought levels. Western immunoassays showed additional cultivar-specific responses of selected mitochondrial proteins. Dehydrin-related tryptic peptides (found in several 2D spots) immunopositive with dehydrin-specific antisera highlighted the relevance of mitochondrial dehydrin-like proteins for the drought response. The abundance of selected mRNAs participating in drought response was also determined. We conclude that mitochondrial biogenesis was strongly, but diversely affected in various cauliflower cultivars, and associated with drought tolerance at the proteomic and functional levels. However, discussed alternative oxidase (AOX) regulation at the RNA and protein level were largely uncoordinated due to the altered availability of transcripts for translation, mRNA/ribosome interactions, and/or miRNA impact on transcript abundance and translation. PMID:29642585

Insights into the energetics and mechanism underlying the interaction of tetraethylammonium bromide with proteins

International Nuclear Information System (INIS)

Banerjee, Tuhina; Kishore, Nand

2008-01-01

Calorimetry has been employed to investigate the quantitative energetic aspects and mechanism underlying protein-tetraethylammonium bromide (TEAB) interactions. Differential scanning calorimetry and UV-Visible spectroscopy have been used to study the thermal unfolding of three proteins of different structure and function (bovine serum albumin, α-lactalbumin, and bovine pancreatic ribonuclease A). The mode of interaction has been studied by using isothermal titration calorimetry, which demonstrates the absence of appreciable specific binding of TEAB to the protein. This suggests the involvement of solvent mediated effects and, possibly weak non-specific binding. The thermal unfolding transitions were found to be calorimetrically reversible for α-lactalbumin and bovine pancreatic ribonuclease A and partially reversible in the case of bovine serum albumin. The results indicate protein destabilization promoted by the TEAB interaction. The preferential interaction parameters of TEAB with α-lactalbumin and ribonuclease A confirm that an increased interaction of the hydrophobic groups of the TEAB with that of the protein upon denaturation is responsible for the reduced thermal stability of the protein. The decrease in the thermal stability of proteins in the presence of TEAB is well supported by a red shift in the intrinsic fluorescence of these proteins leading to conformational change thereby shifting the native ↔ denatured equilibrium towards right. The forces responsible for the thermal denaturation of the proteins of different structure and function in the presence of TEAB are discussed

Analysis of an Interactive Technology Supported Problem-Based Learning STEM Project Using Selected Learning Sciences Interest Areas (SLSIA)

Science.gov (United States)

Kumar, David Devraj

2017-01-01

This paper reports an analysis of an interactive technology-supported, problem-based learning (PBL) project in science, technology, engineering and mathematics (STEM) from a Learning Sciences perspective using the Selected Learning Sciences Interest Areas (SLSIA). The SLSIA was adapted from the "What kinds of topics do ISLS [International…

The Orexin Component of Fasting Triggers Memory Processes Underlying Conditioned Food Selection in the Rat

Science.gov (United States)

Ferry, Barbara; Duchamp-Viret, Patricia

2014-01-01

To test the selectivity of the orexin A (OXA) system in olfactory sensitivity, the present study compared the effects of fasting and of central infusion of OXA on the memory processes underlying odor-malaise association during the conditioned odor aversion (COA) paradigm. Animals implanted with a cannula in the left ventricle received ICV infusion…

Selective Targeting of SH2 Domain–Phosphotyrosine Interactions of Src Family Tyrosine Kinases with Monobodies

Energy Technology Data Exchange (ETDEWEB)

Kükenshöner, Tim; Schmit, Nadine Eliane; Bouda, Emilie; Sha, Fern; Pojer, Florence; Koide, Akiko; Seeliger, Markus; Koide, Shohei; Hantschel, Oliver

2017-05-01

The binding of Src-homology 2 (SH2) domains to phosphotyrosine (pY) sites is critical for the autoinhibition and substrate recognition of the eight Src family kinases (SFKs). The high sequence conservation of the 120 human SH2 domains poses a significant challenge to selectively perturb the interactions of even the SFK SH2 family against the rest of the SH2 domains. We have developed synthetic binding proteins, termed monobodies, for six of the SFK SH2 domains with nanomolar affinity. Most of these monobodies competed with pY ligand binding and showed strong selectivity for either the SrcA (Yes, Src, Fyn, Fgr) or SrcB subgroup (Lck, Lyn, Blk, Hck). Interactome analysis of intracellularly expressed monobodies revealed that they bind SFKs but no other SH2-containing proteins. Three crystal structures of monobody–SH2 complexes unveiled different and only partly overlapping binding modes, which rationalized the observed selectivity and enabled structure-based mutagenesis to modulate inhibition mode and selectivity. In line with the critical roles of SFK SH2 domains in kinase autoinhibition and T-cell receptor signaling, monobodies binding the Src and Hck SH2 domains selectively activated respective recombinant kinases, whereas an Lck SH2-binding monobody inhibited proximal signaling events downstream of the T-cell receptor complex. Our results show that SFK SH2 domains can be targeted with unprecedented potency and selectivity using monobodies. They are excellent tools for dissecting SFK functions in normal development and signaling and to interfere with aberrant SFK signaling networks in cancer cells.

Unraveling interlimb interactions underlying bimanual coordination

NARCIS (Netherlands)

Ridderikhoff, A.; Daffertshofer, A.; Peper, C.E.; Beek, P.J.

2005-01-01

Three sources of interlimb interactions have been postulated to underlie the stability characteristics of bimanual coordination but have never been evaluated in conjunction: integrated timing of feedforward control signals, phase entrainment by contralateral afference, and timing corrections based

Study of decision framework of offshore wind power station site selection based on ELECTRE-III under intuitionistic fuzzy environment: A case of China

International Nuclear Information System (INIS)

Wu, Yunna; Zhang, Jinying; Yuan, Jianping; Geng, Shuai; Zhang, Haobo

2016-01-01

Highlights: • A novel MCDM framework is applied to assist group decision in OWPS site selection. • The index system consisting of veto and evaluation criteria is constructed. • A case study is carried five sites in coastal areas of Shandong in East China. - Abstract: Offshore wind power projects have been rapidly proposed in China due to policy promotion. Site selection immensely decides the success of any offshore wind power development and is a complex multi-criteria decision making (MCDM) problem. However, canonical MCDM methods tend to fail the site selection process due to the following three problems. Firstly, the compensation problem exists in information processing. Secondly, there exists the problem of incomplete utilization of decision information and information loss in the decision process. Thirdly, the interaction problem in the fuzzy environment is easy to be ignored. To deal with the above problems, this study builds a framework for offshore wind farm site selection decision utilizing Elimination et Choix Traduisant la Realité-III (ELECTRE-III) in the intuitionistic fuzzy environment. First of all, the comprehensive index system of OWPS site selection consisting of veto criteria and evaluation criteria is constructed. Then, the intuitionistic fuzzy set is used in the group decision for the decision makers to express the imperfect knowledge. Moreover, the generalized intuitionistic fuzzy ordered weighted geometric interaction averaging (GIFWGIA) operator is applied to deal with the interaction problem. Together with the likelihood-based valued comparisons, imprecise decision information is reasonably used and information loss problem is rationally avoided. Then a case of China is studied based on the proposed framework, demonstrating the site selection methodology valid and practical. This study implements evaluation method for offshore wind power site selection and also provides a theoretical basis for the development of offshore wind power

Selective adsorption of thiophenic compounds from fuel over TiO2/SiO2 under UV-irradiation.

Science.gov (United States)

Miao, Guang; Ye, Feiyan; Wu, Luoming; Ren, Xiaoling; Xiao, Jing; Li, Zhong; Wang, Haihui

2015-12-30

This study investigates selective adsorption of thiophenic compounds from fuel over TiO2/SiO2 under UV-irradiation. The TiO2/SiO2 adsorbents were prepared and then characterized by N2 adsorption, X-ray diffraction and X-ray photoelectron spectroscopy. Adsorption isotherms, selectivity and kinetics of TiO2/SiO2 were measured in a UV built-in batch reactor. It was concluded that (a) with the employment of UV-irradiation, high organosulfur uptake of 5.12 mg/g was achieved on the optimized 0.3TiO2/0.7SiO2 adsorbent at low sulfur concentration of 15 ppmw-S, and its adsorption selectivity over naphthalene was up to 325.5; (b) highly dispersed TiO2 served as the photocatalytic sites for DBT oxidation, while SiO2 acted as the selective adsorption sites for the corresponding oxidized DBT using TiO2 as a promoter, the two types of active sites worked cooperatively to achieve the high adsorption selectivity of TiO2/SiO2; (c) The kinetic rate-determining step for the UV photocatalysis-assisted adsorptive desulfurization (PADS) over TiO2/SiO2 was DBT oxidation; (d) consecutive adsorption-regeneration cycles suggested that the 0.3TiO2/0.7SiO2 adsorbent can be regenerated by acetonitrile washing followed with oxidative air treatment. This work demonstrated an effective PADS approach to greatly enhance adsorption capacity and selectivity of thiophenic compounds at low concentrations for deep desulfurization under ambient conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

Fundamental symmetries and interactions-selected topics

NARCIS (Netherlands)

Jungmann, Klaus P.

2015-01-01

In the field of fundamental interactions and symmetries numerous experiments are underway or planned in order to verify the standard model in particle physics, to search for possible extensions to it or to exploit the standard model for extracting most precise values for fundamental constants. We

Selectivity and coherence for photoexcitation of atoms

International Nuclear Information System (INIS)

Dai Changjian

1995-01-01

The results of both analytic and numerical treatments of the four-level Schroedinger equation are displayed. Transition Probabilities to various states for the cases of on-resonance and off-resonance are calculated. Dependences of probability on time and on characteristics of laser fields are investigated. Selectivity and coherence of the interaction between monochromatic laser fields and isotopic atom are examined. The conditions under which the population inversion takes place derived from the analytic solutions are confirmed

Variation in plant-mediated interactions between rhizobacteria and caterpillars: potential role of soil composition

NARCIS (Netherlands)

Pangesti, N.P.D.; Pineda Gomez, A.M.; Dicke, M.; Loon, van J.J.A.

2015-01-01

Selected strains of non-pathogenic rhizobacteria can trigger induced systemic resistance (ISR) in plants against aboveground insect herbivores. However, the underlying mechanisms of plant-mediated interactions between rhizobacteria and herbivorous insects are still poorly understood. Using

Forward detectors around the CMS interaction point at LHC and their physics potential

CERN Document Server

Grothe, Monika

2008-01-01

Forward physics with CMS at the LHC covers a wide range of physics subjects, including very low-x QCD, underlying event and multiple interactions characteristics, gamma-mediated processes, shower development at the energy scale of primary cosmic ray interactions with the atmosphere, diffraction in the presence of a hard scale and even MSSM Higgs discovery in central exclusive production. We describe the forward detector instrumentation around the CMS interaction point and present selected feasibility studies to illustrate their physics potential.

Nanomaterials modulate stem cell differentiation: biological interaction and underlying mechanisms.

Science.gov (United States)

Wei, Min; Li, Song; Le, Weidong

2017-10-25

Stem cells are unspecialized cells that have the potential for self-renewal and differentiation into more specialized cell types. The chemical and physical properties of surrounding microenvironment contribute to the growth and differentiation of stem cells and consequently play crucial roles in the regulation of stem cells' fate. Nanomaterials hold great promise in biological and biomedical fields owing to their unique properties, such as controllable particle size, facile synthesis, large surface-to-volume ratio, tunable surface chemistry, and biocompatibility. Over the recent years, accumulating evidence has shown that nanomaterials can facilitate stem cell proliferation and differentiation, and great effort is undertaken to explore their possible modulating manners and mechanisms on stem cell differentiation. In present review, we summarize recent progress in the regulating potential of various nanomaterials on stem cell differentiation and discuss the possible cell uptake, biological interaction and underlying mechanisms.

Selective and Stable Ethylbenzene Dehydrogenation to Styrene over Nanodiamonds under Oxygen-lean Conditions.

Science.gov (United States)

Diao, Jiangyong; Feng, Zhenbao; Huang, Rui; Liu, Hongyang; Hamid, Sharifah Bee Abd; Su, Dang Sheng

2016-04-07

For the first time, significant improvement of the catalytic performance of nanodiamonds was achieved for the dehydrogenation of ethylbenzene to styrene under oxygen-lean conditions. We demonstrated that the combination of direct dehydrogenation and oxidative dehydrogenation indeed occurred on the nanodiamond surface throughout the reaction system. It was found that the active sp(2)-sp(3) hybridized nanostructure was well maintained after the long-term test and the active ketonic carbonyl groups could be generated in situ. A high reactivity with 40% ethylbenzene conversion and 92% styrene selectivity was obtained over the nanodiamond catalyst under oxygen-lean conditions even after a 240 h test, demonstrating the potential of this procedure for application as a promising industrial process for the ethylbenzene dehydrogenation to styrene without steam protection. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Convergence in Multispecies Interactions

OpenAIRE

Bittleston, Leonora Sophia; Pierce, Naomi E.; Ellison, Aaron M.; Pringle, Anne

2016-01-01

The concepts of convergent evolution and community convergence highlight how selective pressures can shape unrelated organisms or communities in similar ways. We propose a related concept, convergent interactions, to describe the independent evolution of multispecies interactions with similar physiological or ecological functions. A focus on convergent interactions clarifies how natural selection repeatedly favors particular kinds of associations among species. Characterizing convergent inter...

Underlying Event Studies and Forward Physics at CMS

International Nuclear Information System (INIS)

Krammer, Manfred; Bartalini, Paolo

2010-01-01

Studies of the underlying event and forward processes are important tests of the standard model and inputs for Monte Carlo tuning. By selecting regions transverse and parallel to the hard parton-parton scatter, different aspects of non-perturbative QCD are enhanced and allow fine tuning of different Monte Carlo models. The underlying event in pp interactions, recorded by the CMS detector, is studied measuring the charged multiplicity density and the charged energy density in a region perpendicular to the plane of the hard 2-to-2 scattering. Two different methodologies are adopted to identify the direction and the energy scale of the hard scattering in Minimum Bias events that rely on the leading charged track and on the leading charged jet. The study allows to discriminate between various QCD Monte Carlo models with different multiple parton interaction schemes. In addition, we present the measurement of the underlying event using the jet area/ median approach. We demonstrate its sensitivity to different underlying event scenarios and tunes on generator level after applying detector specific cuts and thresholds. In the forward direction, the first measurement of forward energy flow in 3 35 GeV and compare to model with different multi-parton interaction schemes. In addition, the absence of energy deposition in the forward region is used to observe diffractive events. We compare our results with predictions from Monte Carlo event generators including a simulation of multi-parton scattering. All four measurements can be used to determine the parameters of multi-parton interaction models in a extended region of phase space. (author)

Selective Targeting of SH2 Domain-Phosphotyrosine Interactions of Src Family Tyrosine Kinases with Monobodies.

Science.gov (United States)

Kükenshöner, Tim; Schmit, Nadine Eliane; Bouda, Emilie; Sha, Fern; Pojer, Florence; Koide, Akiko; Seeliger, Markus; Koide, Shohei; Hantschel, Oliver

2017-05-05

The binding of Src-homology 2 (SH2) domains to phosphotyrosine (pY) sites is critical for the autoinhibition and substrate recognition of the eight Src family kinases (SFKs). The high sequence conservation of the 120 human SH2 domains poses a significant challenge to selectively perturb the interactions of even the SFK SH2 family against the rest of the SH2 domains. We have developed synthetic binding proteins, termed monobodies, for six of the SFK SH2 domains with nanomolar affinity. Most of these monobodies competed with pY ligand binding and showed strong selectivity for either the SrcA (Yes, Src, Fyn, Fgr) or SrcB subgroup (Lck, Lyn, Blk, Hck). Interactome analysis of intracellularly expressed monobodies revealed that they bind SFKs but no other SH2-containing proteins. Three crystal structures of monobody-SH2 complexes unveiled different and only partly overlapping binding modes, which rationalized the observed selectivity and enabled structure-based mutagenesis to modulate inhibition mode and selectivity. In line with the critical roles of SFK SH2 domains in kinase autoinhibition and T-cell receptor signaling, monobodies binding the Src and Hck SH2 domains selectively activated respective recombinant kinases, whereas an Lck SH2-binding monobody inhibited proximal signaling events downstream of the T-cell receptor complex. Our results show that SFK SH2 domains can be targeted with unprecedented potency and selectivity using monobodies. They are excellent tools for dissecting SFK functions in normal development and signaling and to interfere with aberrant SFK signaling networks in cancer cells. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Study of the interactions of PAMAM-NH2 G4 dendrimer with selected natural amino acids in aqueous solutions

International Nuclear Information System (INIS)

Buczkowski, Adam; Palecz, Bartlomiej

2014-01-01

Highlights: • Calorimetric titration and dilution calorimetry show strong interactions between PAMAM-NH 2 G4 dendrimer and amino acids. • The more polar the amino acid side chain, the more exothermic the effects of the direct interactions with dendrimer. • Macromolecule of PAMAM-NH 2 G4 dendrimer can coordinate 20 to 40 molecules of amino acid. -- Abstract: The interactions of PAMAM-NH 2 G4 dendrimer with selected natural amino acids (Gly, Ala, Val, Leu, Ile, Phe, Ser, Thr, Met, Asn, Gln, Pro and Trp) in aqueous solutions were measured with the use of the techniques of calorimetric titration and dilution calorimetry. The results of calorimetric measurements show strong interactions between PAMAM-NH 2 G4 dendrimer and amino acids with polar substituents. A macromolecule of PAMAM-NH 2 G4 dendrimer can coordinate 20 to 40 molecules of amino acid

Age-dependent effects on social interaction of NMDA GluN2A receptor subtype-selective antagonism.

Science.gov (United States)

Green, Torrian L; Burket, Jessica A; Deutsch, Stephen I

2016-07-01

NMDA receptor-mediated neurotransmission is implicated in the regulation of normal sociability in mice. The heterotetrameric NMDA receptor is composed of two obligatory GluN1 and either two "modulatory" GluN2A or GluN2B receptor subunits. GluN2A and GluN2B-containing receptors differ in terms of their developmental expression, distribution between synaptic and extrasynaptic locations, and channel kinetic properties, among other differences. Because age-dependent differences in disruptive effects of GluN2A and GluN2B subtype-selective antagonists on sociability and locomotor activity have been reported in rats, the current investigation explored age-dependent effects of PEAQX, a GluN2A subtype-selective antagonist, on sociability, stereotypic behaviors emerging during social interaction, and spatial working memory in 4- and 8-week old male Swiss Webster mice. The data implicate an age-dependent contribution of GluN2A-containing NMDA receptors to the regulation of normal social interaction in mice. Specifically, at a dose of PEAQX devoid of any effect on locomotor activity and mouse rotarod performance, the social interaction of 8-week old mice was disrupted without any effect on the social salience of a stimulus mouse. Moreover, PEAQX attenuated stereotypic behavior emerging during social interaction in 4- and 8-week old mice. However, PEAQX had no effect on spontaneous alternations, a measure of spatial working memory, suggesting that neural circuits mediating sociability and spatial working memory may be discrete and dissociable from each other. Also, the data suggest that the regulation of stereotypic behaviors and sociability may occur independently of each other. Because expression of GluN2A-containing NMDA receptors occurs at a later developmental stage, they may be more involved in mediating the pathogenesis of ASDs in patients with histories of "regression" after a period of normal development than GluN2B receptors. Copyright © 2016 Elsevier Inc. All rights

Theoretical study on the interactions between chlordecone hydrate and acidic surface groups of activated carbon under basic pH conditions.

