Sample records for coevolutionary competitive exclusion

  1. Competitions between prosocial exclusions and punishments in finite populations

    NASA Astrophysics Data System (ADS)

    Liu, Linjie; Chen, Xiaojie; Szolnoki, Attila

    2017-04-01

    Prosocial punishment has been proved to be a powerful mean to promote cooperation. Recent studies have found that social exclusion, which indeed can be regarded as a kind of punishment, can also support cooperation. However, if prosocial punishment and exclusion are both present, it is still unclear which strategy is more advantageous to curb free-riders. Here we first study the direct competition between different types of punishment and exclusion. We find that pool (peer) exclusion can always outperform pool (peer) punishment both in the optional and in the compulsory public goods game, no matter whether second-order sanctioning is considered or not. Furthermore, peer exclusion does better than pool exclusion both in the optional and in the compulsory game, but the situation is reversed in the presence of second-order exclusion. Finally, we extend the competition among all possible sanctioning strategies and find that peer exclusion can outperform all other strategies in the absence of second-order exclusion and punishment, while pool exclusion prevails when second-order sanctioning is possible. Our results demonstrate that exclusion is a more powerful strategy than punishment for the resolution of social dilemmas.

  2. Hybrid Co-Evolutionary Motion Planning via Visibility-Based Repair

    NASA Technical Reports Server (NTRS)

    Dozier, Gerry; McCullough, Shaun; Brown, Edward, Jr.; Homaifar, Abdollah; Bikdash, Mar-wan

    1997-01-01

    This paper introduces a hybrid co-evolutionary system for global motion planning within unstructured environments. This system combines the concept of co-evolutionary search along with a concept that we refer to as the visibility-based repair to form a hybrid which quickly transforms infeasible motions into feasible ones. Also, this system makes use of a novel representation scheme for the obstacles within an environment. Our hybrid evolutionary system differs from other evolutionary motion planners in that (1) more emphasis is placed on repairing infeasible motions to develop feasible motions rather than using simulated evolution exclusively as a means of discovering feasible motions, (2) a continuous map of the environment is used rather than a discretized map, and (3) it develops global motion plans for multiple mobile destinations by co-evolving populations of sub-global motion plans. In this paper, we demonstrate the effectiveness of this system by using it to solve two challenging motion planning problems where multiple targets try to move away from a point robot.

  3. Testing for coevolutionary diversification: linking pattern with process.

    PubMed

    Althoff, David M; Segraves, Kari A; Johnson, Marc T J

    2014-02-01

    Coevolutionary diversification is cited as a major mechanism driving the evolution of diversity, particularly in plants and insects. However, tests of coevolutionary diversification have focused on elucidating macroevolutionary patterns rather than the processes giving rise to such patterns. Hence, there is weak evidence that coevolution promotes diversification. This is in part due to a lack of understanding about the mechanisms by which coevolution can cause speciation and the difficulty of integrating results across micro- and macroevolutionary scales. In this review, we highlight potential mechanisms of coevolutionary diversification, outline approaches to examine this process across temporal scales, and propose a set of minimal requirements for demonstrating coevolutionary diversification. Our aim is to stimulate research that tests more rigorously for coevolutionary diversification. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. The co-evolutionary dynamics of directed network of spin market agents

    NASA Astrophysics Data System (ADS)

    Horváth, Denis; Kuscsik, Zoltán; Gmitra, Martin

    2006-09-01

    The spin market model [S. Bornholdt, Int. J. Mod. Phys. C 12 (2001) 667] is generalized by employing co-evolutionary principles, where strategies of the interacting and competitive traders are represented by local and global couplings between the nodes of dynamic directed stochastic network. The co-evolutionary principles are applied in the frame of Bak-Sneppen self-organized dynamics [P. Bak, K. Sneppen, Phys. Rev. Lett. 71 (1993) 4083] that includes the processes of selection and extinction actuated by the local (node) fitness. The local fitness is related to orientation of spin agent with respect to the instant magnetization. The stationary regime is formed due to the interplay of self-organization and adaptivity effects. The fat tailed distributions of log-price returns are identified numerically. The non-trivial model consequence is the evidence of the long time market memory indicated by the power-law range of the autocorrelation function of volatility with exponent smaller than one. The simulations yield network topology with broad-scale node degree distribution characterized by the range of exponents 1.3<γin<3 coinciding with social networks.

  5. Complex food webs prevent competitive exclusion among producer species.

    PubMed

    Brose, Ulrich

    2008-11-07

    Herbivorous top-down forces and bottom-up competition for nutrients determine the coexistence and relative biomass patterns of producer species. Combining models of predator-prey and producer-nutrient interactions with a structural model of complex food webs, I investigated these two aspects in a dynamic food-web model. While competitive exclusion leads to persistence of only one producer species in 99.7% of the simulated simple producer communities without consumers, embedding the same producer communities in complex food webs generally yields producer coexistence. In simple producer communities, the producers with the most efficient nutrient-intake rates increase in biomass until they competitively exclude inferior producers. In food webs, herbivory predominantly reduces the biomass density of those producers that dominated in producer communities, which yields a more even biomass distribution. In contrast to prior analyses of simple modules, this facilitation of producer coexistence by herbivory does not require a trade-off between the nutrient-intake efficiency and the resistance to herbivory. The local network structure of food webs (top-down effects of the number of herbivores and the herbivores' maximum consumption rates) and the nutrient supply (bottom-up effect) interactively determine the relative biomass densities of the producer species. A strong negative feedback loop emerges in food webs: factors that increase producer biomasses also increase herbivory, which reduces producer biomasses. This negative feedback loop regulates the coexistence and biomass patterns of the producers by balancing biomass increases of producers and biomass fluxes to herbivores, which prevents competitive exclusion.

  6. Comparing a Coevolutionary Genetic Algorithm for Multiobjective Optimization

    NASA Technical Reports Server (NTRS)

    Lohn, Jason D.; Kraus, William F.; Haith, Gary L.; Clancy, Daniel (Technical Monitor)

    2002-01-01

    We present results from a study comparing a recently developed coevolutionary genetic algorithm (CGA) against a set of evolutionary algorithms using a suite of multiobjective optimization benchmarks. The CGA embodies competitive coevolution and employs a simple, straightforward target population representation and fitness calculation based on developmental theory of learning. Because of these properties, setting up the additional population is trivial making implementation no more difficult than using a standard GA. Empirical results using a suite of two-objective test functions indicate that this CGA performs well at finding solutions on convex, nonconvex, discrete, and deceptive Pareto-optimal fronts, while giving respectable results on a nonuniform optimization. On a multimodal Pareto front, the CGA finds a solution that dominates solutions produced by eight other algorithms, yet the CGA has poor coverage across the Pareto front.

  7. A New Framework for Analysis of Coevolutionary Systems-Directed Graph Representation and Random Walks.

    PubMed

    Chong, Siang Yew; Tiňo, Peter; He, Jun; Yao, Xin

    2017-11-20

    Studying coevolutionary systems in the context of simplified models (i.e., games with pairwise interactions between coevolving solutions modeled as self plays) remains an open challenge since the rich underlying structures associated with pairwise-comparison-based fitness measures are often not taken fully into account. Although cyclic dynamics have been demonstrated in several contexts (such as intransitivity in coevolutionary problems), there is no complete characterization of cycle structures and their effects on coevolutionary search. We develop a new framework to address this issue. At the core of our approach is the directed graph (digraph) representation of coevolutionary problems that fully captures structures in the relations between candidate solutions. Coevolutionary processes are modeled as a specific type of Markov chains-random walks on digraphs. Using this framework, we show that coevolutionary problems admit a qualitative characterization: a coevolutionary problem is either solvable (there is a subset of solutions that dominates the remaining candidate solutions) or not. This has an implication on coevolutionary search. We further develop our framework that provides the means to construct quantitative tools for analysis of coevolutionary processes and demonstrate their applications through case studies. We show that coevolution of solvable problems corresponds to an absorbing Markov chain for which we can compute the expected hitting time of the absorbing class. Otherwise, coevolution will cycle indefinitely and the quantity of interest will be the limiting invariant distribution of the Markov chain. We also provide an index for characterizing complexity in coevolutionary problems and show how they can be generated in a controlled manner.

  8. Competitive exclusion over broad spatial extents is a slow process: Evidence and implications for species distribution modeling

    USGS Publications Warehouse

    Yackulic, Charles B.

    2016-01-01

    There is considerable debate about the role of competition in shaping species distributions over broad spatial extents. This debate has practical implications because predicting changes in species' geographic ranges in response to ongoing environmental change would be simpler if competition could be ignored. While this debate has been the subject of many reviews, recent literature has not addressed the rates of relevant processes. This omission is surprising in that ecologists hypothesized decades ago that regional competitive exclusion is a slow process. The goal of this review is to reassess the debate under the hypothesis that competitive exclusion over broad spatial extents is a slow process.Available evidence, including simulations presented for the first time here, suggests that competitive exclusion over broad spatial extents occurs slowly over temporal extents of many decades to millennia. Ecologists arguing against an important role for competition frequently study modern patterns and/or range dynamics over periods of decades, while much of the evidence for competition shaping geographic ranges at broad spatial extents comes from paleoecological studies over time scales of centuries or longer. If competition is slow, as evidence suggests, the geographic distributions of some, perhaps many species, would continue to change over time scales of decades to millennia, even if environmental conditions did not continue to change. If the distributions of competing species are at equilibrium it is possible to predict species distributions based on observed species–environment relationships. However, disequilibrium is widespread as a result of competition and many other processes. Studies whose goal is accurate predictions over intermediate time scales (decades to centuries) should focus on factors associated with range expansion (colonization) and loss (local extinction), as opposed to current patterns. In general, understanding of modern range dynamics would be

  9. Competition-Colonization Trade-Offs, Competitive Uncertainty, and the Evolutionary Assembly of Species

    PubMed Central

    Pillai, Pradeep; Guichard, Frédéric

    2012-01-01

    We utilize a standard competition-colonization metapopulation model in order to study the evolutionary assembly of species. Based on earlier work showing how models assuming strict competitive hierarchies will likely lead to runaway evolution and self-extinction for all species, we adopt a continuous competition function that allows for levels of uncertainty in the outcome of competition. We then, by extending the standard patch-dynamic metapopulation model in order to include evolutionary dynamics, allow for the coevolution of species into stable communities composed of species with distinct limiting similarities. Runaway evolution towards stochastic extinction then becomes a limiting case controlled by the level of competitive uncertainty. We demonstrate how intermediate competitive uncertainty maximizes the equilibrium species richness as well as maximizes the adaptive radiation and self-assembly of species under adaptive dynamics with mutations of non-negligible size. By reconciling competition-colonization tradeoff theory with co-evolutionary dynamics, our results reveal the importance of intermediate levels of competitive uncertainty for the evolutionary assembly of species. PMID:22448253

  10. Cannibalism and Intraguild Predation Community Dynamics: Coexistence, Competitive Exclusion, and the Loss of Alternative Stable States.

    PubMed

    Toscano, Benjamin J; Hin, Vincent; Rudolf, Volker H W

    2017-11-01

    Predators often exert strong top-down regulation of prey, but in many systems, juvenile predators must compete with their future prey for a shared resource. In such life-history intraguild predation (LHIGP) systems, prey can therefore also regulate the recruitment and thus population dynamics of their predator via competition. Theory predicts that such stage-structured systems exhibit a wide range of dynamics, including alternative stable states. Here we show that cannibalism is an exceedingly common interaction within natural LHIGP systems that determines what coexistence states are possible. Using a modeling approach that simulates a range of ontogenetic diet shift scenarios along a productivity gradient, we demonstrate that only if the predator is competitively dominant can cannibalism promote coexistence by allowing prey to persist. If the prey is competitively dominant, cannibalism instead results in competitive exclusion of the predator and the loss of potential alternative stable states. Further, predator exclusion occurs at low cannibalistic preference relative to empirical estimates and is consistent across LHIGP systems in which the predator undergoes a complete diet shift or diet broadening over ontogeny. Given that prey is frequently competitively dominant in natural systems, our results demonstrate that even weak cannibalism can inhibit predator persistence, prompting exploration of mechanisms that reconcile theory with the common occurrence of such interactions in nature.

  11. Competitive exclusion by autologous antibodies can prevent broad HIV-1 antibodies from arising

    DOE PAGES

    Luo, Shishi; Perelson, Alan S.

    2015-08-31

    The past decade has seen the discovery of numerous broad and potent monoclonal antibodies against HIV type 1 (HIV-1). Eliciting these antibodies via vaccination appears to be remarkably difficult, not least because they arise late in infection and are highly mutated relative to germline antibody sequences. Here, using a computational model, we show that broad antibodies could in fact emerge earlier and be less mutated, but that they may be prevented from doing so as a result of competitive exclusion by the autologous antibody response. We further find that this competitive exclusion is weaker in infections founded by multiple distinctmore » strains, with broadly neutralizing antibodies emerging earlier than in infections founded by a single strain. Our computational model simulates coevolving multitype virus and antibody populations. Broadly neutralizing antibodies may therefore be easier for the adaptive immune system to generate than previously thought. As a result, if less mutated broad antibodies exist, it may be possible to elicit them with a vaccine containing a mixture of diverse virus strains.« less

  12. Competitive Exclusion of Heterologous Campylobacter spp. in Chicks

    PubMed Central

    Chen, Hui-Cheng; Stern, Norman J.

    2001-01-01

    Chicken and human isolates of Campylobacter jejuni were used to provide oral challenge of day-old broiler chicks. The isolation ratio of the competing challenge strains was monitored and varied, depending upon the isolates used. A PCR-restriction fragment length polymorphism assay of the flagellin gene (flaA) was used to discriminate between the chick-colonizing isolates. Our observations indicated that the selected C. jejuni colonizers dominated the niche provided by the chicken ceca. Chicken isolates from the flaA type 7 grouping generally had numerical superiority over the human isolates when they were administered in our 1-day-old chick model. Our results suggest that it is possible to use combinations of C. jejuni chicken isolates as a defined bacterial preparation for the competitive exclusion of human-pathogenic C. jejuni in poultry. PMID:11157253

  13. Exclusivity strategies and opportunities in view of the Biologics Price Competition and Innovation Act.

    PubMed

    Gaudry, Kate S

    2011-01-01

    Government-provided exclusivity periods provide pharmaceutical companies with incentives to invest in new drugs. Meanwhile, encouraging competition serves another worthy goal of improving the affordability of medications. Decades ago, the Hatch-Waxman Act set forth provisions attempting to balance these objectives in the context of small-molecule drugs. Recently, the Biologics Price Competition and Innovation Act was enacted to meet similar aims in the context of biologic drugs. This article presents a detailed comparison of these two Acts. While the Acts share many global similarities (e.g., providing exclusivity terms and abbreviated approval processes), many differences are also apparent when analyzing details of the provisions. One area of great departure between the Acts is the requirements of how a generic or follow-on applicant must address patents covering a reference product. After describing these differences, the article presents predictions of how reference product sponsors will adapt their patent-prosecution strategies in view of the new Biologics Act.

  14. Within-host competitive exclusion among species of the anther smut pathogen

    PubMed Central

    Gold, Alexander; Giraud, Tatiana; Hood, Michael E

    2009-01-01

    Background Host individuals represent an arena in which pathogens compete for resources and transmission opportunities, with major implications for the evolution of virulence and the structure of populations. Studies to date have focused on competitive interactions within pathogen species, and the level of antagonism tends to increase with the genetic distance between competitors. Anther-smut fungi, in the genus Microbotryum, have emerged as a tractable model for within-host competition. Here, using two pathogen species that are frequently found in sympatry, we investigated whether the antagonism seen among genotypes of the same species cascades up to influence competition among pathogen species. Results Sequential inoculation of hosts showed that a resident infection most often excludes a challenging pathogen genotype, which is consistent with prior studies. However, the challenging pathogen was significantly more likely to invade the already-infected host if the resident infection was a conspecific genotype compared to challenges involving a closely related species. Moreover, when inter-specific co-infection occurred, the pathogens were highly segregated within the host, in contrast to intra-specific co-infection. Conclusion We show evidence that competitive exclusion during infection can be greater among closely related pathogen species than among genotypes within species. This pattern follows from prior studies demonstrating that genetic distance and antagonistic interactions are positively correlated in Microbotryum. Fungal vegetative incompatibility is a likely mechanism of direct competitive interference, and has been shown in some fungi to be effective both within and across species boundaries. For systems where related pathogen species frequently co-occur in the same host populations, these competitive dynamics may substantially impact the spatial segregation of pathogen species. PMID:19422703

  15. Competitive Exclusion of Dendroctonus rufipennis Induced by Pheromones of Ips tridens and Dryocoetes affaber (Coleoptera: Scolytidae)

    Treesearch

    Therese M. Poland; John H. Borden

    1998-01-01

    We tested the feasibility of competitive exclusion as a potential management tactic for the spruce beetle, Dendroctonus rufipennis Kirby, using pre-attack baiting with pheromones of 2 secondary species, Ips tridens Mannerheim and Dryocoetes affaber Mannerheim. Spruce beetle attack densities, gallery lengths per...

  16. Comparison of competitive exclusion with classical cleaning and disinfection on bacterial load in pig nursery units.

    PubMed

    Luyckx, K; Millet, S; Van Weyenberg, S; Herman, L; Heyndrickx, M; Dewulf, J; De Reu, K

    2016-09-06

    Colonisation of the environment of nursery units by pathogenic micro-organisms is an important factor in the persistence and spread of endemic diseases in pigs and zoonotic pathogens. These pathogens are generally controlled by the use of antibiotics and disinfectants. Since an increasing resistance against these measures has been reported in recent years, methods such as competitive exclusion (CE) are promoted as promising alternatives. This study showed that the infection pressure in CE units after microbial cleaning was not reduced to the same degree as in control units. Despite sufficient administration of probiotic-type spores, the analysed bacteria did not decrease in number after 3 production rounds in CE units, indicating no competitive exclusion. In addition, no differences in feed conversion were found between piglets raised in CE and control units in our study. Also, no differences in faecal consistency (indicator for enteric diseases) was noticed. These results indicate that the CE protocol is not a valuable alternative for classical C&D.

  17. Phylogenetic framework for coevolutionary studies: a compass for exploring jungles of tangled trees.

    PubMed

    Martínez-Aquino, Andrés

    2016-08-01

    Phylogenetics is used to detect past evolutionary events, from how species originated to how their ecological interactions with other species arose, which can mirror cophylogenetic patterns. Cophylogenetic reconstructions uncover past ecological relationships between taxa through inferred coevolutionary events on trees, for example, codivergence, duplication, host-switching, and loss. These events can be detected by cophylogenetic analyses based on nodes and the length and branching pattern of the phylogenetic trees of symbiotic associations, for example, host-parasite. In the past 2 decades, algorithms have been developed for cophylogetenic analyses and implemented in different software, for example, statistical congruence index and event-based methods. Based on the combination of these approaches, it is possible to integrate temporal information into cophylogenetical inference, such as estimates of lineage divergence times between 2 taxa, for example, hosts and parasites. Additionally, the advances in phylogenetic biogeography applying methods based on parametric process models and combined Bayesian approaches, can be useful for interpreting coevolutionary histories in a scenario of biogeographical area connectivity through time. This article briefly reviews the basics of parasitology and provides an overview of software packages in cophylogenetic methods. Thus, the objective here is to present a phylogenetic framework for coevolutionary studies, with special emphasis on groups of parasitic organisms. Researchers wishing to undertake phylogeny-based coevolutionary studies can use this review as a "compass" when "walking" through jungles of tangled phylogenetic trees.

  18. Cost modeling of pseudomonoas fluorescens and pseudomonoas chlororphis biocontrol for competitive exclusion of salmonella enterica on tomatoes

    USDA-ARS?s Scientific Manuscript database

    Biocontrol measures may enhance postharvest interventions, however; published research on process-based models for biocontrol of foodborne pathogens on produce is limited. The aim of this research was to develop cost model estimates for competitive exclusion process using Pseudomonas fluorescens and...

  19. Phylogenetic framework for coevolutionary studies: a compass for exploring jungles of tangled trees

    PubMed Central

    2016-01-01

    Abstract Phylogenetics is used to detect past evolutionary events, from how species originated to how their ecological interactions with other species arose, which can mirror cophylogenetic patterns. Cophylogenetic reconstructions uncover past ecological relationships between taxa through inferred coevolutionary events on trees, for example, codivergence, duplication, host-switching, and loss. These events can be detected by cophylogenetic analyses based on nodes and the length and branching pattern of the phylogenetic trees of symbiotic associations, for example, host–parasite. In the past 2 decades, algorithms have been developed for cophylogetenic analyses and implemented in different software, for example, statistical congruence index and event-based methods. Based on the combination of these approaches, it is possible to integrate temporal information into cophylogenetical inference, such as estimates of lineage divergence times between 2 taxa, for example, hosts and parasites. Additionally, the advances in phylogenetic biogeography applying methods based on parametric process models and combined Bayesian approaches, can be useful for interpreting coevolutionary histories in a scenario of biogeographical area connectivity through time. This article briefly reviews the basics of parasitology and provides an overview of software packages in cophylogenetic methods. Thus, the objective here is to present a phylogenetic framework for coevolutionary studies, with special emphasis on groups of parasitic organisms. Researchers wishing to undertake phylogeny-based coevolutionary studies can use this review as a “compass” when “walking” through jungles of tangled phylogenetic trees. PMID:29491928

  20. Coevolutionary constraints in the sequence-space of macromolecular complexes reflect their self-assembly pathways.

    PubMed

    Mallik, Saurav; Kundu, Sudip

    2017-07-01

    Is the order in which biomolecular subunits self-assemble into functional macromolecular complexes imprinted in their sequence-space? Here, we demonstrate that the temporal order of macromolecular complex self-assembly can be efficiently captured using the landscape of residue-level coevolutionary constraints. This predictive power of coevolutionary constraints is irrespective of the structural, functional, and phylogenetic classification of the complex and of the stoichiometry and quaternary arrangement of the constituent monomers. Combining this result with a number of structural attributes estimated from the crystal structure data, we find indications that stronger coevolutionary constraints at interfaces formed early in the assembly hierarchy probably promotes coordinated fixation of mutations that leads to high-affinity binding with higher surface area, increased surface complementarity and elevated number of molecular contacts, compared to those that form late in the assembly. Proteins 2017; 85:1183-1189. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  1. In vitro selection of enteric microflora for potential use as a competitive exclusion culture against Campylobacter in poultry

    USDA-ARS?s Scientific Manuscript database

    The administration of nonpathogenic microflora in neonatal poultry has been employed to reduce or eliminate the colonization of enteric pathogens. This concept, also called competitive exclusion (CE), although effective against Salmonella, has not consistently worked against Campylobacter. Most CE...

  2. Cost modeling of biocontrol strains Pseudomonas chlororaphis and P. flurorescens for competitive exclusion of Salmonella enterica on tomatoes

    USDA-ARS?s Scientific Manuscript database

    Biological control of foodborne pathogens may complement postharvest intervention measures to enhance food safety of minimally processed produce. The purpose of this research was to develop cost model estimates for application of competitive exclusion process (CEM) using Pseudomonas chlororaphis and...

  3. Complete genome sequence of Lactobacillus johnsonii FI9785, a competitive exclusion agent against pathogens in poultry.

    PubMed

    Wegmann, Udo; Overweg, Karin; Horn, Nikki; Goesmann, Alexander; Narbad, Arjan; Gasson, Michael J; Shearman, Claire

    2009-11-01

    Lactobacillus johnsonii is a member of the acidophilus group of lactobacilli. Because of their probiotic properties, including attachment to epithelial cells, immunomodulation, and competitive exclusion of pathogens, representatives of this group are being intensively studied. Here we report the complete annotated genome sequence of Lactobacillus johnsonii FI9785, a strain which prevents the colonization of specific-pathogen-free chicks by Clostridium perfringens.

  4. Coevolutionary Free Lunches

    NASA Technical Reports Server (NTRS)

    Wolpert, David H.; Macready, William G.

    2005-01-01

    Recent work on the foundations of optimization has begun to uncover its underlying rich structure. In particular, the "No Free Lunch" (NFL) theorems [WM97] state that any two algorithms are equivalent when their performance is averaged across all possible problems. This highlights the need for exploiting problem-specific knowledge to achieve better than random performance. In this paper we present a general framework covering most search scenarios. In addition to the optimization scenarios addressed in the NFL results, this framework covers multi-armed bandit problems and evolution of multiple co-evolving agents. As a particular instance of the latter, it covers "self-play" problems. In these problems the agents work together to produce a champion, who then engages one or more antagonists in a subsequent multi-player game In contrast to the traditional optimization case where the NFL results hold, we show that in self-play there are free lunches: in coevolution some algorithms have better performance than other algorithms, averaged across all possible problems. However in the typical coevolutionary scenarios encountered in biology, where there is no champion, NFL still holds.

  5. Cyber Security Research Frameworks For Coevolutionary Network Defense

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rush, George D.; Tauritz, Daniel Remy

    Several architectures have been created for developing and testing systems used in network security, but most are meant to provide a platform for running cyber security experiments as opposed to automating experiment processes. In the first paper, we propose a framework termed Distributed Cyber Security Automation Framework for Experiments (DCAFE) that enables experiment automation and control in a distributed environment. Predictive analysis of adversaries is another thorny issue in cyber security. Game theory can be used to mathematically analyze adversary models, but its scalability limitations restrict its use. Computational game theory allows us to scale classical game theory to larger,more » more complex systems. In the second paper, we propose a framework termed Coevolutionary Agent-based Network Defense Lightweight Event System (CANDLES) that can coevolve attacker and defender agent strategies and capabilities and evaluate potential solutions with a custom network defense simulation. The third paper is a continuation of the CANDLES project in which we rewrote key parts of the framework. Attackers and defenders have been redesigned to evolve pure strategy, and a new network security simulation is devised which specifies network architecture and adds a temporal aspect. We also add a hill climber algorithm to evaluate the search space and justify the use of a coevolutionary algorithm.« less

  6. Testing co-evolutionary hypotheses over geological timescales: interactions between Mesozoic non-avian dinosaurs and cycads.

    PubMed

    Butler, Richard J; Barrett, Paul M; Kenrick, Paul; Penn, Malcolm G

    2009-02-01

    The significance of co-evolution over ecological timescales is well established, yet it remains unclear to what extent co-evolutionary processes contribute to driving large-scale evolutionary and ecological changes over geological timescales. Some of the most intriguing and pervasive long-term co-evolutionary hypotheses relate to proposed interactions between herbivorous non-avian dinosaurs and Mesozoic plants, including cycads. Dinosaurs have been proposed as key dispersers of cycad seeds during the Mesozoic, and temporal variation in cycad diversity and abundance has been linked to dinosaur faunal changes. Here we assess the evidence for proposed hypotheses of trophic and evolutionary interactions between these two groups using diversity analyses, a new database of Cretaceous dinosaur and plant co-occurrence data, and a geographical information system (GIS) as a visualisation tool. Phylogenetic evidence suggests that the origins of several key biological properties of cycads (e.g. toxins, bright-coloured seeds) likely predated the origin of dinosaurs. Direct evidence of dinosaur-cycad interactions is lacking, but evidence from extant ecosystems suggests that dinosaurs may plausibly have acted as seed dispersers for cycads, although it is likely that other vertebrate groups (e.g. birds, early mammals) also played a role. Although the Late Triassic radiations of dinosaurs and cycads appear to have been approximately contemporaneous, few significant changes in dinosaur faunas coincide with the late Early Cretaceous cycad decline. No significant spatiotemporal associations between particular dinosaur groups and cycads can be identified - GIS visualisation reveals disparities between the spatiotemporal distributions of some dinosaur groups (e.g. sauropodomorphs) and cycads that are inconsistent with co-evolutionary hypotheses. The available data provide no unequivocal support for any of the proposed co-evolutionary interactions between cycads and herbivorous dinosaurs

  7. Coevolutionary dynamics in large, but finite populations

    NASA Astrophysics Data System (ADS)

    Traulsen, Arne; Claussen, Jens Christian; Hauert, Christoph

    2006-07-01

    Coevolving and competing species or game-theoretic strategies exhibit rich and complex dynamics for which a general theoretical framework based on finite populations is still lacking. Recently, an explicit mean-field description in the form of a Fokker-Planck equation was derived for frequency-dependent selection with two strategies in finite populations based on microscopic processes [A. Traulsen, J. C. Claussen, and C. Hauert, Phys. Rev. Lett. 95, 238701 (2005)]. Here we generalize this approach in a twofold way: First, we extend the framework to an arbitrary number of strategies and second, we allow for mutations in the evolutionary process. The deterministic limit of infinite population size of the frequency-dependent Moran process yields the adjusted replicator-mutator equation, which describes the combined effect of selection and mutation. For finite populations, we provide an extension taking random drift into account. In the limit of neutral selection, i.e., whenever the process is determined by random drift and mutations, the stationary strategy distribution is derived. This distribution forms the background for the coevolutionary process. In particular, a critical mutation rate uc is obtained separating two scenarios: above uc the population predominantly consists of a mixture of strategies whereas below uc the population tends to be in homogeneous states. For one of the fundamental problems in evolutionary biology, the evolution of cooperation under Darwinian selection, we demonstrate that the analytical framework provides excellent approximations to individual based simulations even for rather small population sizes. This approach complements simulation results and provides a deeper, systematic understanding of coevolutionary dynamics.

  8. 48 CFR 19.1006 - Exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Exclusions. 19.1006 Section 19.1006 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Small Business Competitiveness Demonstration Program 19.1006 Exclusions...

  9. Co-evolutionary data mining for fuzzy rules: automatic fitness function creation phase space, and experiments

    NASA Astrophysics Data System (ADS)

    Smith, James F., III; Blank, Joseph A.

    2003-03-01

    An approach is being explored that involves embedding a fuzzy logic based resource manager in an electronic game environment. Game agents can function under their own autonomous logic or human control. This approach automates the data mining problem. The game automatically creates a cleansed database reflecting the domain expert's knowledge, it calls a data mining function, a genetic algorithm, for data mining of the data base as required and allows easy evaluation of the information extracted. The co-evolutionary fitness functions, chromosomes and stopping criteria for ending the game are discussed. Genetic algorithm and genetic program based data mining procedures are discussed that automatically discover new fuzzy rules and strategies. The strategy tree concept and its relationship to co-evolutionary data mining are examined as well as the associated phase space representation of fuzzy concepts. The overlap of fuzzy concepts in phase space reduces the effective strategies available to adversaries. Co-evolutionary data mining alters the geometric properties of the overlap region known as the admissible region of phase space significantly enhancing the performance of the resource manager. Procedures for validation of the information data mined are discussed and significant experimental results provided.

  10. Seasonal sexual segregation in two Thalassarche albatross species: competitive exclusion, reproductive role specialization or foraging niche divergence?

    PubMed

    Phillips, R A; Silk, J R D; Phalan, B; Catry, P; Croxall, J P

    2004-06-22

    Sexual segregation by micro- or macrohabitat is common in birds, and usually attributed to size-mediated dominance and exclusion of females by larger males, trophic niche divergence or reproductive role specialization. Our study of black-browed albatrosses, Thalassarche melanophrys, and grey-headed albatrosses, T. chrysostoma, revealed an exceptional degree of sexual segregation during incubation, with largely mutually exclusive core foraging ranges for each sex in both species. Spatial segregation was not apparent during brood-guard or post-guard chick rearing, when adults are constrained to feed close to colonies, providing no evidence for dominance-related competitive exclusion at the macrohabitat level. A comprehensive morphometric comparison indicated considerable species and sexual dimorphism in wing area and wing loading that corresponded, both within and between species, to broad-scale habitat preferences relating to wind strength. We suggest that seasonal sexual segregation in these two species is attributable to niche divergence mediated by differences in flight performance. Such sexual segregation may also have implications for conservation in relation to sex-specific overlap with commercial fisheries.

  11. The impact of hepatitis A virus infection on hepatitis C virus infection: a competitive exclusion hypothesis.

    PubMed

    Amaku, Marcos; Coutinho, Francisco Antonio Bezerra; Chaib, Eleazar; Massad, Eduardo

    2013-01-01

    We address the observation that, in some cases, patients infected with the hepatitis C virus (HCV) are cleared of HCV when super-infected with the hepatitis A virus (HAV). We hypothesise that this phenomenon can be explained by the competitive exclusion principle, including the action of the immune system, and show that the inclusion of the immune system explains both the elimination of one virus and the co-existence of both infections for a certain range of parameters. We discuss the potential clinical implications of our findings.

  12. Predicting protein folding rate change upon point mutation using residue-level coevolutionary information.

    PubMed

    Mallik, Saurav; Das, Smita; Kundu, Sudip

    2016-01-01

    Change in folding kinetics of globular proteins upon point mutation is crucial to a wide spectrum of biological research, such as protein misfolding, toxicity, and aggregations. Here we seek to address whether residue-level coevolutionary information of globular proteins can be informative to folding rate changes upon point mutations. Generating residue-level coevolutionary networks of globular proteins, we analyze three parameters: relative coevolution order (rCEO), network density (ND), and characteristic path length (CPL). A point mutation is considered to be equivalent to a node deletion of this network and respective percentage changes in rCEO, ND, CPL are found linearly correlated (0.84, 0.73, and -0.61, respectively) with experimental folding rate changes. The three parameters predict the folding rate change upon a point mutation with 0.031, 0.045, and 0.059 standard errors, respectively. © 2015 Wiley Periodicals, Inc.

  13. A field test for competitive effects of Aedes albopictus on A. aegypti in South Florida: differences between sites of coexistence and exclusion?

    PubMed Central

    Juliano, Steven A.; Lounibos, L. Philip; O’Meara, George F.

    2007-01-01

    We tested whether interspecific competition from Aedes albopictus had measurable effects on A. aegypti at the typical numbers of larval mosquitoes found in cemetery vases in south Florida. We also tested whether the effect of interspecific competition from A. albopictus on A. aegypti differed between sites where A. aegypti either persists or went extinct following invasion by A. albopictus. Similar experiments manipulating numbers of A. albopictus in cemetery vases were conducted at three sites of A. aegypti persistence and three sites where A. aegypti was apparently extinct. The experiments were done using numbers of larvae that were determined by observed numbers of larvae for each site, and with resources (leaf detritus) that accumulated in experimental vases placed into each field site. In both the early rainy season (when number of mosquito larvae was low) and the late rainy season (when number of mosquito larvae was high), there was a significant effect of treatment on developmental progress of experimental A. aegypti. In the late rainy season, when numbers of larvae were high, there was also a significant effect of treatment on survivorship of A. aegypti. However, the competition treatment × site type (A. aegypti persists vs extinct) interaction was never significant, indicating that the competitive effect of A. albopictus on A. aegypti did not differ systematically between persistence versus extinction sites. Thus, although competition from A. albopictus is strong under field conditions at all sites, we find no evidence that variation in the impact of interspecific competition is associated with coexistence or exclusion. Interspecific competition among larvae is thus a viable explanation for exclusion or reduction of A. aegypti in south Florida, but variation in the persistence of A. aegypti following invasion does not seem to be primarily a product of variation in the conditions in the aquatic environments of cemetery vases. PMID:15024640

  14. Sperm competition risk generates phenotypic plasticity in ovum fertilizability

    PubMed Central

    Firman, Renée C.; Simmons, Leigh W.

    2013-01-01

    Theory predicts that sperm competition will generate sexual conflict that favours increased ovum defences against polyspermy. A recent study on house mice has shown that ovum resistance to fertilization coevolves in response to increased sperm fertilizing capacity. However, the capacity for the female gamete to adjust its fertilizability as a strategic response to sperm competition risk has never, to our knowledge, been studied. We sourced house mice (Mus domesticus) from natural populations that differ in the level of sperm competition and sperm fertilizing capacity, and manipulated the social experience of females during their sexual development to simulate conditions of either a future ‘risk’ or ‘no risk’ of sperm competition. Consistent with coevolutionary predictions, we found lower fertilization rates in ova produced by females from a high sperm competition population compared with ova from a low sperm competition population, indicating that these populations are divergent in the fertilizability of their ova. More importantly, females exposed to a ‘risk’ of sperm competition produced ova that had greater resistance to fertilization than ova produced by females reared in an environment with ‘no risk’. Consequently, we show that variation in sperm competition risk during development generates phenotypic plasticity in ova fertilizability, which allows females to prepare for prevailing conditions during their reproductive life. PMID:24132308

  15. Sperm competition risk generates phenotypic plasticity in ovum fertilizability.

    PubMed

    Firman, Renée C; Simmons, Leigh W

    2013-12-07

    Theory predicts that sperm competition will generate sexual conflict that favours increased ovum defences against polyspermy. A recent study on house mice has shown that ovum resistance to fertilization coevolves in response to increased sperm fertilizing capacity. However, the capacity for the female gamete to adjust its fertilizability as a strategic response to sperm competition risk has never, to our knowledge, been studied. We sourced house mice (Mus domesticus) from natural populations that differ in the level of sperm competition and sperm fertilizing capacity, and manipulated the social experience of females during their sexual development to simulate conditions of either a future 'risk' or 'no risk' of sperm competition. Consistent with coevolutionary predictions, we found lower fertilization rates in ova produced by females from a high sperm competition population compared with ova from a low sperm competition population, indicating that these populations are divergent in the fertilizability of their ova. More importantly, females exposed to a 'risk' of sperm competition produced ova that had greater resistance to fertilization than ova produced by females reared in an environment with 'no risk'. Consequently, we show that variation in sperm competition risk during development generates phenotypic plasticity in ova fertilizability, which allows females to prepare for prevailing conditions during their reproductive life.

  16. Brood-parasite interactions between great spotted cuckoos and magpies: a model system for studying coevolutionary relationships.

    PubMed

    Soler, Juan; Soler, Manuel

    2000-11-01

    Brood parasitism is one of the systems where coevolutionary processes have received the most research. Here, we review experiments that suggest a coevolutionary process between the great spotted cuckoo (Clamator glandarius) and its magpie (Pica pica) host. We focus on different stages of establishment of the relationship, from cuckoos selecting individual hosts and hosts defending their nests from adult cuckoos, to the ability of magpies to detect cuckoo eggs in their nests. Novel coevolutionary insights emerge from our synthesis of the literature, including how the evolution of "Mafia" behaviour in cuckoos does not necessarily inhibit the evolution of host recognition and rejection of cuckoo offspring, and how different populations of black-billed magpies in Europe have evolved specific host traits (e.g. nest and clutch size) as a result of interactions with the great spotted cuckoo. Finally, the results of the synthesis reveal the importance of using a meta-population approach when studying coevolution. This is especially relevant in those cases where gene flow among populations with different degrees of brood parasitism explains patterns of coexistence between defensive and non-defensive host phenotypes. We propose the use of a meta-population approach to distinguish between the "evolutionary equilibrium" hypothesis and the "evolutionary lag" hypothesis.

  17. Migratory behavior of birds affects their coevolutionary relationship with blood parasites.

    PubMed

    Jenkins, Tania; Thomas, Gavin H; Hellgren, Olof; Owens, Ian P F

    2012-03-01

    Host traits, such as migratory behavior, could facilitate the dispersal of disease-causing parasites, potentially leading to the transfer of infections both across geographic areas and between host species. There is, however, little quantitative information on whether variation in such host attributes does indeed affect the evolutionary outcome of host-parasite associations. Here, we employ Leucocytozoon blood parasites of birds, a group of parasites closely related to avian malaria, to study host-parasite coevolution in relation to host behavior using a phylogenetic comparative approach. We reconstruct the molecular phylogenies of both the hosts and parasites and use cophylogenetic tools to assess whether each host-parasite association contributes significantly to the overall congruence between the two phylogenies. We find evidence for a significant fit between host and parasite phylogenies in this system, but show that this is due only to associations between nonmigrant parasites and their hosts. We also show that migrant bird species harbor a greater genetic diversity of parasites compared with nonmigrant species. Taken together, these results suggest that the migratory habits of birds could influence their coevolutionary relationship with their parasites, and that consideration of host traits is important in predicting the outcome of coevolutionary interactions. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  18. The coevolutionary dynamics of obligate ant social parasite systems--between prudence and antagonism.

    PubMed

    Brandt, Miriam; Foitzik, Susanne; Fischer-Blass, Birgit; Heinze, Jürgen

    2005-05-01

    In this synthesis we apply coevolutionary models to the interactions between socially parasitic ants and their hosts. Obligate social parasite systems are ideal models for coevolution, because the close phylogenetic relationship between these parasites and their hosts results in similar evolutionary potentials, thus making mutual adaptations in a stepwise fashion especially likely to occur. The evolutionary dynamics of host-parasite interactions are influenced by a number of parameters, for example the parasite's transmission mode and rate, the genetic structure of host and parasite populations, the antagonists' migration rates, and the degree of mutual specialisation. For the three types of obligate ant social parasites, queen-tolerant and queen-intolerant inquilines and slavemakers, several of these parameters, and thus the evolutionary trajectory, are likely to differ. Because of the fundamental differences in lifestyle between these social parasite systems, coevolution should further select for different traits in the parasites and their hosts. Queen-tolerant inquilines are true parasites that exert a low selection pressure on their host, because of their rarity and the fact that they do not conduct slave raids to replenish their labour force. Due to their high degree of specialisation and the potential for vertical transmission, coevolutionary theory would predict interactions between these workerless parasites and their hosts to become even more benign over time. Queen-intolerant inquilines that kill the host queen during colony take-over are best described as parasitoids, and their reproductive success is limited by the existing worker force of the invaded host nest. These parasites should therefore evolve strategies to best exploit this fixed resource. Slavemaking ants, by contrast, act as parasites only during colony foundation, while their frequent slave raids follow a predator prey dynamic. They often exploit a number of host species at a given site, and

  19. Nonlinear Dynamics of Complex Coevolutionary Systems in Historical Times

    NASA Astrophysics Data System (ADS)

    Perdigão, Rui A. P.

    2016-04-01

    A new theoretical paradigm for statistical-dynamical modeling of complex coevolutionary systems is introduced, with the aim to provide historical geoscientists with a practical tool to analyse historical data and its underlying phenomenology. Historical data is assumed to represent the history of dynamical processes of physical and socio-economic nature. If processes and their governing laws are well understood, they are often treated with traditional dynamical equations: deterministic approach. If the governing laws are unknown or impracticable, the process is often treated as if being random (even if it is not): statistical approach. Although single eventful details - such as the exact spatiotemporal structure of a particular hydro-meteorological incident - may often be elusive to a detailed analysis, the overall dynamics exhibit group properties summarized by a simple set of categories or dynamical regimes at multiple scales - from local short-lived convection patterns to large-scale hydro-climatic regimes. The overwhelming microscale complexity is thus conveniently wrapped into a manageable group entity, such as a statistical distribution. In a stationary setting whereby the distribution is assumed to be invariant, alternating regimes are approachable as dynamical intermittence. For instance, in the context of bimodal climatic oscillations such as NAO and ENSO, each mode corresponds to a dynamical regime or phase. However, given external forcings or longer-term internal variability and multiscale coevolution, the structural properties of the system may change. These changes in the dynamical structure bring about a new distribution and associated regimes. The modes of yesteryear may no longer exist as such in the new structural order of the system. In this context, aside from regime intermittence, the system exhibits structural regime change. New oscillations may emerge whilst others fade into the annals of history, e.g. particular climate fluctuations during

  20. LIFE AFTER COMPETITIVE EXCLUSION: AN ALTERNATIVE STRATEGY FOR A COMPETITIVE INFERIOR

    EPA Science Inventory

    Experimental manipulations in the rocky intertidal have demonstrated that in the absence of predation (Paine 1966, 1974) or physical disturbance (Dayton 1971) a competitive dominant species can monopolize the primary space, thereby excluding competitors. he endpoint of this compe...

  1. Competitive Exclusion and Coexistence of Pathogens in a Homosexually-Transmitted Disease Model

    PubMed Central

    Chai, Caichun; Jiang, Jifa

    2011-01-01

    A sexually-transmitted disease model for two strains of pathogen in a one-sex, heterogeneously-mixing population has been studied completely by Jiang and Chai in (J Math Biol 56:373–390, 2008). In this paper, we give a analysis for a SIS STD with two competing strains, where populations are divided into three differential groups based on their susceptibility to two distinct pathogenic strains. We investigate the existence and stability of the boundary equilibria that characterizes competitive exclusion of the two competing strains; we also investigate the existence and stability of the positive coexistence equilibrium, which characterizes the possibility of coexistence of the two strains. We obtain sufficient and necessary conditions for the existence and global stability about these equilibria under some assumptions. We verify that there is a strong connection between the stability of the boundary equilibria and the existence of the coexistence equilibrium, that is, there exists a unique coexistence equilibrium if and only if the boundary equilibria both exist and have the same stability, the coexistence equilibrium is globally stable or unstable if and only if the two boundary equilibria are both unstable or both stable. PMID:21347222

  2. Coevolutionary dynamics of aspiration and strategy in spatial repeated public goods games

    NASA Astrophysics Data System (ADS)

    Wu, Te; Fu, Feng; Wang, Long

    2018-06-01

    The evolutionary dynamics remain largely unknown for spatial populations where individuals are more likely to interact repeatedly. Under this settings, individuals can make their decisions to cooperate or not based on the decisions previously adopted by others in their neighborhoods. Using repeated public goods game, we construct a spatial model and use a statistical physics approach to study the coevolutionary dynamics of aspiration and strategy. Individuals each have an aspiration towards the groups they are involved. According to the outcome of each group, individuals have assessment of whether their aspirations are satisfied. If satisfied, they cooperate next round. Otherwise, they switch to defecting. Results show threshold phenomenon for harsh collective dilemma: cooperators sticking to high levels of aspiration can prevail over defectors, while cooperators with other levels are invariably wiped out. When the collective dilemma is relaxed, cooperation is greatly facilitated by inducing a high level of diversity of aspiration. Snapshots further show the spatial patterns of how this coevolutionary process leads to the emergence of an optimal solution associated with aspiration level, whose corresponding strategy are most prevalent. This optimal solution lies in one and the highest aspiration level allowed, and depends on the intensity of the social dilemma. By removing the memory effect, our results also confirm that repeated interactions can promote cooperation, but to a limited degree.

  3. An Improved Co-evolutionary Particle Swarm Optimization for Wireless Sensor Networks with Dynamic Deployment

    PubMed Central

    Wang, Xue; Wang, Sheng; Ma, Jun-Jie

    2007-01-01

    The effectiveness of wireless sensor networks (WSNs) depends on the coverage and target detection probability provided by dynamic deployment, which is usually supported by the virtual force (VF) algorithm. However, in the VF algorithm, the virtual force exerted by stationary sensor nodes will hinder the movement of mobile sensor nodes. Particle swarm optimization (PSO) is introduced as another dynamic deployment algorithm, but in this case the computation time required is the big bottleneck. This paper proposes a dynamic deployment algorithm which is named “virtual force directed co-evolutionary particle swarm optimization” (VFCPSO), since this algorithm combines the co-evolutionary particle swarm optimization (CPSO) with the VF algorithm, whereby the CPSO uses multiple swarms to optimize different components of the solution vectors for dynamic deployment cooperatively and the velocity of each particle is updated according to not only the historical local and global optimal solutions, but also the virtual forces of sensor nodes. Simulation results demonstrate that the proposed VFCPSO is competent for dynamic deployment in WSNs and has better performance with respect to computation time and effectiveness than the VF, PSO and VFPSO algorithms.

  4. Coevolutionary diversification creates nested-modular structure in phage–bacteria interaction networks

    PubMed Central

    Beckett, Stephen J.; Williams, Hywel T. P.

    2013-01-01

    Phage and their bacterial hosts are the most diverse and abundant biological entities in the oceans, where their interactions have a major impact on marine ecology and ecosystem function. The structure of interaction networks for natural phage–bacteria communities offers insight into their coevolutionary origin. At small phylogenetic scales, observed communities typically show a nested structure, in which both hosts and phages can be ranked by their range of resistance and infectivity, respectively. A qualitatively different multi-scale structure is seen at larger phylogenetic scales; a natural assemblage sampled from the Atlantic Ocean displays large-scale modularity and local nestedness within each module. Here, we show that such ‘nested-modular’ interaction networks can be produced by a simple model of host–phage coevolution in which infection depends on genetic matching. Negative frequency-dependent selection causes diversification of hosts (to escape phages) and phages (to track their evolving hosts). This creates a diverse community of bacteria and phage, maintained by kill-the-winner ecological dynamics. When the resulting communities are visualized as bipartite networks of who infects whom, they show the nested-modular structure characteristic of the Atlantic sample. The statistical significance and strength of this observation varies depending on whether the interaction networks take into account the density of the interacting strains, with implications for interpretation of interaction networks constructed by different methods. Our results suggest that the apparently complex community structures associated with marine bacteria and phage may arise from relatively simple coevolutionary origins. PMID:24516719

  5. 48 CFR 6.204 - Section 8(a) competition.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Section 8(a) competition. 6.204 Section 6.204 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION ACQUISITION PLANNING COMPETITION REQUIREMENTS Full and Open Competition After Exclusion of Sources 6.204...

  6. Public goods games on adaptive coevolutionary networks

    NASA Astrophysics Data System (ADS)

    Pichler, Elgar; Shapiro, Avi M.

    2017-07-01

    Productive societies feature high levels of cooperation and strong connections between individuals. Public Goods Games (PGGs) are frequently used to study the development of social connections and cooperative behavior in model societies. In such games, contributions to the public good are made only by cooperators, while all players, including defectors, reap public goods benefits, which are shares of the contributions amplified by a synergy factor. Classic results of game theory show that mutual defection, as opposed to cooperation, is the Nash Equilibrium of PGGs in well-mixed populations, where each player interacts with all others. In this paper, we explore the coevolutionary dynamics of a low information public goods game on a complex network in which players adapt to their environment in order to increase individual payoffs relative to past payoffs parameterized by greediness. Players adapt by changing their strategies, either to cooperate or to defect, and by altering their social connections. We find that even if players do not know other players' strategies and connectivity, cooperation can arise and persist despite large short-term fluctuations.

  7. Public goods games on adaptive coevolutionary networks.

    PubMed

    Pichler, Elgar; Shapiro, Avi M

    2017-07-01

    Productive societies feature high levels of cooperation and strong connections between individuals. Public Goods Games (PGGs) are frequently used to study the development of social connections and cooperative behavior in model societies. In such games, contributions to the public good are made only by cooperators, while all players, including defectors, reap public goods benefits, which are shares of the contributions amplified by a synergy factor. Classic results of game theory show that mutual defection, as opposed to cooperation, is the Nash Equilibrium of PGGs in well-mixed populations, where each player interacts with all others. In this paper, we explore the coevolutionary dynamics of a low information public goods game on a complex network in which players adapt to their environment in order to increase individual payoffs relative to past payoffs parameterized by greediness. Players adapt by changing their strategies, either to cooperate or to defect, and by altering their social connections. We find that even if players do not know other players' strategies and connectivity, cooperation can arise and persist despite large short-term fluctuations.

  8. Coevolutionary analysis enabled rational deregulation of allosteric enzyme inhibition in Corynebacterium glutamicum for lysine production.

    PubMed

    Chen, Zhen; Meyer, Weiqian; Rappert, Sugima; Sun, Jibin; Zeng, An-Ping

    2011-07-01

    Product feedback inhibition of allosteric enzymes is an essential issue for the development of highly efficient microbial strains for bioproduction. Here we used aspartokinase from Corynebacterium glutamicum (CgAK), a key enzyme controlling the biosynthesis of industrially important aspartate family amino acids, as a model to demonstrate a fast and efficient approach to the deregulation of allostery. In the last 50 years many researchers and companies have made considerable efforts to deregulate this enzyme from allosteric inhibition by lysine and threonine. However, only a limited number of positive mutants have been identified so far, almost exclusively by random mutation and selection. In this study, we used statistical coupling analysis of protein sequences, a method based on coevolutionary analysis, to systematically clarify the interaction network within the regulatory domain of CgAK that is essential for allosteric inhibition. A cluster of interconnected residues linking different inhibitors' binding sites as well as other regions of the protein have been identified, including most of the previously reported positions of successful mutations. Beyond these mutation positions, we have created another 14 mutants that can partially or completely desensitize CgAK from allosteric inhibition, as shown by enzyme activity assays. The introduction of only one of the inhibition-insensitive CgAK mutations (here Q298G) into a wild-type C. glutamicum strain by homologous recombination resulted in an accumulation of 58 g/liter L-lysine within 30 h of fed-batch fermentation in a bioreactor.

  9. Coevolution between invasive and native plants driven by chemical competition and soil biota.

    PubMed

    Lankau, Richard A

    2012-07-10

    Although reciprocal evolutionary responses between interacting species are a driving force behind the diversity of life, pairwise coevolution between plant competitors has received less attention than other species interactions and has been considered relatively less important in explaining ecological patterns. However, the success of species transported across biogeographic boundaries suggests a stronger role for evolutionary relationships in shaping plant interactions. Alliaria petiolata is a Eurasian species that has invaded North American forest understories, where it competes with native understory species in part by producing compounds that directly and indirectly slow the growth of competing species. Here I show that populations of A. petiolata from areas with a greater density of interspecific competitors invest more in a toxic allelochemical under common conditions. Furthermore, populations of a native competitor from areas with highly toxic invaders are more tolerant to competition from the invader, suggesting coevolutionary dynamics between the species. Field reciprocal transplants confirmed that native populations more tolerant to the invader had higher fitness when the invader was common, but these traits came at a cost when the invader was rare. Exotic species are often detrimentally dominant in their new range due to their evolutionary novelty; however, the development of new coevolutionary relationships may act to integrate exotic species into native communities.

