COOPERATIVE PLAY AFFECTS SOCIAL INTERACTION OF CHILDREN WHO HAVE INTROVERT PERSONALITY

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Ira Rahmawati

2017-04-01

Full Text Available Introduction: One of school age children may developing task is learning to interact with their peer groups. The introvert have problem with their social interaction. One ways that can increase the social skill is play activities with social situation. So social play activities: cooperative play can be one of alternative solution to increase social interaction of children with introvert symptom. This study was aimed to explain effect of social play activities: cooperative play on social interaction of children with introvert symptom. Method: Quasy experiment design was used in this study. The population was school aged children with introvert symptom in SDN Kendangsari III/278 Surabaya. Total sample was 23 respondents consist of 12 respondents as treatment group and 11 respondents as controlled group. The independent variable was social play activities: cooperative play. The dependent was social interaction of children with introvert symptom. The Data was analyzed by Wilcoxon Signed Rank Test and Mann Whitney U Test with level significance ofα ≤ 0.005. Result: Result showed that social play activities: cooperative play had significant effect on social interaction of children with introvert symptom (increased. Wilcoxon Signed Rank Test showed treatment group had p = 0.002 and controlled group had p = 1.00. Mann Whitney U Test showed p = 0.002. Discussion: It concluded that social play activities: cooperative play can be one way to change social interaction of children with introvert symptom. Further studies should involve larger respondents and better measurement tools to obtain more accurate results.

Cooperation among strangers: an experiment with indefinite interaction

OpenAIRE

Gabriele Camera; Marco Casari

2007-01-01

We study the emergence of norms of cooperation in experimental economies populated by strangers interacting indefinitely and lacking formal enforcement institutions. In all treatments the efficient outcome is sustainable as an equilibrium. We address the following questions: can these economies achieve full efficiency? Which institutions for monitoring and enforcement promote cooperation? Finally, what classes of strategies are employed to achieve high efficiency? We find that, first, coopera...

Game theory in communication networks cooperative resolution of interactive networking scenarios

CERN Document Server

Antoniou, Josephina

2012-01-01

A mathematical tool for scientists and researchers who work with computer and communication networks, Game Theory in Communication Networks: Cooperative Resolution of Interactive Networking Scenarios addresses the question of how to promote cooperative behavior in interactive situations between heterogeneous entities in communication networking scenarios. It explores network design and management from a theoretical perspective, using game theory and graph theory to analyze strategic situations and demonstrate profitable behaviors of the cooperative entities. The book promotes the use of Game T

Impact of self interaction on the evolution of cooperation in social spatial dilemmas

International Nuclear Information System (INIS)

Ding, Chenxi; Wang, Juan; Zhang, Ying

2016-01-01

Highlights: • A self interaction mechanism is integrated into two classical game models (PDG and SDG). • An additional payoff will be awarded into the cooperative agents for the payoff calculation. • Beyond the fixed interaction strength, distributed interaction strength is considered. • The collective cooperation can be drastically elevated into a higher level. - Abstract: In this paper, a new self interaction mechanism is integrated into two typical pairwise models including the prisoner’s dilemma and snowdrift games, where an additional payoff will be awarded into the cooperative agents. In the prisoner’s dilemma game, we take three types of additional payoffs into account, to be a fixed constant, a random value situated within the positive unilateral interval and a random one uniformly distributed within a bilateral interval. Large quantities of numerical simulations indicate the promotion of cooperation can be very noticeable whether in the case of von Neumann neighborhood or Moore neighborhood. In the meantime, the self interaction will also be extended into the snowdrift game in which two equilibria exist, and the outcomes clearly show that the collective cooperation is still drastically elevated into a higher level. Current results demonstrate that the self interaction might become a potential and effective means to enhance the behavior of cooperation, and be helpful for us to deeply understand the widespread persistence and emergence of cooperation within many animal and human being societies.

Stochastic heterogeneous interaction promotes cooperation in spatial prisoner's dilemma game.

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Ping Zhu

Full Text Available Previous studies mostly investigate player's cooperative behavior as affected by game time-scale or individual diversity. In this paper, by involving both time-scale and diversity simultaneously, we explore the effect of stochastic heterogeneous interaction. In our model, the occurrence of game interaction between each pair of linked player obeys a random probability, which is further described by certain distributions. Simulations on a 4-neighbor square lattice show that the cooperation level is remarkably promoted when stochastic heterogeneous interaction is considered. The results are then explained by investigating the mean payoffs, the mean boundary payoffs and the transition probabilities between cooperators and defectors. We also show some typical snapshots and evolution time series of the system. Finally, the 8-neighbor square lattice and BA scale-free network results indicate that the stochastic heterogeneous interaction can be robust against different network topologies. Our work may sharpen the understanding of the joint effect of game time-scale and individual diversity on spatial games.

Characterization of mRNA-cytoskeleton interactions in situ using FMTRIP and proximity ligation.

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Jeenah Jung

Full Text Available Many studies have demonstrated an association between the cytoskeleton and mRNA, as well as the asymmetric distribution of mRNA granules within the cell in response to various signaling events. It is likely that the extensive cytoskeletal network directs mRNA transport and localization, with different cytoskeletal elements having their own specific roles. In order to understand the spatiotemporal changes in the interactions between the mRNA and the cytoskeleton as a response to a stimulus, a technique that can visualize and quantify these changes across a population of cells while capturing cell-to-cell variations is required. Here, we demonstrate a method for imaging and quantifying mRNA-cytoskeleton interactions on a per cell basis with single-interaction sensitivity. Using a proximity ligation assay with flag-tagged multiply-labeled tetravalent RNA imaging probes (FMTRIP, we quantified interactions between mRNAs and β-tubulin, vimentin, or filamentous actin (F-actin for two different mRNAs, poly(A + and β-actin mRNA, in two different cell types, A549 cells and human dermal fibroblasts (HDF. We found that the mRNAs interacted predominantly with F-actin (>50% in HDF, >20% in A549 cells, compared to β-tubulin (<5% and vimentin (11-13%. This likely reflects differences in mRNA management by the two cell types. We then quantified changes in these interactions in response to two perturbations, F-actin depolymerization and arsenite-induced oxidative stress, both of which alter either the cytoskeleton itself and mRNA localization. Both perturbations led to a decrease in poly(A + mRNA interactions with F-actin and an increase in the interactions with microtubules, in a time dependent manner.

Comparison of frictional resistance of esthetic and semi-esthetic self-ligating brackets

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M S Kannan

2015-01-01

Full Text Available Aim: The frictional resistance encountered during sliding mechanics has been well established in the orthodontic literature, and it consists of complex interactions between the bracket, archwire, and method of ligation the claim of reduced friction with self-ligating brackets is often cited as a primary advantage over conventional brackets. This study was done to compare and evaluate the frictional forces generated between fully esthetic brackets and semi-aesthetic self-ligating brackets, which are of passive form and SEM (scanning electron microscope study of the Brackets after Frictional evaluation. Materials and Methods: Two types of self-ligating esthetic brackets, Damon clear (Ormco made of fully ceramic and Opal (Ultradent Products, USA and, Two types of self-ligating semi-esthetic brackets, Clarity SL (3M Unitek and Damon 3 (Ormco both of which are made of ceramic with metal slot. Arch wires with different dimensions and quality 17 × 25, 19 × 25 Titanium Molybdenum Alloy (TMA and 17 × 25, 19 × 25 stainless steel that came from plain strands of wire were used for frictional comparison test. The brackets used in this study had 0.022 × 0.028 inch slot. Results: The statistical tests showed significantly smaller amount of kinetic frictional forces is generated by Damon 3 (semi-esthetic self-ligating brackets. For each wire used, Damon 3 displayed significantly lower frictional forces (P ≤ 0.05 than any of the self-ligating system, followed by Opal (fully esthetic self-ligating brackets which generated smaller amount of frictional forces but relatively on the higher side when compared with Damon 3. Damon clear (fully esthetic self-ligating brackets generated the maximum amount of kinetic forces with all types of wire dimensions and properties when compared to the other three types of self-ligating system. Clarity SL (semi-esthetic self-ligating brackets generated smaller amount of frictional forces when compared with Damon clear and

Comparison of frictional resistance of esthetic and semi-esthetic self-ligating brackets.

Science.gov (United States)

Kannan, M S; Murali, R V; Kishorekumar, S; Gnanashanmugam, K; Jayanth, V

2015-04-01

The frictional resistance encountered during sliding mechanics has been well established in the orthodontic literature, and it consists of complex interactions between the bracket, archwire, and method of ligation the claim of reduced friction with self-ligating brackets is often cited as a primary advantage over conventional brackets. This study was done to compare and evaluate the frictional forces generated between fully esthetic brackets and semi-aesthetic self-ligating brackets, which are of passive form and SEM (scanning electron microscope) study of the Brackets after Frictional evaluation. Two types of self-ligating esthetic brackets, Damon clear (Ormco) made of fully ceramic and Opal (Ultradent Products, USA) and, Two types of self-ligating semi-esthetic brackets, Clarity SL (3M Unitek) and Damon 3 (Ormco) both of which are made of ceramic with metal slot. Arch wires with different dimensions and quality 17 × 25, 19 × 25 Titanium Molybdenum Alloy (TMA) and 17 × 25, 19 × 25 stainless steel that came from plain strands of wire were used for frictional comparison test. The brackets used in this study had 0.022 × 0.028 inch slot. The statistical tests showed significantly smaller amount of kinetic frictional forces is generated by Damon 3 (semi-esthetic self-ligating brackets). For each wire used, Damon 3 displayed significantly lower frictional forces (P ≤ 0.05) than any of the self-ligating system, followed by Opal (fully esthetic self-ligating brackets) which generated smaller amount of frictional forces but relatively on the higher side when compared with Damon 3. Damon clear (fully esthetic self-ligating brackets) generated the maximum amount of kinetic forces with all types of wire dimensions and properties when compared to the other three types of self-ligating system. Clarity SL (semi-esthetic self-ligating brackets) generated smaller amount of frictional forces when compared with Damon clear and relatively higher amount of frictional forces

[Self-ligating edgewise brackets. An overview].

Science.gov (United States)

Katsaros, C; Dijkman, J F

2003-01-01

During the last years both the manufactures and the orthodontists seem to show an increased interest in self-ligating brackets. This paper aims to present the history of self-ligating systems, to describe the three mostly used bracketsystems and to review the relevant literature. It seems from the existing data that self-ligating brackets have certain advantages over conventionally ligated brackets. However, the data are still thin and a high need for well designed clinical trials exist.

COOPERATIVE PLAY AFFECTS SOCIAL INTERACTION OF CHILDREN WHO HAVE INTROVERT PERSONALITY

OpenAIRE

Ira Rahmawati; Ah. Yusuf; Ilya Krisnana

2017-01-01

Introduction: One of school age children may developing task is learning to interact with their peer groups. The introvert have problem with their social interaction. One ways that can increase the social skill is play activities with social situation. So social play activities: cooperative play can be one of alternative solution to increase social interaction of children with introvert symptom. This study was aimed to explain effect of social play activities: cooperative play on social inter...

Seeing Cooperation or Competition: Ecological Interactions in Cultural Perspectives.

Science.gov (United States)

Ojalehto, Bethany L; Medin, Douglas L; Horton, William S; Garcia, Salino G; Kays, Estefano G

2015-10-01

Do cultural models facilitate particular ways of perceiving interactions in nature? We explore variability in folkecological principles of reasoning about interspecies interactions (specifically, competitive or cooperative). In two studies, Indigenous Panamanian Ngöbe and U.S. participants interpreted an illustrated, wordless nonfiction book about the hunting relationship between a coyote and badger. Across both studies, the majority of Ngöbe interpreted the hunting relationship as cooperative and the majority of U.S. participants as competitive. Study 2 showed that this pattern may reflect different beliefs about, and perhaps different awareness of, plausible interspecies interactions. Further probes suggest that these models of ecological interaction correlate with recognition of social agency (e.g., communication, morality) in nonhuman animals. We interpret our results in terms of cultural models of nature and nonhuman agency. Copyright © 2015 Cognitive Science Society, Inc.

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

Science.gov (United States)

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.

Structure, complexity and cooperation in parallel external chat interactions

DEFF Research Database (Denmark)

Grønning, Anette

2012-01-01

This article examines structure, complexity and cooperation in external chat interactions at the workplace in which one of the participants is taking part in multiple parallel conversations. The investigation is based on an analysis of nine chat interactions in a work-related context, with partic......This article examines structure, complexity and cooperation in external chat interactions at the workplace in which one of the participants is taking part in multiple parallel conversations. The investigation is based on an analysis of nine chat interactions in a work-related context...... focus is on “turn-taking organisation as the fundamental and generic aspect of interaction organisation” (Drew & Heritage, 1992, p. 25), including the use of turn-taking rules, adjacency pairs, and the importance of pauses. Even though the employee and the union members do not know one another...... and cannot see, hear, or touch one another, it is possible to detect an informal, pleasant tone in their interactions. This challenges the basically asymmetrical relationship between employee and customer, and one can sense a further level of asymmetry. In terms of medium, chat interactions exist via various...

Coevolution of Synchronization and Cooperation in Costly Networked Interactions

Science.gov (United States)

Antonioni, Alberto; Cardillo, Alessio

2017-06-01

Despite the large number of studies on synchronization, the hypothesis that interactions bear a cost for involved individuals has seldom been considered. The introduction of costly interactions leads, instead, to the formulation of a dichotomous scenario in which an individual may decide to cooperate and pay the cost in order to get synchronized with the rest of the population. Alternatively, the same individual can decide to free ride, without incurring any cost, waiting for others to get synchronized to his or her state. Thus, the emergence of synchronization may be seen as the byproduct of an evolutionary game in which individuals decide their behavior according to the benefit-to-cost ratio they accrued in the past. We study the onset of cooperation and synchronization in networked populations of Kuramoto oscillators and report how topology is essential in order for cooperation to thrive. We also display how different classes of topology foster synchronization differently both at microscopic and macroscopic levels.

Evolution of interactions and cooperation in the spatial prisoner's dilemma game.

Directory of Open Access Journals (Sweden)

Chunyan Zhang

Full Text Available We study the evolution of cooperation in the spatial prisoner's dilemma game where players are allowed to establish new interactions with others. By employing a simple coevolutionary rule entailing only two crucial parameters, we find that different selection criteria for the new interaction partners as well as their number vitally affect the outcome of the game. The resolution of the social dilemma is most probable if the selection favors more successful players and if their maximally attainable number is restricted. While the preferential selection of the best players promotes cooperation irrespective of game parametrization, the optimal number of new interactions depends somewhat on the temptation to defect. Our findings reveal that the "making of new friends" may be an important activity for the successful evolution of cooperation, but also that partners must be selected carefully and their number limited.

Spectrum of menstrual problems after tubal ligation

International Nuclear Information System (INIS)

Naqvi, S.S.B.; Akthar, S.; Mubeen, A.; Noor, A.

2014-01-01

To determine the frequency of menstrual problems after tubal ligation. Study Design: Descriptive study. Place and Duration of Study: This study was carried out in gynae department of PAF Hospital Sargodha, Pakistan from September 2011 to September 2012. Patients and methods: Two hundred patients were included in the study with menstrual problems after tubal ligation. Results: Forty seven percent of patients presented with menorrhagia, 28% presented with metrorrhagia, 13% patients were having complaints of polymenorrhoea and 5% patients presented with dysmenorrhea and 7% had oligomenorrhoea after tubal ligation. Thirty one percent of patients ended up in hysterectomy and 37% of patients had improvement of symptoms with medical treatment. Conclusion: Menstrual problem is a common complaint in our gyn ecological patients. A large number of these patients had history of tubal ligation. Menorrhagia, metrorrhagia, polymenorrhoea and dysmenorrhoea can occur after tubal ligation. Patients giving the history of menstrual problems and wants tubal ligation should be counselled earlier for these symptoms. (author)

Orchidopexy san ligation technique of orchidopexy

Directory of Open Access Journals (Sweden)

Jain Vishal

2011-01-01

Full Text Available Pediatric hernia surgery is the most common operation done by pediatric general surgeons and it is a core competency for general surgeons in the developing world. Herniotomy is performed for the surgical repair of hernia and along with orchiopexy for the closure of associated patent processus vaginalis. Traditionally, ligation of hernial sac during orchiopexy is considered mandatory to prevent postoperative development of hernia. The present report was designed to study the results of non-ligation of the hernial sac during orchiopexy. It was found that non-ligation has no untoward effect on early complications and recurrence rate on long-term follow-up. It is suggested that it is not necessary to ligate the hernial sac during orchiopexy in children.

Learning Microbiology Through Cooperation: Designing Cooperative Learning Activities that Promote Interdependence, Interaction, and Accountability

Directory of Open Access Journals (Sweden)

Janine E. Trempy

2009-12-01

Full Text Available A microbiology course and its corresponding learning activities have been structured according to the Cooperative Learning Model. This course, The World According to Microbes, integrates science, math, engineering, and technology (SMET majors and non-SMET majors into teams of students charged with problem solving activities that are microbial in origin. In this study we describe development of learning activities that utilize key components of Cooperative Learning—positive interdependence, promotive interaction, individual accountability, teamwork skills, and group processing. Assessments and evaluations over an 8-year period demonstrate high retention of key concepts in microbiology and high student satisfaction with the course.

Interactions between personality and institutions in cooperative behaviour in humans

Science.gov (United States)

Schroeder, K. B.; Nettle, D.; McElreath, R.

2015-01-01

Laboratory attempts to identify relationships between personality and cooperative behaviour in humans have generated inconsistent results. This may partially stem from different practices in psychology and economics laboratories, with both hypothetical players and incentives typical only in the former. Another possible cause is insufficient consideration of the contexts within which social dilemmas occur. Real social dilemmas are often governed by institutions that change the payoff structure via rewards and punishments. However, such ‘strong situations’ will not necessarily suppress the effects of personality. On the contrary, they may affect some personalities differentially. Extraversion and neuroticism, reflecting variation in reward and punishment sensitivity, should predict modification of cooperative behaviour following changes to the payoff structure. We investigate interactions between personality and a punishment situation via two versions of a public goods game. We find that, even in a strong situation, personality matters and, moreover, it is related to strategic shifts in cooperation. Extraversion is associated with a shift from free-riding to cooperation in the presence of punishment, agreeableness is associated with initially higher contributions regardless of game, and, contrary to our predictions, neuroticism is associated with lower contributions regardless of game. Results should lead to new hypotheses that relate variation in biological functioning to individual differences in cooperative behaviour and that consider three-way interactions among personality, institutional context and sociocultural background. PMID:26503684

Self-Regulation, Cooperative Learning, and Academic Self-Efficacy: Interactions to Prevent School Failure.

Science.gov (United States)

Fernandez-Rio, Javier; Cecchini, Jose A; Méndez-Gimenez, Antonio; Mendez-Alonso, David; Prieto, Jose A

2017-01-01

Learning to learn and learning to cooperate are two important goals for individuals. Moreover, self regulation has been identified as fundamental to prevent school failure. The goal of the present study was to assess the interactions between self-regulated learning, cooperative learning and academic self-efficacy in secondary education students experiencing cooperative learning as the main pedagogical approach for at least one school year. 2.513 secondary education students (1.308 males, 1.205 females), 12-17 years old ( M = 13.85, SD = 1.29), enrolled in 17 different schools belonging to the National Network of Schools on Cooperative Learning in Spain agreed to participate. They all had experienced this pedagogical approach a minimum of one school year. Participants were asked to complete the cooperative learning questionnaire, the strategies to control the study questionnaire and the global academic self-efficacy questionnaire. Participants were grouped based on their perceptions on cooperative learning and self-regulated learning in their classes. A combination of hierarchical and κ -means cluster analyses was used. Results revealed a four-cluster solution: cluster one included students with low levels of cooperative learning, self-regulated learning and academic self-efficacy, cluster two included students with high levels of cooperative learning, self-regulated learning and academic self-efficacy, cluster three included students with high levels of cooperative learning, low levels of self-regulated learning and intermediate-low levels of academic self-efficacy, and, finally, cluster four included students with high levels of self-regulated learning, low levels of cooperative learning, and intermediate-high levels of academic self-efficacy. Self-regulated learning was found more influential than cooperative learning on students' academic self-efficacy. In cooperative learning contexts students interact through different types of regulations: self, co, and

Self-Regulation, Cooperative Learning, and Academic Self-Efficacy: Interactions to Prevent School Failure

Science.gov (United States)

Fernandez-Rio, Javier; Cecchini, Jose A.; Méndez-Gimenez, Antonio; Mendez-Alonso, David; Prieto, Jose A.

2017-01-01

Learning to learn and learning to cooperate are two important goals for individuals. Moreover, self regulation has been identified as fundamental to prevent school failure. The goal of the present study was to assess the interactions between self-regulated learning, cooperative learning and academic self-efficacy in secondary education students experiencing cooperative learning as the main pedagogical approach for at least one school year. 2.513 secondary education students (1.308 males, 1.205 females), 12–17 years old (M = 13.85, SD = 1.29), enrolled in 17 different schools belonging to the National Network of Schools on Cooperative Learning in Spain agreed to participate. They all had experienced this pedagogical approach a minimum of one school year. Participants were asked to complete the cooperative learning questionnaire, the strategies to control the study questionnaire and the global academic self-efficacy questionnaire. Participants were grouped based on their perceptions on cooperative learning and self-regulated learning in their classes. A combination of hierarchical and κ-means cluster analyses was used. Results revealed a four-cluster solution: cluster one included students with low levels of cooperative learning, self-regulated learning and academic self-efficacy, cluster two included students with high levels of cooperative learning, self-regulated learning and academic self-efficacy, cluster three included students with high levels of cooperative learning, low levels of self-regulated learning and intermediate-low levels of academic self-efficacy, and, finally, cluster four included students with high levels of self-regulated learning, low levels of cooperative learning, and intermediate-high levels of academic self-efficacy. Self-regulated learning was found more influential than cooperative learning on students’ academic self-efficacy. In cooperative learning contexts students interact through different types of regulations: self, co, and

Artery ligation in the treatment of hemorrhoidal disease

NARCIS (Netherlands)

Schuurman, J.P.

2012-01-01

The aim of this thesis was to study the working principle in relation to the outcome of the artery ligation procedure; a treatment for hemorrhoidal disease. Hemorrhoidal artery ligation, known as HAL (hemorrhoidal artery ligation) or THD (transanal hemorrhoidal dearterialization) procedure, is a

E-cadherin homophilic ligation inhibits cell growth and epidermal growth factor receptor signaling independently of other cell interactions

DEFF Research Database (Denmark)

Perrais, Michaël; Chen, Xiao; Perez-Moreno, Mirna

2007-01-01

growth inhibitory signals. To address this question, we have selectively formed E-cadherin homophilic bonds at the cell surface of isolated epithelial cells by using functionally active recombinant E-cadherin protein attached to microspheres. We find that E-cadherin ligation alone reduces the frequency...... of cells entering the S phase, demonstrating that E-cadherin ligation directly transduces growth inhibitory signals. E-cadherin binding to beta-catenin is required for cell growth inhibition, but beta-catenin/T-cell factor transcriptional activity is not involved in growth inhibition resulting from...... homophilic binding. Neither E-cadherin binding to p120-catenin nor beta-catenin binding to alpha-catenin, and thereby the actin cytoskeleton, is required for growth inhibition. E-cadherin ligation also inhibits epidermal growth factor (EGF) receptor-mediated growth signaling by a beta...

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

Science.gov (United States)

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.

Impact of interaction style and degree on the evolution of cooperation on Barabási-Albert scale-free network.

Directory of Open Access Journals (Sweden)

Fengjie Xie

Full Text Available In this work, we study an evolutionary prisoner's dilemma game (PDG on Barabási-Albert scale-free networks with limited player interactions, and explore the effect of interaction style and degree on cooperation. The results show that high-degree preference interaction, namely the most applicable interaction in the real world, is less beneficial for emergence of cooperation on scale-free networks than random interaction. Besides, cooperation on scale-free networks is enhanced with the increase of interaction degree regardless whether the interaction is high-degree preference or random. If the interaction degree is very low, the cooperation level on scale-free networks is much lower than that on regular ring networks, which is against the common belief that scale-free networks must be more beneficial for cooperation. Our analysis indicates that the interaction relations, the strategy and the game payoff of high-connectivity players play important roles in the evolution of cooperation on scale-free networks. A certain number of interactions are necessary for scale-free networks to exhibit strong capability of facilitating cooperation. Our work provides important insight for members on how to interact with others in a social organization.

Ligation of MHC class I molecules on peripheral blood T lymphocytes induces new phenotypes and functions

DEFF Research Database (Denmark)

Bregenholt, S; Röpke, M; Skov, S

1996-01-01

of T cell-mediated cytotoxicity. Immediately following MHC-I ligation, the T cells responded with increased protein tyrosine phosphorylation, with new bands appearing in the SDS-PAGE. Exposure of T cells to immobilized anti-MHC-I Ab for 24 h induced an increased surface expression of the TCR/CD3 and CD......28 molecules. MHC-I-induced proliferation of purified T cells was dependent on cellular interactions with non-T cells. Under certain conditions, in which MHC-I was ligated by picogram concentrations of immobilized anti-MHC-I Ab, anti-TCR/CD3 Ab-induced proliferation of T cells was strongly inhibited....... These data clearly demonstrate that ligation of the MHC-I complex on T cells may induce both positive and negative signals. Since the physiologic ligands for MHC-I molecules are TCR and the CD8 molecules, our data may suggest that MHC-I molecules are instrumental in cellular interactions between T cells....

Evaluation of Micro-organism in Ligated Metal and Self-ligating Brackets using Scanning Electron Microscopy: An In Vivo Study.

Science.gov (United States)

Sunil, P C; Michael, Tony; Raju, Aravind S; Paul, Renji K; Mamatha, J; Ebin, T M

2015-07-01

The objective of the study was to determine the sites of plaque accumulation and to compare the plaque accumulated with metal and self-ligating orthodontic brackets in order to know which bracket type had a higher plaque retaining capacity. The study was done on 20 subjects who were scheduled for orthodontic treatment including extraction of four premolars and fixed orthodontic appliances. Mesh-backed edgewise metal brackets ligated with steel ligatures and self-ligating brackets were bonded to the premolars to be extracted using composite (Transbond XT, 3M). The subjects were told to continue their normal oral hygiene regimen. Teeth were extracted at 1, 2, and 3 weeks after bracket bonding. Plaque attached to the buccal surfaces was stained using plaque disclosing agent. The teeth were then immersed in fixative containing 4% formaldehyde and 1% glutaraldehyde in phosphate buffer for 24 h, followed by 0.1 M phosphate buffer for 12 h. The specimens were then mounted on aluminum stubs, and sputter coated with gold prior to Scanning electron microscopy examination. The results showed that increased retention of plaque in metal brackets ligated with steel ligatures and comparatively less in self-ligating brackets at the base of the brackets. This study highlights that higher retention of plaque in metal brackets ligated with steel ligatures and comparatively less plaque retention in self-ligating brackets. Excess composite around the bracket base is the critical site of plaque accumulation associated with fixed appliances due to its rough surface texture.

Hemorrhoidectomy: pedicle ligation vs pedicle coagulation

International Nuclear Information System (INIS)

Shaikh, B.S.; Balaoch, I.B.; Sohu, K.M.

2015-01-01

Objective: To compare the outcome of pedicle ligation vs pedicle coagulation haemorrhoidectomy. Methodology: This comparative prospective study was carried out at Department of Surgery, Ghulam Muhammad Maher Medcial College Hospital, Sukkur, Pakistan from January 2011 to January 2013 and included 300 patients of hemorrhoids. After routine workup, patients were randomly divided into two equal groups with one group receiving pedicle ligation and other pedicle coagulation for hemorrhoidectomy. Postoperatively they were followed for a period of 8 weeks for complications including pain, urinary retention, bleeding and anal stricture. Pain was recorded up to 10th postoperative day on the basis of visual analogue scale. Results: Mean age was 45 years and male to female ratio was 1.7:1. Mean operative time in pedicle ligation group was 15 min (range 14-20 min) and 17 min (15-25 min) in pedicle coagulation group. In Pedicle ligation group, pain was worst in 35 patients, moderate in 85 and mild in 30 patients; on the other hand in pedicle coagulation group, just 09 patients experienced worst pain. Urinary retention was observed in 44 patients in pedicle ligation group and 19 in pedicle coagulation group. Five patients in pedicle ligation group developed bleeding after their discharge from hospital; 7 patients in pedicle coagulation group reported secondary bleeding. Anal stricture was a rare complication and was found equally common in both the groups. Conclusion: Conventional hemorrhoidectomy with pedicle coagulation is an effective treatment modality for hemorrhoids and is associated with less chance of postoperative anal pain and urinary retention. (author)

The effect of ligation on the load deflection characteristics of nickel titanium orthodontic wire.

