The Regulation of electronic money institutions in the SADC region ...

African Journals Online (AJOL)

It looks in particular at how the institutions that issue new electronic money products are regulated ... This development has become global and involves both developed and developing countries, including regions such as the SADC. ... regulatory challenges that came about with the development of electronic money and to ...

Reconsidering the origins of the Southern African regionalism thirty years later: towards a constructivist approach to the origins of SADC

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José Abel Moma

2012-01-01

Full Text Available The creation of SADCC has generated a debate over the real origins of the southern African model of regionalism. This paper develops the idea that the origins of SADC are both internal and external. Thus, southern African regionalism is understood as a constructivist articulation of internal and external inputs, which determined the creation of SADCC and its transformation into SADC.

Influence of Ultrasonic Nonlinear Propagation on Hydrophone Calibration Using Two-Transducer Reciprocity Method

Science.gov (United States)

Yoshioka, Masahiro; Sato, Sojun; Kikuchi, Tsuneo; Matsuda, Yoichi

2006-05-01

In this study, the influence of ultrasonic nonlinear propagation on hydrophone calibration by the two-transducer reciprocity method is investigated quantitatively using the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation. It is proposed that the correction for the diffraction and attenuation of ultrasonic waves used in two-transducer reciprocity calibration can be derived using the KZK equation to remove the influence of nonlinear propagation. The validity of the correction is confirmed by comparing the sensitivities calibrated by the two-transducer reciprocity method and laser interferometry.

Analysis of virtual water flows associated with the trade of maize in the SADC region: importance of scale

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J. M. Dabrowski

2009-10-01

Full Text Available The concept of virtual water encourages a country to view agricultural crops in terms of the amount of water required to produce those crops, with a view to implementing trading policies that promote the saving of scarce water resources. Recently, increased attention has focussed on partitioning the virtual water content of crops into green and blue water (derived from rainfall and irrigation, respectively as the latter has higher opportunity costs associated with its use and therefore impacts directly on scarcity. Maize is the most important crop traded within the SADC region. South Africa is the largest producer and exporter of maize, with the majority of its exports destined for other SADC countries. In comparison to other SADC countries, South Africa produces maize relatively efficiently, with a low virtual water content and a high green (868 m³ t⁻¹ to blue (117 m³ t⁻¹ water ratio. The blue water content is however higher than for maize produced in all other SADC countries, with the exception of Namibia (211 m³ t⁻¹. Current trade patterns therefore result in a net expenditure of blue water (66×10⁶ m³, almost all of which is exported by South Africa (65×10⁶ m³. South Africa is one of the most water scarce countries in the region and analysis of virtual water flows indicates that current SADC maize trading patterns are influenced by national productivity as opposed to water scarcity. The virtual water content of maize was estimated for each of South Africa's nineteen Water Management Area's (WMA and used as a proxy to represent water use efficiency for maize production. The virtual water content varied widely across all of the WMAs, ranging from 360 m³ t⁻¹ in the Ustutu Mhlatuze to 1000 m³ t⁻¹ in the Limpopo. A comparison of the virtual water content and production of maize

The Regulation Of Electronic Money Institutions In The SADC Region: Some Lessons From The EU

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Mmaphuti David Tuba

2014-12-01

Full Text Available This article analyses the different approaches adopted for the regulation of payment systems in a variety of legislative instruments by the European Union (EU. It looks in particular at how the institutions that issue new electronic money products are regulated and supervised by the relevant authorities in the EU, in comparison with existing institutions such as banks. It analyses some of the lessons that may be learned by the South African Development Corporation (SADC from the regulatory approaches for electronic money institutions adopted by the EU. The article asks if the approach adopted by the EU may be useful for the future regulation of electronic money institutions in the SADC. The proliferation of electronic devices that arrived with the invention of the Internet has sparked some regulatory challenges. This development has become global and involves both developed and developing countries, including regions such as the SADC. It is asked if these technological developments should be addressed by means of a concrete regulatory framework while they continue to develop, instead of the regulators waiting to observe and acquaint themselves with the relevant regulatory challenges that underpin the innovations. The EU has attempted to address the anticipated regulatory challenges that came about with the development of electronic money and to align its regulatory approach with other payment systems. This article discusses the regulatory approaches adopted in the EU and provides an overview that the SADC may use in order to adopt an effective regulatory framework for electronic money and the institutions that issue these methods of payment. It analyses both the achievements and the challenges that the EU faced (and continues to face in developing the regulation of e-money, and recommends some possible approaches derived from the lessons learned.

Disentangling social selection and social influence effects on adolescent smoking: the importance of reciprocity in friendships.

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Mercken, Liesbeth; Candel, Math; Willems, Paul; de Vries, Hein

2007-09-01

The goal of this study was to examine social selection and social influence within reciprocal and non-reciprocal friendships, and the role of parents and siblings, as factors explaining similarity of smoking behaviour among adolescent friends. A new social selection-social influence model is proposed. Longitudinal design with two measurements. Data were gathered among Dutch high school students in the control group of the European Smoking prevention Framework Approach (ESFA) study. The sample consisted of 1886 adolescents with a mean age of 12.7 years. The main outcome measures were the smoking behaviours of the respondents, best friends, parents and siblings. We tested the social selection-social influence model with structural equation modelling techniques. Social selection and social influence both played an important role in explaining similarity of smoking behaviour among friends. Within non-reciprocal friendships, only social selection explained similarity of smoking behaviour, whereas within reciprocal friendships, social influence and possibly also social selection explained similarity of smoking behaviour. Sibling smoking behaviour was a more important predictor of adolescent smoking behaviour than parental smoking behaviour. Social selection and social influence both promote similarity of smoking behaviour, and the impact of each process differs with the degree of reciprocity of friendships. These insights may contribute to further refinement of smoking prevention strategies.

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

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Miyaji, Kohei; Tanimoto, Jun; Wang, Zhen; Hagishima, Aya; Ikegaya, Naoki

2013-01-01

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.

An Examination of Reciprocal Influences in Sport Socialization

OpenAIRE

海老原, 修; 横山, 文人; 宮下, 充正

1989-01-01

This study was designed to clarify reciprocal influences in sport socialization. Parent-effects were assessed by their sport involvement before their child participated in organized sport, whereas child-effects were measured by a parent's attitudinal and behavioral changes of sport involvement caused by a child's participation. Eight indicators of sport involvement were selected as follows: 3 types of interest in sport involvement such as activities, sport consumption, and sport activity in o...

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....

SADC and the war in the Democratic republic of Congo : a critical view on the role of a regional organization in a conflict-torn memberstate

OpenAIRE

Dahlen, Inger Anette Sandvand

2005-01-01

During the last decade we have seen a great increase in regional integration projects around the world. Several of them are found within the African continent; the continent holds one of the highest densities of regional organisations in the world. Southern African Development Community (SADC) represents one of the more enduring efforts of regional cooperation in southern Africa. With its 13 member countries SADC covers a vast area in southern Africa . The economic- and political situations i...

A INTEGRAÇÃO SECURITÁRIA NA ÁFRICA AUSTRAL: A SADC E O OPDS

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Nathaly Xavier Schutz

2016-05-01

Full Text Available Os problemas de segurança do Continente Africano são, em sua grande maioria, originários dos processos de colonização e descolonização ocorridos ao longo dos séculos XIX e XX. Na África Austral, em específico, o regime do apartheid da África do Sul marcou de maneira bastante expressiva a construção de uma identidade comum e a aproximação entre os demais países da região em torno dos temas de segurança. O objetivo desse trabalho é avaliar a evolução da SADC ao longo dos anos 90 e 2000 no tocante aos aspectos securitários, visando analisar em que medida a organização contribuiu ou não para a resolução dos problemas políticos e de segurança da região, em especial nos momentos de crise. A análise será concentrada na criação e nas modificações do Órgão para a Cooperação em Política, Defesa e Segurança (OPDS da Comunidade para o Desenvolvimento da África Austral (SADC. A hipótese central do trabalho é de que a SADC, e o OPDS em específico, constituem a principal esfera de tratamento das questões securitárias da África Austral e, ao longo dos anos, contribuiu para evolução da resolução desses problemas. O trabalho irá utilizar a revisão bibliográfica e documental, adotando uma abordagem histórica, visando uma comparação temporal do caso em questão.

Health policy and integrated mental health care in the SADC region: strategic clarification using the Rainbow Model.

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van Rensburg, André Janse; Fourie, Pieter

2016-01-01

Mental illness is a well-known challenge to global development, particularly in low-to-middle income countries. A key health systems response to mental illness is different models of integrated health care, especially popular in the South African Development Community (SADC) region. This complex construct is often not well-defined in health policy, hampering implementation efforts. A key development in this vein has been the Rainbow Model of integrated care, a comprehensive framework and taxonomy of integrated care based on the integrative functions of primary care. The purpose of this study was to explore the nature and strategic forms of integrated mental health care in selected SADC countries, specifically how integrated care is outlined in state-driven policies. Health policies from five SADC countries were analysed using the Rainbow Model as framework. Electronic copies of policy documents were transferred into NVivo 10, which aided in the framework analysis on the different types of integrated mental health care promoted in the countries assessed. Several Rainbow Model components were emphasised. Clinical integration strategies (coordination of person-focused care) such as centrality of client needs, case management and continuity were central considerations, while others such as patient education and client satisfaction were largely lacking. Professional integration (inter-professional partnerships) was mentioned in terms of agreements on interdisciplinary collaboration and performance management, while organisational integration (inter-organisational relationships) emerged under the guise of inter-organisational governance, population needs and interest management. Among others, available resources, population management and stakeholder management fed into system integration strategies (horizontally and vertically integrated systems), while functional integration strategies (financial, management and information system functions) included human resource

Reciprocity in optics

International Nuclear Information System (INIS)

Potton, R J

2004-01-01

The application of reciprocity principles in optics has a long history that goes back to Stokes, Lorentz, Helmholtz and others. Moreover, optical applications need to be seen in the context of applications of reciprocity in particle scattering, acoustics, seismology and the solution of inverse problems, generally. In some of these other fields vector wave propagation is, as it is in optics, of the essence. For this reason the simplified approach to light wave polarization developed by, and named for, Jones is explored initially to see how and to what extent it encompasses reciprocity. The characteristic matrix of a uniform dielectric layer, used in the analysis of interference filters and mirrors, is reciprocal except when the layer is magneto-optical. The way in which the reciprocal nature of a characteristic matrix can be recognized is discussed next. After this, work on the influence of more realistic attributes of a dielectric stack on reciprocity is reviewed. Some of the numerous technological applications of magneto-optic non-reciprocal media are identified and the potential of a new class of non-reciprocal components is briefly introduced. Finally, the extension of the classical reciprocity concept to systems containing components that have nonlinear optical response is briefly mentioned

Symposium proceedings: Exploring transdisciplinarity to address change in the SADC water sector: Establishing the role of social scientists in this vision

CSIR Research Space (South Africa)

Jacobs-Mata, Inga M

2010-11-01

Full Text Available YSF is a WRC-funded initiative that strives to raise awareness about, and build capacity in, transdisciplinarity in the SADC water sector. This forum is an issue-driven, collaborative exchange for young water professionals and students, and one...

Applying the energy productivity index that considers maximized energy reduction on SADC (Southern Africa Development Community) members

International Nuclear Information System (INIS)

Chang, Ming-Chung

2016-01-01

Under the trend of global energy prices continuously going up, this paper considers the concept of maximized energy reduction to model the energy productivity index by decomposing it into energy technical change and energy efficiency change. The paper takes the eight SADC (Southern Africa Development Community ) members as an example to estimate their energy efficiency, energy productivity change, energy technical change, energy efficiency change, and rebound effect on energy use, as well as to test the Jevons Paradox. The time period of the data spans 2005 to 2009. The empirical result shows large energy performance differences among the eight SADC members. Not one country among the eight members is an energy technology innovator. After calculating the rebound effect and testing the Jevons Paradox, the result shows that there seems to be no obvious Jevons Paradox in this economic region. - Highlights: • This paper discusses the concept of maximized energy reduction. • The method is applied towards the Southern Africa Development Community members. • This paper also investigates the rebound effect of energy use. • We offer suggestions on energy use and CO 2 emission reductions.

The neural correlates of reciprocity are sensitive to prior experience of reciprocity.

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Cáceda, Ricardo; Prendes-Alvarez, Stefania; Hsu, Jung-Jiin; Tripathi, Shanti P; Kilts, Clint D; James, G Andrew

2017-08-14

Reciprocity is central to human relationships and is strongly influenced by multiple factors including the nature of social exchanges and their attendant emotional reactions. Despite recent advances in the field, the neural processes involved in this modulation of reciprocal behavior by ongoing social interaction are poorly understood. We hypothesized that activity within a discrete set of neural networks including a putative moral cognitive neural network is associated with reciprocity behavior. Nineteen healthy adults underwent functional magnetic resonance imaging scanning while playing the trustee role in the Trust Game. Personality traits and moral development were assessed. Independent component analysis was used to identify task-related functional brain networks and assess their relationship to behavior. The saliency network (insula and anterior cingulate) was positively correlated with reciprocity behavior. A consistent array of brain regions supports the engagement of emotional, self-referential and planning processes during social reciprocity behavior. Published by Elsevier B.V.

Influence of operator's experience on root canal shaping ability with a rotary nickel-titanium single-file reciprocating motion system.

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Muñoz, Estefanía; Forner, Leopoldo; Llena, Carmen

2014-04-01

The aim of this study was to evaluate the influence of the operator's experience on the shaping of double-curvature simulated root canals with a nickel-titanium single-file reciprocating motion system. Sixty double-curvature root canals simulated in methacrylate blocks were prepared by 10 students without any experience in endodontics and by 10 professionals who had studied endodontics at the postgraduate level. The Reciproc-VDW system's R25 file was used in the root canal preparation. The blocks were photographed before and after the instrumentation, and the time of instrumentation was also evaluated. Changes in root canal dimensions were analyzed in 6 positions. Significant differences (P file reciprocating motion system Reciproc is not seen to be influenced by the operator's experience regarding the increase of the canal area. Previous training and the need to acquire experience are important in the use of this system, in spite of its apparent simplicity. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Groundwater quality characterization to protect biodiversity in SADC region (Southern African Development Community

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Stefania Vitale

2016-06-01

Full Text Available The following paper describes the first phase of a study held in the context of the SECOSUD Phase II project, called “Conservation and equitable use of biological diversity in the SADC region (Southern African Development Community, which aims at promoting biodiversity conservation and sustainable economic development in the SADC [1]. The Southern African Development Community (SADC is an inter-governmental organization, with 15 member states: Angola, Botswana, Democratic Republic of Congo, Lesotho, Mauritius, Malawi, Mozambique, Namibia, Madagascar, Seychelles, South Africa, Swaziland, Tanzania, Zambia, and Zimbabwe. Its aim is to increase socio-economic cooperation and integration among the community. It is one of the richest area in terms of biodiversity. The main goal of the Project is to contribute to stop biodiversity loss by supporting the development of conservation strategies. Biodiversity or biological diversity is formally defined by the Convention on Biological Diversity (CBD as: “the variability among living organisms from all sources including, among others, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems” (UN 1992 Article 2 [2]. Biodiversity is affected by the interaction of multiple drivers and pressures including demographic, economic, socio-political, scientific and technological ones, which are leading to further decline, degradation and loss. The principal pressures on biodiversity include habitat loss and degradation, overexploitation, alien invasive species, climate change and pollution. These pressures are continuing to increase. To use biodiversity and to keep it in a sustainable way, it is necessary to study it, assess its economic value, develop a global strategy and a global network to monitor its status in the biosphere. An important step in developing conservation of biodiversity

SADC establishes a regional action plan.

Science.gov (United States)

Klouda, T

1997-02-01

The regional meeting held on AIDS strategy in Lilongwe, Malawi, in December, 1996, made important advances. The 12 countries of the SADC (Southern Africa Development Community) joined the European Union to institute a regional action plan for the reduction of susceptibility of people to HIV because of social, cultural, and environmental factors; the vulnerability of people with HIV infection to social and other difficulties; and the vulnerability of institutions because of the foregoing impacts. At the conference the issues explored were employment, mining, medical drugs, education, and tourism. An employment charter was seen as crucial for the success of AIDS and workplace activities. Facilitation of travel across borders was important for the reduction of susceptibility to HIV infection. Enhancement of regional policies for essential drugs was vital for drugs for the treatment of AIDS. The clarification of the regional role was critical for regional support of national action (strengthening technical and institutional capacities) and for regional joint action such as studies on research, harmonization of data collection on HIV/AIDS; organization of training; development of information and education on HIV/AIDS; facilitation of manufacturing of drugs and condoms; and the development of a regional information and education program about HIV/AIDS. The conference also clarified HIV/AIDS programs in relation to other health and socioeconomic problems.

Multi-membership and the effectiveness of regional trade agreements in Western and Southern Africa : A comparative study of ECOWAS and SADC

NARCIS (Netherlands)

S.K. Afesorgbor (Sylvanus Kwaku); P.A.G. van Bergeijk (Peter)

2011-01-01

textabstractUsing a gravity model for 35 countries and the years 1995-2006 we estimate the impact of regional trade agreements in Africa (in particular ECOWAS and SADC) and compare this to the a benchmark of North South trade integration (Europe’s preferential trade agreement). We find that •

Reciprocity Outperforms Conformity to Promote Cooperation.

Science.gov (United States)

Romano, Angelo; Balliet, Daniel

2017-10-01

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.

Detecting reciprocity at a global scale

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Frank, Morgan R.; Obradovich, Nick; Sun, Lijun; Woon, Wei Lee; LeVeck, Brad L.; Rahwan, Iyad

2018-01-01

Reciprocity stabilizes cooperation from the level of microbes all the way up to humans interacting in small groups, but does reciprocity also underlie stable cooperation between larger human agglomerations, such as nation states? Famously, evolutionary models show that reciprocity could emerge as a widespread strategy for achieving international cooperation. However, existing studies have only detected reciprocity-driven cooperation in a small number of country pairs. We apply a new method for detecting mutual influence in dynamical systems to a new large-scale data set that records state interactions with high temporal resolution. Doing so, we detect reciprocity between many country pairs in the international system and find that these reciprocating country pairs exhibit qualitatively different cooperative dynamics when compared to nonreciprocating pairs. Consistent with evolutionary theories of cooperation, reciprocating country pairs exhibit higher levels of stable cooperation and are more likely to punish instances of noncooperation. However, countries in reciprocity-based relationships are also quicker to forgive single acts of noncooperation by eventually returning to previous levels of mutual cooperation. By contrast, nonreciprocating pairs are more likely to exploit each other’s cooperation via higher rates of defection. Together, these findings provide the strongest evidence to date that reciprocity is a widespread mechanism for achieving international cooperation. PMID:29326983

Detecting reciprocity at a global scale.

Science.gov (United States)

Frank, Morgan R; Obradovich, Nick; Sun, Lijun; Woon, Wei Lee; LeVeck, Brad L; Rahwan, Iyad

2018-01-01

Reciprocity stabilizes cooperation from the level of microbes all the way up to humans interacting in small groups, but does reciprocity also underlie stable cooperation between larger human agglomerations, such as nation states? Famously, evolutionary models show that reciprocity could emerge as a widespread strategy for achieving international cooperation. However, existing studies have only detected reciprocity-driven cooperation in a small number of country pairs. We apply a new method for detecting mutual influence in dynamical systems to a new large-scale data set that records state interactions with high temporal resolution. Doing so, we detect reciprocity between many country pairs in the international system and find that these reciprocating country pairs exhibit qualitatively different cooperative dynamics when compared to nonreciprocating pairs. Consistent with evolutionary theories of cooperation, reciprocating country pairs exhibit higher levels of stable cooperation and are more likely to punish instances of noncooperation. However, countries in reciprocity-based relationships are also quicker to forgive single acts of noncooperation by eventually returning to previous levels of mutual cooperation. By contrast, nonreciprocating pairs are more likely to exploit each other's cooperation via higher rates of defection. Together, these findings provide the strongest evidence to date that reciprocity is a widespread mechanism for achieving international cooperation.

Five-Year-Old Preschoolers' Sharing is Influenced by Anticipated Reciprocation.

Science.gov (United States)

Xiong, Mingrui; Shi, Jiannong; Wu, Zhen; Zhang, Zhen

2016-01-01

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 non-reciprocal 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.

The influence of the reciprocal hip joint link in the advanced reciprocating gait orthosis on standing performance in paraplegia

NARCIS (Netherlands)

Baardman, G.; IJzerman, Maarten Joost; Hermens, Hermanus J.; Veltink, Petrus H.; Boom, H.B.K.; Zilvold, G.; Zilvold, G.

1997-01-01

The effect of reciprocally linking the hip hinges of a hip-knee-ankle-foot orthosis on standing performance was studied in a comparative trial of the Advanced Reciprocating Gait Orthosis (ARGO) and an ARGO in which the Bowden cable was removed (A_GO). Six male subjects with spinal cord injury (SCI)

Reciprocity of agonistic support in ravens.

Science.gov (United States)

Fraser, Orlaith N; Bugnyar, Thomas

2012-01-01

Cooperative behaviour through reciprocation or interchange of valuable services in primates has received considerable attention, especially regarding the timeframe of reciprocation and its ensuing cognitive implications. Much less, however, is known about reciprocity in other animals, particularly birds. We investigated patterns of agonistic support (defined as a third party intervening in an ongoing conflict to attack one of the conflict participants, thus supporting the other) in a group of 13 captive ravens, Corvus corax. We found support for long-term, but not short-term, reciprocation of agonistic support. Ravens were more likely to support individuals who preened them, kin and dominant group members. These results suggest that ravens do not reciprocate on a calculated tit-for-tat basis, but aid individuals from whom reciprocated support would be most useful and those with whom they share a good relationship. Additionally, dyadic levels of agonistic support and consolation (postconflict affiliation from a bystander to the victim) correlated strongly with each other, but we found no evidence to suggest that receiving agonistic support influences the victim's likelihood of receiving support (consolation) after the conflict ends. Our findings are consistent with an emotionally mediated form of reciprocity in ravens and provide additional support for convergent cognitive evolution in birds and mammals.

Telecommunications Liberalisation in Africa: Proposed Regulatory Model for the SADC Region

Directory of Open Access Journals (Sweden)

Z. Ntozintle Jobodwana

2009-12-01

maintenance and low number of computers with internet connectivity at schools, libraries and other public places. In this paper such challenges are identified and further reforms suggested. The ultimate recommendation is the one that states that a SADC telecommunication independent regulatory agency be established, independent of any government ministry, though consulting with a SADC Ministerial Council. Already, some countries in West Africa have developed a harmonized regulatory framework designed to integrate the Acts covering ICT markets in the sub-region and to keep policy and regulatory frameworks in line with the constant evolution of technologies, applications and services.

[Influences of Hospital Nurses' perceived reciprocity and Emotional Labor on Quality of Nursing Service and Intent to Leave].

Science.gov (United States)

Lee, Mi Aie; Kim, Eunjeong

2016-06-01

This study was performed to investigate the relationship among reciprocity, emotional labor, nursing service quality and intent to leave, and to identify factors influencing nursing service quality and intent to leave. This study was a cross-sectional survey. Participants were 300 nurses working at five general hospitals in two provincial cities in Gyeongsang Province, Korea. From May 1 to June 30, 2014, data were collected using structured questionnaires and analyzed with SPSS/PC ver 20.0 programs. There were relationships between reciprocity and nursing service quality, and intent to leave, and between emotional labor and intent to leave. Participants' general characteristics, reciprocity and emotional labor explained 48.4% of variance in nursing service quality and participants' general characteristics and these two independent variables explained 31.9% of intent to leave. These findings indicate that from the perception of hospital nurses, reciprocity and emotional labor are both very important factors to improve the quality of nursing service and decrease the intent to leave. So nursing managers should try to develop various personnel management programs focused on human emotions, and create a mutual respectable organizational culture and work environment.

Cyclic Fatigue Resistance of Reciproc Blue, Reciproc, and WaveOne Gold Reciprocating Instruments.

Science.gov (United States)

Keskin, Cangül; Inan, Uğur; Demiral, Murat; Keleş, Ali

2017-08-01

The aim of the present study was to compare the cyclic fatigue resistance of Reciproc Blue R25 (VDW, Munich, Germany) with Reciproc R25 (VDW) and WaveOne Gold Primary (Denstply Maillefer, Ballaigues, Switzerland). Fifteen Reciproc Blue R25, 15 Reciproc R25, and 15 WaveOne Gold Primary instruments were collected and tested in a dynamic cyclic fatigue test device, which has an artificial canal with a 60° angle of curvature and a 5-mm radius of curvature. All instruments were operated until fracture occurred, and time to fracture (TF) and the lengths of the fractured fragments were recorded. The mean and standard deviations of TF and fragment length were calculated for each reciprocating system. TF data were subjected to Kruskal-Wallis 1-way analysis of variance and the Dunn test, whereas fractured fragment length data were subjected to 1-way analysis of variance (P  .05). Reciproc Blue R25 instruments had significantly higher cyclic fatigue resistance than WaveOne Gold and Reciproc R25 instruments. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

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. © 2012 Wiley Periodicals, Inc.

Cutting efficiency of Reciproc and waveOne reciprocating instruments.

Science.gov (United States)

Plotino, Gianluca; Giansiracusa Rubini, Alessio; Grande, Nicola M; Testarelli, Luca; Gambarini, Gianluca

2014-08-01

The aim of the present study was to evaluate the cutting efficiency of 2 new reciprocating instruments, Reciproc and WaveOne. Twenty-four new Reciproc R25 and 24 new WaveOne Primary files were activated by using a torque-controlled motor (Silver Reciproc) and divided into 4 groups (n = 12): group 1, Reciproc activated by Reciproc ALL program; group 2, Reciproc activated by WaveOne ALL program; group 3, WaveOne activated by Reciproc ALL program; and group 4, WaveOne activated by WaveOne ALL program. The device used for the cutting test consisted of a main frame to which a mobile plastic support for the handpiece is connected and a stainless steel block containing a Plexiglas block (inPlexiglass, Rome, Italy) against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1 mm. Means and standard deviations of each group were calculated, and data were statistically analyzed with 1-way analysis of variance and Bonferroni test (P cutting efficiency than WaveOne Primary for both the movements used (P cutting efficiency than WaveOne instruments used with their proper reciprocating motion (P .05). Reciproc instruments demonstrated statistically higher cutting efficiency than WaveOne instruments. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Apical extrusion of debris using reciprocating files and rotary ...

African Journals Online (AJOL)

Procedure: Sixty extracted human mandibular premolars were used. The root canals were instrumented using reciprocating (WaveOne, Reciproc, SafeSider) or rotary ... and cross‑sections, and kinematics, and this situation may influence the amount of apically extruded debris through the apical foramen.[15]. The aim of this ...

The Influence of Reciprocal interactions in the Family on Academic Performance among Secondary School Students in Kenya

OpenAIRE

Rael Achieng Ogwari; Dr. Catherine Simiyu; Professor Jonah Nyaga Kindiki

2014-01-01

This study aimed to investigate the influence of reciprocal interactions in the family on academic performance among secondary school students in Siaya District. Stratified and purposive sampling techniques were used to select the study participants. The sample comprised of a total of 243 students (154 boys and 89 girls) drawn from 27 public coeducational schools in the district.  Data was collected using student questionnaires. The researchers’ judgment of the representativeness of the items...

Mutual influences between child emotion regulation and parent-child reciprocity support development across the first 10 years of life: Implications for developmental psychopathology.

Science.gov (United States)

Feldman, Ruth

2015-11-01

Elucidating the mechanisms by which infant birth conditions shape development across lengthy periods is critical for understanding typical and pathological development and for targeted early interventions. This study examined how newborns' regulatory capacities impact 10-year outcomes via the bidirectional influences of child emotion regulation (ER) and reciprocal parenting across early development. Guided by dynamic systems theory, 125 infants were tested at seven time points: birth, 3, 6, 12, and 24 months and 5 and 10 years. Initial regulatory conditions were measured by respiratory sinus arrhythmia (RSA; vagal tone) and neurobehavioral regulation (Brazelton, 1973) at birth. At each assessment between 3 months and 5 years, infant ER was microcoded from age-appropriate paradigms and mother-child reciprocity observed during social interactions. Four regulation-related outcomes were measured at 10 years: child RSA, empathy measured by mother-child conflict discussion and a lab paradigm, accident proneness, and behavior problems. An autoregressive cross-lagged structural model indicated that infant birth conditions impacted 10-year outcomes via three mechanisms. First, child ER and reciprocal parenting were individually stable across development and were each predicted by regulatory birth conditions, describing gradual maturation of ER and reciprocity over time. Second, better ER skills at one time point were related to greater reciprocity at the next time point and vice versa, and these cross-time effects defined a field of individual-context mutual influences that mediated the links between neonatal RSA and 10-year outcomes. Third, direct associations emerged between neonatal regulation and outcome, suggesting that birth conditions may establish a neurobiological milieu that promotes a more mature and resilient system. These mechanisms describe distinct "attractor" states that constrain the system's future options, emphasize the importance of defining behavior

Who takes the most revenge? Individual differences in negative reciprocity norm endorsement.

Science.gov (United States)

Eisenberger, Robert; Lynch, Patrick; Aselage, Justin; Rohdieck, Stephanie

2004-06-01

The authors report that beliefs favoring the reciprocation of unfavorable treatment form a unitary factor that is distinct from beliefs favoring the reciprocation of favorable treatment. Individual differences in endorsement of this negative reciprocity norm were related to (a) beliefs that people are generally malevolent; (b) inclination toward anger in everyday life; (c) anger, disagreement, and ridicule directed toward a new acquaintance who treated participants unfavorably; and (d) reduced anxiety, positive emotional engagement, and encouragement of a new acquaintance who treated participants favorably. These findings suggest that individual differences in endorsement of the negative norm of reciprocity influence the extent of vengeance.

Identification of groundwater flow parameters using reciprocal data from hydraulic interference tests

Science.gov (United States)

Marinoni, Marianna; Delay, Frederick; Ackerer, Philippe; Riva, Monica; Guadagnini, Alberto

2016-08-01

We investigate the effect of considering reciprocal drawdown curves for the characterization of hydraulic properties of aquifer systems through inverse modeling based on interference well testing. Reciprocity implies that drawdown observed in a well B when pumping takes place from well A should strictly coincide with the drawdown observed in A when pumping in B with the same flow rate as in A. In this context, a critical point related to applications of hydraulic tomography is the assessment of the number of available independent drawdown data and their impact on the solution of the inverse problem. The issue arises when inverse modeling relies upon mathematical formulations of the classical single-continuum approach to flow in porous media grounded on Darcy's law. In these cases, introducing reciprocal drawdown curves in the database of an inverse problem is equivalent to duplicate some information, to a certain extent. We present a theoretical analysis of the way a Least-Square objective function and a Levenberg-Marquardt minimization algorithm are affected by the introduction of reciprocal information in the inverse problem. We also investigate the way these reciprocal data, eventually corrupted by measurement errors, influence model parameter identification in terms of: (a) the convergence of the inverse model, (b) the optimal values of parameter estimates, and (c) the associated estimation uncertainty. Our theoretical findings are exemplified through a suite of computational examples focused on block-heterogeneous systems with increased complexity level. We find that the introduction of noisy reciprocal information in the objective function of the inverse problem has a very limited influence on the optimal parameter estimates. Convergence of the inverse problem improves when adding diverse (nonreciprocal) drawdown series, but does not improve when reciprocal information is added to condition the flow model. The uncertainty on optimal parameter estimates is

Reciprocating pellet press

Science.gov (United States)

Jones, Charles W.

1981-04-07

A machine for pressing loose powder into pellets using a series of reciprocating motions has an interchangeable punch and die as its only accurately machines parts. The machine reciprocates horizontally between powder receiving and pressing positions. It reciprocates vertically to press, strip and release a pellet.

Reciprocity of weighted networks.

Science.gov (United States)

Squartini, Tiziano; Picciolo, Francesco; Ruzzenenti, Franco; Garlaschelli, Diego

2013-01-01

In directed networks, reciprocal links have dramatic effects on dynamical processes, network growth, and higher-order structures such as motifs and communities. While the reciprocity of binary networks has been extensively studied, that of weighted networks is still poorly understood, implying an ever-increasing gap between the availability of weighted network data and our understanding of their dyadic properties. Here we introduce a general approach to the reciprocity of weighted networks, and define quantities and null models that consistently capture empirical reciprocity patterns at different structural levels. We show that, counter-intuitively, previous reciprocity measures based on the similarity of mutual weights are uninformative. By contrast, our measures allow to consistently classify different weighted networks according to their reciprocity, track the evolution of a network's reciprocity over time, identify patterns at the level of dyads and vertices, and distinguish the effects of flux (im)balances or other (a)symmetries from a true tendency towards (anti-)reciprocation.

The personal norm of reciprocity

NARCIS (Netherlands)

Perugini, M.; Gallucci, M.; Presaghi, F.; Ercolani, A.P.

2002-01-01

Reciprocity is here considered as an internalized social norm, and a questionnaire to measure individual differences in the internalized norm of reciprocity is presented. The questionnaire, Personal Norm of Reciprocity (PNR), measures three aspects of reciprocity: positive reciprocity, negative

Esquema mental de reciprocidade e influências sobre afetividade no trabalho Mental reciprocity's scheme and its influence on affectivity at work

Directory of Open Access Journals (Sweden)

Mirlene Maria Matias Siqueira

2005-04-01

Full Text Available Noções sociológicas de troca social têm marcante influência sobre como são interpretadas relações entre empregado e organização, destacando-se o papel exercido pela norma de reciprocidade. O presente estudo foi desenvolvido com o objetivo de ampliar a compreensão psicossocial de três conceitos: percepção de suporte, percepção de reciprocidade e comprometimento normativo. Apresentam-se hipóteses sobre sua integração a um esquema mental de reciprocidade e sua influência sobre dois critérios afetivos: satisfação no trabalho e comprometimento organizacional afetivo. Participaram do estudo 483 empregados de empresas particulares e públicas da Grande São Paulo. Os resultados do estudo atestaram a pertinência de se considerar os três conceitos analisados como integrantes do esquema mental de reciprocidade bem como evidenciaram a capacidade deste esquema explicar proporções significativas da variância de dois critérios afetivos. Percepção de suporte organizacional revelou-se o componente cognitivo com maior poder de influência sobre satisfação no trabalho e comprometimento afetivo.Sociological notions of social exchange have outstanding influence on the interpreted relations between employee and organization, being of relevance the role performed by the norm of reciprocity. The present study was developed with the objective of extending the psychological understanding of three concepts: perception of organizational support, perception of organizational reciprocity, and normative organizational commitment. Hypotheses were presented about their integration to a mental reciprocity scheme and about their influence on two affective criterions: job satisfaction and affective organizational commitment. 483 employees of private and public companies of the Great São Paulo took part in the study. The results certified the relevance of the three concepts considered as components of the mental reciprocity scheme, and

An evaluation of the SADC gender and development protocol on equality, empowerment and gender based violence in South Africa (2008-2012) / Mothepane Yaliwe Petunia Selebogo

OpenAIRE

Selebogo, Mothepane Yaliwe Petunia

2013-01-01

Southern Africa must confront a myriad of challenges as it attempts to address effectively the needs and aspirations of its hundred million people, 40 percent of whom live in extreme poverty with per capita incomes ranging from $256 per annum in Zimbabwe to $5099 in Mauritius. The greatest challenge of the Southern African Development Community (SADC) continues to be the need to build a life for its people free from poverty, diseases, human rights abuses, gender inequality and environmental d...

Theoretical and experimental study on the magnetic fluid seal of reciprocating shaft

Science.gov (United States)

Li, Decai; Xu, Haiping; He, Xinzhi; Lan, Huiqing

2005-03-01

The authors obtain anti-pressure formula of reciprocating shaft magnetic fluid seal from general Navier-Stokes equation. In order to verify the correctness of the anti-pressure formula, the authors set up a magnetic fluid anti-pressure experiment rig for a reciprocating seal. Finally, the authors have verified influence of speed and stroke on the seal anti-pressure.

Reciprocity in computer-human interaction: source-based, norm-based, and affect-based explanations.

Science.gov (United States)

Lee, Seungcheol Austin; Liang, Yuhua Jake

2015-04-01

Individuals often apply social rules when they interact with computers, and this is known as the Computers Are Social Actors (CASA) effect. Following previous work, one approach to understand the mechanism responsible for CASA is to utilize computer agents and have the agents attempt to gain human compliance (e.g., completing a pattern recognition task). The current study focuses on three key factors frequently cited to influence traditional notions of compliance: evaluations toward the source (competence and warmth), normative influence (reciprocity), and affective influence (mood). Structural equation modeling assessed the effects of these factors on human compliance with computer request. The final model shows that norm-based influence (reciprocity) increased the likelihood of compliance, while evaluations toward the computer agent did not significantly influence compliance.

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

K-groups of reciprocity functors

OpenAIRE

Ivorra, Florian; Rülling, Kay

2012-01-01

In this work we introduce reciprocity functors, construct the associated K-group of a family of reciprocity functors, which itself is a reciprocity functor, and compute it in several different cases. It may be seen as a first attempt to get close to the notion of reciprocity sheaves imagined by B. Kahn. Commutative algebraic groups, homotopy invariant Nisnevich sheaves with transfers, cycle modules or K\\"ahler differentials are examples of reciprocity functors. As commutative algebraic groups...

Examining reciprocal influences among family climate, school attachment, and academic self-regulation: Implications for school success.

Science.gov (United States)

Xia, Mengya; Fosco, Gregory M; Feinberg, Mark E

2016-06-01

Guided by family systems and ecological theories, this study examined the multicontextual implications of family, school, and individual domains for adolescents' school success. The first goal of this study was to examine reciprocal influences among family climate, school attachment, and academic self-regulation (ASR) during the middle school years. The second goal was to test the relative impact of each of these domains on adolescents' school adjustment and academic achievement after the transition to high school. We applied a cross-lag structural equation modeling approach to longitudinal data from 979 students in the 6th grade and their families, followed over 5 measurement occasions, from 6th through 9th grade. Controlling for family income, parent education, and adolescent gender, the results revealed reciprocal relationships between the family climate and school attachment over time; both of these factors were related to increases in ASR over time. In turn, ASR was a robust predictor of academic success, with unique associations with school adjustment and academic achievement. Family climate and school adjustment had modest to marginal associations with school adjustment, and no association with academic achievement. Applications of these findings for family school interventions are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

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.

The Influence of Reciprocal interactions in the Family on Academic Performance among Secondary School Students in Kenya

Directory of Open Access Journals (Sweden)

Rael Achieng Ogwari

2014-08-01

Full Text Available This study aimed to investigate the influence of reciprocal interactions in the family on academic performance among secondary school students in Siaya District. Stratified and purposive sampling techniques were used to select the study participants. The sample comprised of a total of 243 students (154 boys and 89 girls drawn from 27 public coeducational schools in the district.  Data was collected using student questionnaires. The researchers’ judgment of the representativeness of the items in the questionnaire to the study topic was used to determine content validity of the instrument while Cronbach’s alpha coefficient was used to ascertain validity and reliability of the instrument. Linear regression analysis and one way Analysis of Variance were used to analyze data. The results revealed significant relationship between reciprocal interactions in the family and academic performance of students. There was positive correlation between parental expectation, autonomy granting, cross-sex behaviour and students’ academic performance. Siblings’ sex dyads and birth order were also found to correlate with students’ academic performance. The findings may be used by policy makers to sensitize parents and students on the significance of specific interactions in the family on academic performance.

Rayleigh reciprocity relations: Applications

International Nuclear Information System (INIS)

Lin Ju; Li Xiao-Lei; Wang Ning

2016-01-01

Classical reciprocity relations have wide applications in acoustics, from field representation to generalized optical theorem. In this paper we introduce our recent results on the applications and generalization of classical Rayleigh reciprocity relation: higher derivative reciprocity relations as a generalization of the classical one and a theoretical proof on the Green’s function retrieval from volume noises. (special topic)

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 possi...... of all countries, independently of whether world prices change and independently of the relative numbers of goods and countries.......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...

Marmoset monkeys evaluate third-party reciprocity.

Science.gov (United States)

Kawai, Nobuyuki; Yasue, Miyuki; Banno, Taku; Ichinohe, Noritaka

2014-05-01

Many non-human primates have been observed to reciprocate and to understand reciprocity in one-to-one social exchanges. A recent study demonstrated that capuchin monkeys are sensitive to both third-party reciprocity and violation of reciprocity; however, whether this sensitivity is a function of general intelligence, evidenced by their larger brain size relative to other primates, remains unclear. We hypothesized that highly pro-social primates, even with a relatively smaller brain, would be sensitive to others' reciprocity. Here, we show that common marmosets discriminated between human actors who reciprocated in social exchanges with others and those who did not. Monkeys accepted rewards less frequently from non-reciprocators than they did from reciprocators when the non-reciprocators had retained all food items, but they accepted rewards from both actors equally when they had observed reciprocal exchange between the actors. These results suggest that mechanisms to detect unfair reciprocity in third-party social exchanges do not require domain-general higher cognitive ability based on proportionally larger brains, but rather emerge from the cooperative and pro-social tendencies of species, and thereby suggest this ability evolved in multiple primate lineages. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Belief in reciprocity in a Chinese sample.

Science.gov (United States)

Zhang, Zhen; Zhang, Jianxin

2012-08-01

Belief in reciprocity refers to a personally internalized faith in the reciprocity norm: that people will return positive and negative interactions or favors in kind. The current study aims to examine the relationship between belief in reciprocity and altruism among a Chinese sample. The Personal Norm of Reciprocity Scale, Trait Forgiveness Scale, Prosocial Tendency Measure, and Altruism Scale were used to assess extent of belief in reciprocity, forgiveness, and prosocial motivation, respectively, among 204 Chinese undergraduates. The results indicated that belief in reciprocity was a partially negative, but not neutral, reciprocity norm for Chinese people. Specifically, belief in reciprocity was positively related to negative reciprocity, but not significantly related to positive reciprocity. Moreover, belief in reciprocity was negatively related to both prosocial tendency and altruistic motivation. The results also indicated that forgiveness largely mediated the effect of belief in reciprocity on altruism. Finally, the implications and limitations of the current study were discussed.

Network homophily and the evolution of the pay-it-forward reciprocity.

Directory of Open Access Journals (Sweden)

Yen-Sheng Chiang

Full Text Available The pay-it-forward reciprocity is a type of cooperative behavior that people who have benefited from others return favors to third parties other than the benefactors, thus pushing forward a cascade of kindness. The phenomenon of the pay-it-forward reciprocity is ubiquitous, yet how it evolves to be part of human sociality has not been fully understood. We develop an evolutionary dynamics model to investigate how network homophily influences the evolution of the pay-it-forward reciprocity. Manipulating the extent to which actors carrying the same behavioral trait are linked in networks, the computer simulation model shows that strong network homophily helps consolidate the adaptive advantage of cooperation, yet introducing some heterophily to the formation of network helps advance cooperation's scale further. Our model enriches the literature of inclusive fitness theory by demonstrating the conditions under which cooperation or reciprocity can be selected for in evolution when social interaction is not confined exclusively to relatives.

Network homophily and the evolution of the pay-it-forward reciprocity.

Science.gov (United States)

Chiang, Yen-Sheng; Takahashi, Nobuyuki

2011-01-01

The pay-it-forward reciprocity is a type of cooperative behavior that people who have benefited from others return favors to third parties other than the benefactors, thus pushing forward a cascade of kindness. The phenomenon of the pay-it-forward reciprocity is ubiquitous, yet how it evolves to be part of human sociality has not been fully understood. We develop an evolutionary dynamics model to investigate how network homophily influences the evolution of the pay-it-forward reciprocity. Manipulating the extent to which actors carrying the same behavioral trait are linked in networks, the computer simulation model shows that strong network homophily helps consolidate the adaptive advantage of cooperation, yet introducing some heterophily to the formation of network helps advance cooperation's scale further. Our model enriches the literature of inclusive fitness theory by demonstrating the conditions under which cooperation or reciprocity can be selected for in evolution when social interaction is not confined exclusively to relatives.

