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Sample records for preschoolers indirect reciprocity

  1. Indirect reciprocity with trinary reputations

    CERN Document Server

    Tanabe, Shoma; Masuda, Naoki

    2012-01-01

    Indirect reciprocity is a reputation-based mechanism for cooperation in social dilemma situations when individuals do not repeatedly meet. The conditions under which cooperation based on indirect reciprocity occurs has been examined in great details. Previous theoretical analysis assumed for mathematical tractability that an individual possesses a binary reputation value, i.e., good or bad, which depends on their past actions and other factors. However, in real situations, reputations of individuals may be multiple valued. Another puzzling discrepancy between the theory and experiments is the status of the so-called image scoring, in which cooperation and defection are judged to be good and bad, respectively, independent of other factors. Such an assessment rule is found in behavioral experiments, whereas it is known to be unstable in theory. In the present study, we fill both gaps by theoretical analysis of a trinary reputation model. By an exhaustive search, we identify all the cooperative and stable equili...

  2. Indirect reciprocity with trinary reputations.

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    Tanabe, Shoma; Suzuki, Hideyuki; Masuda, Naoki

    2013-01-21

    Indirect reciprocity is a reputation-based mechanism for cooperation in social dilemma situations when individuals do not repeatedly meet. The conditions under which cooperation based on indirect reciprocity occurs have been examined in great details. Most previous theoretical analysis assumed for mathematical tractability that an individual possesses a binary reputation value, i.e., good or bad, which depends on their past actions and other factors. However, in real situations, reputations of individuals may be multiple valued. Another puzzling discrepancy between the theory and experiments is the status of the so-called image scoring, in which cooperation and defection are judged to be good and bad, respectively, independent of other factors. Such an assessment rule is found in behavioral experiments, whereas it is known to be unstable in theory. In the present study, we fill both gaps by analyzing a trinary reputation model. By an exhaustive search, we identify all the cooperative and stable equilibria composed of a homogeneous population or a heterogeneous population containing two types of players. Some results derived for the trinary reputation model are direct extensions of those for the binary model. However, we find that the trinary model allows cooperation under image scoring under some mild conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Two distinct neural mechanisms underlying indirect reciprocity.

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    Watanabe, Takamitsu; Takezawa, Masanori; Nakawake, Yo; Kunimatsu, Akira; Yamasue, Hidenori; Nakamura, Mitsuhiro; Miyashita, Yasushi; Masuda, Naoki

    2014-03-18

    Cooperation is a hallmark of human society. Humans often cooperate with strangers even if they will not meet each other again. This so-called indirect reciprocity enables large-scale cooperation among nonkin and can occur based on a reputation mechanism or as a succession of pay-it-forward behavior. Here, we provide the functional and anatomical neural evidence for two distinct mechanisms governing the two types of indirect reciprocity. Cooperation occurring as reputation-based reciprocity specifically recruited the precuneus, a region associated with self-centered cognition. During such cooperative behavior, the precuneus was functionally connected with the caudate, a region linking rewards to behavior. Furthermore, the precuneus of a cooperative subject had a strong resting-state functional connectivity (rsFC) with the caudate and a large gray matter volume. In contrast, pay-it-forward reciprocity recruited the anterior insula (AI), a brain region associated with affective empathy. The AI was functionally connected with the caudate during cooperation occurring as pay-it-forward reciprocity, and its gray matter volume and rsFC with the caudate predicted the tendency of such cooperation. The revealed difference is consistent with the existing results of evolutionary game theory: although reputation-based indirect reciprocity robustly evolves as a self-interested behavior in theory, pay-it-forward indirect reciprocity does not on its own. The present study provides neural mechanisms underlying indirect reciprocity and suggests that pay-it-forward reciprocity may not occur as myopic profit maximization but elicit emotional rewards.

  4. Cooperation under indirect reciprocity and imitative trust.

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    Serguei Saavedra

    Full Text Available Indirect reciprocity, a key concept in behavioral experiments and evolutionary game theory, provides a mechanism that allows reciprocal altruism to emerge in a population of self-regarding individuals even when repeated interactions between pairs of actors are unlikely. Recent empirical evidence show that humans typically follow complex assessment strategies involving both reciprocity and social imitation when making cooperative decisions. However, currently, we have no systematic understanding of how imitation, a mechanism that may also generate negative effects via a process of cumulative advantage, affects cooperation when repeated interactions are unlikely or information about a recipient's reputation is unavailable. Here we extend existing evolutionary models, which use an image score for reputation to track how individuals cooperate by contributing resources, by introducing a new imitative-trust score, which tracks whether actors have been the recipients of cooperation in the past. We show that imitative trust can co-exist with indirect reciprocity mechanisms up to a threshold and then cooperation reverses -revealing the elusive nature of cooperation. Moreover, we find that when information about a recipient's reputation is limited, trusting the action of third parties towards her (i.e. imitating does favor a higher collective cooperation compared to random-trusting and share-alike mechanisms. We believe these results shed new light on the factors favoring social imitation as an adaptive mechanism in populations of cooperating social actors.

  5. Cooperation under indirect reciprocity and imitative trust.

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    Saavedra, Serguei; Smith, David; Reed-Tsochas, Felix

    2010-10-27

    Indirect reciprocity, a key concept in behavioral experiments and evolutionary game theory, provides a mechanism that allows reciprocal altruism to emerge in a population of self-regarding individuals even when repeated interactions between pairs of actors are unlikely. Recent empirical evidence show that humans typically follow complex assessment strategies involving both reciprocity and social imitation when making cooperative decisions. However, currently, we have no systematic understanding of how imitation, a mechanism that may also generate negative effects via a process of cumulative advantage, affects cooperation when repeated interactions are unlikely or information about a recipient's reputation is unavailable. Here we extend existing evolutionary models, which use an image score for reputation to track how individuals cooperate by contributing resources, by introducing a new imitative-trust score, which tracks whether actors have been the recipients of cooperation in the past. We show that imitative trust can co-exist with indirect reciprocity mechanisms up to a threshold and then cooperation reverses -revealing the elusive nature of cooperation. Moreover, we find that when information about a recipient's reputation is limited, trusting the action of third parties towards her (i.e. imitating) does favor a higher collective cooperation compared to random-trusting and share-alike mechanisms. We believe these results shed new light on the factors favoring social imitation as an adaptive mechanism in populations of cooperating social actors.

  6. Indirect reciprocity and the evolution of "moral signals"

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    Smead, Rory

    2010-01-01

    Signals regarding the behavior of others are an essential element of human moral systems and there are important evolutionary connections between language and large-scale cooperation. In particular, social communication may be required for the reputation tracking needed to stabilize indirect reciprocity. Additionally, scholars have suggested that the benefits of indirect reciprocity may have been important for the evolution of language and that social signals may have coevolved with large-scale cooperation. This paper investigates the possibility of such a coevolution. Using the tools of evolutionary game theory, we present a model that incorporates primitive "moral signaling" into a simple setting of indirect reciprocity. This model reveals some potential difficulties for the evolution of "moral signals." We find that it is possible for "moral signals" to evolve alongside indirect reciprocity, but without some external pressure aiding the evolution of a signaling system, such a coevolution is unlikely.

  7. The evolution of conditional moral assessment in indirect reciprocity

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    Sasaki, Tatsuya; Nakai, Yutaka

    2016-01-01

    Indirect reciprocity is a major mechanism in the maintenance of cooperation among unfamiliar individuals. Indirect reciprocity leads to conditional cooperation according to social norms that discriminate the good (those who deserve to be rewarded with help) and the bad (those who should be punished by refusal of help). Despite intensive research, however, there is no definitive consensus on what social norms best promote cooperation through indirect reciprocity, and it remains unclear even how those who refuse help to the bad should be assessed. Here we propose a new simple norm called 'Staying' that prescribes to abstain from assessment, with the focal individual's image remaining unchanged, if its opponent has a bad image. We fully analyse the Staying norm in terms of evolutionary game theory and unveil that Staying is most effective in establishing cooperation, compared to the prevailing social norms which rely on constant monitoring and unconditional assessment. The excellence of Staying suggests the limi...

  8. Social Dilemmas and Indirect Reciprocity: A systematic review

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    Cristian Acosta

    2014-08-01

    Full Text Available Indirect reciprocity is an evolutionary theory of altruism and cooperation in social dilemmas. Its explanation of cooperation incorporates information on the reputation people hold of other people regarding whether they are cooperative or not. This study systematically reviewed the current empirical literature on indirect reciprocity in social dilemma situations. The following databases were consulted: ScienceDirect, EBSCO, and OVID, using has key words "indirect reciprocity" AND "dilemma" OR "cooperation" OR "charity". Twenty-three articles were selected which met the inclusion criteria (papers written in English and studies whose methodology was based on experimental games and the theories, objectives, the main types of samples used, and main results were analyzed. The results show that the games used were the indirect reciprocity and public goods games, which may vary according to the objectives. It was found that reputation is a key variable that helps to promote cooperation. In turn, information on previous cooperation helps to build reputation, which is subsequently involved in the decision to cooperate with others. Finally, we highlight the need for more experimental studies that incorporate other explanatory variables and evaluate them in new contexts.

  9. Groupwise information sharing promotes ingroup favoritism in indirect reciprocity

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    Nakamura Mitsuhiro

    2012-11-01

    Full Text Available Abstract Background Indirect reciprocity is a mechanism for cooperation in social dilemma situations. In indirect reciprocity, an individual is motivated to help another to acquire a good reputation and receive help from others afterwards. Another aspect of human cooperation is ingroup favoritism, whereby individuals help members in their own group more often than those in other groups. Ingroup favoritism is a puzzle for the theory of cooperation because it is not easily evolutionarily stable. In the context of indirect reciprocity, ingroup favoritism has been shown to be a consequence of employing a double standard when assigning reputations to ingroup and outgroup members. An example of such a double standard is the situation in which helping an ingroup member is regarded as good, whereas the same action toward an outgroup member is regarded as bad. Results We analyze a computational model of indirect reciprocity in which information sharing is conducted groupwise. In our model, individuals play social dilemma games within and across groups, and the information about their reputations is shared within each group. We show that evolutionarily stable ingroup favoritism emerges even if all the players use the same reputation assignment rule regardless of group (i.e., a single standard. Two reputation assignment rules called simple standing and stern judging yield ingroup favoritism; under these rules, cooperation with (defection against good individuals is regarded as good (bad and defection against bad individuals is regarded as good. Stern judging induces much stronger ingroup favoritism than does simple standing. Simple standing and stern judging are evolutionarily stable against each other when groups employing different assignment rules compete and the number of groups is sufficiently large. In addition, we analytically show as a limiting case that homogeneous populations of reciprocators that use reputations are unstable when individuals

  10. Indirect Reciprocity with Optional Interactions and Private Information

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    Jason Olejarz

    2015-09-01

    Full Text Available We consider indirect reciprocity with optional interactions and private information. A game is offered between two players and accepted unless it is known that the other person is a defector. Whenever a defector manages to exploit a cooperator, his or her reputation is revealed to others in the population with some probability. Therefore, people have different private information about the reputation of others, which is a setting that is difficult to analyze in the theory of indirect reciprocity. Since a defector loses a fraction of his social ties each time he exploits a cooperator, he is less efficient at exploiting cooperators in subsequent rounds. We analytically calculate the critical benefit-to-cost ratio above which cooperation is successful in various settings. We demonstrate quantitative agreement with simulation results of a corresponding Wright–Fisher process with optional interactions and private information. We also deduce a simple necessary condition for the critical benefit-to-cost ratio.

  11. Partner Choice Drives the Evolution of Cooperation via Indirect Reciprocity.

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    Gilbert Roberts

    Full Text Available Indirect reciprocity potentially provides an important means for generating cooperation based on helping those who help others. However, the use of 'image scores' to summarize individuals' past behaviour presents a dilemma: individuals withholding help from those of low image score harm their own reputation, yet giving to defectors erodes cooperation. Explaining how indirect reciprocity could evolve has therefore remained problematic. In all previous treatments of indirect reciprocity, individuals are assigned potential recipients and decide whether to cooperate or defect based on their reputation. A second way of achieving discrimination is through partner choice, which should enable individuals to avoid defectors. Here, I develop a model in which individuals choose to donate to anyone within their group, or to none. Whereas image scoring with random pairing produces cycles of cooperation and defection, with partner choice there is almost maximal cooperation. In contrast to image scoring with random pairing, partner choice results in almost perfect contingency, producing the correlation between giving and receiving required for cooperation. In this way, partner choice facilitates much higher and more stable levels of cooperation through image scoring than previously reported and provides a simple mechanism through which systems of helping those who help others can work.

  12. The evolution of conditional moral assessment in indirect reciprocity

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    Sasaki, Tatsuya; Okada, Isamu; Nakai, Yutaka

    2017-02-01

    Indirect reciprocity is a major mechanism in the maintenance of cooperation among unrelated individuals. Indirect reciprocity leads to conditional cooperation according to social norms that discriminate the good (those who deserve to be rewarded with help) and the bad (those who should be punished by refusal of help). Despite intensive research, however, there is no definitive consensus on what social norms best promote cooperation through indirect reciprocity, and it remains unclear even how those who refuse to help the bad should be assessed. Here, we propose a new simple norm called “Staying” that prescribes abstaining from assessment. Under the Staying norm, the image of the person who makes the decision to give help stays the same as in the last assessment if the person on the receiving end has a bad image. In this case, the choice about whether or not to give help to the potential receiver does not affect the image of the potential giver. We analyze the Staying norm in terms of evolutionary game theory and demonstrate that Staying is most effective in establishing cooperation compared to the prevailing social norms, which rely on constant monitoring and unconditional assessment. The application of Staying suggests that the strict application of moral judgment is limited.

  13. Voting by Hands Promotes Institutionalised Monitoring in Indirect Reciprocity

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    Nakamura, Mitsuhiro

    2016-01-01

    Indirect reciprocity based on reputation is a leading mechanism driving human cooperation, where monitoring of behaviour and sharing reputation-related information are crucial. Because collecting information is costly, a tragedy of the commons can arise, with some individuals free-riding on information supplied by others. This can be overcome by organising monitors that aggregate information, supported by fees from their information users. We analyse a co-evolutionary model of individuals playing a social dilemma game and monitors watching them; monitors provide information and players vote for a more beneficial monitor. We find that (1) monitors that simply rate defection badly cannot stabilise cooperation---they have to overlook defection against ill-reputed players; (2) such overlooking monitors can stabilise cooperation if players vote for monitors rather than to change their own strategy; (3) STERN monitors, who rate cooperation with ill-reputed players badly, stabilise cooperation more easily than MILD ...

  14. Evolution of cooperation under indirect reciprocity and arbitrary exploration rates

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    Santos, Fernando P.; Pacheco, Jorge M.; Santos, Francisco C.

    2016-11-01

    Cooperation has been recognized as an evolutionary puzzle since Darwin, and remains identified as one of the biggest challenges of the XXIst century. Indirect Reciprocity (IR), a key mechanism that humans employ to cooperate with each other, establishes that individual behaviour depends on reputations, which in turn evolve depending on social norms that classify behaviours as good or bad. While it is well known that different social norms give rise to distinct cooperation levels, it remains unclear how the performance of each norm is influenced by the random exploration of new behaviours, often a key component of social dynamics where a plethora of stimuli may compel individuals to deviate from pre-defined behaviours. Here we study, for the first time, the impact of varying degrees of exploration rates – the likelihood of spontaneously adopting another strategy, akin to a mutation probability in evolutionary dynamics – in the emergence of cooperation under IR. We show that high exploration rates may either improve or harm cooperation, depending on the underlying social norm at work. Regarding some of the most popular social norms studied to date, we find that cooperation under Simple-standing and Image-score is enhanced by high exploration rates, whereas the opposite occurs for Stern-judging and Shunning.

  15. Intermediaries in Trust: Indirect Reciprocity, Incentives, and Norms

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    Giangiacomo Bravo

    2015-01-01

    Full Text Available Any trust situation involves a certain amount of risk for trustors that trustees could abuse. In some cases, intermediaries exist who play a crucial role in the exchange by providing reputational information. To examine under what conditions intermediary opinion could have a positive impact on cooperation, we designed two experiments based on a modified version of the investment game where intermediaries rated the behaviour of trustees under various incentive schemes and different role structures. We found that intermediaries can increase trust if there is room for indirect reciprocity between the involved parties. We also found that the effect of monetary incentives and social norms cannot be clearly separable in these situations. If properly designed, monetary incentives for intermediaries can have a positive effect. On the one hand, when intermediary rewards are aligned with the trustor’s interest, investments and returns tend to increase. On the other hand, fixed monetary incentives perform less than any other incentive schemes and endogenous social norms in ensuring trust and fairness. These findings should make us reconsider the mantra of incentivization of social and public conventional policy.

  16. Indirect reciprocity can overcome free-rider problems on costly moral assessment

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    Sasaki, Tatsuya; Nakai, Yutaka

    2016-01-01

    Indirect reciprocity is one of the major mechanisms of the evolution of cooperation. Because constant monitoring and accurate evaluation in moral assessments tend to be costly, indirect reciprocity can be exploited by cost evaders. A recent study crucially showed that a cooperative state achieved by indirect reciprocators is easily destabilized by cost evaders in the case with no supportive mechanism. Here, we present a simple and widely applicable solution that considers pre-assessment of cost evaders. In the pre-assessment, those who fail to pay for costly assessment systems are assigned a nasty image that leads to being rejected by discriminators. We demonstrate that considering the pre-assessment can crucially stabilize reciprocal cooperation for a broad range of indirect reciprocity models. In particular for the most leading social norms we analyse the conditions under which a prosocial state becomes locally stable.

  17. Ingroup favoritism and intergroup cooperation under indirect reciprocity based on group reputation

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    Masuda, Naoki

    2012-01-01

    Indirect reciprocity in which players cooperate with unacquainted other players having good reputations is a mechanism for cooperation in relatively large populations subjected to social dilemma situations. When the population has group structure, as is often found in social networks, players in experiments are considered to show behavior that deviates from existing theoretical models of indirect reciprocity. First, players often show ingroup favoritism (i.e., cooperation only within the group) rather than full cooperation (i.e., cooperation within and across groups) even though the latter is Pareto efficient. Second, in general, humans approximate outgroup members' personal characteristics, presumably including the reputation used for indirect reciprocity, by a single value attached to the group. Humans use such a stereotypic approximation, a phenomenon known as outgroup homogeneity in social psychology. I propose a model of indirect reciprocity in populations with group structure to examine the possibility ...

  18. Indirect reciprocity provides only a narrow margin of efficiency for costly punishment.

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    Ohtsuki, Hisashi; Iwasa, Yoh; Nowak, Martin A

    2009-01-01

    Indirect reciprocity is a key mechanism for the evolution of human cooperation. Our behaviour towards other people depends not only on what they have done to us but also on what they have done to others. Indirect reciprocity works through reputation. The standard model of indirect reciprocity offers a binary choice: people can either cooperate or defect. Cooperation implies a cost for the donor and a benefit for the recipient. Defection has no cost and yields no benefit. Currently there is considerable interest in studying the effect of costly (or altruistic) punishment on human behaviour. Punishment implies a cost for the punished person. Costly punishment means that the punisher also pays a cost. It has been suggested that costly punishment between individuals can promote cooperation. Here we study the role of costly punishment in an explicit model of indirect reciprocity. We analyse all social norms, which depend on the action of the donor and the reputation of the recipient. We allow errors in assigning reputation and study gossip as a mechanism for establishing coherence. We characterize all strategies that allow the evolutionary stability of cooperation. Some of those strategies use costly punishment; others do not. We find that punishment strategies typically reduce the average payoff of the population. Consequently, there is only a small parameter region where costly punishment leads to an efficient equilibrium. In most cases the population does better by not using costly punishment. The efficient strategy for indirect reciprocity is to withhold help for defectors rather than punishing them.

  19. Promotion of cooperation in social dilemma games via generalised indirect reciprocity

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    Chiong, Raymond; Kirley, Michael

    2015-10-01

    This paper presents a novel generalised indirect reciprocity approach for promoting cooperation in social dilemma games. Here, players decide upon an action to play in the game based on public information (or "external cues") rather than individual-specific information. The public information is constantly updated according to the underlying learning model. Comprehensive simulation experiments using the N-player Prisoner's Dilemma (PD) and Snowdrift (SD) games show that generalised indirect reciprocity promotes high levels of cooperation across a wide range of conditions. This is despite the fact that the make-up of player groups is continually changing. As expected, the extent of cooperative behaviour observed in the "constraint-relaxed" N-player SD game is significantly higher than the N-player PD game. Our proposed generalised indirect reciprocity model may shed light on the conundrum of cooperation between anonymous individuals.

  20. The long-term benefits of human generosity in indirect reciprocity.

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    Wedekind, Claus; Braithwaite, Victoria A

    2002-06-25

    Among the theories that have been proposed to explain the evolution of altruism are direct reciprocity and indirect reciprocity. The idea of the latter is that helping someone or refusing to do so has an impact on one's reputation within a group. This reputation is constantly assessed and reassessed by others and is taken into account by them in future social interactions. Generosity in indirect reciprocity can evolve if and only if it eventually leads to a net benefit in the long term. Here, we show that this key assumption is met. We let 114 students play for money in an indirect and a subsequent direct reciprocity game. We found that although being generous, i.e., giving something of value to others, had the obvious short-term costs, it paid in the long run because it builds up a reputation that is rewarded by third parties (who thereby themselves increase their reputation). A reputation of being generous also provided an advantage in the subsequent direct reciprocity game, probably because it builds up trust that can lead to more stable cooperation.

  1. Deception Undermines the Stability of Cooperation in Games of Indirect Reciprocity.

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    Szabolcs Számadó

    Full Text Available Indirect reciprocity is often claimed as one of the key mechanisms of human cooperation. It works only if there is a reputational score keeping and each individual can inform with high probability which other individuals were good or bad in the previous round. Gossip is often proposed as a mechanism that can maintain such coherence of reputations in the face of errors of transmission. Random errors, however, are not the only source of uncertainty in such situations. The possibility of deceptive communication, where the signallers aim to misinform the receiver cannot be excluded. While there is plenty of evidence for deceptive communication in humans the possibility of deception is not yet incorporated into models of indirect reciprocity. Here we show that when deceptive strategies are allowed in the population it will cause the collapse of the coherence of reputations and thus in turn it results the collapse of cooperation. This collapse is independent of the norms and the cost and benefit values. It is due to the fact that there is no selection for honest communication in the framework of indirect reciprocity. It follows that indirect reciprocity can be only proposed plausibly as a mechanism of human cooperation if additional mechanisms are specified in the model that maintains honesty.

  2. Evolution of gossip-based indirect reciprocity on a bipartite network

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    Giardini, Francesca; Vilone, Daniele

    2016-01-01

    Cooperation can be supported by indirect reciprocity via reputation. Thanks to gossip, reputations are built and circulated and humans can identify defectors and ostracize them. However, the evolutionary stability of gossip is allegedly undermined by the fact that it is more error-prone that direct

  3. The Development of Theory of Mind and Positive and Negative Reciprocity in Preschool Children.

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    Schug, Joanna; Takagishi, Haruto; Benech, Catalina; Okada, Hiroyuki

    2016-01-01

    This study examined the relation between the acquisition of false-beliefs theory of mind (ToM) and reciprocity in preschoolers. Preschool-aged children completed a task assessing the understanding of false beliefs, and played an Ultimatum Game (UG) with another child in a face-to-face setting. Negative reciprocity was assessed by examining the rejection of unfair offers made by another child in the UG, while positive reciprocity was assessed by examining allocations made by participants in a Dictator Game (DG) following the UG. The results indicated that children who had passed a task assessing first-order false beliefs were more likely to make generous offers in a DG following a fair offer made by their partner in a proceeding UG, but that false beliefs ToM was unrelated to the rejection of unfair offers in the UG.

  4. Evolutionary stability and resistance to cheating in an indirect reciprocity model based on reputation

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    Martinez-Vaquero, Luis A

    2013-01-01

    Indirect reciprocity is one of the main mechanisms to explain the emergence and sustainment of altruism in societies. The standard approach to indirect reciprocity are reputation models. These are games in which players base their decisions on their opponent's reputation gained in past interactions with other players (moral assessment). The combination of actions and moral assessment leads to a large diversity of strategies, thus determining the stability of any of them against invasions by all the others is a difficult task. We use a variant of a previously introduced reputation-based model that let us systematically analyze all these invasions and determine which ones are successful. Accordingly we are able to identify the third-order strategies (those which, apart from the action, judge considering both the reputation of the donor and that of the recipient) that are evolutionarily stable. Our results reveal that if a strategy resists the invasion of any other one sharing its same moral assessment, it can r...

  5. [The emergence of indirect reciprocity: evolutionary foundation of altruistic behavior based on "strict discriminator"].

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    Mashima, Rie; Takahashi, Nobuyuki

    2005-12-01

    Although there have been a number of studies that theoretically and empirically examined altruism based on direct reciprocity, few have been conducted on how altruism based on indirect reciprocity emerges. Recent advances in biological research, however, have suggested possible answers to the question. For instance, Nowak and Sigmund (1998a, b) proposed that what they called image scoring strategy made indirect reciprocity possible. After critically examining their work, Leimar and Hammerstein (2001) pointed out several limitations to the theory, and instead proposed standing strategy as an explanation. Although careful attempts to replicate the findings by them and Panchanathan and Boyd (2003) supported the arguments against image scoring, we reveal that standing strategy was not a satisfactory answer either. Based on a series of evolutionary simulations, we propose a new strategy, which we call strict discriminator, as an alternative. Strict discriminators are discriminating altruists, similar to the altruists with image scoring or standing strategy, but they are different in that its criterion for discrimination is stricter: unconditional altruists are excluded from their reciprocity.

  6. Ingroup favoritism and intergroup cooperation under indirect reciprocity based on group reputation.

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    Masuda, Naoki

    2012-10-21

    Indirect reciprocity in which players cooperate with unacquainted other players having good reputations is a mechanism for cooperation in relatively large populations subjected to social dilemma situations. When the population has group structure, as is often found in social networks, players in experiments are considered to show behavior that deviates from existing theoretical models of indirect reciprocity. First, players often show ingroup favoritism (i.e., cooperation only within the group) rather than full cooperation (i.e., cooperation within and across groups), even though the latter is Pareto efficient. Second, in general, humans approximate outgroup members' personal characteristics, presumably including the reputation used for indirect reciprocity, by a single value attached to the group. Humans use such a stereotypic approximation, a phenomenon known as outgroup homogeneity in social psychology. I propose a model of indirect reciprocity in populations with group structure to examine the possibility of ingroup favoritism and full cooperation. In accordance with outgroup homogeneity, I assume that players approximate outgroup members' personal reputations by a single reputation value attached to the group. I show that ingroup favoritism and full cooperation are stable under different social norms (i.e., rules for assigning reputations) such that they do not coexist in a single model. If players are forced to consistently use the same social norm for assessing different types of interactions (i.e., ingroup versus outgroup interactions), only full cooperation survives. The discovered mechanism is distinct from any form of group selection. The results also suggest potential methods for reducing ingroup bias to shift the equilibrium from ingroup favoritism to full cooperation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. A Dominant Social Comparison Heuristic Unites Alternative Mechanisms for the Evolution of Indirect Reciprocity

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    Whitaker, Roger M.; Colombo, Gualtiero B.; Allen, Stuart M.; Dunbar, Robin I. M.

    2016-08-01

    Cooperation is a fundamental human trait but our understanding of how it functions remains incomplete. Indirect reciprocity is a particular case in point, where one-shot donations are made to unrelated beneficiaries without any guarantee of payback. Existing insights are largely from two independent perspectives: i) individual-level cognitive behaviour in decision making, and ii) identification of conditions that favour evolution of cooperation. We identify a fundamental connection between these two areas by examining social comparison as a means through which indirect reciprocity can evolve. Social comparison is well established as an inherent human disposition through which humans navigate the social world by self-referential evaluation of others. Donating to those that are at least as reputable as oneself emerges as a dominant heuristic, which represents aspirational homophily. This heuristic is found to be implicitly present in the current knowledge of conditions that favour indirect reciprocity. The effective social norms for updating reputation are also observed to support this heuristic. We hypothesise that the cognitive challenge associated with social comparison has contributed to cerebral expansion and the disproportionate human brain size, consistent with the social complexity hypothesis. The findings have relevance for the evolution of autonomous systems that are characterised by one-shot interactions.

  8. A Dominant Social Comparison Heuristic Unites Alternative Mechanisms for the Evolution of Indirect Reciprocity

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    Whitaker, Roger M.; Colombo, Gualtiero B.; Allen, Stuart M.; Dunbar, Robin I. M.

    2016-01-01

    Cooperation is a fundamental human trait but our understanding of how it functions remains incomplete. Indirect reciprocity is a particular case in point, where one-shot donations are made to unrelated beneficiaries without any guarantee of payback. Existing insights are largely from two independent perspectives: i) individual-level cognitive behaviour in decision making, and ii) identification of conditions that favour evolution of cooperation. We identify a fundamental connection between these two areas by examining social comparison as a means through which indirect reciprocity can evolve. Social comparison is well established as an inherent human disposition through which humans navigate the social world by self-referential evaluation of others. Donating to those that are at least as reputable as oneself emerges as a dominant heuristic, which represents aspirational homophily. This heuristic is found to be implicitly present in the current knowledge of conditions that favour indirect reciprocity. The effective social norms for updating reputation are also observed to support this heuristic. We hypothesise that the cognitive challenge associated with social comparison has contributed to cerebral expansion and the disproportionate human brain size, consistent with the social complexity hypothesis. The findings have relevance for the evolution of autonomous systems that are characterised by one-shot interactions. PMID:27515119

  9. Selective Cooperation in the Supermarket : Field Experimental Evidence for Indirect Reciprocity.

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    Lange, Florian; Eggert, Frank

    2015-12-01

    Numerous laboratory experiments suggest that mechanisms of indirect reciprocity might account for human cooperation. However, conclusive field data supporting the predictions of indirect reciprocity in everyday life situations is still scarce. Here, we attempt to compensate for this lack by examining the determinants of cooperative behavior in a German supermarket. Our methods were as follows: Confederates of the experimenter lined up at the checkout, apparently to buy a single item. As an act of cooperation, the waiting person in front (the potential helper) could allow the confederate to go ahead. By this means, the potential helper could take a cost (additional waiting time) by providing the confederate with a benefit (saved waiting time). We recorded the potential helpers' behavior and the number of items they purchased as a quantitative measure proportional to the confederate's benefit. Moreover, in a field experimental design, we varied the confederates' image by manipulating the item they purchased (beer vs. water). As predicted, the more waiting time they could save, the more likely the confederates were to receive cooperation. This relationship was moderated by the confederates' image. Cost-to-benefit ratios were required to be more favorable for beer-purchasing individuals to receive cooperation. Our results demonstrate that everyday human cooperation can be studied unobtrusively in the field and that cooperation among strangers is selective in a way that is consistent with current models of indirect reciprocity.

  10. Cooperation enhanced by indirect reciprocity in spatial prisoner's dilemma games for social P2P systems

    Science.gov (United States)

    Tian, Lin-Lin; Li, Ming-Chu; Wang, Zhen

    2016-11-01

    With the growing interest in social Peer-to-Peer (P2P) applications, relationships of individuals are further exploited to improve the performances of reputation systems. It is an on-going challenge to investigate how spatial reciprocity aids indirect reciprocity in sustaining cooperation in practical P2P environments. This paper describes the construction of an extended prisoner's dilemma game on square lattice networks with three strategies, i.e., defection, unconditional cooperation, and reciprocal cooperation. Reciprocators discriminate partners according to their reputations based on image scoring, where mistakes in judgment of reputations may occur. The independent structures of interaction and learning neighborhood are discussed, with respect to the situation in which learning environments differ from interaction networks. The simulation results have indicated that the incentive mechanism enhances cooperation better in structured peers than among a well-mixed population. Given the realistic condition of inaccurate reputation scores, defection is still successfully held down when the players interact and learn within the unified neighborhoods. Extensive simulations have further confirmed the positive impact of spatial structure on cooperation with different sizes of lattice neighborhoods. And similar conclusions can also be drawn on regular random networks and scale-free networks. Moreover, for the separated structures of the neighborhoods, the interaction network has a critical effect on the evolution dynamics of cooperation and learning environments only have weaker impacts on the process. Our findings further provide some insights concerning the evolution of collective behaviors in social systems.

  11. A norm knockout method on indirect reciprocity to reveal indispensable norms

    Science.gov (United States)

    Yamamoto, Hitoshi; Okada, Isamu; Uchida, Satoshi; Sasaki, Tatsuya

    2017-03-01

    Although various norms for reciprocity-based cooperation have been suggested that are evolutionarily stable against invasion from free riders, the process of alternation of norms and the role of diversified norms remain unclear in the evolution of cooperation. We clarify the co-evolutionary dynamics of norms and cooperation in indirect reciprocity and also identify the indispensable norms for the evolution of cooperation. Inspired by the gene knockout method, a genetic engineering technique, we developed the norm knockout method and clarified the norms necessary for the establishment of cooperation. The results of numerical investigations revealed that the majority of norms gradually transitioned to tolerant norms after defectors are eliminated by strict norms. Furthermore, no cooperation emerges when specific norms that are intolerant to defectors are knocked out.

  12. Design of non-reciprocal acoustic waveguides by indirect interband transitions

    Science.gov (United States)

    Ishikawa, Atsushi; Tsuruta, Kenji

    2017-07-01

    We numerically demonstrate a non-reciprocal acoustic waveguide by utilizing the indirect interband transition between two guided modes. The waveguide, consisting of a water core sandwiched between parallel steel plates, is designed to support symmetric and asymmetric guided modes with different frequencies and wavevectors. Dynamic mode conversion is then achieved by applying spatio-temporal density modulation in the core of the waveguide to induce both frequency and wavevector shifts of the incident guided wave. Numerical simulations prove that the phase matching condition is satisfied only for the forward propagation, not for the backward one, thus realizing the non-reciprocal acoustic waveguide. Our approach based on a linear dynamic system may achieve wide-band tunable operation with a low-energy consumption, paving the way toward the sophisticated acoustic diode applications.

  13. Stochasticity in economic losses increases the value of reputation in indirect reciprocity.

    Science.gov (United States)

    dos Santos, Miguel; Placì, Sarah; Wedekind, Claus

    2015-12-14

    Recent theory predicts harsh and stochastic conditions to generally promote the evolution of cooperation. Here, we test experimentally whether stochasticity in economic losses also affects the value of reputation in indirect reciprocity, a type of cooperation that is very typical for humans. We used a repeated helping game with observers. One subject (the "Unlucky") lost some money, another one (the "Passer-by") could reduce this loss by accepting a cost to herself, thereby building up a reputation that could be used by others in later interactions. The losses were either stable or stochastic, but the average loss over time and the average efficiency gains of helping were kept constant in both treatments. We found that players with a reputation of being generous were generally more likely to receive help by others, such that investing into a good reputation generated long-term benefits that compensated for the immediate costs of helping. Helping frequencies were similar in both treatments, but players with a reputation to be selfish lost more resources under stochastic conditions. Hence, returns on investment were steeper when losses varied than when they did not. We conclude that this type of stochasticity increases the value of reputation in indirect reciprocity.

  14. Evolution of gossip-based indirect reciprocity on a bipartite network

    Science.gov (United States)

    Giardini, Francesca; Vilone, Daniele

    2016-11-01

    Cooperation can be supported by indirect reciprocity via reputation. Thanks to gossip, reputations are built and circulated and humans can identify defectors and ostracise them. However, the evolutionary stability of gossip is allegedly undermined by the fact that it is more error-prone that direct observation, whereas ostracism could be ineffective if the partner selection mechanism is not robust. The aim of this work is to investigate the conditions under which the combination of gossip and ostracism might support cooperation in groups of different sizes. We are also interested in exploring the extent to which errors in transmission might undermine the reliability of gossip as a mechanism for identifying defectors. Our results show that a large quantity of gossip is necessary to support cooperation, and that group structure can mitigate the effects of errors in transmission.

  15. Direct versus indirect treatment for preschool children who stutter: The RESTART randomized trial

    NARCIS (Netherlands)

    C. de Sonneville (Caroline); E.A. Stolk (Elly); Rietveld, T. (Toni); M.-C. Franken (Marie-Christine)

    2015-01-01

    textabstractObjective Stuttering is a common childhood disorder. There is limited high quality evidence regarding options for best treatment. The aim of the study was to compare the effectiveness of direct treatment with indirect treatment in preschool children who stutter. Methods In this multicent

  16. Direct versus indirect treatment for preschool children who stutter: The RESTART randomized trial

    NARCIS (Netherlands)

    C. de Sonneville (Caroline); E.A. Stolk (Elly); T. Rietveld (Toni); M.-C. Franken (Marie-Christine)

    2015-01-01

    textabstractObjective Stuttering is a common childhood disorder. There is limited high quality evidence regarding options for best treatment. The aim of the study was to compare the effectiveness of direct treatment with indirect treatment in preschool children who stutter. Methods In this

  17. Predictors of Social Skills for Preschool Children at Risk for ADHD: The Relationship between Direct and Indirect Measurements

    Science.gov (United States)

    Thomas, Lisa B.; Shapiro, Edward S.; DuPaul, George J.; Lutz, J. Gary; Kern, Lee

    2011-01-01

    The relationship between direct and indirect measurements of social skills and social problem behaviors for preschool children at risk for attention deficit hyperactivity disorder (ADHD) was examined. Participants included 137 preschool children, aged 3 to 5 years, at risk for ADHD, who were participating in a larger study examining the effects of…

  18. The Development of a Scientific Motive: How Preschool Science and Home Play Reciprocally Contribute to Science Learning

    Science.gov (United States)

    Gomes, Judith; Fleer, Marilyn

    2017-07-01

    There are a growing number of studies that have examined science learning for preschool children. Some research has looked into children's home experiences and some has focused on transition, practices, routines, and traditions in preschool contexts. However, little attention has been directed to the relationship between children's learning experiences at preschool and at home, and how this relationship can assist in the development of science concepts relevant to everyday life. In drawing upon Hedegaard's (Learning and child development, 2002) cultural-historical conception of motives and Vygotsky's (The collected works of L.S. Vygotsky: problems of general psychology, 1987) theory of everyday and scientific concept formation, the study reported in this paper examines one child, Jimmy (4.2 years), and his learning experiences at home and at preschool. Data gathering featured the video recording of 4 weeks of Jimmy's learning in play at home and at preschool (38.5 h), parent questionnaire and interviews, and researcher and family gathered video observations of home play with his parents (3.5 h). Findings show how a scientific motive develops through playful everyday learning moments at home and at preschool when scientific play narratives and resources are aligned. The study contributes to a more nuanced understanding of the science learning of young children and a conception of pedagogy that takes into account the reciprocity of home and school contexts for learning science.

  19. The Reciprocal Influence of Callous-Unemotional Traits, Oppositional Defiant Disorder and Parenting Practices in Preschoolers.

    Science.gov (United States)

    Brown, Caitlin A; Granero, Roser; Ezpeleta, Lourdes

    2017-04-01

    The present study investigates reciprocal associations between positive parenting, parental monitoring, CU traits, and ODD in children assessed at age 3 and again at age 6. Data were collected from a sample of preschoolers (N = 419; 51.58 % female) through diagnostic interviews and questionnaires answered by parents and teachers. Structural equation modeling revealed a bidirectional relationship between poor monitoring and ODD, with poor monitoring at age 3 predicting ODD at age 6 (β = 0.11, p < 0.05), and ODD at age 3 predicting poor monitoring at age 6 (β = 0.10, p < 0.05). While poor monitoring at age 3 predicted CU traits at age 6 (β = 0.11, p < 0.05), CU traits at age 3 predicted positive parenting (β = 0.09, p < 0.05) and ODD (β = 0.13, p < 0.05) at age 6. Results have important implications for early targeted parenting interventions for CU traits and ODD.

  20. Indirect genetic effects influence antipredator behavior in guppies: estimates of the coefficient of interaction psi and the inheritance of reciprocity.

    Science.gov (United States)

    Bleakley, Bronwyn H; Brodie, Edmund D

    2009-07-01

    How and why cooperation evolves, particularly among nonrelatives, remains a major paradox for evolutionary biologists and behavioral ecologists. Although much attention has focused on fitness consequences associated with cooperating, relatively little is known about the second component of evolutionary change, the inheritance of cooperation or reciprocity. The genetics of behaviors that can only be expressed in the context of interactions are particularly difficult to describe because the relevant genes reside in multiple social partners. Indirect genetic effects (IGEs) describe the influence of genes carried in social partners on the phenotype of a focal individual and thus provide a novel approach to quantifying the genetics underlying interactions such as reciprocal cooperation. We used inbred lines of guppies and a novel application of IGE theory to describe the dual genetic control of predator inspection and social behavior, both classic models of reciprocity. We identified effects of focal strain, social group strain, and interactions between focal and group strains on variation in focal behavior. We measured psi, the coefficient of the interaction, which describes the degree to which an individual's phenotype is influenced by the phenotype of its social partners. The genetic identity of social partners substantially influences inspection behavior, measures of threat assessment, and schooling and does so in positively reinforcing manner. We therefore demonstrate strong IGEs for antipredator behavior that represent the genetic variation necessary for the evolution of reciprocity.

  1. Direct versus Indirect Treatment for Preschool Children who Stutter: The RESTART Randomized Trial.

    Directory of Open Access Journals (Sweden)

    Caroline de Sonneville-Koedoot

    Full Text Available Stuttering is a common childhood disorder. There is limited high quality evidence regarding options for best treatment. The aim of the study was to compare the effectiveness of direct treatment with indirect treatment in preschool children who stutter.In this multicenter randomized controlled trial with an 18 month follow-up, preschool children who stutter who were referred for treatment were randomized to direct treatment (Lidcombe Program; n = 99 or indirect treatment (RESTART-DCM treatment; n = 100. Main inclusion criteria were age 3-6 years, ≥3% syllables stuttered (%SS, and time since onset ≥6 months. The primary outcome was the percentage of non-stuttering children at 18 months. Secondary outcomes included stuttering frequency (%SS, stuttering severity ratings by the parents and therapist, severity rating by the child, health-related quality of life, emotional and behavioral problems, and speech attitude.Percentage of non-stuttering children for direct treatment was 76.5% (65/85 versus 71.4% (65/91 for indirect treatment (Odds Ratio (OR, 0.6; 95% CI, 0.1-2.4, p = .42. At 3 months, children treated by direct treatment showed a greater decline in %SS (significant interaction time x therapy: β = -1.89; t(282.82 = -2.807, p = .005. At 18 months, stuttering frequency was 1.2% (SD 2.1 for direct treatment and 1.5% (SD 2.1 for indirect treatment. Direct treatment had slightly better scores on most other secondary outcome measures, but no differences between treatment approaches were significant.Direct treatment decreased stuttering more quickly during the first three months of treatment. At 18 months, however, clinical outcomes for direct and indirect treatment were comparable. These results imply that at 18 months post treatment onset, both treatments are roughly equal in treating developmental stuttering in ways that surpass expectations of natural recovery. Follow-up data are needed to confirm these findings in the longer term

  2. Exploring the cooperative regimes in an agent-based model: indirect reciprocity vs. selfish incentives

    Science.gov (United States)

    Fort, H.

    2003-08-01

    The self-organization in cooperative regimes in a simple mean-field version of a model based on “selfish” agents which play the Prisoner's Dilemma (PD) game is studied. The agents have no memory and use strategies not based on direct reciprocity nor “tags”. Two variables are assigned to each agent k at time t, measuring its capital C( k; t) and its probability of cooperation p( k; t). At each time step t a pair of agents interact by playing the PD game. These two agents update their probability of cooperation p( k; t) as follows: they compare the profits they made in this interaction δC( k; t) with an estimator ε( k; t) and, if δC( k; t)⩾ ε( k; t), agent i increases its p( k; t) while if δC( k; t)punishment)-are analyzed. It turns out that for all these 24 possibilities, after a transient, the system self-organizes into a stationary state with average equilibrium probability of cooperation p¯∞= constant>0 . Depending on the payoff matrix, there are different equilibrium states characterized by their average probability of cooperation and average equilibrium per capita income ( p¯∞, δC¯∞) .

  3. "Not See, Not Hear, Not Speak": Preschoolers Think They Cannot Perceive or Address Others without Reciprocity

    Science.gov (United States)

    Moll, Henrike; Khalulyan, Allie

    2017-01-01

    A curious phenomenon in early social-cognitive development has been identified: Preschoolers deny that they can see others who cannot also see them (Russell, Gee, & Bullard, 2012). The exclusive focus on vision has suggested that this effect is limited to gaze, but children's negations might reflect a broader phenomenon that extends to vocal…

  4. Do Reciprocal Associations Exist between Social and Language Pathways in Preschoolers with Autism Spectrum Disorders?

    Science.gov (United States)

    Bennett, Teresa A.; Szatmari, Peter; Georgiades, Katholiki; Hanna, Steven; Janus, Magdelena; Georgiades, Stelios; Duku, Eric; Bryson, Susan; Fombonne, Eric; Smith, Isabel M.; Mirenda, Pat; Volden, Joanne; Waddell, Charlotte; Roberts, Wendy; Vaillancourt, Tracy; Zwaigenbaum, Lonnie; Elsabbagh, Mayada; Thompson, Ann

    2015-01-01

    Background: Differences in how developmental pathways interact dynamically in children with autism spectrum disorder (ASD) likely contribute in important ways to phenotypic heterogeneity. This study aimed to model longitudinal reciprocal associations between social competence (SOC) and language (LANG) pathways in young children with ASD. Methods:…

  5. Two wrongs don't make a right: the initial viability of different assessment rules in the evolution of indirect reciprocity.