Science.gov (United States)

Kasuya, Shugo; Nagasaka, Satoshi; Hanyuda, Ai; Ishimura, Sadao; Hirashita, Ayao

2007-12-01

This study examined the effect of ligation on the load-deflection characteristics of nickel-titanium (NiTi) orthodontic wire. A modified three-point bending system was used for bending the NiTi round wire, which was inserted and ligated in the slots of three brackets, one of which was bonded to each of the three bender rods. Three different ligation methods, stainless steel ligature (SSL), slot lid (SL), and elastomeric ligature (EL), were employed, as well as a control with neither bracket nor ligation (NBL). The tests were repeated five times under each condition. Comparisons were made of load-deflection curve, load at maximum deflection of 2,000 microm, and load at a deflection of 1,500 microm during unloading. Analysis of Variance (ANOVA) and Dunnett's test were conducted to determine method difference (alpha = 0.05). The interaction between deflection and ligation was tested, using repeated-measures ANOVA (alpha = 0.05). The load values of the ligation groups were two to three times greater than the NBL group at a deflection of 1,500 microm during unloading: 4.37 N for EL, 3.90 N for SSL, 3.02 N for SL, and 1.49 N for NBL (P wire may make NiTi wire exhibit a significantly heavier load than that traditionally expected. NiTi wire exhibited the majority of its true superelasticity with SL, whereas EL may act as a restraint on its superelasticity.

Esophageal variceal ligation in the secondary prevention of variceal ...

African Journals Online (AJOL)

Pan African Medical Journal ... Introduction: Long-term outcome of patients after band ligation have been poorly defined. ... endoscopic band ligation, liver cirrhosis, complication of band ligation, esophageal varices, secondary prevention ...

On Cooperative Behavior in Distributed Teams: The Influence of Organizational Design, Media Richness, Social Interaction, and Interaction Adaptation.

Science.gov (United States)

Håkonsson, Dorthe D; Obel, Børge; Eskildsen, Jacob K; Burton, Richard M

2016-01-01

Self-interest vs. cooperation is a fundamental dilemma in animal behavior as well as in human and organizational behavior. In organizations, how to get people to cooperate despite or in conjunction with their self-interest is fundamental to the achievement of a common goal. While both organizational designs and social interactions have been found to further cooperation in organizations, some of the literature has received contradictory support, just as very little research, if any, has examined their joint effects in distributed organizations, where communication is usually achieved via different communication media. This paper reviews the extant literature and offers a set of hypotheses to integrate current theories and explanations. Further, it discusses how future research should examine the joint effects of media, incentives, and social interactions.

Torque expression in self-ligating orthodontic brackets and conventionally ligated brackets: A systematic review

OpenAIRE

Al-Thomali, Yousef; Mohamed, Roshan-Noor; Basha, Sakeenabi

2017-01-01

Background To evaluate the torque expression of self ligating (SL) orthodontic brackets and conventionally ligated brackets and the torque expression in active and passive SL brackets. Material and Methods Our systematic search included MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus, and key journals and review articles; the date of the last search was April 4th 2016. We graded the methodological quality of the studies by means of the Quality Assessment Tool for Quantitative Studies, developed fo...

Cooperative DNA Recognition Modulated by an Interplay between Protein-Protein Interactions and DNA-Mediated Allostery.

Directory of Open Access Journals (Sweden)

Felipe Merino

2015-06-01

Full Text Available Highly specific transcriptional regulation depends on the cooperative association of transcription factors into enhanceosomes. Usually, their DNA-binding cooperativity originates from either direct interactions or DNA-mediated allostery. Here, we performed unbiased molecular simulations followed by simulations of protein-DNA unbinding and free energy profiling to study the cooperative DNA recognition by OCT4 and SOX2, key components of enhanceosomes in pluripotent cells. We found that SOX2 influences the orientation and dynamics of the DNA-bound configuration of OCT4. In addition SOX2 modifies the unbinding free energy profiles of both DNA-binding domains of OCT4, the POU specific and POU homeodomain, despite interacting directly only with the first. Thus, we demonstrate that the OCT4-SOX2 cooperativity is modulated by an interplay between protein-protein interactions and DNA-mediated allostery. Further, we estimated the change in OCT4-DNA binding free energy due to the cooperativity with SOX2, observed a good agreement with experimental measurements, and found that SOX2 affects the relative DNA-binding strength of the two OCT4 domains. Based on these findings, we propose that available interaction partners in different biological contexts modulate the DNA exploration routes of multi-domain transcription factors such as OCT4. We consider the OCT4-SOX2 cooperativity as a paradigm of how specificity of transcriptional regulation is achieved through concerted modulation of protein-DNA recognition by different types of interactions.

Chemical Ligation Reactions of Oligonucleotides for Biological and Medicinal Applications.

Science.gov (United States)

Abe, Hiroshi; Kimura, Yasuaki

2018-01-01

Chemical ligation of oligonucleotides (ONs) is the key reaction for various ON-based technologies. We have tried to solve the problems of RNA interference (RNAi) technology by applying ON chemical ligation to RNAi. We designed a new RNAi system, called intracellular buildup RNAi (IBR-RNAi), where the RNA fragments are built up into active small-interference RNA (siRNA) in cells through a chemical ligation reaction. Using the phosphorothioate and iodoacetyl groups as reactive functional groups for the ligation, we achieved RNAi effects without inducing immune responses. Additionally, we developed a new chemical ligation for IBR-RNAi, which affords a more native-like structure in the ligated product. The new ligation method should be useful not only for IBR-RNAi but also for the chemical synthesis of biofunctional ONs.

Cooperation in multicultural negotiations: How the cultures of people with low and high power interact.

Science.gov (United States)

Kopelman, Shirli; Hardin, Ashley E; Myers, Christopher G; Tost, Leigh Plunkett

2016-05-01

This study examined whether the cultures of low- and high-power negotiators interact to influence cooperative behavior of low-power negotiators. Managers from 4 different cultural groups (Germany, Hong Kong, Israel, and the United States) negotiated face-to-face in a simulated power-asymmetric commons dilemma. Results supported an interaction effect in which cooperation of people with lower power was influenced by both their culture and the culture of the person with higher power. In particular, in a multicultural setting, low-power managers from Hong Kong, a vertical-collectivist culture emphasizing power differences and group alignment, adjusted their cooperation depending on the culture of the high-power manager with whom they interacted. This study contributes to understanding how culture shapes behavior of people with relatively low power, illustrates how a logic of appropriateness informs cooperation, and highlights the importance of studying multicultural social interactions in the context of negotiations, work teams, and global leadership. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Interaction protocols for cooperative merging and lane reduction scenarios

NARCIS (Netherlands)

Semsar-Kazerooni, E.; Ploeg, J.

2015-01-01

This paper presents the interaction protocols developed for execution of two common scenarios in daily traffic using cooperative automated vehicles. The first proposed scenario addresses merging of a (semi-)automated car on a highway within a platoon of (semi-)automated vehicles. The second scenario

On Cooperative Behavior in Distributed Teams: The Influence of Organizational Design, Media Richness, Social Interaction, and Interaction Adaptation

OpenAIRE

H?konsson, Dorthe D.; Obel, B?rge; Eskildsen, Jacob K.; Burton, Richard M.

2016-01-01

Self-interest vs. cooperation is a fundamental dilemma in animal behavior as well as in human and organizational behavior. In organizations, how to get people to cooperate despite or in conjunction with their self-interest is fundamental to the achievement of a common goal. While both organizational designs and social interactions have been found to further cooperation in organizations, some of the literature has received contradictory support, just as very little research, if any, has examin...

On Cooperative Behavior in Distributed Teams: The Influence of Organizational Design, Media Richness, Social Interaction, and Interaction Adaptation

Science.gov (United States)

Håkonsson, Dorthe D.; Obel, Børge; Eskildsen, Jacob K.; Burton, Richard M.

2016-01-01

Self-interest vs. cooperation is a fundamental dilemma in animal behavior as well as in human and organizational behavior. In organizations, how to get people to cooperate despite or in conjunction with their self-interest is fundamental to the achievement of a common goal. While both organizational designs and social interactions have been found to further cooperation in organizations, some of the literature has received contradictory support, just as very little research, if any, has examined their joint effects in distributed organizations, where communication is usually achieved via different communication media. This paper reviews the extant literature and offers a set of hypotheses to integrate current theories and explanations. Further, it discusses how future research should examine the joint effects of media, incentives, and social interactions. PMID:27242605

Interfacial Interaction of Titania Nanoparticles and Ligated Uranyl Species: A Relativistic DFT Investigation.

Science.gov (United States)

Zhao, Hong-Bo; Zheng, Ming; Schreckenbach, Georg; Pan, Qing-Jiang

2017-03-06

To understand interfacial behavior of actinides adsorbed onto mineral surfaces and unravel their structure-property relationship, the structures, electronic properties, and energetics of various ligated uranyl species adsorbed onto TiO 2 surface nanoparticle clusters (SNCs) were examined using relativistic density functional theory. Rutile (110) and anatase (101) titania surfaces, experimentally known to be stable, were fully optimized. For the former, models studied include clean and water-free Ti 27 O 64 H 20 (dry), partially hydrated (Ti 27 O 64 H 20 )(H 2 O) 8 (sol) and proton-saturated [(Ti 27 O 64 H 20 )(H 2 O) 8 (H) 2 ] 2+ (sat), while defect-free and defected anatase SNCs involving more than 38 TiO 2 units were considered. The aquouranyl sorption onto rutile SNCs is energetically preferred, with interaction energies of -8.54, -10.36, and -2.39 eV, respectively. Energy decomposition demonstrates that the sorption is dominated by orbital attractive interactions and modified by steric effects. Greater hydrogen-bonding involvement leads to increased orbital interactions (i.e., more negative energy) from dry to sol/sat complexes, while much larger steric interaction in the sat complex significantly reduces the sorption interaction (i.e., more positive energy). For dry SNC, adsorbates were varied from aquo to aquo-carbonato, to carbonato, to hydroxo uranyl species. Longer U-O surf /U-Ti distances and more positive sorption energies were calculated upon introducing carbonato and hydroxo ligands, indicative of weaker uranyl sorption onto the substrate. This is consistent with experimental observations that the uranyl sorption rate decreases upon raising solution pH value or adding carbon dioxide. Anatase SNCs adsorbing aquouranyl are even more exothermic, because more bonds are formed than in the case of rutile. Moreover, the anatase sorption can be tuned by surface defects as well as its Ti and O stoichiometry. All the aquouranyl-SNC complexes show similar

Role of lubricants on friction between self-ligating brackets and archwires.

Science.gov (United States)

Leal, Renata C; Amaral, Flávia L B; França, Fabiana M G; Basting, Roberta T; Turssi, Cecilia P

2014-11-01

To evaluate the effect of different lubricants on friction between orthodontic brackets and archwires. Active (Quick, Forestadent) and passive (Damon 3MX, Ormco) self-ligating brackets underwent friction tests in the presence of mucin- and carboxymethylcellulose (CMC)-based artificial saliva, distilled water, and whole human saliva (positive control). Dry friction (no lubricant) was used as the negative control. Bracket/wire samples (0.014 × 0.025 inch, CuNiTi, SDS Ormco) underwent friction tests eight times in a universal testing machine. Two-way analysis of variance showed no significant interaction between bracket type and lubricant (P  =  .324). Friction force obtained with passive self-ligating brackets was lower than that for active brackets (P Friction observed in the presence of artificial saliva did not differ from that generated under lubrication with natural human saliva, as shown by Tukey test. Higher friction forces were found with the use of distilled water or when the test was performed under dry condition (ie, with no lubricant). Lubrication plays a role in friction forces between self-ligating brackets and CuNiTi wires, with mucin- and CMC-based artificial saliva providing a reliable alternative to human natural saliva.

[Friction: self-ligating brackets].

Science.gov (United States)

Thermac, Guilhem; Morgon, Laurent; Godeneche, Julien

2008-12-01

The manufacturers of self-ligating brackets advertise a reduction of the friction engendered between the wire and the bracket, which is an essential parameter for treatment's speed and comfort. We have compared the friction obtained with four types of self-ligating brackets - In-Ovation R, Damon 3, Smart Clip and Quick - with that of a standard bracket Omniarch associated with an elastomeric ligature. All bracket were tested on a bench of traction with three types of wires: steel .019"x.025", TMA .019"x.025" and NEO sentalloy F300 .020"x.020". The results confirm a clear friction reduction for all tested wire.

Arterial ligation versus embolization in epistaxis management: Counterintuitive national trends.

Science.gov (United States)

Sylvester, Michael J; Chung, Sei Y; Guinand, Luis A; Govindan, Aparna; Baredes, Soly; Eloy, Jean Anderson

2017-05-01

Arterial ligation and embolization are treatment modalities indicated in severe and refractory epistaxis. The purpose of this study was to examine temporal trends and compare outcomes in treatment of hospitalized epistaxis patients with ligation or embolization. This retrospective cohort analysis utilized the 2008 to 2013 National Inpatient Sample to identify patients admitted with a primary diagnosis of epistaxis, and an associated procedure code for ligation or embolization. A total of 1,813 cases met the inclusion criteria, with 57.1% undergoing ligation. During the study period, treatment with ligation has trended downward, whereas treatment with embolization has remained constant. Overall, ligated patients were older (64.1 vs. 62.4 years; P = 0.027) and had higher rates of congestive heart failure (15.1% vs. 9.8%; P = 0.001). No significant differences in rates of chronic pulmonary disease, coagulopathy, liver disease, or hereditary hemorrhagic telangiectasia were observed between cohorts. No differences were observed in rates of blood transfusion, stroke, blindness, or in-hospital mortality; however, ligated patients had lower rates of intubation/tracheostomy (2.8% vs. 5.3%; P = 0.009). Ligated patients also experienced shorter hospital stays (3.6 vs. 4.0 days; P = 0.014) and incurred lower hospital charges ($33,029 vs. $69,304; P < 0.001). Compared to embolization, ligation is associated with significantly decreased hospital charges and shorter hospital stay, without an increase in complication rates. Counterintuitively, ligation appears to be trending downward nationally in its use relative to embolization. 2C Laryngoscope, 127:1017-1020, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Self-Regulation, Cooperative Learning, and Academic Self-Efficacy: Interactions to Prevent School Failure

OpenAIRE

Fernández Río, Francisco Javier; Cecchini Estrada, José Antonio; Méndez Giménez, Antonio; Prieto Saborit, José Antonio

2017-01-01

Learning to learn and learning to cooperate are two important goals for individuals. Moreover, self regulation has been identified as fundamental to prevent school failure. The goal of the present study was to assess the interactions between self-regulated learning, cooperative learning and academic self-efficacy in secondary education students experiencing cooperative learning as the main pedagogical approach for at least one school year. 2.513 secondary education students (1.308 males, 1.20...

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

Science.gov (United States)

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.

In-Solution SH2 Domain Binding Assay Based on Proximity Ligation.

Science.gov (United States)

Machida, Kazuya

2017-01-01

Protein-protein interactions mediated by SH2 domains confer specificity in tyrosine kinase pathways. Traditional assays for assessing interactions between an SH2 domain and its interacting protein such as far-Western and pull-down are inherently low throughput. We developed SH2-PLA, an in-solution SH2 domain binding assay, that takes advantage of the speed and sensitivity of proximity ligation and real-time PCR. SH2-PLA allows for rapid assessment of SH2 domain binding to a target protein using only a few microliters of cell lysate, thereby making it an attractive new tool to study tyrosine kinase signaling.

SEARCH OF MECHANISMS AND FORMS OF COOPERATION INTERACTION IN CHAINS OF DELIVERIES

Directory of Open Access Journals (Sweden)

Arseny V. Brykin

2015-01-01

Full Text Available In article features of development of the Russian model of mixed economy and integration of the private, public and state beginnings, and also conditions of financial and economic uncertainty which introduced the additional, difficult operated risks and problems to domestic industrial production are considered. According to the author, in modern conditions, considering external calls and threats, and also internal risks, coordination in cooperation communications is of particular importance. Exactly here the greatest extent of development of cooperation communications and tools of an innovative paradigm of development of business is required. The author gives examples of mechanisms and forms of cooperation interaction in chains of deliveries and offers coordination options in cooperation communications in the conditions of an economic crisis. 

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

Science.gov (United States)

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.

Recovery of testicular blood flow following ligation of testicular vessels

International Nuclear Information System (INIS)

Pascual, J.A.; Villanueva-Meyer, J.; Salido, E.; Ehrlich, R.M.; Mena, I.; Rajfer, J.

1989-01-01

To determine whether initial ligation of the testicular vessels of the high undescended testis followed by a delayed secondary orchiopexy is a viable alternative to the classical Fowler-Stephens procedure, a series of preliminary experiments were conducted in the rat in which testicular blood flow was measured by the 133-xenon washout technique before, and 1 hour and 30 days after ligation of the vessels. In addition, testicular histology, and testis and sex-accessory tissue weights were measured in 6 control, 6 sham operated and 6 testicular vessel ligated rats 54 days after vessel ligation. The data demonstrate that ligation and division of the testicular blood vessels produce an 80 per cent decrease in testicular blood flow 1 hour after ligation of the vessels. However, 30 days later testis blood flow returns to the control and pre-treatment value. There were no significant changes in testis or sex-accessory tissue weights 54 days after vessel ligation. Histologically, 4 of the surgically operated testes demonstrated necrosis of less than 25 per cent of the seminiferous tubules while 1 testis demonstrated more than 75 per cent necrosis. The rest of the tubules in all 6 testes demonstrated normal spermatogenesis. From this study we conclude that initial testicular vessel ligation produces an immediate decrease in testicular blood flow but with time the collateral vessels are able to compensate and return the testis blood flow to its normal pre-treatment value. These preliminary observations lend support for the concept that initial ligation of the testicular vessels followed by a delayed secondary orchiopexy in patients with a high undescended testis may be a possible alternative to the classical Fowler-Stephens approach

[Rubber band ligation in treatment of hemorrhoids: our experience].

Science.gov (United States)

Gaj, F; Biviano, I; Sportelli, G; Candeloro, L

2015-01-01

Hemorrhoids are a very common condition. The treatment depends upon persistence and severity of symptoms. For hemorrhoids of II and III grade the rubber band ligation may be therapeutic. Our aim is to report the outcomes of rubber band ligation of hemorrhoids, with a follow up of 6 months. A total of 50 patients underwent rubber band ligation for symptomatic hemorrhoids (grade II and III) without prolapse, between June 2012 and June 2014. All patients underwent plug test to rule out presence of rectal mucosal prolapse and were classified according to PATE classification (1). Each hemorrhoid was ligated with one rubber band through a ligator. All patients were evaluated immediately at the end of the procedure, after ten days and six months after the treatment. Patient's demographic and operative data were collected and analyzed. The mean patients age was 47.6±12.3 years (range 24-72). All procedures were performed without complications. Before rubber band ligation, 42 patients had rectal bleeding, 38 had perineal discomfort and 27 had itching. Ten days after the treatment, 12 patients presented self-limited rectal bleeding, but 10 of these had more hemorrhoids and underwent a second rubber band ligation. No patients complained perineal discomfort, and 8 patients had itching; 78% and 16% of patients respectively, experienced feeling of a foreign body inside the canal anal and anal pain. After 6 months, only 13 patients were occasionally symptomatic: 4 patients had rectal bleeding, 2 had perineal discomfort and 4 had itching. Three more patients presented both perineal discomfort and hitching. None had the feeling of a foreign body in anal canal or anal pain. Rubber band ligation is an efficacious, cost-effective and simple treatment for the second and third degree hemorrhoids without rectal mucosal prolapsed. In our hands, no severe complications developed and minor complications could be handled with ease.

Inquiry and Groups: Student Interactions in Cooperative Inquiry-Based Science

Science.gov (United States)

Woods-McConney, Amanda; Wosnitza, Marold; Sturrock, Keryn L.

2016-01-01

Science education research has recommended cooperative inquiry based science in the primary science context for more than two decades but after more than 20 years, student achievement in science has not substantially improved. This study, through direct observation and analysis, investigated content-related student interactions in an authentic…

Tubal ligation and risk of ovarian cancer subtypes

DEFF Research Database (Denmark)

Sieh, Weiva; Salvador, Shannon; McGuire, Valerie

2013-01-01

Tubal ligation is a protective factor for ovarian cancer, but it is unknown whether this protection extends to all invasive histological subtypes or borderline tumors. We undertook an international collaborative study to examine the association between tubal ligation and ovarian cancer subtypes....

Evaluation of friction produced by self-ligating, conventional and Barbosa Versatile brackets

Directory of Open Access Journals (Sweden)

Jurandir Antonio BARBOSA

Full Text Available Abstract Introduction The Barbosa Versatile bracket design may provide lower frictional force and greater sliding. However, no in vitro studies have shown its sliding mechanisms and frictional resistance, particularly in comparison with other self-ligating or conventional brackets. Objective To compare the frictional resistance among self-ligating brackets (EasyClip/ Aditek, Damon MX/ Ormco and In Ovation R/ GAC; conventional brackets (Balance Roth/ GAC, and Roth Monobloc/ Morelli; and Barbosa Versatile bracket (Barbosa Versatile/ GAC with different angles and arch wires. Material and method Brackets were tested with the 0.014", 0.018", 0.019"×0.025" and 0.021"×0.025" stainless steel wires, with 0, 5, 10, 15 and 20 degree angulations. Tying was performed with elastomeric ligature for conventional and Barbosa Versatile brackets, or with a built-in clip system of the self-ligating brackets. A universal testing machine was used to obtain sliding strength and friction value readouts between brackets and wires. Result Three-way factorial ANOVA 4×5×6 (brackets × angulation × wire and Tukey tests showed statistically significant differences for all factors and all interactions (p<0.0001. Static frictional resistance showed a lower rate for Barbosa Versatile bracket and higher rates for Roth Monobloc and Balance brackets. Conclusion The lowest frictional resistance was obtained with the Barbosa Versatile bracket and self-ligating brackets in comparison with the conventional type. Increasing the diameter of the wires increased the frictional resistance. Smaller angles produced less frictional resistance.

Convergent synthesis of proteins by kinetically controlled ligation

Science.gov (United States)

Kent, Stephen; Pentelute, Brad; Bang, Duhee; Johnson, Erik; Durek, Thomas

2010-03-09

The present invention concerns methods and compositions for synthesizing a polypeptide using kinetically controlled reactions involving fragments of the polypeptide for a fully convergent process. In more specific embodiments, a ligation involves reacting a first peptide having a protected cysteyl group at its N-terminal and a phenylthioester at its C-terminal with a second peptide having a cysteine residue at its N-termini and a thioester at its C-termini to form a ligation product. Subsequent reactions may involve deprotecting the cysteyl group of the resulting ligation product and/or converting the thioester into a thiophenylester.

Molecular Recognition of Cobalt(III)-ligated Peptides by Serine Proteases: The Role of Electrostatic Effects

DEFF Research Database (Denmark)

Bagger, Sven; Wagner, Kim

1998-01-01

pancreatic trypsin, and proteinase K from Tritirachium album was examined. The efficiency of the substrates was assessed by kinetic measurement of the partition between aminolysis and hydrolysis. The results are discussed with special reference to coulombic interactions between the metal-ligated substrates...

Laparoscopic-assisted percutaneous internal ring ligation in children

African Journals Online (AJOL)

Annals of Pediatric Surgery ... Patients and methods Laparoscopic percutaneous ligation of internal inguinal ring has been ... The mean operative time in our series was 15 (± 3) and 20 (± 5) min for bilateral cases, without anesthesia time. ... Conclusion Laparoscopic percutaneous ligation of internal inguinal ring repair of ...

Brain Interaction during Cooperation: Evaluating Local Properties of Multiple-Brain Network.

Science.gov (United States)

Sciaraffa, Nicolina; Borghini, Gianluca; Aricò, Pietro; Di Flumeri, Gianluca; Colosimo, Alfredo; Bezerianos, Anastasios; Thakor, Nitish V; Babiloni, Fabio

2017-07-21

Subjects' interaction is the core of most human activities. This is the reason why a lack of coordination is often the cause of missing goals, more than individual failure. While there are different subjective and objective measures to assess the level of mental effort required by subjects while facing a situation that is getting harder, that is, mental workload, to define an objective measure based on how and if team members are interacting is not so straightforward. In this study, behavioral, subjective and synchronized electroencephalographic data were collected from couples involved in a cooperative task to describe the relationship between task difficulty and team coordination, in the sense of interaction aimed at cooperatively performing the assignment. Multiple-brain connectivity analysis provided information about the whole interacting system. The results showed that averaged local properties of a brain network were affected by task difficulty. In particular, strength changed significantly with task difficulty and clustering coefficients strongly correlated with the workload itself. In particular, a higher workload corresponded to lower clustering values over the central and parietal brain areas. Such results has been interpreted as less efficient organization of the network when the subjects' activities, due to high workload tendencies, were less coordinated.

Persistent postpartum haemorrhage after failed arterial ligation: value of pelvic embolisation

Energy Technology Data Exchange (ETDEWEB)

Fargeaudou, Yann; Soyer, Philippe; Sirol, Marc; Boudiaf, Mourad; Dahan, Henri; Dref, Olivier le [Hopital Lariboisiere AP-HP et Universite Diderot-Paris 7, Department of Abdominal and Interventional Imaging, Paris (France); Morel, Olivier; Barranger, Emmanuel [Hopital Lariboisiere AP-HP, Department of Obstetrics and Gynecology, Paris (France); Gayat, Etienne; Mebazaa, Alexandre [Hopital Lariboisiere AP-HP, Department of Anesthesiology and Intensive Care Medicine, Paris (France)

2010-07-15

To evaluate the role and efficacy of pelvic embolisation in the treatment of persistent postpartum haemorrhage after failed arterial ligation and to identify the complications of this procedure in this specific population. The clinical files and angiographic examinations of 12 consecutive women (mean age 32 years) who were treated with pelvic embolisation because of persistent, severe postpartum haemorrhage after failed arterial ligation were reviewed. Angiography revealed that persistent bleeding was due to incomplete arterial ligation (n = 4) or the presence of newly developed anastomotic routes (n = 8). In 11 women, pelvic embolisation stopped the bleeding. Hysterectomy was needed in one woman with retained placenta. Two complications due to pelvic embolisation, including leg ischaemia and transient sciatic nerve ischaemia, were identified, both after internal iliac artery ligation. In women with persistent postpartum haemorrhage after failed arterial ligation, pelvic embolisation is an effective treatment in most cases. However, embolisation of the anastomotic routes that contribute to persistent bleeding may result in ischaemic complications. These potential complications reaffirm that arterial ligation should not be the favoured option for postpartum haemorrhage and that special care must be given during pelvic embolisation after failed arterial ligation. (orig.)

Hypotension following patent ductus arteriosus ligation: The role of adrenal hormones

OpenAIRE

Clyman, RI; Wickremasinghe, A; Merritt, TA; Solomon, T; McNamara, P; Jain, A; Singh, J; Chu, A; Noori, S; Sekar, K; Lavoie, PM; Attridge, JT; Swanson, JR; Gillam-Krakauer, M; Reese, J

2014-01-01

Objective To test the hypothesis that an impaired adrenal response to stress might play a role in the hypotension that follows patent ductus arteriosus (PDA) ligation. Study design We performed a multicenter study of infants born at < 32 weeks' gestation who were about to undergo PDA ligation. Serum adrenal steroids were measured 3 times: before and after a cosyntropin (1.0 μg/kg) stimulation test (performed before the ligation), and at 10-12 hours after the ligation. A standardized approach...

Effects of self-ligating and conventional brackets on halitosis and periodontal conditions.

Science.gov (United States)

Kaygisiz, Emine; Uzuner, Fatma Deniz; Yuksel, Sema; Taner, Levent; Çulhaoğlu, Rana; Sezgin, Yasemin; Ateş, Can

2015-05-01

To evaluate the effects of fixed orthodontic treatment with steel-ligated conventional brackets and self-ligating brackets on halitosis and periodontal health. Sixty patients, at the permanent dentition stage aged 12 to 18 years, who had Angle Class I malocclusion with mild-to-moderate crowding were randomly selected. Inclusion criteria were nonsmokers, without systematic disease, and no use of antibiotics and oral mouth rinses during the 2-month period before the study. The patients were subdivided into three groups randomly: the group treated with conventional brackets (group 1, n  =  20) ligated with steel ligature wires, the group treated with self-ligating brackets (group 2, n  =  20), and the control group (group 3, n  =  20). The periodontal records were obtained 1 week before bonding (T1), immediately before bonding (T2), 1 week after bonding (T3), 4 weeks after bonding (T4), and 8 weeks after bonding (T5). Measurements of the control group were repeated within the same periods. The volatile sulfur components determining halitosis were measured with the Halimeter at T2, T3, T4, and T5. A two-way repeated measures of analysis of variance (ANOVA) was used to compare the groups statistically. No statistically significant group × time interactions were found for plaque index, gingival index, pocket depth, bleeding on probing, and halitosis, which means three independent groups change like each other by time. The risk of tongue coating index (TCI) being 2 was 10.2 times higher at T1 than at T5 (P brackets do not have an advantage over conventional brackets with respect to periodontal status and halitosis.

Chemoselective ligation and antigen vectorization.

Science.gov (United States)

Gras-Masse, H

2001-01-01

The interest in cocktail-lipopeptide vaccines has now been confirmed by phase I clinical trials: highly diversified B-, T-helper or cytotoxic T-cell epitopes can be combined with a lipophilic vector for the induction of B- and T-cell responses of predetermined specificity. With the goal of producing an improved vaccine that should ideally induce a multispecific response in non-selected populations, increasing the diversity of the immunizing mixture represents one of the most obvious strategies.The selective delivery of antigens to professional antigen-presenting cells represents another promising approach for the improvement of vaccine efficacy. In this context, the mannose-receptor represents an attractive entry point for the targeting to dendritic cells of antigens linked to clustered glycosides or glycomimetics. In all cases, highly complex but fully characterized molecules must be produced. To develop a modular and flexible strategy which could be generally applicable to a large set of peptide antigens, we elected to explore the potentialities of chemoselective ligation methods. The hydrazone bond was found particularly reliable and fully compatible with sulphide ligation. Hydrazone/thioether orthogonal ligation systems could be developed to account for the nature of the antigens and the solubility of the vector systems. Copyright 2001 The International Association for Biologicals.