Modeling of flexible reciprocating compressor considering the crosshead subsidence

Science.gov (United States)

Xue, Xiaogang; Liu, Shulin; Sun, Xin

2018-01-01

Crank-slider mechanisms are important parts of heavy duty machines, including reciprocating compressors, combustion motors. This paper targets on the dynamic response of the crosshead in a reciprocating compressor, taking into consideration the crosshead deviation from the original level. The traditional model of the compressor is usually a slider-mechanism system without considering the deflection of the crosshead, thus neglecting the influence of the piston rod, which has some flexible features. In this paper, a rigid-flexible model of slider-crank is described theoretically, using the commercial software MATLAB, where the crank, connecting rod and crosshead are treated as rigid bodies, while the piston rod connected to the crosshead is considered as a flexible body. The dynamic response of the mechanism with the crosshead subsidence is discussed detailedly in this paper. After calculated theoretically, the MATLAB simulation showed that the dynamic response of the crosshead will be greatly influenced if the crosshead subsided from the original level. Also, the influence of the crosshead subsidence was also investigated, and some extra vibration of the crosshead arises.

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....

Régimen jurídico de la gestión de los cursos de agua compartidos en la región de la comunidad para el desarrollo del Africa Austral (SADC

Directory of Open Access Journals (Sweden)

Eduardo Chiziane

2013-12-01

Full Text Available En el presente trabajo se da cuenta de la Comunidad para el Desarrollo del África Austral (SADC, por sus siglas en inglés; del régimen jurídico de la gestión de cursos de agua compartidos en ese ámbito espacial; y de la responsabilidad por los daños al medio ambiente en el Protocolo Revisado sobre Cursos de Agua Compartidos para esa región.Partiendo de la situación de especial vulnerabilidad a los impactos ambientales negativos que sufre Mozambique, como resultante de las actividades socio-económicas que, sobre los cursos de agua que comparte con los países vecinos, realizan éstos, integrantes todos de la SADC, con el objetivo de lograr una gestión más eficiente de esos recursos hídricos se propone introducir en  el Protocolo que los regula, el principio contaminador-pagador (PCP consagrado hace ya casi tres décadas, en la Cumbre de la Tierra, con un propósito esencialmente preventivo pero también de redistribución de los costos de la contaminación y de reparación de los daños causados. 

Alcohol expectancies, perceived norms, and drinking behavior among college students: examining the reciprocal determinism hypothesis.

Science.gov (United States)

Wardell, Jeffrey D; Read, Jennifer P

2013-03-01

Social learning mechanisms, such as descriptive norms for drinking behavior (norms) and positive alcohol expectancies (PAEs), play a major role in college student alcohol use. According to the principle of reciprocal determinism (Bandura, 1977), norms and PAEs should be reciprocally associated with alcohol use, each influencing one another over time. However, the nature of these prospective relationships for college students is in need of further investigation. This study provided the first examination of the unique reciprocal associations among norms, PAEs, and drinking together in a single model. PAEs become more stable with age, whereas norms are likely to be more dynamic upon college entry. Thus, we hypothesized that alcohol use would show stronger reciprocal associations with norms than with PAEs for college students. Students (N = 557; 67% women) completed online measures of PAEs, norms, and quantity and frequency of alcohol use in September of their first (T1), second (T2), and third (T3) years of college. Reciprocal associations were analyzed using a cross-lagged panel design. PAEs had unidirectional influences on frequency and quantity of alcohol use, with no prospective effects from alcohol use to PAEs. Reciprocal associations were observed between norms and alcohol use, but only for quantity and not for frequency. Specifically, drinking quantity prospectively predicted quantity norms and quantity norms prospectively predicted drinking quantity. This effect was observed across both years in the model. These findings support the reciprocal determinism hypothesis for norms but not for PAEs in college students and may help to inform norm-based interventions. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Non-reciprocity in nonlinear elastodynamics

Science.gov (United States)

Blanchard, Antoine; Sapsis, Themistoklis P.; Vakakis, Alexander F.

2018-01-01

Reciprocity is a fundamental property of linear time-invariant (LTI) acoustic waveguides governed by self-adjoint operators with symmetric Green's functions. The break of reciprocity in LTI elastodynamics is only possible through the break of time reversal symmetry on the micro-level, and this can be achieved by imposing external biases, adding nonlinearities or allowing for time-varying system properties. We present a Volterra-series based asymptotic analysis for studying spatial non-reciprocity in a class of one-dimensional (1D), time-invariant elastic systems with weak stiffness nonlinearities. We show that nonlinearity is neither necessary nor sufficient for breaking reciprocity in this class of systems; rather, it depends on the boundary conditions, the symmetries of the governing linear and nonlinear operators, and the choice of the spatial points where the non-reciprocity criterion is tested. Extension of the analysis to higher dimensions and time-varying systems is straightforward from a mathematical point of view (but not in terms of new non-reciprocal physical phenomena), whereas the connection of non-reciprocity and time irreversibility can be studied as well. Finally, we show that suitably defined non-reciprocity measures enable optimization, and can provide physical understanding of the nonlinear effects in the dynamics, enabling one to establish regimes of "maximum nonlinearity." We highlight the theoretical developments by means of a numerical example.

Reciprocal influences between negative life events and callous-unemotional traits.

Science.gov (United States)

Kimonis, Eva R; Centifanti, Luna C M; Allen, Jennifer L; Frick, Paul J

2014-11-01

Children with conduct problems and co-occurring callous-unemotional (CU) traits show more severe, stable, and aggressive antisocial behaviors than those without CU traits. Exposure to negative life events has been identified as an important contributing factor to the expression of CU traits across time, although the directionality of this effect has remained unknown due to a lack of longitudinal study. The present longitudinal study examined potential bidirectional effects of CU traits leading to experiencing more negative life events and negative life events leading to increases in CU traits across 3 years among a sample of community-based school-aged (M = 10.9, SD = 1.71 years) boys and girls (N = 98). Repeated rating measures of CU traits, negative life events and conduct problems completed by children and parents during annual assessments were moderately to highly stable across time. Cross-lagged models supported a reciprocal relationship of moderate magnitude between child-reported CU traits and "controllable" negative life events. Parent-reported CU traits predicted "uncontrollable" life events at the earlier time point and controllable life events at the later time point, but no reciprocal effect was evident. These findings have important implications for understanding developmental processes that contribute to the stability of CU traits in youth.

30 CFR 955.16 - Reciprocity.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Reciprocity. 955.16 Section 955.16 Mineral... AND ON INDIAN LANDS § 955.16 Reciprocity. (a) Grant of certificate. OSM shall grant an OSM blaster certificate through reciprocity to any qualified applicant who demonstrates that he or she, and whom OSM finds...

46 CFR 8.120 - Reciprocity.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Reciprocity. 8.120 Section 8.120 Shipping COAST GUARD... § 8.120 Reciprocity. (a) The Commandant may delegate authority to a classification society that has... determine reciprocity on a “case-by-case” basis. (b) In order to demonstrate that the conditions described...

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...

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.

Revisiting "The evolution of reciprocity in sizable groups": continuous reciprocity in the repeated n-person prisoner's dilemma.

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Takezawa, Masanori; Price, Michael E

2010-05-21

For many years in evolutionary science, the consensus view has been that while reciprocal altruism can evolve in dyadic interactions, it is unlikely to evolve in sizable groups. This view had been based on studies which have assumed cooperation to be discrete rather than continuous (i.e., individuals can either fully cooperate or else fully defect, but they cannot continuously vary their level of cooperation). In real world cooperation, however, cooperation is often continuous. In this paper, we re-examine the evolution of reciprocity in sizable groups by presenting a model of the n-person prisoner's dilemma that assumes continuous rather than discrete cooperation. This model shows that continuous reciprocity has a dramatically wider basin of attraction than discrete reciprocity, and that this basin's size increases with efficiency of cooperation (marginal per capita return). Further, we find that assortative interaction interacts synergistically with continuous reciprocity to a much greater extent than it does with discrete reciprocity. These results suggest that previous models may have underestimated reciprocity's adaptiveness in groups. However, we also find that the invasion of continuous reciprocators into a population of unconditional defectors becomes realistic only within a narrow parameter space in which the efficiency of cooperation is close to its maximum bound. Therefore our model suggests that continuous reciprocity can evolve in large groups more easily than discrete reciprocity only under unusual circumstances. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Reciprocity, Elder Satisfaction, and Caregiver Stress and Burden: The Exchange of Aid in the Family Caregiving Relationship.

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Dwyer, Jeffrey W.; And Others

1994-01-01

Examined how older mother's reciprocation of assistance provided by caregiving daughter simultaneously influences satisfaction of mother and stress/burden of caregiver in 135 mother-daughter dyads. Results indicated that reciprocity did not directly or indirectly affect mother's satisfaction but did significantly reduce stress/burden of daughters.…

Tacit Collusion under Fairness and Reciprocity

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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.

Effect of direct reciprocity and network structure on continuing prosperity of social networking services.

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Osaka, Kengo; Toriumi, Fujio; Sugawara, Toshihauru

2017-01-01

Social networking services (SNSs) are widely used as communicative tools for a variety of purposes. SNSs rely on the users' individual activities associated with some cost and effort, and thus it is not known why users voluntarily continue to participate in SNSs. Because the structures of SNSs are similar to that of the public goods (PG) game, some studies have focused on why voluntary activities emerge as an optimal strategy by modifying the PG game. However, their models do not include direct reciprocity between users, even though reciprocity is a key mechanism that evolves and sustains cooperation in human society. We developed an abstract SNS model called the reciprocity rewards and meta-rewards games that include direct reciprocity by extending the existing models. Then, we investigated how direct reciprocity in an SNS facilitates cooperation that corresponds to participation in SNS by posting articles and comments and how the structure of the networks of users exerts an influence on the strategies of users using the reciprocity rewards game. We run reciprocity rewards games on various complex networks and an instance network of Facebook and found that two types of stable cooperation emerged. First, reciprocity slightly improves the rate of cooperation in complete graphs but the improvement is insignificant because of the instability of cooperation. However, this instability can be avoided by making two assumptions: high degree of fun, i.e. articles are read with high probability, and different attitudes to reciprocal and non-reciprocal agents. We then propose the concept of half free riders to explain what strategy sustains cooperation-dominant situations. Second, we indicate that a certain WS network structure affects users' optimal strategy and facilitates stable cooperation without any extra assumptions. We give a detailed analysis of the different characteristics of the two types of cooperation-dominant situations and the effect of the memory of

Reciprocal Modulation of Cognitive and Emotional Aspects in Pianistic Performances

OpenAIRE

Higuchi, Marcia K. Kodama; Fornari, José; Del Ben, Cristina M.; Graeff, Frederico G.; Leite, João Pereira

2011-01-01

Background: High level piano performance requires complex integration of perceptual, motor, cognitive and emotive skills. Observations in psychology and neuroscience studies have suggested reciprocal inhibitory modulation of the cognition by emotion and emotion by cognition. However, it is still unclear how cognitive states may influence the pianistic performance. The aim of the present study is to verify the influence of cognitive and affective attention in the piano performances. Methods an...

Public privacy: Reciprocity and Silence

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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'.

Hidden patterns of reciprocity.

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Syi

2014-03-21

Reciprocity can help the evolution of cooperation. To model both types of reciprocity, we need the concept of strategy. In the case of direct reciprocity there are four second-order action rules (Simple Tit-for-tat, Contrite Tit-for-tat, Pavlov, and Grim Trigger), which are able to promote cooperation. In the case of indirect reciprocity the key component of cooperation is the assessment rule. There are, again, four elementary second-order assessment rules (Image Scoring, Simple Standing, Stern Judging, and Shunning). The eight concepts can be formalized in an ontologically thin way we need only an action predicate and a value function, two agent concepts, and the constant of goodness. The formalism helps us to discover that the action and assessment rules can be paired, and that they show the same patterns. The logic of these patterns can be interpreted with the concept of punishment that has an inherent paradoxical nature. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multistage Effort and the Equity Structure of Venture Investment Based on Reciprocity Motivation

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Chuan Ding

2015-01-01

Full Text Available For venture capitals, it is a long process from an entry to its exit. In this paper, the activity of venture investment will be divided into multistages. And, according to the effort level entrepreneurs will choose, the venture capitalists will provide an equity structure at the very beginning. As a benchmark for comparison, we will establish two game models on multistage investment under perfect rationality: a cooperative game model and a noncooperative one. Further, as a cause of pervasive psychological preference behavior, reciprocity motivation will influence the behavior of the decision-makers. Given this situation, Rabin’s reciprocity motivation theory will be applied to the multistage game model of the venture investment, and multistage behavior game model will be established as well, based on the reciprocity motivation. By looking into the theoretical derivations and simulation studies, we find that if venture capitalists and entrepreneurs both have reciprocity preferences, their utility would have been Pareto improvement compared with those under perfect rationality.

Reciprocal relationships between parenting behavior and disruptive psychopathology from childhood through adolescence.

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Burke, Jeffrey D; Pardini, Dustin A; Loeber, Rolf

2008-07-01

Theoretical models suggest that child behaviors influence parenting behaviors, and specifically that unpleasant child behaviors coerce parents to discontinue engaging in appropriate discipline. This study examined reciprocal relationships between parenting behaviors (supervision, communication, involvement, timid discipline and harsh punishment) and child disruptive disorder symptoms (ADHD, ODD and CD) in a clinic-referred sample of 177 boys. Annual measures, including structured clinical interviews, were obtained from the beginning of the study (when boys were between the ages of 7 to 12) to age 17. Specific reciprocal influence was observed; only timid discipline predicted worsening behavior, namely ODD symptoms, and ODD symptoms predicted increases in timid discipline. Greater influence from child behaviors to parenting practices was found: ODD also predicted poorer communication and decreased involvement, and CD predicted poorer supervision. ADHD was neither predictive of, nor predicted by, parenting behaviors. The results are specifically supportive of a coercive process between child behaviors and parenting behaviors, and generally suggestive of greater influence of child behaviors on parenting behaviors than of parenting behaviors on child behaviors.

Five-Year-Old Preschoolers’ Sharing is Influenced by Anticipated Reciprocation

DEFF Research Database (Denmark)

Xiong, Mingrui; Jiannong, Shi; Wu, Zhen

2016-01-01

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......-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...

Capuchin Monkeys Judge Third-Party Reciprocity

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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…

Imperfect information facilitates the evolution of reciprocity.

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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

Reciprocating Linear Electric Motor

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Goldowsky, M. P.

1984-01-01

Features include structural simplicity and good force/displacement characteristics. Reciprocating motor has simple, rugged construction, relatively low reciprocating weight, improved power delivery, and improved force control. Wear reduced by use of magnetic bearings. Intended to provide drivers for long-lived Stirling-cycle cryogenic refrigerators, concept has less exotic applications, such as fuel pumps.

The Structure of Reciprocity

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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…

Static non-reciprocity in mechanical metamaterials.

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Coulais, Corentin; Sounas, Dimitrios; Alù, Andrea

2017-02-23

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.

A multilevel simultaneous equations model for within-cluster dynamic effects, with an application to reciprocal parent–child and sibling effects

OpenAIRE

Fiona Steele; Jon Rasbash; Jennifer Jenkins

2013-01-01

There has been substantial interest in the social and health sciences in the reciprocal causal influences that people in close relationships have on one another. Most research has considered reciprocal processes involving only 2 units, although many social relationships of interest occur within a larger group (e.g., families, work groups, peer groups, classrooms). This article presents a general longitudinal multilevel modeling framework for the simultaneous estimation of reciprocal relations...

Potential Reciprocal Relationship between Motivation and Achievement: A Longitudinal Study

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Liu, Yuan; Hou, Shumeng

2018-01-01

Among the non-cognitive factors that influence academic achievement, intrinsic motivation has been found to be a potential reciprocal factor. The present study aims to determine the causal relationship between other types of motivation and academic achievement. For this purpose, a large-scale data survey, the National Education Longitudinal Study…

Free-field reciprocity calibration of laboratory standard (LS) microphones using a time selective technique

DEFF Research Database (Denmark)

Rasmussen, Knud; Barrera Figueroa, Salvador

2006-01-01

Although the basic principle of reciprocity calibration of microphones in a free field is simple, the practical problems are complicated due to the low signal-to-noise ratio and the influence of cross talk and reflections from the surroundings. The influence of uncorrelated noise can be reduced...

Study on the Effect of Reciprocating Pump Pipeline System Vibration on Oil Transportation Stations

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Hongfang Lu

2018-01-01

Full Text Available Due to the periodic movement of the piston in the reciprocating pump, the fluid will cause a pressure pulsation, and the resulting pipeline vibration may lead to instrument distortion, pipe failure and equipment damage. Therefore, it is necessary to study the vibration phenomena of reciprocating pump pipelines based on pressure pulsation theory. This paper starts from the reciprocating pump pipe pressure pulsation caused by a fluid, pressure pulsation in the pipeline and the unbalanced exciting force is calculated under the action of the reciprocating pump. Then, the numerical simulation model is established based on the pipe beam model, and the rationality of the numerical simulation method is verified by indoor experiments. Finally, a case study is taken as an example to analyze the vibration law of the pipeline system, and vibration reduction measures are proposed. The following main conclusions are drawn from the analysis: (1 unbalanced exciting forces are produced in the elbows or tee joints, and it can also influence the straight pipe to different levels; (2 in actual engineering, it should be possible to prevent the simultaneous settlement of multiple places; (3 the vibration amplitude increases with the pipe thermal stress, and when the oil temperature is higher than 85 °C, it had a greater influence on the vertical vibration amplitude of the pipe.

Sub-pm{{\\sqrt{Hz}^{-1}}} non-reciprocal noise in the LISA backlink fiber

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Fleddermann, Roland; Diekmann, Christian; Steier, Frank; Tröbs, Michael; Heinzel, Gerhard; Danzmann, Karsten

2018-04-01

The future space-based gravitational wave detector laser interferometer space antenna (LISA) requires bidirectional exchange of light between its two optical benches on board of each of its three satellites. The current baseline foresees a polarization-maintaining single-mode fiber for this backlink connection. Phase changes which are common in both directions do not enter the science measurement, but differential (‘non-reciprocal’) phase fluctuations directly do and must thus be guaranteed to be small enough. We have built a setup consisting of a Zerodur baseplate with fused silica components attached to it using hydroxide-catalysis bonding and demonstrated the reciprocity of a polarization-maintaining single-mode fiber at the 1 pm \\sqrt{Hz}-1 level as is required for LISA. We used balanced detection to reduce the influence of parasitic optical beams on the reciprocity measurement and a fiber length stabilization to avoid nonlinear effects in our phase measurement system (phase meter). For LISA, a different phase meter is planned to be used that does not show this nonlinearity. We corrected the influence of beam angle changes and temperature changes on the reciprocity measurement in post-processing.

Evidence of direct reciprocity, but not of indirect and generalized reciprocity, in the grooming exchanges of wild Barbary macaques (Macaca sylvanus).

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Molesti, Sandra; Majolo, Bonaventura

2017-09-01

Reciprocity is one of the mechanisms that have been proposed to explain the exchange of social behaviors, such as grooming, in animals. Reciprocity assumes that individuals act as the donor and recipient of grooming and switch roles over time to balance the benefits and costs of this behavior. Three main patterns of reciprocity may follow a grooming given: (i) direct reciprocity, where the former recipient returns the grooming to the former donor; (ii) indirect reciprocity, where another individual returns the grooming to the former donor; and (iii) generalized reciprocity, where the former recipient returns the grooming to another individual. While there is evidence that direct reciprocity plays an important role in various species of animals, the role of indirect and generalized reciprocity is less clear and has been rarely analyzed. We tested the role of direct, indirect, and generalized reciprocity in explaining grooming exchanges of wild Barbary macaques, by analyzing the temporal contingency between giving and receiving grooming. We collected the occurrence and latency of the three types of grooming reciprocation during 1 hr long focal sessions run simultaneously on two partners who just stopped grooming (post-grooming session) or who were in proximity (i.e., within 1.5 m) without grooming each other (control session). We ran the analyses on 284 post-grooming and 63 control sessions. The results revealed a temporal contingency of grooming interactions exchanged according to direct reciprocity but not according to indirect or generalized reciprocity. Our results indicate that grooming distribution in Barbary macaques is partner-specific. We discuss the possible role of cognition and emotions in explaining direct reciprocity in animals. © 2017 Wiley Periodicals, Inc.

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.

Reciprocity in therapeutic relationships: A conceptual review.

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Sandhu, Sima; Arcidiacono, Eleonora; Aguglia, Eugenio; Priebe, Stefan

2015-12-01

Reciprocity has generally been understood as a process of giving and taking, within an exchange of emotions or services, and has long been recognized as a central part of human life. However, an understanding of reciprocity in professional helping relationships has seldom received attention, despite movements in mental health care towards more collaborative approaches between service users and professionals. In this review, a systematic search of the published papers was conducted in order to explore how reciprocity is conceptualized and understood as part of the dyadic therapeutic relationship between professionals and service users. Eleven papers met our inclusion criteria and a narrative synthesis was used to synthesize the key concepts of reciprocity. The concepts of: 'dynamic equilibrium', 'shared affect', 'asymmetric alliance', and 'recognition as a fellow human being' were recurrent in understandings of reciprocity in professional contexts. These conceptualizations of reciprocity were also linked to specific behavioural and psychological processes. The findings suggest that reciprocity may be conceptualized and incorporated as a component of mental health care, with recurrent and observable processes which may be harnessed to promote positive outcomes for service users. To this end, we make recommendations for further research to progress and develop reciprocal processes in mental health care. © 2015 Australian College of Mental Health Nurses Inc.

Reciprocity in quantum, electromagnetic and other wave scattering

International Nuclear Information System (INIS)

Deák, L.; Fülöp, T.

2012-01-01

The reciprocity principle is that, when an emitted wave gets scattered on an object, the scattering transition amplitude does not change if we interchange the source and the detector—in other words, if incoming waves are interchanged with appropriate outgoing ones. Reciprocity is sometimes confused with time reversal invariance, or with invariance under the rotation that interchanges the location of the source and the location of the detector. Actually, reciprocity covers the former as a special case, and is fundamentally different from–but can be usefully combined with–the latter. Reciprocity can be proved as a theorem in many situations and is found violated in other cases. The paper presents a general treatment of reciprocity, discusses important examples, shows applications in the field of photon (Mössbauer) scattering, and establishes a fruitful connection with a recently developing area of mathematics. - Highlights: ► A frame independent generalized reciprocity theorem of scattering theory is given. ► Reciprocity for two spin/polarization degrees of freedom is detailed. ► Relationship of reciprocity to time reversal and to 180 degree rotation is discussed. ► Reciprocal and nonreciprocal settings in Mossbauer spectroscopy are studied. ► The symmetry of diffuse omega-scans is explained with the aid of reciprocity.

Reciprocity principle in duct acoustics

Science.gov (United States)

Cho, Y.-C.

1979-01-01

Various reciprocity relations in duct acoustics have been derived on the basis of the spatial reciprocity principle implied in Green's functions for linear waves. The derivation includes the reciprocity relations between mode conversion coefficients for reflection and transmission in nonuniform ducts, and the relation between the radiation of a mode from an arbitrarily terminated duct and the absorption of an externally incident plane wave by the duct. Such relations are well defined as long as the systems remain linear, regardless of acoustic properties of duct nonuniformities which cause the mode conversions.

Emotion understanding, pictorial representations of friendship and reciprocity in school-aged children.

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Laghi, Fiorenzo; Baiocco, Roberto; Di Norcia, Anna; Cannoni, Eleonora; Baumgartner, Emma; Bombi, Anna Silvia

2014-01-01

This study examined the relationship between emotional understanding, friendship representation and reciprocity in school-aged children. Two hundred and fifty-one Caucasian 6-year-old children (111 males and 140 females) took part in the study. The Test of Emotion Comprehension (TEC) and the Pictorial Assessment of Interpersonal Relationships (PAIR) were used. Children having a reciprocal friendship and children having a unilateral friendship with a child named as their "best friend" were compared on the emotional understanding task and on their pictorial representations of friendship. Multilevel analyses indicated that friendship status effects were not influenced by classroom-level differences. Results showed that children with reciprocal friendships drew themselves as more similar to and more cohesive with their best friends, and they showed better understanding of emotions, than children having a unilateral friendship. Finally, the implications of these findings for theoretical and empirical research development on friendship are discussed.

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....

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] and a discuss...

Evolution of cooperation: combining kin selection and reciprocal altruism into matrix games with social dilemmas.

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Som B Ale

Full Text Available Darwinian selection should preclude cooperation from evolving; yet cooperation is widespread among organisms. We show how kin selection and reciprocal altruism can promote cooperation in diverse 2×2 matrix games (prisoner's dilemma, snowdrift, and hawk-dove. We visualize kin selection as non-random interactions with like-strategies interacting more than by chance. Reciprocal altruism emerges from iterated games where players have some likelihood of knowing the identity of other players. This perspective allows us to combine kin selection and reciprocal altruism into a general matrix game model. Both mechanisms operating together should influence the evolution of cooperation. In the absence of kin selection, reciprocal altruism may be an evolutionarily stable strategy but is unable to invade a population of non-co-operators. Similarly, it may take a high degree of relatedness to permit cooperation to supplant non-cooperation. Together, a little bit of reciprocal altruism can, however, greatly reduce the threshold at which kin selection promotes cooperation, and vice-versa. To properly frame applications and tests of cooperation, empiricists should consider kin selection and reciprocal altruism together rather than as alternatives, and they should be applied to a broader class of social dilemmas than just the prisoner's dilemma.

Towards a unified theory of reciprocity.

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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.

Evaluation of the Cyclic Fatigue of WaveOne Gold and Reciproc Blue using Different Irrigating Medium

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Saif alislam Muhammad

2018-01-01

Full Text Available This study aimed to assess the resistance to cyclic fatigue of reciprocating nickel-titanium (NiTi files (Wave One Gold and Reciproc Blue and assess the effect of glyde and sodium hypochlorite 5.25% as a gel and liquid on it during testing. A total of 80 new WaveOne Gold primary and Reciproc Blue R25 were tested. The 40 files of the same brand were randomly assigned into four groups (n=8 and submitted to the irrigating protocol as follows: Group 1: Testing without irrigating media, Group 2: Testing with glyde, Group 3: Testing with sodium hypochlorite 5.25% gel, Group 4: Testing with sodium hypochlorite 5.25% liquid, Group 5: testing with normal saline (control. The cyclic fatigue test was performed using the appropriate preset reciprocating mode (‘RECIPROC ALL’ or ‘WAVEONE ALL’ in a specially designed endodontic motor. Resistance to fracture was determined by recording the time. The instrument tested in stainless artificial canal with 60° angle of curvature and 5 mm radius of curvature. Resistance to cyclic fatigue of the same NiTi was affected by irrigating media. Reciproc Blue R25 was associated with a higher cyclic fatigue resistance in all groups compared to WaveOne Gold Primary. The study concluded that glyde, sodium hypochlorite 5.25% as a gel and as a liquid may reduce the resistance to cyclic fatigue of WaveOne Gold and Reciproc Blue significantly. However, the type of reciprocating instrument influenced cyclic fatigue resistance with Reciproc Blue R25 being more resistant than WaveOne Gold Primary.

23 CFR 1235.8 - Reciprocity.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Reciprocity. 1235.8 Section 1235.8 Highways NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION AND FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION GUIDELINES UNIFORM SYSTEM FOR PARKING FOR PERSONS WITH DISABILITIES § 1235.8 Reciprocity. The State system...

Indirect Reciprocity; A Field Experiment.

Science.gov (United States)

van Apeldoorn, Jacobien; Schram, Arthur

2016-01-01

Indirect reciprocity involves cooperative acts towards strangers, either in response to their kindness to third parties (downstream) or after receiving kindness from others oneself (upstream). It is considered to be important for the evolution of cooperative behavior amongst humans. Though it has been widely studied theoretically, the empirical evidence of indirect reciprocity has thus far been limited and based solely on behavior in laboratory experiments. We provide evidence from an online environment where members can repeatedly ask and offer services to each other, free of charge. For the purpose of this study we created several new member profiles, which differ only in terms of their serving history. We then sent out a large number of service requests to different members from all over the world. We observe that a service request is more likely to be rewarded for those with a profile history of offering the service (to third parties) in the past. This provides clear evidence of (downstream) indirect reciprocity. We find no support for upstream indirect reciprocity (in this case, rewarding the service request after having previously received the service from third parties), however. Our evidence of downstream indirect reciprocity cannot be attributed to reputational effects concerning one's trustworthiness as a service user.

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.

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

Peacekeeping in the Congo, 1999-2001: Success or Failure?

Science.gov (United States)

2014-05-22

War. President Nelson Mandela was the chairman of the South African Development Community (SADC) in the summer of 1998 when the war broke out in the...DRC. President Mandela attempted to use his influence to bring peace to the region. On 3 September 1998, after high-level SADC meetings, President... Mandela announced the community’s support for the military interventions by its member states in the DRC conflict. President Mandela and his

33 CFR 173.17 - Reciprocity.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Reciprocity. 173.17 Section 173.17 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY VESSEL NUMBERING AND CASUALTY AND ACCIDENT REPORTING Numbering § 173.17 Reciprocity. (a) Section...

49 CFR 384.214 - Reciprocity.

Science.gov (United States)

2010-10-01

... 49 Transportation 5 2010-10-01 2010-10-01 false Reciprocity. 384.214 Section 384.214 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... Reciprocity. The State shall allow any person to operate a CMV in the State who is not disqualified from...

Bright lights, big city: influences of ecological light pollution on reciprocal stream-riparian invertebrate fluxes.

Science.gov (United States)

Meyer, Lars A; Sullivan, S Mazeika P

2013-09-01

Cities produce considerable ecological light pollution (ELP), yet the effects of artificial night lighting on biological communities and ecosystem function have not been fully explored. From June 2010 to June 2011, we surveyed aquatic emergent insects, riparian arthropods entering the water, and riparian spiders of the family Tetragnathidae at nine stream reaches representing common ambient ELP levels of Columbus, Ohio, USA, streams (low, 0.1-0.5 lux; moderate, 0.6-2.0 lux; high, 2.1-4.0 lux). In August 2011, we experimentally increased light levels at the low- and moderate-treatment reaches to 10-12 lux to represent urban streams exposed to extremely high levels of ELP. Although season exerted the dominant influence on invertebrate fluxes over the course of the year, when analyzed by season, we found that light strongly influenced multiple invertebrate responses. The experimental light addition resulted in a 44% decrease in tetragnathid spider density (P = 0.035), decreases of 16% in family richness (P = 0.040) and 76% in mean body size (P = 0.022) of aquatic emergent insects, and a 309% increase in mean body size of terrestrial arthropods (P = 0.015). Our results provide evidence that artificial light sources can alter community structure and ecosystem function in streams via changes in reciprocal aquatic-terrestrial fluxes of invertebrates.

The specificity of reciprocity: Young children reciprocate more generously to those who intentionally benefit them.

Science.gov (United States)

Vaish, Amrisha; Hepach, Robert; Tomasello, Michael

2018-03-01

Young children engage in direct reciprocity, but the mechanisms underlying such reciprocity remain unclear. In particular, prior work leaves unclear whether children's reciprocity is simply a response to receiving benefits (regardless of whether the benefits were intended) or driven by a mechanism of rewarding or preferring all benefactors (regardless of whom they benefited). Alternatively, perhaps children engage in genuine reciprocity such that they are particularly prosocial toward benefactors who intentionally provided them with benefits. Our findings support this third, richer possibility; the 3-year-olds who received benefits through the good intentions of a benefactor were subsequently more generous toward the benefactor than children who either (a) received the same benefits from the benefactor unintentionally or (b) observed the benefactor bestow the same benefits on another individual. Thus, young children are especially motivated to benefit those who have demonstrated goodwill toward them, suggesting, as one possible mechanism, an early sense of gratitude. Copyright © 2017 Elsevier Inc. All rights reserved.

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…

Electromagnetic reciprocity in antenna theory

CERN Document Server

Stumpf, Martin

2018-01-01

The reciprocity theorem is among the most intriguing concepts in wave field theory and has become an integral part of almost all standard textbooks on electromagnetic (EM) theory. This book makes use of the theorem to quantitatively describe EM interactions concerning general multiport antenna systems. It covers a general reciprocity-based description of antenna systems, their EM scattering properties, and further related aspects. Beginning with an introduction to the subject, Electromagnetic Reciprocity in Antenna Theory provides readers first with the basic prerequisites before offering coverage of the equivalent multiport circuit antenna representations, EM coupling between multiport antenna systems and their EM interactions with scatterers, accompanied with the corresponding EM compensation theorems.

On Reciprocal Causation in the Evolutionary Process.

Science.gov (United States)

Svensson, Erik I

2018-01-01

Recent calls for a revision of standard evolutionary theory (SET) are based partly on arguments about the reciprocal causation. Reciprocal causation means that cause-effect relationships are bi-directional, as a cause could later become an effect and vice versa. Such dynamic cause-effect relationships raise questions about the distinction between proximate and ultimate causes, as originally formulated by Ernst Mayr. They have also motivated some biologists and philosophers to argue for an Extended Evolutionary Synthesis (EES). The EES will supposedly expand the scope of the Modern Synthesis (MS) and SET, which has been characterized as gene-centred, relying primarily on natural selection and largely neglecting reciprocal causation. Here, I critically examine these claims, with a special focus on the last conjecture. I conclude that reciprocal causation has long been recognized as important by naturalists, ecologists and evolutionary biologists working in the in the MS tradition, although it it could be explored even further. Numerous empirical examples of reciprocal causation in the form of positive and negative feedback are now well known from both natural and laboratory systems. Reciprocal causation have also been explicitly incorporated in mathematical models of coevolutionary arms races, frequency-dependent selection, eco-evolutionary dynamics and sexual selection. Such dynamic feedback were already recognized by Richard Levins and Richard Lewontin in their bok The Dialectical Biologist . Reciprocal causation and dynamic feedback might also be one of the few contributions of dialectical thinking and Marxist philosophy in evolutionary theory. I discuss some promising empirical and analytical tools to study reciprocal causation and the implications for the EES. Finally, I briefly discuss how quantitative genetics can be adapated to studies of reciprocal causation, constructive inheritance and phenotypic plasticity and suggest that the flexibility of this approach

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.

Risk Behavior and Reciprocity of Organ Donation Attitudes in Young Men.

Science.gov (United States)

Vetterli, D C M; Lava, S A G; Essig, S; Milosevic, G; Cajöri, G; Uehlinger, D E; Moor, M B

2015-01-01

Lack of donor organs remains a major obstacle in organ transplantation. Our aim was to evaluate (1) the association between engaging in high-risk recreational activities and attitudes toward organ donation and (2) the degree of reciprocity between organ acceptance and donation willingness in young men. A 17-item, close-ended survey was offered to male conscripts ages 18 to 26 years in all Swiss military conscription centers. Predictors of organ donation attitudes were assessed in bivariate analyses and multiple logistic regression. Reciprocity of the intentions to accept and to donate organs was assessed by means of donor card status. In 1559 responses analyzed, neither motorcycling nor practicing extreme sports reached significant association with donor card holder status. Family communication about organ donation, student, or academic profession and living in a Latin linguistic region were predictors of positive organ donation attitudes, whereas residence in a German-speaking region and practicing any religion predicted reluctance. Significantly more respondents were willing to accept than to donate organs, especially among those without family communication concerning organ donation. For the first time, it was shown that high-risk recreational activities do not influence organ donation attitudes. Second, a considerable discrepancy in organ donation reciprocity was identified. We propose that increasing this reciprocity could eventually increase organ donation rates. Copyright © 2015 Elsevier Inc. All rights reserved.

Pengaruh Pembelajaran Reciprocal Teaching Berbantuan Peta Pikiran (Mind Map) terhadap Kemampuan Metakognitif dan Hasil Belajar Siswa SMA

OpenAIRE

Anita Dian Sukardi; Herawati Susilo; Siti Zubaidah

2015-01-01

Abstract: Metacognitive skill is required for improving students’ learning outcome. To enhance the metacognitive skill, it can be done through reciprocal teaching model. This study aims at examining the influence of mind map assisted reciprocal teaching toward students’ metacognitive and learning outcome. This study used semi-experimental design using non-randomized control group pretest-posttest. This study was conducted within Senior High School whose students possess a low level of metacog...

36 CFR 251.63 - Reciprocity.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Reciprocity. 251.63 Section 251.63 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Special Uses § 251.63 Reciprocity. If it is determined that a right-of-way shall be needed by the United States...

Do infants detect indirect reciprocity?

Science.gov (United States)

Meristo, Marek; Surian, Luca

2013-10-01

In social interactions involving indirect reciprocity, agent A acts prosocially towards B and this prompts C to act prosocially towards A. This happens because A's actions enhanced its reputation in the eyes of third parties. Indirect reciprocity may have been of central importance in the evolution of morality as one of the major mechanisms leading to the selection of helping and fair attitudes. Here we show that 10-month-old infants expect third parties to act positively towards fair donors who have distributed attractive resources equally between two recipients, rather than toward unfair donors who made unequal distributions. Infants' responses were dependent on the reciprocator's perceptual exposure to previous relevant events: they expected the reciprocator to reward the fair donor only when it had seen the distributive actions performed by the donors. We propose that infants were able to generate evaluations of agents that were based on the fairness of their distributive actions and to generate expectations about the social preferences of informed third parties. Copyright © 2013 Elsevier B.V. All rights reserved.

Teacher License Reciprocity. 50-State Review

Science.gov (United States)

Aragon, Stephanie

2017-01-01

This policy report defines and provides a 50-state review of teacher license reciprocity, explores how state-specific licensing requirements impact the teacher labor market, and includes examples of national and state efforts to facilitate reciprocity.

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.

Profit Sharing and Reciprocity: Theory and Survey Evidence

OpenAIRE

Cornelissen, Thomas; Heywood, John S.; Jirjahn, Uwe

2010-01-01

The 1/n problem potentially limits the effectiveness of profit sharing in motivating workers. While the economic literature suggests that reciprocity can mitigate this problem, it remains silent on the optimal degree of reciprocity. We present a representative model demonstrating that reciprocity may increase productive effort but may also increase unproductive effort such as socializing on the job. The model implies that reciprocity increases profit up to a point but decreases profit beyond ...

Development of the reciprocity of self-disclosure.

Science.gov (United States)

Rotenberg, K J; Chase, N

1992-03-01

This study was designed to assess whether children demonstrate covariant and equivalent forms of the reciprocity of self-disclosure, and if so, at what age. Twenty-one kindergarten, 23 second-grade, 24 fourth-grade, and 24 sixth-grade children were shown videotapes of three children (partners) who provided pre-established low-, medium-, and high-intimate disclosures. The subjects were required to send a message to the partners on topics varying in personal content. Fourth-grade children showed evidence of covariant reciprocity of self-disclosure by disclosing higher intimacy to high-intimate partners than to low-intimate partners. Sixth-grade children showed equivalent reciprocity of self-disclosure by providing a greater number of high- and medium-intimate disclosures to high- and medium-intimate partners, respectively, than to low-intimate partners. By contrast, neither form of reciprocity of self-disclosure was shown by kindergarten and second-grade children. Consistent with our expectations, girls provided a greater number of high-intimate disclosures than did boys in three of the four grades. The findings are discussed in terms of interplay between the development of the reciprocity of self-disclosure and the norm of the reciprocity of self-disclosure.

Reciprocal Relationships: Something for Everyone.

Science.gov (United States)

Tumosa, Nina

2017-01-01

Reciprocal relationships based on mutual goals, respect and trust are key to maintaining working relationships and getting reliable research results. Yet relationship building is not a concept taught in academia. These skills are often learned the hard way, with singular solutions found for case-by-case scenarios. Several journeys to identify the components, barriers and rewards of reciprocal relationships are discussed.

Trust and Reciprocity: Are Effort and Money Equivalent?

Science.gov (United States)

Vilares, Iris; Dam, Gregory; Kording, Konrad

2011-01-01

Trust and reciprocity facilitate cooperation and are relevant to virtually all human interactions. They are typically studied using trust games: one subject gives (entrusts) money to another subject, which may return some of the proceeds (reciprocate). Currently, however, it is unclear whether trust and reciprocity in monetary transactions are similar in other settings, such as physical effort. Trust and reciprocity of physical effort are important as many everyday decisions imply an exchange of physical effort, and such exchange is central to labor relations. Here we studied a trust game based on physical effort and compared the results with those of a computationally equivalent monetary trust game. We found no significant difference between effort and money conditions in both the amount trusted and the quantity reciprocated. Moreover, there is a high positive correlation in subjects' behavior across conditions. This suggests that trust and reciprocity may be character traits: subjects that are trustful/trustworthy in monetary settings behave similarly during exchanges of physical effort. Our results validate the use of trust games to study exchanges in physical effort and to characterize inter-subject differences in trust and reciprocity, and also suggest a new behavioral paradigm to study these differences. PMID:21364931

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.

Reciprocity in electron diffraction

International Nuclear Information System (INIS)

Gunning, J.; Goodman, P.

1992-01-01

The symmetry of reciprocity is reviewed in the context of relativistic quantum mechanics with the specific aim of relating to C, P and T invariances. From this investigation global time reversal is found to be a sufficient condition for reciprocity to hold in scattering from a vector potential. The present proof is free from assumptions of small-angle scattering and from restrictions on z-dependent terms in the scattering equation, and by avoiding S-matrix theory is thought to be accessible to undergraduate teaching. (orig.)

Alternative energy efficient membrane bioreactor using reciprocating submerged membrane.

Science.gov (United States)

Ho, J; Smith, S; Roh, H K

2014-01-01

A novel membrane bioreactor (MBR) pilot system, using membrane reciprocation instead of air scouring, was operated at constant high flux and daily fluctuating flux to demonstrate its application under peak and diurnal flow conditions. Low and stable transmembrane pressure was achieved at 40 l/m(2)/h (LMH) by use of repetitive membrane reciprocation. The results reveal that the inertial forces acting on the membrane fibers effectively propel foulants from the membrane surface. Reciprocation of the hollow fiber membrane is beneficial for the constant removal of solids that may build up on the membrane surface and inside the membrane bundle. The membrane reciprocation in the reciprocating MBR pilot consumed less energy than coarse air scouring used in conventional MBR systems. Specific energy consumption for the membrane reciprocation was 0.072 kWh/m(3) permeate produced at 40 LMH flux, which is 75% less than for a conventional air scouring system as reported in literature without consideration of energy consumption for biological aeration (0.29 kWh/m(3)). The daily fluctuating flux test confirmed that the membrane reciprocation is effective to handle fluctuating flux up to 50 LMH. The pilot-scale reciprocating MBR system successfully demonstrated that fouling can be controlled via 0.43 Hz membrane reciprocation with 44 mm or higher amplitude.

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 official...

On reciprocal Baecklund transformations of inverse scattering schemes

International Nuclear Information System (INIS)

Rogers, C.; Wong, P.

1984-01-01

The notion of reciprocally related inverse scattering schemes is introduced and is shown to be a key component in the link between the AKNS and WKI schemes. Reciprocal auto-Baecklund transformations are represented both for a generalised Harry-Dym equation and an equation descriptive of nonlinear oscillation of elastic beams. Further, the N-loop soliton solution of the KIW equation is generated in a convenient parametric form via reciprocal Baecklund transformations. Finally, an important reduction to canonical spectral form is shown to be a reciprocal transformation. (Auth.)

Effect of Glide Path Creating on Cyclic Fatigue Resistance of Reciproc and Reciproc Blue Nickel-titanium Files: A Laboratory Study.

Science.gov (United States)

Özyürek, Taha; Uslu, Gülşah; Yılmaz, Koray; Gündoğar, Mustafa

2018-06-01

The purpose of this article was to compare the cyclic fatigue resistance of Reciproc and Reciproc Blue files (VDW GmbH, Munich, Germany) that were used to prepare root canals of mandibular molar teeth with or without a glide path. Sixty Reciproc R25 and 60 Reciproc Blue R25 files were used. The Reciproc and Reciproc Blue groups were divided into 3 subgroups (ie, as received condition, used without a glide path, and used with a glide path). All the instruments were rotated in a stainless steel artificial canal with an inner diameter of 1.5 mm, a 60° angle of curvature, and a radius of curvature of 5 mm until fracture occurred. The number of cycle to fracture was calculated, and the length of the fractured segments was measured. The Kruskal-Wallis test was performed to statistically analyze the data using SPSS 21.0 software (IBM Corp, Armonk, NY) at a 5% significance level. The cyclic fatigue resistance of as received condition Reciproc Blue files was found to be higher than as received condition Reciproc files (P  .05). There was no statistically significant difference in the mean length of the fractured fragments of the instruments (P > .05). Within the limitations of this in vitro study, it was concluded that creating a glide path using ProGlider files had no effect on the cyclic fatigue resistance of RPC and RPC Blue files. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The influence of prior reputation and reciprocity on dynamic trust-building in adults with and without autism spectrum disorder.