    Science.gov (United States)

    Panchanathan, Karthik

    2011-05-21

    Indirect reciprocity models are meant to correspond to simple moral systems, in which individuals assess the interactions of third parties in order to condition their cooperative behavior. Despite the staggering number of possible assessment rules in even the simplest of these models, previous research suggests that only a handful are evolutionarily stable against invasion by free riders. These successful assessment rules fall into two categories, one which positively judges miscreants when they refuse to help other miscreants, the other which does not. Previous research has not, however, demonstrated that all of these rules can invade an asocial population--a requirement for a complete theory of social evolution. Here, I present a general analytical model of indirect reciprocity and show that the class of assessment rules which positively judges a refusal to help scofflaws cannot invade a population of defectors, whereas the other class can. When rare, assessment rules which positively judge a refusal to help bad people produce a poor correlation between reputation and behavior. It is this correlation that generates the assortment crucial in sustaining cooperation through indirect reciprocity. Only assessment rules that require good deeds to achieve a good reputation guarantee a strong correlation between behavior and reputation.

  6. How the indirect reciprocity with co-evolving norm and strategy for 2 × 2 prisoner's dilemma game works for emerging cooperation

    Science.gov (United States)

    Tanimoto, Jun; Sagara, Hirokji

    2015-11-01

    We built a new indirect reciprocity model based on binary image scores, where an agent's strategy and norm co-evolve. The norm, meaning what behavior is evaluated as "good" or "bad," stipulates how image scores of two agents playing a game is altered, which has been presumed to be a fixed value in most previous studies. Also, unlike former studies, our model allows an agent to play with an agent who has a different norm. This point of relaxing the freedom of the model pulls down cooperation level vis-à-vis the case where an agent always plays with another one having same norm. However, it is observed that a rather larger dilemma shows robust cooperation establishing compared with a smaller dilemma, since a norm that punishes a so-called second-order free-rider is prompted. To encourage the evolution of norms to be able to punish second-order free-riders, a society needs a small number of defectors. This is elucidated by the fact that cases with action error are more cooperative than those without action error.

  7. The conflict of social norms may cause the collapse of cooperation: indirect reciprocity with opposing attitudes towards in-group favoritism.

    Science.gov (United States)

    Matsuo, Tadasu; Jusup, Marko; Iwasa, Yoh

    2014-04-01

    Indirect reciprocity is a cooperation maintaining mechanism based on the social evaluation of players. Here, we consider the case of a group in which two social norms with opposing attitudes towards in-group favoritism are mixed. One norm, called Bushido (the way of warriors), regards cooperation with outsiders as betrayal, whereas the second norm, called Shonindo (the way of merchants), regards cooperation with outsiders as desirable. Each member of the group, irrespective of being a Bushido or a Shonindo player, is evaluated in two different ways and assigned two different labels: "ally" or "enemy" according to the Bushido evaluation; "good" or "bad" according to the Shonindo evaluation. These labels change in response to the action taken (cooperation or defection) when acting as a donor, as well as the label attached to the recipient. In addition to Bushido players, who cooperate with an ally and defect from an enemy, and Shonindo players, who cooperate with a good recipient and defect from a bad recipient, the group contains a third kind of players--unconditional defectors. The fractions of the three types of players follow the replicator dynamics. If the probability of interacting with outsiders is small, and if the cost-to-benefit ratio of cooperation is low, we observe several important patterns. Each social norm is able to maintain a high level of cooperation when dominant. Bushido and Shonindo players evaluate each other unfavorably and engage in a severe conflict. In the end, only one norm permeates the whole group driving the other to the extinction. When both social norms are equally effective, a rare occurrence of unconditional defectors may lead to a successful invasion.

  8. Assortment and the evolution of generalized reciprocity.

    Science.gov (United States)

    Rankin, Daniel J; Taborsky, Michael

    2009-07-01

    Reciprocity is often invoked to explain cooperation. Reciprocity is cognitively demanding, and both direct and indirect reciprocity require that individuals store information about the propensity of their partners to cooperate. By contrast, generalized reciprocity, wherein individuals help on the condition that they received help previously, only relies on whether an individual received help in a previous encounter. Such anonymous information makes generalized reciprocity hard to evolve in a well-mixed population, as the strategy will lose out to pure defectors. Here we analyze a model for the evolution of generalized reciprocity, incorporating assortment of encounters, to investigate the conditions under which it will evolve. We show that, in a well-mixed population, generalized reciprocity cannot evolve. However, incorporating assortment of encounters can favor the evolution of generalized reciprocity in which indiscriminate cooperation and defection are both unstable. We show that generalized reciprocity can evolve under both the prisoner's dilemma and the snowdrift game.

  9. Preschool Teachers' Professional Training, Observational Feedback, Child-Centered Beliefs and Motivation: Direct and Indirect Associations with Social and Emotional Responsiveness

    Science.gov (United States)

    Lang, Sarah N.; Mouzourou, Chryso; Jeon, Lieny; Buettner, Cynthia K.; Hur, Eunhye

    2017-01-01

    Background: Young children's social and emotional competence is a key predictor of their current and future academic and social success. Although preschool teachers are critical socializing agent of children's social and emotional development, we know little about factors associated with preschool teachers' social and emotional responsiveness.…

  10. Preschool Teachers' Professional Training, Observational Feedback, Child-Centered Beliefs and Motivation: Direct and Indirect Associations with Social and Emotional Responsiveness

    Science.gov (United States)

    Lang, Sarah N.; Mouzourou, Chryso; Jeon, Lieny; Buettner, Cynthia K.; Hur, Eunhye

    2017-01-01

    Background: Young children's social and emotional competence is a key predictor of their current and future academic and social success. Although preschool teachers are critical socializing agent of children's social and emotional development, we know little about factors associated with preschool teachers' social and emotional responsiveness.…

  11. The Reciprocalizer

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning

    2013-01-01

    The geometry of reciprocal structures is extremely difficult to predict and control, and it cannot be described with the available CAD software or by hierarchical, associative parametric modellers. The geometry of a network of reciprocally connected elements is a characteristic that emerges, bottom......-up, from the complex interaction between all the elements shape, topology and position, and requires numerical solution of the geometric compatibility. This paper presents a design tool, the “Reciprocalizer”, that is able to solve the geometry of reciprocal structures. The tool has been tested...

  12. Reciprocal inhibition in man.

    Science.gov (United States)

    Crone, C

    1993-11-01

    afferent activity and it was seen at a conditioning-test interval of 3-6 msec. It was initiated by supraspinal pathways and it was seen only during dorsiflexion of the foot. The pathway underlying this inhibitory mechanism is unknown, but it was suggested that it was mediated by a propriospinal pathway. The possible contribution to reciprocal inhibition of presynaptic inhibition of soleus Ia afferent fibers was studied by an indirect method. It was concluded that this presynaptic inhibition was increased during even slight dorsiflexion of the foot and that the increase was mainly dependent upon the peripheral afferent input from the contracting muscle.(ABSTRACT TRUNCATED AT 400 WORDS)

  13. Electromagnetic Reciprocity.

    Energy Technology Data Exchange (ETDEWEB)

    Aldridge, David F.

    2014-11-01

    A reciprocity theorem is an explicit mathematical relationship between two different wavefields that can exist within the same space - time configuration. Reciprocity theorems provi de the theoretical underpinning for mod ern full waveform inversion solutions, and also suggest practical strategies for speed ing up large - scale numerical modeling of geophysical datasets . In the present work, several previously - developed electromagnetic r eciprocity theorems are generalized to accommodate a broader range of medi um, source , and receiver types. Reciprocity relations enabling the interchange of various types of point sources and point receivers within a three - dimensional electromagnetic model are derived. Two numerical modeling algorithms in current use are successfully tested for adherence to reciprocity. Finally, the reciprocity theorem forms the point of departure for a lengthy derivation of electromagnetic Frechet derivatives. These mathe matical objects quantify the sensitivity of geophysical electromagnetic data to variatio ns in medium parameters, and thus constitute indispensable tools for solution of the full waveform inverse problem. ACKNOWLEDGEMENTS Sandia National Labor atories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. Signif icant portions of the work reported herein were conducted under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories (SNL) and CARBO Ceramics Incorporated. The author acknowledges Mr. Chad Cannan and Mr. Terry Pa lisch of CARBO Ceramics, and Ms. Amy Halloran, manager of SNL's Geophysics and Atmospheric Sciences Department, for their interest in and encouragement of this work. Special thanks are due to Dr . Lewis C. Bartel ( recently retired from Sandia National Labo ratories

  14. Beyond Reciprocity

    DEFF Research Database (Denmark)

    Afsah, Ebrahim

    2010-01-01

    , reflecting rather the enormous diversity of the human condition. This makes it difficult to speak of the phenomenon of war as one common observable fact, majestically constant throughout time and space. This historical, cultural, and operational diversity considerably complicates the analysis of war and its...... the effectiveness of reciprocal moderation on which the law of war has traditionally relied as its chief enforcement mechanism. This study seeks to understand why norms take a particular form rather than laying out the applicable rules and applying them to different categories of people under different...... and logically questionable because any privileged regime presupposes a standard regime. The privileges to which lawful combatants are entitled when they become prisoners of war are important, but they must not detract from the far more elementary protections to which anybody else is entitled to...

  15. Direct reciprocity in structured populations.

    Science.gov (United States)

    van Veelen, Matthijs; García, Julián; Rand, David G; Nowak, Martin A

    2012-06-19

    Reciprocity and repeated games have been at the center of attention when studying the evolution of human cooperation. Direct reciprocity is considered to be a powerful mechanism for the evolution of cooperation, and it is generally assumed that it can lead to high levels of cooperation. Here we explore an open-ended, infinite strategy space, where every strategy that can be encoded by a finite state automaton is a possible mutant. Surprisingly, we find that direct reciprocity alone does not lead to high levels of cooperation. Instead we observe perpetual oscillations between cooperation and defection, with defection being substantially more frequent than cooperation. The reason for this is that "indirect invasions" remove equilibrium strategies: every strategy has neutral mutants, which in turn can be invaded by other strategies. However, reciprocity is not the only way to promote cooperation. Another mechanism for the evolution of cooperation, which has received as much attention, is assortment because of population structure. Here we develop a theory that allows us to study the synergistic interaction between direct reciprocity and assortment. This framework is particularly well suited for understanding human interactions, which are typically repeated and occur in relatively fluid but not unstructured populations. We show that if repeated games are combined with only a small amount of assortment, then natural selection favors the behavior typically observed among humans: high levels of cooperation implemented using conditional strategies.

  16. Personal experience and reputation interact in human decisions to help reciprocally

    NARCIS (Netherlands)

    Molleman, Lucas; van den Broek, Eva; Egas, Martijn

    2013-01-01

    There is ample evidence that human cooperative behaviour towards other individuals is often conditioned on information about previous interactions. This information derives both from personal experience (direct reciprocity) and from experience of others (i.e. reputation; indirect reciprocity).

  17. Personal experience and reputation interact in human decisions to help reciprocally.

    NARCIS (Netherlands)

    Molleman, L.; van den Broek, E.; Egas, M.

    2013-01-01

    There is ample evidence that human cooperative behaviour towards other individuals is often conditioned on information about previous interactions. This information derives both from personal experience (direct reciprocity) and from experience of others (i.e. reputation; indirect reciprocity).

  18. Play and Divergent Problem Solving: Evidence Supporting a Reciprocal Relationship.

    Science.gov (United States)

    Wyver, Shirley R.; Spence, Susan H.

    1999-01-01

    Three studies examined the relationship between specific forms of preschoolers' social and pretend play and divergent/convergent problem solving. Naturalistic and experimental designs were used to provide clearer account of relationship and to challenge assumption of single direction of influence. Results support complex reciprocal causality model…

  19. Transient nature of cooperation by pay-it-forward reciprocity.

    Science.gov (United States)

    Horita, Yutaka; Takezawa, Masanori; Kinjo, Takuji; Nakawake, Yo; Masuda, Naoki

    2016-01-20

    Humans often forward kindness received from others to strangers, a phenomenon called the upstream or pay-it-forward indirect reciprocity. Some field observations and laboratory experiments found evidence of pay-it-forward reciprocity in which chains of cooperative acts persist in social dilemma situations. Theoretically, however, cooperation based on pay-it-forward reciprocity is not sustainable. We carried out laboratory experiments of a pay-it-forward indirect reciprocity game (i.e., chained gift-giving game) on a large scale in terms of group size and time. We found that cooperation consistent with pay-it-forward reciprocity occurred only in a first few decisions per participant and that cooperation originated from inherent pro-sociality of individuals. In contrast, the same groups of participants showed persisting chains of cooperation in a different indirect reciprocity game in which participants earned reputation by cooperating. Our experimental results suggest that pay-it-forward reciprocity is transient and disappears when a person makes decisions repeatedly, whereas the reputation-based reciprocity is stable in the same situation.

  20. Reciprocity on the hardwood: passing patterns among professional basketball players.

    Science.gov (United States)

    Willer, Robb; Sharkey, Amanda; Frey, Seth

    2012-01-01

    Past theory and research view reciprocal resource sharing as a fundamental building block of human societies. Most studies of reciprocity dynamics have focused on trading among individuals in laboratory settings. But if motivations to engage in these patterns of resource sharing are powerful, then we should observe forms of reciprocity even in highly structured group environments in which reciprocity does not clearly serve individual or group interests. To this end, we investigated whether patterns of reciprocity might emerge among teammates in professional basketball games. Using data from logs of National Basketball Association (NBA) games of the 2008-9 season, we estimated a series of conditional logistic regression models to test the impact of different factors on the probability that a given player would assist another player in scoring a basket. Our analysis found evidence for a direct reciprocity effect in which players who had "received" assists in the past tended to subsequently reciprocate their benefactors. Further, this tendency was time-dependent, with the probability of repayment highest soon after receiving an assist and declining as game time passed. We found no evidence for generalized reciprocity - a tendency to "pay forward" assists - and only very limited evidence for indirect reciprocity - a tendency to reward players who had sent others many assists. These findings highlight the power of reciprocity to shape human behavior, even in a setting characterized by extensive planning, division of labor, quick decision-making, and a focus on inter-group competition.

  1. Reciprocity on the hardwood: passing patterns among professional basketball players.

    Directory of Open Access Journals (Sweden)

    Robb Willer

    Full Text Available Past theory and research view reciprocal resource sharing as a fundamental building block of human societies. Most studies of reciprocity dynamics have focused on trading among individuals in laboratory settings. But if motivations to engage in these patterns of resource sharing are powerful, then we should observe forms of reciprocity even in highly structured group environments in which reciprocity does not clearly serve individual or group interests. To this end, we investigated whether patterns of reciprocity might emerge among teammates in professional basketball games. Using data from logs of National Basketball Association (NBA games of the 2008-9 season, we estimated a series of conditional logistic regression models to test the impact of different factors on the probability that a given player would assist another player in scoring a basket. Our analysis found evidence for a direct reciprocity effect in which players who had "received" assists in the past tended to subsequently reciprocate their benefactors. Further, this tendency was time-dependent, with the probability of repayment highest soon after receiving an assist and declining as game time passed. We found no evidence for generalized reciprocity - a tendency to "pay forward" assists - and only very limited evidence for indirect reciprocity - a tendency to reward players who had sent others many assists. These findings highlight the power of reciprocity to shape human behavior, even in a setting characterized by extensive planning, division of labor, quick decision-making, and a focus on inter-group competition.

  2. The Value of Reciprocity

    Science.gov (United States)

    Molm, Linda D.; Schaefer, David R.; Collett, Jessica L.

    2007-01-01

    The value of reciprocity in social exchange potentially comprises both instrumental value (the value of the actual benefits received from exchange) and communicative or symbolic value (the expressive and uncertainty reduction value conveyed by features of the act of reciprocity itself). While all forms of exchange provide instrumental value, we…

  3. The Structure of Reciprocity

    Science.gov (United States)

    Molm, Linda D.

    2010-01-01

    Reciprocity is one of the defining features of social exchange and social life, yet exchange theorists have tended to take it for granted. Drawing on work from a decade-long theoretical research program, I argue that reciprocity is structured and variable across different forms of exchange, that these variations in the structure of reciprocity…

  4. The Reciprocity Controversy

    Directory of Open Access Journals (Sweden)

    Gerald Carter

    2014-08-01

    Full Text Available Reciprocity (or ―reciprocal altruism‖ was once considered an important and widespread evolutionary explanation for cooperation, yet many reviews now conclude that it is rare or absent outside of humans. Here, I show that nonhuman reciprocity seems rare mainly because its meaning has changed over time. The original broad concept of reciprocity is well supported by evidence, but subsequent divergent uses of the term have relied on various translations of the strategy ‗tit-for-tat‘ in the repeated Prisoner‘s Dilemma game. This model has resulted in four problematic approaches to defining and testing reciprocity. Authors that deny evidence of nonhuman reciprocity tend to (1 assume that it requires sophisticated cognition, (2 focus exclusively on short-term contingency with a single partner, (3 require paradoxical evidence for a temporary lifetime fitness cost, and (4 assume that responses to investments are fixed. While these restrictions basically define reciprocity out of existence, evidence shows that fungi, plants, fish, birds, rats, and primates enforce mutual benefit by contingently altering their cooperative investments based on the cooperative returns, just as predicted by the original reciprocity theory.

  5. Indirect calorimetry

    NARCIS (Netherlands)

    Gerrits, W.J.J.; Labussière, E.

    2015-01-01

    The use of indirect calorimetry to measure the heat production of men and animals has increased rapidly since the pioneering work of Lavoisier. Measurement of the consumption of oxygen and production of carbon dioxide are the basis for the measurement of heat production. Today, applications of indir

  6. 学前教育专业学生语文素养现状与提升策略研究--基于三元交互决定论%Research on Chinese Accomplishment Status and Promotion Strategies for Pre-school Education Specialty Students---Based on Triadic Reciprocal Determinism

    Institute of Scientific and Technical Information of China (English)

    刘亮

    2016-01-01

    The Chinese quality of kindergarten teachers has great influence on the lifelong development of children. Chinese literacy for five-year higher vocational pre-school education major student presents the characteristics of unsubstantial knowledge or skills, emotional indifference and negative attitude. Triadic reciprocal determinism is a social learning theory that explores the effect of individual, behavior and environment. With the guidance of it, emphasizing the interaction among optimizing individual, improving environment and stimulating potential could promote the improvement of individual quality.%幼儿园教师的语文素养对幼儿的终身发展具有很大影响。高职五年制学前教育专业学生语文素养呈现出知识匮乏、技能薄弱、情感冷漠、态度消极等特点。三元交互决定论是社会学习理论,探讨个体、行为、环境的交互影响对学习效果的影响,以该理论为指导,注重在优化个体、改善环境、激发潜能等方面下功夫,通过三者交互作用,可以促进个体素养的提高。

  7. The logic of indirect speech.

    Science.gov (United States)

    Pinker, Steven; Nowak, Martin A; Lee, James J

    2008-01-22

    When people speak, they often insinuate their intent indirectly rather than stating it as a bald proposition. Examples include sexual come-ons, veiled threats, polite requests, and concealed bribes. We propose a three-part theory of indirect speech, based on the idea that human communication involves a mixture of cooperation and conflict. First, indirect requests allow for plausible deniability, in which a cooperative listener can accept the request, but an uncooperative one cannot react adversarially to it. This intuition is supported by a game-theoretic model that predicts the costs and benefits to a speaker of direct and indirect requests. Second, language has two functions: to convey information and to negotiate the type of relationship holding between speaker and hearer (in particular, dominance, communality, or reciprocity). The emotional costs of a mismatch in the assumed relationship type can create a need for plausible deniability and, thereby, select for indirectness even when there are no tangible costs. Third, people perceive language as a digital medium, which allows a sentence to generate common knowledge, to propagate a message with high fidelity, and to serve as a reference point in coordination games. This feature makes an indirect request qualitatively different from a direct one even when the speaker and listener can infer each other's intentions with high confidence.

  8. The logic of indirect speech

    Science.gov (United States)

    Pinker, Steven; Nowak, Martin A.; Lee, James J.

    2008-01-01

    When people speak, they often insinuate their intent indirectly rather than stating it as a bald proposition. Examples include sexual come-ons, veiled threats, polite requests, and concealed bribes. We propose a three-part theory of indirect speech, based on the idea that human communication involves a mixture of cooperation and conflict. First, indirect requests allow for plausible deniability, in which a cooperative listener can accept the request, but an uncooperative one cannot react adversarially to it. This intuition is supported by a game-theoretic model that predicts the costs and benefits to a speaker of direct and indirect requests. Second, language has two functions: to convey information and to negotiate the type of relationship holding between speaker and hearer (in particular, dominance, communality, or reciprocity). The emotional costs of a mismatch in the assumed relationship type can create a need for plausible deniability and, thereby, select for indirectness even when there are no tangible costs. Third, people perceive language as a digital medium, which allows a sentence to generate common knowledge, to propagate a message with high fidelity, and to serve as a reference point in coordination games. This feature makes an indirect request qualitatively different from a direct one even when the speaker and listener can infer each other's intentions with high confidence. PMID:18199841

  9. Attribution and reciprocity

    DEFF Research Database (Denmark)

    Sebald, Alexander Christopher

    2010-01-01

    , in turn, influence behavior. Dufwenberg and Kirchsteiger [Dufwenberg, M., Kirchsteiger, G., 2004. A theory of sequential reciprocity. Games Econ. Behav. 47 (2), 268-298] formalize this empirical finding in their ‘theory of sequential reciprocity'. This paper extends their analysis by moves of chance. More...... precisely, an extended framework is presented which allows for the analysis of strategic interactions of reciprocal agents in situations in which material outcomes also depend on chance. Moves of chance influence the attribution of responsibilities, people's perceptions about the (un)kindness of others and......, hence, their reciprocal behavior. Furthermore, with the help of two applications it is demonstrated how this framework can be used to explain experimental findings showing that people react very differently in outcomewise-identical situations depending on the moves of chance involved....

  10. Direct and Indirect Cues to Knowledge States during Word Learning

    Science.gov (United States)

    Saylor, Megan M.; Carroll, C. Brooke

    2009-01-01

    The present study investigated three-year-olds' sensitivity to direct and indirect cues to others' knowledge states for word learning purposes. Children were given either direct, physical cues to knowledge or indirect, verbal cues to knowledge. Preschoolers revealed a better ability to learn words from a speaker following direct, physical cues to…

  11. Direct and indirect punishment among strangers in the field.

    Science.gov (United States)

    Balafoutas, Loukas; Nikiforakis, Nikos; Rockenbach, Bettina

    2014-11-11

    Many interactions in modern human societies are among strangers. Explaining cooperation in such interactions is challenging. The two most prominent explanations critically depend on individuals' willingness to punish defectors: In models of direct punishment, individuals punish antisocial behavior at a personal cost, whereas in models of indirect reciprocity, they punish indirectly by withholding rewards. We investigate these competing explanations in a field experiment with real-life interactions among strangers. We find clear evidence of both direct and indirect punishment. Direct punishment is not rewarded by strangers and, in line with models of indirect reciprocity, is crowded out by indirect punishment opportunities. The existence of direct and indirect punishment in daily life indicates the importance of both means for understanding the evolution of cooperation.

  12. Raising a Fit Preschooler

    Science.gov (United States)

    ... Your Preschooler Too Active? Sleep and Your Preschooler Games for Preschoolers Motivating Preschoolers to Be Active Should Your Preschooler Play Sports? Safe Exploring for Preschoolers Your Child's Weight Kids and Exercise Contact Us Print Resources Send to a Friend Permissions Guidelines Note: ...

  13. The Nature of Disclosure Reciprocity: Three Forms of Reciprocation.

    Science.gov (United States)

    Berg, John H.; Archer, Richard L.

    Several theoretical approaches have been offered to explain the phenomenon of reciprocity: trust-liking, social exchange, and modeling. The emphasis of previous research on self-disclosure reciprocity (descriptive reciprocation), the intimacy of the facts an individual reveals about him- or herself, stems largely from the fact that these…

  14. Clustering in large networks does not promote upstream reciprocity.

    Science.gov (United States)

    Masuda, Naoki

    2011-01-01

    Upstream reciprocity (also called generalized reciprocity) is a putative mechanism for cooperation in social dilemma situations with which players help others when they are helped by somebody else. It is a type of indirect reciprocity. Although upstream reciprocity is often observed in experiments, most theories suggest that it is operative only when players form short cycles such as triangles, implying a small population size, or when it is combined with other mechanisms that promote cooperation on their own. An expectation is that real social networks, which are known to be full of triangles and other short cycles, may accommodate upstream reciprocity. In this study, I extend the upstream reciprocity game proposed for a directed cycle by Boyd and Richerson to the case of general networks. The model is not evolutionary and concerns the conditions under which the unanimity of cooperative players is a Nash equilibrium. I show that an abundance of triangles or other short cycles in a network does little to promote upstream reciprocity. Cooperation is less likely for a larger population size even if triangles are abundant in the network. In addition, in contrast to the results for evolutionary social dilemma games on networks, scale-free networks lead to less cooperation than networks with a homogeneous degree distribution.

  15. Clustering in large networks does not promote upstream reciprocity.

    Directory of Open Access Journals (Sweden)

    Naoki Masuda

    Full Text Available Upstream reciprocity (also called generalized reciprocity is a putative mechanism for cooperation in social dilemma situations with which players help others when they are helped by somebody else. It is a type of indirect reciprocity. Although upstream reciprocity is often observed in experiments, most theories suggest that it is operative only when players form short cycles such as triangles, implying a small population size, or when it is combined with other mechanisms that promote cooperation on their own. An expectation is that real social networks, which are known to be full of triangles and other short cycles, may accommodate upstream reciprocity. In this study, I extend the upstream reciprocity game proposed for a directed cycle by Boyd and Richerson to the case of general networks. The model is not evolutionary and concerns the conditions under which the unanimity of cooperative players is a Nash equilibrium. I show that an abundance of triangles or other short cycles in a network does little to promote upstream reciprocity. Cooperation is less likely for a larger population size even if triangles are abundant in the network. In addition, in contrast to the results for evolutionary social dilemma games on networks, scale-free networks lead to less cooperation than networks with a homogeneous degree distribution.

  16. Series of Reciprocal Triangular Numbers

    Science.gov (United States)

    Bruckman, Paul; Dence, Joseph B.; Dence, Thomas P.; Young, Justin

    2013-01-01

    Reciprocal triangular numbers have appeared in series since the very first infinite series were summed. Here we attack a number of subseries of the reciprocal triangular numbers by methodically expressing them as integrals.

  17. Reciprocity, World Prices and Welfare

    DEFF Research Database (Denmark)

    Raimondos-Møller, Pascalis; Woodland, Alan D.

    We examine in detail the circumstances under which reciprocity, as defined in Bagwell and Staiger (1999), leads to fixed world prices. We show that a change of tariffs satisfying reciprocity does not necessarily imply constant world prices in a world of many goods and countries. While...... it is possible to find tariff reforms that are consistent with both reciprocity and constant world prices, these reforms do not follow from the reciprocity condition, but rather from the requirement of unchanged world prices. We propose an alternative reciprocity rule that is guaranteed to raise the welfare...

  18. Strong reciprocity, human cooperation, and the enforcement of social norms.

    Science.gov (United States)

    Fehr, Ernst; Fischbacher, Urs; Gächter, Simon

    2002-03-01

    This paper provides strong evidence challenging the self-interest assumption that dominates the behavioral sciences and much evolutionary thinking. The evidence indicates that many people have a tendency to voluntarily cooperate, if treated fairly, and to punish noncooperators. We call this behavioral propensity "strong reciprocity" and show empirically that it can lead to almost universal cooperation in circumstances in which purely self-interested behavior would cause a complete breakdown of cooperation. In addition, we show that people are willing to punish those who behaved unfairly towards a third person or who defected in a Prisoner's Dilemma game with a third person. This suggests that strong reciprocity is a powerful device for the enforcement of social norms involving, for example, food sharing or collective action. Strong reciprocity cannot be rationalized as an adaptive trait by the leading evolutionary theories of human cooperation (in other words, kin selection, reciprocal altruism, indirect reciprocity, and costly signaling theory). However, multilevel selection theories of cultural evolution are consistent with strong reciprocity.

  19. Direct reciprocity in structured populations

    NARCIS (Netherlands)

    C.M. van Veelen; J. García; D.G. Rand; M.A. Nowak

    2012-01-01

    Reciprocity and repeated games have been at the center of attention when studying the evolution of human cooperation. Direct reciprocity is considered to be a powerful mechanism for the evolution of cooperation, and it is generally assumed that it can lead to high levels of cooperation. Here we expl

  20. Structural Behaviour of Reciprocal Structures

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning

    2013-01-01

    The present paper focuses on the comparison of several two-dimensional and three-dimensional reciprocal configurations. The goal of such comparison is to analyse the structural behaviour when changing the geometric parameters used to describe the geometry of reciprocal structures....

  1. Combinatorial Reciprocity Theorems

    CERN Document Server

    Beck, Matthias

    2012-01-01

    A common theme of enumerative combinatorics is formed by counting functions that are polynomials evaluated at positive integers. In this expository paper, we focus on four families of such counting functions connected to hyperplane arrangements, lattice points in polyhedra, proper colorings of graphs, and $P$-partitions. We will see that in each instance we get interesting information out of a counting function when we evaluate it at a \\emph{negative} integer (and so, a priori the counting function does not make sense at this number). Our goals are to convey some of the charm these "alternative" evaluations of counting functions exhibit, and to weave a unifying thread through various combinatorial reciprocity theorems by looking at them through the lens of geometry, which will include some scenic detours through other combinatorial concepts.

  2. CREATIVITY OF PRESCHOOL AND ELEMENTARY SCHOOL TEACHERS AND THEIR STUDENTS.

    Science.gov (United States)

    Sali, Güneş; Akyol, Aysel Köksal

    2015-12-01

    Although creativity provides a considerable number of advantages, many teachers have direct and indirect prejudices against creative students since they may display distracting and disruptive behaviors toward teachers and classmates. To determine how teachers' creativity affects their students' creative development, 90 preschool and elementary school teachers and 90 pupils were assessed for creative thinking. The children's sex was not correlated with creativity scores. There were small, significant relationships between various measures of preschool teachers' and students' creativity.

  3. Direct reciprocity in spatial populations enhances R-reciprocity as well as ST-reciprocity.

    Directory of Open Access Journals (Sweden)

    Kohei Miyaji

    Full Text Available As is well-known, spatial reciprocity plays an important role in facilitating the emergence of cooperative traits, and the effect of direct reciprocity is also obvious for explaining the cooperation dynamics. However, how the combination of these two scenarios influences cooperation is still unclear. In the present work, we study the evolution of cooperation in 2 × 2 games via considering both spatial structured populations and direct reciprocity driven by the strategy with 1-memory length. Our results show that cooperation can be significantly facilitated on the whole parameter plane. For prisoner's dilemma game, cooperation dominates the system even at strong dilemma, where maximal social payoff is still realized. In this sense, R-reciprocity forms and it is robust to the extremely strong dilemma. Interestingly, when turning to chicken game, we find that ST-reciprocity is also guaranteed, through which social average payoff and cooperation is greatly enhanced. This reciprocity mechanism is supported by mean-field analysis and different interaction topologies. Thus, our study indicates that direct reciprocity in structured populations can be regarded as a more powerful factor for the sustainability of cooperation.

  4. Social evolution: reciprocity there is.

    Science.gov (United States)

    Taborsky, Michael

    2013-06-01

    The theory of cooperation predicts that altruism can be established by reciprocity, yet empirical evidence from nature is contentious. Increasingly though, experimental results from social vertebrates challenge the nearly exclusive explanatory power of relatedness for the evolution of cooperation.

  5. Simpler valve for reciprocating engines

    Science.gov (United States)

    Akkerman, J. W.

    1978-01-01

    Simpler design eliminating camshafts, cams, and mechanical springs should improve reliability of hydrazine powered reciprocating engines. Valve is expected to improve efficiency, and reduce weight of engines in range up to 50 horsepower.

  6. The evolution of reciprocal sharing

    OpenAIRE

    Moore, Jim

    1984-01-01

    Genetical models of the evolution of reciprocal altruism (as distinct from cooperation, mutualism, or nepotism) have difficulty explaining the initial establishment of an altruist gene in a selfish deme. Though potential mechanisms have been suggested, there is an alternative: much "altruistic" behavior may in fact be purely selfish in origin and consequently reciprocity need not be invoked to provide a selective benefit to the actor. _Sharing_ and _helping_ are fundamentally different behavi...

  7. Early prediction of psychosocial risks and their prevention in preschools

    Directory of Open Access Journals (Sweden)

    M.S. Mirimanova

    2013-04-01

    Full Text Available We review approaches to creation of safe learning environment in preschools: protecting, training, personally developing, creative. We explore the possibilities of this environment examination. We reveal child development risks and threats to educational environment security of preschool institutions. A special emphasis is on personal developmental and constructive approaches. Tolerance development in children is seen as a means of prevention and creation conditions for psychological security of educational environment, and indirect control of children social development process. At the same time, the aim is development of interactional culture in preschool educational institution, built on important tolerance principles: non-violence, voluntary choice, personal responsibility, accepting the Other.

  8. Prenatal Testosterone and Preschool Disruptive Behavior Disorders.

    Science.gov (United States)

    Roberts, Bethan A; Martel, Michelle M

    2013-11-01

    Disruptive Behaviors Disorders (DBD), including Oppositional-Defiant Disorder (ODD) and Attention-Deficit/Hyperactivity Disorder (ADHD), are fairly common and highly impairing childhood behavior disorders that can be diagnosed as early as preschool. Prenatal exposure to testosterone may be particularly relevant to these early-emerging DBDs that exhibit a sex-biased prevalence rate favoring males. The current study examined associations between preschool DBD symptom domains and prenatal exposure to testosterone measured indirectly via right 2D:4D finger-length ratios. The study sample consisted of 109 preschool-age children between ages 3 and 6 (64% males;72% with DBD) and their primary caregivers. Primary caregivers completed a semi-structured interview (i.e., Kiddie Disruptive Behavior Disorder Schedule), as well as symptom questionnaires (i.e., Disruptive Behavior Rating Scale, Peer Conflict Scale); teachers and/or daycare providers completed symptom questionnaires and children provided measures of prenatal testosterone exposure, measured indirectly via finger-length ratios (i.e., right 2D:4D). Study results indicated a significant association of high prenatal testosterone (i.e., smaller right 2D:4D) with high hyperactive-impulsive ADHD symptoms in girls but not boys, suggesting that the effect may be driven by, or might only exist in, girls. The present study suggests that prenatal exposure to testosterone may increase risk for early ADHD, particularly hyperactivity-impulsivity, in preschool girls.

  9. Public privacy: Reciprocity and Silence

    Directory of Open Access Journals (Sweden)

    Jenny Kennedy

    2014-10-01

    Full Text Available In his 1958 poem 'Dedication to my Wife' TS Eliot proclaims "these are private words addressed to you in public". Simultaneously written for his wife, Valerie Fletcher, and to the implied you of a discourse network, Eliot's poem helps to illustrate the narrative voices and silences that are constitutive of an intimate public sphere. This paper situates reciprocity as a condition of possibility for public privacy. It shows how reciprocity is enabled by systems of code operating through material and symbolic registers. Code promises to control communication, to produce neutral, systemic forms of meaning. Yet such automation is challenged by uneven and fragmented patterns of reciprocity. Moreover, examining the media of public privacy reveals historical trajectories important for understanding contemporary socio­technical platforms of reciprocity. To explore the implicit requirement of reciprocity in publicly private practices, three sites of communication are investigated framed by a media archaeology perspective: postal networks, the mail­art project PostSecret and the anonymous zine 'You'.

  10. Indirection and computer security.

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Michael J.

    2011-09-01

    The discipline of computer science is built on indirection. David Wheeler famously said, 'All problems in computer science can be solved by another layer of indirection. But that usually will create another problem'. We propose that every computer security vulnerability is yet another problem created by the indirections in system designs and that focusing on the indirections involved is a better way to design, evaluate, and compare security solutions. We are not proposing that indirection be avoided when solving problems, but that understanding the relationships between indirections and vulnerabilities is key to securing computer systems. Using this perspective, we analyze common vulnerabilities that plague our computer systems, consider the effectiveness of currently available security solutions, and propose several new security solutions.

  11. Sleep and Your Preschooler

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Sleep and Your Preschooler KidsHealth > For Parents > Sleep and Your Preschooler Print A A A What's ... Preschoolers need about 11 to 12 hours of sleep each day, which can include a nap. There's ...

  12. Born Reciprocity and Cosmic Accelerations

    CERN Document Server

    Bolognesi, S

    2015-01-01

    The trans-Planckian theory is a model that realizes concretely the Born reciprocity idea, which is the postulate of absolute equivalence between coordinate $x$ and momenta $p$. This model is intrinsically global, and thus it is naturally implemented in a cosmological setting. Cosmology and Born reciprocity are made for each other. Inflation provides the essential mechanism to suppress the terms coming from the dual part of the action. The trans-Planckian theory, on the other hand, provides an explanation for the accelerated periods of the universe scale factor, both the inflationary period and the present period dominated by dark energy. All of this is possible just considering a simple model that contains gravity, one gauge field plus one matter field (to be identified with dark matter) together with the reciprocity principle.

  13. Non-Reciprocal Optical Antennas

    CERN Document Server

    Castro-Lopez, Marta; van Hulst, Niek F

    2014-01-01

    Plasmonics aims to interface photonics and electronics. Finding optical, near-field analogues of much used electro-technical components is crucial to the success of such a platform. Here we present the plasmonic analogue of a non-reciprocal antenna. For non-reciprocality in a plasmonic context, the optical excitation and emission resonances of the antenna need to be an orthogonal set. We show that nonlinear excitation of metal nanoantennas creates a sufficient shift between excitation and emission wavelengths that they can be interpreted as decoupled, allowing for independent tuning of excitation and emission properties along different spatial dimensions. This leads, for given excitation wavelength and polarization, to independent optimization of emission intensity, frequency spectrum, polarization and angular spectrum. Non-reciprocal optical antennas of both gold and aluminum are characterized and shown to be useful as e.g. nonlinear signal transducers or nanoscale sources of widely tunable light.

  14. An experimental study of strong reciprocity in bacteria.

    Science.gov (United States)

    Inglis, R Fredrik; West, Stuart; Buckling, Angus

    2014-02-01

    Strong reciprocity, whereby cooperators punish non-cooperators, may help to explain the evolutionary success of cooperative behaviours. However, theory suggests that selection for strong reciprocity can depend upon tight genetic linkage between cooperation and punishment, to avoid the strategy being outcompeted by non-punishing cooperators. We tested this hypothesis using experimental populations of the bacterium Pseudomonas aeruginosa, which cooperate by producing iron-scavenging siderophores and, in this context, punish non-cooperators with toxins. Consistent with theory, we show that cooperative punishers can indeed invade cheats, but only when the traits are tightly linked. These results emphasize that punishment is only likely to be favoured when the punishment itself leads to a direct or indirect fitness benefit to the actor.

  15. Preschool Science Environment: What Is Available in a Preschool Classroom?

    Science.gov (United States)

    Tu, Tsunghui

    2006-01-01

    This study investigated preschool science environments in 20 preschool classrooms (N=20) in 13 midwestern child care centers. By operationalizing Neuman's concept of "sciencing," this study used The Preschool Classroom Science Materials/Equipment Checklist, the Preschool Classroom Science Activities Checklist, and the Preschool Teacher…

  16. Preschool Staff's View of Emergent Literacy Approaches in Swedish Preschools

    Science.gov (United States)

    Norling, Martina

    2014-01-01

    This study aims to investigate preschool staff's view of emergent literacy approaches in Swedish preschools with the following research question: How do preschool staff describe and explain the approaches they use in the emergent literacy environment of preschool? Focus-group interviews were conducted with 52 participating preschool units.…

  17. Indirect Speech Acts

    Institute of Scientific and Technical Information of China (English)

    李威

    2001-01-01

    Indirect speech acts are frequently used in verbal communication, the interpretation of them is of great importance in order to meet the demands of the development of students' communicative competence. This paper, therefore, intends to present Searle' s indirect speech acts and explore the way how indirect speech acts are interpreted in accordance with two influential theories. It consists of four parts. Part one gives a general introduction to the notion of speech acts theory. Part two makes an elaboration upon the conception of indirect speech act theory proposed by Searle and his supplement and development of illocutionary acts. Part three deals with the interpretation of indirect speech acts. Part four draws implication from the previous study and also serves as the conclusion of the dissertation.

  18. Function, Type, and Distribution of Teacher Questions in Dual-Language Preschool Read Alouds

    Science.gov (United States)

    Gort, Mileidis; Pontier, Ryan W.; Sembiante, Sabrina F.

    2012-01-01

    This exploratory study investigated the nature and distribution of dual-language preschool teachers' questions across parallel Spanish- and English-medium read-aloud activities. The notions of comprehensible input (Krashen, 1985) and language output (Swain, 1985), along with a reciprocal interaction model of teaching (Cummins, 2000), guided our…

  19. A Theory of Sequential Reciprocity

    NARCIS (Netherlands)

    Dufwenberg, M.; Kirchsteiger, G.

    1998-01-01

    Many experimental studies indicate that people are motivated by reciprocity. Rabin (1993) develops techniques for incorporating such concerns into game theory and economics. His model, however, does not fare well when applied to situations with an interesting dynamic structure (like many experimenta

  20. The Principle of Structural Reciprocity

    DEFF Research Database (Denmark)

    Pugnale, Alberto; Parigi, Dario; Kirkegaard, Poul Henning

    2011-01-01

    This paper deals with the principle of structural reciprocity, considering its origins in both Occidental and Orient culture and aiming to highlight the definition, main peculiarities and interesting aspects of such concept referring to its application to the world of construction. Issues spanning...

  1. Reciprocity theory of homogeneous reactions

    Science.gov (United States)

    Agbormbai, Adolf A.

    1990-03-01

    The reciprocity formalism is applied to the homogeneous gaseous reactions in which the structure of the participating molecules changes upon collision with one another, resulting in a change in the composition of the gas. The approach is applied to various classes of dissociation, recombination, rearrangement, ionizing, and photochemical reactions. It is shown that for the principle of reciprocity to be satisfied it is necessary that all chemical reactions exist in complementary pairs which consist of the forward and backward reactions. The backward reaction may be described by either the reverse or inverse process. The forward and backward processes must satisfy the same reciprocity equation. Because the number of dynamical variables is usually unbalanced on both sides of a chemical equation, it is necessary that this balance be established by including as many of the dynamical variables as needed before the reciprocity equation can be formulated. Statistical transformation models of the reactions are formulated. The models are classified under the titles free exchange, restricted exchange and simplified restricted exchange. The special equations for the forward and backward processes are obtained. The models are consistent with the H theorem and Le Chatelier's principle. The models are also formulated in the context of the direct simulation Monte Carlo method.

  2. GENERALIZED RECIPROCAL THEOREMS AND THEIR APPLICATIONS

    Institute of Scientific and Technical Information of China (English)

    付宝连

    2002-01-01

    Generalized reciprocal theorems of non-coupled and coupled systems , which are valid for two deformed bodies with different constitutive relations are established by generalizing the idea of Betti ' s reciprocal theorem. When the constitutive relations of the two deformed bodies are all alike and linear elastic, the generalized reciprocal theorem of non-coupled systems just becomes Betti' s . Meanwhile, the generalized reciprocal theorems are applied to simulate calculations in elasticity.

  3. An Inquiry into Relationship Suicides and Reciprocity

    Science.gov (United States)

    Davis, Mark S.; Callanan, Valerie J.; Lester, David; Haines, Janet

    2009-01-01

    Few theories on suicide have been grounded in the norm of reciprocity. There is literature on suicide, however, describing motivations such as retaliation and retreat which can be interpreted as modes of adaptation to the norm of reciprocity. We propose a reciprocity-based theory to explain suicides associated with relationship problems. Employing…

  4. Reciprocity of Interpersonal Attraction: A Confirmed Hypothesis.

    Science.gov (United States)

    La Voie, Lawrence; Kenny, David A.

    An increase in reciprocity of interpersonal attraction during the early acquaintance period followed by continuing social reciprocity are propositions that are central principles of several social psychological viewpoints. However, there is little empirical evidence of increasing reciprocity of interpersonal attraction over time. Two potential…

  5. Capuchin Monkeys Judge Third-Party Reciprocity

    Science.gov (United States)

    Anderson, James R.; Takimoto, Ayaka; Kuroshima, Hika; Fujita, Kazuo

    2013-01-01

    Increasing interest is being shown in how children develop an understanding of reciprocity in social exchanges and fairness in resource distribution, including social exchanges between third parties. Although there are descriptions of reciprocity on a one-to-one basis in other species, whether nonhumans detect reciprocity and violations of…

  6. 47 CFR 51.221 - Reciprocal compensation.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Reciprocal compensation. 51.221 Section 51.221... Obligations of All Local Exchange Carriers § 51.221 Reciprocal compensation. The rules governing reciprocal compensation are set forth in subpart H of this part....

  7. INDIRECT MICROLARYNGOSTROBOSCOPIC SURGERY

    NARCIS (Netherlands)

    MAHIEU, HF; DIKKERS, FG

    Detailed preoperative laryngostroboscopic examination is a prerequisite for phonosurgical correction of organic dysphonia. Although suspension microlaryngoscopic surgery has proved its value in the past, it excludes functional control during the removal of vocal fold swellings. Using an indirect

  8. INDIRECT MICROLARYNGOSTROBOSCOPIC SURGERY

    NARCIS (Netherlands)

    MAHIEU, HF; DIKKERS, FG

    1992-01-01

    Detailed preoperative laryngostroboscopic examination is a prerequisite for phonosurgical correction of organic dysphonia. Although suspension microlaryngoscopic surgery has proved its value in the past, it excludes functional control during the removal of vocal fold swellings. Using an indirect mic

  9. Indirect neutrino oscillations

    CERN Document Server

    Babu, K S; Wilczek, Frank; Pati, Jogesh C; Wilczek, Frank

    1995-01-01

    We show how two different scales for oscillations between e and \\mu neutrinos, characterized by different mixing angles and effective mass scales, can arise in a simple and theoretically attractive framework. One scale characterizes direct oscillations, which can accommodate the MSW approach to the solar neutrino problem, whereas the other can be considered as arising indirectly, through virtual transitions involving the \\tau neutrino with a mass \\sim 1 eV. This indirect transition allows the possibility of observable \\bar \

  10. Using reciprocity in Boundary Element Calculations

    DEFF Research Database (Denmark)

    Juhl, Peter Møller; Cutanda Henriquez, Vicente

    2010-01-01

    The concept of reciprocity is widely used in both theoretical and experimental work. In Boundary Element calculations reciprocity is sometimes employed in the solution of computationally expensive scattering problems, which sometimes can be more efficiently dealt with when formulated...... as the reciprocal radiation problem. The present paper concerns the situation of having a point source (which is reciprocal to a point receiver) at or near a discretized boundary element surface. The accuracy of the original and the reciprocal problem is compared in a test case for which an analytical solution...