  10. A Multipopulation Coevolutionary Strategy for Multiobjective Immune Algorithm

    PubMed Central

    Shi, Jiao; Gong, Maoguo; Ma, Wenping; Jiao, Licheng

    2014-01-01

    How to maintain the population diversity is an important issue in designing a multiobjective evolutionary algorithm. This paper presents an enhanced nondominated neighbor-based immune algorithm in which a multipopulation coevolutionary strategy is introduced for improving the population diversity. In the proposed algorithm, subpopulations evolve independently; thus the unique characteristics of each subpopulation can be effectively maintained, and the diversity of the entire population is effectively increased. Besides, the dynamic information of multiple subpopulations is obtained with the help of the designed cooperation operator which reflects a mutually beneficial relationship among subpopulations. Subpopulations gain the opportunity to exchange information, thereby expanding the search range of the entire population. Subpopulations make use of the reference experience from each other, thereby improving the efficiency of evolutionary search. Compared with several state-of-the-art multiobjective evolutionary algorithms on well-known and frequently used multiobjective and many-objective problems, the proposed algorithm achieves comparable results in terms of convergence, diversity metrics, and running time on most test problems. PMID:24672330

  11. Nonlocal birth-death competitive dynamics with volume exclusion

    NASA Astrophysics Data System (ADS)

    Khalil, Nagi; López, Cristóbal; Hernández-García, Emilio

    2017-06-01

    A stochastic birth-death competition model for particles with excluded volume is proposed. The particles move, reproduce, and die on a regular lattice. While the death rate is constant, the birth rate is spatially nonlocal and implements inter-particle competition by a dependence on the number of particles within a finite distance. The finite volume of particles is accounted for by fixing an upper value to the number of particles that can occupy a lattice node, compromising births and movements. We derive closed macroscopic equations for the density of particles and spatial correlation at two adjacent sites. Under different conditions, the description is further reduced to a single equation for the particle density that contains three terms: diffusion, a linear death, and a highly nonlinear and nonlocal birth term. Steady-state homogeneous solutions, their stability which reveals spatial pattern formation, and the dynamics of time-dependent homogeneous solutions are discussed and compared, in the one-dimensional case, with numerical simulations of the particle system.

  12. Competition among physicians. Avoiding anticompetitive activities.

    PubMed

    Oliver, D

    1988-12-01

    Increases in both the cost of medical care and the numbers of providers have generated strong pressure for competition in the medical profession. The Federal Trade Commission strives to maintain such competition free from public and private restraints in order to maximize consumer welfare. The author describes the advantages of these types of competitive practices and discusses the competitive restraints that most concern the FTC: restrictions on ethical advertising, exclusion of competitors, restraints on dispensing drugs, and restrictions on commercial practice locations.

  13. Detection of bacteria from a cecal anaerobic competitive exclusion culture with an immunoassay electrochemiluminescence sensor

    NASA Astrophysics Data System (ADS)

    Beier, Ross C.; Young, Colin R.; Stanker, Larry H.

    1999-01-01

    A competitive exclusion (CE) culture of chicken cecal anaerobes has been developed and used in this laboratory for control of Salmonella typhimurium in chickens. The CE culture consists of 29 different species of micro-organisms, and is known as CF3. Detection of one of the CF3 bacteria, Eubacteria, and S. typhimurium were demonstrated using a commercial immunomagnetic (IM) electrochemiluminescence (ECL) sensor, the ORIGENR Analyzer. Analysis was achieved using a sandwich immunoassay. Bacteria were captured on antibody- conjugated 280 micron sized magnetic beads followed by binding of reporter antibodies labelled with ruthenium (II) tris(dipyridyl) chelate [Ru(bpy)32+]. The magnetic beads were then trapped on an electrode in the reaction cell of the ORIGENR Analyzer by a magnet, and the ECL was evoked from Ru(bpy)32+ on the tagged reporter antibodies by an electrical potential at the electrode. Preliminary IM-ECL assays with Eubacteria yielded a detection limit of 105 cfu/mL. Preliminary IM-ECL assays with S. typhimurium yielded a similar detection limit of 105 cfu/mL.

  14. Coevolutionary Analysis Enabled Rational Deregulation of Allosteric Enzyme Inhibition in Corynebacterium glutamicum for Lysine Production ▿

    PubMed Central

    Chen, Zhen; Meyer, Weiqian; Rappert, Sugima; Sun, Jibin; Zeng, An-Ping

    2011-01-01

    Product feedback inhibition of allosteric enzymes is an essential issue for the development of highly efficient microbial strains for bioproduction. Here we used aspartokinase from Corynebacterium glutamicum (CgAK), a key enzyme controlling the biosynthesis of industrially important aspartate family amino acids, as a model to demonstrate a fast and efficient approach to the deregulation of allostery. In the last 50 years many researchers and companies have made considerable efforts to deregulate this enzyme from allosteric inhibition by lysine and threonine. However, only a limited number of positive mutants have been identified so far, almost exclusively by random mutation and selection. In this study, we used statistical coupling analysis of protein sequences, a method based on coevolutionary analysis, to systematically clarify the interaction network within the regulatory domain of CgAK that is essential for allosteric inhibition. A cluster of interconnected residues linking different inhibitors' binding sites as well as other regions of the protein have been identified, including most of the previously reported positions of successful mutations. Beyond these mutation positions, we have created another 14 mutants that can partially or completely desensitize CgAK from allosteric inhibition, as shown by enzyme activity assays. The introduction of only one of the inhibition-insensitive CgAK mutations (here Q298G) into a wild-type C. glutamicum strain by homologous recombination resulted in an accumulation of 58 g/liter l-lysine within 30 h of fed-batch fermentation in a bioreactor. PMID:21531824

  15. Competitive Exclusion Reduces Transmission and Excretion of Extended-Spectrum-β-Lactamase-Producing Escherichia coli in Broilers

    PubMed Central

    van Essen-Zandbergen, Alieda; Smid, Bregtje; Veldman, Kees T.; Boender, Gert Jan; Fischer, Egil A. J.; Mevius, Dik J.

    2017-01-01

    ABSTRACT Extended-spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases (pAmpC) are enzymes able to hydrolyze a large variety of β-lactam antibiotics, including third-generation cephalosporins and monobactams. Broilers and broiler meat products can be highly contaminated with ESBL- and pAmpC-producing Escherichia coli strains, also known as extended-spectrum cephalosporin (ESC)-resistant E. coli strains, and can be a source for human infections. As few data on interventions to reduce the presence of ESC-resistant E. coli in broilers are available, we used transmission experiments to examine the role of competitive exclusion (CE) on reducing transmission and excretion in broilers. A broiler model to study the transmission of ESC-resistant E. coli was set up. Day-old chickens were challenged with an ESBL-producing E. coli strain isolated from healthy broilers in the Netherlands. Challenged and not challenged chicks were housed together in pairs or in groups, and ESBL-producing E. coli transmission was monitored via selective culturing of cloacal swab specimens. We observed a statistically significant reduction in both the transmission and excretion of ESBL-producing E. coli in chicks treated with the probiotic flora before E. coli challenge compared to the transmission and excretion in untreated controls. In conclusion, our results support the use of competitive exclusion as an intervention strategy to control ESC-resistant E. coli in the field. IMPORTANCE Extended-spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases are a primary cause of resistance to β-lactam antibiotics among members of the family Enterobacteriaceae in humans, animals, and the environment. Food-producing animals are not exempt from this, with a high prevalence being seen in broilers, and there is evidence pointing to a possible foodborne source for human contamination. We investigated the effect of administration of a commercial probiotic product as an

  16. Competitive Exclusion Reduces Transmission and Excretion of Extended-Spectrum-β-Lactamase-Producing Escherichia coli in Broilers.

    PubMed

    Ceccarelli, Daniela; van Essen-Zandbergen, Alieda; Smid, Bregtje; Veldman, Kees T; Boender, Gert Jan; Fischer, Egil A J; Mevius, Dik J; van der Goot, Jeanet A

    2017-06-01

    Extended-spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases (pAmpC) are enzymes able to hydrolyze a large variety of β-lactam antibiotics, including third-generation cephalosporins and monobactams. Broilers and broiler meat products can be highly contaminated with ESBL- and pAmpC-producing Escherichia coli strains, also known as extended-spectrum cephalosporin (ESC)-resistant E. coli strains, and can be a source for human infections. As few data on interventions to reduce the presence of ESC-resistant E. coli in broilers are available, we used transmission experiments to examine the role of competitive exclusion (CE) on reducing transmission and excretion in broilers. A broiler model to study the transmission of ESC-resistant E. coli was set up. Day-old chickens were challenged with an ESBL-producing E. coli strain isolated from healthy broilers in the Netherlands. Challenged and not challenged chicks were housed together in pairs or in groups, and ESBL-producing E. coli transmission was monitored via selective culturing of cloacal swab specimens. We observed a statistically significant reduction in both the transmission and excretion of ESBL-producing E. coli in chicks treated with the probiotic flora before E. coli challenge compared to the transmission and excretion in untreated controls. In conclusion, our results support the use of competitive exclusion as an intervention strategy to control ESC-resistant E. coli in the field. IMPORTANCE Extended-spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases are a primary cause of resistance to β-lactam antibiotics among members of the family Enterobacteriaceae in humans, animals, and the environment. Food-producing animals are not exempt from this, with a high prevalence being seen in broilers, and there is evidence pointing to a possible foodborne source for human contamination. We investigated the effect of administration of a commercial probiotic product as an intervention to

  17. 47 CFR 80.1251 - Maritime communications subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Maritime communications subject to competitive... AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Competitive Bidding Procedures § 80.1251 Maritime communications subject to competitive bidding. Mutually exclusive initial applications for VPCSA...

  18. Control of Salmonella Enteritidis in turkeys using organic acids and competitive exclusion product.

    PubMed

    Milbradt, E L; Zamae, J R; Araújo Júnior, J P; Mazza, P; Padovani, C R; Carvalho, V R; Sanfelice, C; Rodrigues, D M; Okamoto, A S; Andreatti Filho, R L

    2014-08-01

    To evaluate the use of organic acids (OAs) and competitive exclusion (CE) product administered continuously in the feed and transiently in drinking water on the control of Salmonella enterica subspecie enterica serotype Enteritidis (SE) prior to slaughter. The influence of treatments were evaluated on pH, population of the lactic acid bacteria (LAB) and bacteria of the family Enterobacteriaceae, concentration of volatile fatty acids and SE colonization in the crop and caecum. The birds were challenged with SE 24 h before being slaughtered, and then, the caeca and crop were removed and subjected to SE counts. Continuous administration of OAs reduced the population of bacteria from the Enterobacteriaceae family in both crop and caecum, positively influenced the butyric acid concentration and reduced SE colonization in the caecum. The diet supplemented with CE product positively influenced the quantity of LAB in the crop and caecum, elevated the butyric acid concentration and reduced both Enterobacteriaceae quantity and SE colonization in the caecum. There was no effect from administering the treatments via drinking water on the variables measured. Continuous supplementation in feed with OAs and CE product reduced SE colonization of the caeca. Supplementation of OAs and CE product in diet to turkeys can reduce the SE load, potentially leading to a lower contamination risk of meat during slaughter. © 2014 The Society for Applied Microbiology.

  19. Social exclusion: the interplay of group goals and individual characteristics.

    PubMed

    Richardson, Cameron B; Hitti, Aline; Mulvey, Kelly Lynn; Killen, Melanie

    2014-08-01

    Past research has shown that adolescents justify social exclusion based on concerns for group functioning, and yet, to date, no study has evaluated whether group functioning justifications shift or remain stable across different exclusion contexts. In this study, we systematically manipulated exclusion context (i.e., competitive or noncompetitive soccer groups) and individual characteristics of the target of exclusion to test the nature of the interaction between these factors during exclusion judgments. Adolescents' (N = 201; 61% Female) exclusion judgments differed across contexts only when an individual's ability was under consideration. Intergroup (i.e., gender, nationality) and interpersonal (i.e., aggression, shyness) characteristics overwhelmed contextual considerations. Results indicate the complexity of factors weighed by adolescents when making exclusion judgments, and suggest the need for extension of the present findings to understand more fully the interaction between the context of exclusion and individual characteristics in exclusion judgments.

  20. Coevolutionary arms race versus host defense chase in a tropical herbivore-plant system.

    PubMed

    Endara, María-José; Coley, Phyllis D; Ghabash, Gabrielle; Nicholls, James A; Dexter, Kyle G; Donoso, David A; Stone, Graham N; Pennington, R Toby; Kursar, Thomas A

    2017-09-05

    Coevolutionary models suggest that herbivores drive diversification and community composition in plants. For herbivores, many questions remain regarding how plant defenses shape host choice and community structure. We addressed these questions using the tree genus Inga and its lepidopteran herbivores in the Amazon. We constructed phylogenies for both plants and insects and quantified host associations and plant defenses. We found that similarity in herbivore assemblages between Inga species was correlated with similarity in defenses. There was no correlation with phylogeny, a result consistent with our observations that the expression of defenses in Inga is independent of phylogeny. Furthermore, host defensive traits explained 40% of herbivore community similarity. Analyses at finer taxonomic scales showed that different lepidopteran clades select hosts based on different defenses, suggesting taxon-specific histories of herbivore-host plant interactions. Finally, we compared the phylogeny and defenses of Inga to phylogenies for the major lepidopteran clades. We found that closely related herbivores fed on Inga with similar defenses rather than on closely related plants. Together, these results suggest that plant defenses might be more evolutionarily labile than the herbivore traits related to host association. Hence, there is an apparent asymmetry in the evolutionary interactions between Inga and its herbivores. Although plants may evolve under selection by herbivores, we hypothesize that herbivores may not show coevolutionary adaptations, but instead "chase" hosts based on the herbivore's own traits at the time that they encounter a new host, a pattern more consistent with resource tracking than with the arms race model of coevolution.

  1. Coevolutionary arms race versus host defense chase in a tropical herbivore–plant system

    PubMed Central

    Coley, Phyllis D.; Ghabash, Gabrielle; Nicholls, James A.; Donoso, David A.; Stone, Graham N.; Pennington, R. Toby; Kursar, Thomas A.

    2017-01-01

    Coevolutionary models suggest that herbivores drive diversification and community composition in plants. For herbivores, many questions remain regarding how plant defenses shape host choice and community structure. We addressed these questions using the tree genus Inga and its lepidopteran herbivores in the Amazon. We constructed phylogenies for both plants and insects and quantified host associations and plant defenses. We found that similarity in herbivore assemblages between Inga species was correlated with similarity in defenses. There was no correlation with phylogeny, a result consistent with our observations that the expression of defenses in Inga is independent of phylogeny. Furthermore, host defensive traits explained 40% of herbivore community similarity. Analyses at finer taxonomic scales showed that different lepidopteran clades select hosts based on different defenses, suggesting taxon-specific histories of herbivore–host plant interactions. Finally, we compared the phylogeny and defenses of Inga to phylogenies for the major lepidopteran clades. We found that closely related herbivores fed on Inga with similar defenses rather than on closely related plants. Together, these results suggest that plant defenses might be more evolutionarily labile than the herbivore traits related to host association. Hence, there is an apparent asymmetry in the evolutionary interactions between Inga and its herbivores. Although plants may evolve under selection by herbivores, we hypothesize that herbivores may not show coevolutionary adaptations, but instead “chase” hosts based on the herbivore’s own traits at the time that they encounter a new host, a pattern more consistent with resource tracking than with the arms race model of coevolution. PMID:28827317

  2. Follow-on biologics: data exclusivity and the balance between innovation and competition.

    PubMed

    Grabowski, Henry

    2008-06-01

    Legislation to create a regulatory pathway for follow-on biologics is currently being considered by the United States Congress. A critical issue in this respect is the period of data exclusivity for innovator companies before a follow-on competitor can rely in part on data obtained for an original biologic for an abbreviated approval. Given the nature of patents on biologics, the period of data exclusivity is anticipated to have a key role in determining how quickly follow-on competitors emerge, and consequently also on the time available for originator companies to recoup their investment. With this issue in mind, this article discusses factors influencing return on investment on biologic research and development. A break-even analysis for a representative portfolio of biologics provides support for a substantial data exclusivity period.

  3. UK Higher Education: Competitive Forces in the 21st Century.

    ERIC Educational Resources Information Center

    Webber, G. C.

    2000-01-01

    Considers United Kingdom higher education in the context of Michael Porter's book, "Competitive Strategy," which discusses five forces governing competition. Focusing mainly, but not exclusively, on teaching, the monograph identifies critical factors that have influenced the balance of competitive forces in higher education and…

  4. Natural Hazard Management from a Coevolutionary Perspective: Exposure and Policy Response in the European Alps.

    PubMed

    Fuchs, Sven; Röthlisberger, Veronika; Thaler, Thomas; Zischg, Andreas; Keiler, Margreth

    2017-03-04

    A coevolutionary perspective is adopted to understand the dynamics of exposure to mountain hazards in the European Alps. A spatially explicit, object-based temporal assessment of elements at risk to mountain hazards (river floods, torrential floods, and debris flows) in Austria and Switzerland is presented for the period from 1919 to 2012. The assessment is based on two different data sets: (1) hazard information adhering to legally binding land use planning restrictions and (2) information on building types combined from different national-level spatial data. We discuss these transdisciplinary dynamics and focus on economic, social, and institutional interdependencies and interactions between human and physical systems. Exposure changes in response to multiple drivers, including population growth and land use conflicts. The results show that whereas some regional assets are associated with a strong increase in exposure to hazards, others are characterized by a below-average level of exposure. The spatiotemporal results indicate relatively stable hot spots in the European Alps. These results coincide with the topography of the countries and with the respective range of economic activities and political settings. Furthermore, the differences between management approaches as a result of multiple institutional settings are discussed. A coevolutionary framework widens the explanatory power of multiple drivers to changes in exposure and risk and supports a shift from structural, security-based policies toward an integrated, risk-based natural hazard management system.

  5. Natural Hazard Management from a Coevolutionary Perspective: Exposure and Policy Response in the European Alps

    PubMed Central

    Fuchs, Sven; Röthlisberger, Veronika; Thaler, Thomas; Zischg, Andreas; Keiler, Margreth

    2017-01-01

    A coevolutionary perspective is adopted to understand the dynamics of exposure to mountain hazards in the European Alps. A spatially explicit, object-based temporal assessment of elements at risk to mountain hazards (river floods, torrential floods, and debris flows) in Austria and Switzerland is presented for the period from 1919 to 2012. The assessment is based on two different data sets: (1) hazard information adhering to legally binding land use planning restrictions and (2) information on building types combined from different national-level spatial data. We discuss these transdisciplinary dynamics and focus on economic, social, and institutional interdependencies and interactions between human and physical systems. Exposure changes in response to multiple drivers, including population growth and land use conflicts. The results show that whereas some regional assets are associated with a strong increase in exposure to hazards, others are characterized by a below-average level of exposure. The spatiotemporal results indicate relatively stable hot spots in the European Alps. These results coincide with the topography of the countries and with the respective range of economic activities and political settings. Furthermore, the differences between management approaches as a result of multiple institutional settings are discussed. A coevolutionary framework widens the explanatory power of multiple drivers to changes in exposure and risk and supports a shift from structural, security-based policies toward an integrated, risk-based natural hazard management system. PMID:28267154

  6. Flood hazard management from a coevolutionary perspective: exposure and policy response in the European Alps

    NASA Astrophysics Data System (ADS)

    Fuchs, Sven; Röthlisberger, Veronika; Thaler, Thomas; Zischg, Andreas; Keiler, Margreth

    2017-04-01

    A coevolutionary perspective is adopted to understand the dynamics of exposure to hydrological hazards in the European Alps. A spatially explicit, object-based temporal assessment of elements at risk to flood hazards (river floods, torrential floods and debris flows) in Austria and Switzerland is presented for the 1919-2012 period. The assessment is based on two different datasets, (a) hazard information adhering to legally binding land use planning restrictions and (b) information on building types combined from different national level spatial data. We discuss these transdisciplinary dynamics and focus on economic, social and institutional interdependencies and interactions between human and physical systems. Exposure changes in the response to multiple drivers, including population growth and land use conflicts. The results show that while some regional assets are associated with a strong increase in exposure to hazards, others are characterized by a below-average level of exposure. The spatiotemporal results indicate relatively stable hot spots in the European Alps. These results coincide with the topography of the countries and with the respective range of economic activities and political settings. Furthermore, the differences between management approaches as a result of multiple institutional settings are discussed. A coevolutionary framework widens the explanatory power of multiple drivers to changes in exposure and risk, and supports a shift from structural, security-based policies towards an integrated, risk-based natural hazard management system.

  7. Success of cuckoo catfish brood parasitism reflects coevolutionary history and individual experience of their cichlid hosts

    PubMed Central

    Polačik, Matej; Smith, Carl; Honza, Marcel; Reichard, Martin

    2018-01-01

    Obligate brood parasites manipulate other species into raising their offspring. Avian and insect brood parasitic systems demonstrate how interacting species engage in reciprocal coevolutionary arms races through behavioral and morphological adaptations and counteradaptations. Mouthbrooding cichlid fishes are renowned for their remarkable evolutionary radiations and complex behaviors. In Lake Tanganyika, mouthbrooding cichlids are exploited by the only obligate nonavian vertebrate brood parasite, the cuckoo catfish Synodontis multipunctatus. We show that coevolutionary history and individual learning both have a major impact on the success of cuckoo catfish parasitism between coevolved sympatric and evolutionarily naïve allopatric cichlid species. The rate of cuckoo catfish parasitism in coevolved Tanganyikan hosts was 3 to 11 times lower than in evolutionarily naïve cichlids. Moreover, using experimental infections, we demonstrate that parasite egg rejection in sympatric hosts was much higher, leading to seven times greater parasite survival in evolutionarily naïve than sympatric hosts. However, a high rejection frequency of parasitic catfish eggs by coevolved sympatric hosts came at a cost of increased rejection of their own eggs. A significant cost of catfish parasitism was universal, except for coevolved sympatric cichlid species with previous experience of catfish parasitism, demonstrating that learning and individual experience both contribute to a successful host response. PMID:29732407

  8. Network intrusion detection by the coevolutionary immune algorithm of artificial immune systems with clonal selection

    NASA Astrophysics Data System (ADS)

    Salamatova, T.; Zhukov, V.

    2017-02-01

    The paper presents the application of the artificial immune systems apparatus as a heuristic method of network intrusion detection for algorithmic provision of intrusion detection systems. The coevolutionary immune algorithm of artificial immune systems with clonal selection was elaborated. In testing different datasets the empirical results of evaluation of the algorithm effectiveness were achieved. To identify the degree of efficiency the algorithm was compared with analogs. The fundamental rules based of solutions generated by this algorithm are described in the article.

  9. Competitive intransitivity promotes species coexistence.

    PubMed

    Laird, Robert A; Schamp, Brandon S

    2006-08-01

    Using a spatially explicit cellular automaton model with local competition, we investigate the potential for varied levels of competitive intransitivity (i.e., nonhierarchical competition) to promote species coexistence. As predicted, on average, increased levels of intransitivity result in more sustained coexistence within simulated communities, although the outcome of competition also becomes increasingly unpredictable. Interestingly, even a moderate degree of intransitivity within a community can promote coexistence, in terms of both the length of time until the first competitive exclusion and the number of species remaining in the community after 500 simulated generations. These results suggest that modest levels of intransitivity in nature, such as those that are thought to be characteristic of plant communities, can contribute to coexistence and, therefore, community-scale biodiversity. We explore a potential connection between competitive intransitivity and neutral theory, whereby competitive intransitivity may represent an important mechanism for "ecological equivalence."

  10. Dynamic use of wetlands by black ducks and mallards: evidence against competitive exclusion

    USGS Publications Warehouse

    McAuley, D.G.; Clugston, D.A.; Longcore, J.R.

    2004-01-01

    The decline of the American black duck (Anas rubripes) has been attributed to competition from mallards (A. platyrhynchos) that led to exclusive use of fertile wetlands by mallards. Data from annual breeding waterfowl surveys provide instantaneous, single observations of breeding pairs, which are used to estimate breeding population size and evaluate the condition of habitat. Data from these surveys have been used to document habitat use by black ducks and mallards. We used quiet-observation surveys from elevated platforms to study sympatric black ducks and mallards in northern Maine during the breeding season. Our objectives were to document occupancy of wetlands by breeding black ducks and mallards throughout the day during prenesting and early nesting periods to determine whether 1) wetlands were occupied by only a single species, 2) pairs of the same species occupied wetlands throughout the period, and 3) single observations of short duration adequately determine numbers and species using a wetland. We observed ducks at 5-minute intervals from elevated platforms on wetland margins to determine numbers and species of indicated pairs using each wetland over time. We visited 80% of the wetlands >2 times, with mean total time per wetland averaging 267 minutes. For each wetland we determined the most frequently observed grouping of black ducks and mallards from all combinations recorded during all intervals (e.g., 1 black duck [BO] pair during 9 intervals; 2 mallard [MA] pairs and 1 BO pair during 22 intervals; 0 pairs during 3 intervals). A single pair, a lone male, or no ducks were recorded during 34% of the 5-minute intervals. For wetlands with >2 hours of observations (n=65), all but 2 were used by >2 different combinations of ducks. On most wetlands, the most frequent grouping was observed during 2 hours were used by both species, random visits detected both species on only 27 wetlands. Our data do not support assertions that the mallard has caused the decline

  11. Multiagent Flight Control in Dynamic Environments with Cooperative Coevolutionary Algorithms

    NASA Technical Reports Server (NTRS)

    Knudson, Matthew D.; Colby, Mitchell; Tumer, Kagan

    2014-01-01

    Dynamic flight environments in which objectives and environmental features change with respect to time pose a difficult problem with regards to planning optimal flight paths. Path planning methods are typically computationally expensive, and are often difficult to implement in real time if system objectives are changed. This computational problem is compounded when multiple agents are present in the system, as the state and action space grows exponentially. In this work, we use cooperative coevolutionary algorithms in order to develop policies which control agent motion in a dynamic multiagent unmanned aerial system environment such that goals and perceptions change, while ensuring safety constraints are not violated. Rather than replanning new paths when the environment changes, we develop a policy which can map the new environmental features to a trajectory for the agent while ensuring safe and reliable operation, while providing 92% of the theoretically optimal performance

  12. Sequence of host contact influences the outcome of competition among Aspergillus flavus isolates during host tissue invasion

    USDA-ARS?s Scientific Manuscript database

    Biological control of aflatoxin contamination by Aspergillus flavus is achieved by competitive exclusion of aflatoxin producers by atoxigenic strains. However, factors dictating the extent to which competitive displacement occurs during host infection are unknown. The role of preemptive exclusion in...

  13. Co-evolutionary dynamics of the human-environment system in the Heihe River basin in the past 2000years.

    PubMed

    Lu, Zhixiang; Wei, Yongping; Feng, Qi; Xie, Jiali; Xiao, Honglang; Cheng, Guodong

    2018-09-01

    There is limited quantitative understanding of interactions between human and environmental systems over the millennial scale. We aim to reveal the co-evolutionary dynamics of the human-environment system in a river basin by simulating the water use and net primary production (NPP) allocation for human and environmental systems over the last 2000years in Heihe River basin (HRB) in northwest China. We partition the catchment total evapotranspiration (ET) into ET for human and environmental systems with a social-hydrological framework and estimate the NPP for human and environmental systems using the Box-Lieth model, then classify the co-evolutionary processes of the human-environment system into distinct phases using the rate of changes of NPP over time, and discover the trade-offs or synergies relationships between them based on the elasticity of change of the NPP for humans to the change of NPP for environment. The co-evolutionary dynamics of human-environment system in the HRB can be divided into four periods, including: Phase I (Han Dynasty-Yuan Dynasty): predevelopment characterized by nearly no trade-offs between human and environment; Phase II (Yuan Dynasty-RC): slow agricultural development: characterized by a small human win due to small trade-offs between human and environment; Phase III (RC-2000): rapid agricultural development: characterized by a large human win due to large trade-offs between human and environment, and Phase IV (2000-2010): a rebalance characterized by large human wins with a small-environment win due to synergies, although these occurred very occasionally. This study provides a quantitative approach to describe the co-evolution of the human-environment system from the perspective of trade-offs and synergies in the millennial scale for the first time. The relationships between humans and environment changed from trade-off to synergy with the implementation of the water reallocation scheme in 2000. These findings improve the

  14. 47 CFR 90.801 - 900 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 900 MHz Specialized Mobile Radio Service § 90.801 900 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 900 MHz SMR service licenses are subject to competitive bidding. The...

  15. 47 CFR 22.201 - Paging geographic area authorizations are subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Licensing Requirements and Procedures Competitive.... Mutually exclusive initial applications for paging geographic area licenses are subject to competitive...

  16. Classification as clustering: a Pareto cooperative-competitive GP approach.

    PubMed

    McIntyre, Andrew R; Heywood, Malcolm I

    2011-01-01

    Intuitively population based algorithms such as genetic programming provide a natural environment for supporting solutions that learn to decompose the overall task between multiple individuals, or a team. This work presents a framework for evolving teams without recourse to prespecifying the number of cooperating individuals. To do so, each individual evolves a mapping to a distribution of outcomes that, following clustering, establishes the parameterization of a (Gaussian) local membership function. This gives individuals the opportunity to represent subsets of tasks, where the overall task is that of classification under the supervised learning domain. Thus, rather than each team member representing an entire class, individuals are free to identify unique subsets of the overall classification task. The framework is supported by techniques from evolutionary multiobjective optimization (EMO) and Pareto competitive coevolution. EMO establishes the basis for encouraging individuals to provide accurate yet nonoverlaping behaviors; whereas competitive coevolution provides the mechanism for scaling to potentially large unbalanced datasets. Benchmarking is performed against recent examples of nonlinear SVM classifiers over 12 UCI datasets with between 150 and 200,000 training instances. Solutions from the proposed coevolutionary multiobjective GP framework appear to provide a good balance between classification performance and model complexity, especially as the dataset instance count increases.

  17. Multiagent Flight Control in Dynamic Environments with Cooperative Coevolutionary Algorithms

    NASA Technical Reports Server (NTRS)

    Colby, Mitchell; Knudson, Matthew D.; Tumer, Kagan

    2014-01-01

    Dynamic environments in which objectives and environmental features change with respect to time pose a difficult problem with regards to planning optimal paths through these environments. Path planning methods are typically computationally expensive, and are often difficult to implement in real time if system objectives are changed. This computational problem is compounded when multiple agents are present in the system, as the state and action space grows exponentially with the number of agents in the system. In this work, we use cooperative coevolutionary algorithms in order to develop policies which control agent motion in a dynamic multiagent unmanned aerial system environment such that goals and perceptions change, while ensuring safety constraints are not violated. Rather than replanning new paths when the environment changes, we develop a policy which can map the new environmental features to a trajectory for the agent while ensuring safe and reliable operation, while providing 92% of the theoretically optimal performance.

  18. Computational Analysis of Residue Interaction Networks and Coevolutionary Relationships in the Hsp70 Chaperones: A Community-Hopping Model of Allosteric Regulation and Communication

    PubMed Central

    Stetz, Gabrielle; Verkhivker, Gennady M.

    2017-01-01

    Allosteric interactions in the Hsp70 proteins are linked with their regulatory mechanisms and cellular functions. Despite significant progress in structural and functional characterization of the Hsp70 proteins fundamental questions concerning modularity of the allosteric interaction networks and hierarchy of signaling pathways in the Hsp70 chaperones remained largely unexplored and poorly understood. In this work, we proposed an integrated computational strategy that combined atomistic and coarse-grained simulations with coevolutionary analysis and network modeling of the residue interactions. A novel aspect of this work is the incorporation of dynamic residue correlations and coevolutionary residue dependencies in the construction of allosteric interaction networks and signaling pathways. We found that functional sites involved in allosteric regulation of Hsp70 may be characterized by structural stability, proximity to global hinge centers and local structural environment that is enriched by highly coevolving flexible residues. These specific characteristics may be necessary for regulation of allosteric structural transitions and could distinguish regulatory sites from nonfunctional conserved residues. The observed confluence of dynamics correlations and coevolutionary residue couplings with global networking features may determine modular organization of allosteric interactions and dictate localization of key mediating sites. Community analysis of the residue interaction networks revealed that concerted rearrangements of local interacting modules at the inter-domain interface may be responsible for global structural changes and a population shift in the DnaK chaperone. The inter-domain communities in the Hsp70 structures harbor the majority of regulatory residues involved in allosteric signaling, suggesting that these sites could be integral to the network organization and coordination of structural changes. Using a network-based formalism of allostery, we

  19. Computational Analysis of Residue Interaction Networks and Coevolutionary Relationships in the Hsp70 Chaperones: A Community-Hopping Model of Allosteric Regulation and Communication.

    PubMed

    Stetz, Gabrielle; Verkhivker, Gennady M

    2017-01-01

    Allosteric interactions in the Hsp70 proteins are linked with their regulatory mechanisms and cellular functions. Despite significant progress in structural and functional characterization of the Hsp70 proteins fundamental questions concerning modularity of the allosteric interaction networks and hierarchy of signaling pathways in the Hsp70 chaperones remained largely unexplored and poorly understood. In this work, we proposed an integrated computational strategy that combined atomistic and coarse-grained simulations with coevolutionary analysis and network modeling of the residue interactions. A novel aspect of this work is the incorporation of dynamic residue correlations and coevolutionary residue dependencies in the construction of allosteric interaction networks and signaling pathways. We found that functional sites involved in allosteric regulation of Hsp70 may be characterized by structural stability, proximity to global hinge centers and local structural environment that is enriched by highly coevolving flexible residues. These specific characteristics may be necessary for regulation of allosteric structural transitions and could distinguish regulatory sites from nonfunctional conserved residues. The observed confluence of dynamics correlations and coevolutionary residue couplings with global networking features may determine modular organization of allosteric interactions and dictate localization of key mediating sites. Community analysis of the residue interaction networks revealed that concerted rearrangements of local interacting modules at the inter-domain interface may be responsible for global structural changes and a population shift in the DnaK chaperone. The inter-domain communities in the Hsp70 structures harbor the majority of regulatory residues involved in allosteric signaling, suggesting that these sites could be integral to the network organization and coordination of structural changes. Using a network-based formalism of allostery, we

  20. An ecocultural model predicts Neanderthal extinction through competition with modern humans.

    PubMed

    Gilpin, William; Feldman, Marcus W; Aoki, Kenichi

    2016-02-23

    Archaeologists argue that the replacement of Neanderthals by modern humans was driven by interspecific competition due to a difference in culture level. To assess the cogency of this argument, we construct and analyze an interspecific cultural competition model based on the Lotka-Volterra model, which is widely used in ecology, but which incorporates the culture level of a species as a variable interacting with population size. We investigate the conditions under which a difference in culture level between cognitively equivalent species, or alternatively a difference in underlying learning ability, may produce competitive exclusion of a comparatively (although not absolutely) large local Neanderthal population by an initially smaller modern human population. We find, in particular, that this competitive exclusion is more likely to occur when population growth occurs on a shorter timescale than cultural change, or when the competition coefficients of the Lotka-Volterra model depend on the difference in the culture levels of the interacting species.

  1. Building toy models of proteins using coevolutionary information

    NASA Astrophysics Data System (ADS)

    Cheng, Ryan; Raghunathan, Mohit; Onuchic, Jose

    2015-03-01

    Recent developments in global statistical methodologies have advanced the analysis of large collections of protein sequences for coevolutionary information. Coevolution between amino acids in a protein arises from compensatory mutations that are needed to maintain the stability or function of a protein over the course of evolution. This gives rise to quantifiable correlations between amino acid positions within the multiple sequence alignment of a protein family. Here, we use Direct Coupling Analysis (DCA) to infer a Potts model Hamiltonian governing the correlated mutations in a protein family to obtain the sequence-dependent interaction energies of a toy protein model. We demonstrate that this methodology predicts residue-residue interaction energies that are consistent with experimental mutational changes in protein stabilities as well as other computational methodologies. Furthermore, we demonstrate with several examples that DCA could be used to construct a structure-based model that quantitatively agrees with experimental data on folding mechanisms. This work serves as a potential framework for generating models of proteins that are enriched by evolutionary data that can potentially be used to engineer key functional motions and interactions in protein systems. This research has been supported by the NSF INSPIRE award MCB-1241332 and by the CTBP sponsored by the NSF (Grant PHY-1427654).

  2. Diversity Increases Indirect Interactions, Attenuates the Intensity of Competition, and Promotes Coexistence.

    PubMed

    Aschehoug, Erik T; Callaway, Ragan M

    2015-10-01

    A fundamental assumption of coexistence theory is that competition inevitably decreases species diversity. Consequently, in the quest to understand the ecological regulators of diversity, there has been a great deal of focus on processes with the potential to reduce competitive exclusion. However, the notion that competition must decrease diversity is largely based on the outcome of two-species interaction experiments and models, despite the fact that species rarely interact only in pairs in natural systems. In a field experiment, we found that competition among native perennial plants in multispecies assemblages was far weaker than competition between those same species in pairwise arrangements and that indirect interactions appeared to weaken direct competitive effects. These results suggest that community assembly theory based on pairwise approaches may overestimate the strength of competition and likelihood of competitive exclusion in species-rich communities. We also found that Centaurea stoebe, a North American invader, retained strong competitive effects when competing against North American natives in both pairwise and multispecies assemblages. Our experimental results support an emerging body of theory suggesting that complex networks of competing species may generate strong indirect interactions that can maintain diversity and that ecological differentiation may not be necessary to attenuate competition.

  3. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., the Commission may use competitive bidding, random selection, or comparative hearings, depending on... exclusive applications in a renewal filing group are designated for comparative consideration in a hearing... applications in the filing group for comparative consideration in a hearing. In this event, the result of the...

  4. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., the Commission may use competitive bidding, random selection, or comparative hearings, depending on... exclusive applications in a renewal filing group are designated for comparative consideration in a hearing... applications in the filing group for comparative consideration in a hearing. In this event, the result of the...

  5. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., the Commission may use competitive bidding, random selection, or comparative hearings, depending on... exclusive applications in a renewal filing group are designated for comparative consideration in a hearing... applications in the filing group for comparative consideration in a hearing. In this event, the result of the...

  6. Exclusion by interference competition? The relationship between red and arctic foxes.

    PubMed

    Tannerfeldt, Magnus; Elmhagen, Bodil; Angerbjörn, Anders

    2002-07-01

    The distribution of many predators may be limited by interactions with larger predator species. The arctic fox in mainland Europe is endangered, while the red fox is increasing its range in the north. It has been suggested that the southern distribution limit of the arctic fox is determined by interspecific competition with the red fox. This has been criticised, on the basis that the species co-exist on a regional scale. However, if the larger red fox is superior and interspecific competition important, the arctic fox should avoid close contact, especially during the breeding season. Consequently, the distribution of breeding dens for the two species would be segregated on a much smaller spatial and temporal scale, in areas where they are sympatric. We tested this hypothesis by analysing den use of reproducing arctic and red foxes over 9 years in Sweden. High quality dens were inhabited by reproducing arctic foxes more often when no red foxes bred in the vicinity. Furthermore, in two out of three cases when arctic foxes did reproduce near red foxes, juveniles were killed by red foxes. We also found that breeding arctic foxes occupied dens at higher altitudes than red foxes did. In a large-scale field experiment, red foxes were removed, but the results were not conclusive. However, we conclude that on the scale of individual territories, arctic foxes avoid areas with red foxes. Through interspecific interference competition, the red fox might thus be excluding the arctic fox from breeding in low altitude habitat, which is most important in years when food abundance is limited and competition is most fierce. With high altitude refuges being less suitable, even small-scale behavioural effects could scale up to significant effects at the population level.

  7. A coevolutionary arms race causes ecological speciation in crossbills.

    PubMed

    Smith, Julie W; Benkman, Craig W

    2007-04-01

    We examined three ecological factors potentially causing premating reproductive isolation to determine whether divergent selection as a result of coevolution between South Hills crossbills (Loxia curvirostra complex) and Rocky Mountain lodgepole pine (Pinus contorta latifolia) promotes ecological speciation. One factor was habitat isolation arising because of enhanced seed defenses of lodgepole pine in the South Hills. This caused the crossbill call types (morphologically and vocally differentiated forms) adapted to alternative resources to be rare. Another occurred when crossbills of other call types moved into the South Hills late in the breeding season and feeding conditions were deteriorating so that relatively few non-South Hills crossbills bred ("immigrant infecundity"). Finally, among those crossbills that bred, pairing was strongly assortative by call type (behavioral isolation). Total reproductive isolation between South Hills crossbills and the two other crossbills most common in the South Hills (call types 2 and 5) summed to .9975 and .9998, respectively, on a scale of 0 (no reproductive isolation) to 1 (complete reproductive isolation). These extremely high levels of reproductive isolation indicate that the divergent selection resulting from the coevolutionary arms race between crossbills and lodgepole pine is causing the South Hills crossbill to speciate.

  8. Epidemiological, evolutionary, and coevolutionary implications of context-dependent parasitism.

    PubMed

    Vale, Pedro F; Wilson, Alastair J; Best, Alex; Boots, Mike; Little, Tom J

    2011-04-01

    Abstract Victims of infection are expected to suffer increasingly as parasite population growth increases. Yet, under some conditions, faster-growing parasites do not appear to cause more damage, and infections can be quite tolerable. We studied these conditions by assessing how the relationship between parasite population growth and host health is sensitive to environmental variation. In experimental infections of the crustacean Daphnia magna and its bacterial parasite Pasteuria ramosa, we show how easily an interaction can shift from a severe interaction, that is, when host fitness declines substantially with each unit of parasite growth, to a tolerable relationship by changing only simple environmental variables: temperature and food availability. We explored the evolutionary and epidemiological implications of such a shift by modeling pathogen evolution and disease spread under different levels of infection severity and found that environmental shifts that promote tolerance ultimately result in populations harboring more parasitized individuals. We also find that the opportunity for selection, as indicated by the variance around traits, varied considerably with the environmental treatment. Thus, our results suggest two mechanisms that could underlie coevolutionary hotspots and coldspots: spatial variation in tolerance and spatial variation in the opportunity for selection.

  9. 47 CFR 73.5000 - Services subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... following broadcast services are subject to competitive bidding: AM; FM; FM translator; analog television; low-power television; television translator; and Class A television. Mutually exclusive applications...

  10. An analysis of parameter sensitivities of preference-inspired co-evolutionary algorithms

    NASA Astrophysics Data System (ADS)

    Wang, Rui; Mansor, Maszatul M.; Purshouse, Robin C.; Fleming, Peter J.

    2015-10-01

    Many-objective optimisation problems remain challenging for many state-of-the-art multi-objective evolutionary algorithms. Preference-inspired co-evolutionary algorithms (PICEAs) which co-evolve the usual population of candidate solutions with a family of decision-maker preferences during the search have been demonstrated to be effective on such problems. However, it is unknown whether PICEAs are robust with respect to the parameter settings. This study aims to address this question. First, a global sensitivity analysis method - the Sobol' variance decomposition method - is employed to determine the relative importance of the parameters controlling the performance of PICEAs. Experimental results show that the performance of PICEAs is controlled for the most part by the number of function evaluations. Next, we investigate the effect of key parameters identified from the Sobol' test and the genetic operators employed in PICEAs. Experimental results show improved performance of the PICEAs as more preferences are co-evolved. Additionally, some suggestions for genetic operator settings are provided for non-expert users.

  11. Are the metabolomic responses to folivory of closely related plant species linked to macroevolutionary and plant-folivore coevolutionary processes?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rivas-Ubach, Albert; Hódar, José A.; Sardans, Jordi

    The debate whether the coevolution of plants and insects or macroevolutionary processes (phylogeny) is the main driver determining the arsenal of molecular defensive compounds of plants remains unresolved. Attacks by herbivorous insects affect not only the composition of defensive compounds in plants but the entire metabolome (the set of molecular metabolites), including defensive compounds. Metabolomes are the final products of genotypes and are directly affected by macroevolutionary processes, so closely related species should have similar metabolomic compositions and may respond in similar ways to attacks by folivores. We analyzed the elemental compositions and metabolomes of needles from Pinus pinaster, P.more » nigra and P. sylvestris to determine if these closely related Pinus species with different coevolutionary histories with the caterpillars of the processionary moth respond similarly to attacks by this lepidopteran. All pines had different metabolomes and metabolic responses to herbivorous attack. The metabolomic variation among the pine species and the responses to folivory reflected their macroevolutionary relationships, with P. pinaster having the most divergent metabolome. The concentrations of phenolic metabolites were generally not higher in the attacked trees, which had lower concentrations of terpenes, suggesting that herbivores avoid individuals with high concentrations of terpenes. Our results suggest that macroevolutionary history plays important roles in the metabolomic responses of these pine species to folivory, but plant-insect coevolution probably constrains those responses. Combinations of different evolutionary factors and trade-offs are likely responsible for the different responses of each species to folivory, which is not necessarily exclusively linked to plant-insect coevolution.« less

  12. Inhibition of Staphylococcus aureus by antimicrobial biofilms formed by competitive exclusion microorganisms on stainless steel.

    PubMed

    Son, Hyeri; Park, Sunhyung; Beuchat, Larry R; Kim, Hoikyung; Ryu, Jee-Hoon

    2016-12-05

    The goal of this study was to develop a desiccation resistant antimicrobial surface using biofilm of competitive exclusion (CE) microorganism inhibitory to Staphylococcus aureus. We isolated 161 microorganisms from soils, foods, and food-contact surfaces that are inhibitory to S. aureus. Among them, three CE microorganisms (Streptomyces spororaveus strain Gaeunsan-18, Bacillus safensis strain Chamnamu-sup 5-25, and Pseudomonas azotoformans strain Lettuce-9) exhibiting strong antibacterial activity and high growth rates were selected for evaluation. These isolates formed biofilms within 24h on stainless steel coupons (SSCs) immersed in Bennet's broth and tryptic soy broth at 25°C. Cells in these biofilms showed significantly (P≤0.05) enhanced resistance to a desiccation (43% relative humidity [RH]) compared to those attached to SSCs but not in biofilms. The antimicrobial activities of biofilms formed by these isolates on SSCs against S. aureus at 25°C and 43% RH were determined. Compared to SSCs lacking biofilms formed by CE microorganisms, populations of S. aureus on SSCs harboring CE biofilms were significantly lower (P≤0.05). Results indicate that persistent antimicrobial activity against S. aureus on stainless steel surfaces can be achieved by the presence of biofilms of CE microorganisms. This information will be useful when developing strategies to improve the microbiological safety of foods during storage, processing, and distribution by facilitating the development of effective antimicrobial food-contact surfaces. Copyright © 2016. Published by Elsevier B.V.

  13. Picking battles wisely: plant behaviour under competition.

    PubMed

    Novoplansky, Ariel

    2009-06-01

    Plants are limited in their ability to choose their neighbours, but they are able to orchestrate a wide spectrum of rational competitive behaviours that increase their prospects to prevail under various ecological settings. Through the perception of neighbours, plants are able to anticipate probable competitive interactions and modify their competitive behaviours to maximize their long-term gains. Specifically, plants can minimize competitive encounters by avoiding their neighbours; maximize their competitive effects by aggressively confronting their neighbours; or tolerate the competitive effects of their neighbours. However, the adaptive values of these non-mutually exclusive options are expected to depend strongly on the plants' evolutionary background and to change dynamically according to their past development, and relative sizes and vigour. Additionally, the magnitude of competitive responsiveness is expected to be positively correlated with the reliability of the environmental information regarding the expected competitive interactions and the expected time left for further plastic modifications. Concurrent competition over external and internal resources and morphogenetic signals may enable some plants to increase their efficiency and external competitive performance by discriminately allocating limited resources to their more promising organs at the expense of failing or less successful organs.

  14. Maternal androgens in avian brood parasites and their hosts: responses to parasitism and competition?

    USGS Publications Warehouse

    Hahn, Caldwell; Wingfield, John C.; Fox, David M.; Walker, Brian G.; Thomley, Jill E

    2017-01-01

    In the coevolutionary dynamic of avian brood parasites and their hosts, maternal (or transgenerational) effects have rarely been investigated. We examined the potential role of elevated yolk testosterone in eggs of the principal brood parasite in North America, the brown-headed cowbird, and three of its frequent host species. Elevated maternal androgens in eggs are a common maternal effect observed in many avian species when breeding conditions are unfavorable. These steroids accelerate embryo development, shorten incubation period, increase nestling growth rate, and enhance begging vigor, all traits that can increase the survival of offspring. We hypothesized that elevated maternal androgens in host eggs are a defense against brood parasitism. Our second hypothesis was that elevated maternal androgens in cowbird eggs are a defense against intra-specific competition. For host species, we found that elevated yolk testosterone was correlated with parasitized nests of small species, those whose nest success is most reduced by cowbird parasitism. For cowbirds, we found that elevated yolk testosterone was correlated with eggs in multiply-parasitized nests, which indicate intra-specific competition for nests due to high cowbird density. We propose experimental work to further examine the use of maternal effects by cowbirds and their hosts.

  15. Dynamics of competitive systems with a single common limiting factor.

    PubMed

    Kon, Ryusuke

    2015-02-01

    The concept of limiting factors (or regulating factors) succeeded in formulating the well-known principle of competitive exclusion. This paper shows that the concept of limiting factors is helpful not only to formulate the competitive exclusion principle, but also to obtain other ecological insights. To this end, by focusing on a specific community structure, we study the dynamics of Kolmogorov equations and show that it is possible to derive an ecologically insightful result only from the information about interactions between species and limiting factors. Furthermore, we find that the derived result is a generalization of the preceding work by Shigesada, Kawasaki, and Teramoto (1984), who examined a certain Lotka-Volterra equation in a different context.

  16. 47 CFR 90.901 - 800 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Competitive Bidding Procedures for 800 MHz Specialized Mobile Radio Service § 90.901 800 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 800 MHz band licenses in Spectrum Blocks A through V are subject to...

  17. The Conundrum of Modern Art : Prestige-Driven Coevolutionary Aesthetics Trumps Evolutionary Aesthetics among Art Experts.

    PubMed

    Verpooten, Jan; Dewitte, Siegfried

    2017-03-01

    Two major mechanisms of aesthetic evolution have been suggested. One focuses on naturally selected preferences (Evolutionary Aesthetics), while the other describes a process of evaluative coevolution whereby preferences coevolve with signals. Signaling theory suggests that expertise moderates these mechanisms. In this article we set out to verify this hypothesis in the domain of art and use it to elucidate Western modern art's deviation from naturally selected preferences. We argue that this deviation is consistent with a Coevolutionary Aesthetics mechanism driven by prestige-biased social learning among art experts. In order to test this hypothesis, we conducted two studies in which we assessed the effects on lay and expert appreciation of both the biological relevance of the given artwork's depicted content, viz., facial beauty, and the prestige specific to the artwork's associated context (MoMA). We found that laypeople appreciate artworks based on their depictions of facial beauty, mediated by aesthetic pleasure, which is consistent with previous studies. In contrast, experts appreciate the artworks based on the prestige of the associated context, mediated by admiration for the artist. Moreover, experts appreciate artworks depicting neutral faces to a greater degree than artworks depicting attractive faces. These findings thus corroborate our contention that expertise moderates the Evolutionary and Coevolutionary Aesthetics mechanisms in the art domain. Furthermore, our findings provide initial support for our proposal that prestige-driven coevolution with expert evaluations plays a decisive role in modern art's deviation from naturally selected preferences. After discussing the limitations of our research as well as the relation that our results bear on cultural evolution theory, we provide a number of suggestions for further research into the potential functions of expert appreciation that deviates from naturally selected preferences, on the one hand, and

  18. Epidemiological, evolutionary and co-evolutionary implications of context-dependent parasitism

    PubMed Central

    Vale, Pedro F.; Wilson, Alastair J.; Best, Alex; Boots, Mike; Little, Tom J.

    2013-01-01

    Victims of infection are expected to suffer increasingly as parasite population growth increases. Yet, under some conditions, faster growing parasites do not appear to cause more damage and infections can be quite tolerable. We studied these conditions by assessing how the relationship between parasite population growth and host health is sensitive to environmental variation. In experimental infections of the crustacean Daphnia magna and its bacterial parasite Pasteuria ramosa we show how easily an interaction can shift from a severe interaction, i.e. when host fitness declines substantially with each unit of parasite growth, to a tolerable relationship by changing only simple environmental variables: temperature and food availability. We explored the evolutionary and epidemiological implications of such a shift by modelling pathogen evolution and disease spread under different levels of infection severity, and find that environmental shifts that promote tolerance ultimately result in populations harbouring more parasitized individuals. We also find that the opportunity for selection, as indicated by the variance around traits, varied considerably with the environmental treatment. Thus our results suggest two mechanisms that could underlie co-evolutionary hot- and coldspots: spatial variation in tolerance and spatial variation in the opportunity for selection. PMID:21460572

  19. The evolution of increased competitive ability, innate competitive advantages, and novel biochemical weapons act in concert for a tropical invader.

    PubMed

    Qin, Rui-Min; Zheng, Yu-Long; Valiente-Banuet, Alfonso; Callaway, Ragan M; Barclay, Gregor F; Pereyra, Carlos Silva; Feng, Yu-Long

    2013-02-01

    There are many non-mutually exclusive mechanisms for exotic invasions but few studies have concurrently tested more than one hypothesis for the same species. Here, we tested the evolution of increased competitive ability (EICA) hypothesis in two common garden experiments in which Chromolaena odorata plants originating from native and nonnative ranges were grown in competition with natives from each range, and the novel weapons hypothesis in laboratory experiments with leachates from C. odorata. Compared with conspecifics originating from the native range, C. odorata plants from the nonnative range were stronger competitors at high nutrient concentrations in the nonnative range in China and experienced far more herbivore damage in the native range in Mexico. In both China and Mexico, C. odorata was more suppressed by species native to Mexico than by species native to China. Species native to China were much more inhibited by leaf extracts from C. odorata than species from Mexico, and this difference in allelopathic effects may provide a possible explanation for the biogeographic differences in competitive ability. Our results indicate that EICA, innate competitive advantages, and novel biochemical weapons may act in concert to promote invasion by C. odorata, and emphasize the importance of exploring multiple, non-mutually exclusive mechanisms for invasions. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  20. Assertiveness of meat-borne Lactococcus piscium strains and their potential for competitive exclusion of spoilage bacteria in situ and in vitro.