Science.gov (United States)

Maurer, Cornelius; Chambon, Valerian; Bourgeois-Gironde, Sacha; Leboyer, Marion; Zalla, Tiziana

2018-03-01

The present study was designed to investigate the effects of reputational priors and direct reciprocity on the dynamics of trust building in adults with (N = 17) and without (N = 25) autism spectrum disorder (ASD) using a multi-round Trust Game (MTG). On each round, participants, who played as investors, were required to maximize their benefits by updating their prior expectations (the partner's positive or negative reputation), based on the partner's directed reciprocity, and adjusting their own investment decisions accordingly. Results showed that reputational priors strongly oriented the initial decision to trust, operationalized as the amount of investment the investor shares with the counterpart. However, while typically developed participants were mainly affected by the direct reciprocity, and rapidly adopted the optimal Tit-for-Tat strategy, participants with ASD continued to rely on reputational priors throughout the game, even when experience of the counterpart's actual behavior contradicted their prior-based expectations. In participants with ASD, the effect of the reputational prior never disappeared, and affected judgments of trustworthiness and reciprocity of the partner even after completion of the game. Moreover, the weight of prior reputation positively correlated with the severity of the ASD participant's social impairments while the reciprocity score negatively correlated with the severity of repetitive and stereotyped behaviors, as measured by the Autism Diagnostic Interview-Revised (ADI-R). In line with Bayesian theoretical accounts, the present findings indicate that individuals with ASD have difficulties encoding incoming social information and using it to revise and flexibly update prior social expectations, and that this deficit might severely hinder social learning and everyday life interactions. Copyright © 2017 Elsevier B.V. All rights reserved.

Reciprocal Trust Mediates Deep Transfer of Learning between Games of Strategic Interaction

Science.gov (United States)

Juvina, Ion; Saleem, Muniba; Martin, Jolie M.; Gonzalez, Cleotilde; Lebiere, Christian

2013-01-01

We studied transfer of learning across two games of strategic interaction. We found that the interpersonal relation between two players during and across two games influence development of reciprocal trust and transfer of learning from one game to another. We show that two types of similarities between the games affect transfer: (1) deep…

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.

Reciprocation of perceived organizational support.

Science.gov (United States)

Eisenberger, R; Armeli, S; Rexwinkel, B; Lynch, P D; Rhoades, L

2001-02-01

Four hundred thirteen postal employees were surveyed to investigate reciprocation's role in the relationships of perceived organizational support (POS) with employees' affective organizational commitment and job performance. The authors found that (a) POS was positively related to employees' felt obligation to care about the organization's welfare and to help the organization reach its objectives; (b) felt obligation mediated the associations of POS with affective commitment, organizational spontaneity, and in-role performance; and (c) the relationship between POS and felt obligation increased with employees' acceptance of the reciprocity norm as applied to work organizations. Positive mood also mediated the relationships of POS with affective commitment and organizational spontaneity. The pattern of findings is consistent with organizational support theory's assumption that POS strengthens affective commitment and performance by a reciprocation process.

Symmetry-based reciprocity: evolutionary constraints on a proximate mechanism.

Science.gov (United States)

Campennì, Marco; Schino, Gabriele

2016-01-01

Background. While the evolution of reciprocal cooperation has attracted an enormous attention, the proximate mechanisms underlying the ability of animals to cooperate reciprocally are comparatively neglected. Symmetry-based reciprocity is a hypothetical proximate mechanism that has been suggested to be widespread among cognitively unsophisticated animals. Methods. We developed two agent-based models of symmetry-based reciprocity (one relying on an arbitrary tag and the other on interindividual proximity) and tested their ability both to reproduce significant emergent features of cooperation in group living animals and to promote the evolution of cooperation. Results. Populations formed by agents adopting symmetry-based reciprocity showed differentiated "social relationships" and a positive correlation between cooperation given and received: two common aspects of animal cooperation. However, when reproduction and selection across multiple generations were added to the models, agents adopting symmetry-based reciprocity were outcompeted by selfish agents that never cooperated. Discussion. In order to evolve, hypothetical proximate mechanisms must be able to stand competition from alternative strategies. While the results of our simulations require confirmation using analytical methods, we provisionally suggest symmetry-based reciprocity is to be abandoned as a possible proximate mechanism underlying the ability of animals to reciprocate cooperative interactions.

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…

Short-Term Reciprocity in Late Parent-Child Relationships

Science.gov (United States)

Leopold, Thomas; Raab, Marcel

2011-01-01

Long-term concepts of parent-child reciprocity assume that the amount of support given and received is only balanced in a generalized fashion over the life course. We argue that reciprocity in parent-child relationships also operates in the short term. Our analysis of short-term reciprocity focuses on concurrent exchange in its main upward and…

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.

Indirect reciprocity with optional interactions.

Science.gov (United States)

Ghang, Whan; Nowak, Martin A

2015-01-21

Indirect reciprocity is a mechanism for the evolution of cooperation that is relevant for prosocial behavior among humans. Indirect reciprocity means that my behavior towards you also depends on what you have done to others. Indirect reciprocity is associated with the evolution of social intelligence and human language. Most approaches to indirect reciprocity assume obligatory interactions, but here we explore optional interactions. In any one round a game between two players is offered. A cooperator accepts a game unless the reputation of the other player indicates a defector. For a game to take place, both players must accept. In a game between a cooperator and a defector, the reputation of the defector is revealed to all players with probability Q. After a sufficiently large number of rounds the identity of all defectors is known and cooperators are no longer exploited. The crucial condition for evolution of cooperation can be written as hQB>1, where h is the average number of rounds per person and B=(b/c)-1 specifies the benefit-to-cost ratio. We analyze both stochastic and deterministic evolutionary game dynamics. We study two extensions that deal with uncertainty: hesitation and malicious gossip. Copyright © 2014 Elsevier Ltd. All rights reserved.

Subjective Well-Being, Test Anxiety, Academic Achievement: Testing for Reciprocal Effects.

Science.gov (United States)

Steinmayr, Ricarda; Crede, Julia; McElvany, Nele; Wirthwein, Linda

2015-01-01

In the context of adolescents' subjective well-being (SWB), research has recently focused on a number of different school variables. The direction of the relationships between adolescents' SWB, academic achievement, and test anxiety is, however, still open although reciprocal causation has been hypothesized. The present study set out to investigate to what extent SWB, academic achievement, and test anxiety influence each other over time. A sample of N = 290 11th grade students (n = 138 female; age: M = 16.54 years, SD = 0.57) completed measures of SWB and test anxiety in the time span of 1 year. Grade point average (GPA) indicated students' academic achievement. We analyzed the reciprocal relations using cross-lagged structural equation modeling. The model fit was satisfactory for all computed models. Results indicated that the worry component of test anxiety negatively and GPA positively predicted changes in the cognitive component of SWB (life satisfaction). Worry also negatively predicted changes in the affective component of SWB. Moreover, worry negatively predicted changes in students' GPA. Directions for future research and the differential predictive influences of academic achievement and test anxiety on adolescents' SWB are discussed with regard to potential underlying processes.

Subjective Well-Being, Test Anxiety, Academic Achievement: Testing for Reciprocal Effects

Directory of Open Access Journals (Sweden)

Ricarda eSteinmayr

2016-01-01

Full Text Available In the context of adolescents’ subjective well-being (SWB, research has recently focused on a number of different school variables. The direction of the relationships between adolescents’ SWB, academic achievement, and test anxiety is however still open although reciprocal causation has been hypothesized. The present study set out to investigate to what extent SWB, academic achievement, and test anxiety influence each other over time. A sample of N = 290 11th grade students (n = 138 female; age: M = 16.54 years, SD = 0.57 completed measures of SWB and test anxiety in the time span of one year. Grade Point Average (GPA indicated students’ academic achievement. We analyzed the reciprocal relations using cross-lagged structural equation modeling. The model fit was satisfactory for all computed models. Results indicated that the worry component of test anxiety negatively and GPA positively predicted changes in the cognitive component of SWB (life satisfaction. Worry also negatively predicted changes in the affective component of SWB. Moreover, worry negatively predicted changes in students’ GPA. Directions for future research and the differential predictive influences of academic achievement and test anxiety on adolescents’ SWB are discussed with regard to potential underlying processes.

Emotional Feeding and Emotional Eating: Reciprocal Processes and the Influence of Negative Affectivity

OpenAIRE

Steinsbekk, Silje; Barker, Edward D.; Llewellyn, Clare; Fildes, Alison; Wichstrøm, Lars

2017-01-01

Emotional eating, that is, eating more in response to negative mood, is often seen in children. But the origins of emotional eating remain unclear. In a representative community sample of Norwegian 4-year-olds followed up at ages 6, 8, and 10 years (analysis sample: n = 801), one potential developmental pathway was examined: a reciprocal relation between parental emotional feeding and child emotional eating. The results revealed that higher levels of emotional feeding predicted higher levels ...

Reciprocal effects of parenting and borderline personality disorder symptoms in adolescent girls.

Science.gov (United States)

Stepp, Stephanie D; Whalen, Diana J; Scott, Lori N; Zalewski, Maureen; Loeber, Rolf; Hipwell, Alison E

2014-05-01

Theories of borderline personality disorder (BPD) postulate that high-risk transactions between caregiver and child are important for the development and maintenance of the disorder. Little empirical evidence exists regarding the reciprocal effects of parenting on the development of BPD symptoms in adolescence. The impact of child and caregiver characteristics on this reciprocal relationship is also unknown. Thus, the current study examines bidirectional effects of parenting, specifically harsh punishment practices and caregiver low warmth, and BPD symptoms in girls aged 14-17 years based on annual, longitudinal data from the Pittsburgh Girls Study (N = 2,451) in the context of child and caregiver characteristics. We examined these associations through the use of autoregressive latent trajectory models to differentiate time-specific variations in BPD symptoms and parenting from the stable processes that steadily influence repeated measures within an individual. The developmental trajectories of BPD symptoms and parenting were moderately associated, suggesting a reciprocal relationship. There was some support for time-specific elevations in BPD symptoms predicting subsequent increases in harsh punishment and caregiver low warmth. There was little support for increases in harsh punishment and caregiver low warmth predicting subsequent elevations in BPD symptoms. Child impulsivity and negative affectivity, and caregiver psychopathology were related to parenting trajectories, while only child characteristics predicted BPD trajectories. The results highlight the stability of the reciprocal associations between parenting and BPD trajectories in adolescent girls and add to our understanding of the longitudinal course of BPD in youth.

Reciprocal- effects of parenting and borderline personality disorder symptoms in adolescent girls

Science.gov (United States)

Stepp, Stephanie D.; Whalen, Diana J.; Scott, Lori N.; Zalewski, Maureen; Loeber, Rolf; Hipwell, Alison E.

2014-01-01

Theories of borderline personality disorder (BPD) postulate that high-risk transactions between caregiver and child are important for the development and maintenance of the disorder. Little empirical evidence exists regarding the reciprocal effects of parenting on the development of BPD symptoms in adolescence. The impact of child and caregiver characteristics on this reciprocal relationship is also unknown. Thus, the current study examines bidirectional effects of parenting, specifically harsh punishment practices and caregiver low warmth, and BPD symptoms in girls aged 14–17 years based on annual, longitudinal data from the Pittsburgh Girls Study (N = 2,451) in the context of child and caregiver characteristics. We examined these associations through the use of autoregressive latent trajectory models to differentiate time-specific variations in BPD symptoms and parenting from the stable processes that steadily influence repeated measures within an individual. The developmental trajectories of BPD symptoms and parenting were moderately associated, suggesting a reciprocal relationship. There was some support for time-specific elevations in BPD symptoms predicting subsequent increases in harsh punishment and caregiver low warmth. There was little support for increases in harsh punishment and caregiver low warmth predicting subsequent elevations in BPD symptoms. Child impulsivity and negative affectivity, and caregiver psychopathology were related to parenting trajectories, while only child characteristics predicted BPD trajectories. The results highlight the stability of the reciprocal associations between parenting and BPD trajectories in adolescent girls and add to our understanding of the longitudinal course of BPD in youth. PMID:24443951

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...

Participation costs can suppress the evolution of upstream reciprocity.

Science.gov (United States)

Peña, Jorge; Pestelacci, Enea; Berchtold, André; Tomassini, Marco

2011-03-21

Indirect reciprocity, one of the many mechanisms proposed to explain the evolution of cooperation, is the idea that altruistic actions can be rewarded by third parties. Upstream or generalized reciprocity is one type of indirect reciprocity in which individuals help someone if they have been helped by somebody else in the past. Although empirically found to be at work in humans, the evolution of upstream reciprocity is difficult to explain from a theoretical point of view. A recent model of upstream reciprocity, first proposed by Nowak and Roch (2007) and further analyzed by Iwagami and Masuda (2010), shows that while upstream reciprocity alone does not lead to the evolution of cooperation, it can act in tandem with mechanisms such as network reciprocity and increase the total level of cooperativity in the population. We argue, however, that Nowak and Roch's model systematically leads to non-uniform interaction rates, where more cooperative individuals take part in more games than less cooperative ones. As a result, the critical benefit-to-cost ratios derived under this model in previous studies are not invariant with respect to the addition of participation costs. We show that accounting for these costs can hinder and even suppress the evolution of upstream reciprocity, both for populations with non-random encounters and graph-structured populations. Copyright © 2011 Elsevier Ltd. All rights reserved.

Detailed balance and reciprocity in solar cells

Energy Technology Data Exchange (ETDEWEB)

Kirchartz, Thomas; Rau, Uwe [IEF5-Photovoltaik, Forschungszentrum Juelich, 52425 Juelich (Germany)

2008-12-15

The limiting efficiency of photovoltaic devices follows from the detailed balance of absorption and emission of a diode according to the Shockley-Queisser theory. However, the principle of detailed balance has more implications for the understanding of photovoltaic devices than only defining the efficiency limit. We show how reciprocity relations between carrier collection and dark carrier injection, between electroluminescence emission and photovoltaic quantum efficiency and between open circuit voltage and light emitting diode quantum efficiency all follow from the principle of detailed balance. We also discuss the validity range of the Shockley-Queisser limit and the reciprocity relations. Discussing the validity of the reciprocity relations helps to deepen the understanding of photovoltaic devices and allows us to identify interrelationships between the superposition principle, the diode ideality and the reciprocity relations. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Histological evaluation of the cleaning effectiveness of two reciprocating single-file systems in severely curved root canals: Reciproc versus WaveOne.

Science.gov (United States)

Carvalho, Maira de Souza; Junior, Emílio Carlos Sponchiado; Bitencourt Garrido, Angela Delfina; Roberti Garcia, Lucas da Fonseca; Franco Marques, André Augusto

2015-01-01

The aim of this study was to evaluate the cleaning effectiveness achieved with two reciprocating single-file systems in severely curved root canals: Reciproc and WaveOne. Twenty-five mesial roots of mandibular molars were randomly separated into two groups, according to the instrumentation system used. The negative control group consisted of five specimens that were not instrumented. The mesial canals (buccal and lingual) in Reciproc Group were instrumented with file R25 and the WaveOne group with the Primary file. The samples were submitted to histological processing and analyzed under a digital microscope. The WaveOne group presented a larger amount of debris than the Reciproc Group, however, without statistically significant difference (P > 0.05). A larger amount of debris in the control group was observed, with statistically significant difference to Reciproc and WaveOne groups (P file instrumentation systems presented similar effectiveness for root canal cleaning.

Apical Extrusion of Debris Produced during Continuous Rotating and Reciprocating Motion

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Giselle Nevares

2015-01-01

Full Text Available This study aimed to analyse and compare apical extrusion of debris in canals instrumented with systems used in reciprocating and continuous motion. Sixty mandibular premolars were randomly divided into 3 groups (n=20: the Reciproc (REC, WaveOne (WO, and HyFlex CM (HYF groups. One Eppendorf tube per tooth was weighed in advance on an analytical balance. The root canals were instrumented according to the manufacturer’s instructions, and standardised irrigation with 2.5% sodium hypochlorite was performed to a total volume of 9 mL. After instrumentation, the teeth were removed from the Eppendorf tubes and incubated at 37°C for 15 days to evaporate the liquid. The tubes were weighed again, and the difference between the initial and final weight was calculated to determine the weight of the debris. The data were statistically analysed using the Shapiro-Wilk, Wilcoxon, and Mann-Whitney tests (α=5%. All systems resulted in the apical extrusion of debris. Reciproc produced significantly more debris than WaveOne (p<0.05, and both systems produced a greater apical extrusion of debris than HyFlex CM (p<0.001. Cross section and motion influenced the results, despite tip standardization.

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.

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.

The Reciprocal Relationship Between Social Connectedness and Mental Health Among Older European Adults: A SHARE-Based Analysis.

Science.gov (United States)

Schwartz, Ella; Litwin, Howard

2017-11-04

The current study aimed to understand the reciprocal relationship between social networks and mental health in old age. It explored the dynamic aspects of that relationship and assessed the influence of social networks on mental health, as well as a concurrent influence of mental health on change in social connectedness. The data came from two measurement points in the Survey of Health, Aging and Retirement in Europe (SHARE). The analytic sample was composed of adults aged 65 years and above (N = 14,706). Analyses were conducted via latent change score models. Analyses showed a reciprocal association between social networks and mental health; baseline social connectedness led to mental health improvements and a better initial mental state led to richer social networks. The results further indicated that the relative effect of mental health on change in social network connectedness was greater than the corresponding effect of social network connectedness on change in mental health. No gender differences were found regarding the reciprocal associations. The results of this study demonstrate the dynamic inter-relationship of social networks and mental health. It highlights the need to take into account both directions of influence when studying the impact of social relationships on mental health. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Information seeking and reciprocity: A transformational analysis

NARCIS (Netherlands)

Gallucci, M.; Perugini, M.

2003-01-01

The motivation to reciprocate is analyzed within the framework of interdependence theory, with focus on the process of transformation of situations. A model of transformation is presented for the motivation to reciprocate and hypotheses regarding allocation behavior and information seeking are

Bah humbug: Unexpected Christmas cards and the reciprocity norm.

Science.gov (United States)

Meier, Brian P

2016-01-01

The reciprocity norm refers to the expectation that people will help those who helped them. A well-known study revealed that the norm is strong with Christmas cards, with 20% of people reciprocating a Christmas card received from a stranger. I attempted to conceptually replicate and extend this effect. In Study 1, 755 participants received a Christmas card supposedly from a more- versus less-similar stranger. The reciprocation rate was unexpectedly low (2%), which did not allow for a test of a similarity effect. Two potential reasons for this low rate were examined in Study 2 in which 494 participants reported their likelihood of reciprocating a Christmas card from a stranger as well as their felt suspicions/threat about the card and their frequency of e-mail use. Reciprocation likelihood was negatively correlated with perceived threat/suspicion and e-mail use. It appears that reciprocating a gift from a stranger in offline settings may be less likely than expected.

Nonreciprocal and Reciprocal Dating Violence and Injury Occurrence among Urban Youth

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Swahn, Monica H

2010-08-01

Full Text Available Objective: Dating violence is a significant health problem among youth that leads to adverse health outcomes, including injuries. Reciprocal violence (perpetrated by both partners is associated with increased injury in adults, but very little is known about the prevalence and context for reciprocal violence, as well as injury rates, among youth. We sought to determine the prevalence and scope of reciprocal dating violence and injury occurrence among urban youth in a high-risk community. Methods: Analyses were based on data from the Youth Violence Survey, conducted in 2004, and administered to over 80% of public school students in grades 7, 9, 11, and 12 (N=4,131 in a high-risk, urban school district. The current analyses were restricted to those who reported dating in the past year and who also reported any dating violence (n=1,158. Dating violence was categorized as reciprocal (the participant reported both violence perpetration and victimization and non-reciprocal (the participant report either violence perpetration or victimization, but not both. Results: Dating violence reciprocity varied by sex. Girls who reported any dating violence were more likely to report reciprocal dating violence (50.4% than were boys (38.9%. However, reciprocity did not vary by race/ethnicity or grade level. Reciprocal dating violence was more common among participants who reported more frequent violence experiences. Reciprocal violence was also associated with greater injury occurrences relative to non-reciprocal relationships (10.1% versus 1.2%. Conclusion: Reciprocal dating violence is common among adolescents and leads more often to injury outcomes. In particular, relationships in which boys report reciprocal violence against their partner appear to lead to more frequent injury occurrences. These findings underscore the importance of addressing dating violence and factors that increase risk for reciprocal violence and therefore exacerbate injury occurrence

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-Raphson i...

Reciprocity in electron diffraction

International Nuclear Information System (INIS)

Gunning, J.; Goodman, P.

1991-01-01

The symmetry of reciprocity is reviewed in the context of relativistic quantum mechanics with the specific aim of relating to P-C-T invariances. From this investigation global time reversal is found to be sufficient condition for reciprocity to hold in scattering from a vector potential. Elastic scattering is assumed. The paper also deals exclusively with the scattering of a charged particle by an electromagnetic field. The present proof is free from assumptions of small angle scattering and from restrictions on z-dependent terms in the scattering equation, and by avoiding S-matrix theory is thought to be accessible to undergraduate teaching. 9 refs., 1 tab., 1 fig

Some properties of generalized self-reciprocal polynomials over finite fields

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Ryul Kim

2014-07-01

Full Text Available Numerous results on self-reciprocal polynomials over finite fields have been studied. In this paper we generalize some of these to a-self reciprocal polynomials defined in [4]. We consider some properties of the divisibility of a-reciprocal polynomials and characterize the parity of the number of irreducible factors for a-self reciprocal polynomials over finite fields of odd characteristic.

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.

Indirect reciprocity in three types of social dilemmas.

Science.gov (United States)

Nakamura, Mitsuhiro; Ohtsuki, Hisashi

2014-08-21

Indirect reciprocity is a key mechanism for the evolution of human cooperation. Previous studies explored indirect reciprocity in the so-called donation game, a special class of Prisoner's Dilemma (PD) with unilateral decision making. A more general class of social dilemmas includes Snowdrift (SG), Stag Hunt (SH), and PD games, where two players perform actions simultaneously. In these simultaneous-move games, moral assessments need to be more complex; for example, how should we evaluate defection against an ill-reputed, but now cooperative, player? We examined indirect reciprocity in the three social dilemmas and identified twelve successful social norms for moral assessments. These successful norms have different principles in different dilemmas for suppressing cheaters. To suppress defectors, any defection against good players is prohibited in SG and PD, whereas defection against good players may be allowed in SH. To suppress unconditional cooperators, who help anyone and thereby indirectly contribute to jeopardizing indirect reciprocity, we found two mechanisms: indiscrimination between actions toward bad players (feasible in SG and PD) or punishment for cooperation with bad players (effective in any social dilemma). Moreover, we discovered that social norms that unfairly favor reciprocators enhance robustness of cooperation in SH, whereby reciprocators never lose their good reputation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acoustic reciprocity: An extension to spherical harmonics domain.

Science.gov (United States)

Samarasinghe, Prasanga; Abhayapala, Thushara D; Kellermann, Walter

2017-10-01

Acoustic reciprocity is a fundamental property of acoustic wavefields that is commonly used to simplify the measurement process of many practical applications. Traditionally, the reciprocity theorem is defined between a monopole point source and a point receiver. Intuitively, it must apply to more complex transducers than monopoles. In this paper, the authors formulate the acoustic reciprocity theory in the spherical harmonics domain for directional sources and directional receivers with higher order directivity patterns.

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...

Loneliness, exchange orientation, and reciprocity in friendships

NARCIS (Netherlands)

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

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

24 CFR 3282.11 - Preemption and reciprocity.

Science.gov (United States)

2010-04-01

... 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... and reciprocity. (a) No State manufactured home standard regarding manufactured home construction and...

Post endodontic pain following single-visit root canal preparation with rotary vs reciprocating instruments: a meta-analysis of randomized clinical trials.

Science.gov (United States)

Hou, Xiao-Mei; Su, Zheng; Hou, Ben-Xiang

2017-05-25

In endodontic therapy, continuous rotary instrumentation reduced debris compared to reciprocal instrumentation, which might affect the incidence of post-endodontic pain (PP). The aim of our study was to assess whether PP incidence and levels were influenced by the choice of rotary or reciprocal instruments. In this meta-analysis the Pubmed and EM databases were searched for prospective clinical randomized trials published before April 20, 2016, using combinations of the keywords: root canal preparation/instrumentation/treatment/therapy; post-operative/endodontic pain; reciprocal and rotary instruments. Three studies were included, involving a total of 1,317 patients, 659 treated with reciprocating instruments and 658 treated with rotary instruments. PP was reported in 139 patients in the reciprocating group and 172 in the rotary group. The PP incidence odds ratio was 1.27 with 95% confidence interval (CI) (0.25, 6.52) favoring rotary instruments. The mild, moderate and severe PP levels odds ratios were 0.31 (0.11, 0.84), 2.24 (0.66, 7.59) and 11.71 (0.63, 218.15), respectively. No evidence of publication bias was found. Rotary instrument choice in endodontic therapy is associated with a lower incidence of PP than reciprocating instruments, while reciprocating instruments are associated with less mild PP incidence.

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.

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.

Born's reciprocity principle in stochastic phase space

International Nuclear Information System (INIS)

Prugovecki, E.

1981-01-01

It is shown that the application of Born's reciprocity principle to relativistic quantum mechanics in stochastic phase space (by the requirement that the proper wave functions of extended particles satisfy the Born-Lande as well as the Klein-Gordon equation) leads to the unique determination of these functions for any given value of their rms radius. The resulting particle propagators display not only Lorentz but also reciprocal invariance. This feature remains true even in the case of mass-zero particles, such as photons, when their localization is achieved by means of extended test particles whose proper wave functions obey the reciprocity principle. (author)

Effects of Glide Path on the Centering Ability and Preparation Time of Two Reciprocating Instruments

Science.gov (United States)

Coelho, Marcelo Santos; Fontana, Carlos Eduardo; Kato, Augusto Shoji; de Martin, Alexandre Sigrist; da Silveira Bueno, Carlos Eduardo

2016-01-01

Introduction: The aim of this in vitro study was to evaluate the effects of establishing glide path on the centering ability and preparation time of two single-file reciprocating systems in mesial root canals of mandibular molars. Methods and Materials: Sixty extracted mandibular molars with curvatures of 25-39 degrees and separate foramina for the mesiobuccal and mesiolingual canals, were divided into four groups (n=15); WaveOne+glide path; WaveOne; Reciproc+glide path and Reciproc. Non-patent canals were excluded and only one canal in each tooth was instrumented. A manual glide path was established in first and third groups with #10, 15 and 20 hand K-files. Preparation was performed with reciprocating in-and-out motion, with a 3-4 mm amplitude and slight apical pressure. Initial and final radiographs were taken to analyze the amount of dentin removed in the instrumented canals. The radiographs were superimposed with an image editing software and examined to assess discrepancies at 3-, 6- and 9-mm distances from the apex. The Kruskal-Wallis test was used for statistical analysis. The level of significance was set at 0.05. Results: Preparation in groups without glide paths was swifter than the other groups (P=0.001). However, no difference was observed regarding centering ability. Conclusion: Establishing a glide path increased the total instrumentation time for preparing curved canals with WaveOne and Reciproc instruments. Glide path had no influence on the centering ability of these systems. PMID:26843875

Strategic culture of the Southern African Development Community ...

African Journals Online (AJOL)

(SADC) Brigade took pride of place at the opening of the 2007 SADC Summit in Lusaka, Zambia. This SADC Brigade is tied in closely to both the security architecture of the African Standby Force (ASF) of the African Union (AU) and the SADC Mutual Defence Pact. In the recent past (1998), military interventions by SADC ...

Reciprocal Tutoring: Design with Cognitive Load Sharing

Science.gov (United States)

Chou, Chih-Yueh; Chan, Tak-Wai

2016-01-01

"Reciprocal tutoring," as reported in "Exploring the design of computer supports for reciprocal tutoring" (Chan and Chou 1997), has extended the meaning and scope of "intelligent tutoring" originally implemented in stand alone computers. This research is a follow-up to our studies on a "learning companion…

Drift stabilizer for reciprocating free-piston devices

Science.gov (United States)

Ward, William C.; Corey, John A.; Swift, Gregory W.

2003-05-20

A free-piston device has a stabilized piston drift. A piston having a frequency of reciprocation over a stroke length and with first and second sides facing first and second variable volumes, respectively, for containing a working fluid defining an acoustic wavelength at the frequency of reciprocation. A bypass tube waveguide connects the first and second variable volumes at all times during reciprocation of the piston. The waveguide has a relatively low impedance for steady flow and a relatively high impedance for oscillating flow at the frequency of reciprocation of the piston, so that steady flow returns fluid leakage from about the piston between the first and second volumes while oscillating flow is not diverted through the waveguide. Thus, net leakage about the piston is returned during each stroke of the piston while oscillating leakage is not allowed and pressure buildup on either the first or second side of the piston is avoided to provide a stable piston location.

Indirect Reciprocity under Incomplete Observation

Science.gov (United States)

Nakamura, Mitsuhiro; Masuda, Naoki

2011-01-01

Indirect reciprocity, in which individuals help others with a good reputation but not those with a bad reputation, is a mechanism for cooperation in social dilemma situations when individuals do not repeatedly interact with the same partners. In a relatively large society where indirect reciprocity is relevant, individuals may not know each other's reputation even indirectly. Previous studies investigated the situations where individuals playing the game have to determine the action possibly without knowing others' reputations. Nevertheless, the possibility that observers of the game, who generate the reputation of the interacting players, assign reputations without complete information about them has been neglected. Because an individual acts as an interacting player and as an observer on different occasions if indirect reciprocity is endogenously sustained in a society, the incompleteness of information may affect either role. We examine the game of indirect reciprocity when the reputations of players are not necessarily known to observers and to interacting players. We find that the trustful discriminator, which cooperates with good and unknown players and defects against bad players, realizes cooperative societies under seven social norms. Among the seven social norms, three of the four suspicious norms under which cooperation (defection) to unknown players leads to a good (bad) reputation enable cooperation down to a relatively small observation probability. In contrast, the three trustful norms under which both cooperation and defection to unknown players lead to a good reputation are relatively efficient. PMID:21829335

Reciprocal burnout model: Interconnectedness of interpersonal and intrapersonal factors

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Andreja Pšeničny

2007-01-01

Full Text Available Burnout can be described as chronic state of extreme psychophysical and emotional exhaustion. Burning out is a stage process consisting of: the stage of exhaustion, the stage of captivity and the final stage – adrenal burnout. Adrenal burnout syndrome (ABS is the final stage of burning out process, resulting in a functional blocade of hypothalamic-pituitary-adrenal axis which causes secondary cortisol insufficiency. Even though they share similar symptoms, burnout and depression are two different types of disorder. They differ mainly in basic cortisol levels and self-esteem. Researchers tend to link the burnout syndrome and environmental stress (interpersonal causes. Recently, some of them found connection between burnout syndrome and personality traits (intrapersonal causes. Reciprocal burnout model links both causes. It shows that in the same circumstances only a few people suffer from adrenal burnout syndrome. It states that personal characteristics are one of the main causes why people suffering from burnout syndrome enroll in nonreciprocal personal and professional relations. Socialization process plays an important role in development of personality traits. The core of the reciprocal burnout model consists of one's attitude towards his or her basic needs' fulfillment, personal system of values, and correlation between fulfillment of basic needs (energy accumulation and burning out process (energy consumption. Reciprocal burnout model is opening a series of questions, concerning the connection between personality traits, life satisfaction and personal values, and burnout syndrome risk behavior, as well as the influence of whole life circumstances on burning out process.

Intrinsic rippling enhances static non-reciprocity in a graphene metamaterial.

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Ho, Duc Tam; Park, Harold S; Kim, Sung Youb

2018-01-18

In mechanical systems, Maxwell-Betti reciprocity means that the displacement at point B in response to a force at point A is the same as the displacement at point A in response to the same force applied at point B. Because the notion of reciprocity is general, fundamental, and is operant for other physical systems like electromagnetics, acoustics, and optics, there is significant interest in understanding systems that are not reciprocal, or exhibit non-reciprocity. However, most studies on non-reciprocity have occurred in bulk-scale structures for dynamic problems involving time reversal symmetry. As a result, little is known about the mechanisms governing static non-reciprocal responses, particularly in atomically-thin two-dimensional materials like graphene. Here, we use classical atomistic simulations to demonstrate that out-of-plane ripples, which are intrinsic to graphene, enable significant, multiple orders of magnitude enhancements in the statically non-reciprocal response of graphene metamaterials. Specifically, we find that a striking interplay between the ripples and the stress fields that are induced in the metamaterials due to their geometry impacts the displacements that are transmitted by the metamaterial, thus leading to a significantly enhanced static non-reciprocal response. This study thus demonstrates the potential of two-dimensional mechanical metamaterials for symmetry-breaking applications.

Mortality salience increases personal relevance of the norm of reciprocity.

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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.

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...

Reciprocal neural response within lateral and ventral medial prefrontal cortex during hot and cold reasoning.

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Goel, Vinod; Dolan, Raymond J

2003-12-01

Logic is widely considered the basis of rationality. Logical choices, however, are often influenced by emotional responses, sometimes to our detriment, sometimes to our advantage. To understand the neural basis of emotionally neutral ("cold") and emotionally salient ("hot") reasoning we studied 19 volunteers using event-related fMRI, as they made logical judgments about arguments that varied in emotional saliency. Despite identical logical form and content categories across "hot" and "cold" reasoning conditions, lateral and ventral medial prefrontal cortex showed reciprocal response patterns as a function of emotional saliency of content. "Cold" reasoning trials resulted in enhanced activity in lateral/dorsal lateral prefrontal cortex (L/DLPFC) and suppression of activity in ventral medial prefrontal cortex (VMPFC). By contrast, "hot" reasoning trials resulted in enhanced activation in VMPFC and suppression of activation in L/DLPFC. This reciprocal engagement of L/DLPFC and VMPFC provides evidence for a dynamic neural system for reasoning, the configuration of which is strongly influenced by emotional saliency.

A comparison of two reciprocating instruments using bending stress and cyclic fatigue tests.

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Scelza, Pantaleo; Harry, Davidowicz; Silva, Licinio Esmeraldo da; Barbosa, Igor Bastos; Scelza, Miriam Zaccaro

2015-01-01

The aim of this study was to comparatively evaluate the bending resistance at 45º, the static and dynamic cyclic fatigue life, and the fracture type of the WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) 25-08 and Reciproc (VDW, Munich, Germany) 25-08 instruments. A total of 60 nickel-titanium (NiTi) instruments (30 Reciproc and 30 WaveOne) from three different lots, each of which was 25 mm in length, were tested. The bending resistance was evaluated through the results of a cantilever-bending test conducted using a universal testing machine. Static and dynamic cyclic fatigue testing was conducted using a custom-made device. For the static and dynamic tests, a cast Ni-Cr-Mo-Ti alloy metal block with an artificial canal measuring 1.77 mm in diameter and 20.00 mm in total length was used. A scanning electron microscope was used to determine the type of fracture. Statistical analyses were performed on the results. The WaveOne instrument was less flexible than the Reciproc (p fatigue tests (p ductile-type fracture characteristics. It can be concluded that the Reciproc 25-08 instrument was more resistant to static and dynamic cyclic fatigue than the WaveOne 25-08 instrument, while the WaveOne 25-08 instrument was less flexible. Bending and resistance to cyclic fracture were influenced by the instruments' geometries and transverse cross-sections. Both of the instruments showed ductile-type fracture characteristics.

Reciprocal Influences Between Maternal Parenting and Child Adjustment in a High-risk Population: A Five-Year Cross-Lagged Analysis of Bidirectional Effects

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Barbot, Baptiste; Crossman, Elizabeth; Hunter, Scott R.; Grigorenko, Elena L.; Luthar, Suniya S.

2014-01-01

This study examines longitudinally the bidirectional influences between maternal parenting (behaviors and parenting stress) and mothers' perceptions of their children's adjustment, in a multivariate approach. Data was gathered from 361 low-income mothers (many with psychiatric diagnoses) reporting on their parenting behavior, parenting stress and their child's adjustment, in a two-wave longitudinal study over 5 years. Measurement models were developed to derive four broad parenting constructs (Involvement, Control, Rejection, and Stress) and three child adjustment constructs (Internalizing problems, Externalizing problems, and Social competence). After measurement invariance of these constructs was confirmed across relevant groups and over time, both measurement models were integrated in a single crossed-lagged regression analysis of latent constructs. Multiple reciprocal influence were observed between parenting and perceived child adjustment over time: Externalizing and internalizing problems in children were predicted by baseline maternal parenting behaviors, while child social competence was found to reduce parental stress and increase parental involvement and appropriate monitoring. These findings on the motherhood experience are discussed in light of recent research efforts to understand mother-child bi-directional influences, and their potential for practical applications. PMID:25089759

A comparison of two reciprocating instruments using bending stress and cyclic fatigue tests

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Pantaleo SCELZA

2015-01-01

Full Text Available The aim of this study was to comparatively evaluate the bending resistance at 45º, the static and dynamic cyclic fatigue life, and the fracture type of the WaveOne (Dentsply Maillefer, Ballaigues, Switzerland 25-08 and Reciproc (VDW, Munich, Germany 25-08 instruments. A total of 60 nickel-titanium (NiTi instruments (30 Reciproc and 30 WaveOne from three different lots, each of which was 25 mm in length, were tested. The bending resistance was evaluated through the results of a cantilever-bending test conducted using a universal testing machine. Static and dynamic cyclic fatigue testing was conducted using a custom-made device. For the static and dynamic tests, a cast Ni-Cr-Mo-Ti alloy metal block with an artificial canal measuring 1.77 mm in diameter and 20.00 mm in total length was used. A scanning electron microscope was used to determine the type of fracture. Statistical analyses were performed on the results. The WaveOne instrument was less flexible than the Reciproc (p < 0.05. The Reciproc instrument showed better resistance in the static and dynamic cyclic fatigue tests (p < 0.05. The transverse cross-section and geometry of the instruments were important factors in their resistance to bending and cyclic fracture. Both of the instruments showed ductile-type fracture characteristics. It can be concluded that the Reciproc 25-08 instrument was more resistant to static and dynamic cyclic fatigue than the WaveOne 25-08 instrument, while the WaveOne 25-08 instrument was less flexible. Bending and resistance to cyclic fracture were influenced by the instruments’ geometries and transverse cross-sections. Both of the instruments showed ductile-type fracture characteristics.

Education, Gift and Reciprocity: A Preliminary Discussion

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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…

Working dogs cooperate among one another by generalised reciprocity.

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Gfrerer, Nastassja; Taborsky, Michael

2017-03-06

Cooperation by generalised reciprocity implies that individuals apply the decision rule "help anyone if helped by someone". This mechanism has been shown to generate evolutionarily stable levels of cooperation, but as yet it is unclear how widely this cooperation mechanism is applied among animals. Dogs (Canis familiaris) are highly social animals with considerable cognitive potential and the ability to differentiate between individual social partners. But although dogs can solve complex problems, they may use simple rules for behavioural decisions. Here we show that dogs trained in an instrumental cooperative task to provide food to a social partner help conspecifics more often after receiving help from a dog before. Remarkably, in so doing they show no distinction between partners that had helped them before and completely unfamiliar conspecifics. Apparently, dogs use the simple decision rule characterizing generalised reciprocity, although they are probably capable of using the more complex decision rule of direct reciprocity: "help someone who has helped you". However, generalized reciprocity involves lower information processing costs and is therefore a cheaper cooperation strategy. Our results imply that generalised reciprocity might be applied more commonly than direct reciprocity also in other mutually cooperating animals.

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

DEFF Research Database (Denmark)

Huck, Steffen; Tyran, Jean-Robert

2007-01-01

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...

The Role of Friendship Reciprocity in University Freshmen's Alcohol Consumption.

Science.gov (United States)

Giese, Helge; Stok, F Marijn; Renner, Britta

2017-07-01

The similarity of friends in the frequency and quantity of alcohol consumption is explored. During their first semester, 57 psychology freshmen indicated weekly drinking frequency and quantity and nominated the three peers of this group they liked most. These nominations were then used to derive the weekly alcohol consumption of friends that either did or did not reciprocate a nomination. Multilevel modeling of weekly variations showed that individuals' drinking frequency was similar to peers who reciprocated a friendship (b = 0.15, p = .001), but not to non-reciprocating peers (b = -0.01, p = .720). In contrast, weekly variation in quantity of individual students' drinking was similar to both reciprocating (b = 0.11, p = .018) and non-reciprocating peers' drinking (b = 0.10, p = .014). Yet across all weeks, quantity tended only to be similar to non-reciprocating peers (b = 0.49, p = .020). Freshmen might spend drinking time with peers who reciprocate a friendship, but are similar regarding the quantity of drinks consumed to all people they find interesting. Thus, alcohol consumption is used strategically for social purposes. This social purpose should also be acknowledged in alcohol-reduction interventions. © 2017 The International Association of Applied Psychology.

Negative reciprocity and retrenched pension rights

OpenAIRE

Montizaan, R.M.; Cörvers, F.; de Grip, A.; Dohmen, T.J.

2012-01-01

We document the importance of negatively reciprocal inclinations in labor relationships by showing that a retrenchment of pension rights, which is perceived as unfair, causes a larger reduction in job motivation the stronger workers' negatively reciprocal inclinations are. We exploit unique matched survey and administrative data on male employees in the public sector in the Netherlands and compare the job motivation of employees born in 1950, who faced a substantial retrenchment of their pens...

The extended reciprocity: Strong belief outperforms persistence.

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Kurokawa, Shun

2017-05-21

The existence of cooperation is a mysterious phenomenon and demands explanation, and direct reciprocity is one key potential explanation for the evolution of cooperation. Direct reciprocity allows cooperation to evolve for cooperators who switch their behavior on the basis of information about the opponent's behavior. Here, relevant to direct reciprocity is information deficiency. When the opponent's last move is unknown, how should players behave? One possibility is to choose cooperation with some default probability without using any further information. In fact, our previous paper (Kurokawa, 2016a) examined this strategy. However, there might be beneficial information other than the opponent's last move. A subsequent study of ours (Kurokawa, 2017) examined the strategy which uses the own last move when the opponent's last move is unknown, and revealed that referring to the own move and trying to imitate it when information is absent is beneficial. Is there any other beneficial information else? How about strong belief (i.e., have infinite memory and believe that the opponent's behavior is unchanged)? Here, we examine the evolution of strategies with strong belief. Analyzing the repeated prisoner's dilemma game and using evolutionarily stable strategy (ESS) analysis against an invasion by unconditional defectors, we find the strategy with strong belief is more likely to evolve than the strategy which does not use information other than the opponent player's last move and more likely to evolve than the strategy which uses not only the opponent player's last move but also the own last move. Strong belief produces the extended reciprocity and facilitates the evolution of cooperation. Additionally, we consider the two strategies game between strategies with strong belief and any strategy, and we consider the four strategies game in which unconditional cooperators, unconditional defectors, pessimistic reciprocators with strong belief, and optimistic reciprocators with

Reciprocity relations in aerodynamics

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Heaslet, Max A; Spreiter, John R

1953-01-01

Reverse flow theorems in aerodynamics are shown to be based on the same general concepts involved in many reciprocity theorems in the physical sciences. Reciprocal theorems for both steady and unsteady motion are found as a logical consequence of this approach. No restrictions on wing plan form or flight Mach number are made beyond those required in linearized compressible-flow analysis. A number of examples are listed, including general integral theorems for lifting, rolling, and pitching wings and for wings in nonuniform downwash fields. Correspondence is also established between the buildup of circulation with time of a wing starting impulsively from rest and the buildup of lift of the same wing moving in the reverse direction into a sharp-edged gust.

Preschool children's behavioral tendency toward social indirect reciprocity.

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Mayuko Kato-Shimizu

Full Text Available Social indirect reciprocity seems to be crucial in enabling large-scale cooperative networks among genetically unrelated individuals in humans. However, there are relatively few studies on social indirect reciprocity in children compared to adults. Investigating whether young children have a behavioral tendency toward social indirect reciprocity will help us understand how and when the fundamental ability to form cooperative relationships among adults is acquired. Using naturalistic observation at a nursery school, this study examined whether 5- to 6-year-olds show a behavioral tendency to engage in social indirect reciprocity in response to their peers' prosocial behavior toward a third party. The results revealed that bystander children tended to display prosocial behavior toward their peers more frequently after observing these peers' prosocial behavior toward third-party peers, compared with control situations; this suggests that 5- to 6-year-olds may have an essential behavioral tendency to establish social indirect reciprocity when interacting with peers in their daily lives. In addition, bystanders tended to display affiliative behavior after observing focal children's prosocial behavior. In other words, observing peers' prosocial behavior toward third-party peers evoked bystanders' positive emotions toward the helpers. Considering both the present results and previous findings, we speculate that in preschoolers, such positive emotions might mediate the increase in the bystander's prosocial behavior toward the helper. In addition, an intuitional emotional process plays an important role in the preschooler's behavioral tendency toward social indirect reciprocity in natural interactions with peers.

