Myozenin: An α-actinin- and γ-filamin-binding protein of skeletal muscle Z lines

PubMed Central

Takada, Fumio; Woude, Douglas L. Vander; Tong, Hui-Qi; Thompson, Terri G.; Watkins, Simon C.; Kunkel, Louis M.; Beggs, Alan H.

2001-01-01

To better understand the structure and function of Z lines, we used sarcomeric isoforms of α-actinin and γ-filamin to screen a human skeletal muscle cDNA library for interacting proteins by using the yeast two-hybrid system. Here we describe myozenin (MYOZ), an α-actinin- and γ-filamin-binding Z line protein expressed predominantly in skeletal muscle. Myozenin is predicted to be a 32-kDa, globular protein with a central glycine-rich domain flanked by α-helical regions with no strong homologies to any known genes. The MYOZ gene has six exons and maps to human chromosome 10q22.1-q22.2. Northern blot analysis demonstrated that this transcript is expressed primarily in skeletal muscle with significantly lower levels of expression in several other tissues. Antimyozenin antisera stain skeletal muscle in a sarcomeric pattern indistinguishable from that seen by using antibodies for α-actinin, and immunogold electron microscopy confirms localization specifically to Z lines. Thus, myozenin is a skeletal muscle Z line protein that may be a good candidate gene for limb-girdle muscular dystrophy or other neuromuscular disorders. PMID:11171996

Filamin A regulates the organization and remodeling of the pericellular collagen matrix.

PubMed

Mezawa, Masaru; Pinto, Vanessa I; Kazembe, Mwayi P; Lee, Wilson S; McCulloch, Christopher A

2016-10-01

Extracellular matrix remodeling by cell adhesion-related processes is critical for proliferation and tissue homeostasis, but how adhesions and the cytoskeleton interact to organize the pericellular matrix (PCM) is not understood. We examined the role of the actin-binding protein, filamin A (FLNa), in pericellular collagen remodeling. Compared with wild-type (WT), mice with fibroblast-specific deletion of FLNa exhibited higher density but reduced organization of collagen fibers after increased loading of the periodontal ligament for 2 wk. In cultured fibroblasts, FLNa knockdown (KD) did not affect collagen mRNA, but after 24 h of culture, FLNa WT cells exhibited ∼2-fold higher cell-surface collagen KD cells and 13-fold higher levels of activated β1 integrins. In FLNa WT cells, there was 3-fold more colocalization of talin with pericellular cleaved collagen than in FLNa KD cells. MMP-9 mRNA and protein expression were >2-fold higher in FLNa KD cells than in WT cells. Cathepsin B, which is necessary for intracellular collagen digestion, was >3-fold higher in FLNa WT cells than in KD cells. FLNa WT cells exhibited 2-fold more collagen phagocytosis than KD cells, which involved the FLNa actin-binding domain. Evidently, FLNa regulates PCM remodeling through its effects on degradation pathways that affect the abundance and organization of collagen.-Mezawa, M., Pinto, V. I., Kazembe, M. P., Lee, W. S., McCulloch, C. A. Filamin A regulates the organization and remodeling of the pericellular collagen matrix. © FASEB.

Does Facial Resemblance Enhance Cooperation?

PubMed Central

Giang, Trang; Bell, Raoul; Buchner, Axel

2012-01-01

Facial self-resemblance has been proposed to serve as a kinship cue that facilitates cooperation between kin. In the present study, facial resemblance was manipulated by morphing stimulus faces with the participants' own faces or control faces (resulting in self-resemblant or other-resemblant composite faces). A norming study showed that the perceived degree of kinship was higher for the participants and the self-resemblant composite faces than for actual first-degree relatives. Effects of facial self-resemblance on trust and cooperation were tested in a paradigm that has proven to be sensitive to facial trustworthiness, facial likability, and facial expression. First, participants played a cooperation game in which the composite faces were shown. Then, likability ratings were assessed. In a source memory test, participants were required to identify old and new faces, and were asked to remember whether the faces belonged to cooperators or cheaters in the cooperation game. Old-new recognition was enhanced for self-resemblant faces in comparison to other-resemblant faces. However, facial self-resemblance had no effects on the degree of cooperation in the cooperation game, on the emotional evaluation of the faces as reflected in the likability judgments, and on the expectation that a face belonged to a cooperator rather than to a cheater. Therefore, the present results are clearly inconsistent with the assumption of an evolved kin recognition module built into the human face recognition system. PMID:23094095

Teaching Cooperation to Enhance Creativity--Theoretical Rationale.

ERIC Educational Resources Information Center

Herrick, James; Herrick, Penny

The paper discusses the major components of creativity, the relationship of competition and cooperation to creativity, and a model for teaching cooperation to enhance creativity. Creative behavior is directed toward the imaginative construction of what is desired and its eventual actualization in everyday life. Components of creativity include…

Peer pressure: enhancement of cooperation through mutual punishment.

PubMed

Yang, Han-Xin; Wu, Zhi-Xi; Rong, Zhihai; Lai, Ying-Cheng

2015-02-01

An open problem in evolutionary game dynamics is to understand the effect of peer pressure on cooperation in a quantitative manner. Peer pressure can be modeled by punishment, which has been proved to be an effective mechanism to sustain cooperation among selfish individuals. We investigate a symmetric punishment strategy, in which an individual will punish each neighbor if their strategies are different, and vice versa. Because of the symmetry in imposing the punishment, one might intuitively expect the strategy to have little effect on cooperation. Utilizing the prisoner's dilemma game as a prototypical model of interactions at the individual level, we find, through simulation and theoretical analysis, that proper punishment, when even symmetrically imposed on individuals, can enhance cooperation. Also, we find that the initial density of cooperators plays an important role in the evolution of cooperation driven by mutual punishment.

Peer pressure: Enhancement of cooperation through mutual punishment

NASA Astrophysics Data System (ADS)

Yang, Han-Xin; Wu, Zhi-Xi; Rong, Zhihai; Lai, Ying-Cheng

2015-02-01

An open problem in evolutionary game dynamics is to understand the effect of peer pressure on cooperation in a quantitative manner. Peer pressure can be modeled by punishment, which has been proved to be an effective mechanism to sustain cooperation among selfish individuals. We investigate a symmetric punishment strategy, in which an individual will punish each neighbor if their strategies are different, and vice versa. Because of the symmetry in imposing the punishment, one might intuitively expect the strategy to have little effect on cooperation. Utilizing the prisoner's dilemma game as a prototypical model of interactions at the individual level, we find, through simulation and theoretical analysis, that proper punishment, when even symmetrically imposed on individuals, can enhance cooperation. Also, we find that the initial density of cooperators plays an important role in the evolution of cooperation driven by mutual punishment.

An adventitious interaction of filamin A with RhoGDI2(Tyr153Glu)

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

Song, Mia; He, Qianjing; Berk, Benjamin-Andreas

2016-01-15

Filamin A (FLNA) is an actin filament crosslinking protein with multiple intracellular binding partners. Mechanical force exposes cryptic FLNA binding sites for some of these ligands. To identify new force-dependent binding interactions, we used a fusion construct composed of two FLNA domains, one of which was previously identified as containing a force-dependent binding site as a bait in a yeast two-hybrid system and identified the Rho dissociation inhibitor 2 (RhoGDI2) as a potential interacting partner. A RhoGDI2 truncate with 81 N-terminal amino acid residues and a phosphomimetic mutant, RhoGDI(Tyr153Glu) interacted with the FLNA construct. However, neither wild-type or full-length RhoGDI2 phosphorylatedmore » at Y153 interacted with FLNA. Our interpretation of these contradictions is that truncation and/or mutation of RhoGDI2 perturbs its conformation to expose a site that adventitiously binds FLNA and is not a bona–fide interaction. Therefore, previous studies reporting that a RhoGDI(Y153E) mutant suppresses the metastasis of human bladder cancer cells must be reinvestigated in light of artificial interaction of this point mutant with FLNA. - Highlights: • RhoGDI2 is identified as a potential filamin A (FLNA)-binding partner. • Phosphomimetic mutant, RhoGDI2(Tyr153Glu) interacts with FLNA. • RhoGDI2 phosphorylated (Tyr153) by src kinase does not interact with FLNA. • Mutation of Tyr-153 to Glu of RhoGDI2 does not mimic phosphorylation. • RhoGDI2(Tyr153Glu) provokes an adventitious interaction with FLNA.« less

The increased risk of predation enhances cooperation

PubMed Central

Krams, Indrikis; Bērziņš, Arnis; Krama, Tatjana; Wheatcroft, David; Igaune, Kristīne; Rantala, Markus J.

2010-01-01

Theory predicts that animals in adverse conditions can decrease individual risks and increase long-term benefits by cooperating with neighbours. However, some empirical studies suggest that animals often focus on short-term benefits, which can reduce the likelihood that they will cooperate with others. In this experimental study, we tested between these two alternatives by evaluating whether increased predation risk (as a correlate of environmental adversity) enhances or diminishes the occurrence of cooperation in mobbing, a common anti-predator behaviour, among breeding pied flycatchers Ficedula hypoleuca. We tested whether birds would join their mobbing neighbours more often and harass a stuffed predator placed near their neighbours' nests more intensely in areas with a higher perceived risk of predation. Our results show that birds attended mobs initiated by their neighbours more often, approached the stuffed predator significantly more closely, and mobbed it at a higher intensity in areas where the perceived risk of predation was experimentally increased. In such high-risk areas, birds also were more often involved in between-pair cooperation. This study demonstrates the positive impact of predation risk on cooperation in breeding songbirds, which might help in explaining the emergence and evolution of cooperation. PMID:19846454

Hypoxia-induced expression of VE-cadherin and filamin B in glioma cell cultures and pseudopalisade structures.

PubMed

Nissou, Marie-France; El Atifi, Michèle; Guttin, Audrey; Godfraind, Catherine; Salon, Caroline; Garcion, Emmanuel; van der Sanden, Boudewijn; Issartel, Jean-Paul; Berger, François; Wion, Didier

2013-06-01

Most of our knowledge regarding glioma cell biology comes from cell culture experiments. For many years the standards for glioma cell culture were the use of cell lines cultured in the presence of serum and 20 % O2. However, in vivo, normoxia in many brain areas is in close to 3 % O2. Hence, in cell culture, the experimental value referred as the norm is hyperoxic compared to any brain physiological value. Likewise, cells in vivo are not usually exposed to serum, and low-passaged glioma neurosphere cultures maintained in serum-free medium is emerging as a new standard. A consequence of changing the experimental normoxic standard from 20 % O2 to the more brain physiological value of 3 % O2, is that a 3 % O2 normoxic reference point enabled a more rigorous characterization of the level of regulation of genes by hypoxia. Among the glioma hypoxia-regulated genes characterized using this approach we found VE-cadherin that is required for blood vessel formation, and filamin B a gene involved in endothelial cell motility. Both VE-cadherin and filamin B were found expressed in pseudopalisades, a glioblastoma pathognomonic structure made of hypoxic migrating cancer cells. These results provide additional clues on the role played by hypoxia in the acquisition of endothelial traits by glioma cells and on the functional links existing between pseudopalisades, hypoxia, and tumor progression.

A novel Amoeba proteus 120 kDa actin-binding protein with only 1 filamin repeat and a coiled-coil region.

PubMed

Sobczak, Magdalena; Kocik, Elzbieta; Redowicz, Maria Jolanta

2007-02-01

A novel 120 kDa actin-binding protein (ApABP-F1) was found in Amoeba proteus. It was distributed throughout the cytoplasm, mainly in the subplasma membrane and perinuclear-nuclear areas, enriched in actin. The full-length cDNA of ApABP consisted of 2672 nucleotides with an open reading frame of 878 amino acids, giving a ~95 kDa protein with a theoretical pI value of 5.11. It had a novel domain organization pattern: the N terminus (residues 1-104) contained 1 calponin-homology (CH) domain, followed by only 1 region that was homologous to the filamin repeat (FR, residues 209-324), and a central region (residues 344-577) exhibiting a very high probability of coiled-coil formation, probably engaged in the observed protein dimerization. A phylogenetic tree constructed for CH domains from 25 various proteins revealed that the CH domain of ApABP was most related to that of the hypothetical mouse KIAA0903-like protein, whereas not much relationship to either filamins or the gelation factor (ABP-120) of Dictyostelium discoideum and Entamoeba histolytica was found.

New role for space station—Enhanced cooperation with Russia?

NASA Astrophysics Data System (ADS)

Leath, Audrey T.

The Clinton administration's recent discussions with Russia on enhanced space cooperation and a possible joint space station prompted a two-part hearing by the House Science Subcommittee on Space, held on October 6 and 14. Subcommittee members, citing rumors and news stories about a joint station, questioned Presidential Science Advisor Jack Gibbons and NASA Administrator Daniel Goldin on the status of the proposed cooperation and heard from additional witnesses regarding the feasibility of and support for the concept.Gibbons reassured subcommittee members that no decision has yet been made on Russian cooperation, and that Congress would be consulted in the process. He explained that, after the Vancouver Summit, establishment of a Joint Commission headed by Vice President Gore and Russian Prime Minister Chernomyrdin provided an opportunity for enhanced cooperation in space, as well as in such other areas as energy, nuclear safety, the environment, business development, science and technology, and defense diversification. Gibbons testified that the study of a cooperative station program took place concurrently with NASA's work on defining the redesigned U.S. space station, now being referred to as “Alpha.” He affirmed that while Alpha's modular design made it adaptable to a joint effort, it could “be built independent of any Russian participation.”

Filamin and Phospholipase C-ε Are Required for Calcium Signaling in the Caenorhabditis elegans Spermatheca

PubMed Central

Kovacevic, Ismar; Orozco, Jose M.; Cram, Erin J.

2013-01-01

The Caenorhabditis elegans spermatheca is a myoepithelial tube that stores sperm and undergoes cycles of stretching and constriction as oocytes enter, are fertilized, and exit into the uterus. FLN-1/filamin, a stretch-sensitive structural and signaling scaffold, and PLC-1/phospholipase C-ε, an enzyme that generates the second messenger IP3, are required for embryos to exit normally after fertilization. Using GCaMP, a genetically encoded calcium indicator, we show that entry of an oocyte into the spermatheca initiates a distinctive series of IP3-dependent calcium oscillations that propagate across the tissue via gap junctions and lead to constriction of the spermatheca. PLC-1 is required for the calcium release mechanism triggered by oocyte entry, and FLN-1 is required for timely initiation of the calcium oscillations. INX-12, a gap junction subunit, coordinates propagation of the calcium transients across the spermatheca. Gain-of-function mutations in ITR-1/IP3R, an IP3-dependent calcium channel, and loss-of-function mutations in LFE-2, a negative regulator of IP3 signaling, increase calcium release and suppress the exit defect in filamin-deficient animals. We further demonstrate that a regulatory cassette consisting of MEL-11/myosin phosphatase and NMY-1/non-muscle myosin is required for coordinated contraction of the spermatheca. In summary, this study answers long-standing questions concerning calcium signaling dynamics in the C. elegans spermatheca and suggests FLN-1 is needed in response to oocyte entry to trigger calcium release and coordinated contraction of the spermathecal tissue. PMID:23671426

Synchronized movement experience enhances peer cooperation in preschool children.

PubMed

Rabinowitch, Tal-Chen; Meltzoff, Andrew N

2017-08-01

Cooperating with other people is a key achievement in child development and is essential for human culture. We examined whether we could induce 4-year-old children to increase their cooperation with an unfamiliar peer by providing the peers with synchronized motion experience prior to the tasks. Children were randomly assigned to independent treatment and control groups. The treatment of synchronous motion caused children to enhance their cooperation, as measured by the speed of joint task completion, compared with control groups that underwent asynchronous motion or no motion at all. Further analysis suggested that synchronization experience increased intentional communication between peer partners, resulting in increased coordination and cooperation. Copyright © 2017 Elsevier Inc. All rights reserved.

75 FR 9380 - Cooperative Conservation Partners Initiative; Wetlands Reserve Enhancement Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-02

... Corporation Cooperative Conservation Partners Initiative; Wetlands Reserve Enhancement Program AGENCY...: Notice of request for proposals through the Mississippi River Basin Healthy Watersheds Initiative... (FY) 2010 for up to $50 million in the Cooperative Conservation Partnership Initiative (CCPI) and $25...

A case of boomerang dysplasia with a novel causative mutation in filamin B: identification of typical imaging findings on ultrasonography and 3D-CT imaging.

PubMed

Tsutsumi, Seiji; Maekawa, Ayako; Obata, Miyuki; Morgan, Timothy; Robertson, Stephen P; Kurachi, Hirohisa

2012-01-01

Boomerang dysplasia is a rare lethal osteochondrodysplasia characterized by disorganized mineralization of the skeleton, leading to complete nonossification of some limb bones and vertebral elements, and a boomerang-like aspect to some of the long tubular bones. Like many short-limbed skeletal dysplasias with accompanying thoracic hypoplasia, the potential lethality of the phenotype can be difficult to ascertain prenatally. We report a case of boomerang dysplasia prenatally diagnosed by use of ultrasonography and 3D-CT imaging, and identified a novel mutation in the gene encoding the cytoskeletal protein filamin B (FLNB) postmortem. Findings that aided the radiological diagnosis of this condition in utero included absent ossification of two out of three long bones in each limb and elements of the vertebrae and a boomerang-like shape to the ulnae. The identified mutation is the third described for this disorder and is predicted to lead to amino acid substitution in the actin-binding domain of the filamin B molecule. Copyright © 2012 S. Karger AG, Basel.

Using technology-enhanced, cooperative, group-project learning for student comprehension and academic performance

NASA Astrophysics Data System (ADS)

Tlhoaele, Malefyane; Suhre, Cor; Hofman, Adriaan

2016-05-01

Cooperative learning may improve students' motivation, understanding of course concepts, and academic performance. This study therefore enhanced a cooperative, group-project learning technique with technology resources to determine whether doing so improved students' deep learning and performance. A sample of 118 engineering students, randomly divided into two groups, participated in this study and provided data through questionnaires issued before and after the experiment. The results, obtained through analyses of variance and structural equation modelling, reveal that technology-enhanced, cooperative, group-project learning improves students' comprehension and academic performance.

Network flow of mobile agents enhances the evolution of cooperation

NASA Astrophysics Data System (ADS)

Ichinose, G.; Satotani, Y.; Nagatani, T.

2018-01-01

We study the effect of contingent movement on the persistence of cooperation on complex networks with empty nodes. Each agent plays the Prisoner's Dilemma game with its neighbors and then it either updates the strategy depending on the payoff difference with neighbors or it moves to another empty node if not satisfied with its own payoff. If no neighboring node is empty, each agent stays at the same site. By extensive evolutionary simulations, we show that the medium density of agents enhances cooperation where the network flow of mobile agents is also medium. Moreover, if the movements of agents are more frequent than the strategy updating, cooperation is further promoted. In scale-free networks, the optimal density for cooperation is lower than other networks because agents get stuck at hubs. Our study suggests that keeping a smooth network flow is significant for the persistence of cooperation in ever-changing societies.

Exponentially Enhanced Light-Matter Interaction, Cooperativities, and Steady-State Entanglement Using Parametric Amplification

NASA Astrophysics Data System (ADS)

Qin, Wei; Miranowicz, Adam; Li, Peng-Bo; Lü, Xin-You; You, J. Q.; Nori, Franco

2018-03-01

We propose an experimentally feasible method for enhancing the atom-field coupling as well as the ratio between this coupling and dissipation (i.e., cooperativity) in an optical cavity. It exploits optical parametric amplification to exponentially enhance the atom-cavity interaction and, hence, the cooperativity of the system, with the squeezing-induced noise being completely eliminated. Consequently, the atom-cavity system can be driven from the weak-coupling regime to the strong-coupling regime for modest squeezing parameters, and even can achieve an effective cooperativity much larger than 100. Based on this, we further demonstrate the generation of steady-state nearly maximal quantum entanglement. The resulting entanglement infidelity (which quantifies the deviation of the actual state from a maximally entangled state) is exponentially smaller than the lower bound on the infidelities obtained in other dissipative entanglement preparations without applying squeezing. In principle, we can make an arbitrarily small infidelity. Our generic method for enhancing atom-cavity interaction and cooperativities can be implemented in a wide range of physical systems, and it can provide diverse applications for quantum information processing.

Enhancing Instruction through Constructivism, Cooperative Learning, and Cloud Computing

ERIC Educational Resources Information Center

Denton, David W.

2012-01-01

Cloud computing technologies, such as Google Docs and Microsoft Office Live, have the potential to enhance instructional methods predicated on constructivism and cooperative learning. Cloud-based application features like file sharing and online publishing are prompting departments of education across the nation to adopt these technologies.…

75 FR 73027 - Cooperative Conservation Partnership Initiative and Wetlands Reserve Enhancement Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-29

... Corporation Cooperative Conservation Partnership Initiative and Wetlands Reserve Enhancement Program AGENCY... Initiative. SUMMARY: The Natural Resources Conservation Service (NRCS) announces the availability of... Partnership Initiative (CCPI) and up to $25 million in the Wetlands Reserve Enhancement Program (WREP) through...

Interplay between cooperation-enhancing mechanisms in evolutionary games with tag-mediated interactions

NASA Astrophysics Data System (ADS)

Hadzibeganovic, Tarik; Stauffer, Dietrich; Han, Xiao-Pu

2018-04-01

Cooperation is fundamental for the long-term survival of biological, social, and technological networks. Previously, mechanisms for the enhancement of cooperation, such as network reciprocity, have largely been studied in isolation and with often inconclusive findings. Here, we present an evolutionary, multiagent-based, and spatially explicit computer model to specifically address the interactive interplay between such mechanisms. We systematically investigate the effects of phenotypic diversity, network structure, and rewards on cooperative behavior emerging in a population of reproducing artificial decision makers playing tag-mediated evolutionary games. Cooperative interactions are rewarded such that both the benefits of recipients and costs of donators are affected by the reward size. The reward size is determined by the number of cooperative acts occurring within a given reward time frame. Our computational experiments reveal that small reward frames promote unconditional cooperation in populations with both low and high diversity, whereas large reward frames lead to cycles of conditional and unconditional strategies at high but not at low diversity. Moreover, an interaction between rewards and spatial structure shows that relative to small reward frames, there is a strong difference between the frequency of conditional cooperators populating rewired versus non-rewired networks when the reward frame is large. Notably, in a less diverse population, the total number of defections is comparable across different network topologies, whereas in more diverse environments defections become more frequent in a regularly structured than in a rewired, small-world network of contacts. Acknowledging the importance of such interaction effects in social dilemmas will have inevitable consequences for the future design of cooperation-enhancing protocols in large-scale, distributed, and decentralized systems such as peer-to-peer networks.

Using Technology-Enhanced, Cooperative, Group-Project Learning for Student Comprehension and Academic Performance

ERIC Educational Resources Information Center

Tlhoaele, Malefyane; Suhre, Cor; Hofman, Adriaan

2016-01-01

Cooperative learning may improve students' motivation, understanding of course concepts, and academic performance. This study therefore enhanced a cooperative, group-project learning technique with technology resources to determine whether doing so improved students' deep learning and performance. A sample of 118 engineering students, randomly…

Interaction of TIF-90 and filamin A in the regulation of rRNA synthesis in leukemic cells.

PubMed

Nguyen, Le Xuan Truong; Chan, Steven M; Ngo, Tri Duc; Raval, Aparna; Kim, Kyeong Kyu; Majeti, Ravindra; Mitchell, Beverly S

2014-07-24

The transcription initiation factor I (TIF-IA) is an important regulator of the synthesis of ribosomal RNA (rRNA) through its facilitation of the recruitment of RNA polymerase I (Pol I) to the ribosomal DNA promoter. Activation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway, which occurs commonly in acute myelogenous leukemia, enhances rRNA synthesis through TIF-IA stabilization and phosphorylation. We have discovered that TIF-IA coexists with a splicing isoform, TIF-90, which is expressed preferentially in the nucleolus and at higher levels in proliferating and transformed hematopoietic cells. TIF-90 interacts directly with Pol I to increase rRNA synthesis as a consequence of Akt activation. Furthermore, TIF-90 binds preferentially to a 90-kDa cleavage product of the actin binding protein filamin A (FLNA) that inhibits rRNA synthesis. Increased expression of TIF-90 overcomes the inhibitory effect of this cleavage product and stimulates rRNA synthesis. Because activated Akt also reduces FLNA cleavage, these results indicate that activated Akt and TIF-90 function in parallel to increase rRNA synthesis and, as a consequence, cell proliferation in leukemic cells. These results provide evidence that the direct targeting of Akt would be an effective therapy in acute leukemias in which Akt is activated. © 2014 by The American Society of Hematology.

Enhancing the Performance of Medical Implant Communication Systems through Cooperative Diversity

PubMed Central

Hegyi, Barnabás; Levendovszky, János

2010-01-01

Battery-operated medical implants—such as pacemakers or cardioverter-defibrillators—have already been widely used in practical telemedicine and telecare applications. However, no solution has yet been found to mitigate the effect of the fading that the in-body to off-body communication channel is subject to. In this paper, we reveal and assess the potential of cooperative diversity to combat fading—hence to improve system performance—in medical implant communication systems. In the particular cooperative communication scenario we consider, multiple cooperating receiver units are installed across the room accommodating the patient with a medical implant inside his/her body. Our investigations have shown that the application of cooperative diversity is a promising approach to enhance the performance of medical implant communication systems in various aspects such as implant lifetime and communication link reliability. PMID:20379346

Dependence of evolutionary cooperation on the additive noise to the enhancement level in the spatial public goods game

NASA Astrophysics Data System (ADS)

Jia, Chun-Xiao; Liu, Run-Ran; Rong, Zhihai

2017-03-01

Either in societies or economic cycles, the benefits of a group can be affected by various unpredictable factors. We study effects of additive spatiotemporal random variations on the evolution of cooperation by introducing them to the enhancement level of the spatial public goods game. Players are located on the sites of a two-dimensional lattice and gain their payoffs from games with their neighbors by choosing cooperation or defection. We observe that a moderate intensity of variations can best favor cooperation at low enhancement levels, which resembles classical coherence resonance. Whereas for high enhancement levels, we find that the random variations cannot increase the cooperation level, but hamper cooperation instead. This discrepancy is attributed to the different roles the additive variations played in the early and late stages of evolution. In the early stage of evolution, the additive variations increase the survival probability of the players with lower average payoffs. However, in the late stage of evolution, the additive variations can promote defectors to destroy the cooperative clusters that have been formed. Our results indicate that additive spatiotemporal noise may not be as universally beneficial for cooperation as the spatial prisoner's dilemma game.

Force-dependent isomerization kinetics of a highly conserved proline switch modulates the mechanosensing region of filamin

PubMed Central

Rognoni, Lorenz; Möst, Tobias; Žoldák, Gabriel; Rief, Matthias

2014-01-01

Proline switches, controlled by cis–trans isomerization, have emerged as a particularly effective regulatory mechanism in a wide range of biological processes. In this study, we use single-molecule mechanical measurements to develop a full kinetic and energetic description of a highly conserved proline switch in the force-sensing domain 20 of human filamin and how prolyl isomerization modulates the force-sensing mechanism. Proline isomerization toggles domain 20 between two conformations. A stable cis conformation with slow unfolding, favoring the autoinhibited closed conformation of filamin’s force-sensing domain pair 20–21, and a less stable, uninhibited conformation promoted by the trans form. The data provide detailed insight into the folding mechanisms that underpin the functionality of this binary switch and elucidate its remarkable efficiency in modulating force-sensing, thus combining two previously unconnected regulatory mechanisms, proline switches and mechanosensing. PMID:24706888

Third-Party Cooperation: How Reducing Material Involvement Enhances Contributions to the Public Good.

PubMed

Losecaat Vermeer, Annabel B; Heerema, Roeland L; Sanfey, Alan G

2016-03-01

Decisions to cooperate are often delegated to a third party. We examined whether cooperation differs when decisions are made for a third party compared with ourselves and specified which motives are important for third-party cooperation. Participants played multiple rounds of a public goods game (PGG). In Study 1, we varied personal involvement from high to low; participants played for themselves (Self), for themselves and a third party (Shared), and solely for a third party (Third Party). Participants contributed most when personal involvement was lowest (i.e., Third Party) and least when personal involvement was high (i.e., Self). Study 2 explored if social motives underlie third-party cooperation by comparing cooperation with social (human) and non-social (computer) group members. Reducing personal involvement in the PGG (i.e., Third Party) increased cooperation in social contexts compared with non-social contexts, indicating enhanced collective interest. Increased cooperation for a third party may result from taking the other's perspective, thereby increasing social norm preferences. © 2016 by the Society for Personality and Social Psychology, Inc.

Active and Inactive Enhancers Cooperate to Exert Localized and Long-Range Control of Gene Regulation.

PubMed

Proudhon, Charlotte; Snetkova, Valentina; Raviram, Ramya; Lobry, Camille; Badri, Sana; Jiang, Tingting; Hao, Bingtao; Trimarchi, Thomas; Kluger, Yuval; Aifantis, Iannis; Bonneau, Richard; Skok, Jane A

2016-06-07

V(D)J recombination relies on the presence of proximal enhancers that activate the antigen receptor (AgR) loci in a lineage- and stage-specific manner. Unexpectedly, we find that both active and inactive AgR enhancers cooperate to disseminate their effects in a localized and long-range manner. Here, we demonstrate the importance of short-range contacts between active enhancers that constitute an Igk super-enhancer in B cells. Deletion of one element reduces the interaction frequency between other enhancers in the hub, which compromises the transcriptional output of each component. Furthermore, we establish that, in T cells, long-range contact and cooperation between the inactive Igk enhancer MiEκ and the active Tcrb enhancer Eβ alters enrichment of CBFβ binding in a manner that impacts Tcrb recombination. These findings underline the complexities of enhancer regulation and point to a role for localized and long-range enhancer-sharing between active and inactive elements in lineage- and stage-specific control. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Active and inactive enhancers co-operate to exert localized and long-range control of gene regulation

PubMed Central

Proudhon, Charlotte; Snetkova, Valentina; Raviram, Ramya; Lobry, Camille; Badri, Sana; Jiang, Tingting; Hao, Bingtao; Trimarchi, Thomas; Kluger, Yuval; Aifantis, Iannis; Bonneau, Richard; Skok, Jane A

2016-01-01

V(D)J recombination relies on the presence of proximal enhancers that activate the antigen receptor (AgR) loci in a lineage and stage specific manner. Unexpectedly we find that both active and inactive AgR enhancers co-operate to disseminate their effects in a localized and long-range manner. Here we demonstrate the importance of short-range contacts between active enhancers that constitute an Igk super-enhancer in B cells. Deletion of one element reduces the interaction frequency between other enhancers in the hub, which compromises the transcriptional output of each component. We further establish that in T cells long-range contact and co-operation between the inactive Igk enhancer, MiEκ and the active Tcrb enhancer, Eβ, alters enrichment of CBFβ binding in a manner that impacts Tcrb recombination. These findings underline the complexities of enhancer regulation and point to a role for localized and long-range enhancer-sharing between active and inactive elements in lineage and stage specific control. PMID:27239026

Cooperative plasmonic effect of Ag and Au nanoparticles on enhancing performance of polymer solar cells.

PubMed

Lu, Luyao; Luo, Zhiqiang; Xu, Tao; Yu, Luping

2013-01-09

This article describes a cooperative plasmonic effect on improving the performance of polymer bulk heterojunction solar cells. When mixed Ag and Au nanoparticles are incorporated into the anode buffer layer, dual nanoparticles show superior behavior on enhancing light absorption in comparison with single nanoparticles, which led to the realization of a polymer solar cell with a power conversion efficiency of 8.67%, accounting for a 20% enhancement. The cooperative plasmonic effect aroused from dual resonance enhancement of two different nanoparticles. The idea was further unraveled by comparing Au nanorods with Au nanoparticles for solar cell application. Detailed studies shed light into the influence of plasmonic nanostructures on exciton generation, dissociation, and charge recombination and transport inside thin film devices.

Enhancing Thinking through Cooperative Learning.

ERIC Educational Resources Information Center

Davidson, Neil, Ed.; Worsham, Toni, Ed.

This collection of papers provides a theoretical foundation on current practice in cooperative thinking. The papers offer many practical methods that can be applied to a full range of classroom settings. After an introduction, "HOTSICLE: Higher Order Thinking Skills in Cooperative Learning Environments" (Neil Davidson and Toni Worsham),…

Nonequilibrium enhancement of Cooper pairing in cold fermion systems

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

Robertson, Andrew; Galitski, Victor M.

2009-12-15

Nonequilibrium stimulation of superfluidity in trapped Fermi gases is discussed by analogy to the work of Eliashberg [Nonequilibrium Superconductivity, edited by D. N. Langenberg and A. I. Larkin (North-Holland, New York, 1986)] on the microwave enhancement of superconductivity. Optical excitation of the fermions balanced by heat loss due to thermal contact with a boson bath and/or evaporative cooling enables stationary nonequilibrium states to exist. Such a state manifests as a shift of the quasiparticle spectrum to higher energies and this effectively raises the pairing transition temperature. As an illustration, we calculate the effective enhancement of Cooper pairing and superfluidity inmore » both the normal and superfluid phases for a mixture of {sup 87}Rb and {sup 6}Li in the limit of small departure from equilibrium. It is argued that in experiment the desirable effect is not limited to such small perturbations and the effective enhancement of the pairing temperature may be quite large.« less

Cooperative synchronized assemblies enhance orientation discrimination.

PubMed

Samonds, Jason M; Allison, John D; Brown, Heather A; Bonds, A B

2004-04-27

There is no clear link between the broad tuning of single neurons and the fine behavioral capabilities of orientation discrimination. We recorded from populations of cells in the cat visual cortex (area 17) to examine whether the joint activity of cells can support finer discrimination than found in individual responses. Analysis of joint firing yields a substantial advantage (i.e., cooperation) in fine-angle discrimination. This cooperation increases to more considerable levels as the population of an assembly is increased. The cooperation in a population of six cells provides encoding of orientation with an information advantage that is at least 2-fold in terms of requiring either fewer cells or less time than independent coding. This cooperation suggests that correlated or synchronized activity can increase information.

Project CREATE Final Report. Cooperative Resources To Enhance Access to Technology Education.

ERIC Educational Resources Information Center

Hampden County Employment and Training Consortium, Springfield, MA.

These materials have been developed by Project CREATE (Cooperative Resources to Enhance Access to Jobs through Technical Education), a demonstration program designed to develop a network, specific activities, and resources that would provide education and support services to a wide audience. A 13-page final report describes the hands-on training…

The Effectiveness of Cooperative Learning Activities in Enhancing EFL Learners' Fluency

ERIC Educational Resources Information Center

Alrayah, Hassan

2018-01-01

This research-paper aims at examining the effectiveness of cooperative learning activities in enhancing EFL learners' fluency. The researcher has used the descriptive approach, recorded interviews for testing fluency as tools of data collection and the software program SPSS as a tool for the statistical treatment of data. Research sample consists…

Novel interactions of ankyrins-G at the costameres: The muscle-specific Obscurin/Titin-Binding-related Domain (OTBD) binds plectin and filamin C

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

Maiweilidan, Yimingjiang; Klauza, Izabela; Kordeli, Ekaterini, E-mail: ekaterini.kordeli@inserm.fr

2011-04-01

Ankyrins, the adapters of the spectrin skeleton, are involved in local accumulation and stabilization of integral proteins to the appropriate membrane domains. In striated muscle, tissue-dependent alternative splicing generates unique Ank3 gene products (ankyrins-G); they share the Obscurin/Titin-Binding-related Domain (OTBD), a muscle-specific insert of the C-terminal domain which is highly conserved among ankyrin genes, and binds obscurin and titin to Ank1 gene products. We previously proposed that OTBD sequences constitute a novel domain of protein-protein interactions which confers ankyrins with specific cellular functions in muscle. Here we searched for muscle proteins binding to ankyrin-G OTBD by yeast two hybrid assay,more » and we found plectin and filamin C, two organizing elements of the cytoskeleton with essential roles in myogenesis, muscle cell cytoarchitecture, and muscle disease. The three proteins coimmunoprecipitate from skeletal muscle extracts and colocalize at costameres in adult muscle fibers. During in vitro myogenesis, muscle ankyrins-G are first expressed in postmitotic myocytes undergoing fusion to myotubes. In western blots of subcellular fractions from C2C12 cells, the majority of muscle ankyrins-G appear associated with membrane compartments. Occasional but not extensive co-localization at nascent costameres suggested that ankyrin-G interactions with plectin and filamin C are not involved in costamere assembly; they would rather reinforce stability and/or modulate molecular interactions in sarcolemma microdomains by establishing novel links between muscle-specific ankyrins-G and the two costameric dystrophin-associated glycoprotein and integrin-based protein complexes. These results report the first protein-protein interactions involving the ankyrin-G OTBD domain and support the hypothesis that OTBD sequences confer ankyrins with a gain of function in vertebrates, bringing further consolidation and resilience of the linkage between

Social penalty promotes cooperation in a cooperative society.

PubMed

Ito, Hiromu; Yoshimura, Jin

2015-08-04

Why cooperation is well developed in human society is an unsolved question in biological and human sciences. Vast studies in game theory have revealed that in non-cooperative games selfish behavior generally dominates over cooperation and cooperation can be evolved only under very limited conditions. These studies ask the origin of cooperation; whether cooperation can evolve in a group of selfish individuals. In this paper, instead of asking the origin of cooperation, we consider the enhancement of cooperation in a small already cooperative society. We ask whether cooperative behavior is further promoted in a small cooperative society in which social penalty is devised. We analyze hawk-dove game and prisoner's dilemma introducing social penalty. We then expand it for non-cooperative games in general. The results indicate that cooperation is universally favored if penalty is further imposed. We discuss the current result in terms of the moral, laws, rules and regulations in a society, e.g., criminology and traffic violation.

Social penalty promotes cooperation in a cooperative society

PubMed Central

Ito, Hiromu; Yoshimura, Jin

2015-01-01

Why cooperation is well developed in human society is an unsolved question in biological and human sciences. Vast studies in game theory have revealed that in non-cooperative games selfish behavior generally dominates over cooperation and cooperation can be evolved only under very limited conditions. These studies ask the origin of cooperation; whether cooperation can evolve in a group of selfish individuals. In this paper, instead of asking the origin of cooperation, we consider the enhancement of cooperation in a small already cooperative society. We ask whether cooperative behavior is further promoted in a small cooperative society in which social penalty is devised. We analyze hawk-dove game and prisoner’s dilemma introducing social penalty. We then expand it for non-cooperative games in general. The results indicate that cooperation is universally favored if penalty is further imposed. We discuss the current result in terms of the moral, laws, rules and regulations in a society, e.g., criminology and traffic violation. PMID:26238521

Cooperative Learning Principles Enhance Online Interaction

ERIC Educational Resources Information Center

Jacobs, George; Seow, Peter

2014-01-01

This paper describes eight principles that can be used to promote cooperative interactions among students working in online environments. The principles derive from a well-established approach to education, known variously as cooperative learning and collaborative learning. Each principle is explained as to what it means, why it is important and…

Cooperative enhancement of the nonlinear optical response in conjugated energetic materials: A TD-DFT study

DOE PAGES

Sifain, Andrew E.; Tadesse, Loza F.; Bjorgaard, Josiah August; ...

2017-03-21

Conjugated energetic molecules (CEMs) are a class of explosives with high nitrogen content that posses both enhanced safety and energetic performance properties and are ideal for direct optical initiation. As isolated molecules, they absorb within the range of conventional lasers. Crystalline CEMs are used in practice, however, and their properties can differ due to intermolecular interaction. Herein, time-dependent density functional theory was used to investigate one-photon absorption (OPA) and two-photon absorption (TPA) of monomers and dimers obtained from experimentally determined crystal structures of CEMs. OPA scales linearly with the number of chromophore units, while TPA scales nonlinearly, where a moremore » than 3-fold enhancement in peak intensity, per chromophore unit, is calculated. Cooperative enhancement depends on electronic delocalization spanning both chromophore units. An increase in sensitivity to nonlinear laser initiation makes these materials suitable for practical use. This is the first study predicting a cooperative enhancement of the nonlinear optical response in energetic materials composed of relatively small molecules. Finally, the proposed model quantum chemistry is validated by comparison to crystal structure geometries and the optical absorption of these materials dissolved in solution.« less

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

NASA Astrophysics Data System (ADS)

Tanimoto, Jun

2013-07-01

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

Cooperation enhanced by habitat destruction in Prisoner's Dilemma Games

NASA Astrophysics Data System (ADS)

Yang, Xiqing; Wang, Wanxiong; Zhang, Feng; Qiao, Hongqiang

2017-11-01

The emergence and maintenance of cooperation is a fundamental problem within groups of selfish individuals, whereby we introduce a model of replicator equations based on the Prisoner's Dilemma game. In the present work, the effect of habitat destruction on the evolution of cooperation will be taken into account. Our results show that cooperators can receive the biggest boost for a moderate value of habitat destruction, and more serious habitat destruction will lead to lower levels of cooperation until zero. Moreover, we also reach the conclusion that the cooperation level decreases monotonously with the increasing of the ratio of cooperative cost to benefit but increases monotonously with the increasing of the encounter probability. Our findings can help to further understand the evolution of cooperation under the harsh external environment.

The Role of Structured Cooperative Learning Groups for Enhancing Chinese Primary Students' Reading Comprehension

ERIC Educational Resources Information Center

Law, Yin-Kum

2014-01-01

The present study aimed to compare the effectiveness of two types of cooperative learning groups used in reciprocal teaching (RT) classes (i.e. high-structured vs. low-structured groups) for enhancing students' reading comprehension. The participants were 235 Hong Kong Chinese Grade 6 students in nine classes. Reading comprehension tests and…

Grade/Study-Performance Contracts, Enhanced Communication, Cooperative Learning, and Student Performance in Undergraduate Organic Chemistry.

ERIC Educational Resources Information Center

Dougherty, Ralph C.

1997-01-01

Describes and evaluates a teaching strategy, designed to increase student retention while maintaining academic performance levels in undergraduate organic chemistry, that uses grade/study-performance contracts, enhanced communication using electronic mail, and cooperative learning. Concludes that a series of interventions can substantially…

Enhanced old-new recognition and source memory for faces of cooperators and defectors in a social-dilemma game.

PubMed

Bell, Raoul; Buchner, Axel; Musch, Jochen

2010-12-01

A popular assumption in evolutionary psychology is that the human mind comprises specialized cognitive modules for social exchange, including a module that serves to enhance memory for faces of cheaters. In the present study, participants played a trust game with computerized opponents, who either defected or cooperated. In a control condition, no interaction took place. In a surprise memory test, old-new recognition for faces and source memory for the associated cooperative or non-cooperative behavior were assessed. A multinomial model was used to measure old-new discrimination, source memory, and guessing biases separately. Inconsistent with the assumption of a memory mechanism that focuses exclusively on cheating, the present study showed enhanced old-new discrimination and source memory for both cooperators and defectors. Rarity of the behavior strategies within the experiment modulated source memory, but only when the differences in base rates were extreme. The findings can be attributed to a mechanism that focuses on exchange-relevant information and flexibly adapts to take into account the relative significance of this information in the encoding context, which may be more beneficial than focusing exclusively on cheaters. Copyright © 2010 Elsevier B.V. All rights reserved.

Enhanced cooperativity for quantum-nondemolition-measurement–induced spin squeezing of atoms coupled to a nanophotonic waveguide

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

Qi, Xiaodong; Jau, Yuan-Yu; Deutsch, Ivan H.

We study the enhancement of cooperativity in the atom-light interface near a nanophotonic waveguide for application to QND measurement of atomic spins. Here the cooperativity per atom is determined by the ratio between the measurement strength and the decoherence rate. Counterintuitively, we find that by placing the atoms at an azimuthal position where the guided probe mode has the lowest intensity, we increase the cooperativity. This arises because the QND measurement strength depends on the interference between the probe and scattered light guided into an orthogonal polarization mode, while the decoherence rate depends on the local intensity of the probe.more » Thus, by proper choice of geometry, the ratio of good to bad scattering can be strongly enhanced for highly anisotropic modes. We apply this to study spin squeezing resulting from QND measurement of spin projection noise via the Faraday effect in two nanophotonic geometries, a cylindrical nano fiber and a square waveguide. We nd, with about 2500 atoms using realistic experimental parameters, ~ 6:3 dB and ~ 13 dB of squeezing can be achieved on the nano fiber and square waveguide, respectively.« less

Enhanced cooperativity for quantum-nondemolition-measurement–induced spin squeezing of atoms coupled to a nanophotonic waveguide

DOE PAGES

Qi, Xiaodong; Jau, Yuan-Yu; Deutsch, Ivan H.

2018-03-16

We study the enhancement of cooperativity in the atom-light interface near a nanophotonic waveguide for application to QND measurement of atomic spins. Here the cooperativity per atom is determined by the ratio between the measurement strength and the decoherence rate. Counterintuitively, we find that by placing the atoms at an azimuthal position where the guided probe mode has the lowest intensity, we increase the cooperativity. This arises because the QND measurement strength depends on the interference between the probe and scattered light guided into an orthogonal polarization mode, while the decoherence rate depends on the local intensity of the probe.more » Thus, by proper choice of geometry, the ratio of good to bad scattering can be strongly enhanced for highly anisotropic modes. We apply this to study spin squeezing resulting from QND measurement of spin projection noise via the Faraday effect in two nanophotonic geometries, a cylindrical nano fiber and a square waveguide. We nd, with about 2500 atoms using realistic experimental parameters, ~ 6:3 dB and ~ 13 dB of squeezing can be achieved on the nano fiber and square waveguide, respectively.« less

Enhanced cooperativity for quantum-nondemolition-measurement-induced spin squeezing of atoms coupled to a nanophotonic waveguide

NASA Astrophysics Data System (ADS)

Qi, Xiaodong; Jau, Yuan-Yu; Deutsch, Ivan H.

2018-03-01

We study the enhancement of cooperativity in the atom-light interface near a nanophotonic waveguide for application to quantum nondemolition (QND) measurement of atomic spins. Here the cooperativity per atom is determined by the ratio between the measurement strength and the decoherence rate. Counterintuitively, we find that by placing the atoms at an azimuthal position where the guided probe mode has the lowest intensity, we increase the cooperativity. This arises because the QND measurement strength depends on the interference between the probe and scattered light guided into an orthogonal polarization mode, while the decoherence rate depends on the local intensity of the probe. Thus, by proper choice of geometry, the ratio of good-to-bad scattering can be strongly enhanced for highly anisotropic modes. We apply this to study spin squeezing resulting from QND measurement of spin projection noise via the Faraday effect in two nanophotonic geometries, a cylindrical nanofiber and a square waveguide. We find that, with about 2500 atoms and using realistic experimental parameters, ˜6.3 and ˜13 dB of squeezing can be achieved on the nanofiber and square waveguide, respectively.

Sporadic periventricular nodular heterotopia: Classification, phenotype and correlation with Filamin A mutations.

PubMed

Liu, Wenyu; Yan, Bo; An, Dongmei; Xiao, Jiahe; Hu, Fayun; Zhou, Dong

2017-07-01

The purpose of this study was to better delineate the clinical spectrum of periventricular nodular heterotopia (PNH) in a large patient population after long term follow up. Specifically, this study aimed to relate PNH subtypes to clinical or epileptic outcomes, epileptic discharges and underlying Filamin A (FLNA) mutations by analyzing anatomical features. The study included 100 patients with radiologically confirmed nodular heterotopia. Patients' FLNA gene sequences and medical records were analyzed. Two-sided Chi-square test and Fisher's exact t-test were used to assess associations between the distribution of PNHs and specific clinical features. Based on imaging data, patients were subdivided into three groups: (a) classical (bilateral frontal and body, n=41 patients), (b) bilateral asymmetrical or posterior (n=16) and (c) unilateral heterotopia (n=43). Most patients with classical heterotopia were females (P=0.033) and were likely to have arachnoid cysts (P=0.025) and cardiac abnormalities (P=0.041), but were mostly seizure-free. Additionally, hippocampal abnormalities (P=0.022), neurological deficits (P=0.028) and cerebellar abnormalities (P=0.005) were more common in patients with bilateral asymmetrical heterotopia. Patients with unilateral heterotopia were prone to develop refractory epilepsy (P=0.041). FLNA mutations were identified in 8 patients. Each group's distinctive genetic mutations, epileptic discharge patterns and overall clinical outcomes confirm that the proposed classification system is reliable. These findings could not only be an indicator of a more severe morphological and clinical phenotype, but could also have clinical implications with respect to the epilepsy management and optimization of therapeutic options. Copyright © 2017 Elsevier B.V. All rights reserved.