Science.gov (United States)

Melchor-Rodríguez, Kenia; Gamboa-Carballo, Juan José; Ferino-Pérez, Anthuan; Passé-Coutrin, Nady; Gaspard, Sarra; Jáuregui-Haza, Ulises Javier

2018-05-01

A theoretical study of the influence of acidic surface groups (SG) of activated carbon (AC) on chlordecone hydrate (CLDh) adsorption is presented, in order to help understanding the adsorption process under basic pH conditions. A seven rings aromatic system (coronene) with a functional group in the edge was used as a simplified model of AC to evaluate the influence of SG in the course of adsorption from aqueous solution at basic pH conditions. Two SG were modeled in their deprotonated form: carboxyl and hydroxyl (COO - and O - ), interacting with CLDh. In order to model the solvation process, all systems under study were calculated with up to three water molecules. Multiple Minima Hypersurface (MMH) methodology was employed to study the interactions of CLDh with SG on AC using PM7 semiempirical Hamiltonian, to explore the potential energy surfaces of the systems and evaluate their thermodynamic association energies. The re-optimization of representative structures obtained from MMH was done using M06-2X Density Functional Theory. The Quantum Theory of Atoms in Molecules (QTAIM) was used to characterize the interaction types. As result, the association of CLDh with acidic SG at basic pH conditions preferentially occurs between the two alcohol groups of CLDh with COO - and O - groups and by dispersive interactions of chlorine atoms of CLDh with the graphitic surface. On the other hand, the presence of covalent interactions between the negatively charged oxygen of SG and one hydrogen atom of CLDh alcohol groups (O - ⋯HO interactions) without water molecules, was confirmed by QTAIM study. It can be concluded that the interactions of CLDh with acidic SG of AC under basic pH conditions confirms the physical mechanisms of adsorption process. Copyright © 2018 Elsevier Inc. All rights reserved.

Ecological and evolutionary consequences of tri-trophic interactions: Spatial variation and effects of plant density.

Science.gov (United States)

Abdala-Roberts, Luis; Parra-Tabla, Víctor; Moreira, Xoaquín; Ramos-Zapata, José

2017-02-01

The factors driving variation in species interactions are often unknown, and few studies have made a link between changes in interactions and the strength of selection. We report on spatial variation in functional responses by a seed predator (SP) and its parasitic wasps associated with the herb Ruellia nudiflora . We assessed the influence of plant density on consumer responses and determined whether density effects and spatial variation in functional responses altered natural selection by these consumers on the plant. We established common gardens at two sites in Yucatan, Mexico, and planted R. nudiflora at two densities in each garden. We recorded fruit output and SP and parasitoid attack; calculated relative fitness (seed number) under scenarios of three trophic levels (accounting for SP and parasitoid effects), two trophic levels (accounting for SP but not parasitoid effects), and one trophic level (no consumer effects); and compared selection strength on fruit number under these scenarios across sites and densities. There was spatial variation in SP recruitment, whereby the SP functional response was negatively density-dependent at one site but density-independent at the other; parasitoid responses were density-independent and invariant across sites. Site variation in SP attack led, in turn, to differences in SP selection on fruit output, and parasitoids did not alter SP selection. There were no significant effects of density at either site. Our results provide a link between consumer functional responses and consumer selection on plants, which deepens our understanding of geographic variation in the evolutionary outcomes of multitrophic interactions. © 2017 Botanical Society of America.

Homophilic and Heterophilic Interactions of Type II Cadherins Identify Specificity Groups Underlying Cell-Adhesive Behavior

Directory of Open Access Journals (Sweden)

Julia Brasch

2018-05-01

Full Text Available Summary: Type II cadherins are cell-cell adhesion proteins critical for tissue patterning and neuronal targeting but whose molecular binding code remains poorly understood. Here, we delineate binding preferences for type II cadherin cell-adhesive regions, revealing extensive heterophilic interactions between specific pairs, in addition to homophilic interactions. Three distinct specificity groups emerge from our analysis with members that share highly similar heterophilic binding patterns and favor binding to one another. Structures of adhesive fragments from each specificity group confirm near-identical dimer topology conserved throughout the family, allowing interface residues whose conservation corresponds to specificity preferences to be identified. We show that targeted mutation of these residues converts binding preferences between specificity groups in biophysical and co-culture assays. Our results provide a detailed understanding of the type II cadherin interaction map and a basis for defining their role in tissue patterning and for the emerging importance of their heterophilic interactions in neural connectivity. : Type II cadherins are a family of vertebrate cell adhesion proteins expressed primarily in the CNS. Brasch et al. measure binding between adhesive fragments, revealing homophilic and extensive selective heterophilic binding with specificities that define groups of similar cadherins. Structures reveal common adhesive dimers, with residues governing cell-adhesive specificity. Keywords: cell adhesion, crystal structure, hemophilic specificity, heterophilic specificity, neural patterning, synaptic targeting, cadherin

Selective incorporation of vRNP into influenza A virions determined by its specific interaction with M1 protein

Energy Technology Data Exchange (ETDEWEB)

Chaimayo, Chutikarn [Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642 (United States); Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700 (Thailand); Hayashi, Tsuyoshi; Underwood, Andrew; Hodges, Erin [Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642 (United States); Takimoto, Toru, E-mail: toru_takimoto@urmc.rochester.edu [Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642 (United States)

2017-05-15

Influenza A viruses contain eight single-stranded, negative-sense RNA segments as viral genomes in the form of viral ribonucleoproteins (vRNPs). During genome replication in the nucleus, positive-sense complementary RNPs (cRNPs) are produced as replicative intermediates, which are not incorporated into progeny virions. To analyze the mechanism of selective vRNP incorporation into progeny virions, we quantified vRNPs and cRNPs in the nuclear and cytosolic fractions of infected cells, using a strand-specific qRT-PCR. Unexpectedly, we found that cRNPs were also exported to the cytoplasm. This export was chromosome region maintenance 1 (CRM1)-independent unlike that of vRNPs. Although both vRNPs and cRNPs were present in the cytosol, viral matrix (M1) protein, a key regulator for viral assembly, preferentially bound vRNPs over cRNPs. These results indicate that influenza A viruses selectively uptake cytosolic vRNPs through a specific interaction with M1 during viral assembly. - Highlights: •Influenza cRNPs are exported from the nucleus of an infected cell via a CRM1-independent pathway. •Influenza A viruses selectively incorporate cytosolic vRNPs through a specific interaction with M1 during viral assembly. •M1 dissociates from vRNP export complex after nuclear export, and is re-associated with vRNPs at the plasma membrane.

Selective incorporation of vRNP into influenza A virions determined by its specific interaction with M1 protein

International Nuclear Information System (INIS)

Chaimayo, Chutikarn; Hayashi, Tsuyoshi; Underwood, Andrew; Hodges, Erin; Takimoto, Toru

2017-01-01

Influenza A viruses contain eight single-stranded, negative-sense RNA segments as viral genomes in the form of viral ribonucleoproteins (vRNPs). During genome replication in the nucleus, positive-sense complementary RNPs (cRNPs) are produced as replicative intermediates, which are not incorporated into progeny virions. To analyze the mechanism of selective vRNP incorporation into progeny virions, we quantified vRNPs and cRNPs in the nuclear and cytosolic fractions of infected cells, using a strand-specific qRT-PCR. Unexpectedly, we found that cRNPs were also exported to the cytoplasm. This export was chromosome region maintenance 1 (CRM1)-independent unlike that of vRNPs. Although both vRNPs and cRNPs were present in the cytosol, viral matrix (M1) protein, a key regulator for viral assembly, preferentially bound vRNPs over cRNPs. These results indicate that influenza A viruses selectively uptake cytosolic vRNPs through a specific interaction with M1 during viral assembly. - Highlights: •Influenza cRNPs are exported from the nucleus of an infected cell via a CRM1-independent pathway. •Influenza A viruses selectively incorporate cytosolic vRNPs through a specific interaction with M1 during viral assembly. •M1 dissociates from vRNP export complex after nuclear export, and is re-associated with vRNPs at the plasma membrane.

Response terminated displays unload selective attention.

Science.gov (United States)

Roper, Zachary J J; Vecera, Shaun P

2013-01-01

Perceptual load theory successfully replaced the early vs. late selection debate by appealing to adaptive control over the efficiency of selective attention. Early selection is observed unless perceptual load (p-Load) is sufficiently low to grant attentional "spill-over" to task-irrelevant stimuli. Many studies exploring load theory have used limited display durations that perhaps impose artificial limits on encoding processes. We extended the exposure duration in a classic p-Load task to alleviate temporal encoding demands that may otherwise tax mnemonic consolidation processes. If the load effect arises from perceptual demands alone, then freeing-up available mnemonic resources by extending the exposure duration should have little effect. The results of Experiment 1 falsify this prediction. We observed a reliable flanker effect under high p-Load, response-terminated displays. Next, we orthogonally manipulated exposure duration and task-relevance. Counter-intuitively, we found that the likelihood of observing the flanker effect under high p-Load resides with the duration of the task-relevant array, not the flanker itself. We propose that stimulus and encoding demands interact to produce the load effect. Our account clarifies how task parameters differentially impinge upon cognitive processes to produce attentional "spill-over" by appealing to visual short-term memory as an additional processing bottleneck when stimuli are briefly presented.

Locus-dependent selection in crop-wild hybrids of lettuce under field conditions and its implication for GM crop development

Science.gov (United States)

Hooftman, Danny A P; Flavell, Andrew J; Jansen, Hans; den Nijs, Hans C M; Syed, Naeem H; Sørensen, Anker P; Orozco-ter Wengel, Pablo; van de Wiel, Clemens C M

2011-01-01

Gene escape from crops has gained much attention in the last two decades, as transgenes introgressing into wild populations could affect the latter's ecological characteristics. However, different genes have different likelihoods of introgression. The mixture of selective forces provided by natural conditions creates an adaptive mosaic of alleles from both parental species. We investigated segregation patterns after hybridization between lettuce (Lactuca sativa) and its wild relative, L. serriola. Three generations of hybrids (S1, BC1, and BC1S1) were grown in habitats mimicking the wild parent's habitat. As control, we harvested S1 seedlings grown under controlled conditions, providing very limited possibility for selection. We used 89 AFLP loci, as well as more recently developed dominant markers, 115 retrotransposon markers (SSAP), and 28 NBS loci linked to resistance genes. For many loci, allele frequencies were biased in plants exposed to natural field conditions, including over-representation of crop alleles for various loci. Furthermore, Linkage disequilibrium was locally changed, allegedly by selection caused by the natural field conditions, providing ample opportunity for genetic hitchhiking. Our study indicates that when developing genetically modified crops, a judicious selection of insertion sites, based on knowledge of selective (dis)advantages of the surrounding crop genome under field conditions, could diminish transgene persistence. PMID:25568012

Locus-dependent selection in crop-wild hybrids of lettuce under field conditions and its implication for GM crop development.

Science.gov (United States)

Hooftman, Danny A P; Flavell, Andrew J; Jansen, Hans; den Nijs, Hans C M; Syed, Naeem H; Sørensen, Anker P; Orozco-Ter Wengel, Pablo; van de Wiel, Clemens C M

2011-09-01

Gene escape from crops has gained much attention in the last two decades, as transgenes introgressing into wild populations could affect the latter's ecological characteristics. However, different genes have different likelihoods of introgression. The mixture of selective forces provided by natural conditions creates an adaptive mosaic of alleles from both parental species. We investigated segregation patterns after hybridization between lettuce (Lactuca sativa) and its wild relative, L. serriola. Three generations of hybrids (S1, BC1, and BC1S1) were grown in habitats mimicking the wild parent's habitat. As control, we harvested S1 seedlings grown under controlled conditions, providing very limited possibility for selection. We used 89 AFLP loci, as well as more recently developed dominant markers, 115 retrotransposon markers (SSAP), and 28 NBS loci linked to resistance genes. For many loci, allele frequencies were biased in plants exposed to natural field conditions, including over-representation of crop alleles for various loci. Furthermore, Linkage disequilibrium was locally changed, allegedly by selection caused by the natural field conditions, providing ample opportunity for genetic hitchhiking. Our study indicates that when developing genetically modified crops, a judicious selection of insertion sites, based on knowledge of selective (dis)advantages of the surrounding crop genome under field conditions, could diminish transgene persistence.

Conflict and expectancies interact to predict sexual behavior under the influence among gay and bisexual men

Science.gov (United States)

Wells, Brooke E; Starks, Tyrel J; Parsons, Jeffrey T; Golub, Sarit

2013-01-01

As the mechanisms of the associations between substance use and risky sex remain unclear, this study investigates the interactive roles of conflicts about casual sex and condom use and expectancies of the sexual effects of substances in those associations among gay men. Conflict interacted with expectancies to predict sexual behavior under the influence; low casual sex conflict coupled with high expectancies predicted the highest number of casual partners, and high condom use conflict and high expectancies predicted the highest number of unprotected sex acts. Results have implications for intervention efforts that aim to improve sexual decision-making and reduce sexual expectancies. PMID:23584507

Distinct interactions of Na+ and Ca2+ ions with the selectivity filter of the bacterial sodium channel NaVAb

International Nuclear Information System (INIS)

Ke, Song; Zangerl, Eva-Maria; Stary-Weinzinger, Anna

2013-01-01

Highlights: ► Ca 2+ translocates slowly in the filter, due to lack of “loose” knock-on mechanism. ► Identification of a high affinity binding site in Na V Ab selectivity filter. ► Changes of EEEE locus triggered by electrostatic interactions with Ca 2+ ions. -- Abstract: Rapid and selective ion transport is essential for the generation and regulation of electrical signaling pathways in living organisms. In this study, we use molecular dynamics simulations and free energy calculations to investigate how the bacterial sodium channel Na V Ab (Arcobacter butzleri) differentiates between Na + and Ca 2+ ions. Multiple nanosecond molecular dynamics simulations revealed distinct binding patterns for these two cations in the selectivity filter and suggested a high affinity calcium binding site formed by backbone atoms of residues Leu-176 and Thr-175 (S CEN ) in the sodium channel selectivity filter

Natural Selection in Virulence Genes of Francisella tularensis.

Science.gov (United States)

Gunnell, Mark K; Robison, Richard A; Adams, Byron J

2016-06-01

A fundamental tenet of evolution is that alleles that are under negative selection are often deleterious and confer no evolutionary advantage. Negatively selected alleles are removed from the gene pool and are eventually extinguished from the population. Conversely, alleles under positive selection do confer an evolutionary advantage and lead to an increase in the overall fitness of the organism. These alleles increase in frequency until they eventually become fixed in the population. Francisella tularensis is a zoonotic pathogen and a potential biothreat agent. The most virulent type of F. tularensis, Type A, is distributed across North America with Type A.I occurring mainly in the east and Type A.II appearing mainly in the west. F. tularensis is thought to be a genome in decay (losing genes) because of the relatively large number of pseudogenes present in its genome. We hypothesized that the observed frequency of gene loss/pseudogenes may be an artifact of evolution in response to a changing environment, and that genes involved in virulence should be under strong positive selection. To test this hypothesis, we sequenced and compared whole genomes of Type A.I and A.II isolates. We analyzed a subset of virulence and housekeeping genes from several F. tularensis subspecies genomes to ascertain the presence and extent of positive selection. Eleven previously identified virulence genes were screened for positive selection along with 10 housekeeping genes. Analyses of selection yielded one housekeeping gene and 7 virulence genes which showed significant evidence of positive selection at loci implicated in cell surface structures and membrane proteins, metabolism and biosynthesis, transcription, translation and cell separation, and substrate binding and transport. Our results suggest that while the loss of functional genes through disuse could be accelerated by negative selection, the genome decay in Francisella could also be the byproduct of adaptive evolution

Synergistic Interaction within Bifunctional Ruthenium Nanoparticle/SILP Catalysts for the Selective Hydrodeoxygenation of Phenols.

Science.gov (United States)

Luska, Kylie L; Migowski, Pedro; El Sayed, Sami; Leitner, Walter

2015-12-21

Ruthenium nanoparticles immobilized on acid-functionalized supported ionic liquid phases (Ru NPs@SILPs) act as efficient bifunctional catalysts in the hydrodeoxygenation of phenolic substrates under batch and continuous flow conditions. A synergistic interaction between the metal sites and acid groups within the bifunctional catalyst leads to enhanced catalytic activities for the overall transformation as compared to the individual steps catalyzed by the separate catalytic functionalities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The evolution of trade-offs under directional and correlational selection.

Science.gov (United States)

Roff, Derek A; Fairbairn, Daphne J

2012-08-01

Using quantitative genetic theory, we develop predictions for the evolution of trade-offs in response to directional and correlational selection. We predict that directional selection favoring an increase in one trait in a trade-off will result in change in the intercept but not the slope of the trade-off function, with the mean value of the selected trait increasing and that of the correlated trait decreasing. Natural selection will generally favor an increase in some combination of trait values, which can be represented as directional selection on an index value. Such selection induces both directional and correlational selection on the component traits. Theory predicts that selection on an index value will also change the intercept but not the slope of the trade-off function but because of correlational selection, the direction of change in component traits may be in the same or opposite directions. We test these predictions using artificial selection on the well-established trade-off between fecundity and flight capability in the cricket, Gryllus firmus and compare the empirical results with a priori predictions made using genetic parameters from a separate half-sibling experiment. Our results support the predictions and illustrate the complexity of trade-off evolution when component traits are subject to both directional and correlational selection. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

A newly developed highly selective Zn2+-AcO- ion-pair sensor through partner preference: equal efficiency under solitary and colonial situation.

Science.gov (United States)

Karar, Monaj; Paul, Suvendu; Biswas, Bhaskar; Majumdar, Tapas; Mallick, Arabinda

2018-05-10

Unusual self-sorting of an ion-pair under highly crowded conditions driven by a synthesized intelligent molecule 2-((E)-(3-((E)-2-hydroxy-3-methoxybenzylideneamino)-2-hydroxypropyl imino)methyl)-6-methoxyphenol, hereafter HBP, is described. When a mixture of various metal salts was allowed to react with HBP, only a specific ion-pair ZnII/AcO- in the solution simultaneously reacted, resulting in high-fidelity ion-pair recognition of HBP. This phenomenon was evidenced by significant changes in the absorption spectra and huge enhancement in emission intensity of HBP. The property that one molecule preferring one particular cation-anion pair over others is a rare but interesting phenomenon. Thus, the potential to interact selectively with the targeted ion-pair resulting in the formation of a specific complex recognized HBP as a new class of molecule that might find future applications in real time and on-site monitoring and separation of new molecules.

Response of nutrients, minerals, antioxidant leaf pigments, vitamins, polyphenol, flavonoid and antioxidant activity in selected vegetable amaranth under four soil water content.

Science.gov (United States)

Sarker, Umakanta; Oba, Shinya

2018-06-30

Four selected vegetable amaranths were grown under four soil water content to evaluate their response in nutrients, minerals, antioxidant leaf pigments, vitamins, polyphenol, flavonoid and total antioxidant activity (TAC). Vegetable amaranth was significantly affected by variety, soil water content and variety × soil water content interactions for all the traits studied. Increase in water stress, resulted in significant changes in proximate compositions, minerals (macro and micro), leaf pigments, vitamin, total polyphenol content (TPC), and total flavonoid content (TFC) of vegetable amaranth. Accessions VA14 and VA16 performed better for all the traits studied. Correlation study revealed a strong antioxidant scavenging activity of leaf pigments, ascorbic acid, TPC and TFC. Vegetable amaranth can tolerate soil water stress without compromising the high quality of the final product in terms of nutrients and antioxidant profiles. Therefore, it could be a promising alternative crop in semi-arid and dry areas and also during dry seasons. Copyright © 2018. Published by Elsevier Ltd.

On site selection of thermoelectric power plants in polluted environment

International Nuclear Information System (INIS)

Gheorghe, A.V.

1992-01-01

This paper discusses the environmental impact of combined heat-power plants. The selection of the site of these plants depends on the spatial distribution law of pollutants and their chemical interaction with environment. The solutions of a diffusion equation describing a system of chemically interacting pollutants are given and discussed. The environmental impacts are described in terms of wind and atmosphere stability, effective and built stack height and the source distance parameters. The optimal constructive solutions are judged upon the concentrations of sulfur and nitrogen oxides at the ground level which must be kept under the maximum admissible limit. (author). 8 figs

Interactive fluka: a world wide web version for a simulation code in proton therapy

International Nuclear Information System (INIS)

Garelli, S.; Giordano, S.; Piemontese, G.; Squarcia, S.

1998-01-01

We considered the possibility of using the simulation code FLUKA, in the framework of TERA. We provided a window under World Wide Web in which an interactive version of the code is available. The user can find instructions for the installation, an on-line FLUKA manual and interactive windows for inserting all the data required by the configuration running file in a very simple way. The database choice allows a more versatile use for data verification and update, recall of old simulations and comparison with selected examples. A completely new tool for geometry drawing under Java has also been developed. (authors)

Sardinians genetic background explained by runs of homozygosity and genomic regions under positive selection.