Preschool children's behavioral tendency toward social indirect reciprocity.

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Kato-Shimizu, Mayuko; Onishi, Kenji; Kanazawa, Tadahiro; Hinobayashi, Toshihiko

2013-01-01

Social indirect reciprocity seems to be crucial in enabling large-scale cooperative networks among genetically unrelated individuals in humans. However, there are relatively few studies on social indirect reciprocity in children compared to adults. Investigating whether young children have a behavioral tendency toward social indirect reciprocity will help us understand how and when the fundamental ability to form cooperative relationships among adults is acquired. Using naturalistic observation at a nursery school, this study examined whether 5- to 6-year-olds show a behavioral tendency to engage in social indirect reciprocity in response to their peers' prosocial behavior toward a third party. The results revealed that bystander children tended to display prosocial behavior toward their peers more frequently after observing these peers' prosocial behavior toward third-party peers, compared with control situations; this suggests that 5- to 6-year-olds may have an essential behavioral tendency to establish social indirect reciprocity when interacting with peers in their daily lives. In addition, bystanders tended to display affiliative behavior after observing focal children's prosocial behavior. In other words, observing peers' prosocial behavior toward third-party peers evoked bystanders' positive emotions toward the helpers. Considering both the present results and previous findings, we speculate that in preschoolers, such positive emotions might mediate the increase in the bystander's prosocial behavior toward the helper. In addition, an intuitional emotional process plays an important role in the preschooler's behavioral tendency toward social indirect reciprocity in natural interactions with peers.

Realizing total reciprocity violation in the phase for photon scattering.

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Deák, László; Bottyán, László; Fülöp, Tamás; Merkel, Dániel Géza; Nagy, Dénes Lajos; Sajti, Szilárd; Schulze, Kai Sven; Spiering, Hartmut; Uschmann, Ingo; Wille, Hans-Christian

2017-02-22

Reciprocity is when wave or quantum scattering satisfies a symmetry property, connecting a scattering process with the reversed one. While reciprocity involves the interchange of source and detector, it is fundamentally different from rotational invariance, and is a generalization of time reversal invariance, occurring in absorptive media as well. Due to its presence at diverse areas of physics, it admits a wide variety of applications. For polarization dependent scatterings, reciprocity is often violated, but violation in the phase of the scattering amplitude is much harder to experimentally observe than violation in magnitude. Enabled by the advantageous properties of nuclear resonance scattering of synchrotron radiation, we have measured maximal, i.e., 180-degree, reciprocity violation in the phase. For accessing phase information, we introduced a new version of stroboscopic detection. The scattering setting was devised based on a generalized reciprocity theorem that opens the way to construct new types of reciprocity related devices.

Crystallization features of ternary reversible reciprocal systems

International Nuclear Information System (INIS)

Tomashik, V.N.; Shcherbak, L.P.; Fejchuk, P.I.; Grytsiv, V.I.

2006-01-01

Some features of the primary crystallization of phases in ternary reversible reciprocal system are considered and discussed. The diagonal join CdTe-GeSe of the CdTe + GeSe = CdSe + GeTe ternary reciprocal system is studied to show that the features in primary and secondary heating and cooling curves in such systems under fully equilibrium conditions are not reproduced upon consecutive heating and cooling sessions, because of the existence of different amounts of the reagents and the reaction products in the mixture; the temperatures of each transformation lie in a range. Those who experimentally investigate other ternary and more complex reversible reciprocal systems should take this fact into account [ru

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

Attitudes toward reciprocity systems for organ donation and allocation for transplantation.

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Burkell, Jacquelyn A; Chandler, Jennifer A; Shemie, Sam D

2013-10-01

Many of those who support organ donation do not register to become organ donors. The use of reciprocity systems, under which some degree of priority is offered to registered donors who require an organ transplant, is one suggestion for increasing registration rates. This article uses a combination of survey and focus group methodologies to explore the reaction of Canadians to a reciprocity proposal. Our results suggest that the response is mixed. Participants are more convinced of the efficacy than they are of the fairness of a reciprocity system. Those more positive about donation (decided donors and those leaning toward donation) rate the system more positively. Although there is general endorsement of the notion that those who wish to receive should be prepared to give (the Golden Rule), this does not translate into universal support for a reciprocity system. In discussions of efficacy, decided donors focus on the positive impact of reciprocity, whereas undecided donors also reflect on the limits of reciprocity for promoting registration. The results demonstrate divided support for reciprocity systems in the Canadian context, with perceptions of efficacy at the cost of fairness. Further studies are warranted prior to considering a reciprocity system in Canada.

Reciprocal link for a coupled Camassa–Holm type equation

International Nuclear Information System (INIS)

Li, Nianhua; Zhang, Jinshun; Wu, Lihua

2016-01-01

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.

Relatedness decreases and reciprocity increases cooperation in Norway rats.

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Schweinfurth, Manon K; Taborsky, Michael

2018-03-14

Kin selection and reciprocity are two mechanisms underlying the evolution of cooperation, but the relative importance of kinship and reciprocity for decisions to cooperate are yet unclear for most cases of cooperation. Here, we experimentally tested the relative importance of relatedness and received cooperation for decisions to help a conspecific in wild-type Norway rats ( Rattus norvegicus ). Test rats provided more food to non-kin than to siblings, and they generally donated more food to previously helpful social partners than to those that had refused help. The rats thus applied reciprocal cooperation rules irrespective of relatedness, highlighting the importance of reciprocal help for cooperative interactions among both related and unrelated conspecifics. © 2018 The Author(s).

Subjective Well-Being, Test Anxiety, Academic Achievement: Testing for Reciprocal Effects

OpenAIRE

Steinmayr, Ricarda; Crede, Julia; McElvany, Nele; Wirthwein, Linda

2016-01-01

In the context of adolescents’ subjective well-being (SWB), research has recently focused on a number of different school variables. The direction of the relationships between adolescents’ SWB, academic achievement, and test anxiety is, however, still open although reciprocal causation has been hypothesized. The present study set out to investigate to what extent SWB, academic achievement, and test anxiety influence each other over time. A sample of N = 290 11th grade students (n = 138 female...

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.

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...

Reciprocity on Demand : Sharing and Exchanging Food in Northwestern Namibia.

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Schnegg, Michael

2015-09-01

Two competing models concerning food transfers prominent in the anthropological literature conceptualize such transfers either as sharing or as exchange. Sharing is understood as situational transactions formed through demands and unconditional giving, whereas reciprocal exchange is understood in terms of networking and keeping score. I propose that the picture is more complicated than these classifications suggests. Drawing on data collected in Northwestern Namibia, I show that sharing and reciprocal exchange are dynamically interrelated in actual food transfers. As a local norm, people can demand food from anyone, and they are typically given food in response to a demand. However, in practice, food transfer networks emerge (N = 62) that are highly reciprocal and fit the exchange model much better. Although the sharing norm makes no restrictions on whom to ask, in practice people often turn to their neighbors. Interpersonal dynamics account for why some of those ties become strongly reciprocal and others do not. Under these circumstances, unconditional sharing, a norm that has been viewed as an alternative to exchange, can lead to reciprocity via reciprocity on demand.

Generalized Gribov-Lipatov Reciprocity and AdS/CFT

International Nuclear Information System (INIS)

Beccaria, M.; Macorini, G.; Forini, V.

2010-01-01

Planar □=4 SYM theory and QCD share the gluon sector, suggesting the investigation of Gribov-Lipatov reciprocity in the supersymmetric theory. Since the AdS/CFT correspondence links □=4 SYM and superstring dynamics on AdS 5 x S5, reciprocity is also expected to show up in the quantum corrected energies of certain classical string configurations dual to gauge theory twist-operators. We review recent results confirming this picture and revisiting the old idea of Gribov-Lipatov reciprocity as a modern theoretical tool useful for the study of open problems in AdS/CFT.

Research on networked manufacturing system for reciprocating pump industry

Science.gov (United States)

Wu, Yangdong; Qi, Guoning; Xie, Qingsheng; Lu, Yujun

2005-12-01

Networked manufacturing is a trend of reciprocating pump industry. According to the enterprises' requirement, the architecture of networked manufacturing system for reciprocating pump industry was proposed, which composed of infrastructure layer, system management layer, application service layer and user layer. Its main functions included product data management, ASP service, business management, and customer relationship management, its physics framework was a multi-tier internet-based model; the concept of ASP service integration was put forward and its process model was also established. As a result, a networked manufacturing system aimed at the characteristics of reciprocating pump industry was built. By implementing this system, reciprocating pump industry can obtain a new way to fully utilize their own resources and enhance the capabilities to respond to the global market quickly.

Is there reciprocity in preferential trade agreements on services?

OpenAIRE

Marchetti, Juan; Roy, Martin; Zoratto, Laura

2012-01-01

Are market access commitments on services in Preferential Trade Agreements (PTAs) reciprocal or simply unilateral? If reciprocal, do concessions granted in services depend on concessions received from the trading partner in other services or in non-services areas as well? In this paper we investigate the presence of reciprocity in bilateral services agreements, by sub-sector, mode of supply and type of agreement (North-North, South-North, South-South). To do so, we use a database of concessio...

The Explanatory Power of Reciprocal Behavior for the Inter-Organizational Exchange Context

Directory of Open Access Journals (Sweden)

Martina Pieperhoff

2018-06-01

Full Text Available In order to create sustainable competitive advantages, organizations are embedded in dyadic exchange relationships, which depend on the coordination of the behavior of the actors involved. Often, coordinated behavior is explained by trust. Since trust develops in a process of reciprocal responses to presumed trustworthy behavior, it is a reciprocity-based concept. While inter-organizational exchange relationships can appear in different stages (forming, establishing, broken, different reciprocity types (direct, indirect, negative can be distinguished. The study links reciprocal behavior to different stages of inter-organizational exchange relationships in order to investigate reciprocity as a possible coordination mechanism of behavior and thus explore the basis of coordination of trust-based behavior. Qualitative Comparative Analysis as a set-theoretic approach is applied to analyze the empirical data consisting of 78 qualitative semi-structured interviews with managers of small-, medium- and large-sized companies. The results show that different reciprocity types become effective in different stages of an inter-organizational exchange relationship: For forming inter-organizational exchange relationships indirect reciprocal behavior, besides direct reciprocity, becomes effective while in establishing inter-organizational exchange relationships, direct reciprocal behavior is evident. Negative reciprocal behavior leads to a break up of relationships. Using these results, on the one hand, the concept of trust can be sharpened by deepening the understanding of the trust-building mechanisms and on the other hand, reciprocity can be seen as coordination mechanism in exchange relationships of different stages. In doing so, with this knowledge, relationships can be coordinated towards a long-term orientation in order to create sustainable advantages.

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

2017-08-01

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 typically developing children (24 girls, 55 boys). While children with autism spectrum disorder showed clear limitations in reciprocal behaviour compared to typically developing children, sex differences were found only in the autism spectrum disorder group: girls with autism spectrum disorder had higher reciprocity scores than boys with autism spectrum disorder. However, compared to typically developing girls, girls with autism spectrum disorder showed subtle differences in reciprocal behaviour. The sex-specific response patterns in autism spectrum disorder can inform and improve the diagnostic assessment of autism in females.

Reciprocally-Rotating Velocity Obstacles

KAUST Repository

Giese, Andrew; Latypov, Daniel; Amato, Nancy M.

2014-01-01

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

BitTorrent's dilemma: Enhancing reciprocity or reducing inequity

NARCIS (Netherlands)

Jia, A.L.; D'Acunto, L.; Meulpolder, M.; Pouwelse, J.A.; Epema, D.H.J.

2011-01-01

Enhancing reciprocity has been one of the primary motivations for the design of incentive policies in BitTorrent-like P2P systems. Reciprocity implies that peers need to contribute their bandwidth to other peers if they want to receive bandwidth in return. However, the over-provisioning that

Guilt driven reciprocity in a psychological signaling game

NARCIS (Netherlands)

Fong, Y.; Huang, C.-Y.; Offerman, T.

2007-01-01

We propose a theory of reciprocity according to which reciprocal behavior is driven by a donor's guilt. Through an experiment we show that subjects respond to factors which induce guilt but do not reflect allocative equity or intention. When the guilt inducing factor is privately observed by the

Guilt driven reciprocity in a psychological signaling game

NARCIS (Netherlands)

Fong, Y.; Huang, C.-Y.; Offerman, T.

2009-01-01

We propose a theory of reciprocity according to which reciprocal behavior is driven by a donor’s guilt. Through an experiment we show that subjects respond to factors which induce guilt but do not reflect allocative equity or intention. When the guilt inducing factor is privately observed by the

Viscoelastic reciprocating contacts in presence of finite rough interfaces: A numerical investigation

Science.gov (United States)

Putignano, Carmine; Carbone, Giuseppe

2018-05-01

Viscoelastic reciprocating contacts are crucial in a number of systems, ranging from sealing components to viscoelastic dampers. Roughness plays in these conditions a central role, but no exhaustive assessment in terms of influence on area, separation and friction has been drawn so far. This is due to the huge number of time and space scales involved in the problem. By means of an innovative Boundary Element methodology, which treats the time as a parameter and then requires only to discretize the space domain, we investigate the viscoelastic reciprocating contact mechanics between rough solids. In particular, we consider the alternate contact of a rigid finite-size rough punch over a viscoelastic layer: the importance of the domain finiteness in the determination of the contact area and the contact solution anisotropy is enlightened. Implications on real system may be drawn on this basis. Finally, we focus on the hysteretic cycle related to the viscoelastic tangential forces.

A Comparison of Several Statistical Tests of Reciprocity of Self-Disclosure.

Science.gov (United States)

Dindia, Kathryn

1988-01-01

Reports the results of a study that used several statistical tests of reciprocity of self-disclosure. Finds little evidence for reciprocity of self-disclosure, and concludes that either reciprocity is an illusion, or that different or more sophisticated methods are needed to detect it. (MS)

The stability of quadratic-reciprocal functional equation

Science.gov (United States)

Song, Aimin; Song, Minwei

2018-04-01

A new quadratic-reciprocal functional equation f ((k +1 )x +k y )+f ((k +1 )x -k y )=2/f (x )f (y )[(k+1 ) 2f (y )+k2f (x )] [(k+1)2f (y )-k2f (x )] 2 is introduced. The Hyers-Ulam stability for the quadratic-reciprocal functional equations is proved in Banach spaces using the direct method and the fixed point method, respectively.

Reciprocity principle in stochastic quantum mechanics

International Nuclear Information System (INIS)

Brooke, J.A.; Guz, W.; Prugovecki, E.

1982-01-01

Born's reciprocity theory can be combined with a recently proposed framework for quantum spacetime by requiring that the free test particle propagators obey the Born-Lande equation in addition to the Klein-Gordon equation. If, furthermore, the coordinate transition amplitudes in between various standards are required to be eigenfunctions of Born's metric operator, then a mass formula results which predicts linear dependence on spin of the squared rest mass of elementary particles. This procedure also leads to a guage and reciprocally invariant formulation of the relativistic canonical commutation relations

Payoff non-linearity sways the effect of mistakes on the evolution of reciprocity.

Science.gov (United States)

Kurokawa, Shun

2016-09-01

The existence of cooperation is considered to require explanation, and reciprocity is a potential explanatory mechanism. Animals sometimes fail to cooperate even when they attempt to do so, and a reciprocator has an Achilles' heel: it is vulnerable to error (the interaction between two reciprocators can lead to an endless vendetta.). However, the strategy favored by natural selection is determined also by its interaction with other strategies. The relationship between two reciprocators leading to a collapse of cooperation through error does not straightforwardly imply that mistakes make the conditions under which reciprocity evolves stringent. Hence, mistakes may facilitate the evolution of reciprocity. However, it has been shown through the analysis of the interaction between reciprocators and unconditional defectors that the existence of mistakes makes the conditions for reciprocators stable against invasion by an unconditional defector more stringent, which indicates that mistakes discourage the evolution of reciprocity. However, this result is based on the assumption that the effects of cooperation are additive (payoff is linear), while the game played by real animals does not always display this feature. In such cases, the result may be swayed. In this paper, we remove this assumption, reexamining whether mistakes disturb the evolution of reciprocity. Using the analysis of an evolutionarily stable strategy (ESS), we show that when extra fitness costs are present in cases where mutual cooperation is established, mistakes can facilitate the evolution of reciprocity; whereas, when the effect of cooperation is additive, mistakes always disturb the evolution of reciprocity, as has been shown previously. Copyright © 2016. Published by Elsevier Inc.

The influence of steepness of dominance hierarchies on reciprocity and interchange in captive groups of bonobos (Pan paniscus)

NARCIS (Netherlands)

Stevens, J.M.G.; Vervaecke, H.; Vries, Han de; Elsacker, L. van

2005-01-01

Biological market models explain variability in reciprocity and interchange between groups. In groups with a shallow dominance gradient, grooming will be mostly exchanged for itself (i.e. exchange will occur). In groups with steep dominance hierarchies, interchange is expected: individuals will

Reciprocity and depressive symptoms in Belgian workers: a cross-sectional multilevel analysis.

Science.gov (United States)

De Clercq, Bart; Clays, Els; Janssens, Heidi; De Bacquer, Dirk; Casini, Annalisa; Kittel, France; Braeckman, Lutgart

2013-07-01

This study examines the multidimensional association between reciprocity at work and depressive symptoms. Data from the Belgian BELSTRESS survey (32 companies; N = 24,402) were analyzed. Multilevel statistical procedures were used to account for company-level associations while controlling for individual-level associations. Different dimensions of individual reciprocity were negatively associated with depressive symptoms. On the company level, only vertical emotional reciprocity was negatively associated (β = -4.660; SE = 1.117) independently from individual reciprocity (β = -0.557; SE = 0.042). Complex interactions were found such that workplace reciprocity (1) may not uniformly benefit individuals and (2) related differently to depressive symptoms, depending on occupational group. This study extends the existing literature with evidence on the multidimensional, contextual, and cross-level interaction associations of reciprocity as a key aspect of social capital on depressive symptoms.

Monkeys fail to reciprocate in an exchange task.

Science.gov (United States)

Pelé, Marie; Thierry, Bernard; Call, Josep; Dufour, Valérie

2010-09-01

Exchanges form the basis of human economies. Animals too can engage in reciprocal interactions but they do not barter goods like humans, which raises the question of the abilities necessary for trading to occur. Previous studies have shown that non-human primates can exchange food with human partners. Here, we tested the ability of brown capuchin monkeys and Tonkean macaques to reciprocate in a task requiring two conspecifics to exchange tokens in order to obtain rewards from an experimenter. We recorded 56 transfers between subjects in capuchin monkeys and 10 in Tonkean macaques. All transfers were passive in both species. Capuchins preferentially picked up tokens valuable for them in the partner's compartment. They tended to manipulate the partner-valued tokens more often than the no-value ones, leading to more opportunities for these tokens to end up within reach of the partner. Despite optimal conditions where values of goods were defined and known by partners, however, none of the pairs tested engaged in short-term reciprocal interactions. These results indicate that calculated reciprocity was difficult if not impossible in the animals tested.

Disjunctured reciprocity: Paradoxes of community-school relationship in Nepal

DEFF Research Database (Denmark)

Pradhan, Uma; Shrestha, Shivana; Valentin, Karen

2018-01-01

and community. This article questions the simplistic assumption through an ethnographic study of community-school relationship in Nepal. While these relationships may conflict with the kind of reciprocity assumed in school governance policies, we argue that this disjunctured reciprocity, firstly, reflects...

Parents’ Monitoring-Relevant Knowledge and Adolescents’ Delinquent Behavior: Evidence of Correlated Developmental Changes and Reciprocal Influences

OpenAIRE

Laird, Robert D.; Pettit, Gregory S.; Bates, John E.; Dodge, Kenneth A.

2003-01-01

Links between parental knowledge and adolescent delinquent behavior were tested for correlated rates of developmental change and reciprocal associations. For 4 years beginning at age 14, adolescents (N = 396) reported on their delinquent behavior and on their parents’ knowledge of their whereabouts and activities. Parents completed measures of their adolescents’ delinquent behavior. Knowledge was negatively correlated with delinquent behaviors at baseline, and increases over time in knowledge...

Cross-cultural differences in the refusal to accept a small gift: the differential influence of reciprocity norms on Asians and North Americans.

Science.gov (United States)

Shen, Hao; Wan, Fang; Wyer, Robert S

2011-02-01

Asians are more likely than North Americans to refuse a small gift that is offered to them by a casual acquaintance. Five experiments confirmed this difference and explored the reasons for its occurrence. Asians, who are inclined to think of themselves in relation to others, are more likely than North Americans to invoke a reciprocity norm in exchanging gifts with casual acquaintances, and they refuse a gift in order to avoid the feeling of indebtedness they would experience if they cannot reciprocate. North Americans, however, who are inclined to think of themselves independently of others, are more likely to base their acceptance of the gift on its attractiveness without considering their obligation to reciprocate. These cultural differences are not evident when the gift is offered by a close friend with whom individuals have a communal relationship. Implications of our findings for miscommunication between members of different cultures are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Effect of load and reciprocating velocity on the transition from mild to severe wear behavior of Al-Si-SiCp composites in reciprocating conditions

International Nuclear Information System (INIS)

Rajeev, V.R.; Dwivedi, D.K.; Jain, S.C.

2010-01-01

In the present paper, the effect of normal load and reciprocating velocity on transition from mild to severe wear of A319/15%SiC p , A336/15%SiC p , and A390/15%SiC p composites have been reported. Composites were produced through liquid metal metallurgy route. Adhesive wear behavior of composites was studied under dry reciprocating conditions using indigenously developed reciprocating friction wear test rig conforming to ASTM Standard G133-05. It was found that increase in normal load increases wear rate and depending upon the reciprocating velocity and type of composites, mode of wear changes from mild oxidative to severe metallic wear was noticed. The load corresponding to the transition from mild to severe wear usually termed as transition load was found to decrease with increase in reciprocating velocity and reduction in silicon content in the alloys used for the development of Al-Si-SiC p composites. At 1 m/s reciprocating velocity, the transition load for A319/15%SiC p , A336/15%SiC p and A390/15%SiC p composites were found to be in the range of 60-90 N, 60-105 N and 60-120 N respectively. Scanning electron microscope (SEM) study of wear surface and wear debris were conducted to analyze the mode of wear and operating wear mechanism. Severe wear was characterized by massive plastic deformation and gross material removal while the mild wear was found to be associated with delamination and scoring as main wear mechanisms responsible for material loss. Wear mechanism maps for different Al-(6-18)%Si-15%SiC p composites were proposed in reciprocating contacts.

Advances in Design and Fabrication of Free-Form Reciprocal Structures

DEFF Research Database (Denmark)

Parigi, Dario

2016-01-01

The paper presents the advances in design and fabrication of free-form Reciprocal Structures, and their application a during a one-week long workshop with the students of the 1st semester of the Master of Science in Architecture and Design, fall 2015, at Aalborg University. Two new factors were...... introduced and tested: a new version of the software Reciprocalizer, and an evolution of the Reciprocalizer Robot. The workshop didactic framework Performance Aided/Assisted Design (PAD) is presented....

Towards a harmonised protection of indigenous knowledge systems ...

African Journals Online (AJOL)

This article explores the need for a policy, regional dialogue and cooperation on the protection of IKS in the Southern African Development Community (SADC). Since 2002 the SADC countries have held annual SADC programmes in the form of workshops on IKS policy development and cooperation. Steady progress has ...

Cooperation under indirect reciprocity and imitative trust.

Science.gov (United States)

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.

Cooperation under indirect reciprocity and imitative trust.

Directory of Open Access Journals (Sweden)

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.

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.

Social Dilemmas and Indirect Reciprocity: A systematic review

Directory of Open Access Journals (Sweden)

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.

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.

Gauge invariance and reciprocity in quantum mechanics

International Nuclear Information System (INIS)

Leung, P. T.; Young, K.

2010-01-01

Reciprocity in wave propagation usually refers to the symmetry of the Green's function under the interchange of the source and the observer coordinates, but this condition is not gauge invariant in quantum mechanics, a problem that is particularly significant in the presence of a vector potential. Several possible alternative criteria are given and analyzed with reference to different examples with nonzero magnetic fields and/or vector potentials, including the case of a multiply connected spatial domain. It is shown that the appropriate reciprocity criterion allows for specific phase factors separable into functions of the source and observer coordinates and that this condition is robust with respect to the addition of any scalar potential. In the Aharonov-Bohm effect, reciprocity beyond monoenergetic experiments holds only because of subsidiary conditions satisfied in actual experiments: the test charge is in units of e and the flux is produced by a condensate of particles with charge 2e.

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.

Transcranial Electrical Neuromodulation Based on the Reciprocity Principle.

Science.gov (United States)

Fernández-Corazza, Mariano; Turovets, Sergei; Luu, Phan; Anderson, Erik; Tucker, Don

2016-01-01

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 modeled 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.

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 sup...

Lack of Acceptance of Reciprocity Norms in Preschool Children.

Science.gov (United States)

Berndt, Thomas J.

1979-01-01

Two studies investigated preschool children's acceptance of the reciprocity norms that allow retaliation and that require returning favors. Children viewed cartoons that portrayed animal puppets involved in reciprocal or nonreciprocal aggressive and prosocial behavior. They were then asked to evaluate the actor in each cartoon as "good"…

Coordinated vigilance provides evidence for direct reciprocity in coral reef fishes.

Science.gov (United States)

Brandl, Simon J; Bellwood, David R

2015-09-25

Reciprocity is frequently assumed to require complex cognitive abilities. Therefore, it has been argued that reciprocity may be restricted to animals that can meet these demands. Here, we provide evidence for the potential presence of direct reciprocity in teleost fishes. We demonstrate that in pairs of coral reef rabbitfishes (f. Siganidae), one fish frequently assumes an upright vigilance position in the water column, while the partner forages in small crevices in the reef substratum. Both behaviours are strongly coordinated and partners regularly alternate their positions, resulting in a balanced distribution of foraging activity. Compared to solitary individuals, fishes in pairs exhibit longer vigilance bouts, suggesting that the help provided to the partner is costly. In turn, fishes in pairs take more consecutive bites and penetrate deeper into crevices than solitary individuals, suggesting that the safety provided by a vigilant partner may outweigh initial costs by increasing foraging efficiency. Thus, the described system appears to meet all of the requirements for direct reciprocity. We argue that the nature of rabbitfish pairs provides favourable conditions for the establishment of direct reciprocity, as continuous interaction with the same partner, simultaneous needs, interdependence, and communication relax the cognitive demands of reciprocal cooperation.

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

NARCIS (Netherlands)

Pessers, D.

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

"Dentinal microcracks after root canal preparation" a comparative evaluation with hand, rotary and reciprocating instrumentation.

Science.gov (United States)

Priya, N Tulasi; Chandrasekhar, Veeramachaneni; Anita, S; Tummala, Muralidhar; Raj, T B Phanindhar; Badami, Vijetha; Kumar, Pradeep; Soujanya, E

2014-12-01

The purpose of this study was to compare the incidence of dentinal micro cracks after instrumentation with various types of NiTi files in rotary and reciprocating motion. One hundred human extracted mandibular central incisors were taken and divided into 10 groups (n=10 teeth per group). Group 1- No preparation, Group 2 - Hand instrumentation, Groups 3,4 - ProTaper files in rotary and reciprocating motion, Groups 5,6 - ProTaper Next files in rotary and reciprocating motion, Groups 7,8 - Oneshape files in rotary and reciprocating motion, Groups 9,10 - Reciproc files in rotary and reciprocating motion. Specimens were sectioned horizontally at 3,6 and 9 mm from the apex and dentinal micro cracks were observed under a stereomicroscope. There was a statistically significant difference between the groups (pProtaper Next - Rot, Protaper Next - Rec, Reciproc - Rec); (ProTaper - Rot, ProTaper - Rec, Oneshape - Rot), (Oneshape - Rot, Reciproc - Rot), (One shape Reciproc, Reciproc - Rec); (p >.05). Least cracks were seen in canals instrumented with Pro Taper Next files both in rotary and reciprocating motion. Full sequence rotary systems showed less cracks than single file systems and full sequence rotary systems showed less cracks in reciprocating motion than in rotary motion.

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.

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

Science.gov (United States)

Sasaki, Tatsuya; Okada, Isamu; Nakai, Yutaka

2016-07-01

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 them 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. © 2016 The Authors.

Supersymmetric reciprocal transformation and its applications

International Nuclear Information System (INIS)

Liu, Q. P.; Popowicz, Ziemowit; Tian Kai

2010-01-01

The supersymmetric analog of the reciprocal transformation is introduced. This is used to establish a transformation between one of the supersymmetric Harry Dym equations and the supersymmetric modified Korteweg-de Vries equation. The reciprocal transformation, as a Baecklund-type transformation between these two equations, is adopted to construct a recursion operator for the supersymmetric Harry Dym equation. By proper factorization of the recursion operator, a bi-Hamiltonian structure is found for the supersymmetric Harry Dym equation. Furthermore, a supersymmetric Kawamoto equation is proposed and is associated with the supersymmetric Sawada-Kotera equation. The recursion operator and odd bi-Hamiltonian structure of the supersymmetric Kawamoto equation are also constructed.

Enhanced additive manufacturing with a reciprocating platen

Science.gov (United States)

Lind, Randall F.; Blue, Craig A.; Love, Lonnie J.; Post, Brian K.; Lloyd, Peter D.

2018-02-06

An additive manufacturing extrusion head that includes a heated nozzle for accepting a feedstock and extruding the feedstock onto a substrate at a deposition plane, the nozzle having a longitudinal extrusion axis. A reciprocating platen surrounds the nozzle, the platen operable to reciprocate along the extrusion axis at or above the deposition plane as the nozzle extrudes feedstock onto the substrate; and wherein the platen flattens the extruded feedstock such that it does not protrude above the deposition plane as the extrusion head traverses over the substrate.

Structural Implications of Reciprocal Exchange: A Power-Dependence Approach

Science.gov (United States)

Bonacich, Phillip; Bienenstock, Elisa Jayne

2009-01-01

This paper presents and tests a general model to predict emergent exchange patterns and power differences in reciprocal exchange networks when individual actors follow the norm of reciprocity. With an interesting qualification, the experimental results reported here support the power-dependence approach (Emerson 1972a, b): those who acquire the…

Incidence of dentinal defects after root canal preparation: reciprocating versus rotary instrumentation.

Science.gov (United States)

Bürklein, Sebastian; Tsotsis, Polymnia; Schäfer, Edgar

2013-04-01

The purpose of this study was to evaluate the incidence of dentinal defects after root canal preparation with reciprocating instruments (Reciproc and WaveOne) and rotary instruments. One hundred human central mandibular incisors were randomly assigned to 5 groups (n = 20 teeth per group). The root canals were instrumented by using the reciprocating single-file systems Reciproc and WaveOne and the full-sequence rotary Mtwo and ProTaper instruments. One group was left unprepared as control. Roots were sectioned horizontally at 3, 6, and 9 mm from the apex and evaluated under a microscope by using 25-fold magnification. The presence of dentinal defects (complete/incomplete cracks and craze lines) was noted and analyzed by using the chi-square test. No defects were observed in the controls. All canal preparation created dentinal defects. Overall, instrumentation with Reciproc was associated with more complete cracks than the full-sequence files (P = .021). Although both reciprocating files produced more incomplete cracks apically (3 mm) compared with the rotary files (P = .001), no statistically significant differences were obtained concerning the summarized values of all cross sections (P > .05). Under the conditions of this study, root canal preparation with both rotary and reciprocating instruments resulted in dentinal defects. At the apical level of the canals, reciprocating files produced significantly more incomplete dentinal cracks than full-sequence rotary systems (P < .05). Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The reciprocal constitutive features of a Middle Eastern partnership: The Russian–Syrian bilateral relations

Directory of Open Access Journals (Sweden)

Theodor Tudoroiu

2015-07-01

Full Text Available Using the concept of reciprocal socialization, this article argues that the Damascus–Moscow partnership has been since 1970 a reciprocal constitutive relation that has influenced considerably the actions, interests, and identities of the two partners. During the last two decades of the Cold War it represented an almost ideal-type example of a relationship between a super-power and its regional ally that, through its complex consequences, shaped significantly the two partners themselves, the Middle Eastern political and security environment, and the international system as a whole. Post-2003 developments and especially the present Syrian crisis also have influenced considerably the two states' identity-building processes. After the US invasion of Iraq, the patterns of renewed bilateral cooperation have mirrored, at least in part, the Cold War ones. The Arab Spring enforced this trend. Yet, today the International Relations identity of Russia is quite different from the Soviet era one. The main consequence is that Moscow's new identity prevents it from supporting the regime in Damascus at any cost. If military operations take a turn threatening seriously the survival of that regime, it is likely that the Kremlin will not escalate its pro-al-Asad involvement, thus accepting the possible fall of its Middle Eastern ally.

Reciprocity in the electronic stopping of slow ions in matter

International Nuclear Information System (INIS)

Sigmund, P.

2008-01-01

The principle of reciprocity, i.e., the invariance of the inelastic excitation in ion-atom collisions against interchange of projectile and target, has been applied to the electronic stopping cross section of low-velocity ions and tested empirically on ion-target combinations supported by a more or less adequate amount of experimental data. Reciprocity is well obeyed (within ∼10%) for many systems studied, and deviations exceeding ∼20% are exceptional. Systematic deviations such as gas-solid or metal-insulator differences have been looked for but not identified on the present basis. A direct consequence of reciprocity is the equivalence of Z 1 with Z 2 structure for random slowing down. This feature is reasonably well supported empirically for ion-target combinations involving carbon, nitrogen, aluminium and argon. Reciprocity may be utilized as a criterion to reject questionable experimental data. In cases where a certain stopping cross section has not been or cannot be measured, the stopping cross section for the inverted system may be available and serve as a first estimate. It is suggested to build in reciprocity as a fundamental requirement into empirical interpolation schemes directed at the stopping of low-velocity ions. Examination of the SRIM and MSTAR codes reveals cases where reciprocity is obeyed accurately, but deviations of up to a factor of two are common. In case of heavy ions such as gold, electronic stopping cross sections predicted by SRIM are asserted to be almost an order of magnitude too high. (authors)

Reciprocity in the electronic stopping of slow ions in matter

Science.gov (United States)

Sigmund, P.

2008-04-01

The principle of reciprocity, i.e., the invariance of the inelastic excitation in ion-atom collisions against interchange of projectile and target, has been applied to the electronic stopping cross section of low-velocity ions and tested empirically on ion-target combinations supported by a more or less adequate amount of experimental data. Reciprocity is well obeyed (within ~10%) for many systems studied, and deviations exceeding ~20% are exceptional. Systematic deviations such as gas-solid or metal-insulator differences have been looked for but not identified on the present basis. A direct consequence of reciprocity is the equivalence of Z1 with Z2 structure for random slowing down. This feature is reasonably well supported empirically for ion-target combinations involving carbon, nitrogen, aluminium and argon. Reciprocity may be utilized as a criterion to reject questionable experimental data. In cases where a certain stopping cross section has not been or cannot be measured, the stopping cross section for the inverted system may be available and serve as a first estimate. It is suggested to build in reciprocity as a fundamental requirement into empirical interpolation schemes directed at the stopping of low-velocity ions. Examination of the SRIM and MSTAR codes reveals cases where reciprocity is obeyed accurately, but deviations of up to a factor of two are common. In case of heavy ions such as gold, electronic stopping cross sections predicted by SRIM are asserted to be almost an order of magnitude too high.

Using Excel's Matrix Operations to Facilitate Reciprocal Cost Allocations

Science.gov (United States)

Leese, Wallace R.; Kizirian, Tim

2009-01-01

The reciprocal method of service department cost allocation requires linear equations to be solved simultaneously. These computations are often so complex as to cause the abandonment of the reciprocal method in favor of the less sophisticated direct or step-down methods. Here is a short example demonstrating how Excel's sometimes unknown matrix…

Regional health governance: A suggested agenda for Southern African health diplomacy.

Science.gov (United States)

Penfold, Erica Dale; Fourie, Pieter

2015-12-01

Regional organisations can effectively promote regional health diplomacy and governance through engagement with regional social policy. Regional bodies make decisions about health challenges in the region, for example, the Union of South American Nations (UNASUR) and the World Health Organisation South East Asia Regional Office (WHO-SEARO). The Southern African Development Community (SADC) has a limited health presence as a regional organisation and diplomatic partner in health governance. This article identifies how SADC facilitates and coordinates health policy, arguing that SADC has the potential to promote regional health diplomacy and governance through engagement with regional social policy. The article identifies the role of global health diplomacy and niche diplomacy in health governance. The role of SADC as a regional organisation and the way it functions is then explained, focusing on how SADC engages with health issues in the region. Recommendations are made as to how SADC can play a more decisive role as a regional organisation to implement South-South management of the regional social policy, health governance and health diplomacy agenda.

Neural precursors of future liking and affective reciprocity.

Science.gov (United States)

Zerubavel, Noam; Hoffman, Mark Anthony; Reich, Adam; Ochsner, Kevin N; Bearman, Peter

2018-04-24

Why do certain group members end up liking each other more than others? How does affective reciprocity arise in human groups? The prediction of interpersonal sentiment has been a long-standing pursuit in the social sciences. We combined fMRI and longitudinal social network data to test whether newly acquainted group members' reward-related neural responses to images of one another's faces predict their future interpersonal sentiment, even many months later. Specifically, we analyze associations between relationship-specific valuation activity and relationship-specific future liking. We found that one's own future (T2) liking of a particular group member is predicted jointly by actor's initial (T1) neural valuation of partner and by that partner's initial (T1) neural valuation of actor. These actor and partner effects exhibited equivalent predictive strength and were robust when statistically controlling for each other, both individuals' initial liking, and other potential drivers of liking. Behavioral findings indicated that liking was initially unreciprocated at T1 yet became strongly reciprocated by T2. The emergence of affective reciprocity was partly explained by the reciprocal pathways linking dyad members' T1 neural data both to their own and to each other's T2 liking outcomes. These findings elucidate interpersonal brain mechanisms that define how we ultimately end up liking particular interaction partners, how group members' initially idiosyncratic sentiments become reciprocated, and more broadly, how dyads evolve. This study advances a flexible framework for researching the neural foundations of interpersonal sentiments and social relations that-conceptually, methodologically, and statistically-emphasizes group members' neural interdependence. Copyright © 2018 the Author(s). Published by PNAS.

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…

Direct reciprocity in animals: The roles of bonding and affective processes.

Science.gov (United States)

Freidin, Esteban; Carballo, Fabricio; Bentosela, Mariana

2017-04-01

The presence of direct reciprocity in animals is a debated topic, because, despite its evolutionary plausibility, it is believed to be uncommon. Some authors claim that stable reciprocal exchanges require sophisticated cognition which has acted as a constraint on its evolution across species. In contrast, a more recent trend of research has focused on the possibility that direct reciprocity occurs within long-term bonds and relies on simple as well as more complex affective mechanisms such as emotional book-keeping, rudimentary and higher forms of empathy, and inequity aversion, among others. First, we present evidence supporting the occurrence of long-term reciprocity in the context of existing bonds in social birds and mammals. Second, we discuss the evidence for affective responses which, modulated by bonding, may underlie altruistic behaviours in different species. We conclude that the mechanisms that may underlie reciprocal exchanges are diverse, and that some act in interaction with bonding processes. From simple associative learning in social contexts, through emotional contagion and behavioural mimicry, to empathy and a sense of fairness, widespread and diverse social affective mechanisms may explain why direct reciprocity may not be a rare phenomenon among social vertebrates. © 2015 International Union of Psychological Science.

Synchronized conductivity modulation to realize broadband lossless magnetic-free non-reciprocity.

Science.gov (United States)

Dinc, Tolga; Tymchenko, Mykhailo; Nagulu, Aravind; Sounas, Dimitrios; Alu, Andrea; Krishnaswamy, Harish

2017-10-06

Recent research has explored the spatiotemporal modulation of permittivity to break Lorentz reciprocity in a manner compatible with integrated-circuit fabrication. However, permittivity modulation is inherently weak and accompanied by loss due to carrier injection, particularly at higher frequencies, resulting in large insertion loss, size, and/or narrow operation bandwidths. Here, we show that the presence of absorption in an integrated electronic circuit may be counter-intuitively used to our advantage to realize a new generation of magnet-free non-reciprocal components. We exploit the fact that conductivity in semiconductors provides a modulation index several orders of magnitude larger than permittivity. While directly associated with loss in static systems, we show that properly synchronized conductivity modulation enables loss-free, compact and extremely broadband non-reciprocity. We apply these concepts to obtain a wide range of responses, from isolation to gyration and circulation, and verify our findings by realizing a millimeter-wave (25 GHz) circulator fully integrated in complementary metal-oxide-semiconductor technology.Optical non-reciprocity achieved through refractive index modulation can have its challenges and limitations. Here, Dinc et al. introduce the concept of non-reciprocity based on synchronized spatio-temporal modulation of conductivity to achieve different types of non-reciprocal functionality.

Reciprocal locomotion of dense swimmers in Stokes flow

International Nuclear Information System (INIS)

Gonzalez-Rodriguez, David; Lauga, Eric

2009-01-01

Due to the kinematic reversibility of Stokes flow, a body executing a reciprocal motion (a motion in which the sequence of body configurations remains identical under time reversal) cannot propel itself in a viscous fluid in the limit of negligible inertia; this result is known as Purcell's scallop theorem. In this limit, the Reynolds numbers based on the fluid inertia and on the body inertia are all zero. Previous studies characterized the breakdown of the scallop theorem with fluid inertia. In this paper we show that, even in the absence of fluid inertia, certain dense bodies undergoing reciprocal motion are able to swim. Using Lorentz's reciprocal theorem, we first derive the general differential equations that govern the locomotion kinematics of a dense swimmer. We demonstrate that no reciprocal swimming is possible if the body motion consists only of tangential surface deformation (squirming). We then apply our general formulation to compute the locomotion of four simple swimmers, each with a different spatial asymmetry, that perform normal surface deformations. We show that the resulting swimming speeds (or rotation rates) scale as the first power of a properly defined 'swimmer Reynolds number', demonstrating thereby a continuous breakdown of the scallop theorem with body inertia.

Chimpanzees trust conspecifics to engage in low-cost reciprocity.

Science.gov (United States)

Engelmann, Jan M; Herrmann, Esther; Tomasello, Michael

2015-02-22

Many of humans' most important social interactions rely on trust, including most notably among strangers. But little is known about the evolutionary roots of human trust. We presented chimpanzees (Pan troglodytes) with a modified version of the human trust game--trust in reciprocity--in which subjects could opt either to obtain a small but safe reward on their own or else to send a larger reward to a partner and trust her to reciprocate a part of the reward that she could not access herself. In a series of three studies, we found strong evidence that in interacting with a conspecific, chimpanzees show spontaneous trust in a novel context; flexibly adjust their level of trust to the trustworthiness of their partner and develop patterns of trusting reciprocity over time. At least in some contexts then, trust in reciprocity is not unique to humans, but rather has its evolutionary roots in the social interactions of humans' closest primate relatives. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

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.

Radiation induced reciprocal translocations and inversions in anopheles albimanus

International Nuclear Information System (INIS)

Kaiser, P.E.; Seawright, J.A.; Benedict, M.Q.; Narang, S.

1982-01-01

Reciprocal translocations and inversions were induced in Anopheles albimanus Wiedemann by irradiation of males with X rays. A total of 1669 sperm were assayed, and 175 new aberrations were identified as follows: 102 reciprocal translocations (67 autosomal and 35 sex-linked), 45 pericentric inversions, and 28 paracentric inversions. Eleven of the translocations were nearly whole-arm interchanges, and these were selected for the construction of 'capture systems' for compound chromosomes. Two double-heterozygous translocation strains and four homozygous translocation strains were established. Anopheles albimanus females were irradiated, and a pseudolinkage scheme involving mutant markers was employed to identify reciprocal translocations. The irradiation of females was very inefficient; only one translocation was recovered from 1080 ova tested

A Journey into Reciprocal Space; A crystallographer's perspective

Science.gov (United States)

Glazer, A. M.