Screening of the Filamin C Gene in a Large Cohort of Hypertrophic Cardiomyopathy Patients.

PubMed

Gómez, Juan; Lorca, Rebeca; Reguero, Julian R; Morís, César; Martín, María; Tranche, Salvador; Alonso, Belén; Iglesias, Sara; Alvarez, Victoria; Díaz-Molina, Beatriz; Avanzas, Pablo; Coto, Eliecer

2017-04-01

Recent exome sequencing studies identified filamin C ( FLNC ) as a candidate gene for hypertrophic cardiomyopathy (HCM). Our aim was to determine the rate of FLNC candidate variants in a large cohort of HCM patients who were also sequenced for the main sarcomere genes. A total of 448 HCM patients were next generation-sequenced (semiconductor chip technology) for the MYH7, MYBPC3 , TNNT2 , TNNI3 , ACTC1 , TNNC1 , MYL2 , MYL3 , TPM1 , and FLNC genes. We also sequenced 450 healthy controls from the same population. Based on the reported population frequencies, bioinformatic criteria, and familial segregation, we identified 20 FLNC candidate variants (13 new; 1 nonsense; and 19 missense) in 22 patients. Compared with the patients, only 1 of the control's missense variants was nonreported ( P =0.007; Fisher exact probability test). Based on the familial segregation and the reported functional studies, 6 of the candidate variants (in 7 patients) were finally classified as likely pathogenic, 10 as variants of uncertain significance, and 4 as likely benign. We provide a compelling evidence of the involvement of FLNC in the development of HCM. Most of the FLNC variants were associated with mild forms of HCM and a reduced penetrance, with few affected in the families to confirm the segregation. Our work, together with others who found FLNC variants among patients with dilated and restrictive cardiomyopathies, pointed to this gene as an important cause of structural cardiomyopathies. © 2017 American Heart Association, Inc.

Enlightening Advantages of Cooperative Learning

ERIC Educational Resources Information Center

Faryadi, Qais

2007-01-01

This appraisal discusses the notion that cooperative learning enhances learners' emotional and social performance. It also observes the perception that cooperative learning dramatically improves students' academic accomplishment. This review also examines the definition of cooperative learning and attempts to define it through the lens of renowned…

Phosphorylation of actin-binding protein (ABP-280; filamin) by tyrosine kinase p56lck modulates actin filament cross-linking.

PubMed

Pal Sharma, C; Goldmann, Wolfgang H

2004-01-01

Actin-binding protein (ABP-280; filamin) is a phosphoprotein present in the periphery of the cytoplasm where it can cross-link actin filaments, associate with lipid membranes, and bind to membrane surface receptors. Given its function and localization in the cell, we decided to investigate the possibility of whether it serves as substrate for p56lck, a lymphocyte-specific member of the src family of protein tyrosine kinases associated with cell surface glycoproteins. The interaction of p56lck with membrane glycoproteins is important for cell development and functional activation. Here, we show that purified p56lck interacts and catalyzes in vitro kinase reactions. Tyrosine phosphorylation by p56lck is restricted to a single peptide of labeled ABP-280 shown by protease digest. The addition of phorbol ester to cells results in the inhibition of phosphorylation of ABP-280 by p56lck. These results show a decrease in phosphorylation suggesting conformationally induced regulation. Dynamic light scattering confirmed increased actin filament cross-linking due to phosphorylation of ABP-280 by p56lck.

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

NASA Astrophysics Data System (ADS)

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

2016-11-01

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

Androgen-Induced Cell Migration: Role of Androgen Receptor/Filamin A Association

PubMed Central

Castoria, Gabriella; D'Amato, Loredana; Ciociola, Alessandra; Giovannelli, Pia; Giraldi, Tiziana; Sepe, Leandra; Paolella, Giovanni; Barone, Maria Vittoria; Migliaccio, Antimo; Auricchio, Ferdinando

2011-01-01

Background Androgen receptor (AR) controls male morphogenesis, gametogenesis and prostate growth as well as development of prostate cancer. These findings support a role for AR in cell migration and invasiveness. However, the molecular mechanism involved in AR-mediated cell migration still remains elusive. Methodology/Principal Findings Mouse embryo NIH3T3 fibroblasts and highly metastatic human fibrosarcoma HT1080 cells harbor low levels of transcriptionally incompetent AR. We now report that, through extra nuclear action, AR triggers migration of both cell types upon stimulation with physiological concentrations of the androgen R1881. We analyzed the initial events leading to androgen-induced cell migration and observed that challenging NIH3T3 cells with 10 nM R1881 rapidly induces interaction of AR with filamin A (FlnA) at cytoskeleton. AR/FlnA complex recruits integrin beta 1, thus activating its dependent cascade. Silencing of AR, FlnA and integrin beta 1 shows that this ternary complex controls focal adhesion kinase (FAK), paxillin and Rac, thereby driving cell migration. FAK-null fibroblasts migrate poorly and Rac inhibition by EHT impairs motility of androgen-treated NIH3T3 cells. Interestingly, FAK and Rac activation by androgens are independent of each other. Findings in human fibrosarcoma HT1080 cells strengthen the role of Rac in androgen signaling. The Rac inhibitor significantly impairs androgen-induced migration in these cells. A mutant AR, deleted of the sequence interacting with FlnA, fails to mediate FAK activation and paxillin tyrosine phosphorylation in androgen-stimulated cells, further reinforcing the role of AR/FlnA interaction in androgen-mediated motility. Conclusions/Significance The present report, for the first time, indicates that the extra nuclear AR/FlnA/integrin beta 1 complex is the key by which androgen activates signaling leading to cell migration. Assembly of this ternary complex may control organ development and prostate cancer

Filamin A Mediates Wound Closure by Promoting Elastic Deformation and Maintenance of Tension in the Collagen Matrix

PubMed Central

Mohammadi, Hamid; Pinto, Vanessa I.; Wang, Yongqiang; Hinz, Boris; Janmey, Paul A.; McCulloch, Christopher A.

2016-01-01

Cell-mediated remodeling and wound closure are critical for efficient wound healing, but the contribution of actin-binding proteins to contraction of the extracellular matrix is not defined. We examined the role of filamin A (FLNa), an actin filament cross-linking protein, in wound contraction and maintenance of matrix tension. Conditional deletion of FLNa in fibroblasts in mice was associated with ~ 4 day delay of full-thickness skin wound contraction compared with wild-type (WT) mice. We modeled the healing wound matrix using cultured fibroblasts plated on grid-supported collagen gels that create lateral boundaries, which are analogues to wound margins. In contrast to WT cells, FLNa knockdown (KD) cells could not completely maintain tension when matrix compaction was resisted by boundaries, which manifested as relaxed matrix tension. Similarly, WT cells on cross-linked collagen, which requires higher levels of sustained tension, exhibited approximately fivefold larger deformation fields and approximately twofold greater fiber alignment compared with FLNa KD cells. Maintenance of boundary-resisted tension markedly influenced the elongation of cell extensions: in WT cells, the number (~50%) and length (~300%) of cell extensions were greater than FLNa KD cells. We conclude that FLNa is required for wound contraction, in part by enabling elastic deformation and maintenance of tension in the matrix. PMID:26134946

Enhancing US-Japan Cooperation to Combat Antimicrobial Resistance

PubMed Central

2014-01-01

The Global Health Security Agenda (GHSA) is aimed at preventing, detecting, and responding to infectious disease threats. To move toward these goals, the United States has committed to partner with at least 30 countries around the world. One of the objectives of the GHSA includes “[p]reventing the emergence and spread of antimicrobial drug resistant organisms.” Antimicrobial resistance (AMR) has become a growing global health security problem, with inappropriate use of antimicrobial medications in humans and animals and a lack of new antimicrobial medications contributing to this problem. While AMR is a growing global concern, working on it regionally can make this multifaceted problem more manageable. The United States and Japan, both world leaders in the life sciences, are close allies that have established cooperative programs in medical research and global health that can be used to work on combating AMR and advance the GHSA. Although the United States and Japan have cooperated on health issues in the past, their cooperation on the growing problem of AMR has been limited. Their existing networks, cooperative programs, and close relationships can and should be used to work on combating this expanding problem. PMID:25470465

Comparative study of an externship program versus a corporate-academic cooperation program for enhancing nursing competence of graduating students

PubMed Central

2013-01-01

Background New graduates report intense stress during the transition from school to their first work settings. Managing this transition is important to reduce turnover rates. This study compared the effects of an externship program and a corporate-academic cooperation program on enhancing junior college students’ nursing competence and retention rates in the first 3 months and 1 year of initial employment. Methods This two-phase study adopted a pretest and posttest quasi-experimental design. All participants were graduating students drawn from a 5-year junior nursing college in Taiwan. There were 19 and 24 students who participated in the phase I externship program and phase II corporate-academic cooperation program, respectively. The nursing competence of the students had to be evaluated by mentors within 48 hours of practicum training and after practicum training. The retention rate was also surveyed at 3 months and 1 year after beginning employment. Results Students who participated in the corporate-academic cooperation program achieved a statistically significant improvement in nursing competence and retention rates relative to those who participated in the externship program (p < 0.01 and p < 0.05, respectively). Conclusions The corporate-academic cooperation program facilitates the transition of junior college nursing students into independent staff nurses, enhances their nursing competence, and boosts retention rates. PMID:23945287

RACK1 interacts with filamin-A to regulate plasma membrane levels of the cystic fibrosis transmembrane conductance regulator

PubMed Central

Smith, Laura; Litman, Paul; Kohli, Ekta; Amick, Joseph; Page, Richard C.; Misra, Saurav

2013-01-01

Mutations in cystic fibrosis transmembrane regulator (CFTR), a chloride channel in the apical membranes of secretory epithelial cells, underlie the fatal genetic disorder cystic fibrosis. Certain CFTR mutations, including the common mutation ΔF508-CFTR, result in greatly decreased levels of active CFTR at the apical membrane. Direct interactions between CFTR and the cytoskeletal adaptors filamin-A (FlnA) and Na+/H+ exchanger regulatory factor 1 (NHERF1) stabilize the expression and localization of CFTR at the plasma membrane. The scaffold protein receptor for activated C kinase 1 (RACK1) also stabilizes CFTR surface expression; however, RACK1 does not interact directly with CFTR and its mechanism of action is unknown. In the present study, we report that RACK1 interacts directly with FlnA in vitro and in a Calu-3 airway epithelial cell line. We mapped the interaction between RACK1 and FlnA to the WD4 and WD6 repeats of RACK1 and to a segment of the large rod domain of FlnA, consisting of immunoglobulin-like repeats 8–15. Disruption of the RACK1-FlnA interaction causes a reduction in CFTR surface levels. Our results suggest that a novel RACK1-FlnA interaction is an important regulator of CFTR surface localization. PMID:23636454

Determinants of public cooperation in multiplex networks

NASA Astrophysics Data System (ADS)

Battiston, Federico; Perc, Matjaž; Latora, Vito

2017-07-01

Synergies between evolutionary game theory and statistical physics have significantly improved our understanding of public cooperation in structured populations. Multiplex networks, in particular, provide the theoretical framework within network science that allows us to mathematically describe the rich structure of interactions characterizing human societies. While research has shown that multiplex networks may enhance the resilience of cooperation, the interplay between the overlap in the structure of the layers and the control parameters of the corresponding games has not yet been investigated. With this aim, we consider here the public goods game on a multiplex network, and we unveil the role of the number of layers and the overlap of links, as well as the impact of different synergy factors in different layers, on the onset of cooperation. We show that enhanced public cooperation emerges only when a significant edge overlap is combined with at least one layer being able to sustain some cooperation by means of a sufficiently high synergy factor. In the absence of either of these conditions, the evolution of cooperation in multiplex networks is determined by the bounds of traditional network reciprocity with no enhanced resilience. These results caution against overly optimistic predictions that the presence of multiple social domains may in itself promote cooperation, and they help us better understand the complexity behind prosocial behavior in layered social systems.

Enhancement of environment and resources engineering studies through an international cooperation network

NASA Astrophysics Data System (ADS)

Caporali, E.; Tuneski, A.

2012-12-01

Higher education plays a very important role in the modern societies development, enhancing social, cultural and economic development for a sustainable growth, environment respectful. In this framework, the European Commission promotes the TEMPUS-Trans European Mobility Programme for University Studies. Curricula harmonization and lifelong learning programme development in higher education are among the focused aspects of the TEMPUS programme. The DEREL-Development of Environment and Resources Engineering Learning, is a three years TEMPUS project coordinated by the University of Firenze, in cooperation with colleagues of the Ss Cyril and Methodius University, Skopje financed and activated since October 2010. The DEREL Project Consortium consists of 4 EU Universities (from Italy, Greece, Germany and Austria), 7 Partner Countries (PC) Universities (from FYR of Macedonia, Serbia and Albania), and 1 PC Ministry, 4 PC National Agencies, 1 PC non governmental organization and 1 PC enterprise. In cooperation with the same 4 EU Universities and the same Macedonian Institutions, in the period 2005-2008 also a TEMPUS JEP entitled DEREC-Development of Environmental and Resources Engineering Curriculum, was also carried out by the University of Firenze in cooperation with colleagues of the Ss Cyril and Methodius University. Within DEREC a new three-years first cycle curriculum in Environmental and Resources Engineering was opened at the University Ss Cyril and Methodius, Skopje, and the necessary conditions for offering a Joint Degree Title, on the basis of an agreement between the Ss. Cyril and Methodius University and the University of Firenze, were fulfilled. The running DEREL project, as a continuation of DEREC, is aimed to introduce a new, up-to-date, postgraduate second cycle curriculum in Environment and Resources Engineering at the Ss Cyril and Methodius University in Skopje, FYR of Macedonia, University of Novi Sad, Serbia and Polytechnic University of Tirana, Albania

Targeting filamin A reduces K-RAS–induced lung adenocarcinomas and endothelial response to tumor growth in mice

PubMed Central

2012-01-01

Background Many human cancer cells express filamin A (FLNA), an actin-binding structural protein that interacts with a diverse set of cell signaling proteins, but little is known about the biological importance of FLNA in tumor development. FLNA is also expressed in endothelial cells, which may be important for tumor angiogenesis. In this study, we defined the impact of targeting Flna in cancer and endothelial cells on the development of tumors in vivo and on the proliferation of fibroblasts in vitro. Methods First, we used a Cre-adenovirus to simultaneously activate the expression of oncogenic K-RAS and inactivate the expression of Flna in the lung and in fibroblasts. Second, we subcutaneously injected mouse fibrosarcoma cells into mice lacking Flna in endothelial cells. Results Knockout of Flna significantly reduced K-RAS–induced lung tumor formation and the proliferation of oncogenic K-RAS–expressing fibroblasts, and attenuated the activation of the downstream signaling molecules ERK and AKT. Genetic deletion of endothelial FLNA in mice did not impact cardiovascular development; however, knockout of Flna in endothelial cells reduced subcutaneous fibrosarcoma growth and vascularity within tumors. Conclusions We conclude that FLNA is important for lung tumor growth and that endothelial Flna impacts local tumor growth. The data shed new light on the biological importance of FLNA and suggest that targeting this protein might be useful in cancer therapeutics. PMID:22857000

Cooperative Learning in Elementary Schools.

ERIC Educational Resources Information Center

Hadderman, Margaret

1992-01-01

Cooperative learning is being recommended as a solution for numerous education problems, from enhancing disadvantaged children's self-esteem to ensuring academic success for all students. Cooperative learning has great potential as a supplement or alternative to traditional teaching methods when students are adequately socialized and motivated.…

Enhancing Student Performance through Cooperative Learning in Physical Sciences

ERIC Educational Resources Information Center

Gupta, Madan L.

2004-01-01

Students in a physical sciences course were introduced to cooperative learning at the University of Queensland, Gatton Campus. Groups of four to five students worked together in tutorial and practical sessions. Mid-term and practical examinations were abolished and 40% of total marks were allocated to the cooperative learning activities. A peer-…

Cooperation for a competitive position: The impact of hospital cooperation behavior on organizational performance.

PubMed

Büchner, Vera Antonia; Hinz, Vera; Schreyögg, Jonas

2015-01-01

Several public policy initiatives, particularly those involving managed care, aim to enhance cooperation between partners in the health care sector because it is expected that such cooperation will reduce costs and generate additional revenue. However, empirical evidence regarding the effects of cooperation on hospital performance is scarce, particularly with respect to creating a comprehensive measure of cooperation behavior. The aim of this study is to investigate the impact of hospital cooperation behavior on organizational performance. We differentiate between horizontal and vertical cooperation using two alternative measures-cooperation depth and cooperation breadth-and include the interaction effects between both cooperation directions. Data are derived from a survey of German hospitals and combined with objective performance information from annual financial statements. Generalized linear regression models are used. The study findings provide insight into the nature of hospitals' cooperation behavior. In particular, we show that there are negative synergies between horizontal administrative cooperation behavior and vertical cooperation behavior. Whereas the depth and breadth of horizontal administrative cooperation positively affect financial performance (when there is no vertical cooperation), vertical cooperation positively affects financial performance (when there is no horizontal administrative cooperation) only when cooperation is broad (rather than deep). Horizontal cooperation is generally more effective than vertical cooperation at improving financial performance. Hospital managers should consider the negative interaction effect when making decisions about whether to recommend a cooperative relationship in a horizontal or vertical direction. In addition, managers should be aware of the limited financial benefit of cooperation behavior.

Generation Z, Meet Cooperative Learning

ERIC Educational Resources Information Center

Igel, Charles; Urquhart, Vicki

2012-01-01

Today's Generation Z teens need to develop teamwork and social learning skills to be successful in the 21st century workplace. Teachers can help students develop these skills and enhance academic achievement by implementing cooperative learning strategies. Three key principles for successful cooperative learning are discussed. (Contains 1 figure.)

Partially Redundant Enhancers Cooperatively Maintain Mammalian Pomc Expression Above a Critical Functional Threshold

PubMed Central

Lam, Daniel D.; de Souza, Flavio S. J.; Nasif, Sofia; Yamashita, Miho; López-Leal, Rodrigo; Meece, Kana; Sampath, Harini; Mercer, Aaron J.; Wardlaw, Sharon L.

2015-01-01

Cell-specific expression of many genes is conveyed by multiple enhancers, with each individual enhancer controlling a particular expression domain. In contrast, multiple enhancers drive similar expression patterns of some genes involved in embryonic development, suggesting regulatory redundancy. Work in Drosophila has indicated that functionally overlapping enhancers canalize development by buffering gene expression against environmental and genetic disturbances. However, little is known about regulatory redundancy in vertebrates and in genes mainly expressed during adulthood. Here we study nPE1 and nPE2, two phylogenetically conserved mammalian enhancers that drive expression of the proopiomelanocortin gene (Pomc) to the same set of hypothalamic neurons. The simultaneous deletion of both enhancers abolished Pomc expression at all ages and induced a profound metabolic dysfunction including early-onset extreme obesity. Targeted inactivation of either nPE1 or nPE2 led to very low levels of Pomc expression during early embryonic development indicating that both enhancers function synergistically. In adult mice, however, Pomc expression is controlled additively by both enhancers, with nPE1 being responsible for ∼80% and nPE2 for ∼20% of Pomc transcription. Consequently, nPE1 knockout mice exhibit mild obesity whereas nPE2-deficient mice maintain a normal body weight. These results suggest that nPE2-driven Pomc expression is compensated by nPE1 at later stages of development, essentially rescuing the earlier phenotype of nPE2 deficiency. Together, these results reveal that cooperative interactions between the enhancers confer robustness of Pomc expression against gene regulatory disturbances and preclude deleterious metabolic phenotypes caused by Pomc deficiency in adulthood. Thus, our study demonstrates that enhancer redundancy can be used by genes that control adult physiology in mammals and underlines the potential significance of regulatory sequence mutations in

Enhanced Old-New Recognition and Source Memory for Faces of Cooperators and Defectors in a Social-Dilemma Game

ERIC Educational Resources Information Center

Bell, Raoul; Buchner, Axel; Musch, Jochen

2010-01-01

A popular assumption in evolutionary psychology is that the human mind comprises specialized cognitive modules for social exchange, including a module that serves to enhance memory for faces of cheaters. In the present study, participants played a trust game with computerized opponents, who either defected or cooperated. In a control condition, no…

Hydrophobic/Hydrophilic Cooperative Janus System for Enhancement of Fog Collection.

PubMed

Cao, Moyuan; Xiao, Jiasheng; Yu, Cunming; Li, Kan; Jiang, Lei

2015-09-09

Harvesting micro-droplets from fog is a promising method for solving global freshwater crisis. Different types of fog collectors have been extensively reported during the last decade. The improvement of fog collection can be attributed to the immediate transportation of harvested water, the effective regeneration of the fog gathering surface, etc. Through learning from the nature's strategy for water preservation, the hydrophobic/hydrophilic cooperative Janus system that achieved reinforced fog collection ability is reported here. Directional delivery of the surface water, decreased re-evaporation rate of the harvested water, and thinner boundary layer of the collecting surface contribute to the enhancement of collection efficiency. Further designed cylinder Janus collector can facilely achieve a continuous process of efficient collection, directional transportation, and spontaneous preservation of fog water. This Janus fog harvesting system should improve the understanding of micro-droplet collection system and offer ideas to solve water resource crisis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Asb2α-Filamin A Axis Is Essential for Actin Cytoskeleton Remodeling During Heart Development.

PubMed

Métais, Arnaud; Lamsoul, Isabelle; Melet, Armelle; Uttenweiler-Joseph, Sandrine; Poincloux, Renaud; Stefanovic, Sonia; Valière, Amélie; Gonzalez de Peredo, Anne; Stella, Alexandre; Burlet-Schiltz, Odile; Zaffran, Stéphane; Lutz, Pierre G; Moog-Lutz, Christel

2018-03-16

Heart development involves differentiation of cardiac progenitors and assembly of the contractile sarcomere apparatus of cardiomyocytes. However, little is known about the mechanisms that regulate actin cytoskeleton remodeling during cardiac cell differentiation. The Asb2α (Ankyrin repeat-containing protein with a suppressor of cytokine signaling box 2) CRL5 (cullin 5 RING E3 ubiquitin ligase) triggers polyubiquitylation and subsequent degradation by the proteasome of FLNs (filamins). Here, we investigate the role of Asb2α in heart development and its mechanisms of action. Using Asb2 knockout embryos, we show that Asb2 is an essential gene, critical to heart morphogenesis and function, although its loss does not interfere with the overall patterning of the embryonic heart tube. We show that the Asb2α E3 ubiquitin ligase controls Flna stability in immature cardiomyocytes. Importantly, Asb2α-mediated degradation of the actin-binding protein Flna marks a previously unrecognized intermediate step in cardiac cell differentiation characterized by cell shape changes and actin cytoskeleton remodeling. We further establish that in the absence of Asb2α, myofibrils are disorganized and that heartbeats are inefficient, leading to embryonic lethality in mice. These findings identify Asb2α as an unsuspected key regulator of cardiac cell differentiation and shed light on the molecular and cellular mechanisms determining the onset of myocardial cell architecture and its link with early cardiac function. Although Flna is known to play roles in cytoskeleton organization and to be required for heart function, this study now reveals that its degradation mediated by Asb2α ensures essential functions in differentiating cardiac progenitors. © 2018 American Heart Association, Inc.

Filamin A Modulates Kinase Activation and Intracellular Trafficking of Epidermal Growth Factor Receptors in Human Melanoma Cells

PubMed Central

Fiori, Jennifer L.; Zhu, Tie-Nian; O'Connell, Michael P.; Hoek, Keith S.; Indig, Fred E.; Frank, Brittany P.; Morris, Christa; Kole, Sutapa; Hasskamp, Joanne; Elias, George; Weeraratna, Ashani T.; Bernier, Michel

2009-01-01

The actin-binding protein filamin A (FLNa) affects the intracellular trafficking of various classes of receptors and has a potential role in oncogenesis. However, it is unclear whether FLNa regulates the signaling capacity and/or down-regulation of the activated epidermal growth factor receptor (EGFR). Here it is shown that partial knockdown of FLNa gene expression blocked ligand-induced EGFR responses in metastatic human melanomas. To gain greater insights into the role of FLNa in EGFR activation and intracellular sorting, we used M2 melanoma cells that lack endogenous FLNa and a subclone in which human FLNa cDNA has been stably reintroduced (M2A7 cells). Both tyrosine phosphorylation and ubiquitination of EGFR were significantly lower in epidermal growth factor (EGF)-stimulated M2 cells when compared with M2A7 cells. Moreover, the lack of FLNa interfered with EGFR interaction with the ubiquitin ligase c-Cbl. M2 cells exhibited marked resistance to EGF-induced receptor degradation, which was very active in M2A7 cells. Despite comparable rates of EGF-mediated receptor endocytosis, internalized EGFR colocalized with the lysosomal marker lysosome-associated membrane protein-1 in M2A7 cells but not M2 cells, in which EGFR was found to be sequestered in large vesicles and subsequently accumulated in punctated perinuclear structures after EGF stimulation. These results suggest the requirement of FLNa for efficient EGFR kinase activation and the sorting of endocytosed receptors into the degradation pathway. PMID:19213840

Vascular and connective tissue anomalies associated with X-linked periventricular heterotopia due to mutations in Filamin A

PubMed Central

Reinstein, Eyal; Frentz, Sophia; Morgan, Tim; García-Miñaúr, Sixto; Leventer, Richard J; McGillivray, George; Pariani, Mitchel; van der Steen, Anthony; Pope, Michael; Holder-Espinasse, Muriel; Scott, Richard; Thompson, Elizabeth M; Robertson, Terry; Coppin, Brian; Siegel, Robert; Bret Zurita, Montserrat; Rodríguez, Jose I; Morales, Carmen; Rodrigues, Yuri; Arcas, Joaquín; Saggar, Anand; Horton, Margaret; Zackai, Elaine; Graham, John M; Rimoin, David L; Robertson, Stephen P

2013-01-01

Mutations conferring loss of function at the FLNA (encoding filamin A) locus lead to X-linked periventricular nodular heterotopia (XL-PH), with seizures constituting the most common clinical manifestation of this disorder in female heterozygotes. Vascular dilatation (mainly the aorta), joint hypermobility and variable skin findings are also associated anomalies, with some reports suggesting that this might represents a separate syndrome allelic to XL-PH, termed as Ehlers-Danlos syndrome-periventricular heterotopia variant (EDS-PH). Here, we report a cohort of 11 males and females with both hypomorphic and null mutations in FLNA that manifest a wide spectrum of connective tissue and vascular anomalies. The spectrum of cutaneous defects was broader than previously described and is inconsistent with a specific type of EDS. We also extend the range of vascular anomalies associated with XL-PH to included peripheral arterial dilatation and atresia. Based on these observations, we suggest that there is little molecular or clinical justification for considering EDS-PH as a separate entity from XL-PH, but instead propose that there is a spectrum of vascular and connective tissues anomalies associated with this condition for which all individuals with loss-of-function mutations in FLNA should be evaluated. In addition, since some patients with XL-PH can present primarily with a joint hypermobility syndrome, we propose that screening for cardiovascular manifestations should be offered to those patients when there are associated seizures or an X-linked pattern of inheritance. PMID:23032111

Enhancing Cooperativity in Bifunctional Acid–Pd Catalysts with Carboxylic Acid-Functionalized Organic Monolayers

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

Coan, Patrick D.; Ellis, Lucas D.; Griffin, Michael B.

Here, cooperative catalysts containing a combination of noble metal hydrogenation sites and Bronsted acid sites are critical for many reactions, including the deoxygenation (DO) of biomass-derived oxygenates in the upgrading of pyrolysis oil. One route toward the design of cooperative catalysts is to tether two different catalytically active functions so that they are in close proximity while avoiding undesirable interactions that can block active sites. Here, we deposited carboxylic acid (CA)-functionalized organophosphonate monolayers onto Al 2O 3-supported Pd nanoparticle catalysts to prepare bifunctional catalysts containing both Bronsted acid and metal sites. Modification with phosphonic acids (PAs) improved activity and selectivitymore » for gas-phase DO reactions, but the degree of improvement was highly sensitive to both the presence and positioning of the CA group, suggesting a significant contribution from both the PA and CA sites. Short spacer lengths of 1-2 methylene groups between the phosphonate head and CA tail were found to yield the best DO rates and selectivities, whereas longer chains performed similarly to self-assembled monolayers having alkyl tails. Results from a combination of density functional theory and Fourier transform infrared spectroscopy suggested that the enhanced catalyst performance on the optimally positioned CAs was due to the generation of strong acid sites on the Al 2O 3 support adjacent to the metal. Furthermore, the high activity of these sites was found to result from a hydrogen-bonded cyclic structure involving cooperativity between the phosphonate head group and CA tail function. More broadly, these results indicate that functional groups tethered to supports via organic ligands can influence catalytic chemistry on metal nanoparticles.« less

Enhancing Cooperativity in Bifunctional Acid–Pd Catalysts with Carboxylic Acid-Functionalized Organic Monolayers

DOE PAGES

Coan, Patrick D.; Ellis, Lucas D.; Griffin, Michael B.; ...

2018-03-05

Here, cooperative catalysts containing a combination of noble metal hydrogenation sites and Bronsted acid sites are critical for many reactions, including the deoxygenation (DO) of biomass-derived oxygenates in the upgrading of pyrolysis oil. One route toward the design of cooperative catalysts is to tether two different catalytically active functions so that they are in close proximity while avoiding undesirable interactions that can block active sites. Here, we deposited carboxylic acid (CA)-functionalized organophosphonate monolayers onto Al 2O 3-supported Pd nanoparticle catalysts to prepare bifunctional catalysts containing both Bronsted acid and metal sites. Modification with phosphonic acids (PAs) improved activity and selectivitymore » for gas-phase DO reactions, but the degree of improvement was highly sensitive to both the presence and positioning of the CA group, suggesting a significant contribution from both the PA and CA sites. Short spacer lengths of 1-2 methylene groups between the phosphonate head and CA tail were found to yield the best DO rates and selectivities, whereas longer chains performed similarly to self-assembled monolayers having alkyl tails. Results from a combination of density functional theory and Fourier transform infrared spectroscopy suggested that the enhanced catalyst performance on the optimally positioned CAs was due to the generation of strong acid sites on the Al 2O 3 support adjacent to the metal. Furthermore, the high activity of these sites was found to result from a hydrogen-bonded cyclic structure involving cooperativity between the phosphonate head group and CA tail function. More broadly, these results indicate that functional groups tethered to supports via organic ligands can influence catalytic chemistry on metal nanoparticles.« less

Environmental influences on cooperation in social dilemmas on networks

NASA Astrophysics Data System (ADS)

Xie, Yunya; Chang, Shuhua; Yan, Ming; Zhang, Zhipeng; Wang, Xinyu

2018-02-01

Environmental influence on cooperation is a classical topic that is widely applicable to social interactions. Here, we introduce a realistic model which depends on both the payoff and the strategy of the environment. As the strategy of the environment rather than the neighbor is imitated with a probability, the model takes more attention on the comprehensive influence of the nearby neighbors. The simulation results show that the cooperation level can be widely enhanced for the prisoner's dilemma game and the snowdrift game with this environment factor. In this environmental model, the mechanism of the survival of cooperators is deeply studied, and the corresponding results can be derived. Although the survival of cooperators also depends on the formation of the cooperator clusters, the enhancement of the cooperation level can be interpreted as the accumulation effect of the transformation of defection into cooperation. Interestingly, there exists a threshold of the initial fraction of the cooperators, and the cooperation increases significantly when this threshold is reached Moreover, the square cooperative cluster is stable, and robust against different levels of the noise parameter and temptation in the strategy adoption process. This work may shed light on the mechanism of cooperation in the real world.

Department of Defense International Space Cooperation Strategy

DTIC Science & Technology

2017-01-01

Secretary of Defense on .January 18. 2017. the unclassified version provides DoD’s approach for invigorating cooperation and collaboration with trusted ...Cooperation Strategy (ISCS) establishes DoD’ s approach for invigorating cooperation and collaboration with trusted allies and partners across the...collaborating with trusted allies and partners to address shared security challenges by leveraging allies’ and partners ’ capabilities to enhance space mission

Punish and voice: punishment enhances cooperation when combined with norm-signalling.

PubMed

Andrighetto, Giulia; Brandts, Jordi; Conte, Rosaria; Sabater-Mir, Jordi; Solaz, Hector; Villatoro, Daniel

2013-01-01

Material punishment has been suggested to play a key role in sustaining human cooperation. Experimental findings, however, show that inflicting mere material costs does not always increase cooperation and may even have detrimental effects. Indeed, ethnographic evidence suggests that the most typical punishing strategies in human ecologies (e.g., gossip, derision, blame and criticism) naturally combine normative information with material punishment. Using laboratory experiments with humans, we show that the interaction of norm communication and material punishment leads to higher and more stable cooperation at a lower cost for the group than when used separately. In this work, we argue and provide experimental evidence that successful human cooperation is the outcome of the interaction between instrumental decision-making and the norm psychology humans are provided with. Norm psychology is a cognitive machinery to detect and reason upon norms that is characterized by a salience mechanism devoted to track how much a norm is prominent within a group. We test our hypothesis both in the laboratory and with an agent-based model. The agent-based model incorporates fundamental aspects of norm psychology absent from previous work. The combination of these methods allows us to provide an explanation for the proximate mechanisms behind the observed cooperative behaviour. The consistency between the two sources of data supports our hypothesis that cooperation is a product of norm psychology solicited by norm-signalling and coercive devices.

Critical mass of public goods and its coevolution with cooperation

NASA Astrophysics Data System (ADS)

Shi, Dong-Mei; Wang, Bing-Hong

2017-07-01

In this study, the enhancing parameter represented the value of the public goods to the public in public goods game, and was rescaled to a Fermi-Dirac distribution function of critical mass. Public goods were divided into two categories, consumable and reusable public goods, and their coevolution with cooperative behavior was studied. We observed that for both types of public goods, cooperation was promoted as the enhancing parameter increased when the value of critical mass was not very large. An optimal value of critical mass which led to the best cooperation was identified. We also found that cooperations emerged earlier for reusable public goods, and defections became extinct earlier for the consumable public goods. Moreover, we observed that a moderate depreciation rate for public goods resulted in an optimal cooperation, and this range became wider as the enhancing parameter increased. The noise influence on cooperation was studied, and it was shown that cooperation density varied non-monotonically as noise amplitude increased for reusable public goods, whereas decreased monotonically for consumable public goods. Furthermore, existence of the optimal critical mass was also identified in other three regular networks. Finally, simulation results were utilized to analyze the provision of public goods in detail.

Punish and Voice: Punishment Enhances Cooperation when Combined with Norm-Signalling

PubMed Central

Andrighetto, Giulia; Brandts, Jordi; Conte, Rosaria; Sabater-Mir, Jordi; Solaz, Hector; Villatoro, Daniel

2013-01-01

Material punishment has been suggested to play a key role in sustaining human cooperation. Experimental findings, however, show that inflicting mere material costs does not always increase cooperation and may even have detrimental effects. Indeed, ethnographic evidence suggests that the most typical punishing strategies in human ecologies (e.g., gossip, derision, blame and criticism) naturally combine normative information with material punishment. Using laboratory experiments with humans, we show that the interaction of norm communication and material punishment leads to higher and more stable cooperation at a lower cost for the group than when used separately. In this work, we argue and provide experimental evidence that successful human cooperation is the outcome of the interaction between instrumental decision-making and the norm psychology humans are provided with. Norm psychology is a cognitive machinery to detect and reason upon norms that is characterized by a salience mechanism devoted to track how much a norm is prominent within a group. We test our hypothesis both in the laboratory and with an agent-based model. The agent-based model incorporates fundamental aspects of norm psychology absent from previous work. The combination of these methods allows us to provide an explanation for the proximate mechanisms behind the observed cooperative behaviour. The consistency between the two sources of data supports our hypothesis that cooperation is a product of norm psychology solicited by norm-signalling and coercive devices. PMID:23776441

High-level secretion of tissue factor-rich extracellular vesicles from ovarian cancer cells mediated by filamin-A and protease-activated receptors.

PubMed

Koizume, Shiro; Ito, Shin; Yoshioka, Yusuke; Kanayama, Tomohiko; Nakamura, Yoshiyasu; Yoshihara, Mitsuyo; Yamada, Roppei; Ochiya, Takahiro; Ruf, Wolfram; Miyagi, Etsuko; Hirahara, Fumiki; Miyagi, Yohei

2016-01-01

Thromboembolic events occur frequently in ovarian cancer patients. Tissue factor (TF) is often overexpressed in tumours, including ovarian clear-cell carcinoma (CCC), a subtype with a generally poor prognosis. TF-coagulation factor VII (fVII) complexes on the cell surface activate downstream coagulation mechanisms. Moreover, cancer cells secrete extracellular vesicles (EVs), which act as vehicles for TF. We therefore examined the characteristics of EVs produced by ovarian cancer cells of various histological subtypes. CCC cells secreted high levels of TF within EVs, while the high-TF expressing breast cancer cell line MDA-MB-231 shed fewer TF-positive EVs. We also found that CCC tumours with hypoxic tissue areas synthesised TF and fVII in vivo, rendering the blood of xenograft mice bearing these tumours hypercoagulable compared with mice bearing MDA-MB-231 tumours. Incorporation of TF into EVs and secretion of EVs from CCC cells exposed to hypoxia were both dependent on the actin-binding protein, filamin-A (filA). Furthermore, production of these EVs was dependent on different protease-activated receptors (PARs) on the cell surface. These results show that CCC cells could produce large numbers of TF-positive EVs dependent upon filA and PARs. This phenomenon may be the mechanism underlying the increased incidence of venous thromboembolism in ovarian cancer patients.

Cooperation is enhanced by inhomogeneous inertia in spatial prisoner's dilemma game

NASA Astrophysics Data System (ADS)

Chang, Shuhua; Zhang, Zhipeng; Wu, Yu'e.; Xie, Yunya

2018-01-01

Inertia is an important factor that cannot be ignored in the real world for some lazy individuals in the process of decision making. In this work, we introduce a simple classification mechanism of strategy changing in evolutionary prisoner's dilemma games on different topologies. In this model, a part of players update their strategies according to not only the payoff difference, but also the inertia factor, which makes nodes heterogeneous and the system inhomogeneous. Moreover, we also study the impact of the number of neighbors on the evolution of cooperation. The results show that the evolution of cooperation will be promoted to a high level when the inertia factor and the inhomogeneous system are combined. In addition, we find that the more neighbors one player has, the higher density of cooperators is sustained in the optimal position. This work could be conducive to understanding the emergence and persistence of cooperative behavior caused by the inertia factor in reality.

Cooperation and age structure in spatial games

NASA Astrophysics Data System (ADS)

Wang, Zhen; Wang, Zhen; Zhu, Xiaodan; Arenzon, Jeferson J.

2012-01-01

We study the evolution of cooperation in evolutionary spatial games when the payoff correlates with the increasing age of players (the level of correlation is set through a single parameter, α). The demographic heterogeneous age distribution, directly affecting the outcome of the game, is thus shown to be responsible for enhancing the cooperative behavior in the population. In particular, moderate values of α allow cooperators not only to survive but to outcompete defectors, even when the temptation to defect is large and the ageless, standard α=0 model does not sustain cooperation. The interplay between age structure and noise is also considered, and we obtain the conditions for optimal levels of cooperation.

Enhancement of cooperation in the spatial prisoner's dilemma with a coherence-resonance effect through annealed randomness at a cooperator-defector boundary; comparison of two variant models

NASA Astrophysics Data System (ADS)

Tanimoto, Jun

2016-11-01

Inspired by the commonly observed real-world fact that people tend to behave in a somewhat random manner after facing interim equilibrium to break a stalemate situation whilst seeking a higher output, we established two models of the spatial prisoner's dilemma. One presumes that an agent commits action errors, while the other assumes that an agent refers to a payoff matrix with an added random noise instead of an original payoff matrix. A numerical simulation revealed that mechanisms based on the annealing of randomness due to either the action error or the payoff noise could significantly enhance the cooperation fraction. In this study, we explain the detailed enhancement mechanism behind the two models by referring to the concepts that we previously presented with respect to evolutionary dynamic processes under the names of enduring and expanding periods.

Pressure to cooperate: is positive reward interdependence really needed in cooperative learning?

PubMed

Buchs, Céline; Gilles, Ingrid; Dutrévis, Marion; Butera, Fabrizio

2011-03-01

BACKGROUND. Despite extensive research on cooperative learning, the debate regarding whether or not its effectiveness depends on positive reward interdependence has not yet found clear evidence. AIMS. We tested the hypothesis that positive reward interdependence, as compared to reward independence, enhances cooperative learning only if learners work on a 'routine task'; if the learners work on a 'true group task', positive reward interdependence induces the same level of learning as reward independence. SAMPLE. The study involved 62 psychology students during regular workshops. METHOD. Students worked on two psychology texts in cooperative dyads for three sessions. The type of task was manipulated through resource interdependence: students worked on either identical (routine task) or complementary (true group task) information. Students expected to be assessed with a Multiple Choice Test (MCT) on the two texts. The MCT assessment type was introduced according to two reward interdependence conditions, either individual (reward independence) or common (positive reward interdependence). A follow-up individual test took place 4 weeks after the third session of dyadic work to examine individual learning. RESULTS. The predicted interaction between the two types of interdependence was significant, indicating that students learned more with positive reward interdependence than with reward independence when they worked on identical information (routine task), whereas students who worked on complementary information (group task) learned the same with or without reward interdependence. CONCLUSIONS. This experiment sheds light on the conditions under which positive reward interdependence enhances cooperative learning, and suggests that creating a real group task allows to avoid the need for positive reward interdependence. © 2010 The British Psychological Society.

Using Cooperative Structures to Promote Deep Learning

ERIC Educational Resources Information Center

Millis, Barbara J.

2014-01-01

The author explores concrete ways to help students learn more and have fun doing it while they support each other's learning. The article specifically shows the relationships between cooperative learning and deep learning. Readers will become familiar with the tenets of cooperative learning and its power to enhance learning--even more so when…

Principles of cooperation across systems: from human sharing to multicellularity and cancer.

PubMed

Aktipis, Athena

2016-01-01

From cells to societies, several general principles arise again and again that facilitate cooperation and suppress conflict. In this study, I describe three general principles of cooperation and how they operate across systems including human sharing, cooperation in animal and insect societies and the massively large-scale cooperation that occurs in our multicellular bodies. The first principle is that of Walk Away: that cooperation is enhanced when individuals can leave uncooperative partners. The second principle is that resource sharing is often based on the need of the recipient (i.e., need-based transfers) rather than on strict account-keeping. And the last principle is that effective scaling up of cooperation requires increasingly sophisticated and costly cheater suppression mechanisms. By comparing how these principles operate across systems, we can better understand the constraints on cooperation. This can facilitate the discovery of novel ways to enhance cooperation and suppress cheating in its many forms, from social exploitation to cancer.

Genetic information transfer promotes cooperation in bacteria

PubMed Central

Dimitriu, Tatiana; Lotton, Chantal; Bénard-Capelle, Julien; Misevic, Dusan; Brown, Sam P.; Lindner, Ariel B.; Taddei, François

2014-01-01

Many bacterial species are social, producing costly secreted “public good” molecules that enhance the growth of neighboring cells. The genes coding for these cooperative traits are often propagated via mobile genetic elements and can be virulence factors from a biomedical perspective. Here, we present an experimental framework that links genetic information exchange and the selection of cooperative traits. Using simulations and experiments based on a synthetic bacterial system to control public good secretion and plasmid conjugation, we demonstrate that horizontal gene transfer can favor cooperation. In a well-mixed environment, horizontal transfer brings a direct infectious advantage to any gene, regardless of its cooperation properties. However, in a structured population transfer selects specifically for cooperation by increasing the assortment among cooperative alleles. Conjugation allows cooperative alleles to overcome rarity thresholds and invade bacterial populations structured purely by stochastic dilution effects. Our results provide an explanation for the prevalence of cooperative genes on mobile elements, and suggest a previously unidentified benefit of horizontal gene transfer for bacteria. PMID:25024219

Heterogeneous Link Weight Promotes the Cooperation in Spatial Prisoner's Dilemma

NASA Astrophysics Data System (ADS)

Ma, Zhi-Qin; Xia, Cheng-Yi; Sun, Shi-Wen; Wang, Li; Wang, Huai-Bin; Wang, Juan

The spatial structure has often been identified as a prominent mechanism that substantially promotes the cooperation level in prisoner's dilemma game. In this paper we introduce a weighting mechanism into the spatial prisoner's dilemma game to explore the cooperative behaviors on the square lattice. Here, three types of weight distributions: exponential, power-law and uniform distributions are considered, and the weight is assigned to links between players. Through large-scale numerical simulations we find, compared with the traditional spatial game, that this mechanism can largely enhance the frequency of cooperators. For most ranges of b, we find that the power-law distribution enables the highest promotion of cooperation and the uniform one leads to the lowest enhancement, whereas the exponential one lies often between them. The great improvement of cooperation can be caused by the fact that the distributional link weight yields inhomogeneous interaction strength among individuals, which can facilitate the formation of cooperative clusters to resist the defector's invasion. In addition, the impact of amplitude of the undulation of weight distribution and noise strength on cooperation is also investigated for three kinds of weight distribution. Current researches can aid in the further understanding of evolutionary cooperation in biological and social science.

Regulation of AQP0 water permeability is enhanced by cooperativity

PubMed Central

Németh-Cahalan, Karin L.; Clemens, Daniel M.

2013-01-01

Aquaporin 0 (AQP0), essential for lens clarity, is a tetrameric protein composed of four identical monomers, each of which has its own water pore. The water permeability of AQP0 expressed in Xenopus laevis oocytes can be approximately doubled by changes in calcium concentration or pH. Although each monomer pore functions as a water channel, under certain conditions the pores act cooperatively. In other words, the tetramer is the functional unit. In this paper, we show that changes in external pH and calcium can induce an increase in water permeability that exhibits either a positive cooperativity switch-like increase in water permeability or an increase in water permeability in which each monomer acts independently and additively. Because the concentrations of calcium and hydrogen ions increase toward the center of the lens, a concentration signal could trigger a regulatory change in AQP0 water permeability. It thus seems plausible that the cooperative modes of water permeability regulation by AQP0 tetramers mediated by decreased pH and elevated calcium are the physiologically important ones in the living lens. PMID:23440275

Effects of Individual's Self-Examination on Cooperation in Prisoner's Dilemma Game

NASA Astrophysics Data System (ADS)

Guan, Jian-Yue; Sun, Jin-Tu; Wang, Ying-Hai

We study a spatial evolutionary prisoner's dilemma game on regular network's one-dimensional regular ring and two-dimensional square lattice. The individuals located on the sites of networks can either cooperate with their neighbors or defect. The effects of individual's self-examination are introduced. Using Monte Carlo simulations and pair approximation method, we investigate the average density of cooperators in the stationary state for various values of payoff parameters b and the time interval Δt. The effects of the fraction p of players in the system who are using the self-examination on cooperation are also discussed. It is shown that compared with the case of no individual's self-examination, the persistence of cooperation is inhibited when the payoff parameter b is small and at certain Δt (Δt > 0) or p (p > 0), cooperation is mostly inhibited, while when b is large, the emergence of cooperation can be remarkably enhanced and mostly enhanced at Δt = 0 or p = 1.