    PubMed

    Hilgarth, M; Nani, M; Vogel, R F

    2018-05-01

    This study aimed to investigate intraspecies assertiveness of meat-borne Lactococcus piscium isolates, inhibitory effects on unwanted and harmful meat spoilers, and the prevalence on beef deliberately inoculated with Lc. piscium. Co-inoculation of Lc. piscium isolates and spoilers (Brochothrix thermosphacta, Leuconostoc gelidum subsp. gasicomitatum, Carnobacterium divergens, Pseudomonas weihenstephanensis, Serratia liquefaciens, Hafnia alvei) were conducted in sterile meat simulation medium. Differentiation of Lc. piscium strains was carried out with colony-based RAPD-PCR. Selective cultivation was used to differentiate spoilers from Lc. piscium. Intraspecies assertiveness revealed Lc. piscium TMW2.1614 as most assertive strain. Co-inoculation of selected Lc. piscium strains caused substantial growth reduction of spoilers while the extent was strain- and spoiler dependent. Monitoring the microbiota on beef steaks deliberately inoculated with Lc. piscium revealed prevalence over the endogenous microbiota while maintaining a ripened sensory impression without undesired alterations. This study reveals Lc. piscium strains TMW2.1612/2.1614/2.1615 as highly competitive against spoilers in vitro while beef deliberately inoculated with these strains maintained acceptable organoleptics. Selected Lc. piscium strains exhibit high potential for application as bioprotective cultures for competitive exclusion on beef in order to extend minimum shelf life and enhance product safety of meat. © 2018 The Society for Applied Microbiology.

  1. Analysis of oxidative stress biomarkers using a simultaneous competitive/non-competitive micromosaic immunoassay.

    PubMed

    Murphy, Brian M; Dandy, David S; Henry, Charles S

    2009-04-27

    Immunoassays represent a core workhorse methodology for many applications ranging from clinical diagnostics to environmental monitoring. In traditional formats such as the enzyme linked immunosorbent assay (ELISA), analytes are measured singly or in small sets. As more biomarkers are identified for disease states, there is a need to develop methods that can measure multiple markers simultaneously. Immunoaffinity arrays are one such chemistry that can achieve multi-marker screening. Most arrays are performed in either competitive or non-competitive formats, where the former are used predominantly for small molecules and the later for macromolecules. To date, ELISA and immunoaffinity array methods have relied exclusively on one of these formats and not the other. Here an immunoaffinity array method capable of performing simultaneous competitive and non-competitive analysis generated using micromosaic immunoassay techniques is introduced for the analysis of metabolites and proteins. In this report, three markers of oxidative stress were used as a model system. The method described here demonstrates the simultaneous analysis of 3-nitrotyrosine, by indirect competitive immunoassay while the enzymes catalase and superoxide dismutase are analyzed by non-competitive sandwich immunoassay. The method requires less than 1 microL sample and 45 min for completion. Logistic curve fits and LOD (limits of detection) statistical analysis of the binding results are presented and show good agreement with published data for these antibody-antigen systems.

  2. 47 CFR 90.901 - 800 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false 800 MHz SMR spectrum subject to competitive... Specialized Mobile Radio Service § 90.901 800 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 800 MHz band licenses in Spectrum Blocks A through V are subject to...

  3. 47 CFR 90.901 - 800 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false 800 MHz SMR spectrum subject to competitive... Specialized Mobile Radio Service § 90.901 800 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 800 MHz band licenses in Spectrum Blocks A through V are subject to...

  4. 47 CFR 90.901 - 800 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false 800 MHz SMR spectrum subject to competitive... Specialized Mobile Radio Service § 90.901 800 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 800 MHz band licenses in Spectrum Blocks A through V are subject to...

  5. 47 CFR 90.901 - 800 MHz SMR spectrum subject to competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false 800 MHz SMR spectrum subject to competitive... Specialized Mobile Radio Service § 90.901 800 MHz SMR spectrum subject to competitive bidding. Mutually exclusive initial applications for 800 MHz band licenses in Spectrum Blocks A through V are subject to...

  6. 47 CFR 22.969 - Cellular RSA licenses subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CARRIER SERVICES PUBLIC MOBILE SERVICES Cellular Radiotelephone Service § 22.969 Cellular RSA licenses subject to competitive bidding. Mutually exclusive applications for initial authorization for the...

  7. Coexistence via coevolution driven by reduced allelochemical effects and increased tolerance to competition between invasive and native plants.

    PubMed

    Huang, Fangfang; Lankau, Richard; Peng, Shaolin

    2018-04-01

    Coevolution can promote long-term coexistence of two competing species if selection acts to reduce the fitness inequality between competitors and/or strengthen negative frequency dependence within each population. However, clear coevolution between plant competitors has been rarely documented. Plant invasions offer opportunities to capture the process of coevolution. Here we investigated how the developing relationship between an invasive forb, Alliaria petiolata, and a native competitor, Pilea pumila, may affect their long-term coexistence, by testing the competitive effects of populations of varying lengths of co-occurrence on each other across a chronosequence of invasion history. Alliaria petiolata and P. pumila tended to develop greater tolerance to competition over invasion history. Their coexistence was promoted more by increases in stabilizing relative to equalizing processes. These changes likely stem in part from reductions in allelopathic traits in the invader and evolution of tolerance in the native. These results suggested that some native species can evolve tolerance against the competitive effects of strong invaders, which likely promoted their persistence in invaded communities. However, the potential for coevolutionary rescue of competing populations is likely to vary across native species, and evolutionary processes should not be expected to compensate for the ecological consequences of exotic invasions. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  8. Spatial variation and density-dependent dispersal in competitive coexistence.

    PubMed Central

    Amarasekare, Priyanga

    2004-01-01

    It is well known that dispersal from localities favourable to a species' growth and reproduction (sources) can prevent competitive exclusion in unfavourable localities (sinks). What is perhaps less well known is that too much emigration can undermine the viability of sources and cause regional competitive exclusion. Here, I investigate two biological mechanisms that reduce the cost of dispersal to source communities. The first involves increasing the spatial variation in the strength of competition such that sources can withstand high rates of emigration; the second involves reducing emigration from sources via density-dependent dispersal. I compare how different forms of spatial variation and modes of dispersal influence source viability, and hence source-sink coexistence, under dominance and pre-emptive competition. A key finding is that, while spatial variation substantially reduces dispersal costs under both types of competition, density-dependent dispersal does so only under dominance competition. For instance, when spatial variation in the strength of competition is high, coexistence is possible (regardless of the type of competition) even when sources experience high emigration rates; when spatial variation is low, coexistence is restricted even under low emigration rates. Under dominance competition, density-dependent dispersal has a strong effect on coexistence. For instance, when the emigration rate increases with density at an accelerating rate (Type III density-dependent dispersal), coexistence is possible even when spatial variation is quite low; when the emigration rate increases with density at a decelerating rate (Type II density-dependent dispersal), coexistence is restricted even when spatial variation is quite high. Under pre-emptive competition, density-dependent dispersal has only a marginal effect on coexistence. Thus, the diversity-reducing effects of high dispersal rates persist under pre-emptive competition even when dispersal is density

  9. Plant Community Richness Mediates Inhibitory Interactions and Resource Competition between Streptomyces and Fusarium Populations in the Rhizosphere.

    PubMed

    Essarioui, Adil; LeBlanc, Nicholas; Kistler, Harold C; Kinkel, Linda L

    2017-07-01

    Plant community characteristics impact rhizosphere Streptomyces nutrient competition and antagonistic capacities. However, the effects of Streptomyces on, and their responses to, coexisting microorganisms as a function of plant host or plant species richness have received little attention. In this work, we characterized antagonistic activities and nutrient use among Streptomyces and Fusarium from the rhizosphere of Andropogon gerardii (Ag) and Lespedeza capitata (Lc) plants growing in communities of 1 (monoculture) or 16 (polyculture) plant species. Streptomyces from monoculture were more antagonistic against Fusarium than those from polyculture. In contrast, Fusarium isolates from polyculture had greater inhibitory capacities against Streptomyces than isolates from monoculture. Although Fusarium isolates had on average greater niche widths, the collection of Streptomyces isolates in total used a greater diversity of nutrients for growth. Plant richness, but not plant host, influenced the potential for resource competition between the two taxa. Fusarium isolates had greater niche overlap with Streptomyces in monoculture than polyculture, suggesting greater potential for Fusarium to competitively challenge Streptomyces in monoculture plant communities. In contrast, Streptomyces had greater niche overlap with Fusarium in polyculture than monoculture, suggesting that Fusarium experiences greater resource competition with Streptomyces in polyculture than monoculture. These patterns of competitive and inhibitory phenotypes among Streptomyces and Fusarium populations are consistent with selection for Fusarium-antagonistic Streptomyces populations in the presence of strong Fusarium resource competition in plant monocultures. Similarly, these results suggest selection for Streptomyces-inhibitory Fusarium populations in the presence of strong Streptomyces resource competition in more diverse plant communities. Thus, landscape-scale variation in plant species richness may be

  10. Determinants of Market Exclusivity for Prescription Drugs in the United States.

    PubMed

    Kesselheim, Aaron S; Sinha, Michael S; Avorn, Jerry

    2017-11-01

    The high prices of brand-name prescription drugs are a growing source of controversy in the United States. Manufacturers of brand-name drugs can command high prices because they are protected from generic competition by two types of government-granted monopoly rights. The first are patents on the drugs that generally define the basic period of brand-name-only sales. The second is awarded at the time of US Food and Drug Administration (FDA) approval and usually defines the minimum time until a generic can be sold. The initial patents last for 20 years and may be extended to account for time spent in clinical trials and regulatory review; other laws prevent approval of other manufacturers' versions of new drugs for about 6 to 7 years, and for new biologics for 12 years. Overall, most new drugs receive about 12 to 16 years of market exclusivity from both kinds of monopoly protection combined. We reviewed the peer-reviewed medical and health policy literature to identify studies that described the different types of patent protection and regulatory exclusivities that shield brand-name prescription drugs from competition and thus help to sustain high drug prices. We also identified potential policy reforms intended to modify exclusivity periods to address public health needs by balancing drug affordability and industry revenue. The goal of policy in this area should be to ensure that drug market exclusivity periods provide for fair return on investment but do not indefinitely block availability of lower-cost generic drugs.

  11. Development of a competitive exclusion product for poultry meeting the regulatory requirements for registration in the European Union.

    PubMed

    Klose, Viviana; Mohnl, Michaela; Plail, Regina; Schatzmayr, Gerd; Loibner, Andreas-Paul

    2006-05-01

    Competitive exclusion treatment is able to increase the pathogen colonization resistance of day-old chicks by applying probiotic bacteria stabilizing the indigenous microflora. In order to develop a safe microbial feed additive, various bacterial strains were isolated out of the gastrointestinal tract of healthy chickens. One hundred twenty-one representatives were selected based on differences in whole-cell protein patterns and screened for antagonistic properties. Five effective strains (Pediococcus acidilactici, Enterococcus faecium, Bifidobacterium animalis ssp. animalis, Lactobacillus reuteri, and Lactobacillus salivarius ssp. salivarius) exhibited in vitro the ability to inhibit a range of common pathogens and were evaluated with regard to the risks associated with genetic transfer of antibiotic resistances from animals to humans via the food chain. The probiotic strains were sensitive to several clinically effective antibiotics, though some of them showed single resistances. None of the vancomycin-resistant (R) strains carried the enterococcal vanA gene. Two tetracycline R strains were shown to harbor a tet(M)-associated resistance. The strains contained no extrachromosomal DNA and were not able to transfer the resistance by means of conjugation. On basis of the collected data the presence of easy transferable resistances was excluded and the chicken strains were considered to be suitable for the use as feed additive.

  12. Long-range RNA pairings contribute to mutually exclusive splicing

    PubMed Central

    Yue, Yuan; Yang, Yun; Dai, Lanzhi; Cao, Guozheng; Chen, Ran; Hong, Weiling; Liu, Baoping; Shi, Yang; Meng, Yijun; Shi, Feng; Xiao, Mu; Jin, Yongfeng

    2016-01-01

    Mutually exclusive splicing is an important means of increasing the protein repertoire, by which the Down's syndrome cell adhesion molecule (Dscam) gene potentially generates 38,016 different isoforms in Drosophila melanogaster. However, the regulatory mechanisms remain obscure due to the complexity of the Dscam exon cluster. Here, we reveal a molecular model for the regulation of the mutually exclusive splicing of the serpent pre-mRNA based on competition between upstream and downstream RNA pairings. Such dual RNA pairings confer fine tuning of the inclusion of alternative exons. Moreover, we demonstrate that the splicing outcome of alternative exons is mediated in relative pairing strength-correlated mode. Combined comparative genomics analysis and experimental evidence revealed similar bidirectional structural architectures in exon clusters 4 and 9 of the Dscam gene. Our findings provide a novel mechanistic framework for the regulation of mutually exclusive splicing and may offer potentially applicable insights into long-range RNA–RNA interactions in gene regulatory networks. PMID:26554032

  13. Coevolutionary, coexisting learning and teaching agents model for prisoner’s dilemma games enhancing cooperation with assortative heterogeneous networks

    NASA Astrophysics Data System (ADS)

    Tanimoto, Jun

    2013-07-01

    Unlike other natural network systems, assortativity can be observed in most human social networks, although it has been reported that a social dilemma situation represented by the prisoner’s dilemma favors dissortativity to enhance cooperation. We established a new coevolutionary model for both agents’ strategy and network topology, where teaching and learning agents coexist. Remarkably, this model enables agents’ enhancing cooperation more than a learners-only model on a time-frozen scale-free network and produces an underlying assortative network with a fair degree of power-law distribution. The model may imply how and why assortative networks are adaptive in human society.

  14. Age structure and cooperation in coevolutionary games on dynamic network

    NASA Astrophysics Data System (ADS)

    Qin, Zilong; Hu, Zhenhua; Zhou, Xiaoping; Yi, Jingzhang

    2015-04-01

    Our proposed model imitates the growth of a population and describes the age structure and the level of cooperation in games on dynamic network with continuous changes of structure and topology. The removal of nodes and links caused by age-dependent attack, together with the nodes addition standing for the newborns of population, badly ruins Matthew effect in this coevolutionary process. Though the network is generated by growth and preferential attachment, it degenerates into random network and it is no longer heterogeneous. When the removal of nodes and links is equal to the addition of nodes and links, the size of dynamic network is maintained in steady-state, so is the low level of cooperation. Severe structure variation, homogeneous topology and continuous invasion of new defection jointly make dynamic network unsuitable for the survival of cooperator even when the probability with which the newborn players initially adopt the strategy cooperation is high, while things change slightly when the connections of newborn players are restricted. Fortunately, moderate interactions in a generation trigger an optimal recovering process to encourage cooperation. The model developed in this paper outlines an explanation of the cohesion changes in the development process of an organization. Some suggestions for cooperative behavior improvement are given in the end.

  15. The genetic basis of a plant–insect coevolutionary key innovation

    PubMed Central

    Wheat, Christopher W.; Vogel, Heiko; Wittstock, Ute; Braby, Michael F.; Underwood, Dessie; Mitchell-Olds, Thomas

    2007-01-01

    Ehrlich and Raven formally introduced the concept of stepwise coevolution using butterfly and angiosperm interactions in an attempt to account for the impressive biological diversity of these groups. However, many biologists currently envision butterflies evolving 50 to 30 million years (Myr) after the major angiosperm radiation and thus reject coevolutionary origins of butterfly biodiversity. The unresolved central tenet of Ehrlich and Raven's theory is that evolution of plant chemical defenses is followed closely by biochemical adaptation in insect herbivores, and that newly evolved detoxification mechanisms result in adaptive radiation of herbivore lineages. Using one of their original butterfly-host plant systems, the Pieridae, we identify a pierid glucosinolate detoxification mechanism, nitrile-specifier protein (NSP), as a key innovation. Larval NSP activity matches the distribution of glucosinolate in their host plants. Moreover, by using five different temporal estimates, NSP seems to have evolved shortly after the evolution of the host plant group (Brassicales) (≈10 Myr). An adaptive radiation of these glucosinolate-feeding Pierinae followed, resulting in significantly elevated species numbers compared with related clades. Mechanistic understanding in its proper historical context documents more ancient and dynamic plant–insect interactions than previously envisioned. Moreover, these mechanistic insights provide the tools for detailed molecular studies of coevolution from both the plant and insect perspectives. PMID:18077380

  16. Complex coevolutionary history of symbiotic Bacteroidales bacteria of various protists in the gut of termites

    PubMed Central

    Noda, Satoko; Hongoh, Yuichi; Sato, Tomoyuki; Ohkuma, Moriya

    2009-01-01

    Background The microbial community in the gut of termites is responsible for the efficient decomposition of recalcitrant lignocellulose. Prominent features of this community are its complexity and the associations of prokaryotes with the cells of cellulolytic flagellated protists. Bacteria in the order Bacteroidales are involved in associations with a wide variety of gut protist species as either intracellular endosymbionts or surface-attached ectosymbionts. In particular, ectosymbionts exhibit distinct morphological patterns of the associations. Therefore, these Bacteroidales symbionts provide an opportunity to investigate not only the coevolutionary relationships with the host protists and their morphological evolution but also how symbiotic associations between prokaryotes and eukaryotes occur and evolve within a complex symbiotic community. Results Molecular phylogeny of 31 taxa of Bacteroidales symbionts from 17 protist genera in 10 families was examined based on 16S rRNA gene sequences. Their localization, morphology, and specificity were also examined by fluorescent in situ hybridizations. Although a monophyletic grouping of the ectosymbionts occurred in three related protist families, the symbionts of different protist genera were usually dispersed among several phylogenetic clusters unique to termite-gut bacteria. Similar morphologies of the associations occurred in multiple lineages of the symbionts. Nevertheless, the symbionts of congeneric protist species were closely related to one another, and in most cases, each host species harbored a unique Bacteroidales species. The endosymbionts were distantly related to the ectosymbionts examined so far. Conclusion The coevolutionary history of gut protists and their associated Bacteroidales symbionts is complex. We suggest multiple independent acquisitions of the Bacteroidales symbionts by different protist genera from a pool of diverse bacteria in the gut community. In this sense, the gut could serve as a

  17. Experimental demonstration of the importance of competition under disturbance.

    PubMed

    Violle, Cyrille; Pu, Zhichao; Jiang, Lin

    2010-07-20

    Ecologists have long recognized the roles of competition and disturbance in shaping ecological communities, and the combinatorial effects of these two factors have been the subject of substantial ecological research. Nevertheless, it is still unclear whether competition remains as an important structuring force in habitats strongly influenced by disturbance. The conventional belief remains that the importance of competition decreases with increasing disturbance, but limited theory suggests otherwise. Using protist communities established in laboratory microcosms, we demonstrate that disturbance does not diminish the importance of competition. Interspecific competition significantly increased rates of species extinction over a broad disturbance gradient, and increasing disturbance intensities increased, rather than decreased, the tempo of competitive exclusion. This community-level pattern is linked to the species-level pattern that interspecific competition led to most frequent extinctions of each species at the highest level of disturbance that the species can tolerate. Consequently, despite a strong tradeoff between competitive ability and disturbance tolerance across the competing species, species diversity generally declined with disturbance. The consistent structuring role of competition throughout the disturbance gradient underscores the need to understand competitive interactions and their consequences even in highly disturbed habitats.

  18. Coevolutionary dynamics with clustering behaviors on cyclic competition

    NASA Astrophysics Data System (ADS)

    Dong, Linrong; Yang, Guangcan

    2012-05-01

    We propose a dynamic model for describing clustering behaviors on a cyclic game, in which the same species form a cluster to compete. The rates of consuming the prey depend not only on the individual competing ability v, but also on the two interacting cluster’s sizes. The fragmentation and coagulation rates of the clusters are related to the cohesive strength among the individuals. A new parameter u is introduced to indicate the uniting degree. We find that the probability distribution of the clustering sizes is almost a power law in a large regime specified by the two parameters, which reflects the scale-free behavior in complex systems. In addition, the exponential magnitudes are mostly in the range of real social systems. Our simulation shows that clustering promotes biodiversity. At steady state, the amounts about the three species evolve tempestuously with asymmetric period; the aggregations about big size’s clusters to compete are obvious and on-off intermittence.

  19. Market Exclusivity Time for Top Selling Originator Drugs in Canada: A Cohort Study.

    PubMed

    Lexchin, Joel

    2017-09-01

    This study looks at market exclusivity time for the top selling originator drugs in Canada. Total sales for drugs without competition were also calculated. A list of the top selling originator drugs by dollar sales from 2009 to 2015 inclusive, except for 2010, was compiled along with their annual sales. Health Canada databases were used to extract the following information: generic name, date of Notice of Compliance (NOC, date of marketing authorization), whether the product was a small molecule drug or a biologic, and date of NOC for a generic or biosimilar. Market exclusivity time was calculated in days for drugs. A total of 121 drugs were identified. There were 96 small molecule drugs (63 with a generic competitor and 33 with no generic competitor) and 25 biologics (none with a biosimilar competitor). The 63 drugs with a competitor had a mean market exclusivity time of 4478 days (12.3 years) (95% CI 4159-4798). The 58 drugs without competition had total annual sales of Can$8.59 billion and were on the market for a median of 5357 days (14.7 years) (interquartile range 3291-6679) as of January 31, 2017. Top selling originator drugs in Canada have a considerably longer period of market exclusivity than the 8 to 10 years that the research-based pharmaceutical industry claims. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  20. Salmonella Enteritidis with double deletion in phoP fliC and a competitive exclusion culture elicit substantial additive protective effects against Salmonella exposure in newly hatched chicks.

    PubMed

    Methner, U; Berndt, A; Locke, M

    2017-10-27

    A live Salmonella Enteritidis vaccine (SE147N ΔphoP fliC), able to express both a homologous intestinal colonisation-inhibition effect and a systemic invasion-inhibition effect, was tested for its potential to generate a postulated additive protective effect in case of combined application with a competitive exclusion (CE) culture against Salmonella exposure in very young chicks. Both, SE147N ΔphoP fliC and the CE culture alone were highly protective against systemic and intestinal colonisation of the challenge strain in case of moderate Salmonella exposure, consequently, additive protective effects in combined use could not be detected. However, in case of high Salmonella Enteritidis challenge with 10 6 cfu/bird at day 3 of life the combination of the ΔphoP fliC vaccine and the CE culture resulted in a protective effect much more pronounced than either of the single preparations and most substantial compared to untreated control birds. The term additive protective effects reflects the recognition that exclusion effects by gut flora cultures and inhibition effects by Salmonella vaccines are caused by different mechanisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Type III Effector Diversification via Both Pathoadaptation and Horizontal Transfer in Response to a Coevolutionary Arms Race

    PubMed Central

    Ma, Wenbo; Dong, Frederick F. T; Stavrinides, John; Guttman, David S

    2006-01-01

    The concept of the coevolutionary arms race holds a central position in our understanding of pathogen–host interactions. Here we identify the molecular mechanisms and follow the stepwise progression of an arms race in a natural system. We show how the evolution and function of the HopZ family of type III secreted effector proteins carried by the plant pathogen Pseudomonas syringae are influenced by a coevolutionary arms race between pathogen and host. We surveyed 96 isolates of P. syringae and identified three homologs (HopZ1, HopZ2, and HopZ3) distributed among ∼45% of the strains. All alleles were sequenced and their expression was confirmed. Evolutionary analyses determined that the diverse HopZ1 homologs are ancestral to P. syringae, and have diverged via pathoadaptive mutational changes into three functional and two degenerate forms, while HopZ2 and HopZ3 have been brought into P. syringae via horizontal transfer from other ecologically similar bacteria. A PAML selection analysis revealed that the C terminus of HopZ1 is under strong positive selection. Despite the extensive genetic variation observed in this family, all three homologs have cysteine–protease activity, although their substrate specificity may vary. The introduction of the ancestral hopZ1 allele into strains harboring alternate alleles results in a resistance protein-mediated defense response in their respective hosts, which is not observed with the endogenous allele. These data indicate that the P. syringae HopZ family has undergone allelic diversification via both pathoadaptive mutational changes and horizontal transfer in response to selection imposed by the host defense system. This genetic diversity permits the pathogen to avoid host defenses while still maintaining a virulence-associated protease, thereby allowing it to thrive on its current host, while simultaneously impacting its host range. PMID:17194219

  2. Coevolutionary dynamics of phenotypic diversity and contingent cooperation

    PubMed Central

    Wang, Long

    2017-01-01

    Phenotypic diversity is considered beneficial to the evolution of contingent cooperation, in which cooperators channel their help preferentially towards others of similar phenotypes. However, it remains largely unclear how phenotypic variation arises in the first place and thus leads to the construction of phenotypic complexity. Here we propose a mathematical model to study the coevolutionary dynamics of phenotypic diversity and contingent cooperation. Unlike previous models, our model does not assume any prescribed level of phenotypic diversity, but rather lets it be an evolvable trait. Each individual expresses one phenotype at a time and only the phenotypes expressed are visible to others. Moreover, individuals can differ in their potential of phenotypic variation, which is characterized by the number of distinct phenotypes they can randomly switch to. Each individual incurs a cost proportional to the number of potentially expressible phenotypes so as to retain phenotypic variation and expression. Our results show that phenotypic diversity coevolves with contingent cooperation under a wide range of conditions and that there exists an optimal level of phenotypic diversity best promoting contingent cooperation. It pays for contingent cooperators to elevate their potential of phenotypic variation, thereby increasing their opportunities of establishing cooperation via novel phenotypes, as these new phenotypes serve as secret tags that are difficult for defector to discover and chase after. We also find that evolved high levels of phenotypic diversity can occasionally collapse due to the invasion of defector mutants, suggesting that cooperation and phenotypic diversity can mutually reinforce each other. Thus, our results provide new insights into better understanding the coevolution of cooperation and phenotypic diversity. PMID:28141806

  3. Long-range RNA pairings contribute to mutually exclusive splicing.

    PubMed

    Yue, Yuan; Yang, Yun; Dai, Lanzhi; Cao, Guozheng; Chen, Ran; Hong, Weiling; Liu, Baoping; Shi, Yang; Meng, Yijun; Shi, Feng; Xiao, Mu; Jin, Yongfeng

    2016-01-01

    Mutually exclusive splicing is an important means of increasing the protein repertoire, by which the Down's syndrome cell adhesion molecule (Dscam) gene potentially generates 38,016 different isoforms in Drosophila melanogaster. However, the regulatory mechanisms remain obscure due to the complexity of the Dscam exon cluster. Here, we reveal a molecular model for the regulation of the mutually exclusive splicing of the serpent pre-mRNA based on competition between upstream and downstream RNA pairings. Such dual RNA pairings confer fine tuning of the inclusion of alternative exons. Moreover, we demonstrate that the splicing outcome of alternative exons is mediated in relative pairing strength-correlated mode. Combined comparative genomics analysis and experimental evidence revealed similar bidirectional structural architectures in exon clusters 4 and 9 of the Dscam gene. Our findings provide a novel mechanistic framework for the regulation of mutually exclusive splicing and may offer potentially applicable insights into long-range RNA-RNA interactions in gene regulatory networks. © 2015 Yue et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  4. Limiting similarity of competitive species and demographic stochasticity

    NASA Astrophysics Data System (ADS)

    Zheng, Xiu-Deng; Deng, Ling-Ling; Qiang, Wei-Ya; Cressman, Ross; Tao, Yi

    2017-04-01

    The limiting similarity of competitive species and its relationship with the competitive exclusion principle is still one of the most important concepts in ecology. In the 1970s, May [R. M. May, Stability and Complexity in Model Ecosystems (Princeton University, Princeton, NJ, 1973)] developed a concise theoretical framework to investigate the limiting similarity of competitive species. His theoretical results show that no limiting similarity threshold of competitive species can be identified in the deterministic model system whereby species more similar than this threshold never coexist. Theoretically, for competitive species coexisting in an unvarying environment, deterministic interspecific interactions and demographic stochasticity can be considered two sides of a coin. To investigate how the "tension" between these two forces affects the coexistence of competing species, a simple two-species competitive system based only on May's model system is transformed into an equivalent replicator equation. The effect of demographic stochasticity on the system stability is measured by the expected drift of the Lyapunov function. Our main results show that the limiting similarity of competitive species should not be considered to be an absolute measure. Specifically, very similar competitive species should be able to coexist in an environment with a high productivity level but big differences between competitive species should be necessary in an ecosystem with a low productivity level.

  5. Specialization and competition in dental health services.

    PubMed

    Grytten, Jostein; Skau, Irene

    2009-04-01

    The number of specialists within dental health services has increased over the last few years. This raises the issue of how the services should be organized and funded. We describe the effect of one way of organizing the services, which is by relying on competition. In Norway, some oral specialists face real competition with general dental practitioners for the same patients (prosthetists, periodontists and endodontists), while other specialists do not (orthodontists and oral surgeons). The latter specialists have skills that give them exclusive possibilities to practice their profession. We find that competition can be effective for the specialists who experience real competition with general dental practitioners for patients. In situations where real competition does not exist, specialists can obtain market power and raise their fees. Our results are based on an analysis of a representative set of data from general dental practitioners and specialists in Norway. The specialities in which practitioners can exercise market power raise challenges related to the type of public policy that can reduce this market power in an appropriate way, and without involving too large costs for the authorities. (c) 2008 John Wiley & Sons, Ltd.

  6. Reciprocal selection causes a coevolutionary arms race between crossbills and lodgepole pine.

    PubMed

    Benkman, Craig W; Parchman, Thomas L; Favis, Amanda; Siepielski, Adam M

    2003-08-01

    Few studies have shown both reciprocal selection and reciprocal adaptations for a coevolving system in the wild. The goal of our study was to determine whether the patterns of selection on Rocky Mountain lodgepole pine (Pinus contorta spp. latifolia) and red crossbills (Loxia curvirostra complex) were concordant with earlier published evidence of reciprocal adaptations in lodgepole pine and crossbills on isolated mountain ranges in the absence of red squirrels (Tamiasciurus hudsonicus). We found that selection (directional) by crossbills on lodgepole pine where Tamiasciurus are absent was divergent from the selection (directional) exerted by Tamiasciurus on lodgepole pine. This resulted in divergent selection between areas with and without Tamiasciurus that was congruent with the geographic patterns of cone variation. In the South Hills, Idaho, where Tamiasciurus are absent and red crossbills are thought to be coevolving with lodgepole pine, crossbills experienced stabilizing selection on bill size, with cone structure as the agent of selection. These results show that crossbills and lodgepole pine exhibit reciprocal adaptations in response to reciprocal selection, and they provide insight into the traits mediating and responding to selection in a coevolutionary arms race.

  7. A further analysis of the role of heterogeneity in coevolutionary spatial games

    NASA Astrophysics Data System (ADS)

    Cardinot, Marcos; Griffith, Josephine; O'Riordan, Colm

    2018-03-01

    Heterogeneity has been studied as one of the most common explanations of the puzzle of cooperation in social dilemmas. A large number of papers have been published discussing the effects of increasing heterogeneity in structured populations of agents, where it has been established that heterogeneity may favour cooperative behaviour if it supports agents to locally coordinate their strategies. In this paper, assuming an existing model of a heterogeneous weighted network, we aim to further this analysis by exploring the relationship (if any) between heterogeneity and cooperation. We adopt a weighted network which is fully populated by agents playing both the Prisoner's Dilemma or the Optional Prisoner's Dilemma games with coevolutionary rules, i.e., not only the strategies but also the link weights evolve over time. Surprisingly, results show that the heterogeneity of link weights (states) on their own does not always promote cooperation; rather cooperation is actually favoured by the increase in the number of overlapping states and not by the heterogeneity itself. We believe that these results can guide further research towards a more accurate analysis of the role of heterogeneity in social dilemmas.

  8. Seed Removal Increased by Scramble Competition with an Invasive Species

    PubMed Central

    Minor, Rebecca L.; Koprowski, John L.

    2015-01-01

    Competition for seeds has a major influence on the evolution of granivores and the plants on which they rely. The complexity of interactions and coevolutionary relationships vary across forest types. The introduction of non-native granivores has considerable potential to alter seed dispersal dynamics. Non-native species are a major cause of endangerment for native species, but the mechanisms are often unclear. As biological invasions continue to rise, it is important to understand mechanisms to build up strategies to mitigate the threat. Our field experiment quantified the impact of introduced Abert’s squirrels (Sciurus aberti) on rates of seed removal within the range of critically endangered Mount Graham red squirrels (Tamiasciurus hudsonicus grahamensis), which consumes similar foods. In the presence of invasive Abert’s squirrels, the time cones were removed was faster than when the invasive was excluded, accounting for a median removal time of cones available to red and Abert’s squirrels that is 32.8% less than that of cones available only to the rare native red squirrels. Moreover, in the presence of Abert’s squirrels, removal rates are higher at great distance from a territorial red squirrel larderhoard and in more open portions of the forest, which suggests differential patterns of seed dispersal. The impact on food availability as a result of cone removal by Abert’s squirrels suggests the potential of food competition as a mechanism of endangerment for the Mount Graham red squirrel. Furthermore, the magnitude and differential spatial patterns of seed removal suggest that non-native granivores may have impacts on forest regeneration and structure. PMID:26650073

  9. Seed Removal Increased by Scramble Competition with an Invasive Species.

    PubMed

    Minor, Rebecca L; Koprowski, John L

    2015-01-01

    Competition for seeds has a major influence on the evolution of granivores and the plants on which they rely. The complexity of interactions and coevolutionary relationships vary across forest types. The introduction of non-native granivores has considerable potential to alter seed dispersal dynamics. Non-native species are a major cause of endangerment for native species, but the mechanisms are often unclear. As biological invasions continue to rise, it is important to understand mechanisms to build up strategies to mitigate the threat. Our field experiment quantified the impact of introduced Abert's squirrels (Sciurus aberti) on rates of seed removal within the range of critically endangered Mount Graham red squirrels (Tamiasciurus hudsonicus grahamensis), which consumes similar foods. In the presence of invasive Abert's squirrels, the time cones were removed was faster than when the invasive was excluded, accounting for a median removal time of cones available to red and Abert's squirrels that is 32.8% less than that of cones available only to the rare native red squirrels. Moreover, in the presence of Abert's squirrels, removal rates are higher at great distance from a territorial red squirrel larderhoard and in more open portions of the forest, which suggests differential patterns of seed dispersal. The impact on food availability as a result of cone removal by Abert's squirrels suggests the potential of food competition as a mechanism of endangerment for the Mount Graham red squirrel. Furthermore, the magnitude and differential spatial patterns of seed removal suggest that non-native granivores may have impacts on forest regeneration and structure.

  10. Escalation of a coevolutionary arms race through host rejection of brood parasitic young.

    PubMed

    Langmore, Naomi E; Hunt, Sarah; Kilner, Rebecca M

    2003-03-13

    Cuckoo nestlings that evict all other young from the nest soon after hatching impose a high reproductive cost on their hosts. In defence, hosts have coevolved strategies to prevent brood parasitism. Puzzlingly, they do not extend beyond the egg stage. Thus, hosts adept at recognizing foreign eggs remain vulnerable to exploitation by cuckoo nestlings. Here we show that the breach of host egg defences by cuckoos creates a new stage in the coevolutionary cycle. We found that defences used during the egg-laying period by host superb fairy-wrens (Malurus cyaneus) are easily evaded by the Horsfield's bronze-cuckoo (Chrysococcyx basalis), a specialist fairy-wren brood parasite. However, although hosts never deserted their own broods, they later abandoned 40% of nests containing a lone Horsfield's bronze-cuckoo nestling, and 100% of nests with a lone shining bronze-cuckoo nestling (Chrysococcyx lucidus), an occasional fairy-wren brood parasite. Our experiments demonstrate that host discrimination against evictor-cuckoo nestlings is possible, and suggest that it has selected for the evolution of nestling mimicry in bronze-cuckoos.

  11. 47 CFR 27.1103 - 2000-2020 MHz and 2180-2200 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false 2000-2020 MHz and 2180-2200 MHz bands subject... MHz, 2000-2020 MHz, and 2180-2200 MHz bands Licensing and Competitive Bidding Provisions § 27.1103 2000-2020 MHz and 2180-2200 MHz bands subject to competitive bidding. Mutually exclusive initial...

  12. Integrating instance selection, instance weighting, and feature weighting for nearest neighbor classifiers by coevolutionary algorithms.

    PubMed

    Derrac, Joaquín; Triguero, Isaac; Garcia, Salvador; Herrera, Francisco

    2012-10-01

    Cooperative coevolution is a successful trend of evolutionary computation which allows us to define partitions of the domain of a given problem, or to integrate several related techniques into one, by the use of evolutionary algorithms. It is possible to apply it to the development of advanced classification methods, which integrate several machine learning techniques into a single proposal. A novel approach integrating instance selection, instance weighting, and feature weighting into the framework of a coevolutionary model is presented in this paper. We compare it with a wide range of evolutionary and nonevolutionary related methods, in order to show the benefits of the employment of coevolution to apply the techniques considered simultaneously. The results obtained, contrasted through nonparametric statistical tests, show that our proposal outperforms other methods in the comparison, thus becoming a suitable tool in the task of enhancing the nearest neighbor classifier.

  13. 47 CFR 22.881 - Air-Ground Radiotelephone Service subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... competitive bidding. 22.881 Section 22.881 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air... exclusive initial applications for commercial Air-Ground Radiotelephone Service licenses are subject to...

  14. Photosynthetic tolerance to non-resource stress influences competition importance and intensity in an invaded estuary.

    PubMed

    Tang, Long; Wolf, Amelia A; Gao, Yang; Wang, Cheng Huan

    2018-06-01

    In an attempt to clarify the role of environmental and biotic interactions on plant growth, there has been a long-running ecological debate over whether the intensity and importance of competition stabilizes, increases or decreases across environmental gradients. We conducted an experiment in a Chinese estuary to investigate the effects of a non-resource stress gradient, soil salinity (from 1.4‰ to 19.0‰ salinity), on the competitive interactions between native Phragmites australis and invasive Spartina alterniflora. We linked these effects to measurements of photosynthetic activities to further elucidate the underlying physiological mechanism behind the competitive interactions and the driver of invasion. The experiments revealed that while biomass of both species decreased in the presence of the other, competition did not alter photosynthetic activity of either species over time. P. australis exhibited high photosynthetic activity, including low chlorophyllase activity, high chlorophyll content, high stomatal conductance and high net photosynthetic rate, at low salinity. Under these conditions, P. australis experienced low competitive intensity, leading to high biomass production and competitive exclusion of S. alterniflora. The opposite was observed for S. alterniflora: while competitive intensity experienced by P. australis increased with increasing salinity, and photosynthetic activity, biomass, competitive dominance and the importance of competition for P. australis growth decreased, those of S. alterniflora were stable. These findings demonstrate that S. alterniflora invasion driven by competitive exclusion are likely to occur and expand in high salinity zones. The change in the nature of competition along a non-resource stress gradient differs between competitors likely due to differences in photosynthetic tolerance to salinity. The driver of growth of the less-tolerant species changes from competition to non-resource stress factors with

  15. Influence of the Host Contact Sequence on the Outcome of Competition among Aspergillus flavus Isolates during Host Tissue Invasion▿

    PubMed Central

    Mehl, H. L.; Cotty, P. J.

    2011-01-01

    Biological control of aflatoxin contamination by Aspergillus flavus is achieved through competitive exclusion of aflatoxin producers by atoxigenic strains. Factors dictating the extent to which competitive displacement occurs during host infection are unknown. The role of initial host contact in competition between pairs of A. flavus isolates coinfecting maize kernels was examined. Isolate success during tissue invasion and reproduction was assessed by quantification of isolate-specific single nucleotide polymorphisms using pyrosequencing. Isolates were inoculated either simultaneously or 1 h apart. Increased success during competition was conferred to the first isolate to contact the host independent of that isolate's innate competitive ability. The first-isolate advantage decreased with the conidial concentration, suggesting capture of limited resources on kernel surfaces contributes to competitive exclusion. Attempts to modify access to putative attachment sites by either coating kernels with dead conidia or washing kernels with solvents did not influence the success of the first isolate, suggesting competition for limited attachment sites on kernel surfaces does not mediate first-isolate advantage. The current study is the first to demonstrate an immediate competitive advantage conferred to A. flavus isolates upon host contact and prior to either germ tube emergence or host colonization. This suggests the timing of host contact is as important to competition during disease cycles as innate competitive ability. Early dispersal to susceptible crop components may allow maintenance within A. flavus populations of genetic types with low competitive ability during host tissue invasion. PMID:21216896

  16. 37 CFR 404.7 - Exclusive, co-exclusive and partially exclusive licenses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... period, the Federal agency has determined that; (A) The public will be served by the granting of the... practical application or otherwise promote the invention's utilization by the public. (B) Exclusive, co... promote the invention's utilization by the public; and (C) The proposed scope of exclusivity is not...

  17. The role of drought- and disturbance-mediated competition in shaping community responses to varied environments.

    PubMed

    Napier, Joseph D; Mordecai, Erin A; Heckman, Robert W

    2016-06-01

    By altering the strength of intra- and interspecific competition, droughts may reshape plant communities. Furthermore, species may respond differently to drought when other influences, such as herbivory, are considered. To explore this relationship, we conducted a greenhouse experiment measuring responses to inter- and intraspecific competition for two grasses, Schedonorus arundinaceus and Paspalum dilatatum, while varying water availability and simulating herbivory via clipping. We then parameterized population growth models to examine the long-term outcome of competition under these conditions. Under drought, S. arundinaceus was less water stressed than P. dilatatum, which exhibited severe water stress; clipping alleviated this stress, increasing the competitive ability of P. dilatatum relative to S. arundinaceus. Although P. dilatatum competed weakly under drought, clipping reduced water stress in P. dilatatum, thereby enhancing its ability to compete with S. arundinaceus under drought. Supporting these observations, population growth models predicted that P. dilatatum would exclude S. arundinaceus when clipped under drought, while S. arundinaceus would exclude P. dilatatum when unclipped under drought. When the modeled environment varied temporally, environmental variation promoted niche differences that, though insufficient to maintain stable coexistence, prevented unconditional competitive exclusion by promoting priority effects. Our results suggest that it is important to consider how species respond not just to stable, but also to variable, environments. When species differ in their responses to drought, competition, and simulated herbivory, stable environments may promote competitive exclusion, while fluctuating environments may promote coexistence. These interactions are critical to understanding how species will respond to global change.

  18. Picture-Induced Semantic Interference Reflects Lexical Competition during Object Naming

    PubMed Central

    Aristei, Sabrina; Zwitserlood, Pienie; Rahman, Rasha Abdel

    2012-01-01

    With a picture–picture experiment, we contrasted competitive and non-competitive models of lexical selection during language production. Participants produced novel noun–noun compounds in response to two adjacently displayed objects that were categorically related or unrelated (e.g., depicted objects: apple and cherry; naming response: “apple–cherry”). We observed semantic interference, with slower compound naming for related relative to unrelated pictures, very similar to interference effects produced by semantically related context words in picture–word-interference paradigms. This finding suggests that previous failures to observe reliable interference induced by context pictures may be due to the weakness of lexical activation and competition induced by pictures, relative to words. The production of both picture names within one integrated compound word clearly enhances lexical activation, resulting in measurable interference effects. We interpret this interference as resulting from lexical competition, because the alternative interpretation, in terms of response-exclusion from the articulatory buffer, does not apply to pictures, even when they are named. PMID:22363304

  19. Exclusive contracts in the hospital setting: a two-edged sword, part 1: legal issues.

    PubMed

    Portman, Robert M

    2007-05-01

    Hospitals routinely enter into contracts with radiology groups for the right to be the exclusive provider of radiology services at the facility in exchange for the group agreeing to provide and manage all aspects of that service within the hospital. These "exclusive contracts" generally result in the radiology department and associated equipment being closed off to physicians who are not part of the contracting group. Exclusive contracts are generally considered to be good for physicians who have them and bad for those excluded by them. In fact, while exclusive contracts offer obvious benefits to the physicians who receive them and obvious disadvantages for those who are excluded, they also present pitfalls for physicians in the chosen group. Part I of this article discusses the legal issues raised by exclusive contracts. Although these agreements appear to be anti-competitive, most courts have rejected antitrust challenges to exclusive contracts. Excluded physicians have had much greater success in attacking exclusive contracting arrangements on breach of contract and procedural/due process grounds. Exclusive contracting arrangements can also raise concerns under the Medicare-Medicaid anti-kickback statute if the contracting physicians are required to pay consideration or accept less than fair market value compensation in exchange for exclusive contracts. These agreements can also raise issues under the Stark II physician self-referral law if the contracting physicians are in a position to refer Medicare or Medicaid patients to the hospital. Part II of this article will discuss the advantages and disadvantages of exclusive contracts for physicians covered and not covered by such contracts, as well as strategies for avoiding them or minimizing their potential adverse impact. It also will discuss specific provisions of exclusive contracts that should be included or avoided.

  20. Substrate-Induced Facilitated Dissociation of the Competitive Inhibitor from the Active Site of O-Acetyl Serine Sulfhydrylase Reveals a Competitive-Allostery Mechanism.

    PubMed

    Singh, Appu Kumar; Ekka, Mary Krishna; Kaushik, Abhishek; Pandya, Vaibhav; Singh, Ravi P; Banerjee, Shrijita; Mittal, Monica; Singh, Vijay; Kumaran, S

    2017-09-19

    By classical competitive antagonism, a substrate and competitive inhibitor must bind mutually exclusively to the active site. The competitive inhibition of O-acetyl serine sulfhydrylase (OASS) by the C-terminus of serine acetyltransferase (SAT) presents a paradox, because the C-terminus of SAT binds to the active site of OASS with an affinity that is 4-6 log-fold (10 4 -10 6 ) greater than that of the substrate. Therefore, we employed multiple approaches to understand how the substrate gains access to the OASS active site under physiological conditions. Single-molecule and ensemble approaches showed that the active site-bound high-affinity competitive inhibitor is actively dissociated by the substrate, which is not consistent with classical views of competitive antagonism. We employed fast-flow kinetic approaches to demonstrate that substrate-mediated dissociation of full length SAT-OASS (cysteine regulatory complex) follows a noncanonical "facilitated dissociation" mechanism. To understand the mechanism by which the substrate induces inhibitor dissociation, we resolved the crystal structures of enzyme·inhibitor·substrate ternary complexes. Crystal structures reveal a competitive allosteric binding mechanism in which the substrate intrudes into the inhibitor-bound active site and disengages the inhibitor before occupying the site vacated by the inhibitor. In summary, here we reveal a new type of competitive allosteric binding mechanism by which one of the competitive antagonists facilitates the dissociation of the other. Together, our results indicate that "competitive allostery" is the general feature of noncanonical "facilitated/accelerated dissociation" mechanisms. Further understanding of the mechanistic framework of "competitive allosteric" mechanism may allow us to design a new family of "competitive allosteric drugs/small molecules" that will have improved selectivity and specificity as compared to their competitive and allosteric counterparts.

  1. High-confidence prediction of global interactomes based on genome-wide coevolutionary networks

    PubMed Central

    Juan, David; Pazos, Florencio; Valencia, Alfonso

    2008-01-01

    Interacting or functionally related protein families tend to have similar phylogenetic trees. Based on this observation, techniques have been developed to predict interaction partners. The observed degree of similarity between the phylogenetic trees of two proteins is the result of many different factors besides the actual interaction or functional relationship between them. Such factors influence the performance of interaction predictions. One aspect that can influence this similarity is related to the fact that a given protein interacts with many others, and hence it must adapt to all of them. Accordingly, the interaction or coadaptation signal within its tree is a composite of the influence of all of the interactors. Here, we introduce a new estimator of coevolution to overcome this and other problems. Instead of relying on the individual value of tree similarity between two proteins, we use the whole network of similarities between all of the pairs of proteins within a genome to reassess the similarity of that pair, thereby taking into account its coevolutionary context. We show that this approach offers a substantial improvement in interaction prediction performance, providing a degree of accuracy/coverage comparable with, or in some cases better than, that of experimental techniques. Moreover, important information on the structure, function, and evolution of macromolecular complexes can be inferred with this methodology. PMID:18199838

  2. High-confidence prediction of global interactomes based on genome-wide coevolutionary networks.

    PubMed

    Juan, David; Pazos, Florencio; Valencia, Alfonso

    2008-01-22

    Interacting or functionally related protein families tend to have similar phylogenetic trees. Based on this observation, techniques have been developed to predict interaction partners. The observed degree of similarity between the phylogenetic trees of two proteins is the result of many different factors besides the actual interaction or functional relationship between them. Such factors influence the performance of interaction predictions. One aspect that can influence this similarity is related to the fact that a given protein interacts with many others, and hence it must adapt to all of them. Accordingly, the interaction or coadaptation signal within its tree is a composite of the influence of all of the interactors. Here, we introduce a new estimator of coevolution to overcome this and other problems. Instead of relying on the individual value of tree similarity between two proteins, we use the whole network of similarities between all of the pairs of proteins within a genome to reassess the similarity of that pair, thereby taking into account its coevolutionary context. We show that this approach offers a substantial improvement in interaction prediction performance, providing a degree of accuracy/coverage comparable with, or in some cases better than, that of experimental techniques. Moreover, important information on the structure, function, and evolution of macromolecular complexes can be inferred with this methodology.

  3. Quantitative genetic insights into the coevolutionary dynamics of male and female genitalia

    PubMed Central

    Evans, Jonathan P.; van Lieshout, Emile; Gasparini, Clelia

    2013-01-01

    The spectacular variability that typically characterizes male genital traits has largely been attributed to the role of sexual selection. Among the evolutionary mechanisms proposed to account for this diversity, two processes in particular have generated considerable interest. On the one hand, females may exploit postcopulatory mechanisms of selection to favour males with preferred genital traits (cryptic female choice; CFC), while on the other hand females may evolve structures or behaviours that mitigate the direct costs imposed by male genitalia (sexual conflict; SC). A critical but rarely explored assumption underlying both processes is that male and female reproductive traits coevolve, either via the classic Fisherian model of preference-trait coevolution (CFC) or through sexually antagonistic selection (SC). Here, we provide evidence for this prediction in the guppy (Poecilia reticulata), a polyandrous livebearing fish in which males transfer sperm internally to females via consensual and forced matings. Our results from a paternal half-sibling breeding design reveal substantial levels of additive genetic variation underlying male genital size and morphology—two traits known to predict mating success during non-consensual matings. Our subsequent finding that physically interacting female genital traits exhibit corresponding levels of genetic (co)variation reveals the potential intersexual coevolutionary dynamics of male and female genitalia, thereby fulfilling a fundamental assumption underlying CFC and SC theory. PMID:23720546

  4. Spatial patterns, ecological niches, and interspecific competition of avian brood parasites: inferring from a case study of Korea.

    PubMed

    Lee, Jin-Won; Noh, Hee-Jin; Lee, Yunkyoung; Kwon, Young-Soo; Kim, Chang-Hoe; Yoo, Jeong-Chil

    2014-09-01

    Since obligate avian brood parasites depend completely on the effort of other host species for rearing their progeny, the availability of hosts will be a critical resource for their life history. Circumstantial evidence suggests that intense competition for host species may exist not only within but also between species. So far, however, few studies have demonstrated whether the interspecific competition really occurs in the system of avian brood parasitism and how the nature of brood parasitism is related to their niche evolution. Using the occurrence data of five avian brood parasites from two sources of nationwide bird surveys in South Korea and publically available environmental/climatic data, we identified their distribution patterns and ecological niches, and applied species distribution modeling to infer the effect of interspecific competition on their spatial distribution. We found that the distribution patterns of five avian brood parasites could be characterized by altitude and climatic conditions, but overall their spatial ranges and ecological niches extensively overlapped with each other. We also found that the predicted distribution areas of each species were generally comparable to the realized distribution areas, and the numbers of individuals in areas where multiple species were predicted to coexist showed positive relationships among species. In conclusion, despite following different coevolutionary trajectories to adapt to their respect host species, five species of avian brood parasites breeding in South Korea occupied broadly similar ecological niches, implying that they tend to conserve ancestral preferences for ecological conditions. Furthermore, our results indicated that contrary to expectation interspecific competition for host availability between avian brood parasites seemed to be trivial, and thus, play little role in shaping their spatial distributions and ecological niches. Future studies, including the complete ranges of avian brood

  5. Competition along productivity gradients: news from heathlands.

    PubMed

    Delerue, Florian; Gonzalez, Maya; Achat, David L; Puzos, Luc; Augusto, Laurent

    2018-05-01

    The importance of competition in low productive habitats is still debated. Studies which simultaneously evaluate preemption of resources and consequences for population dynamics are needed for a comprehensive view of competitive outcomes. We cultivated two emblematic species of European heathlands (Calluna vulgaris and Molinia caerulea) in a nursery for 2 years at two fertility levels, reproducing the productivity gradient found in phosphorus (P)-depleted heathlands in southwest France. The second year, we planted Ulex europaeus seedlings, a ubiquitous heathland species, under the cover of the two species to evaluate its ability to regenerate. Half of the seedlings were placed in tubes for exclusion of competitor roots. We measured the development of the competitors aboveground and belowground and their interception of resources (light, water, inorganic P). Ulex seedlings' growth and survival were also measured. Our results on resources interception were consistent with species distribution in heathlands. Molinia, which dominates rich heathlands, was the strongest competitor for light and water in the rich soil. Calluna, which dominates poor heathlands, increased its root allocation in the poor soil, decreasing water and inorganic P availability. However, the impact of total competition and root competition on Ulex seedlings decreased in the poor soil. Other mechanisms, especially decrease of water stress under neighbouring plant cover, appeared to have more influence on the seedlings' response. We found no formal contradiction between Tilman and Grime's theories. Root competition has a primary role in acquisition of soil resources in poor habitats. However, the importance of competition decreases with decreasing fertility.

  6. Neighbour tolerance, not suppression, provides competitive advantage to non-native plants.

    PubMed

    Golivets, Marina; Wallin, Kimberly F

    2018-05-01

    High competitive ability has often been invoked as a key determinant of invasion success and ecological impacts of non-native plants. Yet our understanding of the strategies that non-natives use to gain competitive dominance remains limited. Particularly, it remains unknown whether the two non-mutually exclusive competitive strategies, neighbour suppression and neighbour tolerance, are equally important for the competitive advantage of non-native plants. Here, we analyse data from 192 peer-reviewed studies on pairwise plant competition within a Bayesian multilevel meta-analytic framework and show that non-native plants outperform their native counterparts due to high tolerance of competition, as opposed to strong suppressive ability. Competitive tolerance ability of non-native plants was driven by neighbour's origin and was expressed in response to a heterospecific native but not heterospecific non-native neighbour. In contrast to natives, non-native species were not more suppressed by hetero- vs. conspecific neighbours, which was partially due to higher intensity of intraspecific competition among non-natives. Heterogeneity in the data was primarily associated with methodological differences among studies and not with phylogenetic relatedness among species. Altogether, our synthesis demonstrates that non-native plants are competitively distinct from native plants and challenges the common notion that neighbour suppression is the primary strategy for plant invasion success. © 2018 John Wiley & Sons Ltd/CNRS.