  11. Tacit Collusion under Fairness and Reciprocity

    Directory of Open Access Journals (Sweden)

    Doruk İriş

    2013-02-01

    Full Text Available This paper departs from the standard profit-maximizing model of firm behavior by assuming that firms are motivated in part by personal animosity–or respect–towards their competitors. A reciprocal firm responds to unkind behavior of rivals with unkind actions (negative reciprocity, while at the same time, it responds to kind behavior of rivals with kind actions (positive reciprocity. We find that collusion is easier to sustain when firms have a concern for reciprocity towards competing firms provided that they consider collusive prices to be kind and punishment prices to be unkind. Thus, reciprocity concerns among firms can have adverse welfare consequences for consumers.

  12. Reciprocal uniparental disomy in yeast.

    Science.gov (United States)

    Andersen, Sabrina L; Petes, Thomas D

    2012-06-19

    In the diploid cells of most organisms, including humans, each chromosome is usually distinguishable from its partner homolog by multiple single-nucleotide polymorphisms. One common type of genetic alteration observed in tumor cells is uniparental disomy (UPD), in which a pair of homologous chromosomes are derived from a single parent, resulting in loss of heterozygosity for all single-nucleotide polymorphisms while maintaining diploidy. Somatic UPD events are usually explained as reflecting two consecutive nondisjunction events. Here we report a previously undescribed mode of chromosome segregation in Saccharomyces cerevisiae in which one cell division produces daughter cells with reciprocal UPD for the same pair of chromosomes without an aneuploid intermediate. One pair of sister chromatids is segregated into one daughter cell and the other pair is segregated into the other daughter cell, mimicking a meiotic chromosome segregation pattern. We term this process "reciprocal uniparental disomy."

  13. Personal experience and reputation interact in human decisions to help reciprocally.

    Science.gov (United States)

    Molleman, Lucas; van den Broek, Eva; Egas, Martijn

    2013-04-22

    There is ample evidence that human cooperative behaviour towards other individuals is often conditioned on information about previous interactions. This information derives both from personal experience (direct reciprocity) and from experience of others (i.e. reputation; indirect reciprocity). Direct and indirect reciprocity have been studied separately, but humans often have access to both types of information. Here, we experimentally investigate information use in a repeated helping game. When acting as donor, subjects can condition their decisions to help recipients with both types of information at a small cost to access such information. We find that information from direct interactions weighs more heavily in decisions to help, and participants tend to react less forgivingly to negative personal experience than to negative reputation. Moreover, effects of personal experience and reputation interact in decisions to help. If a recipient's reputation is positive, the personal experience of the donor has a weak effect on the decision to help, and vice versa. Yet if the two types of information indicate conflicting signatures of helpfulness, most decisions to help follow personal experience. To understand the roles of direct and indirect reciprocity in human cooperation, they should be studied in concert, not in isolation.

  14. Swimming Orientation for Preschoolers.

    Science.gov (United States)

    Smith, Mary Lou

    1990-01-01

    Techniques which are designed to dispel fears and promote confident learning are offered to preschool swimming instructors. Safety, class organization, water games, and class activities are discussed. (IAH)

  15. Imperfect information facilitates the evolution of reciprocity.

    Science.gov (United States)

    Kurokawa, Shun

    2016-06-01

    The existence of cooperation demands explanation since cooperation is costly to the actor. Reciprocity has long been regarded as a potential explanatory mechanism for the existence of cooperation. Reciprocity is a mechanism wherein a cooperator responds to an opponent's behavior by switching his/her own behavior. Hence, a possible problematic case relevant to the theory of reciprocity evolution arises when the mechanism is such that the information regarding an opponent's behavior is imperfect. Although it has been confirmed also by previous theoretical studies that imperfect information interferes with the evolution of reciprocity, this argument is based on the assumption that there are no mistakes in behavior. And, a previous study presumed that it might be expected that when such mistakes occur, reciprocity can more readily evolve in the case of imperfect information than in the case of perfect information. The reason why the previous study considers so is that in the former case, reciprocators can miss defections incurred by other reciprocators' mistakes due to imperfect information, allowing cooperation to persist when such reciprocators meet. However, contrary to this expectation, the previous study has shown that even when mistakes occur, imperfect information interferes with the evolution of reciprocity. Nevertheless, the previous study assumed that payoffs are linear (i.e., that the effect of behavior is additive and there are no synergetic effects). In this study, we revisited the same problem but removed the assumption that payoffs are linear. We used evolutionarily stable strategy analysis to compare the condition for reciprocity to evolve when mistakes occur and information is imperfect with the condition for reciprocity to evolve when mistakes occur and information is perfect. Our study revealed that when payoffs are not linear, imperfect information can facilitate the evolution of reciprocity when mistakes occur; while when payoffs are linear

  16. Indirect Sexism in Discourse

    Institute of Scientific and Technical Information of China (English)

    彭卓

    2008-01-01

    This thesis draws attention to one of the most vigorous debate in sociolinguistics,sexism in discourse,despite the chicken-and egg question whether it is our language shape sexism or sexism creates certain language.Unlike most researches conducted in sexism and language in the past,we challenge the traditional notion of linguistic sexism and direct our view to what we call "an indirect sexism" here.We then argue the difference between direct and indirect sexism and depict how such an undercurrent drives secretly and carefully in our daily discourse.

  17. American Preschoolers on Ritalin.

    Science.gov (United States)

    Leo, Jonathan

    2002-01-01

    Discusses the controversial use of Ritalin among preschool children, examining research from two studies: "Treatment Strategies for Attention-Deficit/Hyperactivity Disorder" and "Preschool ADHD Treatment Study." Examines issues related to the diagnosis and treatment of ADHD and concludes by examining the influence of the human…

  18. Indirect airway challenges

    NARCIS (Netherlands)

    Joos, GF; O'Connor, B; Anderson, SD; Chung, F; Cockcroft, DW; Dahlen, B; DiMaria, G; Foresi, A; Hargreave, FE; Holgate, ST; Inman, M; Lotvall, J; Magnussen, H; Polosa, R; Postma, DS; Riedler, J

    2003-01-01

    Indirect challenges act by causing the release of endogenous mediators that cause the airway smooth muscle to contract. This is in contrast to the direct challenges where agonists such as methacholine or histamine cause airflow limitation predominantly via a direct effect on airway smooth muscle. Di

  19. Onsager Reciprocity in Premelting Solids

    KAUST Repository

    Peppin, S. S. L.

    2009-02-01

    The diffusive motion of foreign particles dispersed in a premelting solid is analyzed within the framework of irreversible thermodynamics. We determine the mass diffusion coefficient, thermal diffusion coefficient and Soret coefficient of the particles in the dilute limit, and find good agreement with experimental data. In contrast to liquid suspensions, the unique nature of premelting solids allows us to derive an expression for the Dufour coefficient and independently verify the Onsager reciprocal relation coupling diffusion to the flow of heat. © 2009 Springer Science+Business Media, LLC.

  20. Towards a unified theory of reciprocity.

    Science.gov (United States)

    Rosas, Alejandro

    2012-02-01

    In a unified theory of human reciprocity, the strong and weak forms are similar because neither is biologically altruistic and both require normative motivation to support cooperation. However, strong reciprocity is necessary to support cooperation in public goods games. It involves inflicting costs on defectors; and though the costs for punishers are recouped, recouping costs requires complex institutions that would not have emerged if weak reciprocity had been enough.

  1. Reciprocally-Rotating Velocity Obstacles

    KAUST Repository

    Giese, Andrew

    2014-05-01

    © 2014 IEEE. Modern multi-agent systems frequently use highlevel planners to extract basic paths for agents, and then rely on local collision avoidance to ensure that the agents reach their destinations without colliding with one another or dynamic obstacles. One state-of-the-art local collision avoidance technique is Optimal Reciprocal Collision Avoidance (ORCA). Despite being fast and efficient for circular-shaped agents, ORCA may deadlock when polygonal shapes are used. To address this shortcoming, we introduce Reciprocally-Rotating Velocity Obstacles (RRVO). RRVO generalizes ORCA by introducing a notion of rotation for polygonally-shaped agents. This generalization permits more realistic motion than ORCA and does not suffer from as much deadlock. In this paper, we present the theory of RRVO and show empirically that it does not suffer from the deadlock issue ORCA has, permits agents to reach goals faster, and has a comparable collision rate at the cost of performance overhead quadratic in the (typically small) user-defined parameter δ.

  2. Indirect resin composites

    Directory of Open Access Journals (Sweden)

    Nandini Suresh

    2010-01-01

    Full Text Available Aesthetic dentistry continues to evolve through innovations in bonding agents, restorative materials, and conservative preparation techniques. The use of direct composite restoration in posterior teeth is limited to relatively small cavities due to polymerization stresses. Indirect composites offer an esthetic alternative to ceramics for posterior teeth. This review article focuses on the material aspect of the newer generation of composites. This review was based on a PubMed database search which we limited to peer-reviewed articles in English that were published between 1990 and 2010 in dental journals. The key words used were ′indirect resin composites,′ composite inlays,′ and ′fiber-reinforced composites.′

  3. Indirect Control and Power

    Directory of Open Access Journals (Sweden)

    Cesarino Bertini

    2016-01-01

    Full Text Available To determine who has the power within a stock corporate company can be a quite complex problem, especially when control is achieved through alliances between shareholders. This problem arises especially in cases of indirect control of corporations, that is, in situations involving shareholders and companies with cross-shareholdings. The first to solve the problem of measuring power in the case of indirect share control were Gianfranco Gambarelli and Guillermo Owen in [10]. In the following years, numerous other models were introduced. In this paper, we critically examine the models of: Gambarelli and Owen, Denti and Prati, Crama and Leruth, Karos and Peters, as well as Mercik and Lobos, taking into account two well-known, illustrative examples, one with an acyclic corporate structure and the other with a cyclic structure. (original abstract

  4. Pedal indirect lymphangiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kil Woo; Hong, Myung Sun; Kim, In Jae [College of Medicine, Hallym University, Seoul (Korea, Republic of)

    1994-04-15

    Recently, indirect lymphangiography has been developed as a relatively good and noninvasive imaging modality of the lymphatic system at extremities. But the disadvantage of the indirect lymphangiography is a low contrast ratio between the surrounding tissues and the contrast media in lymphatic vessels, because dimeric nonionic contrast media is water soluble and diluted in the proximal leg lymphatic vessels. We could have relatively better image than previously published images for the leg lymphatic system, when we injected contrast media with adequate high pressure in intradermal space of the interdigital areas at the foot dorsum. So, we would like to report the results. We could study all 9 lymphedemas(primary: 6, secondary: 3) from April 1990 to May 1993 on outpatient base. They were diagnosed as lymphedema clinically and radiologically. Ten ml of dimeric nonionic aget, iotrolan(Isovist 300) was injected into intradermal space with five 30-gauge needles. The injection speed was more than 0.2 ml/min. We have done one side pedal lymphangiogram in 30 minutes. The evaluation of the anterior superficial lymphatics was according to the criteria of the Weissleder. The results were as follows: 1. All lymphatic vessels from foot to inguinal area could be visualized. 2. Two or three inferior inguinal lymph nodes could be visualized about 42%. 3. The most common abnormal finding of the lymphedma was the neovascularization of the lymphatics on indirect pedal lymphangiogram. If we use adequate technique relatively high pressure injection, correct intradermal needle insertion, adequate soft tissue exposure technique indirect lymphangiography is considered to be a safe and noninvasive imaging modality for the evaluation of the lymphedema of lower extremity lymphatics including inferior inguinal lymph nodes.

  5. Mechanisms through which reciprocal filial values protect wellbeing of Chinese adult-child caregivers in the US.

    Science.gov (United States)

    Hsueh, Kuei-Hsiang; Bachman, Jean A; Richardson, Lloyd I; Cheng, Wen-Yung; Zimmerman, Rick S

    2014-04-01

    In this study, we explored the role of reciprocal filial values in protecting the wellbeing of Chinese adult-child caregivers in the US. Using survey data obtained from 137 Chinese adult-child caregivers living in seven US cities, we tested a latent variable model using structural equation modeling. In this model, informed by role theory, social exchange theory and stress-coping theory, reciprocal filial values affect caregiver wellbeing in the face of caregiver role strain, both directly and indirectly through protective effects of role rewards and coping. In the final model, reciprocal filial values had both direct and indirect protective effects on caregivers' wellbeing, offering evidence to address culturally sensitive issues in family caregivers with similar filial values. © 2014 Wiley Periodicals, Inc.

  6. Loneliness, exchange orientation, and reciprocity in friendships

    NARCIS (Netherlands)

    Buunk, Abraham (Bram); Prins, K.S.

    1998-01-01

    Guided by equity theory this study among 185 Dutch students explored the effects of exchange orientation and reciprocity in the relationship with the best friend upon loneliness. Reciprocity was in general more common in this relationship than feeling advantaged or deprived. The association between

  7. Free-Form Kinetic Reciprocal System

    DEFF Research Database (Denmark)

    Parigi, Dario; Sassone, Mario

    2011-01-01

    Kinetic Reciprocal System (KRS) are innovative moveable structures based on the principle of reciprocity [1] with internal pin-slot constraints [2]. The analysis of KRS kinematic and static determinacy is developed through the construction of kinematic matrices, accordingly with [3...

  8. Education, Gift and Reciprocity: A Preliminary Discussion

    Science.gov (United States)

    Sabourin, Eric

    2013-01-01

    This paper analyzes the importance and role of the reciprocity relationship in education. It presents a review on the mobilization of the principle of reciprocity--in the anthropological but also sociological and economic senses--in educational processes, especially in adult education. The study is divided into three parts. The first part analyzes…

  9. An Introduction to the Onsager Reciprocal Relations

    Science.gov (United States)

    Monroe, Charles W.; Newman, John

    2007-01-01

    The Onsager reciprocal relations are essential to multicomponent transport theory. A discussion of the principles that should be used to derive flux laws for coupled diffusion is presented here. Fluctuation theory is employed to determine the reciprocal relation for transport coefficients that characterize coupled mass and heat transfer in binary…

  10. Implementing Reciprocal Teaching: Was It Effective?

    Science.gov (United States)

    Al-Hilawani, Yasser A.; And Others

    This study was conducted to explore the relationship between teaching methods and students' grades at the college level. Subjects, 58 undergraduate students enrolled in 2 introductory education courses, were organized into groups and exposed to one of two teaching methods: the lecture format and reciprocal teaching. Reciprocal teaching engages…

  11. Loneliness, exchange orientation, and reciprocity in friendships

    NARCIS (Netherlands)

    Buunk, Abraham (Bram); Prins, K.S.

    1998-01-01

    Guided by equity theory this study among 185 Dutch students explored the effects of exchange orientation and reciprocity in the relationship with the best friend upon loneliness. Reciprocity was in general more common in this relationship than feeling advantaged or deprived. The association between

  12. Reciprocity Outperforms Conformity to Promote Cooperation.

    Science.gov (United States)

    Romano, Angelo; Balliet, Daniel

    2017-08-01

    Evolutionary psychologists have proposed two processes that could give rise to the pervasiveness of human cooperation observed among individuals who are not genetically related: reciprocity and conformity. We tested whether reciprocity outperformed conformity in promoting cooperation, especially when these psychological processes would promote a different cooperative or noncooperative response. To do so, across three studies, we observed participants' cooperation with a partner after learning (a) that their partner had behaved cooperatively (or not) on several previous trials and (b) that their group members had behaved cooperatively (or not) on several previous trials with that same partner. Although we found that people both reciprocate and conform, reciprocity has a stronger influence on cooperation. Moreover, we found that conformity can be partly explained by a concern about one's reputation-a finding that supports a reciprocity framework.

  13. Quantum coherence: Reciprocity and distribution

    Science.gov (United States)

    Kumar, Asutosh

    2017-03-01

    Quantum coherence is the outcome of the superposition principle. Recently, it has been theorized as a quantum resource, and is the premise of quantum correlations in multipartite systems. It is therefore interesting to study the coherence content and its distribution in a multipartite quantum system. In this work, we show analytically as well as numerically the reciprocity between coherence and mixedness of a quantum state. We find that this trade-off is a general feature in the sense that it is true for large spectra of measures of coherence and of mixedness. We also study the distribution of coherence in multipartite systems by looking at monogamy-type relation-which we refer to as additivity relation-between coherences of different parts of the system. We show that for the Dicke states, while the normalized measures of coherence violate the additivity relation, the unnormalized ones satisfy the same.

  14. The relationship between reciprocity and burnout in Dutch medical residents

    NARCIS (Netherlands)

    Prins, Jelle T.; Gazendam-Donofrio, Stacey M.; Dillingh, Gea S.; van de Wiel, Harry B. M.; van der Heijden, Frank M. M. A.; Hoekstra-Weebers, Josette E. H. M.

    2008-01-01

    OBJECTIVE This study examined reciprocity in medical residents' relationships with supervisors, fellow residents, nurses and patients, and associations between reciprocity and burnout. Furthermore, we considered if a discrepancy between the perceived and preferred levels of reciprocity influenced th

  15. Indirect radioimmunoassay for interferon

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, S.F.; Schoub, B.D. (University of the Witwatersrand, Johannesburg (South Africa). Dept. of Virology); Chiu, M.N.; Crespi, M. (National Institute for Virology, Johannesburg (South Africa))

    1982-10-01

    An indirect radioimmunoassay for testing the antiviral activity of interferon (IFN) is described. Vero cells are seeded in microtitre plates, treated with appropriate dilutions of interferon and challenged with Sindbis virus. Viral yield is measured using specific antibody and radiolabelled protein A. The assay is able to detect IFN levels of 5 international units (I.U.)/ml, has a high degree of reproducibility, and could be easily adapted to various cell and virus combinations. This microsystem is technically simple, allows testing of small volumes of test material, and eliminates subjectivity in reading of endpoints.

  16. Promoting preschool reading

    OpenAIRE

    2013-01-01

    The thesis titled Promoting preschool reading consists of a theoretiral and an empirical part. In the theoretical part I wrote about reading, the importance of reading, types of reading, about reading motivation, promoting reading motivation, internal and external motivation, influence of reading motivation on the child's reading activity, reading and familial literacy, the role of adults in promotion reading literacy, reading to a child and promoting reading in pre-school years, where I ...

  17. Bioechnology of indirect liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Datta, R.; Jain, M.K.; Worden, R.M.; Grethlein, A.J.; Soni, B.; Zeikus, J.G.; Grethlein, H.

    1990-05-07

    The project on biotechnology of indirect liquefaction was focused on conversion of coal derived synthesis gas to liquid fuels using a two-stage, acidogenic and solventogenic, anaerobic bioconversion process. The acidogenic fermentation used a novel and versatile organism, Butyribacterium methylotrophicum, which was fully capable of using CO as the sole carbon and energy source for organic acid production. In extended batch CO fermentations the organism was induced to produce butyrate at the expense of acetate at low pH values. Long-term, steady-state operation was achieved during continuous CO fermentations with this organism, and at low pH values (a pH of 6.0 or less) minor amounts of butanol and ethanol were produced. During continuous, steady-state fermentations of CO with cell recycle, concentrations of mixed acids and alcohols were achieved (approximately 12 g/l and 2 g/l, respectively) which are high enough for efficient conversion in stage two of the indirect liquefaction process. The metabolic pathway to produce 4-carbon alcohols from CO was a novel discovery and is believed to be unique to our CO strain of B. methylotrophicum. In the solventogenic phase, the parent strain ATCC 4259 of Clostridium acetobutylicum was mutagenized using nitrosoguanidine and ethyl methane sulfonate. The E-604 mutant strain of Clostridium acetobutylicum showed improved characteristics as compared to parent strain ATCC 4259 in batch fermentation of carbohydrates.

  18. Reciprocity and Ethical Tuberculosis Treatment and Control.

    Science.gov (United States)

    Silva, Diego S; Dawson, Angus; Upshur, Ross E G

    2016-03-01

    This paper explores the notion of reciprocity in the context of active pulmonary and laryngeal tuberculosis (TB) treatment and related control policies and practices. We seek to do three things: First, we sketch the background to contemporary global TB care and suggest that poverty is a key feature when considering the treatment of TB patients. We use two examples from TB care to explore the role of reciprocity: isolation and the use of novel TB drugs. Second, we explore alternative means of justifying the use of reciprocity through appeal to different moral and political theoretical traditions (i.e., virtue ethics, deontology, and consequentialism). We suggest that each theory can be used to provide reasons to take reciprocity seriously as an independent moral concept, despite any other differences. Third, we explore general meanings and uses of the concept of reciprocity, with the primary intention of demonstrating that it cannot be simply reduced to other more frequently invoked moral concepts such as beneficence or justice. We argue that reciprocity can function as a mid-level principle in public health, and generally, captures a core social obligation arising once an individual or group is burdened as a result of acting for the benefit of others (even if they derive a benefit themselves). We conclude that while more needs to be explored in relation to the theoretical justification and application of reciprocity, sufficient arguments can be made for it to be taken more seriously as a key principle within public health ethics and bioethics more generally.

  19. ADVANCED RECIPROCATING COMPRESSION TECHNOLOGY (ARCT)

    Energy Technology Data Exchange (ETDEWEB)

    Danny M. Deffenbaugh; Klaus Brun; Ralph E. Harris; J. Pete Harrell; Robert J. Mckee; J. Jeffrey Moore; Steven J. Svedeman; Anthony J. Smalley; Eugene L. Broerman; Robert A Hart; Marybeth G. Nored; Ryan S. Gernentz; Shane P. Siebenaler

    2005-12-01

    The U.S. natural gas pipeline industry is facing the twin challenges of increased flexibility and capacity expansion. To meet these challenges, the industry requires improved choices in gas compression to address new construction and enhancement of the currently installed infrastructure. The current fleet of installed reciprocating compression is primarily slow-speed integral machines. Most new reciprocating compression is and will be large, high-speed separable units. The major challenges with the fleet of slow-speed integral machines are: limited flexibility and a large range in performance. In an attempt to increase flexibility, many operators are choosing to single-act cylinders, which are causing reduced reliability and integrity. While the best performing units in the fleet exhibit thermal efficiencies between 90% and 92%, the low performers are running down to 50% with the mean at about 80%. The major cause for this large disparity is due to installation losses in the pulsation control system. In the better performers, the losses are about evenly split between installation losses and valve losses. The major challenges for high-speed machines are: cylinder nozzle pulsations, mechanical vibrations due to cylinder stretch, short valve life, and low thermal performance. To shift nozzle pulsation to higher orders, nozzles are shortened, and to dampen the amplitudes, orifices are added. The shortened nozzles result in mechanical coupling with the cylinder, thereby, causing increased vibration due to the cylinder stretch mode. Valve life is even shorter than for slow speeds and can be on the order of a few months. The thermal efficiency is 10% to 15% lower than slow-speed equipment with the best performance in the 75% to 80% range. The goal of this advanced reciprocating compression program is to develop the technology for both high speed and low speed compression that will expand unit flexibility, increase thermal efficiency, and increase reliability and integrity

  20. Inequality Aversion and Reciprocity in Moonlighting Games

    Directory of Open Access Journals (Sweden)

    Dirk Engelmann

    2010-10-01

    Full Text Available We study behavior in a moonlighting game with unequal initial endowments. In this game, predictions for second-mover behavior based on inequality aversion are in contrast to reciprocity. We find that inequality aversion explains only few observations. The comparison to a treatment with equal endowments supports the conclusion that behavior is better captured by intuitive notions of reciprocity than by inequality aversion. Extending the model by allowing for alternative reference points promises better performance, but leads to other problems. We conclude that the fact that inequality aversion often works as a good short-hand for reciprocity is driven by biased design choices.

  1. Reciprocity Effects in the Trust Game

    Directory of Open Access Journals (Sweden)

    Alexander Smith

    2013-07-01

    Full Text Available I use data from a previous experiment for classifying subjects based on their behavior in the trust game. Prior literature defines a “reciprocity effect” as the tendency for Second Movers to return proportions increasing in the amounts that they receive. In the data that I use, 31% of Second Movers show reciprocity effects, 31% are neutral, and 25% consistently free-ride, indicating that the aggregate reciprocity effect for the sample as a whole is attributable to a minority of the subjects.

  2. Planning and Evaluating Educational Work in Slovene Preschools

    Directory of Open Access Journals (Sweden)

    Marcela Batistič Zorec

    2012-01-01

    Full Text Available The present article examines the changes in Slovene preschools subsequent to Slovenia’s independence in 1991. In the socialist period, the national education programme for preschools was highly structured, goaland content-oriented and subject to schoolization. The Curriculum for Preschools (1999 brought conceptual changes towards education “based on the child” and the process approach, as well as giving more autonomy to preschool teachers and their assistants. In the empirical study, we examine changes in planning and evaluating educational work compared to the past. The results show that the majority of professional workers have reduced the high level of structure and rigidity in planning, and that there is better cooperation between preschool teachers and teachers’ assistants. Unlike in the past, most professional workers regularly evaluate their educational work. As the data was gathered in two phases, before and after the training of professional workers in the Reggio Emilia concept, we also search for the (probably indirect influencesof this training. We conclude that after the training the participation of children in planning and evaluating educational work is higher.

  3. Spite and Reciprocity in Auctions

    Directory of Open Access Journals (Sweden)

    Yoshikazu Ikeda

    2011-09-01

    Full Text Available The paper presents a complete information model of bidding in second price sealed-bid and ascending-bid (English auctions, in which potential buyers know the unit valuation of other bidders and may spitefully prefer that their rivals earn a lower surplus. Bidders with spiteful preferences should overbid in equilibrium when they know their rival has a higher value than their own, and bidders with a higher value underbid to reciprocate the spiteful overbidding of the lower value bidders. The model also predicts different bidding behavior in second price as compared to ascending-bid auctions. The paper also presents experimental evidence broadly consistent with the model. In the complete information environment, lower value bidders overbid more than higher value bidders, and they overbid more frequently in the second price auction than in the ascending price auction. Overall, the lower value bidder submits bids that exceed value about half the time. These patterns are not found in the incomplete information environment, consistent with the model.

  4. Reciprocity is not give and take: asymmetric reciprocity to positive and negative acts.

    Science.gov (United States)

    Keysar, Boaz; Converse, Benjamin A; Wang, Jiunwen; Epley, Nicholas

    2008-12-01

    Unlike economic exchange, social exchange has no well-defined "value." It is based on the norm of reciprocity, in which giving and taking are to be repaid in equivalent measure. Although giving and taking are colloquially assumed to be equivalent actions, we demonstrate that they produce different patterns of reciprocity. In five experiments utilizing a dictator game, people reciprocated in like measure to apparently prosocial acts of giving, but reciprocated more selfishly to apparently antisocial acts of taking, even when the objective outcomes of the acts of giving and taking were identical. Additional results demonstrate that acts of giving in social exchanges are perceived as more generous than objectively identical acts of taking, that taking tends to escalate, and that the asymmetry in reciprocity is not due to gaining versus losing resources. Reciprocity appears to operate on an exchange rate that assigns value to the meaning of events, in a fashion that encourages prosocial exchanges.

  5. Agenda Setting and Reciprocal Vote Trading

    OpenAIRE

    Urs Fischbacher; Simeon Schudy

    2010-01-01

    We study the implications of reciprocity on agenda setting in a sequential policy decision. We designed a laboratory experiment in which a committee decides sequentially on three independent bills. Selfish committee members would turn down all bills but reCiprocity allows for implicit vote trading. This mechanism gives power to agenda setters. We find that agenda setters use their power when setting the agenda but are rather generous in the voting decision. Legislators benefiting from the cho...

  6. On the coexistence of reciprocity and materialism

    OpenAIRE

    Akiko Maruyama

    2007-01-01

    This paper studies the problem of the long-run preferences distribution in a large population using an evolutionary approach. Special attention is given to the investigation of the property of the mixed population equilibria, in which materialists and reciprocators coexist. Some of the players with reciprocal preference care about not only their own material payoffs but also about those of others, while the remaining ones are materialists who maximize their own material payoffs.

  7. 30 CFR 57.13010 - Reciprocating-type air compressors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Reciprocating-type air compressors. 57.13010... Air and Boilers § 57.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... than 25 percent. (b) However, this standard does not apply to reciprocating-type air compressors...

  8. 30 CFR 56.13010 - Reciprocating-type air compressors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Reciprocating-type air compressors. 56.13010... and Boilers § 56.13010 Reciprocating-type air compressors. (a) Reciprocating-type air compressors... than 25 percent. (b) However, this standard does not apply to reciprocating-type air compressors...

  9. Static non-reciprocity in mechanical metamaterials

    Science.gov (United States)

    Coulais, Corentin; Sounas, Dimitrios; Alù, Andrea

    2017-02-01

    Reciprocity is a general, fundamental principle governing various physical systems, which ensures that the transfer function—the transmission of a physical quantity, say light intensity—between any two points in space is identical, regardless of geometrical or material asymmetries. Breaking this transmission symmetry offers enhanced control over signal transport, isolation and source protection. So far, devices that break reciprocity (and therefore show non-reciprocity) have been mostly considered in dynamic systems involving electromagnetic, acoustic and mechanical wave propagation associated with fields varying in space and time. Here we show that it is possible to break reciprocity in static systems, realizing mechanical metamaterials that exhibit vastly different output displacements under excitation from different sides, as well as one-way displacement amplification. This is achieved by combining large nonlinearities with suitable geometrical asymmetries and/or topological features. In addition to extending non-reciprocity and isolation to statics, our work sheds light on energy propagation in nonlinear materials with asymmetric crystalline structures and topological properties. We anticipate that breaking reciprocity will open avenues for energy absorption, conversion and harvesting, soft robotics, prosthetics and optomechanics.

  10. Structural optimization of free-form reciprocal structures

    DEFF Research Database (Denmark)

    Parigi, Dario

    2014-01-01

    This paper presents an optimization algorithm for the design of structurally efficient free-form reciprocal structures. Because of the geometric complexity of reciprocal structures, only a few structural studies have been carried out so far, and we have a limited knowledge of the relation between...... geometry and structural behaviour in reciprocal structures. This study takes advantage of the preceding work carried by the author on the Reciprocalizer, a software tool for the generation of reciprocal geometries. The Reciprocalizer has been included into a structural optimization algorithm...... for the generation of structurally efficient free-form reciprocal structures....

  11. Relation between language experiences in preschool classrooms and children's kindergarten and fourth-grade language and reading abilities.

    Science.gov (United States)

    Dickinson, David K; Porche, Michelle V

    2011-01-01

    Indirect effects of preschool classroom indexes of teacher talk were tested on fourth-grade outcomes for 57 students from low-income families in a longitudinal study of classroom and home influences on reading. Detailed observations and audiotaped teacher and child language data were coded to measure content and quantity of verbal interactions in preschool classrooms. Preschool teachers' use of sophisticated vocabulary during free play predicted fourth-grade reading comprehension and word recognition (mean age=9; 7), with effects mediated by kindergarten child language measures (mean age=5; 6). In large group preschool settings, teachers' attention-getting utterances were directly related to later comprehension. Preschool teachers' correcting utterances and analytic talk about books, and early support in the home for literacy predicted fourth-grade vocabulary, as mediated by kindergarten receptive vocabulary.

  12. Evaluating Preschool Children Knowledge about Healthy Lifestyle: Preliminary Examination of the Healthy Lifestyle Evaluation Instrument

    Science.gov (United States)

    Grammatikopoulos, Vasilis; Konstantinidou, Elisavet; Tsigilis, Nikolaos; Zachopoulou, Evridiki; Tsangaridou, Niki; Liukkonen, Jarmo

    2008-01-01

    The aim of this study was to develop an instrument to evaluate the knowledge of preschool children about healthy lifestyle behavior. The innovation was that the instrument was designed to get direct evidence about healthy lifestyle from children aged 4-6 years old. Usually, children knowledge is estimated indirectly (parents, teachers), but the…

  13. Parental Support Exceeds Parenting Style for Promoting Active Play in Preschool Children

    Science.gov (United States)

    Schary, David P.; Cardinal, Bradley J.; Loprinzi, Paul D.

    2012-01-01

    Emerging evidence suggests that parenting style may directly or indirectly influence school-aged children's activity behaviour. Given that relatively fewer studies have been conducted among preschool-aged children, this study's primary purpose was to examine the direct relationships between parental support and parenting style on preschool…

  14. Parental Support Exceeds Parenting Style for Promoting Active Play in Preschool Children

    Science.gov (United States)

    Schary, David P.; Cardinal, Bradley J.; Loprinzi, Paul D.

    2012-01-01

    Emerging evidence suggests that parenting style may directly or indirectly influence school-aged children's activity behaviour. Given that relatively fewer studies have been conducted among preschool-aged children, this study's primary purpose was to examine the direct relationships between parental support and parenting style on preschool…

  15. From Hitting to Tattling to Gossip: An Evolutionary Rationale for the Development of Indirect Aggression

    Directory of Open Access Journals (Sweden)

    Gordon P. D. Ingram

    2014-04-01

    Full Text Available Adult humans are characterized by low rates of intra-group physical aggression. Since children tend to be more physically aggressive, an evolutionary developmental account shows promise for explaining how physical aggression is suppressed in adults. I argue that this is achieved partly through extended dominance hierarchies, based on indirect reciprocity and linguistic transmission of reputational information, mediated by indirectly aggressive competition. Reviewing the literature on indirect and related forms of aggression provides three pieces of evidence for the claim that evolutionarily old impulses towards physical aggression are socialized into indirect aggression in humans: (i physical aggression falls in early childhood over the same age range at which indirect aggression increases; (ii the same individuals engage in both direct and indirect aggression; and (iii socially dominant individuals practice indirect aggression more frequently. Consideration of the developmental course of indirect aggression is complemented by analysis of similar developments in verbal behaviors that are not always thought of as aggressive, namely tattling and gossip. An important puzzle concerns why indirect aggression becomes more covert, and tattling more derogated, in preadolescence and adolescence. This may be due to the development of new strategies aimed at renegotiating social identity and friendship alliances in the peer group.

  16. Reciprocity, culture and human cooperation: previous insights and a new cross-cultural experiment.

    Science.gov (United States)

    Gächter, Simon; Herrmann, Benedikt

    2009-03-27

    Understanding the proximate and ultimate sources of human cooperation is a fundamental issue in all behavioural sciences. In this paper, we review the experimental evidence on how people solve cooperation problems. Existing studies show without doubt that direct and indirect reciprocity are important determinants of successful cooperation. We also discuss the insights from a large literature on the role of peer punishment in sustaining cooperation. The experiments demonstrate that many people are 'strong reciprocators' who are willing to cooperate and punish others even if there are no gains from future cooperation or any other reputational gains. We document this in new one-shot experiments, which we conducted in four cities in Russia and Switzerland. Our cross-cultural approach allows us furthermore to investigate how the cultural background influences strong reciprocity. Our results show that culture has a strong influence on positive and in especially strong negative reciprocity. In particular, we find large cross-cultural differences in 'antisocial punishment' of pro-social cooperators. Further cross-cultural research and experiments involving different socio-demographic groups document that the antisocial punishment is much more widespread than previously assumed. Understanding antisocial punishment is an important task for future research because antisocial punishment is a strong inhibitor of cooperation.

  17. Assessment of Attention in Preschoolers

    Science.gov (United States)

    Mahone, E.M.; Schneider, H.E.

    2012-01-01

    In the past two decades, there has been an increased interest in the assessment and treatment of preschool children presenting with concerns about attention problems. This article reviews the research and clinical literature involving assessment of attention and related skills in the preschool years. While inattention among preschoolers is common, symptoms alone do not necessarily indicate a disorder, and most often represent a normal variation in typical preschool child development. Thus, accurate identification of “disordered” attention in preschoolers can be challenging, and development of appropriate, norm-referenced tests of attention for preschoolers is also difficult. The current review suggests that comprehensive assessment of attention and related functions in the preschool child should include thorough review of the child’s history, planned observations, and formal psychometric testing. The three primary methods of psychometric assessment that have been used to characterize attentional functioning in preschool children include performance-based tests, structured caregiver interviews, and rating scales (parent, teacher, and clinician). Among performance-based methods for measurement of attention in the preschool years, tests have been developed to assess sustained attention, selective (focused) attention, span of attention (encoding/manipulation), and (top-down) controlled attention—including freedom from distractibility and set shifting. Many of these tests remain experimental in nature, and review of published methods yields relatively few commercially available, nationally normed tests of attention for preschoolers, and an overall dearth of reliability and validity studies on the available measures. PMID:23090646

  18. Assessment of attention in preschoolers.

    Science.gov (United States)

    Mahone, E M; Schneider, H E

    2012-12-01

    In the past two decades, there has been an increased interest in the assessment and treatment of preschool children presenting with concerns about attention problems. This article reviews the research and clinical literature involving assessment of attention and related skills in the preschool years. While inattention among preschoolers is common, symptoms alone do not necessarily indicate a disorder, and most often represent a normal variation in typical preschool child development. Thus, accurate identification of "disordered" attention in preschoolers can be challenging, and development of appropriate, norm-referenced tests of attention for preschoolers is also difficult. The current review suggests that comprehensive assessment of attention and related functions in the preschool child should include thorough review of the child's history, planned observations, and formal psychometric testing. The three primary methods of psychometric assessment that have been used to characterize attentional functioning in preschool children include performance-based tests, structured caregiver interviews, and rating scales (parent, teacher, and clinician). Among performance-based methods for measurement of attention in the preschool years, tests have been developed to assess sustained attention, selective (focused) attention, span of attention (encoding/manipulation), and (top-down) controlled attention--including freedom from distractibility and set shifting. Many of these tests remain experimental in nature, and review of published methods yields relatively few commercially available, nationally normed tests of attention for preschoolers, and an overall dearth of reliability and validity studies on the available measures.

  19. Preschool Connected Speech Inventory.

    Science.gov (United States)

    DiJohnson, Albert; And Others

    This speech inventory developed for a study of aurally handicapped preschool children (see TM 001 129) provides information on intonation patterns in connected speech. The inventory consists of a list of phrases and simple sentences accompanied by pictorial clues. The test is individually administered by a teacher-examiner who presents the spoken…

  20. Forging Partnerships with Preschools.

    Science.gov (United States)

    Bailie, Patti Ensel

    1999-01-01

    Describes a Head Start program for preschool children directed by the Nature Center at Shaker Lakes in Cleveland, Ohio. Presents information on the content of this program, which is also aligned with the regular Head Start curriculum. Lists contact phone numbers for more information. (YDS)

  1. Blind Pre-School.

    Science.gov (United States)

    Taylor, Billie, Comp.

    Articles pertinent to aiding the pre-school blind child are collected in this publication. Topics include discussion of attitudes and emotional reactions important for parents and teachers of blind children, and optimal development in regard to early motor behavior and emotional and social needs. Common areas of parental concern such as discipline…

  2. Preschool Children's School Readiness

    Science.gov (United States)

    Pekdogan, Serpil; Akgül, Esra

    2017-01-01

    The purpose of this study is to examine preschool teachers' perspectives about children's school readiness. Qualitative and quantitative research methods were used in the study as a mixed method research. Data, in the quantitative aspects of the research, were collected through the use of "School Readiness Form" developed by Boz (2004)…

  3. Child Development: Preschool Children.

    Science.gov (United States)

    Chiam, Heng Keng, Ed.

    This book reports some of the results of an extensive study of the physical, cognitive, language, social, and emotional development of Malaysian children. Chapter 1 of the book describes the demographics of the sample. Subjects were 3,099 preschool children in the state of Selangor and the federal district of Kuala Lumpur, Malaysia. Data is…

  4. Preschool Connected Speech Inventory.

    Science.gov (United States)

    DiJohnson, Albert; And Others

    This speech inventory developed for a study of aurally handicapped preschool children (see TM 001 129) provides information on intonation patterns in connected speech. The inventory consists of a list of phrases and simple sentences accompanied by pictorial clues. The test is individually administered by a teacher-examiner who presents the spoken…

  5. Reciprocating Feed System Development Status

    Science.gov (United States)

    Trewek, Mary (Technical Monitor); Blackmon, James B.; Eddleman, David E.

    2005-01-01

    The reciprocating feed system (RFS) is an alternative means of providing high pressure propellant flow at low cost and system mass, with high fail-operational reliability. The RFS functions by storing the liquid propellants in large, low-pressure tanks and then expelling each propellant through two or three small, high-pressure tanks. Each RFS tank is sequentially filled, pressurized, expelled, vented, and refilled so as to provide a constant, or variable, mass flow rate to the engine. This type of system is much lighter than a conventional pressure fed system in part due to the greatly reduced amount of inert tank weight. The delivered payload for an RFS is superior to that of conventional pressure fed systems for conditions of high total impulse and it is competitive with turbopump systems, up to approximately 2000 psi. An advanced version of the RFS uses autogenous pressurization and thrust augmentation to achieve higher performance. In this version, the pressurization gases are combusted in a small engine, thus making the pressurization system, in effect, part of the propulsion system. The RFS appears to be much less expensive than a turbopump system, due to reduced research and development cost and hardware cost, since it is basically composed of small high- pressure tanks, a pressurization system, and control valves. A major benefit is the high reliability fail-operational mode; in the event of a failure in one of the three tank-systems, it can operate on the two remaining tanks. Other benefits include variable pressure and flow rates, ease of engine restart in micro-gravity, and enhanced propellant acquisition and control under adverse acceleration conditions. We present a system mass analysis tool that accepts user inputs for various design and mission parameters and calculates such output values payload and vehicle weights for the conventional pressure fed system, the RFS, the Autogenous Pressurization Thrust Augmentation (APTA) RFS, and turbopump systems

  6. Theory of reciprocating contact for viscoelastic solids

    Science.gov (United States)

    Putignano, Carmine; Carbone, Giuseppe; Dini, Daniele

    2016-04-01

    A theory of reciprocating contacts for linear viscoelastic materials is presented. Results are discussed for the case of a rigid sphere sinusoidally driven in sliding contact with a viscoelastic half-space. Depending on the size of the contact, the frequency and amplitude of the reciprocating motion, and on the relaxation time of the viscoelastic body, we establish that the contact behavior may range from the steady-state viscoelastic solution, in which traction forces always oppose the direction of the sliding rigid punch, to a more elaborate trend, which is due to the strong interaction between different regions of the path covered during the reciprocating motion. Practical implications span a number of applications, ranging from seismic engineering to biotechnology.

  7. Modelling fluid flow in a reciprocating compressor

    Directory of Open Access Journals (Sweden)

    Tuhovcak Jan

    2015-01-01

    Full Text Available Efficiency of reciprocating compressor is strongly dependent on the valves characteristics, which affects the flow through the suction and discharge line. Understanding the phenomenon inside the compressor is necessary step in development process. Commercial CFD tools offer wide capabilities to simulate the flow inside the reciprocating compressor, however they are too complicated in terms of computational time and mesh creation. Several parameters describing compressor could be therefore examined without the CFD analysis, such is valve characteristic, flow through the cycle and heat transfer. The aim of this paper is to show a numerical tool for reciprocating compressor based on the energy balance through the cycle, which provides valve characteristics, flow through the cycle and heat losses from the cylinder. Spring-damping-mass model was used for the valve description. Boundary conditions were extracted from the performance test of 4-cylinder semihermetic compressor and numerical tool validation was performed with indicated p-V diagram comparison.

  8. Modelling fluid flow in a reciprocating compressor

    Science.gov (United States)

    Tuhovcak, Jan; Hejčík, Jiří; Jícha, Miroslav

    2015-05-01

    Efficiency of reciprocating compressor is strongly dependent on the valves characteristics, which affects the flow through the suction and discharge line. Understanding the phenomenon inside the compressor is necessary step in development process. Commercial CFD tools offer wide capabilities to simulate the flow inside the reciprocating compressor, however they are too complicated in terms of computational time and mesh creation. Several parameters describing compressor could be therefore examined without the CFD analysis, such is valve characteristic, flow through the cycle and heat transfer. The aim of this paper is to show a numerical tool for reciprocating compressor based on the energy balance through the cycle, which provides valve characteristics, flow through the cycle and heat losses from the cylinder. Spring-damping-mass model was used for the valve description. Boundary conditions were extracted from the performance test of 4-cylinder semihermetic compressor and numerical tool validation was performed with indicated p-V diagram comparison.

  9. Examining the reciprocal relation between academic motivation and substance use: effects of family relationships, self-esteem, and general deviance.

    Science.gov (United States)

    Andrews, J A; Duncan, S C

    1997-12-01

    The present study examined the reciprocal relation between academic motivation and cigarette, alcohol, and marijuana use across four annual assessments during adolescence. Data were obtained from 435 adolescents, 13 to 17 years of age at the first assessment, and their mothers. The results of generalized estimating equations (GEE) analysis suggested inverse reciprocal relations across time between academic motivation and both cigarette and marijuana use. Reciprocal relations between academic motivation and alcohol use were not found, possibly due to the normative use of this substance. The examination of mediational mechanisms, including general deviance, self-esteem and family relationships, suggested that the relation between marijuana use and, for younger adolescents, cigarette use and academic motivation is not direct but is indirect, mediated through the general deviance of the adolescent. Deviance, self-esteem, and, for the youngest adolescents, family relationships mediated the relation between academic motivation and subsequent marijuana use.