Template-Directed Ligation of Peptides to Oligonucleotides

Science.gov (United States)

Bruick, Richard K.; Dawson, Philip E.; Kent, Stephen BH; Usman, Nassim; Joyce, Gerald F.

1996-01-01

Synthetic oligonucleotides and peptides have enjoyed a wide range of applications in both biology and chemistry. As a consequence, oligonucleotide-peptide conjugates have received considerable attention, most notably in the development of antisense constructs with improved pharmacological properties. In addition, oligonucleotide-peptide conjugates have been used as molecular tags, in the assembly of supramolecular arrays and in the construction of encoded combinatorial libraries. To make these chimeric molecules more accessible for a broad range of investigations, we sought to develop a facile method for joining fully deprotected oligonucleotides and peptides through a stable amide bond linkage. Furthermore, we wished to make this ligation reaction addressable, enabling one to direct the ligation of specific oligonucleotide and peptide components.To confer specificity and accelerate the rate of the reaction, the ligation process was designed to be dependent on the presence of a complementary oligonucleotide template.

Time course of collagen peak in bile duct-ligated rats.

Science.gov (United States)

Tarcin, Orhan; Basaranoglu, Metin; Tahan, Veysel; Tahan, Gülgün; Sücüllü, Ilker; Yilmaz, Nevin; Sood, Gagan; Snyder, Ned; Hilman, Gilbert; Celikel, Cigdem; Tözün, Nurdan

2011-04-28

One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials. Of the 53 male Wistar rats, 8 (Group 0) were used as a healthy control group. Bile duct ligation (BDL) had been performed in the rest. Bile duct-ligated rates were sacrificed 7 days later in group 1 (10 rats), 14 days later in group 2 (9 rats), 21 days later in group 3(9 rats) and 28 days later in group 4 (9 rats). Eight rats underwent sham-operation (Sham). Hepatic collagen measurements as well as serum levels of liver enzymes and function tests were all analysed. The peak level of collagen was observed biochemically and histomorphometricly at the end of third week (P fibrosis in bile duct-ligated rats is transient, i.e. reverses spontaneously after 3 weeks. This contrasts any situation in patients where hepatic fibrosis is progressive and irreversible as countless studies performed by many investigators in the same animal model.

Ligation versus no ligation of spontaneous portosystemic shunts during liver transplantation: Audit of a prospective series of 66 consecutive patients.

Science.gov (United States)

Gomez Gavara, Concepcion; Bhangui, Prashant; Salloum, Chady; Osseis, Michael; Esposito, Francesco; Moussallem, Toufic; Lahat, Eylon; Fuentes, Liliana; Compagnon, Philippe; Ngongang, Norbert; Lim, Chetana; Azoulay, Daniel

2018-04-01

The management of large spontaneous portosystemic shunt (SPSS) during liver transplantation (LT) is a matter of debate. The aim of this study is to compare the short-term and longterm outcomes of SPSS ligation versus nonligation during LT, when both options are available. From 2011 to 2017, 66 patients with SPSS underwent LT: 56 without and 10 with portal vein thrombosis (PVT), all of whom underwent successful thrombectomy and could have portoportal reconstruction. The SPSS were either splenorenal (n = 40; 60.6%), left gastric (n = 16; 24.2%), or mesenterico-iliac (n = 10; 15.1%). Following portoportal anastomosis, the SPSS was ligated in 36 (54.4%) patients and left in place in 30 (45.5%) patients, based on the effect of the SPSS clamping/unclamping test on portal vein flow during the anhepatic phase. Intraoperatively, satisfactory portal flow was obtained in both groups. Primary nonfunction (PNF) and primary dysfunction (PDF) rates did not differ significantly between the 2 groups. Nonligation of SPSS was significantly associated with a higher rate of postoperative encephalopathy (P SPSS in LT (ie, PNF and PDF, PVT, and encephalopathy) was present in 16 (44.4%) and 22 (73.3%) patients of the ligated and nonligated shunt group, respectively (P = 0.02). Patient (P = 0.05) and graft (P = 0.02) survival rates were better in the ligated shunt group. In conclusion, the present study supports routine ligation of large SPSS during LT whenever feasible. Liver Transplantation 24 505-515 2018 AASLD. © 2018 by the American Association for the Study of Liver Diseases.

Interaction between particles and grain boundaries under conditions of cooperative migration

International Nuclear Information System (INIS)

Marvina, L.A.; Marvin, V.B.

1996-01-01

The analysis of particle grain boundary interaction is performed for dispersion hardened alloys when cooperative migration takes place. It is shown that in a general case the particle experiences a Zener force and a force of grain boundary surface tension due to boundary bending between particles. Approximate numerical estimates are made for the force acting on a particle in dispersion hardened alloy Ni-HfO 2 . It is noted that during cooperative migration of particle and grain boundary the velocity of the particle is directed along the resulting force. The latter equals the sum of surface tension and Zener forces. 6 refs., 2 figs

Portal vein ligation is as effective as sequential portal vein and hepatic artery ligation in inducing contralateral liver hypertrophy in a rat model

NARCIS (Netherlands)

Veteläinen, Reeta; Dinant, Sander; van Vliet, Arlène; van Gulik, Thomas M.

2006-01-01

PURPOSE: Dual embolization of the hepatic artery and portal vein (PV) has been proposed to enhance contralateral liver regeneration before resection. The aim of this study was to evaluate the effect of PV ligation compared with simultaneous or sequential dual ligation on regeneration,

Hemodynamic characterization of chronic bile duct-ligated rats: effect of pentobarbital sodium

International Nuclear Information System (INIS)

Lee, S.S.; Girod, C.; Braillon, A.; Hadengue, A.; Lebrec, D.

1986-01-01

Systemic and splanchnic hemodynamics of the chronic bile duct-ligated rat were characterized by radioactive microspheres. Conscious and pentobarbital sodium-anesthetized, bile duct-ligated and sham-operated rats had cardiac output and regional organ blood flows determined. The conscious bile duct-ligated rat compared with the sham-operated showed a hyperdynamic circulation with an increased cardiac output and portal tributary blood flow. Pentobarbital sodium anesthesia induced marked hemodynamic changes in both sham-operated and bile duct-ligated rats. The latter group was especially sensitive to its effects; thus, comparison of cardiac output and portal tributary blood flow between anesthetized bile duct-ligated and sham-operated rats showed no significant differences. The authors conclude that the rat with cirrhosis due to chronic bile duct ligation is an excellent model for hemodynamic investigations but should be studied in the conscious state, since pentobarbital sodium anesthesia eliminated the hyperdynamic circulation

A Multiagent Cooperation Model Based on Trust Rating in Dynamic Infinite Interaction Environment

Directory of Open Access Journals (Sweden)

Sixia Fan

2018-01-01

Full Text Available To improve the liveness of agents and enhance trust and collaboration in multiagent system, a new cooperation model based on trust rating in dynamic infinite interaction environment (TR-DII is proposed. TR-DII model is used to control agent’s autonomy and selfishness and to make agent do the rational decision. TR-DII model is based on two important components. One is dynamic repeated interaction structure, and the other is trust rating. The dynamic repeated interaction structure is formed with multistage inviting and evaluating actions. It transforms agents’ interactions into an infinity task allocation environment, where controlled and renewable cycle is a component most agent models ignored. Additionally, it influences the expectations and behaviors of agents which may not appear in one-shot time but may appear in long-time cooperation. Moreover, with rewards and punishments mechanism (RPM, the trust rating (TR is proposed to control agent blindness in selection phase. However, RPM is the factor that directly influences decisions, not the reputation as other models have suggested. Meanwhile, TR could monitor agent’s statuses in which they could be trustworthy or untrustworthy. Also, it refines agent’s disrepute in a new way which is ignored by the others. Finally, grids puzzle experiment has been used to test TR-DII model and other five models are used as comparisons. The results show that TR-DII model can effectively adjust the trust level between agents and makes the solvers be more trustworthy and do choices that are more rational. Moreover, through interaction result feedback, TR-DII model could adjust the income function, to control cooperation reputation, and could achieve a closed-loop control.

Learning to Cooperate: The Evolution of Social Rewards in Repeated Interactions.

Science.gov (United States)

Dridi, Slimane; Akçay, Erol

2018-01-01

Understanding the behavioral and psychological mechanisms underlying social behaviors is one of the major goals of social evolutionary theory. In particular, a persistent question about animal cooperation is to what extent it is supported by other-regarding preferences-the motivation to increase the welfare of others. In many situations, animals adjust their behaviors through learning by responding to the rewards they experience as a consequence of their actions. Therefore, we may ask whether learning in social situations can be driven by evolved other-regarding rewards. Here we develop a mathematical model in order to ask whether the mere act of cooperating with a social partner will evolve to be inherently rewarding. Individuals interact repeatedly in pairs and adjust their behaviors through reinforcement learning. We assume that individuals associate with each game outcome an internal reward value. These perceived rewards are genetically evolving traits. We find that conditionally cooperative rewards that value mutual cooperation positively but the sucker's outcome negatively tend to be evolutionarily stable. Purely other-regarding rewards can evolve only under special parameter combinations. On the other hand, selfish rewards that always lead to pure defection are also evolutionarily successful. These findings are consistent with empirical observations showing that humans tend to display conditionally cooperative behavior and also exhibit a diversity of preferences. Our model also demonstrates the need to further integrate multiple levels of biological causation of behavior.

Esophageal variceal ligation for hemostasis of acute variceal bleeding

African Journals Online (AJOL)

Introduction: Endoscopic variceal ligation is widely accepted as the optimum endoscopic treatment for esophageal variceal hemorrhage. In Morocco, there are no data regarding the efficacy of this technique. Our aim was to evaluate the effectiveness and safety of endoscopic variceal ligation in the management of ...

Time course of collagen peak in bile duct-ligated rats

Directory of Open Access Journals (Sweden)

Snyder Ned

2011-04-01

Full Text Available Abstract Background One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials. Methods Of the 53 male Wistar rats, 8 (Group 0 were used as a healthy control group. Bile duct ligation (BDL had been performed in the rest. Bile duct-ligated rates were sacrificed 7 days later in group 1 (10 rats, 14 days later in group 2 (9 rats, 21 days later in group 3(9 rats and 28 days later in group 4 (9 rats. Eight rats underwent sham-operation (Sham. Hepatic collagen measurements as well as serum levels of liver enzymes and function tests were all analysed. Results The peak level of collagen was observed biochemically and histomorphometricly at the end of third week (P Conclusion We have shown that fibrosis in bile duct-ligated rats is transient, i.e. reverses spontaneously after 3 weeks. This contrasts any situation in patients where hepatic fibrosis is progressive and irreversible as countless studies performed by many investigators in the same animal model.

Realizing Serine/Threonine Ligation: Scope and Limitations and Mechanistic Implication Thereof

Directory of Open Access Journals (Sweden)

Clarence T. T. Wong

2014-05-01

Full Text Available Serine/Threonine ligation (STL has emerged as an alternative tool for protein chemical synthesis, bioconjugations as well as macrocyclization of peptides of various sizes. Owning to the high abundance of Ser/Thr residues in natural peptides and proteins, STL is expected to find a wide range of applications in chemical biology research. Herein, we have fully investigated the compatibility of the serine/threonine ligation strategy for X-Ser/Thr ligation sites, where X is any of the 20 naturally occurring amino acids. Our studies have shown that 17 amino acids are suitable for ligation, while Asp, Glu, and Lys are not compatible. Among the working 17 C-terminal amino acids, the retarded reaction resulted from the bulky β-branched amino acid (Thr, Val and Ile is not seen under the current ligation condition. We have also investigated the chemoselectivity involving the amino group of the internal lysine which may compete with the N-terminal Ser/Thr for reaction with the C-terminal salicylaldehyde (SAL ester aldehyde group. The result suggested that the free internal amino group does not adversely slow down the ligation rate.

Template Directed Oligomer Ligation in Eutectic Phases in Water-Ice

DEFF Research Database (Denmark)

Dörr, Mark; Löffler, Philipp M. G.; Wieczorek, Rafal

2011-01-01

achieved, if small, activated, oligonucleotides are ligated on a template. A template directed ligation can lead to autocatalytic or cross- catalytic replication and thus maintain a certain pool of catalyitc species. Important for these processes is a destabilization of the formed douplex....../multiplex to overcome product inhibition. The latest results of our template directed ligation experiments in the eutectic ice phase are presented. Different activation strategies are compared and an outlook towards applications in molecular evolution and artifical cell systems (« protocells ») will be given. Figure 1....... (a) Reaction scheme of the condensation reaction of two oligoribonucleotides : The leaving group in this example is imidazole. (b) Illustration of a possible spatial arrangement of a template (15nt) directed ligation. The 7-mer is activated with imidazole at the 5' phosphate (apical moiety...

Time course of collagen peak in bile duct-ligated rats

OpenAIRE

Tarcin, Orhan; Basaranoglu, Metin; Tahan, Veysel; Tahan, Gülgün; Sücüllü, Ilker; Yilmaz, Nevin; Sood, Gagan; Snyder, Ned; Hilman, Gilbert; Celikel, Cigdem; Tözün, Nurdan

2011-01-01

Abstract Background One of the most useful experimental fibrogenesis models is the "bile duct-ligated rats". Our aim was to investigate the quantitative hepatic collagen content by two different methods during the different stages of hepatic fibrosis in bile duct-ligated rats on a weekly basis. We questioned whether the 1-wk or 4-wk bile duct-ligated model is suitable in animal fibrogenesis trials. Methods Of the 53 male Wistar rats, 8 (Group 0) were used as a healthy control group. Bile duct...

Cooperation, psychological game theory, and limitations of rationality in social interaction.

Science.gov (United States)

Colman, Andrew M

2003-04-01

Rational choice theory enjoys unprecedented popularity and influence in the behavioral and social sciences, but it generates intractable problems when applied to socially interactive decisions. In individual decisions, instrumental rationality is defined in terms of expected utility maximization. This becomes problematic in interactive decisions, when individuals have only partial control over the outcomes, because expected utility maximization is undefined in the absence of assumptions about how the other participants will behave. Game theory therefore incorporates not only rationality but also common knowledge assumptions, enabling players to anticipate their co-players' strategies. Under these assumptions, disparate anomalies emerge. Instrumental rationality, conventionally interpreted, fails to explain intuitively obvious features of human interaction, yields predictions starkly at variance with experimental findings, and breaks down completely in certain cases. In particular, focal point selection in pure coordination games is inexplicable, though it is easily achieved in practice; the intuitively compelling payoff-dominance principle lacks rational justification; rationality in social dilemmas is self-defeating; a key solution concept for cooperative coalition games is frequently inapplicable; and rational choice in certain sequential games generates contradictions. In experiments, human players behave more cooperatively and receive higher payoffs than strict rationality would permit. Orthodox conceptions of rationality are evidently internally deficient and inadequate for explaining human interaction. Psychological game theory, based on nonstandard assumptions, is required to solve these problems, and some suggestions along these lines have already been put forward.

Milrinone use for hemodynamic instability in patent ductus arteriosus ligation.

Science.gov (United States)

Halliday, Matthew; Kavarana, Minoo; Ebeling, Myla; Kiger, James

2017-03-01

Determine if prophylactic milrinone improves cardiovascular or long-term clinical outcomes in preterm neonates who receive surgical patent ductus arteriosus (PDA) ligation. Retrospective review of 45 infants over a 4-year period that received a PDA ligation at one institution. Data were collected on morbidity and mortality outcomes for all infants as well as milrinone therapy perioperatively. Of the 45 infants that were studied 15 received milrinone in the perioperative period of PDA ligation and the remaining 30 infants did not receive milrinone. The use of milrinone showed no statistically significant improvement in acute markers of hemodynamic stability. There was also no statistically significant difference in morbidity and mortality outcomes in milrinone group compared to the non-milrinone group. Prophylactic milrinone use for premature infants following PDA ligation does not show a significant cardiovascular or long-term clinical benefit.

Patent Ductus Arteriosus Ligation and Adverse Outcomes: Causality or Bias?

Science.gov (United States)

Weisz, Dany E.; McNamara, Patrick J.

2014-01-01

Observational studies have associated patent ductus arteriosus (PDA) ligation in preterm infants with increased chronic lung disease (CLD), retinopathy of prematurity, and neurodevelopmental impairment at long-term follow-up. Although the biological rationale for this association is incompletely understood, there is an emerging secular trend toward a permissive approach to the PDA. However, insufficient adjustment for postnatal, pre-ligation confounders, such as intraventricular hemorrhage and the duration and intensity of mechanical ventilation, suggests the presence of residual bias due to confounding by indication, and obliges caution in interpreting the ligation-morbidity relationship. A period of conservative management after failure of medical PDA closure may be considered to reduce the number of infants treated with surgery. Increased mortality and CLD in infants with persistent symptomatic PDA suggests that surgical ligation remains an important treatment modality for preterm infants. PMID:25024972

Sphenopalatine Artery Ligation for Epistaxis: Factors Influencing Outcome and Impact of Timing of Surgery.

Science.gov (United States)

McDermott, Ailbhe M; O'Cathain, Eadaoin; Carey, Brian William; O'Sullivan, Peter; Sheahan, Patrick

2016-03-01

Sphenopalatine artery ligation is a commonly employed surgical intervention for control of posterior epistaxis unresponsive to nasal packing. The objective of the present study was to evaluate the outcome of sphenopalatine artery ligation for control of epistaxis at our institution and the impact of timing and other factors on outcome. Case series with chart review. Academic tertiary referral center. Case notes were reviewed for 45 consecutive patients undergoing sphenopalatine artery ligation for control of epistaxis between October 2008 and October 2014. Forty-one patients had nasal packing prior to sphenopalatine artery ligation, with 33 undergoing ≥2 packings. Postoperatively, 6 patients had rebleeding, which was treated with repacking (n = 4) and return to the operating room (n = 2). The overall success rate of sphenopalatine artery ligation was 87% (39 of 45). Rebleeding rate was not affected by concomitant septoplasty, anterior ethmoidal artery ligation, or postoperative nasal packing. Patients undergoing SPA ligation within the first 24 hours of admission had a significantly shorter hospital length of stay (3 vs 6 days, P = .02) and treatment cost (€5905 vs €10,001, P = .03). Length of stay was not influenced by sphenopalatine artery ligation after ≤1 nasal pack versus ≥2 packs. Timing of sphenopalatine artery ligation did not affect blood transfusion requirement (P = .84). Sphenopalatine artery ligation is an effective management strategy for surgical control of refractory epistaxis. Early timing of sphenopalatine artery ligation may lead to reductions in length of stay. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

Comparative Study of Compensatory Liver Regeneration in a Rat Model: Portal Vein Ligation Only versus Sequential Ligation of the Portal Vein and Hepatic Artery

Energy Technology Data Exchange (ETDEWEB)

Chung, Soo Young [Dept. of Pathology, Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Jeon, Gyeong Sik [Dept. of Radiology, CHA Bundang Medical Center, College of Medicine, CHA University, Seongnam (Korea, Republic of); Lee, Byung Mo [Dept. of Surgery, Seoul Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

2013-04-15

To compare the volume change and the regenerative capacity between portal vein ligation (embolization) (PVL) and heterochronous PVL with hepatic artery ligation (HAL) in a rodent model. The animals were separated into three groups: group I, ligation of the left lateral and median portal vein branches; group II, completion of PVL, followed by ligation of the same branches of the hepatic artery after 48 h; control group, laparotomy without ligation was performed. Five rats from each group were sacrificed on 1, 3, 5, and 7 days after the operation. Volume change measurement, liver function tests and immunohistochemical analysis were performed. The volume of the nonligated lobe between groups I and II was not significantly different by day 5 and day 7. Mean alanine aminotransferase and total bilirubin levels were significantly higher in group II, while the albumin level was higher in group I. Both c-kit- and MIB-5-positive cells used in the activity detection of regeneration were more prevalent in group I on day 1, 3, and 5, with statistical significance. There was no operation related mortality. PVL alone is safe and effective in compensatory liver regeneration. Performing both PVL and HAL does not confer any additional benefits.

Structure, complexity and cooperation in parallel external chat interactions

Directory of Open Access Journals (Sweden)

Anette Grønning

2012-09-01

Full Text Available This article examines structure, complexity and cooperation in external chat interactions at the workplace in which one of the participants is taking part in multiple parallel conversations. The investigation is based on an analysis of nine chat interactions in a work-related context, with particular focus on the content of the parallel time spans of the chat interactions. The analysis was inspired by applied conversation analysis (CA. The empirical material has been placed at my disposal by Kristelig Fagbevægelse (Krifa, which is Denmark’s third-largest trade union. The article’s overall focus is on “turn-taking organisation as the fundamental and generic aspect of interaction organisation” (Drew & Heritage, 1992, p. 25, including the use of turn-taking rules, adjacency pairs, and the importance of pauses. Even though the employee and the union members do not know one another and cannot see, hear, or touch one another, it is possible to detect an informal, pleasant tone in their interactions. This challenges the basically asymmetrical relationship between employee and customer, and one can sense a further level of asymmetry. In terms of medium, chat interactions exist via various references to other media, including telephone calls and e-mails.

Protein chemical synthesis by α-ketoacid-hydroxylamine ligation.

Science.gov (United States)

Harmand, Thibault J; Murar, Claudia E; Bode, Jeffrey W

2016-06-01

Total chemical synthesis of proteins allows researchers to custom design proteins without the complex molecular biology that is required to insert non-natural amino acids or the biocontamination that arises from methods relying on overexpression in cells. We describe a detailed procedure for the chemical synthesis of proteins with the α-ketoacid-hydroxylamine (KAHA ligation), using (S)-5-oxaproline (Opr) as a key building block. This protocol comprises two main parts: (i) the synthesis of peptide fragments by standard fluorenylmethoxycarbonyl (Fmoc) chemistry and (ii) the KAHA ligation between fragments containing Opr and a C-terminal peptide α-ketoacid. This procedure provides an alternative to native chemical ligation (NCL) that could be valuable for the synthesis of proteins, particularly targets that do not contain cysteine residues. The ligation conditions-acidic DMSO/H2O or N-methyl-2-pyrrolidinone (NMP)/H2O-are ideally suited for solubilizing peptide segments, including many hydrophobic examples. The utility and efficiency of the protocol is demonstrated by the total chemical synthesis of the mature betatrophin (also called ANGPTL8), a 177-residue protein that contains no cysteine residues. With this protocol, the total synthesis of the betatrophin protein has been achieved in around 35 working days on a multimilligram scale.

Multicomponent Reactions in Ligation and Bioconjugation Chemistry.

Science.gov (United States)

Reguera, Leslie; Méndez, Yanira; Humpierre, Ana R; Valdés, Oscar; Rivera, Daniel G

2018-05-25

Multicomponent reactions (MCRs) encompass an exciting class of chemical transformations that have proven success in almost all fields of synthetic organic chemistry. These convergent procedures incorporate three or more reactants into a final product in one pot, thus combining high levels of complexity and diversity generation with low synthetic cost. Striking applications of these processes are found in heterocycle, peptidomimetic, and natural product syntheses. However, their potential in the preparation of large macro- and biomolecular constructs has been realized just recently. This Account describes the most relevant results of our group in the utilization of MCRs for ligation/conjugation of biomolecules along with significant contributions from other laboratories that validate the utility of this special class of bioconjugation process. Thus, MCRs have proven to be efficient in the ligation of lipids to peptides and oligosaccharides as well as the ligation of steroids, carbohydrates, and fluorescent and affinity tags to peptides and proteins. In the field of glycolipids, we highlight the power of isocyanide-based MCRs with the one-pot double lipidation of glycan fragments functionalized as either the carboxylic acid or amine. In peptide chemistry, the versatility of the multicomponent ligation strategy is demonstrated in both solution-phase lipidation protocols and solid-phase procedures enabling the simultaneous lipidation and biotinylation of peptides. In addition, we show that MCRs are powerful methods for synchronized lipidation/labeling and macrocyclization of peptides, thus accomplishing in one step what usually requires long sequences. In the realm of protein bioconjugation, MCRs have also proven to be effective in labeling, site-selective modification, immobilization, and glycoconjugation processes. For example, we illustrate a successful application of multicomponent polysaccharide-protein conjugation with the preparation of multivalent

Click nucleic acid ligation: applications in biology and nanotechnology.

Science.gov (United States)

El-Sagheer, Afaf H; Brown, Tom

2012-08-21

Biochemical strategies that use a combination of synthetic oligonucleotides, thermostable DNA polymerases, and DNA ligases can produce large DNA constructs up to 1 megabase in length. Although these ambitious targets are feasible biochemically, comparable technologies for the chemical synthesis of long DNA strands lag far behind. The best available chemical approach is the solid-phase phosphoramidite method, which can be used to assemble DNA strands up to 150 bases in length. Beyond this point, deficiencies in the chemistry make it impossible to produce pure DNA. A possible alternative approach to the chemical synthesis of large DNA strands is to join together carefully purified synthetic oligonucleotides by chemical methods. Click ligation by the copper-catalyzed azide-alkyne (CuAAC) reaction could facilitate this process. In this Account, we describe the synthesis, characterization, and applications of oligonucleotides prepared by click ligation. The alkyne and azide oligonucleotide strands can be prepared by standard protocols, and the ligation reaction is compatible with a wide range of chemical modifications to DNA and RNA. We have employed click ligation to synthesize DNA constructs up to 300 bases in length and much longer sequences are feasible. When the resulting triazole linkage is placed in a PCR template, various DNA polymerases correctly copy the entire base sequence. We have also successfully demonstrated both in vitro transcription and rolling circle amplification through the modified linkage. This linkage has shown in vivo biocompatibility: an antibiotic resistance gene containing triazole linkages functions in E. coli . Using click ligation, we have synthesized hairpin ribozymes up to 100 nucleotides in length and a hammerhead ribozyme with the triazole linkage located at the substrate cleavage site. At the opposite end of the length scale, click-ligated, cyclic mini-DNA duplexes have been used as models to study base pairing. Cyclic duplexes have

The clot thickens: an incompletely ligated left  atrial appendage

Directory of Open Access Journals (Sweden)

Merrill Thomas

2018-05-01

Full Text Available Our patient presented with known mechanical mitral valve endocarditis documented by 2D transesophageal echocardiogram (TOE from a recent hospitalization at an outside facility. On admission to our center, there was no prior knowledge of an incompletely ligated left atrial appendage (LAA according to patient- or family-reported history, review of outside records or the outside facility’s 2D TOE report. A 3D TOE performed at our center to assess her pathology, since a month had passed from her prior hospitalization, revealed a LAA ligation with evidence of communication to the left atrium and with clot present in the appendage. This case report highlights the common finding of incomplete closure of the LAA following surgical ligation, thus making it inadequate for stroke prevention in patients with atrial fibrillation, and that 3D TOE plays a valuable role in assessing the durability of LAA ligation.

Protein-Templated Fragment Ligations-From Molecular Recognition to Drug Discovery.

Science.gov (United States)

Jaegle, Mike; Wong, Ee Lin; Tauber, Carolin; Nawrotzky, Eric; Arkona, Christoph; Rademann, Jörg

2017-06-19

Protein-templated fragment ligation is a novel concept to support drug discovery and can help to improve the efficacy of protein ligands. Protein-templated fragment ligations are chemical reactions between small molecules ("fragments") utilizing a protein's surface as a reaction vessel to catalyze the formation of a protein ligand with increased binding affinity. The approach exploits the molecular recognition of reactive small-molecule fragments by proteins both for ligand assembly and for the identification of bioactive fragment combinations. In this way, chemical synthesis and bioassay are integrated in one single step. This Review discusses the biophysical basis of reversible and irreversible fragment ligations and gives an overview of the available methods to detect protein-templated ligation products. The chemical scope and recent applications as well as future potential of the concept in drug discovery are reviewed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rubber band ligation and infrared photocoagulation for the outpatient treatment of hemorrhoidal disease.

Science.gov (United States)

Ricci, Maurício Pichler; Matos, Délcio; Saad, Sarhan Sydney

2008-01-01

To compare the results of rubber band ligation and infrared photocoagulation for the treatment of hemorrhoidal disease through the analysis of the incidence of complications after each treatment and respective success rate. Forty-eight patients with first, second or third degree hemorrhoidal disease were randomized to receive treatment with either rubber band ligation (n=23) or infrared photocoagulation (n=25). Each patient was assessed at 1 week and 4 week intervals after treatment. We compared the incidence of complications and efficiency of each treatment modality and Qui-square, Fisher's Exact Test and Student's t Test were used to statistical analysis. Bleeding occured in eight (34,7%) patients treated with rubber band ligation and in four (16,0%) after infrared photocoagulation (p=0,243). Thirteen (52,0%) patients felt pain during infrared photocoagulation and 9 (39,1%) after rubber band ligation (p=0,546). After rubber band ligation, 14 (60,8%) required medication for pain relief. One patient (4,0%) required medication after infrared photocoagulation (prubber band ligator and 1 (4,0%) treated with infrared photocoagulation had symptomatic mucosal ulcers. Perianal dermatitis occured in two (8,0%) patients treated with infrared photocoagulation and one patient (4,3%) was observed to have prolapsed thrombosed piles after rubber band ligation. One month after treatment, 17 of 23 patients treated with rubber band ligation (73,9%) and 18 of 25 patients treated with infrared photocoagulation were asymptomatic. Rubber band ligation treated bleeding and prolapse in 90,0% and 82,4% respectively. Infrared photocoagulation treats bleeding and prolapse in 93,7% and 87,5% respectively. Those differences are not significant. Rubber band ligation causes significantly more pain than infrared photocoagulation during the first week after the procedures and their success rate are not different after four weeks of treatment.