Conditional imitation might promote cooperation under high temptations to defect

NASA Astrophysics Data System (ADS)

Dai, Qionglin; Li, Haihong; Cheng, Hongyan; Qian, Xiaolan; Zhang, Mei; Yang, Junzhong

2012-07-01

In this paper we introduce a conditional imitation rule into an evolutionary game, in which the imitation probabilities of individuals are determined by a function of payoff difference and two crucial parameters μ and σ. The parameter μ characterizes the most adequate goal for individuals and the parameter σ characterizes the tolerance of individuals. By using the pair approximation method and numerical simulations, we find an anomalous cooperation enhancement in which the cooperation level shows a nonmonotonic variation with the increase of temptation. The parameter μ affects the regime of the payoff parameter which supports the anomalous cooperation enhancement, whereas the parameter σ plays a decisive role on the appearance of the nonmonotonic variation of the cooperation level. Furthermore, to give explicit implications for the parameters μ and σ we present an alterative form of the conditional imitation rule based on the benefit and the cost incurred to individuals during strategy updates. In this way, we also provide a phenomenological interpretation for the nonmonotonic behavior of cooperation with the increase of temptation. The results give a clue that a higher cooperation level could be obtained under adverse environments for cooperation by applying the conditional imitation rule, which is possible to be manipulated in real life. More generally, the results in this work might point out an efficient way to maintain cooperation in the risky environments to cooperators.

How actin crosslinking and bundling proteins cooperate to generate an enhanced cell mechanical response

NASA Technical Reports Server (NTRS)

Tseng, Yiider; Kole, Thomas P.; Lee, Jerry S H.; Fedorov, Elena; Almo, Steven C.; Schafer, Benjamin W.; Wirtz, Denis

2005-01-01

Actin-crosslinking proteins organize actin filaments into dynamic and complex subcellular scaffolds that orchestrate important mechanical functions, including cell motility and adhesion. Recent mutation studies have shown that individual crosslinking proteins often play seemingly non-essential roles, leading to the hypothesis that they have considerable redundancy in function. We report live-cell, in vitro, and theoretical studies testing the mechanical role of the two ubiquitous actin-crosslinking proteins, alpha-actinin and fascin, which co-localize to stress fibers and the basis of filopodia. Using live-cell particle tracking microrheology, we show that the addition of alpha-actinin and fascin elicits a cell mechanical response that is significantly greater than that originated by alpha-actinin or fascin alone. These live-cell measurements are supported by quantitative rheological measurements with reconstituted actin filament networks containing pure proteins that show that alpha-actinin and fascin can work in concert to generate enhanced cell stiffness. Computational simulations using finite element modeling qualitatively reproduce and explain the functional synergy of alpha-actinin and fascin. These findings highlight the cooperative activity of fascin and alpha-actinin and provide a strong rationale that an evolutionary advantage might be conferred by the cooperative action of multiple actin-crosslinking proteins with overlapping but non-identical biochemical properties. Thus the combination of structural proteins with similar function can provide the cell with unique properties that are required for biologically optimal responses.

Coevolution of cooperation and network structure under natural selection

NASA Astrophysics Data System (ADS)

Yang, D.-P.; Lin, H.; Shuai, J. W.

2011-02-01

A coevolution model by coupling mortality and fertility selection is introduced to investigate the evolution of cooperation and network structure in the prisoner's dilemma game. The cooperation level goes through a continuous phase transition vs. defection temptation b for low mortality selection intensity β and through a discontinuous one for infinite β. The cooperation level is enhanced most at β≈1 for any b. The local and global properties of the network structure, such as cluster and cooperating k-core, are investigated for the understanding of cooperation evolution. Cooperation is promoted by forming a tight cooperating k-core at moderate β, but too large β will destroy the cooperating k-core rapidly resulting in a rapid drop of the cooperation level. Importantly, the infinite β changes the normalized sucker's payoff S from 0 to 1-b and its dynamics of the cooperation level undergoes a very slow power-law decay, which leads the evolution into the regime of neutral evolution.

TGFβ and BMP Dependent Cell Fate Changes Due to Loss of Filamin B Produces Disc Degeneration and Progressive Vertebral Fusions

PubMed Central

Zieba, Jennifer; Forlenza, Kimberly Nicole; Khatra, Jagteshwar Singh; Sarukhanov, Anna; Duran, Ivan; Rigueur, Diana; Lyons, Karen M.; Cohn, Daniel H.; Merrill, Amy E.; Krakow, Deborah

2016-01-01

Spondylocarpotarsal synostosis (SCT) is an autosomal recessive disorder characterized by progressive vertebral fusions and caused by loss of function mutations in Filamin B (FLNB). FLNB acts as a signaling scaffold by linking the actin cytoskleteon to signal transduction systems, yet the disease mechanisms for SCT remain unclear. Employing a Flnb knockout mouse, we found morphologic and molecular evidence that the intervertebral discs (IVDs) of Flnb–/–mice undergo rapid and progressive degeneration during postnatal development as a result of abnormal cell fate changes in the IVD, particularly the annulus fibrosus (AF). In Flnb–/–mice, the AF cells lose their typical fibroblast-like characteristics and acquire the molecular and phenotypic signature of hypertrophic chondrocytes. This change is characterized by hallmarks of endochondral-like ossification including alterations in collagen matrix, expression of Collagen X, increased apoptosis, and inappropriate ossification of the disc tissue. We show that conversion of the AF cells into chondrocytes is coincident with upregulated TGFβ signaling via Smad2/3 and BMP induced p38 signaling as well as sustained activation of canonical and noncanonical target genes p21 and Ctgf. These findings indicate that FLNB is involved in attenuation of TGFβ/BMP signaling and influences AF cell fate. Furthermore, we demonstrate that the IVD disruptions in Flnb–/–mice resemble aging degenerative discs and reveal new insights into the molecular causes of vertebral fusions and disc degeneration. PMID:27019229

Persistence paves the way for cooperation in evolutionary games

NASA Astrophysics Data System (ADS)

Huang, Chang-Wei; Dai, Qiong-Lin

2017-04-01

Cooperation is an effective way to maximize collective benefits, especially in modern human society. The issues on the emergence and maintenance of cooperation have attracted much attention in recent years. Here, we introduce the persistence parameter τ to characterize the time duration of choices held by individuals and consider the effects of τ on cooperation. We find that persistence could promote cooperation in a population no matter what the network structure is. Furthermore, the results on heterogeneous networks show that individuals with larger τ are more inclined to cooperate than those with smaller τ. Moreover, we investigate the effects of correlations between degree and persistence in scale-free networks and find that assortative matching could remarkably enhance cooperation whereas disassortative matching has adverse impacts on the evolution of cooperation.

Implementing Strategies of Cooperation for Enhancing Intrinsic Motivation towards English Language Learning

ERIC Educational Resources Information Center

Zapata, Julian Esteban

2007-01-01

This action research paper dealt with how to increase motivation towards English language learning through cooperative work in a public school in Medellín, Colombia. It was necessary to explore the concepts of teachers' beliefs, social teaching, collaborative and cooperative learning, to understand the conditions and activities that favored…

Evolution of cooperation in a hierarchical society with corruption control.

PubMed

Huang, Feng; Chen, Xiaojie; Wang, Long

2018-07-14

Punishment is widely recognized as a potential promoter in sustaining or even enhancing public cooperation, but it meanwhile induces the problem of second-order free-riders. Particularly, recent evidence shows that costly punishment can be maintained if punishers may engage in corruption. However, how to reduce or eliminate incidents of corruption has been the enduring conundrum in human society. As power asymmetries are associated with hierarchies, we investigate how costly punishment affects the evolution of cooperation in the cases without and with corruption control. In the absence of corruption control, altruistic punishers are incapable of punishing corrupt punishers. Corrupt punishment maintains civilian cooperation but undermines the evolution of altruistic punishment. Otherwise, altruistic punishers can enforce symmetrical or asymmetrical punishment on both corrupt punishers and civilian defectors. In this case, both civilian cooperation and altruistic punishment can be promoted. And as an instrument of corruption control, the policy of asymmetrical punishment is more effective in fostering public cooperation and improving social welfare than symmetrical punishment. Moreover, no matter whether corruption control is considered or not, spiteful corruption that non-cooperative punishers penalize defectors is a more effective form for enhancing cooperation compared with bribery. Our work may thus offer an insight into the effects of corruption on public cooperation and the policy of anti-corruption. Copyright © 2018 Elsevier Ltd. All rights reserved.

Better Together: Outcomes of Cooperation Versus Competition in Social Exergaming.

PubMed

Marker, Arwen M; Staiano, Amanda E

2015-02-01

Children and adolescents most often play active videogames, or exergames, in a social environment. Social play may enhance the potential benefits of an exergaming experience, much like group exercise and team sports are observed to improve physical activity-related outcomes above those of solitary exercise. Two ubiquitous elements of exergames are cooperation and competition. Previous literature suggests that cooperative and competitive aspects of exergames may affect physiological and psychosocial changes. Competitive play has been found to increase energy expenditure and aggression in short bouts of exergaming. Cooperative exergaming has been found to increase motivation, promote continued play, enhance self-efficacy, and increase pro-social behaviors. In one study, a cooperative exergaming condition also resulted in significant weight loss for overweight and obese adolescents. Individual player differences such as individual preferences, competitiveness, weight status, age, gender, and ethnicity may moderate effects. Although the current volume of literature on competition and cooperation in exergaming is small, social exergames hold promise as an engaging alternative to traditional physical activity interventions and may promote a broad range of positive outcomes for children and adolescents. Principles of cooperation and competition are applicable for developers of health-promoting games. Future research is needed to further understand the mechanisms of how competition and cooperation in social exergaming impact physiological and psychosocial outcomes.

The Effect of Using Cooperative and Individual Weblog to Enhance Writing Performance

ERIC Educational Resources Information Center

Karsak, H. Gulhan Orhan; Fer, Seval; Orhan, Feza

2014-01-01

Academic writing, whether individual or cooperative, is an essential skill for today's graduates. However, motivating and helping students to learn to write effectively, either in cooperative or individual scenarios, poses many challenges, many of which can be overcome by technical means. The aim of this study is to investigate the effect of using…

Evolution of cooperation through adaptive interaction in a spatial prisoner's dilemma game

NASA Astrophysics Data System (ADS)

Pan, Qiuhui; Liu, Xuesong; Bao, Honglin; Su, Yu; He, Mingfeng

2018-02-01

In this paper, we study the effect of adaptive interaction on the evolution of cooperation in a spatial prisoner's dilemma game. The connections of players are co-evolutionary with cooperation; whether adjacent players can play the prisoner's dilemma game is associated with the strategies they took in the preceding round. If a player defected in the preceding round, his neighbors will refuse to play the prisoner's dilemma game with him in accordance with a certain probability distribution. We use the disconnecting strength to represent this probability. We discuss the evolution of cooperation with different values of temptation to defect, sucker's payoff and disconnecting strength. The simulation results show that cooperation can be significantly enhanced through increasing the value of the disconnecting strength. In addition, the increase in disconnecting strength can improve the cooperators' ability to resist the increase in temptation and the decrease in reward. We study the parameter ranges for three different evolutionary results: cooperators extinction, defectors extinction, cooperator and defector co-existence. Meanwhile, we recruited volunteers and designed a human behavioral experiment to verify the theoretical simulation results. The punishment of disconnection has a positive effect on cooperation. A higher disconnecting strength will enhance cooperation more significantly. Our research findings reveal some significant insights into efficient mechanisms of the evolution of cooperation.

Cooperation in scale-free networks with limited associative capacities

NASA Astrophysics Data System (ADS)

Poncela, Julia; Gómez-Gardeñes, Jesús; Moreno, Yamir

2011-05-01

In this work we study the effect of limiting the number of interactions (the associative capacity) that a node can establish per round of a prisoner’s dilemma game. We focus on the way this limitation influences the level of cooperation sustained by scale-free networks. We show that when the game includes cooperation costs, limiting the associative capacity of nodes to a fixed quantity renders in some cases larger values of cooperation than in the unrestricted scenario. This allows one to define an optimum capacity for which cooperation is maximally enhanced. Finally, for the case without cooperation costs, we find that even a tight limitation of the associative capacity of nodes yields the same levels of cooperation as in the original network.

Social Environment Shapes the Speed of Cooperation

PubMed Central

Nishi, Akihiro; Christakis, Nicholas A.; Evans, Anthony M.; O’Malley, A. James; Rand, David G.

2016-01-01

Are cooperative decisions typically made more quickly or slowly than non-cooperative decisions? While this question has attracted considerable attention in recent years, most research has focused on one-shot interactions. Yet it is repeated interactions that characterize most important real-world social interactions. In repeated interactions, the cooperativeness of one’s interaction partners (the “social environment”) should affect the speed of cooperation. Specifically, we propose that reciprocal decisions (choices that mirror behavior observed in the social environment), rather than cooperative decisions per se, occur more quickly. We test this hypothesis by examining four independent decision time datasets with a total of 2,088 subjects making 55,968 decisions. We show that reciprocal decisions are consistently faster than non-reciprocal decisions: cooperation is faster than defection in cooperative environments, while defection is faster than cooperation in non-cooperative environments. These differences are further enhanced by subjects’ previous behavior – reciprocal decisions are faster when they are consistent with the subject’s previous choices. Finally, mediation analyses of a fifth dataset suggest that the speed of reciprocal decisions is explained, in part, by feelings of conflict – reciprocal decisions are less conflicted than non-reciprocal decisions, and less decision conflict appears to lead to shorter decision times. PMID:27435940

Collective-goal ascription increases cooperation in humans.

PubMed

Mitkidis, Panagiotis; Sørensen, Jesper; Nielbo, Kristoffer L; Andersen, Marc; Lienard, Pierre

2013-01-01

Cooperation is necessary in many types of human joint activity and relations. Evidence suggests that cooperation has direct and indirect benefits for the cooperators. Given how beneficial cooperation is overall, it seems relevant to investigate the various ways of enhancing individuals' willingness to invest in cooperative endeavors. We studied whether ascription of a transparent collective goal in a joint action promotes cooperation in a group. A total of 48 participants were assigned in teams of 4 individuals to either a "transparent goal-ascription" or an "opaque goal-ascription" condition. After the manipulation, the participants played an anonymous public goods game with another member of their team. We measured the willingness of participants to cooperate and their expectations about the other player's contribution. Between subjects analyses showed that transparent goal ascription impacts participants' likelihood to cooperate with each other in the future, thereby greatly increasing the benefits from social interactions. Further analysis showed that this could be explained with a change in expectations about the partner's behavior and by an emotional alignment of the participants. The study found that a transparent goal ascription is associated with an increase of cooperation. We propose several high-level mechanisms that could explain the observed effect: general affect modulation, trust, expectation and perception of collective efficacy.

3 CFR - Certifications Pursuant to Section 104 of the United States-India Nuclear Cooperation Approval...

Code of Federal Regulations, 2011 CFR

2011-01-01

... States-India Nuclear Cooperation Approval and Nonproliferation Enhancement Act Regarding the Safeguards Agreement Between India and the International Atomic Energy Agency Presidential Documents Other Presidential... of the United States-India Nuclear Cooperation Approval and Nonproliferation Enhancement Act...

Career Maturity: Effects of Secondary School Co-operative Education.

ERIC Educational Resources Information Center

Varner, Jan

Career education programs, such as co-operative education, have been shown to influence career development. The purpose of this study was to investigate whether secondary school co-operative education had the benefit of enhanced career maturity, as measured by the Career Development Inventory. An experimental design called the Solomon four-group…

Cooperation between two ClpB isoforms enhances the recovery of the recombinant {beta}-galactosidase from inclusion bodies

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

Guenther, Izabela; Zolkiewski, Michal; Kedzierska-Mieszkowska, Sabina, E-mail: kedzie@biotech.ug.gda.pl

Highlights: Black-Right-Pointing-Pointer An important role of synergistic cooperation between the two ClpB isoforms. Black-Right-Pointing-Pointer Both ClpB isoforms are associated with IBs of {beta}-galactosidase. Black-Right-Pointing-Pointer ClpB is a key chaperone in IB protein release. -- Abstract: Bacterial ClpB is a molecular chaperone that solubilizes and reactivates aggregated proteins in cooperation with the DnaK chaperone system. The mechanism of protein disaggregation mediated by ClpB is linked to translocation of substrates through the central channel within the ring-hexameric structure of ClpB. Two isoforms of ClpB are produced in vivo: the full-length ClpB95 and the truncated ClpB80 (ClpB{Delta}N), which does not contain the N-terminalmore » domain. The functional specificity of the two ClpB isoforms and the biological role of the N-terminal domain are still not fully understood. Recently, it has been demonstrated that ClpB may achieve its full potential as an aggregate-reactivating chaperone through the functional interaction and synergistic cooperation of its two isoforms. It has been found that the most efficient resolubilization and reactivation of stress-aggregated proteins occurred in the presence of both ClpB95 and ClpB80. In this work, we asked if the two ClpB isoforms functionally cooperate in the solubilization and reactivation of proteins from insoluble inclusion bodies (IBs) in Escherichia coli cells. Using the model {beta}-galactosidase fusion protein (VP1LAC), we found that solubilization and reactivation of enzymes entrapped in IBs occurred more efficiently in the presence of ClpB95 with ClpB80 than with either ClpB95 or ClpB80 alone. The two isoforms of ClpB chaperone acting together enhanced the solubility and enzymatic activity of {beta}-galactosidase sequestered into IBs. Both ClpB isoforms were associated with IBs of {beta}-galactosidase, what demonstrates their affinity to this type of aggregates. These results demonstrate a

Diversity of rationality affects the evolution of cooperation

NASA Astrophysics Data System (ADS)

Chen, Yu-Zhong; Huang, Zi-Gang; Wang, Sheng-Jun; Zhang, Yan; Wang, Ying-Hai

2009-05-01

By modifying the Fermi updating rule, we present the diversity of individual rationality to the evolutionary prisoner’s dilemma game, and our results shows that this diversity heavily influences the evolution of cooperation. Cluster-forming mechanism of cooperators can either be highly enhanced or severely deteriorated by different distributions of rationality. Slight change in the rationality distribution may transfer the whole system from the global absorbing state of cooperators to that of defectors. Based on mean-field argument, quantitative analysis of the stability of cooperative clusters reveals the critical role played by agents with moderate degree values in the evolution of the whole system. The inspiration from our work may provide us a deeper comprehension toward some social phenomena.

Cooperation in the prisoner's dilemma game on tunable community networks

NASA Astrophysics Data System (ADS)

Liu, Penghui; Liu, Jing

2017-04-01

Community networks have attracted lots of attention as they widely exist in the real world and are essential to study properties of networks. As the game theory illustrates the competitive relationship among individuals, studying the iterated prisoner's dilemma games (PDG) on community networks is meaningful. In this paper, we focus on investigating the relationship between the cooperation level of community networks and that of their communities in the prisoner's dilemma games. With this purpose in mind, a type of tunable community networks whose communities inherit not only the scale-free property, but also the characteristic of adjustable cooperation level of Holme and Kim (HK) networks is designed. Both uniform and non-uniform community networks are investigated. We find out that cooperation enhancement of communities can improve the cooperation level of the whole networks. Moreover, simulation results indicate that a large community is a better choice than a small community to improve the cooperation level of the whole networks. Thus, improving the cooperation level of community networks can be divided into a number of sub-problems targeting at improving the cooperation level of individual communities, which can save the computation cost and deal with the problem of improving the cooperation level of huge community networks. Moreover, as the larger community is a better choice, it is reasonable to start with large communities, according to the greedy strategy when the number of nodes can participate in the enhancement is limited.

The evolution of cooperation by the Hankshaw effect.

PubMed

Hammarlund, Sarah P; Connelly, Brian D; Dickinson, Katherine J; Kerr, Benjamin

2016-06-01

The evolution of cooperation-costly behavior that benefits others-faces one clear obstacle. Namely, cooperators are always at a competitive disadvantage relative to defectors, individuals that reap the benefits, but evade the cost of cooperation. One solution to this problem involves genetic hitchhiking, where the allele encoding cooperation becomes linked to a beneficial mutation, allowing cooperation to rise in abundance. Here, we explore hitchhiking in the context of adaptation to a stressful environment by cooperators and defectors with spatially limited dispersal. Under such conditions, clustered cooperators reach higher local densities, thereby experiencing more mutational opportunities than defectors. Thus, the allele encoding cooperation has a greater probability of hitchhiking with alleles conferring stress adaptation. We label this probabilistic enhancement the "Hankshaw effect" after the character Sissy Hankshaw, whose anomalously large thumbs made her a singularly effective hitchhiker. Using an agent-based model, we reveal a broad set of conditions that allow the evolution of cooperation through this effect. Additionally, we show that spite, a costly behavior that harms others, can evolve by the Hankshaw effect. While in an unchanging environment these costly social behaviors have transient success, in a dynamic environment, cooperation and spite can persist indefinitely. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

An Investigative, Cooperative Learning Approach to the General Microbiology Laboratory

ERIC Educational Resources Information Center

Seifert, Kyle; Fenster, Amy; Dilts, Judith A.; Temple, Louise

2009-01-01

Investigative- and cooperative-based learning strategies have been used effectively in a variety of classrooms to enhance student learning and engagement. In the General Microbiology laboratory for juniors and seniors at James Madison University, these strategies were combined to make a semester-long, investigative, cooperative learning experience…

Nanoantenna-Microcavity Hybrids with Highly Cooperative Plasmonic-Photonic Coupling

NASA Astrophysics Data System (ADS)

Liu, Jui-Nung; Huang, Qinglan; Liu, Keng-Ku; Singamaneni, Srikanth; Cunningham, Brian T.

2017-12-01

Nanoantennas concentrate electromagnetic energy into deep-subwavelength volumes (hotspot), which benefits a wide range of applications such as spontaneous emission enhancement, nonlinear optics, nanolaser, and surface-enhanced Raman scattering (SERS). To increase hotspot intensity, methods for sculpting individual nanoantenna resonance have been previously explored. Here, we study a nanoantenna-microcavity hybrid approach for highly cooperative hotspot enhancement, combining gold nanorods (AuNRs) for nanometer-scale light concentration and a resonant photonic crystal (PC) slab for efficient near-field excitation and optical feedback. We experimentally validate the predicted synergistic hybrid enhancement with SERS, and demonstrate that coupling to the modest-Q PC guided resonance (PCGR) boosts the hotspot intensity of the AuNR by at least one order of magnitude in comparison to the Fabry-Perot cavity enhanced (~5X) AuNR. These results exhibit a dissimilar hybrid cooperativity versus previously reported nanoantenna-cavity systems, and pave the new way to further facilitate light-nanoantenna interaction for many applications.

Interpreted Cooper-Harper for broader use

NASA Technical Reports Server (NTRS)

Green, David L.; Andrews, Hal; Gallagher, Donald W.

1993-01-01

The current aircraft assessment process typically makes extensive use of operational personnel during simulations and operational evaluations, with increased emphasis on evaluating the many pilot and/or operator/aircraft control loops. The need for a crew assessment in this broader arena has produced a variety of rating scales. The Cooper-Harper Rating Scale is frequently misused and routinely overlooked in the process, for these applications often extend the scale's use beyond its originally intended application. This paper agrees with the broader application of the Cooper-Harper Rating Scale and presents a concept for the development of a 'use unique' Interpreted Cooper-Harper Scale to help achieve this objective. This interpreted scale concept was conceived during efforts to support an FAA evaluation of a night vision enhancement system. It includes descriptive extensions, which are faithful to the intent of the current Cooper-Harper Scale and should provide the kind of detail that has historically been provided by trained test pilots in their explanatory comments.

Social Networks-Based Adaptive Pairing Strategy for Cooperative Learning

ERIC Educational Resources Information Center

Chuang, Po-Jen; Chiang, Ming-Chao; Yang, Chu-Sing; Tsai, Chun-Wei

2012-01-01

In this paper, we propose a grouping strategy to enhance the learning and testing results of students, called Pairing Strategy (PS). The proposed method stems from the need of interactivity and the desire of cooperation in cooperative learning. Based on the social networks of students, PS provides members of the groups to learn from or mimic…

Asynchronous updates can promote the evolution of cooperation on multiplex networks

NASA Astrophysics Data System (ADS)

Allen, James M.; Hoyle, Rebecca B.

2017-04-01

We study the importance to the frequency of cooperation of the choice of updating strategies in a game played asynchronously or synchronously across layers in a multiplex network. Updating asynchronously in the public goods game leads to higher frequencies of cooperation compared to synchronous updates. How large this effect is depends on the sensitivity of the game dynamics to changes in the number of cooperators surrounding a player, with the largest effect observed when players payoffs are small. The discovery of this effect enhances understanding of cooperation on multiplex networks, and demonstrates a new way to maintain cooperation in these systems.

Cooperation between two ClpB isoforms enhances the recovery of the recombinant β-galactosidase from inclusion bodies.

PubMed

Guenther, Izabela; Zolkiewski, Michal; Kędzierska-Mieszkowska, Sabina

2012-10-05

Bacterial ClpB is a molecular chaperone that solubilizes and reactivates aggregated proteins in cooperation with the DnaK chaperone system. The mechanism of protein disaggregation mediated by ClpB is linked to translocation of substrates through the central channel within the ring-hexameric structure of ClpB. Two isoforms of ClpB are produced in vivo: the full-length ClpB95 and the truncated ClpB80 (ClpBΔN), which does not contain the N-terminal domain. The functional specificity of the two ClpB isoforms and the biological role of the N-terminal domain are still not fully understood. Recently, it has been demonstrated that ClpB may achieve its full potential as an aggregate-reactivating chaperone through the functional interaction and synergistic cooperation of its two isoforms. It has been found that the most efficient resolubilization and reactivation of stress-aggregated proteins occurred in the presence of both ClpB95 and ClpB80. In this work, we asked if the two ClpB isoforms functionally cooperate in the solubilization and reactivation of proteins from insoluble inclusion bodies (IBs) in Escherichia coli cells. Using the model β-galactosidase fusion protein (VP1LAC), we found that solubilization and reactivation of enzymes entrapped in IBs occurred more efficiently in the presence of ClpB95 with ClpB80 than with either ClpB95 or ClpB80 alone. The two isoforms of ClpB chaperone acting together enhanced the solubility and enzymatic activity of β-galactosidase sequestered into IBs. Both ClpB isoforms were associated with IBs of β-galactosidase, what demonstrates their affinity to this type of aggregates. These results demonstrate a synergistic cooperation between the two isoforms of ClpB chaperone. In addition, no significant recovery of the β-galactosidase from IBs in ΔclpB mutant cells suggests that ClpB is a key chaperone in IB protein release. Copyright © 2012 Elsevier Inc. All rights reserved.

F-actin clustering and cell dysmotility induced by the pathological W148R missense mutation of filamin B at the actin-binding domain.

PubMed

Zhao, Yongtong; Shapiro, Sandor S; Eto, Masumi

2016-01-01

Filamin B (FLNB) is a dimeric actin-binding protein that orchestrates the reorganization of the actin cytoskeleton. Congenital mutations of FLNB at the actin-binding domain (ABD) are known to cause abnormalities of skeletal development, such as atelosteogenesis types I and III and Larsen's syndrome, although the underlying mechanisms are poorly understood. Here, using fluorescence microscopy, we characterized the reorganization of the actin cytoskeleton in cells expressing each of six pathological FLNB mutants that have been linked to skeletal abnormalities. The subfractionation assay showed a greater accumulation of the FLNB ABD mutants W148R and E227K than the wild-type protein to the cytoskeleton. Ectopic expression of FLNB-W148R and, to a lesser extent, FLNB-E227K induced prominent F-actin accumulations and the consequent rearrangement of focal adhesions, myosin II, and septin filaments and results in a delayed directional migration of the cells. The W148R protein-induced cytoskeletal rearrangement was partially attenuated by the inhibition of myosin II, p21-activated protein kinase, or Rho-associated protein kinase. The expression of a single-head ABD fragment with the mutations partially mimicked the rearrangement induced by the dimer. The F-actin clustering through the interaction with the mutant FLNB ABD may limit the cytoskeletal reorganization, preventing normal skeletal development. Copyright © 2016 the American Physiological Society.

Cooperative mission execution and planning

NASA Astrophysics Data System (ADS)

Flann, Nicholas S.; Saunders, Kevin S.; Pells, Larry

1998-08-01

Utilizing multiple cooperating autonomous vehicles to perform tasks enhances robustness and efficiency over the use of a single vehicle. Furthermore, because autonomous vehicles can be controlled precisely and their status known accurately in real time, new types of cooperative behaviors are possible. This paper presents a working system called MEPS that plans and executes missions for multiple autonomous vehicles in large structured environments. Two generic spatial tasks are supported, to sweep an area and to visit a location while activating on-board equipment. Tasks can be entered both initially by the user and dynamically during mission execution by both users and vehicles. Sensor data and task achievement data is shared among the vehicles enabling them to cooperatively adapt to changing environmental, vehicle and tasks conditions. The system has been successfully applied to control ATV and micro-robotic vehicles in precision agriculture and waste-site characterization environments.

Costly Advertising and the Evolution of Cooperation

PubMed Central

Brede, Markus

2013-01-01

In this paper, I investigate the co-evolution of fast and slow strategy spread and game strategies in populations of spatially distributed agents engaged in a one off evolutionary dilemma game. Agents are characterized by a pair of traits, a game strategy (cooperate or defect) and a binary ‘advertising’ strategy (advertise or don’t advertise). Advertising, which comes at a cost , allows investment into faster propagation of the agents’ traits to adjacent individuals. Importantly, game strategy and advertising strategy are subject to the same evolutionary mechanism. Via analytical reasoning and numerical simulations I demonstrate that a range of advertising costs exists, such that the prevalence of cooperation is significantly enhanced through co-evolution. Linking costly replication to the success of cooperators exposes a novel co-evolutionary mechanism that might contribute towards a better understanding of the origins of cooperation-supporting heterogeneity in agent populations. PMID:23861752

Costly advertising and the evolution of cooperation.

PubMed

Brede, Markus

2013-01-01

In this paper, I investigate the co-evolution of fast and slow strategy spread and game strategies in populations of spatially distributed agents engaged in a one off evolutionary dilemma game. Agents are characterized by a pair of traits, a game strategy (cooperate or defect) and a binary 'advertising' strategy (advertise or don't advertise). Advertising, which comes at a cost [Formula: see text], allows investment into faster propagation of the agents' traits to adjacent individuals. Importantly, game strategy and advertising strategy are subject to the same evolutionary mechanism. Via analytical reasoning and numerical simulations I demonstrate that a range of advertising costs exists, such that the prevalence of cooperation is significantly enhanced through co-evolution. Linking costly replication to the success of cooperators exposes a novel co-evolutionary mechanism that might contribute towards a better understanding of the origins of cooperation-supporting heterogeneity in agent populations.

Cooperative Lamb shift and superradiance in an optoelectronic device

NASA Astrophysics Data System (ADS)

Frucci, G.; Huppert, S.; Vasanelli, A.; Dailly, B.; Todorov, Y.; Beaudoin, G.; Sagnes, I.; Sirtori, C.

2017-04-01

When a single excitation is shared between a large number of two-level systems, a strong enhancement of the spontaneous emission appears. This phenomenon is known as superradiance. This enhanced rate can be accompanied by a shift of the emission frequency, the cooperative Lamb shift, issued from the exchange of virtual photons between the emitters. In this work we present a semiconductor optoelectronic device allowing the observation of these two phenomena at room temperature. We demonstrate experimentally and theoretically that plasma oscillations in spatially separated quantum wells interact through real and virtual photon exchange. This gives rise to a superradiant mode displaying a large cooperative Lamb shift.

The Globalization of Cooperative Groups.

PubMed

Valdivieso, Manuel; Corn, Benjamin W; Dancey, Janet E; Wickerham, D Lawrence; Horvath, L Elise; Perez, Edith A; Urton, Alison; Cronin, Walter M; Field, Erica; Lackey, Evonne; Blanke, Charles D

2015-10-01

The National Cancer Institute (NCI)-supported adult cooperative oncology research groups (now officially Network groups) have a longstanding history of participating in international collaborations throughout the world. Most frequently, the US-based cooperative groups work reciprocally with the Canadian national adult cancer clinical trial group, NCIC CTG (previously the National Cancer Institute of Canada Clinical Trials Group). Thus, Canada is the largest contributor to cooperative groups based in the United States, and vice versa. Although international collaborations have many benefits, they are most frequently utilized to enhance patient accrual to large phase III trials originating in the United States or Canada. Within the cooperative group setting, adequate attention has not been given to the study of cancers that are unique to countries outside the United States and Canada, such as those frequently associated with infections in Latin America, Asia, and Africa. Global collaborations are limited by a number of barriers, some of which are unique to the countries involved, while others are related to financial support and to US policies that restrict drug distribution outside the United States. This article serves to detail the cooperative group experience in international research and describe how international collaboration in cancer clinical trials is a promising and important area that requires greater consideration in the future. Copyright © 2015 Elsevier Inc. All rights reserved.

The Globalization of Cooperative Groups

PubMed Central

Valdivieso, Manuel; Corn, Benjamin W.; Dancey, Janet E.; Wickerham, D. Lawrence; Horvath, L. Elise; Perez, Edith A.; Urton, Alison; Cronin, Walter M.; Field, Erica; Lackey, Evonne; Blanke, Charles D.

2015-01-01

The National Cancer Institute-supported adult cooperative oncology research groups (now officially Network groups) have a long-standing history of participating in international collaborations throughout the world. Most frequently, the U.S. based cooperative groups work reciprocally with the Canadian national adult cancer clinical trial group, NCIC CTG (previously the National Cancer Institute of Canada Clinical Trials Group). Thus, Canada is the largest contributor to cooperative groups based in the U.S., and vice versa. Although international collaborations have many benefits, they are most frequently utilized to enhance patient accrual to large phase III trials originating in the U.S. or Canada. Within the cooperative group setting, adequate attention has not been given to the study of cancers that are unique to countries outside the U.S. and Canada, such as those frequently associated with infections in Latin America, Asia and Africa. Global collaborations are limited by a number of barriers, some of which are unique to the countries involved, while others are related to financial support and to U.S. policies that restrict drug distribution outside the U.S. This manuscript serves to detail the cooperative group experience in international research and describe how international collaboration in cancer clinical trials is a promising and important area that requires greater consideration in the future. PMID:26433551

Cooperativeness and competitiveness as two distinct constructs: validating the Cooperative and Competitive Personality Scale in a social dilemma context.

PubMed

Lu, Su; Au, Wing-Tung; Jiang, Feng; Xie, Xiaofei; Yam, Paton

2013-01-01

The present research validated the construct and criterion validities of the Cooperative and Competitive Personality Scale (CCPS) in a social dilemma context. The results from three studies supported the notion that cooperativeness and competitiveness are two independent dimensions, challenging the traditional view that they are two ends of a single continuum. First, confirmatory factor analyses revealed that a two-factor structure fit the data significantly better than a one-factor structure. Moreover, cooperativeness and competitiveness were either not significantly correlated (Studies 1 and 3) or only moderately positively correlated (Study 2). Second, cooperativeness and competitiveness were differentially associated with Schwartz's Personal Values. These results further supported the idea that cooperativeness and competitiveness are two distinct constructs. Specifically, the individuals who were highly cooperative emphasized self-transcendent values (i.e., universalism and benevolence) more, whereas the individuals who were highly competitive emphasized self-enhancement values (i.e., power and achievement) more. Finally, the CCPS, which adheres to the trait perspective of personality, was found to be a useful supplement to more prevalent social motive measures (i.e., social value orientation) in predicting cooperative behaviors. Specifically, in Study 2, when social value orientation was controlled for, the CCPS significantly predicted cooperative behaviors in a public goods dilemma (individuals who score higher on cooperativeness scale contributed more to the public goods). In Study 3, when social value orientation was controlled for, the CCPS significantly predicted cooperative behaviors in commons dilemmas (individuals who score higher on cooperativeness scale requested fewer resources from the common resource pool). The practical implications of the CCPS in conflict resolution, as well as in recruitment and selection settings, are discussed.

Organizational choices for international cooperation: East-West European cooperation on regional environmental problems

NASA Astrophysics Data System (ADS)

Connolly, Barbara Mary

This dissertation applies theoretical insights from transaction cost economics to explain and predict the organizational form of cooperative agreements between Eastern and Western Europe in areas of regional environmental and political concern. It examines five contracting problems related to nuclear power safety and acid rain, and describes the history of international negotiations to manage these problems. It argues that the level of interdependence in a given issue area, or costly effects experienced in one state due to activities and decisions of other states, along with the level of transactional vulnerability, or sunk costs invested in support of a particular contractual relationship among these states, are key determinants of the governance structures states choose to facilitate cooperation in that issue area. Empirically, the dissertation traces the evolution of three sets of institutional arrangements related to nuclear safety: governance for western nuclear safety assistance to Eastern Europe, negotiations of a global convention on safety standards for nuclear power plants, and contracts among utilities and multilateral banks to build new nuclear power plants in Eastern Europe. Next it studies European acid rain, chronicling the history of international acid rain controls within the UNECE Convention on Long-Range Transboundary Air Pollution (LRTAP) and the European Union, and finally examining institutional arrangements for burden-sharing to promote European bargains on emissions reduction, including bilateral aid transfers and proposals for multilateral burden sharing. Political actors have a wide range of choice among institutional arrangements to facilitate international cooperation, from simple market-type exchanges, to arbitration-type regimes that provide information and enhance reputation effects, to self-enforcing agreements such as issue-linkage, to supranational governance. The governance structures states devise to manage their cooperative

Thermodynamics-Based Models of Transcriptional Regulation by Enhancers: The Roles of Synergistic Activation, Cooperative Binding and Short-Range Repression

PubMed Central

He, Xin; Samee, Md. Abul Hassan; Blatti, Charles; Sinha, Saurabh

2010-01-01

Quantitative models of cis-regulatory activity have the potential to improve our mechanistic understanding of transcriptional regulation. However, the few models available today have been based on simplistic assumptions about the sequences being modeled, or heuristic approximations of the underlying regulatory mechanisms. We have developed a thermodynamics-based model to predict gene expression driven by any DNA sequence, as a function of transcription factor concentrations and their DNA-binding specificities. It uses statistical thermodynamics theory to model not only protein-DNA interaction, but also the effect of DNA-bound activators and repressors on gene expression. In addition, the model incorporates mechanistic features such as synergistic effect of multiple activators, short range repression, and cooperativity in transcription factor-DNA binding, allowing us to systematically evaluate the significance of these features in the context of available expression data. Using this model on segmentation-related enhancers in Drosophila, we find that transcriptional synergy due to simultaneous action of multiple activators helps explain the data beyond what can be explained by cooperative DNA-binding alone. We find clear support for the phenomenon of short-range repression, where repressors do not directly interact with the basal transcriptional machinery. We also find that the binding sites contributing to an enhancer's function may not be conserved during evolution, and a noticeable fraction of these undergo lineage-specific changes. Our implementation of the model, called GEMSTAT, is the first publicly available program for simultaneously modeling the regulatory activities of a given set of sequences. PMID:20862354

Disruption of the Flnb gene in mice phenocopies the human disease spondylocarpotarsal synostosis syndrome.

PubMed

Farrington-Rock, Claire; Kirilova, Veneta; Dillard-Telm, Lisa; Borowsky, Alexander D; Chalk, Sara; Rock, Matthew J; Cohn, Daniel H; Krakow, Deborah

2008-03-01

Spondylocarpotarsal synostosis syndrome (SCT) is an autosomal recessive disease that is characterized by short stature, and fusions of the vertebrae and carpal and tarsal bones. SCT results from homozygosity or compound heterozygosity for nonsense mutations in FLNB. FLNB encodes filamin B, a multifunctional cytoplasmic protein that plays a critical role in skeletal development. Protein extracts derived from cells of SCT patients with nonsense mutations in FLNB did not contain filamin B, demonstrating that SCT results from absence of filamin B. To understand the role of filamin B in skeletal development, an Flnb-/- mouse model was generated. The Flnb-/- mice were phenotypically similar to individuals with SCT as they exhibited short stature and similar skeletal abnormalities. Newborn Flnb-/- mice had fusions between the neural arches of the vertebrae in the cervical and thoracic spine. At postnatal day 60, the vertebral fusions were more widespread and involved the vertebral bodies as well as the neural arches. In addition, fusions were seen in sternum and carpal bones. Analysis of the Flnb-/- mice phenotype showed that an absence of filamin B causes progressive vertebral fusions, which is contrary to the previous hypothesis that SCT results from failure of normal spinal segmentation. These findings suggest that spinal segmentation can occur normally in the absence of filamin B, but the protein is required for maintenance of intervertebral, carpal and sternal joints, and the joint fusion process commences antenatally.

Automated Cooperative Trajectories for a More Efficient and Responsive Air Transportation System

NASA Technical Reports Server (NTRS)

Hanson, Curt

2015-01-01

The NASA Automated Cooperative Trajectories project is developing a prototype avionics system that enables multi-vehicle cooperative control by integrating 1090 MHz ES ADS-B digital communications with onboard autopilot systems. This cooperative control capability will enable meta-aircraft operations for enhanced airspace utilization, as well as improved vehicle efficiency through wake surfing. This briefing describes the objectives and approach to a flight evaluation of this system planned for 2016.

Cooperation of a Dissatisfied Adaptive Prisoner's Dilemma in Spatial Structures

NASA Astrophysics Data System (ADS)

Zhang, Wen; Li, Yao-Sheng; Du, Peng; Xu, Chen

2013-10-01

We study the cooperative behavior of a dissatisfied adaptive prisoner's dilemma via a pair updating rule. We compare two kinds of relationship among the competing agents, one is the well-mixed population and the other is the two-dimensional square lattice. It is found that the cooperation emerges in both the cases and the frequency of cooperation is enhanced in the square lattice. Though it is impossible for the cooperators to have a higher average payoff than that of the defectors in the well-mixed case, the cooperators in the spatial square lattice could have higher average payoffs in certain regions of the game parameters. We theoretically analyze the well-mixed case exactly and the square lattice by pair approximation. The theoretic results are in agreement with the simulation data.

Effects of lentivirus-mediated CREB expression in the dorsolateral striatum: memory enhancement and evidence for competitive and cooperative interactions with the hippocampus.

PubMed

Kathirvelu, Balachandar; Colombo, Paul J

2013-11-01

Neural systems specialized for memory may interact during memory formation or recall, and the results of interactions are important determinants of how systems control behavioral output. In two experiments, we used lentivirus-mediated expression of the transcription factor CREB (LV-CREB) to test if localized manipulations of cellular plasticity influence interactions between the hippocampus and dorsolateral striatum. In Experiment 1, we tested the hypothesis that infusion of LV-CREB in the dorsolateral striatum facilitates memory for response learning, and impairs memory for place learning. LV-CREB in the dorsolateral striatum had no effect on response learning, but impaired place memory; a finding consistent with competition between the striatum and hippocampus. In Experiment 2, we tested the hypothesis that infusion of LV-CREB in the dorsolateral striatum facilitates memory for cue learning, and impairs memory for contextual fear conditioning. LV-CREB in the dorsolateral striatum enhanced memory for cue learning and, in contrast to our prediction, also enhanced memory for contextual fear conditioning, consistent with a cooperative interaction between the striatum and hippocampus. Overall, the current experiments demonstrate that infusion of LV-CREB in the dorsolateral striatum (1) increases levels of CREB protein locally, (2) does not alter acquisition of place, response, cue, or contextual fear conditioning, (3) facilitates memory for cue learning and contextual fear conditioning, and (4) impairs memory for place learning. Taken together, the present results provide evidence that LV-CREB in the dorsolateral striatum can enhance memory formation and cause both competitive and cooperative interactions with the hippocampus. Copyright © 2013 Wiley Periodicals, Inc.

A sequential-move game for enhancing safety and security cooperation within chemical clusters.

PubMed

Pavlova, Yulia; Reniers, Genserik

2011-02-15

The present paper provides a game theoretic analysis of strategic cooperation on safety and security among chemical companies within a chemical industrial cluster. We suggest a two-stage sequential move game between adjacent chemical plants and the so-called Multi-Plant Council (MPC). The MPC is considered in the game as a leader player who makes the first move, and the individual chemical companies are the followers. The MPC's objective is to achieve full cooperation among players through establishing a subsidy system at minimum expense. The rest of the players rationally react to the subsidies proposed by the MPC and play Nash equilibrium. We show that such a case of conflict between safety and security, and social cooperation, belongs to the 'coordination with assurance' class of games, and we explore the role of cluster governance (fulfilled by the MPC) in achieving a full cooperative outcome in domino effects prevention negotiations. The paper proposes an algorithm that can be used by the MPC to develop the subsidy system. Furthermore, a stepwise plan to improve cross-company safety and security management in a chemical industrial cluster is suggested and an illustrative example is provided. Copyright © 2010 Elsevier B.V. All rights reserved.

Cooperative particle motion in complex (dusty) plasmas

NASA Astrophysics Data System (ADS)

Zhdanov, Sergey; Morfill, Gregor

2014-05-01

Strongly coupled complex (dusty) plasmas give us a unique opportunity to go beyond the limits of continuous media and study various generic processes occurring in liquids or solids at the kinetic level. A particularly interesting and challenging topic is to study dynamic cooperativity at local and intermediate scales. As an important element of self-organization, cooperative particle motion is present in many physical, astrophysical and biological systems. As a rule, cooperative dynamics, bringing to life 'abnormal' effects like enhanced diffusion, self-dragging, or self-propelling of particles, hold aspects of 'strange' kinetics. The synergy effects are also important. Such kind of cooperative behavior was evidenced for string-like formations of colloidal rods, dynamics of mono- and di-vacancies in 2d colloidal crystals. Externally manipulated 'dust molecules' and self-assembled strings in driven 3d particle clusters were other noticeable examples. There is a certain advantage to experiment with complex plasmas merely because these systems are easy to manipulate in a controllable way. We report on the first direct observation of microparticle cooperative movements occurring under natural conditions in a 2d complex plasma.

Role of generosity and forgiveness: Return to a cooperative society

NASA Astrophysics Data System (ADS)

Park, Hye Jin; Kim, Beom Jun; Jeong, Hyeong-Chai

2017-04-01

One's reputation in human society depends on what and how one did in the past. If the reputation of a counterpart is too bad, we often avoid interacting with the individual. We introduce a selective cooperator called the goodie, who participates in the prisoner's dilemma game dependent on the opponent's reputation, and study its role in forming a cooperative society. We observe enhanced cooperation when goodies have a small but nonzero probability of playing the game with an individual who defected in previous rounds. Our finding implies that even this small generosity of goodies can provide defectors chances of encountering the better world of cooperation, encouraging them to escape from their isolated world of selfishness.

Role of generosity and forgiveness: Return to a cooperative society.

PubMed

Park, Hye Jin; Kim, Beom Jun; Jeong, Hyeong-Chai

2017-04-01

One's reputation in human society depends on what and how one did in the past. If the reputation of a counterpart is too bad, we often avoid interacting with the individual. We introduce a selective cooperator called the goodie, who participates in the prisoner's dilemma game dependent on the opponent's reputation, and study its role in forming a cooperative society. We observe enhanced cooperation when goodies have a small but nonzero probability of playing the game with an individual who defected in previous rounds. Our finding implies that even this small generosity of goodies can provide defectors chances of encountering the better world of cooperation, encouraging them to escape from their isolated world of selfishness.

Cooperative spreading processes in multiplex networks.

PubMed

Wei, Xiang; Chen, Shihua; Wu, Xiaoqun; Ning, Di; Lu, Jun-An

2016-06-01

This study is concerned with the dynamic behaviors of epidemic spreading in multiplex networks. A model composed of two interacting complex networks is proposed to describe cooperative spreading processes, wherein the virus spreading in one layer can penetrate into the other to promote the spreading process. The global epidemic threshold of the model is smaller than the epidemic thresholds of the corresponding isolated networks. Thus, global epidemic onset arises in the interacting networks even though an epidemic onset does not arise in each isolated network. Simulations verify the analysis results and indicate that cooperative spreading processes in multiplex networks enhance the final infection fraction.