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Cornelia Di Gaetano

Full Text Available The peculiar position of Sardinia in the Mediterranean sea has rendered its population an interesting biogeographical isolate. The aim of this study was to investigate the genetic population structure, as well as to estimate Runs of Homozygosity and regions under positive selection, using about 1.2 million single nucleotide polymorphisms genotyped in 1077 Sardinian individuals. Using four different methods--fixation index, inflation factor, principal component analysis and ancestry estimation--we were able to highlight, as expected for a genetic isolate, the high internal homogeneity of the island. Sardinians showed a higher percentage of genome covered by RoHs>0.5 Mb (F(RoH%0.5 when compared to peninsular Italians, with the only exception of the area surrounding Alghero. We furthermore identified 9 genomic regions showing signs of positive selection and, we re-captured many previously inferred signals. Other regions harbor novel candidate genes for positive selection, like TMEM252, or regions containing long non coding RNA. With the present study we confirmed the high genetic homogeneity of Sardinia that may be explained by the shared ancestry combined with the action of evolutionary forces.

Semiparametric efficient and robust estimation of an unknown symmetric population under arbitrary sample selection bias

KAUST Repository

Ma, Yanyuan

2013-09-01

We propose semiparametric methods to estimate the center and shape of a symmetric population when a representative sample of the population is unavailable due to selection bias. We allow an arbitrary sample selection mechanism determined by the data collection procedure, and we do not impose any parametric form on the population distribution. Under this general framework, we construct a family of consistent estimators of the center that is robust to population model misspecification, and we identify the efficient member that reaches the minimum possible estimation variance. The asymptotic properties and finite sample performance of the estimation and inference procedures are illustrated through theoretical analysis and simulations. A data example is also provided to illustrate the usefulness of the methods in practice. © 2013 American Statistical Association.

A quantitative quasispecies theory-based model of virus escape mutation under immune selection.

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Woo, Hyung-June; Reifman, Jaques

2012-08-07

Viral infections involve a complex interplay of the immune response and escape mutation of the virus quasispecies inside a single host. Although fundamental aspects of such a balance of mutation and selection pressure have been established by the quasispecies theory decades ago, its implications have largely remained qualitative. Here, we present a quantitative approach to model the virus evolution under cytotoxic T-lymphocyte immune response. The virus quasispecies dynamics are explicitly represented by mutations in the combined sequence space of a set of epitopes within the viral genome. We stochastically simulated the growth of a viral population originating from a single wild-type founder virus and its recognition and clearance by the immune response, as well as the expansion of its genetic diversity. Applied to the immune escape of a simian immunodeficiency virus epitope, model predictions were quantitatively comparable to the experimental data. Within the model parameter space, we found two qualitatively different regimes of infectious disease pathogenesis, each representing alternative fates of the immune response: It can clear the infection in finite time or eventually be overwhelmed by viral growth and escape mutation. The latter regime exhibits the characteristic disease progression pattern of human immunodeficiency virus, while the former is bounded by maximum mutation rates that can be suppressed by the immune response. Our results demonstrate that, by explicitly representing epitope mutations and thus providing a genotype-phenotype map, the quasispecies theory can form the basis of a detailed sequence-specific model of real-world viral pathogens evolving under immune selection.

Organomineral Interactions and Herbicide Sorption in Brazilian Tropical and Subtropical Oxisols under No-Tillage.

Science.gov (United States)

Bonfleur, Eloana J; Kookana, Rai S; Tornisielo, Valdemar L; Regitano, Jussara B

2016-05-25

We evaluated the effects of the soil organic matter (SOM) composition, distribution between soil aggregates size, and their interactions with the mineral phase on herbicide sorption (alachlor, bentazon, and imazethapyr) in tropical and subtropical Oxisols under no-till systems (NT). Using soil physical fractionation approach, sorption experiments were performed on whole soils and their aggregates. SOM chemistry was assessed by CP/MAS (13)C NMR. The lower sorption observed in tropical soils was attributed to the greater blockage of SOM sorption sites than in subtropical soils. When these sites were exposed upon physical fractionation, sorption of the three herbicides in tropical soils increased, especially for imazethapyr. High amounts of poorly crystallized sesquioxides in these soils may have contributed to masking of sorption sites, indicating that organomineral interactions may lead to blockage of sorption sites on SOM in tropical soils.

Interactive bibliographical database on color

Science.gov (United States)

Caivano, Jose L.

2002-06-01

The paper describes the methodology and results of a project under development, aimed at the elaboration of an interactive bibliographical database on color in all fields of application: philosophy, psychology, semiotics, education, anthropology, physical and natural sciences, biology, medicine, technology, industry, architecture and design, arts, linguistics, geography, history. The project is initially based upon an already developed bibliography, published in different journals, updated in various opportunities, and now available at the Internet, with more than 2,000 entries. The interactive database will amplify that bibliography, incorporating hyperlinks and contents (indexes, abstracts, keywords, introductions, or eventually the complete document), and devising mechanisms for information retrieval. The sources to be included are: books, doctoral dissertations, multimedia publications, reference works. The main arrangement will be chronological, but the design of the database will allow rearrangements or selections by different fields: subject, Decimal Classification System, author, language, country, publisher, etc. A further project is to develop another database, including color-specialized journals or newsletters, and articles on color published in international journals, arranged in this case by journal name and date of publication, but allowing also rearrangements or selections by author, subject and keywords.

Detecting loci under recent positive selection in dairy and beef cattle by combining different genome-wide scan methods.

Directory of Open Access Journals (Sweden)

Yuri Tani Utsunomiya

Full Text Available As the methodologies available for the detection of positive selection from genomic data vary in terms of assumptions and execution, weak correlations are expected among them. However, if there is any given signal that is consistently supported across different methodologies, it is strong evidence that the locus has been under past selection. In this paper, a straightforward frequentist approach based on the Stouffer Method to combine P-values across different tests for evidence of recent positive selection in common variations, as well as strategies for extracting biological information from the detected signals, were described and applied to high density single nucleotide polymorphism (SNP data generated from dairy and beef cattle (taurine and indicine. The ancestral Bovinae allele state of over 440,000 SNP is also reported. Using this combination of methods, highly significant (P<3.17×10(-7 population-specific sweeps pointing out to candidate genes and pathways that may be involved in beef and dairy production were identified. The most significant signal was found in the Cornichon homolog 3 gene (CNIH3 in Brown Swiss (P = 3.82×10(-12, and may be involved in the regulation of pre-ovulatory luteinizing hormone surge. Other putative pathways under selection are the glucolysis/gluconeogenesis, transcription machinery and chemokine/cytokine activity in Angus; calpain-calpastatin system and ribosome biogenesis in Brown Swiss; and gangliosides deposition in milk fat globules in Gyr. The composite method, combined with the strategies applied to retrieve functional information, may be a useful tool for surveying genome-wide selective sweeps and providing insights in to the source of selection.

Numerical simulation of wave-current interaction under strong wind conditions

Science.gov (United States)

Larrañaga, Marco; Osuna, Pedro; Ocampo-Torres, Francisco Javier

2017-04-01

Although ocean surface waves are known to play an important role in the momentum and other scalar transfer between the atmosphere and the ocean, most operational numerical models do not explicitly include the terms of wave-current interaction. In this work, a numerical analysis about the relative importance of the processes associated with the wave-current interaction under strong off-shore wind conditions in Gulf of Tehuantepec (the southern Mexican Pacific) was carried out. The numerical system includes the spectral wave model WAM and the 3D hydrodynamic model POLCOMS, with the vertical turbulent mixing parametrized by the kappa-epsilon closure model. The coupling methodology is based on the vortex-force formalism. The hydrodynamic model was forced at the open boundaries using the HYCOM database and the wave model was forced at the open boundaries by remote waves from the southern Pacific. The atmospheric forcing for both models was provided by a local implementation of the WRF model, forced at the open boundaries using the CFSR database. The preliminary analysis of the model results indicates an effect of currents on the propagation of the swell throughout the study area. The Stokes-Coriolis term have an impact on the transient Ekman transport by modifying the Ekman spiral, while the Stokes drift has an effect on the momentum advection and the production of TKE, where the later induces a deepening of the mixing layer. This study is carried out in the framework of the project CONACYT CB-2015-01 255377 and RugDiSMar Project (CONACYT 155793).

Under pressure: response urgency modulates striatal and insula activity during decision-making under risk.

Science.gov (United States)

Jones, Catherine L; Minati, Ludovico; Harrison, Neil A; Ward, Jamie; Critchley, Hugo D

2011-01-01

When deciding whether to bet in situations that involve potential monetary loss or gain (mixed gambles), a subjective sense of pressure can influence the evaluation of the expected utility associated with each choice option. Here, we explored how gambling decisions, their psychophysiological and neural counterparts are modulated by an induced sense of urgency to respond. Urgency influenced decision times and evoked heart rate responses, interacting with the expected value of each gamble. Using functional MRI, we observed that this interaction was associated with changes in the activity of the striatum, a critical region for both reward and choice selection, and within the insula, a region implicated as the substrate of affective feelings arising from interoceptive signals which influence motivational behavior. Our findings bridge current psychophysiological and neurobiological models of value representation and action-programming, identifying the striatum and insular cortex as the key substrates of decision-making under risk and urgency.

An interacting instanton and anti-instanton system under external color magnetic fields

International Nuclear Information System (INIS)

Wakano, M.

1980-01-01

The equilibrium configurations for the instanton and anti-instanton system of the SU(2) gauge field under constant external color magnetic fields are studied by applying the statistical mechanics method. The vacuum has a stabel equilibrium state in the case where the interaction between pseudoparticles is partly considered through the local gauge field in determining the mean dipole moment of instantons. It is shown, however, that there exists no equilibrium state, either stable or unstable, when the dipolar interaction with a particular instanton-size-dependent cutoff is taken into account directly by the second virial coefficient. To analyze this discrepancy a more general cutoff is introduced and the density of instantons is determined for equilibrium states with vanishing external fields, when the cutoff parameter is varied. Above a certain cutoff length there exist two branches of equilibrium configurations with high or low instanton densities, while below it no equilibrium state is obtained. It is shown that we have a critical cutoff length near but slightly larger than the above value and that the equilibrium states on the lower density branch corresponding to cutoff lengths larger than this critical value are stable, while all remaining equilibrium states are unstable. (orig.)

Organic carbon sequestration under selected land use in Padang city, West Sumatra, Indonesia

Science.gov (United States)

Yulnafatmawita; Yasin, S.

2018-03-01

Organic carbon is a potential element to build biomass as well as emitting CO2 to the atmosphere and promotes global warming. This research was aimed to calculate the sequestered Carbon (C) within a 1-m soil depth under selected land use from 6 different sites in Padang city, Indonesia. Disturbed and undisturbed soil samples were taken from several horizons until 100 cm depth at each location. Soil parameters observed were organic carbon (OC), bulk density (BD), and soil texture. The result showed that soil OC content tended to decrease by the depth at all land use types, except under rice field in Kurao-Nanggalo which extremely increased at >65 cm soil depth with the highest carbon stock. The soil organic carbon sequestration from the highest to the lowest according to land use and the location is in the following order mix garden- Kayu Aro > mix garden- Aie Pacah > Rangeland- Parak Laweh >seasonal farming- Teluk Sirih > rice field- Kampuang Jua.

Digest: Plants adapt under attack: genotypic selection and phenotypic plasticity under herbivore pressure.

Science.gov (United States)

Hawkins, Nichola J

2018-03-31

Plant species adapt to changing environmental conditions through phenotypic plasticity and natural selection. Agrawal et al. (2018) found that dandelions responded to the presence of insect pests by producing higher levels of defensive compounds. This defensive response resulted both from phenotypic plasticity, with individual plants' defenses triggered by insect attack, and from evolution by natural selection acting on genetic variation in the plant population. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

A meta-selective C-H borylation directed by a secondary interaction between ligand and substrate

Science.gov (United States)

Kuninobu, Yoichiro; Ida, Haruka; Nishi, Mitsumi; Kanai, Motomu

2015-09-01

Regioselective C-H bond transformations are potentially the most efficient method for the synthesis of organic molecules. However, the presence of many C-H bonds in organic molecules and the high activation barrier for these reactions make these transformations difficult. Directing groups in the reaction substrate are often used to control regioselectivity, which has been especially successful for the ortho-selective functionalization of aromatic substrates. Here, we describe an iridium-catalysed meta-selective C-H borylation of aromatic compounds using a newly designed catalytic system. The bipyridine-derived ligand that binds iridium contains a pendant urea moiety. A secondary interaction between this urea and a hydrogen-bond acceptor in the substrate places the iridium in close proximity to the meta-C-H bond and thus controls the regioselectivity. 1H NMR studies and control experiments support the participation of hydrogen bonds in inducing regioselectivity. Reversible direction of the catalyst through hydrogen bonds is a versatile concept for regioselective C-H transformations.

Cerebro-cerebellar interactions underlying temporal information processing.

Science.gov (United States)

Aso, Kenji; Hanakawa, Takashi; Aso, Toshihiko; Fukuyama, Hidenao

2010-12-01

The neural basis of temporal information processing remains unclear, but it is proposed that the cerebellum plays an important role through its internal clock or feed-forward computation functions. In this study, fMRI was used to investigate the brain networks engaged in perceptual and motor aspects of subsecond temporal processing without accompanying coprocessing of spatial information. Direct comparison between perceptual and motor aspects of time processing was made with a categorical-design analysis. The right lateral cerebellum (lobule VI) was active during a time discrimination task, whereas the left cerebellar lobule VI was activated during a timed movement generation task. These findings were consistent with the idea that the cerebellum contributed to subsecond time processing in both perceptual and motor aspects. The feed-forward computational theory of the cerebellum predicted increased cerebro-cerebellar interactions during time information processing. In fact, a psychophysiological interaction analysis identified the supplementary motor and dorsal premotor areas, which had a significant functional connectivity with the right cerebellar region during a time discrimination task and with the left lateral cerebellum during a timed movement generation task. The involvement of cerebro-cerebellar interactions may provide supportive evidence that temporal information processing relies on the simulation of timing information through feed-forward computation in the cerebellum.

Selective photoionization of isotopic atoms with pulsed lasers

International Nuclear Information System (INIS)

Dai Changjian

1994-01-01

The dynamics of isotopically selective interactions between the radiation of three pulsed lasers and atoms with a four-levels scheme has been studied. Starting from the time-dependent Schroedinger equation with the rotating-wave approximation, authors applied Sylvester theorem to the dynamic equations associated with near-and off-resonant excitations, respectively. Authors obtained the explicit expressions for the four-levels occupation probabilities. The analytic treatment explored the properties of coherent oscillations occurred in the atomic excitation processes with intense monochromatic lasers. The conditions under which the population inversion takes place are derived from near-resonant excitations. The criteria to select the basic parameters of pulsed lasers involved in the process are also provided

The effect of creep cavitation on the fatigue life under creep-fatigue interaction

International Nuclear Information System (INIS)

Nam, S.W.

1995-01-01

Low cycle fatigue tests have been carried out with three different materials (1Cr-Mo-V steel, 12Cr-Mo-V steel and 304 stainless steel) for the investigation of the effect of surface roughness on the fatigue life. To see the effect systematically, we have chosen those materials which may or may not form grain boundary cavities.Test results show that the continuous fatigue life of 1Cr-Mo-V steel and aged 304 stainless steel with a rough surface is decreased compared with that of the specimens with a smooth surface. These two alloys are found to have no grain boundary cavities formed under creep-fatigue test conditions. On the contrary, the fatigue life of 12Cr-Mo-V steel and solutionized 304 stainless steel in which grain boundary cavities are formed under creep-fatigue test conditions is not influenced by the states of surface roughness.The characteristic test results strongly confirm that the fatigue life of the specimen under creep-fatigue interaction, during which creep cavities are forming, may be controlled by the cavity nucleation and growth processes rather than the process of surface crack initiation. ((orig.))

Structural changes and intermolecular interactions of filled ice Ic structure for hydrogen hydrate under high pressure

International Nuclear Information System (INIS)

Machida, S; Hirai, H; Kawamura, T; Yamamoto, Y; Yagi, T

2010-01-01

High-pressure experiments of hydrogen hydrate were performed using a diamond anvil cell under conditions of 0.1-44.2 GPa and at room temperature. Also, high pressure Raman studies of solid hydrogen were performed in the pressure range of 0.1-43.7 GPa. X-ray diffractometry (XRD) for hydrogen hydrate revealed that a known high-pressure structure, filled ice Ic structure, of hydrogen hydrate transformed to a new high-pressure structure at approximately 35-40 GPa. A comparison of the Raman spectroscopy of a vibron for hydrogen molecules between hydrogen hydrate and solid hydrogen revealed that the extraction of hydrogen molecules from hydrogen hydrate occurred above 20 GPa. Also, the Raman spectra of a roton revealed that the rotation of hydrogen molecules in hydrogen hydrate was suppressed at around 20 GPa and that the rotation recovered under higher pressure. These results indicated that remarkable intermolecular interactions in hydrogen hydrate between neighboring hydrogen molecules and between guest hydrogen molecules and host water molecules might occur. These intermolecular interactions could produce the stability of hydrogen hydrate.

Oculomotor selection underlies feature retention in visual working memory.

Science.gov (United States)

Hanning, Nina M; Jonikaitis, Donatas; Deubel, Heiner; Szinte, Martin

2016-02-01

Oculomotor selection, spatial task relevance, and visual working memory (WM) are described as three processes highly intertwined and sustained by similar cortical structures. However, because task-relevant locations always constitute potential saccade targets, no study so far has been able to distinguish between oculomotor selection and spatial task relevance. We designed an experiment that allowed us to dissociate in humans the contribution of task relevance, oculomotor selection, and oculomotor execution to the retention of feature representations in WM. We report that task relevance and oculomotor selection lead to dissociable effects on feature WM maintenance. In a first task, in which an object's location was encoded as a saccade target, its feature representations were successfully maintained in WM, whereas they declined at nonsaccade target locations. Likewise, we observed a similar WM benefit at the target of saccades that were prepared but never executed. In a second task, when an object's location was marked as task relevant but constituted a nonsaccade target (a location to avoid), feature representations maintained at that location did not benefit. Combined, our results demonstrate that oculomotor selection is consistently associated with WM, whereas task relevance is not. This provides evidence for an overlapping circuitry serving saccade target selection and feature-based WM that can be dissociated from processes encoding task-relevant locations. Copyright © 2016 the American Physiological Society.

Network interactions underlying mirror feedback in stroke: A dynamic causal modeling study

Directory of Open Access Journals (Sweden)

Soha Saleh

2017-01-01

Full Text Available Mirror visual feedback (MVF is potentially a powerful tool to facilitate recovery of disordered movement and stimulate activation of under-active brain areas due to stroke. The neural mechanisms underlying MVF have therefore been a focus of recent inquiry. Although it is known that sensorimotor areas can be activated via mirror feedback, the network interactions driving this effect remain unknown. The aim of the current study was to fill this gap by using dynamic causal modeling to test the interactions between regions in the frontal and parietal lobes that may be important for modulating the activation of the ipsilesional motor cortex during mirror visual feedback of unaffected hand movement in stroke patients. Our intent was to distinguish between two theoretical neural mechanisms that might mediate ipsilateral activation in response to mirror-feedback: transfer of information between bilateral motor cortices versus recruitment of regions comprising an action observation network which in turn modulate the motor cortex. In an event-related fMRI design, fourteen chronic stroke subjects performed goal-directed finger flexion movements with their unaffected hand while observing real-time visual feedback of the corresponding (veridical or opposite (mirror hand in virtual reality. Among 30 plausible network models that were tested, the winning model revealed significant mirror feedback-based modulation of the ipsilesional motor cortex arising from the contralesional parietal cortex, in a region along the rostral extent of the intraparietal sulcus. No winning model was identified for the veridical feedback condition. We discuss our findings in the context of supporting the latter hypothesis, that mirror feedback-based activation of motor cortex may be attributed to engagement of a contralateral (contralesional action observation network. These findings may have important implications for identifying putative cortical areas, which may be targeted with

Studies of halo distributions under beam-beam interaction

International Nuclear Information System (INIS)

Chen, T.; Irwin, J.; Siemann, R.H.