  10. Marital conflict and boys' peer relationships: the mediating role of mother-son emotional reciprocity.

    Science.gov (United States)

    Lindsey, Eric W; MacKinnon-Lewis, Carol; Campbell, Jessica; Frabutt, James M; Lamb, Michael E

    2002-12-01

    This study examined the role of mother-son emotional reciprocity in connections between marital conflict and the quality of boys' peer relationships. Parents from 84 intact families with preadolescent boys reported on the level of conflict in their marital relationship. Observations of mother-son interaction were coded for emotional reciprocity, and assessments of boys' peer relationships were obtained from both teachers and classmates. No direct connection between marital conflict and boys' peer relationships was observed. Rather, marital conflict affected boys' social competence indirectly, through its effect on the emotions expressed between mother and son. The findings support the proposal that emotional processes play an important role in connections between marital conflict and children's peer relationships and suggest that family emotional expressiveness deserves greater attention in both research and intervention.

  11. Feasibility analysis of reciprocating magnetic heat pumps

    Science.gov (United States)

    Larson, A. V.; Hartley, J. G.; Shelton, Sam V.; Smith, M. M.

    1989-01-01

    A reciprocating gadolinium core in a regeneration fluid column in the warm bore of a superconducting solenoidal magnet is considered for magnetic refrigeration in 3.517 MW (1000 ton) applications. A procedure is presented to minimize the amount of superconducting cable needed in the magnet design. Estimated system capital costs for an ideal magnetic refrigerator of this type become comparable to conventional chillers as the frequency of reciprocation approaches 10 Hertz. A 1-D finite difference analysis of a regenerator cycling at 0.027 Hertz is presented which exhibits some of the features seen in the experiments of G. V. Brown.

  12. Assessing executive functions in preschoolers using Shape School Task

    Directory of Open Access Journals (Sweden)

    Marta Nieto

    2016-09-01

    Full Text Available Over the last two decades, there has been a growing interest in the study of the development of executive functions in preschool children due to their relationship with different cognitive, psychological, social and academic domains. Early detection of individual differences in executive functioning can have major implications for basic and applied research. Consequently, there is a key need for assessment tools adapted to preschool skills: Shape School has been shown to be a suitable task for this purpose. Our study uses Shape School as the main task to analyze development of inhibition, task-switching and working memory in a sample of 304 preschoolers (age range 3.25-6.50 years. Additionally, we include cognitive tasks for the evaluation of verbal variables (vocabulary, word reasoning and short-term memory and performance variables (picture completion and symbol search, so as to analyze their relationship with executive functions. Our results show age-associated improvements in executive functions and the cognitive variables assessed. Furthermore, correlation analyses reveal positive relationships between executive functions and the other cognitive variables. More specifically, using structural equation modeling and including age direct and indirect effects, our results suggest that executive functions explain to a greater extent performance on verbal and performance tasks. These findings provide further information to support research that considers preschool age to be a crucial period for the development of executive functions and their relationship with other cognitive processes

  13. A simplified indirect bonding technique

    Directory of Open Access Journals (Sweden)

    Radha Katiyar

    2014-01-01

    Full Text Available With the advent of lingual orthodontics, indirect bonding technique has become an integral part of practice. It involves placement of brackets initially on the models and then their transfer to teeth with the help of transfer trays. Problems encountered with current indirect bonding techniques used are (1 the possibility of adhesive flash remaining around the base of the brackets which requires removal (2 longer time required for the adhesive to gain enough bond strength for secure tray removal. The new simplified indirect bonding technique presented here overcomes both these problems.

  14. Low Latency Digit-Recurrence Reciprocal and Square-Root Reciprocal Algorithm and Architecture

    DEFF Research Database (Denmark)

    Antelo, Elisardo; Lang, Tomas; Montuschi, Paolo

    2005-01-01

    The reciprocal and square-root reciprocal operations are important in several applications. For these operations, we present algorithms that combine a digit-by-digit module and one iteration of a quadratic-convergence approximation. The latter is implemented by a digit-recurrence, which uses......-up of about 2 and, because of the approximation part, the area factor is also about 2. We also show a combined implementation for both operations that has essentially the same complexity as that for square-root reciprocal alone....

  15. Direct vs. Indirect Moral Enhancement.

    Science.gov (United States)

    Schaefer, G Owen

    2015-09-01

    Moral enhancement is an ostensibly laudable project. Who wouldn't want people to become more moral? Still, the project's approach is crucial. We can distinguish between two approaches for moral enhancement: direct and indirect. Direct moral enhancements aim at bringing about particular ideas, motives or behaviors. Indirect moral enhancements, by contrast, aim at making people more reliably produce the morally correct ideas, motives or behaviors without committing to the content of those ideas, motives and/or actions. I will argue, on Millian grounds, that the value of disagreement puts serious pressure on proposals for relatively widespread direct moral enhancement. A more acceptable path would be to focus instead on indirect moral enhancements while staying neutral, for the most part, on a wide range of substantive moral claims. I will outline what such indirect moral enhancement might look like, and why we should expect it to lead to general moral improvement.

  16. Ecology: Dynamics of Indirect Extinction.

    Science.gov (United States)

    Montoya, Jose M

    2015-12-01

    The experimental identification of the mechanism by which extinctions of predators trigger further predator extinctions emphasizes the role of indirect effects between species in disturbed ecosystems. It also has deep consequences for the hidden magnitude of the current biodiversity crisis.

  17. Child Sexual Abuse at Preschools--A Research Review of a Complex Issue for Preschool Professionals

    Science.gov (United States)

    Bergström, Helena; Eidevald, Christian; Westberg-Broström, Anna

    2016-01-01

    The objective of this research review is to synthesize research published between 2000 and 2015 regarding child sexual abuse, preschool and preschool teachers. The review identifies themes relevant for the preschool teacher profession: child sexual abuse at preschools, suspicions and consequences for the preschool sector, preventing techniques and…

  18. Child Sexual Abuse at Preschools--A Research Review of a Complex Issue for Preschool Professionals

    Science.gov (United States)

    Bergström, Helena; Eidevald, Christian; Westberg-Broström, Anna

    2016-01-01

    The objective of this research review is to synthesize research published between 2000 and 2015 regarding child sexual abuse, preschool and preschool teachers. The review identifies themes relevant for the preschool teacher profession: child sexual abuse at preschools, suspicions and consequences for the preschool sector, preventing techniques and…

  19. The Effects of Feedback as Interpersonal Reciprocities

    Science.gov (United States)

    Levenstein, Joseph; And Others

    1977-01-01

    Tests the hypothesis that a response to a given feedback statement will be its reciprocal. In Phase 1, a pool of feedback statements was written and scaled along dimensions of power (dominance-submission) and affect (affection-hostility). In Phase 2, these statements were used as the basis for giving feedback and replying to it. (Author)

  20. Reciprocity, Materialism and Welfare: An Evolutionary Model

    DEFF Research Database (Denmark)

    Poulsen, Anders

    2001-01-01

    We analyze preference evolution in a simple bargaining situation. Preferences for reciprocity, who sustain a conflict-free outcome, may be viable if players have enough information about the opponent's preferences. However, depending on the initial starting point preference evolution can in general...

  1. Robustness of Long Span Reciprocal Timber Structures

    DEFF Research Database (Denmark)

    Balfroid, Nathalie; Kirkegaard, Poul Henning; Sassone, Mario SASSONE

    2011-01-01

    engineer may take necessary steps to design robust structures that are insensitive to accidental circumstances. The present paper makes a discussion of such robustness issues related to the future development of reciprocal timber structures. The paper concludes that these kind of structures can have...

  2. Students' Confusions with Reciprocal and Inverse Functions

    Science.gov (United States)

    Kontorovich, Igor'

    2017-01-01

    These classroom notes are focused on undergraduate students' understanding of the polysemous symbol of superscript (-1), which can be interpreted as a reciprocal or an inverse function. Examination of 240 scripts in a mid-term test identified that some first-year students struggle with choosing the contextually correct interpretation and there are…

  3. Human-animal amity and reciprocity

    NARCIS (Netherlands)

    Wissenburg, M.L.J.

    2014-01-01

    Animals are now widely accepted as subjects of justice: not equal but deserving equal consideration; not free but deserving liberties (that is, selfconstraining human duties). But liberty and equality are not all there is to a flourishing society – how about amity and reciprocity? Isn’t a minimal de

  4. Reciprocal altruism under conditions of partner selection

    NARCIS (Netherlands)

    de Vos, H.; Smaniotto, R.C.; Elsas, D.A.

    2001-01-01

    This paper is a contribution to solving the problem of whether reciprocal altruism can emerge and maintain itself in a population of selfish individuals. We use an evolutionary game theoretic simulation model (the Social Evolution Model) to investigate the relative fitness of two versions of a recip

  5. 37 CFR 11.24 - Reciprocal discipline.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Reciprocal discipline. 11.24... discipline. (a) Notification of OED Director. Within thirty days of being publicly censured, publicly... USPTO Director. The OED Director shall, in addition, without Committee on Discipline authorization,...

  6. 78 FR 53792 - Draft Guidance for Reciprocity

    Science.gov (United States)

    2013-08-30

    ...The U.S. Nuclear Regulatory Commission (NRC) is revising its licensing guidance for reciprocity. The NRC is requesting public comment on draft NUREG-1556, Volume 19, Revision 1, ``Consolidated Guidance about Materials Licenses: Guidance for Agreement State Licensees about NRC Form 241 `Report of Proposed Activities in Non- Agreement States, Areas of Exclusive Federal Jurisdiction, of Offshore......

  7. Non-Reciprocal on Wafer Microwave Devices

    Science.gov (United States)

    2015-05-27

    Journal of Applied Physics , (02 2012): 7542. doi: Bijoy K. Kuanr, T. J. Fal, Z...Celinski, R. E. Camley. Iron based microstrip phase shifter; optimization of phase shift, Journal of Applied Physics , (02 2012): 7508. doi: T. J...Fal, R. E. Camley. Non-reciprocal devices using attenuated total reflection and thin filmmagnetic layered structures, Journal of Applied Physics ,

  8. Students' Confusions with Reciprocal and Inverse Functions

    Science.gov (United States)

    Kontorovich, Igor'

    2017-01-01

    These classroom notes are focused on undergraduate students' understanding of the polysemous symbol of superscript (-1), which can be interpreted as a reciprocal or an inverse function. Examination of 240 scripts in a mid-term test identified that some first-year students struggle with choosing the contextually correct interpretation and there are…

  9. The Infinite Sum of Reciprocal of the Fibonacci Numbers

    Institute of Scientific and Technical Information of China (English)

    Guo Jie ZHANG

    2011-01-01

    In this paper,we consider infinite sums of the reciprocals of the Fibonacci numbers.Then applying the floor function to the reciprocals of this sums,we obtain a new identity involving the Fibonacci numbers.

  10. Preschool Teachers' Perspectives on Planning and Documentation in Preschool

    Science.gov (United States)

    Alvestad, Torgeir; Sheridan, Sonja

    2015-01-01

    This article is based on a research project focusing on Norwegian teachers' planning and documentation of children's learning in preschool. Norwegian preschools follow a national curriculum and teachers are obliged to document both professional practice and learning outcomes. The aim of the article is to investigate teachers' experiences of…

  11. Bending Resistance and Cyclic Fatigue Life of Reciproc, Unicone, and WaveOne Reciprocating Instruments.

    Science.gov (United States)

    Silva, Emmanuel João Nogueira Leal; Villarino, Laise Silva; Vieira, Victor Talarico Leal; Accorsi-Mendonça, Thais; Antunes, Henrique Dos Santos; De-Deus, Gustavo; Lopes, Hélio Pereira

    2016-12-01

    This study evaluated the bending resistance and cyclic fatigue life of a new single-file reciprocating instrument (Unicone; Medin, Nové Město na Moravě, Czech Republic). Reciproc (VDW, Munich, Germany) and WaveOne (Dentsply Maillefer) instruments were used as references for comparison. Flexibility was determined by 45° bending tests using a universal testing machine. The cyclic fatigue test was performed using a custom-made device. For this test, an artificial canal with a 60° angle and a 5-mm radius of curvature was used. Scanning electron microscopic analysis was performed to determine the mode of fracture and possible deformations at the helical shaft. Statistical analysis for the bending resistance test was performed using parametric methods (ie, 1-way analysis of variance). Post hoc pair-wise comparisons were performed using the Tukey test for multiple comparisons (P bending resistance than the other tested systems (P  .05). When mean life was compared among the brands, Reciproc lasted longer than WaveOne with a probability of 99.9%, longer than Unicone in the "RECIPROC ALL" mode with a probability of 99.9%, and longer than Unicone in the "WAVEONE ALL" mode with a probability of 99.9% (all statistically significant). Moreover, WaveOne lasted longer than Unicone in the "RECIPROC ALL" mode with a probability of 98.5% and longer than Unicone in the "WAVEONE ALL" mode with a probability of 99.8% (all statistically significant). Finally, Unicone in the "RECIPROC ALL" mode lasted longer than Unicone in the "WAVEONE ALL" mode with a probability of 95.3% (statistically significant). The new reciprocating instrument Unicone showed lower cyclic fatigue resistance compared with Reciproc R25 and WaveOne Primary files. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Quality in preschool in a cultural context

    DEFF Research Database (Denmark)

    Kragh-Müller, Grethe; Ringsmose, Charlotte

    What is educational quality i preschools? How can it be evaluated/measured. How can educational quality be developped in everyday life in preschools?......What is educational quality i preschools? How can it be evaluated/measured. How can educational quality be developped in everyday life in preschools?...

  13. Conceptualizing the Play Policies in Preschool Curriculums

    Science.gov (United States)

    Sener, Tulin

    2013-01-01

    This research attempted to describe the play policies in preschool institutions in Ankara, Turkey. The aim of this study is to determine the approaches of the preschools to the children's play. "Play Policy Questionnaire" administered to all directors and teachers of 20 public preschools and 20 private preschools. Play policy of…

  14. Hybrid Optimization in the Design of Reciprocal Structures

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning; Sassone, Mario

    2012-01-01

    The paper presents a method to generate the geometry of reciprocal structures by means of a hybrid optimization procedure. The geometry of reciprocal structures where elements are sitting on the top or in the bottom of each other is extremely difficult to predict because of the non...... is then applied to a recent example of free-form reciprocal structure....

  15. A 1.5 GFLOPS Reciprocal Unit for Computer Graphics

    DEFF Research Database (Denmark)

    Nannarelli, Alberto; Rasmussen, Morten Sleth; Stuart, Matthias Bo

    2006-01-01

    The reciprocal operation 1/d is a frequent operation performed in graphics processors (GPUs). In this work, we present the design of a radix-16 reciprocal unit based on the algorithm combining the traditional digit-by-digit algorithm and the approximation of the reciprocal by one Newton...

  16. 32 CFR 634.16 - Reciprocal state-military action.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Reciprocal state-military action. 634.16 Section... Reciprocal state-military action. (a) Commanders will recognize the interests of the states in matters of POV... formal military reciprocity, the procedures below will be adopted: (1) Commanders will recognize...

  17. Familial Reciprocity and Subjective Well-Being in Ghana

    Science.gov (United States)

    Tsai, Ming-Chang; Dzorgbo, Dan-Bright S.

    2012-01-01

    The authors investigated variations in reciprocity and the impact of reciprocity on well-being in a West African society. They hypothesized that household size and income diversity encourage reciprocity, which in turn enhances subjective well-being. In empirical testing of these hypotheses the authors used the data of the Core Welfare Indicators…

  18. Indirect comparisons of therapeutic interventions

    Directory of Open Access Journals (Sweden)

    Boulkhemair, Dalila

    2009-07-01

    Full Text Available Health political background: The comparison of the effectiveness of health technologies is not only laid down in German law (Social Code Book V, § 139 and § 35b but also constitutes a central element of clinical guidelines and decision making in health care. Tools supporting decision making (e. g. Health Technology Assessments (HTA are therefore in need of a valid methodological repertoire for these comparisons. Scientific background: Randomised controlled head-to-head trials which directly compare the effects of different therapies are considered the gold standard methodological approach for the comparison of the efficacy of interventions. Because this type of trial is rarely found, comparisons of efficacy often need to rely on indirect comparisons whose validity is being controversially debated. Research questions: Research questions for the current assessment are: Which (statistical methods for indirect comparisons of therapeutic interventions do exist, how often are they applied and how valid are their results in comparison to the results of head-to-head trials? Methods: In a systematic literature research all medical databases of the German Institute of Medical Documentation and Information (DIMDI are searched for methodological papers as well as applications of indirect comparisons in systematic reviews. Results of the literature analysis are summarized qualitatively for the characterisation of methods and quantitatively for the frequency of their application. The validity of the results from indirect comparisons is checked by comparing them to the results from the gold standard – a direct comparison. Data sets from systematic reviews which use both direct and indirect comparisons are tested for consistency by of the z-statistic. Results: 29 methodological papers and 106 applications of indirect methods in systematic reviews are being analysed. Four methods for indirect comparisons can be identified: 1. Unadjusted indirect comparisons

  19. Mother and preschool teacher as assessors of the child's language competence

    Directory of Open Access Journals (Sweden)

    Urška Fekonja Peklaj

    2008-04-01

    Full Text Available Many researchers include child's parents as assessors of his/her language development as the results of many studies suggest their assessments to be valid and reliable measures of child's language competence. In the longitudinal study, presented in this paper, we examined whether child's mother and his/her preschool teacher can provide a valid estimation of child's language development. The sample included 80 Slovenian children from different preschool institutions, aged 3;1 years at first and 4;1 years at second assessment. Children's language competence was assessed individually, directly by the testators using Language Development Scale and Storytelling Test and indirectly by mothers and preschool teachers using the Child's Language Competence Questionnaire for Parents and Preschool Teachers. The achieved results showed that the estimates given by mothers and preschool teachers represent valid measures of child's language competence but not stable in time. The estimations given by mothers and preschool teachers explain a small share in variability of children's achievements on the Language Development Scale and Storytelling Test.

  20. Reciprocity among maternal distress, child behavior, and parenting: transactional processes and early childhood risk.

    Science.gov (United States)

    Ciciolla, Lucia; Gerstein, Emily D; Crnic, Keith A

    2014-01-01

    Transactional theories support that parent-child processes are best studied in conjunction with one another, addressing their reciprocal influence and change across time. This study tested a longitudinal, autoregressive model exploring bidirectional relations among maternal symptomatology, child internalizing/externalizing symptoms, and maternal sensitivity during the preschool period (child ages 3 to 5 years), comparing relations among families of typically developing children and children with developmental risk. This study included 250 families, 110 of which had a child with early developmental delay. Analyses utilized data from maternal report, father report, and observational methods. The results indicated significant stability in maternal symptomatology, child internalizing/externalizing symptoms, and maternal sensitivity over time. Support for bidirectional effects between maternal symptomatology and child internalizing symptoms was found specifically for mothers of children with developmental risk. Maternal symptomatology was found to mediate the influence of child internalizing and externalizing symptoms on maternal sensitivity. The findings underscore critical transactional processes within families of children with early developmental risk that connect increased maternal symptomatology to emerging child internalizing symptoms during the preschool period.

  1. Reciprocity, social ties, and competition in markets for experience goods

    DEFF Research Database (Denmark)

    Huck, Steffen; Tyran, Jean-Robert

    2007-01-01

    Reciprocal customers may disproportionately improve the performance of markets for experience goods. Reciprocal customers reward (punish) firms for providing good (bad) quality by upholding (terminating) the customer relation. This may induce firms to provide good quality which, in turn, may induce...... a positive externality for non-reciprocal customers who would, in the absence of reciprocal types, face market breakdown. This efficiency-enhancing effect of reciprocity is boosted when there are social ties between consumers and competition between firms. The existence of social ties or competition alone...

  2. Preschool Screening: An Examination of the Behavioral and Emotional Screening System Preschool Teacher Form (BESS Preschool)

    Science.gov (United States)

    Dowdy, Erin; Chin, Jenna K.; Quirk, Matthew P.

    2013-01-01

    The preschool years are a critical time to identify and treat early emotional or behavioral problems. Universal screening can be used to identify emotional and behavioral risk in preschoolers and fits well within current service delivery frameworks. This criterion-related validity study examined the use of a brief teacher-rated screener, the…

  3. Collective motion in non-reciprocal swarms

    Institute of Scientific and Technical Information of China (English)

    Bo LIU; Tianguang CHU; Long WANG

    2009-01-01

    This paper studies a non-reciprocal swarm model that consists of a group of mobile autonomous agents with an attraction-repulsion function governing the interaction of the agents. The function is chosen to have infinitely large values of repulsion for vanishing distance between two agents so as to avoid occurrence of collision. It is shown analytically that under the detailed balance condition in coupling weights, all the agents will aggregate and eventually form a cohesive cluster of finite size around the weighted center of the swarm in a finite time. Moreover, the swarm system is completely stable, namely, the motion of all agents converge to the set of equilibrium points. For the general case of non-reciprocal swarms without the detailed balance condition, numerical simulations show that more complex self-organized oscillations can emerge in the swarms. The effect of noise on collective dynamics of the swarm is also examined with a white Gaussian noise model.

  4. Nihility in non-reciprocal bianisotropic media

    Directory of Open Access Journals (Sweden)

    Ra’di Younes

    2015-01-01

    Full Text Available Here we consider electromagnetic response of non-reciprocal bianisotropic materials in some extreme regimes. The magneto-electric coupling is modeled by symmetric and antisymmetric uniaxial dyadics, which correspond to the so called artificial Tellegen media and moving media, respectively. Extreme electromagnetic properties of uniaxial non-reciprocal bianisotropic materials in the limiting case of nihility, when both permittivity and permeability of the media tend to zero, and only the magneto-electric parameters define the material response, are studied. Among other interesting effects, we show that the moving nihility materials provide the extreme asymmetry in the phase shift of transmitted waves propagating along the opposite directions. Furthermore, we reveal a possibility to create an angular filter with extreme sensitivity to the incidence angle, also using moving nihility slabs.

  5. Reciprocal Suffering: Caregiver Concerns During Hospice Care

    Science.gov (United States)

    Wittenberg-Lyles, Elaine; Demiris, George; Oliver, Debra Parker; Burt, Stephanie

    2010-01-01

    Context For many hospice caregivers, the constancy and difficulty of caregiving impact their physical quality of life and cause depression, psychological distress, guilt, loneliness, and restrictions on social activities. Objectives Deviating from traditional unidimensional research on hospice caregivers, this study explored the transactional nature of reciprocal suffering by examining caregiver concerns through four dimensions: physical, psychological, social, and spiritual. Methods Researchers analyzed audiotapes of intervention discussions between hospice caregivers and research social workers. Results Results indicated that of the 125 pain talk utterances, the majority referenced psychological concern (49%), followed by physical (28%), social (22%), and spiritual (2%). Reflections on concerns revealed a global perspective of caregiving, which highlighted the patient’s needs juxtaposed to the caregiver’s recognized limitations. Conclusion By examining the reciprocal nature of suffering for caregivers, this study reinforced the need for assessing caregivers in hospice care, with specific emphasis on the importance of providing caregiver education on pain management. PMID:21146356

  6. Interdependent network reciprocity in evolutionary games

    CERN Document Server

    Wang, Zhen; Perc, Matjaz

    2013-01-01

    Besides the structure of interactions within networks, also the interactions between networks are of the outmost importance. We therefore study the outcome of the public goods game on two interdependent networks that are connected by means of a utility function, which determines how payoffs on both networks jointly influence the success of players in each individual network. We show that an unbiased coupling allows the spontaneous emergence of interdependent network reciprocity, which is capable to maintain healthy levels of public cooperation even in extremely adverse conditions. The mechanism, however, requires simultaneous formation of correlated cooperator clusters on both networks. If this does not emerge or if the coordination process is disturbed, network reciprocity fails, resulting in the total collapse of cooperation. Network interdependence can thus be exploited effectively to promote cooperation past the limits imposed by isolated networks, but only if the coordination between the interdependent n...

  7. Reciprocity-induced bias in digital reputation

    CERN Document Server

    Livan, Giacomo; Aste, Tomaso

    2016-01-01

    The peer-to-peer (P2P) economy relies on establishing trust in distributed networked systems, where the reliability of a user is assessed through digital peer-review processes that aggregate ratings into reputation scores. Here we present evidence of a network effect which biases the digital reputations of the users of P2P networks, showing that P2P networks display exceedingly high levels of reciprocity. In fact, these are so large that they are close to the highest levels structurally compatible with the networks' reputation landscape. This shows that the crowdsourcing process underpinning digital reputation is significantly distorted by the attempt of users to mutually boost reputation, or to retaliate, through the exchange of ratings. We show that the least active users are predominantly responsible for such reciprocity-induced bias, and that this fact can be exploited to suppress the bias itself.

  8. Condition monitoring of reciprocating seal based on FBG sensors

    Science.gov (United States)

    Zhao, Xiuxu; Zhang, Shuanshuan; Wen, Pengfei; Zhen, Wenhan; Ke, Wei

    2016-07-01

    The failure of hydraulic reciprocating seals will seriously affect the normal operation of hydraulic reciprocating machinery, so the potential fault condition monitoring of reciprocating seals is very important. However, it is extremely difficult because of the limitation of reciprocating motion and the structure constraints of seal groove. In this study, an approach using fiber Bragg grating (FBG) sensors is presented. Experimental results show that the contact strain changes of a reciprocating seal can be detected by FBG sensors in the operation process of the hydraulic cylinders. The failure condition of the reciprocating seal can be identified by wavelet packet energy entropy, and the center frequency of power spectrum analysis. It can provide an effective solution for the fault prevention and health management of reciprocating hydraulic rod seals.

  9. Facial Affect Reciprocity in Dyadic Interactions

    Science.gov (United States)

    2012-09-01

    Factor Inventory (NEOFFI; Costa & McCrae , 1989, 1992), a 60-item version of form S of the NEO-PI-R that provides a measure of the five factor model...emotion and reciprocal affective relationships in families of disturbed adolescents. Family Process, 28(3), 337–348. Costa , P. T., & McCrae , R. R...1989). The Neo-PI/Neo-FFI manual supplement. Odessa, FL: Psychological Assessment Resources. Costa , P. T., & McCrae , R. R. (1992). Revised Neo

  10. Nonexistence in Reciprocal and Logarithmic Regression

    Institute of Scientific and Technical Information of China (English)

    Josef Bukac

    2003-01-01

    Fitting logarithmic b ln(clx), a+bln(c+x) or reciprocal b/(c+x), a+b/(c+x) regression models to data by the least squares method asks for the determination of the closure of the set of each type of these functions defined on a finite domain. It follows that a minimal solution may not exist. But it does exist when the closure is considered.

  11. Mills' ratio: Reciprocal concavity and functional inequalities

    CERN Document Server

    Baricz, Árpád

    2010-01-01

    This note contains suficient conditions for the probability density function of an arbitrary continuous univariate distribution such that the corresponding Mills ratio to be reciprocally convex (concave). To illustrate the applications of the main results, the Mills ratio of some common continuous univariate distributions, like gamma, log-normal and Student's t distributions, are discussed in details. The application to monopoly theory is also summarized.

  12. Reciprocity Theorems for Ab Initio Force Calculations

    CERN Document Server

    Wei, C; Mele, E J; Rappe, A M; Lewis, Steven P.; Rappe, Andrew M.

    1996-01-01

    We present a method for calculating ab initio interatomic forces which scales quadratically with the size of the system and provides a physically transparent representation of the force in terms of the spatial variation of the electronic charge density. The method is based on a reciprocity theorem for evaluating an effective potential acting on a charged ion in the core of each atom. We illustrate the method with calculations for diatomic molecules.

  13. Grooming reciprocity in male Tibetan macaques.

    Science.gov (United States)

    Xia, Dong-Po; Li, Jin-Hua; Garber, Paul A; Matheson, Megan D; Sun, Bing-Hua; Zhu, Yong

    2013-10-01

    In several primate species, adult males are reported to compete for access to reproductive partners as well as forming affiliative and cohesive social bonds based on the exchange of goods or services. We hypothesized that among a broad set of fitness-maximizing strategies, grooming can be used by individual adult males to enhance social relationships through reciprocity and/or through the interchange of grooming for a different but equivalent good or service. We used focal animal sampling and continuously recorded dyadic grooming and agonistic interactions to test a series of predictions regarding male social interactions in a free-ranging group of Tibetan macaques (Macaca thibetana) at Huangshan, China. During the non-mating season or between males of similar rank throughout the year, grooming effort given was matched by grooming effort received. However, lower ranking males groomed higher ranking males at a greater rate and/or for a longer duration during both the mating and non-mating periods. We found that higher ranking males directed less aggression towards males with whom they formed a frequent grooming partnership, indicating that grooming received was interchanged for increased social tolerance. These data suggest that individual male Tibetan macaques employ alternative social strategies associated with grooming reciprocity or interchange depending on dominance rank and rates of aggression, and highlight the importance of both biological markets and grooming reciprocity as behavioral mechanisms used by resident adult males to form and maintain affiliative social bonds.

  14. Indirect methods in nuclear astrophysics

    CERN Document Server

    Bertulani, C A; Mukhamedzhanov, A; Kadyrov, A S; Kruppa, A; Pang, D Y

    2015-01-01

    We discuss recent developments in indirect methods used in nuclear astrophysics to determine the capture cross sections and subsequent rates of various stellar burning processes, when it is difficult to perform the corresponding direct measurements. We discuss in brief, the basic concepts of Asymptotic Normalization Coefficients, the Trojan Horse Method, the Coulomb Dissociation Method, (d,p), and charge-exchange reactions.

  15. Indirect bonding technique in orthodontics

    Directory of Open Access Journals (Sweden)

    Kübra Yıldırım

    2016-08-01

    Full Text Available ‘Direct Bonding Technique’ which allows the fixed orthodontic appliances to be directly bonded to teeth without using bands decreased the clinic time for bracket bonding and increased esthetics and oral hygiene during orthodontic treatment. However, mistakes in bracket positioning were observed due to decreased direct visual sight and access to posterior teeth. ‘Indirect Bonding Technique’ was developed for eliminating these problems. Initially, decreased bond strength, higher bond failure rate, periodontal tissue irritation, compromised oral hygiene and increased laboratory time were the main disadvantages of this technique when compared to direct bonding. The newly developed materials and modified techniques help to eliminate these negative consequences. Today, the brackets bonded with indirect technique have similar bond strength with brackets bonded directly. Moreover, indirect and direct bonding techniques have similar effects on periodontal tissues. However, indirect bonding technique requires more attention and precision in laboratory and clinical stage, and has higher cost. Orthodontist's preference between these two bonding techniques may differ according to time spent in laboratory and clinic, cost, patient comfort and personal opinion.

  16. 19 CFR 10.776 - Indirect materials.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect materials. 10.776 Section 10.776 Customs... Rules of Origin § 10.776 Indirect materials. Indirect materials are to be disregarded in determining..., except that the cost of such indirect materials may be included in meeting the value-content requirement...

  17. 19 CFR 10.816 - Indirect materials.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect materials. 10.816 Section 10.816 Customs... Rules of Origin § 10.816 Indirect materials. Indirect materials are to be disregarded in determining..., except that the cost of such indirect materials may be included in meeting the value-content requirement...

  18. Preschool Teachers use of ICTs

    DEFF Research Database (Denmark)

    Masoumi, Davoud

    2015-01-01

    ; and as a communication and documentation tool. In addition, by addressing the teachers’ values and attitudes to the role of ICT in early childhood, the paper also unpacks the stances of teachers who consider ICT to be unsuitable for early childhood education. The findings of this study may bring some clarity......This study aimed to identify the ways in which information and communication technologies (ICT) are integrated in three preschools in south-western Sweden. The case study involved observations of and interviews with preschool teachers. The findings support claims that ICT can enhance preschool...... practices by providing a variety of complementary opportunities to enrich and transform existing curricula. The study shows that in the studied preschools ICTs have been appropriated in distinctive ways: as an object to enrich existing practices; as a cultural mediator; as a way to entertain young children...

  19. Executive functioning in preschoolers with specific language impairment

    Directory of Open Access Journals (Sweden)

    Constance eVissers

    2015-10-01

    Full Text Available The pathogenesis of Specific Language Impairment (SLI is still largely beyond our understanding. In this review, a neuropsychological perspective on language impairments in SLI is taken, focusing specifically on executive functioning (EF in preschoolers (age range: 2.6-6.1 years with SLI. Based on the studies described in this review, it can be concluded that similar to school-aged children with SLI, preschoolers with SLI show difficulties in working memory, inhibition and shifting, as revealed by both performance based measures and behavioural ratings. It seems plausible that a complex, reciprocal relationship exists between language and EF throughout development. Future research is needed to examine if, and if yes how, language and EF interact in SLI. Broad neuropsychological assessment in which both language and EF are taken into account may contribute to early detection of SLI. This in turn can lead to early and tailored treatment of children with (suspected SLI aimed not only at stimulating language development but also at strengthening EF.

  20. Objectively measured sedentary behavior in preschool children: comparison between Montessori and traditional preschools.

    Science.gov (United States)

    Byun, Wonwoo; Blair, Steven N; Pate, Russell R

    2013-01-03

    This study aimed to compare the levels of objectively-measured sedentary behavior in children attending Montessori preschools with those attending traditional preschools. The participants in this study were preschool children aged 4 years old who were enrolled in Montessori and traditional preschools. The preschool children wore ActiGraph accelerometers. Accelerometers were initialized using 15-second intervals and sedentary behavior was defined as Montessori preschools, after adjusting for selected potential correlates of preschoolers' sedentary behavior. Children attending Montessori preschools spent less time in sedentary behavior than those attending traditional preschools during the in-school (44.4. min/hr vs. 47.1 min/hr, P = 0.03), after-school (42.8. min/hr vs. 44.7 min/hr, P = 0.04), and total-day (43.7 min/hr vs. 45.5 min/hr, P = 0. 009) periods. School type (Montessori or traditional), preschool setting (private or public), socio-demographic factors (age, gender, and socioeconomic status) were found to be significant predictors of preschoolers' sedentary behavior. Levels of objectively-measured sedentary behavior were significantly lower among children attending Montessori preschools compared to children attending traditional preschools. Future research should examine the specific characteristics of Montessori preschools that predict the lower levels of sedentary behavior among children attending these preschools compared to children attending traditional preschools.

  1. INDIRECT ACCELERATED ADAPTIVE FUZZY CONTROLLER

    Institute of Scientific and Technical Information of China (English)

    ZHU Liye; FANG Yuan; ZHANG Weidong

    2008-01-01

    According to a type of normal nonlinear system, an indirect adaptive fuzzy (IAF) controller has been applied to those systems where no accurate mathematical models of the systems under control are available. To satisfy with system performance, an indirect accelerated adaptive fuzzy (IAAF) controller is proposed, and its general form is presented. The general form IAAF controller ensures necessary control criteria and system's global stability using Lyapunov Theorem. It has been proved that the close-loop system error converges to a small neighborhood of equilibrium point. The optimal IAAF controller is derived to guarantee the process's shortest settling time. Simulation results indicate the IAAF controller make the system more stable, accurate, and fast.

  2. Mortality salience increases personal relevance of the norm of reciprocity.

    Science.gov (United States)

    Schindler, Simon; Reinhard, Marc-André; Stahlberg, Dagmar

    2012-10-01

    Research on terror management theory found evidence that people under mortality salience strive to live up to salient cultural norms and values, like egalitarianism, pacifism, or helpfulness. A basic, strongly internalized norm in most human societies is the norm of reciprocity: people should support those who supported them (i.e., positive reciprocity), and people should injure those who injured them (i.e., negative reciprocity), respectively. In an experiment (N = 98; 47 women, 51 men), mortality salience overall significantly increased personal relevance of the norm of reciprocity (M = 4.45, SD = 0.65) compared to a control condition (M = 4.19, SD = 0.59). Specifically, under mortality salience there was higher motivation to punish those who treated them unfavourably (negative norm of reciprocity). Unexpectedly, relevance of the norm of positive reciprocity remained unaffected by mortality salience. Implications and limitations are discussed.

  3. Magnetic Force Transmission of a Reciprocating Motion

    Institute of Scientific and Technical Information of China (English)

    Qing-chang Tan; Fu-sheng Zheng; Jian-gang Li

    2008-01-01

    Magnetic force transmission of a reciprocating motion is studied by theoretical analysis and experiment. A mathematical model for calculating the magnetic force is derived using the theory of equivalent magnetic charges. An experimental rig is constructed to test the transmission and the model is verified by experiment. Effect of the transmission parameters on the magnetic force is analyzed theoretically from the model, and characteristic of the transmission is studied experimentally. Since the transmission is without direct contact between two elements, it is suitable for application in an organism.

  4. Pedagogical documentation: Preschool teachers’ perspective

    Directory of Open Access Journals (Sweden)

    Pavlović-Breneselović Dragana

    2012-01-01

    Full Text Available Educational policy shapes the positions of all stakeholders and their mutual relations in the system of preschool education through its attitude towards documentation. The attitude towards the function of pedagogical documentation in preschool education programmes reflects certain views on children, learning and nature of the programmes. Although contemporary approaches to preschool education emphasise the issue of documentation, this problem is dealt with partially and technically in our country. The aim of our research was to explore preschool teachers’ perspective on documentation by investigating the current situation and teachers’ preferences related to documentation type, as well as to study the purpose, meaning and process of documentation. The research was conducted on the sample of 300 preschool teachers. The descriptive method, interviewing and scaling techniques were used. Research data suggest that the field of documentation is marked by contradictions in perceiving the meaning and function of documentation, as well as by discrepancy and lack of integration at the level of conceptions, practice and educational policy. Changing the current situation in the field of documentation is not a technical matter of elaboration of certain types and forms of documentation; it demands explication of the purpose and function of documentation in keeping with the conception of preschool education programmes and a systemic approach to changes originating from the given conception. [Projekat Ministarstva nauke Republike Srbije, br. 179060: Modeli procenjivanja i strategije unapređivanja kvaliteta obrazovanja u Srbiji

  5. Neural correlate of human reciprocity in social interactions.

    Science.gov (United States)

    Sakaiya, Shiro; Shiraito, Yuki; Kato, Junko; Ide, Hiroko; Okada, Kensuke; Takano, Kouji; Kansaku, Kenji

    2013-01-01

    Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human) and strategy (random, tit-for-tat) in repeated prisoner's dilemma games and investigated the neural correlate of reciprocal interaction with humans. Reciprocal cooperation with humans but exploitation of computers by defection was associated with activation in the left amygdala. Amygdala activation was also positively and negatively correlated with a preference change for human partners following tit-for-tat and random strategies, respectively. The correlated activation represented the intensity of positive feeling toward reciprocal and negative feeling toward non-reciprocal partners, and so reflected reciprocity in social interaction. Reciprocity in social interaction, however, might plausibly be misinterpreted and so we also examined the neural coding of insight into the reciprocity of partners. Those with and without insight revealed differential brain activation across the reward-related circuitry (i.e., the right middle dorsolateral prefrontal cortex and dorsal caudate) and theory of mind (ToM) regions [i.e., ventromedial prefrontal cortex (VMPFC) and precuneus]. Among differential activations, activation in the precuneus, which accompanied deactivation of the VMPFC, was specific to those without insight into human partners who were engaged in a tit-for-tat strategy. This asymmetric (de)activation might involve specific contributions of ToM regions to the human search for reciprocity. Consequently, the intensity of emotion attached to human reciprocity was represented in the amygdala, whereas insight into the reciprocity of others was reflected in activation across the reward-related and ToM regions. This suggests the critical role of mentalizing, which was not equated with reward expectation during social interactions.

  6. Static and kinematic formulation of planar reciprocal assemblies

    DEFF Research Database (Denmark)

    Parigi, Dario; Sassone, Mario; Kirkegaard, Poul Henning

    2014-01-01

    Planar reciprocal frames are two dimensional structures formed by elements joined together according to the principle of structural reciprocity. In this paper a rigorous formulation of the static and kinematic problem is proposed and developed extending the theory of pin-jointed assemblies....... This formulation is used to evaluate the static and kinematic determinacy of reciprocal assemblies from the properties of their equilibrium and kinematic matrices...

  7. Neural correlate of human reciprocity in social interactions

    Directory of Open Access Journals (Sweden)

    Shiro eSakaiya

    2013-12-01

    Full Text Available Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human and strategy (random, tit-for-tat in repeated prisoner’s dilemma games and investigated the neural correlate of reciprocal interaction with humans. Reciprocal cooperation with humans but exploitation of computers by defection was associated with activation in the left amygdala. Amygdala activation was also positively and negatively correlated with a preference change for human partners following tit-for-tat and random strategies, respectively. The correlated activation represented the intensity of positive feeling toward reciprocal and negative feeling toward non-reciprocal partners, and so reflected reciprocity in social interaction. Reciprocity in social interaction, however, might plausibly be misinterpreted and so we also examined the neural coding of insight into the reciprocity of partners. Those with and without insight revealed differential brain activation across the reward-related circuitry (i.e., the right middle dorsolateral prefrontal cortex and dorsal caudate and theory of mind (ToM regions (i.e., ventromedial prefrontal cortex [VMPFC] and precuneus. Among differential activations, activation in the precuneus, which accompanied deactivation of the VMPFC, was specific to those without insight into human partners who were engaged in a tit-for-tat strategy. This asymmetric (deactivation might involve specific contributions of ToM regions to the human search for reciprocity. Consequently, the intensity of emotion attached to human reciprocity was represented in the amygdala, whereas insight into the reciprocity of others was reflected in activation across the reward-related and ToM regions. This suggests the critical role of mentalizing, which was not equated with reward expectation during

  8. Institutionalize Reciprocity to Overcome the Public Goods Provision Problem.

    Directory of Open Access Journals (Sweden)

    Hiroki Ozono

    Full Text Available Cooperation is fundamental to human societies, and one of the important paths for its emergence and maintenance is reciprocity. In prisoner's dilemma (PD experiments, reciprocal strategies are often effective at attaining and maintaining high cooperation. In many public goods (PG games or n-person PD experiments, however, reciprocal strategies are not successful at engendering cooperation. In the present paper, we attribute this difficulty to a coordination problem against free riding among reciprocators: Because it is difficult for the reciprocators to coordinate their behaviors against free riders, this may lead to inequality among players, which will demotivate them from cooperating in future rounds. We propose a new mechanism, institutionalized reciprocity (IR, which refers to embedding the reciprocal strategy as an institution (i.e., institutionalizing the reciprocal strategy. We experimentally demonstrate that IR can prevent groups of reciprocators from falling into coordination failure and achieve high cooperation in PG games. In conclusion, we argue that a natural extension of the present study will be to investigate the possibility of IR to serve as a collective punishment system.

  9. Electromagnetic Reciprocal Cloak with Only Axial Material Parameter Spatially Variant

    Directory of Open Access Journals (Sweden)

    Jing Jing Yang

    2012-01-01

    Full Text Available Reciprocal cloak is an intriguing metamaterial device, in which a hidden antenna or a sensor can receive electromagnetic irradiation from the outside but its presence will not be detected. Based on transformation optics, a cylindrical electromagnetic reciprocal cloak with only axial parameter varying with radius is designed and validated by full wave simulation. When two dispersive reciprocal cloaks are put together, they do not interfere with each other. Our work demonstrates the electromagnetic compatibility (EMC ability of the reciprocal cloak which is very important in multi antenna and sensor design.

  10. Institutionalize Reciprocity to Overcome the Public Goods Provision Problem.

    Science.gov (United States)

    Ozono, Hiroki; Kamijo, Yoshio; Shimizu, Kazumi

    2016-01-01

    Cooperation is fundamental to human societies, and one of the important paths for its emergence and maintenance is reciprocity. In prisoner's dilemma (PD) experiments, reciprocal strategies are often effective at attaining and maintaining high cooperation. In many public goods (PG) games or n-person PD experiments, however, reciprocal strategies are not successful at engendering cooperation. In the present paper, we attribute this difficulty to a coordination problem against free riding among reciprocators: Because it is difficult for the reciprocators to coordinate their behaviors against free riders, this may lead to inequality among players, which will demotivate them from cooperating in future rounds. We propose a new mechanism, institutionalized reciprocity (IR), which refers to embedding the reciprocal strategy as an institution (i.e., institutionalizing the reciprocal strategy). We experimentally demonstrate that IR can prevent groups of reciprocators from falling into coordination failure and achieve high cooperation in PG games. In conclusion, we argue that a natural extension of the present study will be to investigate the possibility of IR to serve as a collective punishment system.

  11. Sleep Health: Reciprocal Regulation of Sleep and Innate Immunity

    National Research Council Canada - National Science Library

    Irwin, Michael R; Opp, Mark R

    2017-01-01

    ...://www.neuropsychopharmacologyreviews.org Web End =www.neuropsychopharmacologyreviews.org 129 Sleep Health: Reciprocal Regulation of Sleep and Innate Immunity [notdef][notdef][notdef][notdef][notdef...

  12. Computerized sociometric assessment for preschool children

    NARCIS (Netherlands)

    Endedijk, H.M.; Cillessen, A.H.N.

    2015-01-01

    In preschool classes, sociometric peer ratings are used to measure children's peer relationships. The current study examined a computerized version of preschool sociometric ratings. The psychometric properties were compared of computerized sociometric ratings and traditional peer ratings for prescho

  13. Advanced Natural Gas Reciprocating Engines(s)

    Energy Technology Data Exchange (ETDEWEB)

    Zurlo, James [Dresser, Inc., Addison, TX (United States)

    2012-04-05

    The ARES program was initiated in 2001 to improve the overall brake thermal efficiency of stationary, natural gas, reciprocating engines. The ARES program is a joint award that is shared by Dresser, Inc., Caterpillar and Cummins. The ARES program was divided into three phases; ARES I (achieve 44% BTE), ARES II (achieve 47% BTE) and ARES III (achieve 50% BTE). Dresser, Inc. completed ARES I in March 2005 which resulted in the commercialization of the APG1000 product line. ARES II activities were completed in September 2010 and the technology developed is currently being integrated into products. ARES III activities began in October 2010. The ARES program goal is to improve the efficiency of natural gas reciprocating engines. The ARES project is structured in three phases with higher efficiency goals in each phase. The ARES objectives are as follows: 1. Achieve 44% (ARES I), 47% (ARES II), and 50% brake thermal efficiency (BTE) as a final ARES III objective 2. Achieve 0.1 g/bhp-hr NOx emissions (with after-treatment) 3. Reduce the cost of the produced electricity by 10% 4. Improve or maintain reliability, durability and maintenance costs

  14. The Arts in Turkish Preschool Education

    Science.gov (United States)

    Acer, Dilek

    2015-01-01

    One of the most important factors determining a nation's level of development in the modern world is preschool education. When preschool education is perceived as an entity that affects every aspect of childhood development, this fact is undeniable. Several aspects of preschool education, including art education, play a significant role in a…

  15. Computerized Sociometric Assessment for Preschool Children

    Science.gov (United States)

    Endedijk, Hinke M.; Cillessen, Antonius H. N.