Cooperativity of self-organized Brownian motors pulling on soft cargoes.

PubMed

Orlandi, Javier G; Blanch-Mercader, Carles; Brugués, Jan; Casademunt, Jaume

2010-12-01

We study the cooperative dynamics of Brownian motors moving along a one-dimensional track when an external load is applied to the leading motor, mimicking molecular motors pulling on membrane-bound cargoes in intracellular traffic. Due to the asymmetric loading, self-organized motor clusters form spontaneously. We model the motors with a two-state noise-driven ratchet formulation and study analytically and numerically the collective velocity-force and efficiency-force curves resulting from mutual interactions, mostly hard-core repulsion and weak (nonbinding) attraction. We analyze different parameter regimes including the limits of weak noise, mean-field behavior, rigid coupling, and large numbers of motors, for the different interactions. We present a general framework to classify and quantify cooperativity. We show that asymmetric loading leads generically to enhanced cooperativity beyond the simple superposition of the effects of individual motors. For weakly attracting interactions, the cooperativity is mostly enhanced, including highly coordinated motion of motors and complex nonmonotonic velocity-force curves, leading to self-regulated clusters. The dynamical scenario is enriched by resonances associated to commensurability of different length scales. Large clusters exhibit synchronized dynamics and bidirectional motion. Biological implications are discussed.

Cooperativity of self-organized Brownian motors pulling on soft cargoes

NASA Astrophysics Data System (ADS)

Orlandi, Javier G.; Blanch-Mercader, Carles; Brugués, Jan; Casademunt, Jaume

2010-12-01

We study the cooperative dynamics of Brownian motors moving along a one-dimensional track when an external load is applied to the leading motor, mimicking molecular motors pulling on membrane-bound cargoes in intracellular traffic. Due to the asymmetric loading, self-organized motor clusters form spontaneously. We model the motors with a two-state noise-driven ratchet formulation and study analytically and numerically the collective velocity-force and efficiency-force curves resulting from mutual interactions, mostly hard-core repulsion and weak (nonbinding) attraction. We analyze different parameter regimes including the limits of weak noise, mean-field behavior, rigid coupling, and large numbers of motors, for the different interactions. We present a general framework to classify and quantify cooperativity. We show that asymmetric loading leads generically to enhanced cooperativity beyond the simple superposition of the effects of individual motors. For weakly attracting interactions, the cooperativity is mostly enhanced, including highly coordinated motion of motors and complex nonmonotonic velocity-force curves, leading to self-regulated clusters. The dynamical scenario is enriched by resonances associated to commensurability of different length scales. Large clusters exhibit synchronized dynamics and bidirectional motion. Biological implications are discussed.

Problems and Countermeasures of Zhejiang High-Tech Enterprises Industry-University-Institute Cooperation in China

NASA Astrophysics Data System (ADS)

Zhou, Qing; Mao, Chong-Feng; Hou, Lin

Industry-university-institute cooperation is an important means to accelerate technical development and achievements for high-tech enterprises. Considering that Zhejiang high-tech enterprises existed some problems which included low cooperative level, single distribution, weak secondary R&D ability, obvious risk and so on, government should play an guiding role on improving information service system, enhancing cooperative level, promoting scientific intermediary service organization system construction, and building better environment for Industry-university-institute cooperation.

Supporting cognitive control through competition and cooperation in childhood.

PubMed

Fischer, Paula; Camba, Letizia; Ooi, Seok Hui; Chevalier, Nicolas

2018-04-12

Cognitive control is often engaged in social contexts where actions are socially relevant. Yet, little is known about the immediate influence of the social context on childhood cognitive control. To examine whether competition or cooperation can enhance cognitive control, preschool and school-age children completed the AX Continuous Performance Task (AX-CPT) in competitive, cooperative, and neutral contexts. Children made fewer errors, responded faster, and engaged more cognitive effort, as shown by greater pupil dilation, in the competitive and cooperative social contexts relative to the neutral context. Competition and cooperation yielded greater cognitive control engagement but did not change how control was engaged (reactively or proactively). Manipulating the social context can be a powerful tool to support cognitive control in childhood. Copyright © 2018 Elsevier Inc. All rights reserved.

How to increase the benefits of cooperation: Effects of training in transactive communication on cooperative learning.

PubMed

Jurkowski, Susanne; Hänze, Martin

2015-09-01

Transactive communication means referring to and building on a learning partner's idea, by, for example, extending the partner's idea or interlinking the partner's idea with an idea of one's own. This transforms the partner's idea into a more elaborate one. Previous research found a positive relationship between students' transactive communication and their learning results when working in small groups. To increase the benefits of cooperation, we developed and tested a module for training students in transactive communication. We assumed that this training would enhance students' transactive communication and also increase their knowledge acquisition during cooperative learning. Further, we distinguished between an actor's transactive communication and a learning partner's transactive communication and expected both to be positively associated with an actor's knowledge acquisition. Participants were 80 university students. In an experiment with pre- and post-test measurements, transactive communication was measured by coding students' communication in a cooperative learning situation before training and in another cooperative learning situation after training. For the post-test cooperative learning situation, knowledge was pre-tested and post-tested. Trained students outperformed controls in transactive communication and in knowledge acquisition. Positive training effects on actors' knowledge acquisition were partially mediated by the improved actors' transactive communication. Moreover, actors' knowledge acquisition was positively influenced by learning partners' transactive communication. Results show a meaningful increase in the benefits of cooperation through the training in transactive communication. Furthermore, findings indicate that students benefit from both elaborating on their partner's ideas and having their own ideas elaborated on. © 2015 The British Psychological Society.

Enhancing Expectations of Cooperative Learning Use through Initial Teacher Training

ERIC Educational Resources Information Center

Duran Gisbert, David; Corcelles Seuba, Mariona; Flores Coll, Marta

2017-01-01

Despite its relevance and evidence support, Cooperative Learning (CL) is a challenge for all educational systems due to the difficulties in its implementation. The objective of this study is to identify the effect of Primary Education initial teacher training in the prediction of future CL use. Two groups of 44 and 45 students were conceptually…

Perception without self-matching in conditional tag based cooperation.

PubMed

McAvity, David M; Bristow, Tristen; Bunker, Eric; Dreyer, Alex

2013-09-21

We consider a model for the evolution of cooperation in a population where individuals may have one of a number of different heritable and distinguishable markers or tags. Individuals interact with each of their neighbors on a square lattice by either cooperating by donating some benefit at a cost to themselves or defecting by doing nothing. The decision to cooperate or defect is contingent on each individual's perception of its interacting partner's tag. Unlike in other tag-based models individuals do not compare their own tag to that of their interaction partner. That is, there is no self-matching. When perception is perfect the cooperation rate is substantially higher than in the usual spatial prisoner's dilemma game when the cost of cooperation is high. The enhancement in cooperation is positively correlated with the number of different tags. The more diverse a population is the more cooperative it becomes. When individuals start with an inability to perceive tags the population evolves to a state where individuals gain at least partial perception. With some reproduction mechanisms perfect perception evolves, but with others the ability to perceive tags is imperfect. We find that perception of tags evolves to lower levels when the cost of cooperation is higher. Copyright © 2013 Elsevier Ltd. All rights reserved.

["Hope Dies Last …" - Cross-Sectoral Cooperation in Integrated Care].

PubMed

Ruppert, Daniel; Stegbauer, Constanze; Bramesfeld, Anke; Bestmann, Beate; Szecsenyi, Joachim; Götz, Katja

2017-04-01

Objective Multiple models of Integrated Care (IC) have been implemented in German mental health services in the last decade in order to improve cross-sectoral, interdisciplinary cooperation. This study investigates an IC network model providing home treatment, case management and a 24/7 hotline. The aim of the study was to explore how health professionals working in this service model perceive both cooperation within their facilities and with external stakeholders. Methods 5 focus groups with 39 health professionals working in an IC mental health network were conducted and analyzed with qualitative content analysis. Results Focus groups participants reported on excellent cooperation within their facilities. The cooperation with external stakeholders, i. e. physicians, psychotherapists and psychiatric clinics, leaves room for improvement. Conclusions Until now little consideration has been given to the perspectives of health professionals. Cooperation within IC mental health networks seems to be effective. Cooperation with stakeholders outside the networks needs to be enhanced. © Georg Thieme Verlag KG Stuttgart · New York.

A distinct X-linked syndrome involving joint contractures, keloids, large optic cup-to-disc ratio, and renal stones results from a filamin A (FLNA) mutation.

PubMed

Lah, Melissa; Niranjan, Tejasvi; Srikanth, Sujata; Holloway, Lynda; Schwartz, Charles E; Wang, Tao; Weaver, David D

2016-04-01

We further evaluated a previously reported family with an apparently undescribed X-linked syndrome involving joint contractures, keloids, an increased optic cup-to-disc ratio, and renal stones to elucidate the genetic cause. To do this, we obtained medical histories and performed physical examination on 14 individuals in the family, five of whom are affected males and three are obligate carrier females. Linkage analysis was performed on all but one individual and chromosome X-exome sequencing was done on two affected males. The analysis localized the putative gene to Xq27-qter and chromosome X-exome sequencing revealed a mutation in exon 28 (c.4726G>A) of the filamin A (FLNA) gene, predicting that a conserved glycine had been replaced by arginine at amino acid 1576 (p.G1576R). Segregation analysis demonstrated that all known carrier females tested were heterozygous (G/A), all affected males were hemizygous for the mutation (A allele) and all normal males were hemizygous for the normal G allele. The data and the bioinformatic analysis indicate that the G1576R mutation in the FLNA gene is very likely pathogenic in this family. The syndrome affecting the family shares phenotypic overlap with other syndromes caused by FLNA mutations, but appears to be a distinct phenotype, likely representing a unique genetic syndrome. © 2016 Wiley Periodicals, Inc.

Monte Carlo simulation of the mixed alkali effect with cooperative jumps

NASA Astrophysics Data System (ADS)

Habasaki, Junko; Hiwatari, Yasuaki

2000-12-01

In our previous works on molecular dynamics (MD) simulations of lithium metasilicate (Li2SiO3), it has been shown that the long time behavior of the lithium ions in Li2SiO3 has been characterized by the component showing the enhanced diffusion (Lévy flight) due to cooperative jumps. It has also been confirmed that the contribution of such component decreases by interception of the paths in the mixed alkali silicate (LiKSiO3). Namely, cooperative jumps of like ions are much decreased in number owing to the interception of the path for unlike alkali-metal ions. In the present work, we have performed a Monte Carlo simulation using a cubic lattice in order to establish the role of the cooperative jumps in the transport properties in a mixed alkali glass. Fixed particles (blockage) were introduced instead of the interception of the jump paths for unlike alkali-metal ions. Two types of cooperative motions (a pull type and a push type) were taken into account. Low-dimensionality of the jump path caused by blockage resulted in a decrease of a diffusion coefficient of the particles. The effect of blockage is enhanced when the cooperative motions were introduced.

The risk of predation favors cooperation among breeding prey

PubMed Central

Krama, Tatjana; Berzins, Arnis; Rantala, Markus J

2010-01-01

Empirical studies have shown that animals often focus on short-term benefits under conditions of predation risk, which reduces the likelihood that they will cooperate with others. However, some theoretical studies predict that animals in adverse conditions should not avoid cooperation with their neighbors since it may decrease individual risks and increase long-term benefits of reciprocal help. We experimentally tested these two alternatives to find out whether increased predation risk enhances or diminishes the occurrence of cooperation in mobbing, a common anti-predator behavior, among breeding pied flycatchers, Ficedula hypoleuca. Our results show that birds attended mobs initiated by their neighbors more often, approached the stuffed predator significantly more closely, and mobbed it at a higher intensity in areas where the perceived risk of predation was experimentally increased. This study demonstrates a positive impact of predation risk on cooperation in breeding songbirds, which might help to explain the emergence and evolution of cooperation. PMID:20714404

S6K is a morphogenic protein with a mechanism involving Filamin-A phosphorylation and phosphatidic acid binding.

PubMed

Henkels, Karen M; Mallets, Elizabeth R; Dennis, Patrick B; Gomez-Cambronero, Julian

2015-04-01

Change of cell shape in vivo plays many roles that are central to life itself, such as embryonic development, inflammation, wound healing, and pathologic processes such as cancer metastasis. Nonetheless, the spatiotemporal mechanisms that control the concerted regulation of cell shape remain understudied. Here, we show that ribosomal S6K, which is normally considered a protein involved in protein translation, is a morphogenic protein. Its presence in cells alters the overall organization of the cell surface and cell circularity [(4π × area)/(perimeter)(2)] from 0.47 ± 0.06 units in mock-treated cells to 0.09 ± 0.03 units in S6K-overexpressing macrophages causing stellation and arborization of cell shape. This effect was partially reversed in cells expressing a kinase-inactive S6K mutant and was fully reversed in cells silenced with small interference RNA. Equally important is that S6K is itself regulated by phospholipids, specifically phosphatidic acid, whereby 300 nM 1,2-dioleoyl-sn-glycero-3-phosphate (DOPA), but not the control 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), binds directly to S6K and causes an ∼ 2.9-fold increase in S6K catalytic activity. This was followed by an increase in Filamin A (FLNA) functionality as measured by phospho-FLNA (S(2152)) expression and by a subsequent elevation of actin nucleation. This reliance of S6K on phosphatidic acid (PA), a curvature-inducing phospholipid, explained the extra-large perimeter of cells that overexpressed S6K. Furthermore, the diversity of the response to S6K in several unrelated cell types (fibroblasts, leukocytes, and invasive cancer cells) that we report here indicates the existence of an underlying common mechanism in mammalian cells. This new signaling set, PA-S6K-FLNA-actin, sheds light for the first time into the morphogenic pathway of cytoskeletal structures that are crucial for adhesion and cell locomotion during inflammation and metastasis. © FASEB.

Cognitive diversity and moral enhancement.

PubMed

Gyngell, Chris; Easteal, Simon

2015-01-01

One debate in contemporary bioethics centers on whether the development of cognitive enhancement technologies (CETs) will hasten the need for moral enhancement. In this article we provide a new argument in favor of pursuing these enhancement technologies together. The widespread availability of CETs will likely increase population-level cognitive diversity. Different people will choose to enhance different aspects of their cognition, and some won't enhance themselves at all. Although this has the potential to be beneficial for society, it could also result in harms as people become more different from one another. Aspects of our moral psychology make it difficult for people to cooperate and coordinate actions with those who are very different from themselves. These moral failings could be targeted by moral enhancement technologies, which may improve cooperation among individuals. Moral enhancement technologies will therefore help society maximize the benefits, and reduce the costs, associated with widespread access to cognitive enhancements.

Clonal cooperativity in heterogenous cancers

PubMed Central

Zhou, Hengbo; Neelakantan, Deepika; Ford, Heide L.

2016-01-01

Tumor heterogeneity is a major obstacle to the development of effective therapies and is thus an important focus of cancer research. Genetic and epigenetic alterations, as well as altered tumor microenvironments, result in tumors made up of diverse subclones with different genetic and phenotypic characteristics. Intratumor heterogeneity enables competition, but also supports clonal cooperation via cell-cell contact or secretion of factors, resulting in enhanced tumor progression. Here, we summarize recent findings related to interclonal interactions within a tumor and the therapeutic implications of such interactions, with an emphasis on how different subclones collaborate with each other to promote proliferation, metastasis and therapy-resistance. Furthermore, we propose that disruption of clonal cooperation by targeting key factors (such as Wnt and Hedgehog, amongst others) can be an alternative approach to improving clinical outcomes. PMID:27582427

On fairness, full cooperation, and quantum game with incomplete information

NASA Astrophysics Data System (ADS)

Lei, Zhen-Zhou; Liu, Bo-Yang; Yi, Ying; Dai, Hong-Yi; Zhang, Ming

2018-03-01

Quantum entanglement has emerged as a new resource to enhance cooperation and remove dilemmas. This paper aims to explore conditions under which full cooperation is achievable even when the information of payoff is incomplete. Based on the quantum version of the extended classical cash in a hat game, we demonstrate that quantum entanglement may be used for achieving full cooperation or avoiding moral hazards with the reasonable profit distribution policies even when the profit is uncertain to a certain degree. This research further suggests that the fairness of profit distribution should play an important role in promoting full cooperation. It is hopeful that quantum entanglement and fairness will promote full cooperation among distant people from various interest groups when quantum networks and quantum entanglement are accessible to the public. Project supported by the National Natural Science Foundation of China (Grant Nos. 61673389, 61273202, and 61134008.

The transcription factors SOX9 and SOX5/SOX6 cooperate genome-wide through super-enhancers to drive chondrogenesis

PubMed Central

Liu, Chia-Feng; Lefebvre, Véronique

2015-01-01

SOX9 is a transcriptional activator required for chondrogenesis, and SOX5 and SOX6 are closely related DNA-binding proteins that critically enhance its function. We use here genome-wide approaches to gain novel insights into the full spectrum of the target genes and modes of action of this chondrogenic trio. Using the RCS cell line as a faithful model for proliferating/early prehypertrophic growth plate chondrocytes, we uncover that SOX6 and SOX9 bind thousands of genomic sites, frequently and most efficiently near each other. SOX9 recognizes pairs of inverted SOX motifs, whereas SOX6 favors pairs of tandem SOX motifs. The SOX proteins primarily target enhancers. While binding to a small fraction of typical enhancers, they bind multiple sites on almost all super-enhancers (SEs) present in RCS cells. These SEs are predominantly linked to cartilage-specific genes. The SOX proteins effectively work together to activate these SEs and are required for in vivo expression of their associated genes. These genes encode key regulatory factors, including the SOX trio proteins, and all essential cartilage extracellular matrix components. Chst11, Fgfr3, Runx2 and Runx3 are among many other newly identified SOX trio targets. SOX9 and SOX5/SOX6 thus cooperate genome-wide, primarily through SEs, to implement the growth plate chondrocyte differentiation program. PMID:26150426

Helping enhances productivity in campo flicker ( Colaptes campestris) cooperative groups

NASA Astrophysics Data System (ADS)

Dias, Raphael Igor; Webster, Michael S.; Macedo, Regina H.

2015-06-01

Reproductive adults in many bird species are assisted by non-breeding auxiliary helpers at the nest, yet the impact of auxiliaries on reproduction is variable and not always obvious. In this study, we tested Hamilton's rule and evaluated the effect of auxiliaries on productivity in the facultative cooperative breeder campo flicker ( Colaptes campestris campestris). Campo flickers have a variable mating system, with some groups having auxiliaries and others lacking them (i.e., unassisted pairs). Most auxiliaries are closely related to the breeding pair (primary auxiliaries), but some auxiliaries (secondary auxiliaries) are unrelated females that joined established groups. We found no effect of breeder quality (body condition) or territory quality (food availability) on group productivity, but the presence of auxiliaries increased the number of fledglings produced relative to unassisted pairs. Nonetheless, the indirect benefit of helping was small and did not outweigh the costs of delayed breeding and so seemed insufficient to explain the evolution of cooperative breeding in campo flickers. We concluded that some ecological constraints must limit dispersal or independent breeding, making staying in the group a "best-of-a-bad-job" situation for auxiliaries.

Helping enhances productivity in campo flicker (Colaptes campestris) cooperative groups.

PubMed

Dias, Raphael Igor; Webster, Michael S; Macedo, Regina H

2015-06-01

Reproductive adults in many bird species are assisted by non-breeding auxiliary helpers at the nest, yet the impact of auxiliaries on reproduction is variable and not always obvious. In this study, we tested Hamilton's rule and evaluated the effect of auxiliaries on productivity in the facultative cooperative breeder campo flicker (Colaptes campestris campestris). Campo flickers have a variable mating system, with some groups having auxiliaries and others lacking them (i.e., unassisted pairs). Most auxiliaries are closely related to the breeding pair (primary auxiliaries), but some auxiliaries (secondary auxiliaries) are unrelated females that joined established groups. We found no effect of breeder quality (body condition) or territory quality (food availability) on group productivity, but the presence of auxiliaries increased the number of fledglings produced relative to unassisted pairs. Nonetheless, the indirect benefit of helping was small and did not outweigh the costs of delayed breeding and so seemed insufficient to explain the evolution of cooperative breeding in campo flickers. We concluded that some ecological constraints must limit dispersal or independent breeding, making staying in the group a "best-of-a-bad-job" situation for auxiliaries.

Fibroblast-derived CXCL12/SDF-1α promotes CXCL6 secretion and co-operatively enhances metastatic potential through the PI3K/Akt/mTOR pathway in colon cancer

PubMed Central

Ma, Jia-Chi; Sun, Xiao-Wen; Su, He; Chen, Quan; Guo, Tian-Kang; Li, Yuan; Chen, Xiao-Chang; Guo, Jin; Gong, Zhen-Qiang; Zhao, Xiao-Dan; Qi, Jian-Bo

2017-01-01

AIM To investigate the underlying mechanism by which CXCL12 and CXCL6 influences the metastatic potential of colon cancer and internal relation of colon cancer and stromal cells. METHODS Western blotting was used to detect the expression of CXCL12 and CXCL6 in colon cancer cells and stromal cells. The co-operative effects of CXCL12 and CXCL6 on proliferation and invasion of colon cancer cells and human umbilical vein endothelial cells (HUVECs) were determined by enzyme-linked immunosorbent assay, and proliferation and invasion assays. The angiogenesis of HUVECs through interaction with cancer cells and stromal cells was examined by angiogenesis assay. We eventually investigated activation of PI3K/Akt/mTOR signaling by CXCL12 involved in the metastatic process of colon cancer. RESULTS CXCL12 was expressed in DLD-1 cancer cells and fibroblasts. The secretion level of CXCL6 by colon cancer cells and HUVECs were significantly promoted by fibroblasts derived from CXCL12. CXCL6 and CXCL2 could significantly enhance HUVEC proliferation and migration (P < 0.01). CXCL6 and CXCL2 enhanced angiogenesis by HUVECs when cultured with fibroblast cells and colon cancer cells (P < 0.01). CXCL12 also enhanced the invasion of colon cancer cells. Stromal cell-derived CXCL12 promoted the secretion level of CXCL6 and co-operatively promoted metastasis of colon carcinoma through activation of the PI3K/Akt/mTOR pathway. CONCLUSION Fibroblast-derived CXCL12 enhanced the CXCL6 secretion of colon cancer cells, and both CXCL12 and CXCL6 co-operatively regulated the metastasis via the PI3K/Akt/mTOR signaling pathway. Blocking this pathway may be a potential anti-metastatic therapeutic target for patients with colon cancer. PMID:28811711

Using Weblog in Cooperative Learning to Improve the Achievement of History Learning

ERIC Educational Resources Information Center

Leng, Lim Hooi; Leng, Chin Hai; Abedalaziz, Nabeel

2013-01-01

This research investigates the use of Weblog in Cooperative Learning to enhance students' learning of History. The main issues of this study were the lack of interest and low achievement scores in History learning. The objectives of this study are to explore the incorporation of Weblog in Cooperative Learning within the teaching and learning…

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Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-05

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-71,602] Cooper Tools--Sumter, Cooper Tools Divisions, a Subsidiary of Cooper Industries, Inc., Including On-Site Leased Workers From... January 26, 2010, applicable to workers of Cooper Tools--Sumter, Cooper Tools Division, a subsidiary of...

The nature of crime : Is cheating necessary for cooperation?

PubMed

Machalek, R; Cohen, L E

1991-09-01

The classical social theorist Emile Durkheim proposed the counterintuitive thesis that crime is beneficial for society because it provokes punishment, which enhances social solidarity. His logic, however, is blemished by a reified view of society that leads to group-selectionist thinking and a teleological account of the causes of crime. Reconceptualization of the relationship between crime and punishment in terms of evolutionary game theory, however, suggests that crime (cheating) may confer benefits on cooperating individuals by promoting stability in their patterns of cooperation.

Kinetic Limitations of Cooperativity-Based Drug Delivery Systems

NASA Astrophysics Data System (ADS)

Licata, Nicholas A.; Tkachenko, Alexei V.

2008-04-01

We study theoretically a novel drug delivery system that utilizes the overexpression of certain proteins in cancerous cells for cell-specific chemotherapy. The system consists of dendrimers conjugated with “keys” (ex: folic acid) which “key-lock” bind to particular cell-membrane proteins (ex: folate receptor). The increased concentration of “locks” on the surface leads to a longer residence time for the dendrimer and greater incorporation into the cell. Cooperative binding of the nanocomplexes leads to an enhancement of cell specificity. However, both our theory and detailed analysis of in vitro experiments indicate that the degree of cooperativity is kinetically limited. We demonstrate that cooperativity and hence the specificity to particular cell type can be increased by making the strength of individual bonds weaker, and suggest a particular implementation of this idea.

The emergence of cooperation from a single cooperative mutant

NASA Astrophysics Data System (ADS)

Cremer, Jonas; Melbinger, Anna; Frey, Erwin

2012-02-01

Population structure is one central condition which promotes the stability of cooperation: If cooperators more likely interact with other cooperators (positive assortment), they keep most of their benefit for themselves and are less exploited by non-cooperators. However, positive assortment can only act successfully if cooperation is already well established in the population such that cooperative individuals can successfully assort. But how can cooperation emerge when starting with a single cooperative mutant? Here we study this issue for a generic situation of microbial systems where microbes regularly form new colonies and show strong population growth. We show how and when the dynamical interplay between colony formation, population growth and evolution within colonies can provoke the emergence of cooperation. In particular, the probability for a single cooperative mutant to succeed is robustly large when colony-formation is fast or comparable to the time-scale of growth within colonies; growth supports cooperation.[4pt] [1] A. Melbinger, J. Cremer, and E. Frey, Evolutionary game theory in growing populations, Phys. Rev. Lett. 105, 178101 (2010)[0pt] [2] J. Cremer, A. Melbinger, and E. Frey, Evolutionary and population dynamics: a coupled approach, arXiv:1108.2604

Using SimCPU in Cooperative Learning Laboratories.

ERIC Educational Resources Information Center

Lin, Janet Mei-Chuen; Wu, Cheng-Chih; Liu, Hsi-Jen

1999-01-01

Reports research findings of an experimental design in which cooperative-learning strategies were applied to closed-lab instruction of computing concepts. SimCPU, a software package specially designed for closed-lab usage was used by 171 high school students of four classes. Results showed that collaboration enhanced learning and that blending…

Cooperation enhanced by the coevolution of teaching activity in evolutionary prisoner's dilemma games with voluntary participation.

PubMed

Shen, Chen; Chu, Chen; Geng, Yini; Jin, Jiahua; Chen, Fei; Shi, Lei

2018-01-01

Voluntary participation, as an additional strategy involved in repeated games, has been proved to be an efficient way to promote the evolution of cooperation theoretically and empirically. Besides, current studies show that the coevolution of teaching activity can promote cooperation. Thus, inspired by aforementioned above, we investigate the effect of coevolution of teaching activity on the evolution of cooperation for prisoner's dilemma game with voluntary participation: when the focal player successfully enforces its strategy on the opponent, his teaching ability will get an increase. Through numerical simulation, we have shown that voluntary participation could effectively promote the fraction of cooperation, which is also affected by the value of increment. Furthermore, we investigate the influence of the increment value on the density of different strategies and find that there exists an optimal increment value that plays an utmost role on the evolutionary dynamics. With regard to this observation, we unveil that an optimal value of increment can lead to strongest heterogeneity in agents' teaching ability, further promoting the evolution of cooperation.

Facial Likability and Smiling Enhance Cooperation, but Have No Direct Effect on Moralistic Punishment.

PubMed

Mieth, Laura; Bell, Raoul; Buchner, Axel

2016-09-01

The present study serves to test how positive and negative appearance-based expectations affect cooperation and punishment. Participants played a prisoner's dilemma game with partners who either cooperated or defected. Then they were given a costly punishment option: They could spend money to decrease the payoffs of their partners. Aggregated over trials, participants spent more money for punishing the defection of likable-looking and smiling partners compared to punishing the defection of unlikable-looking and nonsmiling partners, but only because participants were more likely to cooperate with likable-looking and smiling partners, which provided the participants with more opportunities for moralistic punishment. When expressed as a conditional probability, moralistic punishment did not differ as a function of the partners' facial likability. Smiling had no effect on the probability of moralistic punishment, but punishment was milder for smiling in comparison to nonsmiling partners.

Percolation and cooperation with mobile agents: geometric and strategy clusters.

PubMed

Vainstein, Mendeli H; Brito, Carolina; Arenzon, Jeferson J

2014-08-01

We study the conditions for persistent cooperation in an off-lattice model of mobile agents playing the Prisoner's Dilemma game with pure, unconditional strategies. Each agent has an exclusion radius r(P), which accounts for the population viscosity, and an interaction radius r(int), which defines the instantaneous contact network for the game dynamics. We show that, differently from the r(P)=0 case, the model with finite-sized agents presents a coexistence phase with both cooperators and defectors, besides the two absorbing phases, in which either cooperators or defectors dominate. We provide, in addition, a geometric interpretation of the transitions between phases. In analogy with lattice models, the geometric percolation of the contact network (i.e., irrespective of the strategy) enhances cooperation. More importantly, we show that the percolation of defectors is an essential condition for their survival. Differently from compact clusters of cooperators, isolated groups of defectors will eventually become extinct if not percolating, independently of their size.

The Importance of Building and Enhancing Worldwide Industry Cooperation in the Areas of Radiological Protection, Waste Management and Decommissioning

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

Saint-Pierre, S.

2006-07-01

The slow or stagnant rate of nuclear power generation development in many developed countries over the last two decades has resulted in a significant shortage in the population of mid-career nuclear industry professionals. This shortage is even more pronounced in some specific areas of expertise such as radiological protection, waste management and decommissioning. This situation has occurred at a time when the renaissance of nuclear power and the globalization of the nuclear industry are steadily gaining momentum and when the industry's involvement in international and national debates in these three fields of expertise (and the industry's impact on these debates)more » is of vital importance. This paper presents the World Nuclear Association (WNA) approach to building and enhancing worldwide industry cooperation in radiological protection, waste management and decommissioning, which is manifested through the activities of the two WNA working groups on radiological protection (RPWG) and on waste management and decommissioning (WM and DWG). This paper also briefly describes the WNA's participatory role, as of summer 2005, in the International Atomic Energy Agency (IAEA) standard development committees on radiation safety (RASSC), waste safety (WASSC) and nuclear safety (NUSSC). This participation provides the worldwide nuclear industry with an opportunity to be part of IAEA's discussions on shaping changes to the control regime of IAEA safety standards. The review (and the prospect of a revision) of IAEA safety standards, which began in October 2005, makes this WNA participation and the industry ' s involvement at the national level timely and important. All of this excellent industry cooperation and team effort is done through 'collegial' exchanges between key industry experts, which help tackle important issues more effectively. The WNA is continuously looking to enhance its worldwide industry representation in these fields of expertise through the RPWG and WM

Nicotine and ethanol cooperate to enhance ventral tegmental area AMPA receptor function via α6-containing nicotinic receptors.

PubMed

Engle, Staci E; McIntosh, J Michael; Drenan, Ryan M

2015-04-01

Nicotine + ethanol co-exposure results in additive and/or synergistic effects in the ventral tegmental area (VTA) to nucleus accumbens (NAc) dopamine (DA) pathway, but the mechanisms supporting this are unclear. We tested the hypothesis that nAChRs containing α6 subunits (α6* nAChRs) are involved in the response to nicotine + ethanol co-exposure. Exposing VTA slices from C57BL/6 WT animals to drinking-relevant concentrations of ethanol causes a marked enhancement of α-amino-3-hydroxy-5-methyl-isoxazolepropionic acid (AMPA) receptor (AMPAR) function in VTA neurons. This effect was sensitive to α-conotoxin MII (an α6β2* nAChR antagonist), suggesting that α6* nAChR function is required. In mice expressing hypersensitive α6* nAChRs (α6L9S mice), we found that lower concentrations (relative to C57BL/6 WT) of ethanol were sufficient to enhance AMPAR function in VTA neurons. Exposure of live C57BL/6 WT mice to ethanol also produced AMPAR functional enhancement in VTA neurons, and studies in α6L9S mice strongly suggest a role for α6* nAChRs in this response. We then asked whether nicotine and ethanol cooperate to enhance VTA AMPAR function. We identified low concentrations of nicotine and ethanol that were capable of strongly enhancing VTA AMPAR function when co-applied to slices, but that did not enhance AMPAR function when applied alone. This effect was sensitive to both varenicline (an α4β2* and α6β2* nAChR partial agonist) and α-conotoxin MII. Finally, nicotine + ethanol co-exposure also enhanced AMPAR function in VTA neurons from α6L9S mice. Together, these data identify α6* nAChRs as important players in the response to nicotine + ethanol co-exposure in VTA neurons. Copyright © 2014 Elsevier Ltd. All rights reserved.

Energetics and kinetics of cooperative cofilin-actin filament interactions.

PubMed

Cao, Wenxiang; Goodarzi, Jim P; De La Cruz, Enrique M

2006-08-11

We have evaluated the thermodynamic parameters associated with cooperative cofilin binding to actin filaments, accounting for contributions of ion-linked equilibria, and determined the kinetic basis of cooperative cofilin binding. Ions weaken non-contiguous (isolated, non-cooperative) cofilin binding to an actin filament without affecting cooperative filament interactions. Non-contiguous cofilin binding is coupled to the dissociation of approximately 1.7 thermodynamically bound counterions. Counterion dissociation contributes approximately 40% of the total cofilin binding free energy (in the presence of 50 mM KCl). The non-contiguous and cooperative binding free energies are driven entirely by large, positive entropy changes, consistent with a cofilin-mediated increase in actin filament structural dynamics. The rate constant for cofilin binding to an isolated site on an actin filament is slow and likely to be limited by filament breathing. Cooperative cofilin binding arises from an approximately tenfold more rapid association rate constant and an approximately twofold slower dissociation rate constant. The more rapid association rate constant is presumably a consequence of cofilin-dependent changes in the average orientation of subdomain 2, subunit angular disorder and filament twist, which increase the accessibility of a neighboring cofilin-binding site on an actin filament. Cooperative association is more rapid than binding to an isolated site, but still slow for a second-order reaction, suggesting that cooperative binding is limited also by binding site accessibility. We suggest that the dissociation of actin-associated ions weakens intersubunit interactions in the actin filament lattice that enhance cofilin-binding site accessibility, favor cooperative binding and promote filament severing.

Impact of Social Punishment on Cooperative Behavior in Complex Networks

NASA Astrophysics Data System (ADS)

Wang, Zhen; Xia, Cheng-Yi; Meloni, Sandro; Zhou, Chang-Song; Moreno, Yamir

2013-10-01

Social punishment is a mechanism by which cooperative individuals spend part of their resources to penalize defectors. In this paper, we study the evolution of cooperation in 2-person evolutionary games on networks when a mechanism for social punishment is introduced. Specifically, we introduce a new kind of role, punisher, which is aimed at reducing the earnings of defectors by applying to them a social fee. Results from numerical simulations show that different equilibria allowing the three strategies to coexist are possible as well as that social punishment further enhance the robustness of cooperation. Our results are confirmed for different network topologies and two evolutionary games. In addition, we analyze the microscopic mechanisms that give rise to the observed macroscopic behaviors in both homogeneous and heterogeneous networks. Our conclusions might provide additional insights for understanding the roots of cooperation in social systems.

Extortion provides alternative routes to the evolution of cooperation in structured populations

NASA Astrophysics Data System (ADS)

Xu, Xiongrui; Rong, Zhihai; Wu, Zhi-Xi; Zhou, Tao; Tse, Chi Kong

2017-05-01

In this paper, we study the evolution of cooperation in structured populations (individuals are located on either a regular lattice or a scale-free network) in the context of repeated games by involving three types of strategies, namely, unconditional cooperation, unconditional defection, and extortion. The strategy updating of the players is ruled by the replicator-like dynamics. We find that extortion strategies can act as catalysts to promote the emergence of cooperation in structured populations via different mechanisms. Specifically, on regular lattice, extortioners behave as both a shield, which can enwrap cooperators inside and keep them away from defectors, and a spear, which can defeat those surrounding defectors with the help of the neighboring cooperators. Particularly, the enhancement of cooperation displays a resonance-like behavior, suggesting the existence of optimal extortion strength mostly favoring the evolution of cooperation, which is in good agreement with the predictions from the generalized mean-field approximation theory. On scale-free network, the hubs, who are likely occupied by extortioners or defectors at the very beginning, are then prone to be conquered by cooperators on small-degree nodes as time elapses, thus establishing a bottom-up mechanism for the emergence and maintenance of cooperation.

The Cooperative Learning Effects on English Reading Comprehension and Learning Motivation of EFL Freshmen

ERIC Educational Resources Information Center

Pan, Ching-Ying; Wu, Hui-Yi

2013-01-01

This experimental study aims to investigate the effects of using cooperative learning to enhance the English reading comprehension and learning motivation of EFL freshmen by comparing the cooperative learning instruction and traditional lecture instruction. This experiment was implemented in a Freshman English Reading course, a two credit course,…

International Cooperation and Competition in Civilian Space Activities.

ERIC Educational Resources Information Center

Congress of the U.S., Washington, DC. Office of Technology Assessment.

This report assesses the state of international competition in civilian space activities, explores United States civilian objectives in space, and suggests alternative options for enhancing the overall U.S. position in space technologies. It also investigated past, present, and projected international cooperative arrangements for space activities…

Range expansion promotes cooperation in an experimental microbial metapopulation

PubMed Central

Datta, Manoshi Sen; Korolev, Kirill S.; Cvijovic, Ivana; Dudley, Carmel; Gore, Jeff

2013-01-01

Natural populations throughout the tree of life undergo range expansions in response to changes in the environment. Recent theoretical work suggests that range expansions can have a strong effect on evolution, even leading to the fixation of deleterious alleles that would normally be outcompeted in the absence of migration. However, little is known about how range expansions might influence alleles under frequency- or density-dependent selection. Moreover, there is very little experimental evidence to complement existing theory, since expanding populations are difficult to study in the natural environment. In this study, we have used a yeast experimental system to explore the effect of range expansions on the maintenance of cooperative behaviors, which commonly display frequency- and density-dependent selection and are widespread in nature. We found that range expansions favor the maintenance of cooperation in two ways: (i) through the enrichment of cooperators at the front of the expanding population and (ii) by allowing cooperators to “outrun” an invading wave of defectors. In this system, cooperation is enhanced through the coupling of population ecology and evolutionary dynamics in expanding populations, thus providing experimental evidence for a unique mechanism through which cooperative behaviors could be maintained in nature. PMID:23569263

Energy Efficiency of D2D Multi-User Cooperation.

PubMed

Zhang, Zufan; Wang, Lu; Zhang, Jie

2017-03-28

The Device-to-Device (D2D) communication system is an important part of heterogeneous networks. It has great potential to improve spectrum efficiency, throughput and energy efficiency cooperation of multiple D2D users with the advantage of direct communication. When cooperating, D2D users expend extraordinary energy to relay data to other D2D users. Hence, the remaining energy of D2D users determines the life of the system. This paper proposes a cooperation scheme for multiple D2D users who reuse the orthogonal spectrum and are interested in the same data by aiming to solve the energy problem of D2D users. Considering both energy availability and the Signal to Noise Ratio (SNR) of each D2D user, the Kuhn-Munkres algorithm is introduced in the cooperation scheme to solve relay selection problems. Thus, the cooperation issue is transformed into a maximum weighted matching (MWM) problem. In order to enhance energy efficiency without the deterioration of Quality of Service (QoS), the link outage probability is derived according to the Shannon Equation by considering the data rate and delay. The simulation studies the relationships among the number of cooperative users, the length of shared data, the number of data packets and energy efficiency.

Confrontational scavenging as a possible source for language and cooperation

PubMed Central

2011-01-01

The emergence of language and the high degree of cooperation found among humans seems to require more than a straightforward enhancement of primate traits. Some triggering episode unique to human ancestors was likely necessary. Here it is argued that confrontational scavenging was such an episode. Arguments for and against an established confrontational scavenging niche are discussed, as well as the probable effects of such a niche on language and co-operation. Finally, several possible directions for future research are suggested. PMID:21933413

Costs for switching partners reduce network dynamics but not cooperative behaviour

PubMed Central

Bednarik, Peter; Fehl, Katrin; Semmann, Dirk

2014-01-01

Social networks represent the structuring of interactions between group members. Above all, many interactions are profoundly cooperative in humans and other animals. In accordance with this natural observation, theoretical work demonstrates that certain network structures favour the evolution of cooperation. Yet, recent experimental evidence suggests that static networks do not enhance cooperative behaviour in humans. By contrast, dynamic networks do foster cooperation. However, costs associated with dynamism such as time or resource investments in finding and establishing new partnerships have been neglected so far. Here, we show that human participants are much less likely to break links when costs arise for building new links. Especially, when costs were high, the network was nearly static. Surprisingly, cooperation levels in Prisoner's Dilemma games were not affected by reduced dynamism in social networks. We conclude that the mere potential to quit collaborations is sufficient in humans to reach high levels of cooperative behaviour. Effects of self-structuring processes or assortment on the network played a minor role: participants simply adjusted their cooperative behaviour in response to the threats of losing a partner or of being expelled. PMID:25122233

Random topologies and the emergence of cooperation: the role of short-cuts

NASA Astrophysics Data System (ADS)

Vilone, D.; Sánchez, A.; Gómez-Gardeñes, J.

2011-04-01

We study in detail the role of short-cuts in promoting the emergence of cooperation in a network of agents playing the Prisoner's Dilemma game (PDG). We introduce a model whose topology interpolates between the one-dimensional Euclidean lattice (a ring) and the complete graph by changing the value of one parameter (the probability p of adding a link between two nodes not already connected in the Euclidean configuration). We show that there is a region of values of p in which cooperation is greatly enhanced, whilst for smaller values of p only a few cooperators are present in the final state, and for p\\rightarrow 1^- cooperation is totally suppressed. We present analytical arguments that provide a very plausible interpretation of the simulation results, thus unveiling the mechanism by which short-cuts contribute to promoting (or suppressing) cooperation.

Cooperation Dilemma in Finite Populations under Fluctuating Environments

NASA Astrophysics Data System (ADS)

Assaf, Michael; Mobilia, Mauro; Roberts, Elijah

2013-12-01

We present a novel approach allowing the study of rare events like fixation under fluctuating environments, modeled as extrinsic noise, in evolutionary processes characterized by the dominance of one species. Our treatment consists of mapping the system onto an auxiliary model, exhibiting metastable species coexistence, that can be analyzed semiclassically. This approach enables us to study the interplay between extrinsic and demographic noise on the statistics of interest. We illustrate our theory by considering the paradigmatic prisoner’s dilemma game, whose evolution is described by the probability that cooperators fixate the population and replace all defectors. We analytically and numerically demonstrate that extrinsic noise may drastically enhance the cooperation fixation probability and even change its functional dependence on the population size. These results, which generalize earlier works in population genetics, indicate that extrinsic noise may help sustain and promote a much higher level of cooperation than static settings.

We can work it out: an enactive look at cooperation

PubMed Central

Fantasia, Valentina; De Jaegher, Hanne; Fasulo, Alessandra

2014-01-01

The past years have seen an increasing debate on cooperation and its unique human character. Philosophers and psychologists have proposed that cooperative activities are characterized by shared goals to which participants are committed through the ability to understand each other’s intentions. Despite its popularity, some serious issues arise with this approach to cooperation. First, one may challenge the assumption that high-level mental processes are necessary for engaging in acting cooperatively. If they are, then how do agents that do not possess such ability (preverbal children, or children with autism who are often claimed to be mind-blind) engage in cooperative exchanges, as the evidence suggests? Secondly, to define cooperation as the result of two de-contextualized minds reading each other’s intentions may fail to fully acknowledge the complexity of situated, interactional dynamics and the interplay of variables such as the participants’ relational and personal history and experience. In this paper we challenge such accounts of cooperation, calling for an embodied approach that sees cooperation not only as an individual attitude toward the other, but also as a property of interaction processes. Taking an enactive perspective, we argue that cooperation is an intrinsic part of any interaction, and that there can be cooperative interaction before complex communicative abilities are achieved. The issue then is not whether one is able or not to read the other’s intentions, but what it takes to participate in joint action. From this basic account, it should be possible to build up more complex forms of cooperation as needed. Addressing the study of cooperation in these terms may enhance our understanding of human social development, and foster our knowledge of different ways of engaging with others, as in the case of autism. PMID:25152745

Increased cooperative behavior across remitted bipolar I disorder and major depression: Insights utilizing a behavioral economic trust game.

PubMed

Ong, Desmond C; Zaki, Jamil; Gruber, June

2017-01-01

Mood disorders impact social functioning, but might contribute to experiences-like affective distress-that might result in increased cooperative behavior under certain circumstances. We recruited participants with a history of bipolar I disorder (n = 28), major depressive disorder (n = 30), and healthy controls (n = 27)-to play a well-validated behavioral economic Trust Game, a task that provides a well-controlled experimental scenario, to measure cooperative behavior for the first time across both groups. Both remitted mood-disordered groups cooperated significantly more than the control group, but did not differ from one another. These results suggest that, in some contexts, a history of mood disturbance can produce enhanced cooperation, even in the absence of current mood symptoms. We discuss the clinical significance of enhanced cooperation in mood disorders and point to key directions for future research. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Designing a Social Environment for Human-Robot Cooperation.

ERIC Educational Resources Information Center

Amram, Fred M.

Noting that work is partly a social activity, and that workers' psychological and emotional needs influence their productivity, this paper explores avenues for improving human-robot cooperation and for enhancing worker satisfaction in the environment of flexible automation. The first section of the paper offers a brief overview of the…

Non-cooperative game theory in biology and cooperative reasoning in humans.

PubMed

Kabalak, Alihan; Smirnova, Elena; Jost, Jürgen

2015-06-01

The readiness for spontaneous cooperation together with the assumptions that others share this cooperativity has been identified as a fundamental feature that distinguishes humans from other animals, including the great apes. At the same time, cooperativity presents an evolutionary puzzle because non-cooperators do better in a group of cooperators. We develop here an analysis of the process leading to cooperation in terms of rationality concepts, game theory and epistemic logic. We are, however, not attempting to reconstruct the actual evolutionary process. We rather want to provide the logical structure underlying cooperation in order to understand why cooperation is possible and what kind of reasoning and beliefs would lead to cooperative decision-making. Game theory depends on an underlying common belief in non-cooperative rationality of the players, and cooperativity similarly can utilize a common belief in cooperative rationality as its basis. We suggest a weaker concept of rational decision-making in games that encompasses both types of decision-making. We build this up in stages, starting from simple optimization, then using anticipation of the reaction of others, to finally arrive at reflexive and cooperative reasoning. While each stage is more difficult than the preceding, importantly, we also identify a reduction of complexity achieved by the consistent application of higher stage reasoning.

Human Xq28 Inversion Polymorphism: From Sex Linkage to Genomics--A Genetic Mother Lode

ERIC Educational Resources Information Center

Kirby, Cait S.; Kolber, Natalie; Salih Almohaidi, Asmaa M.; Bierwert, Lou Ann; Saunders, Lori; Williams, Steven; Merritt, Robert

2016-01-01

An inversion polymorphism of the filamin and emerin genes at the tip of the long arm of the human X-chromosome serves as the basis of an investigative laboratory in which students learn something new about their own genomes. Long, nearly identical inverted repeats flanking the filamin and emerin genes illustrate how repetitive elements can lead to…

A Course of Study in Cooperation and Cooperatives.

ERIC Educational Resources Information Center

Bjoraker, Walter T., Ed.

Designed for teachers with limited experience in cooperatives, this course of study was prepared by seminar students for use in high school or adult education programs, and emphasizes the principles of cooperation, the operation and management of cooperatives, and the communication required for their effective functioning. Units requiring a total…

Beyond TQM: Competition and Cooperation Create the Agile Institution.

ERIC Educational Resources Information Center

Godbey, Galen

1993-01-01

The market environment for higher education is being shaped by developments in technology, business practices, partnerships between education and industry, and adoption of Total Quality Management principles. Shrewd college administrators will combine competitiveness and cooperation to maintain or enhance their institutions' distinctiveness in the…

From Additivity to Cooperativity in Chemistry: Can Cooperativity Be Measured?