1995-01-01

The halo distribution due to the beam-beam interaction in circular electron-positron colliders is simulated with a program which uses a technique that saves a factor of hundreds to thousands of CPU time. The distribution and the interference between the beam-beam interaction and lattice nonlinearities has been investigated. The effects on the halo distribution due to radiation damping misalignment at the collision point, and chromatic effect are presented

Effect of interactions for one-dimensional asymmetric exclusion processes under periodic and bath-adapted coupling environment

Science.gov (United States)

Midha, Tripti; Kolomeisky, Anatoly B.; Gupta, Arvind Kumar

2018-04-01

Stimulated by the effect of the nearest neighbor interactions in vehicular traffic and motor proteins, we study a 1D driven lattice gas model, in which the nearest neighbor particle interactions are taken in accordance with the thermodynamic concepts. The non-equilibrium steady-state properties of the system are analyzed under both open and periodic boundary conditions using a combination of cluster mean-field analysis and Monte Carlo simulations. Interestingly, the fundamental diagram of current versus density shows a complex behavior with a unimodal dependence for attractions and weak repulsions that turns into the bimodal behavior for stronger repulsive interactions. Specific details of system-reservoir coupling for the open system have a strong effect on the stationary phases. We produce the steady-state phase diagrams for the bulk-adapted coupling to the reservoir using the minimum and maximum current principles. The strength and nature of interaction energy has a striking influence on the number of stationary phases. We observe that interactions lead to correlations having a strong impact on the system dynamical properties. The correlation between any two sites decays exponentially as the distance between the sites increases. Moreover, they are found to be short-range for repulsions and long-range for attractions. Our results also suggest that repulsions and attractions asymmetrically modify the dynamics of interacting particles in exclusion processes.

A two-hybrid assay to study protein interactions within the secretory pathway.

Directory of Open Access Journals (Sweden)

Danielle H Dube

Full Text Available Interactions of transcriptional activators are difficult to study using transcription-based two-hybrid assays due to potent activation resulting in false positives. Here we report the development of the Golgi two-hybrid (G2H, a method that interrogates protein interactions within the Golgi, where transcriptional activators can be assayed with negligible background. The G2H relies on cell surface glycosylation to report extracellularly on protein-protein interactions occurring within the secretory pathway. In the G2H, protein pairs are fused to modular domains of the reporter glycosyltransferase, Och1p, and proper cell wall formation due to Och1p activity is observed only when a pair of proteins interacts. Cells containing interacting protein pairs are identified by selectable phenotypes associated with Och1p activity and proper cell wall formation: cells that have interacting proteins grow under selective conditions and display weak wheat germ agglutinin (WGA binding by flow cytometry, whereas cells that lack interacting proteins display stunted growth and strong WGA binding. Using this assay, we detected the interaction between transcription factor MyoD and its binding partner Id2. Interfering mutations along the MyoD:Id2 interaction interface ablated signal in the G2H assay. Furthermore, we used the G2H to detect interactions of the activation domain of Gal4p with a variety of binding partners. Finally, selective conditions were used to enrich for cells encoding interacting partners. The G2H detects protein-protein interactions that cannot be identified via traditional two-hybrid methods and should be broadly useful for probing previously inaccessible subsets of the interactome, including transcriptional activators and proteins that traffic through the secretory pathway.

Cations form sequence selective motifs within DNA grooves via a combination of cation-pi and ion-dipole/hydrogen bond interactions.

Science.gov (United States)

Stewart, Mikaela; Dunlap, Tori; Dourlain, Elizabeth; Grant, Bryce; McFail-Isom, Lori

2013-01-01

The fine conformational subtleties of DNA structure modulate many fundamental cellular processes including gene activation/repression, cellular division, and DNA repair. Most of these cellular processes rely on the conformational heterogeneity of specific DNA sequences. Factors including those structural characteristics inherent in the particular base sequence as well as those induced through interaction with solvent components combine to produce fine DNA structural variation including helical flexibility and conformation. Cation-pi interactions between solvent cations or their first hydration shell waters and the faces of DNA bases form sequence selectively and contribute to DNA structural heterogeneity. In this paper, we detect and characterize the binding patterns found in cation-pi interactions between solvent cations and DNA bases in a set of high resolution x-ray crystal structures. Specifically, we found that monovalent cations (Tl⁺) and the polarized first hydration shell waters of divalent cations (Mg²⁺, Ca²⁺) form cation-pi interactions with DNA bases stabilizing unstacked conformations. When these cation-pi interactions are combined with electrostatic interactions a pattern of specific binding motifs is formed within the grooves.

The relationship between sexual selection and sexual conflict.

Science.gov (United States)

Kokko, Hanna; Jennions, Michael D

2014-07-18

Evolutionary conflicts of interest arise whenever genetically different individuals interact and their routes to fitness maximization differ. Sexual selection favors traits that increase an individual's competitiveness to acquire mates and fertilizations. Sexual conflict occurs if an individual of sex A's relative fitness would increase if it had a "tool" that could alter what an individual of sex B does (including the parental genes transferred), at a cost to B's fitness. This definition clarifies several issues: Conflict is very common and, although it extends outside traits under sexual selection, sexual selection is a ready source of sexual conflict. Sexual conflict and sexual selection should not be presented as alternative explanations for trait evolution. Conflict is closely linked to the concept of a lag load, which is context-dependent and sex-specific. This makes it possible to ask if one sex can "win." We expect higher population fitness if females win. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

Molecular Determinants Underlying Binding Specificities of the ABL Kinase Inhibitors: Combining Alanine Scanning of Binding Hot Spots with Network Analysis of Residue Interactions and Coevolution.

Directory of Open Access Journals (Sweden)

Amanda Tse

Full Text Available Quantifying binding specificity and drug resistance of protein kinase inhibitors is of fundamental importance and remains highly challenging due to complex interplay of structural and thermodynamic factors. In this work, molecular simulations and computational alanine scanning are combined with the network-based approaches to characterize molecular determinants underlying binding specificities of the ABL kinase inhibitors. The proposed theoretical framework unveiled a relationship between ligand binding and inhibitor-mediated changes in the residue interaction networks. By using topological parameters, we have described the organization of the residue interaction networks and networks of coevolving residues in the ABL kinase structures. This analysis has shown that functionally critical regulatory residues can simultaneously embody strong coevolutionary signal and high network centrality with a propensity to be energetic hot spots for drug binding. We have found that selective (Nilotinib and promiscuous (Bosutinib, Dasatinib kinase inhibitors can use their energetic hot spots to differentially modulate stability of the residue interaction networks, thus inhibiting or promoting conformational equilibrium between inactive and active states. According to our results, Nilotinib binding may induce a significant network-bridging effect and enhance centrality of the hot spot residues that stabilize structural environment favored by the specific kinase form. In contrast, Bosutinib and Dasatinib can incur modest changes in the residue interaction network in which ligand binding is primarily coupled only with the identity of the gate-keeper residue. These factors may promote structural adaptability of the active kinase states in binding with these promiscuous inhibitors. Our results have related ligand-induced changes in the residue interaction networks with drug resistance effects, showing that network robustness may be compromised by targeted mutations

Molecular Determinants Underlying Binding Specificities of the ABL Kinase Inhibitors: Combining Alanine Scanning of Binding Hot Spots with Network Analysis of Residue Interactions and Coevolution

Science.gov (United States)

Tse, Amanda; Verkhivker, Gennady M.

2015-01-01

Quantifying binding specificity and drug resistance of protein kinase inhibitors is of fundamental importance and remains highly challenging due to complex interplay of structural and thermodynamic factors. In this work, molecular simulations and computational alanine scanning are combined with the network-based approaches to characterize molecular determinants underlying binding specificities of the ABL kinase inhibitors. The proposed theoretical framework unveiled a relationship between ligand binding and inhibitor-mediated changes in the residue interaction networks. By using topological parameters, we have described the organization of the residue interaction networks and networks of coevolving residues in the ABL kinase structures. This analysis has shown that functionally critical regulatory residues can simultaneously embody strong coevolutionary signal and high network centrality with a propensity to be energetic hot spots for drug binding. We have found that selective (Nilotinib) and promiscuous (Bosutinib, Dasatinib) kinase inhibitors can use their energetic hot spots to differentially modulate stability of the residue interaction networks, thus inhibiting or promoting conformational equilibrium between inactive and active states. According to our results, Nilotinib binding may induce a significant network-bridging effect and enhance centrality of the hot spot residues that stabilize structural environment favored by the specific kinase form. In contrast, Bosutinib and Dasatinib can incur modest changes in the residue interaction network in which ligand binding is primarily coupled only with the identity of the gate-keeper residue. These factors may promote structural adaptability of the active kinase states in binding with these promiscuous inhibitors. Our results have related ligand-induced changes in the residue interaction networks with drug resistance effects, showing that network robustness may be compromised by targeted mutations of key mediating

Selective logging in tropical forests decreases the robustness of liana-tree interaction networks to the loss of host tree species.

Science.gov (United States)

Magrach, Ainhoa; Senior, Rebecca A; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F; Santamaria, Luis; Edwards, David P

2016-03-16

Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the 'health' and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana-tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of 'extinction debt'. © 2016 The Author(s).

Selective logging in tropical forests decreases the robustness of liana–tree interaction networks to the loss of host tree species

Science.gov (United States)

Magrach, Ainhoa; Senior, Rebecca A.; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F.; Santamaria, Luis; Edwards, David P.

2016-01-01

Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the ‘health’ and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana–tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of ‘extinction debt’. PMID:26936241

Simulation of CO2–water–rock interactions on geologic CO2 sequestration under geological conditions of China

International Nuclear Information System (INIS)

Wang, Tianye; Wang, Huaiyuan; Zhang, Fengjun; Xu, Tianfu

2013-01-01

Highlights: • We determined the feasibilities of geologic CO 2 sequestration in China. • We determined the formation of gibbsite suggested CO 2 can be captured by rocks. • We suggested the mechanisms of CO 2 –water–rock interactions. • We found the corrosion and dissolution of the rock increased as temperature rose. -- Abstract: The main purpose of this study focused on the feasibility of geologic CO 2 sequestration within the actual geological conditions of the first Carbon Capture and Storage (CCS) project in China. This study investigated CO 2 –water–rock interactions under simulated hydrothermal conditions via physicochemical analyses and scanning electron microscopy (SEM). Mass loss measurement and SEM showed that corrosion of feldspars, silica, and clay minerals increased with increasing temperature. Corrosion of sandstone samples in the CO 2 -containing fluid showed a positive correlation with temperature. During reaction at 70 °C, 85 °C, and 100 °C, gibbsite (an intermediate mineral product) formed on the sample surface. This demonstrated mineral capture of CO 2 and supported the feasibility of geologic CO 2 sequestration. Chemical analyses suggested a dissolution–reprecipitation mechanism underlying the CO 2 –water–rock interactions. The results of this study suggested that mineral dissolution, new mineral precipitation, and carbonic acid formation-dissociation are closely interrelated in CO 2 –water–rock interactions

The method of adaptation under the parameters of the subject of the information interaction

Directory of Open Access Journals (Sweden)

Инесса Анатольевна Воробьёва

2014-12-01

Full Text Available To ensure the effectiveness of settings (adaptation created software and hardware on the particular subject of the method was developed for adaptation under the parameters of the subject of information interaction in the form of a set of operations to build a network dialog procedures on the basis of accounting for entry-level qualification of the subject, assessment of the current level of skills and operational restructuring of the network in accordance with the assessment of his level.

Interacting particle systems on graphs

Science.gov (United States)

Sood, Vishal

In this dissertation, the dynamics of socially or biologically interacting populations are investigated. The individual members of the population are treated as particles that interact via links on a social or biological network represented as a graph. The effect of the structure of the graph on the properties of the interacting particle system is studied using statistical physics techniques. In the first chapter, the central concepts of graph theory and social and biological networks are presented. Next, interacting particle systems that are drawn from physics, mathematics and biology are discussed in the second chapter. In the third chapter, the random walk on a graph is studied. The mean time for a random walk to traverse between two arbitrary sites of a random graph is evaluated. Using an effective medium approximation it is found that the mean first-passage time between pairs of sites, as well as all moments of this first-passage time, are insensitive to the density of links in the graph. The inverse of the mean-first passage time varies non-monotonically with the density of links near the percolation transition of the random graph. Much of the behavior can be understood by simple heuristic arguments. Evolutionary dynamics, by which mutants overspread an otherwise uniform population on heterogeneous graphs, are studied in the fourth chapter. Such a process underlies' epidemic propagation, emergence of fads, social cooperation or invasion of an ecological niche by a new species. The first part of this chapter is devoted to neutral dynamics, in which the mutant genotype does not have a selective advantage over the resident genotype. The time to extinction of one of the two genotypes is derived. In the second part of this chapter, selective advantage or fitness is introduced such that the mutant genotype has a higher birth rate or a lower death rate. This selective advantage leads to a dynamical competition in which selection dominates for large populations

Selected Topics on Mass Transport in Gas-solid Interactions

DEFF Research Database (Denmark)

Somers, Marcel A.J.

2004-01-01

The present article is a short review containing examples of the role of mass transport in the solid state during gas-solid interactions. Examples are taken from the authors' research on the interaction of carbon and/or nitrogen with iron-based metals. Topics dealt with are diffusion-controlled d......The present article is a short review containing examples of the role of mass transport in the solid state during gas-solid interactions. Examples are taken from the authors' research on the interaction of carbon and/or nitrogen with iron-based metals. Topics dealt with are diffusion...... on the kinetics of phenomena in the solid state. Various experimental techniques were applied to investigate these phenomena; it is however beyond the scope of the present article to treat experimental conditions in detail. The interested reader is referred to the original work for in depth discussions...

28 CFR 30.6 - What procedures apply to the selection of programs and activities under these regulations?

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 1 2010-07-01 2010-07-01 false What procedures apply to the selection of programs and activities under these regulations? 30.6 Section 30.6 Judicial Administration DEPARTMENT OF... consult with local elected officials. (b) Each state that adopts a process shall notify the Attorney...

49 CFR 17.6 - What procedures apply to the selection of programs and activities under these regulations?

Science.gov (United States)

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false What procedures apply to the selection of programs and activities under these regulations? 17.6 Section 17.6 Transportation Office of the Secretary of Transportation INTERGOVERNMENTAL REVIEW OF DEPARTMENT OF TRANSPORTATION PROGRAMS AND ACTIVITIES § 17.6 What...

Virtual screening of selective inhibitors of phosphopantetheine adenylyltransferase from Mycobacterium tuberculosis

Science.gov (United States)

Podshivalov, D. D.; Timofeev, V. I.; Sidorov-Biryukov, D. D.; Kuranova, I. P.

2017-05-01

Bacterial phosphopantetheine adenylyltransferase from Mycobacterium tuberculosis (PPAT Mt) is a convenient target protein for the directed search for selective inhibitors as potent antituberculosis drugs. Four compounds suitable for the detailed investigation of their interactions with PPAT Mt were found by virtual screening. The active-site region of the enzyme was chosen as the ligand-binding site. The positions of the ligands found by the docking were refined by molecular dynamics simulation. The nearest environment of the ligands, the positions of which in the active site of the enzyme were found in a computational experiment, was analyzed. The compounds under consideration were shown to directly interact with functionally important active-site amino-acid residues and block access of substrates to the active site. Therefore, these compounds can be used for the design of selective inhibitors of PPAT Mt as potent antituberculosis drugs.

Proteomic analysis of JAZ interacting proteins under methyl jasmonate treatment in finger millet.

Science.gov (United States)

Sen, Saswati; Kundu, Sangeeta; Dutta, Samir Kr

2016-11-01

Jasmonic acid (JA) signaling pathway in plants is activated against various developmental processes as well as biotic and abiotic stresses. The Jasmonate ZIM-domain (JAZ) protein family, the key regulator of plant JA signaling pathway, also participates in phytohormone crosstalk. This is the first study revealing the in vivo interactions of finger millet (Eleusine coracana (L.) Gaertn.) JAZ protein (EcJAZ) under methyl jasmonate (MJ) treatment. The aim of the study was to explore not only the JA signaling pathway but also the phytohormone signaling crosstalk of finger millet, a highly important future crop. From the MJ-treated finger millet seedlings, the EcJAZ interacting proteins were purified by affinity chromatography with the EcJAZ-matrix. Twenty-one proteins of varying functionalities were successfully identified by MALDI-TOF-TOF Mass spectrometry. Apart from the previously identified JAZ binding proteins, most prominently, EcJAZ was found to interact with transcription factors like NAC, GATA and also with Cold responsive protein (COR), etc. that might have extended the range of functionalities of JAZ proteins. Moreover, to evaluate the interactions of EcJAZ in the JA-co-receptor complex, we generated ten in-silico models containing the EcJAZ degron and the COI1-SKP1 of five monocot cereals viz., rice, wheat, maize, Sorghum and Setaria with JA-Ile or coronatine. Our results indicated that the EcJAZ protein of finger millet could act as the signaling hub for the JA and other phytohormone signaling pathways, in response to a diverse set of stressors and developmental cues to provide survival fitness to the plant. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Genome-scale detection of positive selection in nine primates predicts human-virus evolutionary conflicts.

Science.gov (United States)

van der Lee, Robin; Wiel, Laurens; van Dam, Teunis J P; Huynen, Martijn A

2017-10-13

Hotspots of rapid genome evolution hold clues about human adaptation. We present a comparative analysis of nine whole-genome sequenced primates to identify high-confidence targets of positive selection. We find strong statistical evidence for positive selection in 331 protein-coding genes (3%), pinpointing 934 adaptively evolving codons (0.014%). Our new procedure is stringent and reveals substantial artefacts (20% of initial predictions) that have inflated previous estimates. The final 331 positively selected genes (PSG) are strongly enriched for innate and adaptive immunity, secreted and cell membrane proteins (e.g. pattern recognition, complement, cytokines, immune receptors, MHC, Siglecs). We also find evidence for positive selection in reproduction and chromosome segregation (e.g. centromere-associated CENPO, CENPT), apolipoproteins, smell/taste receptors and mitochondrial proteins. Focusing on the virus-host interaction, we retrieve most evolutionary conflicts known to influence antiviral activity (e.g. TRIM5, MAVS, SAMHD1, tetherin) and predict 70 novel cases through integration with virus-human interaction data. Protein structure analysis further identifies positive selection in the interaction interfaces between viruses and their cellular receptors (CD4-HIV; CD46-measles, adenoviruses; CD55-picornaviruses). Finally, primate PSG consistently show high sequence variation in human exomes, suggesting ongoing evolution. Our curated dataset of positive selection is a rich source for studying the genetics underlying human (antiviral) phenotypes. Procedures and data are available at https://github.com/robinvanderlee/positive-selection. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Decision-Making Under Risk, but Not Under Ambiguity, Predicts Pathological Gambling in Discrete Types of Abstinent Substance Users.

Science.gov (United States)

Wilson, Michael J; Vassileva, Jasmin

2018-01-01

This study explored how different forms of reward-based decision-making are associated with pathological gambling (PG) among abstinent individuals with prior dependence on different classes of drugs. Participants had lifetime histories of either "pure" heroin dependence ( n = 64), "pure" amphetamine dependence ( n = 51), or polysubstance dependence ( n = 89), or had no history of substance dependence ( n = 133). Decision-making was assessed via two neurocognitive tasks: (1) the Iowa Gambling Task (IGT), a measure of decision-making under ambiguity (i.e., uncertain risk contingencies); and (2) the Cambridge Gambling task (CGT), a measure of decision-making under risk (i.e., explicit risk contingencies). The main effects of neurocognitive performance and drug class on PG (defined as ≥3 DSM-IV PG symptoms) as well as their interactional effects were assessed via multiple linear regression. Two CGT indices of decision-making under risk demonstrated positive main effects on PG. Interaction effects indicated that the effects of decision-making under risk on PG were largely consistent across participant groups. Notably, a linear relationship between greater CGT Risk-Taking and PG symptoms was not observed among amphetamine users, whereas IGT performance was selectively and positively associated with PG in polysubstance users. Overall, results indicate that reward-based decision-making under risk may represent a risk factor for PG across substance users, with some variations in these relationships influenced by specific class of substance of abuse.

Body size, swimming speed, or thermal sensitivity? Predator-imposed selection on amphibian larvae.