  7. Asymmetric competition impacts evolutionary rescue in a changing environment.

    PubMed

    Van Den Elzen, Courtney L; Kleynhans, Elizabeth J; Otto, Sarah P

    2017-06-28

    Interspecific competition can strongly influence the evolutionary response of a species to a changing environment, impacting the chance that the species survives or goes extinct. Previous work has shown that when two species compete for a temporally shifting resource distribution, the species lagging behind the resource peak is the first to go extinct due to competitive exclusion. However, this work assumed symmetrically distributed resources and competition. Asymmetries can generate differences between species in population sizes, genetic variation and trait means. We show that asymmetric resource availability or competition can facilitate coexistence and even occasionally cause the leading species to go extinct first. Surprisingly, we also find cases where traits evolve in the opposite direction to the changing environment because of a 'vacuum of competitive release' created when the lagging species declines in number. Thus, the species exhibiting the slowest rate of trait evolution is not always the most likely to go extinct in a changing environment. Our results demonstrate that the extent to which species appear to be tracking environmental change and the extent to which they are preadapted to that change may not necessarily determine which species will be the winners and which will be the losers in a rapidly changing world. © 2017 The Author(s).

  8. Guidelines for exclusive.

    DOT National Transportation Integrated Search

    1985-01-01

    The objective of this research was to develop guidelines for the use of exclusive/permissive left-turn signal phasing. This was achieved by collecting data on traffic and roadway conditions for exclusive, exclusive/permissive, and permissive left-tur...

  9. Sustainability and collapse in a coevolutionary model of local resource stocks and behavioral patterns on a social network

    NASA Astrophysics Data System (ADS)

    Wiedermann, Marc; Donges, Jonathan F.; Heitzig, Jobst; Kurths, Jürgen

    2014-05-01

    When investigating the causes and consequences of global change, the collective behavior of human beings is considered as having a considerable impact on natural systems. In our work, we propose a conceptual coevolutionary model simulating the dynamics of local renewable resources in interaction with simplistic societal agents exploiting those resources. The society is represented by a social network on which social traits may be transmitted between agents. These traits themselves induce a certain rate of exploitation of the resource, leading either to its depletion or sustainable existence. Traits are exchanged probabilistically according to their instantaneous individual payoff, and hence this process depends on the status of the natural resource. At the same time agents may adaptively restructure their set of acquaintances. Connections with agents having a different trait may be broken while new connections with agents of the same trait are established. We investigate which choices of social parameters, like the frequency of social interaction, rationality and rate of social network adaptation, cause the system to end in a sustainable state and, hence, what can be done to avoid a collapse of the entire system. The importance and influence of the social network structure is analyzed by the variation of link-densities in the underlying network topology and shows significant influence on the expected outcome of the model. For a static network with no adaptation we find a robust phase transition between the two different regimes, sustainable and non-sustainable, which co-exist in parameter space. High connectivity within the social network, e.g., high link-densities, in combination with a fast rate of social learning lead to a likely collapse of the entire co-evolutionary system, whereas slow learning and small network connectivity very likely result in the sustainable existence of the natural resources. Collapse may be avoided by an intelligent rewiring, e

  10. Interspecific Larval Competition Between Aedes albopictus and Aedes japonicus (Diptera: Culicidae) in Northern Virginia

    PubMed Central

    Armistead, J. S.; Arias, J. R.; Nishimura, N.; Lounibos, L. P.

    2008-01-01

    Aedes albopictus (Skuse) and Aedes japonicus (Theobald) are two of the most recent and widespread invasive mosquito species to have become established in the United States. The two species co-occur in water-filled artificial containers, where crowding and limiting resources are likely to promote inter- or intraspecific larval competition. The performance of northern Virginia populations of Ae. japonicus and Ae. albopictus competing as larvae under field conditions was evaluated. Per capita rates of population increase for each species were estimated, and the effects of species composition and larval density were determined. In water-containing cups provided with oak leaves, Ae. albopictus larvae exhibited a competitive advantage over Ae. japonicus as a consequence of higher survivorship, shorter developmental time, and a significantly higher estimated population growth rate under conditions of interspecific competition. Intraspecific competition constrained population performance of Ae. albopictus significantly more than competition with Ae. japonicus. In the context of the Lotka-Volterra model of competition, these findings suggest competitive exclusion of Ae. japonicus in those habitats where this species co-occurs with Ae. albopictus. PMID:18714861

  11. Interspecific larval competition between Aedes albopictus and Aedes japonicus (Diptera: Culicidae) in northern Virginia.

    PubMed

    Armistead, J S; Arias, J R; Nishimura, N; Lounibos, L P

    2008-07-01

    Aedes albopictus (Skuse) and Aedes japonicus (Theobald) are two of the most recent and widespread invasive mosquito species to have become established in the United States. The two species co-occur in water-filled artificial containers, where crowding and limiting resources are likely to promote inter- or intraspecific larval competition. The performance of northern Virginia populations of Ae. japonicus and Ae. albopictus competing as larvae under field conditions was evaluated. Per capita rates of population increase for each species were estimated, and the effects of species composition and larval density were determined. In water-containing cups provided with oak leaves, Ae. albopictus larvae exhibited a competitive advantage over Ae. japonicus as a consequence of higher survivorship, shorter developmental time, and a significantly higher estimated population growth rate under conditions of interspecific competition. Intraspecific competition constrained population performance of Ae. albopictus significantly more than competition with Ae. japonicus. In the context of the Lotka-Volterra model of competition, these findings suggest competitive exclusion of Ae. japonicus in those habitats where this species co-occurs with Ae. albopictus.

  12. Host age modulates within-host parasite competition

    PubMed Central

    Izhar, Rony; Routtu, Jarkko; Ben-Ami, Frida

    2015-01-01

    In many host populations, one of the most striking differences among hosts is their age. While parasite prevalence differences in relation to host age are well known, little is known on how host age impacts ecological and evolutionary dynamics of diseases. Using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa, we examined how host age at exposure influences within-host parasite competition and virulence. We found that multiply-exposed hosts were more susceptible to infection and suffered higher mortality than singly-exposed hosts. Hosts oldest at exposure were least often infected and vice versa. Furthermore, we found that in young multiply-exposed hosts competition was weak, allowing coexistence and transmission of both parasite clones, whereas in older multiply-exposed hosts competitive exclusion was observed. Thus, age-dependent parasite exposure and host demography (age structure) could together play an important role in mediating parasite evolution. At the individual level, our results demonstrate a previously unnoticed interaction of the host's immune system with host age, suggesting that the specificity of immune function changes as hosts mature. Therefore, evolutionary models of parasite virulence might benefit from incorporating age-dependent epidemiological parameters. PMID:25994010

  13. The Impact of Taxes on Competition for CEOs.

    PubMed

    Krenn, Peter

    2017-07-03

    This paper contributes to the question of how taxation of corporate profits and wages affects competition among firms for highly skilled human resources such as CEOs. Use of a theoretical model shows that wage taxes can have a substantial impact on the outcome of such a competition if marginal tax rates are different as in an international labor market. Further, the paper shows that increasing the wage tax rate unilaterally can have an ambiguous effect on observed gross compensation levels. However, in a local labor market for CEOs, observed gross fixed salaries should decline in the wage tax rate. Tax effects in a market for CEOs is a particularly interesting topic because recent developments with respect to compensation practices of top-level managers have opened a public debate about the use of instruments for regulating compensation of those managers. Furthermore, many countries around the world use tax incentives in order to facilitate immigration of highly skilled human resources. The investigation follows an analytical economics-based approach by extending an LEN model with elements of competition for scarce human resources and income taxation. It investigates the impact of differential taxation on the competition between two firms for the exclusive service of a unique, highly skilled CEO.

  14. The Impact of Taxes on Competition for CEOs

    PubMed Central

    Krenn, Peter

    2017-01-01

    Abstract This paper contributes to the question of how taxation of corporate profits and wages affects competition among firms for highly skilled human resources such as CEOs. Use of a theoretical model shows that wage taxes can have a substantial impact on the outcome of such a competition if marginal tax rates are different as in an international labor market. Further, the paper shows that increasing the wage tax rate unilaterally can have an ambiguous effect on observed gross compensation levels. However, in a local labor market for CEOs, observed gross fixed salaries should decline in the wage tax rate. Tax effects in a market for CEOs is a particularly interesting topic because recent developments with respect to compensation practices of top-level managers have opened a public debate about the use of instruments for regulating compensation of those managers. Furthermore, many countries around the world use tax incentives in order to facilitate immigration of highly skilled human resources. The investigation follows an analytical economics-based approach by extending an LEN model with elements of competition for scarce human resources and income taxation. It investigates the impact of differential taxation on the competition between two firms for the exclusive service of a unique, highly skilled CEO. PMID:29097851

  15. Competition in health insurance markets: limitations of current measures for policy analysis.

    PubMed

    Scanlon, Dennis P; Chernew, Michael; Swaminathan, Shailender; Lee, Woolton

    2006-12-01

    Health care reform proposals often rely on increased competition in health insurance markets to drive improved performance in health care costs, access, and quality. We examine a range of data issues related to the measures of health insurance competition used in empirical studies published from 1994-2004. The literature relies exclusively on market structure and penetration variables to measure competition. While these measures are correlated, the degree of correlation is modest, suggesting that choice of measure could influence empirical results. Moreover, certain measurement issues such as the lack of data on PPO enrollment, the treatment of small firms, and omitted market characteristics also could affect the conclusions in empirical studies. Importantly, other types of measures related to competition (e.g., the availability of information on price and outcomes, degree of entry barriers, etc.) are important from both a theoretical and policy perspective, but their impact on market outcomes has not been widely studied.

  16. Marketing energy services in a competitive environment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mykytyn, R.B.

    For nearly six decades electrical utilities have operated in a regulated environment established by the Public Utilities Holding Company Act (PUHCA) of 1935. This legislation granted generators exclusive franchise to market electrical power in a given geographical area in return for the company`s commitment to provide safe, reliable and fairly-priced electrical power to all customers within the region. For close to 40 years, this system of regulated monopoly functioned reasonably well to maintain a balance among the varied, and at times competing, interests in the industry. During the 1970s, however, the public argument in favor of competition within the electricalmore » services industry gained momentum. Spiraling energy costs focused the consumer`s attention on the need for conservation and inspired a variety of technological developments as well as experiments in cogeneration. Today, the electrical utility industry is poised for great change. Soon, this industry will follow the natural gas, telecommunications, and transportation industries into the uncharted waters of deregulation. The most pressing consequence of moving from a regulated environment to one that is deregulated - in other words, a competitive environment - is the need to design and implement a completely new form of marketing program. The response among industry marketing managers ranges from confusion and concern to excitement and eager anticipation. Where you fall along this continuum depends on how well you understand competitive marketing practices and the degree to which your company`s management group is willing to initiate competitive strategies and tactics now in preparation for the coming competitive marketplace.« less

  17. Coevolutionary dynamics of opinion propagation and social balance: The key role of small-worldness

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Chen, Lixue; Sun, Xian; Zhang, Kai; Zhang, Jie; Li, Ping

    2014-03-01

    The propagation of various opinions in social networks, which influences human inter-relationships and even social structure, and hence is a most important part of social life. We have incorporated social balance into opinion propagation in social networks are influenced by social balance. The edges in networks can represent both friendly or hostile relations, and change with the opinions of individual nodes. We introduce a model to characterize the coevolutionary dynamics of these two dynamical processes on Watts-Strogatz (WS) small-world network. We employ two distinct evolution rules (i) opinion renewal; and (ii) relation adjustment. By changing the rewiring probability, and thus the small-worldness of the WS network, we found that the time for the system to reach balanced states depends critically on both the average path length and clustering coefficient of the network, which is different than other networked process like epidemic spreading. In particular, the system equilibrates most quickly when the underlying network demonstrates strong small-worldness, i.e., small average path lengths and large clustering coefficient. We also find that opinion clusters emerge in the process of the network approaching the global equilibrium, and a measure of global contrariety is proposed to quantify the balanced state of a social network.

  18. In vivo characterization of Lactobacillus johnsonii FI9785 for use as a defined competitive exclusion agent against bacterial pathogens in poultry.

    PubMed

    La Ragione, R M; Narbad, A; Gasson, M J; Woodward, M J

    2004-01-01

    To test the efficacy of Lactobacillus johnsonii FI9785 in reducing the colonization and shedding of Salmonella enterica serotype Enteritidis, Escherichia coli O78:K80 and Clostridium perfringens in poultry. Specific pathogen-free chicks (1 day old) were dosed with a single oral inoculum of 1x10(9) CFU. Lactobacillus johnsonii FI9785 and 24 h later were challenged in separate experiments with S. Enteritidis (S1400, nalr) and E. coli O78:K80 (EC34195, nalr). There were no significant effects against S. Enteritidis whereas colonization of the small intestine by E. coli O78:K80 was reduced significantly. Both S. Enteritidis and E. coli colonized the caeca and colon to levels equivalent to control birds and there was no reduction in shedding as assessed by a semi-quantitative cloacal swabbing technique. Specific pathogen-free chicks (20 day old) were dosed with a single oral inoculum of 1x10(9) CFU L. johnsonii FI9785 and 24 h later were challenged with C. perfringens. A single oral dose of L. johnsonii FI9785 was sufficient to suppress all aspects of colonization and persistence of C. perfringens. Lactobacillus johnsonii FI9785 may be given to poultry for use as a competitive exclusion agent to control C. perfringens. Lactobacillus johnsonii FI9785 may be a valuable tool to control the endemic disease of necrotic enteritis, thereby reducing economic losses associated with reduced use of antimicrobials in the poultry industry.

  19. Search for exclusive or semi-exclusive γγ production and observation of exclusive and semi-exclusive e +e - production in pp collisions at $$ \\sqrt{s}=7 $$ TeV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.

    A search for exclusive or semi-exclusive photon pair production, pp to p(*) + photon pair + p(*) (where p(*) stands for a diffractively-dissociated proton), and the observation of exclusive and semi-exclusive electron pair production, pp to p(*) + ee + p(*), in proton-proton collisions at sqrt(s) = 7 TeV, are presented. The analysis is based on a data sample corresponding to an integrated luminosity of 36 inverse picobarns recorded by the CMS experiment at the LHC at low instantaneous luminosities. Candidate photon pair or electron pair events are selected by requiring the presence of two photons or a positron andmore » an electron, each with transverse energy ET > 5.5 GeV and pseudorapidity abs(eta) < 2.5, and no other particles in the region abs(eta) < 5.2. No exclusive or semi-exclusive diphoton candidates are found in the data. An upper limit on the cross section for the reaction pp to p(*) + photon pair + p(*), within the above kinematic selections, is set at 1.18 pb at 95% confidence level. Seventeen exclusive or semi-exclusive dielectron candidates are observed, with an estimated background of 0.85 +/- 0.28 (stat.) events, in agreement with the QED-based prediction of 16.3 +/- 1.3 (syst.) events.« less

  20. Microcystis aeruginosa strengthens the advantage of Daphnia similoides in competition with Moina micrura.

    PubMed

    Tang, Hengxing; Hou, Xinying; Xue, Xiaofeng; Chen, Rui; Zhu, Xuexia; Huang, Yuan; Chen, Yafen

    2017-08-31

    Microcystis blooms are generally associated with zooplankton shifts by disturbing interspecific relationships. The influence of Microcystis on competitive dominance by different sized zooplanktons showed species-specific dependence. We evaluated the competitive responses of small Moina micrura and large Daphnia similoides to the presence of Microcystis using mixed diets comprising 0%, 20%, and 35% of toxic M. aeruginosa, and the rest of green alga Chlorella pyrenoidosa. No competitive exclusion occurred for the two species under the tested diet combinations. In the absence of M. aeruginosa, the biomasses of the two cladocerans were decreased by the competition between them. However, the Daphnia was less inhibited with the higher biomass, suggesting the competitive dominance of Daphnia. M. aeruginosa treatment suppressed the population growths of the two cladocerans, with the reduced carrying capacities. Nonetheless, the population inhibition of Daphnia by competition was alleviated by the increased Microcystis proportion in diet. As a result, the competitive advantage of Daphnia became more pronounced, as indicated by the higher Daphnia: Moina biomass ratio with increased Microcystis proportions. These results suggested that M. aeruginosa strengthens the advantage of D. similoides in competition with M. micrura, which contributes to the diversified zooplankton shifts observed in fields during cyanobacteria blooms.

  1. Delineating the roles of males and females in sperm competition

    PubMed Central

    Evans, Jonathan P.; Rosengrave, Patrice; Gasparini, Clelia; Gemmell, Neil J.

    2013-01-01

    Disentangling the relative roles of males, females and their interactive effects on competitive fertilization success remains a challenge in sperm competition. In this study, we apply a novel experimental framework to an ideally suited externally fertilizing model system in order to delineate these roles. We focus on the chinook salmon, Oncorhynchus tshawytscha, a species in which ovarian fluid (OF) has been implicated as a potential arbiter of cryptic female choice for genetically compatible mates. We evaluated this predicted sexually selected function of OF using a series of factorial competitive fertilization trials. Our design involved a series of 10 factorial crosses, each involving two ‘focal’ rival males whose sperm competed against those from a single ‘standardized’ (non-focal) rival for a genetically uniform set of eggs in the presence of OF from two focal females. This design enabled us to attribute variation in competitive fertilization success among focal males, females (OF) and their interacting effects, while controlling for variation attributable to differences in the sperm competitive ability of rival males, and male-by-female genotypic interactions. Using this experimental framework, we found that variation in sperm competitiveness could be attributed exclusively to differences in the sperm competitive ability of focal males, a conclusion supported by subsequent analyses revealing that variation in sperm swimming velocity predicts paternity success. Together, these findings provide evidence that variation in paternity success can be attributed to intrinsic differences in the sperm competitive ability of rival males, and reveal that sperm swimming velocity is a key target of sexual selection. PMID:24266039

  2. The invisible hand: how British American Tobacco precluded competition in Uzbekistan

    PubMed Central

    Gilmore, Anna B; McKee, Martin; Collin, Jeff

    2007-01-01

    Background Tobacco industry documents provide a unique opportunity to explore the role transnational corporations (TNCs) played in shaping the poor outcomes of privatisation in the former Soviet Union (FSU). This paper examines British American Tobacco's (BAT's) business conduct in Uzbekistan where large‐scale smuggling of BAT's cigarettes, BAT's reversal of tobacco control legislation and its human rights abuses of tobacco farmers have been documented previously. This paper focuses, instead, on BAT's attitude to competition, compares BAT's conduct with international standards and assesses its influence on the privatisation process. Methods Analysis of BAT documents released through litigation. Results BAT secured sole negotiator status precluding the Uzbekistan government from initiating discussions with other parties. Recognising that a competitive tender would greatly increase the cost of investment, BAT went to great lengths to avoid one, ultimately securing President Karimov's support and negotiating a monopoly position in a closed deal. It simultaneously secured exclusion from the monopolies committee, ensuring freedom to set prices, on the basis of a spurious argument that competition would exist from imports. Other anticompetitive moves comprised including all three plants in the deal despite intending to close down two, exclusive dealing and implementing measures designed to prevent market entry by competitors. BAT also secured a large number of exemptions and privileges that further reduced the government's revenue both on a one‐off and ongoing basis. Conclusions BAT's corporate misbehaviour included a wide number of anticompetitive practices, contravened Organisation of Economic Cooperation and Development's and BAT's own business standards on competition and restricted revenue arising from privatisation. This suggests that TNCs have contributed to the failure of privatisation in the FSU. Conducting open tenders and using enforceable codes to

  3. Sarcoporia polyspora (Basidiomycota, Polyporales): a rare wood-decay fungus newly recorded from South America

    Treesearch

    Daiana Bortoluzzi Baldoni; Beatriz Ortiz-Santana; Gilberto Coelho; Zaida I. Antoniolli; Rodrigo J.S. Jacques

    2014-01-01

    Brown-rot fungi degrade almost exclusively wood cellulosic materials participating in the, carbon cycle and soil formation of many forest regions, these are especially important on boreal and cultivated coniferous forests. These fungi and forests may have a common co-evolutionary history. Studying wood-inhabiting fungi in cultivated pine forests in Southern Brazil, we...

  4. Community interactions govern host-switching with implications for host–parasite coevolutionary history

    PubMed Central

    Harbison, Christopher W.; Clayton, Dale H.

    2011-01-01

    Reciprocal selective effects between coevolving species are often influenced by interactions with the broader ecological community. Community-level interactions may also influence macroevolutionary patterns of coevolution, such as cospeciation, but this hypothesis has received little attention. We studied two groups of ecologically similar feather lice (Phthiraptera: Ischnocera) that differ in their patterns of association with a single group of hosts. The two groups, “body lice” and “wing lice,” are both parasites of pigeons and doves (Columbiformes). Body lice are more host-specific and show greater population genetic structure than wing lice. The macroevolutionary history of body lice also parallels that of their columbiform hosts more closely than does the evolutionary history of wing lice. The closer association of body lice with hosts, compared with wing lice, can be explained if body lice are less capable of switching hosts than wing lice. Wing lice sometimes disperse phoretically on parasitic flies (Diptera: Hippoboscidae), but body lice seldom engage in this behavior. We tested the hypothesis that wing lice switch host species more often than body lice, and that the difference is governed by phoresis. Our results show that, where flies are present, wing lice switch to novel host species in sufficient numbers to establish viable populations on the new host. Body lice do not switch hosts, even where flies are present. Thus, differences in the coevolutionary history of wing and body lice can be explained by differences in host-switching, mediated by a member of the broader parasite community. PMID:21606369

  5. The role of adaptations in two-strain competition for sylvatic Trypanosoma cruzi transmission.

    PubMed

    Kribs-Zaleta, Christopher M; Mubayi, Anuj

    2012-01-01

    This study presents a continuous-time model for the sylvatic transmission dynamics of two strains of Trypanosoma cruzi enzootic in North America, in order to study the role that adaptations of each strain to distinct modes of transmission (classical stercorarian transmission on the one hand, and vertical and oral transmission on the other) may play in the competition between the two strains. A deterministic model incorporating contact process saturation predicts competitive exclusion, and reproductive numbers for the infection provide a framework for evaluating the competition in terms of adaptive trade-off between distinct transmission modes. Results highlight the importance of oral transmission in mediating the competition between horizontal (stercorarian) and vertical transmission; its presence as a competing contact process advantages vertical transmission even without adaptation to oral transmission, but such adaptation appears necessary to explain the persistence of (vertically-adapted) T. cruzi IV in raccoons and woodrats in the southeastern United States.

  6. Host age modulates within-host parasite competition.

    PubMed

    Izhar, Rony; Routtu, Jarkko; Ben-Ami, Frida

    2015-05-01

    In many host populations, one of the most striking differences among hosts is their age. While parasite prevalence differences in relation to host age are well known, little is known on how host age impacts ecological and evolutionary dynamics of diseases. Using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa, we examined how host age at exposure influences within-host parasite competition and virulence. We found that multiply-exposed hosts were more susceptible to infection and suffered higher mortality than singly-exposed hosts. Hosts oldest at exposure were least often infected and vice versa. Furthermore, we found that in young multiply-exposed hosts competition was weak, allowing coexistence and transmission of both parasite clones, whereas in older multiply-exposed hosts competitive exclusion was observed. Thus, age-dependent parasite exposure and host demography (age structure) could together play an important role in mediating parasite evolution. At the individual level, our results demonstrate a previously unnoticed interaction of the host's immune system with host age, suggesting that the specificity of immune function changes as hosts mature. Therefore, evolutionary models of parasite virulence might benefit from incorporating age-dependent epidemiological parameters. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  7. Aboveground insect herbivory increases plant competitive asymmetry, while belowground herbivory mitigates the effect

    PubMed Central

    Strengbom, Joachim; Viketoft, Maria; Bommarco, Riccardo

    2016-01-01

    Insect herbivores can shift the composition of a plant community, but the mechanism underlying such shifts remains largely unexplored. A possibility is that insects alter the competitive symmetry between plant species. The effect of herbivory on competition likely depends on whether the plants are subjected to aboveground or belowground herbivory or both, and also depends on soil nitrogen levels. It is unclear how these biotic and abiotic factors interactively affect competition. In a greenhouse experiment, we measured competition between two coexisting grass species that respond differently to nitrogen deposition: Dactylis glomerata L., which is competitively favoured by nitrogen addition, and Festuca rubra L., which is competitively favoured on nitrogen-poor soils. We predicted: (1) that aboveground herbivory would reduce competitive asymmetry at high soil nitrogen by reducing the competitive advantage of D. glomerata; and (2), that belowground herbivory would relax competition at low soil nitrogen, by reducing the competitive advantage of F. rubra. Aboveground herbivory caused a 46% decrease in the competitive ability of F. rubra, and a 23% increase in that of D. glomerata, thus increasing competitive asymmetry, independently of soil nitrogen level. Belowground herbivory did not affect competitive symmetry, but the combined influence of above- and belowground herbivory was weaker than predicted from their individual effects. Belowground herbivory thus mitigated the increased competitive asymmetry caused by aboveground herbivory. D. glomerata remained competitively dominant after the cessation of aboveground herbivory, showing that the influence of herbivory continued beyond the feeding period. We showed that insect herbivory can strongly influence plant competitive interactions. In our experimental plant community, aboveground insect herbivory increased the risk of competitive exclusion of F. rubra. Belowground herbivory appeared to mitigate the influence of

  8. Aboveground insect herbivory increases plant competitive asymmetry, while belowground herbivory mitigates the effect.

    PubMed

    Borgström, Pernilla; Strengbom, Joachim; Viketoft, Maria; Bommarco, Riccardo

    2016-01-01

    Insect herbivores can shift the composition of a plant community, but the mechanism underlying such shifts remains largely unexplored. A possibility is that insects alter the competitive symmetry between plant species. The effect of herbivory on competition likely depends on whether the plants are subjected to aboveground or belowground herbivory or both, and also depends on soil nitrogen levels. It is unclear how these biotic and abiotic factors interactively affect competition. In a greenhouse experiment, we measured competition between two coexisting grass species that respond differently to nitrogen deposition: Dactylis glomerata L., which is competitively favoured by nitrogen addition, and Festuca rubra L., which is competitively favoured on nitrogen-poor soils. We predicted: (1) that aboveground herbivory would reduce competitive asymmetry at high soil nitrogen by reducing the competitive advantage of D. glomerata; and (2), that belowground herbivory would relax competition at low soil nitrogen, by reducing the competitive advantage of F. rubra. Aboveground herbivory caused a 46% decrease in the competitive ability of F. rubra, and a 23% increase in that of D. glomerata, thus increasing competitive asymmetry, independently of soil nitrogen level. Belowground herbivory did not affect competitive symmetry, but the combined influence of above- and belowground herbivory was weaker than predicted from their individual effects. Belowground herbivory thus mitigated the increased competitive asymmetry caused by aboveground herbivory. D. glomerata remained competitively dominant after the cessation of aboveground herbivory, showing that the influence of herbivory continued beyond the feeding period. We showed that insect herbivory can strongly influence plant competitive interactions. In our experimental plant community, aboveground insect herbivory increased the risk of competitive exclusion of F. rubra. Belowground herbivory appeared to mitigate the influence of

  9. Social exclusion in finite populations

    NASA Astrophysics Data System (ADS)

    Li, Kun; Cong, Rui; Wu, Te; Wang, Long

    2015-04-01

    Social exclusion, keeping free riders from benefit sharing, plays an important role in sustaining cooperation in our world. Here we propose two different exclusion regimes, namely, peer exclusion and pool exclusion, to investigate the evolution of social exclusion in finite populations. In the peer exclusion regime, each excluder expels all the defectors independently, and thus bears the total cost on his own, while in the pool exclusion regime, excluders spontaneously form an institution to carry out rejection of the free riders, and each excluder shares the cost equally. In a public goods game containing only excluders and defectors, it is found that peer excluders outperform pool excluders if the exclusion costs are small, and the situation is converse once the exclusion costs exceed some critical points, which holds true for all the selection intensities and different update rules. Moreover, excluders can dominate the whole population under a suitable parameters range in the presence of second-order free riders (cooperators), showing that exclusion has prominent advantages over common costly punishment. More importantly, our finding indicates that the group exclusion mechanism helps the cooperative union to survive under unfavorable conditions. Our results may give some insights into better understanding the prevalence of such a strategy in the real world and its significance in sustaining cooperation.

  10. Health plan competition in local markets.

    PubMed

    Grossman, J M

    2000-04-01

    To examine the structure of local health insurance markets and the strategies health plans were using to respond to competitive pressures in local markets in 1996/1997. Community Tracking Study site visits conducted between May 1996 and April 1997 in 12 U.S. markets selected to be nationally representative. In each site, 36 to 60 interviews on local health system change were conducted with healthcare industry informants representing health plans, providers, and purchasers. Relevant data for this article were abstracted from standardized protocols administered to multiple respondents in each site. Although the competitive threat from national plans was pervasive, local plans in most sites continued to retain strong, often dominant, positions in historically concentrated markets. In all sites, in response to purchaser pressures for stable premiums and provider choice, and the threat of entry and to plans were using three strategies to increase market share and market power: (1) consolidation/geographic expansion, (2) price competition, and (3) product line/segment diversification that focused on broad networks and open-access products. In most markets, in response to the demand for provider choice, the trend was away from ownership and exclusive arrangements with providers. Although local plans were moving to become full-service regional players, there was uncertainty about the abilities of all plans to sustain growth strategies at the expense of margins and organizational stability, and to effectively manage care with broad networks.

  11. The effect of a commercial competitive exclusion product on the selection of enrofloxacin resistance in commensal E. coli in broilers.

    PubMed

    Chantziaras, Ilias; Smet, Annemieke; Filippitzi, Maria Eleni; Damiaans, Bert; Haesebrouck, Freddy; Boyen, Filip; Dewulf, Jeroen

    2018-06-07

    The effect of a competitive exclusion product (Aviguard ® ) on the selection of fluoroquinolone resistance in poultry was assessed in vivo in the absence or presence of fluoroquinolone treatment. Two experiments using a controlled seeder-sentinel animal model (2seeders:4sentinels per group) with one-day-old chicks were used. For both experiments,as soon as the chicks were hatched, the animals of two groups were administered Aviguard ® and two groups were left untreated. Three days later, all groups were inoculated with an enrofloxacin-susceptible commensal E. coli strain. Five days after hatching, two animals per group were inoculated either with a bacteriologically-fit or a bacteriologically non-fit enrofloxacin-resistant commensal E. coli strain. In experiment 2, all groups were orally treated for three consecutive days (Day 8-10) with enrofloxacin. Throughout the experiments, faecal excretion of all inoculated E. coli strains was determined on days 2-5-8-11-18-23 by selective plating (via spiral plater). Linear mixed models were used to assess the effect of Aviguard ® on the selection of fluoroquinolone resistance. The use of Aviguard® (p<0.01) reduced the excretion of enrofloxacin-resistant E. coli when no enrofloxacin treatment was administered. However, this beneficial effect disappeared (p=0.37) when the animals were treated with enrofloxacin. Similarly, bacterial fitness of the enrofloxacin-resistant E. coli strain used for inoculation had an effect (p<0.01) on the selection of enrofloxacin resistance when no treatment was administered, whereas this effect was no longer present when enrofloxacin was administered (p =0.70). Thus, enrofloxacin treatment cancelled the beneficial effects from administrating Aviguard ® in one-day-old broiler chicks and resulted in a enrofloxacin-resistant flora.

  12. Dynamic competition in pharmaceuticals. Patent expiry, generic penetration, and industry structure.

    PubMed

    Magazzini, Laura; Pammolli, Fabio; Riccaboni, Massimo

    2004-06-01

    This paper investigates patterns of industrial dynamics and competition in the pharmaceutical industry, with particular reference to the consequences of patent expiry in different countries. We focus on the competition at the level of single chemical entities, distinguishing between original brands and generic products. Quarterly data, spanning from July 1987 to December 1998, on sales of pharmaceutical products in four countries (USA, UK, Germany, and France) constitute the basis of our analysis. All the products containing major molecules whose patent expiration date lies between 1986 and 1996 are included in our sample. We show how diffusion of generics is linked to the characteristics of the market and investigate how price dynamics of original products are affected by generic competition. Our empirical investigation shows that the dynamics of drug prices and the competition by generic drugs vary significantly across countries. This heterogeneity notwithstanding, a clear distinction seems to emerge. On the one hand, systems that rely on market-based competition in pharmaceuticals promote a clear distinction between firms that act as innovators and firms that act as imitators after patent expiry. Here, original products enjoy premium prices and exclusivity profits under patent protection, and face fierce price competition after patent expiry. On the other hand, in systems that rely on administered prices, penetration by generic drugs tends to be rather limited. Its descriptive and preliminary nature notwithstanding, our analysis seems to have relevant implications at different levels of generality, especially for Europe.

  13. Competitive Science: Is Competition Ruining Science?

    PubMed Central

    Casadevall, Arturo

    2015-01-01

    Science has always been a competitive undertaking. Despite recognition of the benefits of cooperation and team science, reduced availability of funding and jobs has made science more competitive than ever. Here we consider the benefits of competition in providing incentives to scientists and the adverse effects of competition on resource sharing, research integrity, and creativity. The history of science shows that transformative discoveries often occur in the absence of competition, which only emerges once fields are established and goals are defined. Measures to encourage collaboration and ameliorate competition in the scientific enterprise are discussed. PMID:25605760

  14. 47 CFR 27.1103 - 2000-2020 MHz and 2180-2200 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false 2000-2020 MHz and 2180-2200 MHz bands subject... Bidding Provisions § 27.1103 2000-2020 MHz and 2180-2200 MHz bands subject to competitive bidding. Mutually exclusive initial applications for 2000-2020 MHz and 2180-2200 MHz band licenses are subject to...

  15. Competitive science: is competition ruining science?

    PubMed

    Fang, Ferric C; Casadevall, Arturo

    2015-04-01

    Science has always been a competitive undertaking. Despite recognition of the benefits of cooperation and team science, reduced availability of funding and jobs has made science more competitive than ever. Here we consider the benefits of competition in providing incentives to scientists and the adverse effects of competition on resource sharing, research integrity, and creativity. The history of science shows that transformative discoveries often occur in the absence of competition, which only emerges once fields are established and goals are defined. Measures to encourage collaboration and ameliorate competition in the scientific enterprise are discussed. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Demolishing the competition: the longitudinal link between competitive video games, competitive gambling, and aggression.

    PubMed

    Adachi, Paul J C; Willoughby, Teena

    2013-07-01

    The majority of research on the link between video games and aggression has focused on the violent content in games. In contrast, recent experimental research suggests that it is video game competition, not violence, that has the greatest effect on aggression in the short-term. However, no researchers have examined the long-term relationship between video game competition and aggression. In addition, if competition in video games is a significant reason for the link between video game play and aggression, then other competitive activities, such as competitive gambling, also may predict aggression over time. In the current study, we directly assessed the socialization (competitive video game play and competitive gambling predicts aggression over time) versus selection hypotheses (aggression predicts competitive video game play and competitive gambling over time). Adolescents (N = 1,492, 50.8 % female) were surveyed annually from Grade 9 to Grade 12 about their video game play, gambling, and aggressive behaviors. Greater competitive video game play and competitive gambling predicted higher levels of aggression over time, after controlling for previous levels of aggression, supporting the socialization hypothesis. The selection hypothesis also was supported, as aggression predicted greater competitive video game play and competitive gambling over time, after controlling for previous competitive video game play and competitive gambling. Our findings, taken together with the fact that millions of adolescents play competitive video games every day and that competitive gambling may increase as adolescents transition into adulthood, highlight the need for a greater understanding of the relationship between competition and aggression.

  17. Plant water use affects competition for nitrogen: why drought favors invasive species in California.

    PubMed

    Everard, Katherine; Seabloom, Eric W; Harpole, W Stanley; de Mazancourt, Claire

    2010-01-01

    Abstract: Classic resource competition theory typically treats resource supply rates as independent; however, nutrient supplies can be affected by plants indirectly, with important consequences for model predictions. We demonstrate this general phenomenon by using a model in which competition for nitrogen is mediated by soil moisture, with competitive outcomes including coexistence and multiple stable states as well as competitive exclusion. In the model, soil moisture regulates nitrogen availability through soil moisture dependence of microbial processes, leaching, and plant uptake. By affecting water availability, plants also indirectly affect nitrogen availability and may therefore alter the competitive outcome. Exotic annual species from the Mediterranean have displaced much of the native perennial grasses in California. Nitrogen and water have been shown to be potentially limiting in this system. We parameterize the model for a Californian grassland and show that soil moisture-mediated competition for nitrogen can explain the annual species' dominance in drier areas, with coexistence expected in wetter regions. These results are concordant with larger biogeographic patterns of grassland invasion in the Pacific states of the United States, in which annual grasses have invaded most of the hot, dry grasslands in California but perennial grasses dominate the moister prairies of northern California, Oregon, and Washington.

  18. OPTIMIZING THROUGH CO-EVOLUTIONARY AVALANCHES

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    S. BOETTCHER; A. PERCUS

    2000-08-01

    We explore a new general-purpose heuristic for finding high-quality solutions to hard optimization problems. The method, called extremal optimization, is inspired by ''self-organized critically,'' a concept introduced to describe emergent complexity in many physical systems. In contrast to Genetic Algorithms which operate on an entire ''gene-pool'' of possible solutions, extremal optimization successively replaces extremely undesirable elements of a sub-optimal solution with new, random ones. Large fluctuations, called ''avalanches,'' ensue that efficiently explore many local optima. Drawing upon models used to simulate far-from-equilibrium dynamics, extremal optimization complements approximation methods inspired by equilibrium statistical physics, such as simulated annealing. With only onemore » adjustable parameter, its performance has proved competitive with more elaborate methods, especially near phase transitions. Those phase transitions are found in the parameter space of most optimization problems, and have recently been conjectured to be the origin of some of the hardest instances in computational complexity. We will demonstrate how extremal optimization can be implemented for a variety of combinatorial optimization problems. We believe that extremal optimization will be a useful tool in the investigation of phase transitions in combinatorial optimization problems, hence valuable in elucidating the origin of computational complexity.« less

  19. Deferred Growth Inhibition Assay to Quantify the Effect of Bacteria-derived Antimicrobials on Competition

    PubMed Central

    Moran, Josephine C.; Crank, Emma L.; Ghabban, Hanaa A.; Horsburgh, Malcolm J.

    2016-01-01

    Competitive exclusion can occur in microbial communities when, for example, an inhibitor-producing strain outcompetes its competitor for an essential nutrient or produces antimicrobial compounds that its competitor is not resistant to. Here we describe a deferred growth inhibition assay, a method for assessing the ability of one bacterium to inhibit the growth of another through the production of antimicrobial compounds or through competition for nutrients. This technique has been used to investigate the correlation of nasal isolates with the exclusion of particular species from a community. This technique can also be used to screen for lantibiotic producers or potentially novel antimicrobials. The assay is performed by first culturing the test inhibitor-producing strain overnight on an agar plate, then spraying over the test competitor strain and incubating again. After incubation, the extent of inhibition can be measured quantitatively, through the size of the zone of clearing around the inhibitor-producing strain, and qualitatively, by assessing the clarity of the inhibition zone. Here we present the protocol for the deferred inhibition assay, describe ways to minimize variation between experiments, and define a clarity scale that can be used to qualitatively assess the degree of inhibition. PMID:27684443

  20. A specter of coexistence: Is centrifugal community organization haunted by the ghost of competition?

    USGS Publications Warehouse

    Wasserberg, Gideon; Kotler, B.P.; Morris, D.W.; Abramsky, Z.

    2006-01-01

    In a centrifugally organized community species prefer the same habitat (called "core") but differ in their secondary habitat preferences. The first model of centrifugal community organization (CCO) predicted that optimally foraging, symmetrically competing species would share use of the core habitat at all density combinations. But one might also assume that the competition in the core habitat is asymmetrical, that is, that one of the species (the dominant) has a behavioral advantage therein. In this study, we asked how should habitat use evolve in a centrifugally organized community if its species compete asymmetrically in the core habitat? To address this question we developed an "isoleg model". The model predicts that in a centrifugally organized community, asymmetric competition promotes the use of the core habitat exclusively by the dominant species at most points in the state space. The separation of the core habitat use by the species ("the ghost of competition past") may be either complete or partial ("partial ghost"), and behavior at the stable competitive equilibrium between the species could determine whether coexistence should occur at the "complete-" or the "partial ghost" regions. This version of CCO should be a common feature of competitive systems.

  1. The fitness costs and trade-off shapes associated with the exclusion of nine antibiotics by OmpF porin channels.

    PubMed

    Phan, Katherine; Ferenci, Thomas

    2017-06-01

    The trade-off relationship between antibiotic exclusion and nutrient access across the Gram-negative outer membrane is determined by structural constraints in porin channels. The precise nutritional cost of exclusion is unknown for different antibiotics, as are the shapes of the nutrition-susceptibility trade-off. Using a library of 10 engineered isogenic Escherichia coli strains with structural modifications of OmpF porin expressed at a constant level, susceptibilities were measured for nine antibiotics and the nutritional fitness costs estimated by competitions in chemostats. Different antibiotics exhibited a remarkably varied range of geometries in the nutrition-susceptibility trade-off, including convex, concave and sigmoidal trade-off shapes. The trade-off patterns predict the possibility of adaptations in contributing to antibiotic resistance; exclusion of amoxicillin or trimethoprim in ompF mutants can occur with little loss of fitness whereas kanamycin and streptomycin exclusion has a high cost. Some individual OmpF changes even allow positive correlations (trade-ups), resulting in increased fitness and decreased susceptibility specifically to cephalexin or ciprofloxacin. The surprising plasticity of the nutrition-exclusion relationship means that there are no generalisable rules that apply to decreasing susceptibility for all antibiotics. The protein changes are exquisitely specific in determining nutritional fitness and adaptive outcomes in a structural constraint trade-off.

  2. Coevolutionary modeling of protein sequences: Predicting structure, function, and mutational landscapes

    NASA Astrophysics Data System (ADS)

    Weigt, Martin

    Over the last years, biological research has been revolutionized by experimental high-throughput techniques, in particular by next-generation sequencing technology. Unprecedented amounts of data are accumulating, and there is a growing request for computational methods unveiling the information hidden in raw data, thereby increasing our understanding of complex biological systems. Statistical-physics models based on the maximum-entropy principle have, in the last few years, played an important role in this context. To give a specific example, proteins and many non-coding RNA show a remarkable degree of structural and functional conservation in the course of evolution, despite a large variability in amino acid sequences. We have developed a statistical-mechanics inspired inference approach - called Direct-Coupling Analysis - to link this sequence variability (easy to observe in sequence alignments, which are available in public sequence databases) to bio-molecular structure and function. In my presentation I will show, how this methodology can be used (i) to infer contacts between residues and thus to guide tertiary and quaternary protein structure prediction and RNA structure prediction, (ii) to discriminate interacting from non-interacting protein families, and thus to infer conserved protein-protein interaction networks, and (iii) to reconstruct mutational landscapes and thus to predict the phenotypic effect of mutations. References [1] M. Figliuzzi, H. Jacquier, A. Schug, O. Tenaillon and M. Weigt ''Coevolutionary landscape inference and the context-dependence of mutations in beta-lactamase TEM-1'', Mol. Biol. Evol. (2015), doi: 10.1093/molbev/msv211 [2] E. De Leonardis, B. Lutz, S. Ratz, S. Cocco, R. Monasson, A. Schug, M. Weigt ''Direct-Coupling Analysis of nucleotide coevolution facilitates RNA secondary and tertiary structure prediction'', Nucleic Acids Research (2015), doi: 10.1093/nar/gkv932 [3] F. Morcos, A. Pagnani, B. Lunt, A. Bertolino, D. Marks, C

  3. Apparent competition with an exotic plant reduces native plant establishment.

    PubMed

    Orrock, John L; Witter, Martha S; Reichman, O J

    2008-04-01

    Biological invasions can change ecosystem function, have tremendous economic costs, and impact human health; understanding the forces that cause and maintain biological invasions is thus of immediate importance. A mechanism by which exotic plants might displace native plants is by increasing the pressure of native consumers on native plants, a form of indirect interaction termed "apparent competition." Using experimental exclosures, seed addition, and monitoring of small mammals in a California grassland, we examined whether exotic Brassica nigra increases the pressure of native consumers on a native bunchgrass, Nassella pulchra. Experimental plots were weeded to focus entirely on indirect effects via consumers. We demonstrate that B. nigra alters the activity of native small-mammal consumers, creating a gradient of consumption that dramatically reduces N. pulchra establishment. Previous work has shown that N. pulchra is a strong competitor, but that it is heavily seed limited. By demonstrating that consumer pressure is sufficient to curtail establishment, our work provides a mechanism for this seed limitation and suggests that, despite being a good competitor, N. pulchra cannot reestablish close to B. nigra within its old habitats because exotic-mediated consumption preempts direct competitive exclusion. Moreover, we find that apparent competition has a spatial extent, suggesting that consumers may dictate the rate of invasion and the area available for restoration, and that nonspatial studies of apparent competition may miss important dynamics.

  4. Health plan competition in local markets.

    PubMed Central

    Grossman, J M

    2000-01-01

    OBJECTIVE: To examine the structure of local health insurance markets and the strategies health plans were using to respond to competitive pressures in local markets in 1996/1997. DATA SOURCES/STUDY SETTING: Community Tracking Study site visits conducted between May 1996 and April 1997 in 12 U.S. markets selected to be nationally representative. STUDY DESIGN: In each site, 36 to 60 interviews on local health system change were conducted with healthcare industry informants representing health plans, providers, and purchasers. DATA COLLECTION/EXTRACTION METHOD: Relevant data for this article were abstracted from standardized protocols administered to multiple respondents in each site. PRINCIPAL FINDINGS: Although the competitive threat from national plans was pervasive, local plans in most sites continued to retain strong, often dominant, positions in historically concentrated markets. In all sites, in response to purchaser pressures for stable premiums and provider choice, and the threat of entry and to plans were using three strategies to increase market share and market power: (1) consolidation/geographic expansion, (2) price competition, and (3) product line/segment diversification that focused on broad networks and open-access products. In most markets, in response to the demand for provider choice, the trend was away from ownership and exclusive arrangements with providers. CONCLUSIONS: Although local plans were moving to become full-service regional players, there was uncertainty about the abilities of all plans to sustain growth strategies at the expense of margins and organizational stability, and to effectively manage care with broad networks. PMID:10778822

  5. The Social Strategy Game: Resource Competition within Female Social Networks among Small-scale Forager-Horticulturalists.

    PubMed

    Rucas, Stacey L; Gurven, Michael; Kaplan, Hillard; Winking, Jeffrey

    2010-03-10

    This paper examines social determinants of resource competition among Tsimane Amerindian women of Bolivia. We introduce a semi-anonymous experiment (the Social Strategy Game) designed to simulate resource competition among women. Information concerning dyadic social relationships and demographic data were collected to identify variables influencing resource competition intensity, as measured by the number of beads one woman took from another. Relationship variables are used to test how the affiliative or competitive aspects of dyads affect the extent of prosociality in the game. Using a mixed-modeling procedure, we find that women compete with those with whom they are quarreling over accusations of meat theft, mate competition, and rumor spreading. They also compete with members of their social network and with those who were designated as cooperative helpers or as close kin. Women take fewer beads from desired friends, neighbors, and from those viewed as enemies. We interpret favoritism toward enemies as resulting from fear of retribution. Our results suggest that social relations among women are multifaceted and often cannot be simplified by exclusive focus on genetic relatedness, physical proximity, or reciprocity. We argue that a complex understanding of cooperation and competition among women may require important contextual information concerning relationship history in addition to typical features of resource ecology.

  6. Resource and competitive dynamics shape the benefits of public goods cooperation in a plant pathogen

    PubMed Central

    Platt, Thomas G.; Fuqua, Clay; Bever, James D.

    2012-01-01

    Cooperative benefits depend on a variety of ecological factors. Many cooperative bacteria increase the population size of their groups by making a public good available. Increased local population size can alleviate the constraints of kin competition on the evolution of cooperation by enhancing the between-group fitness of cooperators. The cooperative pathogenesis of Agrobacterium tumefaciens causes infected plants to exude opines—resources that provide a nearly exclusive source of nutrient for the pathogen. We experimentally demonstrate that opines provide cooperative A. tumefaciens cells a within-group fitness advantage over saprophytic agrobacteria. Our results are congruent with a resource-consumer competition model, which predicts that cooperative, virulent agrobacteria are at a competitive disadvantage when opines are unavailable, but have an advantage when opines are available at sufficient levels. This model also predicts that freeloading agrobacteria that catabolize opines but cannot infect plants competitively displace the cooperative pathogen from all environments. However, we show that these cooperative public goods also promote increased local population size. A model built from the Price Equation shows that this effect on group size can contribute to the persistence of cooperative pathogenesis despite inherent kin competition for the benefits of pathogenesis. PMID:22671559

  7. Incompatibility and competitive exclusion of genomic segments between sibling Drosophila species.

    PubMed

    Fang, Shu; Yukilevich, Roman; Chen, Ying; Turissini, David A; Zeng, Kai; Boussy, Ian A; Wu, Chung-I

    2012-06-01

    The extent and nature of genetic incompatibilities between incipient races and sibling species is of fundamental importance to our view of speciation. However, with the exception of hybrid inviability and sterility factors, little is known about the extent of other, more subtle genetic incompatibilities between incipient species. Here we experimentally demonstrate the prevalence of such genetic incompatibilities between two young allopatric sibling species, Drosophila simulans and D. sechellia. Our experiments took advantage of 12 introgression lines that carried random introgressed D. sechellia segments in different parts of the D. simulans genome. First, we found that these introgression lines did not show any measurable sterility or inviability effects. To study if these sechellia introgressions in a simulans background contained other fitness consequences, we competed and genetically tracked the marked alleles within each introgression against the wild-type alleles for 20 generations. Strikingly, all marked D. sechellia introgression alleles rapidly decreased in frequency in only 6 to 7 generations. We then developed computer simulations to model our competition results. These simulations indicated that selection against D. sechellia introgression alleles was high (average s = 0.43) and that the marker alleles and the incompatible alleles did not separate in 78% of the introgressions. The latter result likely implies that most introgressions contain multiple genetic incompatibilities. Thus, this study reveals that, even at early stages of speciation, many parts of the genome diverge to a point where introducing foreign elements has detrimental fitness consequences, but which cannot be seen using standard sterility and inviability assays.

  8. Modelling the competition of planktonic and sessile aerobic heterotrophs for complementary nutrients in biofilm reactor.

    PubMed

    Lu, T; Saikaly, P E; Oerther, D B

    2007-01-01

    A comprehensive, simplified microbial biofilm model was developed to evaluate the impact of bioreactor operating parameters on changes in microbial population abundance. Biofilm simulations were conducted using three special cases: fully penetrated, internal mass transfer resistance and external mass transfer resistance. The results of model simulations showed that for certain operating conditions, competition for growth limiting nutrients generated oscillations in the abundance of planktonic and sessile microbial populations. These oscillations resulted in the violation of the competitive exclusion principle where the number of microbial populations was greater than the number of growth limiting nutrients. However, the operating conditions which impacted microbial community diversity were different for the three special cases. Comparing the results of model simulations for dispersed-growth, biofilms and bioflocs showed that oscillations and microbial community diversity were a function of competition as well as other key features of the ecosystem. The significance of the current study is that it is the first to examine competition as a mechanism for controlling microbial community diversity in biofilm reactors.

  9. 42 CFR 1002.213 - Appeals of exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Appeals of exclusions. 1002.213 Section 1002.213... AUTHORITIES PROGRAM INTEGRITY-STATE-INITIATED EXCLUSIONS FROM MEDICAID Permissive Exclusions § 1002.213 Appeals of exclusions. Before imposing an exclusion under § 1002.210, the State agency must give the...

  10. Semantic interference from distractor pictures in single-picture naming: evidence for competitive lexical selection.

    PubMed

    Jescheniak, Jörg D; Matushanskaya, Asya; Mädebach, Andreas; Müller, Matthias M

    2014-10-01

    Picture-naming studies have demonstrated interference from semantic-categorically related distractor words, but not from corresponding distractor pictures, and the lack of generality of the interference effect has been argued to challenge theories viewing lexical selection in speech production as a competitive process. Here, we demonstrate that semantic interference from context pictures does become visible, if sufficient attention is allocated to them. We combined picture naming with a spatial-cuing procedure. When participants' attention was shifted to the distractor, semantically related distractor pictures interfered with the response, as compared with unrelated distractor pictures. This finding supports models conceiving lexical retrieval as competitive (Levelt, Roelofs, & Meyer, 1999) but is difficult to reconcile with the response exclusion hypothesis (Finkbeiner & Caramazza, 2006b) proposed as an alternative.

  11. EDITORIAL: Physics competitions Physics competitions

    NASA Astrophysics Data System (ADS)

    Jordens, H.; Mathelitsch, L.