21 CFR 876.4400 - Hemorrhoidal ligator.

Science.gov (United States)

2010-04-01

...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4400 Hemorrhoidal ligator. (a... of a ligature or band placed around the hemorrhoid. (b) Classification. Class II (performance...

[Comparison of band ligation with sclerotherapy for the treatment of bleeding esophageal varices].

Science.gov (United States)

Ríos, Eddy; Sierralta, Armando; Abarzúa, Marigraciela; Bastías, Joaquín; Barra, María Inés

2012-06-01

Endoscopic band ligation is the treatment of choice for bleeding esophageal varices. However it is not clear if this procedure is associated with less early and late mortality than sclerotherapy. To assess rates of re-bleeding and mortality in cohorts of patients with bleeding esophageal varices treated with endoscopic injection or band ligation. Analysis of medical records and endoscopy reports of two cohorts of patients with bleeding esophageal varices, treated between 1990 and 2010. Of these, 54 patients were treated with sclerotherapy and 90 patients with band ligation. A third cohort of 116 patients that did not require endoscopic treatment, was included. The mean analyzed follow up period was 2.5 years (range 1-16). Collection of data was retrospective for patients treated with sclerotherapy and prospective for patients treated with band ligation. Rates of re-bleeding and medium term mortality were assessed. During the month ensuing the first endoscopic treatment, re-bleeding was recorded in 39 and 72% of patients treated with band ligation and sclerotherapy, respectively (p < 0.01). The relative risk of bleeding after band ligation was 0.53 (95% confidence limits 0.390.73). Death rates until the end of follow up were 20 and 48% among patients with treated with band ligation and sclerotherapy, respectively (p < 0.01), with a relative risk of dying for patients subjected to band ligation of 0.41 (95% confidence limits 0.25-0.68). Band ligation was associated with lower rates of re-bleeding and mortality in these cohorts of patients.

A game theory approach for competition and cooperation among project’s subcontractors with interaction activities

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Ashkan Hafezalkotob

2017-04-01

Full Text Available Some projects are often performed by many subcontractors that cooperate with each other and some of them are conducted by outsourcing them to several firms; so subcontractors carry out activities in competition. Appropriate trade-off between time and cost and achieving more benefit and cost saving are objectives of both models. In this paper, it is investigated that how different subcontractors of a project can cooperate to achieve more advantages if possible and how sub-contractors can compete to make the results better and find the optimum cost to minimize the time for each of them. The competition here does not mean eliminating a competitor, but the aim is to challenge the contractors in order to choose the best decision. The purpose of this study is to address the challenges in time and cost management and to find more profit allocation among subcontractors and fair competition for fair allocation as well. A model based on cooperative game theory in time/cost trade-off problem of projects is suggested and then a competition model among subcontractors based on non-cooperative game theory is proposed. A case study is rep-resented to comprehensively illustrate the problem, the cooperative techniques of cooperative game theory, and the payoff matrix of non-cooperative model among subcontractors. Results of the proposed model reveal that subcontractors can obtain higher profit from cooperation if pos-sible. When they outsource the project and compete with each other, they must consider the in-teraction activities and choose the best strategies for cost saving and gain more reward from the client. Moreover, it is found that some techniques such as Shapley value, Core, Max-Min Core, or Equal Profit Method (EPM are able to fairly assign extra profit of cooperation, and using the payoff matrix, Nash equilibrium, and Nash bargaining helps to find the optimum point to mini-mize time and cost for interaction activities state.

MinT: Middleware for Cooperative Interaction of Things.

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Jeon, Soobin; Jung, Inbum

2017-06-20

This paper proposes an Internet of Things (IoT) middleware called Middleware for Cooperative Interaction of Things (MinT). MinT supports a fully distributed IoT environment in which IoT devices directly connect to peripheral devices easily construct a local or global network, and share their data in an energy efficient manner. MinT provides a sensor abstract layer, a system layer and an interaction layer. These enable integrated sensing device operations, efficient resource management, and active interconnection between peripheral IoT devices. In addition, MinT provides a high-level API to develop IoT devices easily for IoT device developers. We aim to enhance the energy efficiency and performance of IoT devices through the performance improvements offered by MinT resource management and request processing. The experimental results show that the average request rate increased by 25% compared to Californium, which is a middleware for efficient interaction in IoT environments with powerful performance, an average response time decrease of 90% when resource management was used, and power consumption decreased by up to 68%. Finally, the proposed platform can reduce the latency and power consumption of IoT devices.

Antinociceptive synergism of gabapentin and nortriptyline in mice with partial sciatic nerve ligation.

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Miranda, Hugo F; Noriega, Viviana; Zepeda, Ramiro; Zanetta, Pilar; Prieto-Rayo, Josefina; Prieto, Juan Carlos; Sierralta, Fernando

2015-01-01

Neuropathic pain results from nerve injury, and gabapentin, an antiepileptic drug, has been approved for the treatment of several types of neuropathic pain. On the other hand, nortriptyline, an antidepressant drug, has been suggested as an alternative treatment. In partial sciatic nerve ligation (PSNL) mice, the interaction of gabapentin with nortriptyline was evaluated by the hot plate assay using isobolographic analysis. Gabapentin (3-100 mg/kg, i.p.) or nortriptyline (1-30 mg/kg, i.p.) induced dose-dependent antinociception, with an ED50 of 11.60 ± 0.54 mg/kg for gabapentin and of 5.16 ± 0.21 mg/kg for nortriptyline. The potency of gabapentin and nortriptyline in PSNL mice at 7 and 14 days after ligation was significantly increased (p < 0.05). Coadministration of gabapentin with nortriptyline, at a 1:1 ratio of their ED50, had a synergistic effect, with an interaction index of 0.311 and 0.348 for these mice at 7 and 14 days, respectively. The data showed a synergy in antinociception at a gabapentin-to-nortriptyline ratio of 1:1 in PSNL mice. This finding suggests that this combination could provide a therapeutic alternative that can be used for neuropathic pain management. © 2015 S. Karger AG, Basel.

Comparison and transfer testing of multiplex ligation detection methods for GM plants

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Ujhelyi Gabriella

2012-01-01

Full Text Available Abstract Background With the increasing number of GMOs on the global market the maintenance of European GMO regulations is becoming more complex. For the analysis of a single food or feed sample it is necessary to assess the sample for the presence of many GMO-targets simultaneously at a sensitive level. Several methods have been published regarding DNA-based multidetection. Multiplex ligation detection methods have been described that use the same basic approach: i hybridisation and ligation of specific probes, ii amplification of the ligated probes and iii detection and identification of the amplified products. Despite they all have this same basis, the published ligation methods differ radically. The present study investigated with real-time PCR whether these different ligation methods have any influence on the performance of the probes. Sensitivity and the specificity of the padlock probes (PLPs with the ligation protocol with the best performance were also tested and the selected method was initially validated in a laboratory exchange study. Results Of the ligation protocols tested in this study, the best results were obtained with the PPLMD I and PPLMD II protocols and no consistent differences between these two protocols were observed. Both protocols are based on padlock probe ligation combined with microarray detection. Twenty PLPs were tested for specificity and the best probes were subjected to further evaluation. Up to 13 targets were detected specifically and simultaneously. During the interlaboratory exchange study similar results were achieved by the two participating institutes (NIB, Slovenia, and RIKILT, the Netherlands. Conclusions From the comparison of ligation protocols it can be concluded that two protocols perform equally well on the basis of the selected set of PLPs. Using the most ideal parameters the multiplicity of one of the methods was tested and 13 targets were successfully and specifically detected. In the

Therapeutic efficacy of self-ligating brackets: A systematic review.

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Dehbi, Hasnaa; Azaroual, Mohamed Faouzi; Zaoui, Fatima; Halimi, Abdelali; Benyahia, Hicham

2017-09-01

Over the last few years, the use of self-ligating brackets in orthodontics has progressed considerably. These systems have been the subject of numerous studies with good levels of evidence making it possible to evaluate their efficacy and efficiency compared to conventional brackets. The aim of this study was to evaluate the therapeutic efficacy of self-ligating brackets by means of a systematic review of the scientific literature. A systematic study was undertaken in the form of a recent search of the electronic Pubmed database, oriented by the use of several keywords combined by Boolean operators relating to the therapeutic efficacy of self-ligating brackets through the study of tooth alignment, space closure, expansion, treatment duration and degree of discomfort. The search was limited to randomized controlled studies, and two independent readers identified studies corresponding to the selection criteria. The chosen articles comprised 20 randomized controlled trials. The studies analyzed revealed the absence of significant differences between the two types of system on the basis of the clinical criteria adopted, thereby refuting the hypothesis of the superiority of self-ligating brackets over conventional systems. Copyright © 2017 CEO. Published by Elsevier Masson SAS. All rights reserved.

An in vitro study into the efficacy of complex tooth alignment with conventional and self-ligating brackets.

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Montasser, M A; Keilig, L; Bourauel, C

2015-02-01

To evaluate the efficacy of tooth alignment achieved by various small cross-section archwire/bracket combinations using the orthodontic measurement and simulation system. The study comprised three types of orthodontic brackets 1) conventional ligating (Victory Series and Mini-Taurus), 2) self-ligating (SmartClip a passive self-ligating bracket and Time3 an active self-ligating bracket), and 3) a conventional low-friction bracket (Synergy). All brackets had a nominal 0.022″ slot size. Brackets were combined with 1) 0.012″ stainless steel, 2) 0.012″ Orthonol, 3) 0.012″ Thermalloy, and 4) 0.0155″ coaxial archwires. Archwires were tied to the conventional brackets with stainless steel ligatures and elastomeric rings. The malocclusion simulated represented a central upper incisor displaced 2 mm gingivally (x-axis) and 2 mm labially (z-axis). The inciso-gingival correction achieved by the different archwire/bracket combinations ranged from 15 to 95%, while the labio-lingual correction ranged from 10 to 95%. The smallest correction was achieved by coaxial, Orthonol, and thermally archwires when ligated with the elastomeric rings to conventional brackets. Stainless steel archwires achieved from 65 to 90% of inciso-gingival correction and from 60 to 90% of labio-lingual correction. The resultant tooth alignment was the product of interaction between the archwire type, bracket type, and bracket design including ligature type. Small cross-sectional archwires might produce up to 95% correction if combined properly with the bracket system. Elastomeric rings when used with conventional brackets limit the efficacy of malalignment correction. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Efficient DNA ligation in DNA–RNA hybrid helices by Chlorella virus DNA ligase

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Lohman, Gregory J. S.; Zhang, Yinhua; Zhelkovsky, Alexander M.; Cantor, Eric J.; Evans, Thomas C.

2014-01-01

Single-stranded DNA molecules (ssDNA) annealed to an RNA splint are notoriously poor substrates for DNA ligases. Herein we report the unexpectedly efficient ligation of RNA-splinted DNA by Chlorella virus DNA ligase (PBCV-1 DNA ligase). PBCV-1 DNA ligase ligated ssDNA splinted by RNA with kcat ≈ 8 x 10−3 s−1 and KM DNA ligase produced only 5′-adenylylated DNA with a 20-fold lower kcat and a KM ≈ 300 nM. The rate of ligation increased with addition of Mn2+, but was strongly inhibited by concentrations of NaCl >100 mM. Abortive adenylylation was suppressed at low ATP concentrations (8, leading to increased product yields. The ligation reaction was rapid for a broad range of substrate sequences, but was relatively slower for substrates with a 5′-phosphorylated dC or dG residue on the 3′ side of the ligation junction. Nevertheless, PBCV-1 DNA ligase ligated all sequences tested with 10-fold less enzyme and 15-fold shorter incubation times than required when using T4 DNA ligase. Furthermore, this ligase was used in a ligation-based detection assay system to show increased sensitivity over T4 DNA ligase in the specific detection of a target mRNA. PMID:24203707

Vitamin K1 attenuates bile duct ligation-induced liver fibrosis in rats.

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Jiao, Kun; Sun, Quan; Chen, Baian; Li, Shengli; Lu, Jing

2014-06-01

Vitamin K1 is used as a liver protection drug for cholestasis-induced liver fibrosis in China, but the mechanism of vitamin K1's action in liver fibrosis is unclear. In this study, a model of liver fibrosis was achieved via bile duct ligation in rats. The rats were then injected with vitamin K1, and the levels of serum aspartate aminotransferase, alanine transaminase, total bilirubin and the fibrotic grade score, collagen content, the expressions of α-smooth muscle actin (SMA) and cytokeratin 19 (CK19) were measured on day 28 after ligation. The levels of the biochemical parameters, fibrotic score and collagen content were significantly reduced by treatment with vitamin K1 in bile duct-ligated rats. In addition, α-SMA and CK19 expression was significantly reduced by vitamin K1 treatment in bile duct-ligated rats. These results suggested that vitamin K1 may attenuate liver fibrosis by inhibiting hepatic stellate cell activation in bile duct-ligated rats.

Friction behavior of self-ligating and conventional brackets with different ligature systems.

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Szczupakowski, Alexandra; Reimann, Susanne; Dirk, Cornelius; Keilig, Ludger; Weber, Anna; Jäger, Andreas; Bourauel, Christoph

2016-07-01

Self-ligating brackets are widely believed to offer better clinical efficiency and, in particular, less friction. Thus, the goal of this in vitro investigation was to assess the friction behavior of different bracket/archwire/ligature combinations during simulated canine retraction. An important aspect of this work was to determine whether conventional bracket systems behave differently in passive or active self-ligating brackets used with a Slide™ ligature, an elastic ligature, or a steel ligature. Three conventional (Contour, Class One; Discovery(®), Dentaurum; Mystique MB, GAC) and six self-ligating (Carriere SL, Class One; Clarity™ SL, 3M Unitek; Damon3, Ormco; In-Ovation(®) C, GAC; Speed Appliance, Speed System™; QuicKlear(®), Forestadent(®)) bracket systems were analyzed. All brackets featured a 0.022″ slot (0.56 mm). Each conventional system was tested with a steel ligature (0.25 mm; Remanium(®), Dentaurum), an elastic ligature (1.3 mm in diameter; Dentalastics, Dentaurum), and a modified elastic ligature (Slide™; Leone(®)). Each combination was used with four archwires, including rectangular stainless steel (0.46 × 0.64 mm, 0.018 × 0.025″, Dentaurum), rectangular nickel-titanium with Teflon coating (0.46 × 0.64 mm, 0.018 × 0.025″, Forestadent(®)), round coaxial nickel-titanium (0.46 mm, 0.018″, Speed), and half-round/half-square (D-profile) stainless steel (0.46 mm, 0.018″, Speed). In the orthodontic measurement and simulation system (OMSS), retraction of a canine was simulated on a Frasaco model replicated in resin. Based on the force systems, the respective friction values were determined. For each combination of materials, five brackets of the same type were tested and five single measurements performed. Friction values were found to vary distinctly with the different combinations, modifiers being the ligature systems and the archwire types. Any significant friction differences between the steel-ligated, Slide™-ligated

Banding ligation versus beta-blockers as primary prophylaxis in esophageal varices

DEFF Research Database (Denmark)

Gluud, Lise L; Klingenberg, Sarah; Nikolova, Dimitrinka

2007-01-01

To compare banding ligation versus beta-blockers as primary prophylaxis in patients with esophageal varices and no previous bleeding.......To compare banding ligation versus beta-blockers as primary prophylaxis in patients with esophageal varices and no previous bleeding....

Hemothorax following Uncomplicated Endoscopic Variceal Sclerotherapy and Ligation for Esophageal Varices

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Tomoko Ochiai

2017-09-01

Full Text Available Endoscopic variceal sclerotherapy and ligation are standard treatment modalities used for the management of esophageal varices. Reportedly, sclerotherapy and ligation are associated with complications such as hematuria, pulmonary thrombus formation, pleural effusion, renal dysfunction, and esophageal stenosis. However, hemothorax following sclerotherapy and ligation has not yet been reported. We treated a patient who presented with liver cirrhosis and polycythemia vera and later developed hemothorax following the above-mentioned procedures. An 86-year-old man diagnosed with liver cirrhosis due to chronic hepatitis type B and alcohol abuse underwent variceal sclerotherapy using ethanolamine oleate to treat his esophageal varices. Oozing from the esophageal varices continued even after the sclerotherapy procedure; therefore, we performed endoscopic variceal ligation. The patient developed left-sided hemothorax within 24 h after treatment of his varices, and an emergency thoracotomy was performed. A pulmonary ligament of the left lung was bulging and ripping because of mediastinal hematoma, and oozing was noted. Cessation of bleeding was noted after the laceration of the left pulmonary ligament had been sutured. Ours is the first case of hemothorax reported in a patient following an uncomplicated procedure of sclerotherapy and ligation.

Joint effects of asymmetric payoff and reciprocity mechanisms on collective cooperation in water sharing interactions: a game theoretic perspective.

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Cho Nam Ng

Full Text Available Common-pool resource (CPR dilemmas distinguish themselves from general public good problems by encompassing both social and physical features. This paper examines how a physical mechanism, namely asymmetric payoff; and a social mechanism, reciprocity; simultaneously affect collective cooperation in theoretical water sharing interactions. We present an iterative N-person game theoretic model to investigate the joint effects of these two mechanisms in a linear fully connected river system under three information assumptions. From a simple evolutionary perspective, this paper quantitatively addresses the conditions for Nash Equilibrium in which collective cooperation might be established. The results suggest that direct reciprocity increases every actor's motivation to contribute to the collective good of the river system. Meanwhile, various upstream and downstream actors manifest individual disparities as a result of the direct reciprocity and asymmetric payoff mechanisms. More specifically, the downstream actors are less willing to cooperate unless there is a high probability that long-term interactions are ensured; however, a greater level of asymmetries is likely to increase upstream actors' incentives to cooperate even though the interactions could quickly end. The upstream actors also display weak sensitivity to an increase in the total number of actors, which generally results in a reduction in the other actors' motivation for cooperation. It is also shown that the indirect reciprocity mechanism relaxes the overall conditions for cooperative Nash Equilibrium.

Heated oligonucleotide ligation assay (HOLA): an affordable single nucleotide polymorphism assay.

Science.gov (United States)

Black, W C; Gorrochotegui-Escalante, N; Duteau, N M

2006-03-01

Most single nucleotide polymorphism (SNP) detection requires expensive equipment and reagents. The oligonucleotide ligation assay (OLA) is an inexpensive SNP assay that detects ligation between a biotinylated "allele-specific detector" and a 3' fluorescein-labeled "reporter" oligonucleotide. No ligation occurs unless the 3' detector nucleotide is complementary to the SNP nucleotide. The original OLA used chemical denaturation and neutralization. Heated OLA (HOLA) instead uses a thermal stable ligase and cycles of denaturing and hybridization for ligation and SNP detection. The cost per genotype is approximately US$1.25 with two-allele SNPs or approximately US$1.75 with three-allele SNPs. We illustrate the development of HOLA for SNP detection in the Early Trypsin and Abundant Trypsin loci in the mosquito Aedes aegypti (L.) and at the a-glycerophosphate dehydrogenase locus in the mosquito Anopheles gambiae s.s.

[Comparison of root resorption between self-ligating and conventional brackets using cone-beam CT].

Science.gov (United States)

Liu, Yun; Guo, Hong-ming

2016-04-01

To analyze the differences of root resorption between passive self-ligating and conventional brackets, and to determine the relationship between passive self-ligating brackets and root resorption. Fifty patients were randomly divided into 2 groups using passive self-ligating brackets or conventional straight wire brackets (0.022 system), respectively. Cone-beam CT was taken before and after treatment. The amount of external apical root resorption of maxillary incisors was measured on CBCT images. Student's t test was performed to analyze the differences of root apical resorption between the 2 groups with SPSS17.0 software package. No significant difference(P> 0.05) in root resorption of maxillary incisors was found between passive self-ligating brackets and conventional brackets. Passive self-ligating brackets and conventional brackets can cause root resorption, but the difference was not significant. Passive self-ligating brackets do not induce more root resorption.

Synthesis of coumarin or ferrocene labeled nucleosides via Staudinger ligation

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Kois Pavol

2006-11-01

Full Text Available Abstract Background Reaction of azides with triaryl phosphines under mild conditions gives iminophosphoranes which can react with almost any kind of electrophilic reagent, e.g. aldehydes/ketones to form imines or esters to form amides. This so-called Staudinger ligation has been employed in a wide range of applications as a general tool for bioconjugation including specific labeling of nucleic acids. Results A new approach for the preparation of labeled nucleosides via intermolecular Staudinger ligation is described. Reaction of azidonucleosides with triphenylphosphine lead to iminophosphorane intermediates, which react subsequently with derivatives of coumarin or ferrocene to form coumarin or ferrocene labeled nucleosides. Fluorescent properties of coumarin labeled nucleosides are determined. Conclusion New coumarin and ferrocene labeled nucleosides were prepared via intermolecular Staudinger ligation. This reaction joins the fluorescent coumarin and biospecific nucleoside to the new molecule with promising fluorescent and electrochemical properties. The isolated yields of products depend on the structure of azidonucleoside and carboxylic acids. A detailed study of the kinetics of the Staudinger ligation with nucleoside substrates is in progress.

En bloc ligation of renal vessels is safe and reduces duration of surgery

DEFF Research Database (Denmark)

Azawi, Nessn Htum; Hult, Mariam Annalisa Skibsted; Dahl, Claus

2016-01-01

INTRODUCTION: Conventionally, individual ligation of the renal vessels with clips is performed during laparoscopic nephrectomy (LN). Concomitant ligation of the vessels is not a standard procedure due to an expected risk of stapler dysfunction and the development of arteriovenous fistulas (AVF......). Using the EndoGIA stapler 45/2.5 mm, we compared en bloc ligation with individual ligation during LN and nephroureterectomy (LNU) with a special focus on the development of AVF and technique safety. METHODS: This was a retrospective study of all patients undergoing LN or LNU at the Department of Urology......, Roskilde Hospital, Denmark, between January 2010 and April 2014. The follow-up period was minimum six months. RESULTS: A total of 228 patients underwent LN and 56 patients underwent LNU. In the LN group, 77 patients underwent en bloc ligation. The mean surgical time was significantly reduced to 89 minutes...

Interactions between Preservice and Cooperating Teachers and Knowledge Construction during Post-Lesson Interviews

Science.gov (United States)

Chalies, S.; Ria, L.; Bertone, S.; Trohel, J.; Durand, M.

2004-01-01

This study analysed the relationships between (a) the nature of the interactions between preservice teachers and their cooperating teachers and (b) the knowledge that the teachers constructed, validated or invalidated during post-lesson interviews. Six interview excerpts, chosen as having been particularly instructive, were analysed from the…

Interaction of light with planar lattices of atoms: Reflection, transmission, and cooperative magnetometry

Science.gov (United States)

Facchinetti, G.; Ruostekoski, J.

2018-02-01

We study strong, light-mediated, resonant dipole-dipole interactions in two-dimensional planar lattices of cold atoms. We provide a detailed analysis for the description of the dipolar point emitter lattice plane as a "superatom" whose response is similar to electromagnetically induced transparency but which exhibits an ultranarrow collective size-dependent subradiant resonance linewidth. The superatom model provides intuitively simple descriptions for the spectral response of the array, including the complete reflection, full transmission, narrow Fano resonances, and asymptotic expressions for the resonance linewidths of the collective eigenmodes. We propose a protocol to transfer almost the entire radiative excitation to a single correlated subradiant eigenmode in a lattice and show that the medium obtained by stacked lattice arrays can form a cooperative magnetometer. Such a magnetometer utilizes similar principles as magnetometers based on the electromagnetically induced transparency. The accuracy of the cooperative magnetometer, however, is not limited by the single-atom resonance linewidth but the much narrower collective linewidth that results from the strong dipole-dipole interactions.

Exposure to superfluous information reduces cooperation and increases antisocial punishment in reputation-based interactions

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Miguel edos Santos

2014-08-01

Full Text Available Human cooperation is often based on reputation gained from previous interactions with third parties. Such reputation can be built on generous or punitive actions, and both, one’s own reputation and the reputation of others have been shown to influence decision making in experimental games that control for confounding variables. Here we test how reputation-based cooperation and punishment react to disruption of the cognitive processing in different kinds of helping games with observers. Saying a few superfluous words before each interaction was used to possibly interfere with working memory. In a first set of experiments, where reputation could only be based on generosity, the disruption reduced the frequency of cooperation and lowered mean final payoffs. In a second set of experiments where reputation could only be based on punishment, the disruption increased the frequency of antisocial punishment (i.e. of punishing those who helped and reduced the frequency of punishing defectors. Our findings suggest that working memory can easily be constraining in reputation-based interactions within experimental games, even if these games are based on a few simple rules with a visual display that provides all the information the subjects need to play the strategies predicted from current theory. Our findings also highlight a weakness of experimental games, namely that they can be very sensitive to environmental variation and that quantitative conclusions about antisocial punishment or other behavioral strategies can easily be misleading.

Experience of rubber band ligation for haemorrhoidal disease

International Nuclear Information System (INIS)

Hadi, A.; Aman, Z.; Anwar, F.; Khan, M.; Iqbal, Z.

2011-01-01

Objectives: To assess symptomatic relief in haemorrhoidal disease using rubber band ligation. Settings and duration: Surgical unit, Hayatabad Medical Complex, Peshawar from July 2007 to June 2009. Patients and Methods: All patients presenting with rectal bleeding or prolapse underwent proto copy to determine the cause of bleeding. Only patients with first, second and third degree haemorrhoids (bleeding and prolapse) were selected for the study and they underwent rubber band ligation in two sessions, 6 weeks apart. Patients were followed in the OPD at 3 months and one year when their subjective and objective symptoms were noted followed by rectal examination and proctoscopy. Therapeutic response was assessed by symptomatic improvement in bleeding and prolapse of hemorrhoids and any complications. Results: A total of 105 patients underwent rubber band ligation. There were 65(62%) males and 40(38%) females with a male to female ratio of 1.6:1. Age of the patients ranged from 21-65 years (+- 2.4 SD). Twenty three (21.9%) patients had first degree, 50(47.6%) had second degree and 32(30.5%) had third degree haemorrhoids. Forty-eight patients (45.7%) presented with degree, 50(47.6%) had second prolapse, 33(31.4%) had both bleeding and prolapse and 23(21.9%) had bleeding only. At 3 months of follow up rubber band ligation cured 76(72.4%) patients, improved 13(12.4%) and failed in 7(6.7%) patients. At one year follow up, recurrence of bleeding and prolapse occurred in 16(15.2%) patients having third degree haemorrhoids. Overall success was third achieved in 89(84.8%) cases. Complications were seen in 20(19.1%) patients which were of mild to moderate nature and no serious/ life threatening complications were noted. Conclusion: Rubber band legislation is a rapid and safe procedure for testing first, second and and early third degree Conclusions: Rubber band ligation is a rapid and safe non operative procedure for treating first, second and third degree haemorrhoids on out

The Effect of Various Ligation Methods on Friction in Sliding Mechanics

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Amit Gupta

2013-01-01

Conclusion: Slide modules produce least friction followed by loose SS ligation, slick modules, regular modules, tight SS ligation and highest friction was produced by regular modules tied in a ′figure of 8′ pattern. Width of bracket had no influence on friction produced.

Cholestasis progression effects on long-term memory in bile duct ligation rats

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Nasrin Hosseini

2014-01-01

Full Text Available Background : There is evidence that cognitive functions are affected by some liver diseases such as cholestasis. Bile duct ligation induces cholestasis as a result of impaired liver function and cognition. This research investigates the effect of cholestasis progression on memory function in bile duct ligation rats. Materials and Methods: Male Wistar rats were randomly divided into five groups, which include: control group for BDL-7, control group for BDL-21, sham group (underwent laparotomy without bile duct ligation, BDL-7 group (7 days after bile duct ligation, and BDL-21 group (21 days after bile duct ligation. Step-through passive avoidance test was employed to examine memory function. In all groups, short-term (7 days after foot shock and long-term memories (21 days after foot shock were assessed. Results: Our results showed that liver function significantly decreased with cholestasis progression (P < 0.01. Also our findings indicated BDL-21 significantly impaired acquisition time (P < 0.05. Memory retrieval impaired 7 (P < 0.05 and 21 days (P < 0.001 after foot shock in BDL-7 and BDL-21 groups, respectively. Conclusion: Based on these findings, liver function altered in cholestasis and memory (short-term and long-term memory impaired with cholestasis progression in bile duct ligation rats. Further studies are needed to better insight the nature of progression of brain damage in cholestatic disease.