    2015-01-01

    In preschool classes, sociometric peer ratings are used to measure children's peer relationships. The current study examined a computerized version of preschool sociometric ratings. The psychometric properties were compared of computerized sociometric ratings and traditional peer ratings for preschoolers. The distributions, inter-item…

  16. Preschool Facilities: Are States Providing Adequate Guidance?

    Science.gov (United States)

    Lea, Dennis R.; Polster, Patty Poppe

    2010-01-01

    The preschool facility is a critical element of an effective preschool program. The recent economic downturn in the United States makes it difficult for states and individual school districts to consider developing new preschool programs or enhancing current programs or facilities. Yet many Americans still agree that public investment in preschool…

  17. Emergent Literacy: Preschool Teachers' Beliefs and Practices

    Science.gov (United States)

    Sandvik, Jenny Miglis; van Daal, Victor H. P.; Adèr, Herman J.

    2014-01-01

    The present study reports on the construction of a research instrument developed to examine preschool teachers' beliefs and practices in relation to emergent literacy. A 130-item survey (Preschool Literacy Survey, PLS) was completed by a total of 90 preschool teachers in Norway. Items were grouped into homogenous scales, and the relationship…

  18. Preschool Evaluation Report: Year 1 Report.

    Science.gov (United States)

    Cooper, Judith A.; Hebbeler, Kathleen.

    The report documents activities and findings of the Preschool Evaluation Project which is developing a model for evaluating program provision to handicapped preschoolers and creating a longitudinal data base to track the short- and long-term progress of preschool children receiving special services in Montgomery County, Maryland. During the first…

  19. Correlation of positive and negative reciprocity fails to confer an evolutionary advantage: Phase transitions to elementary strategies

    CERN Document Server

    Szolnoki, Attila

    2013-01-01

    Economic experiments reveal that humans value cooperation and fairness. Punishing unfair behavior is therefore common, and according to the theory of strong reciprocity, it is also directly related to rewarding cooperative behavior. However, empirical data fail to confirm that positive and negative reciprocity are correlated. Inspired by this disagreement, we determine whether the combined application of reward and punishment is evolutionary advantageous. We study a spatial public goods game, where in addition to the three elementary strategies of defection, rewarding and punishment, a fourth strategy combining the later two competes for space. We find rich dynamical behavior that gives rise to intricate phase diagrams where continuous and discontinuous phase transitions occur in succession. Indirect territorial competition, spontaneous emergence of cyclic dominance, as well as divergent fluctuations of oscillations that terminate in an absorbing phase are observed. Yet despite the high complexity of solution...

  20. Indirect Medical Education and Disproportionate Share Adj...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Indirect Medical Education and Disproportionate Share Adjustments to Medicare Inpatient Payment Rates The indirect medical education (IME) and disproportionate share...

  1. Indirect Medical Education and Disproportionate Share Adj...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Indirect Medical Education and Disproportionate Share Adjustments to Medicare Inpatient Payment Rates The indirect medical education (IME) and disproportionate share...

  2. Indirect searches for dark matter

    Indian Academy of Sciences (India)

    Marco Cirelli

    2012-11-01

    The current status of indirect searches for dark matter has been reviewed in a schematic way here. The main relevant experimental results of the recent years have been listed and the excitements and disappointments that their phenomenological interpretations in terms of almost-standard annihilating dark matter have brought along have been discussed. The main sources of uncertainties that affect this kind of searches are also listed. [Report number: Saclay T11/206, CERN-PH-TH/2011-257, extended version in arXiv:1202.1454], [Prepared for the Proceedings of Lepton–Photon 2011, Mumbai, India, 22–27 Aug. 2011].

  3. 19 CFR 10.460 - Indirect materials.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect materials. 10.460 Section 10.460 Customs... of Origin § 10.460 Indirect materials. An indirect material, as defined in § 10.402(o), will be considered to be an originating material without regard to where it is produced. Example. Chilean Producer C...

  4. 19 CFR 10.603 - Indirect materials.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect materials. 10.603 Section 10.603 Customs... States Free Trade Agreement Rules of Origin § 10.603 Indirect materials. An indirect material, as defined in § 10.582(m) of this subpart, will be considered to be an originating material without regard to...

  5. 19 CFR 10.541 - Indirect materials.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect materials. 10.541 Section 10.541 Customs... Rules of Origin § 10.541 Indirect materials. An indirect material, as defined in § 10.502(j) of this subpart, will be considered to be an originating material without regard to where it is produced, and its...

  6. Indirect Calorimetry in Mechanically Ventilated Patients

    DEFF Research Database (Denmark)

    Allingstrup, Matilde Jo; Kondrup, Jens; Perner, Anders

    2017-01-01

    BACKGROUND AND AIMS: The 2 currently available indirect calorimeters, CCM Express Indirect Calorimeter (MedGraphics, St Paul, MN) and Quark RMR ICU Indirect Calorimeter (COSMED, Rome, Italy), have not been validated against a gold standard in mechanically ventilated patients. Our aim was to do so...

  7. 46 CFR 154.1720 - Indirect refrigeration.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression....

  8. The evolution of generalized reciprocity on social interaction networks

    NARCIS (Netherlands)

    van Doorn, Gerrit Sander; Taborsky, Michael

    2012-01-01

    Generalized reciprocity (help anyone, if helped by someone) is a minimal strategy capable of supporting cooperation between unrelated individuals. Its simplicity makes it an attractive model to explain the evolution of reciprocal altruism in animals that lack the information or cognitive skills need

  9. Group differences in reciprocity, multiplexity and exchange : measures and application

    NARCIS (Netherlands)

    Agneessens, Filip; Skvoretz, John

    2012-01-01

    Local forces structure social networks. One major and widely researched local force is reciprocity, often assumed to work homogeneously across actors-i.e., all actors are equally subject to the same level of force towards reciprocity. Other local forces, like multiplexity and exchange, are also ofte

  10. Sex Differences in the Reciprocal Behaviour of Children with Autism

    Science.gov (United States)

    Backer van Ommeren, Tineke; Koot, Hans M.; Scheeren, Anke M.; Begeer, Sander

    2017-01-01

    Differences in the social limitations of girls compared to boys on the autism spectrum are still poorly understood. Impaired social-emotional reciprocity is a core diagnostic criterion for an autism spectrum disorder. This study compares sex differences in reciprocal behaviour in children with autism spectrum disorder (32 girls, 114 boys) and in…

  11. Similarity and Reciprocity in the Friendships of Elementary School Children.

    Science.gov (United States)

    Clark, M. L.; Drewry, Debra L.

    1985-01-01

    Investigated the effect of similarity and reciprocity on dyadic friendship choices in third- and sixth-grade students. Reciprocal (mutual) friendships were more similar in proximity, popularity, and self-concept than those in nonreciprocal (nonmutual) dyads. Results are discussed in relation to the interpersonal attraction theories. (Author/DST)

  12. Regular linear systems and their reciprocals : applications to Riccati equations

    NARCIS (Netherlands)

    Curtain, RF

    2003-01-01

    For a regular linear system with zero in the resolvent set of the generator we introduce its reciprocal system, which has bounded generators. We show that there are close relationships between key system theoretic properties of such regular linear systems and their reciprocals. To illustrate the use

  13. Reciprocal link for a coupled Camassa-Holm type equation

    Science.gov (United States)

    Li, Nianhua; Zhang, Jinshun; Wu, Lihua

    2016-04-01

    A coupled Camassa-Holm type equation is linked to the first negative flow in a modified Drinfeld-Sokolov III hierarchy by a transformation of reciprocal type. Meanwhile the Lax pair and bi-Hamiltonian structure behaviors of this coupled Camassa-Holm type equation under the reciprocal transformation are analyzed.

  14. Reciprocal Mentorship: An Effective Support for Online Instructors

    Science.gov (United States)

    Gabriel, Martha A.; Kaufield, Kandra J.

    2008-01-01

    This article presents a reciprocal model of mentoring as an alternative approach to more traditional mentoring models. A mentor, experienced with online course delivery and pedagogy, worked with six online instructors over two academic terms within a reciprocal mentorship model. This model was designed to build a collaborative learning…

  15. Resisting moral wiggle room: How robust is reciprocal behavior?

    NARCIS (Netherlands)

    van der Weele, J.; Kulisa, J.; Kosfeld, M.; Friebel, G.

    2014-01-01

    We provide the second mover in a trust game and a moonlighting game with an excuse for not reciprocating. While this type of manipulation has been shown to strongly reduce giving in the dictator game, we find that the availability of the excuse has no effect on the incidence of reciprocal behavior

  16. Static And Kinematic Formulation Of Planar Reciprocal Assemblies

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning

    2013-01-01

    Planar reciprocal frames are two dimensional structures formed by elements joined together according to the principle of structural reciprocity. In this paper a rigorous formulation of the static and kinematic problem is proposed and developed by extending the work on pin-jointed assemblies by Pe...

  17. Reciprocal Ontological Models Show Indeterminism Comparable to Quantum Theory

    Science.gov (United States)

    Bandyopadhyay, Somshubhro; Banik, Manik; Bhattacharya, Some Sankar; Ghosh, Sibasish; Kar, Guruprasad; Mukherjee, Amit; Roy, Arup

    2016-12-01

    We show that within the class of ontological models due to Harrigan and Spekkens, those satisfying preparation-measurement reciprocity must allow indeterminism comparable to that in quantum theory. Our result implies that one can design quantum random number generator, for which it is impossible, even in principle, to construct a reciprocal deterministic model.

  18. Reciprocal Ontological Models Show Indeterminism Comparable to Quantum Theory

    Science.gov (United States)

    Bandyopadhyay, Somshubhro; Banik, Manik; Bhattacharya, Some Sankar; Ghosh, Sibasish; Kar, Guruprasad; Mukherjee, Amit; Roy, Arup

    2017-02-01

    We show that within the class of ontological models due to Harrigan and Spekkens, those satisfying preparation-measurement reciprocity must allow indeterminism comparable to that in quantum theory. Our result implies that one can design quantum random number generator, for which it is impossible, even in principle, to construct a reciprocal deterministic model.

  19. Reciprocal Relationships between Math Self-Concept and Math Anxiety

    Science.gov (United States)

    Ahmed, Wondimu; Minnaert, Alexander; Kuyper, Hans; van der Werf, Greetje

    2012-01-01

    The present study examined the reciprocal relationships between self-concept and anxiety in mathematics. A sample of 495 grade 7 students (51% girls) completed self-report measures assessing self-concept and anxiety three times in a school year. Structural equation modeling was used to test a cross-lagged panel model of reciprocal effects between…

  20. A Survey of Reciprocal Borrowers at Nichols Library, Naperville, Illinois.

    Science.gov (United States)

    Strack, Nancy C.

    This paper presents results of a survey that examined the spending activities of patrons from other libraries while in Naperville (Illinois) using their reciprocal borrowing privileges at Nichols Library, the local public library. Results of a questionnaire from 100 of the 7,540 registered reciprocal borrowers provide information on: home…

  1. Reciprocal Borrowing Patterns in the North Suburban Library System.

    Science.gov (United States)

    Able Consultants, DeKalb, IL.

    During a 5-day period in 1990, a total of 1,401 reciprocal borrowers in the North Suburban Library System (NSLS) received questionnaires asking about their choice of library and other aspects of borrowing behavior to provide data on the reciprocal borrowing characteristics and patterns within the system. This survey was designed to identify the…

  2. An Analysis of Direct Reciprocal Borrowing among Quebec University Libraries

    Science.gov (United States)

    Duy, Joanna C.; Lariviere, Vincent

    2013-01-01

    An analysis of Quebec academic libraries' direct reciprocal borrowing statistics from 2005 to 2010 reveals that the physical distance separating universities plays an important role in determining the amount of direct reciprocal borrowing activity conducted between institutions. Significant statistical correlations were also seen between the…

  3. Indirect costs of rheumatoid arthritis.

    Science.gov (United States)

    Raciborski, Filip; Kłak, Anna; Kwiatkowska, Brygida

    2015-01-01

    It is estimated that in Poland about 400,000 persons in general suffer from inflammatory joint diseases, including rheumatoid arthritis (RA). Epidemiological surveys documenting the frequency and disturbance of musculoskeletal disorders in the Polish population are few in number. Most of the estimations are based on epidemiological data from other countries (prevalence of 0.5-1%). According to the data of the National Health Fund in Poland 135,000-157,000 persons in total are treated because of rheumatoid arthritis per year [ICD10 (International Statistical Classification of Diseases and Related Health Problems): M05, M06]. In the case of this group of diseases indirect costs significantly outweigh the direct costs. Indirect costs increase together with activity level of the disease. The cost analysis of productivity loss of RA patients indicates that sickness absenteeism and informal care are the most burdensome. At the national level it amounts in total from 1.2 billion to 2.8 billion PLN per year, depending on the method of analysis. These costs could be significantly reduced through early diagnosis and introduction of effective treatment.

  4. Design and Fabrication of a Free-Form Reciprocal Roof

    DEFF Research Database (Denmark)

    Parigi, Dario

    2015-01-01

    The paper presents the framework and the design and construction process of a freeform reciprocal pavilion realized during a one-week long workshop with the students of the 1st semester of the Master of Science in Architecture and Design, fall 2014, at Aalborg University. The workshop didactic...... of relations between design parameters and a wide array of measurable performances. Due to the reciprocal structures geometric complexity, the shape generation process is handled using the Reciprocalizer, a software tool developed by the author that embeds in a computational environment the constructional...... logic of reciprocal structures. It enables to engage in real time in iterative processes that allows unfolding the geometric complexity and turn it into a source of inspiration for expanding the design space and triggering the development of unique, adapted and integrated design solutions. Reciprocal...

  5. Efficient Design And Fabrication Of Free-Form Reciprocal Structures

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning

    2013-01-01

    Structures based on the principle of reciprocity have been autonomously studied and used since the antiquity on the basis of different needs and purposes. The application of the principle of reciprocity requires the presence of at least two elements, at the same time both supporting and being...... supported by the other with no hierarchy, meeting along their span and never in their vertices. A computational method has been developed to predict and control the geometry of large networks of reciprocally connected, round un-notched elements. The method enables the possibility of using reciprocal...... structures to closely fit any free-form geometry through the determination of the geometric parameters that describe the contact position of each element with the others in the assembly. This method has been applied for the design and realization of a free-form reciprocal structure composed of 506 round, un...

  6. Control of coherent backscattering by breaking optical reciprocity

    CERN Document Server

    Bromberg, Y; Popoff, S M; Cao, H

    2015-01-01

    Reciprocity is a universal principle that has a profound impact on many areas of physics. A fundamental phenomenon in condensed-matter physics, optical physics and acoustics, arising from reciprocity, is the constructive interference of quantum or classical waves which propagate along time-reversed paths in disordered media, leading to, for example, weak localization and metal-insulator transition. Previous studies have shown that such coherent effects are suppressed when reciprocity is broken. Here we show that by breaking reciprocity in a controlled manner, we can tune, rather than simply suppress, these phenomena. In particular, we manipulate coherent backscattering of light, also known as weak localization. By utilizing a non-reciprocal magneto-optical effect, we control the interference between time-reversed paths inside a multimode fiber with strong mode mixing, and realize a continuous transition from the well-known peak to a dip in the backscattered intensity. Our results may open new possibilities fo...

  7. Permanent junctional reciprocating tachycardia in a dog.

    Science.gov (United States)

    Santilli, Roberto A; Santos, Luis F N; Perego, Manuela

    2013-09-01

    A 5-year-old male English Bulldog was presented with a 1-year history of paroxysmal supraventricular tachycardia (SVT) partially responsive to amiodarone. At admission the surface ECG showed sustained runs of a narrow QRS complex tachycardia, with a ventricular cycle length (R-R interval) of 260 ms, alternating with periods of sinus rhythm. Endocardial mapping identified the electrogenic mechanism of the SVT as a circus movement tachycardia with retrograde and decremental conduction along a concealed postero-septal atrioventricular pathway (AP) and anterograde conduction along the atrioventricular node. These characteristics were indicative of a permanent junctional reciprocating tachycardia (PJRT). Radiofrequency catheter ablation of the AP successfully terminated the PJRT, with no recurrence of tachycardia on Holter monitoring at 12 months follow-up.

  8. Sleep and exercise: a reciprocal issue?

    Science.gov (United States)

    Chennaoui, Mounir; Arnal, Pierrick J; Sauvet, Fabien; Léger, Damien

    2015-04-01

    Sleep and exercise influence each other through complex, bilateral interactions that involve multiple physiological and psychological pathways. Physical activity is usually considered as beneficial in aiding sleep although this link may be subject to multiple moderating factors such as sex, age, fitness level, sleep quality and the characteristics of the exercise (intensity, duration, time of day, environment). It is therefore vital to improve knowledge in fundamental physiology in order to understand the benefits of exercise on the quantity and quality of sleep in healthy subjects and patients. Conversely, sleep disturbances could also impair a person's cognitive performance or their capacity for exercise and increase the risk of exercise-induced injuries either during extreme and/or prolonged exercise or during team sports. This review aims to describe the reciprocal fundamental physiological effects linking sleep and exercise in order to improve the pertinent use of exercise in sleep medicine and prevent sleep disorders in sportsmen.

  9. Thermal Powered Reciprocating-Force Motor

    Science.gov (United States)

    Tatum, III, Paul F. (Inventor); McDow Elliott, Amelia (Inventor)

    2015-01-01

    A thermal-powered reciprocating-force motor includes a shutter switchable between a first position that passes solar energy and a second position that blocks solar energy. A shape memory alloy (SMA) actuator is coupled to the shutter to control switching thereof between the shutter's first and second position. The actuator is positioned with respect to the shutter such that (1) solar energy impinges on the SMA when the shutter is in its first position so that the SMA experiences contraction in length until the shutter is switched to its second position, and (2) solar energy is impeded from impingement on the SMA when the shutter is in its second position so that the SMA experiences extension in length. Elastic members coupled to the actuator apply a force to the SMA that aids in its extension in length until the shutter is switched to its first position.

  10. Testosterone inhibits trust but promotes reciprocity.

    Science.gov (United States)

    Boksem, Maarten A S; Mehta, Pranjal H; Van den Bergh, Bram; van Son, Veerle; Trautmann, Stefan T; Roelofs, Karin; Smidts, Ale; Sanfey, Alan G

    2013-11-01

    The steroid hormone testosterone has been associated with behavior intended to obtain or maintain high social status. Although such behavior is typically characterized as aggressive and competitive, it is clear that high social status is achieved and maintained not only through antisocial behavior but also through prosocial behavior. In the present experiment, we investigated the impact of testosterone administration on trust and reciprocity using a double-blind randomized control design. We found that a single dose of 0.5 mg of testosterone decreased trust but increased generosity when repaying trust. These findings suggest that testosterone may mediate different types of status-seeking behavior. It may increase competitive, potentially aggressive, and antisocial behavior when social challenges and threats (i.e., abuse of trust and betrayal) need to be considered; however, it may promote prosocial behavior in the absence of these threats, when high status and good reputation may be best served by prosocial behavior.

  11. Non-Reciprocal Brillouiin Scattering Induced Transparency

    CERN Document Server

    Kim, JunHwan; Han, Kewen; Wang, Hailin; Bahl, Gaurav

    2014-01-01

    Electromagnetically induced transparency (EIT) [1, 2] provides a powerful mechanism for controlling light propagation in a dielectric medium, and for producing both slow and fast light. EIT traditionally arises from destructive interference induced by a nonradiative coherence in an atomic system. Stimulated Brillouin scattering (SBS) of light from propagating hypersonic acoustic waves [3] has also been used successfully for the generation of slow and fast light [4-7]. However, EIT-type processes based on SBS were considered infeasible because of the short coherence lifetime of hypersonic phonons. Here, we demonstrate a new Brillouin scattering induced transparency (BSIT) phenomenon generated by acousto-optic interaction of light with long-lived propagating phonons [8, 9]. This transparency is intrinsically non-reciprocal due to the stringent phase-matching requirements. We demonstrate BSIT in a silica microresonator having a specific, naturally occurring, forward-SBS phase-matched modal configuration [8, 9]. ...

  12. 76 FR 8661 - Airworthiness Directives; Lycoming Engines, Fuel Injected Reciprocating Engines

    Science.gov (United States)

    2011-02-15

    ...-14-07, Amendment 39-15602 (73 FR 39574), for certain fuel injected reciprocating engines manufactured... Directives; Lycoming Engines, Fuel Injected Reciprocating Engines AGENCY: Federal Aviation Administration... airworthiness directive (AD) that applies to certain fuel injected reciprocating engines manufactured...

  13. 77 FR 60341 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2012-10-03

    ... Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion... Emission Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines to..., ``National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New...

  14. 26 CFR 1.826-1 - Election by reciprocal underwriters and interinsurers.

    Science.gov (United States)

    2010-04-01

    ... Perpetual Policies Or Premium Deposits) § 1.826-1 Election by reciprocal underwriters and interinsurers. (a... reciprocal and the deductions allocable thereto under the same method of accounting used by the reciprocal...

  15. Gendering in one Icelandic preschool

    Directory of Open Access Journals (Sweden)

    Gudrun Alda Hardardottir

    2014-05-01

    Full Text Available The aim of this article is to shed light on gendering in preschool. It analyzes the opinions and beliefs of preschool teachers with regard to boys and girls in one Icelandic preschool, and how gender performative acts are manifested in the preschool’s children. The preschool, which was observed for one school year, comprised 60 children, aged 18 months to five years, and 20 employees, of which eight were qualified teachers. The research material is analyzed in terms of Judith Butler’s gender constructivism. Butler contends that gender is constituted by, and is a product of, society, and that the individual’s empowerment is therefore limited in relation to society, with individuals typically seeking to identify themselves with the dominant norms concerning gender. The main conclusions suggest that “gendering” is prominent within the preschool. There is a strong tendency among the preschool teachers to classify the children into categories of boys/masculine and girls/feminine, and specific norms direct the children into the dominant feminine and masculine categories, thus maintaining and reinforcing their gender stereotypes. The children used symbols such as colors, locations and types of play as means to instantiate the “girling” and the “boying”. These findings are consistent with previous Nordic research and indicate a prevailing essentialist perspective towards both girls and boys. The originality of the research, however, lies in focusing on children’s gender from the individual’s perspective and how the individual child generally enacts gender performatively within the confines of society’s norms.

  16. Wishful thinking in preschoolers.

    Science.gov (United States)

    Bernard, Stéphane; Clément, Fabrice; Mercier, Hugo

    2016-01-01

    The current experiment sought to demonstrate the presence of wishful thinking--when wishes influence beliefs--in young children. A sample of 77 preschoolers needed to predict, eight times in a row, which of two plastic eggs, one containing one toy and the other containing three toys, would be drawn by a blinded experimenter. On the four trials in which the children could not keep the content of the egg drawn, they were equally likely to predict that either egg would be drawn. By contrast, on the four trials in which the children got to keep the content of the egg, they were more likely to predict that the egg with three toys would be drawn. Any effort the children exerted would be the same across conditions, so that this demonstration of wishful thinking cannot be accounted for by an effort heuristic. One group of children--a subgroup of the 5-year-olds--did not engage in wishful thinking. Children from this subgroup instead used the representativeness heuristic to guide their answers. This result suggests that having an explicit representation of the outcome inhibits children from engaging in wishful thinking in the same way as explicit representations constrain the operation of motivated reasoning in adults.

  17. Indirect photobiomodulation in functional networks

    Science.gov (United States)

    Liu, Timon Cheng-Yi; Zhu, Wei-Wei; Yang, Xiang-Bo

    2012-12-01

    Photobiomodulation (PBM) is a non-damaged modulation of laser irradiation or monochromatic light (LI) on a biosystem function. It depends on whether the function is in its function-specific homeostasis (FSH), a negative feedback response for the function to be performed perfectly. Many redundant pathways (RPs) maintain the same cellular function. The full activation of any of RPs can maintain a normal function in its FSH, but partial activation of all the RPs can only maintain a dysfunctional function far from its FSH. A PBM may self-adaptively modulate the activation of a partially activated RP of a normal function until it is fully activated and the normal function is then upgraded. This PBM is called indirect PBM (iPBM). The iPBM on cells such as tumor cells, myoblast cells and fibroblasts and other biosystems and their applications would be reviewed in this paper.

  18. Aerosols indirectly warm the Arctic

    Directory of Open Access Journals (Sweden)

    T. Mauritsen

    2010-07-01

    Full Text Available On average, airborne aerosol particles cool the Earth's surface directly by absorbing and scattering sunlight and indirectly by influencing cloud reflectivity, life time, thickness or extent. Here we show that over the central Arctic Ocean, where there is frequently a lack of aerosol particles upon which clouds may form, a small increase in aerosol loading may enhance cloudiness thereby likely causing a climatologically significant warming at the ice-covered Arctic surface. Under these low concentration conditions cloud droplets grow to drizzle sizes and fall, even in the absence of collisions and coalescence, thereby diminishing cloud water. Evidence from a case study suggests that interactions between aerosol, clouds and precipitation could be responsible for attaining the observed low aerosol concentrations.

  19. Reciprocal regulation of Yersinia pestis biofilm formation and virulence by RovM and RovA

    OpenAIRE

    Liu, Lei; Fang, Haihong; Yang, Huiying; Zhang, Yiquan; Han, Yanping; Zhou, Dongsheng; Yang, Ruifu

    2016-01-01

    RovA is known to enhance Yersinia pestis virulence by directly upregulating the psa loci. This work presents a complex gene regulatory paradigm involving the reciprocal regulatory action of RovM and RovA on the expression of biofilm and virulence genes as well as on their own genes. RovM and RovA enhance and inhibit Y. pestis biofilm production, respectively, whereas RovM represses virulence in mice. RovM directly stimulates the transcription of hmsT, hmsCDE and rovM, while indirectly enhanci...

  20. 75 FR 80761 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2010-12-23

    ... Reciprocating Internal Combustion Engines AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of... air pollutants for reciprocating internal combustion engines and requesting public comment on one...

  1. Advanced Natural Gas Reciprocating Engine(s)

    Energy Technology Data Exchange (ETDEWEB)

    Kwok, Doris; Boucher, Cheryl

    2009-09-30

    Energy independence and fuel savings are hallmarks of the nation’s energy strategy. The advancement of natural gas reciprocating engine power generation technology is critical to the nation’s future. A new engine platform that meets the efficiency, emissions, fuel flexibility, cost and reliability/maintainability targets will enable American manufacturers to have highly competitive products that provide substantial environmental and economic benefits in the US and in international markets. Along with Cummins and Waukesha, Caterpillar participated in a multiyear cooperative agreement with the Department of Energy to create a 50% efficiency natural gas powered reciprocating engine system with a 95% reduction in NOx emissions by the year 2013. This platform developed under this agreement will be a significant contributor to the US energy strategy and will enable gas engine technology to remain a highly competitive choice, meeting customer cost of electricity targets, and regulatory environmental standard. Engine development under the Advanced Reciprocating Engine System (ARES) program was divided into phases, with the ultimate goal being approached in a series of incremental steps. This incremental approach would promote the commercialization of ARES technologies as soon as they emerged from development and would provide a technical and commercial foundation of later-developing technologies. Demonstrations of the Phase I and Phase II technology were completed in 2004 and 2008, respectively. Program tasks in Phase III included component and system development and testing from 2009-2012. Two advanced ignition technology evaluations were investigated under the ARES program: laser ignition and distributed ignition (DIGN). In collaboration with Colorado State University (CSU), a laser ignition system was developed to provide ignition at lean burn and high boost conditions. Much work has been performed in Caterpillar’s DIGN program under the ARES program. This work

  2. Objectively measured sedentary behavior in preschool children: comparison between Montessori and traditional preschools

    Directory of Open Access Journals (Sweden)

    Byun Wonwoo

    2013-01-01

    Full Text Available Abstract Background This study aimed to compare the levels of objectively-measured sedentary behavior in children attending Montessori preschools with those attending traditional preschools. Methods The participants in this study were preschool children aged 4 years old who were enrolled in Montessori and traditional preschools. The preschool children wore ActiGraph accelerometers. Accelerometers were initialized using 15-second intervals and sedentary behavior was defined as Results Children attending Montessori preschools spent less time in sedentary behavior than those attending traditional preschools during the in-school (44.4. min/hr vs. 47.1 min/hr, P = 0.03, after-school (42.8. min/hr vs. 44.7 min/hr, P = 0.04, and total-day (43.7 min/hr vs. 45.5 min/hr, P = 0. 009 periods. School type (Montessori or traditional, preschool setting (private or public, socio-demographic factors (age, gender, and socioeconomic status were found to be significant predictors of preschoolers’ sedentary behavior. Conclusions Levels of objectively-measured sedentary behavior were significantly lower among children attending Montessori preschools compared to children attending traditional preschools. Future research should examine the specific characteristics of Montessori preschools that predict the lower levels of sedentary behavior among children attending these preschools compared to children attending traditional preschools.

  3. The evolution of reciprocity: social types or social incentives?

    Science.gov (United States)

    André, Jean-Baptiste

    2010-02-01

    The vast majority of human beings regularly engage in reciprocal cooperation with nonrelated conspecifics, and yet the current evolutionary understanding of these behaviors is insufficient. Intuitively, reciprocity should evolve if past behavior conveys information about future behavior. But it is not straightforward to understand why this should be an outcome of evolution. Most evolutionary models assume that individuals' past behavior informs others about their stable social type (defector, cooperator, reciprocator, etc.), which makes it sensible to reciprocate. In this article, after describing the central source of difficulty in the evolutionary understanding of reciprocity, I put forward an alternative explanation based on a work by O. Leimar. It consists of taking into account the fact that the payoffs to individuals in social interactions can change through time. This offers a solution because individuals' past behavior then signals their payoffs, which also makes it sensible to reciprocate. Even though the overwhelming majority of evolutionary models implicitly endorse the social types mechanism, I argue that the social incentives mechanism may underlie reciprocity in humans.

  4. The evolution of generalized reciprocity on social interaction networks.

    Science.gov (United States)

    van Doorn, Gerrit Sander; Taborsky, Michael

    2012-03-01

    Generalized reciprocity (help anyone, if helped by someone) is a minimal strategy capable of supporting cooperation between unrelated individuals. Its simplicity makes it an attractive model to explain the evolution of reciprocal altruism in animals that lack the information or cognitive skills needed for other types of reciprocity. Yet, generalized reciprocity is anonymous and thus defenseless against exploitation by defectors. Recognizing that animals hardly ever interact randomly, we investigate whether social network structure can mitigate this vulnerability. Our results show that heterogeneous interaction patterns strongly support the evolution of generalized reciprocity. The future probability of being rewarded for an altruistic act is inversely proportional to the average connectivity of the social network when cooperators are rare. Accordingly, sparse networks are conducive to the invasion of reciprocal altruism. Moreover, the evolutionary stability of cooperation is enhanced by a modular network structure. Communities of reciprocal altruists are protected against exploitation, because modularity increases the mean access time, that is, the average number of steps that it takes for a random walk on the network to reach a defector. Sparseness and community structure are characteristic properties of vertebrate social interaction patterns, as illustrated by network data from natural populations ranging from fish to primates.

  5. Near optimal graphene terahertz non-reciprocal isolator

    Science.gov (United States)

    Tamagnone, Michele; Moldovan, Clara; Poumirol, Jean-Marie; Kuzmenko, Alexey B.; Ionescu, Adrian M.; Mosig, Juan R.; Perruisseau-Carrier, Julien

    2016-04-01

    Isolators, or optical diodes, are devices enabling unidirectional light propagation by using non-reciprocal optical materials, namely materials able to break Lorentz reciprocity. The realization of isolators at terahertz frequencies is a very important open challenge made difficult by the intrinsically lossy propagation of terahertz radiation in current non-reciprocal materials. Here we report the design, fabrication and measurement of a terahertz non-reciprocal isolator for circularly polarized waves based on magnetostatically biased monolayer graphene, operating in reflection. The device exploits the non-reciprocal optical conductivity of graphene and, in spite of its simple design, it exhibits almost 20 dB of isolation and only 7.5 dB of insertion loss at 2.9 THz. Operation with linearly polarized light can be achieved using quarter-wave plates as polarization converters. These results demonstrate the superiority of graphene with respect to currently used terahertz non-reciprocal materials and pave the way to a novel class of optimal non-reciprocal devices.

  6. Longitudinal, reciprocal effects of social skills and achievement from kindergarten to eighth grade.

    Science.gov (United States)

    Caemmerer, Jacqueline M; Keith, Timothy Z

    2015-08-01

    Previous research suggests that students' social skills and achievement are interrelated, and some findings support bi-directional effects between the two constructs. The purpose of this research study was to estimate the possible longitudinal and reciprocal effects of social skills and achievement for kindergarten through eighth grade students. Data from the Early Childhood Longitudinal Study program were analyzed; teachers' ratings of students' social skills and students' standardized math and reading achievement performance were collected 4 and 5 times, respectively. Latent variable structural equation modeling was used to test a panel model of reciprocal, longitudinal effects of social skills and achievement. The results suggest that the effects of students' social skills and achievement are bi-directional, but the effects of students' achievement on their later social skills are stronger than the effects of social skills on achievement. The significant effects of students' social skills on their later achievement are mostly indirect. These findings suggest that the future social skills of students who struggle academically may be of particular concern to educators, and intervention and prevention efforts aimed to address both social and achievement skills may help remediate the other skill in the future.

  7. Advanced Natural Gas Reciprocating Engine(s)

    Energy Technology Data Exchange (ETDEWEB)

    Kwok, Doris; Boucher, Cheryl

    2009-09-30

    Energy independence and fuel savings are hallmarks of the nation’s energy strategy. The advancement of natural gas reciprocating engine power generation technology is critical to the nation’s future. A new engine platform that meets the efficiency, emissions, fuel flexibility, cost and reliability/maintainability targets will enable American manufacturers to have highly competitive products that provide substantial environmental and economic benefits in the US and in international markets. Along with Cummins and Waukesha, Caterpillar participated in a multiyear cooperative agreement with the Department of Energy to create a 50% efficiency natural gas powered reciprocating engine system with a 95% reduction in NOx emissions by the year 2013. This platform developed under this agreement will be a significant contributor to the US energy strategy and will enable gas engine technology to remain a highly competitive choice, meeting customer cost of electricity targets, and regulatory environmental standard. Engine development under the Advanced Reciprocating Engine System (ARES) program was divided into phases, with the ultimate goal being approached in a series of incremental steps. This incremental approach would promote the commercialization of ARES technologies as soon as they emerged from development and would provide a technical and commercial foundation of later-developing technologies. Demonstrations of the Phase I and Phase II technology were completed in 2004 and 2008, respectively. Program tasks in Phase III included component and system development and testing from 2009-2012. Two advanced ignition technology evaluations were investigated under the ARES program: laser ignition and distributed ignition (DIGN). In collaboration with Colorado State University (CSU), a laser ignition system was developed to provide ignition at lean burn and high boost conditions. Much work has been performed in Caterpillar’s DIGN program under the ARES program. This work

  8. Direct and indirect aggression and victimization in adolescents - associations with the development of psychological difficulties.

    Science.gov (United States)

    Lundh, Lars-Gunnar; Daukantaité, Daiva; Wångby-Lundh, Margit

    2014-01-01

    Previous research has established that direct and indirect forms of aggression differ in their association with gender and type of psychological difficulties. One purpose of the present study was to test if the same applies to direct and indirect victimization. A second purpose was to study these associations not only cross-sectionally (as in most previous research) but also longitudinally. A third purpose was to test the hypotheses that there are prospective bidirectional associations not only between victimization and psychological difficulties (which has been shown in previous research), but also between aggression and psychological difficulties, and that direct and indirect forms of aggression and victimization show different associations with different types of psychological difficulties. The participants were a community sample of all students in two grades of regular school in a Swedish municipality who answered questionnaires as part of a two-wave longitudinal study with a one-year interval. The participants were 13-15 years old, and there were longitudinal data on 893 students, which represented 85% of all students. The cross-sectional associations were primarily tested by semi-partial correlations, and the longitudinal associations by hierarchical multiple regression. The results corroborated the meaningfulness of differentiating not only between direct and indirect aggression but also between direct and indirect victimization. Boys reported being more victim to direct aggression, whereas girls reported being more victim to indirect aggression. Direct aggression predicted increased conduct problems in boys, whereas indirect aggression predicted increased conduct problems in girls, and conduct problems reciprocally predicted increased direct and indirect aggression. Indirect victimization showed prospective bidirectional associations with emotional symptoms and conduct problems, suggesting the potential development of vicious cycles of escalating problems

  9. Preschool teachers’ reasoning about interactive whiteboard embedded in Swedish preschools

    Directory of Open Access Journals (Sweden)

    Maryam Bourbour

    2014-01-01

    Full Text Available This paper aims to investigate the ways in which teachers enact the interactive whiteboard (IWB in Swedish preschools in relation to preschool children’s mathematical learning. Data collected from interviews with four preschool teachers have provided the opportunity to consider the potential of IWB to facilitate a creative approach to young children’s mathematic education. The findings suggest that IWB use in preschool is mostly viewed as “Space for children to involve in problem-solving situations”, “Supporting collaborative learning and mutual negotiation”, “Goal-oriented mathematics learning facilitated by IWB” and “Retaining children’s interest in learning activities”. This study also highlights the importance of teachers’ technological knowledge and skills in mediating the interaction and facilitating the use of IWB in preschool pedagogical practices. Normal 0 21 false false false SV JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Normal tabell"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Cambria","serif"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;}

  10. Reciprocal relativity of noninertial frames: quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Low, Stephen G [4301 Avenue D, Austin, Texas, 78751 (United States)

    2007-04-06

    Noninertial transformations on time-position-momentum-energy space {l_brace}t, q, p, e{r_brace} with invariant Born-Green metric ds{sup 2} = -dt{sup 2} + 1/c{sup 2} dq{sup 2} + 1/b{sup 2} (dp{sup 2} = 1/c{sup 2} de{sup 2}) and the symplectic metric -de and dt + dp and dq are studied. This U 1,3) group of transformations contains the Lorentz group as the inertial special case and, in the limit of small forces and velocities, reduces to the expected Hamilton transformations leaving invariant the symplectic metric and the nonrelativistic line element ds{sup 2} -dt{sup 2}. The U(1,3) transformations bound relative velocities by c and relative forces by b. Spacetime is no longer an invariant subspace but is relative to noninertial observer frames. In the limit of b {yields} {infinity}, spacetime is invariant. Born was lead to the metric by a concept of reciprocity between position and momentum degrees of freedom and for this reason we call this reciprocal relativity. For large b, such effects will almost certainly only manifest in a quantum regime. Wigner showed that special relativistic quantum mechanics follows from the projective representations of the inhomogeneous Lorentz group. Projective representations of a Lie group are equivalent to the unitary representations of its central extension. The same method of projective representations for the inhomogeneous U(1,3) group is used to define the quantum theory in the noninertial case. The central extension of the inhomogeneous U(1,3) group is the cover of the quaplectic group Q(1,3) U(1,3) x{sub s} H(4), H(4) is the Weyl-Heisenberg group. The H(4) group, and the associated Heisenberg commutation relations central to quantum mechanics, results directly from requiring projective representations. A set of second-order wave equations result from the representations of the Casimir operators.

  11. Indirect Lightning Safety Assessment Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Ong, M M; Perkins, M P; Brown, C G; Crull, E W; Streit, R D

    2009-04-24

    Lightning is a safety hazard for high-explosives (HE) and their detonators. In the However, the current flowing from the strike point through the rebar of the building The methodology for estimating the risk from indirect lighting effects will be presented. It has two parts: a method to determine the likelihood of a detonation given a lightning strike, and an approach for estimating the likelihood of a strike. The results of these two parts produce an overall probability of a detonation. The probability calculations are complex for five reasons: (1) lightning strikes are stochastic and relatively rare, (2) the quality of the Faraday cage varies from one facility to the next, (3) RF coupling is inherently a complex subject, (4) performance data for abnormally stressed detonators is scarce, and (5) the arc plasma physics is not well understood. Therefore, a rigorous mathematical analysis would be too complex. Instead, our methodology takes a more practical approach combining rigorous mathematical calculations where possible with empirical data when necessary. Where there is uncertainty, we compensate with conservative approximations. The goal is to determine a conservative estimate of the odds of a detonation. In Section 2, the methodology will be explained. This report will discuss topics at a high-level. The reasons for selecting an approach will be justified. For those interested in technical details, references will be provided. In Section 3, a simple hypothetical example will be given to reinforce the concepts. While the methodology will touch on all the items shown in Figure 1, the focus of this report is the indirect effect, i.e., determining the odds of a detonation from given EM fields. Professor Martin Uman from the University of Florida has been characterizing and defining extreme lightning strikes. Using Professor Uman's research, Dr. Kimball Merewether at Sandia National Laboratory in Albuquerque calculated the EM fields inside a Faraday-cage type

  12. Characterizations of some bivariate models using reciprocal coordinate subtangents

    Directory of Open Access Journals (Sweden)

    Sreenarayanapurath Madhavan Sunoj

    2014-06-01

    Full Text Available In the present paper, we consider the bivariate version of reciprocal coordinate subtangent (RCST and study its usefulness in characterizing some important bivariate models.  In particular, characterization results are proved for a general bivariate model whose conditional distributions are proportional hazard rate models (see Navarro and Sarabia, 2011, Sarmanov family and Ali-Mikhail-Haq family of bivariate distributions.  We also study the relationship between local dependence function and reciprocal subtangent and a characterization result is proved for a bivariate model proposed by Jones (1998.  Further, the concept of reciprocal coordinate subtangent is extended to conditionally specified models.

  13. Physical Activity Lessons in Preschools

    Science.gov (United States)

    Obeng, Cecilia Sem

    2010-01-01

    A review of the current literature indicates that childhood obesity is on the rise. What is more disconcerting is that this epidemic has significantly affected the preschool-age population, with the percentage of overweight children increasing from 5.0% to 12.4%, as indicated by National Health and Nutrition Examination Survey (NHANES) surveys…

  14. Physical Activity Lessons in Preschools

    Science.gov (United States)

    Obeng, Cecilia Sem

    2010-01-01

    A review of the current literature indicates that childhood obesity is on the rise. What is more disconcerting is that this epidemic has significantly affected the preschool-age population, with the percentage of overweight children increasing from 5.0% to 12.4%, as indicated by National Health and Nutrition Examination Survey (NHANES) surveys…

  15. Preschool Integration: An Experimental Classroom.

    Science.gov (United States)

    Marshall, Linda; And Others

    1986-01-01

    The study compared four methods of increasing quantity and quality of play interactions between nonhandicapped and 11 moderately/severely handicapped children in an integrated preschool. Results of contingent reinforcement, reinforcement plus modeling, reinforcement plus behavior management, and reinforcement plus modeling plus behavior management…

  16. Inclusion in Malaysian Integrated Preschools

    Science.gov (United States)

    Sukumaran, Sailajah; Loveridge, Judith; Green, Vanessa A.

    2015-01-01

    Inclusive education has been introduced through a number of policy developments in Malaysia over the last 10 years but there is little research investigating the extent and nature of inclusive education for preschoolers with special educational needs (SEN). This study surveyed both regular and special education teachers in Malaysian integrated…

  17. Developing preschool children social aptitudes

    Directory of Open Access Journals (Sweden)

    Ana Teresa Brás

    2012-12-01

    Full Text Available The kindergarten teachers must be aware of the importance of the acquisition of social skills for children, with a view to appropriate adaptation and overcoming the various challenges that will have those throughout existence. This article is the presentation of a research work within the pre-school educational context, in the field of ʻSocial and Personal Educationʼ which may lead to improved social skills within the group of children. In order to accomplish this, after the teaching training with the pre-school class which focussed on the acquisition of social competence, an assessment of the modified social skills within the class was carried out. These activities were included in the preschool lesson planning during the ʻSupervised Teaching Practiceʼ. They were developed based on childrenʼs daily life situations, focussing mainly on using games in the learning contexts. The aim of these games was to motivate and involve the children in order to enhance their balanced social development. The results obtained suggest that the introduction of this type of learning activities may be an asset in Pre-school Education because they develop both childrenʼs social skills and social competence. Moreover, this type of learning activities may also lead to changes in childrenʼs social interaction with both adults and their peers which may favour pro social behaviour.

  18. Preschoolers' Quarantining of Fantasy Stories

    Science.gov (United States)

    Richert, Rebekah A.; Smith, Erin I.

    2011-01-01

    Preschool-aged children are exposed to fantasy stories with the expectation that they will learn messages in those stories that are applied to real-world situations. We examined children's transfer from fantastical and real stories. Over the course of 2 studies, 3 1/2- to 5 1/2-year-old children were less likely to transfer problem solutions from…

  19. Inclusion in Malaysian Integrated Preschools

    Science.gov (United States)

    Sukumaran, Sailajah; Loveridge, Judith; Green, Vanessa A.