    2009-11-01

    1. Physics competitions: aims and realizations One aim of physics competitions is to increase the interest of young students, primarily at upper secondary level, to physics and natural sciences in general. A competition has motivational aspects known usually from sports events or games—comparing one's own ability with others, of course with the desire to be better and to win. If competitions reach nationwide and even international levels, additional stimulation is created. Competitions provide greatest attraction to possible winners, to the group of gifted people in a particular field. This implies that science contests are excellent tools for the promotion of talented students. Traditional teaching has been shown to have problems in supporting this group of students. Very often teachers are overstretched with the demands of teaching both low- and high-level students. Extracurricular activities are therefore a good chance to relieve the teacher, and to give talented students the opportunity for appropriate training and challenge. The competitions, however, have a broader impact and address more young people than one might guess from the statements above. Training courses and selection at school level give a larger group of students extra and, to some extent, complimentary education in physics. The degree of complexity of the tasks corresponds very often to the standards of the next level of education in the school system. Interestingly, many physics competitions have their origin in countries beyond the former Iron Curtain. They started as regional and national tournaments, were joined by neighbouring countries and have grown, in some cases, to events with participants from more than 80 countries. Although the features mentioned above are common to the different competitions, there are distinct differences between them [1]. The International Physics Olympiad (IPhO) is the oldest international physics competition for students at upper secondary level [2]. It dates

  12. Exclusion and Education in South Africa: An Education Law Perspective of Emerging Alternative Understandings of Exclusion

    ERIC Educational Resources Information Center

    Beckmann, Johan

    2016-01-01

    The new democratic dispensation in South Africa (1994) was accompanied by law and policy aimed at preventing unfair exclusion from educational opportunities and promoting equal access to educational opportunities. However, feelings of unfair exclusion remain and new understandings of exclusion are emerging. This paper examines the new policy and…

  13. Developing Competitive and Sustainable Polish Generic Medicines Market

    PubMed Central

    Simoens, Steven

    2009-01-01

    Aim To descriptively analyze the policy environment surrounding the Polish generic medicines retail market. Method The policy analysis was based on an international literature review. Also, a simulation exercise was carried out to compute potential savings from substituting generic for originator medicines in Poland using IMS Health pharmaceutical intelligence data. Results Poland has a mature, high-volume, low-value generic medicines market, primarily driven by the establishment of the reference price at the price of the cheapest medicine in combination with pricing regulation and the low level of medicine prices. The practice of discounting in the distribution chain implies that the National Health Fund and patients do not capture the potential savings from a generic medicines market where companies compete on price. This high-volume market has benefited in the past from the limited availability of originator medicines and a short data exclusivity period, even though there are no incentives for physicians to prescribe generic medicines and a financial disincentive for pharmacists to dispense generic medicines. Increased generic substitution would be expected to reduce public expenditure on originator medicines by 21%. Conclusion To develop a competitive and sustainable market, Poland needs to consider moving away from competition by discount to competition by price. This could be achieved by replacing maximum distribution margins by fixed margins. Also, Poland may wish to raise reference prices as a temporary measure to boost market entry for medicine classes with few generic medicines. PMID:19839067

  14. Developing competitive and sustainable Polish generic medicines market.

    PubMed

    Simoens, Steven

    2009-10-01

    To descriptively analyze the policy environment surrounding the Polish generic medicines retail market. The policy analysis was based on an international literature review. Also, a simulation exercise was carried out to compute potential savings from substituting generic for originator medicines in Poland using IMS Health pharmaceutical intelligence data. Poland has a mature, high-volume, low-value generic medicines market, primarily driven by the establishment of the reference price at the price of the cheapest medicine in combination with pricing regulation and the low level of medicine prices. The practice of discounting in the distribution chain implies that the National Health Fund and patients do not capture the potential savings from a generic medicines market where companies compete on price. This high-volume market has benefited in the past from the limited availability of originator medicines and a short data exclusivity period, even though there are no incentives for physicians to prescribe generic medicines and a financial disincentive for pharmacists to dispense generic medicines. Increased generic substitution would be expected to reduce public expenditure on originator medicines by 21%. To develop a competitive and sustainable market, Poland needs to consider moving away from competition by discount to competition by price. This could be achieved by replacing maximum distribution margins by fixed margins. Also, Poland may wish to raise reference prices as a temporary measure to boost market entry for medicine classes with few generic medicines.

  15. The role of leaf height in plant competition for sunlight: analysis of a canopy partitioning model.

    PubMed

    Nevai, Andrew L; Vance, Richard R

    2008-01-01

    A global method of nullcline endpoint analysis is employed to determine the outcome of competition for sunlight between two hypothetical plant species with clonal growth form that differ solely in the height at which they place their leaves above the ground. This difference in vertical leaf placement, or canopy partitioning, produces species differences in sunlight energy capture and stem metabolic maintenance costs. The competitive interaction between these two species is analyzed by considering a special case of a canopy partitioning model (RR Vance and AL Nevai, J. Theor. Biol. 2007, 245:210-219; AL Nevai and RR Vance, J. Math. Biol. 2007, 55:105-145). Nullcline endpoint analysis is used to partition parameter space into regions within which either competitive exclusion or competitive coexistence occurs. The principal conclusion is that two clonal plant species which compete for sunlight and place their leaves at different heights above the ground but differ in no other way can, under suitable parameter values, experience stable coexistence even though they occupy an environment which varies neither over horizontal space nor through time.

  16. RELIGIOUS EXCLUSIVITY AND PSYCHOSOCIAL FUNCTIONING.

    PubMed

    Gegelashvili, M; Meca, A; Schwartz, S J

    2015-01-01

    In the present study we sought to clarify links between religious exclusivity, as form of intergroup favoritism, and indices of psychosocial functioning. The study of in group favoritism has generally been invoked within Social Identity Theory and related perspectives. However, there is a lack of literature regarding religious exclusivity from the standpoint of social identity. In particular, the ways in which religious exclusivity is linked with other dimensions of religious belief and practice, and with psychosocial functioning, among individuals from different religious backgrounds are not well understood. A sample of 8545 emerging-adult students from 30 U.S. universities completed special measures. Measure of religious exclusivity was developed and validated for this group. The results suggest that exclusivity appears as predictor for impaired psychosocial functioning, low self-esteem and low psychosocial well-being for individuals from organized faiths, as well as for those identifying as agnostic, atheist, or spiritual/nonreligious. These findings are discussed in terms of Social Identity Theory and Terror Management Theory (TMT).

  17. 36 CFR 907.10 - Categorical exclusion.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and environmental assessments. (c) Changes to the list of categorical exclusion. (1) The PADC List of... ENVIRONMENTAL QUALITY § 907.10 Categorical exclusion. The CEQ Regulations provide for the categorical exclusion... human environment. Therefore, neither an environmental assessment nor an environmental impact statement...

  18. Size- and food-dependent growth drives patterns of competitive dominance along productivity gradients.

    PubMed

    Huss, Magnus; Gårdmark, Anna; Van Leeuwen, Anieke; de Roos, André M

    2012-04-01

    Patterns of coexistence among competing species exhibiting size- and food-dependent growth remain largely unexplored. Here we studied mechanisms behind coexistence and shifts in competitive dominance in a size-structured fish guild, representing sprat and herring stocks in the Baltic Sea, using a physiologically structured model of competing populations. The influence of degree of resource overlap and the possibility of undergoing ontogenetic diet shifts were studied as functions of zooplankton and zoobenthos productivity. By imposing different size-dependent mortalities, we could study the outcome of competition under contrasting environmental regimes representing poor and favorable growth conditions. We found that the identity of the dominant species shifted between low and high productivity. Adding a herring-exclusive benthos resource only provided a competitive advantage over sprat when size-dependent mortality was high enough to allow for rapid growth in the zooplankton niche. Hence, the importance of a bottom-up effect of varying productivity was dependent on a strong top-down effect. Although herring could depress shared resources to lower levels than could sprat and also could access an exclusive resource, the smaller size at maturation of sprat allowed it to coexist with herring and, in some cases, exclude it. Our model system, characterized by interactions among size cohorts, allowed for consumer coexistence even at full resource overlap at intermediate productivities when size-dependent mortality was low. Observed shifts in community patterns were crucially dependent on the explicit consideration of size- and food-dependent growth. Accordingly, we argue that accounting for food-dependent growth and size-dependent interactions is necessary to better predict changes in community structure and dynamics following changes in major ecosystem drivers such as resource productivity and mortality, which are fundamental for our ability to manage exploitation of

  19. Competitive epidemic spreading over arbitrary multilayer networks.

    PubMed

    Darabi Sahneh, Faryad; Scoglio, Caterina

    2014-06-01

    This study extends the Susceptible-Infected-Susceptible (SIS) epidemic model for single-virus propagation over an arbitrary graph to an Susceptible-Infected by virus 1-Susceptible-Infected by virus 2-Susceptible (SI_{1}SI_{2}S) epidemic model of two exclusive, competitive viruses over a two-layer network with generic structure, where network layers represent the distinct transmission routes of the viruses. We find analytical expressions determining extinction, coexistence, and absolute dominance of the viruses after we introduce the concepts of survival threshold and absolute-dominance threshold. The main outcome of our analysis is the discovery and proof of a region for long-term coexistence of competitive viruses in nontrivial multilayer networks. We show coexistence is impossible if network layers are identical yet possible if network layers are distinct. Not only do we rigorously prove a region of coexistence, but we can quantitate it via interrelation of central nodes across the network layers. Little to no overlapping of the layers' central nodes is the key determinant of coexistence. For example, we show both analytically and numerically that positive correlation of network layers makes it difficult for a virus to survive, while in a network with negatively correlated layers, survival is easier, but total removal of the other virus is more difficult.

  20. Sodium and potassium competition in potassium-selective and non-selective channels

    NASA Astrophysics Data System (ADS)

    Sauer, David B.; Zeng, Weizhong; Canty, John; Lam, Yeeling; Jiang, Youxing

    2013-11-01

    Potassium channels selectively conduct K+, primarily to the exclusion of Na+, despite the fact that both ions can bind within the selectivity filter. Here we perform crystallographic titration and single-channel electrophysiology to examine the competition of Na+ and K+ binding within the filter of two NaK channel mutants; one is the potassium-selective NaK2K mutant and the other is the non-selective NaK2CNG, a CNG channel pore mimic. With high-resolution structures of these engineered NaK channel constructs, we explicitly describe the changes in K+ occupancy within the filter upon Na+ competition by anomalous diffraction. Our results demonstrate that the non-selective NaK2CNG still retains a K+-selective site at equilibrium, whereas the NaK2K channel filter maintains two high-affinity K+ sites. A double-barrier mechanism is proposed to explain K+ channel selectivity at low K+ concentrations.

  1. 36 CFR 907.10 - Categorical exclusion.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Categorical exclusion. 907.10 Section 907.10 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT CORPORATION ENVIRONMENTAL QUALITY § 907.10 Categorical exclusion. The CEQ Regulations provide for the categorical exclusion...

  2. Competition drives trait evolution and character displacement between Mimulus species along an environmental gradient.

    PubMed

    Kooyers, Nicholas J; James, Brooke; Blackman, Benjamin K

    2017-05-01

    Closely related species may evolve to coexist stably in sympatry through niche differentiation driven by in situ competition, a process termed character displacement. Alternatively, past evolution in allopatry may have already sufficiently reduced niche overlap to permit establishment in sympatry, a process called ecological sorting. The relative importance of each process to niche differentiation is contentious even though they are not mutually exclusive and are both mediated via multivariate trait evolution. We explore how competition has impacted niche differentiation in two monkeyflowers, Mimulus alsinoides and M. guttatus, which often co-occur. Through field observations, common gardens, and competition experiments, we demonstrate that M. alsinoides is restricted to marginal habitats in sympatry and that the impacts of character displacement on niche differentiation are complex. Competition with M. guttatus alters selection gradients and has favored taller M. alsinoides with earlier seasonal flowering at low elevation and floral shape divergence at high elevation. However, no trait exhibits the pattern typically associated with character displacement, higher divergence between species in sympatry than allopatry. Thus, although character displacement was unlikely the process driving initial divergence along niche axes necessary for coexistence, we conclude that competition in sympatry has likely driven trait evolution along additional niche axes. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  3. Spatial vegetation patterns and neighborhood competition among woody plants in an East African savanna.

    PubMed

    Dohn, Justin; Augustine, David J; Hanan, Niall P; Ratnam, Jayashree; Sankaran, Mahesh

    2017-02-01

    The majority of research on savanna vegetation dynamics has focused on the coexistence of woody and herbaceous vegetation. Interactions among woody plants in savannas are relatively poorly understood. We present data from a 10-yr longitudinal study of spatially explicit growth patterns of woody vegetation in an East African savanna following exclusion of large herbivores and in the absence of fire. We examined plant spatial patterns and quantified the degree of competition among woody individuals. Woody plants in this semiarid savanna exhibit strongly clumped spatial distributions at scales of 1-5 m. However, analysis of woody plant growth rates relative to their conspecific and heterospecific neighbors revealed evidence for strong competitive interactions at neighborhood scales of up to 5 m for most woody plant species. Thus, woody plants were aggregated in clumps despite significantly decreased growth rates in close proximity to neighbors, indicating that the spatial distribution of woody plants in this region depends on dispersal and establishment processes rather than on competitive, density-dependent mortality. However, our documentation of suppressive effects of woody plants on neighbors also suggests a potentially important role for tree-tree competition in controlling vegetation structure and indicates that the balanced-competition hypothesis may contribute to well-known patterns in maximum tree cover across rainfall gradients in Africa. © 2016 by the Ecological Society of America.

  4. 42 CFR 1002.203 - Mandatory exclusion.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Mandatory exclusion. 1002.203 Section 1002.203 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES PROGRAM INTEGRITY-STATE-INITIATED EXCLUSIONS FROM MEDICAID Mandatory Exclusion § 1002.203...

  5. Nano-fabricated size exclusion chromatograph

    NASA Technical Reports Server (NTRS)

    Svehla, D.; Feldman, S.; Feldman, J.; Grunthaner, F.; Shakkottai, P.; Castillo, L. del; White, V.

    2002-01-01

    This paper describes the development of a nano-fabricated size exclusion chromatograph (nSEC) based on the principle that molecules traveling through amicrocolumn containing nano-fabricated features will have characteristic elution times that directly correlate to molecular weight. Compared to conventional size exclusion chromatography, the nSEC offers greater control over the size exclusion process; mass fabrication; integration of the separation column with associated valves, pumps, and detectors; and dramatic reductions in instrument mass and power requirements.

  6. Optimal duration of exclusive breastfeeding.

    PubMed

    Kramer, Michael S; Kakuma, Ritsuko

    2012-08-15

    Although the health benefits of breastfeeding are widely acknowledged, opinions and recommendations are strongly divided on the optimal duration of exclusive breastfeeding. Since 2001, the World Health Organization has recommended exclusive breastfeeding for six months. Much of the recent debate in developed countries has centred on the micronutrient adequacy, as well as the existence and magnitude of health benefits, of this practice. To assess the effects on child health, growth, and development, and on maternal health, of exclusive breastfeeding for six months versus exclusive breastfeeding for three to four months with mixed breastfeeding (introduction of complementary liquid or solid foods with continued breastfeeding) thereafter through six months. We searched The Cochrane Library (2011, Issue 6), MEDLINE (1 January 2007 to 14 June 2011), EMBASE (1 January 2007 to 14 June 2011), CINAHL (1 January 2007 to 14 June 2011), BIOSIS (1 January 2007 to 14 June 2011), African Index Medicus (searched 15 June 2011), Index Medicus for the WHO Eastern Mediterranean Region (IMEMR) (searched 15 June 2011), LILACS (Latin American and Caribbean Health Sciences) (searched 15 June 2011). We also contacted experts in the field.The search for the first version of the review in 2000 yielded a total of 2668 unique citations. Contacts with experts in the field yielded additional published and unpublished studies. The updated literature review in December 2006 yielded 835 additional unique citations. We selected all internally-controlled clinical trials and observational studies comparing child or maternal health outcomes with exclusive breastfeeding for six or more months versus exclusive breastfeeding for at least three to four months with continued mixed breastfeeding until at least six months. Studies were stratified according to study design (controlled trials versus observational studies), provenance (developing versus developed countries), and timing of compared feeding groups

  7. B Cell Antigen Receptor Signaling and Internalization Are Mutually Exclusive Events

    PubMed Central

    Hou, Ping; Araujo, Elizabeth; Zhao, Tong; Zhang, Miao; Massenburg, Don; Veselits, Margaret; Doyle, Colleen; Dinner, Aaron R; Clark, Marcus R

    2006-01-01

    Engagement of the B cell antigen receptor initiates two concurrent processes, signaling and receptor internalization. While both are required for normal humoral immune responses, the relationship between these two processes is unknown. Herein, we demonstrate that following receptor ligation, a small subpopulation of B cell antigen receptors are inductively phosphorylated and selectively retained at the cell surface where they can serve as scaffolds for the assembly of signaling molecules. In contrast, the larger population of non-phosphorylated receptors is rapidly endocytosed. Each receptor can undergo only one of two mutually exclusive fates because the tyrosine-based motifs that mediate signaling when phosphorylated mediate internalization when not phosphorylated. Mathematical modeling indicates that the observed competition between receptor phosphorylation and internalization enhances signaling responses to low avidity ligands. PMID:16719564

  8. Frontier mutualism: coevolutionary patterns at the northern range limit of the leaf-cutter ant–fungus symbiosis

    PubMed Central

    Mueller, Ulrich G.; Mikheyev, Alexander S.; Solomon, Scott E.; Cooper, Michael

    2011-01-01

    Tropical leaf-cutter ants cultivate the fungus Attamyces bromatificus in a many-to-one, diffuse coevolutionary relationship where ant and fungal partners re-associate frequently over time. To evaluate whether ant–Attamyces coevolution is more specific (tighter) in peripheral populations, we characterized the host-specificities of Attamyces genotypes at their northern, subtropical range limits (southern USA, Mexico and Cuba). Population-genetic patterns of northern Attamyces reveal features that have so far not been observed in the diffusely coevolving, tropical ant–Attamyces associations. These unique features include (i) cases of one-to-one ant–Attamyces specialization that tighten coevolution at the northern frontier; (ii) distributions of genetically identical Attamyces clones over large areas (up to 81 000 km2, approx. the area of Ireland, Austria or Panama); (iii) admixture rates between Attamyces lineages that appear lower in northern than in tropical populations; and (iv) long-distance gene flow of Attamyces across a dispersal barrier for leaf-cutter ants (ocean between mainland North America and Cuba). The latter suggests that Attamyces fungi may occasionally disperse independently of the ants, contrary to the traditional assumption that Attamyces fungi depend entirely on leaf-cutter queens for dispersal. Peripheral populations in Argentina or at mid-elevation sites in the Andes may reveal additional regional variants in ant–Attamyces coevolution. Studies of such populations are most likely to inform models of coextinctions of obligate mutualistic partners that are doubly stressed by habitat marginality and by environmental change. PMID:21389026

  9. 27 CFR 10.51 - Exclusion, in general.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Exclusion, in general. 10.51 Section 10.51 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS COMMERCIAL BRIBERY Exclusion § 10.51 Exclusion, in general. (a) Exclusion...

  10. Modelling growth-competition relationships in trembling aspen and white spruce mixed boreal forests of Western Canada.

    PubMed

    Huang, Jian-Guo; Stadt, Kenneth J; Dawson, Andria; Comeau, Philip G

    2013-01-01

    We examined the effect of competition on stem growth of Picea glauca and Populus tremuloides in boreal mixedwood stands during the stem exclusion stage. We combined traditional approaches of collecting competition data with dendrochronology to provide retrospective measurements of stem diameter growth. Several competition indices including stand basal area (BA), the sum of stem diameter at breast height (SDBH), and density (N) for the broadleaf and coniferous species, as well as similar indices considering only trees with diameters greater than each subject (BAGR, SDBHGR, and NGR), were evaluated. We used a nonlinear mixed model to characterize the basal area increment over the past 5, 10, 15, 20, 25, 30, and 35 years as a function of growth of nearby dominant trees, the size of the subject trees, deciduous and coniferous competition indices, and ecoregions. SDBHGR and BAGR were better predictors for spruce, and SDBHGR and NGR were better for aspen, respectively, than other indices. Results showed strongest correlations with long-term stem growth, as the best models integrated growth for 10-25 years for aspen and ≥ 25 for spruce. Our model demonstrated a remarkable capability (adjusted R(2)>0.67) to represent this complex variation in growth as a function of site, size and competition.

  11. Modelling Growth-Competition Relationships in Trembling Aspen and White Spruce Mixed Boreal Forests of Western Canada

    PubMed Central

    Huang, Jian-Guo; Stadt, Kenneth J.; Dawson, Andria; Comeau, Philip G.

    2013-01-01

    We examined the effect of competition on stem growth of Picea glauca and Populus tremuloides in boreal mixedwood stands during the stem exclusion stage. We combined traditional approaches of collecting competition data with dendrochronology to provide retrospective measurements of stem diameter growth. Several competition indices including stand basal area (BA), the sum of stem diameter at breast height (SDBH), and density (N) for the broadleaf and coniferous species, as well as similar indices considering only trees with diameters greater than each subject (BAGR, SDBHGR, and NGR), were evaluated. We used a nonlinear mixed model to characterize the basal area increment over the past 5, 10, 15, 20, 25, 30, and 35 years as a function of growth of nearby dominant trees, the size of the subject trees, deciduous and coniferous competition indices, and ecoregions. SDBHGR and BAGR were better predictors for spruce, and SDBHGR and NGR were better for aspen, respectively, than other indices. Results showed strongest correlations with long-term stem growth, as the best models integrated growth for 10–25 years for aspen and ≥25 for spruce. Our model demonstrated a remarkable capability (adjusted R2>0.67) to represent this complex variation in growth as a function of site, size and competition. PMID:24204891

  12. Environmental structure and competitive scoring advantages in team competitions.

    PubMed

    Merritt, Sears; Clauset, Aaron

    2013-10-29

    In most professional sports, playing field structure is kept neutral so that scoring imbalances may be attributed to differences in team skill. It thus remains unknown what impact environmental heterogeneities can have on scoring dynamics or competitive advantages. Applying a novel generative model of scoring dynamics to roughly 10 million team competitions drawn from an online game, we quantify the relationship between the structure within a competition and its scoring dynamics, while controlling the impact of chance. Despite wide structural variations, we observe a common three-phase pattern in the tempo of events. Tempo and balance are highly predictable from a competition's structural features alone and teams exploit environmental heterogeneities for sustained competitive advantage. Surprisingly, the most balanced competitions are associated with specific environmental heterogeneities, not from equally skilled teams. These results shed new light on the design principles of balanced competition, and illustrate the potential of online game data for investigating social dynamics and competition.

  13. Environmental structure and competitive scoring advantages in team competitions

    NASA Astrophysics Data System (ADS)

    Merritt, Sears; Clauset, Aaron

    2013-10-01

    In most professional sports, playing field structure is kept neutral so that scoring imbalances may be attributed to differences in team skill. It thus remains unknown what impact environmental heterogeneities can have on scoring dynamics or competitive advantages. Applying a novel generative model of scoring dynamics to roughly 10 million team competitions drawn from an online game, we quantify the relationship between the structure within a competition and its scoring dynamics, while controlling the impact of chance. Despite wide structural variations, we observe a common three-phase pattern in the tempo of events. Tempo and balance are highly predictable from a competition's structural features alone and teams exploit environmental heterogeneities for sustained competitive advantage. Surprisingly, the most balanced competitions are associated with specific environmental heterogeneities, not from equally skilled teams. These results shed new light on the design principles of balanced competition, and illustrate the potential of online game data for investigating social dynamics and competition.

  14. Exclusive and Semi-Exclusive Reactions at a Higher Energy CEBAF

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Carl Carlson

    More energy at CEBAF provides more opportunity for studies of hadron and nuclear properties. Many of the experiments that could be done are extensions of things already done at lower energies. Others represent new initiatives that could not work or could not theoretically be interpreted at lower energies. The author concentrates on the new initiatives, but do not wish our thinking to neglect what can be learned from continuations of lower energy work. The author begins with a list of some things that should be continued into a new energy regime. (1) Baryon and meson spectroscopy of higher mass states.more » With 4 GeV incoming electron energy, strange mesons are limited to 1.8 GeV in mass and charm is not producible. (2) Exclusive reactions, including meson and baryon form factors and reactions on few nucleon systems. The latter includes deuteron photodisintegration, the A and B form factors of the deuteron, and the deuteron tensor polarization T{sub 20}. (And we should not forget T{sub 20} in inclusive scattering.) (3) Hadrons in the nuclear medium, with such topics as color transparency, electroproduction of {rho} mesons, virtual Compton scattering off nuclei, and backward hadrons from e-d reactions. The very last must be especially important, since it gives the logo used in the advertizing for this conference. In addition, there are new initiatives that this talk will call attention to, in particular: (1) semi-exclusive meson production; (2) duality in semi-exclusive reactions; and (3) new views of exclusive reactions and perturbative QCD (leading to ''off-forward parton distributions'').« less

  15. Competition.

    PubMed

    Chambers, D W

    1997-01-01

    Our ambivalence toward competition can be traced to an unspoken preference for certain types of competition which give us an advantage over the types we value less. Four types are defined (a) pure (same rules, same objectives), (b) collaborative (same rules, shared objective), (c) market share (different rules, same objectives), and (d) market growth (different rules, value added orientation). The defining characteristics of the four types of competition are respectively: needing a referee, arguing over the spoils, differentiation and substitutability, and customer focus. Dentistry has features of all four types of competition, thus making it difficult to have a meaningful discussion or frame a coherent policy on this topic.

  16. Prevalence of dental erosion in adolescent competitive swimmers exposed to gas-chlorinated swimming pool water.

    PubMed

    Buczkowska-Radlińska, J; Łagocka, R; Kaczmarek, W; Górski, M; Nowicka, A

    2013-03-01

    The purpose of this study was to analyze the prevalence of dental erosion among competitive swimmers of the local swimming club in Szczecin, Poland, who train in closely monitored gas-chlorinated swimming pool water. The population for this survey consisted of a group of junior competitive swimmers who had been training for an average of 7 years, a group of senior competitive swimmers who had been training for an average of 10 years, and a group of recreational swimmers. All subjects underwent a clinical dental examination and responded to a questionnaire regarding aspects of dental erosion. In pool water samples, the concentration of calcium, magnesium, phosphate, sodium, and potassium ions and pH were determined. The degree of hydroxyapatite saturation was also calculated. Dental erosion was found in more than 26 % of the competitive swimmers and 10 % of the recreational swimmers. The lesions in competitive swimmers were on both the labial and palatal surfaces of the anterior teeth, whereas erosions in recreational swimmers developed exclusively on the palatal surfaces. Although the pH of the pool water was neutral, it was undersaturated with respect to hydroxyapatite. The factors that increase the risk of dental erosion include the duration of swimming and the amount of training. An increased risk of erosion may be related to undersaturation of pool water with hydroxyapatite components. To decrease the risk of erosion in competitive swimmers, the degree of dental hydroxyapatite saturation should be a controlled parameter in pool water.

  17. Impact of biased scores on ranking in bipartite competition networks and inference of modular structure via generalized modularity

    NASA Astrophysics Data System (ADS)

    Jeon, Gyuhyeon; Park, Juyong

    2017-02-01

    In the common jury-contestant competition format, a jury consisting of multiple judges grade contestants on their performances to determine their ranking. Unlike in another common competition format where two contestants play a head-to-head match to produce the winner such as in football or basketball, the objectivity of judges are often called into question, potentially undermining the public's trust in the fairness of the competition. In this work we show, by modeling the jury-contestant competition format as a weighted bipartite network, how one can identify biased scores and how they impact the competition and its structure. Analyzing the prestigious International Chopin Piano Competition of 2015 as an example with a well-publicized scoring controversy, we show that the presence of even a very small fraction of biased edges can gravely distort our inference of the network structure —in the example a single biased edge is shown to lead to an incorrect “solution” that also wrongly appears to be robust exclusively, dominating other reasonable solutions— highlighting the importance of bias detection and elimination in network inference. In the process our work also presents a modified modularity measure for the one-mode projection of weighted complete bipartite networks.

  18. Predation, Competition, and Abiotic Disturbance: Population Dynamics of Small Mammals

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yunger, John A.; /Northern Illinois U. /Northern Illinois U.

    Predation and food availability have been implicated in annual non-cyclic fluctuations of vertebrate prey at mid-latitudes. The timing and magnitude of these factors are unclear due to a lack of large-scale field experiments, little attention to interactions, and a failure to closely link vertebrate predators with their prey. From October 1992 to January 1996, small mammal populations were censused on eight 0.6 ha plots at monthly intervals in a 32-ha prairie restoration at Fermi National Accelerator Laboratory, Illinois. Terrestrial vertebrate predators were excluded after July 1993 from four of the eight plots and canid diets monitored. Both terrestrial and avianmore » vertebrate predators were excluded in March 1994. During 1993 small mammal densities (i.e., Microtus Pennsylvanicus, Peromyscus leucopus, and P. maniculatus) were relatively high. Following peak densities in late summer, Microtus numbers wer 2-3x greater on exclusion plots relative to controls due to preferential selection of Microtus by canids, as reflected in dits. Following an ice-storm and crash in small mammal numbers (particularly Microtus), vertebrate predator exclusion had no detectable effect on P. leucopus numbers, probably due to an abundance of alternative prey (i.e., Sylvilagus floridanus). Meadow vole numbers began to increase in Fall 1995, and a numerical effect of predator exclusion, similar to that in 1993, was observed. Predator exclusion had no detectable effect on the movements and spatial patterns of Microtus during 1993. There was a significant decrease in home range and a significant increase in home range overlap for P. leucopus on the predator exclusion plots. The change in spatial behavior may be due to interspecific competition with Microtus resulting from increased densities on exclusion plots. Thus, predators had an indirect effect on P. leucopus spatial patterns mediated through M. Pennsylvanicus. The role of food limitation was studied using natural and manipulative

  19. Predation, Competition, and Abiotic Disturbance: Population Dynamics of Small Mammals

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yunger, John A.

    Predation and food availability have been implicated in annual non-cyclic fluctuations of vertebrate prey at mid-latitudes. The timing and magnitude of these factors are unclear due to a lack of large-scale field experiments, little attention to interactions, and a failure to closely link vertebrate predators with their prey. From October 1992 to January 1996, small mammal populations were censused on eight 0.6 ha plots at monthly intervals in a 32-ha prairie restoration at Fermi National Accelerator Laboratory, Illinois. Terrestrial vertebrate predators were excluded after July 1993 from four of the eight plots and canid diets monitored. Both terrestrial and avianmore » vertebrate predators were excluded in March 1994. During 1993 small mammal densities (i.e., Microtus pennsylvanicus, Peromyscus leucopus, and P. maniculatus) were relatively high. Following peak densities in late summer, Microtus numbers were 2-3x greater on exclusion plots relative to controls due to preferential selection of Microtus by canids, as reflected in diets. Following an ice-storm and crash in small mammal numbers (particularly Microtus), vertebrate predator exclusion had no detectable effect on P. leucopus numbers, probably due to an abundance of alternative prey (i.e., Sylvilagus floridanus). Meadow vole numbers began to increase in Fall 1995, and a numerical effect of predator exclusion, similar to that in 1993, was observed. Predator exclusion had no detectable effect on the movements and spatial patterns of Microtus during 1993. There was a significant decrease in home range and a significant increase in home range overlap for £.. leucopus on the predator exclusion plots. The change in spatial behavior may be due to interspecific competition with Microtus resulting from increased densities on exclusion plots. Thus, predators had an indirect effect on .f.. leucopus spatial patterns mediated through M. pennsylvanicus. The role of food limitation was studied using natural and

  20. 27 CFR 6.151 - Exclusion, in general.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Exclusion, in general. 6.151 Section 6.151 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS âTIED-HOUSEâ Exclusion § 6.151 Exclusion, in general. (a) Exclusion, in whole or in part occurs: (1) When a practice...

  1. 27 CFR 6.151 - Exclusion, in general.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Exclusion, in general. 6.151 Section 6.151 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS âTIED-HOUSEâ Exclusion § 6.151 Exclusion, in general. (a) Exclusion, in whole or in part occurs: (1) When a practice...

  2. Competition between yogurt probiotics and periodontal pathogens in vitro.

    PubMed

    Zhu, Yunwo; Xiao, Liying; Shen, Da; Hao, Yuqing

    2010-09-01

    To investigate the competition between probiotics in bio-yogurt and periodontal pathogens in vitro. The antimicrobial activity of bio-yogurt was studied by agar diffusion assays, using eight species of putative periodontal pathogens and a 'protective bacteria' as indicator strains. Four probiotic bacterial species (Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus, and Bifidobacterium) were isolated from yogurt and used to rate the competitive exclusion between probiotics and periodontal pathogens. Fresh yogurt inhibited all the periodontal pathogens included in this work, showing inhibition zones ranging from 9.3 (standard deviation 0.6) mm to 17.3 (standard deviation 1.7) mm, whereas heat-treated yogurt showed lower antimicrobial activity. In addition, neither fresh yogurt nor heat-treated yogurt inhibited the 'protective bacteria', Streptococcus sanguinis. The competition between yogurt probiotics and periodontal pathogens depended on the sequence of inoculation. When probiotics were inoculated first, Bifidobacterium inhibited Porphyromonas gingivalis, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Porphyromonas circumdentaria, and Prevotella nigrescens; L. acidophilus inhibited P. gingivalis, A. actinomycetemcomitans, P. circumdentaria, P. nigrescens, and Peptostreptococcus anaerobius; L. bulgaricus inhibited P. gingivalis, A. actinomycetemcomitans, and P. nigrescens; and S. thermophilus inhibited P. gingivalis, F. nucleatum, and P. nigrescens. However, their antimicrobial properties were reduced when both species (probiotics and periodontal pathogens) were inoculated simultaneously. When periodontal pathogens were inoculated first, Prevotella intermedia inhibited Bifidobacterium and S. thermophilus. The results demonstrated that bio-yogurt and the probiotics that it contains are capable of inhibiting specific periodontal pathogens but have no effect on the periodontal protective bacteria.

  3. Socio-hydrologic modeling to understand and mediate the competition for water between agriculture development and environmental health: Murrumbidgee River basin, Australia

    NASA Astrophysics Data System (ADS)

    van Emmerik, T. H. M.; Li, Z.; Sivapalan, M.; Pande, S.; Kandasamy, J.; Savenije, H. H. G.; Chanan, A.; Vigneswaran, S.

    2014-10-01

    Competition for water between humans and ecosystems is set to become a flash point in the coming decades in many parts of the world. An entirely new and comprehensive quantitative framework is needed to establish a holistic understanding of that competition, thereby enabling the development of effective mediation strategies. This paper presents a modeling study centered on the Murrumbidgee River basin (MRB). The MRB has witnessed a unique system dynamics over the last 100 years as a result of interactions between patterns of water management and climate driven hydrological variability. Data analysis has revealed a pendulum swing between agricultural development and restoration of environmental health and ecosystem services over different stages of basin-scale water resource development. A parsimonious, stylized, quasi-distributed coupled socio-hydrologic system model that simulates the two-way coupling between human and hydrological systems of the MRB is used to mimic and explain dominant features of the pendulum swing. The model consists of coupled nonlinear ordinary differential equations that describe the interaction between five state variables that govern the co-evolution: reservoir storage, irrigated area, human population, ecosystem health, and environmental awareness. The model simulations track the propagation of the external climatic and socio-economic drivers through this coupled, complex system to the emergence of the pendulum swing. The model results point to a competition between human "productive" and environmental "restorative" forces that underpin the pendulum swing. Both the forces are endogenous, i.e., generated by the system dynamics in response to external drivers and mediated by humans through technology change and environmental awareness, respectively. Sensitivity analysis carried out with the model further reveals that socio-hydrologic modeling can be used as a tool to explain or gain insight into observed co-evolutionary dynamics of diverse

  4. Effects of an introduced pathogen and fire exclusion on the demography of sugar pine

    USGS Publications Warehouse

    van Mantgem, Phillip J.; Stephenson, Nathan L.; Keifer, MaryBeth; Keeley, Jon E.

    2004-01-01

    An introduced pathogen, white pine blister rust (Cronartium ribicola), has caused declines in five-needled pines throughout North America. Simultaneously, fire exclusion has resulted in dense stands in many forest types, which may create additional stress for these generally shade-intolerant pines. Fire exclusion also allows fuels to accumulate, and it is unclear how affected populations will respond to the reintroduction of fire. Although white pine blister rust and fire exclusion are widely recognized threats, long-term demographic data that document the effects of these stressors are rare. We present population trends from 2168 individuals over 5–15 years for an affected species, sugar pine (Pinus lambertiana), at several burned and unburned sites in the Sierra Nevada of California. Size-based matrix models indicate that most unburned populations have negative growth rates (λ range: 0.82–1.04). The growth rate of most populations was, however, indistinguishable from replacement levels (λ = 1.0), implying that, if populations are indeed declining, the progression of any such decline is slow, and longer observations are needed to clearly determine population trends. We found significant differences among population growth rates, primarily due to variation in recruitment rates. Deaths associated with blister rust and stress (i.e., resource competition) were common, suggesting significant roles for both blister rust and fire exclusion in determining population trajectories. Data from 15 prescribed fires showed that the immediate effect of burning was the death of many small trees, with the frequency of mortality returning to pre-fire levels within five years. In spite of a poor prognosis for sugar pine, our results suggest that we have time to apply and refine management strategies to protect this species.

  5. Sexual size dimorphism, canine dimorphism, and male-male competition in primates: where do humans fit in?

    PubMed

    Plavcan, J Michael

    2012-03-01

    Sexual size dimorphism is generally associated with sexual selection via agonistic male competition in nonhuman primates. These primate models play an important role in understanding the origins and evolution of human behavior. Human size dimorphism is often hypothesized to be associated with high rates of male violence and polygyny. This raises the question of whether human dimorphism and patterns of male violence are inherited from a common ancestor with chimpanzees or are uniquely derived. Here I review patterns of, and causal models for, dimorphism in humans and other primates. While dimorphism in primates is associated with agonistic male mate competition, a variety of factors can affect male and female size, and thereby dimorphism. The causes of human sexual size dimorphism are uncertain, and could involve several non-mutually-exclusive mechanisms, such as mate competition, resource competition, intergroup violence, and female choice. A phylogenetic reconstruction of the evolution of dimorphism, including fossil hominins, indicates that the modern human condition is derived. This suggests that at least some behavioral similarities with Pan associated with dimorphism may have arisen independently, and not directly from a common ancestor.

  6. 40 CFR 68.126 - Exclusion.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Exclusion. 68.126 Section 68.126 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Regulated Substances for Accidental Release Prevention § 68.126 Exclusion...

  7. 75 FR 80798 - Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of Inventions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ... Partially-Exclusive Licensing of Inventions Concerning an Inactivated Dengue Virus Vaccine and a Method and Kit for Detection of Dengue Virus AGENCY: Department of the Army, DoD. ACTION: Notice. SUMMARY... which issued July 3, 2001, entitled ``Inactivated Dengue Virus Vaccine,'' and U.S. Patent 6,190,859...

  8. Evasion of superinfection exclusion and elimination of primary viral RNA by an adapted strain of hepatitis C virus.

    PubMed

    Webster, Brian; Ott, Melanie; Greene, Warner C

    2013-12-01

    Cells that are productively infected by hepatitis C virus (HCV) are refractory to a second infection by HCV via a block in viral replication known as superinfection exclusion. The block occurs at a postentry step and likely involves translation or replication of the secondary viral RNA, but the mechanism is largely unknown. To characterize HCV superinfection exclusion, we selected for an HCV variant that could overcome the block. We produced a high-titer HC-J6/JFH1 (Jc1) viral genome with a fluorescent reporter inserted between NS5A and NS5B and used it to infect Huh7.5 cells containing a Jc1 replicon. With multiple passages of these infected cells, we isolated an HCV variant that can superinfect cells at high levels. Notably, the superinfectious virus rapidly cleared the primary replicon from superinfected cells. Viral competition experiments, using a novel strategy of sequence-barcoding viral strains, as well as superinfection of replicon cells demonstrated that mutations in E1, p7, NS5A, and the poly(U/UC) tract of the 3' untranslated region were important for superinfection. Furthermore, these mutations dramatically increased the infectivity of the virus in naive cells. Interestingly, viruses with a shorter poly(U/UC) and an NS5A domain II mutation were most effective in overcoming the postentry block. Neither of these changes affected viral RNA translation, indicating that the major barrier to postentry exclusion occurs at viral RNA replication. The evolution of the ability to superinfect after less than a month in culture and the concomitant exclusion of the primary replicon suggest that superinfection exclusion dramatically affects viral fitness and dynamics in vivo.

  9. Consumer effects on the vital rates of their resource can determine the outcome of competition between consumers.

    PubMed

    Lee, Charlotte T; Miller, Tom E X; Inouye, Brian D

    2011-10-01

    Current competition theory does not adequately address the fact that competitors may affect the survival, growth, and reproductive rates of their resources. Ecologically important interactions in which consumers affect resource vital rates range from parasitism and herbivory to mutualism. We present a general model of competition that explicitly includes consumer-dependent resource vital rates. We build on the classic MacArthur model of competition for multiple resources, allowing direct comparison with expectations from established concepts of resource-use overlap. Consumers share a stage-structured resource population but may use the different stages to different extents, as they do the different independent resources in the classic model. Here, however, the stages are dynamically linked via consumer-dependent vital rates. We show that consumers' effects on resource vital rates result in two important departures from classic results. First, consumers can coexist despite identical use of resource stages, provided each competitor shifts the resource stage distribution toward stages that benefit other species. Second, consumers specializing on different resource stages can compete strongly, possibly resulting in competitive exclusion despite a lack of resource stage-use overlap. Our model framework demonstrates the critical role that consumer-dependent resource vital rates can play in competitive dynamics in a wide range of biological systems.

  10. Softening the Blow of Social Exclusion: The Responsive Theory of Social Exclusion

    PubMed Central

    Freedman, Gili; Williams, Kipling D.; Beer, Jennifer S.

    2016-01-01

    Social exclusion is an interactive process between multiple people, yet previous research has focused almost solely on the negative impacts on targets. What advice is there for people on the other side (i.e., sources) who want to minimize its negative impact and preserve their own reputation? To provide an impetus for research on the interactive nature of exclusion, we propose the Responsive Theory of Social Exclusion. Our theory postulates that targets and sources’ needs are better maintained if sources use clear, explicit verbal communication. We propose that sources have three options: explicit rejection (clearly stating no), ostracism (ignoring), and ambiguous rejection (being unclear). Drawing on psychology, sociology, communications, and business research, we propose that when sources use explicit rejection, targets’ feelings will be less hurt, their needs will be better protected, and sources will experience less backlash and emotional toil than if sources use ambiguous rejection or ostracism. Finally, we propose how the language of rejections may impact both parties. PMID:27777566

  11. Softening the Blow of Social Exclusion: The Responsive Theory of Social Exclusion.

    PubMed

    Freedman, Gili; Williams, Kipling D; Beer, Jennifer S

    2016-01-01

    Social exclusion is an interactive process between multiple people, yet previous research has focused almost solely on the negative impacts on targets. What advice is there for people on the other side (i.e., sources) who want to minimize its negative impact and preserve their own reputation? To provide an impetus for research on the interactive nature of exclusion, we propose the Responsive Theory of Social Exclusion. Our theory postulates that targets and sources' needs are better maintained if sources use clear, explicit verbal communication. We propose that sources have three options: explicit rejection (clearly stating no), ostracism (ignoring), and ambiguous rejection (being unclear). Drawing on psychology, sociology, communications, and business research, we propose that when sources use explicit rejection, targets' feelings will be less hurt, their needs will be better protected, and sources will experience less backlash and emotional toil than if sources use ambiguous rejection or ostracism. Finally, we propose how the language of rejections may impact both parties.

  12. 40 CFR 113.5 - Exclusions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 22 2014-07-01 2013-07-01 true Exclusions. 113.5 Section 113.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS LIABILITY LIMITS FOR SMALL ONSHORE STORAGE FACILITIES Oil Storage Facilities § 113.5 Exclusions. This subpart does not apply...

  13. 40 CFR 113.5 - Exclusions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 23 2012-07-01 2012-07-01 false Exclusions. 113.5 Section 113.5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS LIABILITY LIMITS FOR SMALL ONSHORE STORAGE FACILITIES Oil Storage Facilities § 113.5 Exclusions. This subpart does not apply...

  14. Detritus Type Alters the Outcome of Interspecific Competition Between Aedes aegypti and Aedes albopictus (Diptera: Culicidae)

    PubMed Central

    MURRELL, EBONY G.; JULIANO, STEVEN A.

    2008-01-01

    Many studies of interspecific competition between Aedes albopictus (Skuse) and Aedes aegypti (L.) (Diptera: Culicidae) larvae show that Ae. albopictus are superior resource competitors to Ae. aegypti. Single-species studies indicate that growth and survival of Ae. albopictus and Ae. aegypti larvae are affected by the type of detritus present in containers, which presumably affects the amount and quality of microorganisms that the mosquito larvae consume. We tested whether different detritus types alter the intensity of larval competition by raising 10 different density/species combinations of Ae. albopictus and Ae. aegypti larvae under standard laboratory conditions, with one of four detritus types (oak, pine, grass, or insect) provided as a nutrient base. Intraspecific competitive effects on survival were present with all detritus types. Ae. albopictus survivorship was unaffected by interspecific competition in all treatments. Negative interspecific effects on Ae. aegypti survivorship were present with three of four detritus types, but absent with grass. Estimated finite rate of increase (λ’) was lower with pine detritus than with any other detritus type for both species. Furthermore, Ae. aegypti λ’ was negatively affected by high interspecific density in all detritus types except grass. Thus, our experiment confirms competitive asymmetry in favor of Ae. albopictus with oak, pine, or insect detritus, but also demonstrates that certain detritus types may eliminate interspecific competition among the larvae of these species, which may allow for stable coexistence. Such variation in competitive outcome with detritus type may help to account for observed patterns of coexistence/exclusion of Ae. albopictus and Ae. aegypti in the field. PMID:18533429

  15. Competitive Intelligence.

    ERIC Educational Resources Information Center

    Bergeron, Pierrette; Hiller, Christine A.

    2002-01-01

    Reviews the evolution of competitive intelligence since 1994, including terminology and definitions and analytical techniques. Addresses the issue of ethics; explores how information technology supports the competitive intelligence process; and discusses education and training opportunities for competitive intelligence, including core competencies…

  16. Healthy Competition and Unsound Comparison: Reforming Educational Competition in Singapore

    ERIC Educational Resources Information Center

    Christensen, Søren

    2015-01-01

    It is frequently claimed that the "competition state" responds to external competition by making competition increasingly central to its internal processes as well. This article discusses education reform in Singapore as departing from the opposite position. In Singapore "excessive" competition in education is now targeted by…

  17. 76 FR 22386 - Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of an Invention...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-21

    ... Partially-Exclusive Licensing of an Invention Concerning the Method and Apparatus for Stereo Imaging AGENCY... ``Method and Apparatus for Stereo Imaging,'' filed on March 11, 2011. The United States Government, as...: The invention relates to a method and apparatus for the generation of macro scale extremely high...

  18. 78 FR 77107 - Notice of Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of an...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ..., or Partially-Exclusive Licensing of an Invention Concerning Preoperative Recommendations Engine..., entitled ``Preoperative Recommendations Engine,'' filed on January 14, 2013. The United States Government.... Army Medical Research and Materiel Command, ATTN: Command Judge Advocate, MCMR-JA, 504 Scott Street...

  19. Exclusive breastfeeding in Vietnam: an attainable goal.

    PubMed

    Almroth, Stina; Arts, Maaike; Quang, Nguyen Dinh; Hoa, Pham Thi Thuy; Williams, Carol

    2008-08-01

    To explore community views on the feasibility of exclusive breastfeeding in Vietnam. A total of 118 interviews were conducted with mothers, grandmothers, fathers, health workers and 'oldest women' in rural and urban areas in the north and south of Vietnam. Special issues were further examined through 12 'strategic interviews'. Exclusive breastfeeding was rare because it was poorly understood and little appreciated, by health professionals as well as lay persons, as the best way to feed an infant during the first 6 months. Early fluid supplementation was the rule and most infants received water and milk in addition to breast milk. While a majority of the women worked, they had found ways to manage their work so that it did not need to interfere with exclusive breastfeeding. Family members expressed a readiness to support exclusive breastfeeding when it was explained to them. Exclusive breastfeeding in Vietnam, while currently uncommon, is an attainable goal. Establishing exclusive breastfeeding as the norm in the general population would make it easier for HIV-infected women, for whom replacement feeding is not acceptable, feasible, affordable, sustainable and safe, to breastfeed exclusively.

  20. EDITORIAL: Physics competitions Physics competitions

    NASA Astrophysics Data System (ADS)

    Jordens, H.; Mathelitsch, L.

    2010-07-01

    This editorial opens the second special section on physics competitions in European Journal of Physics. In the first section last year, we asked for feedback on the idea of such a section and on the content of the articles. We received no answer whatsoever, which can be interpreted in two ways: the section is not interesting enough to raise motivation for feedback, or the reader is satisfied. Having no indication which scenario is the correct one, we are optimistic and favour the second. The section at hand contains three articles. Again, as last year, the organizer of the annual Olympiad reports on tasks and outcomes of this competition. The Olympiad took place in Merida, Mexico, and was by far the largest event with 316 contestants from 68 countries. Again, the predominance of Asian/Chinese students was manifest, showing how serious the training is taken by both their authorities and students. Unfortunately, the winners of the last International Young Physicists' Tournament (IYPT), the team from Korea, did not accept the offer to report on their prize-winning contribution. We are thankful that two students from Austria, who achieved second place with their team, took over and reported on the task which they presented in the finals of the competition. It connects the fields of sport and physics and explains a special move in skateboarding. The third contribution introduces a different competition, 'International Conference of Young Scientists'. On one hand, as in the Olympiad, it addresses individuals, not teams. On the other, as in the IYPT, students have several months to prepare and also the quality of the presentation is an important element of the judgment. In fact, this competition comes closer to real scientific research compared to the other events. Finally and again, we hope that this section will serve several purposes: To show the competitions as a very important tool in the support of gifted students. To raise awareness amongst university teachers, and

  1. Lunabotics Mining Competition

    NASA Technical Reports Server (NTRS)

    Mueller, Rob; Murphy, Gloria

    2010-01-01

    This slide presentation describes a competition to design a lunar robot (lunabot) that can be controlled either remotely or autonomously, isolated from the operator, and is designed to mine a lunar aggregate simulant. The competition is part of a systems engineering curriculum. The 2010 competition winners in five areas of the competition were acknowledged, and the 2011 competition was announced.

  2. Memory-based multiagent coevolution modeling for robust moving object tracking.

    PubMed

    Wang, Yanjiang; Qi, Yujuan; Li, Yongping

    2013-01-01

    The three-stage human brain memory model is incorporated into a multiagent coevolutionary process for finding the best match of the appearance of an object, and a memory-based multiagent coevolution algorithm for robust tracking the moving objects is presented in this paper. Each agent can remember, retrieve, or forget the appearance of the object through its own memory system by its own experience. A number of such memory-based agents are randomly distributed nearby the located object region and then mapped onto a 2D lattice-like environment for predicting the new location of the object by their coevolutionary behaviors, such as competition, recombination, and migration. Experimental results show that the proposed method can deal with large appearance changes and heavy occlusions when tracking a moving object. It can locate the correct object after the appearance changed or the occlusion recovered and outperforms the traditional particle filter-based tracking methods.

  3. Life history trade-offs, the intensity of competition, and coexistence in novel and evolving communities under climate change.

    PubMed

    Lancaster, Lesley T; Morrison, Gavin; Fitt, Robert N

    2017-01-19

    The consequences of climate change for local biodiversity are little understood in process or mechanism, but these changes are likely to reflect both changing regional species pools and changing competitive interactions. Previous empirical work largely supports the idea that competition will intensify under climate change, promoting competitive exclusions and local extinctions, while theory and conceptual work indicate that relaxed competition may in fact buffer communities from biodiversity losses that are typically witnessed at broader spatial scales. In this review, we apply life history theory to understand the conditions under which these alternative scenarios may play out in the context of a range-shifting biota undergoing rapid evolutionary and environmental change, and at both leading-edge and trailing-edge communities. We conclude that, in general, warming temperatures are likely to reduce life history variation among competitors, intensifying competition in both established and novel communities. However, longer growing seasons, severe environmental stress and increased climatic variability associated with climate change may buffer these communities against intensified competition. The role of life history plasticity and evolution has been previously underappreciated in community ecology, but may hold the key to understanding changing species interactions and local biodiversity under changing climates.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'. © 2016 The Author(s).

  4. Life history trade-offs, the intensity of competition, and coexistence in novel and evolving communities under climate change

    PubMed Central

    Morrison, Gavin; Fitt, Robert N.

    2017-01-01

    The consequences of climate change for local biodiversity are little understood in process or mechanism, but these changes are likely to reflect both changing regional species pools and changing competitive interactions. Previous empirical work largely supports the idea that competition will intensify under climate change, promoting competitive exclusions and local extinctions, while theory and conceptual work indicate that relaxed competition may in fact buffer communities from biodiversity losses that are typically witnessed at broader spatial scales. In this review, we apply life history theory to understand the conditions under which these alternative scenarios may play out in the context of a range-shifting biota undergoing rapid evolutionary and environmental change, and at both leading-edge and trailing-edge communities. We conclude that, in general, warming temperatures are likely to reduce life history variation among competitors, intensifying competition in both established and novel communities. However, longer growing seasons, severe environmental stress and increased climatic variability associated with climate change may buffer these communities against intensified competition. The role of life history plasticity and evolution has been previously underappreciated in community ecology, but may hold the key to understanding changing species interactions and local biodiversity under changing climates. This article is part of the themed issue ‘Human influences on evolution, and the ecological and societal consequences’. PMID:27920390

  5. 33 CFR 2.30 - Exclusive Economic Zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Exclusive Economic Zone. 2.30... JURISDICTION Jurisdictional Terms § 2.30 Exclusive Economic Zone. (a) With respect to the United States... States exercises sovereignty, exclusive economic zone means the zone seaward of and adjacent to the...

  6. 42 CFR 1002.211 - Effect of exclusion.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Effect of exclusion. 1002.211 Section 1002.211 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES PROGRAM INTEGRITY-STATE-INITIATED EXCLUSIONS FROM MEDICAID Permissive Exclusions § 1002.211 Effect...

  7. 33 CFR 2.30 - Exclusive Economic Zone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Exclusive Economic Zone. 2.30... JURISDICTION Jurisdictional Terms § 2.30 Exclusive Economic Zone. (a) With respect to the United States... States exercises sovereignty, exclusive economic zone means the zone seaward of and adjacent to the...

  8. 33 CFR 2.30 - Exclusive Economic Zone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Exclusive Economic Zone. 2.30... JURISDICTION Jurisdictional Terms § 2.30 Exclusive Economic Zone. (a) With respect to the United States... States exercises sovereignty, exclusive economic zone means the zone seaward of and adjacent to the...

  9. 33 CFR 2.30 - Exclusive Economic Zone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Exclusive Economic Zone. 2.30... JURISDICTION Jurisdictional Terms § 2.30 Exclusive Economic Zone. (a) With respect to the United States... States exercises sovereignty, exclusive economic zone means the zone seaward of and adjacent to the...