Effect of Growing Size of Interaction Neighbors on the Evolution of Cooperation in Spatial Snowdrift Game

International Nuclear Information System (INIS)

Zhang Juanjuan; Sun Shiwen; Wang Li; Xia Chengyi; Wang Juan; Wang Zhen

2012-01-01

In this paper, we study the influence of the size of interaction neighbors (k) on the evolution of cooperation in the spatial snowdrift game. At first, we consider the effects of noise K and cost-to-benefit ratio r, the simulation results indicate that the evolution of cooperation depends on the combined action of noise and cost-to-benefit ratio. For a lower r, the cooperators are multitudinous and the cooperation frequency ultimately increases to 1 as the increase of noise. However, for a higher r, the defectors account for the majority of the game and dominate the game if the noise is large enough. Then we mainly investigate how k influences the evolution of cooperation by varying the noise in detail. We find that the frequency of cooperators is closely related to the size of neighborhood and cost-to-benefit ratio r. In the case of lower r, the augmentation of k plays no positive role in promoting the cooperation as compared with that of k = 4, while for higher r the cooperation is improved for a growing size of neighborhood. At last, based on the above discussions, we explore the cluster-forming mechanism among the cooperators. The current results are beneficial to further understand the evolution of cooperation in many natural, social and biological systems. (general)

Urokinase-type plasminogen activator receptor (uPAR) ligation induces a raft-localized integrin signaling switch that mediates the hypermotile phenotype of fibrotic fibroblasts.

Science.gov (United States)

Grove, Lisa M; Southern, Brian D; Jin, Tong H; White, Kimberly E; Paruchuri, Sailaja; Harel, Efrat; Wei, Ying; Rahaman, Shaik O; Gladson, Candece L; Ding, Qiang; Craik, Charles S; Chapman, Harold A; Olman, Mitchell A

2014-05-02

The urokinase-type plasminogen activator receptor (uPAR) is a glycosylphosphatidylinositol-linked membrane protein with no cytosolic domain that localizes to lipid raft microdomains. Our laboratory and others have documented that lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) exhibit a hypermotile phenotype. This study was undertaken to elucidate the molecular mechanism whereby uPAR ligation with its cognate ligand, urokinase, induces a motile phenotype in human lung fibroblasts. We found that uPAR ligation with the urokinase receptor binding domain (amino-terminal fragment) leads to enhanced migration of fibroblasts on fibronectin in a protease-independent, lipid raft-dependent manner. Ligation of uPAR with the amino-terminal fragment recruited α5β1 integrin and the acylated form of the Src family kinase, Fyn, to lipid rafts. The biological consequences of this translocation were an increase in fibroblast motility and a switch of the integrin-initiated signal pathway for migration away from the lipid raft-independent focal adhesion kinase pathway and toward a lipid raft-dependent caveolin-Fyn-Shc pathway. Furthermore, an integrin homologous peptide as well as an antibody that competes with β1 for uPAR binding have the ability to block this effect. In addition, its relative insensitivity to cholesterol depletion suggests that the interactions of α5β1 integrin and uPAR drive the translocation of α5β1 integrin-acylated Fyn signaling complexes into lipid rafts upon uPAR ligation through protein-protein interactions. This signal switch is a novel pathway leading to the hypermotile phenotype of IPF patient-derived fibroblasts, seen with uPAR ligation. This uPAR dependent, fibrotic matrix-selective, and profibrotic fibroblast phenotype may be amenable to targeted therapeutics designed to ameliorate IPF.

Vocal cord paralysis post patent ductus arteriosus ligation surgery: risks and co-morbidities.

Science.gov (United States)

Rukholm, Gavin; Farrokhyar, Forough; Reid, Diane

2012-11-01

1. To determine the prevalence of left vocal cord paralysis (LVCP) post patent ductus arteriosus (PDA) ligation at a Tertiary Care Centre. 2. To identify risk factors associated with LVCP. 3. To identify co-morbidities associated with LVCP. 4. To determine the frequency of pre- and post-operative nasopharyngolaryngoscopic (NPL) examination in this patient population. Retrospective chart review of all infants who underwent PDA ligation surgery at a tertiary care academic hospital between July 2003 and July 2010. Data on patient age, gender, weight, method of PDA ligation, and results of NPL scoping were collected, as well as patient co-morbidities post PDA ligation. One hundred and fifteen patients underwent PDA ligation surgery. Four patients were excluded due to bilateral vocal cord paralysis. Of the remaining 111 patients, nineteen patients (17.1%) were found to have LVCP. Low birth weight was identified as a significant risk factor for LVCP (p=0.002). Gastroesophageal reflux was identified as a significant co-morbidity associated with LVCP post PDA ligation (p=0.002). Only 0.9% of patients were scoped pre-operatively, and 27.9% were scoped postoperatively. LVCP is associated with multiple morbidities. The authors strongly recommend routine post-operative scoping of all patients post PDA ligation surgery, and preoperative scoping when possible. A prospective study is warranted, in order to confirm the prevalence of LVCP as well as risk factors and associated co-morbidities. Crown Copyright © 2012. Published by Elsevier Ireland Ltd. All rights reserved.

Corrosion behavior of self-ligating and conventional metal brackets

Directory of Open Access Journals (Sweden)

Lúcio Henrique Esmeraldo Gurgel Maia

2014-04-01

Full Text Available Objective: To test the null hypothesis that the aging process in self-ligating brackets is not higher than in conventional brackets. Methods: Twenty-five conventional (GN-3M/Unitek; GE-GAC; VE-Aditek and 25 self-ligating (SCs-3M/Unitek; INs-GAC; ECs-Aditek metal brackets from three manufacturers (n = 150 were submitted to aging process in 0.9% NaCl solution at a constant temperature of 37 ± 1ºC for 21 days. The content of nickel, chromium and iron ions in the solution collected at intervals of 7, 14 and 21 days was quantified by atomic absorption spectrophotometry. After the aging process, the brackets were analyzed by scanning electron microscopy (SEM under 22X and 1,000X magnifications. Results: Comparison of metal release in self-ligating and conventional brackets from the same manufacturer proved that the SCs group released more nickel (p < 0.05 than the GN group after 7 and 14 days, but less chromium (p < 0.05 after 14 days and less iron (p < 0.05 at the three experimental time intervals. The INs group released less iron (p < 0.05 than the GE group after 7 days and less nickel, chromium and iron (p < 0.05 after 14 and 21 days. The ECs group released more nickel, chromium and iron (p < 0.05 than the VE group after 14 days, but released less nickel and chromium (p < 0.05 after 7 days and less chromium and iron (p < 0.05 after 21 days. The SEM analysis revealed alterations on surface topography of conventional and self-ligating brackets. Conclusions: The aging process in self-ligating brackets was not greater than in conventional brackets from the same manufacturer. The null hypothesis was accepted.

Combining ligation reaction and capillary gel electrophoresis to obtain reliable long DNA probes.

Science.gov (United States)

García-Cañas, Virginia; Mondello, Monica; Cifuentes, Alejandro

2011-05-01

New DNA amplification methods are continuously developed for sensitive detection and quantification of specific DNA target sequences for, e.g. clinical, environmental or food applications. These new applications often require the use of long DNA oligonucleotides as probes for target sequences hybridization. Depending on the molecular technique, the length of DNA probes ranges from 40 to 450 nucleotides, solid-phase chemical synthesis being the strategy generally used for their production. However, the fidelity of chemical synthesis of DNA decreases for larger DNA probes. Defects in the oligonucleotide sequence result in the loss of hybridization efficiency, affecting the sensitivity and selectivity of the amplification method. In this work, an enzymatic procedure has been developed as an alternative to solid-phase chemical synthesis for the production of long oligonucleotides. The enzymatic procedure for probe production was based on ligation of short DNA sequences. Long DNA probes were obtained from smaller oligonucleotides together with a short sequence that acts as bridge stabilizing the molecular complex for DNA ligation. The ligation reactions were monitored by capillary gel electrophoresis with laser-induced fluorescence detection (CGE-LIF) using a bare fused-silica capillary. The capillary gel electrophoresis-LIF method demonstrated to be very useful and informative for the characterization of the ligation reaction, providing important information about the nature of some impurities, as well as for the fine optimization of the ligation conditions (i.e. ligation cycles, oligonucleotide and enzyme concentration). As a result, the yield and quality of the ligation product were highly improved. The in-lab prepared DNA probes were used in a novel multiplex ligation-dependent genome amplification (MLGA) method for the detection of genetically modified maize in samples. The great possibilities of the whole approach were demonstrated by the specific and sensitive

Infrared coagulation versus rubber band ligation in early stage hemorrhoids.

Science.gov (United States)

Gupta, P J

2003-10-01

The ideal therapy for early stages of hemorrhoids is always debated. Some are more effective but are more painful, others are less painful but their efficacy is also lower. Thus, comfort or efficacy is a major concern. In the present randomized study, a comparison is made between infrared coagulation and rubber band ligation in terms of effectiveness and discomfort. One hundred patients with second degree bleeding piles were randomized prospectively to either rubber band ligation (N = 54) or infrared coagulation (N = 46). Parameters measured included postoperative discomfort and pain, time to return to work, relief in incidence of bleeding, and recurrence rate. The mean age was 38 years (range 19-68 years). The mean duration of disease was 17.5 months (range 12 to 34 months). The number of male patients was double that of females. Postoperative pain during the first week was more intense in the band ligation group (2-5 vs 0-3 on a visual analogue scale). Post-defecation pain was more intense with band ligation and so was rectal tenesmus (P = 0.0059). The patients in the infrared coagulation group resumed their duties earlier (2 vs 4 days, P = 0.03), but also had a higher recurrence or failure rate (P = 0.03). Thus, we conclude that band ligation, although more effective in controlling symptoms and obliterating hemorrhoids, is associated with more pain and discomfort to the patient. As infrared coagulation can be conveniently repeated in case of recurrence, it could be considered to be a suitable alternative office procedure for the treatment of early stage hemorrhoids.

Optimal distribution of incentives for public cooperation in heterogeneous interaction environments

Directory of Open Access Journals (Sweden)

Xiaojie eChen

2014-07-01

Full Text Available In the framework of evolutionary games with institutional reciprocity, limited incentives are at disposal for rewarding cooperators and punishing defectors. In the simplest case, it can be assumed that, depending on their strategies, all players receive equal incentives from the common pool. The question arises, however, what is the optimal distribution of institutional incentives? How should we best reward and punish individuals for cooperation to thrive? We study this problem for the public goods game on a scale-free network. We show that if the synergetic effects of group interactions are weak, the level of cooperation in the population can be maximized simply by adopting the simplest ''equal distribution'' scheme. If synergetic effects are strong, however, it is best to reward high-degree nodes more than low-degree nodes. These distribution schemes for institutional rewards are independent of payoff normalization. For institutional punishment, however, the same optimization problem is more complex, and its solution depends on whether absolute or degree-normalized payoffs are used. We find that degree-normalized payoffs require high-degree nodes be punished more lenient than low-degree nodes. Conversely, if absolute payoffs count, then high-degree nodes should be punished stronger than low-degree nodes.

Neural mirroring and social interaction: Motor system involvement during action observation relates to early peer cooperation.

Science.gov (United States)

Endedijk, H M; Meyer, M; Bekkering, H; Cillessen, A H N; Hunnius, S

2017-04-01

Whether we hand over objects to someone, play a team sport, or make music together, social interaction often involves interpersonal action coordination, both during instances of cooperation and entrainment. Neural mirroring is thought to play a crucial role in processing other's actions and is therefore considered important for social interaction. Still, to date, it is unknown whether interindividual differences in neural mirroring play a role in interpersonal coordination during different instances of social interaction. A relation between neural mirroring and interpersonal coordination has particularly relevant implications for early childhood, since successful early interaction with peers is predictive of a more favorable social development. We examined the relation between neural mirroring and children's interpersonal coordination during peer interaction using EEG and longitudinal behavioral data. Results showed that 4-year-old children with higher levels of motor system involvement during action observation (as indicated by lower beta-power) were more successful in early peer cooperation. This is the first evidence for a relation between motor system involvement during action observation and interpersonal coordination during other instances of social interaction. The findings suggest that interindividual differences in neural mirroring are related to interpersonal coordination and thus successful social interaction. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Decentralized Interactive Architecture for Aerial and Ground Mobile Robots Cooperation

OpenAIRE

Harik, El Houssein Chouaib; Guérin, François; Guinand, Frédéric; Brethé, Jean-François; Pelvillain, Hervé

2014-01-01

International audience; —This paper presents a novel decentralized interactive architecture for aerial and ground mobile robots cooperation. The aerial mobile robot is used to provide a global coverage during an area inspection, while the ground mobile robot is used to provide a local coverage of ground features. We include a human-in-the-loop to provide waypoints for the ground mobile robot to progress safely in the inspected area. The aerial mobile robot follows continuously the ground mobi...

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

Science.gov (United States)

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.

Ligation of internal iliac arteries for control of pelvic haemorrhage.

Directory of Open Access Journals (Sweden)

Nandanwar Y

1993-10-01

Full Text Available This is a retrospective review of the internal iliac ligations (IAL done over a period of 3 years. Both gynaecological and obstetric cases were considered. A total of 46 ligations were performed. The additional treatment required was hysterectomy to control haemorrhage. Intra-and post-operative complications were noted. A comparative review of the effectiveness of IAL in different situations is done and alternative modalities of treatment are considered.

Coronary ligation reduces maximum sustained swimming speed in Chinook salmon, Oncorhynchus tshawytscha

DEFF Research Database (Denmark)

Farrell, A P; Steffensen, J F

1987-01-01

The maximum aerobic swimming speed of Chinook salmon (Oncorhynchus tshawytscha) was measured before and after ligation of the coronary artery. Coronary artery ligation prevented blood flow to the compact layer of the ventricular myocardium, which represents 30% of the ventricular mass, and produced...

Azobenzene Photoswitches for Staudinger-Bertozzi Ligation

NARCIS (Netherlands)

Szymanski, Wiktor; Wu, Bian; Poloni, Claudia; Janssen, Dick B.; Feringa, Ben L.

2013-01-01

A novel family of azobenzenes containing residues needed for aqueous Staudinger–Bertozzi ligation to azides was designed. The resulting photochromes show stable and reversible switching behavior in water, with a photostationary state (PSS) of up to 95:5 cis/trans. Applications in model systems

Isolation and characterization of portal branch ligation-stimulated Hmga2-positive bipotent hepatic progenitor cells

International Nuclear Information System (INIS)

Sakai, Hiroshi; Tagawa, Yoh-ichi; Tamai, Miho; Motoyama, Hiroaki; Ogawa, Shinichiro; Soeda, Junpei; Nakata, Takenari; Miyagawa, Shinichi

2010-01-01

Research highlights: → Hepatic progenitor cells were isolated from the portal branch-ligated liver of mice. → Portal branch ligation-stimulated hepatic progenitor cells (PBLHCs) express Hmga2. → PBLHCs have bidirectional differentiation capability in vitro. -- Abstract: Hepatic stem/progenitor cells are one of several cell sources that show promise for restoration of liver mass and function. Although hepatic progenitor cells (HPCs), including oval cells, are induced by administration of certain hepatotoxins in experimental animals, such a strategy would be inappropriate in a clinical setting. Here, we investigated the possibility of isolating HPCs in a portal branch-ligated liver model without administration of any chemical agents. A non-parenchymal cell fraction was prepared from the portal branch-ligated or non-ligated lobe, and seeded onto plates coated with laminin. Most of the cells died, but a small number were able to proliferate. These proliferating cells were cloned as portal branch ligation-stimulated hepatic cells (PBLHCs) by the limiting dilution method. The PBLHCs expressed cytokeratin19, albumin, and Hmga2. The PBLHCs exhibited metabolic functions such as detoxification of ammonium ions and synthesis of urea on Matrigel-coated plates in the presence of oncostatin M. In Matrigel mixed with type I collagen, the PBLHCs became rearranged into cystic and tubular structures. Immunohistochemical staining demonstrated the presence of Hmga2-positive cells around the interlobular bile ducts in the portal branch-ligated liver lobes. In conclusion, successful isolation of bipotent hepatic progenitor cell clones, PBLHCs, from the portal branch-ligated liver lobes of mice provides the possibility of future clinical application of portal vein ligation to induce hepatic progenitor cells.

Radiological study on the change of duct-ligated parotid gland

International Nuclear Information System (INIS)

Ohnishi, Takashi

1994-01-01

The change of the parotid gland with time following ligation of the main duct was investigated. The duct-ligated parotid gland in rabbit was examined by salivary gland scintigraphy with 99m Tc-pertechnetate ( 99m TcO 4 - ), sialography and microscopic observation. The third day after ligation of the main duct, the outward form of the parotid gland on the static scintigram was not well-defined. On the seventh day, 99m TcO 4 - accumulation was decreased slightly. On the 14th day, atrophy of the parotid gland occurred. The degree of atrophy produced by ligation increases as the duration of the ligation increases. On the 42nd day, the presence of the parotid gland was not recorded practically. The main duct was dilated on the third day. On the seventh day, the intraglandular ducts were bent and strictured. Disappearance of the peripheral duct and atrophy of the parotid gland parenchyma was observed. On microscopic observation, the intraglandular tributaries and the lumen were dilated on the third day. And the reticular fiber was observed that was irregularly formed in parts. The acinar cells were pressed by large and small dilated lumen on the seventh day. On the 14th day, the collagenous fiber around the acini and the duct was increased still more. In addition, fibrosis of the lobule interspace was observed. The degree of atrophy of the acini and lobule was increased maximally on the 42nd day. These results of the salivary gland scintigraphy closely connected with sialograms and microscopic findings. The parotid gland tissue decreases and changings of the duct system were indicated by these imaging methods in detail. (author)

Infrared coagulation versus rubber band ligation in early stage hemorrhoids

Directory of Open Access Journals (Sweden)

P.J. Gupta

2003-10-01

Full Text Available The ideal therapy for early stages of hemorrhoids is always debated. Some are more effective but are more painful, others are less painful but their efficacy is also lower. Thus, comfort or efficacy is a major concern. In the present randomized study, a comparison is made between infrared coagulation and rubber band ligation in terms of effectiveness and discomfort. One hundred patients with second degree bleeding piles were randomized prospectively to either rubber band ligation (N = 54 or infrared coagulation (N = 46. Parameters measured included postoperative discomfort and pain, time to return to work, relief in incidence of bleeding, and recurrence rate. The mean age was 38 years (range 19-68 years. The mean duration of disease was 17.5 months (range 12 to 34 months. The number of male patients was double that of females. Postoperative pain during the first week was more intense in the band ligation group (2-5 vs 0-3 on a visual analogue scale. Post-defecation pain was more intense with band ligation and so was rectal tenesmus (P = 0.0059. The patients in the infrared coagulation group resumed their duties earlier (2 vs 4 days, P = 0.03, but also had a higher recurrence or failure rate (P = 0.03. Thus, we conclude that band ligation, although more effective in controlling symptoms and obliterating hemorrhoids, is associated with more pain and discomfort to the patient. As infrared coagulation can be conveniently repeated in case of recurrence, it could be considered to be a suitable alternative office procedure for the treatment of early stage hemorrhoids.

International cooperation and shortage of doctors: an analysis of the interaction between Brazil, Angola and Cuba.

Science.gov (United States)

Alves, Sandra Mara Campos; Oliveira, Felipe Proenço de; Matos, Mateus Falcão Martins; Santos, Leonor Maria Pacheco; Delduque, Maria Celia

2017-07-01

The shortage of doctors, especially in remote areas, is a critical issue for the development of national health systems and has thus been the focus of a number of international cooperation projects. An exploratory and qualitative study was conducted to examine cooperation between Brazil, Angola and Cuba. A nonsystematic literature review was conducted of selected open access articles and official documents addressing relevant health cooperation initiatives. Previously selected characteristics of actions designed to redress the shortage of doctors were compared. It was concluded that the interactions between the three countries were fruitful and potentially beneficial for the health of the population of these countries. South-South cooperation between these countries showed positive results in the educational and regulatory dimensions and adopted a non-dependence perspective that seeks to strengthen endogenous capacity, which are important factors for evaluating the structural components of health systems.

Effects of cholestasis on learning and locomotor activity in bile duct ligated rats.

Science.gov (United States)

Hosseini, Nasrin; Alaei, Hojjatallah; Nasehi, Mohammad; Radahmadi, Maryam; Mohammad Reza, Zarrindast

2014-01-01

Cognitive functions are impaired in patients with liver disease. Bile duct ligation causes cholestasis that impairs liver function. This study investigated the impact of cholestasis progression on the acquisition and retention times in the passive avoidance test and on the locomotor activity of rats. Cholestasis was induced in male Wistar rats by ligating the main bile duct. Locomotor activity, learning and memory were assessed by the passive avoidance learning test at day 7, day 14, and day 21 post-bile duct ligation. The serum levels of bilirubin, alanine aminotransferase, and alkaline phosphatase were measured. The results showed that acquisition time and locomotor activity were not affected at day 7 and day 14, but they were significantly (P locomotor activity were impaired at 21 days after bile duct ligation following the progression of cholestasis.

Interaction between Dutch soccer teams and fans: a mathematical analysis through cooperative game theory

NARCIS (Netherlands)

Hou, D.; Driessen, Theo

2012-01-01

Inspired by the first lustrum of the Club Positioning Matrix (CPM) for professional Dutch soccer teams, we model the interaction between soccer teams and their potential fans as a cooperative cost game based on the annual voluntary sponsorships of fans in order to validate their fan registration in

NetCooperate: a network-based tool for inferring host-microbe and microbe-microbe cooperation.

Science.gov (United States)

Levy, Roie; Carr, Rogan; Kreimer, Anat; Freilich, Shiri; Borenstein, Elhanan

2015-05-17

Host-microbe and microbe-microbe interactions are often governed by the complex exchange of metabolites. Such interactions play a key role in determining the way pathogenic and commensal species impact their host and in the assembly of complex microbial communities. Recently, several studies have demonstrated how such interactions are reflected in the organization of the metabolic networks of the interacting species, and introduced various graph theory-based methods to predict host-microbe and microbe-microbe interactions directly from network topology. Using these methods, such studies have revealed evolutionary and ecological processes that shape species interactions and community assembly, highlighting the potential of this reverse-ecology research paradigm. NetCooperate is a web-based tool and a software package for determining host-microbe and microbe-microbe cooperative potential. It specifically calculates two previously developed and validated metrics for species interaction: the Biosynthetic Support Score which quantifies the ability of a host species to supply the nutritional requirements of a parasitic or a commensal species, and the Metabolic Complementarity Index which quantifies the complementarity of a pair of microbial organisms' niches. NetCooperate takes as input a pair of metabolic networks, and returns the pairwise metrics as well as a list of potential syntrophic metabolic compounds. The Biosynthetic Support Score and Metabolic Complementarity Index provide insight into host-microbe and microbe-microbe metabolic interactions. NetCooperate determines these interaction indices from metabolic network topology, and can be used for small- or large-scale analyses. NetCooperate is provided as both a web-based tool and an open-source Python module; both are freely available online at http://elbo.gs.washington.edu/software_netcooperate.html.

Direct Interaction between the Voltage Sensors Produces Cooperative Sustained Deactivation in Voltage-gated H+ Channel Dimers*

OpenAIRE

Okuda, Hiroko; Yonezawa, Yasushige; Takano, Yu; Okamura, Yasushi; Fujiwara, Yuichiro

2016-01-01

The voltage-gated H+ channel (Hv) is a voltage sensor domain-like protein consisting of four transmembrane segments (S1?S4). The native Hv structure is a homodimer, with the two channel subunits functioning cooperatively. Here we show that the two voltage sensor S4 helices within the dimer directly cooperate via a ?-stacking interaction between Trp residues at the middle of each segment. Scanning mutagenesis showed that Trp situated around the original position provides the slow gating kineti...

Chemical Ligation of Folded Recombinant Proteins: Segmental Isotopic Labeling of Domains for NMR Studies

Science.gov (United States)

Xu, Rong; Ayers, Brenda; Cowburn, David; Muir, Tom W.

1999-01-01

A convenient in vitro chemical ligation strategy has been developed that allows folded recombinant proteins to be joined together. This strategy permits segmental, selective isotopic labeling of the product. The src homology type 3 and 2 domains (SH3 and SH2) of Abelson protein tyrosine kinase, which constitute the regulatory apparatus of the protein, were individually prepared in reactive forms that can be ligated together under normal protein-folding conditions to form a normal peptide bond at the ligation junction. This strategy was used to prepare NMR sample quantities of the Abelson protein tyrosine kinase-SH(32) domain pair, in which only one of the domains was labeled with 15N Mass spectrometry and NMR analyses were used to confirm the structure of the ligated protein, which was also shown to have appropriate ligand-binding properties. The ability to prepare recombinant proteins with selectively labeled segments having a single-site mutation, by using a combination of expression of fusion proteins and chemical ligation in vitro, will increase the size limits for protein structural determination in solution with NMR methods. In vitro chemical ligation of expressed protein domains will also provide a combinatorial approach to the synthesis of linked protein domains.

Self-ligating versus conventional metallic brackets on Streptococcus mutans retention: A systematic review.

Science.gov (United States)

Longoni, Juliano N; Lopes, Beatriz M; Freires, Irlan A; Dutra, Kamile L; Franco, Ademir; Paranhos, Luiz R

2017-01-01

The present study aimed to review the literature systematically and assess comparatively whether self-ligating metallic brackets accumulate less Streptococcus mutans biofilm than conventional metallic brackets. The systematic search was performed following PRISMA guidelines and registration in PROSPERO. Seven electronic databases (Google Scholar, LILACS, Open Grey, PubMed, SciELO, ScienceDirect, and Scopus) were consulted until April 2016, with no restriction of language and time of publication. Only randomized clinical studies verifying S. mutans colonization in metallic brackets (self-ligating and conventional) were included. All steps were performed independently by two operators. The search resulted in 546 records obtained from the electronic databases. Additionally, 216 references obtained from the manual search of eligible articles were assessed. Finally, a total of 5 studies were included in the qualitative synthesis. In 1 study, the total bacterial count was not different among self-ligating and conventional brackets, whereas in 2 studies the amount was lower for self-ligating brackets. Regarding the specific count of S. mutans , 2 studies showed less accumulation in self-ligating than in conventional brackets. Based on the limited evidence, self-ligating metallic brackets accumulate less S. mutans than conventional ones. However, these findings must be interpreted in conjunction with particularities individual for each patient - such as hygiene and dietary habits, which are components of the multifactorial environment that enables S. Mutans to proliferate and keep retained in the oral cavity.

Factors Promoting Tubal Ligation in Females Presenting to Tertiary Care Centers

Directory of Open Access Journals (Sweden)

Hammad Ali Qazi

2009-09-01

Full Text Available Objective: Despite development of new contraceptive methods, sterilization remained the most widely used method. Our objective was to determine the factors contributing to decision making for tubal ligation in females.Materials and methods: A cross sectional study was conducted in Jinnah Post graduate Medical Centre (JPMC between March - November 2008. About 505 Females using contraceptive measures were consecutively included. Those having any severe debilitating disease and unfamiliar with “urdu” language were excluded. Three trained co researchers conducted structured interviews to determine the frequency and factors associated with tubal ligation.Results: The final multiple logistic regression showed illiteracy [AOR 2.91 95% CI 1.53-5.53], number of children < 3 [AOR 6.15 95% CI 2.61-14.50], age of women < 30 [AOR 0.12 95% CI 0.06-0.22] years and information gained through health worker [AOR 3.04 95% CI 1.60-5.80] to be statistically significant.Conclusion: This highlights tubal ligation was more common in uneducated women of age > 35 years having <3 children. The most common means of promoting tubal ligation was information gained through health workers.

Catecholamine-resistant hypotension and myocardial performance following patent ductus arteriosus ligation.

LENUS (Irish Health Repository)

Noori, S

2014-08-14

Objective:We performed a multicenter study of preterm infants, who were about to undergo patent ductus arteriosus ligation, to determine whether echocardiographic indices of impaired myocardial performance were associated with subsequent development of catecholamine-resistant hypotension following ligation.Study Design:A standardized treatment approach for hypotension was followed at each center. Infants were considered to have catecholamine-resistant hypotension if their dopamine infusion was >15 μg kg(-1)min(-1). Echocardiograms and cortisol measurements were obtained between 6 and 14 h after the ligation (prior to the presence of catecholamine-resistant hypotension).Result:Forty-five infants were enrolled, 10 received catecholamines (6 were catecholamine-responsive and 4 developed catecholamine-resistant hypotension). Catecholamine-resistant hypotension was not associated with decreased preload, shortening fraction or ventricular output. Infants with catecholamine-resistant hypotension had significantly lower levels of systemic vascular resistance and postoperative cortisol concentration.Conclusion:We speculate that low cortisol levels and impaired vascular tone may have a more important role than impaired cardiac performance in post-ligation catecholamine-resistant hypotension.Journal of Perinatology advance online publication, 14 August 2014; doi:10.1038\\/jp.2014.151.

Evaluation of frictional forces of polycarbonate self-ligating brackets.