    2015-01-01

    Inclusive education has been introduced through a number of policy developments in Malaysia over the last 10 years but there is little research investigating the extent and nature of inclusive education for preschoolers with special educational needs (SEN). This study surveyed both regular and special education teachers in Malaysian integrated…

  20. Why Preschoolers Need Physical Education

    Science.gov (United States)

    Pica, Rae

    2011-01-01

    NAEYC, the National Association for Sport and Physical Education, and the US Department of Health and Human Services all recommend that preschool programs offer physical education. There are many reasons why. First, young children form healthy habits early in life. Before entering elementary school they learn to brush their teeth, bathe…

  1. Controlling Relationships in Preschool Children

    Science.gov (United States)

    Munoz, Jose Manuel; Braza, Francisco; Carreras, Rosario

    2004-01-01

    In order to facilitate the comprehension of social structure in preschool children, our research has two foci: first, to define controlling behaviours (nonaggressive group organisation) and to determine their organisational principles, and second, to analyse the relation of the controlling behaviours with aggressive behaviours. Through direct…

  2. Evaluation of Praxis in Preschoolers.

    Science.gov (United States)

    Parham, L. Diane

    1987-01-01

    A rationale and procedures are presented for occupational therapy evaluation of the preschooler whose problems suggest dyspraxia. Two evaluative domains are examined: sensory processing (assessment of tactile, proprioceptive, vestibular, auditory and visual functions) and praxis (ideation, motor planning and execution). Procedures include…

  3. Mozart Effect in Preschool Children?

    Science.gov (United States)

    Hui, Ken

    2006-01-01

    In 1993, Rauscher et al. reported a temporary increase in spatial-temporal ability after listening to Mozart's music. This led to numerous replication and extension studies with mixed findings in the past decade. This study investigated the "Mozart effect" in preschool children. Forty-one boys and girls, aged three to five, attempted a series of…

  4. Mozart Effect in Preschool Children?

    Science.gov (United States)

    Hui, Ken

    2006-01-01

    In 1993, Rauscher et al. reported a temporary increase in spatial-temporal ability after listening to Mozart's music. This led to numerous replication and extension studies with mixed findings in the past decade. This study investigated the "Mozart effect" in preschool children. Forty-one boys and girls, aged three to five, attempted a series of…

  5. Reducing Poverty through Preschool Interventions

    Science.gov (United States)

    Duncan, Greg J.; Ludwig, Jens; Magnuson, Katherine A.

    2007-01-01

    Greg Duncan, Jens Ludwig, and Katherine Magnuson explain how providing high-quality care to disadvantaged preschool children can help reduce poverty. In early childhood, they note, children's cognitive and socioemotional skills develop rapidly and are sensitive to "inputs" from parents, home learning environments, child care settings, and the…

  6. Indirect discrimination and breast screening.

    Science.gov (United States)

    Botha, J L; Manku-Scott, T K; Moledina, F; Williams, A

    1993-01-01

    Uptake of screening services in inner-city communities has been low, particularly in older age groups, lower social classes, and ethnic minorities. In Leicester City, where up to 25% of the population belong to ethnic minorities, this may have important implications for breast screening. We randomly sampled 701 inner-city women aged 45 to 64 years, stratified by neighborhood and by women's "likely home language." Trained interviewers succeeded in interviewing 79% of those eligible, and we report here a preliminary analysis of 413 respondents. Knowledge of breast cancer and screening varied markedly and significantly by actual language: 60.4% of English-speaking and 12.5% of non-English-speaking women correctly answered 10 or more questions (of 14) about breast cancer and screening (chi 2(1) = 89.884; P = .000). Despite that, 80% or more women stated their intention to attend for screening and assessment if necessary, irrespective of neighborhood, language, age, or social class. We suggest that the difference in knowledge between language groups arose from indirect discrimination in the way in which health-related information is disseminated in British society. However, after providing appropriate screening information, we report similarly high intended acceptance rates in the two language groups.

  7. Stochastic evolutionary dynamics of direct reciprocity.

    Science.gov (United States)

    Imhof, Lorens A; Nowak, Martin A

    2010-02-01

    Evolutionary game theory is the study of frequency-dependent selection. The success of an individual depends on the frequencies of strategies that are used in the population. We propose a new model for studying evolutionary dynamics in games with a continuous strategy space. The population size is finite. All members of the population use the same strategy. A mutant strategy is chosen from some distribution over the strategy space. The fixation probability of the mutant strategy in the resident population is calculated. The new mutant takes over the population with this probability. In this case, the mutant becomes the new resident. Otherwise, the existing resident remains. Then, another mutant is generated. These dynamics lead to a stationary distribution over the entire strategy space. Our new approach generalizes classical adaptive dynamics in three ways: (i) the population size is finite; (ii) mutants can be drawn non-locally and (iii) the dynamics are stochastic. We explore reactive strategies in the repeated Prisoner's Dilemma. We perform 'knock-out experiments' to study how various strategies affect the evolution of cooperation. We find that 'tit-for-tat' is a weak catalyst for the emergence of cooperation, while 'always cooperate' is a strong catalyst for the emergence of defection. Our analysis leads to a new understanding of the optimal level of forgiveness that is needed for the evolution of cooperation under direct reciprocity.

  8. Improving reading comprehension through Reciprocal Teaching Method

    Directory of Open Access Journals (Sweden)

    Endang Komariah

    2015-10-01

    Full Text Available This study is aimed at discovering the benefits of the Reciprocal Teaching Method (RTM in the reading classroom, finding out the achievements of students after four comprehension training sessions of using RTM, and exploring the perceptions of students on the use of RTM. This method uses four comprehension strategies: predicting, questioning, clarifying, and summarizing, to help learners monitor their development of reading comprehension by themselves. Students work in groups of four or five and the members are divided into five roles which are the leader, predictor, clarifier, questioner, and summarizer. The subjects were 24 students from the twelfth grade at a high school in Banda Aceh. Observations, tests, documents and interviews were collected to get the data. The results showed that the students were more active and productive in the reading classroom after RTM sessions and their reading proficiency improved. They learnt how to apply several of the strategies from RTM while reading. The results also showed that they preferred this method for teaching-learning reading compared to the conventional one. Therefore, teachers are suggested to consider using this method for teaching reading that instils the students on how to apply the four comprehension strategies used in reading.

  9. Indirect Self-Destructiveness and Emotional Intelligence.

    Science.gov (United States)

    Tsirigotis, Konstantinos

    2016-06-01

    While emotional intelligence may have a favourable influence on the life and psychological and social functioning of the individual, indirect self-destructiveness exerts a rather negative influence. The aim of this study has been to explore possible relations between indirect self-destructiveness and emotional intelligence. A population of 260 individuals (130 females and 130 males) aged 20-30 (mean age of 24.5) was studied by using the Polish version of the chronic self-destructiveness scale and INTE, i.e., the Polish version of the assessing emotions scale. Indirect self-destructiveness has significant correlations with all variables of INTE (overall score, factor I, factor II), and these correlations are negative. The intensity of indirect self-destructiveness differentiates significantly the height of the emotional intelligence and vice versa: the height of the emotional intelligence differentiates significantly the intensity of indirect self-destructiveness. Indirect self-destructiveness has negative correlations with emotional intelligence as well as its components: the ability to recognize emotions and the ability to utilize emotions. The height of emotional intelligence differentiates the intensity of indirect self-destructiveness, and vice versa: the intensity of indirect self-destructiveness differentiates the height of emotional intelligence. It seems advisable to use emotional intelligence in the prophylactic and therapeutic work with persons with various types of disorders, especially with the syndrome of indirect self-destructiveness.

  10. An Examination of Parents' and Preschool Workers' Perspectives on Bullying in Preschool

    Science.gov (United States)

    Cameron, David Lansing; Kovac, Velibor Bobo

    2016-01-01

    Parents (n = 141) and preschool workers (n = 81) completed a survey regarding their perspectives towards: (a) the existence of bullying in preschool, (b) interpretations of bullying, (c) the roles of bullies and victims, and (d) gender differences. Findings suggest that both groups largely believe that bullying occurs in preschool. Excluding…

  11. The Effects of Los Angeles Universal Preschool on Quality Preschool Teacher Retention in Los Angeles County

    Science.gov (United States)

    Lopez Stevens, Holly Anne

    2010-01-01

    The purpose of this study was to determine if the implementation of Los Angeles Universal Preschool (LAUP) programs has a positive effect on the retention of quality preschool teachers in Los Angeles County. In prior work, preschool teacher retention is associated with wages, program structure, program process, professional development, and…

  12. Emotional Competence and Emotion Socialization in Preschoolers: The Viewpoint of Preschool Teachers

    Science.gov (United States)

    Kiliç, Sükran

    2015-01-01

    The aim of this research is to thoroughly investigate preschool teachers' opinions about emotional competence and emotion socialization. The study group was comprised of 20 preschool teachers working in preschools in the city-center of Aksaray. A semi-structured interview form prepared by the researcher was used as the data collection tool. Data…

  13. Assessing Preschool Children's Pretend Play: Preliminary Validation of the Affect in Play Scale-Preschool Version

    Science.gov (United States)

    Kaugars, Astrida Seja; Russ, Sandra W.

    2009-01-01

    Research Findings: A description of the development and preliminary validation of the Affect in Play Scale-Preschool version (APS-P) is presented by demonstrating associations among preschool children's play, creativity, and daily behavior using multiple methodologies. Thirty-three preschool-age children completed a standardized 5-minute play task…

  14. Preschool Teachers' Views on Competence in the Context of Home and Preschool Collaboration

    Science.gov (United States)

    Vuorinen, Tuula; Sandberg, Anette; Sheridan, Sonja; Williams, Pia

    2014-01-01

    The purpose of this article is to analyse and discuss preschool teachers' views regarding competence within their profession in the context of home and preschool collaboration. The question addressed is as follows: In what situations do preschool teachers perceive that their competence becomes visible for parents? The results, based on interviews…

  15. Reciprocity revisited: Give and take in Dutch and immigrant families

    NARCIS (Netherlands)

    A. Komter; J.M.D. Schans

    2008-01-01

    Classical theory suggests that "generalized reciprocity," giving without clear expectations of returns, is characteristic for exchange within the family. Modern theory assumes differences between Western, "individualistic" cultures, and non-Western, more "collectivistic" cultures, presumably leading

  16. Feasibility of Applying Controllable Lubrication Techniques to Reciprocating Machines

    DEFF Research Database (Denmark)

    Pulido, Edgar Estupinan

    modified hydrostatic lubrication. In this case, the hydrostatic lubrication is modified by injecting oil at controllable pressures, through orifices circumferentially located around the bearing surface. In order to study the performance of journal bearings of reciprocating machines, operating under...... conventional lubrication conditions, a mathematical model of a reciprocating mechanism connected to a rigid / flexible rotor via thin fluid films was developed. The mathematical model involves the use of multibody dynamics theory for the modelling of the reciprocating mechanism (rigid bodies), finite elements...... of the reciprocating engine, obtained with the help of multibody dynamics (rigid components) and finite elements method (flexible components), and the global system of equations is numerically solved. The analysis of the results was carried out with focus on the behaviour of the journal orbits, maximum fluid film...

  17. Reciprocal Rights and Responsibilities in Parent-Child Relations

    Science.gov (United States)

    Baumrind, Diana

    1978-01-01

    This article examines critically the case for protecting children's rights as against the case for protecting children's welfare. The principle of reciprocity in parent-child relations is rejected. (Author/AM)

  18. Reciprocal Rights and Responsibilities in Parent-Child Relations

    Science.gov (United States)

    Baumrind, Diana

    1978-01-01

    This article examines critically the case for protecting children's rights as against the case for protecting children's welfare. The principle of reciprocity in parent-child relations is rejected. (Author/AM)

  19. Reciprocity revisited: Give and take in Dutch and immigrant families

    NARCIS (Netherlands)

    Komter, A.; Schans, J.M.D.

    2008-01-01

    Classical theory suggests that "generalized reciprocity," giving without clear expectations of returns, is characteristic for exchange within the family. Modern theory assumes differences between Western, "individualistic" cultures, and non-Western, more "collectivistic" cultures, presumably leading

  20. Experienced teacher learning within the context of reciprocal peer coaching

    NARCIS (Netherlands)

    Zwart, R.C.; Wubbels, T.; Bergen, Th.C.M.; Bolhuis, S.

    2007-01-01

    A considerable amount of literature on peer coaching suggests that the professional development of teachers can be improved through experimentation, observation, reflection, the exchange of professional ideas, and shared problem-solving. Reciprocal peer coaching provides teachers with an opportunity

  1. Reciprocal relations for transmission coefficients - Theory and application

    Science.gov (United States)

    Qu, Jianmin; Achenbach, Jan D.; Roberts, Ronald A.

    1989-01-01

    The authors present a rigorous proof of certain intuitively plausible reciprocal relations for time harmonic plane-wave transmission and reflection at the interface between a fluid and an anisotropic elastic solid. Precise forms of the reciprocity relations for the transmission coefficients and for the transmitted energy fluxes are derived, based on the reciprocity theorem of elastodynamics. It is shown that the reciprocity relations can be used in conjunction with measured values of peak amplitudes for transmission through a slab of the solid (water-solid-water) to obtain the water-solid coefficients. Experiments were performed for a slab of a unidirectional fiber-reinforced composite. Good agreement of the experimentally measured transmission coefficients with theoretical values was obtained.

  2. Reciprocal link for a coupled Camassa–Holm type equation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nianhua, E-mail: linianh@hqu.edu.cn; Zhang, Jinshun; Wu, Lihua

    2016-04-08

    Highlights: • We construct a reciprocal transformation for a coupled Camassa–Holm type equation proposed by Geng and Xue. • The transformed coupled Camassa–Holm type system is a reduction of the first negative flow in a modified Drinfeld–Sokolov III hierarchy. • The Lax pair and bi-Hamiltonian structure behaviors of the coupled Camassa–Holm type equation under the reciprocal transformation are analyzed. - Abstract: A coupled Camassa–Holm type equation is linked to the first negative flow in a modified Drinfeld–Sokolov III hierarchy by a transformation of reciprocal type. Meanwhile the Lax pair and bi-Hamiltonian structure behaviors of this coupled Camassa–Holm type equation under the reciprocal transformation are analyzed.

  3. EFRC guidelines for vibrations in reciprocating compressor systems

    NARCIS (Netherlands)

    Eijk, A.

    2008-01-01

    One of the disadvantages of a reciprocating compressor is that it generates pulsations and vibrations, which, without limitation and proper attention during design, manufacturing, installation and operation, can lead to fatigue failures, inefficiency, capacity limitations and unsafe situations. To j

  4. 47 CFR 97.107 - Reciprocal operating authority.

    Science.gov (United States)

    2010-10-01

    ... the United States has a multilateral or bilateral agreement: (1) The terms of the agreement between... service is regulated by the FCC, provided there is in effect a multilateral or bilateral reciprocal...

  5. Chaotic hypothesis: Onsager reciprocity and fluctuation-dissipation theorem

    Energy Technology Data Exchange (ETDEWEB)

    Gallavotti, G. [Rutgers Univ., New Brunswick, NJ (United States)

    1996-09-01

    It is shown that the chaoticity hypothesis recently introduced in statistical mechanics, which is analogous to Ruelle`s principle for turbulence, implies the Onsager reciprocity and the fluctuation-dissipation theorem in various reversible models for coexisting transport phenomena.

  6. Chaotic hypothesis Onsager reciprocity and fluctuation-dissipation theorem

    CERN Document Server

    Gallavotti, G

    1996-01-01

    It is shown that the "chaoticity hypothesis", analogous to Ruelle's principle for turbulence and recently introduced in statistical mechanics, implies the Onsager reciprocity and the fluctuation dissipation theorem in various models for coexisting transport phenomena.

  7. The Diagnosis of Reciprocating Machinery by Bayesian Networks

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A Bayesian Network is a reasoning tool based on probability theory and has many advantages that other reasoning tools do not have. This paper discusses the basic theory of Bayesian networks and studies the problems in constructing Bayesian networks. The paper also constructs a Bayesian diagnosis network of a reciprocating compressor. The example helps us to draw a conclusion that Bayesian diagnosis networks can diagnose reciprocating machinery effectively.

  8. A New Robust Image Matching Method Based on Distance Reciprocal

    Institute of Scientific and Technical Information of China (English)

    赵春江; 施文康; 邓勇

    2004-01-01

    Object matching between two-dimensional images is an important problem in computer vision. The purpose of object matching is to decide the similarity between two objects. A new robust image matching method based on distance reciprocal was presented. The distance reciprocal is based on human visual perception. This method is simple and effective. Moreover, it is robust against noise. The experiments show that this method outperforms the Hausdorff distance, when the images with noise interfered need to be recognized.

  9. The general chain transform and self-reciprocal functions

    Directory of Open Access Journals (Sweden)

    Cyril Nasim

    1985-01-01

    Full Text Available A theory of a generalized form of the chain transforms of order n is developed, and various properties of these are established including the Parseval relation. Most known cases of the standard theory are derived as special cases. Also a theory of self-reciprocal functions is given, based on these general chain transforms; and relations among various classes of self-reciprocal functions are established.

  10. Breaking reciprocity in nanophotonics: optomechanical interactions (Conference Presentation)

    Science.gov (United States)

    Alù, Andrea

    2016-09-01

    Lorentz reciprocity refers to a fundamental symmetry relation that governs several physical systems. In this talk, we will discuss our recent theoretical, design, experimental, and commercialization efforts in the area of non-reciprocal photonics, using temporal modulation of metamaterial elements to realize isolation for guided waves in nanophotonic systems and radio-frequency circuits, and for propagating waves in free-space, as well as to break the symmetry between emission and absorption in optical and radio-frequency open systems.

  11. Reciprocal cooperation in avian mobbing: playing nice pays.

    Science.gov (United States)

    Wheatcroft, David J; Price, Trevor D

    2008-08-01

    Unrelated passerine birds often join together while mobbing, a widespread antipredator behavior during which birds harass a predator. Although previous analyses concluded that mobbing could not have evolved via reciprocity, Krams and colleagues' field experiments show that birds preferentially join mobs with neighbors that have aided them previously, suggesting that these birds utilize reciprocity-based strategies involving individual recognition and recollection of previous interactions with others. This implies a level of sophistication in bird communities greater than had previously been realized.

  12. Mechanical characteristics of counterfeit Reciproc instruments: a call for attention.

    Science.gov (United States)

    Rodrigues, C S; Vieira, V T L; Antunes, H S; De-Deus, G; Elias, C N; Moreira, E J L; Silva, E J N L

    2017-05-04

    To report the main differences seen by direct visual inspection between original and counterfeit Reciproc instruments, together with an evaluation of instrument bending resistance, cyclic fatigue, surface finish, Vickers microhardness and chemical composition. The visual aspects of original Reciproc R25 (VDW, Munich, Germany) and counterfeit Reciproc R25 instruments (claimed to be original, supposedly with dimensions similar to those of Reciproc R25 files, bought at www.mercadolivre.com.br) were evaluated under direct observation, stereomicroscopy and scanning electron microscope. The flexibility of original and counterfeit Reciproc R25 was determined via 45° bending tests according to the ISO 3630-1 specification. Instruments were also subjected to cyclic fatigue resistance, measuring the time to fracture in an artificial stainless steel canal with a 60° angle and 5-mm radius of curvature. The fracture surfaces of all fragments were examined under a scanning electron microscope. Roughness of the instruments was quantified using a profilometer, and the microhardness test was carried out using a Vickers hardness tester. Energy-dispersive X-ray microanalysis (EDX) was also carried out. Results were analysed statistically using the Student's t-test at a significance level of P differences were observed such as ISO colour coding, measurement marks, stopper and morphologic characteristics. Original Reciproc instruments had significantly longer cyclic fatigue life and significantly lower bending resistance than counterfeit Reciproc instruments (P differences in the chemical composition of the instruments (P different raw material. Original Reciproc files outperformed counterfeit instruments in all tests. It is thus important that identification strategies for these counterfeit instruments be developed, thereby preventing their inadvertent use. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  13. Competition or collaboration? The reciprocity effect in loan syndication

    OpenAIRE

    Jian Cai

    2009-01-01

    It is well recognized that loan syndication generates a moral hazard problem by diluting the lead arranger's incentive to monitor the borrower. This paper proposes and tests a novel view that reciprocal arrangements among lead arrangers serve as an effective mechanism to mitigate this agency problem. Lender arrangements in about seven out of ten syndicated loans are reciprocal in the sense that lead arrangers also participate in loans that are led by their participant lenders. I develop a mod...

  14. Critical Breakdown of Discourse Categories in Relation to (Preschool Teacher’s Oral Performance

    Directory of Open Access Journals (Sweden)

    Petek Tomaž

    2013-11-01

    Full Text Available The discussion presents an attempt of a critical breakdown of discourse categories in relation to the (preschool teacher’s oral performance in class and during activities related to school or kindergarten. We established that during the educational process, (preschool teachers find themselves in different situations and circumstances of oral performances. Since they use discourses in their communication rather than individual sentences or even words, they must, among other things, be familiar with the characteristics of different discourse categories in order to be efficient. When researching the discourse categories we have, in compliance with different scientific definitions, somewhat modified the Toporišič Žagar classification in accordance with communication methods and functional varieties and limited ourselves to the discourse categories that are directly or indirectly related to a (preschool teacher’s oral performance in class. During the discussion, we focused on whether the (preschool teacher already starts his or her oral performance when entering the classroom and whether at least a part of class is an oral performance.

  15. Coordination in orientation games of preschool children

    OpenAIRE

    Kastelic, Erika

    2013-01-01

    In the thesis we studied how orientation games have effect on preschool children whilst growing up. Even though the games in available litterature are meant for school children some authors stress that the games are appropriate for preschool children though you do have to have be careful when implementing them for preschoolers. Orientation games in their original form improve orientation, endurance and encourage competition. With participation we can improve all motor functions but for presch...

  16. A theoretical framework for analysing preschool teaching

    DEFF Research Database (Denmark)

    Chaiklin, Seth

    2014-01-01

    This article introduces a theoretical framework for analysing preschool teaching as a historically-grounded societal practice. The aim is to present a unified framework that can be used to analyse and compare both historical and contemporary examples of preschool teaching practice within and across...... national traditions. The framework has two main components, an analysis of preschool teaching as a practice, formed in relation to societal needs, and an analysis of the categorical relations which necessarily must be addressed in preschool teaching activity. The framework is introduced and illustrated...

  17. Analytical Assessment of the Reciprocating Feed System

    Science.gov (United States)

    Eddleman, David E.; Blackmon, James B.; Morton, Christopher D.

    2006-01-01

    A preliminary analysis tool has been created in Microsoft Excel to determine deliverable payload mass, total system mass, and performance of spacecraft systems using various types of propellant feed systems. These mass estimates are conducted by inserting into the user interface the basic mission parameters (e.g., thrust, burn time, specific impulse, mixture ratio, etc.), system architecture (e.g., propulsion system type and characteristics, propellants, pressurization system type, etc.), and design properties (e.g., material properties, safety factors, etc.). Different propellant feed and pressurization systems are available for comparison in the program. This gives the user the ability to compare conventional pressure fed, reciprocating feed system (RFS), autogenous pressurization thrust augmentation (APTA RFS), and turbopump systems with the deliverable payload, inert mass, and total system mass being the primary comparison metrics. Analyses of several types of missions and spacecraft were conducted and it was found that the RFS offers a performance improvement, especially in terms of delivered payload, over conventional pressure fed systems. Furthermore, it is competitive with a turbopump system at low to moderate chamber pressures, up to approximately 1,500 psi. Various example cases estimating the system mass and deliverable payload of several types of spacecraft are presented that illustrate the potential system performance advantages of the RFS. In addition, a reliability assessment of the RFS was conducted, comparing it to simplified conventional pressure fed and turbopump systems, based on MIL-STD 756B; these results showed that the RFS offers higher reliability, and thus substantially longer periods between system refurbishment, than turbopump systems, and is competitive with conventional pressure fed systems. This is primarily the result of the intrinsic RFS fail-operational capability with three run tanks, since the system can operate with just two run

  18. Indirect calorimetry during incubation of hatching eggs

    NARCIS (Netherlands)

    Brand, van den H.; Heetkamp, M.J.W.; Kemp, B.

    2015-01-01

    Indirect calorimetry can be used during incubation of avian eggs to monitor the quality of the incubation process, the development of the embryo and the utilization of nutrients. Indirect calorimetry has several benefits above direct calorimetry, particularly in hatching eggs. However, to obtain rel

  19. The Indirectness of Young Goodman Brown

    Institute of Scientific and Technical Information of China (English)

    袁臣

    2010-01-01

    Young Goodman Brown is one the best short fictions written by Nathaniel Hawthorne in 1835. The indirectness of the Young Goodman Brown can be seen from the produce, narration and the characteristics of the short fiction. The indirectness of expression or description leaves enough space for readers to understand the theme of the short fiction by themselves.

  20. Factors of Politeness and Indirect Speech Acts

    Institute of Scientific and Technical Information of China (English)

    杨雪梅

    2016-01-01

    Polite principle is influenced deeply by a nation's history,culture,custom and so on,therefor different countries have different understandings and expressions of politeness and indirect speech acts.This paper shows some main factors influencing a polite speech.Through this article,readers can comprehensively know about politeness and indirect speech acts.

  1. JUSTIFICATION FOR INDIRECT DISCRIMINATION IN EU

    OpenAIRE

    Catalina-Adriana IVANUS

    2014-01-01

    The right to non-discrimination is very important for a civilized society. EU legislation establishes direct and indirect discrimination, harassment, sexual harassment, instruction to discriminate and any less favourable treatment of a woman related to pregnancy or maternity leave as forms of discrimination. The law and the Court of Justice permit the justification of indirect discrimination.

  2. Indirect techniques in nuclear astrophysics: a review.

    Science.gov (United States)

    Tribble, R E; Bertulani, C A; Cognata, M La; Mukhamedzhanov, A M; Spitaleri, C

    2014-10-01

    In this review, we discuss the present status of three indirect techniques that are used to determine reaction rates for stellar burning processes, asymptotic normalization coefficients, the Trojan Horse method and Coulomb dissociation. A comprehensive review of the theory behind each of these techniques is presented. This is followed by an overview of the experiments that have been carried out using these indirect approaches.

  3. 48 CFR 31.203 - Indirect costs.

    Science.gov (United States)

    2010-10-01

    ... contract or other work, indirect costs are those remaining to be allocated to intermediate or two or more... basis of the benefits accruing to intermediate and final cost objectives. When substantially the same... for allocating indirect costs is the cost accounting period during which such costs are incurred...

  4. Comparison of direct and indirect radionuclide cystography

    Energy Technology Data Exchange (ETDEWEB)

    Bower, G.; Lovegrove, F.T.; Geijsel, H.; Van der Schaff, A.; Guelfi, G.

    1985-05-01

    Thirty children were studied using both direct (catheter) and indirect techniques of radionuclide cystography. Of 54 ureters able to be compared, six showed vesicoureteric reflux (VUR) on the direct study but were read as negative on the indirect cystogram, and five showed no reflux on the direct cystogram but were read as positive for VUR on the indirect study. Regarding ureters read as true positives on indirect study, if that ureter has ever shown reflux at any time, or if it drained a scarred kidney specificity was improved to 97% without changing the sensitivity. Concerns about the validity of indirect cystogram results and the ease of assessment and low radiation dose from the direct cystogram has made direct cystography our preferred technique.

  5. Photovoltaic efficiency of an indirect bandgap material

    Science.gov (United States)

    Tomasik, Michelle; Mangan, Niall; Grossman, Jeffrey

    2015-03-01

    Photovoltaic materials with direct band gap transitions absorb light more readily than those with indirect gaps, allowing for thinner devices. However, direct bands also suffer faster rates of radiative recombination than indirect bandgap materials. Some novel photovoltaic absorber materials, such as tin sulfide, have both direct and indirect gaps. Such materials raise the question of whether the multiple energy states benefit or harm device efficiency. We develop a model for current in a device with direct and indirect band gaps using detailed balance, similar to the Shockley-Quiesser model for direct band photovoltaics. We explore the effects of the following on device performance: transition probability of carriers between the direct and indirect state, and relative transport rate in each band.

  6. Food additives and preschool children.

    Science.gov (United States)

    Martyn, Danika M; McNulty, Breige A; Nugent, Anne P; Gibney, Michael J

    2013-02-01

    Food additives have been used throughout history to perform specific functions in foods. A comprehensive framework of legislation is in place within Europe to control the use of additives in the food supply and ensure they pose no risk to human health. Further to this, exposure assessments are regularly carried out to monitor population intakes and verify that intakes are not above acceptable levels (acceptable daily intakes). Young children may have a higher dietary exposure to chemicals than adults due to a combination of rapid growth rates and distinct food intake patterns. For this reason, exposure assessments are particularly important in this age group. The paper will review the use of additives and exposure assessment methods and examine factors that affect dietary exposure by young children. One of the most widely investigated unfavourable health effects associated with food additive intake in preschool-aged children are suggested adverse behavioural effects. Research that has examined this relationship has reported a variety of responses, with many noting an increase in hyperactivity as reported by parents but not when assessed using objective examiners. This review has examined the experimental approaches used in such studies and suggests that efforts are needed to standardise objective methods of measuring behaviour in preschool children. Further to this, a more holistic approach to examining food additive intakes by preschool children is advisable, where overall exposure is considered rather than focusing solely on behavioural effects and possibly examining intakes of food additives other than food colours.

  7. 45 CFR 605.38 - Preschool and adult education.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Preschool and adult education. 605.38 Section 605... Preschool, Elementary, and Secondary Education § 605.38 Preschool and adult education. A recipient to which this subpart applies that provides preschool education or day care or adult education may not, on the...

  8. Expression of future prospective in indirect speech

    Directory of Open Access Journals (Sweden)

    Bodnaruk Elena Vladimirovna

    2015-03-01

    Full Text Available The article analyzes the characteristics and use of grammatical semantics and lexical and grammatical means used to create future prospects in double indirect discourse. The material for the study were epic works by contemporary German writers. In the analysis of the empirical material it has been pointed out that indirect discourse has preterial basis and is the kind of most frequent inner speech of characters. The most widely used form with future semantics in preterial indirect speech is conditional I, formally having a conjunctive basis, but is mostly used with the indicative semantics. Competitive to conditional I in indirect speech is preterial indicative. A characteristic feature of the indirect speech is the use of modal verbs, which, thanks to its semantics is usually referred as an action at a later term, creating the prospect of future statements. The most frequent were modal verbs wollen and sollen in the form of the preterite, more rare verbs were m ssen and k nnen. German indirect speech distinguishes the ability to use forms on the basis of conjunctive: preterite and plusquamperfect of conjunctive. Both forms express values similar to those of the indicative. However, conjunctive forms the basis of the data shown in a slightly more pronounced seme of uncertainty that accompanies future uses of these forms in indirect speech. In addition, plusquamperfect conjunctive differs from others by the presence of the seme of completeness.

  9. Assessing the Development of Preschoolers' Mathematical Patterning

    Science.gov (United States)

    Mitchelmore, Michael C.; Papic, Marina M.; Mulligan, Joanne T.

    2011-01-01

    The development of patterning strategies during the year prior to formal schooling was studied in 53 children from 2 similar preschools. One preschool implemented a 6-month intervention focusing on repeating and spatial patterns. Children from the intervention group demonstrated greater understanding of unit of repeat and spatial structuring, and…

  10. PPT: The Preschool Preparation and Transition Project.

    Science.gov (United States)

    Noonan, Mary Jo; Ratokalau, Nancy B.

    1992-01-01

    The University of Hawaii Department of Special Education conducted the Preschool Preparation and Transition Project, a federally funded demonstration program, to support families and their children with special needs in the transition from infant programs to least restrictive preschool placements. The program addressed this goal through three…

  11. Documentation and Communication in Swedish Preschools

    Science.gov (United States)

    Emilson, Anette; Pramling Samuelsson, Ingrid

    2014-01-01

    The aim of this study is to investigate communication between preschool teachers and children in documentation situations. The focus is also on what preschool teachers actually document. The research questions are: What characterizes the communication between teachers and children when these teachers are documenting at the same time? What is the…

  12. Grapheme-Phoneme Acquisition of Deaf Preschoolers

    Science.gov (United States)

    Beal-Alvarez, Jennifer S.; Lederberg, Amy R.; Easterbrooks, Susan R.

    2012-01-01

    We examined acquisition of grapheme-phoneme correspondences by 4 deaf and hard-of-hearing preschoolers using instruction from a curriculum designed specifically for this population supplemented by Visual Phonics. Learning was documented through a multiple baseline across content design as well as descriptive analyses. Preschoolers who used sign…

  13. Preschool Teachers' Constructions of Early Reading

    Science.gov (United States)

    Walker, Karen E.

    2015-01-01

    Research concerning preschool teachers' constructions of early reading has potential to influence teachers' curricular decisions and classroom practice. Six preschool teachers in North Texas were interviewed in regard to what they think about early reading and how they develop these understandings or constructions. The systematic, inductive…

  14. Phonological Production in Spanish-Speaking Preschoolers.

    Science.gov (United States)

    Goldstein, Brian A.; Iglesias, Aquiles

    Approximately 10 percent of Latino preschoolers are at risk for developing communication problems unrelated to second language acquisition. Many of these children are Spanish-speaking and have difficulties in producing speech sounds in their native language. One of the services afforded Latino preschoolers by speech-language pathologists is the…

  15. Documentation and Communication in Swedish Preschools

    Science.gov (United States)

    Emilson, Anette; Pramling Samuelsson, Ingrid

    2014-01-01

    The aim of this study is to investigate communication between preschool teachers and children in documentation situations. The focus is also on what preschool teachers actually document. The research questions are: What characterizes the communication between teachers and children when these teachers are documenting at the same time? What is the…

  16. Managing Challenging Behaviors in Preschool Settings

    Science.gov (United States)

    Mitchell, Bridgitt Lenore

    2014-01-01

    Despite state mandated early childhood education (ECE) teacher competencies, many children are removed from preschool settings for behaviors related to socioemotional problems. This study's rationale was the propensity of expulsions among children exhibiting challenging behaviors in preschool programs. Guided by Bronfenbrenner's ecological model…

  17. Creative Inspiration for Preschoolers from Museums

    Science.gov (United States)

    Rönkkö, Marja-Leena; Aerila, Juli-Anna; Grönman, Satu

    2016-01-01

    This research explores the learning outcomes of preschool children produced through visits to an historic house museum environment. The new Finnish preschool curriculum identifies the importance of arts-based approaches for children and that these approaches should be closely aligned to experiential and holistic education. The aim of the research…

  18. Direct and indirect laryngoscopy: equipment and techniques.

    Science.gov (United States)

    Collins, Stephen R

    2014-06-01

    Visualization of the larynx by direct or indirect means is referred to as laryngoscopy and is the principal aim during airway management for passage of a tracheal tube. This paper presents a brief background regarding the development and practice of laryngoscopy and examines the equipment and techniques for both direct and indirect methods. Patient evaluation during the airway examination is discussed, as are predictors for difficult intubation. Laryngoscope blade design, newer intubating techniques, and a variety of indirect laryngoscopic technologies are reviewed, as is the learning curve for these techniques and devices.

  19. Indirect Kalman Filter in Mobile Robot Application

    Directory of Open Access Journals (Sweden)

    Surachai Panich

    2010-01-01

    Full Text Available Problem statement: The most successful applications of Kalman filtering are to linearize about some nominal trajectory in state space that does not depend on the measurement data. The resulting filter is usually referred to as simply a linearized Kalman filter. Approach: This study introduced mainly indirect Kalman filter to estimate robot’s position. A developed differential encoder system integrated accelerometer is experimental tested in square shape. Results: Experimental results confirmed that indirect Kalman filter improves the accuracy and confidence of position estimation. Conclusion: In summary, we concluded that indirect Kalman filter has good potential to reduce error of measurement data.

  20. Indirect estimators in US federal programs

    CERN Document Server

    1996-01-01

    In 1991, a subcommittee of the Federal Committee on Statistical Methodology met to document the use of indirect estimators - that is, estimators which use data drawn from a domain or time different from the domain or time for which an estimate is required. This volume comprises the eight reports which describe the use of indirect estimators and they are based on case studies from a variety of federal programs. As a result, many researchers will find this book provides a valuable survey of how indirect estimators are used in practice and which addresses some of the pitfalls of these methods.

  1. Physical Education at Preschools: The Meaning of "Physical Education" to Practitioners at Three Preschool Settings in Scotland

    Science.gov (United States)

    McEvilly, Nollaig; Verheul, Martine; Atencio, Matthew

    2015-01-01

    Background: Preschool physical education has been largely unexplored by researchers. This article examines the meaning of the term "physical education", in relation to preschool contexts, to 14 practitioners working at three preschool settings in Scotland. Our focus on preschool physical education reflects a change in the language…

  2. Comments on scaling effect of reciprocity in BRDF study

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hongrui; WANG Jindi

    2004-01-01

    Reciprocity principle is a common theory in electromagnetics and optics. It is also one of the general principles of the radiation transformation theory. However, in many remote sensing studies, this principle cannot be always supported by experimental data, especially when the scaling effect of the remote sensing image pixel is considered. The debate over the issue of whether the reciprocity principle can be used as a fundamental standard in evaluating the effectiveness of remote sensing observations has lasted for years. Using geometrical optics model, Li and Wan proved the existence of the scaling effect in applying the reciprocity principle to a remote sensing image pixel in 1998. In 2002, Snyder challenged Li's proof, and attempted to prove that reciprocity principle is universally valid without any scale limitation. In this paper, we will argue with Snyder's theory and point out that Snyder's theory had neglected an important condition used in Li's proof and, as a result, drawn the wrong conclusion. Here we will restate Li's condition in his demonstration and offer a further proof to verify that reciprocity principle cannot be applied unconditionally to the study of bi-directional reflectance distribution function (BRDF) of land surfaces in field or satellite remote sensing observation scale.

  3. EEG Asymmetry and ERN: Behavioral Outcomes in Preschoolers

    Science.gov (United States)

    Begnoche, J. Patrick; Brooker, Rebecca J.; Vess, Matthew

    2016-01-01

    Research has documented reciprocal influences between approach-related and inhibition-related neural activity in adults. However, associations between neural systems of approach and inhibition have not been tested in children. It is thus unclear whether these links are present early in life and whether associations between neural systems of approach and inhibition have long-term behavioral consequences. To address these gaps in the literature, we used electroencephalography (EEG) to examine associations between approach-related neural activity (i.e., hemispheric asymmetry) and inhibition-related neural activity (i.e., error-related negativity [ERN]) in preschool-aged children. Furthermore, we explored whether interactions between asymmetry and ERN predicted social inhibition, a precursor to anxiety problems, or symptoms of Attention Deficit Hyperactivity Disorder (ADHD) six months later. Similar to research on adults, greater left asymmetry (i.e., greater approach-related neural activity) was correlated with reduced ERN amplitude (i.e., weaker inhibition-related neural activity). The interactive effect of asymmetry and ERN amplitude did not predict ADHD symptoms, but did predict social inhibition. When ERN was greater, less left asymmetry was associated with higher levels of social inhibition. Results were most prominent at parietal EEG sites. Implications for understanding the development of the overlap in neural systems of approach and inhibition are discussed. PMID:27223612

  4. Physical Activity and Health in Preschool Children

    DEFF Research Database (Denmark)

    Christensen, Line Brinch

    Physical activity is beneficial in relation to several life style diseases and the association between physical activity and early predictors of life style diseases seem to be present already in preschool age. Since physical activity and other health behaviours are established during childhood...... and track from childhood into adult life, it is relevant to address physical activity already in the preschool age. The research in preschool children’s physical activity is relatively new, and because of methodological inconsistencies, the associations between physical activity and health are less clear...... in this age group. The objective of this thesis was to contribute to the knowledge base regarding physical activity in preschoolers; How active are preschoolers? Are activity levels related to specific settings during a typical week? And are the activity levels related to a range of health outcomes...

  5. Informing The Society About Preschool And Preprimary Education – Education Policy Implementation In Lithuania

    Directory of Open Access Journals (Sweden)

    Ausra Kazlauskiene

    2012-04-01

    Full Text Available Modern society also distinguishes itself by a large information flow that has to be selected according to one’s needs.  A considerable number of researches proved that the spread of information about education is insufficiently efficient, so far the society is too little informed, and there is a lack of information about provided preschool and preprimary education services, in rural areas in particular. Therefore, parents, teachers and other groups of the society, which are either directly or indirectly related to preschool education, cannot use the opportunities provided by this link of education if they are not informed. For this reason it is important to analyse main documents on education of theRepublicofLithuania, to investigate the situation of informing the society about preschool and preprimary education in education policy implementation. The article is based on the content analysis, which generalizes the documents on education policy that regulate informing of the society about preschool and preprimary education inLithuania.The analysis of the documents on education of the Republic of Lithuania demonstrated that, informing about preschool and preprimary education, focal attention is paid to the target groups that directly participate in  the child’s education processes – parents/foster parents and the staff of the education system. Only the context enables us to presume what information is forwarded to other groups of the society that indirectly participate in children’s education processes. Such situation may be influenced by the approach consolidated in the documents on education of theRepublicofLithuaniaabout preschool education as an intermediate, transitional link between the family and the school; it is sought “to prove parents and the society the efficiency and necessity of qualified children’s education”. It is likely that the lack of systematic attitude towards informing various societal groups as potential

  6. Nutritional practices in full-day-care pre-schools.

    LENUS (Irish Health Repository)

    Jennings, A

    2011-06-01

    Full-day-care pre-schools contribute significantly to the nutritional intake and acquisition of dietary habits of the pre-school child. The present study investigated nutritional practices in full-day-care pre-schools in Dublin, Ireland, aiming to determine the nutritional support that pre-school managers deem necessary, thereby facilitating the amelioration of existing pre-school nutritional training and practices.

  7. Investigation on the Reciprocity Principle with In-Situ Pumping Test in Confined Aquifer

    Science.gov (United States)

    Chen, Yong-Lin; Lin, Hong-Ru; Huang, Shao-Yang; Yeh, Tian-Chyi J.; Wen, Jet-Chau

    2016-04-01

    In this study, the pumping test of reciprocity between wells is developed for 11 wells located on campus of NYUST. The reciprocity analysis is conducted with the heterogeneous hydraulic properties distributions of the site. The mathematical theory of reciprocity implies that choose one as stimulation point and the other as observed response point in two known points at the same random field. Repeat the above action, the response behavior should have the reciprocity between the two points. However, the lack of literature with the field experiment to prove that reciprocity principle. Therefore, this study is expected to investigate the reciprocity of drawdown with the pumping test which will have heterogeneous hydraulic properties distributions obtained by inverse process. In general, there are two ways to investigate the reciprocity of pumping tests of two wells. One way is to evaluate the drawdown reciprocity of two sequential wells. From the evaluation the reciprocity of the drawdown behavior during the sequential pumping wells, the reciprocity of the drawdown behavior is investigated. The other one is to estimate cross-correlation between the drawdown behavior of the sequential pumping wells and heterogeneous hydraulic properties distributions. The reciprocity of between the drawdown and the heterogeneous hydraulic properties distributions is therefore can be investigated. This study proved the reciprocity of drawdown with the sequential pumping test and heterogeneous hydraulic properties distributions obtained by inverse method. Meanwhile, we proved the reciprocity is existed during the pumping test in the confined aquifer. Keywords: Reciprocity, Cross-correlation, Confined aquifer, Stimulation, Response

  8. Outcome indicators for direct and indirect caregiving.

    Science.gov (United States)

    Schoenfelder, D P; Swanson, E A; Specht, J K; Maas, M; Johnson, M

    2000-02-01

    Informal caregiving and outcomes for caregiving are an important part of health care and of particular importance in nursing. The purpose of this research is to report the results of a survey mailed to nursing experts for validation of the outcome labels Caregiver Role Performance: Direct Care and Caregiver Role Performance: Indirect Care and their accompanying indicators. Experts were asked to rate how important the identified indicators were for assessing those two outcomes. In addition, the respondents were asked to what extent nursing interventions influence the achievement of each identified indicator for Caregiver Role Performance: Direct Care and Caregiver Role Performance: Indirect Care. In general, the validity of the concept analysis work by the caregiver focus group was supported. Ten indicators for Caregiver Performance: Direct Care were retained, 1 was dropped that was considered most appropriate for indirect care, and 3 new indicators were added to reflect the nurse experts surveyed. For Caregiver Performance: Indirect Care, all of the indicators were retained.

  9. Indirect composite resin materials for posterior applications.

    Science.gov (United States)

    Shellard, E; Duke, E S

    1999-12-01

    Indirect composite resin restorations were introduced a number of years ago as possible alternatives to traditional metallic or ceramic-based indirect restorations. However, the earlier formulations did not provide evidence of improvement in mechanical and physical properties over chairside-placed direct composite resin materials. Because they required more tooth structure removal than direct restorations, their use became unpopular and was abandoned by most clinicians. Over the past few years, a new class of composite resin indirect materials has surfaced in the profession. Various technologies have been suggested as reinforcement mechanisms. Fibers, matrix modifications, and an assortment of innovations have been proposed for enhancing indirect composite resin restorations. Applications are from inlay restorations all the way to multi-unit fixed prostheses. This manuscript summarizes some of the progress made in this area. When available, data is presented to provide clinicians with guidelines and indications for the use of these materials.

  10. Indirect self-destructiveness in homosexual individuals

    Directory of Open Access Journals (Sweden)

    Konstantinos - Tsirigotis

    2015-06-01

    The research results indicate that, as compared with the group of heterosexual individuals, in the group of homosexuals there occurs a worsening in psychological functioning, which may be also manifested by an increased indirect self-destructiveness index. The increased intensity of indirect self-destructiveness in homosexual individuals may be considered a manifestation of worsened psychological functioning. The homosexual individuals look after their health similarly to heterosexuals.

  11. Reciprocal Feedback: Closing the Loop on Postactivity Surveys.

    Science.gov (United States)

    Watson, Richard A

    2015-01-01

    Those who conduct feedback surveys, which follow almost every CME presentation and medical-school lecture, would do well to offer participants' reciprocal feedback. That is, the course director should provide each survey respondent, on request, a brief summary of the comments received from this survey and the extent to which the recommendations will lead to objective improvements in the future. Surveyors who provide respondents with reciprocal feedback can expect heightened credibility, more reliable feedback in the future, and an added incentive to effect significant change for the better. Feedback has not circled all the way back until we have provided a succinct summary of results to those who have offered us their comments and suggestions. Let us close the loop; let reciprocal feedback become the last word in CME surveys.