Science.gov (United States)

Gvoždík, Lumír; Smolinský, Radovan

2015-11-02

Many animals rely on their escape performance during predator encounters. Because of its dependence on body size and temperature, escape velocity is fully characterized by three measures, absolute value, size-corrected value, and its response to temperature (thermal sensitivity). The primary target of the selection imposed by predators is poorly understood. We examined predator (dragonfly larva)-imposed selection on prey (newt larvae) body size and characteristics of escape velocity using replicated and controlled predation experiments under seminatural conditions. Specifically, because these species experience a wide range of temperatures throughout their larval phases, we predict that larvae achieving high swimming velocities across temperatures will have a selective advantage over more thermally sensitive individuals. Nonzero selection differentials indicated that predators selected for prey body size and both absolute and size-corrected maximum swimming velocity. Comparison of selection differentials with control confirmed selection only on body size, i.e., dragonfly larvae preferably preyed on small newt larvae. Maximum swimming velocity and its thermal sensitivity showed low group repeatability, which contributed to non-detectable selection on both characteristics of escape performance. In the newt-dragonfly larvae interaction, body size plays a more important role than maximum values and thermal sensitivity of swimming velocity during predator escape. This corroborates the general importance of body size in predator-prey interactions. The absence of an appropriate control in predation experiments may lead to potentially misleading conclusions about the primary target of predator-imposed selection. Insights from predation experiments contribute to our understanding of the link between performance and fitness, and further improve mechanistic models of predator-prey interactions and food web dynamics.

Stability of selected volatile contact allergens in different patch test chambers under different storage conditions

DEFF Research Database (Denmark)

Mose, Kristian Fredløv; Andersen, Klaus Ejner; Christensen, Lars Porskjaer

2012-01-01

Background. Patch test preparations of volatile substances may evaporate during storage, thereby giving rise to reduced patch test concentrations. Objectives. To investigate the stability of selected acrylates/methacrylates and fragrance allergens in three different test chambers under different...... both storage conditions, whereas MMA and 2-HPA required cool storage for maintenance of the limit. Conclusion. The Van der Bend® transport container was the best device for storage of samples of volatile contact allergens....

Under Pressure: Interactions between Commensal Microbiota and the Teleost Immune System

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Cecelia Kelly

2017-05-01

Full Text Available Commensal microorganisms inhabit every mucosal surface of teleost fish. At these surfaces, microorganisms directly and indirectly shape the teleost immune system. This review provides a comprehensive overview of how the microbiota and microbiota-derived products influence both the mucosal and systemic immune system of fish. The cross talk between the microbiota and the teleost immune system shifts significantly under stress or disease scenarios rendering commensals into opportunists or pathogens. Lessons learnt from germ-free fish models as well as from oral administration of live probiotics to fish highlight the vast impact that microbiota have on immune development, antibody production, mucosal homeostasis, and resistance to stress. Future studies should dissect the specific mechanisms by which different members of the fish microbiota and the metabolites they produce interact with pathogens, with other commensals, and with the teleost immune system.

The dual role of autophagy under hypoxia-involvement of interaction between autophagy and apoptosis.

Science.gov (United States)

Li, Mengmeng; Tan, Jin; Miao, Yuyang; Lei, Ping; Zhang, Qiang

2015-06-01

Hypoxia is one of severe cellular stress and it is well known to be associated with a worse outcome since a lack of oxygen accelerates the induction of apoptosis. Autophagy, an important and evolutionarily conserved mechanism for maintaining cellular homeostasis, is closely related to the apoptosis caused by hypoxia. Generally autophagy blocks the induction of apoptosis and inhibits the activation of apoptosis-associated caspase which could reduce cellular injury. However, in special cases, autophagy or autophagy-relevant proteins may help to induce apoptosis, which could aggravate cell damage under hypoxia condition. In addition, the activation of apoptosis-related proteins-caspase can also degrade autophagy-related proteins, such as Atg3, Atg4, Beclin1 protein, inhibiting autophagy. Although the relationship between autophagy and apoptosis has been known for rather complex for more than a decade, the underlying regulatory mechanisms have not been clearly understood. This short review discusses and summarizes the dual role of autophagy and the interaction and molecular regulatory mechanisms between autophagy and apoptosis under hypoxia.

Response terminated displays unload selective attention

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Zachary Joseph Jackson Roper

2013-12-01

Full Text Available Perceptual load theory successfully replaced the early versus late selection debate by appealing to adaptive control over the efficiency of selective attention. Early selection is observed unless perceptual load (p-Load is sufficiently low to grant attentional ‘spill-over‘ to task-irrelevant stimuli. Many studies exploring load theory have used limited display durations that perhaps impose artificial limits on encoding processes. We extended the exposure duration in a classic p-Load task to alleviate temporal encoding demands that may otherwise tax mnemonic consolidation processes. If the load effect arises from perceptual demands alone, then freeing-up available mnemonic resources by extending the exposure duration should have little effect. The results of Experiment 1 falsify this prediction. We observed a reliable flanker effect under high p-Load, response-terminated displays. Next, we orthogonally manipulated exposure duration and task-relevance. Counter-intuitively, we found that the likelihood of observing the flanker effect under high p-Load resides with the duration of the task-relevant array, not the flanker itself. We propose that stimulus and encoding demands interact to produce the load effect. Our account clarifies how task parameters differentially impinge upon cognitive processes to produce attentional ‘spill-over’ by appealing to visual short-term memory as an additional processing bottleneck when stimuli are briefly presented.

TOUCH INTERACTION WITH 3D GEOGRAPHICAL VISUALIZATION ON WEB: SELECTED TECHNOLOGICAL AND USER ISSUES

Directory of Open Access Journals (Sweden)

L. Herman

2016-10-01

Full Text Available The use of both 3D visualization and devices with touch displays is increasing. In this paper, we focused on the Web technologies for 3D visualization of spatial data and its interaction via touch screen gestures. At the first stage, we compared the support of touch interaction in selected JavaScript libraries on different hardware (desktop PCs with touch screens, tablets, and smartphones and software platforms. Afterward, we realized simple empiric test (within-subject design, 6 participants, 2 simple tasks, LCD touch monitor Acer and digital terrain models as stimuli focusing on the ability of users to solve simple spatial tasks via touch screens. An in-house testing web tool was developed and used based on JavaScript, PHP, and X3DOM languages and Hammer.js libraries. The correctness of answers, speed of users’ performances, used gestures, and a simple gesture metric was recorded and analysed. Preliminary results revealed that the pan gesture is most frequently used by test participants and it is also supported by the majority of 3D libraries. Possible gesture metrics and future developments including the interpersonal differences are discussed in the conclusion.

Evaluation and Selection of Predicaments in Pharmaceutical Supply Chain using AHP under Fuzzy Environment

Science.gov (United States)

Nikhil, E. V. S.; Sai Ram, V.; Charan Yadav, V.; Kiran Kumar, Kalla; Nagaraju, Dega

2017-05-01

Pharmaceutical sector plays an important role in the medical and health system. Due to the globalization of the business, increasing demand and supply for drugs, growing regulatory requirements, all stages of the pharmaceutical supply chain (SC) are facing numerous predicaments. The traditional way of selection and evaluation of these predicaments is customarily done using technical information. This approach lacks the ability to project the burning issue that to be addressed first. Hence, a computing method of selecting the crucial issue from the existing issues is essential in a pharmaceutical supply chain. This paper considers seven different predicaments as criteria and five sub-criteria under each main predicament of a pharmaceutical supply chain. The intention of this project is to manifest the process of assessing and selecting the issue that to be addressed first by using multi-criteria decision making technique (MCDM), i.e., fuzzy analytical hierarchy process (FAHP). The criteria and sub-criteria weights are calculated and priority assessment of the predicaments is done by using FAHP. Finally, from the findings of this work, the predicaments are ranked from most important to least important. This gives information to the decision maker (DM) to solve the issue that is affecting the SC the most with respect to the others.

Under pressure: response urgency modulates striatal and insula activity during decision-making under risk.

Directory of Open Access Journals (Sweden)

Catherine L Jones

Full Text Available When deciding whether to bet in situations that involve potential monetary loss or gain (mixed gambles, a subjective sense of pressure can influence the evaluation of the expected utility associated with each choice option. Here, we explored how gambling decisions, their psychophysiological and neural counterparts are modulated by an induced sense of urgency to respond. Urgency influenced decision times and evoked heart rate responses, interacting with the expected value of each gamble. Using functional MRI, we observed that this interaction was associated with changes in the activity of the striatum, a critical region for both reward and choice selection, and within the insula, a region implicated as the substrate of affective feelings arising from interoceptive signals which influence motivational behavior. Our findings bridge current psychophysiological and neurobiological models of value representation and action-programming, identifying the striatum and insular cortex as the key substrates of decision-making under risk and urgency.

Quantum theory for magnons and phonons interactions under time-varying magnetic fields

International Nuclear Information System (INIS)

Guerreiro, S.C.

1971-01-01

The magnon-fonon interaction in a ferromagnetic material submited to a time-varying magnetic field is studied by quantum methods. This problem has already been solved by semi-classical methods, and one of its results is that under certain conditions a state of lattice vibrations may be completely converted into spin oscillations. The main proporties of magnetoelastic waves in static magnetic fields and extend the quantum treatment for the time varying magnetic field case is revised. Field operators whose equations of motion are analogous to the classical ones are introduced. Their equations, which appear as a linear system of first order coupled equations, are converted into equations for complex functions by an expansion of the field operators in a time t as linear combinations of the same operators in a time t 0 prior to the variation of the magnetic field. The quantity g vector obtained from the classical solution is quantized and shown to be the linear momentum density of the magnetoelastic system, the quantum field spin density operator is deduced for the two interacting fields, and finally the results are used to study the magnetization and lattice displacement vector fields in the case of a system described by a coherent state of one of its normal modes

Genetic Gains in Yield and Yield Related Traits under Drought Stress and Favorable Environments in a Maize Population Improved Using Marker Assisted Recurrent Selection

Directory of Open Access Journals (Sweden)

Folusho Bankole

2017-05-01

Full Text Available The objective of marker assisted recurrent selection (MARS is to increase the frequency of favorable marker alleles in a population before inbred line extraction. This approach was used to improve drought tolerance and grain yield (GY in a biparental cross of two elite drought tolerant lines. The testcrosses of randomly selected 50 S1 lines from each of the three selection cycles (C0, C1, C2 of the MARS population, parental testcrosses and the cross between the two parents (F1 were evaluated under drought stress (DS and well watered (WW well as under rainfed conditions to determine genetic gains in GY and other agronomic traits. Also, the S1 lines derived from each selection types were genotyped with single nucleotide polymorphism (SNP markers. Testcrosses derived from C2 produced significantly higher grain field under DS than those derived from C0 with a relative genetic gain of 7% per cycle. Also, the testcrosses of S1 lines from C2 showed an average genetic gain of 1% per cycle under WW condition and 3% per cycle under rainfed condition. Molecular analysis revealed that the frequency of favorable marker alleles increased from 0.510 at C0 to 0.515 at C2, while the effective number of alleles (Ne per locus decreased from C0 (1.93 to C2 (1.87. Our results underscore the effectiveness of MARS for improvement of GY under DS condition.

Selection of risk reduction portfolios under interval-valued probabilities

International Nuclear Information System (INIS)

Toppila, Antti; Salo, Ahti

2017-01-01

A central problem in risk management is that of identifying the optimal combination (or portfolio) of improvements that enhance the reliability of the system most through reducing failure event probabilities, subject to the availability of resources. This optimal portfolio can be sensitive with regard to epistemic uncertainties about the failure events' probabilities. In this paper, we develop an optimization model to support the allocation of resources to improvements that mitigate risks in coherent systems in which interval-valued probabilities defined by lower and upper bounds are employed to capture epistemic uncertainties. Decision recommendations are based on portfolio dominance: a resource allocation portfolio is dominated if there exists another portfolio that improves system reliability (i) at least as much for all feasible failure probabilities and (ii) strictly more for some feasible probabilities. Based on non-dominated portfolios, recommendations about improvements to implement are derived by inspecting in how many non-dominated portfolios a given improvement is contained. We present an exact method for computing the non-dominated portfolios. We also present an approximate method that simplifies the reliability function using total order interactions so that larger problem instances can be solved with reasonable computational effort. - Highlights: • Reliability allocation under epistemic uncertainty about probabilities. • Comparison of alternatives using dominance. • Computational methods for generating the non-dominated alternatives. • Deriving decision recommendations that are robust with respect to epistemic uncertainty.

Plasma-surface interactions under high heat and particle fluxes

NARCIS (Netherlands)

De Temmerman, G.; Bystrov, K.; Liu, F.; Liu, W.; Morgan, T.; Tanyeli, I.; van den Berg, M.; Xu, H.; Zielinski, J.

2013-01-01

The plasma-surface interactions expected in the divertor of a future fusion reactor are characterized by extreme heat and particle fluxes interacting with the plasma-facing surfaces. Powerful linear plasma generators are used to reproduce the expected plasma conditions and allow plasma-surface

Co-evolutionary interactions between host resistance and pathogen avirulence genes in rice-Magnaporthe oryzae pathosystem.

Science.gov (United States)

Singh, Pankaj Kumar; Ray, Soham; Thakur, Shallu; Rathour, Rajeev; Sharma, Vinay; Sharma, Tilak Raj

2018-06-01

Rice and Magnaporthe oryzae constitutes an ideal pathosystem for studying host-pathogen interaction in cereals crops. There are two alternative hypotheses, viz. Arms race and Trench warfare, which explain the co-evolutionary dynamics of hosts and pathogens which are under continuous confrontation. Arms race proposes that both R- and Avr- genes of host and pathogen, respectively, undergo positive selection. Alternatively, trench warfare suggests that either R- or Avr- gene in the pathosystem is under balanced selection intending to stabilize the genetic advantage gained over the opposition. Here, we made an attempt to test the above-stated hypotheses in rice-M. oryzae pathosystem at loci of three R-Avr gene pairs, Piz-t-AvrPiz-t, Pi54-AvrPi54 and Pita-AvrPita using allele mining approach. Allele mining is an efficient way to capture allelic variants existing in the population and to study the selective forces imposed on the variants during evolution. Results of nucleotide diversity, neutrality statistics and phylogenetic analyses reveal that Piz-t, Pi54 and AvrPita are diversified and under positive selection at their corresponding loci, while their counterparts, AvrPiz-t, AvrPi54 and Pita are conserved and under balancing selection, in nature. These results imply that rice-M. oryzae populations are engaged in a trench warfare at least at the three R/Avr loci studied. It is a maiden attempt to study the co-evolution of three R-Avr gene pairs in this pathosystem. Knowledge gained from this study will help in understanding the evolutionary dynamics of host-pathogen interaction in a better way and will also aid in developing new durable blast resistant rice varieties in future. Copyright © 2018 Elsevier Inc. All rights reserved.

Different types of interactions of links in artificial and natural ecosystems under anthropogenic pressure

Science.gov (United States)

Somova, Lydia; Pisman, Tamara; Mikheeva, Galina; Pechurkin, Nickolay

The life of organisms in an ecosystem depends not only on abiotic factors, but also on the interaction of organisms in which they come with each other. The study of mechanisms of the bioregulation based on ecological - biochemical interactions of ecosystem links is necessary to know the ecosystem development, its stability, survival of ecosystem organisms. It is of high importance as for the creation of artificial ecosystems, and also for the study of natural ecosystems under anthropogenic pressure on them. To create well-functioning ecosystems is necessary to study and consider the basic types of relationships between organisms. The basic types of interactions between organisms have been studied with simple terrestrial and water ecosystems. 1. The interaction of microbiocenoses and plants were studied in experiments with agrocenoses. Microbiocenosis proposed for increase of productivity of plants and for obtaining ecologically pure production of plants has been created taking into account mutual relationships between species of microorganisms. 2. The experimental model of the atmosphere closed «autotroph - heterotroph» system in which heterotrophic link was the mixed population of yeasts (Candida utilis and Candida guilliermondii) was studied. The algae Chlorella vulgaris was used as an autotroph link. It was shown, that the competition result for heterotrophic link depended on strategy of populations of yeast in relation to a substrate and oxygen utilization. 3. As a result of experimental and theoretical modelling of a competition of algae Chlorella vulgaris and Scenedesmus quadricauda at continuous cultivation, the impossibility of their coexistence in the conditions of limitation on nitrogen was shown. 4. Pray-predator interactions between algae (Chlorella vulgaris, Scenedesmus quadricauda) and invertebrates (Paramecium caudatum, Brachionus plicatilis) were studied in experimental closed ecosystem. This work was partly supported by the Russian Foundation for

The neural bases of host plant selection in a Neuroecology framework

Directory of Open Access Journals (Sweden)

Carolina E Reisenman

2015-08-01

Full Text Available Understanding how animals make use of environmental information to guide behavior is a fundamental problem in the field of neuroscience. Similarly, the field of ecology seeks to understand the role of behavior in shaping interactions between organisms at various levels of organization, including population-, community- and even ecosystem-level scales. Together, the newly emerged field of Neuroecology seeks to unravel this fundamental question by studying both the function of neurons at many levels of the sensory pathway and the interactions between organisms and their natural environment. The interactions between herbivorous insects and their host plants are ideal examples of Neuroecology given the strong ecological and evolutionary forces and the underlying physiological and behavioral mechanisms that shaped these interactions. In this review we focus on an exemplary herbivorous insect within the Lepidoptera, the giant sphinx moth Manduca sexta, as much is known about the natural behaviors related to hostplant selection and the involved neurons at several level of the sensory pathway. We also discuss how herbivore-induced plant odorants and secondary metabolites in floral nectar in turn can affect moth behavior, and the underlying neural mechanisms.

The neural bases of host plant selection in a Neuroecology framework.

Science.gov (United States)

Reisenman, Carolina E; Riffell, Jeffrey A

2015-01-01

Understanding how animals make use of environmental information to guide behavior is a fundamental problem in the field of neuroscience. Similarly, the field of ecology seeks to understand the role of behavior in shaping interactions between organisms at various levels of organization, including population-, community- and even ecosystem-level scales. Together, the newly emerged field of "Neuroecology" seeks to unravel this fundamental question by studying both the function of neurons at many levels of the sensory pathway and the interactions between organisms and their natural environment. The interactions between herbivorous insects and their host plants are ideal examples of Neuroecology given the strong ecological and evolutionary forces and the underlying physiological and behavioral mechanisms that shaped these interactions. In this review we focus on an exemplary herbivorous insect within the Lepidoptera, the giant sphinx moth Manduca sexta, as much is known about the natural behaviors related to host plant selection and the involved neurons at several level of the sensory pathway. We also discuss how herbivore-induced plant odorants and secondary metabolites in floral nectar in turn can affect moth behavior, and the underlying neural mechanisms.

Noncontextuality with Marginal Selectivity in Reconstructing Mental Architectures

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Ru eZhang

2015-06-01

Full Text Available We present a general theory of series-parallel mental architectures with selectively influenced stochastically non-independent components. A mental architecture is a hypothetical network of processes aimed at performing a task, of which we only observe the overall time it takes under variable parameters of the task. It is usually assumed that the network contains several processes selectively influenced by different experimental factors, and then the question is asked as to how these processes are arranged within the network, e.g., whether they are concurrent or sequential. One way of doing this is to consider the distribution functions for the overall processing time and compute certain linear combinations thereof (interaction contrasts. The theory of selective influences in psychology can be viewed as a special application of the interdisciplinary theory of (noncontextuality having its origins and main applications in quantum theory. In particular, lack of contextuality is equivalent to the existence of a hidden random entity of which all the random variables in play are functions. Consequently, for any given value of this common random entity, the processing times and their compositions (minima, maxima, or sums become deterministic quantities. These quantities, in turn, can be treated as random variables with (shifted Heaviside distribution functions, for which one can easily compute various linear combinations across different treatments, including interaction contrasts. This mathematical fact leads to a simple method, more general than the previously used ones, to investigate and characterize the interaction contrast for different types of series-parallel architectures.

Specificity and evolvability in eukaryotic protein interaction networks.

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Pedro Beltrao

2007-02-01

Full Text Available Progress in uncovering the protein interaction networks of several species has led to questions of what underlying principles might govern their organization. Few studies have tried to determine the impact of protein interaction network evolution on the observed physiological differences between species. Using comparative genomics and structural information, we show here that eukaryotic species have rewired their interactomes at a fast rate of approximately 10(-5 interactions changed per protein pair, per million years of divergence. For Homo sapiens this corresponds to 10(3 interactions changed per million years. Additionally we find that the specificity of binding strongly determines the interaction turnover and that different biological processes show significantly different link dynamics. In particular, human proteins involved in immune response, transport, and establishment of localization show signs of positive selection for change of interactions. Our analysis suggests that a small degree of molecular divergence can give rise to important changes at the network level. We propose that the power law distribution observed in protein interaction networks could be partly explained by the cell's requirement for different degrees of protein binding specificity.