Science.gov (United States)

Fernandes, Daniel J; Miguel, José Augusto M; Quintão, Catia C A; Elias, Carlos N

2010-01-01

To evaluate the frictional forces generated by ceramic- (Opal, Ultradent) and glass-fiber-reinforced polycarbonate self-ligating brackets (Oyster, Gestenco) and compare the effectiveness of these ligatureless systems with glass-fiber-reinforced polycarbonate conventional brackets (Blonde, Gestenco). The hypothesis is that there is no difference between frictional forces generated by ceramic- and glass-fiber-reinforced polycarbonate self-ligating and glass-fiber-reinforced polycarbonate conventional brackets. Twelve preadjusted 0.022 3 0.028-inch maxillary canine brackets were tested, divided into three groups: Opal, Oyster, and Blonde. Frictional tests were conducted with the Emic DL 10000 testing machine with a 20 N loadcell for 40 seconds at a 0.5 cm/min speed. Each bracket-wire combination was tested five times. The data generated were analyzed by parametric analysis of variance (one-way ANOVA) and Bonferroni tests. Analysis of variance indicated significant differences for the three groups (Pfrictional forces of the Oyster glass-fiber-reinforced polycarbonate self-ligating brackets were significantly lower (37.0 ± 8.9 cN) than those of the Opal ceramic-reinforced polycarbonate self-ligating brackets (49.5 ± 10.1 cN), while the Blonde glass-fiber-reinforced conventional bracket frictional forces were 105.8 ± 6.4 cN. Oyster glass-fiber-reinforced polycarbonate brackets produced less friction than Opal ceramic-reinforced polycarbonate brackets. The polycarbonate ligatureless system showed significantly lower frictional forces compared to Blonde conventional polycarbonate brackets tied with elastomeric ligatures. The study rejected the initial hypothesis because there are significant differences of frictional forces among the tested systems. © 2010 BY QUINTESSENCE PUBLISHING CO, INC.

The effect of ligation method on friction in sliding mechanics.

Science.gov (United States)

Hain, Max; Dhopatkar, Ashish; Rock, Peter

2003-04-01

During orthodontic tooth movement with the preadjusted edgewise system, friction generated at the bracket/archwire interface tends to impede the desired movement. The method of ligation is an important contributor to this frictional force. This in vitro study investigated the effect of ligation method on friction and evaluated the efficacy of the new slick elastomeric modules from TP Orthodontics (La Porte, Ind), which are claimed to reduce friction at the module/wire interface. Slick modules were compared with regular nonslick modules, stainless steel ligatures, and the SPEED self-ligating bracket system (Strite Industries, Cambridge, Ontario, Canada). The effect of using slick modules with metal-reinforced ceramic (Clarity, 3M Unitek, Monrovia, Calif) and miniature brackets (Minitwin, 3M Unitek) was also examined. Results showed that, when considering tooth movement along a 0.019 x 0.025-in stainless steel archwire, saliva-lubricated slick modules can reduce static friction at the module/archwire interface by up to 60%, regardless of the bracket system. The SPEED brackets produced the lowest friction compared with the 3 other tested bracket systems when regular modules were used. The use of slick modules, however, with all of the ligated bracket types tested significantly reduced friction to below the values recorded in the SPEED groups. Loosely tied stainless steel ligatures were found to generate the least friction.

Cooperative Structures of Interaction in a Public School EFL Classroom in Bogotá

Directory of Open Access Journals (Sweden)

Fernando Parga Herrera

2011-09-01

Full Text Available In deprived socio cultural contexts like those characterizing the suburbs of Bogotá, cooperative learning (CL appears as an alternativeto cope with student problems of interpersonal communication and conflict derived largely from gossiping, information distortion, and verbal aggressiveness that result in an inappropriate learning environment. As a result of implementing this action research study with 8th graders in a public school of Usme, in the south east of Bogotá, students’ original negative influence over their peers turned into positive mediation, featured by peer monitoring, peer correction, and peer feedback. Such a change, which was evident in class audio and video recordings, as well a ssuccessful CL task development, occurred thanks to the joint establishment of rules for cooperative interaction with their corresponding roles, functions, times, and spaces immersed in the implemented CL structures of interaction. This way, students raised awareness of the crucial factors involved in effective oral communication and the importance of reporting information accurately for well-informed opinions and decisions. Students’ improvement in the oral communication processes contributed significantly to a better classroom social environment for learning.

Open-Ended Interaction in Cooperative Pro-to-typing: A Video-based Analysis

DEFF Research Database (Denmark)

Bødker, Susanne; Grønbæk, Kaj; Trigg, Randal

1991-01-01

Cooperative Prototyping can be characterized as the use and development of prototypes as catalysts during discussions between designers and potential users – the overall intention being one of mutual learning. On the one hand, the designers learn more about the work practices of the users in ways...... that are tied concretely to some current version of the prototype. On the other hand, the users learn more about the potential for change in their work practice, whether computer-based or otherwise. This paper presents the results of a field study of the cooperative prototyping process. The study is based...... on a fine-grained video-based analysis of a single prototyping session, and focuses on the effects of an open-ended style of interaction between users and designers around a prototype. An analysis of focus shifts, initiative and storytelling during the session is brought to bear on the question of whether...

Gene assembly via one-pot chemical ligation of DNA promoted by DNA nanostructures

DEFF Research Database (Denmark)

Manuguerra, Ilenia; Croce, Stefano; El-Sagheer, Afaf H.

2018-01-01

Current gene synthesis methods are driven by enzymatic reactions. Here we report the one-pot synthesis of a chemically-ligated gene from 14 oligonucleotides. The chemical ligation benefits from the highly efficient click chemistry approach templated by DNA nanostructures, and produces modified DNA...

The collective benefits of feeling good and letting go: positive emotion and (disinhibition interact to predict cooperative behavior.

Directory of Open Access Journals (Sweden)

David G Rand

Full Text Available Cooperation is central to human existence, forming the bedrock of everyday social relationships and larger societal structures. Thus, understanding the psychological underpinnings of cooperation is of both scientific and practical importance. Recent work using a dual-process framework suggests that intuitive processing can promote cooperation while deliberative processing can undermine it. Here we add to this line of research by more specifically identifying deliberative and intuitive processes that affect cooperation. To do so, we applied automated text analysis using the Linguistic Inquiry and Word Count (LIWC software to investigate the association between behavior in one-shot anonymous economic cooperation games and the presence inhibition (a deliberative process and positive emotion (an intuitive process in free-response narratives written after (Study 1, N = 4,218 or during (Study 2, N = 236 the decision-making process. Consistent with previous results, across both studies inhibition predicted reduced cooperation while positive emotion predicted increased cooperation (even when controlling for negative emotion. Importantly, there was a significant interaction between positive emotion and inhibition, such that the most cooperative individuals had high positive emotion and low inhibition. This suggests that inhibition (i.e., reflective or deliberative processing may undermine cooperative behavior by suppressing the prosocial effects of positive emotion.

Total synthesis of cytochrome b562 by native chemical ligation using a removable auxiliary

Science.gov (United States)

Low, Donald W.; Hill, Michael G.; Carrasco, Michael R.; Kent, Stephen B. H.; Botti, Paolo

2001-01-01

We have completed the total chemical synthesis of cytochrome b562 and an axial ligand analogue, [SeMet7]cyt b562, by thioester-mediated chemical ligation of unprotected peptide segments. A novel auxiliary-mediated native chemical ligation that enables peptide ligation to be applied to protein sequences lacking cysteine was used. A cleavable thiol-containing auxiliary group, 1-phenyl-2-mercaptoethyl, was added to the α-amino group of one peptide segment to facilitate amide bond-forming ligation. The amine-linked 1-phenyl-2-mercaptoethyl auxiliary was stable to anhydrous hydrogen fluoride used to cleave and deprotect peptides after solid-phase peptide synthesis. Following native chemical ligation with a thioester-containing segment, the auxiliary group was cleanly removed from the newly formed amide bond by treatment with anhydrous hydrogen fluoride, yielding a full-length unmodified polypeptide product. The resulting polypeptide was reconstituted with heme and folded to form the functional protein molecule. Synthetic wild-type cyt b562 exhibited spectroscopic and electrochemical properties identical to the recombinant protein, whereas the engineered [SeMet7]cyt b562 analogue protein was spectroscopically and functionally distinct, with a reduction potential shifted by ≈45 mV. The use of the 1-phenyl-2-mercaptoethyl removable auxiliary reported here will greatly expand the applicability of total protein synthesis by native chemical ligation of unprotected peptide segments. PMID:11390992

Weak interactions and cooperativity effects on disiloxane: a look at the building block of silicones

Science.gov (United States)

Martín-Fernández, Carlos; Montero-Campillo, M. Merced; Alkorta, Ibon; Elguero, José

2018-06-01

The behaviour of disiloxane 1 towards a set of Lewis acids (LA) and Lewis bases (LB) forming complexes through its oxygen and silicon atoms, respectively, was studied at the MP2/aug‧-cc-pVTZ level of theory, exploring a wide variety of non-covalent interactions. Disiloxane is a moderate electron acceptor and a good electron donor, exhibiting in the latter case binding energies up to almost -100 kJ/mol with BeCl2. Cooperativity effects were also analysed by looking at ternary 1:LA:LB complexes. Shorter intermolecular distances than in the corresponding binary complexes and a negative contribution of the three-body term to the binding energy indicate that the non-covalent interactions allowed by disiloxane through its acid and basic centres cooperate between them to reinforce both donor-acceptor pairs. These effects are particularly strong in complexes involving beryllium and triel bonds, but are also relevant for complexes containing hydrogen bonds.

Transcatheter closure of re-canalized patent ductus arteriosus after surgical ligation

International Nuclear Information System (INIS)

Zhang Qingqiao; Jiang Shiliang; Huang Lianjun; Zhao Shihua; Zheng Hong; Ling Jian; Jin Jinglin; Xu Zhongying; Xie Ruolan; Dai Ruping

2002-01-01

Objective: To evaluate the effectiveness of transcatheter closure of re-canalized patent ductus arteriosus (PDA) after surgical ligation. Methods: Between June 1995 and November 2000, 14 patients (5 male, 9 female) with re-canalized PDA after surgical ligation underwent transcatheter closure, their median age was 13 years (range 4 to 48 years). The time between surgical ligation and the interventional procedure ranged from one month to twenty-two years. Implantations of Amplatzer duct occluder and Rashkind occluder were performed trans-venously. Cook coil occlusions was performed trans-arterially. Follow-up with X-ray radiograph and echocardiography was made 24 hours, 1, 3, 6 months, and more than 1 year after the procedure. Results: Twelve PDAs were of funnel shape, and the remaining two PDAs were of tubular shape. The median minimum diameter of re-canalized PDA after ligation was 4 mm (range 1 to 8 mm). Aortograms ten minutes after closure showed complete closure and trivial residual shunt in 11 and 3 patients, respectively. The technical success rate was 100%, and there were no complications. Echocardiography showed complete closure in all patients within 24 hours. All patients were discharged in one to two days after the procedure. At a follow-up of one to eighteen months in ten patients, there were no migration of devices and residual PDA. Conclusion: Transcatheter closure using Amplatzer duct occluder, coil (Cook company or Pfm company) and Rashkind occluder was an effective method for patients with re-canalized PDA after surgical ligation. It may be an alternative to second surgery owing to its safety, reliability, min-invasiveness, and short hospitalization

Transcatheter closure of re-canalized patent ductus arteriosus after surgical ligation

Energy Technology Data Exchange (ETDEWEB)

Qingqiao, Zhang; Shiliang, Jiang; Lianjun, Huang; Shihua, Zhao; Hong, Zheng; Jian, Ling; Jinglin, Jin; Zhongying, Xu; Ruolan, Xie; Ruping, Dai [Chinese Academy of Medical Science, Beijing Union Medical College, Beijing (China). Cardiovascular Inst. and Fuwai Hospital, Dept. of Radiology

2002-02-01

Objective: To evaluate the effectiveness of transcatheter closure of re-canalized patent ductus arteriosus (PDA) after surgical ligation. Methods: Between June 1995 and November 2000, 14 patients (5 male, 9 female) with re-canalized PDA after surgical ligation underwent transcatheter closure, their median age was 13 years (range 4 to 48 years). The time between surgical ligation and the interventional procedure ranged from one month to twenty-two years. Implantations of Amplatzer duct occluder and Rashkind occluder were performed trans-venously. Cook coil occlusions was performed trans-arterially. Follow-up with X-ray radiograph and echocardiography was made 24 hours, 1, 3, 6 months, and more than 1 year after the procedure. Results: Twelve PDAs were of funnel shape, and the remaining two PDAs were of tubular shape. The median minimum diameter of re-canalized PDA after ligation was 4 mm (range 1 to 8 mm). Aortograms ten minutes after closure showed complete closure and trivial residual shunt in 11 and 3 patients, respectively. The technical success rate was 100%, and there were no complications. Echocardiography showed complete closure in all patients within 24 hours. All patients were discharged in one to two days after the procedure. At a follow-up of one to eighteen months in ten patients, there were no migration of devices and residual PDA. Conclusion: Transcatheter closure using Amplatzer duct occluder, coil (Cook company or Pfm company) and Rashkind occluder was an effective method for patients with re-canalized PDA after surgical ligation. It may be an alternative to second surgery owing to its safety, reliability, min-invasiveness, and short hospitalization.

Debris and friction of self-ligating and conventional orthodontic brackets after clinical use.

Science.gov (United States)

Araújo, Raíssa Costa; Bichara, Lívia Monteiro; Araujo, Adriana Monteiro de; Normando, David

2015-07-01

To compare the degree of debris and friction of conventional and self-ligating orthodontic brackets before and after clinical use. Two sets of three conventional and self-ligating brackets were bonded from the first molar to the first premolar in eight individuals, for a total of 16 sets per type of brackets. A passive segment of 0.019 × 0.025-inch stainless steel archwire was inserted into each group of brackets. Frictional force and debris level were evaluated as received and after 8 weeks of intraoral exposure. Two-way analysis of variance and Wilcoxon signed-rank test were applied at P brackets (P brackets showed a higher amount of debris compared with the conventional brackets. The frictional force in conventional brackets was significantly higher when compared with self-ligating brackets before clinical use (P brackets, when exposed to the intraoral environment, showed a significant increase in frictional force during the sliding mechanics. Debris accumulation was higher for the self-ligating system.

Ectopic pregnancy after two times tubal ligation: a case report

Directory of Open Access Journals (Sweden)

Farideh Keypour

2013-06-01

Full Text Available Background: Tubal sterilization is the permanent and effective contraception method. This can be performed at any time, but at least half are performed in conjunction with cesarean or vaginal delivery and are termed puerperal. The most complication after tubal ligation is ectopic pregnancy. Ectopic pregnancy is the leading cause of maternal death in first trimester.Case presentation: We present a 33 years old woman gravida5, para4, all normal vaginal delivery, presented with complaints of delayed menstrual period, pelvic pain and spotting. She underwent tubal ligation for two times. For the first time she had puerperal Pomeroy tubal sterilization after third child delivery. Intra uterine pregnancy occurred three years later. One day after vaginal delivery of fourth child, she underwent post partum tubal ligation with the Parkland method. Tubal pregnancy occurred nine months later. Physical examination identified acute abdomen. Pelvic ultrasound showed no gestational sac in uterine cavity. The sac with fetal pole was in right adnexa. Beta-HCG was 2840mIU/ml. She underwent laparotomy. Surgical management included salpingectomy with cornual resection in both sides. The surgery identified Ectopic pregnancy.Conclusion: Any symptoms of pregnancy in a woman after tubal ligation must be investigated; an ectopic pregnancy should be excluded. Ectopic pregnancy must be considered, in any woman with lower abdominal pain, missed period and vaginal bleed-ing. Conception after tubal sterilization can be explained by fistula formation and re-canalization of fallopian tube.

Neuro-Fuzzy Prediction of Cooperation Interaction Profile of Flexible Road Train Based on Hybrid Automaton Modeling

Directory of Open Access Journals (Sweden)

Banjanovic-Mehmedovic Lejla

2016-01-01

Full Text Available Accurate prediction of traffic information is important in many applications in relation to Intelligent Transport systems (ITS, since it reduces the uncertainty of future traffic states and improves traffic mobility. There is a lot of research done in the field of traffic information predictions such as speed, flow and travel time. The most important research was done in the domain of cooperative intelligent transport system (C-ITS. The goal of this paper is to introduce the novel cooperation behaviour profile prediction through the example of flexible Road Trains useful road cooperation parameter, which contributes to the improvement of traffic mobility in Intelligent Transportation Systems. This paper presents an approach towards the control and cooperation behaviour modelling of vehicles in the flexible Road Train based on hybrid automaton and neuro-fuzzy (ANFIS prediction of cooperation profile of the flexible Road Train. Hybrid automaton takes into account complex dynamics of each vehicle as well as discrete cooperation approach. The ANFIS is a particular class of the ANN family with attractive estimation and learning potentials. In order to provide statistical analysis, RMSE (root mean square error, coefficient of determination (R2 and Pearson coefficient (r, were utilized. The study results suggest that ANFIS would be an efficient soft computing methodology, which could offer precise predictions of cooperative interactions between vehicles in Road Train, which is useful for prediction mobility in Intelligent Transport systems.

Ergonomic varicocele ligation: laparoscopic intracorporeal knot-tying

African Journals Online (AJOL)

Department of Pediatric Surgery, Sevket Yilmaz Education and Research. Hospital, Bursa, Turkey ... laparoscopic approach to varicocelectomy has been the high associated ... bilateral varicoceles, a 3 mm trocar was placed at the right. McBurney's .... open-high or subinguinal ligation (microsurgical), laparo- scopic methods ...

Cooperation in human-computer communication

OpenAIRE

Kronenberg, Susanne

2000-01-01

The goal of this thesis is to simulate cooperation in human-computer communication to model the communicative interaction process of agents in natural dialogs in order to provide advanced human-computer interaction in that coherence is maintained between contributions of both agents, i.e. the human user and the computer. This thesis contributes to certain aspects of understanding and generation and their interaction in the German language. In spontaneous dialogs agents cooperate by the pro...

MR imaging of salivary glands after ductal ligation and stimulation by pilocarpine

International Nuclear Information System (INIS)

Patronas, N.J.; Tsuchimoch, M.; Webber, R.; Ruttimann, U.; Fox, P.; Bacher, J.; Schellinger, D.

1988-01-01

This paper presents an assessment of the usefulness of MR imaging in pathologic conditions of the salivary gland. The authors performed MR imaging in six dogs after ductal ligation on one side, followed by secretory stimulation with intraperitoneal injection of pilocarpine (5 mg/kg). On the images obtained after ductal ligation and before stimulation, there was no significant change in the signal intensity on either side. After injection of pilocarpine, however, T2-weighted images showed an obvious increase in signal intensity of the ligated gland in every instance. Their results indicate that MR images obtained after pilocarpine stimulation will be useful to study patients with ductal obstruction and that they may provide an objective basis for a noninvasive diagnostic test for unilateral stenosis

Association of Patent Ductus Arteriosus Ligation With Death or Neurodevelopmental Impairment Among Extremely Preterm Infants

Science.gov (United States)

Mirea, Lucia; Rosenberg, Erin; Jang, Maximus; Ly, Linh; Church, Paige T.; Kelly, Edmond; Kim, S. Joseph; Jain, Amish; McNamara, Patrick J.; Shah, Prakesh S.

2017-01-01

Importance Observational studies have associated patent ductus arteriosus (PDA) ligation among preterm infants with adverse neonatal outcomes and neurodevelopmental impairment in early childhood, with a resultant secular trend away from surgical treatment. However, to our knowledge, studies have inadequately addressed sources of residual bias, including survival bias and major neonatal morbidities arising before exposure to ligation. Objective Evaluate the association between PDA ligation vs medical management and neonatal and neurodevelopmental outcomes. Design, Setting, and Participants This retrospective cohort study of preterm infants younger than 28 weeks gestational age born between January 1, 2006, and December 31, 2012, with clinical and echocardiography diagnoses of hemodynamically significant PDA was conducted at 3 tertiary neonatal intensive care units and affiliated follow-up programs. Exposure Surgical ligation vs medical management. Main Outcomes and Measures The primary outcome was a composite of death or neurodevelopmental impairment (NDI) at 18 to 24 months corrected age. Secondary outcomes included death before discharge, NDI, moderate-severe chronic lung disease, and severe retinopathy of prematurity. Multivariable logistic regression analysis was used to adjust for perinatal and postnatal confounders. Results Of 754 infants with hemodynamically significant PDA (mean [standard deviation] gestational age 25.7 [1.2] weeks and birth weight 813 [183] grams), 184 (24%) underwent ligation. Infants who underwent ligation had a higher frequency of morbidities before PDA closure, including sepsis, necrotizing enterocolitis, and a dependence on mechanical ventilation. After adjusting for perinatal characteristics and preligation morbidities, there was no difference in the odds of death or NDI (adjusted odds ratio (aOR), 0.83; 95% CI, 0.52-1.32), NDI (aOR, 1.27; 95% CI, 0.78-2.06), chronic lung disease (aOR, 1.36; 95% CI, 0.78-2.39) or severe retinopathy of

Rapid production of functionalized recombinant proteins: marrying ligation independent cloning and in vitro protein ligation.

Science.gov (United States)

Kushnir, Susanna; Marsac, Yoann; Breitling, Reinhard; Granovsky, Igor; Brok-Volchanskaya, Vera; Goody, Roger S; Becker, Christian F W; Alexandrov, Kirill

2006-01-01

Functional genomics and proteomics have been very active fields since the sequencing of several genomes was completed. To assign a physiological role to the newly discovered coding genes with unknown function, new generic methods for protein production, purification, and targeted functionalization are needed. This work presents a new vector, pCYSLIC, that allows rapid generation of Escherichia coli expression constructs via ligation-independent cloning (LIC). The vector is designed to facilitate protein purification by either Ni-NTA or GSH affinity chromatography. Subsequent proteolytic removal of affinity tags liberates an N-terminal cysteine residue that is then used for covalent modification of the target protein with different biophysical probes via protein ligation. The described system has been tested on 36 mammalian Rab GTPases, and it was demonstrated that recombinant GTPases produced with pCYSLIC could be efficiently modified with fluorescein or biotin in vitro. Finally, LIC was compared with the recently developed In-Fusion cloning method, and it was demonstrated that In-Fusion provides superior flexibility in choice of expression vector. By the application of In-Fusion cloning Cys-Rab6A GTPase with an N-terminal cysteine residue was generated employing unmodified pET30a vector and TVMV protease.

The significance of the interconnection of second-level cooperatives and their peer-associated cooperatives for productivity growth

International Nuclear Information System (INIS)

Martínez-Victoria, M.; Maté-Sánchez-Val, M.L.; Arcas-Lario, N.

2017-01-01

Cooperatives are especially important in current agri-food markets. These companies have responded to the current demand requirements with greater market orientation strategies to attract and satisfy customers. To do so, cooperatives have adopted different collaboration alternatives. In Spain, the most common alliance between cooperatives is materialised in second-level cooperatives, which are cooperatives integrated by at least two first-level cooperatives. The aim of this study was to analyse the interaction effects between first- and second level agri-food cooperatives on their productive growth and its components. To get this purpose, a Cobb-Douglas specification with spatial econometrics techniques was applied to evaluate this relationship. We included a spatial connectivity matrix to establish the interconnection among cooperatives of first- and second-level. Our results show a positive interaction effect highlighting the importance of these alliances on the productivity growth in the agri-food sector. The scarce amount of empirical papers explaining how second-level cooperatives influence the performance of first-level cooperatives shows the relevance of our study.

The significance of the interconnection of second-level cooperatives and their peer-associated cooperatives for productivity growth

Energy Technology Data Exchange (ETDEWEB)

Martínez-Victoria, M.; Maté-Sánchez-Val, M.L.; Arcas-Lario, N.

2017-09-01

Cooperatives are especially important in current agri-food markets. These companies have responded to the current demand requirements with greater market orientation strategies to attract and satisfy customers. To do so, cooperatives have adopted different collaboration alternatives. In Spain, the most common alliance between cooperatives is materialised in second-level cooperatives, which are cooperatives integrated by at least two first-level cooperatives. The aim of this study was to analyse the interaction effects between first- and second level agri-food cooperatives on their productive growth and its components. To get this purpose, a Cobb-Douglas specification with spatial econometrics techniques was applied to evaluate this relationship. We included a spatial connectivity matrix to establish the interconnection among cooperatives of first- and second-level. Our results show a positive interaction effect highlighting the importance of these alliances on the productivity growth in the agri-food sector. The scarce amount of empirical papers explaining how second-level cooperatives influence the performance of first-level cooperatives shows the relevance of our study.

Cross-catalytic peptide nucleic acid (PNA) replication based on templated ligation

DEFF Research Database (Denmark)

Singhal, Abhishek; Nielsen, Peter E

2014-01-01

We report the first PNA self-replicating system based on template directed cross-catalytic ligation, a process analogous to biological replication. Using two template PNAs and four pentameric precursor PNAs, all four possible carbodiimide assisted amide ligation products were detected...... precursors. Cross-catalytic product formation followed product inhibited kinetics, but approximately two replication rounds were observed. Analogous but less efficient replication was found for a similar tetrameric system. These results demonstrate that simpler nucleobase replication systems than natural...

Subcutaneous endoscopically assisted ligation using miniport for ...

African Journals Online (AJOL)

Background This report describes the first miniport method using subcutaneous endoscopically assisted ligation (SEAL) for the treatment of girls with inguinal hernia. To validate its safety and efficacy, the authors evaluated their early experiences. Methods Between April 2014 and December 2014, 19 SEALs using miniport ...

Template-directed ligation of tethered mononucleotides by t4 DNA ligase for kinase ribozyme selection.

Directory of Open Access Journals (Sweden)

David G Nickens

Full Text Available BACKGROUND: In vitro selection of kinase ribozymes for small molecule metabolites, such as free nucleosides, will require partition systems that discriminate active from inactive RNA species. While nucleic acid catalysis of phosphoryl transfer is well established for phosphorylation of 5' or 2' OH of oligonucleotide substrates, phosphorylation of diffusible small molecules has not been demonstrated. METHODOLOGY/PRINCIPAL FINDINGS: This study demonstrates the ability of T4 DNA ligase to capture RNA strands in which a tethered monodeoxynucleoside has acquired a 5' phosphate. The ligation reaction therefore mimics the partition step of a selection for nucleoside kinase (deoxyribozymes. Ligation with tethered substrates was considerably slower than with nicked, fully duplex DNA, even though the deoxynucleotides at the ligation junction were Watson-Crick base paired in the tethered substrate. Ligation increased markedly when the bridging template strand contained unpaired spacer nucleotides across from the flexible tether, according to the trends: A(2>A(1>A(3>A(4>A(0>A(6>A(8>A(10 and T(2>T(3>T(4>T(6 approximately T(1>T(8>T(10. Bridging T's generally gave higher yield of ligated product than bridging A's. ATP concentrations above 33 microM accumulated adenylated intermediate and decreased yields of the gap-sealed product, likely due to re-adenylation of dissociated enzyme. Under optimized conditions, T4 DNA ligase efficiently (>90% joined a correctly paired, or TratioG wobble-paired, substrate on the 3' side of the ligation junction while discriminating approximately 100-fold against most mispaired substrates. Tethered dC and dG gave the highest ligation rates and yields, followed by tethered deoxyinosine (dI and dT, with the slowest reactions for tethered dA. The same kinetic trends were observed in ligase-mediated capture in complex reaction mixtures with multiple substrates. The "universal" analog 5-nitroindole (dNI did not support ligation when

Cooperativity effect involving drug-DNA/RNA intermolecular interaction: A B3LYP-D3 and MP2 theoretical investigation on ketoprofen⋯cytosine⋯H2O system.

Science.gov (United States)

Zhen, Jun-Ping; Wei, Xiao-Chun; Shi, Wen-Jing; Huang, Zhu-Yuan; Jin, Bo; Zhou, Yu-Kun

2017-11-14

In order to examine the origin of the drug action and design new DNA/RNA-targeted drugs, the cooperativity effect involving drug-DNA/RNA intermolecular interaction in ketoprofen⋯cytosine⋯H 2 O ternary system were investigated by the B3LYP, B3LYP-D3, and MP2 methods with the 6-311++G(2d,p) basis set. The thermodynamic cooperativity was also evaluated at 310.15 K. The N-H⋯O, O-H⋯O, O-H⋯N, C-H⋯N, and C-H⋯O H bonds coexist in ternary complexes. The intermolecular interactions obtained by B3LYP-D3 are close to those calculated by MP2. The steric effects and van der Waals interactions have little influence on the cooperativity effects. The anti-cooperativity effect in ket⋯cyt⋯H 2 O is far more notable than the cooperativity effect, and the stability of the cyclic structure with anti-cooperativity effect is higher than that of the linear structure with cooperativity effect, as is confirmed by the AIM (atoms in molecules) and RDG (reduced density gradient) analysis. Thus, it can be inferred that, in the presence of H 2 O, the anti-cooperativity effect plays a dominant role in the drug-DNA/RNA interaction, and the nature of the hydration in the binding of drugs to DNA/RNA bases is the H-bonding anti-cooperativity effect. Furthermore, the drug always links simultaneously with DNA/RNA base and H 2 O, and only in this way can the biological activity of drugs play a role. In most cases, the enthalpy change is the major factor driving the cooperativity, as is different from most of biomacromolecule complexes.

Recovery of vocal fold immobility following isolated patent ductus arteriosus ligation.