PubMed

Tebben, Ludger; Mück-Lichtenfeld, Christian; Fernández, Gustavo; Grimme, Stefan; Studer, Armido

2017-05-02

Cooperative effects can be observed in various research areas in chemistry; cooperative catalysis is well-established, the assembly of compounds on surfaces can be steered by cooperative effects, and supramolecular polymerization can proceed in a cooperative manner. In biological systems, cooperativity is observed in protein-protein, protein-lipid and protein-molecule interactions. Synergistic effects are relevant in frustrated Lewis pairs, organic multispin systems, multimetallic clusters and also in nanoparticles. However, a general approach to determine cooperativity in the different chemical systems is currently not known. In the present concept paper it is suggested that, at least for simpler systems that can be described at the molecular level, cooperativity can be defined based on energy considerations. For systems in which no chemical transformation occurs, determination of interaction energies of the whole system with respect to the interaction energies between all individual component pairs (subsystems) will allow determination of cooperativity. For systems comprising of chemical transformations, cooperativity can be evaluated by determining the activation energy of the synergistic system and by comparing this with activation energies of the corresponding subsystems that lack an activating moiety. For more complex systems, cooperativity is generally determined at a qualitative level. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

To Cooperate or Not to Cooperate: Why Behavioural Mechanisms Matter

PubMed Central

2016-01-01

Mutualistic cooperation often requires multiple individuals to behave in a coordinated fashion. Hence, while the evolutionary stability of mutualistic cooperation poses no particular theoretical difficulty, its evolutionary emergence faces a chicken and egg problem: an individual cannot benefit from cooperating unless other individuals already do so. Here, we use evolutionary robotic simulations to study the consequences of this problem for the evolution of cooperation. In contrast with standard game-theoretic results, we find that the transition from solitary to cooperative strategies is very unlikely, whether interacting individuals are genetically related (cooperation evolves in 20% of all simulations) or unrelated (only 3% of all simulations). We also observe that successful cooperation between individuals requires the evolution of a specific and rather complex behaviour. This behavioural complexity creates a large fitness valley between solitary and cooperative strategies, making the evolutionary transition difficult. These results reveal the need for research on biological mechanisms which may facilitate this transition. PMID:27148874

Shape matters: Lifecycle of cooperative patches promotes cooperation in bulky populations

PubMed Central

Misevic, Dusan; Frénoy, Antoine; Lindner, Ariel B; Taddei, François

2015-01-01

Natural cooperative systems take many forms, ranging from one-dimensional cyanobacteria arrays to fractal-like biofilms. We use in silico experimental systems to study a previously overlooked factor in the evolution of cooperation, physical shape of the population. We compare the emergence and maintenance of cooperation in populations of digital organisms that inhabit bulky (100 × 100 cells) or slender (4 × 2500) toroidal grids. Although more isolated subpopulations of secretors in a slender population could be expected to favor cooperation, we find the opposite: secretion evolves to higher levels in bulky populations. We identify the mechanistic explanation for the shape effect by analyzing the lifecycle and dynamics of cooperator patches, from their emergence and growth, to invasion by noncooperators and extinction. Because they are constrained by the population shape, the cooperator patches expand less in slender than in bulky populations, leading to fewer cooperators, less public good secretion, and generally lower cooperation. The patch dynamics and mechanisms of shape effect are robust across several digital cooperation systems and independent of the underlying basis for cooperation (public good secretion or a cooperation game). Our results urge for a greater consideration of population shape in the study of the evolution of cooperation across experimental and modeling systems. PMID:25639379

An Overview of the Cooperative Effort between the United States Department of Energy and the China Atomic Energy Authority to Enhance MPC&A Inspections for Civil Nuclear Facilities in China

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

Ahern, Keith; Daming, Liu; Hanley, Tim

The United States Department of Energy, National Nuclear Security Administration (DOE/NNSA) and the China Atomic Energy Authority (CAEA) are cooperating to enhance the domestic regulatory inspections capacity for special nuclear material protection, control and accounting (MPC&A) requirements for civil nuclear facilities in China. This cooperation is conducted under the auspices of the Agreement between the Department of Energy of the United States of America and the State Development and Planning Commission of the People s Republic of China on Cooperation Concerning Peaceful Uses of Nuclear Technology. This initial successful effort was conducted in three phases. Phase I focused on introducingmore » CAEA personnel to DOE and U. S. Nuclear Regulatory Commission inspection methods for U. S. facilities. This phase was completed in January 2008 during meetings in Beijing. Phase II focused on developing physical protection and material control and accounting inspection exercises that enforced U. S. inspection methods identified during Phase 1. Hands on inspection activities were conducted in the United States over a two week period in July 2009. Simulated deficiencies were integrated into the inspection exercises. The U. S. and Chinese participants actively identified and discussed deficiencies noted during the two week training course. The material control and accounting inspection exercises were conducted at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, KY. The physical protection inspection exercises were conducted at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, TN. Phase III leveraged information provided under Phase I and experience gained under Phase II to develop a formal inspection guide that incorporates a systematic approach to training for Chinese MPC&A field inspectors. Additional hands on exercises that are applicable to Chinese regulations were incorporated into the Phase III training material. Phase III was completed in May 2010 at

Cooperative gene regulation by microRNA pairs and their identification using a computational workflow

PubMed Central

Schmitz, Ulf; Lai, Xin; Winter, Felix; Wolkenhauer, Olaf; Vera, Julio; Gupta, Shailendra K.

2014-01-01

MicroRNAs (miRNAs) are an integral part of gene regulation at the post-transcriptional level. Recently, it has been shown that pairs of miRNAs can repress the translation of a target mRNA in a cooperative manner, which leads to an enhanced effectiveness and specificity in target repression. However, it remains unclear which miRNA pairs can synergize and which genes are target of cooperative miRNA regulation. In this paper, we present a computational workflow for the prediction and analysis of cooperating miRNAs and their mutual target genes, which we refer to as RNA triplexes. The workflow integrates methods of miRNA target prediction; triplex structure analysis; molecular dynamics simulations and mathematical modeling for a reliable prediction of functional RNA triplexes and target repression efficiency. In a case study we analyzed the human genome and identified several thousand targets of cooperative gene regulation. Our results suggest that miRNA cooperativity is a frequent mechanism for an enhanced target repression by pairs of miRNAs facilitating distinctive and fine-tuned target gene expression patterns. Human RNA triplexes predicted and characterized in this study are organized in a web resource at www.sbi.uni-rostock.de/triplexrna/. PMID:24875477

Culture and the evolution of human cooperation

PubMed Central

Boyd, Robert; Richerson, Peter J.

2009-01-01

The scale of human cooperation is an evolutionary puzzle. All of the available evidence suggests that the societies of our Pliocene ancestors were like those of other social primates, and this means that human psychology has changed in ways that support larger, more cooperative societies that characterize modern humans. In this paper, we argue that cultural adaptation is a key factor in these changes. Over the last million years or so, people evolved the ability to learn from each other, creating the possibility of cumulative, cultural evolution. Rapid cultural adaptation also leads to persistent differences between local social groups, and then competition between groups leads to the spread of behaviours that enhance their competitive ability. Then, in such culturally evolved cooperative social environments, natural selection within groups favoured genes that gave rise to new, more pro-social motives. Moral systems enforced by systems of sanctions and rewards increased the reproductive success of individuals who functioned well in such environments, and this in turn led to the evolution of other regarding motives like empathy and social emotions like shame. PMID:19805434

Cooperative Education: Characteristics and Effectiveness. ERIC Digest No. 91.

ERIC Educational Resources Information Center

Kerka, Sandra

Cooperative education can enhance classroom instruction by providing practical work experience that is relevant to students' career goals. Among co-op's benefits to students are increased relevance of learning and motivation for study; improved self-reliance, self-confidence, and responsibility; contacts with potential employers; and higher…

Science Integrating Learning Objectives: A Cooperative Learning Group Process

ERIC Educational Resources Information Center

Spindler, Matt

2015-01-01

The integration of agricultural and science curricular content that capitalizes on natural and inherent connections represents a challenge for secondary agricultural educators. The purpose of this case study was to create information about the employment of Cooperative Learning Groups (CLG) to enhance the science integrating learning objectives…

Cooperatively enhanced ionic hydrogen bonds in Cl-(CH3OH)(1-3)Ar clusters.

PubMed

Beck, Jordan P; Lisy, James M

2010-09-23

Infrared predissociation (IRPD) spectra of Cl−(CH3OH)1-3Ar and Cl-(CH3OD)1-3Ar were obtained in the OH and CH stretching regions. The use of methanol-d1 was necessary to distinguish between CH stretches and hydrogen-bonded OH features. The spectra of Cl-(CH3OH)2-3Ar show intense features at frequencies lower than the CH stretches, indicating structures with very strong hydrogen bonds. These strong hydrogen bonds arise from structures in which a Cl-···methanol ionic hydrogen bond is cooperatively enhanced by the presence of a second shell and, in the case of Cl-(CH3OH)3Ar, a third shell methanol. The strongest hydrogen bond is observed in the Cl-(CH3OH)3Ar spectrum at 2733 cm-1, shifted a remarkable -948 cm-1 from the neutral, gas-phase methanol value. Harmonic, ab initio frequency calculations are not adequate in describing these strong hydrogen bonds. Therefore, we describe a simple computational approach to better approximate the hydrogen bond frequencies. Overall, the results of this study indicate that high-energy isomers are very efficiently trapped using our experimental method of introducing Cl- into neutral, cold methanol-argon clusters.

Separating conditional and unconditional cooperation in a sequential Prisoner’s Dilemma game

PubMed Central

Mieth, Laura; Buchner, Axel

2017-01-01

Most theories of social exchange distinguish between two different types of cooperation, depending on whether or not cooperation occurs conditional upon the partner’s previous behaviors. Here, we used a multinomial processing tree model to distinguish between positive and negative reciprocity and cooperation bias in a sequential Prisoner’s Dilemma game. In Experiments 1 and 2, the facial expressions of the partners were varied to manipulate cooperation bias. In Experiment 3, an extinction instruction was used to manipulate reciprocity. The results confirm that people show a stronger cooperation bias when interacting with smiling compared to angry-looking partners, supporting the notion that a smiling facial expression in comparison to an angry facial expression helps to construe a situation as cooperative rather than competitive. Reciprocity was enhanced for appearance-incongruent behaviors, but only when participants were encouraged to form expectations about the partners’ future behaviors. Negative reciprocity was not stronger than positive reciprocity, regardless of whether expectations were manipulated or not. Experiment 3 suggests that people are able to ignore previous episodes of cheating as well as previous episodes of cooperation if these turn out to be irrelevant for predicting a partner’s future behavior. The results provide important insights into the mechanisms of social cooperation. PMID:29121671

Dynamical Cooper pairing in nonequilibrium electron-phonon systems

DOE PAGES

Knap, Michael; Babadi, Mehrtash; Refael, Gil; ...

2016-12-08

In this paper, we analyze Cooper pairing instabilities in strongly driven electron-phonon systems. The light-induced nonequilibrium state of phonons results in a simultaneous increase of the superconducting coupling constant and the electron scattering. We demonstrate that the competition between these effects leads to an enhanced superconducting transition temperature in a broad range of parameters. Finally, our results may explain the observed transient enhancement of superconductivity in several classes of materials upon irradiation with high intensity pulses of terahertz light, and may pave new ways for engineering high-temperature light-induced superconducting states.

Investment and Return in International Space Life Sciences Research Cooperation

NASA Technical Reports Server (NTRS)

McPhee, Jancy C.; White, Ronald J.

2007-01-01

Today, a worldwide community of life scientists interested in space research is attempting to improve the understanding of general biological processes, aid the development of procedures to reduce the biomedically-related risks of space flight, and/or directly support the health care of people who fly in space. Unfortunately, limited resource and subject availability and the technical challenges of performing space experiments have all hampered the full growth and development of space life sciences research. For many years, international cooperation in this field has been considered an attractive approach towards overcoming some of these difficulties, since pooling resources and sharing results would enhance the knowledge of all cooperating partners. International cooperative activities, however, require an investment by each partner and, just as in many other endeavors, the research gain can be directly related to the investment made. In this paper, the authors will discuss three possible levels of cooperation: sharing of data from independent investigations, harmonious integration of pre-designed independent investigations, and de novo design of an integrated suite of investigations using a joint investigator team. The degree of investment and potential return for each level of cooperation will be described.

Exploring Technology Supported Collaborative and Cooperative Group Formation Mechanisms

ERIC Educational Resources Information Center

Carapina, Mia; Boticki, Ivica

2015-01-01

This paper reflects on the systematic literature review paper (in progress), which analyzes technology enhanced collaborative and cooperative learning in elementary education worldwide from 2004 to 2015, focusing on the exploration of technology mediated group formation. The review paper reports on only a few cases of technology supported methods…

Cooperation, but not competition, improves 4-year-old children's reasoning about others' diverse desires.

PubMed

Jin, Xinyi; Li, Pengchao; He, Jie; Shen, Mowei

2017-05-01

Three experiments examined whether cooperation or competition affects 4-year-old children's reasoning about other people's desires-which differed from their own-in a gift selection task. Experiment 1 (N=72) found that children's performance in selecting an adult-preferred gift for an adult experimenter was enhanced by a short period of preceding cooperative, but not competitive or individualistic, play with the experimenter. Experiment 2 (N=24) ruled out the alternative explanation that children resisted satisfying their opponent after competition. Experiment 3 (N=48) replicated the cooperation advantage in selecting a gift for someone else, indicating that children's understanding of diverse desires was generally improved by cooperation but not competition. These findings support the constructivist view of social development and highlight the advantage of cooperation. Copyright © 2016 Elsevier Inc. All rights reserved.

Understanding cooperative behavior in structurally disordered populations

NASA Astrophysics Data System (ADS)

Xu, C.; Zhang, W.; Du, P.; Choi, C. W.; Hui, P. M.

2016-06-01

The effects of an inhomogeneous competing environment on the extent of cooperation are studied within the context of a site-diluted evolutionary snowdrift game on a square lattice, with the occupied sites representing the players, both numerically and analytically. The frequency of cooperation ℱ C generally shows a non-monotonic dependence on the fraction of occupied sites ρ, for different values of the payoff parameter r. Slightly diluting a lattice leads to a lower cooperation for small and high values of r. For a range of r, however, dilution leads to an enhanced cooperation. An analytic treatment is developed for ℱC I + ℱC II, with ℱC I emphasizing the importance of the small clusters of players especially for ℱC II from the other players is shown to be inadequate. A local configuration approximation (LCA) that treats the local competing configurations as the variables and amounts to include spatial correlation up to the neighborhood of a player's neighbors is developed. Results of ℱ C ( ρ) and the number of different local configurations from LCA are in good agreement with simulation results. A transparent physical picture of the dynamics stemming from LCA is also presented. The theoretical approach provides a framework that can be readily applied to competing agent-based models in structurally ordered and disordered populations.

Testosterone is associated with cooperation during intergroup competition by enhancing parochial altruism

PubMed Central

Reimers, Luise; Diekhof, Esther K.

2015-01-01

The steroid hormone testosterone is widely associated with negative behavioral effects, such as aggression or dominance. However, recent studies applying economic exchange tasks revealed conflicting results. While some point to a prosocial effect of testosterone by increasing altruistic behavior, others report that testosterone promotes antisocial tendencies. Taking into account additional factors such as parochial altruism (i.e., ingroup favoritism and outgroup hostility) might help to explain this contradiction. First evidence for a link between testosterone and parochial altruism comes from recently reported data of male soccer fans playing the ultimatum game. In this study high levels of endogenous testosterone predicted increased altruistic punishment during outgroup interactions and at the same time heightened ingroup generosity. Here, we report findings of another experimental task, the prisoner's dilemma, applied in the same context to examine the role of testosterone on parochial tendencies in terms of cooperation. In this task, 50 male soccer fans were asked to decide whether or not they wanted to cooperate with partners marked as either fans of the subject's own favorite team (ingroup) or fans of other teams (outgroups). Our results show that high testosterone levels were associated with increased ingroup cooperation during intergroup competition. In addition, subjects displaying a high degree of parochialism during intergroup competition had significantly higher levels of testosterone than subjects who did not differentiate much between the different groups. In sum, the present data demonstrate that the behavioral effects of testosterone are not limited to aggressive and selfish tendencies but may imply prosocial aspects depending on the context. By this means, our results support the previously reported findings on testosterone-dependent intergroup bias and indicate that this social hormone might be an important factor driving parochial altruism. PMID

Testosterone is associated with cooperation during intergroup competition by enhancing parochial altruism.

PubMed

Reimers, Luise; Diekhof, Esther K

2015-01-01

The steroid hormone testosterone is widely associated with negative behavioral effects, such as aggression or dominance. However, recent studies applying economic exchange tasks revealed conflicting results. While some point to a prosocial effect of testosterone by increasing altruistic behavior, others report that testosterone promotes antisocial tendencies. Taking into account additional factors such as parochial altruism (i.e., ingroup favoritism and outgroup hostility) might help to explain this contradiction. First evidence for a link between testosterone and parochial altruism comes from recently reported data of male soccer fans playing the ultimatum game. In this study high levels of endogenous testosterone predicted increased altruistic punishment during outgroup interactions and at the same time heightened ingroup generosity. Here, we report findings of another experimental task, the prisoner's dilemma, applied in the same context to examine the role of testosterone on parochial tendencies in terms of cooperation. In this task, 50 male soccer fans were asked to decide whether or not they wanted to cooperate with partners marked as either fans of the subject's own favorite team (ingroup) or fans of other teams (outgroups). Our results show that high testosterone levels were associated with increased ingroup cooperation during intergroup competition. In addition, subjects displaying a high degree of parochialism during intergroup competition had significantly higher levels of testosterone than subjects who did not differentiate much between the different groups. In sum, the present data demonstrate that the behavioral effects of testosterone are not limited to aggressive and selfish tendencies but may imply prosocial aspects depending on the context. By this means, our results support the previously reported findings on testosterone-dependent intergroup bias and indicate that this social hormone might be an important factor driving parochial altruism.

Simultaneously selecting appropriate partners for gaming and strategy adaptation to enhance network reciprocity in the prisoner's dilemma

NASA Astrophysics Data System (ADS)

Tanimoto, Jun

2014-01-01

Network reciprocity is one mechanism for adding social viscosity, which leads to cooperative equilibrium in 2 × 2 prisoner's dilemma games. Previous studies have shown that cooperation can be enhanced by using a skewed, rather than a random, selection of partners for either strategy adaptation or the gaming process. Here we show that combining both processes for selecting a gaming partner and an adaptation partner further enhances cooperation, provided that an appropriate selection rule and parameters are adopted. We also show that this combined model significantly enhances cooperation by reducing the degree of activity in the underlying network; we measure the degree of activity with a quantity called effective degree. More precisely, during the initial evolutionary stage in which the global cooperation fraction declines because initially allocated cooperators becoming defectors, the model shows that weak cooperative clusters perish and only a few strong cooperative clusters survive. This finding is the most important key to attaining significant network reciprocity.

Cooperative Learning--Part 3. Electronic Cooperative Quizzes.

ERIC Educational Resources Information Center

Jensen, Murray; Moore, Randy; Hatch, Jay

2002-01-01

Introduces the Electronic Cooperative Quiz (ECQ) program which aims to investigate the implementation of cooperative quizzes to the World Wide Web. Describes the creation and design of the program and evaluates the two different methods used with students. (YDS)

Spatially correlated heterogeneous aspirations to enhance network reciprocity

NASA Astrophysics Data System (ADS)

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.

A hierarchical model of the evolution of cooperation in cultural systems.

PubMed

Savatsky, K; Reynolds, R G

1989-01-01

In this paper the following problem is addressed: "Under what conditions can a collection of individual organisms learn to cooperate when cooperation appears to outwardly degrade individual performance at the outset. In order to attempt a theoretical solution to this problem, data from a real world problem in anthropology is used. A distributed simulation model of this system was developed to assess its long term behavior using using an approach suggested by Zeigler (Zeigler, B.P., 1984, Multifaceted Modelling and Discrete Event Simulation (Academic Press, London)). The results of the simulation are used to show that although cooperation degrades the performance potential of each individual, it enhances the persistence of the individual's partial solution to the problem in certain situations."

Preferential interactions promote blind cooperation and informed defection.

PubMed

Pérez-Escudero, Alfonso; Friedman, Jonathan; Gore, Jeff

2016-12-06

It is common sense that costs and benefits should be carefully weighed before deciding on a course of action. However, we often disapprove of people who do so, even when their actual decision benefits us. For example, we prefer people who directly agree to do us a favor over those who agree only after securing enough information to ensure that the favor will not be too costly. Why should we care about how people make their decisions, rather than just focus on the decisions themselves? Current models show that punishment of information gathering can be beneficial because it forces blind decisions, which under some circumstances enhances cooperation. Here we show that aversion to information gathering can be beneficial even in the absence of punishment, due to a different mechanism: preferential interactions with reliable partners. In a diverse population where different people have different-and unknown-preferences, those who seek additional information before agreeing to cooperate reveal that their preferences are close to the point where they would choose not to cooperate. Blind cooperators are therefore more likely to keep cooperating even if conditions change, and aversion to information gathering helps to interact preferentially with them. Conversely, blind defectors are more likely to keep defecting in the future, leading to a preference for informed defectors over blind ones. Both mechanisms-punishment to force blind decisions and preferential interactions-give qualitatively different predictions, which may enable experimental tests to disentangle them in real-world situations.

From cooperation to conflict? Swedish rehabilitation professionals' experiences of interorganizational cooperation.

PubMed

Ståhl, Christian; Svensson, Tommy; Ekberg, Kerstin

2011-09-01

This article analyses Swedish rehabilitation professionals' experiences of interorganizational cooperation in return-to-work and labour market reintegration. Two groups (n = 15) from different organizations met on a regular basis to discuss their practice from a cooperation perspective. The participants had experience of cooperation in the organizational setting of Coordination Associations. The groups worked with a tutor according to a problem-based methodology, to discuss how their practice is influenced by new structures for cooperation. The material was analysed inductively using qualitative content analysis. Interorganizational cooperation in rehabilitation is generally perceived as promoting coherence and communication. Nevertheless, there are several contradictory factors in the implementation of such work forms, primarily inflexible sickness insurance regulations and inability of managers to implement cooperation in regular practice. While interorganizational cooperation promotes professional discretion and tailored solutions, the insurance system contradicts such ambitions through increased governance. Ultimately, the contradictory tendencies of cooperative initiatives and the stricter governance of sickness insurance regulations are political matters. If political attempts to promote interorganizational cooperation are to succeed, the increasing sectorization that results from strict governance of sickness insurance regulations needs to be targeted on a system level.

Reasons to Co-Operate: Co-Operative Solutions for Schools

ERIC Educational Resources Information Center

Roach, Patrick

2013-01-01

The NASUWT's landmark agreement with the Schools Co-operative Society has provided a new spur to co-operation, collaboration and collegiality in schools. Against a background of rapid and radical changes to the education landscape, co-operative schools are viewed by many as a means to maintaining public service ethos and values in education. The…

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

PubMed Central

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

2012-01-01

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

Cooperative Effects in Closely Packed Quantum Emitters with Collective Dephasing

NASA Astrophysics Data System (ADS)

Prasanna Venkatesh, B.; Juan, M. L.; Romero-Isart, O.

2018-01-01

In a closely packed ensemble of quantum emitters, cooperative effects are typically suppressed due to the dephasing induced by the dipole-dipole interactions. Here, we show that by adding sufficiently strong collective dephasing, cooperative effects can be restored. Specifically, we show that the dipole force on a closely packed ensemble of strongly driven two-level quantum emitters, which collectively dephase, is enhanced in comparison to the dipole force on an independent noninteracting ensemble. Our results are relevant to solid-state systems with embedded quantum emitters such as color centers in diamond and superconducting qubits in microwave cavities and waveguides.

Evolution of cooperation on complex networks with synergistic and discounted group interactions

NASA Astrophysics Data System (ADS)

Zhou, Lei; Li, Aming; Wang, Long

2015-06-01

In the real world individuals often engage in group interactions and their payoffs are determined by many factors, including the typical nonlinear interactions, i.e., synergy and discounting. Previous literatures assume that individual payoffs are either synergistically enhanced or discounted with the additional cooperators. Such settings ignore the interplay of these two factors, which is in sharp contrast with the fact that they ubiquitously coexist. Here we investigate how the coexistence and periodical switching of synergistic and discounted group interactions affect the evolution of cooperation on various complex networks. We show that scale-free networks facilitate the emergence of cooperation in terms of fixation probability for group interactions. With nonlinear interactions the heterogeneity of the degree acts as a double-edged sword: below the neutral drift it is the best for cooperation while above the neutral drift it instead provides the least opportunity for cooperators to be fixed. The advantages of the heterogeneity fade as interactive attributes switch between synergy and discounting, which suggests that the heterogeneity of population structures cannot favor cooperators in group interactions even with simple nonlinear interactions. Nonetheless, scale-free networks always guarantee cooperators the fastest rate of fixation. Our work implies that even very simple nonlinear group interactions could greatly shape the fixation probability and fixation time of cooperators in structured populations indicated by complex networks.

An IUR evolutionary game model on the patent cooperate of Shandong China

NASA Astrophysics Data System (ADS)

Liu, Mengmeng; Ma, Yinghong; Liu, Zhiyuan; You, Xuemei

2017-06-01

Organizations of industries and university & research institutes cooperate to meet their respective needs based on social contacts, trust and share complementary resources. From the perspective of complex network together with the patent data of Shandong province in China, a novel evolutionary game model on patent cooperation network is presented. Two sides in the game model are industries and universities & research institutes respectively. The cooperation is represented by a connection when a new patent is developed together by the two sides. The optimal strategy of the evolutionary game model is quantified by the average positive cooperation probability p ¯ and the average payoff U ¯ . The feasibility of this game model is simulated on the parameters such as the knowledge spillover, the punishment, the development cost and the distribution coefficient of the benefit. The numerical simulations show that the cooperative behaviors are affected by the variation of parameters. The knowledge spillover displays different behaviors when the punishment is larger than the development cost or less than it. Those results indicate that reasonable punishment would improve the positive cooperation. The appropriate punishment will be useful to enhance the big degree nodes positively cooperate with industries and universities & research institutes. And an equitable plan for the distribution of cooperative profits is half-and-half distribution strategy for the two sides in game.

The Relationship Between Empathic Dentist Behavior and Children's Cooperation.

ERIC Educational Resources Information Center

Stave, Jonathan A.

1983-01-01

A study confirmed the dual hypotheses that the more empathic behavior a dental student showed, the greater the cooperation of children patients, and the more often the patients' verbal behavior is dentist-directed rather than self-directed. It is suggested that training in more socially sensitive behavior would enhance patient care. (MSE)

[Enhancement of quality by employing qualification-oriented staff and team-oriented cooperation].

PubMed

Meyenburg-Altwarg, Iris; Tecklenburg, Andreas

2010-01-01

Taking three practical examples from a university hospital the present article describes how quality can be improved by linking deployment of qualification-oriented staff with team-oriented cooperation, especially with regard to the professional groups of physicians and nurses. In the first example, a cross-professional work group defined tasks which--in a legally acceptable manner--allow selected activities to be transferred from physicians to nurses, improving the work processes of all persons concerned. Work and duty profiles, training and modified work processes were created and implemented according to the PDCA circle-based process. The first evaluation took place after nine months using interviews, questionnaires (patients, physicians, and nurses) as well as CIRS. In the second example, emphasis was placed on offers of supplementary services for private patients resulting in a lightening of the workload on the nursing staff. These supplementary services are intended to enhance the wellbeing of the patients. Special external-service staff provide high standard hotel services. These services consistently receive high ratings from the patients. The methods used for introduction and evaluation are analogous to those used in the first example. The third example is concerned with the extension of nursing care and patient empowerment beyond the boundaries of ward and hospital. The guidelines were the implementation of the national expert standard for discharge management according to the DNQP. The methods of introduction were analogous to those used in example 1. For the evaluation interviews were conducted with all participating groups. In all examples actual quantitative measures (key ratios) are not yet available; however, the data collected from the interviews and questionnaires of all the participants are promising.

Third-party punishment increases cooperation in children through (misaligned) expectations and conditional cooperation

PubMed Central

Lergetporer, Philipp; Angerer, Silvia; Glätzle-Rützler, Daniela; Sutter, Matthias

2014-01-01

The human ability to establish cooperation, even in large groups of genetically unrelated strangers, depends upon the enforcement of cooperation norms. Third-party punishment is one important factor to explain high levels of cooperation among humans, although it is still somewhat disputed whether other animal species also use this mechanism for promoting cooperation. We study the effectiveness of third-party punishment to increase children’s cooperative behavior in a large-scale cooperation game. Based on an experiment with 1,120 children, aged 7 to 11 y, we find that the threat of third-party punishment more than doubles cooperation rates, despite the fact that children are rarely willing to execute costly punishment. We can show that the higher cooperation levels with third-party punishment are driven by two components. First, cooperation is a rational (expected payoff-maximizing) response to incorrect beliefs about the punishment behavior of third parties. Second, cooperation is a conditionally cooperative reaction to correct beliefs that third party punishment will increase a partner’s level of cooperation. PMID:24778231

Third-party punishment increases cooperation in children through (misaligned) expectations and conditional cooperation.

PubMed

Lergetporer, Philipp; Angerer, Silvia; Glätzle-Rützler, Daniela; Sutter, Matthias

2014-05-13

The human ability to establish cooperation, even in large groups of genetically unrelated strangers, depends upon the enforcement of cooperation norms. Third-party punishment is one important factor to explain high levels of cooperation among humans, although it is still somewhat disputed whether other animal species also use this mechanism for promoting cooperation. We study the effectiveness of third-party punishment to increase children's cooperative behavior in a large-scale cooperation game. Based on an experiment with 1,120 children, aged 7 to 11 y, we find that the threat of third-party punishment more than doubles cooperation rates, despite the fact that children are rarely willing to execute costly punishment. We can show that the higher cooperation levels with third-party punishment are driven by two components. First, cooperation is a rational (expected payoff-maximizing) response to incorrect beliefs about the punishment behavior of third parties. Second, cooperation is a conditionally cooperative reaction to correct beliefs that third party punishment will increase a partner's level of cooperation.

Long-range Cooper pair splitter with high entanglement production rate

PubMed Central

Chen, Wei; Shi, D. N.; Xing, D. Y.

2015-01-01

Cooper pairs in the superconductor are a natural source of spin entanglement. The existing proposals of the Cooper pair splitter can only realize a low efficiency of entanglement production, and its size is constrained by the superconducting coherence length. Here we show that a long-range Cooper pair splitter can be implemented in a normal metal-superconductor-normal metal (NSN) junction by driving a supercurrent in the S. The supercurrent results in a band gap modification of the S, which significantly enhances the crossed Andreev reflection (CAR) of the NSN junction and simultaneously quenches its elastic cotunneling. Therefore, a high entanglement production rate close to its saturation value can be achieved by the inverse CAR. Interestingly, in addition to the conventional entangled electron states between opposite energy levels, novel entangled states with equal energy can also be induced in our proposal. PMID:25556521

Networked Experiments and Scientific Resource Sharing in Cooperative Knowledge Spaces

ERIC Educational Resources Information Center

Cikic, Sabine; Jeschke, Sabina; Ludwig, Nadine; Sinha, Uwe; Thomsen, Christian

2007-01-01

Cooperative knowledge spaces create new potentials for the experimental fields in natural sciences and engineering because they enhance the accessibility of experimental setups through virtual laboratories and remote technology, opening them for collaborative and distributed usage. A concept for extending existing virtual knowledge spaces for the…

Measuring for enhancing high school students’ cooperative attitude and responsibilities in learning closed electrical circuits through STEM approach

NASA Astrophysics Data System (ADS)

Rusnayati, H.; Masripah, I.; Suwarma, I. R.

2018-05-01

This study conducted by the finding of the lack of students’ cooperative attitude that gained 35.29% and the students’ responsibility 29.41%. It also looks at the preliminary study that conducted by the observation group obtained the students’ cooperative attitude (34%) and student’s responsibility (30%). The purpose of this study to determine students’ cooperative attitude and responsibility at the time of learning a closed electrical circuit through STEM approach. This research method is the descriptive study with the pre-experimental design and the paradigm of one shot case study. The population of this study is the tenth-grade high school students with a sample size of 40 students that consist of 24 female and 16 male. The data collection techniques that utilized is the attitude rubric and the attitude measurement format. The result of this study showed that the percentage of students’ cooperative attitude in the first and second meeting is 83% and 81% with very high criteria. Meanwhile, the attitude of responsibility answerable for the first and second meeting was 81% and 79% with very high and high criteria. This indicates that the STEM approach can improve students’ cooperative attitude and responsibility.

Effect of self-interaction on the evolution of cooperation in complex topologies

NASA Astrophysics Data System (ADS)

Wu, Yu'e.; Zhang, Zhipeng; Chang, Shuhua

2017-09-01

Self-interaction, as a significant mechanism explaining the evolution of cooperation, has attracted great attention both theoretically and experimentally. In this text, we consider a new self-interaction mechanism in the two typical pairwise models including the prisoner's dilemma and the snowdrift games, where the cooperative agents will gain extra bonus for their selfless behavior. We find that under the mechanism the collective cooperation is elevated to a very high level especially after adopting the finite population analogue of replicator dynamics for evolution. The robustness of the new mechanism is tested for different complex topologies for the prisoner's dilemma game. All the presented results demonstrate that the enhancement effects are independent of the structure of the applied spatial networks and the potential evolutionary games, and thus showing a high degree of universality. Our conclusions might shed light on the understanding of the evolution of cooperation in the real world.

An Energy Efficient Cooperative Hierarchical MIMO Clustering Scheme for Wireless Sensor Networks

PubMed Central

Nasim, Mehwish; Qaisar, Saad; Lee, Sungyoung

2012-01-01

In this work, we present an energy efficient hierarchical cooperative clustering scheme for wireless sensor networks. Communication cost is a crucial factor in depleting the energy of sensor nodes. In the proposed scheme, nodes cooperate to form clusters at each level of network hierarchy ensuring maximal coverage and minimal energy expenditure with relatively uniform distribution of load within the network. Performance is enhanced by cooperative multiple-input multiple-output (MIMO) communication ensuring energy efficiency for WSN deployments over large geographical areas. We test our scheme using TOSSIM and compare the proposed scheme with cooperative multiple-input multiple-output (CMIMO) clustering scheme and traditional multihop Single-Input-Single-Output (SISO) routing approach. Performance is evaluated on the basis of number of clusters, number of hops, energy consumption and network lifetime. Experimental results show significant energy conservation and increase in network lifetime as compared to existing schemes. PMID:22368459

A new cooperative strategy for space in the 21st century

NASA Technical Reports Server (NTRS)

Delpech, J. F.; Logsdon, J. M.; Meslin, B.

1993-01-01

The context within which the major government space programs of the world are planned and obtain political approval has changed dramatically with the end of the Cold War. International economic competition has become a central issue in international affairs. Economic and political constraints require that space agencies adapt the ambitious plans they put forward in the 1980s to the realities of this decade and beyond. This paper argues that in this changed context, enhanced international space cooperation can make important contributions to advancing the core interests of nations and firms, and that in some situations, increased and more intimate cooperation may be the only way to achieve ambitious space goals. The paper contains a series of policy-oriented findings and recommendations that together comprise a 'new cooperative strategy' for space.

Social diversity promotes the emergence of cooperation in public goods games.

PubMed

Santos, Francisco C; Santos, Marta D; Pacheco, Jorge M

2008-07-10

Humans often cooperate in public goods games and situations ranging from family issues to global warming. However, evolutionary game theory predicts that the temptation to forgo the public good mostly wins over collective cooperative action, and this is often also seen in economic experiments. Here we show how social diversity provides an escape from this apparent paradox. Up to now, individuals have been treated as equivalent in all respects, in sharp contrast with real-life situations, where diversity is ubiquitous. We introduce social diversity by means of heterogeneous graphs and show that cooperation is promoted by the diversity associated with the number and size of the public goods game in which each individual participates and with the individual contribution to each such game. When social ties follow a scale-free distribution, cooperation is enhanced whenever all individuals are expected to contribute a fixed amount irrespective of the plethora of public goods games in which they engage. Our results may help to explain the emergence of cooperation in the absence of mechanisms based on individual reputation and punishment. Combining social diversity with reputation and punishment will provide instrumental clues on the self-organization of social communities and their economical implications.

Towards Reliable and Energy-Efficient Incremental Cooperative Communication for Wireless Body Area Networks.

PubMed

Yousaf, Sidrah; Javaid, Nadeem; Qasim, Umar; Alrajeh, Nabil; Khan, Zahoor Ali; Ahmed, Mansoor

2016-02-24

In this study, we analyse incremental cooperative communication for wireless body area networks (WBANs) with different numbers of relays. Energy efficiency (EE) and the packet error rate (PER) are investigated for different schemes. We propose a new cooperative communication scheme with three-stage relaying and compare it to existing schemes. Our proposed scheme provides reliable communication with less PER at the cost of surplus energy consumption. Analytical expressions for the EE of the proposed three-stage cooperative communication scheme are also derived, taking into account the effect of PER. Later on, the proposed three-stage incremental cooperation is implemented in a network layer protocol; enhanced incremental cooperative critical data transmission in emergencies for static WBANs (EInCo-CEStat). Extensive simulations are conducted to validate the proposed scheme. Results of incremental relay-based cooperative communication protocols are compared to two existing cooperative routing protocols: cooperative critical data transmission in emergencies for static WBANs (Co-CEStat) and InCo-CEStat. It is observed from the simulation results that incremental relay-based cooperation is more energy efficient than the existing conventional cooperation protocol, Co-CEStat. The results also reveal that EInCo-CEStat proves to be more reliable with less PER and higher throughput than both of the counterpart protocols. However, InCo-CEStat has less throughput with a greater stability period and network lifetime. Due to the availability of more redundant links, EInCo-CEStat achieves a reduced packet drop rate at the cost of increased energy consumption.

A novel cooperative localization algorithm using enhanced particle filter technique in maritime search and rescue wireless sensor network.

PubMed

Wu, Huafeng; Mei, Xiaojun; Chen, Xinqiang; Li, Junjun; Wang, Jun; Mohapatra, Prasant

2018-07-01

Maritime search and rescue (MSR) play a significant role in Safety of Life at Sea (SOLAS). However, it suffers from scenarios that the measurement information is inaccurate due to wave shadow effect when utilizing wireless Sensor Network (WSN) technology in MSR. In this paper, we develop a Novel Cooperative Localization Algorithm (NCLA) in MSR by using an enhanced particle filter method to reduce measurement errors on observation model caused by wave shadow effect. First, we take into account the mobility of nodes at sea to develop a motion model-Lagrangian model. Furthermore, we introduce both state model and observation model to constitute a system model for particle filter (PF). To address the impact of the wave shadow effect on the observation model, we develop an optimal parameter derived by Kullback-Leibler divergence (KLD) to mitigate the error. After the optimal parameter is acquired, an improved likelihood function is presented. Finally, the estimated position is acquired. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

New Cooperative Mechanisms of Low-Energy Nuclear Reactions Using Super Low-Energy External Field

NASA Astrophysics Data System (ADS)

Gareev, F. A.; Zhidkova, I. E.

We propose a new mechanism of LENR: cooperative processes in the whole system, nuclei + atoms + condensed matter, can occur at a smaller threshold energies than the corresponding ones on free constituents. The cooperative processes can be induced and enhanced by low-energy external fields. The excess heat is the emission of internal energy and transmutations at LENR are the result of redistribution of inner energy of the whole system.

Cooperation between parents and school nurses in primary schools: parents' perceptions.

PubMed

Mäenpää, Tiina; Astedt-Kurki, Päivi

2008-03-01

Cooperation between pupils' parents and school nurses is an important part of health promotion in primary schools. Developing frank and trusting relationships contributes to easy and uninhibited cooperation. Cooperation between parents and school nurses has not been widely researched internationally. This article reports on parents' views on cooperation with school nurses in primary schools. The study aims at contributing to school nurses' work so that instead of focusing only on the children, family nursing approaches could be improved. Nineteen parents from 13 families from southern Finland were interviewed for the study in 2004. The data were analysed by grounded theory and the constant comparative method was utilized. Six concepts describing parents' views on cooperation were generated on the basis of the data. Cooperation consists of supporting the child's well-being. School nurses take children's and parents' concerns seriously and intervene effectively if the child's health is threatened. School nurses' expertise is not very visible within school communities. Hoping to receive information and desiring parental involvement are important concepts of cooperation with the school nurse. The child's family is not sufficiently known or taken holistically into consideration when the child's health is promoted. Parents are the initiators of cooperation within school health care and parents describe this by the concept of one-sided communication. Parents do not know about school nurses' work and school health services. They would like to be more involved in school nursing activities. When developing children's health services, parents' expertise in their children's well-being should be paid more attention. This study enhances the knowledge of family nursing by describing Finnish parents' perceptions of cooperation with school nurses. The findings facilitate the understanding of cooperation in school health services.

Greed and Fear in Network Reciprocity: Implications for Cooperation among Organizations.

PubMed

Kitts, James A; Leal, Diego F; Felps, Will; Jones, Thomas M; Berman, Shawn L

2016-01-01

Extensive interdisciplinary literatures have built on the seminal spatial dilemmas model, which depicts the evolution of cooperation on regular lattices, with strategies propagating locally by relative fitness. In this model agents may cooperate with neighbors, paying an individual cost to enhance their collective welfare, or they may exploit cooperative neighbors and diminish collective welfare. Recent research has extended the model in numerous ways, incorporating behavioral noise, implementing other network topologies or adaptive networks, and employing alternative dynamics of replication. Although the underlying dilemma arises from two distinct dimensions-the gains for exploiting cooperative partners (Greed) and the cost of cooperating with exploitative partners (Fear)-most work following from the spatial dilemmas model has argued or assumed that the dilemma can be represented with a single parameter: This research has typically examined Greed or Fear in isolation, or a composite such as the K-index of Cooperation or the ratio of the benefit to cost of cooperation. We challenge this claim on theoretical grounds-showing that embedding interaction in networks generally leads Greed and Fear to have divergent, interactive, and highly nonlinear effects on cooperation at the macro level, even when individuals respond identically to Greed and Fear. Using computational experiments, we characterize both dynamic local behavior and long run outcomes across regions of this space. We also simulate interventions to investigate changes of Greed and Fear over time, showing how model behavior changes asymmetrically as boundaries in payoff space are crossed, leading some interventions to have irreversible effects on cooperation. We then replicate our experiments on inter-organizational network data derived from links through shared directors among 2,400 large US corporations, thus demonstrating our findings for Greed and Fear on a naturally-occurring network. In closing, we

Greed and Fear in Network Reciprocity: Implications for Cooperation among Organizations

PubMed Central

Kitts, James A.; Leal, Diego F.; Felps, Will; Jones, Thomas M.; Berman, Shawn L.

2016-01-01

Extensive interdisciplinary literatures have built on the seminal spatial dilemmas model, which depicts the evolution of cooperation on regular lattices, with strategies propagating locally by relative fitness. In this model agents may cooperate with neighbors, paying an individual cost to enhance their collective welfare, or they may exploit cooperative neighbors and diminish collective welfare. Recent research has extended the model in numerous ways, incorporating behavioral noise, implementing other network topologies or adaptive networks, and employing alternative dynamics of replication. Although the underlying dilemma arises from two distinct dimensions—the gains for exploiting cooperative partners (Greed) and the cost of cooperating with exploitative partners (Fear)–most work following from the spatial dilemmas model has argued or assumed that the dilemma can be represented with a single parameter: This research has typically examined Greed or Fear in isolation, or a composite such as the K-index of Cooperation or the ratio of the benefit to cost of cooperation. We challenge this claim on theoretical grounds—showing that embedding interaction in networks generally leads Greed and Fear to have divergent, interactive, and highly nonlinear effects on cooperation at the macro level, even when individuals respond identically to Greed and Fear. Using computational experiments, we characterize both dynamic local behavior and long run outcomes across regions of this space. We also simulate interventions to investigate changes of Greed and Fear over time, showing how model behavior changes asymmetrically as boundaries in payoff space are crossed, leading some interventions to have irreversible effects on cooperation. We then replicate our experiments on inter-organizational network data derived from links through shared directors among 2,400 large US corporations, thus demonstrating our findings for Greed and Fear on a naturally-occurring network. In closing

Effect of Vibrio cholerae neuraminidase on the mitogen response of T lymphocytes. I. Enhancement of macrophage T-lymphocyte cooperation in concanavalin-A-induced lymphocyte activation.

PubMed

Knop, J

1980-12-01

Vibrio cholerae neuraminidase (VCN) enhances the immune response of lymphocytes in various systems, such as antigen- and mitogen-induced blastogenesis, mixed lymphocyte culture (MLC) and tumor-cell response. We used macrophage-depleted and reconstituted murine lymph-node T-cells to investigate the effect of VCN on macrophage-T-lymphocyte co-operation in Con-A-induced lymphocyte activation. In unfractionated lymph-node cells VCN enhanced the Con-A-induced lymphocyte activation as measured by 3H-thymidine (3H-dThd) incorporation. Removing macrophages from the cells resulted in a significantly diminished response. In addition the enhancing effect of VCN was greatly reduced. Reconstitution of the lymphocyte cultures with macrophages in increasing numbers and from various sources rstored the lymphocyte response and the enhancing effect of VCN. VCN proved to be most efficient in cultures reconstituted with normal peritoneal macrophages. Some effect was also observed using bone-marrow-derived (BM) macrophages. However, higher numbers of normal PE macrophages in the presence of VCN inhibited lymphocyte activation, and inhibition by thioglycollate-broth-induced macrophages was considerably increased by VCN. These results suggest that VCN acts by increasing the efficiency of macrophage-T lymphocyte interaction.

43 CFR 46.155 - Consultation, coordination, and cooperation with other agencies.

Code of Federal Regulations, 2010 CFR

2010-10-01

... governments and other bureaus and Federal agencies concerning the environmental effects of any Federal action... Interior IMPLEMENTATION OF THE NATIONAL ENVIRONMENTAL POLICY ACT OF 1969 Protection and Enhancement of Environmental Quality § 46.155 Consultation, coordination, and cooperation with other agencies. The Responsible...

Fuzzy restrictions and an application to cooperative games with restricted cooperation

NASA Astrophysics Data System (ADS)

Gallardo, J. M.; Jiménez, N.; Jiménez-Losada, A.

2017-10-01

The concept of restriction, which is an extension of that of interior operator, was introduced to model limited cooperation in cooperative game theory. In this paper, a fuzzy version of restrictions is presented. We show that these new operators, called fuzzy restrictions, can be characterized by the transitivity of the fuzzy dependence relations that they induce. As an application, we introduce cooperative games with fuzzy restriction, which are used to model cooperative situations in which each player in a coalition has a level of cooperation within the coalition. A value for these games is defined and characterized.

Interleukin (IL)-18, cooperatively with IL-23, induces prominent inflammation and enhances psoriasis-like epidermal hyperplasia.

PubMed

Shimoura, Noriko; Nagai, Hiroshi; Fujiwara, Susumu; Jimbo, Haruki; Yoshimoto, Takayuki; Nishigori, Chikako

2017-05-01

The interleukin (IL)-23/IL-17 axis is strongly implicated in the pathogenesis of psoriasis. Previous studies showed that IL-18 was elevated in early active and progressive plaque-type psoriatic lesions and that serum or plasma levels of IL-18 correlated with the Psoriasis Area and Severity Index. However, the mechanism whereby IL-18 affects disease severity remains unknown. In this study, we investigated the effects of IL-18 on a psoriasis-like skin inflammation model induced by recombinant mouse IL-23. We found that IL-18, cooperatively with IL-23, induced prominent inflammation and enhanced psoriasis-like epidermal hyperplasia. In the skin of mice treated with IL-23 plus IL-18, the expression of interferon-γ was significantly upregulated and that of chemokine (C-X-C motif) ligand 9 (CXCL9) was synergistically increased. Histologically, strong positive signals of CXCL9 were observed around the infiltrating inflammatory cells. The current results suggest that IL-18 might synergize with IL-23 to induce a T helper 1 immune reaction, without inhibiting the IL-23/IL-17 axis, and thus may aggravate psoriatic inflammation.