Vega-Lite: A Grammar of Interactive Graphics.

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Satyanarayan, Arvind; Moritz, Dominik; Wongsuphasawat, Kanit; Heer, Jeffrey

2017-01-01

We present Vega-Lite, a high-level grammar that enables rapid specification of interactive data visualizations. Vega-Lite combines a traditional grammar of graphics, providing visual encoding rules and a composition algebra for layered and multi-view displays, with a novel grammar of interaction. Users specify interactive semantics by composing selections. In Vega-Lite, a selection is an abstraction that defines input event processing, points of interest, and a predicate function for inclusion testing. Selections parameterize visual encodings by serving as input data, defining scale extents, or by driving conditional logic. The Vega-Lite compiler automatically synthesizes requisite data flow and event handling logic, which users can override for further customization. In contrast to existing reactive specifications, Vega-Lite selections decompose an interaction design into concise, enumerable semantic units. We evaluate Vega-Lite through a range of examples, demonstrating succinct specification of both customized interaction methods and common techniques such as panning, zooming, and linked selection.

The orexin component of fasting triggers memory processes underlying conditioned food selection in the rat.

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Ferry, Barbara; Duchamp-Viret, Patricia

2014-03-14

To test the selectivity of the orexin A (OXA) system in olfactory sensitivity, the present study compared the effects of fasting and of central infusion of OXA on the memory processes underlying odor-malaise association during the conditioned odor aversion (COA) paradigm. Animals implanted with a cannula in the left ventricle received ICV infusion of OXA or artificial cerebrospinal fluid (ACSF) 1 h before COA acquisition. An additional group of intact rats were food-deprived for 24 h before acquisition. Results showed that the increased olfactory sensitivity induced by fasting and by OXA infusion was accompanied by enhanced COA performance. The present results suggest that fasting-induced central OXA release influenced COA learning by increasing not only olfactory sensitivity, but also the memory processes underlying the odor-malaise association.

Switches of stimulus tagging frequencies interact with the conflict-driven control of selective attention, but not with inhibitory control.

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Scherbaum, Stefan; Frisch, Simon; Dshemuchadse, Maja

2016-01-01

Selective attention and its adaptation by cognitive control processes are considered a core aspect of goal-directed action. Often, selective attention is studied behaviorally with conflict tasks, but an emerging neuroscientific method for the study of selective attention is EEG frequency tagging. It applies different flicker frequencies to the stimuli of interest eliciting steady state visual evoked potentials (SSVEPs) in the EEG. These oscillating SSVEPs in the EEG allow tracing the allocation of selective attention to each tagged stimulus continuously over time. The present behavioral investigation points to an important caveat of using tagging frequencies: The flicker of stimuli not only produces a useful neuroscientific marker of selective attention, but interacts with the adaptation of selective attention itself. Our results indicate that RT patterns of adaptation after response conflict (so-called conflict adaptation) are reversed when flicker frequencies switch at once. However, this effect of frequency switches is specific to the adaptation by conflict-driven control processes, since we find no effects of frequency switches on inhibitory control processes after no-go trials. We discuss the theoretical implications of this finding and propose precautions that should be taken into account when studying conflict adaptation using frequency tagging in order to control for the described confounds. Copyright © 2015 Elsevier B.V. All rights reserved.

Contemporary Ecological Interactions Improve Models of Past Trait Evolution.

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Hutchinson, Matthew C; Gaiarsa, Marília P; Stouffer, Daniel B

2018-02-20

Despite the fact that natural selection underlies both traits and interactions, evolutionary models often neglect that ecological interactions may, and in many cases do, influence the evolution of traits. Here, we explore the interdependence of ecological interactions and functional traits in the pollination associations of hawkmoths and flowering plants. Specifically, we develop an adaptation of the Ornstein-Uhlenbeck model of trait evolution that allows us to study the influence of plant corolla depth and observed hawkmoth-plant interactions on the evolution of hawkmoth proboscis length. Across diverse modelling scenarios, we find that the inclusion of contemporary interactions can provide a better description of trait evolution than the null expectation. Moreover, we show that the pollination interactions provide more-likely models of hawkmoth trait evolution when interactions are considered at increasingly finescale groups of hawkmoths. Finally, we demonstrate how the results of best-fit modelling approaches can implicitly support the association between interactions and trait evolution that our method explicitly examines. In showing that contemporary interactions can provide insight into the historical evolution of hawkmoth proboscis length, we demonstrate the clear utility of incorporating additional ecological information to models designed to study past trait evolution.

Application of proteomics to investigate barley-Fusarium graminearum interaction

DEFF Research Database (Denmark)

Yang, Fen

in plants under low N and iv) proteomes of uninfected plants were similar under two N levels. Correlation of level of proteolysis induced by the fungus with measurement of Fusarium-damaged kernels, fungal biomass and mycotoxin levels indicated that FHB was more severe in barley with low N. In Chapter 3......, the molecular mechanisms of barley defense to Fusarium graminearum at the early infection stage were studied. Antibodies against barley β-amylases were shown to be the markers for infection at proteome level and for selection of the time for proteome analysis before extensive degradation caused by the fungus...... the disease. Due to the advantages of gel-based proteomics that differentially expressed proteins involved in the interaction can be directly detected by comparing protein profiles displayed on 2-D gels, it is used as a tool for studying the barley- Fusarium graminearum interaction form three different...

Effectiveness of beneficial plant-microbe interactions under hypobaric and hypoxic conditions in an advanced life support system

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MacIntyre, Olathe; Stasiak, Michael; Cottenie, Karl; Trevors, Jack; Dixon, Mike

An assembled microbial community in the hydroponics solution of an advanced life support system may improve plant performance and productivity in three ways: (1) exclusion of plant pathogens from the initial community, (2) resistance to infection, and (3) plant-growth promotion. However, the plant production area is likely to have a hypobaric (low pressure) and hypoxic (low oxygen) atmosphere to reduce structural mass and atmosphere leakage, and these conditions may alter plant-microbe interactions. Plant performance and productivity of radish (Raphanus sativus L. cv. Cherry Bomb II) grown under hypobaric and hypoxic conditions were investigated at the University of Guelph's Controlled Environment Systems Research Facility. Changes in the microbial communities that routinely colonized the re-circulated nutrient solution, roots, and leaves of radishes in these experiments were quantified in terms of similarity in community composition, abundance of bacteria, and community diversity before and after exposure to hypobaric and hypoxic conditions relative to communities maintained at ambient growth conditions. The microbial succession was affected by extreme hypoxia (2 kPa oxygen partial pressure) while hypobaria as low as 10 kPa total pressure had little effect on microbial ecology. There were no correlations found between the physiological profile of these unintentional microbial communities and radish growth. The effects of hypobaric and hypoxic conditions on specific plant-microbe interactions need to be determined before beneficial gnotobiotic communities can be developed for use in space. The bacterial strains Tal 629 of Bradyrhizobium japonicum and WCS417 of Pseudomonas fluorescens, and the plant pathogen Fusarium oxysporum f. sp. raphani will be used in future experiments. B. japonicum Tal 629 promotes radish growth in hydroponics systems and P. fluorescens WCS417 induces systemic resistance to fusarium wilt (F. oxysporum f. sp. raphani) in radish under ambient

Tuning of the PYTHIA 6.4 Multiple Parton Interaction model to Minimum Bias and Underlying Event data

CERN Document Server

Firdoua, Nameequa

QCD has been quite successful in describing hadronic interactions at large transfer momenta, also known as hard interactions. However high energy pp and p p collisions are dominated by soft partonic collisions. Di erent phenomenological models are implemented in several Monte Carlo (MC) event generators such as PYTHIA, PHOJET and HERWIG etc., which attempt to simulate these interactions. These MC event generators have free parameters which need to be tuned to improve the agreement with the data. In this thesis the MC event generator PYTHIA6.424 is considered and the optimization of its model parameters have been presented. This work mainly focuses on tuning of multiple parton interaction parameters to Minimum Bias and Underlying event published data from ATLAS at 0.9 and 7TeV and from CDF II at 1.96 TeV. The method employed to tune the parameters is based on a linear and iterative approach and allows the simultaneous variation of many parameters. Six parameters are tuned, which are found to be...

Molecular evolution of pentatricopeptide repeat genes reveals truncation in species lacking an editing target and structural domains under distinct selective pressures

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Hayes Michael L

2012-05-01

Full Text Available Abstract Background Pentatricopeptide repeat (PPR proteins are required for numerous RNA processing events in plant organelles including C-to-U editing, splicing, stabilization, and cleavage. Fifteen PPR proteins are known to be required for RNA editing at 21 sites in Arabidopsis chloroplasts, and belong to the PLS class of PPR proteins. In this study, we investigate the co-evolution of four PPR genes (CRR4, CRR21, CLB19, and OTP82 and their six editing targets in Brassicaceae species. PPR genes are composed of approximately 10 to 20 tandem repeats and each repeat has two α-helical regions, helix A and helix B, that are separated by short coil regions. Each repeat and structural feature was examined to determine the selective pressures on these regions. Results All of the PPR genes examined are under strong negative selection. Multiple independent losses of editing site targets are observed for both CRR21 and OTP82. In several species lacking the known editing target for CRR21, PPR genes are truncated near the 17th PPR repeat. The coding sequences of the truncated CRR21 genes are maintained under strong negative selection; however, the 3’ UTR sequences beyond the truncation site have substantially diverged. Phylogenetic analyses of four PPR genes show that sequences corresponding to helix A are high compared to helix B sequences. Differential evolutionary selection of helix A versus helix B is observed in both plant and mammalian PPR genes. Conclusion PPR genes and their cognate editing sites are mutually constrained in evolution. Editing sites are frequently lost by replacement of an edited C with a genomic T. After the loss of an editing site, the PPR genes are observed with three outcomes: first, few changes are detected in some cases; second, the PPR gene is present as a pseudogene; and third, the PPR gene is present but truncated in the C-terminal region. The retention of truncated forms of CRR21 that are maintained under strong negative

Molecular evolution of pentatricopeptide repeat genes reveals truncation in species lacking an editing target and structural domains under distinct selective pressures.

Science.gov (United States)

Hayes, Michael L; Giang, Karolyn; Mulligan, R Michael

2012-05-14

Pentatricopeptide repeat (PPR) proteins are required for numerous RNA processing events in plant organelles including C-to-U editing, splicing, stabilization, and cleavage. Fifteen PPR proteins are known to be required for RNA editing at 21 sites in Arabidopsis chloroplasts, and belong to the PLS class of PPR proteins. In this study, we investigate the co-evolution of four PPR genes (CRR4, CRR21, CLB19, and OTP82) and their six editing targets in Brassicaceae species. PPR genes are composed of approximately 10 to 20 tandem repeats and each repeat has two α-helical regions, helix A and helix B, that are separated by short coil regions. Each repeat and structural feature was examined to determine the selective pressures on these regions. All of the PPR genes examined are under strong negative selection. Multiple independent losses of editing site targets are observed for both CRR21 and OTP82. In several species lacking the known editing target for CRR21, PPR genes are truncated near the 17th PPR repeat. The coding sequences of the truncated CRR21 genes are maintained under strong negative selection; however, the 3' UTR sequences beyond the truncation site have substantially diverged. Phylogenetic analyses of four PPR genes show that sequences corresponding to helix A are high compared to helix B sequences. Differential evolutionary selection of helix A versus helix B is observed in both plant and mammalian PPR genes. PPR genes and their cognate editing sites are mutually constrained in evolution. Editing sites are frequently lost by replacement of an edited C with a genomic T. After the loss of an editing site, the PPR genes are observed with three outcomes: first, few changes are detected in some cases; second, the PPR gene is present as a pseudogene; and third, the PPR gene is present but truncated in the C-terminal region. The retention of truncated forms of CRR21 that are maintained under strong negative selection even in the absence of an editing site target

Continuous-Time Portfolio Selection and Option Pricing under Risk-Minimization Criterion in an Incomplete Market

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Xinfeng Ruan

2013-01-01

Full Text Available We study option pricing with risk-minimization criterion in an incomplete market where the dynamics of the risky underlying asset are governed by a jump diffusion equation. We obtain the Radon-Nikodym derivative in the minimal martingale measure and a partial integrodifferential equation (PIDE of European call option. In a special case, we get the exact solution for European call option by Fourier transformation methods. Finally, we employ the pricing kernel to calculate the optimal portfolio selection by martingale methods.

Understanding Molecular Interactions within Chemically Selective Layered Polymer Assemblies

Energy Technology Data Exchange (ETDEWEB)

Gary J. Blanchard

2009-06-30

This work focuses on two broad issues. These are (1) the molecular origin of the chemical selectivity achieved with ultrathin polymer multilayers, and (2) how the viscoelastic properties of the polymer layers are affected by exposure to solvent and analytes. These issues are inter-related, and to understand them we need to design experiments that probe both the energetic and kinetic aspects of interfacial adsorption processes. This project focuses on controling the chemical structure, thickness, morphology and sequential ordering of polymer layers bound to interfaces using maleimide-vinyl ether and closely related alternating copolymerization chemistry and efficient covalent cross-linking reactions that allow for layer-by-layer polymer deposition. This chemistry has been developed during the funding cycle of this Grant. We have measure the equilibrium constants for interactions between specific layers within the polymer interfaces and size-controlled, surface-functionalized gold nanoparticles. The ability to control both size and functionality of gold nanoparticle model analytes allows us to evaluate the average “pore size” that characterizes our polymer films. We have measured the “bulk” viscosity and shear modulus of the ultrathin polymer films as a function of solvent overlayer identity using quartz crystal microbalance complex impedance measurements. We have measured microscopic viscosity at specific locations within the layered polymer interfaces with time-resolved fluorescence lifetime and depolarization techniques. We combine polymer, cross-linking and nanoparticle synthetic expertise with a host of characterization techniques, including QCM gravimetry and complex impedance analysis, steady state and time-resolved spectroscopies.

Fuel-coolant interaction-phenomena under prompt burst conditions

International Nuclear Information System (INIS)

Jacobs, H.; Young, M.F.; Reil, K.O.

1979-01-01

The Prompt Burst Energetics (PBE) experiments conducted at Sandia Laboratories are a series of in-pile tests with fresh uranium oxide or uranium carbide fuel pins in stagnant sodium. Fuel-coolant-interactions in PBE-9S (oxide/sodium system) and PBE-SG2 (carbide/sodium) have been analyzed with the MURTI parametric FCI code. The purpose is to gain insight into possible FCI scenarios in the experiments and sensitivity of results to input parameters. Results are in approximate agreement for the second (triggered) event in PBE-9S (32 MPa peak) and the initial interaction in PBE-SG2

Selective abrogation of the uPA-uPAR interaction in vivo reveals a novel role in suppression of fibrin-associated inflammation

DEFF Research Database (Denmark)

Connolly, Brian M; Choi, Eun Young; Gårdsvoll, Henrik

2010-01-01

the interaction between endogenous uPA and uPAR is selectively abrogated, whereas other functions of both the protease and its receptor are retained. Specifically, we introduced 4 amino acid substitutions into the growth factor domain (GFD) of uPA that abrogate uPAR binding while preserving the overall structure...... a principal in vivo role of the uPA-uPAR interaction in cell-associated fibrinolysis critical for suppression of fibrin accumulation and fibrin-associated inflammation and provides a valuable model for further exploration of this multifunctional receptor....

Alcohol, Tannins, and Mannoprotein and their Interactions Influence the Sensory Properties of Selected Commercial Merlot Wines: A Preliminary Study.

Science.gov (United States)

Diako, Charles; McMahon, Kenneth; Mattinson, Scott; Evans, Marc; Ross, Carolyn

2016-08-01

The objective of this study was to assess the influence of the interaction among alcohol, tannins, and mannoproteins on the aroma, flavor, taste, and mouthfeel characteristics of selected commercial Merlot wines. Merlot wines (n = 61) were characterized for wine chemistry parameters, including pH, titratable acidity, alcohol, glucose, fructose, tannin profile, total proteins, and mannoprotein content. Agglomerative clustering of these physicochemical characteristics revealed 6 groups of wines. Two wines were selected from each group (n = 12) and profiled by a trained sensory evaluation panel. One wine from each group was evaluated using the electronic tongue (e-tongue). Sensory evaluation results showed complex effects among tannins, alcohol, and mannoproteins on the perception of most aromas, flavors, tastes, and mouthfeel attributes (P wines as indicated by a high discrimination index (DI = 95). Strong correlations (r(2) > 0.930) were reported between the e-tongue and sensory perception of sweet, sour, bitter, burning, astringent, and metallic. This study showed that interactions among wine matrix components influence the resulting sensory perceptions. The strong correlation between the e-tongue and trained panel evaluations indicated the e-tongue can complement sensory evaluations to improve wine quality assessment. © 2016 Institute of Food Technologists®

Selective Population of Edge States in a 2D Topological Band System.

Science.gov (United States)

Galilo, Bogdan; Lee, Derek K K; Barnett, Ryan

2015-12-11

We consider a system of interacting spin-one atoms in a hexagonal lattice under the presence of a synthetic gauge field. Quenching the quadratic Zeeman field is shown to lead to a dynamical instability of the edge modes. This, in turn, leads to a spin current along the boundary of the system which grows exponentially fast in time following the quench. Tuning the magnitude of the quench can be used to selectively populate edge modes of different momenta. Implications of the intrinsic symmetries of the Hamiltonian on the dynamics are discussed. The results hold for atoms with both antiferromagnetic and ferromagnetic interactions.

Application of multi-objective optimization based on genetic algorithm for sustainable strategic supplier selection under fuzzy environment

Energy Technology Data Exchange (ETDEWEB)

Hashim, M.; Nazam, M.; Yao, L.; Baig, S.A.; Abrar, M.; Zia-ur-Rehman, M.

2017-07-01

The incorporation of environmental objective into the conventional supplier selection practices is crucial for corporations seeking to promote green supply chain management (GSCM). Challenges and risks associated with green supplier selection have been broadly recognized by procurement and supplier management professionals. This paper aims to solve a Tetra “S” (SSSS) problem based on a fuzzy multi-objective optimization with genetic algorithm in a holistic supply chain environment. In this empirical study, a mathematical model with fuzzy coefficients is considered for sustainable strategic supplier selection (SSSS) problem and a corresponding model is developed to tackle this problem. Design/methodology/approach: Sustainable strategic supplier selection (SSSS) decisions are typically multi-objectives in nature and it is an important part of green production and supply chain management for many firms. The proposed uncertain model is transferred into deterministic model by applying the expected value mesurement (EVM) and genetic algorithm with weighted sum approach for solving the multi-objective problem. This research focus on a multi-objective optimization model for minimizing lean cost, maximizing sustainable service and greener product quality level. Finally, a mathematical case of textile sector is presented to exemplify the effectiveness of the proposed model with a sensitivity analysis. Findings: This study makes a certain contribution by introducing the Tetra ‘S’ concept in both the theoretical and practical research related to multi-objective optimization as well as in the study of sustainable strategic supplier selection (SSSS) under uncertain environment. Our results suggest that decision makers tend to select strategic supplier first then enhance the sustainability. Research limitations/implications: Although the fuzzy expected value model (EVM) with fuzzy coefficients constructed in present research should be helpful for solving real world

Application of multi-objective optimization based on genetic algorithm for sustainable strategic supplier selection under fuzzy environment

Directory of Open Access Journals (Sweden)

Muhammad Hashim

2017-05-01

Full Text Available Purpose:  The incorporation of environmental objective into the conventional supplier selection practices is crucial for corporations seeking to promote green supply chain management (GSCM. Challenges and risks associated with green supplier selection have been broadly recognized by procurement and supplier management professionals. This paper aims to solve a Tetra “S” (SSSS problem based on a fuzzy multi-objective optimization with genetic algorithm in a holistic supply chain environment. In this empirical study, a mathematical model with fuzzy coefficients is considered for sustainable strategic supplier selection (SSSS problem and a corresponding model is developed to tackle this problem. Design/methodology/approach: Sustainable strategic supplier selection (SSSS decisions are typically multi-objectives in nature and it is an important part of green production and supply chain management for many firms. The proposed uncertain model is transferred into deterministic model by applying the expected value mesurement (EVM and genetic algorithm with weighted sum approach for solving the multi-objective problem. This research focus on a multi-objective optimization model for minimizing lean cost, maximizing sustainable service and greener product quality level. Finally, a mathematical case of textile sector is presented to exemplify the effectiveness of the proposed model with a sensitivity analysis. Findings: This study makes a certain contribution by introducing the Tetra ‘S’ concept in both the theoretical and practical research related to multi-objective optimization as well as in the study of sustainable strategic supplier selection (SSSS under uncertain environment. Our results suggest that decision makers tend to select strategic supplier first then enhance the sustainability. Research limitations/implications: Although the fuzzy expected value model (EVM with fuzzy coefficients constructed in present research should be helpful for

Application of multi-objective optimization based on genetic algorithm for sustainable strategic supplier selection under fuzzy environment

International Nuclear Information System (INIS)

Hashim, M.; Nazam, M.; Yao, L.; Baig, S.A.; Abrar, M.; Zia-ur-Rehman, M.