  10. 33 CFR 2.30 - Exclusive Economic Zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Exclusive Economic Zone. 2.30... JURISDICTION Jurisdictional Terms § 2.30 Exclusive Economic Zone. (a) With respect to the United States... States exercises sovereignty, exclusive economic zone means the zone seaward of and adjacent to the...

  11. 76 FR 3119 - Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of an Invention...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... Partially-Exclusive Licensing of an Invention Concerning a Urinary Field Sampling Kit for the Determination.... Provisional Patent Application Serial No. 61/458,797, entitled ``Urinary Field Sampling Kit for the... INFORMATION: The invention relates to a urinary field sampling kit and method of its use for collecting and...

  12. 42 CFR 1003.108 - Penalty, assessment, and exclusion not exclusive.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... AND HUMAN SERVICES OIG AUTHORITIES CIVIL MONEY PENALTIES, ASSESSMENTS AND EXCLUSIONS § 1003.108... this part are in addition to any other penalties prescribed by law. [59 FR 32126, June 22, 1994] ...

  13. Factors Influencing Exclusive Breastfeeding in Tabuk, Saudi Arabia

    PubMed Central

    Alzaheb, Riyadh A

    2017-01-01

    Background: Breast milk contains all the nutrients infants need for their first 6 months of life. However, only a minority of Saudi Arabian mothers exclusively breastfeed, so the influencing factors must be examined to encourage more to do so. The study aimed to determine the prevalence of exclusive breastfeeding at 6 months and its associated factors in Tabuk, North West Saudi Arabia. Methods: A total of 589 mothers of healthy infants aged between 6 and 24 months were interviewed while attending Well-Baby Clinics within 5 primary health care centers. Interviews deployed a structured questionnaire to collect sociodemographic information and detailed data concerning breastfeeding practices. A logistic regression analysis was then performed on the data to identify the factors independently associated with exclusive breastfeeding practice for infants at 6 months. Results: Exclusive breastfeeding was practiced by 31.4% of mothers for the first 6 months of their infant’s life. The logistic regressions indicated that exclusive breastfeeding at 6 months was less likely to be practiced by working mothers, Saudi nationals, and for babies born via cesarean delivery or at low birth weights. Conversely, the mother’s awareness of the recommended exclusive breastfeeding duration was positively associated with exclusive breastfeeding. Conclusions: Programs promoting 6 months of exclusive breastfeeding should target high-risk groups. Two factors identified by this study are modifiable: working mothers and mothers’ awareness of the exclusive breastfeeding duration recommendation. Strategies to improve exclusive breastfeeding rates should therefore focus on workplace facilities and increasing awareness of the exclusive breastfeeding recommendation. PMID:28469519

  14. Cooperation induced by random sequential exclusion

    NASA Astrophysics Data System (ADS)

    Li, Kun; Cong, Rui; Wang, Long

    2016-06-01

    Social exclusion is a common and powerful tool to penalize deviators in human societies, and thus to effectively elevate collaborative efforts. Current models on the evolution of exclusion behaviors mostly assume that each peer excluder independently makes the decision to expel the defectors, but has no idea what others in the group would do or how the actual punishment effect will be. Thus, a more realistic model, random sequential exclusion, is proposed. In this mechanism, each excluder has to pay an extra scheduling cost and then all the excluders are arranged in a random order to implement the exclusion actions. If one free rider has already been excluded by an excluder, the remaining excluders will not participate in expelling this defector. We find that this mechanism can help stabilize cooperation under more unfavorable conditions than the normal peer exclusion can do, either in well-mixed population or on social networks. However, too large a scheduling cost may undermine the advantage of this mechanism. Our work validates the fact that collaborative practice among punishers plays an important role in further boosting cooperation.

  15. Academic Competitions.

    ERIC Educational Resources Information Center

    Marin County Office of Education, San Rafael, CA.

    Descriptions of scholastic competitions for Marin County (California) students are presented. Following a rationale for conducting scholastic competitions, community groups and businesses which lend support are listed along with the type of support given. Participating grade levels, dates of competition during the 1983-84 school year, and a brief…

  16. 10 CFR 851.2 - Exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Exclusions. 851.2 Section 851.2 Energy DEPARTMENT OF ENERGY WORKER SAFETY AND HEALTH PROGRAM General Provisions § 851.2 Exclusions. (a) This part does not apply to work at a DOE site: (1) Regulated by the Occupational Safety and Health Administration; or (2...

  17. 10 CFR 830.2 - Exclusions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Exclusions. 830.2 Section 830.2 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT § 830.2 Exclusions. This part does not apply to: (a) Activities that are... 1974, as amended; and (e) Activities related to the launch approval and actual launch of nuclear energy...

  18. 10 CFR 830.2 - Exclusions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Exclusions. 830.2 Section 830.2 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT § 830.2 Exclusions. This part does not apply to: (a) Activities that are... 1974, as amended; and (e) Activities related to the launch approval and actual launch of nuclear energy...

  19. 10 CFR 830.2 - Exclusions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Exclusions. 830.2 Section 830.2 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT § 830.2 Exclusions. This part does not apply to: (a) Activities that are... 1974, as amended; and (e) Activities related to the launch approval and actual launch of nuclear energy...

  20. Evaluating Alternatives to Exclusive "He."

    ERIC Educational Resources Information Center

    Todd-Mancillas, William R.

    A study was conducted to determine the effects on reading comprehension of the use of the exclusive pronoun "he" and more or less contrived alternatives. Subjects, 358 students enrolled in an introduction to human communication at a large northeastern university, read three different forms of the same essay. One essay form exclusively used "he,"…

  1. 10 CFR 830.2 - Exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Exclusions. 830.2 Section 830.2 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT § 830.2 Exclusions. This part does not apply to: (a) Activities that are... 1974, as amended; and (e) Activities related to the launch approval and actual launch of nuclear energy...

  2. 10 CFR 830.2 - Exclusions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Exclusions. 830.2 Section 830.2 Energy DEPARTMENT OF ENERGY NUCLEAR SAFETY MANAGEMENT § 830.2 Exclusions. This part does not apply to: (a) Activities that are... 1974, as amended; and (e) Activities related to the launch approval and actual launch of nuclear energy...

  3. 28 CFR 301.319 - Exclusiveness of remedy.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Exclusiveness of remedy. 301.319 Section... COMPENSATION Compensation for Work-Related Physical Impairment or Death § 301.319 Exclusiveness of remedy... Accident Compensation procedure was declared by the U.S. Supreme Court to be the exclusive remedy in the...

  4. 21 CFR 1404.945 - Excluded or exclusion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Excluded or exclusion. 1404.945 Section 1404.945 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 1404.945 Excluded or exclusion. Excluded or exclusion means— (a) That a person or...

  5. 77 FR 13566 - Notice of Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of an...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ... invention set forth in ``Radiation Detector System for Locating and Identifying Special Nuclear Material in..., or Partially-Exclusive Licensing of an Invention Concerning a Radiation Detector System for Locating and Identifying Special Nuclear Material in Moving Vehicles AGENCY: Defense Threat Reduction Agency...

  6. Host-parasite coevolution can promote the evolution of seed banking as a bet-hedging strategy.

    PubMed

    Verin, Mélissa; Tellier, Aurélien

    2018-04-20

    Seed (egg) banking is a common bet-hedging strategy maximizing the fitness of organisms facing environmental unpredictability by the delayed emergence of offspring. Yet, this condition often requires fast and drastic stochastic shifts between good and bad years. We hypothesize that the host seed banking strategy can evolve in response to coevolution with parasites because the coevolutionary cycles promote a gradually changing environment over longer times than seed persistence. We study the evolution of host germination fraction as a quantitative trait using both pairwise competition and multiple mutant competition methods, while the germination locus can be genetically linked or unlinked with the host locus under coevolution. In a gene-for-gene model of coevolution, hosts evolve a seed bank strategy under unstable coevolutionary cycles promoted by moderate to high costs of resistance or strong disease severity. Moreover, when assuming genetic linkage between coevolving and germination loci, the resistant genotype always evolves seed banking in contrast to susceptible hosts. Under a matching-allele interaction, both hosts' genotypes exhibit the same seed banking strategy irrespective of the genetic linkage between loci. We suggest host-parasite coevolution as an additional hypothesis for the evolution of seed banking as a temporal bet-hedging strategy. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

  7. Reversing the negative psychological sequelae of exclusion: inclusion is ameliorative but not protective against the aversive consequences of exclusion.

    PubMed

    Tang, Helen H Y; Richardson, Rick

    2013-02-01

    Social exclusion can have devastating personal, social, and clinical consequences, but several recent studies have identified factors that can reduce its aversive impact (e.g., distraction from rumination, control over a noise). In this study, we continued to explore possible strategies for reducing the aversive experiences of being excluded. Three experiments investigated whether an experience of inclusion reduced the impact of exclusion. Specifically, participants engaged in two rounds of a computer ball toss game (Cyberball) in which they were either included or excluded. Participants were told either that they played the two games with the same two sources (Experiment 1), with a different pair of sources (Experiment 2), or with people and then computer controlled sources (Experiment 3). We measured the impact of exclusion and inclusion on the psychological states of belonging, control, self esteem, meaningful existence, hurt feelings, anger, and affect. Across all three experiments, if inclusion occurred after exclusion then it was found to have an ameliorative benefit. However, if inclusion occurred before exclusion there was no protective benefit. Finally, we compared the ratings following one versus two experiences of exclusion, with no additive impact found. Taken together, the results indicate that inclusion can reduce the impact of exclusion, but only if it occurs after exclusion. Further, inclusion is ameliorative even when it is by a different group or a computer program. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  8. 75 FR 20828 - Availability for Non-Exclusive, Exclusive, or Partially Exclusive Licensing of U.S. Patent...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-21

    ... Partially Exclusive Licensing of U.S. Patent Application Concerning a Chimeric Ebola and Marburg Virus Glycoproteins Virus Like Particle Vaccine To Protect Against Diverse Ebola and Marburg Viruses AGENCY... Ebola and Marburg Virus Glycoproteins Virus Like Particle Vaccine To Protect Against Diverse Ebola and...

  9. 76 FR 63910 - Notice of Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of an...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-14

    ..., or Partially-Exclusive Licensing of an Invention Concerning Method for Estimating Core Body... Serial No. 61/572,677, entitled ``Method for Estimating Core Body Temperature from Heart Rate,'' filed on... core temperature from heart rate. The invention further relates to a method of determining impending...

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

    PubMed

    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.

  11. Social Exclusion/Inclusion: Foucault's Analytics of Exclusion, the Political Ecology of Social Inclusion and the Legitimation of Inclusive Education

    ERIC Educational Resources Information Center

    Peters, Michael A.; Besley, Tina A. C.

    2014-01-01

    This article offers a broad philosophical and historical background to the dyad of social exclusion/inclusion by examining the analytics and politics of exclusion first by reference to Michel Foucault who studies the modern history of exclusion and makes it central to his approach in understanding the development of modern institutions of emerging…

  12. Competition in Education.

    ERIC Educational Resources Information Center

    Rich, John Martin; DeVitis, Joseph L.

    This book discusses various major aspects of competition in education. It identifies competition within educational policies, programs, and practices, as well as the problems that certain forms of competition create. It also traces the influences of American competitive values on education. Chapter 1 provides an introductory overview of the…

  13. Formation of new stimulus equivalence classes by exclusion.

    PubMed

    Plazas, Elberto A; Villamil, Carlos-Wilcen

    2018-03-01

    This study presents three experiments that aimed to show the formation of stimulus equivalence relations among stimuli that had been previously related only by exclusion. In Experiment 1, participants were trained on baseline conditional discriminations to establish two 3-member equivalence classes. Then, they were exposed to exclusion trials, without feedback, in which undefined stimuli had to be matched by rejecting the defined baseline stimuli. Finally, participants responded to test trials evaluating the emergence of symmetry and transitivity among the undefined stimuli from the exclusion trials. For half of the participants, the stimuli related by exclusion were introduced as S- stimuli in the baseline trials, whereas for the other half they were not. Further, half of the participants were assessed for emergent relations with stimuli from all the classes, whereas the other half was assessed for emergent relations with only the stimuli related by exclusion. In Experiment 2, the S- comparisons in the emergent relations test trials with stimuli only related by exclusion were stimuli from a null class. In Experiment 3, the number of exclusion trials was doubled. Across experiments, most participants showed emergence of equivalence relations among the stimuli related by exclusion. Some conditions of stimulus control associated with exclusion learning and the emergence of equivalence relations are discussed. © 2018 Society for the Experimental Analysis of Behavior.

  14. 77 FR 8223 - Notice of Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of an...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-14

    ..., or Partially-Exclusive Licensing of an Invention Concerning a Computer Controlled System for Laser... provides a computer controlled system for laser energy delivery to the retina. Information is received from... Application Serial No. 13/130,380, entitled ``Computer Controlled System for Laser Energy Delivery to the...

  15. 75 FR 4793 - Availability for Non-Exclusive, Exclusive, or Partially Exclusive Licensing of U.S. Provisional...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-29

    ... Partially Exclusive Licensing of U.S. Provisional Patent Application Concerning Blast Wave Sensor AGENCY... ``Blast Wave Sensor,'' filed January 4, 2010. The United States Government, as represented by the... wave sensors and their use to detect blast induced pressure changes, and, in particular, a blast wave...

  16. Improved self-exclusion program: preliminary results.

    PubMed

    Tremblay, Nicole; Boutin, Claude; Ladouceur, Robert

    2008-12-01

    The gambling industry has offered self-exclusion programs for quite a long time. Such measures are designed to limit access to gaming opportunities and provide problem gamblers with the help they need to cease or limit their gambling behaviour. However, few studies have empirically evaluated these programs. This study has three objectives: (1) to observe the participation in an improved self-exclusion program that includes an initial voluntary evaluation, phone support, and a mandatory meeting, (2) to evaluate satisfaction and usefulness of this service as perceived by self-excluders, (3) to measure the preliminary impact of this improved program. One hundred sixteen self-excluders completed a questionnaire about their satisfaction and their perception of the usefulness during the mandatory meeting. Among those participants, 39 attended an initial meeting. Comparisons between data collected at the initial meeting and data taken at the final meeting were made for those 39 participants. Data showed that gamblers chose the improved self-exclusion program 75% of the time; 25% preferred to sign a regular self-exclusion contract. Among those who chose the improved service, 40% wanted an initial voluntary evaluation and 37% of these individuals actually attended that meeting. Seventy percent of gamblers came to the mandatory meeting, which was a required condition to end their self-exclusion. The majority of participants were satisfied with the improved self-exclusion service and perceived it as useful. Major improvements were observed between the final and the initial evaluation on time and money spent, consequences of gambling, DSM-IV score, and psychological distress. The applicability of an improved self-exclusion program is discussed and, as shown in our study, the inclusion of a final mandatory meeting might not be so repulsive for self-excluders. Future research directives are also proposed.

  17. Teenage pregnancy and exclusive breastfeeding rates.

    PubMed

    Puapompong, Pawin; Raungrongmorakot, Kasem; Manolerdtewan, Wichian; Ketsuwan, Sukwadee; Wongin, Sinutchanan

    2014-09-01

    Teenage pregnancy is an important health issue globally and in Thailand Younger age mothers decide on the breastfeeding practices ofthe first 6-month. To find the rates of 6-month exclusive breastfeeding practices of teenage mothers and compare them with the rates of 6-month exclusive breastfeeding practices in mothers who are 20 years of age or more. Three thousand five hundred sixty three normal, postpartum women, who delivered without complications at the HRH Princess Maha Chakri Sirindhorn Medical Center in the Nakhon Nayok Province between 2010 and2013 were included in this study. At the second daypostpartum, the data of latch scores and the data of the practice of exclusive breastfeeding were collected Telephone follow-ups on the seventh, fourteenth, and forty-fifth postpartum days and at the second, fourth, and sixth month postpartum month were collected and used for exclusive breastfeeding data following discharge. Demographic data included the maternal age, parity, gestational age, marital status, occupation, religion, route ofdelivery, estimated blood loss, body mass index, nipple length, and the childs birth weight. The collected data was analyzed by the t-test, Chi-square, and odds ratio with 95% confidence interval. The percentage of teenage pregnancies was at 14.8% (527 cases). On postpartum day 2, the percentage of latch scores of 8 or less was 66.4%. At the seventh, fourteenth, and forty-fifth day and at the second, fourth, and sixth months postpartum, the exclusive breastfeeding rates were 88.5, 78.5, 57.6, 43.1, 32.9, and27.0%, respectively. Comparison of the 6-month exclusive breastfeeding rates between teenage mothers and mothers 20 years ofage or older were not statistically significant (p<0.05). The 6-month exclusive breastfeeding rate of teenage mothers was at 27.0% and had no significant differences from the rates of mothers 20 years of age or more.

  18. 47 CFR 76.107 - Exclusivity contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Exclusivity contracts. 76.107 Section 76.107 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout...

  19. 47 CFR 76.107 - Exclusivity contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Exclusivity contracts. 76.107 Section 76.107 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout...

  20. 47 CFR 76.107 - Exclusivity contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Exclusivity contracts. 76.107 Section 76.107 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout...

  1. 47 CFR 76.107 - Exclusivity contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Exclusivity contracts. 76.107 Section 76.107 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout...

  2. 47 CFR 76.107 - Exclusivity contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Exclusivity contracts. 76.107 Section 76.107 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Network Non-duplication Protection, Syndicated Exclusivity and Sports Blackout...

  3. 76 FR 63910 - Notice of Availability for Exclusive, Non-Exclusive, or Partially-Exclusive Licensing of an...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-14

    ..., or Partially-Exclusive Licensing of an Invention Concerning a Device and Method for Inducing Brain... Application Serial No. 61/521,446, entitled ``A Device and Method for Inducing Brain Injury in Animal Test... and method for inducing brain injury in animal test subjects through inflicting pressure-wave or...

  4. Testing for effects of climate change on competitive relationships and coexistence between two bird species.

    PubMed

    Stenseth, Nils Chr; Durant, Joël M; Fowler, Mike S; Matthysen, Erik; Adriaensen, Frank; Jonzén, Niclas; Chan, Kung-Sik; Liu, Hai; De Laet, Jenny; Sheldon, Ben C; Visser, Marcel E; Dhondt, André A

    2015-05-22

    Climate change is expected to have profound ecological effects, yet shifts in competitive abilities among species are rarely studied in this context. Blue tits (Cyanistes caeruleus) and great tits (Parus major) compete for food and roosting sites, yet coexist across much of their range. Climate change might thus change the competitive relationships and coexistence between these two species. Analysing four of the highest-quality, long-term datasets available on these species across Europe, we extend the textbook example of coexistence between competing species to include the dynamic effects of long-term climate variation. Using threshold time-series statistical modelling, we demonstrate that long-term climate variation affects species demography through different influences on density-dependent and density-independent processes. The competitive interaction between blue tits and great tits has shifted in one of the studied sites, creating conditions that alter the relative equilibrium densities between the two species, potentially disrupting long-term coexistence. Our analyses show that long-term climate change can, but does not always, generate local differences in the equilibrium conditions of spatially structured species assemblages. We demonstrate how long-term data can be used to better understand whether (and how), for instance, climate change might change the relationships between coexisting species. However, the studied populations are rather robust against competitive exclusion. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  5. Is competition needed for ecological character displacement? Does displacement decrease competition?

    PubMed Central

    Abrams, Peter A.; Cortez, Michael H.

    2015-01-01

    Interspecific competition for resources is generally considered to be the selective force driving ecological character displacement, and displacement is assumed to reduce competition. Skeptics of the prevalence of character displacement often cite lack of evidence of competition. The present article uses a simple model to examine whether competition is needed for character displacement and whether displacement reduces competition. It treats systems with competing resources, and considers cases when only one consumer evolves. It quantifies competition using several different measures. The analysis shows that selection for divergence of consumers occurs regardless of the level of between‐resource competition or whether the indirect interaction between the consumers is competition (−,−), mutualism (+,+), or contramensalism (+,−). Also, divergent evolution always decreases the equilibrium population size of the evolving consumer. Whether divergence of one consumer reduces or increases the impact of a subsequent perturbation of the other consumer depends on the parameters and the method chosen for measuring competition. Divergence in mutualistic interactions may reduce beneficial effects of subsequent increases in the other consumer's population. The evolutionary response is driven by an increase in the relative abundance of the resource the consumer catches more rapidly. Such an increase can occur under several types of interaction. PMID:26548922

  6. Gender and competitive preferences: The role of competition size.

    PubMed

    Hanek, Kathrin J; Garcia, Stephen M; Tor, Avishalom

    2016-08-01

    In a series of 8 studies, we examine whether gender differences in competition entry preferences are moderated by the size of the competition. Drawing on theories of gender roles and stereotypes, we show that women, relative to men, prefer to enter smaller compared with larger competitions. Studies 1a and 1b demonstrate this effect in observational data on preferences for working in differently sized firms and applying to differently sized colleges. Studies 2a and 2b replicate the effect with real behavioral decisions in different domains. We also find empirical evidence that prescriptive gender norms and stereotypes underlie this effect. In Study 3, we find experimental evidence that women and men differ in their preferences for differently sized groups under competition, but not in noncompetitive settings. Three additional experimental studies (Studies 4, 5a, and 5b) show that perceptions of comfort in small versus larger competitions underlie women's preferences. These findings suggest that women's preferences for smaller competitions may be driven by an adherence to prescriptive gender norms. We discuss the implications of the current findings for gender inequalities in organizations. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  7. Memory-Based Multiagent Coevolution Modeling for Robust Moving Object Tracking

    PubMed Central

    Wang, Yanjiang; Qi, Yujuan; Li, Yongping

    2013-01-01

    The three-stage human brain memory model is incorporated into a multiagent coevolutionary process for finding the best match of the appearance of an object, and a memory-based multiagent coevolution algorithm for robust tracking the moving objects is presented in this paper. Each agent can remember, retrieve, or forget the appearance of the object through its own memory system by its own experience. A number of such memory-based agents are randomly distributed nearby the located object region and then mapped onto a 2D lattice-like environment for predicting the new location of the object by their coevolutionary behaviors, such as competition, recombination, and migration. Experimental results show that the proposed method can deal with large appearance changes and heavy occlusions when tracking a moving object. It can locate the correct object after the appearance changed or the occlusion recovered and outperforms the traditional particle filter-based tracking methods. PMID:23843739

  8. 47 CFR 73.132 - Territorial exclusivity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Territorial exclusivity. 73.132 Section 73.132 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.132 Territorial exclusivity. No licensee of an AM broadcast station shall have any...

  9. 47 CFR 73.132 - Territorial exclusivity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Territorial exclusivity. 73.132 Section 73.132 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.132 Territorial exclusivity. No licensee of an AM broadcast station shall have any...

  10. 47 CFR 73.132 - Territorial exclusivity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Territorial exclusivity. 73.132 Section 73.132 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.132 Territorial exclusivity. No licensee of an AM broadcast station shall have any...

  11. 47 CFR 73.132 - Territorial exclusivity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Territorial exclusivity. 73.132 Section 73.132 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.132 Territorial exclusivity. No licensee of an AM broadcast station shall have any...

  12. 47 CFR 73.132 - Territorial exclusivity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Territorial exclusivity. 73.132 Section 73.132 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.132 Territorial exclusivity. No licensee of an AM broadcast station shall have any...

  13. 27 CFR 8.52 - Practices which result in exclusion.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Practices which result in..., DEPARTMENT OF THE TREASURY ALCOHOL EXCLUSIVE OUTLETS Exclusion § 8.52 Practices which result in exclusion. The practices specified in this section result in exclusion under section 105(a) of the Act. The...

  14. 27 CFR 8.52 - Practices which result in exclusion.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Practices which result in..., DEPARTMENT OF THE TREASURY ALCOHOL EXCLUSIVE OUTLETS Exclusion § 8.52 Practices which result in exclusion. The practices specified in this section result in exclusion under section 105(a) of the Act. The...

  15. 27 CFR 8.52 - Practices which result in exclusion.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Practices which result in..., DEPARTMENT OF THE TREASURY LIQUORS EXCLUSIVE OUTLETS Exclusion § 8.52 Practices which result in exclusion. The practices specified in this section result in exclusion under section 105(a) of the Act. The...

  16. 27 CFR 8.52 - Practices which result in exclusion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Practices which result in..., DEPARTMENT OF THE TREASURY LIQUORS EXCLUSIVE OUTLETS Exclusion § 8.52 Practices which result in exclusion. The practices specified in this section result in exclusion under section 105(a) of the Act. The...

  17. 27 CFR 8.52 - Practices which result in exclusion.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Practices which result in..., DEPARTMENT OF THE TREASURY LIQUORS EXCLUSIVE OUTLETS Exclusion § 8.52 Practices which result in exclusion. The practices specified in this section result in exclusion under section 105(a) of the Act. The...

  18. Competitive bidding in Medicare: who benefits from competition?

    PubMed

    Song, Zirui; Landrum, Mary Beth; Chernew, Michael E

    2012-09-01

    To conduct the first empirical study of competitive bidding in Medicare. We analyzed 2006-2010 Medicare Advantage data from the Centers for Medicare and Medicaid Services using longitudinal models adjusted for market and plan characteristics. A $1 increase in Medicare's payment to health maintenance organization (HMO) plans led to a $0.49 (P <.001) increase in plan bids, with $0.34 (P <.001) going to beneficiaries in the form of extra benefits or lower cost sharing. With preferred provider organization and private fee-for-service plans included, higher Medicare payments increased bids less ($0.33 per dollar), suggesting more competition among these latter plans. As a market-based alternative to cost control through administrative pricing, competitive bidding relies on private insurance plans proposing prices they are willing to accept for insuring a beneficiary. However, competition is imperfect in the Medicare bidding market. As much as half of every dollar in increased plan payment went to higher bids rather than to beneficiaries. While having more insurers in a market lowered bids, the design of any bidding system for Medicare should recognize this shortcoming of competition.

  19. Competitive Bidding in Medicare: Who Benefits From Competition?

    PubMed Central

    Song, Zirui; Landrum, Mary Beth; Chernew, Michael E.

    2012-01-01

    Objectives To conduct the first empirical study of competitive bidding in Medicare. Study Design and Methods We analyzed 2006–2010 Medicare Advantage data from the Centers for Medicare & Medicaid Services using longitudinal models adjusted for market and plan characteristics. Results A $1 increase in Medicare's payment to health maintenance organization (HMO) plans led to a $0.49 (P <.001) increase in plan bids, with $0.34 (P <.001) going to beneficiaries in the form of extra benefits or lower cost sharing. With preferred provider organization and private fee-for-service plans included, higher Medicare payments increased bids less ($0.33 per dollar), suggesting more competition among these latter plans. Conclusions As a market-based alternative to cost control through administrative pricing, competitive bidding relies on private insurance plans proposing prices they are willing to accept for insuring a beneficiary. However, competition is imperfect in the Medicare bidding market. As much as half of every dollar in increased plan payment went to higher bids rather than to beneficiaries. While having more insurers in a market lowered bids, the design of any bidding system for Medicare should recognize this shortcoming of competition. PMID:23009305

  20. Competition Underway at NASA 2017 Robotic Mining Competition

    NASA Image and Video Library

    2017-05-24

    NASA’s Eighth Annual Robotic Mining Competition (RMC) began its first of three days of actual competition at Kennedy Space Center in Florida. Forty-five teams of college undergraduate and graduate students – and their uniquely-designed and built mining robots – race against the clock to collect and move the most simulated Martian soil. Students also are judged on how they use their robots to inspire their community about science, technology, engineering and math (STEM). Competition continues through Friday. Managed by, and held annually at Kennedy Space Center, RMC is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in STEM fields by expanding opportunities for student research and design. The project provides a competitive environment to foster innovative ideas and solutions with potential use on NASA’s deep space exploration missions, including to Mars.

  1. Is competition needed for ecological character displacement? Does displacement decrease competition?

    PubMed

    Abrams, Peter A; Cortez, Michael H

    2015-12-01

    Interspecific competition for resources is generally considered to be the selective force driving ecological character displacement, and displacement is assumed to reduce competition. Skeptics of the prevalence of character displacement often cite lack of evidence of competition. The present article uses a simple model to examine whether competition is needed for character displacement and whether displacement reduces competition. It treats systems with competing resources, and considers cases when only one consumer evolves. It quantifies competition using several different measures. The analysis shows that selection for divergence of consumers occurs regardless of the level of between-resource competition or whether the indirect interaction between the consumers is competition (-,-), mutualism (+,+), or contramensalism (+,-). Also, divergent evolution always decreases the equilibrium population size of the evolving consumer. Whether divergence of one consumer reduces or increases the impact of a subsequent perturbation of the other consumer depends on the parameters and the method chosen for measuring competition. Divergence in mutualistic interactions may reduce beneficial effects of subsequent increases in the other consumer's population. The evolutionary response is driven by an increase in the relative abundance of the resource the consumer catches more rapidly. Such an increase can occur under several types of interaction. © 2015 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

  2. 27 CFR 8.53 - Practice not resulting in exclusion.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Practice not resulting in..., DEPARTMENT OF THE TREASURY ALCOHOL EXCLUSIVE OUTLETS Exclusion § 8.53 Practice not resulting in exclusion. The practice specified in this section is deemed not to result in exclusion under section 105(a) of...

  3. 27 CFR 8.53 - Practice not resulting in exclusion.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Practice not resulting in..., DEPARTMENT OF THE TREASURY LIQUORS EXCLUSIVE OUTLETS Exclusion § 8.53 Practice not resulting in exclusion. The practice specified in this section is deemed not to result in exclusion under section 105(a) of...

  4. 27 CFR 8.53 - Practice not resulting in exclusion.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Practice not resulting in..., DEPARTMENT OF THE TREASURY LIQUORS EXCLUSIVE OUTLETS Exclusion § 8.53 Practice not resulting in exclusion. The practice specified in this section is deemed not to result in exclusion under section 105(a) of...

  5. 27 CFR 8.53 - Practice not resulting in exclusion.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Practice not resulting in..., DEPARTMENT OF THE TREASURY ALCOHOL EXCLUSIVE OUTLETS Exclusion § 8.53 Practice not resulting in exclusion. The practice specified in this section is deemed not to result in exclusion under section 105(a) of...

  6. 27 CFR 8.53 - Practice not resulting in exclusion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Practice not resulting in..., DEPARTMENT OF THE TREASURY LIQUORS EXCLUSIVE OUTLETS Exclusion § 8.53 Practice not resulting in exclusion. The practice specified in this section is deemed not to result in exclusion under section 105(a) of...

  7. 7 CFR 205.671 - Exclusion from organic sale.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Exclusion from organic sale. 205.671 Section 205.671... PROVISIONS NATIONAL ORGANIC PROGRAM Administrative Inspection and Testing, Reporting, and Exclusion from Sale § 205.671 Exclusion from organic sale. When residue testing detects prohibited substances at levels that...

  8. 46 CFR 16.109 - Public Interest Exclusion (PIE).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Public Interest Exclusion (PIE). 16.109 Section 16.109 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN CHEMICAL TESTING General § 16.109 Public Interest Exclusion (PIE). Service agents are subject to Public Interest Exclusion...

  9. 20 CFR 416.1218 - Exclusion of the automobile.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Exclusion of the automobile. 416.1218 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1218 Exclusion of the automobile. (a) Automobile; defined. As used in this section, the term automobile includes, in addition to passenger cars, other...

  10. 20 CFR 416.1218 - Exclusion of the automobile.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Exclusion of the automobile. 416.1218 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1218 Exclusion of the automobile. (a) Automobile; defined. As used in this section, the term automobile includes, in addition to passenger cars, other...

  11. 20 CFR 416.1218 - Exclusion of the automobile.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Exclusion of the automobile. 416.1218 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1218 Exclusion of the automobile. (a) Automobile; defined. As used in this section, the term automobile includes, in addition to passenger cars, other...

  12. 20 CFR 416.1218 - Exclusion of the automobile.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Exclusion of the automobile. 416.1218 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1218 Exclusion of the automobile. (a) Automobile; defined. As used in this section, the term automobile includes, in addition to passenger cars, other...

  13. 20 CFR 416.1218 - Exclusion of the automobile.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Exclusion of the automobile. 416.1218 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1218 Exclusion of the automobile. (a) Automobile; defined. As used in this section, the term automobile includes, in addition to passenger cars, other...

  14. Species interactions and response time to climate change: ice-cover and terrestrial run-off shaping Arctic char and brown trout competitive asymmetries

    NASA Astrophysics Data System (ADS)

    Finstad, A. G.; Palm Helland, I.; Jonsson, B.; Forseth, T.; Foldvik, A.; Hessen, D. O.; Hendrichsen, D. K.; Berg, O. K.; Ulvan, E.; Ugedal, O.

    2011-12-01

    There has been a growing recognition that single species responses to climate change often mainly are driven by interaction with other organisms and single species studies therefore not are sufficient to recognize and project ecological climate change impacts. Here, we study how performance, relative abundance and the distribution of two common Arctic and sub-Arctic freshwater fishes (brown trout and Arctic char) are driven by competitive interactions. The interactions are modified both by direct climatic effects on temperature and ice-cover, and indirectly through climate forcing of terrestrial vegetation pattern and associated carbon and nutrient run-off. We first use laboratory studies to show that Arctic char, which is the world's most northernmost distributed freshwater fish, outperform trout under low light levels and also have comparable higher growth efficiency. Corresponding to this, a combination of time series and time-for-space analyses show that ice-cover duration and carbon and nutrient load mediated by catchment vegetation properties strongly affected the outcome of the competition and likely drive the species distribution pattern through competitive exclusion. In brief, while shorter ice-cover period and decreased carbon load favored brown trout, increased ice-cover period and increased carbon load favored Arctic char. Length of ice-covered period and export of allochthonous material from catchments are major, but contrasting, climatic drivers of competitive interaction between these two freshwater lake top-predators. While projected climate change lead to decreased ice-cover, corresponding increase in forest and shrub cover amplify carbon and nutrient run-off. Although a likely outcome of future Arctic and sub-arctic climate scenarios are retractions of the Arctic char distribution area caused by competitive exclusion, the main drivers will act on different time scales. While ice-cover will change instantaneously with increasing temperature

  15. Long-term competitive dynamics of two cryptic rotifer species: diapause and fluctuating conditions.

    PubMed

    Gabaldón, Carmen; Carmona, María José; Montero-Pau, Javier; Serra, Manuel

    2015-01-01

    Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However, the species differ in life-history traits involving sexual reproduction and diapause, and respond differently to salinity and temperature. As in the case of certain other species that are extremely similar in morphology, a fluctuating environment are considered to be important for their coexistence. We studied the long-term competitive dynamics of B. plicatilis and B. manjavacas under different salinity regimes (constant and fluctuating). Moreover, we focused on the dynamics of the diapausing egg bank to explore how the outcome of the entire life cycle of these rotifers can work to mediate stable coexistence. We demonstrated that these species do not coexist under constant-salinity environment, as the outcome of competition is affected by the level of salinity-at low salinity, B. plicatilis excluded B. manjavacas, and the opposite outcome occurred at high salinity. Competitive dynamics under fluctuating salinity showed that the dominance of one species over the other also tended to fluctuate. The duration of co-occurrence of these species was favoured by salinity fluctuation and perhaps by the existence of a diapausing egg bank. Stable coexistence was not found in our system, which suggests that other factors or other salinity fluctuation patterns might act as stabilizing

  16. Long-Term Competitive Dynamics of Two Cryptic Rotifer Species: Diapause and Fluctuating Conditions

    PubMed Central

    Gabaldón, Carmen; Carmona, María José; Montero-Pau, Javier; Serra, Manuel

    2015-01-01

    Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However, the species differ in life-history traits involving sexual reproduction and diapause, and respond differently to salinity and temperature. As in the case of certain other species that are extremely similar in morphology, a fluctuating environment are considered to be important for their coexistence. We studied the long-term competitive dynamics of B. plicatilis and B. manjavacas under different salinity regimes (constant and fluctuating). Moreover, we focused on the dynamics of the diapausing egg bank to explore how the outcome of the entire life cycle of these rotifers can work to mediate stable coexistence. We demonstrated that these species do not coexist under constant-salinity environment, as the outcome of competition is affected by the level of salinity—at low salinity, B. plicatilis excluded B. manjavacas, and the opposite outcome occurred at high salinity. Competitive dynamics under fluctuating salinity showed that the dominance of one species over the other also tended to fluctuate. The duration of co-occurrence of these species was favoured by salinity fluctuation and perhaps by the existence of a diapausing egg bank. Stable coexistence was not found in our system, which suggests that other factors or other salinity fluctuation patterns might act as stabilizing

  17. Climate-driven Sympatry does not Lead to Foraging Competition Between Adélie and Gentoo Penguins

    NASA Astrophysics Data System (ADS)

    Cimino, M. A.; Moline, M. A.; Fraser, W.; Patterson-Fraser, D.; Oliver, M. J.

    2016-02-01

    Climate-driven sympatry may lead to competition for food resources between species, population shifts and changes in ecosystem structure. Rapid warming in the West Antarctic Peninsula (WAP) is coincident with increasing gentoo penguin and decreasing Adélie penguin populations, suggesting that competition for food may exacerbate the Adélie penguin decline. At Palmer Station, we tested for foraging competition between these species by comparing their prey, Antarctic krill, distributions and penguin foraging behaviors on fine scales. To study these predator-prey dynamics, we simultaneously deployed penguin satellite transmitters, and a REMUS autonomous underwater vehicle that acoustically detected krill aggregations and measured physical and biological properties of the water column. We detected krill aggregations within the horizontal and vertical foraging ranges of Adélie and gentoo penguin. In the upper 100 m of the water column, the distribution of krill aggregations were mainly associated with CHL and light, suggesting that krill selected for habitats that balance the need to consume food and avoid predation. Adélie and gentoo penguins mainly had spatially segregated foraging areas but in areas of overlap, gentoo penguins switched foraging behavior by foraging at deeper depths, a strategy which limits competition with Adélie penguins. This suggests that climate-driven sympatry does not necessarily result in competitive exclusion. Contrary to a recent theory, which suggests that increased competition for krill is the major driver of Adélie penguin population declines, we suggest that declines in Adélie penguins along the WAP are more likely due to direct and indirect climate impacts on their life histories.

  18. 20 CFR 416.1230 - Exclusion of life insurance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Exclusion of life insurance. 416.1230 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1230 Exclusion of life insurance. (a) General. In determining the resources of an individual (and spouse, if any), life insurance owned by the individual (and...

  19. 20 CFR 416.1230 - Exclusion of life insurance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Exclusion of life insurance. 416.1230 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1230 Exclusion of life insurance. (a) General. In determining the resources of an individual (and spouse, if any), life insurance owned by the individual (and...

  20. 20 CFR 416.1230 - Exclusion of life insurance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Exclusion of life insurance. 416.1230 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1230 Exclusion of life insurance. (a) General. In determining the resources of an individual (and spouse, if any), life insurance owned by the individual (and...

  1. 20 CFR 416.1230 - Exclusion of life insurance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Exclusion of life insurance. 416.1230 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1230 Exclusion of life insurance. (a) General. In determining the resources of an individual (and spouse, if any), life insurance owned by the individual (and...

  2. 20 CFR 416.1230 - Exclusion of life insurance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Exclusion of life insurance. 416.1230 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1230 Exclusion of life insurance. (a) General. In determining the resources of an individual (and spouse, if any), life insurance owned by the individual (and...

  3. Lunar Regolith Excavation Competition

    NASA Technical Reports Server (NTRS)

    Liles, Cassandra

    2009-01-01

    The Lunar Regolith Excavation Competition is a new competition that needs graphics, logos, rules, as well as an arena. Although this is the first year of the competition, the competition is modeled after an existing competition, the Centennial Lunar Excavator Challenge. This competition however is aimed at college students. This makes the challenge identifying key aspects of the original competition and modeling them to fit into an easier task, and creating exciting advertisement that helps encourage participation. By using a youth focus group, young insight, as well as guiding advice from experts in the field, hopefully an arena can be designed and built, rules can be molded and created to fit, and alluring graphics can be printed to bring about a successful first year of the Lunar Regolith Excavation Competition.

  4. EDITORIAL: Physics competitions Physics competitions

    NASA Astrophysics Data System (ADS)

    Jordens, H.; Mathelitsch, L.

    2011-07-01

    International tests on competences, such as TIMSS or PISA, and knowledge of young students have revealed low average scores in many countries, often unexpectedly. One effective measure to increase the average standard of a population is to bring the last third of the group to a higher level. Therefore, many nations put some effort into this activity. This brings the danger that not enough attention is paid to students at the other end, those who are talented. Indeed, it is a very difficult task for a teacher to support the less able and at the same time challenge the gifted students, to lead them to the limits of their abilities and provide for a smooth transition to university study. Physics competitions have been proven to fulfil these last demands to a large degree, and therefore are an important additional and, to some extent, complementary tool for the promotion of talented students. This third special section on physics competitions in European Journal of Physics contains three papers, each dealing with a different form of science contest. The first continues the series of presentations of tasks performed at the International Young Physicists' Tournament, which was held in Vienna in 2011. First place went to the team from Singapore, and they have put their investigation on vertical oscillations of coupled magnets into written form (not required by the tournament, where an oral presentation and a defence and discussion are the central aspects). Their paper shows how rich in physics this problem is, and what level of solutions high-school students can already achieve. Sadly, those responsible for the organization of last year's International Physics Olympiad did not provide us with a report on this competition. This is unfortunate, since the Olympiad in Zagreb was very successful and, in particular, the experimental tasks were creative and demanding. Very similar to the aims and the execution of the Physics Olympiad is the International Olympiad on Astronomy

  5. Justice Experiences and Feelings of Exclusion

    ERIC Educational Resources Information Center

    Umlauft, Sören; Dalbert, Claudia

    2017-01-01

    To explain feelings of social exclusion, sociological factors, such as occupation, income and education, come to mind. Feelings of social exclusion, however, may be the result of psychological processes and in particular of (in)justice experiences. Based on just-world research, we hypothesized that (1) the more young people feel treated justly by…

  6. Exploring an Age Difference in Preschool Children's Competitiveness Following a Competition.

    PubMed

    Hu, Yu; Zhu, Yi

    2018-01-01

    Literature suggests that resource acquisition compels competition in young children. However, little is still known about the development of preschool children's competitiveness. In this preliminary study, 166 children (aged 2-4 and 5-6 years) engaged in a dyadic competition which resulted in a winning and a losing group (in a control/non-competition group, participants engaged in a similar task which did not lead to winning/losing outcome), and then experimenters tracked their decisions to compete again with a rival (i.e., an individual they interacted in the previous competition task) and a non-rival competitor (i.e., an anonymous classmate they did not interact in the previous competition task) for a reward, respectively. As expected, results showed an age-related decreasing trend in the percentage of choices to compete with a competitor. However, this age difference was only significant in the control group when participants played with the partner with whom they interacted in the previous game and in the losing group when participants competed with a non-rival competitor. This study contributes to our knowledge of how competitiveness develop in preschool childhood, and calls for further research on the roles of motivation and cognitive control in children's competitiveness.

  7. AUSTRALIAN COMPETITION AND CONSUMER COMMISSION v PFIZER: EVERGREENING AND MARKET POWER AS A BLOCKBUSTER DRUG GOES OFF PATENT.

    PubMed

    Faunce, Thomas

    2015-06-01

    In Australian Competition and Consumer Commission v Pfizer Australia Pty Ltd [2015] FCA 113, the ACCC alleged that Pfizer's "Project LEAP" involved a scheme to lock pharmacists into substituting its generic version of the high sales volume anti-cholesterol drug, patent-expired atorvastatin (Lipitor), which took advantage of a substantial degree of market power for a purpose proscribed by s 46(1)(c) of the Competition and Consumer Act 2010 (Cth). The ACCC also claimed that Pfizer's actions constituted a course of exclusive dealing pursuant to s 47(1)(d) and (e) for the proscribed purpose of lessening competition. Flick J in the Federal Court of Australia, in a judgment heavy with quotations but sparse in reasoning, dismissed the ACCC's Amended Originating Application alleging abuse of market power and ordered the ACCC to pay Pfizer's costs. The ACCC has now appealed the decision. This column explores this case in the context of Pfizer's broader strategies to preserve its income globally from this high sales volume drug in the period following its patent expiration.

  8. The Curious Case of the Camelthorn: Competition, Coexistence, and Nest-Site Limitation in a Multispecies Mutualism.

    PubMed

    Campbell, Heather; Fellowes, Mark D E; Cook, James M

    2015-12-01

    Myrmecophyte plants house ants within domatia in exchange for protection against herbivores. Ant-myrmecophyte mutualisms exhibit two general patterns due to competition between ants for plant occupancy: (i) domatia nest sites are a limiting resource and (ii) each individual plant hosts one ant species at a time. However, individual camelthorn trees (Vachellia erioloba) typically host two to four ant species simultaneously, often coexisting in adjacent domatia on the same branch. Such fine-grain spatial coexistence brings into question the conventional wisdom on ant-myrmecophyte mutualisms. Camelthorn ants appear not to be nest-site limited, despite low abundance of suitable domatia, and have random distributions of nest sites within and across trees. These patterns suggest a lack of competition between ants for domatia and contrast strongly with other ant-myrmecophyte systems. Comparison of this unusual case with others suggests that spatial scale is crucial to coexistence or competitive exclusion involving multiple ant species. Furthermore, coexistence may be facilitated when co-occurring ant species diverge strongly on at least one niche axis. Our conclusions provide recommendations for future ant-myrmecophyte research, particularly in utilizing multispecies systems to further our understanding of mutualism biology.

  9. 20 CFR 416.1234 - Exclusion of Indian lands.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Exclusion of Indian lands. 416.1234 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1234 Exclusion of Indian lands. In determining the resources of an individual (and spouse, if any) who is of Indian descent from a federally recognized Indian...

  10. 20 CFR 416.1234 - Exclusion of Indian lands.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Exclusion of Indian lands. 416.1234 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1234 Exclusion of Indian lands. In determining the resources of an individual (and spouse, if any) who is of Indian descent from a federally recognized Indian...

  11. 20 CFR 416.1234 - Exclusion of Indian lands.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Exclusion of Indian lands. 416.1234 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1234 Exclusion of Indian lands. In determining the resources of an individual (and spouse, if any) who is of Indian descent from a federally recognized Indian...

  12. 20 CFR 416.1234 - Exclusion of Indian lands.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Exclusion of Indian lands. 416.1234 Section..., BLIND, AND DISABLED Resources and Exclusions § 416.1234 Exclusion of Indian lands. In determining the resources of an individual (and spouse, if any) who is of Indian descent from a federally recognized Indian...

  13. Outcomes of Hip Arthroscopy in Competitive Athletes.

    PubMed

    Perets, Itay; Hartigan, David E; Chaharbakhshi, Edwin O; Ashberg, Lyall; Ortiz-Declet, Victor; Domb, Benjamin G

    2017-08-01

    To evaluate the minimum 2-year postoperative clinical outcomes and the rate of return to sports in athletes who underwent capsular plication for the treatment of ligamentous laxity and/or borderline dysplasia during hip arthroscopy for the treatment of femoroacetabular impingement and labral pathology. Since 2008, data were prospectively collected on patients who underwent hip arthroscopy for the treatment of femoroacetabular impingement and/or labral tears. Inclusion criteria were as follows: athlete at the high school, collegiate, or professional levels preoperatively, underwent capsular plication, and preoperatively recorded patient-reported outcome scores including modified Harris hip score (mHHS), nonarthritic athletic hip score (NAHS), hip outcome score-sports-specific subscale (HOS-SSS), and visual analog scale (VAS). Exclusion criteria were as follows: <16 years old, preoperative Tönnis grade >1, and previous hip conditions. Sports activity and competitive levels were collected at a minimum of 2 years postoperatively. Fifty-one hips (49 patients) met the inclusion criteria, and 41 hips (39 patients) had minimum 2-year follow-up (80.4% follow-up). Mean mHHS increased from 67.1 preoperatively to 83.5 (P < .0001). Mean NAHS increased from 66.8 to 88.8 (P < .0001). Mean HOS-SSS improved from 46.8 to 80.1 (P < .0001). Mean VAS decreased from 5.1 to 1.7 (P < .0001). Thirty-five (85.4%) hip arthroscopies allowed the patients to return to sports at follow-up. Thirty-four (82.9%) hip arthroscopies allowed the patients to maintain their competitive physical abilities at follow-up. Patient-reported outcomes and VAS in athletes significantly improved at a minimum of 2 years after capsular plication as a part of hip arthroscopy addressing varying pathologies. In addition, most patients returned to sports at similar or higher competitive levels. These results suggest that capsular plication is a favorable treatment option in athletes with ligamentous laxity and

  14. 20 CFR 416.1212 - Exclusion of the home.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Exclusion of the home. 416.1212 Section 416..., BLIND, AND DISABLED Resources and Exclusions § 416.1212 Exclusion of the home. (a) Defined. A home is... individual resides, the land on which the shelter is located and related outbuildings. (b) Home not counted...

  15. 20 CFR 416.1212 - Exclusion of the home.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Exclusion of the home. 416.1212 Section 416..., BLIND, AND DISABLED Resources and Exclusions § 416.1212 Exclusion of the home. (a) Defined. A home is... individual resides, the land on which the shelter is located and related outbuildings. (b) Home not counted...

  16. 20 CFR 416.1212 - Exclusion of the home.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Exclusion of the home. 416.1212 Section 416..., BLIND, AND DISABLED Resources and Exclusions § 416.1212 Exclusion of the home. (a) Defined. A home is... individual resides, the land on which the shelter is located and related outbuildings. (b) Home not counted...

  17. 20 CFR 416.1212 - Exclusion of the home.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Exclusion of the home. 416.1212 Section 416..., BLIND, AND DISABLED Resources and Exclusions § 416.1212 Exclusion of the home. (a) Defined. A home is... individual resides, the land on which the shelter is located and related outbuildings. (b) Home not counted...

  18. 20 CFR 416.1212 - Exclusion of the home.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Exclusion of the home. 416.1212 Section 416..., BLIND, AND DISABLED Resources and Exclusions § 416.1212 Exclusion of the home. (a) Defined. A home is... individual resides, the land on which the shelter is located and related outbuildings. (b) Home not counted...

  19. Novel weapons and invasion: biogeographic differences in the competitive effects of Centaurea maculosa and its root exudate (+/-)-catechin.

    PubMed

    He, Wei-Ming; Feng, Yulong; Ridenour, Wendy M; Thelen, Giles C; Pollock, Jarrod L; Diaconu, Alecu; Callaway, Ragan M

    2009-04-01

    Recent studies suggest that the invasive success of Centaurea maculosa may be related to its stronger allelopathic effects on native North American species than on related European species, one component of the "novel weapons" hypothesis. Other research indicates that C. maculosa plants from the invasive range in North America have evolved to be larger and better competitors than conspecifics from the native range in Europe, a component of the "evolution of increased competitive ability" hypothesis. These hypotheses are not mutually exclusive, but this evidence sets the stage for comparing the relative importance of evolved competitive ability to inherent competitive traits. In a competition experiment with a large number of C. maculosa populations, we found no difference in the competitive effects of C. maculosa plants from North America and Europe on other species. However, both North American and European C. maculosa were much better competitors against plants native to North America than congeners native to Romania, collected in areas where C. maculosa is also native. These results are consistent with the novel weapons hypothesis. But, in a second experiment using just one population from North America and Europe, and where North American and European species were collected from a broader range of sites, competitive interactions were weaker overall, and the competitive effects of C. maculosa were slightly stronger against European species than against North American species. Also consistent with the novel weapons hypothesis, (+/-)-catechin had stronger effects on native North American species than on native European species in two experiments. Our results suggest that the regional composition of the plant communities being invaded by C. maculosa may be more important for invasive success than the evolution of increased size and competitive ability.

  20. "Wanna Race?": Primary Student Preference for Competitive or Non-Competitive Singing Games

    ERIC Educational Resources Information Center

    Roberts, J. Christopher

    2016-01-01

    This study compared primary student preference for competitive and non-competitive singing games. Students in three intact classes of second graders (n = 65) and three classes of fourth graders (n = 67) at one school in the USA served as subjects. After playing a pair of games, one competitive and one non-competitive, over the course of five…

  1. Diversifying evolution of competitiveness.

    PubMed

    Baldauf, Sebastian A; Engqvist, Leif; Weissing, Franz J

    2014-10-29

    In many species, individuals express phenotypic characteristics that enhance their competitiveness, that is, the ability to acquire resources in competition with others. Moreover, the degree of competitiveness varies considerably across individuals and in time. By means of an evolutionary model, we provide an explanation for this finding. We make the assumption that investment into competitiveness enhances the probability to acquire a high-quality resource, but at the same time reduces the ability of exploiting acquired resources with maximal efficiency. The model reveals that under a broad range of conditions competitiveness either converges to a polymorphic state, where individuals differing in competitive ability stably coexist, or is subject to perpetual transitions between periods of high and low competitiveness. The dynamics becomes even more complex if females can evolve preferences for (or against) competitive males. In extreme cases, such preferences can even drive the population to extinction.

  2. Amino acid positions subject to multiple coevolutionary constraints can be robustly identified by their eigenvector network centrality scores.

    PubMed

    Parente, Daniel J; Ray, J Christian J; Swint-Kruse, Liskin

    2015-12-01

    As proteins evolve, amino acid positions key to protein structure or function are subject to mutational constraints. These positions can be detected by analyzing sequence families for amino acid conservation or for coevolution between pairs of positions. Coevolutionary scores are usually rank-ordered and thresholded to reveal the top pairwise scores, but they also can be treated as weighted networks. Here, we used network analyses to bypass a major complication of coevolution studies: For a given sequence alignment, alternative algorithms usually identify different, top pairwise scores. We reconciled results from five commonly-used, mathematically divergent algorithms (ELSC, McBASC, OMES, SCA, and ZNMI), using the LacI/GalR and 1,6-bisphosphate aldolase protein families as models. Calculations used unthresholded coevolution scores from which column-specific properties such as sequence entropy and random noise were subtracted; "central" positions were identified by calculating various network centrality scores. When compared among algorithms, network centrality methods, particularly eigenvector centrality, showed markedly better agreement than comparisons of the top pairwise scores. Positions with large centrality scores occurred at key structural locations and/or were functionally sensitive to mutations. Further, the top central positions often differed from those with top pairwise coevolution scores: instead of a few strong scores, central positions often had multiple, moderate scores. We conclude that eigenvector centrality calculations reveal a robust evolutionary pattern of constraints-detectable by divergent algorithms--that occur at key protein locations. Finally, we discuss the fact that multiple patterns coexist in evolutionary data that, together, give rise to emergent protein functions. © 2015 Wiley Periodicals, Inc.