Two-agent cooperative search using game models with endurance-time constraints

NASA Astrophysics Data System (ADS)

Sujit, P. B.; Ghose, Debasish

2010-07-01

In this article, the problem of two Unmanned Aerial Vehicles (UAVs) cooperatively searching an unknown region is addressed. The search region is discretized into hexagonal cells and each cell is assumed to possess an uncertainty value. The UAVs have to cooperatively search these cells taking limited endurance, sensor and communication range constraints into account. Due to limited endurance, the UAVs need to return to the base station for refuelling and also need to select a base station when multiple base stations are present. This article proposes a route planning algorithm that takes endurance time constraints into account and uses game theoretical strategies to reduce the uncertainty. The route planning algorithm selects only those cells that ensure the agent will return to any one of the available bases. A set of paths are formed using these cells which the game theoretical strategies use to select a path that yields maximum uncertainty reduction. We explore non-cooperative Nash, cooperative and security strategies from game theory to enhance the search effectiveness. Monte-Carlo simulations are carried out which show the superiority of the game theoretical strategies over greedy strategy for different look ahead step length paths. Within the game theoretical strategies, non-cooperative Nash and cooperative strategy perform similarly in an ideal case, but Nash strategy performs better than the cooperative strategy when the perceived information is different. We also propose a heuristic based on partitioning of the search space into sectors to reduce computational overhead without performance degradation.

Cooperative Game Theoretic Models for Decision-Making in Contexts of Library Cooperation.

ERIC Educational Resources Information Center

Hayes, Robert M.

2003-01-01

Presents a brief summary of Cooperative Economic Game Theory, followed by a summary of specific measures identified by Nash, Shapley, and Harsanyi. Reviews contexts in which negotiation and cooperation among libraries is of special economic importance, and for two of these contexts-cooperative acquisitions and cooperative automation-illustrates…

Density of founder cells affects spatial pattern formation and cooperation in Bacillus subtilis biofilms

PubMed Central

van Gestel, Jordi; Weissing, Franz J; Kuipers, Oscar P; Kovács, Ákos T

2014-01-01

In nature, most bacteria live in surface-attached sedentary communities known as biofilms. Biofilms are often studied with respect to bacterial interactions. Many cells inhabiting biofilms are assumed to express ‘cooperative traits', like the secretion of extracellular polysaccharides (EPS). These traits can enhance biofilm-related properties, such as stress resilience or colony expansion, while being costly to the cells that express them. In well-mixed populations cooperation is difficult to achieve, because non-cooperative individuals can reap the benefits of cooperation without having to pay the costs. The physical process of biofilm growth can, however, result in the spatial segregation of cooperative from non-cooperative individuals. This segregation can prevent non-cooperative cells from exploiting cooperative neighbors. Here we examine the interaction between spatial pattern formation and cooperation in Bacillus subtilis biofilms. We show, experimentally and by mathematical modeling, that the density of cells at the onset of biofilm growth affects pattern formation during biofilm growth. At low initial cell densities, co-cultured strains strongly segregate in space, whereas spatial segregation does not occur at high initial cell densities. As a consequence, EPS-producing cells have a competitive advantage over non-cooperative mutants when biofilms are initiated at a low density of founder cells, whereas EPS-deficient cells have an advantage at high cell densities. These results underline the importance of spatial pattern formation for competition among bacterial strains and the evolution of microbial cooperation. PMID:24694715

Density of founder cells affects spatial pattern formation and cooperation in Bacillus subtilis biofilms.

PubMed

van Gestel, Jordi; Weissing, Franz J; Kuipers, Oscar P; Kovács, Akos T

2014-10-01

In nature, most bacteria live in surface-attached sedentary communities known as biofilms. Biofilms are often studied with respect to bacterial interactions. Many cells inhabiting biofilms are assumed to express 'cooperative traits', like the secretion of extracellular polysaccharides (EPS). These traits can enhance biofilm-related properties, such as stress resilience or colony expansion, while being costly to the cells that express them. In well-mixed populations cooperation is difficult to achieve, because non-cooperative individuals can reap the benefits of cooperation without having to pay the costs. The physical process of biofilm growth can, however, result in the spatial segregation of cooperative from non-cooperative individuals. This segregation can prevent non-cooperative cells from exploiting cooperative neighbors. Here we examine the interaction between spatial pattern formation and cooperation in Bacillus subtilis biofilms. We show, experimentally and by mathematical modeling, that the density of cells at the onset of biofilm growth affects pattern formation during biofilm growth. At low initial cell densities, co-cultured strains strongly segregate in space, whereas spatial segregation does not occur at high initial cell densities. As a consequence, EPS-producing cells have a competitive advantage over non-cooperative mutants when biofilms are initiated at a low density of founder cells, whereas EPS-deficient cells have an advantage at high cell densities. These results underline the importance of spatial pattern formation for competition among bacterial strains and the evolution of microbial cooperation.

Self-Enhancing Seminars and Experiential Journals for Cooperating Teachers: A Professional Growth Model.

ERIC Educational Resources Information Center

Hauser, Jerald; Zimmerman, Gloria

Since 1989, professional growth seminars at St. Norbert College (Wisconsin) have brought cooperating teachers together to share their thoughts and emotions related to the experience of student teacher mentoring. In these seminars, the mentors gather for mutual instruction and support. Each seminar series consists of six 2-hour meetings during a…

Cooperation and conflict between women in the family.

PubMed

Mace, Ruth

2013-01-01

Here I review recent research on reproductive conflict between females in families and how it influences their reproductive behaviour. Kin selection can favor cooperation between parent and offspring, siblings, or unrelated co-residents who share interests in other family members such as grand-offspring. However, these are also the individuals most likely to be sharing resources, and so conflict can also emerge. While substantial interest has arisen in evolutionary anthropology, especially over the last two decades, in the possibility of cooperative breeding in humans, less attention has been paid to reproductive conflict among female kin. Communal breeding in animals is generally understood as emerging from competition over the resources needed to breed. Competition for household resources is a problem that also faces human families. Models suggest that in some circumstances, inclusive fitness can be maximized by sharing reproduction rather than harming relatives by fighting with them, even if the shares that emerge are not equal. Thus, competition and cooperation turn out to be strongly related to each other. Reproductive competition within and between families may have underpinned the biological evolution of fertility patterns (such as menopause) and the cultural evolution of marriage, residence, and inheritance norms (such as late male marriage or primogeniture), which can enhance cooperation and minimize the observed incidence of such conflicts. Copyright © 2013 Wiley Periodicals, Inc.

Effects of ecstasy on cooperative behaviour and perception of trustworthiness: a naturalistic study.

PubMed

Stewart, L H; Ferguson, B; Morgan, C J A; Swaboda, N; Jones, L; Fenton, R; Wall, M B; Curran, H V

2014-11-01

Acute recreational use of 3,4-methylenedioxymethamphetamine (MDMA; 'ecstasy') can promote pro-social effects which may alter interpersonal perceptions. To explore such effects, this study investigated whether acute recreational use of ecstasy was associated with changes in individual perception of trustworthiness of people's faces and co-operative behaviours. An independent group, repeated measures design was used in which 17 ecstasy users were tested on the night of drug use (day 0) and again three days later (day 3); 22 controls were tested on parallel days. On each day, participants rated the trustworthiness of 66 faces, carried out three co-operative behaviour tasks (public good; dictator; ultimatum game) and completed mood self-ratings. Acute ecstasy use was associated with increased face trustworthiness ratings and increased cooperative behaviour on the dictator and ultimatum games; on day 3 there were no group differences on any task. Self-ratings showed the standard acute ecstasy effects (euphoria, energy, jaw clenching) with negative effects (less empathy, compassion, more distrust, hostility) emerging on day 3. Our findings of increased perceived trustworthiness and co-operative behaviours following use of ecstasy suggest that a single dose of the drug enhances aspects of empathy. This may in turn contribute to its popularity as a recreational drug and potentially to its enhancement of the therapeutic alliance in psychotherapy. © The Author(s) 2014.

Cooperative Binding of Cyclodextrin Dimers to Isoflavone Analogues Elucidated by Free Energy Calculations.

PubMed

Zhang, Haiyang; Tan, Tianwei; Hetényi, Csaba; Lv, Yongqin; van der Spoel, David

2014-04-03

Dimerization of cyclodextrin (CD) molecules is an elementary step in the construction of CD-based nanostructured materials. Cooperative binding of CD cavities to guest molecules facilitates the dimerization process and, consequently, the overall stability and assembly of CD nanostructures. In the present study, all three dimerization modes (head-to-head, head-to-tail, and tail-to-tail) of β-CD molecules and their binding to three isoflavone drug analogues (puerarin, daidzin, and daidzein) were investigated in explicit water surrounding using molecular dynamics simulations. Total and individual contributions from the binding partners and solvent environment to the thermodynamics of these binding reactions are quantified in detail using free energy calculations. Cooperative drug binding to two CD cavities gives an enhanced binding strength for daidzin and daidzein, whereas for puerarin no obvious enhancement is observed. Head-to-head dimerization yields the most stable complexes for inclusion of the tested isoflavones (templates) and may be a promising building block for construction of template-stabilized CD nanostructures. Compared to the case of CD monomers, the desolvation of CD dimers and entropy changes upon complexation prove to be influential factors of cooperative binding. Our results shed light on key points of the design of CD-based supramolecular assemblies. We also show that structure-based calculation of binding thermodynamics can quantify stabilization caused by cooperative effects in building blocks of nanostructured materials.

The Effect of Geographical Proximity on Scientific Cooperation among Chinese Cities from 1990 to 2010

PubMed Central

Ma, Haitao; Fang, Chuanglin; Pang, Bo; Li, Guangdong

2014-01-01

Background The relations between geographical proximity and spatial distance constitute a popular topic of concern. Thus, how geographical proximity affects scientific cooperation, and whether geographically proximate scientific cooperation activities in fact exhibit geographic scale features should be investigated. Methodology Selected statistics from the ISI database on cooperatively authored papers, the authors of which resided in 60 typical cites in China, and which were published in the years 1990, 1995, 2000, 2005, and 2010, were used to establish matrices of geographic distance and cooperation levels between cities. By constructing a distance-cooperation model, the degree of scientific cooperation based on spatial distance was calculated. The relationship between geographical proximity and scientific cooperation, as well as changes in that relationship, was explored using the fitting function. Result (1) Instead of declining, the role of geographical proximity in inter-city scientific cooperation has increased gradually but significantly with the popularization of telecommunication technologies; (2) the relationship between geographical proximity and scientific cooperation has not followed a perfect declining curve, and at certain spatial scales, the distance-decay regularity does not work; (3) the Chinese scientific cooperation network gathers around different regional center cities, showing a trend towards a regional network; within this cooperation network the amount of inter-city cooperation occurring at close range increased greatly. Conclusion The relationship between inter-city geographical distance and scientific cooperation has been enhanced and strengthened over time. PMID:25365449

Cooperative interplay of let-7 mimic and HuR with MYC RNA

PubMed Central

Gunzburg, Menachem J; Sivakumaran, Andrew; Pendini, Nicole R; Yoon, Je-Hyun; Gorospe, Myriam; Wilce, Matthew Cj; Wilce, Jacqueline A

2015-01-01

Both RNA-binding proteins (RBP) and miRNA play important roles in the regulation of mRNA expression, often acting together to regulate a target mRNA. In some cases the RBP and miRNA have been reported to act competitively, but in other instances they function cooperatively. Here, we investigated HuR function as an enhancer of let-7-mediated translational repression of c-Myc despite the separation of their binding sites. Using an in vitro system, we determined that a let-7 mimic, consisting of single-stranded (ss)DNA complementary to the let-7 binding site, enhanced the affinity of HuR for a 122-nt MYC RNA encompassing both binding sites. This finding supports the biophysical principle of cooperative binding by an RBP and miRNA purely through interactions at distal mRNA binding sites. PMID:26177105

Cooperative interplay of let-7 mimic and HuR with MYC RNA.

PubMed

Gunzburg, Menachem J; Sivakumaran, Andrew; Pendini, Nicole R; Yoon, Je-Hyun; Gorospe, Myriam; Wilce, Matthew C J; Wilce, Jacqueline A

2015-01-01

Both RNA-binding proteins (RBP) and miRNA play important roles in the regulation of mRNA expression, often acting together to regulate a target mRNA. In some cases the RBP and miRNA have been reported to act competitively, but in other instances they function cooperatively. Here, we investigated HuR function as an enhancer of let-7-mediated translational repression of c-Myc despite the separation of their binding sites. Using an in vitro system, we determined that a let-7 mimic, consisting of single-stranded (ss)DNA complementary to the let-7 binding site, enhanced the affinity of HuR for a 122-nt MYC RNA encompassing both binding sites. This finding supports the biophysical principle of cooperative binding by an RBP and miRNA purely through interactions at distal mRNA binding sites.

Cooperation and charity in spatial public goods game under different strategy update rules

NASA Astrophysics Data System (ADS)

Li, Yixiao; Jin, Xiaogang; Su, Xianchuang; Kong, Fansheng; Peng, Chengbin

2010-03-01

Human cooperation can be influenced by other human behaviors and recent years have witnessed the flourishing of studying the coevolution of cooperation and punishment, yet the common behavior of charity is seldom considered in game-theoretical models. In this article, we investigate the coevolution of altruistic cooperation and egalitarian charity in spatial public goods game, by considering charity as the behavior of reducing inter-individual payoff differences. Our model is that, in each generation of the evolution, individuals play games first and accumulate payoff benefits, and then each egalitarian makes a charity donation by payoff transfer in its neighborhood. To study the individual-level evolutionary dynamics, we adopt different strategy update rules and investigate their effects on charity and cooperation. These rules can be classified into two global rules: random selection rule in which individuals randomly update strategies, and threshold selection rule where only those with payoffs below a threshold update strategies. Simulation results show that random selection enhances the cooperation level, while threshold selection lowers the threshold of the multiplication factor to maintain cooperation. When charity is considered, it is incapable in promoting cooperation under random selection, whereas it promotes cooperation under threshold selection. Interestingly, the evolution of charity strongly depends on the dispersion of payoff acquisitions of the population, which agrees with previous results. Our work may shed light on understanding human egalitarianism.

The report on The Western Hemisphere Energy Cooperation Study

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

Not Available

1990-10-01

The Report on the Western Hemisphere Energy Cooperation Study is forwarded in accordance with Public Law 100-373, which directed the Secretary of Energy, in cooperation with the Secretaries of State and Commerce, to conduct a study on how best to enhance cooperation between the United States and other countries of the Western Hemisphere with respect to energy policy including stable supplies of, and stable prices for, energy.'' This report highlights the direct relationship between US national energy security and energy developments in the rest of the world, particularly in the Americas. The recommendations of the report are designed to identifymore » new opportunities for effective energy cooperation leading to the adoption of market-based energy policies. The recommendations of the report will, however, have no effect on the current budgets of the applicable agencies. The report calls for: the establishment of active relationships with regional energy organizations; the expansion of the network of bilateral energy consultations with key countries in the region; greater utilization of US energy technologies in the Hemisphere; and the establishment of a policy working group to assure that energy programs of the aid agencies are consistent and support economic development and environmental goals.« less

Towards Reliable and Energy-Efficient Incremental Cooperative Communication for Wireless Body Area Networks

PubMed Central

Yousaf, Sidrah; Javaid, Nadeem; Qasim, Umar; Alrajeh, Nabil; Khan, Zahoor Ali; Ahmed, Mansoor

2016-01-01

In this study, we analyse incremental cooperative communication for wireless body area networks (WBANs) with different numbers of relays. Energy efficiency (EE) and the packet error rate (PER) are investigated for different schemes. We propose a new cooperative communication scheme with three-stage relaying and compare it to existing schemes. Our proposed scheme provides reliable communication with less PER at the cost of surplus energy consumption. Analytical expressions for the EE of the proposed three-stage cooperative communication scheme are also derived, taking into account the effect of PER. Later on, the proposed three-stage incremental cooperation is implemented in a network layer protocol; enhanced incremental cooperative critical data transmission in emergencies for static WBANs (EInCo-CEStat). Extensive simulations are conducted to validate the proposed scheme. Results of incremental relay-based cooperative communication protocols are compared to two existing cooperative routing protocols: cooperative critical data transmission in emergencies for static WBANs (Co-CEStat) and InCo-CEStat. It is observed from the simulation results that incremental relay-based cooperation is more energy efficient than the existing conventional cooperation protocol, Co-CEStat. The results also reveal that EInCo-CEStat proves to be more reliable with less PER and higher throughput than both of the counterpart protocols. However, InCo-CEStat has less throughput with a greater stability period and network lifetime. Due to the availability of more redundant links, EInCo-CEStat achieves a reduced packet drop rate at the cost of increased energy consumption. PMID:26927104

Cooperating in Constructing Knowledge: Case Studies from Chemistry and Citizenship

ERIC Educational Resources Information Center

Barbosa, Rejane; Jofili, Zelia; Watts, Mike

2004-01-01

This paper looks at three case studies within the teaching and learning of chemistry. Each case considers the effectiveness of group learning activities in terms of the ways in which they enhance cooperative learning. Group tasks are generally undertaken in order to encourage learners to develop their understanding of particular issues, lthough…

Cooperative Learning: Smart Pedagogy and Tools for Online and Hybrid Courses

ERIC Educational Resources Information Center

Gradel, Kathleen; Edson, Alden J.

2011-01-01

This article focuses on meshing technology-enhanced learning with cooperative learning pedagogy, to address teaching/learning challenges in higher education online and hybrid courses. Illustrations of implementation are made using coursework exemplars. Start-up solutions and sample applications are summarized. The purposes of this article are to…

Cooperative integrin/ITAM signaling in platelets enhances thrombus formation in vitro and in vivo

PubMed Central

Zhi, Huiying; Rauova, Lubica; Hayes, Vincent; Gao, Cunji; Boylan, Brian; Newman, Debra K.; McKenzie, Steven E.; Cooley, Brian C.; Poncz, Mortimer; Newman, Peter J.

2013-01-01

The integrin family is composed of a series of 24 αβ heterodimer transmembrane adhesion receptors that mediate cell-cell and cell-extracellular matrix interactions. Adaptor molecules bearing immunoreceptor tyrosine-based activation motifs (ITAMs) have recently been shown to cooperate with specific integrins to increase the efficiency of transmitting ligand-binding–induced signals into cells. In human platelets, Fc receptor γ-chain IIa (FcγRIIa) has been identified as an ITAM-bearing transmembrane receptor responsible for mediating “outside-in” signaling through αIIbβ3, the major adhesion receptor on the platelet surface. To explore the importance of FcγRIIa in thrombosis and hemostasis, we subjected FcγRIIa-negative and FcγRIIa-positive murine platelets to a number of well-accepted models of platelet function. Compared with their FcγRIIa-negative counterparts, FcγRIIa-positive platelets exhibited increased tyrosine phosphorylation of Syk and phospholipase Cγ2 and increased spreading upon interaction with immobilized fibrinogen, retracted a fibrin clot faster, and showed markedly enhanced thrombus formation when perfused over a collagen-coated flow chamber under conditions of arterial and venous shear. They also displayed increased thrombus formation and fibrin deposition in in vivo models of vascular injury. Taken together, these data establish FcγRIIa as a physiologically important functional conduit for αIIbβ3-mediated outside-in signaling, and suggest that modulating the activity of this novel integrin/ITAM pair might be effective in controlling thrombosis. PMID:23264598

A cooperative strategy for parameter estimation in large scale systems biology models.

PubMed

Villaverde, Alejandro F; Egea, Jose A; Banga, Julio R

2012-06-22

Mathematical models play a key role in systems biology: they summarize the currently available knowledge in a way that allows to make experimentally verifiable predictions. Model calibration consists of finding the parameters that give the best fit to a set of experimental data, which entails minimizing a cost function that measures the goodness of this fit. Most mathematical models in systems biology present three characteristics which make this problem very difficult to solve: they are highly non-linear, they have a large number of parameters to be estimated, and the information content of the available experimental data is frequently scarce. Hence, there is a need for global optimization methods capable of solving this problem efficiently. A new approach for parameter estimation of large scale models, called Cooperative Enhanced Scatter Search (CeSS), is presented. Its key feature is the cooperation between different programs ("threads") that run in parallel in different processors. Each thread implements a state of the art metaheuristic, the enhanced Scatter Search algorithm (eSS). Cooperation, meaning information sharing between threads, modifies the systemic properties of the algorithm and allows to speed up performance. Two parameter estimation problems involving models related with the central carbon metabolism of E. coli which include different regulatory levels (metabolic and transcriptional) are used as case studies. The performance and capabilities of the method are also evaluated using benchmark problems of large-scale global optimization, with excellent results. The cooperative CeSS strategy is a general purpose technique that can be applied to any model calibration problem. Its capability has been demonstrated by calibrating two large-scale models of different characteristics, improving the performance of previously existing methods in both cases. The cooperative metaheuristic presented here can be easily extended to incorporate other global and

A cooperative strategy for parameter estimation in large scale systems biology models

PubMed Central

2012-01-01

Background Mathematical models play a key role in systems biology: they summarize the currently available knowledge in a way that allows to make experimentally verifiable predictions. Model calibration consists of finding the parameters that give the best fit to a set of experimental data, which entails minimizing a cost function that measures the goodness of this fit. Most mathematical models in systems biology present three characteristics which make this problem very difficult to solve: they are highly non-linear, they have a large number of parameters to be estimated, and the information content of the available experimental data is frequently scarce. Hence, there is a need for global optimization methods capable of solving this problem efficiently. Results A new approach for parameter estimation of large scale models, called Cooperative Enhanced Scatter Search (CeSS), is presented. Its key feature is the cooperation between different programs (“threads”) that run in parallel in different processors. Each thread implements a state of the art metaheuristic, the enhanced Scatter Search algorithm (eSS). Cooperation, meaning information sharing between threads, modifies the systemic properties of the algorithm and allows to speed up performance. Two parameter estimation problems involving models related with the central carbon metabolism of E. coli which include different regulatory levels (metabolic and transcriptional) are used as case studies. The performance and capabilities of the method are also evaluated using benchmark problems of large-scale global optimization, with excellent results. Conclusions The cooperative CeSS strategy is a general purpose technique that can be applied to any model calibration problem. Its capability has been demonstrated by calibrating two large-scale models of different characteristics, improving the performance of previously existing methods in both cases. The cooperative metaheuristic presented here can be easily extended

[A questionnaire survey of medical cooperation by the Iwaki Medical Association].

PubMed

Midorikawa, Yasuhiko

2013-12-01

It has been pointed out that currently, Iwaki City faces an insufficiency of doctors working at hospitals, compared with before. Such an insufficiency became more remarkable after the 2011 Tohoku Earthquake and Fukushima Nuclear Disaster, as about 30,000 people relocated to Iwaki City from the evacuation areas. In this regard, the Iwaki Medical Association conducted a questionnaire survey to investigate the problems of medical cooperation and utilize the data to improve medical cooperation within hospitals and clinics. A total of 159 doctors answered the questionnaires: 64% were community physicians, 36% were doctors working at hospitals, and 42% were physicians. About 60% of the doctors were satisfied with the present medical cooperation. Home health care was performed by 25% of the doctors working at hospitals and 45% of the community physicians. Approximately 80% of the doctors felt the need for additional physicians to perform home health care, although more than half of the doctors answered that they do not perform it. Various problems exist in the context of medical cooperation, but many doctors still hope for its improvement, according to the answers in the questionnaires. Efforts have to be exerted further in order to enhance medical cooperation among the health care team.

Cooperative Games: A Way to Modify Aggressive and Cooperative Behaviors in Young Children.

ERIC Educational Resources Information Center

Bay-Hinitz, April K.; And Others

1994-01-01

Aggressive and cooperative behaviors of 70 preschool children were measured during game conditions and subsequent free-play periods. Cooperative behavior increased and aggression decreased during cooperative games and free play; conversely, competitive games were followed by increases in aggressive behavior and decreases in cooperative behavior.…

Culture and cooperation

PubMed Central

Gächter, Simon; Herrmann, Benedikt; Thöni, Christian

2010-01-01

Does the cultural background influence the success with which genetically unrelated individuals cooperate in social dilemma situations? In this paper, we provide an answer by analysing the data of Herrmann et al. (2008a), who studied cooperation and punishment in 16 subject pools from six different world cultures (as classified by Inglehart & Baker (2000)). We use analysis of variance to disentangle the importance of cultural background relative to individual heterogeneity and group-level differences in cooperation. We find that culture has a substantial influence on the extent of cooperation, in addition to individual heterogeneity and group-level differences identified by previous research. The significance of this result is that cultural background has a substantial influence on cooperation in otherwise identical environments. This is particularly true in the presence of punishment opportunities. PMID:20679109

Multiple tolerances dilute the second order cooperative dilemma

NASA Astrophysics Data System (ADS)

Sui, Xiukai; Wu, Bin; Wang, Long

2017-12-01

A peer punisher directly imposes fines upon defectors at a cost to himself. It is one of the mechanisms promoting cooperation, which is ubiquitous in nature. Typically, it is assumed that a peer punisher punishes provided that there is one defector in the group. The threshold that triggers punishment, however, is not necessarily one. The larger the threshold is, the more tolerant the peer punisher is. We study the evolutionary dynamics of those diverse tolerant peer punishment strategies in public goods game. We find that, i) less tolerant punishers prevail over tolerant ones; ii) large group size could enhance punishment, in contrast with the case in the first-order cooperative dilemma. Our analytical results are based on weak selection limit and large population size, which are verified by simulations. Our work sheds light on how punishment of diverse tolerance evolves.

Declaration of the European Ministers of Vocational Education and Training, and the European Commission, Convened in Copenhagen on 29 and 30 November 2002, on Enhanced European Cooperation in Vocational Education and Training. "The Copenhagen Declaration."

ERIC Educational Resources Information Center

European Commission, Brussels (Belgium).

Enhanced cooperation in vocational education and training (VET) will be an important contribution toward ensuring a successful enlargement of the European Union. The social partners play an indispensable role in development, validation, and recognition of vocational competencies and qualifications at all levels and are partners in promotion of…

When cooperation begets cooperation: the role of key individuals in galvanizing support.

PubMed

McAuliffe, Katherine; Wrangham, Richard; Glowacki, Luke; Russell, Andrew F

2015-12-05

Life abounds with examples of conspecifics actively cooperating to a common end, despite conflicts of interest being expected concerning how much each individual should contribute. Mathematical models typically find that such conflict can be resolved by partial-response strategies, leading investors to contribute relatively equitably. Using a case study approach, we show that such model expectations can be contradicted in at least four disparate contexts: (i) bi-parental care; (ii) cooperative breeding; (iii) cooperative hunting; and (iv) human cooperation. We highlight that: (a) marked variation in contributions is commonplace; and (b) individuals can often respond positively rather than negatively to the contributions of others. Existing models have surprisingly limited power in explaining these phenomena. Here, we propose that, although among-individual variation in cooperative contributions will be influenced by differential costs and benefits, there is likely to be a strong genetic or epigenetic component. We then suggest that selection can maintain high investors (key individuals) when their contributions promote support by increasing the benefits and/or reducing the costs for others. Our intentions are to raise awareness in--and provide testable hypotheses of--two of the most poorly understood, yet integral, questions regarding cooperative ventures: why do individuals vary in their contributions and when does cooperation beget cooperation? © 2015 The Author(s).

When cooperation begets cooperation: the role of key individuals in galvanizing support

PubMed Central

McAuliffe, Katherine; Wrangham, Richard; Glowacki, Luke; Russell, Andrew F.

2015-01-01

Life abounds with examples of conspecifics actively cooperating to a common end, despite conflicts of interest being expected concerning how much each individual should contribute. Mathematical models typically find that such conflict can be resolved by partial-response strategies, leading investors to contribute relatively equitably. Using a case study approach, we show that such model expectations can be contradicted in at least four disparate contexts: (i) bi-parental care; (ii) cooperative breeding; (iii) cooperative hunting; and (iv) human cooperation. We highlight that: (a) marked variation in contributions is commonplace; and (b) individuals can often respond positively rather than negatively to the contributions of others. Existing models have surprisingly limited power in explaining these phenomena. Here, we propose that, although among-individual variation in cooperative contributions will be influenced by differential costs and benefits, there is likely to be a strong genetic or epigenetic component. We then suggest that selection can maintain high investors (key individuals) when their contributions promote support by increasing the benefits and/or reducing the costs for others. Our intentions are to raise awareness in—and provide testable hypotheses of—two of the most poorly understood, yet integral, questions regarding cooperative ventures: why do individuals vary in their contributions and when does cooperation beget cooperation? PMID:26503685

Stimulated emission of Cooper pairs in a high-temperature cuprate superconductor

DOE PAGES

Zhang, Wentao; Miller, Tristan; Smallwood, Christopher L.; ...

2016-07-01

The concept of stimulated emission of bosons has played an important role in modern science and technology, and constitutes the working principle for lasers. In a stimulated emission process, an incoming photon enhances the probability that an excited atomic state will transition to a lower energy state and generate a second photon of the same energy. It is expected, but not experimentally shown, that stimulated emission contributes significantly to the zero resistance current in a superconductor by enhancing the probability that scattered Cooper pairs will return to the macroscopically occupied condensate instead of entering any other state. Here, we usemore » time- and angle-resolved photoemission spectroscopy to study the initial rise of the non-equilibrium quasiparticle population in a Bi 2 Sr 2 CaCu 2 O 8+δ cuprate superconductor induced by an ultrashort laser pulse. Our finding reveals significantly slower buildup of quasiparticles in the superconducting state than in the normal state. The slower buildup only occurs when the pump pulse is too weak to deplete the superconducting condensate, and for cuts inside the Fermi arc region. We propose this is a manifestation of stimulated recombination of broken Cooper pairs, and signals an important momentum space dichotomy in the formation of Cooper pairs inside and outside the Fermi arc region.« less

Cooperative Activities for the Home: Parents Working with Teachers to Support Cooperative Learning.

ERIC Educational Resources Information Center

Holm, Audray; And Others

A collection of activities is presented for use at home to foster cooperative attitudes and build social skills. The activities are aimed at strengthening the cooperative bond in a family and giving family members practice in the skills needed to cooperate effectively. This handbook explains the cooperative learning concept, outlines the rules for…

DEADS: Depth and Energy Aware Dominating Set Based Algorithm for Cooperative Routing along with Sink Mobility in Underwater WSNs.

PubMed

Umar, Amara; Javaid, Nadeem; Ahmad, Ashfaq; Khan, Zahoor Ali; Qasim, Umar; Alrajeh, Nabil; Hayat, Amir

2015-06-18

Performance enhancement of Underwater Wireless Sensor Networks (UWSNs) in terms of throughput maximization, energy conservation and Bit Error Rate (BER) minimization is a potential research area. However, limited available bandwidth, high propagation delay, highly dynamic network topology, and high error probability leads to performance degradation in these networks. In this regard, many cooperative communication protocols have been developed that either investigate the physical layer or the Medium Access Control (MAC) layer, however, the network layer is still unexplored. More specifically, cooperative routing has not yet been jointly considered with sink mobility. Therefore, this paper aims to enhance the network reliability and efficiency via dominating set based cooperative routing and sink mobility. The proposed work is validated via simulations which show relatively improved performance of our proposed work in terms the selected performance metrics.

Effect of playing violent video games cooperatively or competitively on subsequent cooperative behavior.

PubMed

Ewoldsen, David R; Eno, Cassie A; Okdie, Bradley M; Velez, John A; Guadagno, Rosanna E; DeCoster, Jamie

2012-05-01

Research on video games has yielded consistent findings that violent video games increase aggression and decrease prosocial behavior. However, these studies typically examined single-player games. Of interest is the effect of cooperative play in a violent video game on subsequent cooperative or competitive behavior. Participants played Halo II (a first-person shooter game) cooperatively or competitively and then completed a modified prisoner's dilemma task to assess competitive and cooperative behavior. Compared with the competitive play conditions, players in the cooperative condition engaged in more tit-for-tat behaviors-a pattern of behavior that typically precedes cooperative behavior. The social context of game play influenced subsequent behavior more than the content of the game that was played.

Cooperative Education.

ERIC Educational Resources Information Center

North Dakota State Board for Vocational Education, Bismarck.

This guidebook is designed to assist school administrators and teacher-coordinators in planning for cooperative occupational education programs. In addition, ideas and concepts are presented to assist other school personnel and laymen with the operational detail of vocational programs in cooperative occupational education. Major section titles…

Cooperating with machines.

PubMed

Crandall, Jacob W; Oudah, Mayada; Tennom; Ishowo-Oloko, Fatimah; Abdallah, Sherief; Bonnefon, Jean-François; Cebrian, Manuel; Shariff, Azim; Goodrich, Michael A; Rahwan, Iyad

2018-01-16

Since Alan Turing envisioned artificial intelligence, technical progress has often been measured by the ability to defeat humans in zero-sum encounters (e.g., Chess, Poker, or Go). Less attention has been given to scenarios in which human-machine cooperation is beneficial but non-trivial, such as scenarios in which human and machine preferences are neither fully aligned nor fully in conflict. Cooperation does not require sheer computational power, but instead is facilitated by intuition, cultural norms, emotions, signals, and pre-evolved dispositions. Here, we develop an algorithm that combines a state-of-the-art reinforcement-learning algorithm with mechanisms for signaling. We show that this algorithm can cooperate with people and other algorithms at levels that rival human cooperation in a variety of two-player repeated stochastic games. These results indicate that general human-machine cooperation is achievable using a non-trivial, but ultimately simple, set of algorithmic mechanisms.

Impact of shill intervention on the evolution of cooperation

NASA Astrophysics Data System (ADS)

Sun, Changhao; Duan, Haibin

2015-09-01

The practical significance of effective intervention in collective behavior has its roots not only in frequent migration in the modern society, but also in the actual demands of real-world applications for system efficiency improvement. Within the framework of soft control, this paper focuses on an evolutionary public goods game staged on a scale free network and explores the dependence of the evolution of cooperation on the intervention of a fraction of shills, who follow the Fixed-Cost-per-Player paradigm while the locals follow the Fixed-Cost-per-Game paradigm. We demonstrate that higher cooperation levels and better social welfare could be simultaneously induced by tuning the distribution coefficient α, where desirable outcomes are associated with large α > 0 for tense dilemmas while small α < 0 leads to satisfactory results when the enhancement factor γ increases. Moreover, we observe a transition of the composition of equilibrium cooperators from full dominance of shills to co-existence of shills and locals, and the boundary has a positive correlation with α. These results are somehow affected when we attenuate the heterogeneity of the network by relating individual fitness to payoffs averaged over its connectivity. Our findings may not only shed some light on the mechanism behind the evolution of cooperation from the perspective of external intervention, but also provide a feasible way to effectively intervene in the evolutionary outcomes of negative scenarios.

Cooperative Trust Games

DTIC Science & Technology

2013-01-01

the more widely recognized competitive (non-cooperative) game theory. Cooperative game theory focuses on what groups of self-interested agents can...provides immediate justification for using non-cooperative game theory as the basis for modeling the purely competitive agents. 2.4. Superadditive...the competitive and altruistic contributions of the subset team. Definition: Given a payoff function ( ) in a subset team game , the total marginal

Assessing cooperativity in supramolecular systems.

PubMed

von Krbek, Larissa K S; Schalley, Christoph A; Thordarson, Pall

2017-05-09

This tutorial review summarises different aspects of cooperativity in supramolecular complexes. We propose a systematic categorisation of cooperativity into cooperative aggregation, intermolecular (allosteric) cooperativity, intramolecular (chelate) cooperativity and interannular cooperativity and discuss approaches to quantify them thermodynamically using cooperativity factors. A brief summary of methods to determine the necessary thermodynamic data is given with emphasis on isothermal titration calorimetry (ITC), a method still underrepresented in supramolecular chemistry, which however offers some advantages over others. Finally, a discussion of very few selected examples, which highlight different aspects to illustrate why such an analysis is useful, rounds up this review.

A new view for nanoparticle assemblies: from crystalline to binary cooperative complementarity.

PubMed

Yan, Cong; Wang, Tie

2017-03-06

Studies on nanoparticle assemblies and their applications have been research frontiers in nanoscience in the past few decades and remarkable progress has been made in the synthetic strategies and techniques. Recently, the design and fabrication of the nanoparticle-based nanomaterials or nanodevices with integrated and enhanced properties compared to those of the individual components have gradually become the mainstream. However, a systematic solution to provide a big picture for future development and guide the investigation of different aspects of the study of nanoparticle assemblies remains a challenge. The binary cooperative complementary principle could be an answer. The binary cooperative complementary principle is a universal discipline and can describe the fundamental properties of matter from the subatomic particles to the universe. According to its definition, a variety of nanoparticle assemblies, which represent the cutting-edge work in the nanoparticle studies, are naturally binary cooperative complementary materials. Therefore, the introduction of the binary cooperative complementary principle in the studies of nanoparticle assemblies could provide a unique perspective for reviewing this field and help in the design and fabrication of novel functional nanoparticle assemblies.

Cooperative learning with role play in Chinese pharmacology education.

PubMed

Wang, Jun; Hu, Xiamin; Xi, Jinglei

2012-03-01

Cooperative learning (CL) and role play are both efficient educational tools for enhancing Chinese student active learning and communication skills. This study was designed to obtain student feedback on the format of CL together with role play in the study of pharmacology in Chinese pharmaceutical undergraduates. CL was used in the self-study of new drugs used clinically but neglected in textbook and class teaching, so that groups of students were assigned to become "specialists" in one area of new drugs. Then, these "specialists" taught their new-found knowledge to other groups in role play approach involving an interaction between the pharmacist and a patient. Student perceptions of CL together with role play were examined using an eight-item survey instrument. Students were satisfied with CL together with role play. Majority of the students believed this teaching method enhanced their learning experience, made them gain more pharmacological expertise, increased the awareness of their career in future and self-educational abilities, and fostered their cooperation spirit and confidence. The materials on CL and role play were also believed pertinent. Only 63.4-76.5% and 63.1-37.3% of the students thought "CL and role-play were very funny" and "I felt very relaxed during CL together with role-play", respectively. CL together with role play is an efficient educational tool for enhancing student active-learning and communication skills. But Chinese students will take some time to adapt to this new teaching method.

Cooperative Education.

ERIC Educational Resources Information Center

Office of Education (DHEW), Washington, DC.

Cooperative education programs, a nontraditional blending of practice and theory, have become an important feature of current higher education. Some educators estimate that by 1984 half of the higher education institutions in the United States will have developed some form of cooperative education. The Federal government's recent involvement in…

Storytelling of co-operative team meetings in acute psychiatric care.

PubMed

Vuokila-Oikkonen, Päivi; Janhonen, Sirpa; Saarento, Outi; Harri, Marja

2002-10-01

One of the goals of co-operative psychiatric nursing and co-operative team meetings is to improve patients' and significant others' participation and thus, to enhance patients' resources outside the hospital. The objective of this paper is to describe the different expert interventions that either enabled or prevented patient and his/her significant others participation in co-operative team meetings in acute psychiatric wards. The data consisted of 11 videotaped team meetings. The participants were voluntary patients, significant others and experts in health and social care. A narrative approach focused on the storytelling of all members in the meetings. The method of modified dialogue analysis was used to identify the ideas of the stories. The same topic of discussion was shared in active participation. The experts asked open-ended questions, the patient and his/her significant others' were free to express their viewpoints and the experts' interpretation was based on their stories. The experts presented the reasons for their questions, and the contents of the questions were verbalized. In passive participation, the experts questions were based on their own point of view, and the patient and his significant others merely answered these questions. If the expert opinion appeared too dominating at the co-operative team meeting, the patient's and his/her significant others' participation was in jeopardy. The physician either dominates the storytelling or gives space for free expressions of various viewpoints during the co-operative team meetings.

Cooperative wireless network control based health and activity monitoring system.

PubMed

Prakash, R; Ganesh, A Balaji; Girish, Siva V

2016-10-01

A real-time cooperative communication based wireless network is presented for monitoring health and activity of an end-user in their environment. The cooperative communication offers better energy consumption and also an opportunity to aware the current location of a user non-intrusively. The link between mobile sensor node and relay node is dynamically established by using Received Signal Strength Indicator (RSSI) and Link Quality Indicator (LQI) based on adaptive relay selection scheme. The study proposes a Linear Acceleration based Transmission Power Decision Control (LA-TPDC) algorithm to further enhance the energy efficiency of cooperative communication. Further, the occurrences of false alarms are carefully prevented by introducing three stages of sequential warning system. The real-time experiments are carried-out by using the nodes, namely mobile sensor node, relay nodes and a destination node which are indigenously developed by using a CC430 microcontroller integrated with an in-built transceiver at 868 MHz. The wireless node performance characteristics, such as energy consumption, Signal-Noise ratio (SNR), Bit Error Rate (BER), Packet Delivery Ratio (PDR) and transmission offset are evaluated for all the participated nodes. The experimental results observed that the proposed linear acceleration based transmission power decision control algorithm almost doubles the battery life time than energy efficient conventional cooperative communication.

How is human cooperation different?

PubMed Central

Melis, Alicia P.; Semmann, Dirk

2010-01-01

Although cooperation is a widespread phenomenon in nature, human cooperation exceeds that of all other species with regard to the scale and range of cooperative activities. Here we review and discuss differences between humans and non-humans in the strategies employed to maintain cooperation and control free-riders. We distinguish forms of cooperative behaviour based on their influence on the immediate payoffs of actor and recipient. If the actor has immediate costs and only the recipient obtains immediate benefits, we term this investment. If the behaviour has immediate positive effects for both actor and recipient, we call this a self-serving mutually beneficial behaviour or mutual cooperation. We argue that humans, in contrast to all other species, employ a wider range of enforcement mechanisms, which allow higher levels of cooperation to evolve and stabilize among unrelated individuals and in large groups. We also discuss proximate mechanisms underlying cooperative behaviour and focus on our experimental work with humans and our closest primate relatives. Differences in the proximate mechanisms also seem to contribute to explaining humans' greater ability to cooperate and enforce cooperation. PMID:20679110

A Cooperative Learning Group Procedure for Improving CTE and Science Integration

ERIC Educational Resources Information Center

Spindler, Matt

2016-01-01

The purpose of this case study was to create information about the employment of Cooperative Learning Groups (CLG) to enhance the science integrating learning objectives utilized in secondary CTE courses. The objectives of the study were to determine if CLGs were an effective means for increasing the number of: a) science integrating learning…

Performance analysis of cooperative virtual MIMO systems for wireless sensor networks.

PubMed

Rafique, Zimran; Seet, Boon-Chong; Al-Anbuky, Adnan

2013-05-28

Multi-Input Multi-Output (MIMO) techniques can be used to increase the data rate for a given bit error rate (BER) and transmission power. Due to the small form factor, energy and processing constraints of wireless sensor nodes, a cooperative Virtual MIMO as opposed to True MIMO system architecture is considered more feasible for wireless sensor network (WSN) applications. Virtual MIMO with Vertical-Bell Labs Layered Space-Time (V-BLAST) multiplexing architecture has been recently established to enhance WSN performance. In this paper, we further investigate the impact of different modulation techniques, and analyze for the first time, the performance of a cooperative Virtual MIMO system based on V-BLAST architecture with multi-carrier modulation techniques. Through analytical models and simulations using real hardware and environment settings, both communication and processing energy consumptions, BER, spectral efficiency, and total time delay of multiple cooperative nodes each with single antenna are evaluated. The results show that cooperative Virtual-MIMO with Binary Phase Shift Keying-Wavelet based Orthogonal Frequency Division Multiplexing (BPSK-WOFDM) modulation is a promising solution for future high data-rate and energy-efficient WSNs.

Performance Analysis of Cooperative Virtual MIMO Systems for Wireless Sensor Networks

PubMed Central

Rafique, Zimran; Seet, Boon-Chong; Al-Anbuky, Adnan

2013-01-01

Multi-Input Multi-Output (MIMO) techniques can be used to increase the data rate for a given bit error rate (BER) and transmission power. Due to the small form factor, energy and processing constraints of wireless sensor nodes, a cooperative Virtual MIMO as opposed to True MIMO system architecture is considered more feasible for wireless sensor network (WSN) applications. Virtual MIMO with Vertical-Bell Labs Layered Space-Time (V-BLAST) multiplexing architecture has been recently established to enhance WSN performance. In this paper, we further investigate the impact of different modulation techniques, and analyze for the first time, the performance of a cooperative Virtual MIMO system based on V-BLAST architecture with multi-carrier modulation techniques. Through analytical models and simulations using real hardware and environment settings, both communication and processing energy consumptions, BER, spectral efficiency, and total time delay of multiple cooperative nodes each with single antenna are evaluated. The results show that cooperative Virtual-MIMO with Binary Phase Shift Keying-Wavelet based Orthogonal Frequency Division Multiplexing (BPSK-WOFDM) modulation is a promising solution for future high data-rate and energy-efficient WSNs. PMID:23760087

Cooperation and cheating in microbes

NASA Astrophysics Data System (ADS)

Gore, Jeff

2011-03-01

Understanding the cooperative and competitive dynamics within and between species is a central challenge in evolutionary biology. Microbial model systems represent a unique opportunity to experimentally test fundamental theories regarding the evolution of cooperative behaviors. In this talk I will describe our experiments probing cooperation in microbes. In particular, I will compare the cooperative growth of yeast in sucrose and the cooperative inactivation of antibiotics by bacteria. In both cases we find that cheater strains---which don't contribute to the public welfare---are able to take advantage of the cooperator strains. However, this ability of cheaters to out-compete cooperators occurs only when cheaters are present at low frequency, thus leading to steady-state coexistence. These microbial experiments provide fresh insight into the evolutionary origin of cooperation.

Operation Cooperation.

ERIC Educational Resources Information Center

Hohl, K. Robert

The needs of teachers for high-demand and seasonal films have been met by a cooperative effort of the Berks County Educational Television Committee, local school districts, the Berks and Suburban TV cable companies and the Berks County Intermediate Unit in a project called Operation Cooperation. Regionalization of the instructional media services…

Effects of dynamical grouping on cooperation in N-person evolutionary snowdrift game

NASA Astrophysics Data System (ADS)

Ji, M.; Xu, C.; Hui, P. M.

2011-09-01

A population typically consists of agents that continually distribute themselves into different groups at different times. This dynamic grouping has recently been shown to be essential in explaining many features observed in human activities including social, economic, and military activities. We study the effects of dynamic grouping on the level of cooperation in a modified evolutionary N-person snowdrift game. Due to the formation of dynamical groups, the competition takes place in groups of different sizes at different times and players of different strategies are mixed by the grouping dynamics. It is found that the level of cooperation is greatly enhanced by the dynamic grouping of agents, when compared with a static population of the same size. As a parameter β, which characterizes the relative importance of the reward and cost, increases, the fraction of cooperative players fC increases and it is possible to achieve a fully cooperative state. Analytically, we present a dynamical equation that incorporates the effects of the competing game and group size distribution. The distribution of cooperators in different groups is assumed to be a binomial distribution, which is confirmed by simulations. Results from the analytic equation are in good agreement with numerical results from simulations. We also present detailed simulation results of fC over the parameter space spanned by the probabilities of group coalescence νm and group fragmentation νp in the grouping dynamics. A high νm and low νp promotes cooperation, and a favorable reward characterized by a high β would lead to a fully cooperative state.

Brief, cooperative peer-instruction sessions during lectures enhance student recall and comprehension*

PubMed Central

Zhang, Niu; Henderson, Charles N.R.