  12. Repeated games and direct reciprocity under active linking.

    Science.gov (United States)

    Pacheco, Jorge M; Traulsen, Arne; Ohtsuki, Hisashi; Nowak, Martin A

    2008-02-21

    Direct reciprocity relies on repeated encounters between the same two individuals. Here we examine the evolution of cooperation under direct reciprocity in dynamically structured populations. Individuals occupy the vertices of a graph, undergoing repeated interactions with their partners via the edges of the graph. Unlike the traditional approach to evolutionary game theory, where individuals meet at random and have no control over the frequency or duration of interactions, we consider a model in which individuals differ in the rate at which they seek new interactions. Moreover, once a link between two individuals has formed, the productivity of this link is evaluated. Links can be broken off at different rates. Whenever the active dynamics of links is sufficiently fast, population structure leads to a simple transformation of the payoff matrix, effectively changing the game under consideration, and hence paving the way for reciprocators to dominate defectors. We derive analytical conditions for evolutionary stability.

  13. Lightweight Interactions for Reciprocal Cooperation in a Social Network Game

    CERN Document Server

    Takano, Masanori; Fukuda, Ichiro

    2016-01-01

    The construction of reciprocal relationships requires cooperative interactions during the initial meetings. However, cooperative behavior with strangers is risky because the strangers may be exploiters. In this study, we show that people increase the likelihood of cooperativeness of strangers by using lightweight non-risky interactions in risky situations based on the analysis of a social network game (SNG). They can construct reciprocal relationships in this manner. The interactions involve low-cost signaling because they are not generated at any cost to the senders and recipients. Theoretical studies show that low-cost signals are not guaranteed to be reliable because the low-cost signals from senders can lie at any time. However, people used low-cost signals to construct reciprocal relationships in an SNG, which suggests the existence of mechanisms for generating reliable, low-cost signals in human evolution.

  14. The quadratic reciprocity law a collection of classical proofs

    CERN Document Server

    Baumgart, Oswald

    2015-01-01

    This book is the English translation of Baumgart’s thesis on the early proofs of the quadratic reciprocity law (“Über das quadratische Reciprocitätsgesetz. Eine vergleichende Darstellung der Beweise”), first published in 1885. It is divided into two parts. The first part presents a very brief history of the development of number theory up to Legendre, as well as detailed descriptions of several early proofs of the quadratic reciprocity law. The second part highlights Baumgart’s comparisons of the principles behind these proofs. A current list of all known proofs of the quadratic reciprocity law, with complete references, is provided in the appendix. This book will appeal to all readers interested in elementary number theory and the history of number theory.

  15. Reciprocating Joule-cycle engine for domestic CHP systems

    Energy Technology Data Exchange (ETDEWEB)

    Moss, R.W.; Roskilly, A.P.; Nanda, S.K. [University of Newcastle upon Tyne (United Kingdom). School of Marine Science and Technology

    2005-02-01

    The reciprocating Joule-cycle engine operates on a recuperated gas-turbine cycle and is intended to provide high thermal efficiency in small sizes (1-10 kW). It is designed to achieve a higher efficiency than a comparable gas-turbine by using a reciprocating compressor and expander to provide very high compression and expansion efficiencies. Possible power plants for small combined heat-and-power systems currently include Stirling engines, internal-combustion engines, gas-turbines and fuel cells. The reciprocating Joule-cycle engine appears to have considerable advantages compared with other prime movers in terms of efficiency, emissions and multi-fuel capability. The present study estimates the performance of such an engine and is the first stage in a larger project that will in due course produce a demonstration engine. (author)

  16. The evolution of generalized reciprocity in social interaction networks.

    Science.gov (United States)

    Voelkl, Bernhard

    2015-09-01

    Generalized reciprocity has been proposed as a mechanism for enabling continued cooperation between unrelated individuals. It can be described by the simple rule "help somebody if you received help from someone", and as it does not require individual recognition, complex cognition or extended memory capacities, it has the potential to explain cooperation in a large number of organisms. In a panmictic population this mechanism is vulnerable to defection by individuals who readily accept help but do not help themselves. Here, I investigate to what extent the limitation of social interactions to a social neighborhood can lead to conditions that favor generalized reciprocity in the absence of population structuring. It can be shown that cooperation is likely to evolve if one assumes certain sparse interaction graphs, if strategies are discrete, and if spontaneous helping and reciprocating are independently inherited.

  17. Reciprocal relations for effective conductivities of anisotropic media

    Science.gov (United States)

    Nevard, John; Keller, Joseph B.

    1985-11-01

    Any pair of two-dimensional anisotropic media with local conductivity tensors that are functions of position and that are related to one another in a certain reciprocal way are considered. It is proved that their effective conductivity tensors are related to each other in the same way for both spatially periodic media and statistically stationary random media. An inequality involving the effective conductivity tensors of two three-dimensional media that are reciprocally related is also proved. These results extend the corresponding results for locally isotropic media obtained by Keller, Mendelsohn, Hansen, Schulgasser, and Kohler and Papanicolau. They also yield a relation satisfied by the effective conductivity tensor of a medium reciprocal to a translated or rotated copy of itself.

  18. Performance Comparison of Capacity Control Methods for Reciprocating Compressors

    Science.gov (United States)

    Wang, L.; Liu, G. B.; Zhao, Y. Y.; Li, L. L.

    2015-08-01

    Different capacity control methods are used for adjusting suction flow of reciprocating compressors to meet process need. Compared with recycle or bypass and suction throttling, three capacity control methods of speed control, clearance pockets and suction valve unloading are preferred due to their energy-saving at operating condition of partial load. The paper reviewed state of the art of the current capacity control technologies and their principles. A comprehensive mathematical model was developed to predict thermodynamic and dynamic performance of reciprocating compressors equipped with the capacity control systems of four above-mentioned methods. Comparison of shaft work and mechanical efficiency were conducted for different capacity control methods at the same condition. In addition, their influence on p-v diagram and valve motion were also studied, which is important for reliability and life of the reciprocating compressors. These results were helpful for selection of the capacity control systems by end-users and optimum design by manufacturers.

  19. Reciprocity and the Tragedies of Maintaining and Providing the Commons.

    Science.gov (United States)

    Gächter, Simon; Kölle, Felix; Quercia, Simone

    2017-09-01

    Social cooperation often requires collectively beneficial but individually costly restraint to maintain a public good1-4, or it needs costly generosity to create one1,5. Status quo effects6 predict that maintaining a public good is easier than providing a new one. Here we show experimentally and with simulations that even under identical incentives, low levels of cooperation (the 'tragedy of the commons'2) are systematically more likely in Maintenance than Provision. Across three series of experiments, we find that strong and weak positive reciprocity, known to be fundamental tendencies underpinning human cooperation7-10, are substantially diminished under Maintenance compared to Provision. As we show in a fourth experiment, the opposite holds for negative reciprocity ('punishment'). Our findings suggest that incentives to avoid the 'tragedy of the commons' need to contend with dilemma-specific reciprocity.

  20. An Indirect Route for Ethanol Production

    Energy Technology Data Exchange (ETDEWEB)

    Eggeman, T.; Verser, D.; Weber, E.

    2005-04-29

    The ZeaChem indirect method is a radically new approach to producing fuel ethanol from renewable resources. Sugar and syngas processing platforms are combined in a novel way that allows all fractions of biomass feedstocks (e.g. carbohydrates, lignins, etc.) to contribute their energy directly into the ethanol product via fermentation and hydrogen based chemical process technologies. The goals of this project were: (1) Collect engineering data necessary for scale-up of the indirect route for ethanol production, and (2) Produce process and economic models to guide the development effort. Both goals were successfully accomplished. The projected economics of the Base Case developed in this work are comparable to today's corn based ethanol technology. Sensitivity analysis shows that significant improvements in economics for the indirect route would result if a biomass feedstock rather that starch hydrolyzate were used as the carbohydrate source. The energy ratio, defined as the ratio of green energy produced divided by the amount of fossil energy consumed, is projected to be 3.11 to 12.32 for the indirect route depending upon the details of implementation. Conventional technology has an energy ratio of 1.34, thus the indirect route will have a significant environmental advantage over today's technology. Energy savings of 7.48 trillion Btu/yr will result when 100 MMgal/yr (neat) of ethanol capacity via the indirect route is placed on-line by the year 2010.

  1. Design and Fabrication of a Reciprocal Trees Pavilion

    DEFF Research Database (Denmark)

    Parigi, Dario

    2014-01-01

    and tools presented in the course, in relation to embedded tectonics methodology. The structure is based on the principle of reciprocity, a construction system used in the past, among the others, by Leonardo da Vinci. The pavilion aim is to show the potential of the application of new computational tool...... to traditional construction systems. The geometry of the network of elements is a property emerging, bottom-up, from the complex and simultaneous interaction among all the elements in the configuration. The structure was designed using the “Reciprocalizer”, an agile deign tool for reciprocal structures developed...

  2. Fairness and Reciprocity in the Hawk-Dove Game

    DEFF Research Database (Denmark)

    Poulsen, Anders; Neugebauer, Tibor; Schram, Arthur

    2002-01-01

    We study fairness and reciprocity in a Hawk-Dove game, using an experimental approach. This allows us to test various models in one framework. We observe a large extent of selfish and rational behavior. Our results are inconsistent with leading models in this field.......We study fairness and reciprocity in a Hawk-Dove game, using an experimental approach. This allows us to test various models in one framework. We observe a large extent of selfish and rational behavior. Our results are inconsistent with leading models in this field....

  3. Ubiquity of Benfords law and emergence of the reciprocal distribution

    CERN Document Server

    Friar, J L; Perez-Mercader, J

    2016-01-01

    We apply the Law of Total Probability to the construction of scale-invariant probability distribution functions (pdfs), and require that probability measures be dimensionless and unitless under a continuous change of scales. If the scale-change distribution function is scale invariant then the constructed distribution will also be scale invariant. Repeated application of this construction on an arbitrary set of (normalizable) pdfs results again in scale-invariant distributions. The invariant function of this procedure is given uniquely by the reciprocal distribution, suggesting a kind of universality. We separately demonstrate that the reciprocal distribution results uniquely from requiring maximum entropy for size-class distributions with uniform bin sizes.

  4. Attachment anxiety and reciprocity as moderators of interpersonal attraction.

    Science.gov (United States)

    Sperling, M B; Borgaro, S

    1995-02-01

    In integrating the interpersonal domains of attraction, perceived reciprocity, and attachment security, the prediction was made that positive interpersonal feedback (reciprocity) would lead to a greater increase in attraction ratings for anxiously versus securely attached individuals and, correspondingly, negative interpersonal feedback would cause a greater diminution in attraction ratings for anxiously versus securely attached individuals, with neutral feedback having no differential effect. For a sample of 154 college students, these predictions as well as an unanticipated gender finding were supported. The findings and clinical implications concerning the susceptibility of anxiously attached individuals to positive interpersonal cues are discussed in terms of a compromised sense of the availability and responsiveness of attachment figures.

  5. On the Power Series Expansion of the Reciprocal Gamma Function

    OpenAIRE

    Fekih-Ahmed, Lazhar

    2014-01-01

    Corrected a sign in equation (3.21) due to a minor error in (3.19) where the fraction was inadvertently inverted. Now the rough approximation provides an elementary proof that the order of the reciprocal gamma function is 1 and that its type is maximal.; Using the reflection formula of the Gamma function, we derive a new formula for the Taylor coefficients of the reciprocal Gamma function. The new formula provides effective asymptotic values for the coefficients even for very small values of ...

  6. A surface-scattering model satisfying energy conservation and reciprocity

    CERN Document Server

    Sasihithlu, Karthik; Hugonin, Jean-Paul; Greffet, Jean-Jacques

    2015-01-01

    In order for surface scattering models to be accurate they must necessarily satisfy energy conservation and reciprocity principles. Roughness scattering models based on Kirchoff's approximation or perturbation theory do not satisfy these criteria in all frequency ranges. Here we present a surface scattering model based on analysis of scattering from a layer of particles on top of a substrate in the dipole approximation which satisfies both energy conservation and reciprocity and is thus accurate in all frequency ranges. The model takes into account the absorption in the substrate induced by the particles but does not take into account the near-field interactions between the particles.

  7. Quality of preschool education in preschool institution and children's social competence

    OpenAIRE

    Vesna Lešnik; Ljubica Marjanovič Umek

    2006-01-01

    The present study addressed the relation between the quality of preschool education and children's social competence. The main purpose of the study was to examine how professional workers (preschool teachers and preschool teachers' assistants) evaluate their work with children in the context of stimulating children's social development, and to determine the relationship between the professional workers' self-evaluations and children's social competence. Professional worker...

  8. Choosing Starting Values for Newton-Raphson Computation of Reciprocals, Square-Roots and Square-Root Reciprocals

    OpenAIRE

    Kornerup, Peter; Muller, Jean-Michel

    2003-01-01

    We aim at finding the best possible seed values when computing reciprocals, square-roots and square-root reciprocals in a given interval using Newton-Raph- son iterations. A natural choice of the seed value would be the one that best approximates the expected result. It turns out that in most cases, the best seed value can be quite far from this natural choice. When we evaluate a monotone function f(a) in the interval [a_min,a_max], by building the sequence x_n defined by the Newton-Raphson i...

  9. Word order preferences for direct and indirect objects in children learning Korean.

    Science.gov (United States)

    Cho, Sookeun; Lee, Miseon; O'Grady, William; Song, Minsun; Suzuki, Takaaki; Yoshinaga, Naoko

    2002-11-01

    Pre-school Korean children typically manifest higher comprehension rates on the 'unmarked' SOV sentences of their language than on the 'scrambled' OSV patterns. To date, however, scant attention has been paid to children's ordering preferences with respect to direct and indirect objects. The results of an act-out comprehension experiment involving 40 subjects (aged 4;0 to 7;0) show a strong, statistically significant preference for the accusative-dative order, despite evidence that the reverse order is more common in mother-to-child speech. Two hypotheses are considered, one involving the relationship between word order and grammatical relations and the other involving the relationship between word order and the types of situations denoted by the sentences in question. The results of a follow-up study involving transitive verbs with instrument arguments provide strong evidence in favour of the latter hypothesis.

  10. Indirect combustion noise of auxiliary power units

    Science.gov (United States)

    Tam, Christopher K. W.; Parrish, Sarah A.; Xu, Jun; Schuster, Bill

    2013-08-01

    Recent advances in noise suppression technology have significantly reduced jet and fan noise from commercial jet engines. This leads many investigators in the aeroacoustics community to suggest that core noise could well be the next aircraft noise barrier. Core noise consists of turbine noise and combustion noise. There is direct combustion noise generated by the combustion processes, and there is indirect combustion noise generated by the passage of combustion hot spots, or entropy waves, through constrictions in an engine. The present work focuses on indirect combustion noise. Indirect combustion noise has now been found in laboratory experiments. The primary objective of this work is to investigate whether indirect combustion noise is also generated in jet and other engines. In a jet engine, there are numerous noise sources. This makes the identification of indirect combustion noise a formidable task. Here, our effort concentrates exclusively on auxiliary power units (APUs). This choice is motivated by the fact that APUs are relatively simple engines with only a few noise sources. It is, therefore, expected that the chance of success is higher. Accordingly, a theoretical model study of the generation of indirect combustion noise in an Auxiliary Power Unit (APU) is carried out. The cross-sectional areas of an APU from the combustor to the turbine exit are scaled off to form an equivalent nozzle. A principal function of a turbine in an APU is to extract mechanical energy from the flow stream through the exertion of a resistive force. Therefore, the turbine is modeled by adding a negative body force to the momentum equation. This model is used to predict the ranges of frequencies over which there is a high probability for indirect combustion noise generation. Experimental spectra of internal pressure fluctuations and far-field noise of an RE220 APU are examined to identify anomalous peaks. These peaks are possible indirection combustion noise. In the case of the

  11. [Indirect costs in health technology assessment].

    Science.gov (United States)

    Jakubczyk, Michał; Wrona, Witold; Macioch, Tomasz; Golicki, Dominik; Niewada, Maciej; Hermanowski, Tomasz

    2010-01-01

    In the health technology assessment it is crucial to define the perspective of the analysis. When the societal perspective is chosen it is necessary to include all the costs incurred by the society, also the costs of lost productivity resulting from absence of sick employees from work or their reduced efficiency at work. The aim of this article is to present the notion of indirect costs, their importance in health technology assessment and the methods of calculation. The economic literature has been reviewed for the state of knowledge on indirect costs. Three methods of calculation are described: human capital method, friction cost method or health state valuation. Indirect costs in Western European countries can amount to more than half of total costs attributed to the illness and its treatment. In the literature there is no consensus regarding the proper method of indirect costs calculation. It is necessary to conduct further theoretical and empirical research in the area of indirect costs and enhance discussion among Polish pharmacoeconomists.

  12. Non-traditional vibration mitigation methods for reciprocating compressor system

    NARCIS (Netherlands)

    Eijk, A.; Lange, T.J. de; Vreugd, J. de; Slis, E.J.P.

    2016-01-01

    Reciprocating compressors generate vibrations caused by pulsation-induced forces, mechanical (unbalanced) free forces and moments, crosshead guide forces and cylinder stretch forces. The traditional way of mitigating the vibration and cyclic stress levels to avoid fatigue failure of parts of the

  13. Reciprocity experiments on the transmission of sound in ships

    NARCIS (Netherlands)

    Wolde, T. ten

    1973-01-01

    The general reciprocity theorem for linear dynamical systems was formulated by Rayleigh about a century ago (ref. 1.1). Nevertheless, in the fields of acoustics and structural dynamics the principle is not generally accepted as a useful tool and the number of applications is very limited. The limite

  14. Variable speed hermetic reciprocating compressors for domestic refrigerators

    DEFF Research Database (Denmark)

    Rasmussen, Bjarne D.

    1998-01-01

    This article describes the results of a both theoretical and experimental investigation of the performance of variable speed hermetic reciprocating compressors for domestic refrigerators. The investigation was performed as a part of a larger research project with the objective of reducing...

  15. Up-regulation of reciprocal inhibition by explosive strength training

    DEFF Research Database (Denmark)

    Geertsen, Svend Sparre; Jensen, Jesper Lundbye; Nielsen, Jens Bo

    At the onset of dorsiflexion disynaptic reciprocal inhibition (DRI) of soleus motoneurones is increased in order to prevent activation of the antagonistic plantarflexors. This is caused by descending facilitation of transmission in the DRI pathway. Since the risk of eliciting stretch reflexes...

  16. Evidence of Reciprocity in Reports on International Partnerships

    Directory of Open Access Journals (Sweden)

    Rachel A. Umoren

    2012-01-01

    Full Text Available The increase in global health opportunities in medical education has been accompanied by calls for ethical and reciprocal institutional partnerships. The Working Group on Ethics Guidelines in Global Health Training (WEIGHT guidelines were developed in 2010 and are widely accepted by the global health community. We reviewed 43 articles on international partnerships from 1970 to 2010 for eight principles of reciprocity derived from the WEIGHT guidelines. The results showed that, while few articles reflected all principles, there was a trend to increasing consideration of the international partner’s local needs, pre-departure cultural training, and collaborative authorship. However, learner supervision and consideration of local cost/benefit ratios decreased over the same time period. Partnerships with only one international partner or with institutional partners in Africa had lower reciprocity scores than those with two or more partners and institutional partners in Asia and South America. We recommend that a new focus on ethics in global health partnerships leads to the inclusion of the principles of reciprocity in model program descriptions in order to enable and encourage ethical, sustainable, and mutually beneficial institutional partnerships.

  17. Reciprocal Interactions Between Industrial Clusters and City Suburbs Development

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Industrial clusters which create competitive advantage are new trends in industry development. Establishing innovatory clusters in city suburbs which provide better environments for cluster development in return will greatly accelerate the development of suburbs. Thus there are reciprocal interactions between industrial clusters and city suburbs development. The relations and some suggestions about how to plan industrial clusters in suburbs were given.

  18. Subjective performance evaluations and reciprocity in principal-agent relations

    DEFF Research Database (Denmark)

    Sebald, Alexander Christopher; Walzl, Markus

    2014-01-01

    . In contrast to existing models of reciprocity, we find that agents tend to sanction whenever the feedback of principals is below their subjective self-evaluations even if agents' pay-offs are independent of it. In turn, principals provide more positive feedback (relative to their actual performance assessment...

  19. Grooming reciprocity in female tibetan macaques macaca thibetana.

    Science.gov (United States)

    Xia, Dongpo; Li, Jinhua; Garber, Paul A; Sun, Lixing; Zhu, Yong; Sun, Binghua

    2012-06-01

    Grooming among nonhuman primates is widespread and may represent an important service commodity that is exchanged within a biological marketplace. In this study, using focal animal sampling methods, we recorded grooming relationships among 12 adult females in a free-ranging group of Tibetan macaques (Macaca thibetana) at Huangshan, China, to determine the influence of rank and kinship on grooming relationships, and whether females act as reciprocal traders (exchange grooming received for grooming given) or interchange traders (interchange grooming for social tolerance or other commodities). The results showed that: (1) grooming given was positively correlated with grooming received; (2) kinship did not exert a significant influence on grooming reciprocity; and (3) grooming reciprocity occurred principally between individuals of adjacent rank; however, when females of different rank groomed, females tended to groom up the hierarchy (lower ranking individuals groomed higher ranking individuals more than vice versa). Our results support the contention that both grooming reciprocity and the interchange of grooming for tolerance represent important social tactics used by female Tibetan macaques.

  20. Reciprocity Revisited : Give and Take in Dutch and Immigrant Families

    NARCIS (Netherlands)

    Komter, Aafke; Schans, Djamila

    2008-01-01

    The idea that reciprocity is the basic principle underlying forms of social organization, among which the family, is as old as classical anthropology and sociology. The essence of the principle is that giving prompts receiving, thereby creating forms of ongoing exchange and durable cooperation. Reci

  1. 24 CFR 3282.11 - Preemption and reciprocity.

    Science.gov (United States)

    2010-04-01

    ... the system established in these regulations or which go beyond this system to require remedial actions... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Preemption and reciprocity. 3282.11 Section 3282.11 Housing and Urban Development Regulations Relating to Housing and Urban Development...

  2. Reciprocal Symmetric Boltzmann Function and Unified Boson-Fermion Statistics

    OpenAIRE

    2007-01-01

    The differential equation for Boltzmann's function is replaced by the corresponding discrete finite difference equation. The difference equation is, then, symmetrized so that the equation remains invariant when step d is replaced by -d. The solutions of this equation come in Boson-Fermion pairs. Reciprocal symmetric Boltzmann's function, thus, unifies both Bosonic and Fermionic distributions.

  3. Reciprocal genomic evolution in the ant-fungus agricultural symbiosis

    DEFF Research Database (Denmark)

    Nygaard, Sanne; Hu, Haofu; Li, Cai;

    2016-01-01

    The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal cul...

  4. Reciprocity and its utilization in ultrasonic flow meters

    Energy Technology Data Exchange (ETDEWEB)

    Lunde, Per; Vestrheim, Magne; Boe, Reidar; Smoergrav, Skule; Abrahamsen, Atle K.

    2005-07-01

    In ultrasonic transit time flow meters for gas and liquid (USMs), the flow direction, the flow velocity and the sound velocity are estimated from the measured up- and downstream transit times. At no-flow conditions, the up- and downstream transit times of such meters should ideally be the same, or the difference should be negligible. This may not be the case unless special precautions are made. In order to reduce the possibility of the meter to detect a false flow at no-flow conditions, USMs are typically ''dry calibrated'' before being installed in the field. ''Dry calibration'' (which may be made in different ways), in general involves measurement of (a) the time delays due to electronics, cables and transducers, (b) the so called ''{delta}t-correction'' (for each acoustic path, also denoted ''zero flow offset factor''), and (c) geometrical parameters. Various {delta}t-correction approaches may be used by different manufacturers, but these are basically similar and have the same purpose: to reduce the false flow detection and improve the accuracy at low and no-flow conditions (''zero flow adjustment''), without significantly affecting the accuracy at the high velocity measurements. The AGA-9 report and the API MPMS Ch. 5.8 standard both prescribe need for ''zero flow verification test (zero test)'' or ''zeroing the meter'', for gas and liquid USMs, respectively. Advances in USM technology based on the electro acoustic reciprocity principle have provided methods for reduction or even neglect ion of the need for ''{delta} t-correction'' of USMs. That means, if the USM measurement system is reciprocal, and operated in a ''sufficiently reciprocal'' way, the ''{delta}t-correction'' may be negligibly small over the operational range of pressure and temperature, and

  5. Old Portuguese reciprocal constructions. An emergent grammatical subsystem

    Directory of Open Access Journals (Sweden)

    Mikołaj Nkollo

    2013-01-01

    Full Text Available The main goal of this paper is to identify various methods of expressing reciprocity encountered in Old Portuguese texts (from 13th to 15th centuries and to account for putative evolutionary mechanisms conducive to their emergence and their subsequent shape. Most of the grammaticalization pathways documented in human languages have been implemented in Old Portuguese, as well. Only syntactically built reciprocals will be taken into account; their lexical counterparts, where reciprocity is an inherent semantic property, will be evoked incidentally. Peculiar characteristics exhibited by ancient Portuguese reciprocal constructions comprise: a shaky selection of determiners distributed over the bipartite indefinite "um ao outro" and its varieties, a rather peripheral, though clearly distinct exponent "d’huũa parte e d’ooutra" designed to highlight a twofold (and not manifold internal structure of states of affairs, a remarkable mobility of "se" and, finally, a blurred distinction between "entre eles" (preferably anaphoric and "entre si" (used seemingly at random, with either indefinite and definite objects. Compared to other incipient Romance languages, a system built around this set of markers was rather scanty. It relied on numerous makeshift solutions, as typically do the languages whose particular grammatical areas are merely on the point of coming into existence.

  6. A Reciprocal Peer Review System to Support College Students' Writing

    Science.gov (United States)

    Yang, Yu-Fen

    2011-01-01

    As students' problem-solving processes in writing are rarely observed in face-to-face instruction, they have few opportunities to participate collaboratively in peer review to improve their texts. This study reports the design of a reciprocal peer review system for students to observe and learn from each other when writing. A sample of 95…

  7. Self-Esteem and Adolescent Problems: Modeling Reciprocal Effects.

    Science.gov (United States)

    Rosenberg, Morris; And Others

    1989-01-01

    Explores the reciprocal relationships between self-esteem and the following three problems of youth: (1) juvenile delinquency; (2) poor school performance; and (3) psychological depression. Findings include the following: (1) low self-esteem fosters delinquency, which may enhance self-esteem; (2) school performance affects self-esteem; and (3)…

  8. Modeling time-lagged reciprocal psychological empowerment-performance relationships.

    Science.gov (United States)

    Maynard, M Travis; Luciano, Margaret M; D'Innocenzo, Lauren; Mathieu, John E; Dean, Matthew D

    2014-11-01

    Employee psychological empowerment is widely accepted as a means for organizations to compete in increasingly dynamic environments. Previous empirical research and meta-analyses have demonstrated that employee psychological empowerment is positively related to several attitudinal and behavioral outcomes including job performance. While this research positions psychological empowerment as an antecedent influencing such outcomes, a close examination of the literature reveals that this relationship is primarily based on cross-sectional research. Notably, evidence supporting the presumed benefits of empowerment has failed to account for potential reciprocal relationships and endogeneity effects. Accordingly, using a multiwave, time-lagged design, we model reciprocal relationships between psychological empowerment and job performance using a sample of 441 nurses from 5 hospitals. Incorporating temporal effects in a staggered research design and using structural equation modeling techniques, our findings provide support for the conventional positive correlation between empowerment and subsequent performance. Moreover, accounting for the temporal stability of variables over time, we found support for empowerment levels as positive influences on subsequent changes in performance. Finally, we also found support for the reciprocal relationship, as performance levels were shown to relate positively to changes in empowerment over time. Theoretical and practical implications of the reciprocal psychological empowerment-performance relationships are discussed. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  9. Reciprocity between Reading and Writing: Strategic Processing as Common Ground

    Science.gov (United States)

    Anderson, Nancy L.; Briggs, Connie

    2011-01-01

    Connecting reading and writing has important implications for all readers, but particularly for those who struggle in learning to read and write. Based on their work with children who struggle, the authors focus on reciprocal cognitive operations or strategies that draw on sources of knowledge used in both reading and writing. Their aim in this…

  10. Emerging signs of strong reciprocity in human ontogeny

    Directory of Open Access Journals (Sweden)

    Erin eRobbins

    2011-12-01

    Full Text Available Strong reciprocity is considered here as the propensity to sacrifice resources to be kind or to punish in response to prior acts, a behavior not simply reducible to self-interest and a likely force behind human cooperation and sociality. The aim was to capture emerging signs of strong reciprocity in human ontogeny. Three- and five-year-old middle class American children (N=162 were tested in a simple, multiple round, three-way sharing game involving the child, a generous puppet, and a stingy puppet. At the end of the game, the child was offered an opportunity to sacrifice some of her personal gains to punish one of the puppets. By three years, American children demonstrate a willingness to engage in costly punishment. However, only five-year-olds show some evidence of strong reciprocity by orienting their punishment systematically toward the stingy puppet. Further analyses and 3 additional control conditions demonstrate that such propensity is not simply reducible to a straight imitation, or b inequity aversion. To assess the relative universality of such development, a group of five- to six-year-old children from rural Samoa (N=14 were tested and compared to age and gender matched American children. Samoan children did not manifest the same propensity toward strong reciprocity. The results are interpreted as pointing to 1 the developmental emergence of an ethical stance between three and five years of age, and 2 that the expression of such stance by young children could depend on culture.

  11. Aging, Neighborhood Attachment, and Fear of Crime: Testing Reciprocal Effects

    Science.gov (United States)

    Oh, Joong-Hwan; Kim, Sangmoon

    2009-01-01

    This study attempts to examine the reciprocal effects between fear of crime and neighborhood attachment because aging is a critical factor in both discussions of fear of crime and neighborhood attachment (friendship, neighboring, social cohesion and trust, informal social control, and participation in neighborhood watch program). Using data from…

  12. Reciprocal Teaching of Comprehension Strategies Improves EFL Learners' Writing Ability

    Science.gov (United States)

    Ghorbani, Mohammad Reza; Gangeraj, Atefeh Ardeshir; Alavi, Sahar Zahed

    2013-01-01

    Although the importance of reading in developing writing ability is undeniable, few competent readers in EFL contexts develop into competent writers. Since students are not aware that reading can assist them in writing, this study examined the effect of reciprocal teaching--which focuses on four reading comprehension strategies, namely…

  13. Three-dimensional Reciprocal Structures: Morphology, Concepts, Generative Rules

    DEFF Research Database (Denmark)

    Parigi, Dario; Pugnale, Alberto

    2012-01-01

    This paper present seven different three dimensional structures based on the principle of structural reciprocity with superimposition joint and standardized un-notched elements. Such typology could be regarded as being intrinsically three-dimensional because elements sit one of the top of the oth...

  14. Attachment and Reciprocity in the Two-Year-Old Child.

    Science.gov (United States)

    Marvin, Robert S., II

    This paper reported a pilot study on issues relevant to the social development of the 2-year-old child and discussed the results within the framework of the evolutionary-control-systems theory proposed by Bowlby (1958, 1969) and Ainsworth (1967, 1969). The issues examined were (1) attachment and (2) reciprocity, or the ability of the child-mother…

  15. Reciprocal Relationships between Job Resources, Personal Resources, and Work Engagement

    Science.gov (United States)

    Xanthopoulou, Despoina; Bakker, Arnold B.; Demerouti, Evangelia; Schaufeli, Wilmar B.

    2009-01-01

    This study examined longitudinal relationships between job resources, personal resources, and work engagement. On the basis of Conservation of Resources theory, we hypothesized that job resources, personal resources, and work engagement are reciprocal over time. The study was conducted among 163 employees, who were followed-up over a period of 18…

  16. Design and Fabrication of a Reciprocal Trees Pavilion

    DEFF Research Database (Denmark)

    Parigi, Dario

    2014-01-01

    to traditional construction systems. The geometry of the network of elements is a property emerging, bottom-up, from the complex and simultaneous interaction among all the elements in the configuration. The structure was designed using the “Reciprocalizer”, an agile deign tool for reciprocal structures developed...... by Dario Parigi and fabricated with a purposely developed fabrication machine....

  17. Unilateral or Reciprocal Climate Policy? Experimental Evidence from China

    Directory of Open Access Journals (Sweden)

    Thomas Bernauer

    2016-09-01

    Full Text Available The traditional political economy account of global climate change governance directs our attention to fundamental collective action problems associated with global public goods provision, resulting from positive or negative externalities as well as freeriding. The governance architecture of the 1997 Kyoto Protocol uses the traditional approaches of international diplomacy for addressing such challenges: legally binding commitments based on principles of reciprocity and (fair cost/burden sharing via formalized carbon-budgeting. Yet, the 2015 Paris Agreement has essentially abandoned this approach, as it now operates on the basis of internationally coordinated and monitored unilateralism. On the presumption that public opinion matters for government policy, we examine how citizens view this shift in climate policy from reciprocity to unilateralism, after many years of exposure to strong reciprocity rhetoric by governments and stakeholders. To that end, we fielded a survey experiment in China, the world’s largest greenhouse gas (GHG emitter. The results show that there is, perhaps surprisingly, strong and robust public support for unilateral, non-reciprocal climate policy. To the extent China is interested in pushing ahead with ambitious and thus costly GHG reduction policies, our results suggest that China can leverage segments of public support in order to overcome domestic obstacles to GHG mitigation policies.

  18. 32 CFR 148.1 - Intergency reciprocal acceptance .

    Science.gov (United States)

    2010-07-01

    ... reciprocal acceptance of security policies and procedures for approving, accrediting, and maintaining the secure posture of shared facilities will reduce aggregate costs, promote interoperability of agency security systems, preserve vitality of the U.S. industrial base, and advance national security objectives....

  19. Five year old preschoolers’ sharing is influenced by anticipated reciprocation

    Directory of Open Access Journals (Sweden)

    Mingrui eXiong

    2016-03-01

    Full Text Available Whether children share in anticipation of future benefits returned by a partner is an interesting question. In this study, 5-year-old children and an adult partner played a sharing game, in which children donated first and the partner donated afterward. In Experiment 1, the partner’s resources were more attractive than the child’s. In the reciprocal condition, the child was told that s/he would be a recipient when the partner played as a donor. In the nonreciprocal condition, however, the child was told that an anonymous child would be the recipient when the partner donated. Results showed that children shared more with the partner when they knew that they would be a recipient later. In Experiment 2, the child was always the recipient when the partner donated, but the partner’s resources were more desirable than the child’s in the high-value condition, and less desirable in the low-value condition. We found that children were more generous when the partner’s resources were valued higher. These findings demonstrate that 5-year-old preschoolers’ sharing choices take into account the anticipated reciprocity of the recipient, suggesting either self-interested tactical sharing or direct reciprocity in advance of receiving. Specifically, they adjust their sharing behavior depending on whether a partner has the potential to reciprocate, and whether it is worth sharing relative to the value of the payback.

  20. Reciprocal Relationships between Job Resources, Personal Resources, and Work Engagement

    Science.gov (United States)

    Xanthopoulou, Despoina; Bakker, Arnold B.; Demerouti, Evangelia; Schaufeli, Wilmar B.

    2009-01-01

    This study examined longitudinal relationships between job resources, personal resources, and work engagement. On the basis of Conservation of Resources theory, we hypothesized that job resources, personal resources, and work engagement are reciprocal over time. The study was conducted among 163 employees, who were followed-up over a period of 18…

  1. Longitudinal Study on Reciprocity between Personality Traits and Parenting Stress

    Science.gov (United States)

    Rantanen, Johanna; Tillemann, Kati; Metsäpelto, Riitta-Leena; Kokko, Katja; Pulkkinen, Lea

    2015-01-01

    Reciprocal associations between the Big Five personality traits and parenting stress--including both parents' feelings of their distress and perception of their incompetence as parents--were studied with 248 participants (49% of which were males). Longitudinal data, collected at ages 33/36, 42 and 50 years, were used. Cross-lagged path analysis…

  2. Reciprocal genomic evolution in the ant-fungus agricultural symbiosis

    DEFF Research Database (Denmark)

    Nygaard, Sanne; Hu, Haofu; Li, Cai

    2016-01-01

    The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal...

  3. Three cases of mosaicism for balanced reciprocal translocations

    NARCIS (Netherlands)

    Leegte, B; Sikkema-Raddatz, B; Hordijk, R; Bouman, K; van Essen, T; Castedo, S; de Jong, B

    1998-01-01

    Mosaicism for a balanced reciprocal translocation (BRTM) is rare. As far as we know only 26 cases of BRTM, demonstrated in lymphocyte cultures, have been described, five of which had an abnormal phenotype. Prenatally three confirmed cases with a normal phenotypic outcome have been described. Here we

  4. The Centrality of Reciprocity to Communication and Democracy.

    Science.gov (United States)

    Rucinski, Dianne

    1991-01-01

    Focuses on the implications of participatory democratic theory, as compared to elite democratic theory, for political communication theorists. Discusses how reciprocity provides political communication researchers with a tool for gauging the successes of various communication systems in enhancing participatory democracy. Suggests how mass-mediated…

  5. Reciprocal genomic evolution in the ant-fungus agricultural symbiosis

    DEFF Research Database (Denmark)

    Nygaard, Sanne; Hu, Haofu; Li, Cai;

    2016-01-01

    The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal...

  6. Effects of Reciprocal Teaching Strategies on Reading Comprehension

    Science.gov (United States)

    Choo, Tan Ooi Leng; Eng, Tan Kok; Ahmad, Norlida

    2011-01-01

    Reading Comprehension is one of the four components tested by the "MUET" (Malaysian University English Test) for Sixth-Form students in Malaysia, and school teachers are charged with the task of helping these students improve. This article discusses how "reciprocal teaching strategies" could help low-proficiency Sixth-Form students improve their…

  7. Piaget on the Moral Development of Forgiveness: Identity or Reciprocity?

    Science.gov (United States)

    Enright, Robert D.; And Others

    1994-01-01

    Proposes a cognitive mechanism that makes forgiveness possible. Revises Piaget's theory that ideal reciprocity is the underlying cognitive operation that makes understanding and appreciation of forgiveness possible. Draws on modern philosophical inquiry, empirical study, and theory to argue instead that abstract identity provides--philosophically…

  8. Modern Social Science Concepts, Proportionate Reciprocity, Modesty, and Democracy

    Directory of Open Access Journals (Sweden)

    Gerasimos T. SOLDATOS

    2014-06-01

    Full Text Available Proportionate Reciprocity, Modesty, and Democracy, are the key concepts in Aristotle’s economics of exchange. The following correspondence of these concepts with modern social science may be contemplated: (a Ideally, reciprocal justice in bilateral bargaining to minimize expenditure given utility levels results in Pareto-efficient, envy-free, equitable outcomes. (b Practically, bargaining under the threat or actual recontracting may act as a surrogate of reciprocal justice, leading to an N-person contract topology. (c But, recontracting is subject to practical limitations too, in which case near-reciprocal justice/general equilibrium outcomes may be fostered if, as a surrogate of recontracting, modesty in interaction is exhibited in an evolutionarily-stable-strategy fashion. (d That is, incomplete recontracting amounts to asymmetric agent-type information, which in turn lays the ground for injustices; the same lack of information prevents rectificatory justice from being efficient and hence, modesty can be efficient only if it operates as a social norm and hence, only in a modest polity, which can be no other than democracy.

  9. Explaining Cooperation in Groups: Testing Models of Reciprocity and Learning

    Science.gov (United States)

    Biele, Guido; Rieskamp, Jorg; Czienskowski, Uwe

    2008-01-01

    What are the cognitive processes underlying cooperation in groups? This question is addressed by examining how well a reciprocity model, two learning models, and social value orientation can predict cooperation in two iterated n-person social dilemmas with continuous contributions. In the first of these dilemmas, the public goods game,…

  10. Experienced Teacher Learning within the Context of Reciprocal Peer Coaching

    Science.gov (United States)

    Zwart, R. C.; Wubbels, T.; Bergen, T. C. M.; Bolhuis, S.

    2007-01-01

    A considerable amount of literature on peer coaching suggests that the professional development of teachers can be improved through experimentation, observation, reflection, the exchange of professional ideas, and shared problem-solving. Reciprocal peer coaching provides teachers with an opportunity to engage in such activities in an integrated…

  11. Learning through reciprocal peer coaching; an analysis of activity sequences

    NARCIS (Netherlands)

    Zwart, R.C.; Wubbels, T.; Bolhuis, S.; Bergen, Th.C.M.

    2008-01-01

    Just what and how eight experienced teachers in four coaching dyads learned during a 1-year reciprocal peer coaching trajectory was examined in the present study. The learning processes were mapped by providing a detailed description of reported learning activities, reported learning outcomes, and t

  12. Reciprocal Relationships between Math Self-Concept and Math Anxiety

    NARCIS (Netherlands)

    Ahmed, Wondimu; Minnaert, Alexander; Kuyper, Hans; Van der Werf, Greetje

    2012-01-01

    The present study examined the reciprocal relationships between self-concept and anxiety in mathematics. A sample of 495 grade 7 students (51% girls) completed self-report measures assessing self-concept and anxiety three times in a school year. Structural equation modeling was used to test a cross-

  13. Standard guide for determining friction energy dissipation in reciprocating tribosystems

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide covers and is intended for use in interpreting the friction forces recorded in reciprocating tribosystems. The guide applies to any reciprocating tribosystem, whether it is a wear or fretting test or an actual machine or device. 1.2 The energy dissipation guide was developed in analyzing friction results in the Test Method G133 reciprocating ball-on-flat test, but it applies to other ASTM or ISO reciprocating tests. This technique is frequently used to record the friction response in fretting tribosystems. 1.3 Specimen material may play some role in the results if the materials under test display viscoelastic behavior. This guide as written is for metals, plastics, and ceramics that do not display viscoelastic behavior. It also applies to lubricated and non-lubricated contacts. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address all of the safety concerns, if any, asso...

  14. Reciprocal Relationships between Math Self-Concept and Math Anxiety

    NARCIS (Netherlands)

    Ahmed, Wondimu; Minnaert, Alexander; Kuyper, Hans; Van der Werf, Greetje

    2012-01-01

    The present study examined the reciprocal relationships between self-concept and anxiety in mathematics. A sample of 495 grade 7 students (51% girls) completed self-report measures assessing self-concept and anxiety three times in a school year. Structural equation modeling was used to test a cross-

  15. Reciprocal Teaching of Lecture Comprehension Skills in College Students

    Science.gov (United States)

    Spivey, Norman R.; Cuthbert, Andrea

    2006-01-01

    This study explored the effects of a reciprocal teaching intervention designed to enhance the lecture comprehension skills of college students. Forty low-verbal ability students and 40 high-verbal ability students (as measured by SAT scores) were chosen for the study and randomly assigned to experimental or control groups. The experimental groups…

  16. Unilateral or Reciprocal Climate Policy? Experimental Evidence from China

    Directory of Open Access Journals (Sweden)

    Thomas Bernauer

    2016-09-01

    Full Text Available The traditional political economy account of global climate change governance directs our attention to fundamental collective action problems associated with global public goods provision, resulting from positive or negative externalities as well as freeriding. The governance architecture of the 1997 Kyoto Protocol uses the traditional approaches of international diplomacy for addressing such challenges: legally binding commitments based on principles of reciprocity and (fair cost/burden sharing via formalized carbon-budgeting. Yet, the 2015 Paris Agreement has essentially abandoned this approach, as it now operates on the basis of internationally coordinated and monitored unilateralism. On the presumption that public opinion matters for government policy, we examine how citizens view this shift in climate policy from reciprocity to unilateralism, after many years of exposure to strong reciprocity rhetoric by governments and stakeholders. To that end, we fielded a survey experiment in China, the world’s largest greenhouse gas (GHG emitter. The results show that there is, perhaps surprisingly, strong and robust public support for unilateral, non-reciprocal climate policy. To the extent China is interested in pushing ahead with ambitious and thus costly GHG reduction policies, our results suggest that China can leverage segments of public support in order to overcome domestic obstacles to GHG mitigation policies.

  17. Longitudinal Study on Reciprocity between Personality Traits and Parenting Stress

    Science.gov (United States)

    Rantanen, Johanna; Tillemann, Kati; Metsäpelto, Riitta-Leena; Kokko, Katja; Pulkkinen, Lea

    2015-01-01

    Reciprocal associations between the Big Five personality traits and parenting stress--including both parents' feelings of their distress and perception of their incompetence as parents--were studied with 248 participants (49% of which were males). Longitudinal data, collected at ages 33/36, 42 and 50 years, were used. Cross-lagged path…

  18. Reciprocal Relationships between Math Self-Concept and Math Anxiety

    NARCIS (Netherlands)

    Ahmed, Wondimu; Minnaert, Alexander; Kuyper, Hans; Van der Werf, Greetje

    The present study examined the reciprocal relationships between self-concept and anxiety in mathematics. A sample of 495 grade 7 students (51% girls) completed self-report measures assessing self-concept and anxiety three times in a school year. Structural equation modeling was used to test a

  19. Coaction versus reciprocity in continuous-time models of cooperation.

    Science.gov (United States)

    van Doorn, G Sander; Riebli, Thomas; Taborsky, Michael

    2014-09-07

    Cooperating animals frequently show closely coordinated behaviours organized by a continuous flow of information between interacting partners. Such real-time coaction is not captured by the iterated prisoner's dilemma and other discrete-time reciprocal cooperation games, which inherently feature a delay in information exchange. Here, we study the evolution of cooperation when individuals can dynamically respond to each other's actions. We develop continuous-time analogues of iterated-game models and describe their dynamics in terms of two variables, the propensity of individuals to initiate cooperation (altruism) and their tendency to mirror their partner's actions (coordination). These components of cooperation stabilize at an evolutionary equilibrium or show oscillations, depending on the chosen payoff parameters. Unlike reciprocal altruism, cooperation by coaction does not require that those willing to initiate cooperation pay in advance for uncertain future benefits. Correspondingly, we show that introducing a delay to information transfer between players is equivalent to increasing the cost of cooperation. Cooperative coaction can therefore evolve much more easily than reciprocal cooperation. When delays entirely prevent coordination, we recover results from the discrete-time alternating prisoner's dilemma, indicating that coaction and reciprocity are connected by a continuum of opportunities for real-time information exchange.