Science.gov (United States)

Nichols, Brent G; Jabbour, Jad; Hehir, David A; Ghanayem, Nancy S; Beste, David; Martin, Timothy; Woods, Ronald; Robey, Thomas

2014-08-01

Identify laryngoscopic and functional outcomes of infants with vocal fold immobility (VFI) following patent ductus arteriosus (PDA) ligation and identify predictors of recovery. Retrospective review of patients with VFI following PDA ligation from 2001 to 2012 at a single institution. Inclusion criteria were: (1) PDA ligation as only cardiac surgical procedure; (2) left VFI documented by laryngoscopy; (3) minimum follow up 120 days, with at least 2 laryngoscopies performed. Resolution of VFI was determined at follow-up laryngoscopy. Univariate logistic regression models were used to identify variables associated with VFI recovery. 66 subjects were included with median follow up of 3.0 (± 2.1) years. The mean gestational age was 24.5 ± 1.4 weeks, mean birth weight 673 ± 167 g, and mean age at procedure was 18.6 ± 14.3 days. Patients presented with respiratory symptoms (39%), dysphonia (78%) and dysphagia (55%). Resolution of VFI was observed in 2/66 (3%) patients. Recovery was documented at 20 days and 11 months respectively. Respiratory symptoms, dysphagia, and dysphonia persisted at last follow up in 11%, 47%, and 20% of patients. VFI associated with ligation of the ductus arteriosus has a low rate of recovery. Clinical symptoms frequently persist, and as such regular follow-up by otolaryngologists to mitigate morbidity is indicated. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Covalent attachment of proteins to solid supports and surfaces via Sortase-mediated ligation.

Directory of Open Access Journals (Sweden)

Lilyan Chan

Full Text Available BACKGROUND: There is growing interest in the attachment of proteins to solid supports for the development of supported catalysts, affinity matrices, and micro devices as well as for the development of planar and bead based protein arrays for multiplexed assays of protein concentration, interactions, and activity. A critical requirement for these applications is the generation of a stable linkage between the solid support and the immobilized, but still functional, protein. METHODOLOGY: Solid supports including crosslinked polymer beads, beaded agarose, and planar glass surfaces, were modified to present an oligoglycine motif to solution. A range of proteins were ligated to the various surfaces using the Sortase A enzyme of S. aureus. Reactions were carried out in aqueous buffer conditions at room temperature for times between one and twelve hours. CONCLUSIONS: The Sortase A transpeptidase of S. aureus provides a general, robust, and gentle approach to the selective covalent immobilization of proteins on three very different solid supports. The proteins remain functional and accessible to solution. Sortase mediated ligation is therefore a straightforward methodology for the preparation of solid supported enzymes and bead based assays, as well as the modification of planar surfaces for microanalytical devices and protein arrays.

Cooperation: the foundation of improvement.

Science.gov (United States)

Clemmer, T P; Spuhler, V J; Berwick, D M; Nolan, T W

1998-06-15

Cooperation--working together to produce mutual benefit or attain a common purpose--is almost inseparable from the quest for improvement. Although the case for cooperation can be made on ethical grounds, neither the motivation for nor the effects of cooperation need to be interpreted solely in terms of altruism. Cooperation can be a shrewd and pragmatic strategy for accomplishing personal goals in an interdependent system. Earlier papers in this series have explored the conceptual roots of modern approaches to improvement, which lie in systems theory. To improve systems, we must usually attend first and foremost to interactions. Among humans, "better interaction" is almost synonymous with "better cooperation." Physicians have ample opportunities and, indeed, an obligation to cooperate with other physicians in the same or different specialties, with nurses and other clinical workers, with administrators, and with patients and families. Many intellectual disciplines have made cooperation an object of study. These include anthropology; social psychology; genetics; biology; mathematics; game theory; linguistics; operations research; economics; and, of course, moral and rational philosophy. Scientifically grounded methods to enhance cooperation include developing a shared purpose; creating an open, safe environment; including all who share a common purpose and encouraging diverse viewpoints; negotiating agreement; and insisting on fairness and equity in the application of rules. These methods apply at the organizational level and at the level of the individual physician. This paper describes the application of these methods at the organizational level and focuses on one especially successful example of system-level cooperation in a care delivery site where interactions matter a great deal: the modern intensive care unit.

Can interposition of a silicone implant after sapheno-femoral ligation prevent recurrent varicose veins?

NARCIS (Netherlands)

de Maeseneer, M. G.; Giuliani, D. R.; van Schil, P. E.; de Hert, S. G.

2002-01-01

OBJECTIVES: To investigate whether a silicone implant at the sapheno-femoral ligation site could prevent recurrent varicosities. MATERIALS AND METHODS: Two non-randomised groups of patients were studied prospectively. In group A 173 patients and 212 limbs had sapheno-femoral ligation, while 172

The collective benefits of feeling good and letting go: positive emotion and (dis)inhibition interact to predict cooperative behavior.

Science.gov (United States)

Rand, David G; Kraft-Todd, Gordon; Gruber, June

2015-01-01

Cooperation is central to human existence, forming the bedrock of everyday social relationships and larger societal structures. Thus, understanding the psychological underpinnings of cooperation is of both scientific and practical importance. Recent work using a dual-process framework suggests that intuitive processing can promote cooperation while deliberative processing can undermine it. Here we add to this line of research by more specifically identifying deliberative and intuitive processes that affect cooperation. To do so, we applied automated text analysis using the Linguistic Inquiry and Word Count (LIWC) software to investigate the association between behavior in one-shot anonymous economic cooperation games and the presence inhibition (a deliberative process) and positive emotion (an intuitive process) in free-response narratives written after (Study 1, N = 4,218) or during (Study 2, N = 236) the decision-making process. Consistent with previous results, across both studies inhibition predicted reduced cooperation while positive emotion predicted increased cooperation (even when controlling for negative emotion). Importantly, there was a significant interaction between positive emotion and inhibition, such that the most cooperative individuals had high positive emotion and low inhibition. This suggests that inhibition (i.e., reflective or deliberative processing) may undermine cooperative behavior by suppressing the prosocial effects of positive emotion.

Probing Nitrosyl Ligation of Surface-Confined Metalloporphyrins by Inelastic Electron Tunneling Spectroscopy

Science.gov (United States)

2013-01-01

Complexes obtained by the ligation of nitric oxide (NO) to metalloporphyrins represent important model systems with biological relevance. Herein we report a molecular-level investigation of surface-confined cobalt tetraphenyl porphyrin (Co-TPP) species and their interaction with NO under ultrahigh vacuum conditions. It is demonstrated that individual NO adducts can be desorbed using the atomically sharp tip of a scanning tunneling microscope, whereby a writing process is implemented for fully saturated regular metalloporphyrin arrays. The low-energy vibrational characteristics of individual Co-TPP-nitrosyl complexes probed by inelastic electron tunneling spectroscopy (IETS) reveal a prominent signature at an energy of ≃31 meV. Using density functional theory-based IETS simulations—the first to be performed on such an extensive interfacial nanosystem—we succeed to reproduce the low-frequency spectrum for the NO-ligated complex and explain the absence of IETS activity for bare Co-TPP. Moreover, we can conclusively assign the IETS peak of NO-Co-TPP to a unique vibration mode involving the NO complexation site, namely, the in-plane Co–N–O rocking mode. In addition, we verify that the propensity rules previously designed on small aromatic systems and molecular fragments hold true for a metal–organic entity. This work notably permits one to envisage IETS spectroscopy as a sensitive tool to chemically characterize hybrid interfaces formed by complex metal–organic units and gaseous adducts. PMID:23718257

Frictional resistance of self-ligating versus conventional brackets in different bracket-archwire-angle combinations

Science.gov (United States)

MONTEIRO, Maria Regina Guerra; da SILVA, Licinio Esmeraldo; ELIAS, Carlos Nelson; VILELLA, Oswaldo de Vasconcellos

2014-01-01

Objective To compare the influence of archwire material (NiTi, beta-Ti and stainless steel) and brackets design (self-ligating and conventional) on the frictional force resistance. Material and Methods Two types of brackets (self-ligating brackets - Smartclip, 3M/Unitek - and conventional brackets - Gemini, 3M/Unitek) with three (0, 5, and 10 degrees) slot angulation attached with elastomeric ligatures (TP Orthodontics) were tested. All brackets were tested with archwire 0.019"x0.025" nickel-titanium, beta-titanium, and stainless steel (Unitek/3M). The mechanical testing was performed with a universal testing machine eMIC DL 10000 (eMIC Co, Brazil). The wires were pulled from the bracket slots at a cross-head speed of 3 mm/min until 2 mm displacement. Results Self-ligating brackets produced significantly lower friction values compared with those of conventional brackets. Frictional force resistance values were directly proportional to the increase in the bracket/ wire angulation. With regard to conventional brackets, stainless steel wires had the lowest friction force values, followed by nickel-titanium and beta-titanium ones. With regard to self-ligating brackets, the nickel-titanium wires had the lowest friction values, significantly lower than those of other materials. Conclusion even at different angulations, the self-ligating brackets showed significantly lower friction force values than the conventional brackets. Combined with nickel-titanium wires, the self-ligating brackets exhibit much lower friction, possibly due to the contact between nickel-titanium clips and wires of the same material. PMID:25025564

Frictional resistance of self-ligating versus conventional brackets in different bracket-archwire-angle combinations

Directory of Open Access Journals (Sweden)

Maria Regina Guerra MONTEIRO

2014-06-01

Full Text Available Objective: To compare the influence of archwire material (NiTi, beta-Ti and stainless steel and brackets design (self-ligating and conventional on the frictional force resistance. Material and Methods: Two types of brackets (self-ligating brackets - Smartclip, 3M/Unitek - and conventional brackets - Gemini, 3M/Unitek with three (0, 5, and 10 degrees slot angulation attached with elastomeric ligatures (TP Orthodontics were tested. All brackets were tested with archwire 0.019"x0.025" nickel-titanium, beta-titanium, and stainless steel (Unitek/3M. The mechanical testing was performed with a universal testing machine eMIC DL 10000 (eMIC Co, Brazil. The wires were pulled from the bracket slots at a cross-head speed of 3 mm/min until 2 mm displacement. Results: Self-ligating brackets produced significantly lower friction values compared with those of conventional brackets. Frictional force resistance values were directly proportional to the increase in the bracket/ wire angulation. With regard to conventional brackets, stainless steel wires had the lowest friction force values, followed by nickel-titanium and beta-titanium ones. With regard to self-ligating brackets, the nickel-titanium wires had the lowest friction values, significantly lower than those of other materials. Conclusion: even at different angulations, the self-ligating brackets showed significantly lower friction force values than the conventional brackets. Combined with nickel-titanium wires, the self-ligating brackets exhibit much lower friction, possibly due to the contact between nickel-titanium clips and wires of the same material.

Comparison of Frictional Forces Generated by a New Ceramic Bracket with the Conventional Brackets using Unconventional and Conventional Ligation System and the Self-ligating Brackets: An In Vitro Study.

Science.gov (United States)

Pasha, Azam; Vishwakarma, Swati; Narayan, Anjali; Vinay, K; Shetty, Smitha V; Roy, Partha Pratim

2015-09-01

Fixed orthodontic mechanotherapy is associated with friction between the bracket - wire - ligature interfaces during the sliding mechanics. A sound knowledge of the various factors affecting the magnitude of friction is of paramount importance. The present study was done to analyze and compare the frictional forces generated by a new ceramic (Clarity Advanced) bracket with the conventional, (metal and ceramic) brackets using unconventional and conventional ligation system, and the self-ligating (metal and ceramic) brackets in the dry condition. The various bracket wire ligation combinations were tested in dry condition. The brackets used were of 0.022″ × 0.028″ nominal slot dimension of MBT prescription: Stainless steel (SS) self-ligating bracket (SLB) of (SmartClip), SS Conventional bracket (CB) (Victory series), Ceramic SLB (Clarity SL), Conventional Ceramic bracket with metal slot (Clarity Bracket), Clarity Advanced Ceramic Brackets (Clarity(™) ADVANCED, 3M Unitek). These brackets were used with two types of elastomeric ligatures: Conventional Elastomeric Ligatures (CEL) (Clear medium mini modules) and Unconventional Elastomeric Ligatures (UEL) (Clear medium slide ligatures, Leone orthodontic products). The aligning and the retraction wires were used, i.e., 0.014″ nickel titanium (NiTi) wires and 0.019″ × 0.025″ SS wires, respectively. A universal strength testing machine was used to measure the friction produced between the different bracket, archwires, and ligation combination. This was done with the use of a custom-made jig being in position. Mean, standard deviation, and range were computed for the frictional values obtained. Results were subjected to statistical analysis through ANOVA. The frictional resistance observed in the new Clarity Advanced bracket with a conventional elastomeric ligature was almost similar with the Clarity metal slot bracket with a conventional elastomeric ligature. When using the UEL, the Clarity Advanced bracket

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

Science.gov (United States)

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

Sensitivity and specificity of in situ proximity ligation for protein interaction analysis in a model of steatohepatitis with Mallory-Denk bodies.

Directory of Open Access Journals (Sweden)

Bernhard Zatloukal

Full Text Available The in situ proximity ligation assay (isPLA is an increasingly used technology for in situ detection of protein interactions, post-translational modifications, and spatial relationships of antigens in cells and tissues, in general. In order to test its performance we compared isPLA with immunofluorescence microscopy by analyzing protein interactions in cytoplasmic protein aggregates, so-called Mallory Denk bodies (MDBs. These structures represent protein inclusions in hepatocytes typically found in human steatohepatitis and they can be generated in mice by feeding of 3,5-diethoxy-carbonyl-1,4-dihydrocollidine (DDC. We investigated the colocalization of all three key MDB components, namely keratin 8 (K8, keratin 18 (K18, and p62 (sequestosome 1 by isPLA and immunofluorescence microscopy. Sensitivity and specificity of isPLA was assessed by using Krt8-/- and Krt18-/- mice as biological controls, along with a series of technical controls. isPLA signal visualization is a robust technology with excellent sensitivity and specificity. The biological relevance of signals generated critically depends on the performance of antibodies used, which requires careful testing of antibodies like in immunofluorescence microscopy. There is a clear advantage of isPLA in visualizing protein co-localization, particularly when antigens are present at markedly different concentrations. Furthermore, isPLA is superior to confocal microscopy with respect to spatial resolution of colocalizing antigens. Disadvantages compared to immunofluorescence are increased costs and longer duration of the laboratory protocol.

Digestion-ligation-only Hi-C is an efficient and cost-effective method for chromosome conformation capture.

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Lin, Da; Hong, Ping; Zhang, Siheng; Xu, Weize; Jamal, Muhammad; Yan, Keji; Lei, Yingying; Li, Liang; Ruan, Yijun; Fu, Zhen F; Li, Guoliang; Cao, Gang

2018-05-01

Chromosome conformation capture (3C) technologies can be used to investigate 3D genomic structures. However, high background noise, high costs, and a lack of straightforward noise evaluation in current methods impede the advancement of 3D genomic research. Here we developed a simple digestion-ligation-only Hi-C (DLO Hi-C) technology to explore the 3D landscape of the genome. This method requires only two rounds of digestion and ligation, without the need for biotin labeling and pulldown. Non-ligated DNA was efficiently removed in a cost-effective step by purifying specific linker-ligated DNA fragments. Notably, random ligation could be quickly evaluated in an early quality-control step before sequencing. Moreover, an in situ version of DLO Hi-C using a four-cutter restriction enzyme has been developed. We applied DLO Hi-C to delineate the genomic architecture of THP-1 and K562 cells and uncovered chromosomal translocations. This technology may facilitate investigation of genomic organization, gene regulation, and (meta)genome assembly.

An experimental microangiographic study on injured liver acinus by ligation of common bile duct

International Nuclear Information System (INIS)

Park, Jong Yeon; Kim, Yoon Gyu; Moon, Ki Ho; Lee, Suek Hong; Kim, Byung Soo; Han, Gun Taik

1994-01-01

The purpose of this study was to evaluate the morphologic changes of the injured hepatic acini following ligation of common bile duct and to investigate the pathophysiologic process of hepatic failure and biliary liver cirrhosis in the extrahepatic cholestasis. The common bile ducts of 18 rabbits were ligated partially. The rabbits were killed and selective microangiography was carried out with infusion of barium suspensio via portal vein 4 to 24 weeks after ligation. Selective microangiography was also carried out in two normal rabbits. The microangiographic findings were evaluated and correlated with histopathologic features. The sinusoids of the liver acinus showed distortion, varying degrees of luminal widening, and irregularities in architecture. Terminal branches of the portal vein (TPV) showed increased number of branches, luminal narrowing, tortuosity, distortion, and beaded appearance. Peribiliary plexi were found as thin curvilinear, barium-filled structures along the wall of the dilated bile duct. The microangiographic findings were well correlated with histopathologic findings. The grades of microangiographic and histopathologic findings were poorly correlated with the duration of the ligation of CBD. Changes in microvasculature of the liver scinus following partial ligation of common bile duct were demonstrated by microangiography. Although the microvascular changes were evoked secondary to the injury, they might have some active roles in the pathophysiologic process in the liver

Air-powder polishing on self-ligating brackets after clinical use: effects on debris levels.

Science.gov (United States)

Aragón, Mônica L S Castro; Lima, Leandro Santiago; Normando, David

2016-01-01

Debris buildup on brackets and arch surfaces is one of the main factors that can influence the intensity of friction between bracket and orthodontic wire. This study sought to evaluate the effect of air-powder polishing cleaning on debris levels of self-ligating ceramic brackets at the end of orthodontic treatment, compared to the behavior of conventional brackets. Debris levels were evaluated in metal conventional orthodontic brackets (n = 42) and ceramic self-ligating brackets (n = 42) on canines and premolars, arranged in pairs. There were brackets with and without air-powder polishing. At the end of orthodontic treatment, a hemiarch served as control and the contralateral hemiarch underwent prophylaxis with air-powder polishing. Debris buildup in bracket slots was assessed through images, and Wilcoxon test was used to analyze the results. The median debris levels were statistically lower in the conventional metal brackets compared to self-ligating ones (p = 0.02), regarding brackets not submitted to air-powder polishing. Polishing significantly reduced debris buildup to zero in both systems, without differences between groups. Ceramic self-ligating brackets have a higher debris buildup in comparison to conventional metal brackets in vivo, but prophylaxis with sodium bicarbonate jet was effective in reducing debris levels in self-ligating and also in conventional brackets.

OUTCOMES OF HILAR PEDICLE CONTROL USING SUTURE LIGATION DURING LAPAROSCOPIC SPLENECTOMY.

Science.gov (United States)

Makgoka, M

2017-06-01

Laparoscopic splenectomy is a well described gold standard procedure for various indications. One of the key steps during laparoscopic splenectomy is the hilar pedicle vessels control, which can be challenging in most cases. Most centres around the world recommend the use Ligaclib or endovascular staplers as Methods of choice for hilar pedicle control but the issue is the cost and efficiency of the laparoscopic haemostatic devices. A descriptive retrospective study of patients who had laparoscopic splenectomy from 2013 to present. Hilar splenic vessel control was done with suture ligation. We looked at outcomes of patients offered this technique, complications of this technique, and describing the technique of hilar control in laparoscopic splenectomy. Total of 27 patients had laparoscopic splenectomy with splenic hilar pedicle control with suture ligation. Mean operative time, mean blood volume loss, length of hospital stay, postoperative complications conversion to laparotomy. Laparoscopic hilar pedicle control with suture ligation is safe and effective for the patient in our hospital setting.

Uncovering the dynamics of interaction in development cooperation

DEFF Research Database (Denmark)

Fejerskov, Adam Moe; Lundsgaarde, Erik; Cold-Ravnkilde, Signe

The rising prominence of new state and non-state actors in international politics has stimulated extensive discussion in the social sciences over the last decade and development cooperation has been a central arena for conceptualising the encounter between old and new powers. This working paper...... critically reflects on the substantial body of scholarship that seeks to document the characteristics of new actors in international development and chart the consequences of their engagement for global development governance. This review underlines the importance of questioning the homogeneity of actor...... constellations, relationships and ideas. Specifically, it addresses the extent to which the commonly-used binary concepts of development cooperation provider groups adequately capture relevant distinctions among the actors and add analytical value to research on development cooperation. The paper advocates...

Subcutaneous endoscopically assisted ligation using miniport for ...

African Journals Online (AJOL)

miniport for the treatment of girls with inguinal hernia. Akinari Hinoki*, Ikeda ... method using subcutaneous endoscopically assisted ligation (SEAL) for the ... the open technique and an additional 2 mm miniport). A ... (unilateral, n = 9) or 42 ± 8 min (bilateral, n = 5). The mean .... Methods of laparoscopic repair have recently ...

Adaptive play stabilizes cooperation in continuous public goods games

Science.gov (United States)

Wu, Te; Wang, Long

2018-04-01

We construct a model to study the effects of repeated interaction on the evolution of cooperation in continuous public goods games. Instead of preassigning the duration of repeatedness, the likelihood of group entering next round interaction is positively dependent on the group's current cooperativeness. Meanwhile, when the disturbance happens, the interaction terminates. Under rare mutations, we show that such adaptive play can lead to the dominance of full cooperative state for weak disturbance. For fairly strong disturbance, all-or-none cooperative states share higher fractions of time in the long run, results similar to the ones reported in the study (Pinheiro et al., 2014) while differing from the ones reported in another relevant study (Van Segbroeck et al., 2012), although only strategy space and way determining next round vary. Our results remain valid when groups enter next round with a given probability independent of groups' cooperativeness. In the synergic public goods games, the positive effects of repeated interactions on promoting cooperation is further strengthened. In the discounted public goods game, only very weak disturbance can lead to the dominance of full cooperative state while fairly strong disturbance can favor both full cooperative state and a partially cooperative state. Our study thus enriches the literature on the evolution of cooperation in repeated public goods games.

Acute kidney injury secondary to iatrogenic bilateral ureteric ligation ...

African Journals Online (AJOL)

Acute kidney injury secondary to iatrogenic bilateral ureteric ligation following emergency abdominal hysterectomy. Oluseyi A. Adejumo, Olurotimi S. Ogundiniyi, Ayodeji A. Akinbodewa, Lawrence A. Adesunloro, Oladimeji J. Olafisoye ...

Optimization of proximity ligation assay (PLA) for detection of protein interactions and fusion proteins in non-adherent cells: application to pre-B lymphocytes.

Science.gov (United States)

Debaize, Lydie; Jakobczyk, Hélène; Rio, Anne-Gaëlle; Gandemer, Virginie; Troadec, Marie-Bérengère

2017-01-01

Genetic abnormalities, including chromosomal translocations, are described for many hematological malignancies. From the clinical perspective, detection of chromosomal abnormalities is relevant not only for diagnostic and treatment purposes but also for prognostic risk assessment. From the translational research perspective, the identification of fusion proteins and protein interactions has allowed crucial breakthroughs in understanding the pathogenesis of malignancies and consequently major achievements in targeted therapy. We describe the optimization of the Proximity Ligation Assay (PLA) to ascertain the presence of fusion proteins, and protein interactions in non-adherent pre-B cells. PLA is an innovative method of protein-protein colocalization detection by molecular biology that combines the advantages of microscopy with the advantages of molecular biology precision, enabling detection of protein proximity theoretically ranging from 0 to 40 nm. We propose an optimized PLA procedure. We overcome the issue of maintaining non-adherent hematological cells by traditional cytocentrifugation and optimized buffers, by changing incubation times, and modifying washing steps. Further, we provide convincing negative and positive controls, and demonstrate that optimized PLA procedure is sensitive to total protein level. The optimized PLA procedure allows the detection of fusion proteins and protein interactions on non-adherent cells. The optimized PLA procedure described here can be readily applied to various non-adherent hematological cells, from cell lines to patients' cells. The optimized PLA protocol enables detection of fusion proteins and their subcellular expression, and protein interactions in non-adherent cells. Therefore, the optimized PLA protocol provides a new tool that can be adopted in a wide range of applications in the biological field.

Elevated mitochondrial gene expression during rat liver regeneration after portal vein ligation.

Science.gov (United States)

Shimizu, Y; Suzuki, H; Nimura, Y; Onoue, S; Nagino, M; Tanaka, M; Ozawa, T

1995-10-01

We explored the molecular basis of mitochondrial energy production during rat liver regeneration after portal vein ligation. Ligation of the left branch of the portal vein induces an increase in the weight of the nonligated lobe, counterbalancing the reduced weight of the ligated lobe. Using this model, we investigated changes in mitochondrial DNA-binding proteins, mitochondrial DNA, and mitochondrial messenger RNA (mRNA) in rat hepatocytes of the nonligated lobes. The amount of mitochondrial DNA-binding protein increased maximally (200% to 300% of the preoperative level) at 12 hours after the operation, before an increase (390%) in mitochondrial DNA content at 24 hours, and parallel to an increase (240%) in mitochondrial mRNA levels at 12 hours. These results suggest that the energy supply for liver regeneration is achieved through enhancement of mitochondrial DNA replication as well as transcription, in which the mitochondrial DNA-binding proteins probably play regulatory roles. We also found that in the nonligated lobes, mRNA levels of hepatocyte growth factor increased to a detectable level only 12 hours after the operation. These molecular biochemical data help explain why preoperative portal vein embolization, which is a modification of portal vein branch ligation, is an effective method to prevent posthepatectomy liver failure.

Effects of competition and cooperation interaction between agents on networks in the presence of a market capacity

Science.gov (United States)

Sonubi, A.; Arcagni, A.; Stefani, S.; Ausloos, M.

2016-08-01

A network effect is introduced taking into account competition, cooperation, and mixed-type interaction among agents along a generalized Verhulst-Lotka-Volterra model. It is also argued that the presence of a market capacity undoubtedly enforces a definite limit on the agent's size growth. The state stability of triadic agents, i.e., the most basic network plaquette, is investigated analytically for possible scenarios, through a fixed-point analysis. It is discovered that: (i) market demand is only satisfied for full competition when one agent monopolizes the market; (ii) growth of agent size is encouraged in full cooperation; (iii) collaboration among agents to compete against one single agent may result in the disappearance of this single agent out of the market; and (iv) cooperating with two rivals may become a growth strategy for an intelligent agent.

Effects of competition and cooperation interaction between agents on networks in the presence of a market capacity.

Science.gov (United States)

Sonubi, A; Arcagni, A; Stefani, S; Ausloos, M

2016-08-01

A network effect is introduced taking into account competition, cooperation, and mixed-type interaction among agents along a generalized Verhulst-Lotka-Volterra model. It is also argued that the presence of a market capacity undoubtedly enforces a definite limit on the agent's size growth. The state stability of triadic agents, i.e., the most basic network plaquette, is investigated analytically for possible scenarios, through a fixed-point analysis. It is discovered that: (i) market demand is only satisfied for full competition when one agent monopolizes the market; (ii) growth of agent size is encouraged in full cooperation; (iii) collaboration among agents to compete against one single agent may result in the disappearance of this single agent out of the market; and (iv) cooperating with two rivals may become a growth strategy for an intelligent agent.

Access to bifunctionalized biomolecular platforms using oxime ligation

Czech Academy of Sciences Publication Activity Database

Křenek, Karel; Gažák, Radek; Daskhan, G. Ch.; Garcia, J.; Fiore, M.; Dumy, P.; Šulc, Miroslav; Křen, Vladimír; Renaudet, O.

2014-01-01

Roč. 393, JUL 2014 (2014), s. 9-14 ISSN 0008-6215 R&D Projects: GA MŠk(CZ) LD13042 Institutional support: RVO:61388971 Keywords : Chemoselective ligation * Glycocluster * Cyclopeptide Subject RIV: CC - Organic Chemistry Impact factor: 1.929, year: 2014

Evaluation of common vaginal tunic ligation during field castration in draught colts.

Science.gov (United States)

Carmalt, J L; Shoemaker, R W; Wilson, D G

2008-09-01

The objective of this study was to determine if ligation of the common vaginal tunic could prevent or reduce the incidence of omental herniation and eventration in draught colts undergoing routine field castration. It was found that common vaginal tunic ligation, while not completely preventing omental herniation and evisceration, significantly reduced the incidence of these complications and should be considered in those males deemed at increased risk of significant post castration complications.

First Graders' Interpersonal Understanding during Cooperative and Competitive Games

Science.gov (United States)

Zan, Betty; Hildebrandt, Carolyn

2003-01-01

Differences in children's social interactions during cooperative and competitive games were investigated. Thirty-seven children from two first grade classes with cooperative classroom climates were videotaped while playing a cooperative and a competitive board game. Children's social interactions were coded using Selman's Levels of Enacted…

A label-free electrochemiluminescent sensor for ATP detection based on ATP-dependent ligation.

Science.gov (United States)

Zhao, Tingting; Lin, Chunshui; Yao, Qiuhong; Chen, Xi

2016-07-01

In this work, we describe a new label-free, sensitive and highly selective strategy for the electrochemiluminescent (ECL) detection of ATP at the picomolar level via ATP-induced ligation. The molecular-beacon like DNA probes (P12 complex) are self-assembled on a gold electrode. The presence of ATP leads to the ligation of P12 complex which blocks the digestion by Exonuclease III (Exo III). The protected P12 complex causes the intercalation of numerous ECL indicators (Ru(phen)3(2+)) into the duplex DNA grooves, resulting in significantly amplified ECL signal output. Since the ligating site of T4 DNA ligase and the nicking site of Exo III are the same, it involves no long time of incubation for conformation change. The proposed strategy combines the amplification power of enzyme and the inherent high sensitivity of the ECL technique and enables picomolar detection of ATP. The developed strategy also shows high selectivity against ATP analogs, which makes our new label-free and highly sensitive ligation-based method a useful addition to the amplified ATP detection arena. Copyright © 2016 Elsevier B.V. All rights reserved.