2016-01-01

Objective: The objective of this study was to evaluate the academic impact of cooperative peer instruction during lecture pauses in an immunology/endocrinology course. Methods: Third-quarter students participated across iterations of the course. Each class offered 20 lectures of 50 minutes each. Classes were divided into a peer-instruction group incorporating cooperative peer instruction and a control group receiving traditional lectures. Peer-instruction group lectures were divided into 2–3 short presentations followed by a multiple-choice question (MCQ). Students recorded an initial answer and then had 1 minute to discuss answers with group peers. Following this, students could submit a revised answer. The control group received the same lecture material, but without MCQs or peer discussions. Final-exam scores were compared across study groups. A mixed-design analysis of covariance was used to analyze the data. Results: There was a statistically significant main effect for the peer-instruction activity (F(1, 93) = 6.573, p = .012, r = .257), with recall scores higher for MCQs asked after peer-instruction activities than for those asked before peer instruction. Final-exam scores at the end of term were greater in the peer-instruction group than the control group (F(1, 193) = 9.264, p = .003, r = .214; question type, F(1, 193) = 26.671, p = .000, r = .348). Conclusion: Lectures with peer-instruction pauses increase student recall and comprehension compared with traditional lectures. PMID:26967766

Social heuristics shape intuitive cooperation.

PubMed

Rand, David G; Peysakhovich, Alexander; Kraft-Todd, Gordon T; Newman, George E; Wurzbacher, Owen; Nowak, Martin A; Greene, Joshua D

2014-04-22

Cooperation is central to human societies. Yet relatively little is known about the cognitive underpinnings of cooperative decision making. Does cooperation require deliberate self-restraint? Or is spontaneous prosociality reined in by calculating self-interest? Here we present a theory of why (and for whom) intuition favors cooperation: cooperation is typically advantageous in everyday life, leading to the formation of generalized cooperative intuitions. Deliberation, by contrast, adjusts behaviour towards the optimum for a given situation. Thus, in one-shot anonymous interactions where selfishness is optimal, intuitive responses tend to be more cooperative than deliberative responses. We test this 'social heuristics hypothesis' by aggregating across every cooperation experiment using time pressure that we conducted over a 2-year period (15 studies and 6,910 decisions), as well as performing a novel time pressure experiment. Doing so demonstrates a positive average effect of time pressure on cooperation. We also find substantial variation in this effect, and show that this variation is partly explained by previous experience with one-shot lab experiments.

Multiphoton, confocal, and lifetime microscopy for molecular imaging in cartilage

NASA Astrophysics Data System (ADS)

Wachsmann-Hogiu, Sebastian; Krakow, Deborah; Kirilova, Veneta T.; Cohn, Daniel H.; Bertolotto, Cristina; Acuna, Dora; Fang, Qiyin; Krivorov, Nikola; Farkas, Daniel L.

2005-03-01

It has recently been shown that mutations in Filamin A and B genes produce a large spectrum of skeletal disorders in developing fetuses. However, high-resolution optical microscopy in cartilage growth plate using fluorescent antibody assays, which should elucidate molecular aspects of these disorders, is extremely difficult due to the high level of autofluoresce in this tissue. We apply multiphoton, confocal, lifetime and spectral microscopy to (i) image and characterize autofluorophores in chondrocytes and subtract their contributions to obtain a corrected antibody-marker fluorescence signal, and (ii) measure the interaction between Filamin A and B proteins by detecting the fluorescence resonance energy transfer (FRET) between markers of the two proteins. Taking advantage of the different fluorescence spectra of the endogenous and exogenous markers, we can significantly reduce the autofluorescence background. Preliminary results of the FRET experiments suggest no interaction between Filamin A and B proteins. However, developing of new antibodies targeting the carboxy-terminal immunoglobulin-like domain may be necessary to confirm this result.

Cooperative Education Coordinator's Handbook.

ERIC Educational Resources Information Center

Worley, Tom

Designed to serve as a guide for teacher-coordinators, counselors, administrators, and the employing community, this handbook is a performance-oriented desk reference that provides a base for cooperative education program operations. Chapter 1 overviews cooperative education, contrasts cooperative training and work experience programs, and…

The sound of cooperation: Musical influences on cooperative behavior.

PubMed

Kniffin, Kevin M; Yan, Jubo; Wansink, Brian; Schulze, William D

2017-03-01

Music as an environmental aspect of professional workplaces has been closely studied with respect to consumer behavior while sparse attention has been given to its relevance for employee behavior. In this article, we focus on the influence of music upon cooperative behavior within decision-making groups. Based on results from two extended 20-round public goods experiments, we find that happy music significantly and positively influences cooperative behavior. We also find a significant positive association between mood and cooperative behavior. Consequently, while our studies provide partial support for the relevance of affect in relation to cooperation within groups, we also show an independently important function of happy music that fits with a theory of synchronous and rhythmic activity as a social lubricant. More generally, our findings indicate that music and perhaps other atmospheric variables that are designed to prime consumer behavior might have comparably important effects for employees and consequently warrant closer investigation. Copyright © 2016 The Authors Journal of Organizational Behavior Published by John Wiley & Sons Ltd.

Cooperative Learning: Professional's Guide.

ERIC Educational Resources Information Center

Grisham, Dana L.; Molinelli, Paul M.

Noting that since the 1970s cooperative learning has been widely investigated regarding its implementation and efficacy, this booklet is designed to introduce the teaching strategy of cooperative learning to classroom teachers. The booklet first provides an overview and supplies a context for cooperative learning and then defines cooperative…

Fostering cooperation of selfish agents through public goods in relation to the loners

NASA Astrophysics Data System (ADS)

Zhang, Jianlei; Chen, Zengqiang; Liu, Zhongxin

2016-03-01

Altruistic behaviors in multiplayer groups have obtained great attention in the context of the public goods game, which poses a riddle from the evolutionary viewpoint. Here we focus on a particular type of public goods game model in which the benefits of cooperation are either discounted or synergistically enhanced at the appearance of multiple cooperators in a group. Moreover, we focus on the three-strategies profile by adding the role of loners, besides the often-used cooperation and defection. Using the replicator dynamic equations, we investigate a range of dynamical portraits that characterizes the properties of the steady state. Analysis results indicate that loners and cooperators both have chances to be the stable equilibrium points in the presence of perturbations, while defectors fail to do so in this three-strategy competition. Moreover, the coexistence state, in which all three strategies exist in equilibrium, can be led by suitable parameters and stabilized for perturbations. These results elucidate the interplay between the characteristics of the public goods game and evolutionary dynamics in well-mixed systems.

Cooperative Monitoring Center Occasional Paper/8: Cooperative Border Security for Jordan: Assessment and Options

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

Qojas, M.

1999-03-01

This document is an analysis of options for unilateral and cooperative action to improve the security of Jordan's borders. Sections describe the current political, economic, and social interactions along Jordan's borders. Next, the document discusses border security strategy for cooperation among neighboring countries and the adoption of confidence-building measures. A practical cooperative monitoring system would consist of hardware for early warning, command and control, communications, and transportation. Technical solutions can expand opportunities for the detection and identification of intruders. Sensors (such as seismic, break-wire, pressure-sensing, etc.) can warn border security forces of intrusion and contribute to the identification of themore » intrusion and help formulate the response. This document describes conceptual options for cooperation, offering three scenarios that relate to three hypothetical levels (low, medium, and high) of cooperation. Potential cooperative efforts under a low cooperation scenario could include information exchanges on military equipment and schedules to prevent misunderstandings and the establishment of protocols for handling emergency situations or unusual circumstances. Measures under a medium cooperation scenario could include establishing joint monitoring groups for better communications, with hot lines and scheduled meetings. The high cooperation scenario describes coordinated responses, joint border patrols, and sharing border intrusion information. Finally, the document lists recommendations for organizational, technical, and operational initiatives that could be applicable to the current situation.« less

Influence of different recombinant systems on the cooperativity exhibited by cytochrome P4503A4.

PubMed

Zhang, Z; Li, Y; Shou, M; Zhang, Y; Ngui, J S; Stearns, R A; Evans, D C; Baillie, T A; Tang, W

2004-05-01

1. The in vitro cooperativity exhibited by cytochrome P450 (CYP) 3A4 is influenced by the nature of the recombinant system in which the phenomenon is studied. Diclofenac, piroxicam and R-warfarin were used as model substrates, and quinidine was the effector. 2. The 5-, 5'- and 10-hydroxylation of diclofenac, piroxicam and R-warfarin, respectively, were enhanced five- to sevenfold by quinidine in human liver microsomal incubations. Whereas these cooperative drug interactions were apparent in incubations with CYP3A4 expressed in human lymphoblast cells, similar phenomena were not observed with the enzyme expressed in insect cells. 3. Insect cell microsomes were treated with a detergent and CYP3A4 was solubilized into a buffer medium. In incubations with CYP3A4 'freed' from its host membrane, the 5-hydroxylation of diclofenac increased with increasing quinidine concentrations, reaching a maximal eightfold elevation relative to controls. The metabolism of piroxicam and warfarin was similarly enhanced by quinidine. 4. Kinetically, enhancement by quinidine of the 5-hydroxylation of diclofenac in incubations with solubilized CYP3A4 was characterized by increases in the rate of metabolism with little change in the substrate-binding affinity. Conversely, the 3-hydroxylation of quinidine was not affected by diclofenac. 5. The data suggest that certain properties of CYP3A4 are masked by expression of the protein in insect cells and reinforce the concept that the enzyme possesses multiple binding domains. The absence of cooperative drug interactions with quinidine when CYP3A4 was expressed in insect cells might be due to an absence of enzyme conformation changes on quinidine binding, or the inability of quinidine to gain access to a putative effector-binding domain. 6. Caution should be exercised when comparing models for CYP3A4 cooperativity derived from different recombinant preparations of the enzyme.

Learning to Learn Cooperatively

ERIC Educational Resources Information Center

Byrd, Anne Hammond

2009-01-01

Cooperative learning, put quite simply, is a type of instruction whereby students work together in small groups to achieve a common goal. Cooperative learning has become increasingly popular as a feature of Communicative Language Teaching (CLT) with benefits that include increased student interest due to the quick pace of cooperative tasks,…

Effect of cooperation level of group on punishment for non-cooperators: a functional magnetic resonance imaging study.

PubMed

Kodaka, Fumitoshi; Takahashi, Hidehiko; Yamada, Makiko; Takano, Harumasa; Nakayama, Kazuhiko; Ito, Hiroshi; Suhara, Tetsuya

2012-01-01

Sometimes we punish non-cooperators in our society. Such behavior could be derived from aversive emotion for inequity (inequity aversion) to make non-cooperators cooperative. Thus, punishing behavior derived from inequity is believed to be important for maintaining our society. Meanwhile, our daily experiences suggest that the degree of cooperation by the members of society (cooperation level of the group) could change the punishing behavior for non-cooperators even if the inequity were equal. Such effect of the cooperation level of the group cannot be explained by simple inequity aversion. Although punishment-related brain regions have been reported in previous functional magnetic resonance imaging (fMRI) study, little is known about such regions affected by the cooperation level of the group. In the present fMRI study, we investigated the effect of the cooperation level of the group on the punishing behavior for non-cooperators and its related brain activations by a paradigm in which the degree of the cooperative state varied from low to high. Punishment-related activations were observed in brain regions such as the anterior insula, dorsolateral prefrontal cortex (DLPFC), and anterior cingulate cortex (ACC). The quantity of punishment in a high cooperation context was greater than in a low cooperation context, and activation in the right DLPFC and ACC in a high cooperation context showed greater activity than in a low cooperation context. This indicates that the cooperation level of the group, as well as aversive emotion for inequity, is the important factor of punishing behavior.

International cooperation in water resources

USGS Publications Warehouse

Jones, J.R.; Beall, R.M.; Giusti, E.V.

1979-01-01

Advancements in hydrology proceeded slowly until the late 1800's when new ventures created a surge of interest and accomplishment. Progress waned again until the middle 20th century when an International Hydrological Decade was conceived, eventually receiving wide multinational support from governmental agencies and nongovernmental institutions. Organized by UNESCO, the Decade program was launched January 1, 1965. Participation included 107 nations, six United Nations agencies, and more than a dozen international scientific organizations. The initial program emphasized scientific research, and international cooperation; the second half of the Decade, emphasized technical assistance and technology transfer, largerly through education, training and demonstration. The success of the Decade led to the establishment of the International Hydrological Program, again under the aegis of UNESCO, to continue the work of the Decade indefinitely. The five major program activities, now involving about 90 countries and several international organizations, include: the scientific program, the promotion of education and training, the enhancement of information exchange, support of technical assistance, and the enlargement of regional cooperation. A significant amount of activity related to hydrological data networks and forecasting is carried on in an Operational Hydrology Programme by the WMO, chiefly through its Commission for Hydrology. Other international governmental organizations with a strong interest in water include the UN, the UN Development Programme, the FAO, the WHO, the International Atomic Energy Agency, the UN Environment Programme, the International Standardization Organization, and developmental institutions such as the World Bank. The specialized interests of researchers outside of the governmental structure, are met through association in various scientific and technical organizations which are world wide in scope and membership. Notwithstanding a sometimes

Relationships between cooperation and goal orientation among male professional and semi-professional team athletes.

PubMed

Lameiras, João; Almeida, Pedro L; Garcia-Mas, Alexandre

2014-12-01

In team sports, athletes' goals may focus on the task (enhancing performance, developing better skills, etc.) or on ego (being better than the others, achieving superiority, etc.). This study investigated the relationships between athletes' goal orientation and their tendency to cooperate with teammates and coaches. 158 professional men (M age = 24.1 yr., SD = 4.6) who played on various sport teams participated in this study. Goal orientation was measured with the Portuguese version of the Task and Ego Orientation in Sport Questionnaire, and cooperation was measured with the Questionário de Cooperação Desportiva. Cooperation was positively correlated with task orientation, and negatively correlated with ego orientation. Overall, the findings support that in sports, directing the players' focus on task may promote prosocial behavior.

What is a cooperative?

Treesearch

Kimberly Zeuli

2006-01-01

Groups of individuals throughout time have worked together in pursuit of common goals. The earliest forms of hunting and agriculture required a great deal of cooperation among humans. Although the word "cooperative" can be applied to many different types of group activities, in this publication it refers to a formal business model. Cooperative businesses are...

Comparison of technology-based cooperative learning with technology-based individual learning in enhancing fundamental nursing proficiency.

PubMed

Lin, Zu-Chun

2013-05-01

The aim of nursing education is to prepare students with critical thinking, high interests in profession and high proficiency in patient care. Cooperative learning promotes team work and encourages knowledge building upon discussion. It has been viewed as one of the most powerful learning methods. Technology has been considered an influential tool in teaching and learning. It assists students in gathering more information to solve the problems and master skills better. The purpose of this study was to compare the effect of technology-based cooperative learning with technology-based individual learning in nursing students' critical thinking in catheterization knowledge gaining, error discovering, skill acquisitions, and overall scores. This study used a pretest-posttest experimental design. Ninety-eight students were assigned randomly to one of two groups. Questionnaires and tests were collected at baseline and after completion of intervention. The results of this study showed that there was no significant difference in related catheterization skill performance. However, the remaining variables differed greatly between the two groups. CONCLUSIONS AND APPLICATIONS: This study's findings guide the researchers and instructors to use technology-based cooperative learning more appropriately. Future research should address the design of the course module and the availability of mobile devices to reach student-centered and learn on the move goals. Copyright © 2011 Elsevier Ltd. All rights reserved.

7 CFR 1000.18 - Cooperative association.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Cooperative association. 1000.18 Section 1000.18... Definitions § 1000.18 Cooperative association. Cooperative association means any cooperative marketing... milk products for its members. A federation of 2 or more cooperatives incorporated under the laws of...

Test and evaluation of vehicle platooning proof-of-concept based on cooperative adaptive cruise control

DOT National Transportation Integrated Search

2017-04-01

This report presents a high-level test and evaluation framework for cooperative driving automation systems that have the potential to significantly improve mobility and enhance traffic flow stability with better safety. It focuses on the test and eva...

Group Cooperation without Group Selection: Modest Punishment Can Recruit Much Cooperation.

PubMed

Krasnow, Max M; Delton, Andrew W; Cosmides, Leda; Tooby, John

2015-01-01

Humans everywhere cooperate in groups to achieve benefits not attainable by individuals. Individual effort is often not automatically tied to a proportionate share of group benefits. This decoupling allows for free-riding, a strategy that (absent countermeasures) outcompetes cooperation. Empirically and formally, punishment potentially solves the evolutionary puzzle of group cooperation. Nevertheless, standard analyses appear to show that punishment alone is insufficient, because second-order free riders (those who cooperate but do not punish) can be shown to outcompete punishers. Consequently, many have concluded that other processes, such as cultural or genetic group selection, are required. Here, we present a series of agent-based simulations that show that group cooperation sustained by punishment easily evolves by individual selection when you introduce into standard models more biologically plausible assumptions about the social ecology and psychology of ancestral humans. We relax three unrealistic assumptions of past models. First, past models assume all punishers must punish every act of free riding in their group. We instead allow punishment to be probabilistic, meaning punishers can evolve to only punish some free riders some of the time. This drastically lowers the cost of punishment as group size increases. Second, most models unrealistically do not allow punishment to recruit labor; punishment merely reduces the punished agent's fitness. We instead realistically allow punished free riders to cooperate in the future to avoid punishment. Third, past models usually restrict agents to interact in a single group their entire lives. We instead introduce realistic social ecologies in which agents participate in multiple, partially overlapping groups. Because of this, punitive tendencies are more expressed and therefore more exposed to natural selection. These three moves toward greater model realism reveal that punishment and cooperation easily evolve by

Group Cooperation without Group Selection: Modest Punishment Can Recruit Much Cooperation

PubMed Central

Cosmides, Leda; Tooby, John

2015-01-01

Humans everywhere cooperate in groups to achieve benefits not attainable by individuals. Individual effort is often not automatically tied to a proportionate share of group benefits. This decoupling allows for free-riding, a strategy that (absent countermeasures) outcompetes cooperation. Empirically and formally, punishment potentially solves the evolutionary puzzle of group cooperation. Nevertheless, standard analyses appear to show that punishment alone is insufficient, because second-order free riders (those who cooperate but do not punish) can be shown to outcompete punishers. Consequently, many have concluded that other processes, such as cultural or genetic group selection, are required. Here, we present a series of agent-based simulations that show that group cooperation sustained by punishment easily evolves by individual selection when you introduce into standard models more biologically plausible assumptions about the social ecology and psychology of ancestral humans. We relax three unrealistic assumptions of past models. First, past models assume all punishers must punish every act of free riding in their group. We instead allow punishment to be probabilistic, meaning punishers can evolve to only punish some free riders some of the time. This drastically lowers the cost of punishment as group size increases. Second, most models unrealistically do not allow punishment to recruit labor; punishment merely reduces the punished agent’s fitness. We instead realistically allow punished free riders to cooperate in the future to avoid punishment. Third, past models usually restrict agents to interact in a single group their entire lives. We instead introduce realistic social ecologies in which agents participate in multiple, partially overlapping groups. Because of this, punitive tendencies are more expressed and therefore more exposed to natural selection. These three moves toward greater model realism reveal that punishment and cooperation easily evolve by

Resource heterogeneity can facilitate cooperation.

PubMed

Kun, Ádám; Dieckmann, Ulf

2013-01-01

Although social structure is known to promote cooperation, by locally exposing selfish agents to their own deeds, studies to date assumed that all agents have access to the same level of resources. This is clearly unrealistic. Here we find that cooperation can be maintained when some agents have access to more resources than others. Cooperation can then emerge even in populations in which the temptation to defect is so strong that players would act fully selfishly if their resources were distributed uniformly. Resource heterogeneity can thus be crucial for the emergence and maintenance of cooperation. We also show that resource heterogeneity can hinder cooperation once the temptation to defect is significantly lowered. In all cases, the level of cooperation can be maximized by managing resource heterogeneity.

Spontaneous cooperation for prosocials, but not for proselfs: Social value orientation moderates spontaneous cooperation behavior

PubMed Central

Mischkowski, Dorothee; Glöckner, Andreas

2016-01-01

Cooperation is essential for the success of societies and there is an ongoing debate whether individuals have therefore developed a general spontaneous tendency to cooperate or not. Findings that cooperative behavior is related to shorter decision times provide support for the spontaneous cooperation effect, although contrary results have also been reported. We show that cooperative behavior is better described as person × situation interaction, in that there is a spontaneous cooperation effect for prosocial but not for proself persons. In three studies, one involving population representative samples from the US and Germany, we found that cooperation in a public good game is dependent on an interaction between individuals’ social value orientation and decision time. Increasing deliberation about the dilemma situation does not affect persons that are selfish to begin with, but it is related to decreasing cooperation for prosocial persons that gain positive utility from outcomes of others and score high on the related general personality trait honesty/humility. Our results demonstrate that the spontaneous cooperation hypothesis has to be qualified in that it is limited to persons with a specific personality and social values. Furthermore, they allow reconciling conflicting previous findings by identifying an important moderator for the effect. PMID:26876773

Tuning the mechanical properties of graphene oxide paper and its associated polymer nanocomposites by controlling cooperative intersheet hydrogen bonding.

PubMed

Compton, Owen C; Cranford, Steven W; Putz, Karl W; An, Zhi; Brinson, L Catherine; Buehler, Markus J; Nguyen, SonBinh T

2012-03-27

The mechanical properties of pristine graphene oxide paper and paper-like films of polyvinyl alcohol (PVA)-graphene oxide nanocomposite are investigated in a joint experimental-theoretical and computational study. In combination, these studies reveal a delicate relationship between the stiffness of these papers and the water content in their lamellar structures. ReaxFF-based molecular dynamics (MD) simulations elucidate the role of water molecules in modifying the mechanical properties of both pristine and nanocomposite graphene oxide papers, as bridge-forming water molecules between adjacent layers in the paper structure enhance stress transfer by means of a cooperative hydrogen-bonding network. For graphene oxide paper at an optimal concentration of ~5 wt % water, the degree of cooperative hydrogen bonding within the network comprising adjacent nanosheets and water molecules was found to optimally enhance the modulus of the paper without saturating the gallery space. Introducing PVA chains into the gallery space further enhances the cooperativity of this hydrogen-bonding network, in a manner similar to that found in natural biomaterials, resulting in increased stiffness of the composite. No optimal water concentration could be found for the PVA-graphene oxide nanocomposite papers, as dehydration of these structures continually enhances stiffness until a final water content of ~7 wt % (additional water cannot be removed from the system even after 12 h of annealing). © 2011 American Chemical Society

The Cooperative Family.

ERIC Educational Resources Information Center

Bass, Michele B.

1989-01-01

Cooperative learning approaches can create a cooperative family environment, involving positive interdependence and appropriate social and communication skills. This is especially important in families with a special needs child. Activities which can minimize competition among family members include participative rule-making, planning special…

Optimal interdependence between networks for the evolution of cooperation.

PubMed

Wang, Zhen; Szolnoki, Attila; Perc, Matjaž

2013-01-01

Recent research has identified interactions between networks as crucial for the outcome of evolutionary games taking place on them. While the consensus is that interdependence does promote cooperation by means of organizational complexity and enhanced reciprocity that is out of reach on isolated networks, we here address the question just how much interdependence there should be. Intuitively, one might assume the more the better. However, we show that in fact only an intermediate density of sufficiently strong interactions between networks warrants an optimal resolution of social dilemmas. This is due to an intricate interplay between the heterogeneity that causes an asymmetric strategy flow because of the additional links between the networks, and the independent formation of cooperative patterns on each individual network. Presented results are robust to variations of the strategy updating rule, the topology of interdependent networks, and the governing social dilemma, thus suggesting a high degree of universality.

Eliciting Survey Cooperation: Incentives, Self-Interest, and Norms of Cooperation

ERIC Educational Resources Information Center

Kropf, Martha E.; Blair, Johnny

2005-01-01

Given the weaker ties to community as noted by scholars such as Robert Putnam, survey researchers should not be surprised by a decline in survey participation over the past 10 years. This research analyzes the use of incentives coupled with introductory themes emphasizing cooperation and helpfulness--cooperative norms in American society--to…

Silviculture in cooperation with hunters: The Kinzua Quality Deer Cooperative

Treesearch

Scott Reitz; Andrea Hille; Susan Stout

2004-01-01

The long history of deer overabundance in Pennsylvania is associated with very high reforestation costs and substantial threats to diversity and sustainability. In response to this legacy, several landowners and agency personnel formed the Kinzua Quality Deer Cooperative (KQDC) in partnership with the Sand County Foundation. This Cooperative focuses on about 74,000...

Academic-Industry Collaboration under Federal Grants and Cooperative Agreements: Financial, Administrative, and Regulatory Compliance

ERIC Educational Resources Information Center

Ferreira, William F.

2011-01-01

Federal sponsorship of collaboration between academic institutions and industry is on the rise. Many government programs emphasize cooperation between universities and the commercial sector as a means to merge basic and applied research, promote economic development, and enhance knowledge dissemination. The intersection between academia and…

I Dare You to Punish Me—Vendettas in Games of Cooperation

PubMed Central

Fehl, Katrin; Sommerfeld, Ralf D.; Semmann, Dirk; Krambeck, Hans-Jürgen; Milinski, Manfred

2012-01-01

Everybody has heard of neighbours, who have been fighting over some minor topic for years. The fight goes back and forth, giving the neighbours a hard time. These kind of reciprocal punishments are known as vendettas and they are a cross-cultural phenomenon. In evolutionary biology, punishment is seen as a mechanism for maintaining cooperative behaviour. However, this notion of punishment excludes vendettas. Vendettas pose a special kind of evolutionary problem: they incur high costs on individuals, i.e. costs of punishing and costs of being punished, without any benefits. Theoretically speaking, punishment should be rare in dyadic relationships and vendettas would not evolve under natural selection. In contrast, punishment is assumed to be more efficient in group environments which then can pave the way for vendettas. Accordingly, we found that under the experimental conditions of a prisoner’s dilemma game, human participants punished only rarely and vendettas are scarce. In contrast, we found that participants retaliated frequently in the group environment of a public goods game. They even engaged in cost-intense vendettas (i.e. continuous retaliation), especially when the first punishment was unjustified or ambiguous. Here, punishment was mainly targeted at defectors in the beginning, but provocations led to mushrooming of counter-punishments. Despite the counter-punishing behaviour, participants were able to enhance cooperation levels in the public goods game. Few participants even seemed to anticipate the outbreak of costly vendettas and delayed their punishment to the last possible moment. Overall, our results highlight the importance of different social environments while studying punishment as a cooperation-enhancing mechanism. PMID:23028776

I dare you to punish me-vendettas in games of cooperation.

PubMed

Fehl, Katrin; Sommerfeld, Ralf D; Semmann, Dirk; Krambeck, Hans-Jürgen; Milinski, Manfred

2012-01-01

Everybody has heard of neighbours, who have been fighting over some minor topic for years. The fight goes back and forth, giving the neighbours a hard time. These kind of reciprocal punishments are known as vendettas and they are a cross-cultural phenomenon. In evolutionary biology, punishment is seen as a mechanism for maintaining cooperative behaviour. However, this notion of punishment excludes vendettas. Vendettas pose a special kind of evolutionary problem: they incur high costs on individuals, i.e. costs of punishing and costs of being punished, without any benefits. Theoretically speaking, punishment should be rare in dyadic relationships and vendettas would not evolve under natural selection. In contrast, punishment is assumed to be more efficient in group environments which then can pave the way for vendettas. Accordingly, we found that under the experimental conditions of a prisoner's dilemma game, human participants punished only rarely and vendettas are scarce. In contrast, we found that participants retaliated frequently in the group environment of a public goods game. They even engaged in cost-intense vendettas (i.e. continuous retaliation), especially when the first punishment was unjustified or ambiguous. Here, punishment was mainly targeted at defectors in the beginning, but provocations led to mushrooming of counter-punishments. Despite the counter-punishing behaviour, participants were able to enhance cooperation levels in the public goods game. Few participants even seemed to anticipate the outbreak of costly vendettas and delayed their punishment to the last possible moment. Overall, our results highlight the importance of different social environments while studying punishment as a cooperation-enhancing mechanism.

Cooperative Factors, Cooperative Innovation Effect and Innovation Performance for Chinese Firms: an Empirical Study

NASA Astrophysics Data System (ADS)

Xie, Xuemei

Based on a survey to 1206 Chinese firms, this paper empirically explores the factors impacting cooperative innovation effect of firms, and seeks to explore the relationship between cooperative innovation effect (CIE) and innovation performance using the technique of Structural Equation Modeling (SEM). The study finds there are significant positive relationships between basic sustaining factors, factors of government and policy, factors of cooperation mechanism and social network, and cooperative innovation effect. However, the result reveals that factors of government and policy demonstrate little impact on the CIE of firms compared with other factors. It is hoped that the findings can pave the way for future studies in improving cooperative innovation capacity for firms in emerging countries.

Technical cooperation on nuclear security between the United States and China : review of the past and opportunities for the future.

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

Pregenzer, Arian Leigh

2011-12-01

The United States and China are committed to cooperation to address the challenges of the next century. Technical cooperation, building on a long tradition of technical exchange between the two countries, can play an important role. This paper focuses on technical cooperation between the United States and China in the areas of nonproliferation, arms control and other nuclear security topics. It reviews cooperation during the 1990s on nonproliferation and arms control under the U.S.-China Arms Control Exchange, discusses examples of ongoing activities under the Peaceful Uses of Technology Agreement to enhance security of nuclear and radiological material, and suggests opportunitiesmore » for expanding technical cooperation between the defense nuclear laboratories of both countries to address a broader range of nuclear security topics.« less

Synergy between intention recognition and commitments in cooperation dilemmas

NASA Astrophysics Data System (ADS)

Han, The Anh; Santos, Francisco C.; Lenaerts, Tom; Pereira, Luís Moniz

2015-03-01

Commitments have been shown to promote cooperation if, on the one hand, they can be sufficiently enforced, and on the other hand, the cost of arranging them is justified with respect to the benefits of cooperation. When either of these constraints is not met it leads to the prevalence of commitment free-riders, such as those who commit only when someone else pays to arrange the commitments. Here, we show how intention recognition may circumvent such weakness of costly commitments. We describe an evolutionary model, in the context of the one-shot Prisoner's Dilemma, showing that if players first predict the intentions of their co-player and propose a commitment only when they are not confident enough about their prediction, the chances of reaching mutual cooperation are largely enhanced. We find that an advantageous synergy between intention recognition and costly commitments depends strongly on the confidence and accuracy of intention recognition. In general, we observe an intermediate level of confidence threshold leading to the highest evolutionary advantage, showing that neither unconditional use of commitment nor intention recognition can perform optimally. Rather, our results show that arranging commitments is not always desirable, but that they may be also unavoidable depending on the strength of the dilemma.

Evolution of Humans: Understanding the Nature and Methods of Science through Cooperative Learning

ERIC Educational Resources Information Center

Lee, Yeung Chung

2011-01-01

This article describes the use of an enquiry-based approach to the study of human evolution in a practical context, integrating role-playing, jigsaw cooperative learning and scientific argumentation. The activity seeks to unravel the evolutionary relationships of five hominids and one ape from rather "messy" evidence. This approach enhanced the…

The Cooperative Companion Digest (No. 1-4). Thinking about the Nature and Power of Cooperative Learning.

ERIC Educational Resources Information Center

Daniels, Ed; Gatto, Mike

These digests provide information for educators about the nature of cooperation and how cooperative principles can be used to restructure classrooms, administrative hierarchies, and work relationships of all types. Digest 1 describes the competitive, individual, and cooperative interaction patterns and examines the impact of cooperative learning…

Cooperative nanomaterials systems for cancer diagnosis and therapeutics

NASA Astrophysics Data System (ADS)

Park, Ji Ho

developed. Gold nanorods localized through vascular circulation to the tumor region, where they reported their location and converted near infrared (NIR) radiation to thermal energy. The local photothermal heating enabled to enhance tumor-specific drug release from thermally labile therapeutic liposomes or induce more binding sites for targeted therapeutic liposomes. The combination of local hyperthermia and chemotherapy in the cooperative nanosystems significantly enhanced therapeutic efficacy relative to individual therapies.

Germplasm Enhancement of Maize: Allelic Diversity and Double Haploid Update

USDA-ARS?s Scientific Manuscript database

The Germplasm Enhancement of Maize (GEM) Project is a collaborative effort of public and private sector researchers to broaden and enhance the germplasm base. To date, 235 germplasm lines have been released to cooperators representing approximately 25 races. These lines were selected based on yiel...

Direct labelling of the human P2X7 receptor and identification of positive and negative cooperativity of binding.

PubMed

Michel, A D; Chambers, L J; Clay, W C; Condreay, J P; Walter, D S; Chessell, I P

2007-05-01

The P2X(7) receptor exhibits complex pharmacological properties. In this study, binding of a [(3)H]-labelled P2X(7) receptor antagonist to human P2X(7) receptors has been examined to further understand ligand interactions with this receptor. The P2X(7) receptor antagonist, N-[2-({2-[(2-hydroxyethyl)amino]ethyl}amino)-5-quinolinyl]-2-tricyclo[3.3.1.1(3,7)]dec-1-ylacetamide (compound-17), was radiolabelled with tritium and binding studies were performed using membranes prepared from U-2 OS or HEK293 cells expressing human recombinant P2X(7) receptors. Binding of [(3)H]-compound-17 was higher in membranes prepared from cells expressing P2X(7) receptors than from control cells and was inhibited by ATP suggesting labelled sites represented human P2X(7) receptors. Binding was reversible, saturable and modulated by P2X(7) receptor ligands (Brilliant Blue G, KN62, ATP, decavanadate). Furthermore, ATP potency was reduced in the presence of divalent cations or NaCl. Radioligand binding exhibited both positive and negative cooperativity. Positive cooperativity was evident from bell shaped Scatchard plots, reduction in radioligand dissociation rate by unlabelled compound-17 and enhancement of radioligand binding by KN62 and unlabelled compound-17. ATP and decavanadate inhibited binding in a negative cooperative manner as they enhanced radioligand dissociation. These data demonstrate that human P2X(7) receptors can be directly labelled and provide novel insights into receptor function. The positive cooperativity observed suggests that binding of compound-17 to one subunit in the P2X(7) receptor complex enhances subsequent binding to other P2X(7) subunits in the same complex. The negative cooperative effects of ATP suggest that ATP and compound-17 bind at separate, interacting, sites on the P2X(7) receptor.

QoS and energy aware cooperative routing protocol for wildfire monitoring wireless sensor networks.

PubMed

Maalej, Mohamed; Cherif, Sofiane; Besbes, Hichem

2013-01-01

Wireless sensor networks (WSN) are presented as proper solution for wildfire monitoring. However, this application requires a design of WSN taking into account the network lifetime and the shadowing effect generated by the trees in the forest environment. Cooperative communication is a promising solution for WSN which uses, at each hop, the resources of multiple nodes to transmit its data. Thus, by sharing resources between nodes, the transmission quality is enhanced. In this paper, we use the technique of reinforcement learning by opponent modeling, optimizing a cooperative communication protocol based on RSSI and node energy consumption in a competitive context (RSSI/energy-CC), that is, an energy and quality-of-service aware-based cooperative communication routing protocol. Simulation results show that the proposed algorithm performs well in terms of network lifetime, packet delay, and energy consumption.

Globalization and human cooperation.

PubMed

Buchan, Nancy R; Grimalda, Gianluca; Wilson, Rick; Brewer, Marilynn; Fatas, Enrique; Foddy, Margaret

2009-03-17

Globalization magnifies the problems that affect all people and that require large-scale human cooperation, for example, the overharvesting of natural resources and human-induced global warming. However, what does globalization imply for the cooperation needed to address such global social dilemmas? Two competing hypotheses are offered. One hypothesis is that globalization prompts reactionary movements that reinforce parochial distinctions among people. Large-scale cooperation then focuses on favoring one's own ethnic, racial, or language group. The alternative hypothesis suggests that globalization strengthens cosmopolitan attitudes by weakening the relevance of ethnicity, locality, or nationhood as sources of identification. In essence, globalization, the increasing interconnectedness of people worldwide, broadens the group boundaries within which individuals perceive they belong. We test these hypotheses by measuring globalization at both the country and individual levels and analyzing the relationship between globalization and individual cooperation with distal others in multilevel sequential cooperation experiments in which players can contribute to individual, local, and/or global accounts. Our samples were drawn from the general populations of the United States, Italy, Russia, Argentina, South Africa, and Iran. We find that as country and individual levels of globalization increase, so too does individual cooperation at the global level vis-à-vis the local level. In essence, "globalized" individuals draw broader group boundaries than others, eschewing parochial motivations in favor of cosmopolitan ones. Globalization may thus be fundamental in shaping contemporary large-scale cooperation and may be a positive force toward the provision of global public goods.

An investigative, cooperative learning approach to the general microbiology laboratory.

PubMed

Seifert, Kyle; Fenster, Amy; Dilts, Judith A; Temple, Louise

2009-01-01

Investigative- and cooperative-based learning strategies have been used effectively in a variety of classrooms to enhance student learning and engagement. In the General Microbiology laboratory for juniors and seniors at James Madison University, these strategies were combined to make a semester-long, investigative, cooperative learning experience involving culture and identification of microbial isolates that the students obtained from various environments. To assess whether this strategy was successful, students were asked to complete a survey at the beginning and at the end of the semester regarding their comfort level with a variety of topics. For most of the topics queried, the students reported that their comfort had increased significantly during the semester. Furthermore, this group of students thought that the quality of this investigative lab experience was much better than that of any of their previous lab experiences.

An Investigative, Cooperative Learning Approach to the General Microbiology Laboratory

PubMed Central

Seifert, Kyle; Fenster, Amy; Dilts, Judith A.

2009-01-01

Investigative- and cooperative-based learning strategies have been used effectively in a variety of classrooms to enhance student learning and engagement. In the General Microbiology laboratory for juniors and seniors at James Madison University, these strategies were combined to make a semester-long, investigative, cooperative learning experience involving culture and identification of microbial isolates that the students obtained from various environments. To assess whether this strategy was successful, students were asked to complete a survey at the beginning and at the end of the semester regarding their comfort level with a variety of topics. For most of the topics queried, the students reported that their comfort had increased significantly during the semester. Furthermore, this group of students thought that the quality of this investigative lab experience was much better than that of any of their previous lab experiences. PMID:19487504

Cooperation in the noisy case: Prisoner's dilemma game on two types of regular random graphs

NASA Astrophysics Data System (ADS)

Vukov, Jeromos; Szabó, György; Szolnoki, Attila

2006-06-01

We have studied an evolutionary prisoner’s dilemma game with players located on two types of random regular graphs with a degree of 4. The analysis is focused on the effects of payoffs and noise (temperature) on the maintenance of cooperation. When varying the noise level and/or the highest payoff, the system exhibits a second-order phase transition from a mixed state of cooperators and defectors to an absorbing state where only defectors remain alive. For the random regular graph (and Bethe lattice) the behavior of the system is similar to those found previously on the square lattice with nearest neighbor interactions, although the measure of cooperation is enhanced by the absence of loops in the connectivity structure. For low noise the optimal connectivity structure is built up from randomly connected triangles.

Regional cooperation in South Asia in the field of mental health.

PubMed

Trivedi, Jitendra K; Goel, Dishanter; Kallivayalil, Roy A; Isaac, Mohan; Shrestha, Dhruba M; Gambheera, Harish C

2007-02-01

The South Asian region accounts for around one fourth of the world population and one fifth of psychiatrically ill patients in the world. The region lacks mental health policies and infrastructure. Issues like community care, trained manpower, patient satisfaction and better legislation have been a focus of attention in recent years. As this region is fast developing, cooperation is needed in the field of mental health to keep pace with the other areas. Cooperation is needed to develop culturally acceptable forms of psychotherapy and new technologies for delivery of mental health services. Another area of potential cooperation is the development of a classification of mental disorders that is more informative in our setting. The development of a mental health programme and its inclusion at various levels of health care delivery has also gained precedence. As most of countries in the area have limited financial resources, the funds are to be used in the most cost-effective manner, and for this a greater collaboration amongst the countries is needed. New research needs to be undertaken in the area especially to meet the local requirements and to understand diseases in a regional perspective, but research cannot be fruitful if regional cooperation is lacking. To enhance the cooperation in mental health, world bodies like the WPA will need to come forward and bring all the countries at a common platform. The WPA has done commendable work in this regard and has always extended support to the regional bodies to uplift the mental health in this region.

7 CFR 1150.119 - Cooperative association.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 9 2010-01-01 2009-01-01 true Cooperative association. 1150.119 Section 1150.119 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... Order Definitions § 1150.119 Cooperative association. Cooperative association means any cooperative...

Human Xq28 inversion polymorphism: From sex linkage to Genomics--A genetic mother lode.

PubMed

Kirby, Cait S; Kolber, Natalie; Salih Almohaidi, Asmaa M; Bierwert, Lou Ann; Saunders, Lori; Williams, Steven; Merritt, Robert

2016-01-01

An inversion polymorphism of the filamin and emerin genes at the tip of the long arm of the human X-chromosome serves as the basis of an investigative laboratory in which students learn something new about their own genomes. Long, nearly identical inverted repeats flanking the filamin and emerin genes illustrate how repetitive elements can lead to alterations in genome structure (inversions) through nonallelic homologous recombination. The near identity of the inverted repeats is an example of concerted evolution through gene conversion. While the laboratory in its entirety is designed for college level genetics courses, portions of the laboratory are appropriate for courses at other levels. Because the polymorphism is on the X-chromosome, the laboratory can be used in introductory biology courses to enhance understanding of sex-linkage and to test for Hardy-Weinberg equilibrium in females. More advanced topics, such as chromosome interference, the molecular model for recombination, and inversion heterozygosity suppression of recombination can be explored in upper-level genetics and evolution courses. DNA isolation, restriction digests, ligation, long PCR, and iPCR provide experience with techniques in molecular biology. This investigative laboratory weaves together topics stretching from molecular genetics to cytogenetics and sex-linkage, population genetics and evolutionary genetics. © 2016 The International Union of Biochemistry and Molecular Biology.

Situational trust and co-operative partnerships between physicians and their patients: a theoretical explanation transferable from business practice.

PubMed

Dibben, M R; Morris, S E; Lean, M E

2000-01-01

A model to explain interpersonal trust development, and its consequences for co-operative behaviour in doctor/patient partnerships derived from the context of business relationships is applied to patient/physician relationships. Threshold barriers exist against all human behaviours or actions and trust is the process by which barriers to co-operation and compliance are overcome. Dispositional trust (a psychological trait to be trusting) is dominant in the early stages of a relationship and contributes to the weight of subsequent trust development. Co-operative behaviour or compliance ultimately requires a secure situational trust emerging from consultations, which is carried forward as learnt trust and modified in each subsequent consultation. The model comprises three types of situational trust (calculus-based, knowledge-based, and identification trust) and five co-operation criteria from which to determine an individual's tendency for co- operative behaviour. These model components can be identified and mapped from a range of qualitative data, with the aim of enhancing co-operative behaviour and efficiently achieving optimal patient compliance.

Exploiting Outage and Error Probability of Cooperative Incremental Relaying in Underwater Wireless Sensor Networks

PubMed Central

Nasir, Hina; Javaid, Nadeem; Sher, Muhammad; Qasim, Umar; Khan, Zahoor Ali; Alrajeh, Nabil; Niaz, Iftikhar Azim

2016-01-01

This paper embeds a bi-fold contribution for Underwater Wireless Sensor Networks (UWSNs); performance analysis of incremental relaying in terms of outage and error probability, and based on the analysis proposition of two new cooperative routing protocols. Subject to the first contribution, a three step procedure is carried out; a system model is presented, the number of available relays are determined, and based on cooperative incremental retransmission methodology, closed-form expressions for outage and error probability are derived. Subject to the second contribution, Adaptive Cooperation in Energy (ACE) efficient depth based routing and Enhanced-ACE (E-ACE) are presented. In the proposed model, feedback mechanism indicates success or failure of data transmission. If direct transmission is successful, there is no need for relaying by cooperative relay nodes. In case of failure, all the available relays retransmit the data one by one till the desired signal quality is achieved at destination. Simulation results show that the ACE and E-ACE significantly improves network performance, i.e., throughput, when compared with other incremental relaying protocols like Cooperative Automatic Repeat reQuest (CARQ). E-ACE and ACE achieve 69% and 63% more throughput respectively as compared to CARQ in hard underwater environment. PMID:27420061

43 CFR 43.620 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Cooperative agreement. 43.620 Section 43... DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 43.620 Cooperative agreement. Cooperative... activity contemplated by the award. The term does not include cooperative research and development...

28 CFR 46.114 - Cooperative research.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Cooperative research. 46.114 Section 46... Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each institution is...

28 CFR 46.114 - Cooperative research.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Cooperative research. 46.114 Section 46... Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each institution is...

28 CFR 46.114 - Cooperative research.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Cooperative research. 46.114 Section 46... Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each institution is...

10 CFR 745.114 - Cooperative research.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Cooperative research. 745.114 Section 745.114 Energy DEPARTMENT OF ENERGY PROTECTION OF HUMAN SUBJECTS § 745.114 Cooperative research. Cooperative research... of cooperative research projects, each institution is responsible for safeguarding the rights and...

10 CFR 745.114 - Cooperative research.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Cooperative research. 745.114 Section 745.114 Energy DEPARTMENT OF ENERGY PROTECTION OF HUMAN SUBJECTS § 745.114 Cooperative research. Cooperative research... of cooperative research projects, each institution is responsible for safeguarding the rights and...

10 CFR 745.114 - Cooperative research.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Cooperative research. 745.114 Section 745.114 Energy DEPARTMENT OF ENERGY PROTECTION OF HUMAN SUBJECTS § 745.114 Cooperative research. Cooperative research... of cooperative research projects, each institution is responsible for safeguarding the rights and...

10 CFR 745.114 - Cooperative research.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Cooperative research. 745.114 Section 745.114 Energy DEPARTMENT OF ENERGY PROTECTION OF HUMAN SUBJECTS § 745.114 Cooperative research. Cooperative research... of cooperative research projects, each institution is responsible for safeguarding the rights and...

28 CFR 46.114 - Cooperative research.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Cooperative research. 46.114 Section 46... Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each institution is...

10 CFR 745.114 - Cooperative research.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Cooperative research. 745.114 Section 745.114 Energy DEPARTMENT OF ENERGY PROTECTION OF HUMAN SUBJECTS § 745.114 Cooperative research. Cooperative research... of cooperative research projects, each institution is responsible for safeguarding the rights and...

28 CFR 46.114 - Cooperative research.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Cooperative research. 46.114 Section 46... Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each institution is...

[Child protection--cooperation and conflict management].

PubMed

Averbeck, Birgit; Hermans, Björn Enno

2010-01-01

When people have to deal with conflicts or opposing views they often refer to the term cooperation. But after lengthy discussions the question may be raised if it is more useful not to cooperate. The authors of this article analyse why cooperation is often called for but frequently fails. In this article key prerequisites for successful cooperation are described before the authors present their practical method of 'sYpport'. 'SYpport' mostly refers to trans-institutional cooperation and focuses on the required attitude of those involved. The authors' simple but crucial conclusion is that cooperation requires faith in others.