2017-01-01

The incorporation of environmental objective into the conventional supplier selection practices is crucial for corporations seeking to promote green supply chain management (GSCM). Challenges and risks associated with green supplier selection have been broadly recognized by procurement and supplier management professionals. This paper aims to solve a Tetra “S” (SSSS) problem based on a fuzzy multi-objective optimization with genetic algorithm in a holistic supply chain environment. In this empirical study, a mathematical model with fuzzy coefficients is considered for sustainable strategic supplier selection (SSSS) problem and a corresponding model is developed to tackle this problem. Design/methodology/approach: Sustainable strategic supplier selection (SSSS) decisions are typically multi-objectives in nature and it is an important part of green production and supply chain management for many firms. The proposed uncertain model is transferred into deterministic model by applying the expected value mesurement (EVM) and genetic algorithm with weighted sum approach for solving the multi-objective problem. This research focus on a multi-objective optimization model for minimizing lean cost, maximizing sustainable service and greener product quality level. Finally, a mathematical case of textile sector is presented to exemplify the effectiveness of the proposed model with a sensitivity analysis. Findings: This study makes a certain contribution by introducing the Tetra ‘S’ concept in both the theoretical and practical research related to multi-objective optimization as well as in the study of sustainable strategic supplier selection (SSSS) under uncertain environment. Our results suggest that decision makers tend to select strategic supplier first then enhance the sustainability. Research limitations/implications: Although the fuzzy expected value model (EVM) with fuzzy coefficients constructed in present research should be helpful for solving real world

Response to multi-generational selection under elevated [CO2] in two temperature regimes suggests enhanced carbon assimilation and increased reproductive output in Brassica napus L

DEFF Research Database (Denmark)

Frenck, Georg; van der Linden, Leon; Mikkelsen, Teis Nørgaard

2013-01-01

different temperature regimes. To reveal phenotypic divergence at the manipulated [CO2] and temperature conditions, a full-factorial natural selection regime was established in a phytotron environment over the range of four generations. It is demonstrated that a directional response to selection at elevated......Functional plant traits are likely to adapt under the sustained pressure imposed by environmental changes through natural selection. Employing Brassica napus as a model, a multi-generational study was performed to investigate the potential trajectories of selection at elevated [CO2] in two...... subjected to increased levels of CO2 over the generational range investigated. The results of this study suggest that phenotypic divergence of plants selected under elevated atmospheric CO2 concentration may drive the future functions of plant productivity to be different from projections that do...

Accounting for animal movement in estimation of resource selection functions: sampling and data analysis.

Science.gov (United States)

Forester, James D; Im, Hae Kyung; Rathouz, Paul J

2009-12-01

Patterns of resource selection by animal populations emerge as a result of the behavior of many individuals. Statistical models that describe these population-level patterns of habitat use can miss important interactions between individual animals and characteristics of their local environment; however, identifying these interactions is difficult. One approach to this problem is to incorporate models of individual movement into resource selection models. To do this, we propose a model for step selection functions (SSF) that is composed of a resource-independent movement kernel and a resource selection function (RSF). We show that standard case-control logistic regression may be used to fit the SSF; however, the sampling scheme used to generate control points (i.e., the definition of availability) must be accommodated. We used three sampling schemes to analyze simulated movement data and found that ignoring sampling and the resource-independent movement kernel yielded biased estimates of selection. The level of bias depended on the method used to generate control locations, the strength of selection, and the spatial scale of the resource map. Using empirical or parametric methods to sample control locations produced biased estimates under stronger selection; however, we show that the addition of a distance function to the analysis substantially reduced that bias. Assuming a uniform availability within a fixed buffer yielded strongly biased selection estimates that could be corrected by including the distance function but remained inefficient relative to the empirical and parametric sampling methods. As a case study, we used location data collected from elk in Yellowstone National Park, USA, to show that selection and bias may be temporally variable. Because under constant selection the amount of bias depends on the scale at which a resource is distributed in the landscape, we suggest that distance always be included as a covariate in SSF analyses. This approach to

The Genetics Underlying Natural Variation in the Biotic Interactions of Arabidopsis thaliana: The Challenges of Linking Evolutionary Genetics and Community Ecology.

Science.gov (United States)

Roux, F; Bergelson, J

2016-01-01

In the context of global change, predicting the responses of plant communities in an ever-changing biotic environment calls for a multipronged approach at the interface of evolutionary genetics and community ecology. However, our understanding of the genetic basis of natural variation involved in mediating biotic interactions, and associated adaptive dynamics of focal plants in their natural communities, is still in its infancy. Here, we review the genetic and molecular bases of natural variation in the response to biotic interactions (viruses, bacteria, fungi, oomycetes, herbivores, and plants) in the model plant Arabidopsis thaliana as well as the adaptive value of these bases. Among the 60 identified genes are a number that encode nucleotide-binding site leucine-rich repeat (NBS-LRR)-type proteins, consistent with early examples of plant defense genes. However, recent studies have revealed an extensive diversity in the molecular mechanisms of defense. Many types of genetic variants associate with phenotypic variation in biotic interactions, even among the genes of large effect that tend to be identified. In general, we found that (i) balancing selection rather than directional selection explains the observed patterns of genetic diversity within A. thaliana and (ii) the cost/benefit tradeoffs of adaptive alleles can be strongly dependent on both genomic and environmental contexts. Finally, because A. thaliana rarely interacts with only one biotic partner in nature, we highlight the benefit of exploring diffuse biotic interactions rather than tightly associated host-enemy pairs. This challenge would help to improve our understanding of coevolutionary quantitative genetics within the context of realistic community complexity. © 2016 Elsevier Inc. All rights reserved.

Women's Education and Health Inequalities in Under-Five Mortality in Selected Sub-Saharan African Countries, 1990–2015

Science.gov (United States)

Bado, Aristide Romaric; Sathiya Susuman, A.

2016-01-01

Background The aim of the study was to analyse trends in the relationship between mother’s educational level and mortality of children under the year of five in Sub-Saharan Africa, from 1990 to 2015. Data and Methods Data used in this study came from different waves of Demographic and Health Surveys (DHS) of Sub-Saharan countries. Logistic regression and Buis’s decomposition method were used to explore the effect of mother’s educational level on the mortality of children under five years. Results Although the results of our study in the selected countries show that under-five mortality rates of children born to mothers without formal education are higher than the mortality rates of children of educated mothers, it appears that differences in mortality were reduced over the past two decades. In selected countries for our study, we noticed a significant decline in mortality among children of non-educated mothers compared to the decrease in mortality rates among children of educated mothers during the period of 1990–2010. The results show that the decline in mortality of children under five years was much higher among the children born to mothers who have never received formal education—112 points drop in Malawi, over 80 in Zambia and Zimbabwe, 65 points in Burkina Faso, 56 in Congo, 43 in Namibia, 27 in Guinea, Cameroon, and 22 to 15 in Niger. However, we noted a variation in results among the countries selected for the study—in Burkina Faso (OR = 0.7), in Cameroon (OR = 0.8), in Guinea (OR = 0.8) and Niger (OR = 0.8). It is normally observed that children of mothers with 0–6 years of education are about 20% more likely to survive until their fifth year compared to children of mothers who have not been to school. Conversely, the results did not reveal significant differences between the under-five deaths of children born to non-educated mothers and children of low-level educated mothers in Congo, Malawi and Namibia. Conclusion The decline in under

Modeling of creep-fatigue interaction of zirconium α under cyclic loading at 200 C

International Nuclear Information System (INIS)

Vogel, C.

1996-04-01

The present work deals with mechanical behaviour of zirconium alpha at 200 deg. C and crack initiation prediction methods, particularly when loading conditions lead to interaction of fatigue and creep phenomena. A classical approach used to study interaction between cyclic effects and constant loading effects does not give easy understanding of experimental results. Therefore, a new approach has been developed, which allow to determine a number of cycles for crack initiation for complex structures under large loading conditions. To study influence of fatigue and creep interaction on crack initiation, a model was chosen, using a scalar variable, giving representation of the material deterioration state. The model uses a non linear cumulating effect between the damage corresponding to cyclic loads and the damage correlated to time influence. The model belongs to uncoupled approaches between damage and behaviour, which is described here by a two inelastic deformations model. This mechanical behaviour model is chosen because it allows distinction between a plastic and a viscous part in inelastic flow. Cyclic damage is function of stress amplitude and mean stress. For the peculiar sensitivity of the material to creep, a special parameter bas been defined to be critical toward creep damage. It is the kinematic term associated to state variables describing this type of hardening in the viscous mechanism. (author)

A new perspective on the perceptual selectivity of attention under load

DEFF Research Database (Denmark)

Giesbrecht, Barry; Sy, Jocelyn; Bundesen, Claus

2014-01-01

The human attention system helps us cope with a complex environment by supporting the selective processing of information relevant to our current goals. Understanding the perceptual, cognitive, and neural mechanisms that mediate selective attention is a core issue in cognitive neuroscience. One...... prominent model of selective attention, known as load theory, offers an account of how task demands determine when information is selected and an account of the efficiency of the selection process. However, load theory has several critical weaknesses that suggest that it is time for a new perspective. Here...... is integrated to provide efficient attentional selection and allocation of perceptual processing resources....

Right-handed neutrino dark matter under the B−L gauge interaction

Energy Technology Data Exchange (ETDEWEB)

Kaneta, Kunio [Center for Theoretical Physics of the Universe, Institute for Basic Science,Daejeon 34051 (Korea, Republic of); Kang, Zhaofeng [School of Physics, Korea Institute for Advanced Study,Seoul 02455 (Korea, Republic of); Lee, Hye-Sung [Center for Theoretical Physics of the Universe, Institute for Basic Science,Daejeon 34051 (Korea, Republic of)

2017-02-07

We study the right-handed neutrino (RHN) dark matter candidate in the minimal U(1){sub B−L} gauge extension of the standard model. The U(1){sub B−L} gauge symmetry offers three RHNs which can address the origin of the neutrino mass, the relic dark matter, and the matter-antimatter asymmetry of the universe. The lightest among the three is taken as the dark matter candidate, which is under the B−L gauge interaction. We investigate various scenarios for this dark matter candidate with the correct relic density by means of the freeze-out or freeze-in mechanism. A viable RHN dark matter mass lies in a wide range including keV to TeV scale. We emphasize the sub-electroweak scale light B−L gauge boson case, and identify the parameter region motivated from the dark matter physics, which can be tested with the planned experiments including the CERN SHiP experiment.

Interactive benchmarking

DEFF Research Database (Denmark)

Lawson, Lartey; Nielsen, Kurt

2005-01-01

We discuss individual learning by interactive benchmarking using stochastic frontier models. The interactions allow the user to tailor the performance evaluation to preferences and explore alternative improvement strategies by selecting and searching the different frontiers using directional...... in the suggested benchmarking tool. The study investigates how different characteristics on dairy farms influences the technical efficiency....

Plasma-material interaction under simulated disruption conditions

International Nuclear Information System (INIS)

Arkhipov, N.I.; Bakhtin, V.P.; Safronov, V.M.; Toporkov, D.A.; Vasenin, S.G.; Wurz, H.; Zhitlukhin, A.M.

1995-01-01

Sudden evaporation of divertor plate surface under high heat load during tokamak plasma disruption instantaneously produces a vapor shield. The cloud of vaporized material prevents the divertor plates from the bulk of incoming energy flux and thus reduces the further material erosion. Dynamics and effectiveness of the vapor shield are studied experimentally at the 2MK-200 facility under simulated disruption conditions. (orig.)

Effects of trawl selectivity and genetic parameters on fish body length under long-term trawling

Science.gov (United States)

Yu, Yang; Sun, Peng; Cui, He; Sheng, Huaxiang; Zhao, Fenfang; Tang, Yanli; Chen, Zelin

2015-10-01

Long-term fishing pressure affects the biological characteristics of exploited fish stocks. The biological characteristics of hairtail ( Trichiurus lepturus) in the East China Sea are unable to recover because of long-term trawling. Fishing induces evolutionary effects on the fish's biological characteristics. Evidence of these changes includes small size at age, a shift to earlier age structure, and early maturation. Natural and artificial selection usually affect the fish's life history. Selection can induce different chances of reproduction, and individual fish can give a different genetic contribution to the next generation. In this study, analysis of time-dependent probability of significance and test of sensitivity were used to explore the effects of fish exploitation rate, mesh size, and heritability with long-term trawling. Results showed that fishing parameters were important drivers to exploited fish population. However, genetic traits altered by fishing were slow, and the changes in biological characteristics were weaker than those caused by fishing selection. Exploitation rate and mesh size exhibited similar evolutionary trend tendency under long-term fishing. The time-dependent probability of significance trend showed a gradual growth and tended to be stable. Therefore, the direction of fishing-induced evolution and successful management of fish species require considerable attention to contribute to sustainable fisheries in China.

An interactive roof bolting selection and performance system

Energy Technology Data Exchange (ETDEWEB)

Agioutantis, Z.; Stiakakis, C.; Stiakakis, N. [Technical Univ. of Crete, Chania (Greece); Karmis, M. [Virginia Polytechnic Inst. and State Univ. (United States)

2001-07-01

In the last decades, bolting has become one of the most dominant support methods in underground construction, including both mining as well as civil engineering applications. A variety of bolt types has been developed in order to meet the support needs of different geological and geotechnical settings. The selection of the appropriate bolt type, as well as the troubleshooting procedures in case of failure or suspected failure, are often complex and require extensive experience. To facilitate bolt type selection as well as troubleshooting, various tools have been presented in the form of nomograms, computer programs or trouble shooting guides. The approach described in this paper incorporates information and data developed by laboratory and field investigations and has led to the development of a dynamic knowledge base system that can aid in the selection of appropriate bolting systems and, also, help troubleshoot existing installations. Additionally, the user can enhance the functionality of the existing database with site-specific information and geological behavior as experienced by field personnel. The package is developed as a Windows trademark based application, where data is stored in Microsoft Access trademark database. (orig.)

Short-term selective alleviation of glucotoxicity and lipotoxicity ameliorates the suppressed expression of key β-cell factors under diabetic conditions

Energy Technology Data Exchange (ETDEWEB)

Shimo, Naoki [Department of Metabolic Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871 (Japan); Matsuoka, Taka-aki, E-mail: matsuoka@endmet.med.osaka-u.ac.jp [Department of Metabolic Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871 (Japan); Miyatsuka, Takeshi [Department of Metabolic Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871 (Japan); Department of Metabolism and Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunky-ku, Tokyo, 113-8421 (Japan); Takebe, Satomi; Tochino, Yoshihiro; Takahara, Mitsuyoshi [Department of Metabolic Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871 (Japan); Kaneto, Hideaki [Division of Diabetes, Endocrinology and Metabolism, Kawasaki Medical School, 577 Matsushima, Kurashiki-city, Okayama, 701-0192 (Japan); Shimomura, Iichiro [Department of Metabolic Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871 (Japan)

2015-11-27

Alleviation of hyperglycaemia and hyperlipidemia improves pancreatic β-cell function in type 2 diabetes. However, the underlying molecular mechanisms are still not well clarified. In this study, we aimed to elucidate how the expression alterations of key β-cell factors are altered by the short-term selective alleviation of glucotoxicity or lipotoxicity. We treated db/db mice for one week with empagliflozin and/or bezafibrate to alleviate glucotoxicity and/or liptotoxicity, respectively. The gene expression levels of Pdx1 and Mafa, and their potential targets, insulin 1, Slc2a2, and Glp1r, were higher in the islets of empagliflozin-treated mice, and levels of insulin 2 were higher in mice treated with both reagents, than in untreated mice. Moreover, compared to the pretreatment levels, Mafa and insulin 1 expression increased in empagliflozin-treated mice, and Slc2a2 increased in combination-treated mice. In addition, empagliflozin treatment enhanced β-cell proliferation assessed by Ki-67 immunostaining. Our date clearly demonstrated that the one-week selective alleviation of glucotoxicity led to the better expression levels of the key β-cell factors critical for β-cell function over pretreatment levels, and that the alleviation of lipotoxicity along with glucotoxicity augmented the favorable effects under diabetic conditions. - Highlights: • One-week selective reduction of gluco- and lipo-toxicity in db/db mice was performed. • Selective glucotoxicity reduction increases key pancreatic β-cell factors expression. • Selective glucotoxicity reduction improves β-cell factors over pretreatment levels. • Selective glucotoxicity reduction turns β-cell mass toward increase. • Lipotoxicity reduction has additive effects on glucotoxicity reduction.

Interaction rules underlying group decisions in homing pigeons

Science.gov (United States)

Pettit, Benjamin; Perna, Andrea; Biro, Dora; Sumpter, David J. T.

2013-01-01

Travelling in groups gives animals opportunities to share route information by following cues from each other's movement. The outcome of group navigation will depend on how individuals respond to each other within a flock, school, swarm or herd. Despite the abundance of modelling studies, only recently have researchers developed techniques to determine the interaction rules among real animals. Here, we use high-resolution GPS (global positioning system) tracking to study these interactions in pairs of pigeons flying home from a familiar site. Momentary changes in velocity indicate alignment with the neighbour's direction, as well as attraction or avoidance depending on distance. Responses were stronger when the neighbour was in front. From the flocking behaviour, we develop a model to predict features of group navigation. Specifically, we show that the interactions between pigeons stabilize a side-by-side configuration, promoting bidirectional information transfer and reducing the risk of separation. However, if one bird gets in front it will lead directional choices. Our model further predicts, and observations confirm, that a faster bird (as measured from solo flights) will fly slightly in front and thus dominate the choice of homing route. Our results explain how group decisions emerge from individual differences in homing flight behaviour. PMID:24068173

An α-Helix-Mimicking 12,13-Helix: Designed α/β/γ-Foldamers as Selective Inhibitors of Protein-Protein Interactions.

Science.gov (United States)

Grison, Claire M; Miles, Jennifer A; Robin, Sylvie; Wilson, Andrew J; Aitken, David J

2016-09-05

A major current challenge in bioorganic chemistry is the identification of effective mimics of protein secondary structures that act as inhibitors of protein-protein interactions (PPIs). In this work, trans-2-aminocyclobutanecarboxylic acid (tACBC) was used as the key β-amino acid component in the design of α/β/γ-peptides to structurally mimic a native α-helix. Suitably functionalized α/β/γ-peptides assume an α-helix-mimicking 12,13-helix conformation in solution, exhibit enhanced proteolytic stability in comparison to the wild-type α-peptide parent sequence from which they are derived, and act as selective inhibitors of the p53/hDM2 interaction. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Improvement of localised corrosion resistance of AISI 2205 Duplex Stainless Steel joints made by gas metal arc welding under electromagnetic interaction of low intensity

Energy Technology Data Exchange (ETDEWEB)

García-Rentería, M.A., E-mail: crazyfim@gmail.com [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); López-Morelos, V.H., E-mail: vhlopez@umich.mx [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); García-Hernández, R., E-mail: rgarcia@umich.mx [Instituto de Investigación en Metalurgia y Materiales, Universidad Michoacana de San Nicolás de Hidalgo, A.P. 888, CP 58000, Morelia, Michoacán (Mexico); Dzib-Pérez, L., E-mail: luirdzib@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico); García-Ochoa, E.M., E-mail: emgarcia@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico); González-Sánchez, J., E-mail: jagonzal@uacam.mx [Centre for Corrosion Research, Autonomous University of Campeche, Av. Agustín Melgar s/n, Col. Buenavista, CP 24039, Campeche, Cam (Mexico)

2014-12-01

Highlights: • Electromagnetic interaction in welding improved localised corrosion resistance. • Electromagnetic interaction in welding enhanced γ/δ phase balance of DuplexSS. • Welding under Electromagnetic interaction repress formation and growth of detrimental phases. • Welds made with gas protection (2% O{sub 2} + 98% Ar) have better microstructural evolution during welding. - Abstract: The resistance to localised corrosion of AISI 2205 duplex stainless steel plates joined by Gas Metal Arc Welding (GMAW) under the effect of electromagnetic interaction of low intensity (EMILI) was evaluated with sensitive electrochemical methods. Welds were made using two shielding gas mixtures: 98% Ar + 2% O{sub 2} (M1) and 97% Ar + 3% N{sub 2} (M2). Plates were welded under EMILI using the M1 gas with constant welding parameters. The modified microstructural evolution in the high temperature heat affected zone and at the fusion zone induced by application of EMILI during welding is associated with the increase of resistance to localised corrosion of the welded joints. Joints made by GMAW using the shielding gas M2 without the application of magnetic field presented high resistance to general corrosion but high susceptibility to undergo localised attack.