  3. Robotics Competitions: An Overview of First© Events and VEX© Competitions

    ERIC Educational Resources Information Center

    Habib, Maria A.

    2012-01-01

    Robotics competitions generate excitement and raise the profile of a robotics program. This article provides an overview of robotics competitions, concentrating on those sponsored by FIRST (For Inspiration and Recognition of Science and Technology) and RECF (Robotics Education and Competition Foundation). FIRST® LEGO® League and VEX® robotics…

  4. [Atopic dermatitis and prolonged exclusive breast-feeding].

    PubMed

    Amri, M; Elhani, I; Doussari, S; Amir, A

    2012-04-01

    We sought to compare the prevalence of exclusive breastfeeding throughout at least the first 6 months of life in patients presenting atopic dermatitis (AD) with a control group, and to check for a correlation between the duration of exclusive breastfeeding and the severity of AD. We conducted a case-control study with prospective inclusion over a period of 3 years. The study group consisted of 114 patients aged less than 15 years, from an urban area, presenting AD but with no personal or family history of atopy. Each patient was compared with two controls from the same town, matched for age and gender, with no personal or family history of atopy, and free of AD. Data analysis was performed using the SPSS software package, version 15.0. A P-value of less than 0.05 was considered as statistically significant. The prevalence of exclusive breastfeeding for at least the first 6 months of life in the patient group was significantly lower than in the control group (P=0.0413). On the other hand, AD was significantly less severe in patients exclusively breastfed for longer than 9 months (P=0.0079). The correlations recorded in our study do not allow us to draw any definite conclusions about a protective effect of exclusive breastfeeding with regard to AD. However, other benefits of extended exclusive breastfeeding justify supporting breastfeeding in a community with an existing sociocultural predisposition for this feeding method. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  5. Model of reversible vesicular transport with exclusion

    NASA Astrophysics Data System (ADS)

    Bressloff, Paul C.; Karamched, Bhargav R.

    2016-08-01

    A major question in neurobiology concerns the mechanics behind the motor-driven transport and delivery of vesicles to synaptic targets along the axon of a neuron. Experimental evidence suggests that the distribution of vesicles along the axon is relatively uniform and that vesicular delivery to synapses is reversible. A recent modeling study has made explicit the crucial role that reversibility in vesicular delivery to synapses plays in achieving uniformity in vesicle distribution, so called synaptic democracy (Bressloff et al 2015 Phys. Rev. Lett. 114 168101). In this paper we generalize the previous model by accounting for exclusion effects (hard-core repulsion) that may occur between molecular motor-cargo complexes (particles) moving along the same microtubule track. The resulting model takes the form of an exclusion process with four internal states, which distinguish between motile and stationary particles, and whether or not a particle is carrying vesicles. By applying a mean field approximation and an adiabatic approximation we reduce the system of ODEs describing the evolution of occupation numbers of the sites on a 1D lattice to a system of hydrodynamic equations in the continuum limit. We find that reversibility in vesicular delivery allows for synaptic democracy even in the presence of exclusion effects, although exclusion does exacerbate nonuniform distributions of vesicles in an axon when compared with a model without exclusion. We also uncover the relationship between our model and other models of exclusion processes with internal states.

  6. The Four Faces of Competition: The Development of the Multidimensional Competitive Orientation Inventory

    PubMed Central

    Orosz, Gábor; Tóth-Király, István; Büki, Noémi; Ivaskevics, Krisztián; Bőthe, Beáta; Fülöp, Márta

    2018-01-01

    To date, no short scale exists with established factor structure that can assess individual differences in competition. The aim of the present study was to uncover and operationalize the facets of competitive orientations with theoretical underpinning and strong psychometric properties. A total of 2676 respondents were recruited for four studies. The items were constructed based on qualitative research in different cultural contexts. A combined method of exploratory structural equation modeling (ESEM) and confirmatory factor analysis (CFA) was employed. ESEM resulted in a four-factor structure of the competitive orientations and this structure was supported by a series of CFAs on different comprehensive samples. The Multidimensional Competitive Orientation Inventory (MCOI) included 12 items and four factors: hypercompetitive orientation, self-developmental competitive orientation, anxiety-driven competition avoidance, and lack of interest toward competition. Strong gender invariance was established. The four facets of competition have differentiated relationship patterns with adaptive and maladaptive personality and motivational constructs. The MCOI can assess the adaptive and maladaptive facets of competitive orientations with a short, reliable, valid and theoretically underlined multidimensional measure. PMID:29872415

  7. Definition of Exclusion Zones Using Seismic Data

    NASA Astrophysics Data System (ADS)

    Bartal, Y.; Villagran, M.; Ben Horin, Y.; Leonard, G.; Joswig, M.

    - In verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT), there is a motivation to be effective, efficient and economical and to prevent abuse of the right to conduct an On-site Inspection (OSI) in the territory of a challenged State Party. In particular, it is in the interest of a State Party to avoid irrelevant search in specific areas. In this study we propose several techniques to determine `exclusion zones', which are defined as areas where an event could not have possibly occurred. All techniques are based on simple ideas of arrival time differences between seismic stations and thus are less prone to modeling errors compared to standard event location methods. The techniques proposed are: angular sector exclusion based on a tripartite micro array, half-space exclusion based on a station pair, and closed area exclusion based on circumferential networks.

  8. Using Classroom Competitions to Prepare Students for the Competitive Business World

    ERIC Educational Resources Information Center

    Gibson, Fay Y.; Kincade, Doris H.; Frasier, Pamela Y.

    2013-01-01

    This paper describes how a university, collaborating with industry, integrated research with active learning (e.g., collaboration in teams and competitions) for fashion majors. The redesigned introductory course uses two strategies: team competitions and a genius bar to guide students, give ongoing feedback, and judge final competitions. Active…

  9. Salt exclusion in silane-laced epoxy coatings.

    PubMed

    Wang, Peng; Schaefer, Dale W

    2010-01-05

    The corrosion protection mechanism of a one-step silane-laced epoxy coating system was investigated using neutron reflectivity. Pure epoxy and silane-laced epoxy films were examined at equilibrium with saturated NaCl water solution. The results demonstrate that the addition of silane introduces a salt-exclusion effect to epoxy coating. Specifically, the addition of silane densifies the epoxy network, which leads to exclusion of hydrated salt ions by a size effect. The effect is particularly significant at the metal-coating interface. Exclusion of ions improves the corrosion resistance, particularly for metals susceptible to pitting.

  10. Mechanisms linking affective reactions to competition-related and competition-extraneous concerns in male martial artists

    PubMed Central

    Cerin, E; Barnett, A

    2011-01-01

    The main aim of this study was to examine affective linkages between competition-related and competition-extraneous concern domains. A secondary purpose was to establish the contributions of pre-competition affects to post-competition performance appraisals, independent of pre-competition performance expectations. Thirty-nine highly skilled male martial artists were assessed at five random times a day for a week and 1 h before a major competition on affective states and sources of concern. They also reported their performance expectations and post-competition performance appraisals. Affective states triggered by competition-related and competition-extraneous concerns persisted in time. Carry-over effects were stronger after reports of competition-related concerns, emphasizing the subjective importance of the competitive event. Although positive (enjoyment and surprise) and negative (sadness and guilt) affective spill-over was observed from competition-extraneous to competition-related concerns, the reverse held true only for disgust. These findings may be due to the athletes' ability to regulate affective reactions within a sporting setting, in particular. Spill-over from competition-extraneous to competition-related concerns is indicative of a lesser degree of control over work/study and family life. Given that average weekly negative affects and anger/disgust were independent predictors of post-competition performance appraisals, the phenomenon of spill-over and other affective linkage mechanisms in sport warrant further investigation. PMID:21917020

  11. How similar can co-occurring species be in the presence of competition and ecological drift?

    PubMed

    Capitán, José A; Cuenda, Sara; Alonso, David

    2015-09-06

    If two species live on a single resource, the one with a slight advantage will out-compete the other: complete competitors cannot coexist. This is known as the competitive exclusion principle. If no extinction occurs, it is because evolutionary adaptation to slightly different niches takes place. Therefore, it is widely accepted that ecological communities are assembled by evolutionary differentiation and progressive adaptation of species to different niches. However, some ecologists have recently challenged this classic paradigm highlighting the importance of chance and stochasticity. Using a synthetic framework for community dynamics, here we show that, while deterministic descriptors predict coexistence, species similarity is limited in a more restrictive way in the presence of stochasticity. We analyse the stochastic extinction phenomenon, showing that extinction occurs as competitive overlap increases above a certain threshold well below its deterministic counterpart. We also prove that the extinction threshold cannot be ascribed only to demographic fluctuations around small population sizes. The more restrictive limit to species similarity is, therefore, a consequence of the complex interplay between competitive interactions and ecological drift. As a practical implication, we show that the existence of a stochastic limit to similarity has important consequences in the recovery of fragmented habitats. © 2015 The Author(s).

  12. How similar can co-occurring species be in the presence of competition and ecological drift?

    PubMed Central

    Capitán, José A.; Cuenda, Sara; Alonso, David

    2015-01-01

    If two species live on a single resource, the one with a slight advantage will out-compete the other: complete competitors cannot coexist. This is known as the competitive exclusion principle. If no extinction occurs, it is because evolutionary adaptation to slightly different niches takes place. Therefore, it is widely accepted that ecological communities are assembled by evolutionary differentiation and progressive adaptation of species to different niches. However, some ecologists have recently challenged this classic paradigm highlighting the importance of chance and stochasticity. Using a synthetic framework for community dynamics, here we show that, while deterministic descriptors predict coexistence, species similarity is limited in a more restrictive way in the presence of stochasticity. We analyse the stochastic extinction phenomenon, showing that extinction occurs as competitive overlap increases above a certain threshold well below its deterministic counterpart. We also prove that the extinction threshold cannot be ascribed only to demographic fluctuations around small population sizes. The more restrictive limit to species similarity is, therefore, a consequence of the complex interplay between competitive interactions and ecological drift. As a practical implication, we show that the existence of a stochastic limit to similarity has important consequences in the recovery of fragmented habitats. PMID:26269234

  13. Approximate kernel competitive learning.

    PubMed

    Wu, Jian-Sheng; Zheng, Wei-Shi; Lai, Jian-Huang

    2015-03-01

    Kernel competitive learning has been successfully used to achieve robust clustering. However, kernel competitive learning (KCL) is not scalable for large scale data processing, because (1) it has to calculate and store the full kernel matrix that is too large to be calculated and kept in the memory and (2) it cannot be computed in parallel. In this paper we develop a framework of approximate kernel competitive learning for processing large scale dataset. The proposed framework consists of two parts. First, it derives an approximate kernel competitive learning (AKCL), which learns kernel competitive learning in a subspace via sampling. We provide solid theoretical analysis on why the proposed approximation modelling would work for kernel competitive learning, and furthermore, we show that the computational complexity of AKCL is largely reduced. Second, we propose a pseudo-parallelled approximate kernel competitive learning (PAKCL) based on a set-based kernel competitive learning strategy, which overcomes the obstacle of using parallel programming in kernel competitive learning and significantly accelerates the approximate kernel competitive learning for large scale clustering. The empirical evaluation on publicly available datasets shows that the proposed AKCL and PAKCL can perform comparably as KCL, with a large reduction on computational cost. Also, the proposed methods achieve more effective clustering performance in terms of clustering precision against related approximate clustering approaches. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Phytoplankton competition and coexistence: Intrinsic ecosystem dynamics and impact of vertical mixing

    NASA Astrophysics Data System (ADS)

    Perruche, Coralie; Rivière, Pascal; Pondaven, Philippe; Carton, Xavier

    2010-04-01

    This paper aims at studying analytically the functioning of a very simple ecosystem model with two phytoplankton species. First, using the dynamical system theory, we determine its nonlinear equilibria, their stability and characteristic timescales with a focus on phytoplankton competition. Particular attention is paid to the model sensitivity to parameter change. Then, the influence of vertical mixing and sinking of detritus on the vertically-distributed ecosystem model is investigated. The analytical results reveal a high diversity of ecosystem structures with fixed points and limit cycles that are mainly sensitive to variations of light intensity and total amount of nitrogen matter. The sensitivity to other parameters such as re-mineralisation, growth and grazing rates is also specified. Besides, the equilibrium analysis shows a complete segregation of the two phytoplankton species in the whole parameter space. The embedding of our ecosystem model into a one-dimensional numerical model with diffusion turns out to allow coexistence between phytoplankton species, providing a possible solution to the 'paradox of plankton' in the sense that it prevents the competitive exclusion of one phytoplankton species. These results improve our knowledge of the factors that control the structure and functioning of plankton communities.

  15. 76 FR 2889 - Notice of Intent To Grant Exclusive and Co-Exclusive Patent License; NanoDynamics Life Sciences...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-18

    ... DEPARTMENT OF DEFENSE Department of the Navy Notice of Intent To Grant Exclusive and Co-Exclusive Patent License; NanoDynamics Life Sciences, Inc. AGENCY: Department of the Navy, DOD. ACTION: Notice. SUMMARY: The Department of the Navy hereby gives notice of its intent to grant to NanoDynamics Life...

  16. The Combat-Exclusion Policy for Military Women.

    ERIC Educational Resources Information Center

    Schneider, Dorothy; Schneider, Carl J.

    1986-01-01

    Reviews the history and meaning of the combat exclusion policy for United States servicewomen. Noting that combat duty is often essential to career advancement in the military, this article describes several cases of discrimination resulting from the effects of the combat exclusion. (JDH)

  17. Exclusive Reactions Involving Pions and Nucleons

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Blattnig, Steve R.; Tripathi, R. K.

    2002-01-01

    The HZETRN code requires inclusive cross sections as input. One of the methods used to calculate these cross sections requires knowledge of all exclusive processes contributing to the inclusive reaction. Conservation laws are used to determine all possible exclusive reactions involving strong interactions between pions and nucleons. Inclusive particle masses are subsequently determined and are needed in cross-section calculations for inclusive pion production.

  18. Exploring an Age Difference in Preschool Children’s Competitiveness Following a Competition

    PubMed Central

    Hu, Yu; Zhu, Yi

    2018-01-01

    Literature suggests that resource acquisition compels competition in young children. However, little is still known about the development of preschool children’s competitiveness. In this preliminary study, 166 children (aged 2–4 and 5–6 years) engaged in a dyadic competition which resulted in a winning and a losing group (in a control/non-competition group, participants engaged in a similar task which did not lead to winning/losing outcome), and then experimenters tracked their decisions to compete again with a rival (i.e., an individual they interacted in the previous competition task) and a non-rival competitor (i.e., an anonymous classmate they did not interact in the previous competition task) for a reward, respectively. As expected, results showed an age-related decreasing trend in the percentage of choices to compete with a competitor. However, this age difference was only significant in the control group when participants played with the partner with whom they interacted in the previous game and in the losing group when participants competed with a non-rival competitor. This study contributes to our knowledge of how competitiveness develop in preschool childhood, and calls for further research on the roles of motivation and cognitive control in children’s competitiveness. PMID:29593610

  19. Social Support and Exclusive Breast feeding among Canadian Women.

    PubMed

    Laugen, Chris M; Islam, Nazrul; Janssen, Patricia A

    2016-09-01

    The World Health Organization recommendation for exclusive breast feeding for 6 months has been endorsed by Health Canada, the Canadian Pediatric Society, Dietitians of Canada, and the Breastfeeding Committee for Canada as of 2012. This study examines whether social support is associated with exclusive breast feeding up to 6 months among Canadian mothers. We utilised data from the Canadian Community Health Survey and limited our sample to mothers who gave birth in the 5 years prior to the 2009-2010 survey (n = 2133). Multivariable logistic regression was used to examine the relationship between exclusive breast feeding and four dimensions of social support: (i) tangible, (ii) affectionate, (iii) positive social interaction, and (iv) emotional and informational, based on the Medical Outcomes Study Social Support Scale. Absolute and relative differences in the probability of breast feeding exclusively and their 95% confidence intervals were calculated. In adjusted models, differences in the probability of exclusive breast feeding for 6 months were not different among women with high vs. low social support. The association between social support and breastfeeding exclusively was modified by education level, with significantly higher probability of breast feeding exclusively among women with lower education and high vs. low levels of tangible and affectionate support. Among women with education below a high school level, high tangible and affectionate support significantly increased probability of exclusive breast feeding for 6 months in this study. Efforts to encourage exclusive breast feeding need to address social support for mothers, especially those with lower education. © 2016 John Wiley & Sons Ltd.

  20. Baby-Friendly hospital practices and meeting exclusive breastfeeding intention

    PubMed Central

    Perrine, Cria G.; Scanlon, Kelley S.; Li, Ruowei; Odom, Erika; Grummer-Strawn, Laurence M.

    2015-01-01

    Objective To describe mothers’ exclusive breastfeeding intentions and whether Baby-Friendly hospital practices are associated with achieving these intentions. Methods In the 2005–2007 Infant Feeding Practices Study II, women completed a prenatal questionnaire and approximately monthly questionnaires through 12 months. Mothers met their prenatal exclusive breastfeeding intention if their duration after the hospital stay (excluding hospital supplementation) equaled or exceeded their intention. Primary predictor variables included 6 Baby-Friendly hospital practices: breastfeeding within one hour of birth, giving only breast milk, rooming in, breastfeeding on demand, no pacifiers, and information on breastfeeding support. Results Among women who prenatally intended to exclusively breastfeed (n=1457), more than 85% intended to do so for 3 months or more. However, only 32.4% of mothers achieved their intended exclusive breastfeeding duration. Mothers who were married and multiparous were more likely to achieve their exclusive breastfeeding intention, while mothers who were obese, smoked, or had longer intended exclusive breastfeeding duration were less likely to meet their intention. Beginning breastfeeding within one hour of birth and not being given supplemental feedings or pacifiers were associated with achieving exclusive breastfeeding intention. After adjustment for all other hospital practices only not receiving supplemental feedings remained significant (aOR=2.3, 95% CI=1.8, 3.1). Conclusion The majority of mothers who intend to exclusively breastfeed are not meeting their intended duration. Increased Baby-Friendly hospital practices, particularly giving only breast milk in the hospital, may help more mothers achieve their exclusive breastfeeding intentions. PMID:22665406

  1. 20 CFR 416.1238 - Exclusion of certain housing assistance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Exclusion of certain housing assistance. 416.1238 Section 416.1238 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Resources and Exclusions § 416.1238 Exclusion of certain housing...

  2. FIRST 2002, 2003, 2004 Robotics Competition(s)

    NASA Technical Reports Server (NTRS)

    Purman, Richard

    2004-01-01

    The New Horizons Regional Education Center (NHREC) in Hampton, VA sought and received NASA funding to support its participation in the 2002, 2003, and 2004 FIRST Robotics Competitions. FIRST, Inc. (For Inspiration and Recognition of Science and Technology) is an organization which encourages the application of creative science, math, and computer science principles to solve real-world engineering problems. The FIRST competition is an international engineering contest featuring high school, government, and business partnerships.

  3. 21 CFR 1316.04 - Exclusion from inspection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Exclusion from inspection. 1316.04 Section 1316.04 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE ADMINISTRATIVE FUNCTIONS, PRACTICES, AND PROCEDURES Administrative Inspections § 1316.04 Exclusion from inspection. (a) Unless the...

  4. [Allergic colitis in exclusively breast-fed infants].

    PubMed

    Sierra Salinas, C; Blasco Alonso, J; Olivares Sánchez, L; Barco Gálvez, A; del Río Mapelli, L

    2006-02-01

    Eosinophilic colitis is induced by antigens present in cow's milk proteins in formula or human milk. In the last few years, an increasing number of cases have been diagnosed in exclusively breast-fed infants. We performed a retrospective study of 13 infants diagnosed with allergic colitis in our unit between January 1997 and January 2004. All the infants had been exclusively breast-fed. In all patients, initial symptoms were digestive (12 with mucus and bloody stools). Onset of symptoms occurred at 0-3 months in 77 %. Laboratory data of the allergic compound were negative. The main locations were the descending and sigmoid colon (75 %). Biopsy demonstrated acute inflammation, with neutrophil infiltration and an increase in eosinophils. In all patients, initial treatment consisted of exclusion of cow's milk proteins from the mother's diet. Ten of the 13 patients showed no improvement, requiring exclusive administration of protein-free hydrolyzate. In 3 infants, breastfeeding was maintained (breastfeeding without cow's milk proteins plus hydrolyzate). Diagnosis of eosinophilic colitis is based on exclusion of other causes of specific colitis and typical endoscopic and ultrastructural findings. Moreover, a satisfactory response to dietary treatment must be demonstrated. This diagnosis should be considered in breast-fed infants with rectal bleeding without involvement of general health status.

  5. The Relationship Between Exclusions from Gambling Arcades and Accessibility: Evidence from a Newly Introduced Exclusion Program in Hesse, Germany.

    PubMed

    Strohäker, Tanja; Becker, Tilman

    2018-02-28

    An exclusion system for gambling arcades has been introduced recently in the state of Hesse. The aim of this paper is to identify significant predictors that are useful in explaining the variation of exclusions between different Hessian communities. Next to socio-demographic factors, we control for three different accessibility variables in two models: the number of electronic gambling machines (EGMs) in model I, and the number of locations and density of gambling machines at a location in model II. We disentangle the association between EGMs and exclusions of model I into a location and a clustering effect. Considering the socio-demographic variables, the explanatory power of our cross-sectional models is rather low. Only the age group of the 30-39 years old and those who are not in a partnership (in model I) yield significant results. As self-exclusion systems reduce availability for the group of vulnerable players, this analysis provides evidence for the assumption that the two groups-pathological gamblers and vulnerable players-seem to have little overlap concerning sociodemographic characteristics. The accessibility variables, on the other hand, turn out to be significantly associated with the number of exclusions. All three of them are statistically significant and their association is positive. The results of model II show that the location effect is more pronounced then the clustering effect of EGMs, i.e. the effect of an additional single-licensed arcade on the number of exclusions is stronger than the increase in the number of license at one location.

  6. 31 CFR 598.503 - Exclusion from licenses.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Exclusion from licenses. 598.503 Section 598.503 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... Licenses, Authorizations, and Statements of Licensing Policy § 598.503 Exclusion from licenses. The...

  7. 31 CFR 598.503 - Exclusion from licenses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Exclusion from licenses. 598.503 Section 598.503 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... Licenses, Authorizations, and Statements of Licensing Policy § 598.503 Exclusion from licenses. The...

  8. 31 CFR 598.503 - Exclusion from licenses.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Exclusion from licenses. 598.503 Section 598.503 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... Licenses, Authorizations, and Statements of Licensing Policy § 598.503 Exclusion from licenses. The...

  9. 31 CFR 598.503 - Exclusion from licenses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Exclusion from licenses. 598.503 Section 598.503 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... Licenses, Authorizations, and Statements of Licensing Policy § 598.503 Exclusion from licenses. The...

  10. 31 CFR 598.503 - Exclusion from licenses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Exclusion from licenses. 598.503 Section 598.503 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... Licenses, Authorizations, and Statements of Licensing Policy § 598.503 Exclusion from licenses. The...

  11. Sperm competition games: a general model for precopulatory male-male competition.

    PubMed

    Parker, Geoff A; Lessells, Catherine M; Simmons, Leigh W

    2013-01-01

    Reproductive males face a trade-off between expenditure on precopulatory male-male competition--increasing the number of females that they secure as mates--and sperm competition--increasing their fertilization success with those females. Previous sperm allocation models have focused on scramble competition in which males compete by searching for mates and the number of matings rises linearly with precopulatory expenditure. However, recent studies have emphasized contest competition involving precopulatory expenditure on armaments, where winning contests may be highly dependent on marginal increases in relative armament level. Here, we develop a general model of sperm allocation that allows us to examine the effect of all forms of precopulatory competition on sperm allocation patterns. The model predicts that sperm allocation decreases if either the "mate-competition loading,"a, or the number of males competing for each mating, M, increases. Other predictions remain unchanged from previous models: (i) expenditure per ejaculate should increase and then decrease, and (ii) total postcopulatory expenditure should increase, as the level of sperm competition increases. A negative correlation between a and M is biologically plausible, and may buffer deviations from the previous models. There is some support for our predictions from comparative analyses across dung beetle species and frog populations. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  12. Work outside the home is the primary barrier to exclusive breastfeeding in rural Viet Nam: insights from mothers who exclusively breastfed and worked.

    PubMed

    Dearden, Kirk A; Quan, Le Nga; Do, Mai; Marsh, David R; Pachón, Helena; Schroeder, Dirk G; Lang, Tran Thi

    2002-12-01

    This study assessed barriers to exclusive breastfeeding in rural Viet Nam and identified how a few mothers were able to exclusively breastfeed despite barriers. A cross-sectional quantitative and qualitative assessment was carried out among 120 mothers of infants less than six months old in northern Viet Nam. Only 24% of the mothers exclusively breastfed. Adjusting for infant's age and who attended delivery, the risk of not exclusively breastfeeding was 14.0 times greater for women who had returned to work than for women who had not. Exclusively breastfeeding mothers (n = 4) who worked differed from other mothers in important ways. They all felt they had enough milk, all knew the appropriate time to introduce foods and liquids, and most were supported in their breastfeeding decisions by commune health workers and family members. This research suggests strategies that can be implemented now to increase exclusive breastfeeding in rural work environments. These include improving knowledge about the introduction of water and semi-solids, addressing perceptions of milk insufficiency, securing support from others, and presenting mothers with options for exclusively breastfeeding, even when they work outside the home.

  13. 40 CFR 152.83 - Definition of exclusive use study.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Protection of Data Submitters' Rights § 152.83 Definition of exclusive use study. A study is an exclusive use... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Definition of exclusive use study. 152.83 Section 152.83 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE...

  14. Efficient and Competitive Rationing

    DTIC Science & Technology

    1988-05-01

    that state S enterprises can organize markets that implement priority service efficiently. In Section 5 we study the operation of competitive markets ...exposition.) 5. COMPETITIVE RATIONING We examine next the incentives for profit-maximizing firms in competitive markets to offer priority service. Our...importantly, those equilibria that do exist show that firms have an incentive not to differentiate. It seems clear, 59 therefore, that in competitive markets

  15. Maternal Competition in Women.

    PubMed

    Linney, Catherine; Korologou-Linden, Laurel; Campbell, Anne

    2017-03-01

    We examined maternal competition, an unexplored form of competition between women. Given women's high investment in offspring and mothers' key role in shaping their reproductive, social, and cultural success as adults, we might expect to see maternal competition between women as well as mate competition. Predictions about the effect of maternal characteristics (age, relationship status, educational background, number of children, investment in the mothering role) and child variables (age, sex) were drawn from evolutionary theory and sociological research. Mothers of primary school children (in two samples: N = 210 and 169) completed a series of questionnaires. A novel nine-item measure of maternal competitive behavior (MCQ) and two subscales assessing Covert (MCQ-C) and Face-to-Face (MCQ-FF) forms of competition were developed using confirmatory factor analysis. Competitiveness (MCQ score) was predicted by maternal investment, single motherhood, fewer children, and (marginally) child's older age. The effect of single motherhood (but not other predictors) was partially mediated by greater maternal investment. In response to a scenario of their child underperforming relative to their peers, a mother's competitive distress was a positive function of the importance she ascribed to their success and her estimation of her child's ability. Her competitive distress was highly correlated with the distress she attributed to a female friend, hinting at bidirectional dyadic effects. Qualitative responses indicated that nonspecific bragging and boasting about academic achievements were the most common irritants. Although 40% of women were angered or annoyed by such comments, less than 5% endorsed a direct hostile response. Instead, competitive mothers were conversationally shunned and rejected as friends. We suggest that the interdependence of mothers based on reciprocal childcare has supported a culture of egalitarianism that is violated by explicit competitiveness.

  16. 42 CFR 1001.102 - Length of exclusion.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Length of exclusion. 1001.102 Section 1001.102 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES PROGRAM INTEGRITY-MEDICARE AND STATE HEALTH CARE PROGRAMS Mandatory Exclusions § 1001.102 Length...

  17. 42 CFR 1001.102 - Length of exclusion.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Length of exclusion. 1001.102 Section 1001.102 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES PROGRAM INTEGRITY-MEDICARE AND STATE HEALTH CARE PROGRAMS Mandatory Exclusions § 1001.102 Length...

  18. 42 CFR 1001.102 - Length of exclusion.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Length of exclusion. 1001.102 Section 1001.102 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES PROGRAM INTEGRITY-MEDICARE AND STATE HEALTH CARE PROGRAMS Mandatory Exclusions § 1001.102 Length...

  19. 42 CFR 1001.102 - Length of exclusion.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Length of exclusion. 1001.102 Section 1001.102 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES PROGRAM INTEGRITY-MEDICARE AND STATE HEALTH CARE PROGRAMS Mandatory Exclusions § 1001.102 Length...

  20. 42 CFR 1001.102 - Length of exclusion.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Length of exclusion. 1001.102 Section 1001.102 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES PROGRAM INTEGRITY-MEDICARE AND STATE HEALTH CARE PROGRAMS Mandatory Exclusions § 1001.102 Length...

  1. Disciplinary Exclusion: The Influence of School Ethos

    ERIC Educational Resources Information Center

    Hatton, Lucy Ann

    2013-01-01

    Disciplinary exclusion is a strategy used by some schools in response to challenging behaviour. While some studies have explored interventions that can be implemented to reduce the exclusion of "at risk" pupils, others have considered how the underlying school ethos influences how challenging behaviour is understood and managed. The…

  2. 41 CFR 105-1.101-50 - Exclusions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Exclusions. 105-1.101-50 Section 105-1.101-50 Public Contracts and Property Management Federal Property Management Regulations... Exclusions. (a) Certain GSA property management and related policies and procedures which come within the...

  3. 31 CFR 510.503 - Exclusion from licenses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Exclusion from licenses. 510.503 Section 510.503 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE..., Authorizations, and Statements of Licensing Policy § 510.503 Exclusion from licenses. The Office of Foreign...

  4. 31 CFR 510.503 - Exclusion from licenses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Exclusion from licenses. 510.503 Section 510.503 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE..., Authorizations, and Statements of Licensing Policy § 510.503 Exclusion from licenses. The Office of Foreign...

  5. 31 CFR 510.503 - Exclusion from licenses.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Exclusion from licenses. 510.503 Section 510.503 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE..., Authorizations, and Statements of Licensing Policy § 510.503 Exclusion from licenses. The Office of Foreign...

  6. 42 CFR 1001.1801 - Waivers of exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OIG AUTHORITIES PROGRAM INTEGRITY-MEDICARE AND STATE HEALTH CARE PROGRAMS Waivers and Effect of Exclusion § 1001... health care program that an exclusion from that program be waived with respect to an individual or entity...

  7. Social Judgments and Emotion Attributions about Exclusion in Switzerland

    ERIC Educational Resources Information Center

    Malti, Tina; Killen, Melanie; Gasser, Luciano

    2012-01-01

    Adolescents' social judgments and emotion attributions about exclusion in three contexts, nationality, gender, and personality, were measured in a sample of 12- and 15-year-old Swiss and non-Swiss adolescents (N = 247). Overall, adolescents judged exclusion based on nationality as less acceptable than exclusion based on gender or personality.…

  8. Getting Competitive: Competitive Intelligence Is a Smart next Step for Information Pros

    ERIC Educational Resources Information Center

    Correia, Cynthia Cheng

    2006-01-01

    Competitive Intelligence (CI) has become an attractive concept for Library and Information Science professionals, as information and research functions have become commoditized by end users, and financial, competitive, and performance pressures increase the need to demonstrate value. In the current competitive and cost-cutting environment,…

  9. Exclusive processes and the fundamental structure of hadrons

    DOE PAGES

    Brodsky, Stanley J.

    2015-01-20

    I review the historical development of QCD predictions for exclusive hadronic processes, beginning with constituent counting rules and the quark interchange mechanism, phenomena which gave early validation for the quark structure of hadrons. The subsequent development of pQCD factorization theorems for hard exclusive amplitudes and the development of evolution equations for the hadron distribution amplitudes provided a rigorous framework for calculating hadronic form factors and hard scattering exclusive scattering processes at high momentum transfer. I also give a brief introduction to the field of "light-front holography" and the insights it brings to quark confinement, the behavior of the QCD couplingmore » in the nonperturbative domain, as well as hadron spectroscopy and the dynamics of exclusive processes.« less

  10. Exclusive processes and the fundamental structure of hadrons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Brodsky, Stanley J.

    I review the historical development of QCD predictions for exclusive hadronic processes, beginning with constituent counting rules and the quark interchange mechanism, phenomena which gave early validation for the quark structure of hadrons. The subsequent development of pQCD factorization theorems for hard exclusive amplitudes and the development of evolution equations for the hadron distribution amplitudes provided a rigorous framework for calculating hadronic form factors and hard scattering exclusive scattering processes at high momentum transfer. I also give a brief introduction to the field of "light-front holography" and the insights it brings to quark confinement, the behavior of the QCD couplingmore » in the nonperturbative domain, as well as hadron spectroscopy and the dynamics of exclusive processes.« less

  11. Details on Exclusive Use Data Protection for Minor Use Registrations

    EPA Pesticide Factsheets

    This document provides information about issues related to exclusive use data protection for minor use registrations, including extension of the exclusive use period and establishing a new exclusive use period.

  12. 21 CFR 316.34 - FDA recognition of exclusive approval.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 5 2011-04-01 2011-04-01 false FDA recognition of exclusive approval. 316.34... (CONTINUED) DRUGS FOR HUMAN USE ORPHAN DRUGS Orphan-drug Exclusive Approval § 316.34 FDA recognition of exclusive approval. (a) FDA will send the sponsor (or, the permanent-resident agent, if applicable) timely...

  13. 21 CFR 316.34 - FDA recognition of exclusive approval.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false FDA recognition of exclusive approval. 316.34... (CONTINUED) DRUGS FOR HUMAN USE ORPHAN DRUGS Orphan-drug Exclusive Approval § 316.34 FDA recognition of exclusive approval. (a) FDA will send the sponsor (or, the permanent-resident agent, if applicable) timely...

  14. 21 CFR 316.34 - FDA recognition of exclusive approval.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 5 2013-04-01 2013-04-01 false FDA recognition of exclusive approval. 316.34... (CONTINUED) DRUGS FOR HUMAN USE ORPHAN DRUGS Orphan-drug Exclusive Approval § 316.34 FDA recognition of exclusive approval. (a) FDA will send the sponsor (or, the permanent-resident agent, if applicable) timely...

  15. 21 CFR 316.34 - FDA recognition of exclusive approval.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 5 2014-04-01 2014-04-01 false FDA recognition of exclusive approval. 316.34... (CONTINUED) DRUGS FOR HUMAN USE ORPHAN DRUGS Orphan-drug Exclusive Approval § 316.34 FDA recognition of exclusive approval. (a) FDA will send the sponsor (or, the permanent-resident agent, if applicable) timely...

  16. 21 CFR 316.34 - FDA recognition of exclusive approval.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false FDA recognition of exclusive approval. 316.34... (CONTINUED) DRUGS FOR HUMAN USE ORPHAN DRUGS Orphan-drug Exclusive Approval § 316.34 FDA recognition of exclusive approval. (a) FDA will send the sponsor (or, the permanent-resident agent, if applicable) timely...

  17. 7 CFR 1b.3 - Categorical exclusions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Categorical exclusions. 1b.3 Section 1b.3 Agriculture Office of the Secretary of Agriculture NATIONAL ENVIRONMENTAL POLICY ACT § 1b.3 Categorical exclusions... individual or cumulative effect on the human environment and are excluded from the preparation of...

  18. Competition for land

    PubMed Central

    Smith, Pete; Gregory, Peter J.; van Vuuren, Detlef; Obersteiner, Michael; Havlík, Petr; Rounsevell, Mark; Woods, Jeremy; Stehfest, Elke; Bellarby, Jessica

    2010-01-01

    A key challenge for humanity is how a future global population of 9 billion can all be fed healthily and sustainably. Here, we review how competition for land is influenced by other drivers and pressures, examine land-use change over the past 20 years and consider future changes over the next 40 years. Competition for land, in itself, is not a driver affecting food and farming in the future, but is an emergent property of other drivers and pressures. Modelling studies suggest that future policy decisions in the agriculture, forestry, energy and conservation sectors could have profound effects, with different demands for land to supply multiple ecosystem services usually intensifying competition for land in the future. In addition to policies addressing agriculture and food production, further policies addressing the primary drivers of competition for land (population growth, dietary preference, protected areas, forest policy) could have significant impacts in reducing competition for land. Technologies for increasing per-area productivity of agricultural land will also be necessary. Key uncertainties in our projections of competition for land in the future relate predominantly to uncertainties in the drivers and pressures within the scenarios, in the models and data used in the projections and in the policy interventions assumed to affect the drivers and pressures in the future. PMID:20713395

  19. 10 CFR 781.52 - Exclusive and partially exclusive licenses.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... subsidiaries and to affiliates within the corporate structure of which the licensee is a part, if any. However... on competition in the U.S.; (3) Projected market size; (4) The benefit to the U.S. Government, U.S... United States (including any Government agency), the States, and domestic municipal governments, unless...

  20. Polyandrous females provide sons with more competitive sperm: Support for the sexy-sperm hypothesis in the rattlebox moth (Utetheisa ornatrix).

    PubMed

    Egan, Andrea L; Hook, Kristin A; Reeve, H Kern; Iyengar, Vikram K

    2016-01-01

    Given the costs of multiple mating, why has female polyandry evolved? Utetheisa ornatrix moths are well suited for studying multiple mating in females because females are highly polyandrous over their life span, with each male mate transferring a substantial spermatophore with both genetic and nongenetic material. The accumulation of resources might explain the prevalence of polyandry in this species, but another, not mutually exclusive, possibility is that females mate multiply to increase the probability that their sons will inherit more-competitive sperm. This latter "sexy-sperm" hypothesis posits that female multiple mating and male sperm competitiveness coevolve via a Fisherian runaway process. We tested the sexy-sperm hypothesis by using competitive double matings to compare the sperm competition success of sons of polyandrous versus monandrous females. In accordance with sexy-sperm theory, we found that in 511 offspring across 17 families, the male whose polyandrous mother mated once with each of three different males sired significantly more of all total offspring (81%) than did the male whose monandrous mother was mated thrice to a single male. Interestingly, sons of polyandrous mothers had a significantly biased sex ratio of their brood toward sons, also in support of the hypothesis. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  1. 26 CFR 1.72-4 - Exclusion ratio.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... consideration is given for a particular contract which provides for two or more annuity elements, an exclusion... aggregate of the expected returns under all the annuity elements provided thereunder. However, where the... elements are acquired for a single consideration, see paragraph (b)(1) of § 1.72-6. (3) The exclusion ratio...

  2. 26 CFR 1.72-4 - Exclusion ratio.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... consideration is given for a particular contract which provides for two or more annuity elements, an exclusion... aggregate of the expected returns under all the annuity elements provided thereunder. However, where the... elements are acquired for a single consideration, see paragraph (b)(1) of § 1.72-6. (3) The exclusion ratio...

  3. 26 CFR 1.72-4 - Exclusion ratio.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... consideration is given for a particular contract which provides for two or more annuity elements, an exclusion... aggregate of the expected returns under all the annuity elements provided thereunder. However, where the... elements are acquired for a single consideration, see paragraph (b)(1) of § 1.72-6. (3) The exclusion ratio...

  4. 26 CFR 1.72-4 - Exclusion ratio.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... consideration is given for a particular contract which provides for two or more annuity elements, an exclusion... aggregate of the expected returns under all the annuity elements provided thereunder. However, where the... elements are acquired for a single consideration, see paragraph (b)(1) of § 1.72-6. (3) The exclusion ratio...

  5. Exclusion from School and Recognition of Difference

    ERIC Educational Resources Information Center

    McCluskey, Gillean; Riddell, Sheila; Weedon, Elisabet; Fordyce, Mariela

    2016-01-01

    There has been an overall decrease in exclusion rates and numbers in recent years across the UK. This change has often been heralded as evidence that national inclusion policies are "working" and that schools themselves are becoming increasingly inclusive. This article examines findings from a recent study on school exclusion in Wales,…

  6. Competition for Assistance Agreements

    EPA Pesticide Factsheets

    It is EPA policy to promote competition in the award of assistance agreements to the maximum extent practicable.When assistance agreements are awarded competitively, it is EPA policy that the competitive process be fair and open & that no applicant receive

  7. 42 CFR 438.808 - Exclusion of entities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Exclusion of entities. 438.808 Section 438.808... Exclusion of entities. (a) General rule. FFP is available in payments under MCO contracts only if the State excludes from the contracts any entities described in paragraph (b) of this section. (b) Entities that must...

  8. 42 CFR 438.808 - Exclusion of entities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Exclusion of entities. 438.808 Section 438.808... Exclusion of entities. (a) General rule. FFP is available in payments under MCO contracts only if the State excludes from the contracts any entities described in paragraph (b) of this section. (b) Entities that must...

  9. 29 CFR 780.309 - Man-day exclusion.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Man-day exclusion. 780.309 Section 780.309 Labor...) Statutory Provisions § 780.309 Man-day exclusion. Section 3(e)(1) specifically excludes from the employer's man-day total (as defined in section 3(u)) employees who qualify for exemption under section 13(a)(6...

  10. 29 CFR 780.317 - Man-day exclusion.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Man-day exclusion. 780.317 Section 780.317 Labor...) Statutory Provisions § 780.317 Man-day exclusion. Section 3(e)(2) specifically excludes from the employer's man-day total (as defined in section 3(u)) employees who qualify for exemption under section 13(a)(6...

  11. 29 CFR 780.317 - Man-day exclusion.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Man-day exclusion. 780.317 Section 780.317 Labor...) Statutory Provisions § 780.317 Man-day exclusion. Section 3(e)(2) specifically excludes from the employer's man-day total (as defined in section 3(u)) employees who qualify for exemption under section 13(a)(6...

  12. 29 CFR 780.317 - Man-day exclusion.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Man-day exclusion. 780.317 Section 780.317 Labor...) Statutory Provisions § 780.317 Man-day exclusion. Section 3(e)(2) specifically excludes from the employer's man-day total (as defined in section 3(u)) employees who qualify for exemption under section 13(a)(6...

  13. 29 CFR 780.309 - Man-day exclusion.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Man-day exclusion. 780.309 Section 780.309 Labor...) Statutory Provisions § 780.309 Man-day exclusion. Section 3(e)(1) specifically excludes from the employer's man-day total (as defined in section 3(u)) employees who qualify for exemption under section 13(a)(6...

  14. 29 CFR 780.309 - Man-day exclusion.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Man-day exclusion. 780.309 Section 780.309 Labor...) Statutory Provisions § 780.309 Man-day exclusion. Section 3(e)(1) specifically excludes from the employer's man-day total (as defined in section 3(u)) employees who qualify for exemption under section 13(a)(6...

  15. 29 CFR 780.317 - Man-day exclusion.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Man-day exclusion. 780.317 Section 780.317 Labor...) Statutory Provisions § 780.317 Man-day exclusion. Section 3(e)(2) specifically excludes from the employer's man-day total (as defined in section 3(u)) employees who qualify for exemption under section 13(a)(6...

  16. 29 CFR 780.309 - Man-day exclusion.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Man-day exclusion. 780.309 Section 780.309 Labor...) Statutory Provisions § 780.309 Man-day exclusion. Section 3(e)(1) specifically excludes from the employer's man-day total (as defined in section 3(u)) employees who qualify for exemption under section 13(a)(6...

  17. Competition-cooperation relationship networks characterize the competition and cooperation between proteins

    PubMed Central

    Li, Hong; Zhou, Yuan; Zhang, Ziding

    2015-01-01

    By analyzing protein-protein interaction (PPI) networks, one can find that a protein may have multiple binding partners. However, it is difficult to determine whether the interactions with these partners occur simultaneously from binary PPIs alone. Here, we construct the yeast and human competition-cooperation relationship networks (CCRNs) based on protein structural interactomes to clearly exhibit the relationship (competition or cooperation) between two partners of the same protein. If two partners compete for the same interaction interface, they would be connected by a competitive edge; otherwise, they would be connected by a cooperative edge. The properties of three kinds of hubs (i.e., competitive, modest, and cooperative hubs) are analyzed in the CCRNs. Our results show that competitive hubs have higher clustering coefficients and form clusters in the human CCRN, but these tendencies are not observed in the yeast CCRN. We find that the human-specific proteins contribute significantly to these differences. Subsequently, we conduct a series of computational experiments to investigate the regulatory mechanisms that avoid competition between proteins. Our comprehensive analyses reveal that for most yeast and human protein competitors, transcriptional regulation plays an important role. Moreover, the human-specific proteins have a particular preference for other regulatory mechanisms, such as alternative splicing. PMID:26108281

  18. 29 CFR 18.615 - Exclusion of witnesses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OFFICE OF ADMINISTRATIVE LAW JUDGES Rules of Evidence Witnesses § 18.615 Exclusion of witnesses. At the... authorize exclusion of a party who is a natural person, or an officer or employee of a party which is not a natural person designated as its representative by its attorney, or a person whose presence is shown by a...

  19. 29 CFR 18.615 - Exclusion of witnesses.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OFFICE OF ADMINISTRATIVE LAW JUDGES Rules of Evidence Witnesses § 18.615 Exclusion of witnesses. At the... authorize exclusion of a party who is a natural person, or an officer or employee of a party which is not a natural person designated as its representative by its attorney, or a person whose presence is shown by a...

  20. 29 CFR 18.615 - Exclusion of witnesses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OFFICE OF ADMINISTRATIVE LAW JUDGES Rules of Evidence Witnesses § 18.615 Exclusion of witnesses. At the... authorize exclusion of a party who is a natural person, or an officer or employee of a party which is not a natural person designated as its representative by its attorney, or a person whose presence is shown by a...

  1. 29 CFR 18.615 - Exclusion of witnesses.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OFFICE OF ADMINISTRATIVE LAW JUDGES Rules of Evidence Witnesses § 18.615 Exclusion of witnesses. At the... authorize exclusion of a party who is a natural person, or an officer or employee of a party which is not a natural person designated as its representative by its attorney, or a person whose presence is shown by a...

  2. 29 CFR 18.615 - Exclusion of witnesses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OFFICE OF ADMINISTRATIVE LAW JUDGES Rules of Evidence Witnesses § 18.615 Exclusion of witnesses. At the... authorize exclusion of a party who is a natural person, or an officer or employee of a party which is not a natural person designated as its representative by its attorney, or a person whose presence is shown by a...

  3. Preschoolers' Perceptions of Performance and Satisfaction under Competitive and Non-Competitive Conditions

    ERIC Educational Resources Information Center

    Tsiakara, Angeliki A.; Digelidis, Nikolaos M.

    2015-01-01

    The aim of this study was to explore preschool children's perceptions of their performance under competitive and non-competitive conditions (NCC) and their satisfaction. Eighty preschool children (40 boys, 40 girls) aged 4-6 years (M age?=?5.48, SD?=?0.57) took part in this study. Preschool children built a tower under competitive and NCC and…

  4. Environmental determinism, and not interspecific competition, drives morphological variability in Australasian warblers (Acanthizidae).

    PubMed

    García-Navas, Vicente; Rodríguez-Rey, Marta; Marki, Petter Z; Christidis, Les

    2018-04-01

    Interspecific competition is thought to play a key role in determining the coexistence of closely related species within adaptive radiations. Competition for ecological resources can lead to different outcomes from character displacement to, ultimately, competitive exclusion. Accordingly, divergent natural selection should disfavor those species that are the most similar to their competitor in resource use, thereby increasing morphological disparity. Here, we examined ecomorphological variability within an Australo-Papuan bird radiation, the Acanthizidae, which include both allopatric and sympatric complexes. In addition, we investigated whether morphological similarities between species are related to environmental factors at fine scale (foraging niche) and/or large scale (climate). Contrary to that predicted by the competition hypothesis, we did not find a significant correlation between the morphological similarities found between species and their degree of range overlap. Comparative modeling based on both a priori and data-driven identification of selective regimes suggested that foraging niche is a poor predictor of morphological variability in acanthizids. By contrast, our results indicate that climatic conditions were an important factor in the formation of morphological variation. We found a significant negative correlation between species scores for PC1 (positively associated to tarsus length and tail length) and both temperature and precipitation, whereas PC2 (positively associated to bill length and wing length) correlated positively with precipitation. In addition, we found that species inhabiting the same region are closer to each other in morphospace than to species outside that region regardless of genus to which they belong or its foraging strategy. Our results indicate that the conservative body form of acanthizids is one that can work under a wide variety of environments (an all-purpose morphology), and the observed interspecific similarity is

  5. In Defence of Competition.

    ERIC Educational Resources Information Center

    Prvulovich, Zika Rad

    1982-01-01

    Examines objections to competition as presented by educational philosopher Michael Fielding and others. The two major types of criticism of competition are that it is unfair and divisive and that it is selfish and immoral. The author advocates educational experiences which combine self-competition with cooperation. (AM)

  6. Strategizing for Intense Competition.

    ERIC Educational Resources Information Center

    Hahn, William; Bourgeois, Ernest J., Jr.

    1999-01-01

    Examines trend toward more aggressive student recruiting strategies by colleges and universities, applying a model that assesses five competitive forces-cause and effect of competition, the expanding marketplace, substitute products, buyer power, and supplier power, and examines various strategies for dealing with these competitive forces, such as…

  7. Changes in Subjective Sleep Quality Before a Competition and Their Relation to Competitive Anxiety.

    PubMed

    Ehrlenspiel, Felix; Erlacher, Daniel; Ziegler, Matthias

    2016-12-09

    The aim of this study was to examine the effects of competitions on subjective sleep quality. Previous studies have been inconclusive and lack differentiated and standardized measurements of subjective sleep quality. Furthermore the temporal relation between precompetitive anxiety and sleep quality was investigated. Anxiety and nervousness associated with competitions are considered to cause sleep impairments. A convenience sample of N = 79 elite male athletes from various sports participated. In a time-to-event paradigm, sleep quality and competitive anxiety were assessed via standardized self-report measurements 4 days before a competition and on the day of the competition. Univariate analyses were used to examine differences between time points. To examine cross-lagged effects between anxiety and sleep quality a latent change score model (LCSM) was specified that tested an effect of anxiety on changes in sleep quality. Evaluations of nocturnal sleep deteriorated significantly from 4 days before competition to the day of competition, but there were no differences regarding perceptions of the restorative value of sleep. LCSM revealed that athletes who reported more intense worry symptoms 4 days before competition also reported greater deterioration in evaluations of nocturnal sleep. The findings support earlier reports of impaired subjective sleep quality before competitions. Precompetitive sleep impairments appear also to be preceded by cognitive anxiety. Whereas interventions should thus address worry-cognitions associated with competition and sleep, research should address the practical importance of these perceptions of sleep impairments.

  8. An assessment of exclusive.

    DOT National Transportation Integrated Search

    1982-01-01

    More than 70% of motorists returning a questionnaire distributed for the study favored the exclusive/permissive signal, while about 17% said the signal reduced delays, and 30% said it created a hazard. Intersections with one or more right-turn-on-red...

  9. Peer Exclusion During the Pubertal Transition: The Role of Social Competence.

    PubMed

    Carter, Rona; Halawah, Amira; Trinh, Sarah L

    2018-01-01

    For some youth, early puberty is accompanied by peer exclusion. Yet early developers may experience less peer exclusion if they have social competence, which would bolster their ability to develop and maintain positive relationships with their peers. Accordingly, the present study tests whether pubertal timing and tempo predicts decrements in children's social competence and whether decrements in social competence account for associations between puberty (timing and tempo) and peer exclusion over time. Longitudinal data were drawn from 1364 families (48% female; 76% White; M = 9.32 years, SD = .48, at Wave 3) who participated in Waves 3-5 (i.e., grades 4-6) of Phase III of the NICHD-SECCYD. The results from latent growth curve models indicated that earlier pubertal timing and more rapid pubertal tempo among girls were associated with high initial levels of peer exclusion. Moreover, mediation analyses revealed that early developers' susceptibility to peer exclusion was associated with their initial level of social competence. In boys, pubertal timing and tempo were not directly associated with peer exclusion; instead, indirect effects of pubertal timing on peer exclusion (intercept, slope) occurred through initial levels of social competence. On average, early developers' who had low levels of social competence also had high initial levels of peer exclusion but experienced decrements in peer exclusion over time. The association between the intercepts for puberty and peer exclusion and the slopes for social competence and peer exclusion were stronger for boys than girls. Overall, our findings suggest that early developers' susceptibility to and experiences of peer exclusion are associated with their development of social competence.

  10. Direct Versus Indirect Competition.

    ERIC Educational Resources Information Center

    Billing, John

    Competition in sport and physical education programs has been used to motivate the learning of skills, increase physical fitness, and to create environments purportedly conducive to the development of desirable personality qualities. However, the way in which competition is conceptualized is of great importance. In direct competition, achievement…

  11. 78 FR 61398 - Notice of Intent To Grant Exclusive License

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... NATIONAL AERONAUTICS AND SPACE ADMINISTRATION [Notice 13-117] Notice of Intent To Grant Exclusive License AGENCY: National Aeronautics and Space Administration. ACTION: Notice of intent to grant exclusive... Aeronautics and Space Administration. The prospective exclusive license will comply with the terms and...

  12. The effects of nurse staffing on hospital financial performance: competitive versus less competitive markets.

    PubMed

    Everhart, Damian; Neff, Donna; Al-Amin, Mona; Nogle, June; Weech-Maldonado, Robert

    2013-01-01

    Hospitals facing financial uncertainty have sought to reduce nurse staffing as a way to increase profitability. However, nurse staffing has been found to be important in terms of quality of patient care and nursing-related outcomes. Nurse staffing can provide a competitive advantage to hospitals and as a result of better financial performance, particularly in more competitive markets. In this study, we build on the Resource-Based View of the Firm to determine the effect of nurse staffing on total profit margin in more competitive and less competitive hospital markets in Florida. By combining a Florida statewide nursing survey with the American Hospital Association Annual Survey and the Area Resource File, three separate multivariate linear regression models were conducted to determine the effect of nurse staffing on financial performance while accounting for market competitiveness. The analysis was limited to acute care hospitals. Nurse staffing levels had a positive association with financial performance (β = 3.3, p = .02) in competitive hospital markets, but no significant association was found in less competitive hospital markets. Hospitals in more competitive hospital markets should reconsider reducing nursing staff, as these cost-cutting measures may be inefficient and negatively affect financial performance.