2017-10-01

This book introduces undergraduate and graduate students to a crystallographer's view of real and reciprocal space, a concept that has been of particular use by crystallographers to understand the patterns of spots when x-rays are diffracted by crystals. It then proceeds to develop the concept in a form suitable for physics applications; such as how solid-state physicists use reciprocal space to explain various solid-state properties such as thermal and electrical phenomena.

Sex differences in the reciprocal behaviour of children with autism

NARCIS (Netherlands)

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

Experimental investigation of the discharge valve dynamics in a reciprocating compressor for trans-critical CO2 refrigeration cycle

International Nuclear Information System (INIS)

Ma Yuan; He Zhilong; Peng Xueyuan; Xing Ziwen

2012-01-01

The self-acting valve has a significant influence on the efficiency and reliability of the reciprocating compressor. In the trans-critical CO 2 cycle, the large density and high pressure difference across the valve cause serious bending and impact stresses in the valve, offering great challenges for successful valve design. Experimental investigation of the valve dynamics is required in order to design a self-acting valve with a high efficiency and long life span for the trans-critical CO 2 compressor. A semi-hermetic reciprocating compressor was developed for application in CO 2 refrigeration, and a test system was incorporated into the compressor performance test rig, with a focus on investigating the dynamics of the discharge valves. With the experimental results, the movement of the valve was discussed in detail for the trans-critical CO 2 compressor, allowing for the study of the thermodynamic performance of the compressor. While varying design parameters such as pressure ratio, valve lift, spring stiffness and compressor speed, the movement of the discharge valve in the reciprocating CO 2 compressor was measured in order to investigate the major factors that influence the valve dynamics. The average valve speed increased from 0.71 m/s to 0.81 m/s as the discharge pressure changed from 7.8 MPa to 12 MPa. The experimental methods and results discussed in this paper could provide useful information for both valve testing and the optimization of their reliability in trans-critical CO 2 compressors.

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

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

NARCIS (Netherlands)

Agneessens, Filip; Skvoretz, John

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

Apically extruded debris with reciprocating single-file and full-sequence rotary instrumentation systems.

Science.gov (United States)

Bürklein, Sebastian; Schäfer, Edgar

2012-06-01

The purpose of this in vitro study was to assess the amount of apically extruded debris using rotary and reciprocating nickel-titanium instrumentation systems. Eighty human mandibular central incisors were randomly assigned to 4 groups (n = 20 teeth per group). The root canals were instrumented according to the manufacturers' instructions using the 2 reciprocating single-file systems Reciproc (VDW, Munich, Germany) and WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) and the 2 full-sequence rotary Mtwo (VDW, Munich, Germany) and ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) instruments. Bidistilled water was used as irrigant. The apically extruded debris was collected in preweighted glass vials using the Myers and Montgomery method. After drying, the mean weight of debris was assessed with a microbalance and statistically analyzed using analysis of variance and the post hoc Student-Newman-Keuls test. The time required to prepare the canals with the different instruments was also recorded. The reciprocating files produced significantly more debris compared with both rotary systems (P rotary instruments (P > .05), the reciprocating single-file system Reciproc produced significantly more debris compared with all other instruments (P Instrumentation was significantly faster using Reciproc than with all other instrument (P rotary instrumentation was associated with less debris extrusion compared with the use of reciprocating single-file systems. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The TORE SUPRA fast reciprocating RF probe

International Nuclear Information System (INIS)

Thomas, C.E. Jr.; Harris, J.H.; Haste, G.R.

1994-01-01

A fast reciprocating ICRF (Ion Cyclotron Range of Frequencies) probe was installed and operated on TORE SUPRA during 1992/1993. The body of the probe was originally used on the ATF experiment at ORNL. The probe was adapted for use on TORE SUPRA, and mounted on one of the two fast reciprocating probe mounts. The probe consists of two orthogonal single-turn wire loops, mounted so that one loop senses toroidal RF magnetic fields and the other senses poloidal RF magnetic fields. The probe began operation in June, 1993. The probe active area is approximately 5 cm long by 2 cm, and the reciprocating mount has a slow stroke (5 cm/sec) of 30 cm by 2 cm, and the reciprocating mount has a slow stroke (5 cm/sec) of 30 cm and a fast stroke (1.5 m/sec) of about 10 cm. The probe was operated at distances from the plasma edge ranging from 30 cm to -5 cm (i.e., inside the last closed flux surface). The probe design, electronics, calibration, data acquisition and data processing are discussed. First data from the probe are presented as a function of ICRF power, distance from the plasma, loop orientation, and other plasma parameters. Initial data shows parametric instabilities do not play an important role for ICRF in the TORE SUPRA edge and scrape-off-layer (SOL) plasmas. Additionally it is observed that the probe signal has little or no dependence on position in the SOL/plasma edge

Influences of Scholarship Aid on the Social Exchange Cycle: A Qualitative Exploration of Scholarship Recipients and Direct Reciprocity

Science.gov (United States)

Forrest, Jeannie

2010-01-01

Social exchange theory asserts that individuals who receive a gift will be pressed by an internal sense of obligation to give back in turn (Mauss, 2002). While there is a great deal of literature devoted to giving, there is little literature about the receiving end of the exchange cycle. Deeply impacted by the effects of direct reciprocity are…

The Personal Norm of Reciprocity among mental health service users: conceptual development and measurement.

Science.gov (United States)

Matejkowski, Jason; McCarthy, Kevin S; Draine, Jeffrey

2011-01-01

A measure of an individual's level of internalization of the norm of reciprocity may signal exchange preferences and indicate whether "active" or "passive" mental health services are preferable to consumers. We evaluated the psychometric properties of one such measure, the Personal Norm of Reciprocity (PNR) scale. We recruited 70 persons receiving mental health services and 65 comparison participants to complete questionnaires assessing reciprocity tendencies and correlates of mental illness. Two of three subscales of a shortened PNR showed evidence of reliability and validity. Consumers endorsed higher levels of the reciprocity norm than persons not seeking services. Persons in "active" service settings displayed greater rigidity in application of the reciprocity norm than individuals in "passive" service settings or comparison participants. The shortened PNR can be a useful measure of individual reciprocity preferences. Measurement of the internalization of the norm of reciprocity may assist practitioners in identifying what types of services are more likely to retain and benefit mental health service consumers.

Reciprocity-based reasons for benefiting research participants: most fail, the most plausible is problematic.

Science.gov (United States)

Sofaer, Neema

2014-11-01

A common reason for giving research participants post-trial access (PTA) to the trial intervention appeals to reciprocity, the principle, stated most generally, that if one person benefits a second, the second should reciprocate: benefit the first in return. Many authors consider it obvious that reciprocity supports PTA. Yet their reciprocity principles differ, with many authors apparently unaware of alternative versions. This article is the first to gather the range of reciprocity principles. It finds that: (1) most are false. (2) The most plausible principle, which is also problematic, applies only when participants experience significant net risks or burdens. (3) Seldom does reciprocity support PTA for participants or give researchers stronger reason to benefit participants than equally needy non-participants. (4) Reciprocity fails to explain the common view that it is bad when participants in a successful trial have benefited from the trial intervention but lack PTA to it. © 2013 John Wiley & Sons Ltd.

Spatially correlated heterogeneous aspirations to enhance network reciprocity

Science.gov (United States)

Tanimoto, Jun; Nakata, Makoto; Hagishima, Aya; Ikegaya, Naoki

2012-02-01

Perc & Wang demonstrated that aspiring to be the fittest under conditions of pairwise strategy updating enhances network reciprocity in structured populations playing 2×2 Prisoner's Dilemma games (Z. Wang, M. Perc, Aspiring to the fittest and promoted of cooperation in the Prisoner's Dilemma game, Physical Review E 82 (2010) 021115; M. Perc, Z. Wang, Heterogeneous aspiration promotes cooperation in the Prisoner's Dilemma game, PLOS one 5 (12) (2010) e15117). Through numerical simulations, this paper shows that network reciprocity is even greater if heterogeneous aspirations are imposed. We also suggest why heterogeneous aspiration fosters network reciprocity. It distributes strategy updating speed among agents in a manner that fortifies the initially allocated cooperators' clusters against invasion. This finding prompted us to further enhance the usual heterogeneous aspiration cases for heterogeneous network topologies. We find that a negative correlation between degree and aspiration level does extend cooperation among heterogeneously structured agents.

Powering up with indirect reciprocity in a large-scale field experiment.

Science.gov (United States)

Yoeli, Erez; Hoffman, Moshe; Rand, David G; Nowak, Martin A

2013-06-18

A defining aspect of human cooperation is the use of sophisticated indirect reciprocity. We observe others, talk about others, and act accordingly. We help those who help others, and we cooperate expecting that others will cooperate in return. Indirect reciprocity is based on reputation, which spreads by communication. A crucial aspect of indirect reciprocity is observability: reputation effects can support cooperation as long as peoples' actions can be observed by others. In evolutionary models of indirect reciprocity, natural selection favors cooperation when observability is sufficiently high. Complimenting this theoretical work are experiments where observability promotes cooperation among small groups playing games in the laboratory. Until now, however, there has been little evidence of observability's power to promote large-scale cooperation in real world settings. Here we provide such evidence using a field study involving 2413 subjects. We collaborated with a utility company to study participation in a program designed to prevent blackouts. We show that observability triples participation in this public goods game. The effect is over four times larger than offering a $25 monetary incentive, the company's previous policy. Furthermore, as predicted by indirect reciprocity, we provide evidence that reputational concerns are driving our observability effect. In sum, we show how indirect reciprocity can be harnessed to increase cooperation in a relevant, real-world public goods game.

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 spannin...

Indirect Reciprocity : A Field Experiment

NARCIS (Netherlands)

van Apeldoorn, J.; Schram, A.

2016-01-01

Indirect reciprocity involves cooperative acts towards strangers, either in response to their kindness to third parties (downstream) or after receiving kindness from others oneself (upstream). It is considered to be important for the evolution of cooperative behavior amongst humans. Though it has

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.

High-Resolution Reciprocal Space Mapping for Characterizing Deformation Structures

DEFF Research Database (Denmark)

Pantleon, Wolfgang; Wejdemann, Christian; Jakobsen, Bo

2014-01-01

With high-angular resolution three-dimensional X-ray diffraction (3DXRD), quantitative information is gained about dislocation structures in individual grains in the bulk of a macroscopic specimen by acquiring reciprocal space maps. In high-resolution 3D reciprocal space maps of tensile......-deformed copper, individual, almost dislocation-free subgrains are identified from high-intensity peaks and distinguished by their unique combination of orientation and elastic strain; dislocation walls manifest themselves as a smooth cloud of lower intensity. The elastic strain shows only minor variations within...... dynamics is followed in situ during varying loading conditions by reciprocal space mapping: during uninterrupted tensile deformation, formation of subgrains is observed concurrently with broadening of Bragg reflections shortly after the onset of plastic deformation. When the traction is terminated, stress...

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.

Gain-loss framing effects in dilemmas of trust and reciprocity

NARCIS (Netherlands)

Evans, A.M.; van Beest, I.

2017-01-01

How do trust and reciprocity decisions change when outcomes are framed in terms of potential losses (vs gains)? In two studies, with 7464 trust decisions from 359 participants and 2723 reciprocity decisions from 221 participants, we find that loss framing increases mean-level trust, but has no

Reciprocity and Dependency Considerations in Adult Donating and Verbal Judgments.

Science.gov (United States)

Peterson, Lizette; McCommis, Bruce

The norms of social responsibility and reciprocity govern altruistic behavior. Children and adults show a consistent developmental trend in comparisons of their responses to positive reciprocal situations and their subsequent altruism. Research indicates, however, that children, given the choice to behaviorally aid a needy individual, choose more…

Neural signatures of trust in reciprocity: A coordinate-based meta-analysis.

Science.gov (United States)

Bellucci, Gabriele; Chernyak, Sergey V; Goodyear, Kimberly; Eickhoff, Simon B; Krueger, Frank

2017-03-01

Trust in reciprocity (TR) is defined as the risky decision to invest valued resources in another party with the hope of mutual benefit. Several fMRI studies have investigated the neural correlates of TR in one-shot and multiround versions of the investment game (IG). However, an overall characterization of the underlying neural networks remains elusive. Here, a coordinate-based meta-analysis was employed (activation likelihood estimation method, 30 articles) to investigate consistent brain activations in each of the IG stages (i.e., the trust, reciprocity and feedback stage). Results showed consistent activations in the anterior insula (AI) during trust decisions in the one-shot IG and decisions to reciprocate in the multiround IG, likely related to representations of aversive feelings. Moreover, decisions to reciprocate also consistently engaged the intraparietal sulcus, probably involved in evaluations of the reciprocity options. On the contrary, trust decisions in the multiround IG consistently activated the ventral striatum, likely associated with reward prediction error signals. Finally, the dorsal striatum was found consistently recruited during the feedback stage of the multiround IG, likely related to reinforcement learning. In conclusion, our results indicate different neural networks underlying trust, reciprocity, and feedback learning. These findings suggest that although decisions to trust and reciprocate may elicit aversive feelings likely evoked by the uncertainty about the decision outcomes and the pressing requirements of social standards, multiple interactions allow people to build interpersonal trust for cooperation via a learning mechanism by which they arguably learn to distinguish trustworthy from untrustworthy partners. Hum Brain Mapp 38:1233-1248, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Towards an understanding of the relative strengths of positive and negative reciprocity

Directory of Open Access Journals (Sweden)

Omar Al-Ubaydli

2010-12-01

Full Text Available Scholars in economics and psychology have created a large literature studying reward, punishment and reciprocity. Labor markets constitute a popular application of this body of work, with particular emphasis on how reciprocity helps regulate workplace relationships where managers are unable to perfectly monitor workers. We study how idiosyncratic features of the labor market (compared to most scenarios in which reciprocity applies affect the nature of worker reciprocity. In particular, we show how having an excess supply of workers (simulating unemployment and managers who can observe the reciprocal behavior of workers and hire/fire them on that basis (simulating the reputational concerns inherent in labor market transactions profoundly alters worker reciprocity. In the absence of reputational concerns, workers tend to reward kind behavior and punish unkind behavior by managers in approximately equal measure. In the presence of reputational concerns, workers exhibit a marked increase (decrease in the propensity to reward kind (punish unkind behavior by managers. We demonstrate how this is a consequence of workers and managers responding to changes in the strategic incentives to reward and punish. %JEL codes: D03, D63, J3, J53

A reciprocity-based formula for the capacitance with quadrupolar electrodes

Energy Technology Data Exchange (ETDEWEB)

Cho, Sungbo [Gachon University of Medicine and Science, Incheon (Korea, Republic of)

2011-11-15

A new capacitance formula for the practical design and characterization of quadrupolar electrode arrays with capacitive structures was derived based on the reciprocal theorem. The reciprocity-based capacitance formula agreed with the empirical equations established to estimate the capacitance of a single strip line or disk electrode compensating for the fringing field effect that occurs at the electrode edge. The reciprocity-based formula was applied to compute the capacitance measurable by using a quadrupolar square electrode array with a symmetric dipole-dipole configuration and was compared with the analytical equation established based on the image method assuming that the electrodes were points. The results showed that the capacitance of the quadrupolar electrodes was determined by the size of the quadrupolar electrodes relative to the separation distance between the electrodes and that the reciprocity-based capacitance formula was in agreement with the established analytical equation if the separated distance between the electrodes relative to the electrode size was large enough.

A reciprocity-based formula for the capacitance with quadrupolar electrodes

International Nuclear Information System (INIS)

Cho, Sungbo

2011-01-01

A new capacitance formula for the practical design and characterization of quadrupolar electrode arrays with capacitive structures was derived based on the reciprocal theorem. The reciprocity-based capacitance formula agreed with the empirical equations established to estimate the capacitance of a single strip line or disk electrode compensating for the fringing field effect that occurs at the electrode edge. The reciprocity-based formula was applied to compute the capacitance measurable by using a quadrupolar square electrode array with a symmetric dipole-dipole configuration and was compared with the analytical equation established based on the image method assuming that the electrodes were points. The results showed that the capacitance of the quadrupolar electrodes was determined by the size of the quadrupolar electrodes relative to the separation distance between the electrodes and that the reciprocity-based capacitance formula was in agreement with the established analytical equation if the separated distance between the electrodes relative to the electrode size was large enough.

Sorting genomes by reciprocal translocations, insertions, and deletions.

Science.gov (United States)

Qi, Xingqin; Li, Guojun; Li, Shuguang; Xu, Ying

2010-01-01

The problem of sorting by reciprocal translocations (abbreviated as SBT) arises from the field of comparative genomics, which is to find a shortest sequence of reciprocal translocations that transforms one genome Pi into another genome Gamma, with the restriction that Pi and Gamma contain the same genes. SBT has been proved to be polynomial-time solvable, and several polynomial algorithms have been developed. In this paper, we show how to extend Bergeron's SBT algorithm to include insertions and deletions, allowing to compare genomes containing different genes. In particular, if the gene set of Pi is a subset (or superset, respectively) of the gene set of Gamma, we present an approximation algorithm for transforming Pi into Gamma by reciprocal translocations and deletions (insertions, respectively), providing a sorting sequence with length at most OPT + 2, where OPT is the minimum number of translocations and deletions (insertions, respectively) needed to transform Pi into Gamma; if Pi and Gamma have different genes but not containing each other, we give a heuristic to transform Pi into Gamma by a shortest sequence of reciprocal translocations, insertions, and deletions, with bounds for the length of the sorting sequence it outputs. At a conceptual level, there is some similarity between our algorithm and the algorithm developed by El Mabrouk which is used to sort two chromosomes with different gene contents by reversals, insertions, and deletions.

[The reciprocity rule in the construction of relationships as the key in relational processes].

Science.gov (United States)

Fenelli, Antonio; Volpi, Cecilia; Guarracino, Emanuele; Galli, Virginia; Esposito, Massimo

2011-01-01

Reciprocity as an expression of the therapist-patient relationship is pointed-out by Mario Reda who refers to Comparetti's studies on the mother-foetus reciprocity, mediated by the so-called "jumps". Reciprocal behaviours are clearly observable during bird and other animal courtship behaviour, whereas in the Sapiens sapiens species, we may observe the establishing of a very complex reciprocity system, which starts with gestures and bodily attitudes, subsequently activating sensory-motor emotional schemata and internal working models, thus enabling the construction of personal meanings. A relationship may result from an encounter provided that "compatible" meanings are constructed in the context of "possible reciprocity" of significant systems. The observation of reciprocity provides a concrete possibility to reduce the risk of absolute subjectivity related to the I or the you, superceding it through the us.

Talking about Service-Learning: Product or Process? Reciprocity or Solidarity?

Science.gov (United States)

Clifford, Joan

2017-01-01

Through an exploration of values of the neoliberal university and critical service-learning, this article explores how associating service-learning with products and relationships based on reciprocity negatively impacts its connection to social justice. By emphasizing the constructs of process and solidarity, instead of products and reciprocity,…

State Authorization Reciprocity Agreement: Participation and Access to Higher Education

Science.gov (United States)

Onwuameze, Nkechi

2017-01-01

The State Authorization Reciprocity Agreement initiative was launched in 2014 to provide a uniform standard for the regulation of distance education across states in the United States. The system established by the National Council for State Authorization Reciprocity Agreement (NC-SARA) allows willing post-secondary institutions to participate…

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.

Apically extruded dentin debris by reciprocating single-file and multi-file rotary system.

Science.gov (United States)

De-Deus, Gustavo; Neves, Aline; Silva, Emmanuel João; Mendonça, Thais Accorsi; Lourenço, Caroline; Calixto, Camila; Lima, Edson Jorge Moreira

2015-03-01

This study aims to evaluate the apical extrusion of debris by the two reciprocating single-file systems: WaveOne and Reciproc. Conventional multi-file rotary system was used as a reference for comparison. The hypotheses tested were (i) the reciprocating single-file systems extrude more than conventional multi-file rotary system and (ii) the reciprocating single-file systems extrude similar amounts of dentin debris. After solid selection criteria, 80 mesial roots of lower molars were included in the present study. The use of four different instrumentation techniques resulted in four groups (n = 20): G1 (hand-file technique), G2 (ProTaper), G3 (WaveOne), and G4 (Reciproc). The apparatus used to evaluate the collection of apically extruded debris was typical double-chamber collector. Statistical analysis was performed for multiple comparisons. No significant difference was found in the amount of the debris extruded between the two reciprocating systems. In contrast, conventional multi-file rotary system group extruded significantly more debris than both reciprocating groups. Hand instrumentation group extruded significantly more debris than all other groups. The present results yielded favorable input for both reciprocation single-file systems, inasmuch as they showed an improved control of apically extruded debris. Apical extrusion of debris has been studied extensively because of its clinical relevance, particularly since it may cause flare-ups, originated by the introduction of bacteria, pulpal tissue, and irrigating solutions into the periapical tissues.

Calibration of photographic and spectroscopic films. 1: Film batch variations of reciprocity failure in IIaO film. 2: Thermal and aging effects in relationship to reciprocity failure. 3: Shifting of reciprocity failure points as a function of thermal and aging effects. Semiannual report, December 1986

International Nuclear Information System (INIS)

Peters, K.A.; Atkinson, P.F.; Hammond, E.C. Jr.

1986-01-01

Reciprocity failure was examined for IIaO spectroscopic film. Three separate experiments were performed in order to study film batch variations, thermal and aging effects in relationship to reciprocity failure, and shifting of reciprocity failure points as a function of thermal and aging effects. The failure was examined over ranges of time between 5 and 60 seconds. The variation to illuminance was obtained by using thirty neutral density filters. A standard sensitometer device imprinted the wedge pattern on the film as exposure time was subjected to variation. The results indicate that film batch differences, temperature, and aging play an important role in reciprocity failure of IIaO spectroscopic film. A shifting of the failure points was also observed in various batches of film

76 FR 12923 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

Science.gov (United States)

2011-03-09

... National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines... pollutants for existing stationary spark ignition reciprocating internal combustion engines. The final rule... reciprocating internal combustion generation, engine. transmission, or distribution. 622110 Medical and surgical...

75 FR 51569 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

Science.gov (United States)

2010-08-20

... Air Pollutants for Reciprocating Internal Combustion Engines; Final Rule #0;#0;Federal Register / Vol... for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines AGENCY: Environmental... hazardous air pollutants for existing stationary spark ignition reciprocating internal combustion engines...

Groupwise information sharing promotes ingroup favoritism in indirect reciprocity.

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Nakamura, Mitsuhiro; Masuda, Naoki

2012-11-05

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. 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 independently infer reputations of individuals

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

Magneto-optical non-reciprocal devices in silicon photonics

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Yuya Shoji

2014-01-01

Full Text Available Silicon waveguide optical non-reciprocal devices based on the magneto-optical effect are reviewed. The non-reciprocal phase shift caused by the first-order magneto-optical effect is effective in realizing optical non-reciprocal devices in silicon waveguide platforms. In a silicon-on-insulator waveguide, the low refractive index of the buried oxide layer enhances the magneto-optical phase shift, which reduces the device footprints. A surface activated direct bonding technique was developed to integrate a magneto-optical garnet crystal on the silicon waveguides. A silicon waveguide optical isolator based on the magneto-optical phase shift was demonstrated with an optical isolation of 30 dB and insertion loss of 13 dB at a wavelength of 1548 nm. Furthermore, a four port optical circulator was demonstrated with maximum isolations of 15.3 and 9.3 dB in cross and bar ports, respectively, at a wavelength of 1531 nm.

Propagation of Economic Inequality Through Reciprocity and Reputation.

Science.gov (United States)

Hackel, Leor M; Zaki, Jamil

2018-04-01

Reciprocity and reputation are powerful tools for encouraging cooperation on a broad scale. Here, we highlight a potential side effect of these social phenomena: exacerbating economic inequality. In two novel economic games, we manipulated the amount of money with which participants were endowed and then gave them the opportunity to share resources with others. We found that people reciprocated more toward higher-wealth givers, compared with lower-wealth givers, even when those givers were equally generous. Wealthier givers also achieved better reputations than less wealthy ones and therefore received more investments in a social marketplace. These discrepancies were well described by a formal model of reinforcement learning: Individuals who weighted monetary outcomes, rather than generosity, when learning about interlocutors also most strongly helped wealthier individuals. This work demonstrates that reciprocity and reputation-although globally increasing prosociality-can widen wealth gaps and provides a precise account of how inequality grows through social processes.

Publications | Page 238 | IDRC - International Development ...

International Development Research Centre (IDRC) Digital Library (Canada)

Understanding maternal mortality in Colombia : the influence of health ... In spite of a high coverage of institutional deliveries and prenatal consultations and the ... of innovative strategies in the organization of Primary Health Care (open access) ... the South African Development Community (SADC) and internationally, and ...

Parent-specific reciprocity from infancy to adolescence shapes children's social competence and dialogical skills.

Science.gov (United States)

Feldman, Ruth; Bamberger, Esther; Kanat-Maymon, Yaniv

2013-01-01

Reciprocity - the capacity to engage in social exchange that integrates inputs from multiple partners into a unified social event - is a cornerstone of adaptive social life that is learned within dyad-specific attachments during an early period of neuroplasticity. Yet, very little research traced the expression of children's reciprocity with their mother and father in relation to long-term outcomes. Guided by evolutionary models, we followed mothers, fathers, and their firstborn child longitudinally and observed mother-child and father-child reciprocity in infancy, preschool, and adolescence. In preschool, children's social competence, aggression, and prosocial behavior were observed at kindergarten. In adolescence, children's dialogical skills were assessed during positive and conflict interactions with same-sex best friends. Father-child and mother-child reciprocity were individually stable, inter-related at each stage, and consisted of distinct behavioral components. Structural equation modeling indicated that early maternal and paternal reciprocity were each uniquely predictive of social competence and lower aggression in preschool, which, in turn, shaped dialogical skills in adolescence. Father-adolescent reciprocity contributed to the dialogical negotiation of conflict, whereas mother-adolescent reciprocity predicted adolescents' dialogical skills during positive exchanges. Results highlight the role of parent-child reciprocity in shaping children's social collaboration and intimate relationships with non-kin members of their social world.

Thermodynamic Analysis of an Irreversible Maisotsenko Reciprocating Brayton Cycle

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Fuli Zhu

2018-03-01

Full Text Available An irreversible Maisotsenko reciprocating Brayton cycle (MRBC model is established using the finite time thermodynamic (FTT theory and taking the heat transfer loss (HTL, piston friction loss (PFL, and internal irreversible losses (IILs into consideration in this paper. A calculation flowchart of the power output (P and efficiency (η of the cycle is provided, and the effects of the mass flow rate (MFR of the injection of water to the cycle and some other design parameters on the performance of cycle are analyzed by detailed numerical examples. Furthermore, the superiority of irreversible MRBC is verified as the cycle and is compared with the traditional irreversible reciprocating Brayton cycle (RBC. The results can provide certain theoretical guiding significance for the optimal design of practical Maisotsenko reciprocating gas turbine plants.

Social evolution: reciprocity there is.

Science.gov (United States)

Taborsky, Michael

2013-06-03

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. Copyright © 2013 Elsevier Ltd. All rights reserved.

Reciprocal Learning: One Teacher's Narrative

Institute of Scientific and Technical Information of China (English)

Adrienne RIGLER

2017-01-01

This paper is a personal narrative from the perspective of one teacher in Toronto who participated in the Canada-China Reciprocal Learning in Teacher Education and School Education Partnership Grant Project.I took part in a Sister School partnership between 2013 and 2017.Over the four years,I came to understand relationships in an international professional learning community.Participating in the project gave me the benefit of seeing my practice through an international lens.For my students,it offered a global citizenship experience.Although there are numerous professional development opportunities in Toronto,this partnership extends beyond a lunch and learn,or a full day professional learning.The commitment to my partners has fueled my desire to incorporate new teaching ideas and has required ongoing reflection on my own teaching practice.In this article,I will explain some of the challenges,stages of development,reciprocal learning,and implications for future international professional learning communities.

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…

Measurements of reciprocity law failure in green-sensitive X-ray films.

Science.gov (United States)

Arnold, B A; Eisenberg, H; Bjärngard, B E

1978-02-01

Reciprocity law failure was measured for four brands of medical x-ray films exposed with intensifying screens. Three of the films are green light-sensitized for use in combination with green light-emitting rare-earth screens. These films showed larger reciprocity failure effects than one conventional blue-sensitive film, Dupont Cronex-2. Development conditions had a small effect on reciprocity failure. As part of the investigation, a detector was constructed with a response that accurately monitors the light emission from the double screen-cassette combination over a wide range of x-ray photon energies.

Exploring the Triple Reciprocity Nature of Organizational Value Cocreation Behavior Using Multicriteria Decision Making Analysis

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Huan-Ming Chuang

2015-01-01

Full Text Available Service-dominant (S-D logic is a service science framework that is more robust than the traditional goods-dominant (G-D logic. It emphasizes the importance of operant resources and value Cocreation. This study employs social cognitive theory to explore the triple reciprocity of organizational value Cocreation behavior. Further, this study uses DEMATEL-based ANP to examine the dynamic nature of organizational value Cocreation behavior. The major results of this study can be described as follows. First, the triadic reciprocity of personal, environmental, and behavioral factors are validated. Second, the dominant influencing trends are clearly identified. From a dimensional point of view, environmental factors affect personal factors and behavioral factors, and personal factors affect behavioral factors. Similarly, in terms of organizational value Cocreation behavior, organizational identification affects altruistic behavior and knowledge-sharing behavior, and altruistic behavior affects knowledge-sharing behavior. These findings may provide helpful guidance in effectively promoting organizational value cocreation behavior, enabling organizations to leverage operant resources to their maximum potential.

Trust, Reciprocity and Institutional Design: Lessons from Behavioural Economics

OpenAIRE

Pelligra, Vittorio

2006-01-01

Trust and reciprocity are the bond of society (Locke), but economic agents are both self-interested and intrinsically untrustworthy. These assumptions impair severely economists' accounts of social relationships. The paper examines strategies to escape this paradox by enlarging our conception of rationality: the assumptions of self-interest and consequentialism are critically discussed as well as relational behavioural principles (e.g. trust and reciprocity). The implications of this enlarged...

Comparison of heat transfer models for reciprocating compressor

International Nuclear Information System (INIS)

Tuhovcak, J.; Hejcik, J.; Jicha, M.

2016-01-01

Highlights: • Comparison of integral heat transfer models. • Influence of heat transfer model on volumetric and isentropic efficiency. • Various gases used as working fluid. - Abstract: One of the main factors affecting the efficiency of reciprocating compressor is heat transfer inside the cylinder. An analysis of heat transfer could be done using numerical models or integral correlations developed mainly from approaches used in combustion engines; however their accuracy is not completely verified due to the complicated experimental set up. The goal of this paper is to analyse the effect of heat transfer on compressor efficiency. Various integral correlations were compared for different compressor settings and fluids. CoolProp library was used in the code to obtain the properties of common coolants and gases. A comparison was done using the in-house code developed in Matlab, based on 1st Law of Thermodynamics.

General practitioners' perceptions of the stigma of dementia and the role of reciprocity.

Science.gov (United States)

Gove, Dianne; Small, Neil; Downs, Murna; Vernooij-Dassen, Myrra

2017-10-01

A qualitative exploration of the stigma of dementia reported that general practitioners described lack of reciprocity as one way in which people with dementia are perceived within society. This was closely linked to their perception of dementia as a stigma. In this article, we explore whether general practitioners perceive people with dementia as lacking reciprocity and, if so, if this is linked with societal opinions about dementia as a stigma. The implications of both perceptions of people with dementia failing to reciprocate and of stigma for timely diagnosis are explored. Our approach is to follow the thread of reciprocity in the data from our initial study. In this follow-up study, general practitioners' perceptions of societal views of people with dementia included a perception of a lack of reciprocity specifically linked with; failing to respond to human contact, the absence of an appropriate return on social investment and failing to contribute to, or being a burden on, society. General practitioners reported a link between societal perceptions of lack of reciprocity and stereotypes about advanced dementia, difficulties communicating with people with dementia, and lack of opportunities for people with dementia to reciprocate. General practitioners occupy a key position, they can challenge stereotypes and, with support and targeted training about communicating with people living with dementia, can emphasize the ways in which people with dementia can communicate, thereby enhancing their potential to reciprocate. Such changes have implications for improved care and quality of life through the continued maintenance of social inclusion and perceptions of personhood.

A DISCUSSIN OVER RECIPROCITY PRINCIPLE’S AFFECT ON SOCIAL CAPITAL’S PROLIFICACY

OpenAIRE

Mustafa Latif Emek

2014-01-01

In this study two concepts, social capital and reciprocity principles, have been introduced and their reciprocal relationship and affects also been discussed. Social Capital, an indispensable notion for the development of society from all aspects has a close relationship with reciprocity principle which regulates and forms relationship webs. In this study we firstly examined both from emergence point and sources of social capital concept which can also be entitled as social webs. Afterward...

A reciprocidade nos contratos: uma análise expressivista Contractual reciprocity: an expressivist analysis

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Leandro Martins Zanitelli

2011-06-01

regulation of contractual activity, makes clear its adhesion to the value of reciprocity as equality in exchange or denying of exploitation of one of the parties by the other. The paper argues that the legal expression of the value of reciprocity - which may take place through either a general principle of contractual equality or more specific requirements, as such that of complying with the mean price (or “market price” or that of not establishing certain clauses - is important for two kinds of reasons. first, the expression by the law of the value of reciprocity should be deemed important because the expressive content of the law is intrinsically important. in the case of reciprocity, it is argued that the law, as it manifests the wish that there be some correspondence between the sacrifice made and the advantage obtained by each party, ends up proclaiming, indirectly, The more basic values of equality and fraternity. Second, the legal expression of the value of reciprocity is important in face of its consequences. These consequences are not circumscribed to the ones coming from limits imposed to the freedom of the contractual parties or to the refusal of the courts to enforce unfair contracts, since the legal endorsement of the value of reciprocity may influence the reasons for acting of the contractual parties. As a result, instead of acting only in order to maximize her own gain, each party may include the protection of the interests of the other one among the reasons of her decisions. This paper was organized as follows. After the introduction, which contains some brief remarks on legal expressivism, part II offers a broad definition and some particular conceptions of contractual reciprocity. About each one of these conceptions, some difficulties or inconveniences, which are mostly tied to the attempt of imposing reciprocity through the restrictions of the legal efficacy of voluntarily made agreements, are referred to. Part III is dedicated to two forms of

Unilateral or Reciprocal Climate Policy? Experimental Evidence from China

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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.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Who Shapes Whom in the Family: Reciprocal Links between Autonomy Support in the Family and Parents' and Adolescents' Coping Behaviors

Science.gov (United States)

Seiffge-Krenke, Inge; Pakalniskiene, Vilmante

2011-01-01

Coping research has neglected the study of the reciprocal links between parents' and adolescents' coping behaviors and the potential influence of parental support for the development of adolescent autonomy. This study, therefore, analyzed the coping behaviors of fathers, mothers, and children (53% females) in 196 families who participated in a…

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....

Management of Common Resources and Reciprocity: the contributions of Elinor Ostrom to the Debate

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Eric Sabourin

2010-12-01

Full Text Available This paper analyzes the importance of reciprocity in the processes and procedures recorded in the management of common resources. It examines first the role that E. Ostrom attributes to the norm of reciprocity in her approach to common property resources. A second part interprets economic and social relations in the management of common resources as seen by economic anthropology’s theory of reciprocity. Finally, the conclusion attempts to establish a dialogue between Ostrom’s proposals and the theory of reciprocity.

Reciprocity and Humility in Wonderland

Science.gov (United States)

Harry, Beth

2011-01-01

This article supports the perspective of Jan Valle regarding the importance of recognizing the subjectivity inherent in decisions about Learning Disabilities. The author argues that the perspectives of both parents and professionals are informed by subjective judgments that must be taken into account in decision making. A reciprocal approach to…

Reciprocity: A Predictor of Mental Health and Continuity in Elderly People's Relationships? A Review

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Live Fyrand

2010-01-01

Full Text Available Many studies have demonstrated that social relationships confer mental health benefits. This paper aims to identify whether and how reciprocity in social relationships predicts or is associated with mental health benefits as well as with continuity in elderly people's social relationships. The studies reviewed in this paper show that, among elders, being in a balanced or underbenefited reciprocal position predicts better mental health and life quality than being in an overbenefited position. Throughout the course of life, reciprocity evens out present and earlier reciprocal imbalances, securing continuity in close relationships—particularly between spouses and between elderly parents and adult children. In friendships, securing continuity seems to be based on the maintenance of independence based on balanced reciprocal relations, making these relationships more vulnerable. Due to the problems of conceptualization and measurement in the reviewed studies, one should be cautious in stating a final conclusion that the reciprocity norm has a universal positive effect on mental health and continuity in elderly people's relationships.

Reciprocity: A Predictor of Mental Health and Continuity in Elderly People's Relationships? A Review.

Science.gov (United States)

Fyrand, Live

2010-01-01

Many studies have demonstrated that social relationships confer mental health benefits. This paper aims to identify whether and how reciprocity in social relationships predicts or is associated with mental health benefits as well as with continuity in elderly people's social relationships. The studies reviewed in this paper show that, among elders, being in a balanced or underbenefited reciprocal position predicts better mental health and life quality than being in an overbenefited position. Throughout the course of life, reciprocity evens out present and earlier reciprocal imbalances, securing continuity in close relationships-particularly between spouses and between elderly parents and adult children. In friendships, securing continuity seems to be based on the maintenance of independence based on balanced reciprocal relations, making these relationships more vulnerable. Due to the problems of conceptualization and measurement in the reviewed studies, one should be cautious in stating a final conclusion that the reciprocity norm has a universal positive effect on mental health and continuity in elderly people's relationships.

Reduced reciprocal giving in social anxiety - Evidence from the Trust Game.

Science.gov (United States)

Anderl, Christine; Steil, Regina; Hahn, Tim; Hitzeroth, Patricia; Reif, Andreas; Windmann, Sabine

2018-06-01

Social anxiety is known to impair interpersonal relationships. These impairments are thought to partly arise from difficulties to engage in affiliative interactions with others, such as sharing favors or reciprocating prosocial acts. Here, we examined whether individuals high compared to low in social anxiety differ in giving towards strangers in an economic game paradigm. One hundred and twenty seven non-clinical participants who had been pre-screened to be either particularly high or low in social anxiety played an incentivized Trust Game to assess trustful and reciprocal giving towards strangers in addition to providing information on real life interpersonal functioning (perceived social support and attachment style). We found that reciprocal, but not trustful giving, was significantly decreased among highly socially anxious individuals. Both social anxiety and reciprocal giving furthermore showed significant associations with self-reported real life interpersonal functioning. Participants played the Trust Game with the strategy method; results need replication with a clinical sample. Individuals high in social anxiety showed reduced reciprocal, but intact trustful giving, pointing to a constraint in responsiveness. The research may contribute to the development of new treatment and prevention programs to reduce the interpersonal impairments in socially anxious individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

A multilevel simultaneous equations model for within-cluster dynamic effects, with an application to reciprocal parent-child and sibling effects.

Science.gov (United States)

Steele, Fiona; Rasbash, Jon; Jenkins, Jennifer

2013-03-01

There has been substantial interest in the social and health sciences in the reciprocal causal influences that people in close relationships have on one another. Most research has considered reciprocal processes involving only 2 units, although many social relationships of interest occur within a larger group (e.g., families, work groups, peer groups, classrooms). This article presents a general longitudinal multilevel modeling framework for the simultaneous estimation of reciprocal relationships among individuals with unique roles operating in a social group. We use family data for illustrative purposes, but the model is generalizable to any social group in which measurements of individuals in the social group occur over time, individuals have unique roles, and clustering of the data is evident. We allow for the possibility that the outcomes of family members are influenced by a common set of unmeasured family characteristics. The multilevel model we propose allows for residual variation in the outcomes of parents and children at the occasion, individual, and family levels and residual correlation between parents and children due to the unmeasured shared environment, genetic factors, and shared measurement. Another advantage of this method over approaches used in previous family research is it can handle mixed family sizes. The method is illustrated in an analysis of maternal depression and child delinquency using data from the Avon Brothers and Sisters Study. PsycINFO Database Record (c) 2013 APA, all rights reserved.

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. © 2013 Wiley Periodicals, Inc.

Reciprocity in Vector Acoustics

Science.gov (United States)

2017-03-01

Green’s Theorem to the left hand side of Equation (3.2) converts it to a surface integral that vanishes for the impedance boundary conditions one...There are situations where this assumption does not hold, such as at boundaries between layers or in an inhomogeneous layer , because the density gradient...instead of requiring one model run for each source location. Application of the vector-scalar reciprocity principle is demonstrated with analytic

Leading God's People: Perceptions of Influence Among African-American Pastors.

Science.gov (United States)

Harmon, Brook E; Strayhorn, Shaila; Webb, Benjamin L; Hébert, James R

2018-01-31

Religious leaders, particularly African-American pastors, are believed to play a key role in addressing health disparities. Despite the role African-American pastors may play in improving health, there is limited research on pastoral influence. The purpose of this study was to examine African-American pastors' perceptions of their influence in their churches and communities. In-depth interviews were conducted with 30 African-American pastors and analyzed using a grounded theory approach. Three themes emerged: the historical role of the church; influence as contextual, with pastors using comparisons with other pastors to describe their ability to be influential; and a reciprocal relationship existing such that pastors are influenced by factors such as God and their community while these factors also aid them in influencing others. A conceptual model of pastoral influence was created using data from this study and others to highlight factors that influence pastors, potential outcomes and moderators as well as the reciprocal nature of pastoral influence.

Rejection of unfair offers in the ultimatum game is no evidence of strong reciprocity

Science.gov (United States)

Yamagishi, Toshio; Horita, Yutaka; Mifune, Nobuhiro; Hashimoto, Hirofumi; Li, Yang; Shinada, Mizuho; Miura, Arisa; Inukai, Keigo; Takagishi, Haruto; Simunovic, Dora

2012-01-01

The strong reciprocity model of the evolution of human cooperation has gained some acceptance, partly on the basis of support from experimental findings. The observation that unfair offers in the ultimatum game are frequently rejected constitutes an important piece of the experimental evidence for strong reciprocity. In the present study, we have challenged the idea that the rejection response in the ultimatum game provides evidence of the assumption held by strong reciprocity theorists that negative reciprocity observed in the ultimatum game is inseparably related to positive reciprocity as the two sides of a preference for fairness. The prediction of an inseparable relationship between positive and negative reciprocity was rejected on the basis of the results of a series of experiments that we conducted using the ultimatum game, the dictator game, the trust game, and the prisoner’s dilemma game. We did not find any correlation between the participants’ tendencies to reject unfair offers in the ultimatum game and their tendencies to exhibit various prosocial behaviors in the other games, including their inclinations to positively reciprocate in the trust game. The participants’ responses to postexperimental questions add support to the view that the rejection of unfair offers in the ultimatum game is a tacit strategy for avoiding the imposition of an inferior status. PMID:23188801

Rejection of unfair offers in the ultimatum game is no evidence of strong reciprocity.

Science.gov (United States)

Yamagishi, Toshio; Horita, Yutaka; Mifune, Nobuhiro; Hashimoto, Hirofumi; Li, Yang; Shinada, Mizuho; Miura, Arisa; Inukai, Keigo; Takagishi, Haruto; Simunovic, Dora

2012-12-11

The strong reciprocity model of the evolution of human cooperation has gained some acceptance, partly on the basis of support from experimental findings. The observation that unfair offers in the ultimatum game are frequently rejected constitutes an important piece of the experimental evidence for strong reciprocity. In the present study, we have challenged the idea that the rejection response in the ultimatum game provides evidence of the assumption held by strong reciprocity theorists that negative reciprocity observed in the ultimatum game is inseparably related to positive reciprocity as the two sides of a preference for fairness. The prediction of an inseparable relationship between positive and negative reciprocity was rejected on the basis of the results of a series of experiments that we conducted using the ultimatum game, the dictator game, the trust game, and the prisoner's dilemma game. We did not find any correlation between the participants' tendencies to reject unfair offers in the ultimatum game and their tendencies to exhibit various prosocial behaviors in the other games, including their inclinations to positively reciprocate in the trust game. The participants' responses to postexperimental questions add support to the view that the rejection of unfair offers in the ultimatum game is a tacit strategy for avoiding the imposition of an inferior status.