Determinants of Environmental Degradation under the Perspective of Globalization: A Panel Analysis of Selected MENA Nations

OpenAIRE

Audi, Marc; Ali, Amjad

2018-01-01

This paper has examined the determinants of environmental degradation under the perspective of globalization in the case of selected MENA nations (Jordan, United Arab Emirates, Saudi Arabia, Algeria, Qatar, Lebanon, Egypt, Bahrain, Iran, Morocco, Israel, Kuwait, Oman and Tunisia) over the period of 1980 to 2013. ADF - Fisher Chi-square, Im, Pesaran and Shin W-stat, Levin, Lin & Chu t*, and PP-Fisher Chi-square unit root tests are used for analyzing the stationarity of the variables. This stud...

Non-sensitized selective photochemical reduction of CO2 to CO under visible light with an iron molecular catalyst.

Science.gov (United States)

Rao, Heng; Bonin, Julien; Robert, Marc

2017-03-02

A substituted tetraphenyl iron porphyrin, bearing positively charged trimethylammonio groups at the para position of each phenyl ring, demonstrates its ability as a homogeneous molecular catalyst to selectively reduce CO 2 to CO under visible light irradiation in organic media without the assistance of a sensitizer and no competitive hydrogen evolution for several days.

Application of numerical modeling of selective NOx reduction by hydrocarbon under diesel transient conditions in consideration of hydrocarbon adsorption and desorption process

International Nuclear Information System (INIS)

Watanabe, Y.; Asano, A.; Banno, K.; Yokota, K.; Sugiura, M.

2001-01-01

A model of NO x selective reduction by hydrocarbon (HC) was developed, which takes into account the adsorption and desorption of HC. The model was applied for predicting the performance of a De-NO x catalytic reactor, working under transient conditions such as a legislative driving cycle. Diesel fuel was used as a supplemental reductant. The behavior of HC and NO x reactions and HC adsorption and desorption has been simulated successfully by our numerical approach under the transient conditions of the simulated Japanese 10-15 driving cycle. Our model is expected to optimize the design of selective diesel NO x reduction systems using a diesel fuel as a supplemental reductant

Elaborate cellulosome architecture of Acetivibrio cellulolyticus revealed by selective screening of cohesin–dockerin interactions

Directory of Open Access Journals (Sweden)

Yuval Hamberg

2014-10-01

Full Text Available Cellulosic waste represents a significant and underutilized carbon source for the biofuel industry. Owing to the recalcitrance of crystalline cellulose to enzymatic degradation, it is necessary to design economical methods of liberating the fermentable sugars required for bioethanol production. One route towards unlocking the potential of cellulosic waste lies in a highly complex class of molecular machines, the cellulosomes. Secreted mainly by anaerobic bacteria, cellulosomes are structurally diverse, cell surface-bound protein assemblies that can contain dozens of catalytic components. The key feature of the cellulosome is its modularity, facilitated by the ultra-high affinity cohesin–dockerin interaction. Due to the enormous number of cohesin and dockerin modules found in a typical cellulolytic organism, a major bottleneck in understanding the biology of cellulosomics is the purification of each cohesin- and dockerin-containing component, prior to analyses of their interaction. As opposed to previous approaches, the present study utilized proteins contained in unpurified whole-cell extracts. This strategy was made possible due to an experimental design that allowed for the relevant proteins to be “purified” via targeted affinity interactions as a function of the binding assay. The approach thus represents a new strategy, appropriate for future medium- to high-throughput screening of whole genomes, to determine the interactions between cohesins and dockerins. We have selected the cellulosome of Acetivibrio cellulolyticus for this work due to its exceptionally complex cellulosome systems and intriguing diversity of its cellulosomal modular components. Containing 41 cohesins and 143 dockerins, A. cellulolyticus has one of the largest number of potential cohesin–dockerin interactions of any organism, and contains unusual and novel cellulosomal features. We have surveyed a representative library of cohesin and dockerin modules spanning the

Multi-core MgO NPs(at)C core-shell nanospheres for selective CO2 capture under mild conditions

International Nuclear Information System (INIS)

Tae Kyung Kim; Kyung Joo Lee; Hoi Ri Moon; Junhan Yuh; Sang Kyu Kwak

2014-01-01

The core-shell structures have attracted attention in catalysis, because the outer shells isolate the catalytically active NP cores and prevent the possibility of sintering of core particles during catalytic reaction under physically and chemically harsh conditions. We aimed to adopt this core-shell system for CO 2 sorption materials. In this study, a composite material of multi-core 3 nm-sized magnesium oxide nanoparticles embedded in porous carbon nanospheres (MgO NPs(at)C) was synthesized by a gas phase reaction via a solvent-free process. It showed selective CO 2 adsorption capacity over N 2 under mild regeneration conditions. (authors)

Spatially balanced topological interaction grants optimal cohesion in flocking models.

Science.gov (United States)

Camperi, Marcelo; Cavagna, Andrea; Giardina, Irene; Parisi, Giorgio; Silvestri, Edmondo

2012-12-06

Models of self-propelled particles (SPPs) are an indispensable tool to investigate collective animal behaviour. Originally, SPP models were proposed with metric interactions, where each individual coordinates with neighbours within a fixed metric radius. However, recent experiments on bird flocks indicate that interactions are topological: each individual interacts with a fixed number of neighbours, irrespective of their distance. It has been argued that topological interactions are more robust than metric ones against external perturbations, a significant evolutionary advantage for systems under constant predatory pressure. Here, we test this hypothesis by comparing the stability of metric versus topological SPP models in three dimensions. We show that topological models are more stable than metric ones. We also show that a significantly better stability is achieved when neighbours are selected according to a spatially balanced topological rule, namely when interacting neighbours are evenly distributed in angle around the focal individual. Finally, we find that the minimal number of interacting neighbours needed to achieve fully stable cohesion in a spatially balanced model is compatible with the value observed in field experiments on starling flocks.

Mating System Evolution under Strong Pollen Limitation: Evidence of Disruptive Selection through Male and Female Fitness in Clarkia xantiana.

Science.gov (United States)

Briscoe Runquist, Ryan D; Geber, Monica A; Pickett-Leonard, Michael; Moeller, David A

2017-05-01

Selection on floral traits in hermaphroditic plants is determined by both male and female reproductive success. However, predictions regarding floral trait and mating system evolution are often based solely on female fitness. Selection via male fitness has the potential to affect the outcomes of floral evolution. In this study, we used paternity analysis to assess individual selfing rates and selection on floral traits via male and female fitness in an experimental population of Clarkia xantiana where pollen limitation of seed set was strong. We detected selection through both female and male fitness with reinforcing or noninterfering patterns of selection through the two sex functions. For female fitness, selection favored reduced herkogamy and protandry, traits that promote increased autonomous selfing. For male fitness, selection on petal area was disruptive, with higher trait values conferring greater pollinator attraction and outcross siring success and smaller trait values leading to higher selfed siring success. Combining both female and male fitness, selection on petal area and protandry was disruptive because intermediate phenotypes were less successful as both males and females. Finally, functional relationships among male and female fertility components indicated that selfing resulted in seed discounting and pollen discounting. Under these functional relationships, the evolutionarily stable selfing rate can be intermediate or predominantly selfing or outcrossing, depending on the segregating load of deleterious mutations.

Ultrafast dynamics of ligand and substrate interaction in endothelial nitric oxide synthase under Soret excitation.

Science.gov (United States)

Hung, Chih-Chang; Yabushita, Atsushi; Kobayashi, Takayoshi; Chen, Pei-Feng; Liang, Keng S

2016-01-01

Ultrafast transient absorption spectroscopy of endothelial NOS oxygenase domain (eNOS-oxy) was performed to study dynamics of ligand or substrate interaction under Soret band excitation. Photo-excitation dissociates imidazole ligand in 4ps. The eNOS-oxy without additive is partially bound with water molecule, thus its photoexcited dynamics also shows ligand dissociation in <800fs. Then it followed by vibrational cooling coupled with charge transfer in 4.8ps, and recombination of ligand to distal side of heme in 12ps. Copyright © 2016 Elsevier B.V. All rights reserved.

The effect of pre-plasma formation under nonlocal transport conditions for ultra-relativistic laser-plasma interaction

Science.gov (United States)

Holec, M.; Nikl, J.; Vranic, M.; Weber, S.

2018-04-01

Interaction of high-power lasers with solid targets is in general strongly affected by the limited contrast available. The laser pre-pulse ionizes the target and produces a pre-plasma which can strongly modify the interaction of the main part of the laser pulse with the target. This is of particular importance for future experiments which will use laser intensities above 1021 W cm-2 and which are subject to the limited contrast. As a consequence the main part of the laser pulse will be modified while traversing the pre-plasma, interacting with it partially. A further complication arises from the fact that the interaction of a high-power pre-pulse with solid targets very often takes place under nonlocal transport conditions, i.e. the characteristic mean-free-path of the particles and photons is larger than the characteristic scale-lengths of density and temperature. The classical diffusion treatment of radiation and heat transport in the hydrodynamic model is then insufficient for the description of the pre-pulse physics. These phenomena also strongly modify the formation of the pre-plasma which in turn affects the propagation of the main laser pulse. In this paper nonlocal radiation-hydrodynamic simulations are carried out and serve as input for subsequent kinetic simulations of ultra-high intensity laser pulses interacting with the plasma in the ultra-relativistic regime. It is shown that the results of the kinetic simulations differ considerably whether a diffusive or nonlocal transport is used for the radiation-hydrodynamic simulations.

Kin Selection - Mutation Balance

DEFF Research Database (Denmark)

Dyken, J. David Van; Linksvayer, Timothy Arnold; Wade, Michael J.

2011-01-01

selection-mutation balance, which provides an evolutionary null hypothesis for the statics and dynamics of cheating. When social interactions have linear fitness effects and Hamilton´s rule is satisfied, selection is never strong enough to eliminate recurrent cheater mutants from a population, but cheater...

Selection of relatively exact reference genes for gene expression studies in goosegrass (Eleusine indica) under herbicide stress.

Science.gov (United States)

Chen, Jingchao; Huang, Zhaofeng; Huang, Hongjuan; Wei, Shouhui; Liu, Yan; Jiang, Cuilan; Zhang, Jie; Zhang, Chaoxian

2017-04-21

Goosegrass (Eleusine indica) is one of the most serious annual grassy weeds worldwide, and its evolved herbicide-resistant populations are more difficult to control. Quantitative real-time PCR (qPCR) is a common technique for investigating the resistance mechanism; however, there is as yet no report on the systematic selection of stable reference genes for goosegrass. This study proposed to test the expression stability of 9 candidate reference genes in goosegrass in different tissues and developmental stages and under stress from three types of herbicide. The results show that for different developmental stages and organs (control), eukaryotic initiation factor 4 A (eIF-4) is the most stable reference gene. Chloroplast acetolactate synthase (ALS) is the most stable reference gene under glyphosate stress. Under glufosinate stress, eIF-4 is the best reference gene. Ubiquitin-conjugating enzyme (UCE) is the most stable reference gene under quizalofop-p-ethyl stress. The gene eIF-4 is the recommended reference gene for goosegrass under the stress of all three herbicides. Moreover, pairwise analysis showed that seven reference genes were sufficient to normalize the gene expression data under three herbicides treatment. This study provides a list of reliable reference genes for transcript normalization in goosegrass, which will facilitate resistance mechanism studies in this weed species.

Incorporation of Eu(III) into calcite under recrystallization conditions

International Nuclear Information System (INIS)

Hellebrandt, S.E.; Jordan, Norbert; Barkleit, Astrid; Schmidt, Moritz; Hofmann, S.

2017-01-01

The interaction of three calcite powders with Eu(III) under recrystallization conditions was studied on the molecular level using site-selective time-resolved laser fluorescence spectroscopy (TRLFS). Batch contact studies with reaction times from 1 week up to 3 years revealed that the speciation differs from that observed previously in co-precipitation experiments and is dominated by a newly identified species ''γ''. The speed of formation of this species was found to depend greatly on the recrystallization rate of the studied minerals.

Incorporation of Eu(III) into calcite under recrystallization conditions

Energy Technology Data Exchange (ETDEWEB)

Hellebrandt, S.E. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology; Jordan, Norbert [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes; Barkleit, Astrid [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Chemistry of the F-Elements; Schmidt, Moritz [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). HGF Young Investigator Group; Hofmann, S.

2017-06-01

The interaction of three calcite powders with Eu(III) under recrystallization conditions was studied on the molecular level using site-selective time-resolved laser fluorescence spectroscopy (TRLFS). Batch contact studies with reaction times from 1 week up to 3 years revealed that the speciation differs from that observed previously in co-precipitation experiments and is dominated by a newly identified species ''γ''. The speed of formation of this species was found to depend greatly on the recrystallization rate of the studied minerals.

Selected recent results from AMANDA

CERN Document Server

Andrés, E; Bai, X; Barouch, G; Barwick, S W; Bay, R C; Becker, K H; Bergström, L; Bertrand, D; Bierenbaum, D; Biron, A; Booth, J; Botner, O; Bouchta, A; Boyce, M M; Carius, S; Chen, A; Chirkin, D; Conrad, J; Cooley, J; Costa, C G S; Cowen, D F; Dailing, J; Dalberg, E; De Young, T R; Desiati, P; Dewulf, J P; Doksus, P; Edsjö, J; Ekstrom, P; Erlandsson, B; Feser, T; Gaug, M; Goldschmidt, A; Goobar, A; Gray, L; Haase, H; Hallgren, A; Halzen, F; Hanson, K; Hardtke, R; He, Y D; Hellwig, M; Heukenkamp, H; Hill, G C; Hulth, P O; Hundertmark, S; Jacobsen, J; Kandhadai, V; Karle, A; Kim, J; Koci, B; Köpke, L; Kowalski, M; Leich, H; Leuthold, M; Lindahl, P; Liubarsky, I; Loaiza, P; Lowder, D M; Ludvig, J; Madsen, J; Marciniewski, P; Matis, H S; Mihályi, A; Mikolajski, T; Miller, T C; Minaeva, Y; Miocinovic, P; Mock, P C; Morse, R; Neunhoffer, T; Newcomer, F M; Niessen, P; Nygren, D R; Ogelman, H; Heros, C P D L; Porrata, R; Price, P B; Rawlins, K; Reed, C; Rhode, W; Richards, A; Richter, S; Martino, J R; Romenesko, P; Ross, D; Rubinstein, H; Sander, H G; Scheider, T; Schmidt, T; Schneider, D; Schneider, E; Schwarzl, R; Silvestri, A; Solarz, M; Spiczak, G M; Spiering, C; Starinsky, N; Steele, D; Steffen, P; Stokstad, R G; Streicher, O; Sun, A; Taboada, I; Thollander, L; Thon, T; Tilav, S; Usechak, N; Donckt, M V; Walck, C; Weinheimer, C; Wiebusch, C; Wischnewski, R; Wissing, H; Woschnagg, K; Wu, W; Yodh, G; Young, S

2001-01-01

We present a selection of results based on data taken in 1997 with the 302-PMT Antarctic Muon and Neutrino Detector Array-B10 ("AMANDA-B10") array. Atmospheric neutrinos created in the northern hemisphere are observed indirectly through their charged current interactions which produce relativistic, Cherenkov-light-emitting upgoing muons in the South Pole ice cap. The reconstructed angular distribution of these events is in good agreement with expectation and demonstrates the viability of this ice-based device as a neutrino telescope. Studies of nearly vertical upgoing muons limit the available parameter space for WIMP dark matter under the assumption that WIMPS are trapped in the earth's gravitational potential well and annihilate with one another near the earth's center.

Association of time under immunosuppression and different immunosuppressive medication on periodontal parameters and selected bacteria of patients after solid organ transplantation.

Science.gov (United States)

Schmalz, G; Berisha, L; Wendorff, H; Widmer, F; Marcinkowski, A; Teschler, H; Sommerwerck, U; Haak, R; Kollmar, O; Ziebolz, D

2018-05-01

Aim of this study was to investigate the association of the time under immunosuppression and different immunosuppressive medication on periodontal parameters and selected periodontal pathogenic bacteria of immunosuppressed patients after solid organ transplantation (SOT). 169 Patients after SOT (lung, liver or kidney) were included and divided into subgroups according their time under (0-1, 1-3, 3-6, 6-10 and >10 years) and form of immunosuppression (Tacrolimus, Cyclosporine, Mycophenolate, Glucocorticoids, Sirolimus and monotherapy vs. combination). Periodontal probing depth (PPD) and clinical attachment loss (CAL) were assessed. Periodontal disease severity was classified as healthy/mild, moderate or severe periodontitis. Subgingival biofilm samples were investigated for eleven selected potentially periodontal pathogenic bacteria using polymerasechainreaction. The mean PPD and CAL as well as prevalence of Treponema denticola and Capnocytophaga species was shown to be different but heterogeneous depending on time under immunosuppression (pperiodontal condition compared to patients without Cyclosporine (pperiodontal and microbiological parameters of patients after SOT. Patients under Cyclosporine medication should receive increased attention. Differences in subgingival biofilm, but not in clinical parameters were found for Glucocorticoids, Mycophenolate and combination therapy, making the clinical relevance of this finding unclear.

IGLANCE: interactive free viewpoint for 3D TV

NARCIS (Netherlands)

Zinger, S.; Do, Q.L.; Ruijters, D.; With, de P.H.N.

2010-01-01

The iGLANCE project aims at making interactive free viewpoint selection possible in 3D TV broadcasted media. This means that the viewer can select and interactively change the viewpoint of a stereoscopic streamed video. The interactivity is enabled by broad-casting a number of video streams from

A new perspective on the perceptual selectivity of attention under load.

Science.gov (United States)

Giesbrecht, Barry; Sy, Jocelyn; Bundesen, Claus; Kyllingsbaek, Søren

2014-05-01

The human attention system helps us cope with a complex environment by supporting the selective processing of information relevant to our current goals. Understanding the perceptual, cognitive, and neural mechanisms that mediate selective attention is a core issue in cognitive neuroscience. One prominent model of selective attention, known as load theory, offers an account of how task demands determine when information is selected and an account of the efficiency of the selection process. However, load theory has several critical weaknesses that suggest that it is time for a new perspective. Here we review the strengths and weaknesses of load theory and offer an alternative biologically plausible computational account that is based on the neural theory of visual attention. We argue that this new perspective provides a detailed computational account of how bottom-up and top-down information is integrated to provide efficient attentional selection and allocation of perceptual processing resources. © 2014 New York Academy of Sciences.

Temporal Context in Speech Processing and Attentional Stream Selection: A Behavioral and Neural perspective

Science.gov (United States)

Zion Golumbic, Elana M.; Poeppel, David; Schroeder, Charles E.

2012-01-01

The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the ‘Cocktail Party’ effect. Yet, the neural mechanisms underlying on-line speech decoding and attentional stream selection are not well understood. We review findings from behavioral and neurophysiological investigations that underscore the importance of the temporal structure of speech for achieving these perceptual feats. We discuss the hypothesis that entrainment of ambient neuronal oscillations to speech’s temporal structure, across multiple time-scales, serves to facilitate its decoding and underlies the selection of an attended speech stream over other competing input. In this regard, speech decoding and attentional stream selection are examples of ‘active sensing’, emphasizing an interaction between proactive and predictive top-down modulation of neuronal dynamics and bottom-up sensory input. PMID:22285024

High-Arctic Plant-Herbivore Interactions under Climate Influence