  20. Coaction versus reciprocity in continuous-time models of cooperation

    NARCIS (Netherlands)

    van Doorn, G. Sander; Riebli, Thomas; Taborsky, Michael

    2014-01-01

    Cooperating animals frequently show closely coordinated behaviours organized by a continuous flow of information between interacting partners. Such real-time coaction is not captured by the iterated prisoner's dilemma and other discrete-time reciprocal cooperation games, which inherently feature a d

  1. 14 CFR 440.17 - Reciprocal waiver of claims requirements.

    Science.gov (United States)

    2010-01-01

    ... each of its contractors and subcontractors, each customer and each of the customer's contractors and..., and its customer shall enter into a three-party reciprocal waiver of claims agreement. The three-party..., or Appendix C of this part, for permitted activity, of this part or in a form that satisfies...

  2. The Reciprocal Organization of Constructive Activity in Drug Addiction

    Science.gov (United States)

    Akhmetzyanova, Anna I.; Nikishina, Vera B.; Klyueva, Nadezhda V.; Petrash, Ekaterina A.

    2016-01-01

    The urgency of the problem stated in the article is caused by the fact that modern scientific studies show that sustainable neuro-associative connections with the object of addiction arise at chemical addiction. The aim of this study is to examine the features of the reciprocal organization of constructive activities in drug addiction. Study of…

  3. Reciprocal relationships between job demands, job resources, and recovery opportunities

    NARCIS (Netherlands)

    A. Rodríguez-Muñoz (Alfredo); A.I. Sanz-Vergel (Ana Isabel); E. Demerouti (Eva); A.B. Bakker (Arnold)

    2012-01-01

    textabstractThe aim of this study was to explore longitudinal relationships between job demands, job resources, and recovery opportunities. On the basis of the Job Demands-Resources model and Conservation of Resources theory we hypothesized that we would find reciprocal relations between job demands

  4. 78 FR 54606 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2013-09-05

    ... Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion... emission standards for hazardous air pollutants for stationary reciprocating internal combustion engines and the standards of performance for stationary internal combustion engines. Subsequently, the EPA...

  5. 75 FR 75937 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

    Science.gov (United States)

    2010-12-07

    ... Reciprocating Internal Combustion Engines AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of... ignition stationary reciprocating internal combustion engines. Subsequently, the Administrator received two... internal generation, combustion engine. transmission, or distribution. 622110 Medical and surgical...

  6. Acoustical evaluation of preschool classrooms

    Science.gov (United States)

    Yang, Wonyoung; Hodgson, Murray

    2003-10-01

    An investigation was made of the acoustical environments in the Berwick Preschool, Vancouver, in response to complaints by the teachers. Reverberation times (RT), background noise levels (BNL), and in-class sound levels (Leq) were measured for acoustical evaluation in the classrooms. With respect to the measured RT and BNL, none of the classrooms in the preschool were acceptable according to the criteria relevant to this study. A questionnaire was administered to the teachers to assess their subjective responses to the acoustical and nonacoustical environments of the classrooms. Teachers agreed that the nonacoustical environments in the classrooms were fair, but that the acoustical environments had problems. Eight different classroom configurations were simulated to improve the acoustical environments, using the CATT room acoustical simulation program. When the surface absorption was increased, both the RT and speech levels decreased. RASTI was dependent on the volumes of the classrooms when the background noise levels were high; however, it depended on the total absorption of the classrooms when the background noise levels were low. Ceiling heights are critical as well. It is recommended that decreasing the volume of the classrooms is effective. Sound absorptive materials should be added to the walls or ceiling.

  7. Dark matter dynamics and indirect detection

    Energy Technology Data Exchange (ETDEWEB)

    Bertone, Gianfranco; /Fermilab; Merritt, David; /Rochester Inst. Tech.

    2005-04-01

    Non-baryonic, or ''dark'', matter is believed to be a major component of the total mass budget of the universe. We review the candidates for particle dark matter and discuss the prospects for direct detection (via interaction of dark matter particles with laboratory detectors) and indirect detection (via observations of the products of dark matter self-annihilations), focusing in particular on the Galactic center, which is among the most promising targets for indirect detection studies. The gravitational potential at the Galactic center is dominated by stars and by the supermassive black hole, and the dark matter distribution is expected to evolve on sub-parsec scales due to interaction with these components. We discuss the dominant interaction mechanisms and show how they can be used to rule out certain extreme models for the dark matter distribution, thus increasing the information that can be gleaned from indirect detection searches.

  8. L’indirection en communication publique

    OpenAIRE

    Gauthier, Gilles

    2015-01-01

    Le texte a pour objectif d’analyser le recours à l’indirection dans les débats télévisés tenus à l’occasion des élections canadiennes et québécoises depuis une quarantaine d’années. Dans un premier temps, le procédé expressif de l’indirection est caractérisé. Ensuite, sont discutés les huit procédés distincts d’indirection utilisés dans les débats télévisés. Des exemples sont donnés de ces huit procédés. Une analyse quantitative de leur utilisation dans les débats est aussi faite. Finalement,...

  9. Indirect taxes on food in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Denize Mirian da Silva

    2013-12-01

    Full Text Available The objective of this paper is to estimate the indirect tax burden on food for ten income classes, based on income and household total expenditure in southern Brazil. Thus it can be seen as indirect taxes on foods affect the monetary income and consumption pattern of households. To reach the objectives proposed, will be used the Pintos-Payeras (2008 model. The database iscomposed by microdata from the Household Budgeting Survey (POF 2008-2009 and the tax regulations of the country and the southern states of Brazil. The results show that indirect taxes on food in Southern Brazil is regressive when based on income and expenditure of household , ie , the poorest people pay proportionately more taxes and have their consumption pattern highest taxed ICMS (Brazilian value added tax is the tax that contributes most to the regressivity.

  10. Application of NVC to English Teaching for Preschool Education Major

    Institute of Scientific and Technical Information of China (English)

    HU Li-rong

    2014-01-01

    In view of the present situation of college English teaching for Preschool Education Major is rather unsatisfactory, this paper briefly introduced Nonverbal Communication (NVC) and laid the emphasis on guiding college English teachers to apply useful nonverbal stimuli to inspiring Preschool Education major’s English-learning interest, improving their learning results, and helping them master various preschool English teaching skills. It further proved the nonverbal means and relative training meth-ods are helpful and practical to improve Preschool Education majors’nonverbal communicative competence and develop their preschool English teaching ability. Therefore, it will contribute to the study of English teaching for Preschool Education Major.

  11. Transcranial electrical neuromodulation based on the reciprocity principle

    Directory of Open Access Journals (Sweden)

    Mariano eFernandez Corazza

    2016-05-01

    Full Text Available A key challenge in multi-electrode transcranial electrical stimulation (TES or transcranial direct current stimulation (tDCS is to find a current injection pattern that delivers the necessary current density at a target and minimizes it in the rest of the head, which is mathematically modelled as an optimization problem. Such an optimization with the Least Squares (LS or Linearly Constrained Minimum Variance (LCMV algorithms is generally computationally expensive and requires multiple independent current sources. Based on the reciprocity principle in electroencephalography (EEG and TES, it could be possible to find the optimal TES patterns quickly whenever the solution of the forward EEG problem is available for a brain region of interest. Here, we investigate the reciprocity principle as a guideline for finding optimal current injection patterns in TES that comply with safety constraints. We define four different trial cortical targets in a detailed seven-tissue finite element head model, and analyze the performance of the reciprocity family of TES methods in terms of electrode density, targeting error, focality, intensity, and directionality using the LS and LCMV solutions as the reference standards. It is found that the reciprocity algorithms show good performance comparable to the LCMV and LS solutions. Comparing the 128 and 256 electrode cases, we found that use of greater electrode density improves focality, directionality, and intensity parameters. The results show that reciprocity principle can be used to quickly determine optimal current injection patterns in TES and help to simplify TES protocols that are consistent with hardware and software availability and with safety constraints.

  12. Kinetics of reciprocating drug delivery to the inner ear.

    Science.gov (United States)

    Pararas, Erin E Leary; Chen, Zhiqiang; Fiering, Jason; Mescher, Mark J; Kim, Ernest S; McKenna, Michael J; Kujawa, Sharon G; Borenstein, Jeffrey T; Sewell, William F

    2011-06-10

    Reciprocating drug delivery is a means of delivering soluble drugs directly to closed fluid spaces in the body via a single cannula without an accompanying fluid volume change. It is ideally suited for drug delivery into small, sensitive and unique fluid spaces such as the cochlea. We characterized the pharmacokinetics of reciprocating drug delivery to the scala tympani within the cochlea by measuring the effects of changes in flow parameters on the distribution of drug throughout the length of the cochlea. Distribution was assessed by monitoring the effects of DNQX, a reversible glutamate receptor blocker, delivered directly to the inner ear of guinea pigs using reciprocating flow profiles. We then modeled the effects of those parameters on distribution using both an iterative curve-fitting approach and a computational fluid dynamic model. Our findings are consistent with the hypothesis that reciprocating delivery distributes the drug into a volume in the base of the cochlea, and suggest that the primary determinant of distribution throughout more distal regions of the cochlea is diffusion. Increases in flow rate distributed the drug into a larger volume that extended more apically. Over short time courses (less than 2h), the apical extension, though small, significantly enhanced apically directed delivery of drug. Over longer time courses (>5h) or greater distances (>3mm), maintenance of drug concentration in the basal scala tympani may prove more advantageous for extending apical delivery than increases in flow rate. These observations demonstrate that this reciprocating technology is capable of providing controlled delivery kinetics to the closed fluid space in the cochlea, and may be suitable for other applications such as localized brain and retinal delivery.

  13. Indirect Comorbidity in Childhood and Adolescence

    Directory of Open Access Journals (Sweden)

    William eCopeland

    2013-11-01

    Full Text Available Objective: Comorbidity between psychiatric disorders is common, but pairwise associations between two disorders may be explained by the presence of other diagnoses that are associated with both disorders or indirect comorbidity. Method: Comorbidities of common childhood psychiatric disorders were tested in three community samples of children ages 6 to 17 (8931 observations of 2965 subjects. Psychiatric disorder status in all three samples was assessed with the Child and Adolescent Psychiatric Assessment. Indirect comorbidity was defined as A-B associations that decreased from significance to nonsignificance after adjusting for other disorders. Results: All tested childhood psychiatric disorders were positively associated in bivariate analyses. After adjusting for comorbidities, many ssociations involving a behavioral disorder and an emotional disorder were attenuated suggesting indirect comorbidity. Generalized anxiety and depressive disorders displayed a very high level of overlap (adjusted OR=37.9. All analyses were rerun with depressive disorders grouped with generalized anxiety disorder in a single distress disorders category. In these revised models, all associations between and emotional disorder and a behavior disorder met our criteria for indirect comorbidity except for the association of oppositional defiant disorder with distress disorders (OR=11.3. Follow-up analyses suggested that the indirect associations were primarily accounted for by oppositional defiant disorder and the distress disorder category. There was little evidence of either sex differences or differences by developmental period Conclusions: After accounting for the overlap between depressive disorders with generalized anxiety disorder, direct comorbidity between emotional and behavioral disorders was uncommon. When there was evidence of indirect comorbidity, ODD and distress disorders were the key intermediary diagnoses accounting for the apparent associations.

  14. Gender differentiation of indirect self-destructiveness

    Directory of Open Access Journals (Sweden)

    Konstantinos Tsirigotis

    2013-02-01

    Full Text Available Objectives: The objective of this study was to examine the sex (gender differentiation of indirect self-destructiveness intensity and its manifestations, as well as relationships between indirect self-destructiveness and its manifestations (categories and the psychological dimensions of masculinity and femininity, also from the point of view of assessing occupational health and safety. Materials and Methods: A population of 558 individuals (399 females and 159 males aged 19–25 (mean age: 22.6 was studied. The Polish version of the “Chronic Self-Destructiveness Scale” (CS-DS by Kelley adapted by Suchańska was used in order to examine indirect self-destructiveness and its manifestations. Gender testing applied the Polish version of the Bem Sex Role Inventory (BSRI by Bem in its adaptation by Kuczyńska. Results: Males’ scores are signifi cantly higher than those of females for the majority of CS-DS scales/indices: Indirect Self-Destructiveness (general index, Poor Health Maintenance (A2, Lack of Planfulness (A4, and Helplessness, Passiveness (A5. Moreover, there are statistically signifi cant correlations between CS-DS scales and the masculinity dimension (positive as well as the femininity dimension (negative. Conclusions: Masculinity is a factor that may predispose towards indirectly self-destructive behaviors, while femininity is a factor protecting against those. The study results may prove useful in preventing indirectly and directly self-destructive behaviors as well as in therapy work with the individuals who display such tendencies or have made attempts on their own lives, in particular taking into account their being of a specifi c sex/gender and in the context of work (especially in diffi cult or dangerous conditions or both.

  15. Biomass Indirect Liquefaction Strategy Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-07-01

    This report is based on the proceedings of the U.S. Department of Energy Bioenergy Technologies Office Biomass Indirect Liquefaction Strategy Workshop. The workshop, held March 20–21, 2014, in Golden, Colorado, discussed and detailed the research and development needs for biomass indirect liquefaction. Discussions focused on pathways that convert biomass-based syngas (or any carbon monoxide, hydrogen gaseous stream) to liquid intermediates (alcohols or acids) and further synthesize those intermediates to liquid hydrocarbons that are compatible as either a refinery feed or neat fuel.

  16. Clinical guidelines for indirect resin restorations.

    Science.gov (United States)

    Shannon, A

    1997-06-01

    Ongoing advances in adhesive dentistry have made it possible to successfully and predictably bond tooth-supporting restorations using conservative preparation techniques. Improvements in the durability and esthetic properties of tooth-colored restorative materials have also increased the range of available treatment options. However, dentists have been slow to accept both direct and indirect posterior esthetics. This article provides a step-by-step technique for practitioners who choose to treat their patients with indirect resin esthetic restorations. It will not discuss other posterior restorative treatment techniques or materials (i.e. gold, porcelain, amalgam, bonded amalgam, or direct resin).

  17. The Normative Foundation of Legal Orders: A Balance between Reciprocity and Mutuality

    NARCIS (Netherlands)

    D. Pessers

    2014-01-01

    Reciprocity seems to figure as a self-evident normative foundation of legal orders. Yet a clear understanding of the often opaque role that reciprocity plays in this regard demands drawing a conceptual distinction. This article views reciprocity as a social morality of duties, in opposition to mutua

  18. EFRC guidelines on how to avoid liquid problems in reciprocating compressor systems

    NARCIS (Netherlands)

    Shoeibi Omrani, P.; Eijk, A.

    2014-01-01

    Reciprocating compressors are widely used in a variety of industries. Issues with using reciprocating compressors are reliability concerns, especially system failures due to the presence of liquids. The working principle of reciprocating compressors are based on the gas compression of a closed

  19. EFRC guidelines on how to avoid liquid problems in reciprocating compressor systems

    NARCIS (Netherlands)

    Shoeibi Omrani, P.; Eijk, A.

    2014-01-01

    Reciprocating compressors are widely used in a variety of industries. Issues with using reciprocating compressors are reliability concerns, especially system failures due to the presence of liquids. The working principle of reciprocating compressors are based on the gas compression of a closed volum

  20. Reciprocal altruism and group formation : The degree of segmentation of reciprocal altruists who prefer 'old-helping-partners'

    NARCIS (Netherlands)

    Zeggelink, E.P.H.; de Vos, H.; Elsas, D.A.

    2000-01-01

    To what degree does reciprocal altruism add to the explanation of the human way of group living? That is the main question of this paper. In order to find an answer to this question, we use the Social Evolution Model (SEM) that has been developed earlier. It allows us to investigate both the conditi

  1. The Effect of Reciprocal Peer Tutoring and Non-Reciprocal Peer Tutoring on the Performance of Students in College Physics

    Science.gov (United States)

    Dioso-Henson, Luzale

    2012-01-01

    Formalised peer-to-peer collaboration and the use of web-enhanced materials that are consistent with course objectives, graded assessments and learning outcomes is well known in educational practice. This study compared the academic gains of college students enrolled in Physics using Reciprocal Peer Tutoring (RPT) with others using non-Reciprocal…

  2. Harmonious Parents and Their Preschool Children

    Science.gov (United States)

    Baumrind, Diana

    1971-01-01

    This brief report describes harmonious parents and their children. The six preschool daughters whose parents were harmonious were outstandingly competent but the opposite was true of the two sons. (Author/WY)

  3. Naps May Sharpen a Preschooler's Language Skills

    Science.gov (United States)

    ... fullstory_163510.html Naps May Sharpen a Preschooler's Language Skills Kids who slept after learning new verbs understood ... have an advantage when it comes to developing language skills, a new study suggests. Researchers assessed 39 youngsters ...

  4. Harmonious Parents and Their Preschool Children

    Science.gov (United States)

    Baumrind, Diana

    1971-01-01

    This brief report describes harmonious parents and their children. The six preschool daughters whose parents were harmonious were outstandingly competent but the opposite was true of the two sons. (Author/WY)

  5. Academic Language in Preschool: Research and Context

    Science.gov (United States)

    Michael Luna, Sara

    2017-01-01

    Developing and scaffolding academic language is an important job of preschool teachers. This Teaching Tip provides five strategies that extend the topic of academic language by integrating previous research and field-based data into classroom practice.

  6. Noise and stress effects on preschool personnel

    Directory of Open Access Journals (Sweden)

    Fredrik Sjödin

    2012-01-01

    Full Text Available The aim of the study was to analyze the presence of stress-related health problems among preschool employees and the way in which these reactions are related to noise and other work parameters. The investigation included 101 employees at 17 preschools in Umeå County, located in northern Sweden. Individual noise recordings and recordings in dining rooms and play halls were made at two departments from each preschool. The adverse effects on the employees were analyzed by use of different validated questionnaires and by saliva cortisol samples. Stress and energy output were pronounced among the employees, and about 30% of the staff experienced strong burnout syndromes. Mental recovery after work was low, indicated by remaining high levels of stress after work. The burnout symptoms were associated with reduced sleep quality and morning sleepiness. Cortisol levels supported the conclusion about pronounced daily stress levels of the preschool employees.

  7. Green Settings for Children in Preschools

    DEFF Research Database (Denmark)

    Lerstrup, Inger Elisabeth

    This Danish study investigates the relationship between children in preschool (age range 3-6.5 years) and the outdoor environments they use. The main aim is to describe and analyse the outdoor features of significance for children’s activities and of importance for design and management of green...... settings for preschools. The intent is to facilitate transfer of knowledge from preschools to planners and managers of green settings such as woodland, parks, green lots and playgrounds. The central concept applied is that of affordances, here defined as the meaningful action possibilities...... between forest features and manufactured features, a detailed account of the affordances of ditches, and a description of the forest sites used by a Danish forest preschool. Children were attracted to features with changing and not fully explored action possibilities; forest features added variation...

  8. Affiliative Subgroups in Preschool Classrooms: Integrating Constructs and Methods from Social Ethology and Sociometric Traditions.

    Directory of Open Access Journals (Sweden)

    António J Santos

    Full Text Available Recent studies of school-age children and adolescents have used social network analyses to characterize selection and socialization aspects of peer groups. Fewer network studies have been reported for preschool classrooms and many of those have focused on structural descriptions of peer networks, and/or, on selection processes rather than on social functions of subgroup membership. In this study we started by identifying and describing different types of affiliative subgroups (HMP- high mutual proximity, LMP- low mutual proximity, and ungrouped children in a sample of 240 Portuguese preschool children using nearest neighbor observations. Next, we used additional behavioral observations and sociometric data to show that HMP and LMP subgroups are functionally distinct: HMP subgroups appear to reflect friendship relations, whereas LMP subgroups appear to reflect common social goals, but without strong, within-subgroup dyadic ties. Finally, we examined the longitudinal implications of subgroup membership and show that children classified as HMP in consecutive years had more reciprocated friendships than did children whose subgroup classification changed from LMP or ungrouped to HMP. These results extend previous findings reported for North American peer groups.

  9. Maternal Effects on Seed and Seedling Phenotypes in Reciprocal F1 Hybrids of the Common Bean (Phaseolus vulgaris L.)

    Science.gov (United States)

    Singh, Jugpreet; Clavijo Michelangeli, Jose A.; Gezan, Salvador A.; Lee, Hyungwon; Vallejos, C. Eduardo

    2017-01-01

    Maternal control of seed size in the common bean provides an opportunity to study genotype-independent seed weight effects on early seedling growth and development. We set out to test the hypothesis that the early heterotrophic growth of bean seedlings is determined by both the relative amount of cotyledon storage reserves and the genotype of the seedling, provided the hybrid genotype could be fully expressed in the seedlings. The hypothesis was tested via comparison of seed weight and seedling growth phenotypes of small-seeded (wild, ~0.10 g) and large-seeded (landrace, ~0.55 g) parents and their reciprocal F1 hybrids. Akaike's Information Criteria were used to estimate growth parameters and identify the phenotypic model that best represented the data. The analysis presented here indicates that the hybrid embryo genotype is not fully expressed during both seed and seedling growth and development. The analysis presented here shows that seed growth and development are controlled by the sporophyte. The strong similarity in seed size and shape of the reciprocal hybrid seed with seeds of the maternal parents is evidence of this control. The analysis also indicates that since the maternal sporophyte controls seed size and therefore the amount of cotyledon reserves, the maternal sporophyte indirectly controls early seedling growth because the cotyledons are the primary nutrient source during heterotrophic growth. The most interesting and surprising results indicated that the maternal effects extended to the root architecture of the reciprocal hybrid seedlings. This phenomenon could not be explained by seed size, but by alterations in the control of the pattern of gene expression of the seedling, which apparently was set by a maternally controlled mechanism. Although seed weight increase was the main target of bean domestication, it also had positive repercussions on early-growth traits and stand establishment. PMID:28174586

  10. Social and Ideological Entanglements of Preschool Education

    Directory of Open Access Journals (Sweden)

    Urszula Dzikiewicz-Gazda

    2012-11-01

    Full Text Available In this article I address a phenomenon that I call “neo-liberal entanglements” of preschool education, clearly observable in the project “Enterprising Preschooler” currently underway in Wroclaw's preschools. I provide a critical analysis of the project, exposing the ideological mechanisms that contribute to the commercialization of children’s life worlds and their early socialization into the mechanisms of market consumerism.

  11. Reciprocity and its utilization in ultrasonic flow meters

    Energy Technology Data Exchange (ETDEWEB)

    Lunde, Per; Vestrheim, Magne; Boe, Reidar; Smoergrav, Skule; Abrahamsen, Atle K.

    2005-07-01

    In ultrasonic transit time flow meters for gas and liquid (USMs), the flow direction, the flow velocity and the sound velocity are estimated from the measured up- and downstream transit times. At no-flow conditions, the up- and downstream transit times of such meters should ideally be the same, or the difference should be negligible. This may not be the case unless special precautions are made. In order to reduce the possibility of the meter to detect a false flow at no-flow conditions, USMs are typically ''dry calibrated'' before being installed in the field. ''Dry calibration'' (which may be made in different ways), in general involves measurement of (a) the time delays due to electronics, cables and transducers, (b) the so called ''{delta}t-correction'' (for each acoustic path, also denoted ''zero flow offset factor''), and (c) geometrical parameters. Various {delta}t-correction approaches may be used by different manufacturers, but these are basically similar and have the same purpose: to reduce the false flow detection and improve the accuracy at low and no-flow conditions (''zero flow adjustment''), without significantly affecting the accuracy at the high velocity measurements. The AGA-9 report and the API MPMS Ch. 5.8 standard both prescribe need for ''zero flow verification test (zero test)'' or ''zeroing the meter'', for gas and liquid USMs, respectively. Advances in USM technology based on the electro acoustic reciprocity principle have provided methods for reduction or even neglect ion of the need for ''{delta} t-correction'' of USMs. That means, if the USM measurement system is reciprocal, and operated in a ''sufficiently reciprocal'' way, the ''{delta}t-correction'' may be negligibly small over the operational range of pressure and temperature, and

  12. Correlation of Positive and Negative Reciprocity Fails to Confer an Evolutionary Advantage: Phase Transitions to Elementary Strategies

    Directory of Open Access Journals (Sweden)

    Attila Szolnoki

    2013-11-01

    Full Text Available Economic experiments reveal that humans value cooperation and fairness. Punishing unfair behavior is therefore common, and according to the theory of strong reciprocity, it is also directly related to rewarding cooperative behavior. However, empirical data fail to confirm that positive and negative reciprocity are correlated. Inspired by this disagreement, we determine whether the combined application of reward and punishment is evolutionarily advantageous. We study a spatial public goods game, where in addition to the three elementary strategies of defection, rewarding, and punishment, a fourth strategy that combines the latter two competes for space. We find rich dynamical behavior that gives rise to intricate phase diagrams where continuous and discontinuous phase transitions occur in succession. Indirect territorial competition, spontaneous emergence of cyclic dominance, as well as divergent fluctuations of oscillations that terminate in an absorbing phase are observed. Yet, despite the high complexity of solutions, the combined strategy can survive only in very narrow and unrealistic parameter regions. Elementary strategies, either in pure or mixed phases, are much more common and likely to prevail. Our results highlight the importance of patterns and structure in human cooperation, which should be considered in future experiments.

  13. Correlation of Positive and Negative Reciprocity Fails to Confer an Evolutionary Advantage: Phase Transitions to Elementary Strategies

    Science.gov (United States)

    Szolnoki, Attila; Perc, Matjaž

    2013-10-01

    Economic experiments reveal that humans value cooperation and fairness. Punishing unfair behavior is therefore common, and according to the theory of strong reciprocity, it is also directly related to rewarding cooperative behavior. However, empirical data fail to confirm that positive and negative reciprocity are correlated. Inspired by this disagreement, we determine whether the combined application of reward and punishment is evolutionarily advantageous. We study a spatial public goods game, where in addition to the three elementary strategies of defection, rewarding, and punishment, a fourth strategy that combines the latter two competes for space. We find rich dynamical behavior that gives rise to intricate phase diagrams where continuous and discontinuous phase transitions occur in succession. Indirect territorial competition, spontaneous emergence of cyclic dominance, as well as divergent fluctuations of oscillations that terminate in an absorbing phase are observed. Yet, despite the high complexity of solutions, the combined strategy can survive only in very narrow and unrealistic parameter regions. Elementary strategies, either in pure or mixed phases, are much more common and likely to prevail. Our results highlight the importance of patterns and structure in human cooperation, which should be considered in future experiments.

  14. Physical Activity in Preschool Children: Comparison between Montessori and Traditional Preschools

    Science.gov (United States)

    Pate, Russell R.; O'Neill, Jennifer R.; Byun, Wonwoo; McIver, Kerry L.; Dowda, Marsha; Brown, William H.

    2014-01-01

    Background: Little is known about the influence of Montessori methods on children's physical activity (PA). This cross-sectional study compared PA of children attending Montessori and traditional preschools. Methods: We enrolled 301 children in 9 Montessori and 8 traditional preschools in Columbia, South Carolina. PA was measured by accelerometry…

  15. Physical Activity in Preschool Children: Comparison between Montessori and Traditional Preschools

    Science.gov (United States)

    Pate, Russell R.; O'Neill, Jennifer R.; Byun, Wonwoo; McIver, Kerry L.; Dowda, Marsha; Brown, William H.

    2014-01-01

    Background: Little is known about the influence of Montessori methods on children's physical activity (PA). This cross-sectional study compared PA of children attending Montessori and traditional preschools. Methods: We enrolled 301 children in 9 Montessori and 8 traditional preschools in Columbia, South Carolina. PA was measured by accelerometry…

  16. Disentangling Directand Indirect Effects of Credence Labels

    NARCIS (Netherlands)

    Dentoni, D.; Tonsor, G.; Calantone, R.; Peterson, C.

    2014-01-01

    The purpose of this paper is to disentangle the direct and indirect effects of three credence labels (Australian, animal welfare and grass-fed) on US consumer attitudes toward buying beef steaks. Furthermore, it explores the impact of consumer attribute knowledge, usage frequency, education and opin

  17. Indirect processes in electron-ion scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bottcher, C.; Griffin, D.C.; Pindzola, M.S.; Phaneuf, R.A.

    1983-10-01

    A summary is given of an informal workshop held at Oak Ridge National Laboratory on June 22-23, 1983, in which the current status of theoretical calculations of indirect processes in electron-ion scattering was reviewed. Processes of particular interest in astrophysical and fusion plasmas were emphasized. Topics discussed include atomic structure effects, electron-impact ionization, and dielectronic recombination.

  18. Goals and Indirect Objects in Seri.

    Science.gov (United States)

    Marlett, Stephen A.

    A number of Seri verbs display a sensitivity to whether a goal, which is a term used for recipients, adressees, etc., is singular or plural. The data presented in this paper are of typological interest. It is argued that Seri has indirect objects, but that there is no one-to-one mapping between the semantic role goal and either the syntactic…

  19. Have Indirect Emissions from Biofuels Been Exaggerated?

    Science.gov (United States)

    Kicklighter, D. W.; Gurgel, A.; Melillo, J. M.; Reilly, J. M.; Cronin, T.; Felzer, B. S.; Paltsev, S.; Schlosser, C. A.; Sokolov, A. P.

    2009-12-01

    The production of biofuels may lead to enhanced greenhouse gas (GHG) emissions from land to the atmosphere either by directly converting land to biofuel crops, or indirectly, by causing the displacement of food production and other land uses which then require additional land conversions. The importance of indirect GHG emissions from biofuel-related displacement of food production and other land uses is not known and is highly controversial. Here, we examine the direct and indirect land-use emissions over the 21st century from an expanded global bioenergy program, using a linked economic and terrestrial biogeochemistry modeling system under two different land use policies. We account for the dynamics of potential carbon losses or gains from land-use change along with nitrous oxide emissions from increased N fertilizer application. We find that: 1) indirect emissions from land use are responsible for substantially more carbon loss (up to twice as much) than direct land use; 2) increased nitrous oxide emissions over the century are more important to the GHG balance than the carbon losses themselves; 3) the GHG effects of biofuels change in both sign and magnitude over time so that the GHG cost/benefit of biofuels depends on the time horizon considered; and 4) the economics of biofuels become favorable sooner with the protection of forests. While biofuels can be an effective low carbon energy source from a GHG balance perspective, the associated land conversions may lead to an unacceptable loss of other ecosystem services.

  20. 19 CFR 18.26 - Indirect exportation.

    Science.gov (United States)

    2010-04-01

    ... merchandise to be exported and provide such evidence of exportation as required by the port director under... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect exportation. 18.26 Section 18.26 Customs... TRANSPORTATION IN BOND AND MERCHANDISE IN TRANSIT Exportation from Customs Custody of Merchandise Unentered...

  1. 19 CFR 18.43 - Indirect exportation.

    Science.gov (United States)

    2010-04-01

    .... port to another for actual exportation at the second port, any export declarations required to be... 19 Customs Duties 1 2010-04-01 2010-04-01 false Indirect exportation. 18.43 Section 18.43 Customs... TRANSPORTATION IN BOND AND MERCHANDISE IN TRANSIT Merchandise Not Otherwise Subject to Customs Control...

  2. The Use of Reciprocity in Atmospheric Source Inversion Problems

    Energy Technology Data Exchange (ETDEWEB)

    Nitao, J J

    2004-10-13

    The goal of the Event Reconstruction Project is to find the location and strength of atmospheric release points, both stationary and moving. Source inversion relies on observational data as input. The methodology is sufficiently general to allow various forms of data. In this report, the authors will focus primarily on concentration measurements obtained at point monitoring locations at various times. The algorithms being investigated in the Project are the MCMC (Markov Chain Monte Carlo), SMC (Sequential Monte Carlo) Methods, classical inversion methods, and hybrids of these. They refer the reader to the report by Johannesson et al. (2004) for explanations of these methods. These methods require computing the concentrations at all monitoring locations for a given ''proposed'' source characteristic (locations and strength history). It is anticipated that the largest portion of the CPU time will take place performing this computation. MCMC and SMC will require this computation to be done at least tens of thousands of times. Therefore, an efficient means of computing forward model predictions is important to making the inversion practical. In this report they show how Green's functions and reciprocal Green's functions can significantly accelerate forward model computations. First, instead of computing a plume for each possible source strength history, they can compute plumes from unit impulse sources only. By using linear superposition, they can obtain the response for any strength history. This response is given by the forward Green's function. Second, they may use the law of reciprocity. Suppose that they require the concentration at a single monitoring point x{sub m} due to a potential (unit impulse) source that is located at x{sub s}. instead of computing a plume with source location x{sub s}, they compute a ''reciprocal plume'' whose (unit impulse) source is at the monitoring locations x{sub m}. The

  3. "No Hablo Ingles": Bilingualism and Multiculturalism in Preschool Settings.

    Science.gov (United States)

    Fernandez, Roy Ceferino

    2000-01-01

    Discusses the role and components of both bilingualism and multiculturalism in preschool settings. Notes implications for the preparation of teachers and suggests strategies that preschool administrators could utilize in meeting needs of bilingual communities. (Author/DLH)

  4. "No Hablo Ingles": Bilingualism and Multiculturalism in Preschool Settings.

    Science.gov (United States)

    Fernandez, Roy Ceferino

    2000-01-01

    Discusses the role and components of both bilingualism and multiculturalism in preschool settings. Notes implications for the preparation of teachers and suggests strategies that preschool administrators could utilize in meeting needs of bilingual communities. (Author/DLH)

  5. Poor Sleep in Preschool Years Could Mean Behavior Troubles Later

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_164075.html Poor Sleep in Preschool Years Could Mean Behavior Troubles Later ... 2017 (HealthDay News) -- Preschoolers who get too little sleep may be more likely to have trouble paying ...

  6. Influence of agricultural biodiversity on dietary diversity of preschool ...

    African Journals Online (AJOL)

    Influence of agricultural biodiversity on dietary diversity of preschool children in Matungu ... African Journal of Food, Agriculture, Nutrition and Development ... preschool children was drawn from Matungu division using multistage, proportional

  7. Pearls of Meaning: Preschool Children Respond to Multicultural Picturebooks

    National Research Council Canada - National Science Library

    Xiufang Chen; Susan Browne

    2015-01-01

      Employing a qualitative practitioner research method, this study examined pre-school children's responses to multicultural picture books and gained insight into how pre-school children make meaning...

  8. Free Field Reciprocity Calibration in a Convergent Spherical Acoustic Wave of a Focusing Transducer

    Institute of Scientific and Technical Information of China (English)

    寿文德; 严加勇; 王鸿樟; 钱德初

    2002-01-01

    Based on the reciprocity theorem of the acoustic field, we derive the formula of the reciprocity coefficient of a convergent spherical acoustic wave and we calculate a series of diffraction corrective factor curves of the reciprocity coefficient of transducers. Using these formulae and corrective factors, we calibrate the free field transmitting current response and the free field voltage sensitivity of a focusing transducer using the self-reciprocity method.The experimental results of the reciprocity calibration of the focusing transducer in the frequency range of 2 MHz to 5.4 MHz are presented.

  9. Preschool teachers´ views on childrens learning

    DEFF Research Database (Denmark)

    Frøkjær, Thorleif; Brostrøm, Stig; Sandberg, Anette

    2014-01-01

    This comparative study investigated the perspectives of preschool teachers in Australia, Denmark, Estonia, German, Greece and Sweden about learning and participation in preschool. A structured survey questionnaire investigated four main questions: What situations can be characterised as learning......? What activities are important for learning? What are the best conditions for children's learning? How do preschool teachers understand participation in relation to children's learning in preschool? Results suggest that play, interactions with other children and adults, the provision of different...

  10. Preschool teachers’ views on children's learning: an international perspective

    DEFF Research Database (Denmark)

    Broström, Stig; Sandberg, Anette; Johansson, Inge

    2015-01-01

    This comparative study investigated the perspectives of preschool teachers in Australia, Denmark, Estonia, German, Greece and Sweden about learning and participation in preschool. A structured survey questionnaire investigated four main questions: What situations can be characterised as learning......? What activities are important for learning? What are the best conditions for children’s learning? How do preschool teachers understand participation in relation to children’s learning in preschool? Results suggest that play, interactions with other children and adults, the provision of different...

  11. Modeling of nonlinear responses for reciprocal transducers involving polarization switching

    DEFF Research Database (Denmark)

    Willatzen, Morten; Wang, Linxiang

    2007-01-01

    Nonlinearities and hysteresis effects in a reciprocal PZT transducer are examined by use of a dynamical mathematical model on the basis of phase-transition theory. In particular, we consider the perovskite piezoelectric ceramic in which the polarization process in the material can be modeled....... We present numerical results for the reciprocal-transducer system and identify the influence of nonlinearities on the system dynamics at high and low frequency as well as electrical impedance effects due to tuning by a series inductance. It is found that nonlinear effects are not important at high...... by Landau theory for the first-order phase transformation, in which each polarization state is associated with a minimum of the Landau free-energy function. Nonlinear constitutive laws are obtained by using thermodynamical equilibrium conditions, and hysteretic behavior of the material can be modeled...

  12. How evolution affects network reciprocity in Prisoner's Dilemma

    CERN Document Server

    Cimini, Giulio

    2014-01-01

    Cooperative behavior lies at the foundations of human societies, yet why people cooperate remains a conundrum. The issue, known as network reciprocity, of whether population structure can foster cooperation in social dilemmas has been addressed by many, but theoretical studies have yielded contradictory results so far---as the problem is very sensitive to how players adapt their strategy. However, recent experiments with the prisoner's dilemma game on different networks have shown that humans do not consider neighbors' payoffs when making their decisions, and that the network structure does not influence the final outcome. In this work we carry out an extensive analysis of different evolutionary dynamics for players' strategies, showing that the absence of network reciprocity is a general feature of those dynamics that do not take neighbors' payoffs into account. Our results, together with experimental evidence, hint at how to properly model real people's behavior.

  13. Experience sharing, emotional reciprocity, and turn-taking

    Directory of Open Access Journals (Sweden)

    Melisa eStevanovic

    2015-04-01

    Full Text Available In this perspective article, we consider the relationship between experience sharing and turn-taking. There is much evidence suggesting that human social interaction is permeated by two temporal organizations: (1 the sequential framework of turn-taking and (2 the concurrent framework of emotional reciprocity. From this perspective, we introduce two alternative hypotheses about how the relationship between experience sharing and turn-taking could be viewed. According to the first hypothesis, the home environment of experience sharing is in the concurrent framework of emotional reciprocity, while the motivation to share experiences is in tension with the sequential framework of turn-taking. According to the second hypothesis, then again, people’s inclination to coordinate their actions in terms of turn-taking is motivated precisely by their propensity to share experiences. We consider theoretical and empirical ideas in favor of both of these hypotheses and discuss their implications for future research.

  14. Born reciprocity in string theory and the nature of spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Freidel, Laurent, E-mail: lfreidel@perimeterinstitute.ca [Perimeter Institute for Theoretical Physics, 31 Caroline St., N, Ontario N2L 2Y5, Waterloo (Canada); Leigh, Robert G., E-mail: rgleigh@uiuc.edu [Department of Physics, University of Illinois, 1110 West Green St., Urbana, IL 61801 (United States); Minic, Djordje, E-mail: dminic@vt.edu [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States)

    2014-03-07

    After many years, the deep nature of spacetime in string theory remains an enigma. In this Letter we incorporate the concept of Born reciprocity in order to provide a new point of view on string theory in which spacetime is a derived dynamical concept. This viewpoint may be thought of as a dynamical chiral phase space formulation of string theory, in which Born reciprocity is implemented as a choice of a Lagrangian submanifold of the phase space, and amounts to a generalization of T-duality. In this approach the fundamental symmetry of string theory contains phase space diffeomorphism invariance and the underlying string geometry should be understood in terms of dynamical bi-Lagrangian manifolds and an apparently new geometric structure, somewhat reminiscent of para-quaternionic geometry, which we call Born geometry.

  15. Reciprocal teaching of social studies in inclusive elementary classrooms.

    Science.gov (United States)

    Lederer, J M

    2000-01-01

    Reading comprehension relies on the use of metacognitive strategies. Reciprocal teaching has been found to be an effective comprehension technique to use with students with learning disabilities. This study examined the effectiveness of reciprocal teaching during social studies instruction with several students with learning disabilities in fourth-, fifth-, and sixth-grade inclusive classrooms. One hundred and twenty-eight students in Grades 4, 5, and 6 participated. Four comprehension assessments were administered, as well as an external measure and 30-day maintenance assessment. A mixed-design MANOVA was used to determine interaction on three reading comprehension measures. Results indicated that all students improved their performance on comprehension measures compared with students in the control groups. Improvement continued to be displayed after 30 days in both the sixth and the fourth grades. Students with learning disabilities significantly improved their ability to compose summaries compared to the control students.

  16. Predicting online extremism, content adopters, and interaction reciprocity

    CERN Document Server

    Ferrara, Emilio; Varol, Onur; Flammini, Alessandro; Galstyan, Aram

    2016-01-01

    We present a machine learning framework that leverages a mixture of metadata, network, and temporal features to detect extremist users, and predict content adopters and interaction reciprocity in social media. We exploit a unique dataset containing millions of tweets generated by more than 25 thousand users who have been manually identified, reported, and suspended by Twitter due to their involvement with extremist campaigns. We also leverage millions of tweets generated by a random sample of 25 thousand regular users who were exposed to, or consumed, extremist content. We carry out three forecasting tasks, (i) to detect extremist users, (ii) to estimate whether regular users will adopt extremist content, and finally (iii) to predict whether users will reciprocate contacts initiated by extremists. All forecasting tasks are set up in two scenarios: a post hoc (time independent) prediction task on aggregated data, and a simulated real-time prediction task. The performance of our framework is extremely promising...

  17. Balanced reciprocal translocation 5,18: a case report

    Directory of Open Access Journals (Sweden)

    Shahram Savad

    2014-05-01

    Conclusion: A balanced reciprocal translocation carrier is phenotypically normal, but during meiosis І, carrier chromosomes cant pair normally and form quadrivalant instead of bivalant that depend on type of their segregation (alternate, adjacent 1, adjacent 2,3:1,4:0, produce gametes that are chromosomally unbalanced which can result in early fetus abortion. Considering the number of abnormal gametes, the most effective way to help couples with this problem seems to be PGD 24sure, since it can identify reciprocal and Robertsonian translocation and allows concurrent screening of all chromosomes for aneuploidy. Another technique that can be compared with PGD 24sure is fluorescence in situ hybridization (FISH, but it has several technical limitations such as it is expensive and complexity, in addition it has only few probes (for chromosomes 21, 13, 18, X, Y so sometimes necessary to create patient specific protocols.

  18. Experimental verification of reciprocity relations in quantum thermoelectric transport

    Science.gov (United States)

    Matthews, J.; Battista, F.; Sánchez, D.; Samuelsson, P.; Linke, H.

    2014-10-01

    Fundamental symmetries in thermoelectric quantum transport, beyond Onsagers relations, were predicted two decades ago but have to date not been observed in experiments. Recent works have predicted the symmetries to be sensitive to energy-dependent, inelastic scattering, raising the question whether they exist in practice. Here, we answer this question affirmatively by experimentally verifying the thermoelectric reciprocity relations in a four-terminal mesoscopic device where each terminal can be electrically and thermally biased individually. The linear-response thermoelectric coefficients are found to be symmetric under simultaneous reversal of magnetic field and exchange of injection and emission contacts. We also demonstrate a controllable breakdown of the reciprocity relations by increasing thermal bias, putting in prospect enhanced thermoelectric performance.

  19. Hybrid Optimization in the Design of Reciprocal Structures

    DEFF Research Database (Denmark)

    Parigi, Dario; Kirkegaard, Poul Henning; Sassone, Mario

    2012-01-01

    that explore the global domain of solutions as genetic algorithms (GAs). The benchmark tests show that when the control on the topology is required the best result is obtained by a hybrid approach that combines the global search of the GA with the local search of a GB algorithm. The optimization method......The paper presents a method to generate the geometry of reciprocal structures by means of a hybrid optimization procedure. The geometry of reciprocal structures where elements are sitting on the top or in the bottom of each other is extremely difficult to predict because of the non....... In this paper it is shown that the geometrically compatible position of the elements could be determined by local search algorithm gradient-based (GB). However the control on which bar sit on the top or in the bottom at each connection can be regarded as a topological problem and require the use of algorithms...

  20. Fault detection in reciprocating compressor valves under varying load conditions

    Science.gov (United States)

    Pichler, Kurt; Lughofer, Edwin; Pichler, Markus; Buchegger, Thomas; Klement, Erich Peter; Huschenbett, Matthias

    2016-03-01

    This paper presents a novel approach for detecting cracked or broken reciprocating compressor valves under varying load conditions. The main idea is that the time frequency representation of vibration measurement data will show typical patterns depending on the fault state. The problem is to detect these patterns reliably. For the detection task, we make a detour via the two dimensional autocorrelation. The autocorrelation emphasizes the patterns and reduces noise effects. This makes it easier to define appropriate features. After feature extraction, classification is done using logistic regression and support vector machines. The method's performance is validated by analyzing real world measurement data. The results will show a very high detection accuracy while keeping the false alarm rates at a very low level for different compressor loads, thus achieving a load-independent method. The proposed approach is, to our best knowledge, the first automated method for reciprocating compressor valve fault detection that can handle varying load conditions.