32 CFR 2001.44 - Reciprocity of use and inspection of facilities.

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Reciprocity of use and inspection of facilities. 2001.44 Section 2001.44 National Defense Other Regulations Relating to National Defense INFORMATION... INFORMATION Safeguarding § 2001.44 Reciprocity of use and inspection of facilities. (a) Once a facility is...

Reciprocal relations of transport coefficients in simple materials

International Nuclear Information System (INIS)

Lam, L.

1977-01-01

The cross effects of viscosity and heat conduction in anisotropic simple materials (solids or liquids) are given in the linear regime, using our dissipation function theory introduced recently. Depending on whether the temperature gradient or the heat flux is used in the dissipation function, we show that two different but unambiguous reciprocal relations between the transport coefficients follow. These are compared and contrasted with the confusing predictions from the Onsager theory, and to the results of rational thermodynamics. The uncertain experimental situation in regard to these reciprocal relations is discussed. Experimental tests are strongly urged. (orig.) [de

Quantum coherence: Reciprocity and distribution

Energy Technology Data Exchange (ETDEWEB)

Kumar, Asutosh, E-mail: asukumar@hri.res.in [Harish-Chandra Research Institute, Allahabad-211019 (India); Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India)

2017-03-18

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. - Highlights: • Quantum coherence. • Reciprocity between quantum coherence and mixedness. • Distribution of quantum coherence in multipartite quantum systems. • Additivity relation for distribution of quantum coherence in Dicke and “X” states.

Reciprocal inhibition between motor neurons of the tibialis anterior and triceps surae in humans.

Science.gov (United States)

Yavuz, Utku Ş; Negro, Francesco; Diedrichs, Robin; Farina, Dario

2018-05-01

Motor neurons innervating antagonist muscles receive reciprocal inhibitory afferent inputs to facilitate the joint movement in the two directions. The present study investigates the mutual transmission of reciprocal inhibitory afferent inputs between the tibialis anterior (TA) and triceps surae (soleus and medial gastrocnemius) motor units. We assessed this mutual mechanism in large populations of motor units for building a statistical distribution of the inhibition amplitudes during standardized input to the motor neuron pools to minimize the effect of modulatory pathways. Single motor unit activities were identified using high-density surface electromyography (HDsEMG) recorded from the TA, soleus (Sol), and medial gastrocnemius (GM) muscles during isometric dorsi- and plantarflexion. Reciprocal inhibition on the antagonist muscle was elicited by electrical stimulation of the tibial (TN) or common peroneal nerves (CPN). The probability density distributions of reflex strength for each muscle were estimated to examine the strength of mutual transmission of reciprocal inhibitory input. The results showed that the strength of reciprocal inhibition in the TA motor units was fourfold greater than for the GM and the Sol motor units. This suggests an asymmetric transmission of reciprocal inhibition between ankle extensor and flexor muscles. This asymmetry cannot be explained by differences in motor unit type composition between the investigated muscles since we sampled low-threshold motor units in all cases. Therefore, the differences observed for the strength of inhibition are presumably due to a differential reciprocal spindle afferent input and the relative contribution of nonreciprocal inhibitory pathways. NEW & NOTEWORTHY We investigated the mutual transmission of reciprocal inhibition in large samples of motor units using a standardized input (electrical stimulation) to the motor neurons. The results demonstrated that the disynaptic reciprocal inhibition exerted

Self-Efficacy and Performance in Mathematics: Reciprocal Determinism in 33 Nations

Science.gov (United States)

Williams, Trevor; Williams, Kitty

2010-01-01

Reciprocal determinism is a central premise of Bandura's (1986) social cognitive theory. Studies of the relationship between self-beliefs and performance tend to draw on this or related theories and usually endorse the notion of reciprocal determinism at a substantive-theoretical level. However, attempts to model this postulated mutual influence…

Using Excel's Solver Function to Facilitate Reciprocal Service Department Cost Allocations

Science.gov (United States)

Leese, Wallace R.

2013-01-01

The reciprocal method of service department cost allocation requires linear equations to be solved simultaneously. These computations are often so complex as to cause the abandonment of the reciprocal method in favor of the less sophisticated and theoretically incorrect direct or step-down methods. This article illustrates how Excel's Solver…

Reciprocity in Online Markets: Empirical Studies of Auction and Barter Markets

Science.gov (United States)

Ye, Shun

2013-01-01

My dissertation seeks to understand how reciprocity affects transaction outcomes and mechanism design in online markets. The first essay examines negative reciprocity illustrated as feedback-revoking behavior in the eBay auction market, focusing on its impact and implications for reputation system design. I utilize the biggest policy change of…

Corrupt reciprocity: An experiment

OpenAIRE

Graf Lambsdorff, Johann; Frank, Björn

2007-01-01

We let students play a corruption game, embedded into a variant of the ultimatum game. Those allotted the role of public servants chose between whistleblowing, opportunism and reciprocity by delivery (of a contract) and those acting as businesspeople chose how to frame the game and whether to blow the whistle. While opportunism and abstaining from whistleblowing is the Nash equilibrium, another likely outcome was that businesspeople allocate resources to punishing public servants for non-deli...

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

Science.gov (United States)

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

2003-08-01

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

Asymmetric information capacities of reciprocal pairs of quantum channels

Science.gov (United States)

Rosati, Matteo; Giovannetti, Vittorio

2018-05-01

Reciprocal pairs of quantum channels are defined as completely positive transformations which admit a rigid, distance-preserving, yet not completely positive transformation that allows one to reproduce the outcome of one from the corresponding outcome of the other. From a classical perspective these transmission lines should exhibit the same communication efficiency. This is no longer the case in the quantum setting: explicit asymmetric behaviors are reported studying the classical communication capacities of reciprocal pairs of depolarizing and Weyl-covariant channels.

Reciprocity relations in transmission electron microscopy: A rigorous derivation.

Science.gov (United States)

Krause, Florian F; Rosenauer, Andreas

2017-01-01

A concise derivation of the principle of reciprocity applied to realistic transmission electron microscopy setups is presented making use of the multislice formalism. The equivalence of images acquired in conventional and scanning mode is thereby rigorously shown. The conditions for the applicability of the found reciprocity relations is discussed. Furthermore the positions of apertures in relation to the corresponding lenses are considered, a subject which scarcely has been addressed in previous publications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Toward An Ethics of Reciprocity: Ethnobotanical Knowledge and Medicinal Plants as Cancer Therapies

Directory of Open Access Journals (Sweden)

John Charles Ryan

2014-10-01

Full Text Available This article develops a reciprocity ethics of the environment through a discussion of ethnobotanical medicines used in the treatment of cancer. The moral virtue of reciprocity, defined as the returning of good when good is received or anticipated, is central to the posthumanist rethinking of human relationships to the plant world. As herbal medicines are used progressively more around the globe and as plant diversity decreases as a result of habitat loss and climate change, an ethics of reciprocity should be a concern for environmental philosophers and conservationists. Aldo Leopold’s land ethic and J. Baird Callicott’s distinction between deontological and prudential environmental ethics provide theoretical contexts for the development of a reciprocity ethics vis-à-vis ethnobotanical species. While this article does not necessarily specify modes or forms of reciprocity, it does outline some of the more prominent ethnobotanical species used in the treatment of cancer, including those from Native American, African, Chinese, and Indian traditions. In the form of a dialogue between the fields of ethnobotany, herbal medicine, and environmental philosophy, this article presents a position from which further articulations of reciprocity can be developed, particularly those involving the rights of indigenous cultures and plants.

A new measure of child vocal reciprocity in children with autism spectrum disorder.

Science.gov (United States)

Harbison, Amy L; Woynaroski, Tiffany G; Tapp, Jon; Wade, Joshua W; Warlaumont, Anne S; Yoder, Paul J

2018-03-06

Children's vocal development occurs in the context of reciprocal exchanges with a communication partner who models "speechlike" productions. We propose a new measure of child vocal reciprocity, which we define as the degree to which an adult vocal response increases the probability of an immediately following child vocal response. Vocal reciprocity is likely to be associated with the speechlikeness of vocal communication in young children with autism spectrum disorder (ASD). Two studies were conducted to test the utility of the new measure. The first used simulated vocal samples with randomly sequenced child and adult vocalizations to test the accuracy of the proposed index of child vocal reciprocity. The second was an empirical study of 21 children with ASD who were preverbal or in the early stages of language development. Daylong vocal samples collected in the natural environment were computer analyzed to derive the proposed index of child vocal reciprocity, which was highly stable when derived from two daylong vocal samples and was associated with speechlikeness of vocal communication. This association was significant even when controlling for chance probability of child vocalizations to adult vocal responses, probability of adult vocalizations, or probability of child vocalizations. A valid measure of children's vocal reciprocity might eventually improve our ability to predict which children are on track to develop useful speech and/or are most likely to respond to language intervention. A link to a free, publicly-available software program to derive the new measure of child vocal reciprocity is provided. Autism Res 2018. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. Children and adults often engage in back-and-forth vocal exchanges. The extent to which they do so is believed to support children's early speech and language development. Two studies tested a new measure of child vocal reciprocity using computer-generated and real

Constructing and deriving reciprocal trigonometric relations: a functional analytic approach.

Science.gov (United States)

Ninness, Chris; Dixon, Mark; Barnes-Holmes, Dermot; Rehfeldt, Ruth Anne; Rumph, Robin; McCuller, Glen; Holland, James; Smith, Ronald; Ninness, Sharon K; McGinty, Jennifer

2009-01-01

Participants were pretrained and tested on mutually entailed trigonometric relations and combinatorially entailed relations as they pertained to positive and negative forms of sine, cosine, secant, and cosecant. Experiment 1 focused on training and testing transformations of these mathematical functions in terms of amplitude and frequency followed by tests of novel relations. Experiment 2 addressed training in accordance with frames of coordination (same as) and frames of opposition (reciprocal of) followed by more tests of novel relations. All assessments of derived and novel formula-to-graph relations, including reciprocal functions with diversified amplitude and frequency transformations, indicated that all 4 participants demonstrated substantial improvement in their ability to identify increasingly complex trigonometric formula-to-graph relations pertaining to same as and reciprocal of to establish mathematically complex repertoires.

Intensity and resolution of a general scan in reciprocal space

International Nuclear Information System (INIS)

Lebech, B.; Nielsen, M.

1975-01-01

Elastic neutron scattering on single crystals is traditionally carried out either by rotating the sample and keeping the detector fixed, or by coupling the detector rotation to the sample rotation in the the ratio 2:1. In recent years, a number of papers have discussed the feasibility of other types of scans. General scans at oblique angles to reciprocal lattice vectors are commonly used in inelastic neutron scattering. Such scans are also useful in elastic neutron scattering and may easily be made by means of computer or tape controlled diffractometers. Formulas are derived for the intensity and width of Bragg reflections measured by scanning at oblique angles to reciprocal lattice vectors. The results of the calculations are compared to experimental results on simple structures. The limitations of general scans in reciprocal space are also discussed

Domains of reciprocity beyond monetary compensation: How do non-pecuniary factors affect effort and shirking?

Directory of Open Access Journals (Sweden)

Akinori Tomohara

2016-12-01

Full Text Available This empirical study examines how sources of reciprocity are related to work motivation by distinguishing positive and negative work attitudes in practical working environments. We move away from the unidimensional perspective of monetary compensation and investigate employees’ reciprocal behaviors, together with non-pecuniary aspects of work relations such as human relationships and company management. The results show that positive reciprocity, represented by effort, is fundamentally distinct from negative reciprocity, represented by shirking, when examining the multi-dimensional sources of reciprocity. Additionally, our analyses reveal that non-pecuniary factors in the working environment have a relatively large degree of association with work motivation, even when compared to monetary compensation. Our results complement those from controlled laboratory experiments.

Procurement Under The UNCITRAL Model Law: A Southern Africa Perspective

Directory of Open Access Journals (Sweden)

Stephen De La Harpe

2015-12-01

Full Text Available In Africa, economic integration, realised through regional integration, is seen as one of the driving factors that will improve the lives of its people. To enable regionalisation, economic growth and to unlock the potential of Africa its infrastructure will have to be improved. Infrastructure will on the whole be realised through public procurement. The stages for opening up procurement markets, referred to by Yukins and Schooner, is discussed and it is concluded that the states in SADC is still in the initial stages of opening its public procurement markets for regional competition. Although COMESA is not yet in full compliance with all four the stages great strides have been made and have elements of all stages been addressed. Because of the influence the Model Law has already played in COMESA, and the rest of Africa, it would be contra productive should SADC not take the same route as COMESA. If regard is had to the four categories of procurement rules that serves as barriers to national procurement markets, as set out by Arrowsmith it is clear that all of these are present in most SADC member states. Also in the case of COMESA these barriers still exist albeit to a lesser extent. What is necessary is a phased approach to address all of these barriers. This will be possible under the UNCITRAL Model Law as the 2011 Model Law does provide for the possibility of complying with international obligations and for states to allow for socio economic objectives in their procurement regimes. There can be little doubt that the 1994 Model Law has already had a marked influence on public procurement regulation in Africa and that the 2011 Model Law will in future continue to do so. Public procurement is essential for economic development and is the integration and harmonisation thereof on a regional basis the first step In this regard SADC, and especially South Africa, has an important role to play.

Effect of processing conditions on quality of green beans subjected to reciprocating agitation thermal processing.

Science.gov (United States)

Singh, Anika; Singh, Anubhav Pratap; Ramaswamy, Hosahalli S

2015-12-01

The effect of reciprocating agitation thermal processing (RA-TP) on quality of canned beans was evaluated in a lab-scale reciprocating retort. Green beans were selected due to their soft texture and sensitive color. Green beans (2.5cm length×0.8cm diameter) were filled into 307×409 cans with carboxylmethylcellulose (0-2%) solutions and processed at different temperatures (110-130°C) and reciprocation frequency (1-3Hz) for predetermined heating times to achieve a process lethality (F o ) of 10min. Products processed at higher temperatures and higher reciprocation frequencies resulted in better retention of chlorophyll and antioxidant activity. However, high reciprocation frequency also resulted in texture losses, with higher breakage of beans, increased turbidity and higher leaching. There was total loss of product quality at the highest agitation speed, especially with low viscosity covering solutions. Results suggest that reciprocating agitation frequency needs to be adequately moderated to get the best quality. For getting best quality, particularly for canned liquid particulate foods with soft particulates and those susceptible to high impact agitation, a gentle reciprocating motion (~1Hz) would be a good compromise. Copyright © 2015 Elsevier Ltd. All rights reserved.

Alcohol peer influence of participating in organized school activities: a network approach.

Science.gov (United States)

Fujimoto, Kayo; Valente, Thomas W

2013-10-01

This study compares the network influences on adolescent substance use from peers who coparticipated in school-sponsored organized activities (affiliation-based peer influence) with the influence both from their "nominated" friends (i.e., the adolescent named the alter as a friend), and only "reciprocated" friends (i.e., both adolescents mutually named each other as friends). The study also attempts to parse affiliation-based peer influence into the influence of both activity members who are also friends and those who are not, to address the potential confounding of these sources of peer influence. The study data consisted of a nationally representative sample of 12,551 adolescents in Grades 7-12 within 106 schools from the Add Health data. Ordinal logistic regression was conducted to estimate the effects of affiliation-based and friends influence on alcohol use and drinking frequency. Peer influence via organized activities (sports or clubs) with drinkers and the influence of friends who drink had significant effects on adolescent drinking. Peer influence through club activities with drinkers had a stronger effect on any drinking behavior than through sports activities with drinkers. After decomposing peer influence through activities by friendship status, influence through sport activities had a significant effect on drinking only when coparticipant drinkers were also reciprocated friends (but not nominated friends), whereas influence through club activities had a significant effect on drinking, regardless of friendship reciprocation. The design and implementation of school based substance use prevention and treatment programs should consider the contextual effects of school-sponsored activities. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

Supervisory behavior, reciprocity and subordinate absenteeism

NARCIS (Netherlands)

Dierendonck, van D.; Blanc, Le P.M.; Breukelen, van W.

2002-01-01

The present study among 242 professionals working in a lung clinic and nursing home was designed to test a model that links supervisory behavior (i.e. leader member exchange (LMX) behavior and conflict management behavior) and reciprocity in the supervisor/subordinate relationship to objectively

Rapid characterization of a nanomaterial structure using X-ray reciprocal-lattice-space imaging

International Nuclear Information System (INIS)

Sakata, Osami; Yoshimoto, Mamoru; Miki, Kazushi

2006-01-01

The X-ray reciprocal-lattice-space imaging method is able to record the reciprocal-lattice-space of nanostructure by sample-and-detector fixed geometry. This method was developed by the surface structure analysis beam line BL13XU of SPring-8. Outline of the X-ray diffraction method and basic principles of the X-ray reciprocal-lattice-space imaging method, and application examples are stated. The method is able to find out the Bragg conditions of nanostructure of surface in the atmosphere. The reciprocal-lattice of the embedded trace atomic wires was observed. The trace atoms of Bi atomic wires embedded in silicone showed the diffraction signal and image by a short exposure time. This method is useful at rapid non-destructive measurement of nanostructure. (S.Y.)

Punishment diminishes the benefits of network reciprocity in social dilemma experiments.

Science.gov (United States)

Li, Xuelong; Jusup, Marko; Wang, Zhen; Li, Huijia; Shi, Lei; Podobnik, Boris; Stanley, H Eugene; Havlin, Shlomo; Boccaletti, Stefano

2018-01-02

Network reciprocity has been widely advertised in theoretical studies as one of the basic cooperation-promoting mechanisms, but experimental evidence favoring this type of reciprocity was published only recently. When organized in an unchanging network of social contacts, human subjects cooperate provided the following strict condition is satisfied: The benefit of cooperation must outweigh the total cost of cooperating with all neighbors. In an attempt to relax this condition, we perform social dilemma experiments wherein network reciprocity is aided with another theoretically hypothesized cooperation-promoting mechanism-costly punishment. The results reveal how networks promote and stabilize cooperation. This stabilizing effect is stronger in a smaller-size neighborhood, as expected from theory and experiments. Contrary to expectations, punishment diminishes the benefits of network reciprocity by lowering assortment, payoff per round, and award for cooperative behavior. This diminishing effect is stronger in a larger-size neighborhood. An immediate implication is that the psychological effects of enduring punishment override the rational response anticipated in quantitative models of cooperation in networks. Copyright © 2017 the Author(s). Published by PNAS.

Harbingers of Artin's Reciprocity Law. I. The Continuing Story of Auxiliary Primes

OpenAIRE

Lemmermeyer, Franz

2011-01-01

In this article we present the history of auxiliary primes used in proofs of reciprocity laws from the quadratic to Artin's reciprocity law. We also show that the gap in Legendre's proof can be closed with a simple application of Gauss's genus theory.

Hydropower harvesting from a small scale reciprocating system

Energy Technology Data Exchange (ETDEWEB)

Malla, Ramesh B.; Shrestha, Binu; Bagtzoglou, Amvrossios; Drasdis, Jonathon [Department of Civil and Environmental Engineering, University of Connecticut, 261 Glenbrook Road, Storrs, CT 06269-2037 (United States); Johnson, Paul [eGen LLC, 1084 Shennecossett Road, Groton, CT 06340 (United States)

2011-05-15

Conventional hydropower systems that can take advantage of low head movement of water require substantial flow rates. However, these systems cannot harvest hydro energy from small sources of water with low head and low discharge, such as streams and creeks. The reciprocating hydropower system discussed in this paper can harvest power from such low flow discharge and low head sources. This paper presents a detailed proof-of-concept study of the hydropower model, including the underlining theoretical principles. Laboratory test results demonstrating the dependence of the lift force in the reciprocating small scale hydropower model as a function of flow velocity, size and rotational speed of the cylinder and comparison of the results with a previous study are also included. Two methods of power harvesting from the output displacement obtained from the hydropower system are discussed. The first employs electromagnetic induction principles and the other is based on a linear inertial generator using a conventional second order spring mass damper system. Finally, results from a finite element analysis of the hydropower system are presented and facilitate future design of the structural aspects of the housing for the reciprocating cylinder. (author)

Peer influence on marijuana use in different types of friendships.

Science.gov (United States)

Tucker, Joan S; de la Haye, Kayla; Kennedy, David P; Green, Harold D; Pollard, Michael S

2014-01-01

Although several social network studies have demonstrated peer influence effects on adolescent substance use, findings for marijuana use have been equivocal. This study examines whether structural features of friendships moderate friends' influence on adolescent marijuana use over time. Using 1-year longitudinal data from the National Longitudinal Study of Adolescent Health, this article examines whether three structural features of friendships moderate friends' influence on adolescent marijuana use: whether the friendship is reciprocated, the popularity of the nominated friend, and the popularity/status difference between the nominated friend and the adolescent. The sample consists of students in grade 10/11 at wave I, who were in grade 11/12 at wave II, from two large schools with complete grade-based friendship network data (N = 1,612). In one school, friends' influence on marijuana use was more likely to occur within mutual, reciprocated friendships compared with nonreciprocated relationships. In the other school, friends' influence was stronger when the friends were relatively popular within the school setting or much more popular than the adolescents themselves. Friends' influence on youth marijuana use may play out in different ways, depending on the school context. In one school, influence occurred predominantly within reciprocated relationships that are likely characterized by closeness and trust, whereas in the other school adopting friends' drug use behaviors appeared to be a strategy to attain social status. Further research is needed to better understand the conditions under which structural features of friendships moderate friends' influence on adolescent marijuana use. Copyright © 2014 Society for Adolescent Health and Medicine. All rights reserved.

The Reciprocal Principle of Selectand-Selector-Systems in Supramolecular Chromatography †.

Science.gov (United States)

Schurig, Volker

2016-11-15

In selective chromatography and electromigration methods, supramolecular recognition of selectands and selectors is due to the fast and reversible formation of association complexes governed by thermodynamics. Whereas the selectand molecules to be separated are always present in the mobile phase, the selector employed for the separation of the selectands is either part of the stationary phase or is added to the mobile phase. By the reciprocal principle, the roles of selector and selectand can be reversed. In this contribution in honor of Professor Stig Allenmark, the evolution of the reciprocal principle in chromatography is reviewed and its advantages and limitations are outlined. Various reciprocal scenarios, including library approaches, are discussed in efforts to optimize selectivity in separation science.

A reciprocal framework for spatial K-anonymity

KAUST Repository

Ghinita, Gabriel; Zhao, Keliang; Papadias, Dimitris; Kalnis, Panos

2010-01-01

Spatial K-anonymity (SKA) exploits the concept of K-anonymity in order to protect the identity of users from location-based attacks. The main idea of SKA is to replace the exact location of a user U with an anonymizing spatial region (ASR) that contains at least K-1 other users, so that an attacker can pinpoint U with probability at most 1/K. Simply generating an ASR that includes K users does not guarantee SKA. Previous work defined the reciprocity property as a sufficient condition for SKA. However, the only existing reciprocal method, Hilbert Cloak, relies on a specialized data structure. In contrast, we propose a general framework for implementing reciprocal algorithms using any existing spatial index on the user locations. We discuss ASR construction methods with different tradeoffs on effectiveness (i.e., ASR size) and efficiency (i.e., construction cost). Then, we present case studies of applying our framework on top of two popular spatial indices (namely, R*-trees and Quad-trees). Finally, we consider the case where the attacker knows the query patterns of each user. The experimental results verify that our methods outperform Hilbert Cloak. Moreover, since we employ general-purpose spatial indices, the proposed system is not limited to anonymization, but supports conventional spatial queries as well. © 2009 Elsevier B.V. All rights reserved.

A reciprocal framework for spatial K-anonymity

KAUST Repository

Ghinita, Gabriel

2010-05-01

Spatial K-anonymity (SKA) exploits the concept of K-anonymity in order to protect the identity of users from location-based attacks. The main idea of SKA is to replace the exact location of a user U with an anonymizing spatial region (ASR) that contains at least K-1 other users, so that an attacker can pinpoint U with probability at most 1/K. Simply generating an ASR that includes K users does not guarantee SKA. Previous work defined the reciprocity property as a sufficient condition for SKA. However, the only existing reciprocal method, Hilbert Cloak, relies on a specialized data structure. In contrast, we propose a general framework for implementing reciprocal algorithms using any existing spatial index on the user locations. We discuss ASR construction methods with different tradeoffs on effectiveness (i.e., ASR size) and efficiency (i.e., construction cost). Then, we present case studies of applying our framework on top of two popular spatial indices (namely, R*-trees and Quad-trees). Finally, we consider the case where the attacker knows the query patterns of each user. The experimental results verify that our methods outperform Hilbert Cloak. Moreover, since we employ general-purpose spatial indices, the proposed system is not limited to anonymization, but supports conventional spatial queries as well. © 2009 Elsevier B.V. All rights reserved.

Rural development within the context of development, sustainability ...

African Journals Online (AJOL)

This article provides an overview of some developments, internationally, regionally and in the SADC, in relation to development, that may be expected to influence the South African government's response to the development needs of the people in the country. An overview is provided of the somewhat haphazard way in ...

Violation of Gribov-Lipatov reciprocity due to preconfinement

International Nuclear Information System (INIS)

Kawabe, Tetsuji

1981-01-01

On the basis of the preconfinement picture we study the hadronization of quark jets. Since this picture prepares in the final stage of QCD evolution the color singlet cluster for the adjacent q anti q pair distribution, the color of partons can be compensated in the hard region. We show that the resulting fragmentation function satisfies no longer the Gribov-Lipatov reciprocity derived in the case of the two-parton distribution. It is pointed out that the violation of the reciprocity is expected as the evidence of the realization of the preconfinement picture and the pattern of the violation is not inconsistent with data. (author)

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

Science.gov (United States)

2010-04-01

... reciprocal. A reciprocal making the election is allowed a credit for the amount of tax paid by the attorney... attorney-in-fact with respect to which the election allowed by section 826(a) and this section is in effect; the district in which such attorney-in-fact filed its return for the taxable year; and a copy of the...

Collaborative Leadership Effects on School Improvement: Integrating Unidirectional- and Reciprocal-Effects Models

Science.gov (United States)

Heck, Ronald H.; Hallinger, Philip

2010-01-01

Researchers have persisted in framing leadership as the driver for change and performance improvement in schools despite convincing theoretical commentary that proposes leadership as a process of reciprocal interaction. Although conceptualizing leadership as a reciprocal process offers leverage for understanding leadership effects on learning,…

Ultimate and proximate explanations of strong reciprocity.

Science.gov (United States)

Vromen, Jack

2017-08-23

Strong reciprocity (SR) has recently been subject to heated debate. In this debate, the "West camp" (West et al. in Evol Hum Behav 32(4):231-262, 2011), which is critical of the case for SR, and the "Laland camp" (Laland et al. in Science, 334(6062):1512-1516, 2011, Biol Philos 28(5):719-745, 2013), which is sympathetic to the case of SR, seem to take diametrically opposed positions. The West camp criticizes advocates of SR for conflating proximate and ultimate causation. SR is said to be a proximate mechanism that is put forward by its advocates as an ultimate explanation of human cooperation. The West camp thus accuses advocates of SR for not heeding Mayr's original distinction between ultimate and proximate causation. The Laland camp praises advocates of SR for revising Mayr's distinction. Advocates of SR are said to replace Mayr's uni-directional view on the relation between ultimate and proximate causes by the bi-directional one of reciprocal causation. The paper argues that both the West camp and the Laland camp misrepresent what advocates of SR are up to. The West camp is right that SR is a proximate cause of human cooperation. But rather than putting forward SR as an ultimate explanation, as the West camp argues, advocates of SR believe that SR itself is in need of ultimate explanation. Advocates of SR tend to take gene-culture co-evolutionary theory as the correct meta-theoretical framework for advancing ultimate explanations of SR. Appearances notwithstanding, gene-culture coevolutionary theory does not imply Laland et al.'s notion of reciprocal causation. "Reciprocal causation" suggests that proximate and ultimate causes interact simultaneously, while advocates of SR assume that they interact sequentially. I end by arguing that the best way to understand the debate is by disambiguating Mayr's ultimate-proximate distinction. I propose to reserve "ultimate" and "proximate" for different sorts of explanations, and to use other terms for distinguishing

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.

Non-Reciprocal Geometric Wave Diode by Engineering Asymmetric Shapes of Nonlinear Materials

Energy Technology Data Exchange (ETDEWEB)

Ren, Jie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Li, Nianbei [Tongji Univ., Shanghai Shi (China)

2014-02-18

Unidirectional nonreciprocal transport is at the heart of many fundamental problems and applications in both science and technology. Here we study how to design the novel wave diode devices to realize the non-reciprocal wave propagations. Analytical results reveal that such non-reciprocal wave propagation can be purely induced by asymmetric geometry in nonlinear materials. The detailed numerical simulations are performed for a more realistic geometric wave diode model with typical asymmetric shape, where good non-reciprocal wave diode effect has been demonstrated. The results open a way for making wave diodes efficiently simply through shape engineering.

Facilitators on networks reveal optimal interplay between information exchange and reciprocity.

Science.gov (United States)

Szolnoki, Attila; Perc, Matjaž; Mobilia, Mauro

2014-04-01

Reciprocity is firmly established as an important mechanism that promotes cooperation. An efficient information exchange is likewise important, especially on structured populations, where interactions between players are limited. Motivated by these two facts, we explore the role of facilitators in social dilemmas on networks. Facilitators are here mirrors to their neighbors-they cooperate with cooperators and defect with defectors-but they do not participate in the exchange of strategies. As such, in addition to introducing direct reciprocity, they also obstruct information exchange. In well-mixed populations, facilitators favor the replacement and invasion of defection by cooperation as long as their number exceeds a critical value. In structured populations, on the other hand, there exists a delicate balance between the benefits of reciprocity and the deterioration of information exchange. Extensive Monte Carlo simulations of social dilemmas on various interaction networks reveal that there exists an optimal interplay between reciprocity and information exchange, which sets in only when a small number of facilitators occupy the main hubs of the scale-free network. The drawbacks of missing cooperative hubs are more than compensated for by reciprocity and, at the same time, the compromised information exchange is routed via the auxiliary hubs with only marginal losses in effectivity. These results indicate that it is not always optimal for the main hubs to become leaders of the masses, but rather to exploit their highly connected state to promote tit-for-tat-like behavior.

Dynamic Reciprocity in the Wound Microenvironment

Science.gov (United States)

Schultz, Gregory S.; Davidson, Jeffrey M.; Kirsner, Robert S.; Bornstein, Paul; Herman, Ira M.

2011-01-01

Here, we define dynamic reciprocity (DR) as an ongoing, bidirectional interaction amongst cells and their surrounding microenvironment. In the review, we posit that DR is especially meaningful during wound healing as the DR-driven biochemical, biophysical and cellular responses to injury play pivotal roles in regulating tissue regenerative responses. Such cell-extracellular matrix interactions not only guide and regulate cellular morphology, but cellular differentiation, migration, proliferation, and survival during tissue development, including e.g. embryogenesis, angiogenesis, as well as during pathologic processes including cancer diabetes, hypertension and chronic wound healing. Herein, we examine DR within the wound microenvironment while considering specific examples across acute and chronic wound healing. This review also considers how a number of hypotheses that attempt to explain chronic wound pathophysiology, which may be understood within the DR framework. The implications of applying the principles of dynamic reciprocity to optimize wound care practice and future development of innovative wound healing therapeutics are also briefly considered. PMID:21362080

Bending-active reciprocal structures based on equilateral polyhedral geometries

DEFF Research Database (Denmark)

Popovic Larsen, Olga; BRANCART, Stijn; DE TEMMERMAN, Niels

2017-01-01

As mutually supported beam structures, reciprocal frames limit the number of components that are joined at each connection to two. However, this system of intermediate connections introduces undesirable bending moments in the beam elements. By utilising elastic deformation to create curved...... of parts of reciprocal bending-active components based on a selection of polyhedral dome types. To simplify the assembly of the structures and avoid the manual bending of the components on site, we introduce the concept of a double-layered, pre-bent component. Finally, this paper presents the development...

Exposure to Hedione Increases Reciprocity in Humans

Directory of Open Access Journals (Sweden)

Sebastian Berger

2017-05-01

Full Text Available Cooperation among unrelated humans is frequently regarded as a defining feature in the evolutionary success of our species. Whereas, much research has addressed the strategic and cognitive mechanisms that underlie cooperation, investigations into chemosensory processes have received very limited research attention. To bridge that gap, we build on recent research that has identified the chemically synthesized odorant Hedione (HED as a ligand for the putative human pheromone receptor (VN1R1 expressed in the olfactory mucosa, and hypothesize that exposure to HED may increase reciprocity. Applying behavioral economics paradigms, the present research shows that exposure to the ligand causes differentiated behavioral effects in reciprocal punishments (Study 1 as well as rewards (Study 2, two types of behaviors that are frequently regarded as essential for the development and maintenance of cooperation.

Exposure to Hedione Increases Reciprocity in Humans

Science.gov (United States)

Berger, Sebastian; Hatt, Hanns; Ockenfels, Axel

2017-01-01

Cooperation among unrelated humans is frequently regarded as a defining feature in the evolutionary success of our species. Whereas, much research has addressed the strategic and cognitive mechanisms that underlie cooperation, investigations into chemosensory processes have received very limited research attention. To bridge that gap, we build on recent research that has identified the chemically synthesized odorant Hedione (HED) as a ligand for the putative human pheromone receptor (VN1R1) expressed in the olfactory mucosa, and hypothesize that exposure to HED may increase reciprocity. Applying behavioral economics paradigms, the present research shows that exposure to the ligand causes differentiated behavioral effects in reciprocal punishments (Study 1) as well as rewards (Study 2), two types of behaviors that are frequently regarded as essential for the development and maintenance of cooperation. PMID:28512400

Matching times of leading and following suggest cooperation through direct reciprocity during V-formation flight in ibis.

Science.gov (United States)

Voelkl, Bernhard; Portugal, Steven J; Unsöld, Markus; Usherwood, James R; Wilson, Alan M; Fritz, Johannes

2015-02-17

One conspicuous feature of several larger bird species is their annual migration in V-shaped or echelon formation. When birds are flying in these formations, energy savings can be achieved by using the aerodynamic up-wash produced by the preceding bird. As the leading bird in a formation cannot profit from this up-wash, a social dilemma arises around the question of who is going to fly in front? To investigate how this dilemma is solved, we studied the flight behavior of a flock of juvenile Northern bald ibis (Geronticus eremita) during a human-guided autumn migration. We could show that the amount of time a bird is leading a formation is strongly correlated with the time it can itself profit from flying in the wake of another bird. On the dyadic level, birds match the time they spend in the wake of each other by frequent pairwise switches of the leading position. Taken together, these results suggest that bald ibis cooperate by directly taking turns in leading a formation. On the proximate level, we propose that it is mainly the high number of iterations and the immediacy of reciprocation opportunities that favor direct reciprocation. Finally, we found evidence that the animals' propensity to reciprocate in leading has a substantial influence on the size and cohesion of the flight formations.

Integral Inequalities for Self-Reciprocal Polynomials

Indian Academy of Sciences (India)

Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Proceedings – Mathematical Sciences; Volume 120; Issue 2. Integral Inequalities for Self-Reciprocal Polynomials. Horst Alzer. Volume 120 Issue 2 April 2010 ...

Mechanism of magnetic liquid flowing in the magnetic liquid seal gap of reciprocating shaft

Science.gov (United States)

Li, Decai; Xu, Haiping; He, Xinzhi; Lan, Huiqing

2005-03-01

In order to solve the problems that exist in the magnetic liquid seal of reciprocating shaft, we have set up an experimental facility, which composes a camera, microscope, step-by-step motor, pin roller screw, reciprocating motion shaft, pole pieces, permanent magnet and the magnetic liquid in the seal gap. Through the optical technology and image process of the experimental facility, we have studied the magnetic liquid flow in the seal gap when the reciprocating shaft moves with different velocities and strokes. This study specially concentrates on: (1) the regular pattern of such flow; (2) the loss quantity of magnetic liquid caused by the reciprocating motion shaft; (3) the failure reasons of this magnetic liquid seal; and (4) the design of a new structure for the magnetic liquid seal of reciprocating shaft. The application indicates that the new structure is very effective in some occasions. The new structure was accepted as the state patent in 2001 and authenticated as the achievement in the scientific research in 2002.

Mechanism of magnetic liquid flowing in the magnetic liquid seal gap of reciprocating shaft

International Nuclear Information System (INIS)

Li Decai; Xu Haiping; He Xinzhi; Lan Huiqing

2005-01-01

In order to solve the problems that exist in the magnetic liquid seal of reciprocating shaft, we have set up an experimental facility, which composes a camera, microscope, step-by-step motor, pin roller screw, reciprocating motion shaft, pole pieces, permanent magnet and the magnetic liquid in the seal gap. Through the optical technology and image process of the experimental facility, we have studied the magnetic liquid flow in the seal gap when the reciprocating shaft moves with different velocities and strokes. This study specially concentrates on: (1) the regular pattern of such flow; (2) the loss quantity of magnetic liquid caused by the reciprocating motion shaft; (3) the failure reasons of this magnetic liquid seal; and (4) the design of a new structure for the magnetic liquid seal of reciprocating shaft. The application indicates that the new structure is very effective in some occasions. The new structure was accepted as the state patent in 2001 and authenticated as the achievement in the scientific research in 2002

Root canal anatomy preservation of WaveOne reciprocating files with or without glide path.

Science.gov (United States)

Berutti, Elio; Paolino, Davide Salvatore; Chiandussi, Giorgio; Alovisi, Mario; Cantatore, Giuseppe; Castellucci, Arnaldo; Pasqualini, Damiano

2012-01-01

This study evaluated the influence of glide path on canal curvature and axis modification after instrumentation with WaveOne Primary reciprocating files. Thirty ISO 15, 0.02 taper Endo Training Blocks were used. In group 1, glide path was created with PathFile 1, 2, and 3 at working length, whereas in group 2, glide path was not performed. In both groups, canals were shaped with WaveOne Primary reciprocating files at working length. Preinstrumentation and postinstrumentation digital images were superimposed and processed with Matlab r2010b software to analyze the curvature radius ratio (CRr) and the relative axis error (rAe), representing canal curvature modification. Data were analyzed with 1-way balanced analyses of variance at 2 levels (P < .05). Glide path was found to be extremely significant for both CRr parameter (F = 9.59; df = 1; P = .004) and rAe parameter (F = 13.55; df = 1; P = .001). Canal modifications seem to be significantly reduced when previous glide path is performed by using the new WaveOne nickel-titanium single-file system. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A game-theoretical approach for reciprocal security-related prevention investment decisions

International Nuclear Information System (INIS)

Reniers, Genserik; Soudan, Karel

2010-01-01

Every company situated within a chemical cluster faces important security risks from neighbouring companies. Investing in reciprocal security preventive measures is therefore necessary to avoid major accidents. These investments do not, however, provide a direct return on investment for the investor-company and thus plants are hesitative to invest. Moreover, there is likelihood that even if a company has fully invested in reciprocal security prevention, its neighbour has not, and as a result the company can experience a major accident caused by an initial (minor or major) accident that occurred in an adjacent chemical enterprise. In this article we employ a game-theoretic approach to interpret and model behaviour of two neighbouring chemical plants while negotiating and deciding on reciprocal security prevention investments.

Evolutionary robotics simulations help explain why reciprocity is rare in nature.

Science.gov (United States)

André, Jean-Baptiste; Nolfi, Stefano

2016-09-12

The relative rarity of reciprocity in nature, contrary to theoretical predictions that it should be widespread, is currently one of the major puzzles in social evolution theory. Here we use evolutionary robotics to solve this puzzle. We show that models based on game theory are misleading because they neglect the mechanics of behavior. In a series of experiments with simulated robots controlled by artificial neural networks, we find that reciprocity does not evolve, and show that this results from a general constraint that likely also prevents it from evolving in the wild. Reciprocity can evolve if it requires very few mutations, as is usually assumed in evolutionary game theoretic models, but not if, more realistically, it requires the accumulation of many adaptive mutations.

Endodontic retreatment: clinical comparison of reciprocating systems versus rotary system in disinfecting root canals.

Science.gov (United States)

Martinho, Frederico C; Freitas, Lilian F; Nascimento, Gustavo G; Fernandes, Aleteia M; Leite, Fabio R M; Gomes, Ana P M; Camões, Izabel C G

2015-07-01

This clinical study was conducted to compare the effectiveness of single-file reciprocating systems and rotary systems in removing endotoxins and cultivable bacteria in endodontic retreatment. Thirty endodontically treated teeth with post-treatment apical periodontitis were selected. The specimens were divided into three groups according to the system used: WaveOne (n = 10), Reciproc instrument (n = 10), and ProTaper Universal Retreatment system (n = 10). Samples were collected before and after chemomechanical preparation. The irrigation was performed by using 2.5% sodium hypochlorite. A chromogenic limulus amebocyte lysate assay test was used to quantify endotoxins. Culture techniques were used to determine bacterial colony-forming unit counts. At baseline, endotoxins and cultivable bacteria were recovered from 100% of the root canal samples in a median value of 5.84 EU/mL and 4.98 × 10(3) CFU/mL, respectively. After CMP, no differences were found in the median percentage values of endotoxin reduction achieved with reciprocating systems-WaveOne [94.11%] and Reciproc [93.29%] and with rotary systems-ProTaper [94.98%] (P > 0.05). Both single-file reciprocating systems [WaveOne (98.27%) and Reciproc (99.54%)] and rotary system [ProTaper (98.73%)] were effective in reducing bacterial load (P > 0.05). Moreover, no differences were found among the systems tested. The Reciproc and WaveOne reciprocating systems were as effective as the ProTaper system for removal of endotoxins and bacteria in endodontic retreatment. All systems tested were effective to remove cultivable bacteria and endotoxin in endodontic retreatment. As no differences among systems were observed, it is possible to suggest that clinicians should choose the preferred technique to perform endodontic.

Time-dependent pseudo-reciprocity relations in neutronics

International Nuclear Information System (INIS)

Modak, R.S.; Sahni, D.C.

2002-01-01

Earlier, certain reciprocity-like relations have been shown to hold in some restricted steady state cases in neutron diffusion and transport theories. Here, the possibility of existence of similar relations in time-dependent situations is investigated

Reciprocal Exchange: Understanding the Community Partner Perspective in Higher Education Service-Learning

Science.gov (United States)

Petri, Alexis Nicolle

2012-01-01

This study investigates service-learning from the community partners' perspective, especially in terms of reciprocity. As a central construct in the theory of service-learning, reciprocity for community partners is virtually unknown. Little scholarship exists that explains or explores the benefits and opportunity costs of service-learning. One…

Reciprocal Accountability for Transformative Change: New Hampshire's Performance Assessment of Competency Education

Science.gov (United States)

Marion, Scott F.; Vander Els, Jonathan; Leather, Paul

2017-01-01

In New Hampshire, a new performance assessment system focuses on reciprocal accountability and shared leadership among teachers and leaders at the school, district, and state levels. This concept of reciprocal accountability, developed by school improvement expert Richard Elmore, is at the core of New Hampshire's Performance Assessment of…

A new incomplete-repair model based on a ''reciprocal-time'' pattern of sublethal damage repair

International Nuclear Information System (INIS)

Dale, R.G.; Fowler, J.F.

1999-01-01

A radiobiological model for closely spaced non-instantaneous radiation fractions is presented, based on the premise that the time process of sublethal damage (SLD) repair is 'reciprocal-time' (second order), rather than exponential (first order), in form. The initial clinical implications of such an incomplete-repair model are assessed. A previously derived linear-quadratic-based model was revised to take account of the possibility that SLD may repair with time such that the fraction of an element of initial damage remaining at time t is given as 1/(1+zt), where z is an appropriate rate constant; z is the reciprocal of the first half-time (τ) of repair. The general equation so derived for incomplete repair is applicable to all types of radiotherapy delivered at high, low and medium dose-rate in fractions delivered at regular time intervals. The model allows both the fraction duration and interfraction intervals to vary between zero and infinity. For any given value of z, reciprocal repair is associated with an apparent 'slowing-down' in the SLD repair rate as treatment proceeds. The instantaneous repair rates are not directly governed by total dose or dose per fraction, but are influenced by the treatment duration and individual fraction duration. Instantaneous repair rates of SLD appear to be slower towards the end of a continuous treatment, and are also slower following 'long' fractions than they are following 'short' fractions. The new model, with its single repair-rate parameter, is shown to be capable of providing a degree of quantitative explanation for some enigmas that have been encountered in clinical studies. A single-component reciprocal repair process provides an alternative explanation for the apparent existence of a range of repair rates in human tissues, and which have hitherto been explained by postulating the existence of a multi-exponential repair process. The build-up of SLD over extended treatments is greater than would be inferred using a

Reciprocity principle for scattered fields from discontinuities in waveguides.