  13. 20 CFR 416.1233 - Exclusion of certain underpayments from resources.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Exclusion of certain underpayments from resources. 416.1233 Section 416.1233 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Resources and Exclusions § 416.1233 Exclusion of certain...

  14. Family support and exclusive breastfeeding among Yogyakarta mothers in employment.

    PubMed

    Ratnasari, Dewi; Paramashanti, Bunga Astria; Hadi, Hamam; Yugistyowati, Anafrin; Astiti, Dewi; Nurhayati, Eka

    2017-06-01

    Exclusive breastfeeding provides many benefits to both infants and mothers. Despite the introduction of laws aimed at protecting the practice of exclusive breastfeeding, the coverage of exclusive breastfeeding remains low, particularly for working mothers. This crosssectional study recruited working mothers employed in medium and large companies in Bantul District, Daerah Istimewa Yogyakarta, Indonesia. The study participants were 158 working mothers whose children were aged 6- 12 months, and they were selected using the probability proportional to size technique. The data were analyzed using descriptive statistics, chi-square tests, and multiple logistic regression. Adequate family support for breastfeeding (OR: 2.86; 95% CI: 1.25-6.53) and a high paternal education level (OR: 2.68; 95% CI: 1.11- 6.48) were significantly associated with the practice of exclusive breastfeeding among working mothers. However, the infant's sex and age, parity, and the mother's age and education level were unassociated with exclusive breastfeeding. Family support and a high paternal education level are crucial in enabling working mothers to practice exclusive breastfeeding. Interventions that promote exclusive breastfeeding should focus on involving the husband and other family members in health care programs related to breastfeeding.

  15. Children's judgements and emotions about social exclusion based on weight.

    PubMed

    Nguyen, Christine; Malti, Tina

    2014-09-01

    This study examined children's judgements and emotions associated with weight-based social exclusion using an ethnically diverse sample of one hundred and seventeen 9- and 13-year-old children. Children were interviewed about three scenarios depicting weight-based exclusion in athletic, academic, and social contexts. Children's judgements of exclusion, emotions attributed to the excluder and excluded targets, and justifications for judgements and emotions were examined. Overall, children judged weight-based exclusion to be wrong for moral reasons. However, they viewed weight-based exclusion in athletic contexts as less wrong compared with academic contexts, and they used more social-conventional reasoning to justify judgements and emotions attributed to excluders in athletic contexts compared with academic and social contexts. Children also expected excluded targets to feel negative emotions, whereas a range of positive and negative emotions was attributed to excluders. In addition, older children were more accepting of weight-based exclusion in athletic contexts than in academic and social contexts. We discuss the results in relation to the development of children's understanding of, and emotions associated with, exclusion based on weight. © 2014 The British Psychological Society.

  16. Pollinator-mediated competition between two congeners, Limnanthes douglasii subsp. rosea and L. alba (Limnanthaceae).

    PubMed

    Briscoe Runquist, Ryan D

    2012-07-01

    Pollinator visits are essential for reproduction in many plants, yet interspecific movements of pollinators can also lead to competitive interactions between coflowering species. Pollination-mediated reductions in fertility could potentially lead to exclusion of competing plant species, and may generate spatial variation in the associations among coflowering species across a landscape. I documented the potential for heterospecific pollen transfer to cause competitive interactions between two annual grassland species native to California, Limnanthes douglasii subsp. rosea and L. alba, two reproductively incompatible species that have broadly overlapping geographic ranges in the foothills of the Sierra Nevada. I observed pollinator movement in constructed arrays and controlled crosses in the greenhouse and field to investigate the consequences of heterospecific pollen transfer. Pollinators move readily between species when they are presented together in experimental arrays. In the greenhouse, deposition of heterospecific pollen decreased fertility in both species. The decrease in seeds produced per flower was much more pronounced in L. d. rosea (90.6% reduction) than in L. alba (40.8% reduction). In field experiments, L. d. rosea plants that received pollen from heterospecific neighbors first showed >50% reduction in per-flower fertility. Under natural pollination conditions, heterospecific pollen transfer has the ability to decrease the fertility of L. d. rosea when it occurs at low frequency in mixed stands. Accordingly, pollinator-mediated competition may contribute to the locally disjunct distributions of these two species. It may also influence important restoration decisions in vernal pool habitats.

  17. Testing the exclusivity effect in location memory.

    PubMed

    Clark, Daniel P A; Dunn, Andrew K; Baguley, Thom

    2013-01-01

    There is growing literature exploring the possibility of parallel retrieval of location memories, although this literature focuses primarily on the speed of retrieval with little attention to the accuracy of location memory recall. Baguley, Lansdale, Lines, and Parkin (2006) found that when a person has two or more memories for an object's location, their recall accuracy suggests that only one representation can be retrieved at a time (exclusivity). This finding is counterintuitive given evidence of non-exclusive recall in the wider memory literature. The current experiment explored the exclusivity effect further and aimed to promote an alternative outcome (i.e., independence or superadditivity) by encouraging the participants to combine multiple representations of space at encoding or retrieval. This was encouraged by using anchor (points of reference) labels that could be combined to form a single strongly associated combination. It was hypothesised that the ability to combine the anchor labels would allow the two representations to be retrieved concurrently, generating higher levels of recall accuracy. The results demonstrate further support for the exclusivity hypothesis, showing no significant improvement in recall accuracy when there are multiple representations of a target object's location as compared to a single representation.

  18. The Analysis of Competitive Strategy and Suggestions for Didi under the Background of the New Car-hailing Regulation

    NASA Astrophysics Data System (ADS)

    Wang, Tingting; Zhao, Lei

    2017-10-01

    The emergence of car-hailing service satisfies the need of public travel in Internet era. Didi—the representative of car-hailing service, provides users with cost-effective service and great travel experience and quickly became the leader in the field of mobile travel depending on its price advantage, market segmentation, fast respond and some other competitive strategies. However, the promulgation of the new car-hailing regulation brings many challenges to Didi. After the new regulation, it is hard for Didi to gap away significantly from its competitors in scale and price. Thus the differentiated service is the competitive focus for all platforms. So there is an urgent need for Didi to do something to make difference, such as improving the interface design of the platform and the process of order allocation, establishing exclusive ‘station’, increasing the interaction between drivers and passengers. By doing so, Didi can reduce the information asymmetry and increase the user engagement and loyalty with high quality service.

  19. Rationality alters the rank between peer punishment and social exclusion

    NASA Astrophysics Data System (ADS)

    Sui, Xiukai; Wu, Bin; Wang, Long

    2018-02-01

    Peer punishment and social exclusion are two ways to punish free-riders. Previous work usually focuses on how their presence, either peer punishment or social exclusion, shapes the evolution of cooperation. Little attention has been given to which of these two strategies is favored by natural selection when they are both present. Here we investigate how rationality alters the ranking of these two strategies. Under weak rationality, for compulsory public goods games, peer punishment has an evolutionary advantage over social exclusion if the efficiency of punishment or the cost of exclusion is high. Furthermore, this rank is preserved for voluntary public goods games where loners are involved. Under strong rationality, however, peer punishment cannot prevail over social exclusion for both compulsory and voluntary public goods games. This indicates that rationality greatly alters the rank between peer punishment and social exclusion. Moreover, we find that this ranking is sensitive to the rationality. Our work thus gives an insight into how different types of punishment evolve.

  20. Social exclusion impairs distractor suppression but not target enhancement in selective attention.

    PubMed

    Xu, Mengsi; Li, Zhiai; Diao, Liuting; Fan, Lingxia; Zhang, Lijie; Yuan, Shuge; Yang, Dong

    2017-11-01

    Social exclusion has been thought to weaken one's ability to exert inhibitory control. Existing studies have primarily focused on the relationship between exclusion and behavioral inhibition, and have reported that exclusion impairs behavioral inhibition. However, whether exclusion also affects selective attention, another important aspect of inhibitory control, remains unknown. Therefore, the current study aimed to explore whether social exclusion impairs selective attention, and to specifically examine its effect on two hypothesized mechanisms of selective attention: target enhancement and distractor suppression. The Cyberball game was used to manipulate social exclusion. Participants then performed a visual search task while event-related potentials were recorded. In the visual search task, target and salient distractor were either both presented laterally or one was presented on the vertical midline and the other laterally. Results showed that social exclusion differentially affected target and distractor processing. While exclusion impaired distractor suppression, reflected as smaller distractor-positivity (Pd) amplitudes for the exclusion group compared to the inclusion group, it did not affect target enhancement, reflected as similar target-negativity (Nt) amplitudes for both the exclusion and inclusion groups. Together, these results extend our understanding of the relationship between exclusion and inhibitory control, and suggest that social exclusion affects selective attention in a more complex manner than previously thought. Copyright © 2017. Published by Elsevier B.V.

  1. Exclusive Breastfeeding Experiences among Mexican American Women.

    PubMed

    Wambach, Karen; Domian, Elaine Williams; Page-Goertz, Sallie; Wurtz, Heather; Hoffman, Kelli

    2016-02-01

    According to the Centers for Disease Control and Prevention, Hispanic breastfeeding mothers begin early formula supplementation at higher rates than other ethnic groups, which can lead to shorter breastfeeding duration and decreased exclusive breastfeeding. Acculturation, the process of adopting beliefs and behaviors of another culture, appears to influence breastfeeding practices of Hispanic women in the United States. Little is known about Mexican American mothers' formula use and exclusive breastfeeding within the context of acculturation. Our study identified perceived benefits and barriers to exclusive breastfeeding and levels of acculturation among Mexican American women living in a Midwestern city. We used a qualitative descriptive design integrating Pender's Health Promotion Model concepts. Individual interviews were conducted in English or Spanish (N = 21). The revised Acculturation Rating Scale for Mexican Americans was used to examine acculturation levels. Acculturation scores indicated that the majority (66%) of the sample was "very Mexican oriented." Most women exclusively breastfed, with a few using early supplementation for "insufficient milk production." Three themes emerged: (1) It is natural that a woman give life and also provide the best food for her baby; (2) Breastfeeding is ultimately a woman's decision but is influenced by tradition, guidance, and encouragement; and (3) Breast milk is superior but life circumstances can challenge one's ability to breastfeed. Strong familial/cultural traditions supported and normalized breastfeeding. Barriers to exclusive breastfeeding were similar to breastfeeding women in general, in the United States. Findings support the need for culturally competent and individualized lactation care. © The Author(s) 2015.

  2. Social Exclusion in Childhood: A Developmental Intergroup Perspective

    ERIC Educational Resources Information Center

    Killen, Melanie; Mulvey, Kelly Lynn; Hitti, Aline

    2013-01-01

    "Interpersonal" rejection and "intergroup" exclusion in childhood reflect different, but complementary, aspects of child development. Interpersonal rejection focuses on individual differences in personality traits, such as wariness and being fearful, to explain bully-victim relationships. In contrast, intergroup exclusion focuses on how in-group…

  3. The exclusion problem in seasonally forced epidemiological systems.

    PubMed

    Greenman, J V; Adams, B

    2015-02-21

    The pathogen exclusion problem is the problem of finding control measures that will exclude a pathogen from an ecological system or, if the system is already disease-free, maintain it in that state. To solve this problem we work within a holistic control theory framework which is consistent with conventional theory for simple systems (where there is no external forcing and constant controls) and seamlessly generalises to complex systems that are subject to multiple component seasonal forcing and targeted variable controls. We develop, customise and integrate a range of numerical and algebraic procedures that provide a coherent methodology powerful enough to solve the exclusion problem in the general case. An important aspect of our solution procedure is its two-stage structure which reveals the epidemiological consequences of the controls used for exclusion. This information augments technical and economic considerations in the design of an acceptable exclusion strategy. Our methodology is used in two examples to show how time-varying controls can exploit the interference and reinforcement created by the external and internal lag structure and encourage the system to 'take over' some of the exclusion effort. On-off control switching, resonant amplification, optimality and controllability are important issues that emerge in the discussion. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Prevalence of exclusive breastfeeding in the healthy newborn.

    PubMed

    Mazo-Tomé, Pedro Luis Del; Suárez-Rodríguez, Marta

    2018-01-01

    The best nourishment for infants during the first 6 months of life is exclusive breastfeeding. It is recommended along with other food to complement the diet until the child is 2 years old, as long as the mother and the child are willing to continue with it. The objectives of this study were to determine he exclusive breastfeeding rate in full term newborns at hospital discharge and 15 days later and to analyze the factors that positively affect the exclusive breastfeeding. A prospective study was conducted in which a sample of postpartum women with full term newborns was recruited during hospital admission. Different variables were compiled and two interviews were made to determine the kind of feeding they were giving their children and if it was maintained at 15 days of birth. Exclusive breastfeeding rate at hospital discharge is much lower than recommended. It significantly decreases at 15 days of birth, increasing artificial feeding. It seems that having a vaginal birth, no complications giving birth, providing early breastfeeding and skin-to-skin contact in the delivery room are predisposing factors necessary to establish a good breastfeeding at hospital discharge. Despite the efforts of professionals, the percentage of newborns with exclusive breastfeeding at birth is not enough for the current recommendations. Copyright: © 2018 Permanyer.

  5. Is healthy competition healthy? New evidence of the impact of hospital competition.

    PubMed

    Gift, Thomas L; Arnould, Richard; DeBrock, Larry

    2002-01-01

    Competition among hospitals is commonly regarded as inefficient due to the medical arms race phenomenon, but most evidence for this hypothesis predates the Medicare prospective payment system and preferred provider legislation. Recent studies indicate hospital competition reduces costs and prices, but nearly all such research has focused on California. We add to the body of literature that analyzes the effects of competition in hospital markets. Using data from the state of Washington, we show that hospitals assume more risk in competitive markets by being more likely to accept prospective payment arrangements with insurers. If the arrangement is retrospective, the hospital is more likely to offer a discount as the number of competing hospitals increases. Both findings indicate that competitive forces operate the same in hospital markets as in most others: as the number of competitors increases, prices decrease and market power shifts from the suppliers to purchasers. The medical arms race hypothesis that favors more concentrated hospital markets no longer appears to be valid.

  6. Competition between health maintenance organizations and nonintegrated health insurance companies in health insurance markets.

    PubMed

    Baranes, Edmond; Bardey, David

    2015-12-01

    This article examines a model of competition between two types of health insurer: Health Maintenance Organizations (HMOs) and nonintegrated insurers. HMOs vertically integrate health care providers and pay them at a competitive price, while nonintegrated health insurers work as indemnity plans and pay the health care providers freely chosen by policyholders at a wholesale price. Such difference is referred to as an input price effect which, at first glance, favors HMOs. Moreover, we assume that policyholders place a positive value on the provider diversity supplied by their health insurance plan and that this value increases with the probability of disease. Due to the restricted choice of health care providers in HMOs a risk segmentation occurs: policyholders who choose nonintegrated health insurers are characterized by higher risk, which also tends to favor HMOs. Our equilibrium analysis reveals that the equilibrium allocation only depends on the number of HMOs in the case of exclusivity contracts between HMOs and providers. Surprisingly, our model shows that the interplay between risk segmentation and input price effects may generate ambiguous results. More precisely, we reveal that vertical integration in health insurance markets may decrease health insurers' premiums.

  7. The Effects of Nurse Staffing on Hospital Financial Performance: Competitive Versus Less Competitive Markets

    PubMed Central

    Everhart, Damian; Neff, Donna; Al-Amin, Mona; Nogle, June; Weech-Maldonado, Robert

    2013-01-01

    Background Hospitals facing financial uncertainty have sought to reduce nurse staffing as a way to increase profitability. However, nurse staffing has been found to be important in terms of quality of patient care and nursing related outcomes. Nurse staffing can provide a competitive advantage to hospitals and as a result better financial performance, particularly in more competitive markets Purpose In this study we build on the Resource-Based View of the Firm to determine the effect of nurse staffing on total profit margin in more competitive and less competitive hospital markets in Florida. Methodology/Approach By combining a Florida statewide nursing survey with the American Hospital Association Annual Survey and the Area Resource File, three separate multivariate linear regression models were conducted to determine the effect of nurse staffing on financial performance while accounting for market competitiveness. The analysis was limited to acute care hospitals. Findings Nurse staffing levels had a positive association with financial performance (β=3.3; p=0.02) in competitive hospital markets, but no significant association was found in less competitive hospital markets. Practice Implications Hospitals in more competitive hospital markets should reconsider reducing nursing staff, as these cost cutting measures may be inefficient and negatively affect financial performance. PMID:22543824

  8. Co-evolutionary Analysis of Domains in Interacting Proteins Reveals Insights into Domain–Domain Interactions Mediating Protein–Protein Interactions

    PubMed Central

    Jothi, Raja; Cherukuri, Praveen F.; Tasneem, Asba; Przytycka, Teresa M.

    2006-01-01

    Recent advances in functional genomics have helped generate large-scale high-throughput protein interaction data. Such networks, though extremely valuable towards molecular level understanding of cells, do not provide any direct information about the regions (domains) in the proteins that mediate the interaction. Here, we performed co-evolutionary analysis of domains in interacting proteins in order to understand the degree of co-evolution of interacting and non-interacting domains. Using a combination of sequence and structural analysis, we analyzed protein–protein interactions in F1-ATPase, Sec23p/Sec24p, DNA-directed RNA polymerase and nuclear pore complexes, and found that interacting domain pair(s) for a given interaction exhibits higher level of co-evolution than the noninteracting domain pairs. Motivated by this finding, we developed a computational method to test the generality of the observed trend, and to predict large-scale domain–domain interactions. Given a protein–protein interaction, the proposed method predicts the domain pair(s) that is most likely to mediate the protein interaction. We applied this method on the yeast interactome to predict domain–domain interactions, and used known domain–domain interactions found in PDB crystal structures to validate our predictions. Our results show that the prediction accuracy of the proposed method is statistically significant. Comparison of our prediction results with those from two other methods reveals that only a fraction of predictions are shared by all the three methods, indicating that the proposed method can detect known interactions missed by other methods. We believe that the proposed method can be used with other methods to help identify previously unrecognized domain–domain interactions on a genome scale, and could potentially help reduce the search space for identifying interaction sites. PMID:16949097

  9. 42 CFR 1002.210 - Permissive exclusions; general authority.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Permissive exclusions; general authority. 1002.210 Section 1002.210 Public Health OFFICE OF INSPECTOR GENERAL-HEALTH CARE, DEPARTMENT OF HEALTH AND HUMAN... § 1002.210 Permissive exclusions; general authority. The State agency must have administrative procedures...

  10. 9 CFR 354.246 - Exclusion of diseased persons.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Exclusion of diseased persons. 354.246 Section 354.246 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Sanitary Conditions and Precautions Against Contamination of Products § 354.246 Exclusion of diseased...

  11. 17 CFR 242.505 - Exclusion for news media.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Exclusion for news media. 242.505 Section 242.505 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED...-Analyst Certification § 242.505 Exclusion for news media. No provision of this Regulation AC shall apply...

  12. 17 CFR 242.505 - Exclusion for news media.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Exclusion for news media. 242.505 Section 242.505 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED...-Analyst Certification § 242.505 Exclusion for news media. No provision of this Regulation AC shall apply...

  13. 17 CFR 242.505 - Exclusion for news media.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Exclusion for news media. 242.505 Section 242.505 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED...-Analyst Certification § 242.505 Exclusion for news media. No provision of this Regulation AC shall apply...

  14. 17 CFR 242.505 - Exclusion for news media.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Exclusion for news media. 242.505 Section 242.505 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED...-Analyst Certification § 242.505 Exclusion for news media. No provision of this Regulation AC shall apply...

  15. 17 CFR 242.505 - Exclusion for news media.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Exclusion for news media. 242.505 Section 242.505 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED...-Analyst Certification § 242.505 Exclusion for news media. No provision of this Regulation AC shall apply...

  16. Competitive Strategies

    DTIC Science & Technology

    1988-05-27

    Competitive Strategies Individual Essay 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(@) S. CONTRACT OR GRANT NUMBER( e ) Robert M. Davis, LTC, AD S...DO FOe 1473 emIotN or, Nov es IS OBSOLETE -JA I Unclassifi fed SECURITY CLASSIFICATION OF THIS PA7. E (Whrn Does Entered) Unclassified SECURITY...focus within the Department of Defense to provide technical and tactical leverage over the Soviets. Competitive Strategies are a management tool which

  17. Competitive styles in men and women.

    PubMed

    Reed, S; Reed, R C; Lantz, J

    1997-01-01

    Competition is a function intrinsic to current clinical practice. Of the two competitive styles, goal competitiveness is found by both men and women to be more worthy of respect. Interpersonal competitiveness is manifested more by highly competitive women than by highly competitive men, especially in relationships with female co-workers, representing a significant problem for organizations and employees. The styles and their effects are described, their possible sources discussed, additional research outlined, and recommendations proposed.

  18. 76 FR 23819 - Prospective Granting of an Exclusive License

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-28

    ... contemplating granting a worldwide exclusive license to AES Raptor, LLC, located in North Kansas City, Missouri. Under this exclusive license, only AES Raptor, LLC would be permitted to commercialize the technology...

  19. 21 CFR 529.469 - Competitive exclusion culture.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... for use. For early establishment of intestinal microflora in chickens to reduce Salmonella... this chapter. (c) [Reserved] (d) Conditions of use. Chickens—(1) Amount. Apply 25 milliliters of... administer antibiotics to treated chickens. [63 FR 25164, May 7, 1998] ...

  20. 21 CFR 529.469 - Competitive exclusion culture.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... for use. For early establishment of intestinal microflora in chickens to reduce Salmonella... this chapter. (c) [Reserved] (d) Conditions of use. Chickens—(1) Amount. Apply 25 milliliters of... administer antibiotics to treated chickens. [63 FR 25164, May 7, 1998] ...

  1. 21 CFR 529.469 - Competitive exclusion culture.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... for use. For early establishment of intestinal microflora in chickens to reduce Salmonella... this chapter. (c) [Reserved] (d) Conditions of use. Chickens—(1) Amount. Apply 25 milliliters of... administer antibiotics to treated chickens. [63 FR 25164, May 7, 1998] ...

  2. 76 FR 35480 - Notice of Intent To Grant Exclusive License

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... Exclusive License AGENCY: National Aeronautics and Space Administration. ACTION: Notice of intent to grant exclusive license. SUMMARY: This notice is issued in accordance with 35 U.S.C. 209(c)(1) and 37 CFR 404.7(a)(1)(i). NASA hereby gives notice of its intent to grant an exclusive patent and copyright license in...

  3. 12 CFR 367.5 - Exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... also prohibited from conducting business with FDIC as agents or representatives of other contractors... bars to contracting are shown to exist, the existence of a cause for exclusion does not necessarily...

  4. Competition Among Near-Substitutable Systems

    DTIC Science & Technology

    2012-09-01

    the context of the dominant “Weapon System Franchise ” model of competition for major defense acquisition programs (MDAPs). Competition between near...leading to the award of a franchise . AoAs or other cost-effectiveness analyses can be pivotal in bringing attention to near-substitute systems. However...dominant ?Weapon System Franchise ? model of competition for major defense acquisition programs (MDAPs). Competition between near-substitutes can occur

  5. Deterrence in Oligopolistic Competition.

    DTIC Science & Technology

    1987-03-01

    maneuvering for advantage in an oligopolistic market . Competitive battles for entry into a market , and subsequently for market shares or continued survival...on institutional features peculiar to market competition among firms, the available case studies and sta- tistical evidence are not described here...that might enter the market in competition with the present incumbents, which is usually detrimental to the incumbents. Each firm can affect its market

  6. Effect of Serotype on Pneumococcal Competition in a Mouse Colonization Model.

    PubMed

    Trzciński, Krzysztof; Li, Yuan; Weinberger, Daniel M; Thompson, Claudette M; Cordy, Derrick; Bessolo, Andrew; Malley, Richard; Lipsitch, Marc

    2015-09-15

    Competitive interactions between Streptococcus pneumoniae strains during host colonization could influence the serotype distribution in nasopharyngeal carriage and pneumococcal disease. We evaluated the competitive fitness of strains of serotypes 6B, 14, 19A, 19F, 23F, and 35B in a mouse model of multiserotype carriage. Isogenic variants were constructed using clinical strains as the capsule gene donors. Animals were intranasally inoculated with a mixture of up to six pneumococcal strains of different serotypes, with separate experiments involving either clinical isolates or isogenic capsule-switch variants of clinical strain TIGR4. Upper-respiratory-tract samples were repeatedly collected from animals in order to monitor changes in the serotype ratios using quantitative PCR. A reproducible hierarchy of capsular types developed in the airways of mice inoculated with multiple strains. Serotype ranks in this hierarchy were similar among pneumococcal strains of different genetic backgrounds in different strains of mice and were not altered when tested under a range of host conditions. This rank correlated with the measure of the metabolic cost of capsule synthesis and in vitro measure of pneumococcal cell surface charge, both parameters considered to be predictors of serotype-specific fitness in carriage. This study demonstrates the presence of a robust competitive hierarchy of pneumococcal serotypes in vivo that is driven mainly, but not exclusively, by the capsule itself. Streptococcus pneumoniae (pneumococcus) is the leading cause of death due to respiratory bacterial infections but also a commensal frequently carried in upper airways. Available vaccines induce immune responses against polysaccharides coating pneumococcal cells, but with over 90 different capsular types (serotypes) identified, they can only target strains of the selected few serotypes most prevalent in disease. Vaccines not only protect vaccinated individuals against disease but also protect by

  7. Apparent competition and native consumers exacerbate the strong competitive effect of an exotic plant species.

    PubMed

    Orrock, John L; Dutra, Humberto P; Marquis, Robert J; Barber, Nicholas

    2015-04-01

    Direct and indirect effects can play a key role in invasions, but experiments evaluating both are rare. We examined the roles of direct competition and apparent competition by exotic Amur honeysuckle (Lonicera maackii) by manipulating (1) L. maackii vegetation, (2) presence of L. maackii fruits, and (3) access to plants by small mammals and deer. Direct competition with L. maackii reduced the abundance and richness of native and exotic species, and native consumers significantly reduced the abundance and richness of native species. Although effects of direct competition and consumption were more pervasive, richness of native plants was also reduced through apparent competition, as small-mammal consumers reduced richness only when L. maackii fruits were present. Our experiment reveals the multiple, interactive pathways that affect the success and impact of an invasive exotic plant: exotic plants may directly benefit from reduced attack by native consumers, may directly exert strong competitive effects on native plants, and may also benefit from apparent competition.

  8. 48 CFR 32.404 - Exclusions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... REQUIREMENTS CONTRACT FINANCING Advance Payments for Non-Commercial Items 32.404 Exclusions. (a) This subpart... equivalent amount of the applicable foreign currency); and (ii) The advance payment is required by the laws...

  9. 48 CFR 32.404 - Exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... REQUIREMENTS CONTRACT FINANCING Advance Payments for Non-Commercial Items 32.404 Exclusions. (a) This subpart... equivalent amount of the applicable foreign currency); and (ii) The advance payment is required by the laws...

  10. Measuring social exclusion in healthcare settings: a scoping review.

    PubMed

    O'Donnell, Patrick; O'Donovan, Diarmuid; Elmusharaf, Khalifa

    2018-02-02

    Social exclusion is a concept that has been widely debated in recent years; a particular focus of the discussion has been its significance in relation to health. The meanings of the phrase "social exclusion", and the closely associated term "social inclusion", are contested in the literature. Both of these concepts are important in relation to health and the area of primary healthcare in particular. Thus, several tools for the measurement of social exclusion or social inclusion status in health care settings have been developed. A scoping review of the peer-reviewed and grey literature was conducted to examine tools developed since 2000 that measure social exclusion or social inclusion. We focused on those measurement tools developed for use with individual patients in healthcare settings. Efforts were made to obtain a copy of each of the original tools, and all relevant background literature. All tools retrieved were compared in tables, and the specific domains that were included in each measure were tabulated. Twenty-two measurement tools were included in the final scoping review. The majority of these had been specifically developed for the measurement of social inclusion or social exclusion, but a small number were created for the measurement of other closely aligned concepts. The majority of the tools included were constructed for engaging with patients in mental health settings. The tools varied greatly in their design, the scoring systems and the ways they were administered. The domains covered by these tools varied widely and some of the tools were quite narrow in the areas of focus. A review of the definitions of both social inclusion and social exclusion also revealed the variations among the explanations of these complex concepts. There are several definitions of both social inclusion and social exclusion in use and they differ greatly in scope. While there are many tools that have been developed for measuring these concepts in healthcare settings, these

  11. Young mothers, first time parenthood and exclusive breastfeeding in Kenya.

    PubMed

    Naanyu, Violet

    2008-12-01

    Breastfeeding behaviour is explored in Kenya using data collected in the town of Eldoret, Kenya. This paper specifically examines duration of exclusive breastfeeding among young mothers below 20 years of age as compared to older cohorts. Additionally, focus is laid on the effect of first time motherhood and breastfeeding difficulties on exclusive breastfeeding. Results show that Eldoret mothers are aware of benefits of breastfeeding; nevertheless, the mean duration for exclusive breastfeeding in this sample is 2.4 months. Higher durations of exclusive breastfeeding are associated with increasing age and first time motherhood. Predictably, breastfeeding difficulties bear a negative association with exclusive breastfeeding. While HIV is transmissible through breastfeeding, breast milk remains a vital source of nourishment for infants in Sub-Saharan Africa. More research on mothering should examine the changing socio-economic milieu and its influence on women's infant feeding decisions

  12. Cooperation and competition: nepotistic tolerance and intrasexual aggression in western bluebird winter groups

    USGS Publications Warehouse

    Dickinson, J.L.; Euaparadorn, M.; Greenwald, K.; Mitra, C.; Shizuka, Daizaburo

    2009-01-01

    Two hypothesized benefits of delayed dispersal are access to resources and prolonged brood care (or??parental nepotism). Resource abundance (mistletoe wealth) is a key factor influencing whether sons stay home in western bluebirds, Sialia mexicana, but nepotism is also observed. Western bluebird sons commonly remain in their family groups throughout the winter, whereas daughters usually disperse before winter. Because pairing often takes place in winter groups, with newly formed pairs settling on exclusive all-purpose territories in spring, selection for sexual competition and nepotism co-occur and may simultaneously influence patterns of aggression within groups. We measured aggression at mealworm feeder stations, finding evidence of (1) intrasexual aggression against unrelated group members by experienced breeders of both sexes and (2) nepotism towards sons and daughters by experienced breeder females but not by experienced breeder males. Females showed much higher levels of aggression towards same-sex immigrants than males did. Experienced breeder males did not evict their sons from the natal territory, but they were 12 times more aggressive towards sons than breeder females were towards daughters. They were also equally aggressive towards sons and immigrant males, suggesting that local breeding competition and the benefits of intrasexual dominance counter the benefits of paternal nepotism towards sons. ?? 2009 The Association for the Study of Animal Behaviour.

  13. Who Are the Children Most Vulnerable to Social Exclusion? The Moderating Role of Self-Esteem, Popularity, and Nonverbal Intelligence on Cognitive Performance Following Social Exclusion.

    PubMed

    Tobia, Valentina; Riva, Paolo; Caprin, Claudia

    2017-05-01

    Social exclusion has a profound emotional impact on children. However, there is still limited and partly conflicting experimental evidence for the possible effect of social exclusion on children's cognitive performance. In the present study, we tested the possibility that some children are more vulnerable than others to the negative effects of social exclusion on cognitive performance. We selected 4 potential candidates that could moderate the effects of social exclusion: relational self-esteem, peer ratings of popularity, rejection sensitivity and nonverbal intelligence. Individual differences in these 4 potential moderating factors were first assessed in a sample of 318 children (45.6 % females; mean age = 9.92 years). Then, in a subsequent experimental session, the participants were either socially included or excluded using a typical manipulation (i.e., the Cyberball paradigm). Following the manipulation, the children's cognitive performance was assessed using a logical reasoning test. The results showed that the children with lower scores for relational self-esteem (the bottom 37.46 % of the sample), lower popularity (43.49 %) or weaker nonverbal intelligence (37.80 %) performed worse on the logical reasoning test following social exclusion. Moreover, children with combined low self-esteem, popularity and nonverbal intelligence were the most affected by social exclusion. This study identified factors that make some children more vulnerable to the negative effects of social exclusion. Overall, the present work underscores the value of considering basic cognitive and relational individual differences when developing interventions aimed at preventing the negative effects of social exclusion among children.

  14. Voices of students in competition: Health Science First Year at the University of Otago, Dunedin.

    PubMed

    Jameson, Madgerie; Smith, Jeffrey

    2011-07-08

    The experiences and adjustments of students enrolled in Health Science First Year (HSFY) at the University of Otago (Dunedin, New Zealand) were explored to understand students' response to competition. The paper highlights the expressions of past and present HSFY students' impressions of the programme, their experiences, coping strategies and the lessons they learned from the programme. Qualitative data were collected from past (n=15) and present (n=20) HSFY students who wanted to pursue medicine. Eight semi-structured interview questions were used to answer four research questions that aimed to answer the following: students' impressions of HSFY, students' experiences of HSFY; students' adjustments to HSFY, and lessons learned from HSFY. The interviews were analysed using narrative analysis to gain a greater understanding of their experiences and adjustment. The results indicate students perceive the programme as demanding and stressful. The highly competitive nature of the programme inhibited their engagement and involvement in other aspects of university life. Students identified their experiences as successes and challenges. In terms of adjustment, students used cognitive restructuring, self regulation and social support. Students learned that they need to balance academic and social life because spending too much time almost exclusively on academics didn't enrich their first year at university. The nature of the learning environment impacts on students' holistic development. The competitive nature of the programme elicited undue stress on students. However, they had to employ strategies to help minimise the impact of stress on their functioning.

  15. Behavioral and life-history evidence for interspecific competition in the larvae of two heliconian butterflies

    NASA Astrophysics Data System (ADS)

    Millan, Carolina; Borges, Simone Silva; Rodrigues, Daniela; Moreira, Gilson Rudinei Pires

    2013-10-01

    Interspecific competition in herbivorous insects remains a controversial issue. To date, many studied systems have not met assumptions of the traditional competition theory, and a new paradigm has been emerging. We examined the behavioral and life-history consequences of common host plant use of Heliconius erato and Dryas iulia (Nymphalidae) in relation to Passiflora suberosa (Passifloraceae). Larvae of the former use the apical portion of this host; the latter is presumably able to explore all plant parts. We assessed host use pattern in relation to leaf age, when reared either alone ( D. iulia) or together ( D. iulia and H. erato). Larval feeding choice tests with respect to leaf age were performed, and performance was recorded. Observations were made to assess antagonistic behavior of H. erato and D. iulia towards each other, if any. Similarly to H. erato, D. iulia fed on the young leaves significantly more than the mature ones; larvae were not induced to prefer mature leaves. First instars of H. erato used only the apical parts of P. suberosa and displayed aggressive behavior towards D. iulia, which moved to the lower shoot portions. Larval mortality and development time of both species significantly increased when reared together; such performance costs were more pronounced in D. iulia than H. erato. Our study gathers evidences that use of P. suberosa by these heliconian butterflies represent a case of competitive exclusion resulting in niche differentiation, where costs are higher for D. iulia than H. erato.

  16. Behavioral and life-history evidence for interspecific competition in the larvae of two heliconian butterflies.

    PubMed

    Millan, Carolina; Borges, Simone Silva; Rodrigues, Daniela; Moreira, Gilson Rudinei Pires

    2013-10-01

    Interspecific competition in herbivorous insects remains a controversial issue. To date, many studied systems have not met assumptions of the traditional competition theory, and a new paradigm has been emerging. We examined the behavioral and life-history consequences of common host plant use of Heliconius erato and Dryas iulia (Nymphalidae) in relation to Passiflora suberosa (Passifloraceae). Larvae of the former use the apical portion of this host; the latter is presumably able to explore all plant parts. We assessed host use pattern in relation to leaf age, when reared either alone (D. iulia) or together (D. iulia and H. erato). Larval feeding choice tests with respect to leaf age were performed, and performance was recorded. Observations were made to assess antagonistic behavior of H. erato and D. iulia towards each other, if any. Similarly to H. erato, D. iulia fed on the young leaves significantly more than the mature ones; larvae were not induced to prefer mature leaves. First instars of H. erato used only the apical parts of P. suberosa and displayed aggressive behavior towards D. iulia, which moved to the lower shoot portions. Larval mortality and development time of both species significantly increased when reared together; such performance costs were more pronounced in D. iulia than H. erato. Our study gathers evidences that use of P. suberosa by these heliconian butterflies represent a case of competitive exclusion resulting in niche differentiation, where costs are higher for D. iulia than H. erato.

  17. Alcohol, poverty and social exclusion: Alcohol consumption among the homeless and those at risk of social exclusion in Madrid.

    PubMed

    Panadero, Sonia; Vázquez, José Juan; Martín, Rosa María

    2016-06-14

    The work analyzes different aspects related to alcohol consumption among homeless people and people at risk of social exclusion. The data was gathered from a representative sample of homeless people in Madrid (n = 188) and a sample of people at risk of social exclusion (n = 164) matched in sex, age, and origin (Spaniards vs. foreigners). The results showed that homeless people present a greater consumption of alcohol and have experienced more problems derived from its consumption than people at risk of social exclusion. Most of the homeless people who had alcohol-related problems had had them prior to their homelessness, and they stated they had poorer health and had experienced a greater number of homelessness episodes. Despite the relevance of problems related to alcohol among our sample, only a small percentage of the sample had participated in treatment programs for alcohol consumption.

  18. 26 CFR 25.2503-2 - Exclusions from gifts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Exclusions from gifts. 25.2503-2 Section 25... GIFT TAXES GIFT TAX; GIFTS MADE AFTER DECEMBER 31, 1954 Determination of Tax Liability § 25.2503-2 Exclusions from gifts. (a) Except as provided in paragraph (f) of this section (involving gifts to a...

  19. 2017 Robotic Mining Competition

    NASA Image and Video Library

    2017-05-23

    College team members prepare to enter the robotic mining arena for a test run during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.

  20. 2017 Robotic Mining Competition

    NASA Image and Video Library

    2017-05-24

    The robotic miner from Mississippi State University digs in the mining arena during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.

  1. 2017 Robotic Mining Competition

    NASA Image and Video Library

    2017-05-24

    A robotic miner digs in the mining arena during NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.

  2. 2017 Robotic Mining Competition

    NASA Image and Video Library

    2017-05-24

    Energy levels are high in the RoboPit as teams prepare for NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. arel using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.

  3. 2017 Robotic Mining Competition

    NASA Image and Video Library

    2017-05-23

    NASA Kennedy Space Center Director Bob Cabana welcomes participants to the agency's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.

  4. The Janus face of Darwinian competition.

    PubMed

    Hintze, Arend; Phillips, Nathaniel; Hertwig, Ralph

    2015-09-10

    Without competition, organisms would not evolve any meaningful physical or cognitive abilities. Competition can thus be understood as the driving force behind Darwinian evolution. But does this imply that more competitive environments necessarily evolve organisms with more sophisticated cognitive abilities than do less competitive environments? Or is there a tipping point at which competition does more harm than good? We examine the evolution of decision strategies among virtual agents performing a repetitive sampling task in three distinct environments. The environments differ in the degree to which the actions of a competitor can affect the fitness of the sampling agent, and in the variance of the sample. Under weak competition, agents evolve decision strategies that sample often and make accurate decisions, which not only improve their own fitness, but are good for the entire population. Under extreme competition, however, the dark side of the Janus face of Darwinian competition emerges: Agents are forced to sacrifice accuracy for speed and are prevented from sampling as often as higher variance in the environment would require. Modest competition is therefore a good driver for the evolution of cognitive abilities and of the population as a whole, whereas too much competition is devastating.

  5. 40 CFR 35.6555 - Competition.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... current and include enough qualified sources to ensure maximum open and free competition. Recipients must... transactions in a manner providing maximum full and open competition. (a) Restrictions on competition... bonding requirements; (3) Noncompetitive pricing practices between firms or between affiliated companies...

  6. Public healthcare interests require strict competition enforcement.

    PubMed

    Loozen, Edith M H

    2015-07-01

    Several countries have introduced competition in their health systems in order to maintain the supply of high quality health care in a cost-effective manner. The introduction of competition triggers competition enforcement. Since healthcare is characterized by specific market failures, many favor healthcare-specific competition enforcement in order not only to account for the competition interest, but also for the healthcare interests. The question is whether healthcare systems based on competition can succeed when competition enforcement deviates from standard practice. This paper analyzes whether healthcare-specific competition enforcement is theoretically sound and practically effective. This is exemplified by the Dutch system that is based on regulated competition and thus crucially depends on getting competition enforcement right. Governments are responsible for correcting market failures. Markets are responsible for maximizing the public healthcare interests. By securing sufficient competitive pressure, competition enforcement makes sure they do. When interpreted according to welfare-economics, competition law takes into account both costs and benefits specific market behavior may have for healthcare. Competition agencies and judiciary are not legitimized to deviate from standard evidentiary requirements. Dutch case law shows that healthcare-specific enforcement favors the healthcare undertakings concerned, but to the detriment of public health care. Healthcare-specific competition enforcement is conceptually flawed and counterproductive. In order for healthcare systems based on competition to succeed, competition enforcement should be strict. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Effect of antenatal counselling on exclusive breastfeeding.

    PubMed

    Ahmad, Muhammad Owais; Sughra, Ume; Kalsoom, Umay; Imran, Muhammad; Hadi, Usman

    2012-01-01

    The promotion and support of breastfeeding is a global priority. However, in reality most of the mothers are unable to practice exclusive breastfeeding. Most mothers discontinue breastfeeding because of lack of confidence in their ability to breastfeed, problem with infant suckling, breast pain, perception of insufficient milk, in addition to other unspecified difficulties. Some these problems can be solved if the women are counselled antenataly about the benefits of breastfeeding and prepared mentally for exclusive breastfeeding. The aim of the study was to determine whether the mothers with antenatal counselling on breastfeeding would improve their exclusive breast feeding and compare this with that of the mothers without antenatal counselling. It was a cross-sectional comparative study which took place at the Maternity ward of Fauji Foundation Hospital, Rawalpindi. Hundred mothers selected by consecutive non probability sampling divided in two groups. Group A: 50 mothers who were counselled on breastfeeding and Group B: 50 mothers who were not counselled on breastfeeding. Fifty mothers practicing breast feeding after antenatal counselling in the maternity ward of Fauji Foundation Hospital, Rawalpindi were recruited in the study. Another fifty mothers practicing breastfeeding without antenatal counselling were asked to take part in the study as a control group. Performa was completed and an informed consent was obtained. As compared to the not counselled group, the mothers who initiated breastfeeding immediately after birth were statistically significantly higher (p < 0.046) in the counselled group (84% and 96% respectively). Similarly the number of counselled mothers who practiced exclusive breastfeeding was statistically very highly significantly more (p < 0.001) than the not counselled group (68% and 16% respectively). Antenatal counselling helps in motivating the mothers for initiation of breastfeeding immediately after birth and practicing exclusive

  8. Predictors of competitive achievement among pubescent synchronized swimmers: an analysis of the solo-figure competition.

    PubMed

    Peric, M; Cavar, M; Zenic, N; Sekulic, D; Sajber, D

    2014-02-01

    This study examined the applicability of sport-specific fitness tests (SSTs), anthropometrics, and respiratory parameters in predicting competitive results among pubescent synchronized swimmers. A total of 25 synchronized swimmers (16-17 years; 166.2 ± 5.4 cm; and 58.4 ± 4.3 kg) volunteered for this study. The independent variables were body mass, body height, Body Mass Index (BMI), body fat percentage (BF%), lean body mass percentage, respiratory variables, and four SSTs (two specific power tests plus one aerobic- and one anaerobic-endurance test). The dependent variable was competitive achievement in the solo figure competition. The reliability analyses, Pearson's correlation coefficient and forward stepwise regression were calculated. The SSTs were reliable for testing fitness status among pubescent synchronized swimmers. The forward stepwise regression retained two SSTs, BF% and forced vital capacity (FVC, relative for age and stature) in a set of predictors of competitive achievement. Significant Beta coefficients are found for aerobic-endurance, SST and FVC. The sport-specific measure of aerobic endurance and FVC appropriately predicted competitive achievement with regard to the figures used in the competition when competitive results (the dependent variable) were obtained. Athletes and coaches should be aware of the probable negative influence of very low body fat levels on competitive achievement.

  9. 7 CFR 1b.4 - Exclusion of agencies.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Exclusion of agencies. 1b.4 Section 1b.4 Agriculture Office of the Secretary of Agriculture NATIONAL ENVIRONMENTAL POLICY ACT § 1b.4 Exclusion of agencies. (a... activities that have been found to have no individual or cumulative effect on the human environment. The USDA...

  10. 7 CFR 1b.4 - Exclusion of agencies.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Exclusion of agencies. 1b.4 Section 1b.4 Agriculture Office of the Secretary of Agriculture NATIONAL ENVIRONMENTAL POLICY ACT § 1b.4 Exclusion of agencies. (a... activities that have been found to have no individual or cumulative effect on the human environment. The USDA...

  11. Schools as Agents of Social Exclusion and Inclusion

    ERIC Educational Resources Information Center

    Razer, Michal; Friedman, Victor J.; Warshofsky, Boaz

    2013-01-01

    Although schools are usually regarded as important agents for social inclusion, research has shown that they may also function as agents of exclusion itself. The goal of this paper is to deepen our understanding of how schools function as agents of exclusion and how they can become more effective agents of inclusion. It is based on action research…

  12. Career Guidance and Social Exclusion: A Cautionary Tale.

    ERIC Educational Resources Information Center

    Watts, A. G.

    2001-01-01

    Examines the relationship of career guidance to public-policy interventions designed to address social exclusion. Analyzes the nature and origin of the concept of social exclusion and reviews the roles of career guidance in response to it, particularly in relation to young people who have dropped out of formal education or are at high risk of…

  13. Competitive Intelligence and Social Advantage.

    ERIC Educational Resources Information Center

    Davenport, Elisabeth; Cronin, Blaise

    1994-01-01

    Presents an overview of issues concerning civilian competitive intelligence (CI). Topics discussed include competitive advantage in academic and research environments; public domain information and libraries; covert and overt competitive intelligence; data diversity; use of the Internet; cooperative intelligence; and implications for library and…

  14. The role of spatial and temporal heterogeneity and competition in structuring trematode communities in the great pond snail, Lymnaea stagnalis (L.)

    USGS Publications Warehouse

    Soldánová, Miroslava; Kuris, Armand M.; Scholz, Tomáš; Lafferty, Kevin D.

    2012-01-01

    We assessed how spatial and temporal heterogeneity and competition structure larval trematode communities in the pulmonate snail Lymnaea stagnalis. To postulate a dominance hierarchy, mark-release-recapture was used to monitor replacements of trematode species within snails over time. In addition, we sampled the trematode community in snails in different ponds in 3 consecutive years. A total of 7,623 snails (10,382 capture events) was sampled in 7 fishponds in the Jindřichův Hradec and Třeboň areas in South Bohemia (Czech Republic) from August 2006 to October 2008. Overall, 39% of snails were infected by a community of 14 trematode species; 7% of snails were infected with more than 1 trematode species (constituting 16 double- and 4 triple-species combinations). Results of the null-model analyses suggested that spatial heterogeneity in recruitment among ponds isolated trematode species from each other, whereas seasonal pulses in recruitment increased species interactions in some ponds. Competitive exclusion among trematodes led to a rarity of multiple infections compared to null-model expectations. Competitive relationships among trematode species were hypothesized as a dominance hierarchy based on direct evidence of replacement and invasion and on indirect evidence. Seven top dominant species with putatively similar competitive abilities (6 rediae and 1 sporocyst species) reduced the prevalence of the other trematode species developing in sporocysts only.

  15. 47 CFR 90.165 - Procedures for mutually exclusive applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... 90.165 Section 90.165 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND... Governing Facilities Used to Provide Commercial Mobile Radio Services § 90.165 Procedures for mutually exclusive applications. Mutually exclusive commercial mobile radio service applications are processed in...

  16. 19 CFR 10.452 - Exclusions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Chile Free Trade Agreement Rules of Origin § 10.452 Exclusions. A good will not be considered to be an originating good and a material...

  17. Evaluation of water resources system vulnerability based on co-operative co-evolutionary genetic algorithm and projection pursuit model under the DPSIR framework

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Su, X. H.; Wang, M. H.; Li, Z. Y.; Li, E. K.; Xu, X.

    2017-08-01

    Water resources vulnerability control management is essential because it is related to the benign evolution of socio-economic, environmental and water resources system. Research on water resources system vulnerability is helpful to realization of water resources sustainable utilization. In this study, the DPSIR framework of driving forces-pressure-state-impact-response was adopted to construct the evaluation index system of water resources system vulnerability. Then the co-evolutionary genetic algorithm and projection pursuit were used to establish evaluation model of water resources system vulnerability. Tengzhou City in Shandong Province was selected as a study area. The system vulnerability was analyzed in terms of driving forces, pressure, state, impact and response on the basis of the projection value calculated by the model. The results show that the five components all belong to vulnerability Grade II, the vulnerability degree of impact and state were higher than other components due to the fierce imbalance in supply-demand and the unsatisfied condition of water resources utilization. It is indicated that the influence of high speed socio-economic development and the overuse of the pesticides have already disturbed the benign development of water environment to some extents. While the indexes in response represented lower vulnerability degree than the other components. The results of the evaluation model are coincident with the status of water resources system in the study area, which indicates that the model is feasible and effective.

  18. A model for competitiveness level analysis in sports competitions: Application to basketball

    NASA Astrophysics Data System (ADS)

    de Saá Guerra, Y.; Martín González, J. M.; Sarmiento Montesdeoca, S.; Rodríguez Ruiz, D.; García-Rodríguez, A.; García-Manso, J. M.

    2012-05-01

    The degree of overall competitiveness of a sport league is a complex phenomenon. It is difficult to assess and quantify all elements that yield the final standing. In this paper, we analyze the general behavior of the result matrices of each season and we use the corresponding results as a probably density. Thus, the results of previous seasons are a way to investigate the probability that each team has to reach a certain number of victories. We developed a model based on Shannon entropy using two extreme competitive structures (a hierarchical structure and a random structure), and applied this model to investigate the competitiveness of two of the best professional basketball leagues: the NBA (USA) and the ACB (Spain). Both leagues’ entropy levels are high (NBA mean 0.983; ACB mean 0.980), indicating high competitiveness, although the entropy of the ACB (from 0.986 to 0.972) demonstrated more seasonal variability than that of the NBA (from 0.985 to 0.990), a possible result of greater sporting gradients in the ACB. The use of this methodology has proven useful for investigating the competitiveness of sports leagues as well as their underlying variability across time.

  19. Competition Experiments for Legume Infection Identify Burkholderia phymatum as a Highly Competitive β-Rhizobium

    PubMed Central

    Lardi, Martina; de Campos, Samanta Bolzan; Purtschert, Gabriela; Eberl, Leo; Pessi, Gabriella

    2017-01-01

    Members of the genus Burkholderia (β-proteobacteria) have only recently been shown to be able to establish a nitrogen-fixing symbiosis with several legumes, which is why they are also referred to as β-rhizobia. Therefore, very little is known about the competitiveness of these species to nodulate different legume host plants. In this study, we tested the competitiveness of several Burkholderia type strains (B. diazotrophica, B. mimosarum, B. phymatum, B. sabiae, B. symbiotica and B. tuberum) to nodulate four legumes (Phaseolus vulgaris, Macroptilium atropurpureum, Vigna unguiculata and Mimosa pudica) under our closely defined growth conditions. The assessment of nodule occupancy of these species on different legume host plants revealed that B. phymatum was the most competitive strain in the three papilionoid legumes (bean, cowpea and siratro), while B. mimosarum outcompeted the other strains in mimosa. The analysis of phenotypes known to play a role in nodulation competitiveness (motility, exopolysaccharide production) and additional in vitro competition assays among β-rhizobial strains suggested that B. phymatum has the potential to be a very competitive legume symbiont. PMID:28861050

  20. Burkholderia spp. are the most competitive symbionts of Mimosa, particularly under N-limited conditions.

    PubMed

    Elliott, Geoffrey N; Chou, Jui-Hsing; Chen, Wen-Ming; Bloemberg, Guido V; Bontemps, Cyril; Martínez-Romero, Esperanza; Velázquez, Encarna; Young, J Peter W; Sprent, Janet I; James, Euan K

    2009-04-01

    Bacteria isolated from Mimosa nodules in Taiwan, Papua New Guinea, Mexico and Puerto Rico were identified as belonging to either the alpha- or beta-proteobacteria. The beta-proteobacterial Burkholderia and Cupriavidus strains formed effective symbioses with the common invasive species Mimosa diplotricha, M. pigra and M. pudica, but the alpha-proteobacterial Rhizobium etli and R. tropici strains produced a range of symbiotic phenotypes from no nodulation through ineffective to effective nodulation, depending on Mimosa species. Competition studies were performed between three of the alpha-proteobacteria (R. etli TJ167, R. tropici NGR181 and UPRM8021) and two of the beta-rhizobial symbionts (Burkholderia mimosarum PAS44 and Cupriavidus taiwanensis LMG19424) for nodulation of these invasive Mimosa species. Under flooded conditions, B. mimosarum PAS44 out-competed LMG19424 and all three alpha-proteobacteria to the point of exclusion. This advantage was not explained by initial inoculum levels, rates of bacterial growth, rhizobia-rhizobia growth inhibition or individual nodulation rate. However, the competitive domination of PAS44 over LMG19424 was reduced in the presence of nitrate for all three plant hosts. The largest significant effect was for M. pudica, in which LMG19424 formed 57% of the nodules in the presence of 0.5 mM potassium nitrate. In this host, ammonium also had a similar, but lesser, effect. Comparable results were also found using an N-containing soil mixture, and environmental N levels are therefore suggested as a factor in the competitive success of the bacterial symbiont in vivo.