Globalization and human cooperation

PubMed Central

Buchan, Nancy R.; Grimalda, Gianluca; Wilson, Rick; Brewer, Marilynn; Fatas, Enrique; Foddy, Margaret

2009-01-01

Globalization magnifies the problems that affect all people and that require large-scale human cooperation, for example, the overharvesting of natural resources and human-induced global warming. However, what does globalization imply for the cooperation needed to address such global social dilemmas? Two competing hypotheses are offered. One hypothesis is that globalization prompts reactionary movements that reinforce parochial distinctions among people. Large-scale cooperation then focuses on favoring one's own ethnic, racial, or language group. The alternative hypothesis suggests that globalization strengthens cosmopolitan attitudes by weakening the relevance of ethnicity, locality, or nationhood as sources of identification. In essence, globalization, the increasing interconnectedness of people worldwide, broadens the group boundaries within which individuals perceive they belong. We test these hypotheses by measuring globalization at both the country and individual levels and analyzing the relationship between globalization and individual cooperation with distal others in multilevel sequential cooperation experiments in which players can contribute to individual, local, and/or global accounts. Our samples were drawn from the general populations of the United States, Italy, Russia, Argentina, South Africa, and Iran. We find that as country and individual levels of globalization increase, so too does individual cooperation at the global level vis-à-vis the local level. In essence, “globalized” individuals draw broader group boundaries than others, eschewing parochial motivations in favor of cosmopolitan ones. Globalization may thus be fundamental in shaping contemporary large-scale cooperation and may be a positive force toward the provision of global public goods. PMID:19255433

Optimal interdependence between networks for the evolution of cooperation

PubMed Central

Wang, Zhen; Szolnoki, Attila; Perc, Matjaž

2013-01-01

Recent research has identified interactions between networks as crucial for the outcome of evolutionary games taking place on them. While the consensus is that interdependence does promote cooperation by means of organizational complexity and enhanced reciprocity that is out of reach on isolated networks, we here address the question just how much interdependence there should be. Intuitively, one might assume the more the better. However, we show that in fact only an intermediate density of sufficiently strong interactions between networks warrants an optimal resolution of social dilemmas. This is due to an intricate interplay between the heterogeneity that causes an asymmetric strategy flow because of the additional links between the networks, and the independent formation of cooperative patterns on each individual network. Presented results are robust to variations of the strategy updating rule, the topology of interdependent networks, and the governing social dilemma, thus suggesting a high degree of universality. PMID:23959086

Cooperative polymerization of α-helices induced by macromolecular architecture

NASA Astrophysics Data System (ADS)

Baumgartner, Ryan; Fu, Hailin; Song, Ziyuan; Lin, Yao; Cheng, Jianjun

2017-07-01

Catalysis observed in enzymatic processes and protein polymerizations often relies on the use of supramolecular interactions and the organization of functional elements in order to gain control over the spatial and temporal elements of fundamental cellular processes. Harnessing these cooperative interactions to catalyse reactions in synthetic systems, however, remains challenging due to the difficulty in creating structurally controlled macromolecules. Here, we report a polypeptide-based macromolecule with spatially organized α-helices that can catalyse its own formation. The system consists of a linear polymeric scaffold containing a high density of initiating groups from which polypeptides are grown, forming a brush polymer. The folding of polypeptide side chains into α-helices dramatically enhances the polymerization rate due to cooperative interactions of macrodipoles between neighbouring α-helices. The parameters that affect the rate are elucidated by a two-stage kinetic model using principles from nucleation-controlled protein polymerizations; the key difference being the irreversible nature of this polymerization.

Loss of an actin crosslinker uncouples cell spreading from cell stiffening on gels with a gradient of stiffness

NASA Astrophysics Data System (ADS)

Wen, Qi; Byfield, Fitzroy J.; Nordstrom, Kerstin; Arratia, Paulo E.; Miller, R. Tyler; Janmey, Paul A.

2009-03-01

We use microfluidics techniques to produce gels with a gradient of stiffness to show the essential function of the actin crosslinker filamin A in cell responses to mechanical stimuli. M2 melanoma cells null for filamin A do not alter their adherent area in response to increased substrate stiffness when they link to the substrate only through collagen receptors, but change adherent area normally when bound through fibronectin receptors. In contrast, filamin A-replete A7 cells change adherent area on both substrates and respond more strongly to collagen 1-coated gels than to fibronectin-coated gels. A7 cells alter their stiffness, as measured by atomic force microscopy, to match the elastic modulus of the substrate immediately adjacent to them on the gradient. M2 cells, in contrast, maintain a constant stiffness on all substrates that is as low as that of A7 cells on the softest gels achievable (1000 Pa). By contrasting the responses of these cell types to different adhesive substrates, cell spreading can be dissociated from stiffening.

Cooperative learning: An inside story

NASA Astrophysics Data System (ADS)

Andre, Kathleen M.

1999-09-01

Cooperative learning is one innovative technique used in an engineering physics course at Ohio State. Student opinions on the cooperative element were solicited near the end of the course. These comments provide useful insight into why students believe cooperative learning is helpful in learning physics.

36 CFR 1212.620 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Cooperative agreement. 1212... § 1212.620 Cooperative agreement. Cooperative agreement means an award of financial assistance that... include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

32 CFR 219.114 - Cooperative research.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 2 2012-07-01 2012-07-01 false Cooperative research. 219.114 Section 219.114...) MISCELLANEOUS PROTECTION OF HUMAN SUBJECTS § 219.114 Cooperative research. Cooperative research projects are... cooperative research projects, each institution is responsible for safeguarding the rights and welfare of...

14 CFR 1230.114 - Cooperative research.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Cooperative research. 1230.114 Section 1230... § 1230.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

15 CFR 27.114 - Cooperative research.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Cooperative research. 27.114 Section... § 27.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

14 CFR 1230.114 - Cooperative research.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Cooperative research. 1230.114 Section 1230... § 1230.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

15 CFR 27.114 - Cooperative research.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Cooperative research. 27.114 Section... § 27.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

16 CFR 1028.114 - Cooperative research.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Cooperative research. 1028.114 Section 1028... § 1028.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

38 CFR 16.114 - Cooperative research.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Cooperative research. 16... OF HUMAN SUBJECTS § 16.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research...

14 CFR 1230.114 - Cooperative research.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Cooperative research. 1230.114 Section 1230... § 1230.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

16 CFR 1028.114 - Cooperative research.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Cooperative research. 1028.114 Section 1028... § 1028.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

16 CFR 1028.114 - Cooperative research.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Cooperative research. 1028.114 Section 1028... § 1028.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

14 CFR 1230.114 - Cooperative research.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Cooperative research. 1230.114 Section 1230... § 1230.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

32 CFR 219.114 - Cooperative research.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 2 2013-07-01 2013-07-01 false Cooperative research. 219.114 Section 219.114...) MISCELLANEOUS PROTECTION OF HUMAN SUBJECTS § 219.114 Cooperative research. Cooperative research projects are... cooperative research projects, each institution is responsible for safeguarding the rights and welfare of...

15 CFR 27.114 - Cooperative research.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Cooperative research. 27.114 Section... § 27.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

38 CFR 16.114 - Cooperative research.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Cooperative research. 16... OF HUMAN SUBJECTS § 16.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research...

32 CFR 219.114 - Cooperative research.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 2 2010-07-01 2010-07-01 false Cooperative research. 219.114 Section 219.114...) MISCELLANEOUS PROTECTION OF HUMAN SUBJECTS § 219.114 Cooperative research. Cooperative research projects are... cooperative research projects, each institution is responsible for safeguarding the rights and welfare of...

15 CFR 27.114 - Cooperative research.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Cooperative research. 27.114 Section... § 27.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

38 CFR 16.114 - Cooperative research.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Cooperative research. 16... OF HUMAN SUBJECTS § 16.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research...

38 CFR 16.114 - Cooperative research.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Cooperative research. 16... OF HUMAN SUBJECTS § 16.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research...

38 CFR 16.114 - Cooperative research.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Cooperative research. 16... OF HUMAN SUBJECTS § 16.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research...

15 CFR 27.114 - Cooperative research.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Cooperative research. 27.114 Section... § 27.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

16 CFR 1028.114 - Cooperative research.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Cooperative research. 1028.114 Section 1028... § 1028.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research projects, each...

32 CFR 219.114 - Cooperative research.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 2 2014-07-01 2014-07-01 false Cooperative research. 219.114 Section 219.114...) MISCELLANEOUS PROTECTION OF HUMAN SUBJECTS § 219.114 Cooperative research. Cooperative research projects are... cooperative research projects, each institution is responsible for safeguarding the rights and welfare of...

32 CFR 219.114 - Cooperative research.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 2 2011-07-01 2011-07-01 false Cooperative research. 219.114 Section 219.114...) MISCELLANEOUS PROTECTION OF HUMAN SUBJECTS § 219.114 Cooperative research. Cooperative research projects are... cooperative research projects, each institution is responsible for safeguarding the rights and welfare of...

21 CFR 1405.620 - Cooperative agreement.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 9 2012-04-01 2012-04-01 false Cooperative agreement. 1405.620 Section 1405.620... WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1405.620 Cooperative agreement. Cooperative agreement means... contemplated by the award. The term does not include cooperative research and development agreements as defined...

36 CFR 1212.620 - Cooperative agreement.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Cooperative agreement. 1212... § 1212.620 Cooperative agreement. Cooperative agreement means an award of financial assistance that... include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

28 CFR 83.620 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Cooperative agreement. 83.620 Section 83...-FREE WORKPLACE (GRANTS) Definitions § 83.620 Cooperative agreement. Cooperative agreement means an... by the award. The term does not include cooperative research and development agreements as defined in...

7 CFR 1415.17 - Cooperative agreements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 10 2011-01-01 2011-01-01 false Cooperative agreements. 1415.17 Section 1415.17... Cooperative agreements. (a) NRCS may enter into cooperative agreements which establish terms and conditions... cooperative agreement with those eligible entities selected for funding. Once a proposal is selected by the...

21 CFR 1405.620 - Cooperative agreement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Cooperative agreement. 1405.620 Section 1405.620... WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1405.620 Cooperative agreement. Cooperative agreement means... contemplated by the award. The term does not include cooperative research and development agreements as defined...

7 CFR 1415.17 - Cooperative agreements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 10 2012-01-01 2012-01-01 false Cooperative agreements. 1415.17 Section 1415.17... Cooperative agreements. (a) NRCS may enter into cooperative agreements which establish terms and conditions... cooperative agreement with those eligible entities selected for funding. Once a proposal is selected by the...

7 CFR 3021.620 - Cooperative agreement.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 15 2011-01-01 2011-01-01 false Cooperative agreement. 3021.620 Section 3021.620...) Definitions § 3021.620 Cooperative agreement. Cooperative agreement means an award of financial assistance... not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

22 CFR 312.620 - Cooperative agreement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Cooperative agreement. 312.620 Section 312.620...) Definitions § 312.620 Cooperative agreement. Cooperative agreement means an award of financial assistance that... cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

21 CFR 1405.620 - Cooperative agreement.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 9 2013-04-01 2013-04-01 false Cooperative agreement. 1405.620 Section 1405.620... WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1405.620 Cooperative agreement. Cooperative agreement means... contemplated by the award. The term does not include cooperative research and development agreements as defined...

22 CFR 312.620 - Cooperative agreement.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Cooperative agreement. 312.620 Section 312.620...) Definitions § 312.620 Cooperative agreement. Cooperative agreement means an award of financial assistance that... cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

36 CFR 1212.620 - Cooperative agreement.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Cooperative agreement. 1212... § 1212.620 Cooperative agreement. Cooperative agreement means an award of financial assistance that... include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

Neural correlates of social cooperation and non-cooperation as a function of psychopathy.

PubMed

Rilling, James K; Glenn, Andrea L; Jairam, Meeta R; Pagnoni, Giuseppe; Goldsmith, David R; Elfenbein, Hanie A; Lilienfeld, Scott O

2007-06-01

Psychopathy is a disorder involving a failure to experience many emotions that are necessary for appropriate social behavior. In this study, we probed the behavioral, emotional, and neural correlates of psychopathic traits within the context of a dyadic social interaction. Thirty subjects were imaged with functional magnetic resonance imaging while playing an iterated Prisoner's Dilemma game with human confederates who were outside the scanner. Subjects also completed two self-report psychopathy questionnaires. Subjects scoring higher on psychopathy, particularly males, defected more often and were less likely to continue cooperating after establishing mutual cooperation with a partner. Further, they experienced more outcomes in which their cooperation was not reciprocated (cooperate-defect outcome). After such outcomes, subjects scoring high in psychopathy showed less amygdala activation, suggesting weaker aversive conditioning to those outcomes. Compared with low-psychopathy subjects, subjects higher in psychopathy also showed weaker activation within orbitofrontal cortex when choosing to cooperate and showed weaker activation within dorsolateral prefrontal and rostral anterior cingulate cortex when choosing to defect. These findings suggest that whereas subjects scoring low on psychopathy have emotional biases toward cooperation that can only be overcome with effortful cognitive control, subjects scoring high on psychopathy have an opposing bias toward defection that likewise can only be overcome with cognitive effort.

'Shared-rhythm cooperation' in cooperative team meetings in acute psychiatric inpatient care.

PubMed

Vuokila-Oikkonen, P; Janhonen, S; Vaisanen, L

2004-04-01

The cooperative team meeting is one of the most important interventions in psychiatric care. The purpose of this study was to describe the participation of patients and significant others in cooperative team meetings in terms of unspoken stories. The narrative approach focused on storytelling. The data consisted of videotaped cooperative team meetings (n = 11) in two acute closed psychiatric wards. The QRS NVivo computer program and the Holistic Content Reading method were used. During the process of analysis, the spoken and unspoken stories were analysed at the same time. According to the results, while there was some evident shared-rhythm cooperation (the topics of discussion were shared and the participants had eye contact), there were many instances where the interaction was controlled and defined by health care professionals. This lack of shared rhythm in cooperation, as defined in terms of storytelling, was manifested as monologue and the following practices: the health care professionals controlled the storytelling by sticking to their opinions, by giving the floor or by pointing with a finger and visually scanning the participants, by interrupting the speaker or by allowing the other experts to sit passively. Implications for mental health nursing practice are discussed.

Cooperation and control in multiplayer social dilemmas

PubMed Central

Hilbe, Christian; Wu, Bin; Traulsen, Arne; Nowak, Martin A.

2014-01-01

Direct reciprocity and conditional cooperation are important mechanisms to prevent free riding in social dilemmas. However, in large groups, these mechanisms may become ineffective because they require single individuals to have a substantial influence on their peers. However, the recent discovery of zero-determinant strategies in the iterated prisoner’s dilemma suggests that we may have underestimated the degree of control that a single player can exert. Here, we develop a theory for zero-determinant strategies for iterated multiplayer social dilemmas, with any number of involved players. We distinguish several particularly interesting subclasses of strategies: fair strategies ensure that the own payoff matches the average payoff of the group; extortionate strategies allow a player to perform above average; and generous strategies let a player perform below average. We use this theory to describe strategies that sustain cooperation, including generalized variants of Tit-for-Tat and Win-Stay Lose-Shift. Moreover, we explore two models that show how individuals can further enhance their strategic options by coordinating their play with others. Our results highlight the importance of individual control and coordination to succeed in large groups. PMID:25349400

Using cooperative learning for a drug information assignment.

PubMed

Earl, Grace L

2009-11-12

To implement a cooperative learning activity to engage students in analyzing tertiary drug information resources in a literature evaluation course. The class was divided into 4 sections to form expert groups and each group researched a different set of references using the jigsaw technique. Each member of each expert group was reassigned to a jigsaw group so that each new group was composed of 4 students from 4 different expert groups. The jigsaw groups met to discuss search strategies and rate the usefulness of the references. In addition to group-based learning, teaching methods included students' writing an independent research paper to enhance their abilities to search and analyze drug information resources. The assignment and final course grades improved after implementation of the activity. Students agreed that class discussions were a useful learning experience and 75% (77/102) said they would use the drug information references for other courses. The jigsaw technique was successful in engaging students in cooperative learning to improve critical thinking skills regarding drug information.

Cooperative Learning: Developments in Research

ERIC Educational Resources Information Center

Gillies, Robyn M.

2014-01-01

Cooperative learning is widely recognized as a pedagogical practice that promotes socialization and learning among students from kindergarten through to college level and across different subject areas. Cooperative learning involves students working together to achieve common goals or complete group tasks. Interest in cooperative learning has…

An Odyssey into Cooperative Learning.

ERIC Educational Resources Information Center

Lemke, Thomas L.; Basile, Carole

1997-01-01

An experiment using cooperative learning in a introductory pharmacy course in medicinal chemistry revealed general acceptance of the cooperative learning approach by students, and some perceived advantages for both students and teachers. Although quantitative evidence supporting superiority of the cooperative learning approach was not found,…

Fifty Views of Cooperative Education.

ERIC Educational Resources Information Center

Hunt, Donald C.

A series of opinions on many facets of the administration of cooperative education programming is presented. Part One reviews the philosophy of cooperative education including Lawrence Canjar's "convert" speech, a comparison of experiential and cooperative education, and discussions of parallel programs. In Part Two employers discuss cooperative…

Reciprocity Outperforms Conformity to Promote Cooperation.

PubMed

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.

49 CFR 32.620 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Cooperative agreement. 32.620 Section 32.620... (FINANCIAL ASSISTANCE) Definitions § 32.620 Cooperative agreement. Cooperative agreement means an award of... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

7 CFR 1491.20 - Cooperative agreements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Cooperative agreements. 1491.20 Section 1491.20... Cooperative Agreements and Conservation Easement Deeds § 1491.20 Cooperative agreements. (a) NRCS, on behalf of CCC, shall enter into a cooperative agreement with those entities selected for funding. Once a...

29 CFR 94.620 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 1 2010-07-01 2010-07-01 true Cooperative agreement. 94.620 Section 94.620 Labor Office of...) Definitions § 94.620 Cooperative agreement. Cooperative agreement means an award of financial assistance that... cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

7 CFR 1425.19 - Member cooperatives.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Member cooperatives. 1425.19 Section 1425.19... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COOPERATIVE MARKETING ASSOCIATIONS § 1425.19 Member cooperatives. A CMA may obtain loans or LDP's on behalf of a member cooperative when the member...

45 CFR 690.114 - Cooperative research.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 3 2014-10-01 2014-10-01 false Cooperative research. 690.114 Section 690.114... OF HUMAN SUBJECTS § 690.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research...

45 CFR 690.114 - Cooperative research.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 3 2013-10-01 2013-10-01 false Cooperative research. 690.114 Section 690.114... OF HUMAN SUBJECTS § 690.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research...

45 CFR 690.114 - Cooperative research.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Cooperative research. 690.114 Section 690.114... OF HUMAN SUBJECTS § 690.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research...

45 CFR 690.114 - Cooperative research.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 3 2011-10-01 2011-10-01 false Cooperative research. 690.114 Section 690.114... OF HUMAN SUBJECTS § 690.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research...

45 CFR 690.114 - Cooperative research.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 3 2012-10-01 2012-10-01 false Cooperative research. 690.114 Section 690.114... OF HUMAN SUBJECTS § 690.114 Cooperative research. Cooperative research projects are those projects covered by this policy which involve more than one institution. In the conduct of cooperative research...

26 CFR 601.802 - Cooperative agreements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 20 2011-04-01 2011-04-01 false Cooperative agreements. 601.802 Section 601.802... STATEMENT OF PROCEDURAL RULES Tax Counseling for the Elderly § 601.802 Cooperative agreements. (a) General... cooperative agreements with the Internal Revenue Service. Use of cooperative agreements is in accordance with...

29 CFR 94.620 - Cooperative agreement.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 1 2014-07-01 2013-07-01 true Cooperative agreement. 94.620 Section 94.620 Labor Office of...) Definitions § 94.620 Cooperative agreement. Cooperative agreement means an award of financial assistance that... cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

7 CFR 1491.20 - Cooperative agreements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 10 2011-01-01 2011-01-01 false Cooperative agreements. 1491.20 Section 1491.20... Cooperative Agreements and Conservation Easement Deeds § 1491.20 Cooperative agreements. (a) NRCS, on behalf of CCC, shall enter into a cooperative agreement with those entities selected for funding. Once a...

36 CFR 212.3 - Cooperative work.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Cooperative work. 212.3... MANAGEMENT Administration of the Forest Transportation System § 212.3 Cooperative work. (a) Cooperative... for expenditure from the appropriation “Cooperative Work, Forest Service.” If a State, county or other...

Helping Children Cooperate

ERIC Educational Resources Information Center

Pica, Rae

2011-01-01

There are occasions in life when the competitive process is appropriate. But when people consider the relationships in their lives--with friends, family members, coworkers, and the larger community--they realize the value of cooperation. When adults give children the chance to cooperate, to work together toward a solution or a common goal like…

Testimony: Writing Cooperatively.

ERIC Educational Resources Information Center

Sasser, Linda; Cromwell, Carole

A lesson plan and supportive materials for an exercise in reading comprehension and cooperative writing are presented. The exercise is based on a story entitled "Testimony," in which a writer expresses feelings about a boxing match. The lesson plan outlines procedures for presentation of the exercise to the class, for the cooperative teams to…

Political Ideology, Trust, and Cooperation

PubMed Central

Balliet, Daniel; Tybur, Joshua M.; Wu, Junhui; Antonellis, Christian; Van Lange, Paul A. M.

2016-01-01

Theories suggest that political ideology relates to cooperation, with conservatives being more likely to pursue selfish outcomes, and liberals more likely to pursue egalitarian outcomes. In study 1, we examine how political ideology and political party affiliation (Republican vs. Democrat) predict cooperation with a partner who self-identifies as Republican or Democrat in two samples before (n = 362) and after (n = 366) the 2012 US presidential election. Liberals show slightly more concern for their partners’ outcomes compared to conservatives (study 1), and in study 2 this relation is supported by a meta-analysis (r = .15). However, in study 1, political ideology did not relate to cooperation in general. Both Republicans and Democrats extend more cooperation to their in-group relative to the out-group, and this is explained by expectations of cooperation from in-group versus out-group members. We discuss the relation between political ideology and cooperation within and between groups. PMID:29593363

Soft cooperation systems and games

NASA Astrophysics Data System (ADS)

Fernández, J. R.; Gallego, I.; Jiménez-Losada, A.; Ordóñez, M.

2018-04-01

A cooperative game for a set of agents establishes a fair allocation of the profit obtained for their cooperation. In order to obtain this allocation, a characteristic function is known. It establishes the profit of each coalition of agents if this coalition decides to act alone. Originally players are considered symmetric and then the allocation only depends on the characteristic function; this paper is about cooperative games with an asymmetric set of agents. We introduced cooperative games with a soft set of agents which explains those parameters determining the asymmetry among them in the cooperation. Now the characteristic function is defined not over the coalitions but over the soft coalitions, namely the profit depends not only on the formed coalition but also on the attributes considered for the players in the coalition. The best known of the allocation rules for cooperative games is the Shapley value. We propose a Shapley kind solution for soft games.

17 CFR 202.12 - Policy statement concerning cooperation by individuals in its investigations and related...

Code of Federal Regulations, 2010 CFR

2010-04-01

..., in the case of a violation involving a business organization, by notifying members of management not... enforcement actions can contribute significantly to the success of the agency's mission. Cooperation can enhance the Commission's ability to detect violations of the federal securities laws, increase the...

17 CFR 202.12 - Policy statement concerning cooperation by individuals in its investigations and related...

Code of Federal Regulations, 2011 CFR

2011-04-01

..., in the case of a violation involving a business organization, by notifying members of management not... enforcement actions can contribute significantly to the success of the agency's mission. Cooperation can enhance the Commission's ability to detect violations of the federal securities laws, increase the...

Hierarchy is Detrimental for Human Cooperation.

PubMed

Cronin, Katherine A; Acheson, Daniel J; Hernández, Penélope; Sánchez, Angel

2015-12-22

Studies of animal behavior consistently demonstrate that the social environment impacts cooperation, yet the effect of social dynamics has been largely excluded from studies of human cooperation. Here, we introduce a novel approach inspired by nonhuman primate research to address how social hierarchies impact human cooperation. Participants competed to earn hierarchy positions and then could cooperate with another individual in the hierarchy by investing in a common effort. Cooperation was achieved if the combined investments exceeded a threshold, and the higher ranked individual distributed the spoils unless control was contested by the partner. Compared to a condition lacking hierarchy, cooperation declined in the presence of a hierarchy due to a decrease in investment by lower ranked individuals. Furthermore, hierarchy was detrimental to cooperation regardless of whether it was earned or arbitrary. These findings mirror results from nonhuman primates and demonstrate that hierarchies are detrimental to cooperation. However, these results deviate from nonhuman primate findings by demonstrating that human behavior is responsive to changing hierarchical structures and suggests partnership dynamics that may improve cooperation. This work introduces a controlled way to investigate the social influences on human behavior, and demonstrates the evolutionary continuity of human behavior with other primate species.

Kin competition and the evolution of cooperation

PubMed Central

Platt, Thomas G.; Bever, James D.

2017-01-01

Kin and multilevel selection theories predict that genetic structure is required for the evolution of cooperation. However, local competition among relatives can limit cooperative benefits, antagonizing the evolution of cooperation. We show that several ecological factors determine the extent to which kin competition constrains cooperative benefits. In addition, we argue that cooperative acts that expand local carrying capacity are less constrained by kin competition than other cooperative traits, and are therefore more likely to evolve. These arguments are particularly relevant to microbial cooperation, which often involves the production of public goods that promote population expansion. The challenge now is to understand how an organism’s ecology influences how much cooperative groups contribute to future generations and thereby the evolution of cooperation. PMID:19409651

China's Rural Cooperative Medical Scheme: a type of health insurance or a type of health cooperative?

PubMed

Wang, Fang; Liang, Yuan

2017-03-01

The Cooperative Medical Scheme (CMS) was popular in rural China in the 1960s and 1970s, having garnered praise from the World Bank and World Health Organization as an unprecedented example of a successful health care model in a low-income developing country. However, the CMS almost collapsed in the 1980s. Based on its historical origins and main activities, we think the CMS functioned as a health cooperative rather than a health insurance scheme. Perhaps, however, the importance to the CMS of cooperation between institutions has been overestimated. Overlooked, yet equally important, has been the cooperation between health workers and farmers to target health-related risk factors associated with agricultural work and ways of life. The 'cooperative' character of the CMS includes two aspects: cooperative institutions and cooperative behaviour. Although the CMS collapsed in China, similar schemes are flourishing elsewhere in the world. In the future, in-depth analysis of these schemes is required.

Defectors Can Create Conditions That Rescue Cooperation

PubMed Central

Waite, Adam James; Cannistra, Caroline; Shou, Wenying

2015-01-01

Cooperation based on the production of costly common goods is observed throughout nature. This is puzzling, as cooperation is vulnerable to exploitation by defectors which enjoy a fitness advantage by consuming the common good without contributing fairly. Depletion of the common good can lead to population collapse and the destruction of cooperation. However, population collapse implies small population size, which, in a structured population, is known to favor cooperation. This happens because small population size increases variability in cooperator frequency across different locations. Since individuals in cooperator-dominated locations (which are most likely cooperators) will grow more than those in defector-dominated locations (which are most likely defectors), cooperators can outgrow defectors globally despite defectors outgrowing cooperators in each location. This raises the possibility that defectors can lead to conditions that sometimes rescue cooperation from defector-induced destruction. We demonstrate multiple mechanisms through which this can occur, using an individual-based approach to model stochastic birth, death, migration, and mutation events. First, during defector-induced population collapse, defectors occasionally go extinct before cooperators by chance, which allows cooperators to grow. Second, empty locations, either preexisting or created by defector-induced population extinction, can favor cooperation because they allow cooperator but not defector migrants to grow. These factors lead to the counterintuitive result that the initial presence of defectors sometimes allows better survival of cooperation compared to when defectors are initially absent. Finally, we find that resource limitation, inducible by defectors, can select for mutations adaptive to resource limitation. When these mutations are initially present at low levels or continuously generated at a moderate rate, they can favor cooperation by further reducing local population size

22 CFR 133.620 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Cooperative agreement. 133.620 Section 133.620... (FINANCIAL ASSISTANCE) Definitions § 133.620 Cooperative agreement. Cooperative agreement means an award of... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

34 CFR 84.620 - Cooperative agreement.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 34 Education 1 2013-07-01 2013-07-01 false Cooperative agreement. 84.620 Section 84.620 Education... (FINANCIAL ASSISTANCE) Definitions § 84.620 Cooperative agreement. Cooperative agreement means an award of... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a...

50 CFR 81.3 - Cooperative Agreement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Cooperative Agreement. 81.3 Section 81.3... SPECIES OF FISH, WILDLIFE, AND PLANTS-COOPERATION WITH THE STATES § 81.3 Cooperative Agreement. Upon... Secretary shall enter into an Agreement with the State. A Cooperative Agreement is necessary before a...

50 CFR 81.3 - Cooperative Agreement.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Cooperative Agreement. 81.3 Section 81.3... SPECIES OF FISH, WILDLIFE, AND PLANTS-COOPERATION WITH THE STATES § 81.3 Cooperative Agreement. Upon... Secretary shall enter into an Agreement with the State. A Cooperative Agreement is necessary before a...

22 CFR 133.620 - Cooperative agreement.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Cooperative agreement. 133.620 Section 133.620... (FINANCIAL ASSISTANCE) Definitions § 133.620 Cooperative agreement. Cooperative agreement means an award of... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

34 CFR 84.620 - Cooperative agreement.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 1 2014-07-01 2014-07-01 false Cooperative agreement. 84.620 Section 84.620 Education... (FINANCIAL ASSISTANCE) Definitions § 84.620 Cooperative agreement. Cooperative agreement means an award of... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a...

22 CFR 1008.620 - Cooperative agreement.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Cooperative agreement. 1008.620 Section 1008.620... ASSISTANCE) Definitions § 1008.620 Cooperative agreement. Cooperative agreement means an award of financial... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

22 CFR 1509.620 - Cooperative agreement.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Cooperative agreement. 1509.620 Section 1509.620... (FINANCIAL ASSISTANCE) Definitions § 1509.620 Cooperative agreement. Cooperative agreement means an award of... award. The term does not include cooperative research and development agreements as defined in 15 U.S.C...

22 CFR 133.620 - Cooperative agreement.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Cooperative agreement. 133.620 Section 133.620... (FINANCIAL ASSISTANCE) Definitions § 133.620 Cooperative agreement. Cooperative agreement means an award of... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

45 CFR 1155.620 - Cooperative agreement.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 3 2013-10-01 2013-10-01 false Cooperative agreement. 1155.620 Section 1155.620... ASSISTANCE) Definitions § 1155.620 Cooperative agreement. Cooperative agreement means an award of financial... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

22 CFR 1509.620 - Cooperative agreement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Cooperative agreement. 1509.620 Section 1509.620... (FINANCIAL ASSISTANCE) Definitions § 1509.620 Cooperative agreement. Cooperative agreement means an award of... award. The term does not include cooperative research and development agreements as defined in 15 U.S.C...

34 CFR 84.620 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false Cooperative agreement. 84.620 Section 84.620 Education... (FINANCIAL ASSISTANCE) Definitions § 84.620 Cooperative agreement. Cooperative agreement means an award of... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a...

45 CFR 1155.620 - Cooperative agreement.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 3 2011-10-01 2011-10-01 false Cooperative agreement. 1155.620 Section 1155.620... ASSISTANCE) Definitions § 1155.620 Cooperative agreement. Cooperative agreement means an award of financial... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

45 CFR 1155.620 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Cooperative agreement. 1155.620 Section 1155.620... ASSISTANCE) Definitions § 1155.620 Cooperative agreement. Cooperative agreement means an award of financial... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

22 CFR 210.620 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Cooperative agreement. 210.620 Section 210.620... (FINANCIAL ASSISTANCE) Definitions § 210.620 Cooperative agreement. Cooperative agreement means an award of... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

45 CFR 1173.620 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Cooperative agreement. 1173.620 Section 1173.620... (FINANCIAL ASSISTANCE) Definitions § 1173.620 Cooperative agreement. Cooperative agreement means an award of... award. The term does not include cooperative research and development agreements as defined in 15 U.S.C...

22 CFR 1008.620 - Cooperative agreement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Cooperative agreement. 1008.620 Section 1008.620... ASSISTANCE) Definitions § 1008.620 Cooperative agreement. Cooperative agreement means an award of financial... term does not include cooperative research and development agreements as defined in 15 U.S.C. 3710a. ...

Cooperative Learning in Elementary Schools

ERIC Educational Resources Information Center

Slavin, Robert E.

2015-01-01

Cooperative learning refers to instructional methods in which students work in small groups to help each other learn. Although cooperative learning methods are used for different age groups, they are particularly popular in elementary (primary) schools. This article discusses methods and theoretical perspectives on cooperative learning for the…

The Hard Problem of Cooperation

PubMed Central

Eriksson, Kimmo; Strimling, Pontus

2012-01-01

Based on individual variation in cooperative inclinations, we define the “hard problem of cooperation” as that of achieving high levels of cooperation in a group of non-cooperative types. Can the hard problem be solved by institutions with monitoring and sanctions? In a laboratory experiment we find that the answer is affirmative if the institution is imposed on the group but negative if development of the institution is left to the group to vote on. In the experiment, participants were divided into groups of either cooperative types or non-cooperative types depending on their behavior in a public goods game. In these homogeneous groups they repeatedly played a public goods game regulated by an institution that incorporated several of the key properties identified by Ostrom: operational rules, monitoring, rewards, punishments, and (in one condition) change of rules. When change of rules was not possible and punishments were set to be high, groups of both types generally abided by operational rules demanding high contributions to the common good, and thereby achieved high levels of payoffs. Under less severe rules, both types of groups did worse but non-cooperative types did worst. Thus, non-cooperative groups profited the most from being governed by an institution demanding high contributions and employing high punishments. Nevertheless, in a condition where change of rules through voting was made possible, development of the institution in this direction was more often voted down in groups of non-cooperative types. We discuss the relevance of the hard problem and fit our results into a bigger picture of institutional and individual determinants of cooperative behavior. PMID:22792282

Cooperation and depressive symptoms.

PubMed

Brendan Clark, C; Thorne, Christopher B; Hardy, Sonya; Cropsey, Karen L

2013-09-25

Deficits in pro-social cooperation are common in many individuals with mental illnesses such as depression. For decades, researchers have used economic game paradigms to compare cross-cultural cooperative behavior. However, research using economic games to assess cooperative behavior in clinical populations is in the early stages. We hypothesized that individuals with greater depressive symptoms would struggle to maintain reciprocity in iterative games, but not in single-iteration games measuring personal values. Participants (n=41) played four computer-based economic games (prisoner's dilemma, the public goods game, the ultimatum game, and the trust game) measuring different aspects of cooperation. Participants completed the Depression Anxiety and Stress Scale (DASS) and other measures of personality and demographics. Analyses assessed the relationships between game performance and psychological distress as measured by the DASS. Significant correlations were found between game performance and depressive symptoms, but not symptoms of anxiety or stress. Performance in the prisoner's dilemma and public goods game was significantly related to depression in a linear regression even when known associations with depressive affect such as age, gender, race, education, marital status, and neuroticism were controlled for. Depressive symptoms were associated with an inability to sustain reciprocal cooperation. Participants showed the predicted deficits in cooperation in these economic games. Economic games show the potential for assessing the social deficits associated with depressive symptoms. © 2013 Elsevier B.V. All rights reserved.

Achieving cooperative success

Treesearch

Kimberly Zeuli

2006-01-01

Success of a cooperative depends on the foundation built during its organization. Successful businesses are not started overnight. Careful and deliberate planning must be started long before the co-op opens its doors. This chapter begins with an outline of six fundamental steps that should be followed when organizing any cooperative. From initial concept to the start...

10 CFR 603.1240 - Cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Cooperative agreement. 603.1240 Section 603.1240 Energy... Used in this Part § 603.1240 Cooperative agreement. A legal instrument which, consistent with 31 U.S.C... carrying out the activity contemplated by the cooperative agreement. The term does not include “cooperative...

Does intuition cause cooperation?

PubMed

Verkoeijen, Peter P J L; Bouwmeester, Samantha

2014-01-01

Recently, researchers claimed that people are intuitively inclined to cooperate with reflection causing them to behave selfishly. Empirical support for this claim came from experiments using a 4-player public goods game with a marginal return of 0.5 showing that people contributed more money to a common project when they had to decide quickly (i.e., a decision based on intuition) than when they were instructed to reflect and decide slowly. This intuitive-cooperation effect is of high scientific and practical importance because it argues against a central assumption of traditional economic and evolutionary models. The first experiment of present study was set up to examine the generality of the intuitive-cooperation effect and to further validate the experimental task producing the effect. In Experiment 1, we investigated Amazon Mechanical Turk (AMT) workers' contributions to a 4-player public goods game with a marginal return of 0.5 while we manipulated the knowledge about the other players' contribution to the public goods game (contribution known vs. contribution unknown), the identity of the other players (humans vs. computers randomly generating contributions) and the time constraint (time pressure/intuition vs. forced delay/reflection). However, the results of Experiment 1 failed to reveal an intuitive-cooperation effect. Furthermore, four subsequent direct replications attempts with AMT workers (Experiments 2a, 2b, 2c and Experiment 3, which was conducted with naïve/inexperienced participants) also failed to demonstrate intuitive-cooperation effects. Taken together, the results of the present study could not corroborate the idea that people are intuitively cooperative, hence suggesting that the theoretical relationship between intuition and cooperation should be further scrutinized.

Does Intuition Cause Cooperation?

PubMed Central

Verkoeijen, Peter P. J. L.; Bouwmeester, Samantha

2014-01-01

Recently, researchers claimed that people are intuitively inclined to cooperate with reflection causing them to behave selfishly. Empirical support for this claim came from experiments using a 4-player public goods game with a marginal return of 0.5 showing that people contributed more money to a common project when they had to decide quickly (i.e., a decision based on intuition) than when they were instructed to reflect and decide slowly. This intuitive-cooperation effect is of high scientific and practical importance because it argues against a central assumption of traditional economic and evolutionary models. The first experiment of present study was set up to examine the generality of the intuitive-cooperation effect and to further validate the experimental task producing the effect. In Experiment 1, we investigated Amazon Mechanical Turk (AMT) workers' contributions to a 4-player public goods game with a marginal return of 0.5 while we manipulated the knowledge about the other players' contribution to the public goods game (contribution known vs. contribution unknown), the identity of the other players (humans vs. computers randomly generating contributions) and the time constraint (time pressure/intuition vs. forced delay/reflection). However, the results of Experiment 1 failed to reveal an intuitive-cooperation effect. Furthermore, four subsequent direct replications attempts with AMT workers (Experiments 2a, 2b, 2c and Experiment 3, which was conducted with naïve/inexperienced participants) also failed to demonstrate intuitive-cooperation effects. Taken together, the results of the present study could not corroborate the idea that people are intuitively cooperative, hence suggesting that the theoretical relationship between intuition and cooperation should be further scrutinized. PMID:24801381

Cooperative answers in database systems

NASA Technical Reports Server (NTRS)

Gaasterland, Terry; Godfrey, Parke; Minker, Jack; Novik, Lev

1993-01-01

A major concern of researchers who seek to improve human-computer communication involves how to move beyond literal interpretations of queries to a level of responsiveness that takes the user's misconceptions, expectations, desires, and interests into consideration. At Maryland, we are investigating how to better meet a user's needs within the framework of the cooperative answering system of Gal and Minker. We have been exploring how to use semantic information about the database to formulate coherent and informative answers. The work has two main thrusts: (1) the construction of a logic formula which embodies the content of a cooperative answer; and (2) the presentation of the logic formula to the user in a natural language form. The information that is available in a deductive database system for building cooperative answers includes integrity constraints, user constraints, the search tree for answers to the query, and false presuppositions that are present in the query. The basic cooperative answering theory of Gal and Minker forms the foundation of a cooperative answering system that integrates the new construction and presentation methods. This paper provides an overview of the cooperative answering strategies used in the CARMIN cooperative answering system, an ongoing research effort at Maryland. Section 2 gives some useful background definitions. Section 3 describes techniques for collecting cooperative logical formulae. Section 4 discusses which natural language generation techniques are useful for presenting the logic formula in natural language text. Section 5 presents a diagram of the system.

Amplify-and-forward cooperative diversity for green UWB-based WBSNs.

PubMed

Shaban, Heba; Abou El-Nasr, Mohamad

2013-01-01

This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e - 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs.

Amplify-and-Forward Cooperative Diversity for Green UWB-Based WBSNs

PubMed Central

2013-01-01

This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e − 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs. PMID:24307880

The Gulf Cooperation Council.

PubMed

Tompkins, Olga

2012-06-01

The Gulf Cooperation Council was formed in 1981 to create economic, scientific, and business cooperation among its members. The opportunity exists for scientific collaboration on nursing education, practice, and research. Copyright 2012, SLACK Incorporated.

Resilient cooperators stabilize long-run cooperation in the finitely repeated Prisoner's Dilemma

PubMed Central

Mao, Andrew; Dworkin, Lili; Suri, Siddharth; Watts, Duncan J.

2017-01-01

Learning in finitely repeated games of cooperation remains poorly understood in part because their dynamics play out over a timescale exceeding that of traditional lab experiments. Here, we report results of a virtual lab experiment in which 94 subjects play up to 400 ten-round games of Prisoner's Dilemma over the course of twenty consecutive weekdays. Consistent with previous work, the typical round of first defection moves earlier for several days; however, this unravelling process stabilizes after roughly one week. Analysing individual strategies, we find that approximately 40% of players behave as resilient cooperators who avoid unravelling even at significant cost to themselves. Finally, using a standard learning model we predict that a sufficiently large minority of resilient cooperators can permanently stabilize unravelling among a majority of rational players. These results shed hopeful light on the long-term dynamics of cooperation, and demonstrate the importance of long-run experiments. PMID:28082739

Costly punishment and cooperation in the evolutionary snowdrift game

NASA Astrophysics Data System (ADS)

Xu, C.; Ji, M.; Yap, Yee Jiun; Zheng, Da-Fang; Hui, P. M.

2011-05-01

The role of punishments in promoting cooperation is an important issue. We incorporate costly punishments into the snowdrift game (SG) by introducing a third punishing (P) character, and study the effects. The punishers, who carry basically a cooperative (C) character, are willing to pay a cost α so as to punish a non-cooperative (D) opponent by β. Depending on the initial fractions of the characters, α, β, and the cost-to-benefit ratio r in the SG, the three-character system evolves into a steady state consisting either only of C and P characters or only of C and D characters, in a well-mixed population. The former situation represents an enhancement in cooperation relative to the SG, while the latter is similar to the SG. The dynamics in approaching these different steady states are found to be different. Analytically, the key features in the dynamics and the steady states observed in simulations are captured by a set of differential equations. The sensitivity to the initial distribution of characters is studied by depicting the flow in a phase portrait and analyzing the nature of fixed points. The analysis also shows the role of P-character agents in preventing a system from invasion by D-character agents. Starting from a population consisting only of C and P agents, a D-character agent intended to invade the system cannot survive when the initial fraction of P agents is greater than r/β. Our model, defined intentionally as a simulation algorithm, can be readily generalized to incorporate many interesting effects, such as those in a networked population.

26 CFR 1.1382-3 - Taxable income of cooperatives; special deductions for exempt farmers' cooperatives.

Code of Federal Regulations, 2010 CFR

2010-04-01

... deductions for exempt farmers' cooperatives. 1.1382-3 Section 1.1382-3 Internal Revenue INTERNAL REVENUE... Patrons § 1.1382-3 Taxable income of cooperatives; special deductions for exempt farmers' cooperatives. (a) In general. (1) Section 1382(c) provides that in determining the taxable income of a farmers', fruit...

Social learning in cooperative dilemmas

PubMed Central

Lamba, Shakti

2014-01-01

Helping is a cornerstone of social organization and commonplace in human societies. A major challenge for the evolutionary sciences is to explain how cooperation is maintained in large populations with high levels of migration, conditions under which cooperators can be exploited by selfish individuals. Cultural group selection models posit that such large-scale cooperation evolves via selection acting on populations among which behavioural variation is maintained by the cultural transmission of cooperative norms. These models assume that individuals acquire cooperative strategies via social learning. This assumption remains empirically untested. Here, I test this by investigating whether individuals employ conformist or payoff-biased learning in public goods games conducted in 14 villages of a forager–horticulturist society, the Pahari Korwa of India. Individuals did not show a clear tendency to conform or to be payoff-biased and are highly variable in their use of social learning. This variation is partly explained by both individual and village characteristics. The tendency to conform decreases and to be payoff-biased increases as the value of the modal contribution increases. These findings suggest that the use of social learning in cooperative dilemmas is contingent on individuals' circumstances and environments, and question the existence of stably transmitted cultural norms of cooperation. PMID:24870041

Evolution of cooperation with shared costs and benefits

PubMed Central

Brown, Joel S; Vincent, Thomas L

2008-01-01

The quest to determine how cooperation evolves can be based on evolutionary game theory, in spite of the fact that evolutionarily stable strategies (ESS) for most non-zero-sum games are not cooperative. We analyse the evolution of cooperation for a family of evolutionary games involving shared costs and benefits with a continuum of strategies from non-cooperation to total cooperation. This cost–benefit game allows the cooperator to share in the benefit of a cooperative act, and the recipient to be burdened with a share of the cooperator's cost. The cost–benefit game encompasses the Prisoner's Dilemma, Snowdrift game and Partial Altruism. The models produce ESS solutions of total cooperation, partial cooperation, non-cooperation and coexistence between cooperation and non-cooperation. Cooperation emerges from an interplay between the nonlinearities in the cost and benefit functions. If benefits increase at a decelerating rate and costs increase at an accelerating rate with the degree of cooperation, then the ESS has an intermediate level of cooperation. The game also exhibits non-ESS points such as unstable minima, convergent-stable minima and unstable maxima. The emergence of cooperative behaviour in this game represents enlightened self-interest, whereas non-cooperative solutions illustrate the Tragedy of the Commons. Games having either a stable maximum or a stable minimum have the property that small changes in the incentive structure (model parameter values) or culture (starting frequencies of strategies) result in correspondingly small changes in the degree of cooperation. Conversely, with unstable maxima or unstable minima, small changes in the incentive structure or culture can result in a switch from non-cooperation to total cooperation (and vice versa). These solutions identify when human or animal societies have the potential for cooperation and whether cooperation is robust or fragile. PMID:18495622

Hierarchy is Detrimental for Human Cooperation

PubMed Central

Cronin, Katherine A.; Acheson, Daniel J.; Hernández, Penélope; Sánchez, Angel

2015-01-01

Studies of animal behavior consistently demonstrate that the social environment impacts cooperation, yet the effect of social dynamics has been largely excluded from studies of human cooperation. Here, we introduce a novel approach inspired by nonhuman primate research to address how social hierarchies impact human cooperation. Participants competed to earn hierarchy positions and then could cooperate with another individual in the hierarchy by investing in a common effort. Cooperation was achieved if the combined investments exceeded a threshold, and the higher ranked individual distributed the spoils unless control was contested by the partner. Compared to a condition lacking hierarchy, cooperation declined in the presence of a hierarchy due to a decrease in investment by lower ranked individuals. Furthermore, hierarchy was detrimental to cooperation regardless of whether it was earned or arbitrary. These findings mirror results from nonhuman primates and demonstrate that hierarchies are detrimental to cooperation. However, these results deviate from nonhuman primate findings by demonstrating that human behavior is responsive to changing hierarchical structures and suggests partnership dynamics that may improve cooperation. This work introduces a controlled way to investigate the social influences on human behavior, and demonstrates the evolutionary continuity of human behavior with other primate species. PMID:26692287

Static network structure can stabilize human cooperation.

PubMed

Rand, David G; Nowak, Martin A; Fowler, James H; Christakis, Nicholas A

2014-12-02

The evolution of cooperation in network-structured populations has been a major focus of theoretical work in recent years. When players are embedded in fixed networks, cooperators are more likely to interact with, and benefit from, other cooperators. In theory, this clustering can foster cooperation on fixed networks under certain circumstances. Laboratory experiments with humans, however, have thus far found no evidence that fixed network structure actually promotes cooperation. Here, we provide such evidence and help to explain why others failed to find it. First, we show that static networks can lead to a stable high level of cooperation, outperforming well-mixed populations. We then systematically vary the benefit that cooperating provides to one's neighbors relative to the cost required to cooperate (b/c), as well as the average number of neighbors in the network (k). When b/c > k, we observe high and stable levels of cooperation. Conversely, when b/c ≤ k or players are randomly shuffled, cooperation decays. Our results are consistent with a quantitative evolutionary game theoretic prediction for when cooperation should succeed on networks and, for the first time to our knowledge, provide an experimental demonstration of the power of static network structure for stabilizing human cooperation.