Science.gov (United States)

Pau, Annamaria; Capecchi, Danilo; Vestroni, Fabrizio

2015-01-01

This study investigates the scattering of guided waves from a discontinuity exploiting the principle of reciprocity in elastodynamics, written in a form that applies to waveguides. The coefficients of reflection and transmission for an arbitrary mode can be derived as long as the principle of reciprocity is satisfied at the discontinuity. Two elastodynamic states are related by the reciprocity. One is the response of the waveguide in the presence of the discontinuity, with the scattered fields expressed as a superposition of wave modes. The other state is the response of the waveguide in the absence of the discontinuity oscillating according to an arbitrary mode. The semi-analytical finite element method is applied to derive the needed dispersion relation and wave mode shapes. An application to a solid cylinder with a symmetric double change of cross-section is presented. This model is assumed to be representative of a damaged rod. The coefficients of reflection and transmission of longitudinal waves are investigated for selected values of notch length and varying depth. Copyright © 2014 Elsevier B.V. All rights reserved.

Market powers predict reciprocal grooming in golden snub-nosed monkeys (Rhinopithecus roxellana).

Science.gov (United States)

Wei, Wei; Qi, Xiao-Guang; Guo, Song-Tao; Zhao, Da-Peng; Zhang, Peng; Huang, Kang; Li, Bao-Guo

2012-01-01

Social grooming is a common form of affiliative behavior in primates. Biological market theory suggests that grooming can be traded either for grooming or other social commodities and services. When no other services are exchanged, grooming is predicted to be approximately reciprocated within a dyad. In contrast, the amount of reciprocal grooming should decrease as other offered services increase. We studied grooming patterns between polygamous male and female in golden snub-nosed monkeys (Rhinopithecus roxellana) from the Qinling Mountains of central China and found that about 29.7% of grooming bouts were reciprocated. However, the durations of grooming bouts offered and returned was asymmetrical within dyads. In bisexual dyads, more grooming was initiated by females than males, which became more pronounced as the number of females per one-male unit increased. The rate of copulation per day for each female was positively correlated with the total duration of grooming time females invested in males.. Females without an infant (non-mothers) directed more grooming towards females with an infant (mothers) and were significantly more likely to be non-reciprocated. There was a significant negative relationship between non-mother and mother grooming duration and the rate of infants per female in each one-male unit. High-ranking females also received more grooming from low-ranking females than vice versa. The rate of food-related aggressive interactions was per day for low-ranking females was negatively correlated with the duration of grooming that low-ranking females gave to high-ranking females. Our results showed that grooming reciprocation in R. roxellana was discrepancy. This investment-reciprocity rate could be explained by the exchange of other social services in lieu of grooming.

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.

Postoperative Pain after Endodontic Retreatment Using Rotary or Reciprocating Instruments: A Randomized Clinical Trial.

Science.gov (United States)

Comparin, Daniel; Moreira, Edson Jorge Lima; Souza, Erick M; De-Deus, Gustavo; Arias, Ana; Silva, Emmanuel João Nogueira Leal

2017-07-01

The aim of this randomized clinical trial was to evaluate the influence of rotary or reciprocating retreatment techniques on the incidence, intensity, duration of postoperative pain, and medication intake. After power analysis calculations, 65 patients who needed endodontic retreatment were randomly assigned to 1 of 2 groups according to the instrumentation system used: Mtwo (VDW, Munich, Germany) or Reciproc (VDW). Retreatments were performed in a single visit by an endodontic specialist. Participants were asked to rate the incidence and intensity of the postoperative pain on a verbal rating scale 24, 48, and 72 hours after treatment. Patients were also asked to record the number of prescribed analgesic medication tablets (ibuprofen 400 mg) taken. A logistic regression analysis was used to assess both the incidence and duration of pain. Differences in the intensity of pain were analyzed using the ordinal (linear) chi-square test, and the Mann-Whitney U test was used to assess differences in the intake of analgesic medication between groups. No statistically significant difference was found among the 2 groups in relation to postoperative pain or analgesic medication intake at the 3 time points assessed (P > .05). Multivariate analysis showed a significantly higher incidence of pain after 24 hours when preoperative pain was present and a significantly longer duration of pain for men than women independently of the retreatment technique used. The reciprocating system and the continuous rotary system were found to be equivalent regarding the incidence, intensity, duration of postoperative pain, and intake of analgesic medication. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Reciprocal cooperation between unrelated rats depends on cost to donor and benefit to recipient

Directory of Open Access Journals (Sweden)

Schneeberger Karin

2012-03-01

Full Text Available Abstract Background Although evolutionary models of cooperation build on the intuition that costs of the donor and benefits to the receiver are the most general fundamental parameters, it is largely unknown how they affect the decision of animals to cooperate with an unrelated social partner. Here we test experimentally whether costs to the donor and need of the receiver decide about the amount of help provided by unrelated rats in an iterated prisoner's dilemma game. Results Fourteen unrelated Norway rats were alternately presented to a cooperative or defective partner for whom they could provide food via a mechanical apparatus. Direct costs for this task and the need of the receiver were manipulated in two separate experiments. Rats provided more food to cooperative partners than to defectors (direct reciprocity. The propensity to discriminate between helpful and non-helpful social partners was contingent on costs: An experimentally increased resistance in one Newton steps to pull food for the social partner reduced the help provided to defectors more strongly than the help returned to cooperators. Furthermore, test rats provided more help to hungry receivers that were light or in poor condition, which might suggest empathy, whereas this relationship was inverse when experimental partners were satiated. Conclusions In a prisoner's dilemma situation rats seem to take effect of own costs and potential benefits to a receiver when deciding about helping a social partner, which confirms the predictions of reciprocal cooperation. Thus, factors that had been believed to be largely confined to human social behaviour apparently influence the behaviour of other social animals as well, despite widespread scepticism. Therefore our results shed new light on the biological basis of reciprocity.

A hierarchical generalization of the acoustic reciprocity theorem involving higher-order derivatives and interaction quantities.

Science.gov (United States)

Lin, Ju; Li, Jie; Li, Xiaolei; Wang, Ning

2016-10-01

An acoustic reciprocity theorem is generalized, for a smoothly varying perturbed medium, to a hierarchy of reciprocity theorems including higher-order derivatives of acoustic fields. The standard reciprocity theorem is the first member of the hierarchy. It is shown that the conservation of higher-order interaction quantities is related closely to higher-order derivative distributions of perturbed media. Then integral reciprocity theorems are obtained by applying Gauss's divergence theorem, which give explicit integral representations connecting higher-order interactions and higher-order derivative distributions of perturbed media. Some possible applications to an inverse problem are also discussed.

A note on number fields having reciprocal integer generators | Zaïmi ...

African Journals Online (AJOL)

We prove that a totally complex algebraic number field K; having a conjugate which is not closed under complex conjugation, can be generated by a reciprocal integer, when the Galois group of its normal closure is contained in the hyperoctahedral group Bdeg(K)/2. Keywords: Reciprocal integers, unit primitive elements, ...

Measuring Reciprocity in High Functioning Children and Adolescents with Autism Spectrum Disorders

Science.gov (United States)

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

2012-01-01

Few instruments have been developed that measure impairments in reciprocity, a defining feature of autism. We introduce a new test assessing the quality of reciprocal behaviour: the interactive drawing test (IDT). Children and adolescents (n = 49) with and without high functioning autism spectrum disorders (HFASD) were invited to collaborate with…

Grooming-related feeding motivates macaques to groom and affects grooming reciprocity and episode duration in Japanese macaques (Macaca fuscata).

Science.gov (United States)

Onishi, Kenji; Yamada, Kazunori; Nakamichi, Masayuki

2013-01-01

Allogrooming is considered as an altruistic behavior wherein primates exchange grooming as a tradable commodity for reciprocal grooming or other commodities such as support during aggression and tolerance during co-feeding. First, we report a case of the grooming relationships of the lowest-ranking adult female in a group of Japanese macaques (Macaca fuscata). The female (Lp) had lost a portion of the fur and was groomed by higher-ranking individuals without providing reciprocal grooming or other commodities. The groomers probably fed on lice eggs from the fur of Lp more frequently than from that of other adult groomees. This suggests that grooming-related feeding (GRF) motivated many individuals to groom Lp and influenced grooming reciprocity in dyads. Second, we investigated quantitative grooming data for adult females. A high GRF rate was found to lengthen the duration of grooming, suggesting that GRF motivates groomers to groom. From these results, we proposed 2 possible reasons for groomers' sensitivity to GRF rate: (1) the nutritional benefit from GRF compensates for part of the cost of giving grooming and facilitates giving grooming and (2) groomer's sensitivity to the GRF rate maintains the efficiency of removing lice eggs and ensures the groomee's hygienic benefit in receiving grooming. Copyright © 2012 Elsevier B.V. All rights reserved.

TORE SUPRA fast reciprocating radio frequency probe

International Nuclear Information System (INIS)

Thomas, C.E. Jr.; Harris, J.H.; Haste, G.R.; Kwon, M.; Goulding, R.H.; Hoffman, D.J.; Saoutic, B.; Becoulet, A.; Fraboulet, D.; Beaumont, B.; Kuus, H.; Ladurelle, L.; Pascal, J.Y.

1995-01-01

A fast reciprocating ion cyclotron range of frequencies (ICRF) probe was installed and operated on TORE SUPRA during 1992/1993. The body of the probe was originally used on the ATF experiment at Oak Ridge National Laboratory. The probe was adapted for use on TORE SUPRA, and mounted on one of the two fast reciprocating probe mounts. The probe consists of two orthogonal single-turn wire loops, mounted so that one loop senses toroidal rf magnetic fields and the other senses poloidal rf magnetic fields. The probe began operation in June, 1993. The probe active area is approximately 5 cm long by 2 cm, and the reciprocating mount has a slow stroke (5 cm/s) of 30 cm and a fast stroke (1.5 m/s) of about 10 cm. The probe was operated at distances from the plasma edge ranging from 30 to -5 cm (i.e., inside the last closed flux surface). The probe design, electronics, calibration, data acquisition, and data processing are discussed. First data from the probe are presented as a function of ICRF power, distance from the plasma, loop orientation, and other plasma parameters. Initial data show parametric instabilities do not play an important role for ICRF in the TORE SUPRA edge and scrape-off-layer (SOL) plasmas. Additionally it is observed that the probe signal has little or no dependence on position in the SOL/plasma edge

Degree and reciprocity of self-disclosure in online forums.

Science.gov (United States)

Barak, Azy; Gluck-Ofri, Orit

2007-06-01

Cyberspace has become a common social environment in which people interact and operate in many ways. The purpose of the present study was to investigate the occurrence and reciprocity of self-disclosure, two subjects that are extensively studied in face-to-face interactions but only to a limited degree in virtual, computer-mediated, textual communication. Data was based on 240 first messages in a thread, sampled in equal numbers from six Internet forums (three discussion and three support groups), and written in equal numbers by each gender, and 240 first responses to them (a total of 480 forum messages). Trained, expert judges blindly rated each message on the degree to which it disclosed personal information, thoughts, and feelings. Linguistic parameters (total number of words and number of first-voice words) were also used as dependent variables. Results showed the following: (a) self-disclosure in support forums was much higher than in discussion forums, in terms of both total number and type of disclosure; (b) messages in support forums were longer and included more first-voice words than in discussion forums; (c) there were no gender differences interacting with level of self-disclosure; (d) reciprocity of self-disclosure was evident, yielding positive correlations between the measures of self-disclosure in messages and responses to them; (e) some differences appeared in level of reciprocity of self-disclosure between male and female participants, with female respondents tending to be more reciprocal than male respondents. The implications of these results are discussed in light of growing social interactions online, and possible applications are suggested.

Indirect reciprocity provides a narrow margin of efficiency for costly punishment

Science.gov (United States)

Iwasa, Yoh; Nowak, Martin A.

2008-01-01

Indirect reciprocity1-5 is a key mechanism for the evolution of human cooperation. Our behavior toward other people depends not only on what they have done to us, but also on what they have done to others. Indirect reciprocity works via reputation5-17. 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 behavior18-25. 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 analyze 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, while 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 punish them. PMID:19122640

Reciprocity as a Foundation of Financial Economics.

Science.gov (United States)

Johnson, Timothy C

This paper argues that the subsistence of the fundamental theorem of contemporary financial mathematics is the ethical concept 'reciprocity'. The argument is based on identifying an equivalence between the contemporary, and ostensibly 'value neutral', Fundamental Theory of Asset Pricing with theories of mathematical probability that emerged in the seventeenth century in the context of the ethical assessment of commercial contracts in a framework of Aristotelian ethics. This observation, the main claim of the paper, is justified on the basis of results from the Ultimatum Game and is analysed within a framework of Pragmatic philosophy. The analysis leads to the explanatory hypothesis that markets are centres of communicative action with reciprocity as a rule of discourse. The purpose of the paper is to reorientate financial economics to emphasise the objectives of cooperation and social cohesion and to this end, we offer specific policy advice.

Does Theorizing on Reciprocal Altruism Apply to the Relationships of Individuals with a Spinal Cord Injury?

NARCIS (Netherlands)

Buunk, A. P.; Zurriaga, Rosario; Gonzalez, Pilar

2012-01-01

From the perspective of reciprocal altruism, we examined the role of reciprocity in the close relationships of people inflicted with a spinal cord injury (SCI) (n = 70). We focused on the help receiver rather than on the help giver. Participants perceived more reciprocity in relationships with

Reciprocity theorem in high-temperature superconductors

Czech Academy of Sciences Publication Activity Database

Janeček, I.; Vašek, Petr

2003-01-01

Roč. 390, - (2003), s. 330-340 ISSN 0921-4534 R&D Projects: GA ČR GA202/00/1602; GA AV ČR IAA1010919 Institutional research plan: CEZ:AV0Z1010914 Keywords : transport properties * reciprocity theorem Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.192, year: 2003

Peer characteristics associated with improved glycemic control in a randomized controlled trial of a reciprocal peer support program for diabetes.

Science.gov (United States)

Kaselitz, Elizabeth; Shah, Megha; Choi, Hwajung; Heisler, Michele

2018-01-01

Objective In a secondary analysis of a randomized controlled trial of diabetes reciprocal peer support, we examined characteristics of peers associated with improvements in their partner's glycemic control. Methods A total of 102 adults with diabetes were randomized to the reciprocal peer support arm (vs. a nurse care management arm). The primary outcome was change in A1c over six months. Intermediate outcomes were insulin initiation and peer engagement. A number of baseline characteristics of peers were hypothesized to influence outcomes for their peer, and concordant characteristics of peer dyads were hypothesized that would influence outcomes for both peer partners. Results Improvement in A1c was associated with having a peer older than oneself ( P peers who reported poorer health at baseline had worse glycemic control at follow-up ( P peers had a more controlled self-regulation style were more likely to initiate insulin ( P peers whose partners were older and reported more diabetes distress at baseline supports the need for further research into the peer characteristics that lead to improved outcomes. This could allow for better matching and more effective partnerships.

Dynamic reciprocity in bio-inspired supramolecular materials

NARCIS (Netherlands)

Bastings, M.M.C.

2012-01-01

Dynamic reciprocity, the spatio-temporal bidirectional process between evolving partners in a functional system is not only found in nature, but also applies to supramolecularly assembling architectures. In this thesis, the focus was on the understanding of nature-inspired supramolecular

Mathematical modelling of Bit-Level Architecture using Reciprocal Quantum Logic

Science.gov (United States)

Narendran, S.; Selvakumar, J.

2018-04-01

Efficiency of high-performance computing is on high demand with both speed and energy efficiency. Reciprocal Quantum Logic (RQL) is one of the technology which will produce high speed and zero static power dissipation. RQL uses AC power supply as input rather than DC input. RQL has three set of basic gates. Series of reciprocal transmission lines are placed in between each gate to avoid loss of power and to achieve high speed. Analytical model of Bit-Level Architecture are done through RQL. Major drawback of reciprocal Quantum Logic is area, because of lack in proper power supply. To achieve proper power supply we need to use splitters which will occupy large area. Distributed arithmetic uses vector- vector multiplication one is constant and other is signed variable and each word performs as a binary number, they rearranged and mixed to form distributed system. Distributed arithmetic is widely used in convolution and high performance computational devices.

Social reciprocity and health: new scientific evidence and policy implications.

Science.gov (United States)

Siegrist, Johannes

2005-11-01

The work contract is based on the norm of social reciprocity where appropriate rewards are provided for efforts and achievements at work. The effort-reward imbalance model of work stress maintains that contractual non-reciprocity in terms of high efforts spent and low rewards received is frequent if people have no alternative choice in the labour market, if they are exposed to heavy competition or if they are intrinsically motivated to engage in excessive work-related commitment. According to the model, long-term exposure to effort-reward imbalance increases the risk of stress-related disorders. An overview of results from prospective epidemiological investigations testing the model is given. Overall, people who experience failed reciprocity at work are twice as likely to suffer from incident cardiovascular disease, depression or alcohol dependence compared to those who are not exposed. Associations are stronger for men than for women. Policy implications of findings for improved worksite health promotion are discussed.

Market powers predict reciprocal grooming in golden snub-nosed monkeys (Rhinopithecus roxellana.

Directory of Open Access Journals (Sweden)

Wei Wei

Full Text Available Social grooming is a common form of affiliative behavior in primates. Biological market theory suggests that grooming can be traded either for grooming or other social commodities and services. When no other services are exchanged, grooming is predicted to be approximately reciprocated within a dyad. In contrast, the amount of reciprocal grooming should decrease as other offered services increase. We studied grooming patterns between polygamous male and female in golden snub-nosed monkeys (Rhinopithecus roxellana from the Qinling Mountains of central China and found that about 29.7% of grooming bouts were reciprocated. However, the durations of grooming bouts offered and returned was asymmetrical within dyads. In bisexual dyads, more grooming was initiated by females than males, which became more pronounced as the number of females per one-male unit increased. The rate of copulation per day for each female was positively correlated with the total duration of grooming time females invested in males.. Females without an infant (non-mothers directed more grooming towards females with an infant (mothers and were significantly more likely to be non-reciprocated. There was a significant negative relationship between non-mother and mother grooming duration and the rate of infants per female in each one-male unit. High-ranking females also received more grooming from low-ranking females than vice versa. The rate of food-related aggressive interactions was per day for low-ranking females was negatively correlated with the duration of grooming that low-ranking females gave to high-ranking females. Our results showed that grooming reciprocation in R. roxellana was discrepancy. This investment-reciprocity rate could be explained by the exchange of other social services in lieu of grooming.

An FPGA-based slowcontrol module and a baseline shifting extension card for the sampling-ADC readout of the crystal barrel calorimeter

Energy Technology Data Exchange (ETDEWEB)

Urff, Georg; Poller, Timo [Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Collaboration: CBELSA/TAPS-Collaboration

2016-07-01

At the electron accelerator ELSA (Bonn) the CBELSA/TAPS experiment investigates the photoproduction of mesons off protons and neutrons. The CsI(Tl)-crystals of the Crystal Barrel calorimeter are being upgraded from a PIN-diode readout to an APD readout. In the context of this upgrade, an FPGA-based Sampling-ADC (SADC) is presently being developed (HK 304). A Slow-control Module for the SADC with TCP/Telnet access has been developed on the basis of a Spartan6 FPGA. Control and monitoring of the SADC's power supply as well as control of parameters of the analog and digital data processing in the SADC is realized via PMBus/I{sup 2}C. The prototype as well as an overview of its functionality will be presented. In order to fully utilize the dynamic input range of the SADCs, an interfacing extension board was designed. It receives the differential signal generated by previous amplification stages and adds an individual DC offset voltage to each channel supplied by a digital-to-analog converter. The circuit and the used techniques as well as simulations and measurements are presented.

PENINGKATAN KEMANDIRIAN MAHASISWA PENDIDIKAN FISIKA PADA MATA KULIAH MEKANIKA MELALUI METODE RECIPROCAL TEACHING

Directory of Open Access Journals (Sweden)

Fajar Fitri

2016-03-01

Full Text Available This research aims to describe thestudent independence after follow the Reciprocal Teaching of Learning. The subjects of this research are students in study program of physics education Ahmad Dahlan University who are studying Mechanics at school year of 2015/2016. Classroom Action Research consists of plan, do, and reflection. This activity repeated two cycles. The result is after follow the Reciprocal Teaching of Learning 80,3% students reached good individual and classical independence.This research aims to describe thestudent independence after follow the Reciprocal Teaching of Learning. The subjects of this research are students in study program of physics education Ahmad Dahlan University who are studying Mechanics at school year of 2015/2016. Classroom Action Research consists of plan, do, and reflection. This activity repeated two cycles. The result is after follow the Reciprocal Teaching of Learning 80,3% students reached good individual and classical independence.

Two new supersymmetric equations of Harry Dym type and their supersymmetric reciprocal transformations

International Nuclear Information System (INIS)

Tian, Kai; Liu, Q.P.

2012-01-01

A new N=1 supersymmetric Harry Dym equation is constructed by applying supersymmetric reciprocal transformation to a trivial supersymmetric Harry Dym equation, and its recursion operator and Lax formulation are also obtained. Within the framework of symmetry approach, a class of 3rd order supersymmetric equations of Harry Dym type are considered. In addition to five known integrable equations, a new supersymmetric equation, admitting 5th order generalized symmetry, is shown to be linearizable through supersymmetric reciprocal transformation. Furthermore, its Lax representation and recursion operator are given so that the integrability of this new equation is confirmed. -- Highlights: ► A new supersymmetric Harry Dym equation is constructed through supersymmetric reciprocal transformations. ► The recursion operator and Lax formulation are established for the new supersymmetric Harry Dym equation. ► A supersymmetric equation of Harry Dym type is shown to be linearized through supersymmetric reciprocal transformation.

Self-centered social exchange: differential use of costs versus benefits in prosocial reciprocity.

Science.gov (United States)

Zhang, Yan; Epley, Nicholas

2009-11-01

Maintaining equitable social relations often requires reciprocating "in kind" for others' prosocial favors. Such in-kind reciprocity requires assessing the value of a prosocial action, an assessment that can lead to egocentric biases in perceived value between favor givers versus favor receivers. In any prosocial exchange, 1 person (the giver) incurs a cost to provide a benefit for another person (the receiver). Six experiments suggest that givers may attend more to the costs they incur in performing a prosocial act than do receivers, who tend to focus relatively more on the benefits they receive. Givers may therefore expect to be reciprocated on the basis of the costs they incur, whereas receivers actually reciprocate primarily on the basis of the benefit they receive. This research identifies 1 challenge to maintaining a sense of equity in social relations and predicts when people are likely to feel fairly versus unfairly valued in their relationships.

Non-reciprocality of waves in inhomogeneous gyrotropic media and multi layer systems with gyrotropic layers

International Nuclear Information System (INIS)

Gevorgyan, A.A.

2002-01-01

There has been considered the dispersion of electromagnetic waves in natural gyrotropic, inhomogeneous media. There has been discovered a new mechanism of waves non-reciprocality conditioned by simultaneous presence of one of the media gradients and natural gyrotropy. The non- reciprocality of waves in multilayer systems with gydrotropic layers has been investigated. It was considered a simple multilayer system glass (1)- cholesteric liquid crystal- glass(2) and demonstrated that non-reciprocality of waves in multilayer system offers good challenges for establishing simple systems with greater reciprocality. It has been shown that the multilayer systems with cholesteric liquid crystal layer can be used as optic diodes

Tuition Reciprocity in the United States

Science.gov (United States)

Stewart, Gregory; Wright, Dianne Brown; Kennedy, Angelica

2008-01-01

Reciprocity agreements are contracts between two or more parties whereby students pay reduced tuition rates. The rate of reduction is determined by the parameters set forth in each individual state's agreement but may range from a modest reduction in fees to a waiver of full non-resident tuition. In addition to providing tuition relief,…

Reciprocity in Preschool Peers' Social Interaction.

Science.gov (United States)

Chiu, Jih-Perng Peter

This study sought to describe the norms of reciprocity in social interaction from the viewpoint of immediate behavioral exchanges by examining the social interaction of preschool peers in a free-play situation. Seventeen 4-year-old children, eight girls and nine boys, were observed during free play activity periods after a picture sociometric test…

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)

Reciprocal effects of exercise and nutrition treatment-induced weight loss with improved body image and physical self-concept.

Science.gov (United States)

Annesi, James J; Porter, Kandice J

2015-01-01

Improvements in self-image and mood are often reported as outcomes of obesity interventions. However, they may also concurrently influence weight loss, suggesting a reciprocal effect. Although previously reported for overweight women, such relationships were untested in morbidly obese women whose psychosocial responses to treatment may be different, and health-risks greater. Women (N = 161, Meanage = 42 years) with morbid obesity (MeanBMI = 45.1 kg/m(2)) participated in a 6-month, behaviorally based physical activity and nutrition treatment. Significant within-group improvements in weight-loss behaviors (physical activity and eating), weight, body satisfaction, physical self-concept, and depression were found. After controlling for age, mediation analyses indicated that, as a result of the treatment, weight loss was both an outcome and mediator of improvements in body-areas satisfaction and physical self-concept (reciprocal effects), but not depression. Results replicated findings from women with lower degrees of overweight, and suggested that weight-loss treatments emphasize changes in self-perception.

Indirect reciprocity with trinary reputations.

Science.gov (United States)

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.

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.

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

Science.gov (United States)

Számadó, Szabolcs; Szalai, Ferenc; Scheuring, István

2016-01-01

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.

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

Directory of Open Access Journals (Sweden)

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.

Attitude towards reciprocity as a motive for oocyte donation.

Science.gov (United States)

Pennings, Guido; Ravel, Célia; Girard, Jean-Maxime; Domin-Bernhard, Mathilde; Provoost, Veerle

2018-06-01

Finding out whether patients would be motivated by reciprocity when considering donating oocytes to others. This is a prospective monocentric study in the CECOS of the Centre Hospitalier Universitaire (CHU) of Rennes (France) on the opinion of patients regarding reciprocity. Couples who had a child with donor sperm were asked whether they would consider oocyte donation as a way of giving something back. Twenty six couples and one man answered the questionnaire. About half of the respondents (49%) felt that they should contribute to the system from which they benefitted. Although the patients would benefit from a reduction in waiting time, this advantage was only important for one in four persons. The only items on which the answers between men and women were significantly different concerned the results of the donation: women would think more often about the potential recipient and the child and they more often wanted to know whether children were born from their donation. The results show that beside altruism, reciprocity may be an important moral reason for people to donate gametes. Copyright © 2018 Elsevier B.V. All rights reserved.

Relationship Reciprocation Modulates Resource Allocation in Adolescent Social Networks: Developmental Effects.

Science.gov (United States)

Burnett Heyes, Stephanie; Jih, Yeou-Rong; Block, Per; Hiu, Chii-Fen; Holmes, Emily A; Lau, Jennifer Y F

2015-01-01

Adolescence is characterized as a period of social reorientation toward peer relationships, entailing the emergence of sophisticated social abilities. Two studies (Study 1: N = 42, ages 13-17; Study 2: N = 81, ages 13-16) investigated age group differences in the impact of relationship reciprocation within school-based social networks on an experimental measure of cooperation behavior. Results suggest development between mid- and late adolescence in the extent to which reciprocation of social ties predicted resource allocation. With increasing age group, investment decisions increasingly reflected the degree to which peers reciprocated feelings of friendship. This result may reflect social-cognitive development, which could facilitate the ability to navigate an increasingly complex social world in adolescence and promote positive and enduring relationships into adulthood. © 2015 The Authors. Child Development published by Wiley Periodicals, Inc. on behalf of Society for Research in Child Development.

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

Science.gov (United States)

2010-12-07

... National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines... internal combustion engines. Subsequently, the Administrator received two petitions for reconsideration... Any industry using a stationary 2211 Electric power reciprocating internal generation, combustion...

Temporal Dynamics and Decomposition of Reciprocal Determinism: A Reply to Phillips and Orton.

Science.gov (United States)

Bandura, Albert

1983-01-01

In their analysis of reciprocal determinism, Phillips and Orton (TM 509 061) mistakenly assume that behavior, cognitive and other personal factors, and environmental events operate as a simultaneous wholistic interaction. Contrary to this belief, the interactants in triadic reciprocality work their mutual effects sequentially over variable time…

Decrease of sexual organ reciprocity between heterostylous primrose species, with possible functional and evolutionary implications.

Science.gov (United States)

Keller, Barbara; de Vos, Jurriaan M; Conti, Elena

2012-11-01

Heterostyly is a floral polymorphism that has fascinated evolutionary biologists since Darwin's seminal studies on primroses. The main morphological characteristic of heterostyly is the reciprocal placement of anthers and stigmas in two distinct (distyly) floral morphs. Variation in the degree of intermorph sexual reciprocity is relatively common and known to affect patterns of pollen transfer within species. However, the partitioning of sexual organ reciprocity within and between closely related species remains unknown. This study aimed at testing whether intermorph sexual reciprocity differs within vs. between primrose species that hybridize in nature and whether the positions of sexual organs are correlated with other floral traits. Six floral traits were measured in both floral morphs of 15 allopatric populations of Primula elatior, P. veris and P. vulgaris, and anther-stigma reciprocity was estimated within and between species. A combination of univariate and multivariate approaches was used to test whether positions of reproductive organs were less reciprocal between than within species, to assess correlations between sexual organ positions and other corolla traits, and to quantify differences between morphs and species. The three species were morphologically well differentiated in most floral traits, except that P. veris and P. vulgaris did not differ significantly in sexual organ positions. Overall, lower interspecific than intraspecific sexual organ reciprocity was detected. This decrease was marked between P. elatior and P. vulgaris, intermediate and variable between P. elatior and P. veris, but negligible between P. veris and P. vulgaris. Differences in anther and stigma heights between the analysed primrose species were of the same magnitude or larger than intraspecific differences that altered pollen flow within other heterostylous systems. Therefore, it is possible to suggest that considerable reductions of sexual organ reciprocity between species may

Relationship Reciprocation Modulates Resource Allocation in Adolescent Social Networks: Developmental Effects

OpenAIRE

Burnett Heyes, Stephanie; Jih, Yeou?Rong; Block, Per; Hiu, Chii?Fen; Holmes, Emily A.; Lau, Jennifer Y. F.

2015-01-01

Adolescence is characterized as a period of social reorientation toward peer relationships, entailing the emergence of sophisticated social abilities. Two studies (Study 1: N?=?42, ages 13?17; Study 2: N?=?81, ages 13?16) investigated age group differences in the impact of relationship reciprocation within school?based social networks on an experimental measure of cooperation behavior. Results suggest development between mid? and late adolescence in the extent to which reciprocation of social...

A generalized linear-quadratic model incorporating reciprocal time pattern of radiation damage repair

International Nuclear Information System (INIS)

Huang, Zhibin; Mayr, Nina A.; Lo, Simon S.; Wang, Jian Z.; Jia Guang; Yuh, William T. C.; Johnke, Roberta

2012-01-01

Purpose: It has been conventionally assumed that the repair rate for sublethal damage (SLD) remains constant during the entire radiation course. However, increasing evidence from animal studies suggest that this may not the case. Rather, it appears that the repair rate for radiation-induced SLD slows down with increasing time. Such a slowdown in repair would suggest that the exponential repair pattern would not necessarily accurately predict repair process. As a result, the purpose of this study was to investigate a new generalized linear-quadratic (LQ) model incorporating a repair pattern with reciprocal time. The new formulas were tested with published experimental data. Methods: The LQ model has been widely used in radiation therapy, and the parameter G in the surviving fraction represents the repair process of sublethal damage with T r as the repair half-time. When a reciprocal pattern of repair process was adopted, a closed form of G was derived analytically for arbitrary radiation schemes. The published animal data adopted to test the reciprocal formulas. Results: A generalized LQ model to describe the repair process in a reciprocal pattern was obtained. Subsequently, formulas for special cases were derived from this general form. The reciprocal model showed a better fit to the animal data than the exponential model, particularly for the ED50 data (reduced χ 2 min of 2.0 vs 4.3, p = 0.11 vs 0.006), with the following gLQ parameters: α/β = 2.6-4.8 Gy, T r = 3.2-3.9 h for rat feet skin, and α/β = 0.9 Gy, T r = 1.1 h for rat spinal cord. Conclusions: These results of repair process following a reciprocal time suggest that the generalized LQ model incorporating the reciprocal time of sublethal damage repair shows a better fit than the exponential repair model. These formulas can be used to analyze the experimental and clinical data, where a slowing-down repair process appears during the course of radiation therapy.

Coupling of reciprocal vectors and corresponding degeneracy effect in a dual-periodic optical superlattice

International Nuclear Information System (INIS)

Qin Yiqiang

2006-01-01

A dual-periodic structure for quasi-phase matching cascaded optical parametric interactions is proposed. Due to the coupling of reciprocal vectors between the original and imposed periodic sequence, the reciprocal vectors and the corresponding effective nonlinear coefficients is no longer the simple combination of two periodic structures. The new analytical expression of the effective nonlinear coefficients is deduced and given. The degeneracy phenomena and the novel extinction rule resulting from the coupling of reciprocal vectors are found and investigated. The corresponding physical nature is also discussed

The transition probabilities of the reciprocity model

NARCIS (Netherlands)

Snijders, T.A.B.

1999-01-01

The reciprocity model is a continuous-time Markov chain model used for modeling longitudinal network data. A new explicit expression is derived for its transition probability matrix. This expression can be checked relatively easily. Some properties of the transition probabilities are given, as well

Nebula: reconstruction and visualization of scattering data in reciprocal space.

Science.gov (United States)

Reiten, Andreas; Chernyshov, Dmitry; Mathiesen, Ragnvald H

2015-04-01

Two-dimensional solid-state X-ray detectors can now operate at considerable data throughput rates that allow full three-dimensional sampling of scattering data from extended volumes of reciprocal space within second to minute time-scales. For such experiments, simultaneous analysis and visualization allows for remeasurements and a more dynamic measurement strategy. A new software, Nebula , is presented. It efficiently reconstructs X-ray scattering data, generates three-dimensional reciprocal space data sets that can be visualized interactively, and aims to enable real-time processing in high-throughput measurements by employing parallel computing on commodity hardware.

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

Science.gov (United States)

2012-10-03

... National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines AGENCY: Environmental Protection... Pollutants for Stationary Reciprocating Internal Combustion Engines to solicit comment on specific issues...

77 FR 37361 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

Science.gov (United States)

2012-06-21

... National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines AGENCY: Environmental Protection... Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source Performance...

Reciprocal Teaching: Analyzing Interactive Dynamics in the Co-Construction of a Text's Meaning

Science.gov (United States)

Tarchi, Christian; Pinto, Giuliana

2016-01-01

Reciprocal teaching is one of the most successfully implemented cooperative learning practices, yet many aspects of the process it follows are still unclear. The authors' aim was two-fold: To analyze whether reciprocal teaching activates diversity in discourse moves, communicative functions, and interaction sequences; and to determine whether…

On an integrable deformed affinsphären equation. A reciprocal gasdynamic connection

International Nuclear Information System (INIS)

Rogers, C.; Huang, Yehui

2012-01-01

The integrable affinsphären equation originally arose in a geometric context but has an interesting gasdynamic connection. Here, an integrable deformed version of the affinsphären equation is derived in a novel manner via the action of reciprocal transformations on a related anisentropic gasdynamics system. A linear representation for the deformed affinsphären equation is constructed by means of the reciprocal transformations. The latter are then employed to derive a class of exact solutions in parametric form. -- Highlights: ► A deformed affinsphären equation is derived via a reciprocal transformation. ► A linear representation for the deformed affinsphären equation is constructed. ► A class of exact solutions of the deformed affinsphären equation is presented.

Cyclic fatigue resistance of 3 different nickel-titanium reciprocating instruments in artificial canals.

Science.gov (United States)

Higuera, Oscar; Plotino, Gianluca; Tocci, Luigi; Carrillo, Gabriela; Gambarini, Gianluca; Jaramillo, David E

2015-06-01

The purpose of this study was to evaluate the cyclic fatigue resistance of 3 different nickel-titanium reciprocating instruments. A total of 45 nickel-titanium instruments were tested and divided into 3 experimental groups (n = 15): group 1, WaveOne Primary instruments; group 2, Reciproc R25 instruments; and group 3, Twisted File (TF) Adaptive M-L1 instruments. The instruments were then subjected to cyclic fatigue test on a static model consisting of a metal block with a simulated canal with 60° angle of curvature and a 5-mm radius of curvature. WaveOne Primary, Reciproc R25, and TF Adaptive instruments were activated by using their proprietary movements, WaveOne ALL, Reciproc ALL, and TF Adaptive, respectively. All instruments were activated until fracture occurred, and the time to fracture was recorded visually for each file with a 1/100-second chronometer. Mean number of cycles to failure and standard deviations were calculated for each group, and data were statistically analyzed (P fatigue resistance of Reciproc R25 and TF Adaptive M-L1 was significantly higher than that of WaveOne Primary (P = .009 and P = .002, respectively). The results showed no statistically significant difference between TF Adaptive M-L1 and Reciproc R25 (P = .686). Analysis of the fractured portion under scanning electron microscopy indicated that all instruments showed morphologic characteristics of ductile fracture that were due to accumulation of metal fatigue. No statistically significant differences were found between the instruments tested except for WaveOne Primary, which showed the lowest resistance to cyclic fatigue. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Applying the reciprocal dose principle to heterogeneous phantoms: practical experience from Monte Carlo studies

International Nuclear Information System (INIS)

Cristy, M.; Williams, L.R.

1983-01-01

The reciprocity theorem states that for any pair of regions in a uniform isotropic or uniform scatterless model, the specific fraction (PHI) is independent of which region is designated source and which is designated target. Although the conditions of these models are not met by phantoms heterogeneous in tissue composition and density, calculations with a Monte Carlo radiation transport code show that in many cases the reciprocal PHIs from photon radiation are approximately equal. This 'reciprocity principle' is valid within a factor of 2(Snyder) or about 20% (Mayneord and Clarke), except when one of the organs in the pair considered is the skeleton, where the reciprocal PHIs may differ by as much as a factor of 4. The principle holds within at least 10% when both organs are of near-unit-density. When one of the organs is near the tissue-vacuum boundary (skin, breasts, or testes), reciprocal PHIs may differ by as much as 10% or so at energies where scattering is marked. When one of the organs is the lungs or the whole body, a comparable error may occur at some energies. (author)

75 FR 37732 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

Science.gov (United States)

2010-06-30

... National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines... hazardous air pollutants for existing stationary compression ignition reciprocating internal combustion... combustion engines. 40 CFR 63.6590 was amended by revising paragraphs (b)(1) and (3). Inadvertently...

77 FR 33811 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

Science.gov (United States)

2012-06-07

... 63 National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source Performance Standards for Stationary Internal Combustion Engines; Proposed Rule #0;#0... Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines; New Source...

Reciprocity as Sustainability in Campus-Community Partnership

Science.gov (United States)

Bloomgarden, Alan

2013-01-01

The concept of reciprocity permeates the literature on campus-community partnership as a matter of principle, aspiration, and--ideally--best practice. More recently, principles and practices of sustainability have pervaded scholarly and popular discourse, emerging from and applying to environmental studies, economic development, and social justice…

Reciprocity relationships in vector acoustics and their application to vector field calculations.

Science.gov (United States)

Deal, Thomas J; Smith, Kevin B

2017-08-01

The reciprocity equation commonly stated in underwater acoustics relates pressure fields and monopole sources. It is often used to predict the pressure measured by a hydrophone for multiple source locations by placing a source at the hydrophone location and calculating the field everywhere for that source. A similar equation that governs the orthogonal components of the particle velocity field is needed to enable this computational method to be used for acoustic vector sensors. This paper derives a general reciprocity equation that accounts for both monopole and dipole sources. This vector-scalar reciprocity equation can be used to calculate individual components of the received vector field by altering the source type used in the propagation calculation. This enables a propagation model to calculate the received vector field components for an arbitrary number of source locations with a single model run for each vector field component instead of requiring one model run for each source location. Application of the vector-scalar reciprocity principle is demonstrated with analytic solutions for a range-independent environment and with numerical solutions for a range-dependent environment using a parabolic equation model.

Mutuality and reciprocity in the psychological contracts of employees and employers.

Science.gov (United States)

Dabos, Guillermo E; Rousseau, Denise M

2004-02-01

The authors assessed the joint perceptions of the employee and his or her employer to examine mutuality and reciprocity in the employment relationship. Paired psychological contract reports were obtained from 80 employee-employer dyads in 16 university-based research centers. On the basis of in-depth study of the research setting, research directors were identified as primary agents for the university (employer) in shaping the terms of employment of staff scientists (employees). By assessing the extent of consistency between employee and employer beliefs regarding their exchange agreement, the present study mapped the variation and consequences of mutuality and reciprocity in psychological contracts. Results indicate that both mutuality and reciprocity are positively related to archival indicators of research productivity and career advancement, in addition to self-reported measures of Met Expectations and intention to continue working with the employer. Implications for psychological contract theory are presented. ((c) 2004 APA, all rights reserved)

76 FR 12863 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

Science.gov (United States)

2011-03-09

... National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion Engines... combustion engines. The final rule was published on August 20, 2010. This direct final action amends certain... Emission Standards for Hazardous Air Pollutant for Stationary Reciprocating Internal Combustion Engines...

The influence of reciprocating sliding wear on the oxidation behaviour of Fe-12Cr steel

International Nuclear Information System (INIS)

Smith, A.F.

1988-04-01

Medium-chromium ferritic alloys are used extensively in the boiler and core sections of advanced gas cooled reactors. It was discovered in the early 1970s, that under certain conditions these alloys could undergo the phenomenon known as breakaway oxidation. In this type of oxidation the rate limiting step is located at the oxide/metal interface rather than the more usual gas/oxide interface and results in linear oxidation kinetics. It has been shown that repeated removal of oxide layers can expose chromium depleted metal to the oxidising gas and promote nucleation of breakaway oxidation. The question has been addressed as to whether high temperature sliding wear processes can also disrupt the surface so as to make the material potentially susceptible to breakaway oxidation. To this end high temperature reciprocating wear of Fe-12Cr material in both low and high pressure reactor gas has been investigated. (author)

Reciprocal Teaching and Emotional Intelligence: A Study of Iranian EFL Learners' Reading Comprehension

Science.gov (United States)

Izadi, Mehri; Nowrouzi, Hossein

2016-01-01

The present study aimed at exploring the effect of reciprocal reading strategies instruction on reading comprehension of EFL learners. Emotional intelligence, another variable of interest, was assessed to indicate whether it plays a role in learners' comprehension. In a pre- and post-test study, forty-two learners went through a reciprocal reading…

Spatial externalities, openness and financial development in the ...

African Journals Online (AJOL)

Spatial externalities, openness and financial development in the SADC. Alex Bara, Gift Mugano, Pierre Le Roux. Abstract. This study empirically evaluates spatial externalities in financial development in the Southern African Development Community (SADC) in line with spatial proximity theory. The study specifically tests ...

Bank concentration, country income and financial development in ...

African Journals Online (AJOL)

kirstam

between bank concentration and financial development in the SADC region. ... 5The study findings suggest that bank assets in SADC are concentrated in ... a country's cities/administrative regions, or across countries within a regional ... sector emphasises the importance of local embeddedness, networks, ...... The Case of.

Onsager's reciprocity theorem in extended irreversible thermodynamics

International Nuclear Information System (INIS)

Garcia-Colin, L.S.; Velasco, R.M.

1992-01-01

In this paper we shall discuss the Onsager relations for the transport coefficients in a dilute monatomic gas described by the extended irreversible thermodynamics. Our discussion is based on a 26 variables description of the system and its corresponding comparison with the kinetic reciprocity between coefficients is shown (Author)

Novel Long Stroke Reciprocating Compressor for Energy Efficient Jaggery Making

Science.gov (United States)

Rane, M. V.; Uphade, D. B.

2017-08-01

Novel Long Stroke Reciprocating Compressor is analysed for jaggery making while avoiding burning of bagasse for concentrating juice. Heat of evaporated water vapour along with small compressor work is recycled to enable boiling of juice. Condensate formed during heating of juice is pure water, as oil-less compressor is used. Superheat of compressor is suppressed by flow of superheated vapours through condensate. It limits heating surface temperature and avoids caramelization of sugar. Thereby improves quality of jaggery and eliminates need to use chemicals for colour improvement. Stroke to bore ratio is 0.6 to 1.2 in conventional reciprocating drives. Long stroke in reciprocating compressors enhances heat dissipation to surrounding by providing large surface area and increases isentropic efficiency by reducing compressor outlet temperature. Longer stroke increases inlet and exit valve operation timings, which reduces inertial effects substantially. Thereby allowing use of sturdier valves. This enables handling liquid along with vapour in compressors. Thereby supressing the superheat and reducing compressor power input. Longer stroke increases stroke to clearance ratios which increases volumetric efficiency and ability of compressor to compress through higher pressure ratios efficiently. Stress-strain simulation is performed in SolidWorks for gear drive. Long Stroke Reciprocating Compressor is developed at Heat Pump Laboratory, stroke/bore 292 mm/32 mm. It is operated and tested successfully at different speeds for operational stability of components. Theoretical volumetric efficiency is 93.9% at pressure ratio 2.0. Specific energy consumption is 108.3 kWhe/m3 separated water, considering free run power.

Elucidations on the reciprocal lattice and the Ewald sphere

International Nuclear Information System (INIS)

Foadi, J; Evans, G

2008-01-01

The reciprocal lattice is derived through the Fourier transform of a generic crystal lattice, as done previously in the literature. A few key derivations are this time handled in detail, and the connection with x-ray diffraction is clearly pointed out. The Ewald sphere is subsequently thoroughly explained and a few comments on its representation in a mixed real-reciprocal space are made. In particular, it appears that the majority of textbooks or papers on the subject are limited in their way of picturing it. This paper will be useful to solid state and/or crystallography teachers. It is also suitable for graduate students researching these subjects and for talented undergraduate students

Promotion of trade in service in developing economy: challenges and prospects

Directory of Open Access Journals (Sweden)

AA Okharedia

2014-01-01

Full Text Available In the past, trade in services was not considered important by international Economists. One of the main arguments put forward for ignoring the concept of trade in service was that services were non- tradable In view of this, this paper attempts to investigate the role played by service industries and the associated challenges in a developing economy with particular reference to the SADC countries. This investigation shows that the service industries are uncompetitive and inefficient when compared with their peers in developed economy. This paper recommends that there is an urgent need for a major-shake up especially within the core economic infrastructure services. This paper also highlights that the service industries in the SADC region contributes greatly to GDP, creates employment opportunity, improved access to transport which translates into improved access to customers and suppliers. The transport sector is of crucial importance in poverty alleviation and regional economic integration. Some of the challenges identified include, the need for SADC countries to conform to international standards in delivery of its services since most SADC countries are members of GATS, ILO and WTO. The other challenge is the different legislative framework in the service industries within the SADC region. There is an urgent need to harmonise the different legislative framework.

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

Social Support Reciprocity and Occupational Self-Efficacy Beliefs during Mothers' Organizational Re-Entry

Science.gov (United States)

Jaeckel, Dalit; Seiger, Christine P.; Orth, Ulrich; Wiese, Bettina S.

2012-01-01

The present study assesses the effects of a lack of social support reciprocity at work on employees' occupational self-efficacy beliefs. We assume that the self-efficacy effects of received support and support reciprocity depend on the specific work context (e.g., phase in the process of organizational socialization). 297 women who returned to…

The evolution of conditional moral assessment in indirect reciprocity

Science.gov (United States)

Sasaki, Tatsuya; Okada, Isamu; Nakai, Yutaka

2017-01-01

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. PMID:28150808

The measure and mismeasure of reciprocity in heterostylous flowers.

Science.gov (United States)

Armbruster, W Scott; Bolstad, Geir H; Hansen, Thomas F; Keller, Barbara; Conti, Elena; Pélabon, Christophe

2017-07-01

The goal of biological measurement is to capture underlying biological phenomena in numerical form. The reciprocity index applied to heterostylous flowers is meant to measure the degree of correspondence between fertile parts of opposite sex on complementary (inter-compatible) morphs, reflecting the correspondence of locations of pollen placement on, and stigma contact with, pollinators. Pollen of typical heterostylous flowers can achieve unimpeded fertilization only on opposite-morph flowers. Thus, the implicit goal of this measurement is to assess the likelihood of 'legitimate' pollinations between compatible morphs, and hence reproductive fitness. Previous reciprocity metrics fall short of this goal on both empirical and theoretical grounds. We propose a new measure of reciprocity based on theory that relates floral morphology to reproductive fitness. This method establishes a scale based on adaptive inaccuracy, a measure of the fitness cost of the deviation of phenotypes in a population from the optimal phenotype. Inaccuracy allows the estimation of independent contributions of maladaptive bias (mean departure from optimum) and imprecision (within-population variance) to the phenotypic mismatch (inaccuracy) of heterostylous morphs on a common scale. We illustrate this measure using data from three species of Primula (Primulaceae). © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

The evolution of conditional moral assessment in indirect reciprocity.

Science.gov (United States)

Sasaki, Tatsuya; Okada, Isamu; Nakai, Yutaka

2017-02-02

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.

The evolution of conditional moral assessment in indirect reciprocity

Science.gov (United States)

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.

The evolution of strong reciprocity: cooperation in heterogeneous populations.

Science.gov (United States)

Bowles, Samuel; Gintis, Herbert

2004-02-01

How do human groups maintain a high level of cooperation despite a low level of genetic relatedness among group members? We suggest that many humans have a predisposition to punish those who violate group-beneficial norms, even when this imposes a fitness cost on the punisher. Such altruistic punishment is widely observed to sustain high levels of cooperation in behavioral experiments and in natural settings. We offer a model of cooperation and punishment that we call STRONG RECIPROCITY: where members of a group benefit from mutual adherence to a social norm, strong reciprocators obey the norm and punish its violators, even though as a result they receive lower payoffs than other group members, such as selfish agents who violate the norm and do not punish, and pure cooperators who adhere to the norm but free-ride by never punishing. Our agent-based simulations show that, under assumptions approximating likely human environments over the 100000 years prior to the domestication of animals and plants, the proliferation of strong reciprocators when initially rare is highly likely, and that substantial frequencies of all three behavioral types can be sustained in a population. As a result, high levels of cooperation are sustained. Our results do not require that group members be related or that group extinctions occur.

Effect of reciprocating file motion on microcrack formation in root canals: an SEM study.

Science.gov (United States)

Ashwinkumar, V; Krithikadatta, J; Surendran, S; Velmurugan, N

2014-07-01

To compare dentinal microcrack formation whilst using Ni-Ti hand K-files, ProTaper hand and rotary files and the WaveOne reciprocating file. One hundred and fifty mandibular first molars were selected. Thirty teeth were left unprepared and served as controls, and the remaining 120 teeth were divided into four groups. Ni-Ti hand K-files, ProTaper hand files, ProTaper rotary files and WaveOne Primary reciprocating files were used to prepare the mesial canals. Roots were then sectioned 3, 6 and 9 mm from the apex, and the cut surface was observed under scanning electron microscope (SEM) and checked for the presence of dentinal microcracks. The control and Ni-Ti hand K-files groups were not associated with microcracks. In roots prepared with ProTaper hand files, ProTaper rotary files and WaveOne Primary reciprocating files, dentinal microcracks were present. There was a significant difference between control/Ni-Ti hand K-files group and ProTaper hand files/ProTaper rotary files/WaveOne Primary reciprocating file group (P ProTaper rotary files producing the most microcracks. No significant difference was observed between teeth prepared with ProTaper hand files and WaveOne Primary reciprocating files. ProTaper rotary files were associated with significantly more microcracks than ProTaper hand files and WaveOne Primary reciprocating files. Ni-Ti hand K-files did not produce microcracks at any levels inside the root canals. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Apical extrusion of bacteria when using reciprocating single-file and rotary multifile instrumentation systems.

Science.gov (United States)

Tinoco, J M; De-Deus, G; Tinoco, E M B; Saavedra, F; Fidel, R A S; Sassone, L M

2014-06-01

To evaluate ex vivo, apical bacterial extrusion associated with two reciprocating single-file systems (WaveOne and Reciproc) compared with a conventional multifile rotary system (BioRace). Forty-five human single-rooted mandibular incisors were used. Endodontic access cavities were prepared, and root canals were contaminated with an Enterococcus faecalis suspension. Following incubation at 37 °C for thirty days, the contaminated teeth were divided into three groups of 15 specimens each (G1 - Reciproc, G2 - WaveOne and G3 - BioRace). Positive and negative controls consisted of 5 infected teeth and 3 uninfected incisors that were instrumented with one of the tested NiTi systems, respectively. Bacteria extruded from the apical foramen during instrumentation were collected into vials containing 0.9% NaCl. The microbiological samples were taken from the vials and incubated in brain heart agar medium for 24 h. The resulting bacterial titre, in colony-forming units (CFU) per mL, was determined, and these data were analysed by Wilcoxon matched-pairs signed rank test and Kruskal-Wallis H-test. The level of significance was set at α = 0.05. No significant difference was found in the number of CFU between the two reciprocating systems (P = 0.41). The conventional multifile rotary system group was associated with significantly higher CFU than both of the two reciprocating groups (P = 0.01). All instrumentation systems extruded bacteria beyond the foramen. However, both reciprocating single-file systems extruded fewer bacteria apically than the conventional multifile rotary system. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Exotic distributions of rigid unit modes in the reciprocal spaces of framework aluminosilicates

International Nuclear Information System (INIS)

Dove, Martin T; Pryde, Alexandra K A; Heine, Volker; Hammonds, Kenton D

2007-01-01

Until recently it was assumed that rigid unit modes, defined as the zero-frequency solutions to the dynamical equations for an infinite framework of rigid corner-linked tetrahedra, were confined to a small set of normal modes with wavevectors on lines or planes of special symmetry in reciprocal space. Using a search method that explores the full three-dimensional reciprocal space, we have located rigid unit modes with wavevectors on exotic curved surfaces in reciprocal space for a range of silicate minerals. This has led to the realization that the crystal structures of these minerals contain rather more topological floppiness than had previously been realized. The origin of the exotic RUM surfaces remains to be understood

TORE SUPRA fast reciprocating radio frequency probe (abstract)

International Nuclear Information System (INIS)

Thomas, C.E. Jr.; Harris, J.H.; Haste, G.R.; Kwon, M.; Goulding, R.H.; Hoffman, D.J.; Saoutic, B.; Becoulet, A.; Fraboulet, D.; Beaumont, B.; Kuus, H.; Ladurelle, L.; Pascal, J.Y.

1995-01-01

A fast reciprocating ion cyclotron range of frequencies (ICRF) probe was installed and operated on TORE SUPRA during 1992/1993. The body of the probe was originally used on the ATF experiment at Oak Ridge National Laboratory. The probe was adapted for use on TORE SUPRA, and mounted on one of the two fast reciprocating probe mounts. The probe consists of two orthogonal single-turn wire loops, mounted so that one loop senses toroidal rf magnetic fields and the other senses poloidal rf magnetic fields. The probe began operation in June, 1993. The probe active area is approximately 5 cm long by 2 cm, and the reciprocating mount has a slow stroke (5 cm/s) of 30 cm and a fast stroke (1.5 m/s) of about 10 cm. The probe was operated at distances from the plasma edge ranging from 30 to -5 cm (i.e., inside the last closed flux surface). The probe design, electronics, calibration, data acquisition, and data processing are discussed. First data from the probe are presented as a function of ICRF power, distance from the plasma, loop orientation, and other plasma parameters. Initial data show parametric instabilities do not play an important role for ICRF in the TORE SUPRA edge and scrape-off-layer (SOL) plasmas. Additionally it is observed that the probe signal has little or no dependence on position in the SOL/plasma edge

The strong non-reciprocity of metamaterial absorber: characteristic, interpretation and modelling

Energy Technology Data Exchange (ETDEWEB)

Li Yuanxun; Xie Yunsong; Zhang Huaiwu; Liu Yingli; Wen Qiye; Ling Weiwei, E-mail: liyuanxun@uestc.edu.c [State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054 (China)

2009-05-07

We simulated the metamaterial absorbers in two propagation conditions and observed the universal phenomenon of strong non-reciprocity. It is found that this non-reciprocity cannot be well interpreted using the effective medium theory, which indicates that the designing and understanding for the metamaterial absorber based on the proposed effective medium theory could not be applicable. The reason is pointed out that the metamaterial absorber does not satisfy the homogeneous-effective limit. So we put forward a three-parameter modified effective medium theory to fully describe the metamaterial absorbers. We have also investigated the relationships of S-parameters and absorptance among the metamaterial absorbers and the two components inside. Then the power absorption distributions in these three structures are discussed in detail. It can be concluded that the absorption is derived from the ERR structure and is enhanced largely by the coupling mechanism, and the strong non-reciprocity results from the different roles which wire structure plays in both propagation conditions.

The strong non-reciprocity of metamaterial absorber: characteristic, interpretation and modelling

International Nuclear Information System (INIS)

Li Yuanxun; Xie Yunsong; Zhang Huaiwu; Liu Yingli; Wen Qiye; Ling Weiwei

2009-01-01

We simulated the metamaterial absorbers in two propagation conditions and observed the universal phenomenon of strong non-reciprocity. It is found that this non-reciprocity cannot be well interpreted using the effective medium theory, which indicates that the designing and understanding for the metamaterial absorber based on the proposed effective medium theory could not be applicable. The reason is pointed out that the metamaterial absorber does not satisfy the homogeneous-effective limit. So we put forward a three-parameter modified effective medium theory to fully describe the metamaterial absorbers. We have also investigated the relationships of S-parameters and absorptance among the metamaterial absorbers and the two components inside. Then the power absorption distributions in these three structures are discussed in detail. It can be concluded that the absorption is derived from the ERR structure and is enhanced largely by the coupling mechanism, and the strong non-reciprocity results from the different roles which wire structure plays in both propagation conditions.

Reciprocal relationships between parent and adolescent internalizing symptoms.

Science.gov (United States)

Hughes, Elizabeth K; Gullone, Eleonora

2010-04-01

Previous investigations of the association between parent and adolescent internalizing problems have been largely restricted to the unidirectional effect of parent symptoms on their children. This study therefore aimed to investigate potential reciprocal relationships between parent and adolescent internalizing symptoms. One-hundred and seventy-seven adolescents ages 14 to 18 years and their parents (172 mothers, 124 fathers) completed measures of depressive and anxiety symptoms at two time points, 6 months apart. Results supported reciprocity between maternal and adolescent internalizing symptoms but not between paternal and adolescent internalizing symptoms. In addition, the relationship between maternal symptoms and later adolescent symptoms was found to be partially mediated by maternal parenting self-esteem. The study highlights the potential impact of adolescent internalizing problems on maternal well-being, a phenomenon previously neglected in the literature. 2010 APA, all rights reserved

Commercial forestry

CSIR Research Space (South Africa)

Naidoo, Sasha

2017-10-01

Full Text Available states. Forest cover is concentrated in a few countries in the SADC region. The Democratic Republic of Congo, Angola, Zambia and Mozambique have the largest forest areas and account for close to three-quarters of the total forest area in the SADC region...

Antimicrobial activity of rosemary-pepper essential oil and barbatimao dry crude extract against bacteria isolated from milk

Directory of Open Access Journals (Sweden)

João Paulo Ramos Costa

2011-12-01

Full Text Available The aim of this study was to evaluate the in vitro antimicrobial activity of Lippia sidoides essential oil (LsEO, popularly known as “rosemary-pepper”, and the Stryphnodendron adstringens dry crude extract (SaDCE, or “barbatimao”, against bacteria isolated from total milk flock, from small farms of northern Minas Gerais state. SaDCE was obtained from the peel of the vegetable through static distillation in ethanol 99.9% during eight days. LsEO was obtained through hydro-distillation of its fresh leaves. The bacteria Escherichia coli and Staphylococcus aureus isolated from milk underwent the test of disk-diffusion and minimum bacterial concentration (MBC, using concentrations of 320, 160, 80, 40, 20 and 0μl/mL of LsEO and 400, 200, 100, 50, 25 and 0mg/mL of SaDCE. All bacteria were sensitive to the vegetable extracts, except the Escherichia coli which was not inhibited by any test when SaDCE was used.

Optimization of Reciprocals and Square Roots on the i860 Microprocessor

DEFF Research Database (Denmark)

Sinclair, Robert

1996-01-01

The i860 microprocessor lacks both a divide and a square root instruction. The consequences of this for code involving many reciprocal square roots, such as many-body simulations involving Coulomb-like potentials, are discussed with a particular emphasis on high performance.......The i860 microprocessor lacks both a divide and a square root instruction. The consequences of this for code involving many reciprocal square roots, such as many-body simulations involving Coulomb-like potentials, are discussed with a particular emphasis on high performance....

Eyes are on us, but nobody cares: are eye cues relevant for strong reciprocity?

Science.gov (United States)

Fehr, Ernst; Schneider, Frédéric

2010-05-07

Strong reciprocity is characterized by the willingness to altruistically reward cooperative acts and to altruistically punish norm-violating, defecting behaviours. Recent evidence suggests that subtle reputation cues, such as eyes staring at subjects during their choices, may enhance prosocial behaviour. Thus, in principle, strong reciprocity could also be affected by eye cues. We investigate the impact of eye cues on trustees' altruistic behaviour in a trust game and find zero effect. Neither the subjects who are classified as prosocial nor the subjects who are classified as selfish respond to these cues. In sharp contrast to the irrelevance of subtle reputation cues for strong reciprocity, we find a large effect of explicit, pecuniary reputation incentives on the trustees' prosociality. Trustees who can acquire a good reputation that benefits them in future interactions honour trust much more than trustees who cannot build a good reputation. These results cast doubt on hypotheses suggesting that strong reciprocity is easily malleable by implicit reputation cues not backed by explicit reputation incentives.

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...

Development of Trust and Reciprocity in Adolescence

Science.gov (United States)

van den Bos, Wouter; Westenberg, Michiel; van Dijk, Eric; Crone, Eveline A.

2010-01-01

We investigate the development of two types of prosocial behavior, trust and reciprocity, as defined using a game-theoretical task that allows investigation of real-time social interaction, among 4 age groups from 9 to 25 years. By manipulating the possible outcome alternatives, we could distinguish among important determinants of trust and…

Reciprocity-based experimental determination of dynamic forces and moments: A feasibility study

Science.gov (United States)

Ver, Istvan L.; Howe, Michael S.

1994-01-01

BBN Systems and Technologies has been tasked by the Georgia Tech Research Center to carry Task Assignment No. 7 for the NASA Langley Research Center to explore the feasibility of 'In-Situ Experimental Evaluation of the Source Strength of Complex Vibration Sources Utilizing Reciprocity.' The task was carried out under NASA Contract No. NAS1-19061. In flight it is not feasible to connect the vibration sources to their mounting points on the fuselage through force gauges to measure dynamic forces and moments directly. However, it is possible to measure the interior sound field or vibration response caused by these structureborne sound sources at many locations and invoke principle of reciprocity to predict the dynamic forces and moments. The work carried out in the framework of Task 7 was directed to explore the feasibility of reciprocity-based measurements of vibration forces and moments.

Splines and their reciprocal-bases in volume-integral equations

International Nuclear Information System (INIS)

Sabbagh, H.A.

1993-01-01

The authors briefly outline the use of higher-order splines and their reciprocal-bases in discretizing the volume-integral equations of electromagnetics. The discretization is carried out by means of the method of moments, in which the expansion functions are the higher-order splines, and the testing functions are the corresponding reciprocal-basis functions. These functions satisfy an orthogonality condition with respect to the spline expansion functions. Thus, the method is not Galerkin, but the structure of the resulting equations is quite regular, nevertheless. The theory is applied to the volume-integral equations for the unknown current density, or unknown electric field, within a scattering body, and to the equations for eddy-current nondestructive evaluation. Numerical techniques for computing the matrix elements are also given

77 FR 63221 - Waiver of Requirement To Enter Into a Reciprocal Waiver of Claims Agreement With All Customers

Science.gov (United States)

2012-10-16

... To Enter Into a Reciprocal Waiver of Claims Agreement With All Customers AGENCY: Federal Aviation... a launch operator enter into a reciprocal waiver of claims with each customer. The FAA grants the... enter into a reciprocal waiver of claims (a ``cross-waiver'') with each of its customers. The FAA...

Dual Logic and Cerebral Coordinates for Reciprocal Interaction in Eye Contact

Science.gov (United States)

Lee, Ray F.

2015-01-01

In order to scientifically study the human brain’s response to face-to-face social interaction, the scientific method itself needs to be reconsidered so that both quantitative observation and symbolic reasoning can be adapted to the situation where the observer is also observed. In light of the recent development of dyadic fMRI which can directly observe dyadic brain interacting in one MRI scanner, this paper aims to establish a new form of logic, dual logic, which provides a theoretical platform for deductive reasoning in a complementary dual system with emergence mechanism. Applying the dual logic in the dfMRI experimental design and data analysis, the exogenous and endogenous dual systems in the BOLD responses can be identified; the non-reciprocal responses in the dual system can be suppressed; a cerebral coordinate for reciprocal interaction can be generated. Elucidated by dual logic deductions, the cerebral coordinate for reciprocal interaction suggests: the exogenous and endogenous systems consist of the empathy network and the mentalization network respectively; the default-mode network emerges from the resting state to activation in the endogenous system during reciprocal interaction; the cingulate plays an essential role in the emergence from the exogenous system to the endogenous system. Overall, the dual logic deductions are supported by the dfMRI experimental results and are consistent with current literature. Both the theoretical framework and experimental method set the stage to formally apply the scientific method in studying complex social interaction. PMID:25885446

Dual logic and cerebral coordinates for reciprocal interaction in eye contact.

Directory of Open Access Journals (Sweden)

Ray F Lee

Full Text Available In order to scientifically study the human brain's response to face-to-face social interaction, the scientific method itself needs to be reconsidered so that both quantitative observation and symbolic reasoning can be adapted to the situation where the observer is also observed. In light of the recent development of dyadic fMRI which can directly observe dyadic brain interacting in one MRI scanner, this paper aims to establish a new form of logic, dual logic, which provides a theoretical platform for deductive reasoning in a complementary dual system with emergence mechanism. Applying the dual logic in the dfMRI experimental design and data analysis, the exogenous and endogenous dual systems in the BOLD responses can be identified; the non-reciprocal responses in the dual system can be suppressed; a cerebral coordinate for reciprocal interaction can be generated. Elucidated by dual logic deductions, the cerebral coordinate for reciprocal interaction suggests: the exogenous and endogenous systems consist of the empathy network and the mentalization network respectively; the default-mode network emerges from the resting state to activation in the endogenous system during reciprocal interaction; the cingulate plays an essential role in the emergence from the exogenous system to the endogenous system. Overall, the dual logic deductions are supported by the dfMRI experimental results and are consistent with current literature. Both the theoretical framework and experimental method set the stage to formally apply the scientific method in studying complex social interaction.

Building Social Capital: How the news and the strength of the ties in the political discussion foster reciprocity

Directory of Open Access Journals (Sweden)

Alberto Ardèvol-Abreu

2018-03-01

Full Text Available Reciprocity, a social principle that emerges in non-negotiated, inter-personal exchange, is arguably a key construct in generating social capital. However, little research has made this empirical connection. Building on an Orientation-Stimulus-Reasoning-Orientation-Response model, this study advances a theoretical and empirical model in which news use and political discussion tie strength contributes to the development of reciprocity and social capital. Drawing on two-wave panel data, results suggest that reciprocity is a strong predictor of social capital. News media use also directly predicts reciprocity, as well as political discussion with both strong and weak ties, and social capital. Additionally, discussion with weak ties and reciprocity mediate the relationship between news use and social capital.

Journal for Juridical Science - Vol 28, No 3 (2003)

African Journals Online (AJOL)

Regime on foreign direct investment within the Southern African Development Community (SADC): a comparative study of foreign direct investment (FDI) laws of select Southern African countries. J Baloro, Q Nulliah. Trade in services: examples for SADC. PM Lehloenya. Dispute resolution in NAFTA and the WTO: a useful ...

ISSN 1727-3781

African Journals Online (AJOL)

mnyenti

2012-03-13

Mar 13, 2012 ... protect the rights of those likely to be affected. 4 .... geared towards the promotion of adequate social protection in the region. ..... management of SADC programmes, the implementation of decisions of SADC policy organs and .... services generally purchase a private health insurance policy or contribute ...

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.

Onsager Reciprocity in Premelting Solids

KAUST Repository

Peppin, S. S. L.; Spannuth, M. J.; Wettlaufer, J. S.

2009-01-01

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.

Reciprocity of mobile phone calls

OpenAIRE

Kovanen, Lauri; Saramaki, Jari; Kaski, Kimmo

2010-01-01

We present a study of the reciprocity of human behaviour based on mobile phone usage records. The underlying question is whether human relationships are mutual, in the sense that both are equally active in keeping up the relationship, or is it on the contrary typical that relationships are lopsided, with one party being significantly more active than the other. We study this question with the help of a mobile phone data set consisting of all mobile phone calls between 5.3 million customers of...

How is your day going? Reciprocity Norm in Everyday Communication.

Science.gov (United States)

Stocks, Eric L; Mirghassemi, Felicia; Oceja, Luis V

2016-07-21

In 6 experiments, we manipulated the length of a communication message to assess reciprocity norm-following behaviour during conversational interaction. In Studies 1 and 2, scripts of different length were used in an online chat, and chat logs were analysed. In Studies 3 and 4, participants e-mailed scripts that varied in length to acquaintances, and replies were analysed. In Studies 5 and 6, a confederate initiated conversations with either strangers or acquaintances and recorded the amount of time the person responded. The results suggest that conversation partners reciprocate length across different communication media, regardless of the depth of the information disclosed. © 2016 International Union of Psychological Science.

Generalized Staeckel transform and reciprocal transformations for finite-dimensional integrable systems

Energy Technology Data Exchange (ETDEWEB)

Sergyeyev, Artur [Mathematical Institute, Silesian University in Opava, Na RybnIcku 1, 746 01 Opava (Czech Republic); Blaszak, Maciej [Institute of Physics, A Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland)], E-mail: Artur.Sergyeyev@math.slu.cz, E-mail: blaszakm@amu.edu.pl

2008-03-14

We present a multiparameter generalization of the Staeckel transform (the latter is also known as the coupling-constant metamorphosis) and show that under certain conditions this generalized Staeckel transform preserves Liouville integrability, noncommutative integrability and superintegrability. The corresponding transformation for the equations of motion proves to be nothing but a reciprocal transformation of a special form, and we investigate the properties of this reciprocal transformation. Finally, we show that the Hamiltonians of the systems possessing separation curves of apparently very different form can be related through a suitably chosen generalized Staeckel transform.

Noncommutative reciprocity laws on algebraic surfaces: the case of tame ramification

Energy Technology Data Exchange (ETDEWEB)

Osipov, D V [Steklov Mathematical Institute of the Russian Academy of Sciences (Russian Federation)

2013-12-31

We prove noncommutative reciprocity laws on an algebraic surface defined over a perfect field. These reciprocity laws establish that some central extensions of globally constructed groups split over certain subgroups constructed by points or projective curves on a surface. For a two-dimensional local field with a last finite residue field, the local central extension which is constructed is isomorphic to the central extension which comes from the case of tame ramification of the Abelian two-dimensional local Langlands correspondence suggested by Kapranov. Bibliography: 9 titles.

Noncommutative reciprocity laws on algebraic surfaces: the case of tame ramification

International Nuclear Information System (INIS)

Osipov, D V

2013-01-01

We prove noncommutative reciprocity laws on an algebraic surface defined over a perfect field. These reciprocity laws establish that some central extensions of globally constructed groups split over certain subgroups constructed by points or projective curves on a surface. For a two-dimensional local field with a last finite residue field, the local central extension which is constructed is isomorphic to the central extension which comes from the case of tame ramification of the Abelian two-dimensional local Langlands correspondence suggested by Kapranov. Bibliography: 9 titles

Reciprocating piston pump system with screw drive

Science.gov (United States)

Perkins, Gerald S. (Inventor); Moore, Nicholas R. (Inventor)

1981-01-01

A pump system of the reciprocating piston type is described, which facilitates direct motor drive and cylinder sealing. A threaded middle potion of the piston is engaged by a nut connected to rotate with the rotor of an electric motor, in a manner that minimizes loading on the rotor by the use of a coupling that transmits torque to the nut but permits it to shift axially and radially with respect to the rotor. The nut has a threaded hydrostatic bearing for engaging the threaded piston portion, with an oil-carrying groove in the nut being interrupted. A fluid emitting seal located at the entrance to each cylinder, can serve to center the piston within the cylinder, wash the piston, and to aid in sealing. The piston can have a long stroke to diameter ratio to minimize reciprocations and wear on valves at high pressures. The voltage applied to the motor can be reversed prior to the piston reaching the end of its stroke, to permit pressure on the piston to aid in reversing the motor.

fMRI reveals reciprocal inhibition between social and physical cognitive domains

Science.gov (United States)

Jack, Anthony I.; Dawson, Abigail; Begany, Katelyn; Leckie, Regina L.; Barry, Kevin; Ciccia, Angela; Snyder, Abraham

2012-01-01

Two lines of evidence indicate that there exists a reciprocal inhibitory relationship between opposed brain networks. First, most attention-demanding cognitive tasks activate a stereotypical set of brain areas, known as the task-positive network and simultaneously deactivate a different set of brain regions, commonly referred to as the task negative or default mode network. Second, functional connectivity analyses show that these same opposed networks are anti-correlated in the resting state. We hypothesize that these reciprocally inhibitory effects reflect two incompatible cognitive modes, each of which is directed towards understanding the external world. Thus, engaging one mode activates one set of regions and suppresses activity in the other. We test this hypothesis by identifying two types of problem-solving task which, on the basis of prior work, have been consistently associated with the task positive and task negative regions: tasks requiring social cognition, i.e., reasoning about the mental states of other persons, and tasks requiring physical cognition, i.e., reasoning about the causal/mechanical properties of inanimate objects. Social and mechanical reasoning tasks were presented to neurologically normal participants during fMRI. Each task type was presented using both text and video clips. Regardless of presentation modality, we observed clear evidence of reciprocal suppression: social tasks deactivated regions associated with mechanical reasoning and mechanical tasks deactivated regions associated with social reasoning. These findings are not explained by self-referential processes, task engagement, mental simulation, mental time travel or external vs. internal attention, all factors previously hypothesized to explain default mode network activity. Analyses of resting state data revealed a close match between the regions our tasks identified as reciprocally inhibitory and regions of maximal anti-correlation in the resting state. These results indicate

fMRI reveals reciprocal inhibition between social and physical cognitive domains.

Science.gov (United States)

Jack, Anthony I; Dawson, Abigail J; Begany, Katelyn L; Leckie, Regina L; Barry, Kevin P; Ciccia, Angela H; Snyder, Abraham Z

2013-02-01

Two lines of evidence indicate that there exists a reciprocal inhibitory relationship between opposed brain networks. First, most attention-demanding cognitive tasks activate a stereotypical set of brain areas, known as the task-positive network and simultaneously deactivate a different set of brain regions, commonly referred to as the task negative or default mode network. Second, functional connectivity analyses show that these same opposed networks are anti-correlated in the resting state. We hypothesize that these reciprocally inhibitory effects reflect two incompatible cognitive modes, each of which may be directed towards understanding the external world. Thus, engaging one mode activates one set of regions and suppresses activity in the other. We test this hypothesis by identifying two types of problem-solving task which, on the basis of prior work, have been consistently associated with the task positive and task negative regions: tasks requiring social cognition, i.e., reasoning about the mental states of other persons, and tasks requiring physical cognition, i.e., reasoning about the causal/mechanical properties of inanimate objects. Social and mechanical reasoning tasks were presented to neurologically normal participants during fMRI. Each task type was presented using both text and video clips. Regardless of presentation modality, we observed clear evidence of reciprocal suppression: social tasks deactivated regions associated with mechanical reasoning and mechanical tasks deactivated regions associated with social reasoning. These findings are not explained by self-referential processes, task engagement, mental simulation, mental time travel or external vs. internal attention, all factors previously hypothesized to explain default mode network activity. Analyses of resting state data revealed a close match between the regions our tasks identified as reciprocally inhibitory and regions of maximal anti-correlation in the resting state. These results

Polar-phase indices of perioral muscle reciprocity during syllable production in Parkinson's disease.

Science.gov (United States)

Chu, Shin Ying; Barlow, Steven M; Lee, Jaehoon; Wang, Jingyan

2017-12-01

This research characterised perioral muscle reciprocity and amplitude ratio in lower lip during bilabial syllable production [pa] at three rates to understand the neuromotor dynamics and scaling of motor speech patterns in individuals with Parkinson's disease (PD). Electromyographic (EMG) signals of the orbicularis oris superior [OOS], orbicularis oris inferior [OOI] and depressor labii inferioris [DLI] were recorded during syllable production and expressed as polar-phase notations. PD participants exhibited the general features of reciprocity between OOS, OOI and DLI muscles as reflected in the EMG during syllable production. The control group showed significantly higher integrated EMG amplitude ratio in the DLI:OOS muscle pairs than PD participants. No speech rate effects were found in EMG muscle reciprocity and amplitude magnitude across all muscle pairs. Similar patterns of muscle reciprocity in PD and controls suggest that corticomotoneuronal output to the facial nucleus and respective perioral muscles is relatively well-preserved in our cohort of mild idiopathic PD participants. Reduction of EMG amplitude ratio among PD participants is consistent with the putative reduction in the thalamocortical activation characteristic of this disease which limits motor cortex drive from generating appropriate commands which contributes to bradykinesia and hypokinesia of the orofacial mechanism.

Duality and reciprocity of fluctuation-dissipation relations in conductors.

Science.gov (United States)

Reggiani, Lino; Alfinito, Eleonora; Kuhn, Tilmann

2016-09-01

By analogy with linear response, we formulate the duality and reciprocity properties of current and voltage fluctuations expressed by Nyquist relations, including the intrinsic bandwidths of the respective fluctuations. For this purpose, we individuate total-number and drift-velocity fluctuations of carriers inside a conductor as the microscopic sources of noise. The spectral densities at low frequency of the current and voltage fluctuations and the respective conductance and resistance are related in a mutually exclusive way to the corresponding noise source. The macroscopic variances of current and voltage fluctuations are found to display a dual property via a plasma conductance that admits a reciprocal plasma resistance. Analogously, the microscopic noise sources are found to obey a dual property and a reciprocity relation. The formulation is carried out in the frame of the grand canonical (for current noise) and canonical (for voltage noise) ensembles, and results are derived that are valid for classical as well as degenerate statistics, including fractional exclusion statistics. The unifying theory so developed sheds new light on the microscopic interpretation of dissipation and fluctuation phenomena in conductors. In particular, it is proven that for fermions, as a consequence of the Pauli principle, nonvanishing single-carrier velocity fluctuations at zero temperature are responsible for diffusion but not for current noise, which vanishes in this limit.

RECIPROCITY PRINCIPLE AS THE FOUNDATION FOR SOCIAL ECONOMY MANIFESTATION

Directory of Open Access Journals (Sweden)

GRAȚIELA MIHAELA FERARU

2017-12-01

Full Text Available Social economy appears as a bilateral impulse that gathers potential customers and professionals who secure the demand and the supply for services. Therefore, needs turn from individual to collective and allow the persons involved to identify new needs and to respond to them by mobilizing public or voluntary resources. A social enterprise interacts both with market and public sector when operating in complex areas where the state is involved. Once established, they tend to form a hybrid economic model in which the commercial activities (self-financed by selling goods or performing services, non-market but monetary (public financing, donations from churches and foundations and non-market ones (voluntary work of its members or others combine. The ability to gather various forms of economic activity in an entrepreneurial framework as well as the ability to engage customers and service performers in a democratic decision making process, based on reciprocity principle, offers a regulatory role to social economy. Reciprocity as an economic principle ensures the main instrument to distinguish what is essential and constant regarding social economy from what is secondary and transitory. Reciprocity enables the manifestation of the practices and economic resources mobilization forms with the scope of satisfying human needs that do not belong to profit seeking organizations nor to the public institutions.

Study on reciprocal relation of pore water pressure with genetic algorithm and neural network model (Contract research)

International Nuclear Information System (INIS)

Seno, Shoji; Nakajima, Makoto; Toida, Masaru; Kunimaru, Takanori; Watanabe, Kunio; Sohail Ahmed Rai

2009-12-01

Horonobe Underground Research Center has carried out the Horonobe Underground Research Laboratory Project which is a comprehensive research project to investigate the deep geological environment within sedimentary rock. In this project, long-term observation of the pore water pressure has been conducted with monitoring systems introduced in 9 of 11 boreholes drilled in phase I (surface-based investigation). Since August 2003 the monitoring systems have been settled successively in the boreholes, and a certain amount of the pore water pressure data has been already accumulated. Using 6 borehole data (HDB-1,3,6,7,8,9) among this, this report summarized the result of a study on reciprocal relation of pore water pressure to investigate the hydrogeological environment of this site. At first, to exclude the influences of working of nature such as tide and atmospheric pressure from the source data, an analysis with Bayesian model was progressed. As the result of the estimation of these influences calculated by BAYTAP-G (Bayesian Tidal Analysis Program Grouping Model), it was found that the influence of the atmospheric pressure was comparatively large and that of tide was comparatively small. Secondly, an analysis on the reciprocal relation of the pore water pressure was carried out to investigate the relation between the different depth points of the same borehole and the relation between different boreholes. As the result of the calculations with genetic algorithm (GA) and neural network models (BPANN, GAANN), it was found that estimation by GA models was better than other models in the case where analyzing data included radical changes. And the result also showed that in regions lower than GL.-400m of HDB-3,6,7,8, the pore water pressures change in the same manner. These results indicate the effectiveness of this analysis method. (author)

Film, Parable, Reciprocity. Frederick Wiseman’s “Reality Fictions” and Social Change

Directory of Open Access Journals (Sweden)

Alyda Faber

2016-11-01

Full Text Available This essay argues that social criticism may be an effect of Frederick Wiseman’s “re¬ality fiction” films only if that effect is understood as analogous to that of parable, an awakened responsiveness to the unknown and the unresolved. The irresolution witnessed repeatedly in his films is the reality of “radical inequality” within institu¬tions in democracy, with domination ranging from explicit exploitative relations to subtle aural and bodily cues. Within those relations, Wiseman opens up the space of parable as a vision and practice of reciprocity and more-than-reciprocity through, among others, filmic strategies of “lyric portraiture” and expressive “democratic noise”. Furthermore, Wiseman’s camera extends more-than-reciprocity to animals in a filmic style that shows human and animal relations as visceral markers of what otherwise might remain unseen in human-to-human relations.

Using video modeling to teach reciprocal pretend play to children with autism.

Science.gov (United States)

MacDonald, Rebecca; Sacramone, Shelly; Mansfield, Renee; Wiltz, Kristine; Ahearn, William H

2009-01-01

The purpose of the present study was to use video modeling to teach children with autism to engage in reciprocal pretend play with typically developing peers. Scripted play scenarios involving various verbalizations and play actions with adults as models were videotaped. Two children with autism were each paired with a typically developing child, and a multiple-probe design across three play sets was used to evaluate the effects of the video modeling procedure. Results indicated that both children with autism and the typically developing peers acquired the sequences of scripted verbalizations and play actions quickly and maintained this performance during follow-up probes. In addition, probes indicated an increase in the mean number of unscripted verbalizations as well as reciprocal verbal interactions and cooperative play. These findings are discussed as they relate to the development of reciprocal pretend-play repertoires in young children with autism.

Hidden symmetry of the beam spread function resulting from the reciprocity theorem

International Nuclear Information System (INIS)

Dolin, Lev S.

2016-01-01

It is shown that the optical reciprocity theorem imposes certain constraints on the radiation field structure of a unidirectional point source (beam spread function (BSF)) in a turbid medium with spatially uniform optical properties. To satisfy the reciprocal relation, the BSF should have an additional symmetry property along with axial symmetry. This paper mathematically formulates the BSF symmetry condition that follows from the reciprocity theorem and discusses test results of some approximate analytical BSF models for their compliance with the symmetry requirement. A universal method for eliminating symmetry errors of approximate BSF models is proposed. - Highlights: • Symmetry properties of beam spread function (BSF) are considered. • In uniform turbid medium BSF has hidden symmetry property besides axial symmetry. • The examples of BSF models with and without the required symmetry are given. • A universal method for BSF symmetry error elimination is proposed.

Overcoming selfishness: reciprocity, inhibition, and cardiac-autonomic control in the ultimatum game.

Science.gov (United States)

Sütterlin, Stefan; Herbert, Cornelia; Schmitt, Michael; Kübler, Andrea; Vögele, Claus

2011-01-01

The processes underlying decision-making in response to unfair offers in the ultimatum game (UG) have recently been discussed in light of models of reciprocity and fairness-related behavior. It has been suggested that behavior following norm-oriented, internalized expectations of reciprocity requires overcoming economic self-interest. In this study we investigated both, behavioral and peripheral-physiological indicators of inhibitory capacity related to neuronal networks that are likely to be involved in the behavioral response to unfair offers. Both heart-rate variability as an index of inhibitory capacity, and performance in a motor response inhibition task predicted rejection of unfair offers in an UG, suggesting an important role of inhibitory processes in overcoming economic temptations and regulating behavior conforming to social norms of reciprocity and fairness. The role of parasympathetic activity as a physiological trait-marker predicting inter-individual differences in the rejection of unfair offers is discussed.

Host microenvironment in breast cancer development: Inflammatory cells, cytokines and chemokines in breast cancer progression: reciprocal tumor–microenvironment interactions

International Nuclear Information System (INIS)

Ben-Baruch, A

2003-01-01

A comprehensive overview of breast cancer development and progression suggests that the process is influenced by intrinsic properties of the tumor cells, as well as by microenvironmental factors. Indeed, in breast carcinoma, an intensive interplay exists between the tumor cells on one hand, and inflammatory cells/cytokines/chemokines on the other. The purpose of the present review is to outline the reciprocal interactions that exist between these different elements, and to shed light on their potential involvement in breast cancer development and progression

Organization of intrinsic functional brain connectivity predicts decisions to reciprocate social behavior.

Science.gov (United States)

Cáceda, Ricardo; James, G Andrew; Gutman, David A; Kilts, Clinton D

2015-10-01

Reciprocation of trust exchanges is central to the development of interpersonal relationships and societal well-being. Understanding how humans make pro-social and self-centered decisions in dyadic interactions and how to predict these choices has been an area of great interest in social neuroscience. A functional magnetic resonance imaging (fMRI) based technology with potential clinical application is the study of resting state brain connectivity. We tested if resting state connectivity may predict choice behavior in a social context. Twenty-nine healthy adults underwent resting state fMRI before performing the Trust Game, a two person monetary exchange game. We assessed the ability of patterns of resting-state functional brain organization, demographic characteristics and a measure of moral development, the Defining Issues Test (DIT-2), to predict individuals' decisions to reciprocate money during the Trust Game. Subjects reciprocated in 74.9% of the trials. Independent component analysis identified canonical resting-state networks. Increased functional connectivity between the salience (bilateral insula/anterior cingulate) and central executive (dorsolateral prefrontal cortex/ posterior parietal cortex) networks significantly predicted the choice to reciprocate pro-social behavior (R(2) = 0.20, p = 0.015). Stepwise linear regression analysis showed that functional connectivity between these two networks (p = 0.002), age (p = 0.007) and DIT-2 personal interest schema score (p = 0.032) significantly predicted reciprocity behavior (R(2) = 0.498, p = 0.001). Intrinsic functional connectivity between neural networks in conjunction with other individual characteristics may be a valuable tool for predicting performance during social interactions. Future replication and temporal extension of these findings may bolster the understanding of decision making in clinical, financial and marketing settings. Copyright © 2015 Elsevier B.V. All rights reserved.

No longer in suspense: Clarifying the human rights jurisdiction of the ...

African Journals Online (AJOL)

Unfortunately, the same judgment resulted in the suspension of the SADC Tribunal in 2010 because it had purportedly acted beyond its mandate when it adjudicated over a case concerning a human rights dispute. This article investigates whether the SADC Tribunal had jurisdiction to deal with cases involving allegations of ...

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 gener...... both enhance and reduce welfare, relative to the situation where all players have materialistic perferences....

Microflown based monopole sound sources for reciprocal measurements

NARCIS (Netherlands)

Bree, H.E. de; Basten, T.G.H.

2008-01-01

Monopole sound sources (i.e. omni directional sound sources with a known volume velocity) are essential for reciprocal measurements used in vehicle interior panel noise contribution analysis. Until recently, these monopole sound sources use a sound pressure transducer sensor as a reference sensor. A

Comparative evaluation of fracture and defect in reciproc and rotary files in severe curved root canals