Gossip and ostracism promote cooperation in groups.

Science.gov (United States)

Feinberg, Matthew; Willer, Robb; Schultz, Michael

2014-03-01

The widespread existence of cooperation is difficult to explain because individuals face strong incentives to exploit the cooperative tendencies of others. In the research reported here, we examined how the spread of reputational information through gossip promotes cooperation in mixed-motive settings. Results showed that individuals readily communicated reputational information about others, and recipients used this information to selectively interact with cooperative individuals and ostracize those who had behaved selfishly, which enabled group members to contribute to the public good with reduced threat of exploitation. Additionally, ostracized individuals responded to exclusion by subsequently cooperating at levels comparable to those who were not ostracized. These results suggest that the spread of reputational information through gossip can mitigate egoistic behavior by facilitating partner selection, thereby helping to solve the problem of cooperation even in noniterated interactions.

Ligation bias in illumina next-generation DNA libraries: implications for sequencing ancient genomes.

Directory of Open Access Journals (Sweden)

Andaine Seguin-Orlando

Full Text Available Ancient DNA extracts consist of a mixture of endogenous molecules and contaminant DNA templates, often originating from environmental microbes. These two populations of templates exhibit different chemical characteristics, with the former showing depurination and cytosine deamination by-products, resulting from post-mortem DNA damage. Such chemical modifications can interfere with the molecular tools used for building second-generation DNA libraries, and limit our ability to fully characterize the true complexity of ancient DNA extracts. In this study, we first use fresh DNA extracts to demonstrate that library preparation based on adapter ligation at AT-overhangs are biased against DNA templates starting with thymine residues, contrarily to blunt-end adapter ligation. We observe the same bias on fresh DNA extracts sheared on Bioruptor, Covaris and nebulizers. This contradicts previous reports suggesting that this bias could originate from the methods used for shearing DNA. This also suggests that AT-overhang adapter ligation efficiency is affected in a sequence-dependent manner and results in an uneven representation of different genomic contexts. We then show how this bias could affect the base composition of ancient DNA libraries prepared following AT-overhang ligation, mainly by limiting the ability to ligate DNA templates starting with thymines and therefore deaminated cytosines. This results in particular nucleotide misincorporation damage patterns, deviating from the signature generally expected for authenticating ancient sequence data. Consequently, we show that models adequate for estimating post-mortem DNA damage levels must be robust to the molecular tools used for building ancient DNA libraries.

Friction between various self-ligating brackets and archwire couples during sliding mechanics.

Science.gov (United States)

Stefanos, Sennay; Secchi, Antonino G; Coby, Guy; Tanna, Nipul; Mante, Francis K

2010-10-01

The aim of this study was to evaluate the frictional resistance between active and passive self-ligating brackets and 0.019 × 0.025-in stainless steel archwire during sliding mechanics by using an orthodontic sliding simulation device. Maxillary right first premolar active self-ligating brackets In-Ovation R, In-Ovation C (both, GAC International, Bohemia, NY), and SPEED (Strite Industries, Cambridge, Ontario, Canada), and passive self-ligating brackets SmartClip (3M Unitek, Monrovia, Calif), Synergy R (Rocky Mountain Orthodontics, Denver, Colo), and Damon 3mx (Ormco, Orange, Calif) with 0.022-in slots were used. Frictional force was measured by using an orthodontic sliding simulation device attached to a universal testing machine. Each bracket-archwire combination was tested 30 times at 0° angulation relative to the sliding direction. Statistical comparisons were performed with 1-way analysis of variance (ANOVA) followed by Dunn multiple comparisons. The level of statistical significance was set at P <0.05. The Damon 3mx brackets had significantly the lowest mean static frictional force (8.6 g). The highest mean static frictional force was shown by the SPEED brackets (83.1 g). The other brackets were ranked as follows, from highest to lowest, In-Ovation R, In-Ovation C, SmartClip, and Synergy R. The mean static frictional forces were all statistically different. The ranking of the kinetic frictional forces of bracket-archwire combinations was the same as that for static frictional forces. All bracket-archwire combinations showed significantly different kinetic frictional forces except SmartClip and In-Ovation C, which were not significantly different from each other. Passive self-ligating brackets have lower static and kinetic frictional resistance than do active self-ligating brackets with 0.019 × 0.025-in stainless steel wire. Copyright © 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Arterial Ligation for Infected Femoral Psuedo-Aneurysm in Drug Injecting Abusers

Directory of Open Access Journals (Sweden)

Mohammadzade Mohammad Ali

2009-10-01

Full Text Available Pseudo-aneurysm of the femoral artery is the most common arterial complication in drug injecting abusers. Scholars in vascular surgery have published debating statements regarding techniques of successful surgical management during last two decades. We present the results of simple arterial ligation in a series of 32 patients presenting with infected femoral pseudo-aneurysm. Most of the patients were males (89%. Young persons in the age group of 15-44 years were mostly affected. Site of lesion included common femoral artery in 65% , superficial femoral artery 28% and at bifurcation 6.2%. celulitis in 14 (53%, abscess & "ncelulitis in 6 (19%, necrosing fasciitis in 2 (6.2% and vascular abscess in 7 (22% cases were the forms of associated local infection. There was no hemorrhage, vascular thrombosis, amputation, or mortality. Claudicating were the only complications identified in 2 patients with Tripe ligation. Ligation is the optimal management for infected pseudo-aneurysms because it is easy, cost-effective, and safe. Early reconstruction is not recommended, since there is an extended infection in the location of the pseudo-aneurysm.

Motorboat noise disrupts co-operative interspecific interactions.

Science.gov (United States)

Nedelec, Sophie L; Mills, Suzanne C; Radford, Andrew N; Beldade, Ricardo; Simpson, Stephen D; Nedelec, Brendan; Côté, Isabelle M

2017-08-01

Human-made noise is contributing increasingly to ocean soundscapes. Its physical, physiological and behavioural effects on marine organisms are potentially widespread, but our understanding remains largely limited to intraspecific impacts. Here, we examine how motorboats affect an interspecific cleaning mutualism critical for coral reef fish health, abundance and diversity. We conducted in situ observations of cleaning interactions between bluestreak cleaner wrasses (Labroides dimidiatus) and their fish clients before, during and after repeated, standardised approaches with motorboats. Cleaners inspected clients for longer and were significantly less cooperative during exposure to boat noise, and while motorboat disturbance appeared to have little effect on client behaviour, as evidenced by consistency of visit rates, clientele composition, and use of cleaning incitation signals, clients did not retaliate as expected (i.e., by chasing) in response to increased cheating by cleaners. Our results are consistent with the idea of cognitive impairments due to distraction by both parties. Alternatively, cleaners might be taking advantage of distracted clients to reduce their service quality. To more fully understand the importance of these findings for conservation and management, further studies should elucidate whether the efficacy of ectoparasite removal by cleaners is affected and explore the potential for habituation to boat noise in busy areas.

Increased secretion of insulin and proliferation of islet β-cells in rats with mesenteric lymph duct ligation

International Nuclear Information System (INIS)

Nagino, Ko; Yokozawa, Junji; Sasaki, Yu; Matsuda, Akiko; Takeda, Hiroaki; Kawata, Sumio

2012-01-01

Highlights: ► Insulin secretion was increased during the OGTT or IVGTT in mesenteric lymph duct-ligated rats. ► Proliferation of islet β-cells was upregulated in lymph duct-ligated rats. ► Mesenteric lymph duct flow has a role in glucose metabolism. -- Abstract: Background and aims: It has been suggested that intestinal lymph flow plays an important role in insulin secretion and glucose metabolism after meals. In this study, we investigated the influence of ligation of the mesenteric lymph duct on glucose metabolism and islet β-cells in rats. Methods: Male Sprague–Dawley rats (10 weeks old) were divided into two groups: one underwent ligation of the mesenteric lymph duct above the cistern (ligation group), and the other underwent a sham operation (sham group). After 1 and 2 weeks, fasting plasma concentrations of glucose, insulin, triglyceride, glucose-dependent insulinotropic polypeptide (GIP), and the active form of glucagon-like peptide-1 (GLP-1) were measured. At 2 weeks after the operation, the oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT) were performed. After the rats had been sacrificed, the insulin content of the pancreas was measured and the proliferation of β-cells was assessed immunohistochemically using antibodies against insulin and Ki-67. Results: During the OGTT, the ligation group showed a significant decrease in the plasma glucose concentration at 120 min (p < 0.05) and a significant increase in the plasma insulin concentration by more than 2-fold at 15 min (p < 0.01). On the other hand, the plasma GIP concentration was significantly decreased at 60 min (p < 0.01) in the ligated group, while the active form of GLP-1 showed a significantly higher level at 90 min (1.7-fold; p < 0.05) and 120 min (2.5-fold; p < 0.01). During the IVGTT, the plasma insulin concentration in the ligation group was significantly higher at 2 min (more than 1.4-fold; p < 0.05). Immunohistochemistry showed that the ratios of �

Sphenopalatine artery ligation: technical note.

Science.gov (United States)

Pothier, David D; Mackeith, Samuel; Youngs, Robin

2005-10-01

Epistaxis is a common problem. Most patients presenting to hospital will stop bleeding with simple first-aid measures or with nasal packing. Those who do not stop will usually require surgical management. For persistent posterior epistaxis, the sphenopalatine artery may be ligated as the artery leaves the sphenopalatine foramen to enter the nasal mucosa of the lateral wall of the nose. This may be performed endoscopically. We describe the anatomy of the area and the surgical technique. We also present a brief review of the literature on this technique.

Hypernetworks Reveal Compound Variables That Capture Cooperative and Competitive Interactions in a Soccer Match.

Science.gov (United States)

Ramos, João; Lopes, Rui J; Marques, Pedro; Araújo, Duarte

2017-01-01

The combination of sports sciences theorization and social networks analysis (SNA) has offered useful new insights for addressing team behavior. However, SNA typically represents the dynamics of team behavior during a match in dyadic interactions and in a single cumulative snapshot. This study aims to overcome these limitations by using hypernetworks to describe illustrative cases of team behavior dynamics at various other levels of analyses. Hypernetworks simultaneously access cooperative and competitive interactions between teammates and opponents across space and time during a match. Moreover, hypernetworks are not limited to dyadic relations, which are typically represented by edges in other types of networks. In a hypernetwork, n-ary relations (with n > 2) and their properties are represented with hyperedges connecting more than two players simultaneously (the so-called simplex -plural, simplices ). Simplices can capture the interactions of sets of players that may include an arbitrary number of teammates and opponents. In this qualitative study, we first used the mathematical formalisms of hypernetworks to represent a multilevel team behavior dynamics, including micro (interactions between players), meso (dynamics of a given critical event, e.g., an attack interaction), and macro (interactions between sets of players) levels. Second, we investigated different features that could potentially explain the occurrence of critical events, such as, aggregation or disaggregation of simplices relative to goal proximity. Finally, we applied hypernetworks analysis to soccer games from the English premier league (season 2010-2011) by using two-dimensional player displacement coordinates obtained with a multiple-camera match analysis system provided by STATS (formerly Prozone). Our results show that (i) at micro level the most frequently occurring simplices configuration is 1vs.1 (one attacker vs. one defender); (ii) at meso level, the dynamics of simplices

Hypernetworks Reveal Compound Variables That Capture Cooperative and Competitive Interactions in a Soccer Match

Directory of Open Access Journals (Sweden)

João Ramos

2017-08-01

Full Text Available The combination of sports sciences theorization and social networks analysis (SNA has offered useful new insights for addressing team behavior. However, SNA typically represents the dynamics of team behavior during a match in dyadic interactions and in a single cumulative snapshot. This study aims to overcome these limitations by using hypernetworks to describe illustrative cases of team behavior dynamics at various other levels of analyses. Hypernetworks simultaneously access cooperative and competitive interactions between teammates and opponents across space and time during a match. Moreover, hypernetworks are not limited to dyadic relations, which are typically represented by edges in other types of networks. In a hypernetwork, n-ary relations (with n > 2 and their properties are represented with hyperedges connecting more than two players simultaneously (the so-called simplex—plural, simplices. Simplices can capture the interactions of sets of players that may include an arbitrary number of teammates and opponents. In this qualitative study, we first used the mathematical formalisms of hypernetworks to represent a multilevel team behavior dynamics, including micro (interactions between players, meso (dynamics of a given critical event, e.g., an attack interaction, and macro (interactions between sets of players levels. Second, we investigated different features that could potentially explain the occurrence of critical events, such as, aggregation or disaggregation of simplices relative to goal proximity. Finally, we applied hypernetworks analysis to soccer games from the English premier league (season 2010–2011 by using two-dimensional player displacement coordinates obtained with a multiple-camera match analysis system provided by STATS (formerly Prozone. Our results show that (i at micro level the most frequently occurring simplices configuration is 1vs.1 (one attacker vs. one defender; (ii at meso level, the dynamics of simplices

A "typodont" study of rate of orthodontic space closure: self-ligating systems vs. conventional systems.

Science.gov (United States)

Saporito, I; Butti, A C; Salvato, A; Biagi, R

2011-01-01

The aim of this study was to compare the effectiveness of space closure of two bracket systems, self-ligating and conventional ones, considering two systems with the same design and prescription. The experimental model of this study aims to identify in general if one type of system is more suitable for planning the extractive therapy, without considering the clinical aspect necessary for an adequate orthodontic approach. A resin maxilla without the first premolars was used to test the self-ligating and conventional brackets system. Space closure was achieved on 0.016x0.022" in stainless steel wires with nickel-titanium coil springs 150 grams in strength and 10 mm in length. Two experiment settings have been prepared. The first setting was made bonding conventional bracket on the right side and self-ligating on the left; the last one was made bonding self-ligating bracket on the right side and conventional on the left. All measurements (runs) have been repeated seven times for both settings. During the closing phase of extraction spaces both systems are equable since there are no significant statistical differences (P=0.70). Our typodont model showed no significant difference in the efficiency of space closure between the self-ligating bracket and conventional bracket tied with stainless steel ligatures.

Coronary ligation reduces maximum sustained swimming speed in Chinook salmon, Oncorhynchus tshawytscha

DEFF Research Database (Denmark)

Farrell, A P; Steffensen, J F

1987-01-01

The maximum aerobic swimming speed of Chinook salmon (Oncorhynchus tshawytscha) was measured before and after ligation of the coronary artery. Coronary artery ligation prevented blood flow to the compact layer of the ventricular myocardium, which represents 30% of the ventricular mass, and produced...... a statistically significant 35.5% reduction in maximum swimming speed. We conclude that the coronary circulation is important for maximum aerobic swimming and implicit in this conclusion is that maximum cardiac performance is probably necessary for maximum aerobic swimming performance....

Elastic band ligation of hemorrhoids using flexible gastroscope

Directory of Open Access Journals (Sweden)

Hadi Abd Zaid Al-Khattabi

2017-03-01

Conclusion High success rate, cost effectiveness and the simplicity of rubber band ligation as an outpatient procedure promote its use as the frst line of treatment for frst, second and early third degree hemorrhoids.

Demonstration of metabolic and cellular effects of portal vein ligation using multi-modal PET/MRI measurements in healthy rat liver.

Directory of Open Access Journals (Sweden)

András Fülöp

Full Text Available OBJECTIVES: In the early recognition of portal vein ligation (PVL induced tumor progression, positron emission tomography and magnetic resonance imaging (PET/MRI could improve diagnostic accuracy of conventionally used methods. It is unknown how PVL affects metabolic patterns of tumor free hepatic tissues. The aim of this preliminary study is to evaluate the effect of PVL on glucose metabolism, using PET/MRI imaging in healthy rat liver. MATERIALS AND METHODS: Male Wistar rats (n=30 underwent PVL. 2-deoxy-2-(18Ffluoro-D-glucose (FDG PET/MRI imaging (nanoScan PET/MRI and morphological/histological examination were performed before (Day 0 and 1, 2, 3, and 7 days after PVL. Dynamic PET data were collected and the standardized uptake values (SUV for ligated and non-ligated liver lobes were calculated in relation to cardiac left ventricle (SUVVOI/SUVCLV and mean liver SUV (SUVVOI/SUVLiver. RESULTS: PVL induced atrophy of ligated lobes, while non-ligated liver tissue showed compensatory hypertrophy. Dynamic PET scan revealed altered FDG kinetics in both ligated and non-ligated liver lobes. SUVVOI/SUVCLV significantly increased in both groups of lobes, with a maximal value at the 2nd postoperative day and returned near to the baseline 7 days after the ligation. After PVL, ligated liver lobes showed significantly higher tracer uptake compared to the non-ligated lobes (significantly higher SUVVOI/SUVLiver values were observed at postoperative day 1, 2 and 3. The homogenous tracer biodistribution observed before PVL reappeared by 7th postoperative day. CONCLUSION: The observed alterations in FDG uptake dynamics should be taken into account during the assessment of PET data until the PVL induced atrophic and regenerative processes are completed.

Bis-ligated Ti and Zr complexes of chelating N-heterocyclic carbenes

KAUST Repository

El-Batta, Amer

2011-07-01

In this communication we report the synthesis of novel titanium and zirconium complexes ligated by bidentate "salicylaldimine-like" N-heterocyclic carbenes (NHC). Double addition of the NHC chelate to either TiCl4(thf)2 or ZrCl4 forms bis-ligated organometallic fragments with a distorted octahedral geometry. These complexes are rare examples of group IV transition-metal NHC adducts. Preliminary catalytic tests demonstrate that in the presence of methylaluminoxane (MAO) these complexes are useful initiators for the polymerization of ethylene and the copolymerization of ethylene with norbornene and 1-octene. © 2011 Elsevier B.V. All rights reserved.

Extrahepatic portal venous obstruction: The effects of early ligation of splenic artery during splenectomy.

Science.gov (United States)

Gazula, Suhasini; Pawar, D K; Seth, T; Bal, C S; Bhatnagar, V

2009-10-01

To objectively demonstrate the gain in blood volume and blood components following early ligation of splenic artery during splenectomy and splenorenal shunts in children with extra hepatic portal venous obstruction (EHPVO). Twenty-eight children (20 males and 8 females, mean age: 9.9 (+/-3.2) years) with EHPVO and hypersplenism were recruited. We followed a protocol of systematically locating and ligating the splenic artery first, followed by a 30-minute waiting period to allow the massive spleen to decongest via the splenic vein and venous collaterals and then completing the splenectomy by standard procedure. No intravenous fluid was administered during this 30-minute period. Blood samples were drawn just prior to splenic artery ligation and soon after splenectomy for the estimation of hematological and biochemical parameters. We noticed a highly significant increase in the hemoglobin, hematocrit, leukocyte, platelet, and RBC counts by early ligation of the splenic artery (p platelet count was equivalent to a platelet transfusion of atleast 4 units of platelet concentrates in an adult. There is a positive correlation between the splenic weight and the platelet gain (p= 0.0568) and the splenic volume on preoperative imaging and the platelet gain (p= 0.0251). Early ligation of the splenic artery during splenectomy results in passive splenic decongestion and thereby a significant gain in blood components. This protocol appears to be a feasible blood conservation method to avoid blood transfusions in this group of hypersplenic EHPVO patients.

Orchidopexy san ligation technique of orchidopexy | Jain | African ...

African Journals Online (AJOL)

Herniotomy is performed for the surgical repair of hernia and along with orchiopexy for the closure of associated patent processus vaginalis. Traditionally, ligation of hernial sac during orchiopexy is considered mandatory to prevent postoperative development of hernia. The present report was designed to study the results of ...

Evaluation of mesenteric lymphangiography and thoracic duct ligation in cats with chylothorax: 19 cases (1987-1992)

International Nuclear Information System (INIS)

Kerpsack, S.J.; McLoughlin, M.A.; Birchard, S.J.; Smeak, D.D.; Biller, D.S.

1994-01-01

Mesenteric lymphangiography and thoracic duct ligation were performedon 19 cats with chylothorax between 1987 to 1992. Chylothorax was diagnosed on the basis of detection of chylomicrons in the pleural effusion or determination of a cholesterol concentration:triglyceride concentration ratio of 12 months after surgery. Four cats died between 2 and 13 days after thoracic duct ligation, but pleural effusion had resolved in 3 of these 4 cats at the time of death. Five cats were euthanatized 8 to 36 days after surgery because of persistent chylous effusion after thoracic duct ligation

Selective desulfurization of cysteine in the presence of Cys(Acm) in polypeptides obtained by native chemical ligation.

Science.gov (United States)

Pentelute, Brad L; Kent, Stephen B H

2007-02-15

Increased versatility for the synthesis of proteins and peptides by native chemical ligation requires the ability to ligate at positions other than Cys. Here, we report that Raney nickel can be used under standard conditions for the selective desulfurization of Cys in the presence of Cys(Acm). This simple and practical tactic enables the more common Xaa-Ala junctions to be used as ligation sites for the chemical synthesis of Cys-containing peptides and proteins. [reaction: see text].

Rubber band ligation and infrared photocoagulation for the outpatient treatment of hemorrhoidal disease

OpenAIRE

Ricci,Maurício Pichler; Matos,Délcio; Saad,Sarhan Sydney

2008-01-01

PURPOSE: To compare the results of rubber band ligation and infrared photocoagulation for the treatment of hemorrhoidal disease through the analysis of the incidence of complications after each treatment and respective success rate. METHODS: Forty-eight patients with first, second or third degree hemorrhoidal disease were randomized to recieve treatment with either rubber band ligation (n=23) or infrared photocoagulation (n=25). Each patient was assessed at 1 week and 4 week intervals after t...

Idiopathic chylopericardium treated by percutaneous thoracic duct embolization after failed surgical thoracic duct ligation

Energy Technology Data Exchange (ETDEWEB)

Courtney, Malachi; Ayyagari, Raj R. [Yale School of Medicine, Yale New Haven Hospital, New Haven, CT (United States); Division of Interventional Radiology, Department of Radiology, 789 Howard Avenue, P.O. Box 208042, New Haven, CT (United States)

2015-06-15

Chylopericardium rarely occurs in pediatric patients, but when it does it is most often a result of lymphatic injury during cardiothoracic surgery. Primary idiopathic chylopericardium is especially rare, with few cases in the pediatric literature. We report a 10-year-old boy who presented with primary idiopathic chylopericardium after unsuccessful initial treatment with surgical lymphatic ligation and creation of a pericardial window. Following readmission to the hospital for a right-side chylothorax resulting from the effluent from the pericardial window, he had successful treatment by interventional radiology with percutaneous thoracic duct embolization. This case illustrates the utility of thoracic duct embolization as a less-invasive alternative to surgical thoracic duct ligation, or as a salvage procedure when surgical ligation fails. (orig.)

Idiopathic chylopericardium treated by percutaneous thoracic duct embolization after failed surgical thoracic duct ligation

International Nuclear Information System (INIS)

Courtney, Malachi; Ayyagari, Raj R.

2015-01-01

Chylopericardium rarely occurs in pediatric patients, but when it does it is most often a result of lymphatic injury during cardiothoracic surgery. Primary idiopathic chylopericardium is especially rare, with few cases in the pediatric literature. We report a 10-year-old boy who presented with primary idiopathic chylopericardium after unsuccessful initial treatment with surgical lymphatic ligation and creation of a pericardial window. Following readmission to the hospital for a right-side chylothorax resulting from the effluent from the pericardial window, he had successful treatment by interventional radiology with percutaneous thoracic duct embolization. This case illustrates the utility of thoracic duct embolization as a less-invasive alternative to surgical thoracic duct ligation, or as a salvage procedure when surgical ligation fails. (orig.)

Management of IVC Injury: Repair or Ligation? A Propensity Score Matching Analysis Using the National Trauma Data Bank.

Science.gov (United States)

Matsumoto, Shokei; Jung, Kyoungwon; Smith, Alan; Coimbra, Raul

2018-03-01

Ligation can be used as part of damage-control operations under critical conditions after IVC injury. Inferior vena cava ligation could potentially yield greater survival benefit compared with repair after injury. We hypothesized that ligation significantly improves outcomes compared with repair. The National Trauma Data Bank dataset for 2007-2014 was reviewed. Eligible patients included those sustaining IVC injury who underwent surgical ligation or repair. Data on demographics, outcomes, and complications were collected. Comparative analysis of demographic characteristics, complications and outcomes were performed. There were 4,865 patients identified in the National Trauma Data Bank with IVC injury. A total of 1,316 patients met inclusion criteria. Four hundred and forty-seven patients (34.0%) underwent ligation and 869 (66.0%) underwent repair. Before matching, the ligation group was sicker than the repair group and the in-hospital mortality was significantly higher in the ligation group (43.8% vs 36.2%; odds ratio [OR] 1.37; 95% CI 1.09 to 1.73). One to one propensity score matching generated 310 pairs. After propensity score matching, in-hospital mortality was similar (41.3% vs 39.0%; OR 1.10; 95% CI 0.80 to 1.52). However, IVC ligation was associated with significantly higher complication rates of extremity compartment syndrome (OR 5.23; 95% CI 1.50 to 18.24), pneumonia (OR 1.76; 95% CI 1.08 to 2.86), deep venous thrombosis (OR 2.83 95% CI 1.70 to 4.73), pulmonary embolism (OR 3.63; 95% CI 1.18 to 11.17), and longer hospital length of stay (17.0 days [interquartile range 1.0 to 35.0 days] vs 9.0 days [interquartile range 1.0 to 22.0 days]; p = 0.002). Inferior vena cava ligation is not superior to repair in terms of decreasing mortality in patients with IVC injury, but it is associated with higher complication rates and hospital LOS. Copyright © 2018 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Lipid raft facilitated ligation of K-{alpha}1-tubulin by specific antibodies on epithelial cells: Role in pathogenesis of chronic rejection following human lung transplantation

Energy Technology Data Exchange (ETDEWEB)

Tiriveedhi, Venkataswarup; Angaswamy, Nataraju [Department of Surgery, Pathology and Immunology, Washington University School of Medicine, St. Louis, MO (United States); Weber, Joseph [Department of Medicine, Washington University School of Medicine, St. Louis, MO (United States); Mohanakumar, T., E-mail: kumart@wustl.edu [Department of Surgery, Pathology and Immunology, Washington University School of Medicine, St. Louis, MO (United States)

2010-08-20

Research highlights: {yields} Addition of KAT Abs (+) sera to NHBE culture causes upregulation of growth factors. {yields} Cholesterol depletion causes down regulation of growth factor expression. {yields} Cholesterol depletion is accompanied by loss of membrane bound caveolin. {yields} Thus, we demonstrate lipid raft are critical for efficient ligation of the KAT Abs. -- Abstract: Long term function of human lung allografts is hindered by development of chronic rejection manifested as Bronchiolitis Obliterans Syndrome (BOS). We have previously identified the development of antibodies (Abs) following lung transplantation to K-{alpha}1-tubulin (KAT), an epithelial surface gap junction cytoskeletal protein, in patients who develop BOS. However, the biochemical and molecular basis of the interactions and signaling cascades mediated by KAT Abs are yet to be defined. In this report, we investigated the biophysical basis of the epithelial cell membrane surface interaction between KAT and its specific Abs. Towards this, we analyzed the role of the lipid raft-domains in the membrane interactions which lead to cell signaling and ultimately increased growth factor expression. Normal human bronchial epithelial (NHBE) cells, upon specific ligation with Abs to KAT obtained either from the serum of BOS(+) patients or monoclonal KAT Abs, resulted in upregulation of growth factors VEGF, PDGF, and bFGF (6.4 {+-} 1.1-, 3.2 {+-} 0.9-, and 3.4 {+-} 1.1-fold increase, respectively) all of which are important in the pathogenesis of BOS. To define the role for lipid raft in augmenting surface interactions, we analyzed the changes in the growth factor expression pattern upon depletion and enrichment with lipid raft following the ligation of the epithelial cell membranes with Abs specific for KAT. NHBE cells cultured in the presence of {beta}-methyl cyclodextran ({beta}MCD) had significantly reduced growth factor expression (1.3 {+-} 0.3, vs {beta}MCD untreated being 6.4 {+-} 1.1-fold

Lipid raft facilitated ligation of K-α1-tubulin by specific antibodies on epithelial cells: Role in pathogenesis of chronic rejection following human lung transplantation

International Nuclear Information System (INIS)

Tiriveedhi, Venkataswarup; Angaswamy, Nataraju; Weber, Joseph; Mohanakumar, T.

2010-01-01

Research highlights: → Addition of KAT Abs (+) sera to NHBE culture causes upregulation of growth factors. → Cholesterol depletion causes down regulation of growth factor expression. → Cholesterol depletion is accompanied by loss of membrane bound caveolin. → Thus, we demonstrate lipid raft are critical for efficient ligation of the KAT Abs. -- Abstract: Long term function of human lung allografts is hindered by development of chronic rejection manifested as Bronchiolitis Obliterans Syndrome (BOS). We have previously identified the development of antibodies (Abs) following lung transplantation to K-α1-tubulin (KAT), an epithelial surface gap junction cytoskeletal protein, in patients who develop BOS. However, the biochemical and molecular basis of the interactions and signaling cascades mediated by KAT Abs are yet to be defined. In this report, we investigated the biophysical basis of the epithelial cell membrane surface interaction between KAT and its specific Abs. Towards this, we analyzed the role of the lipid raft-domains in the membrane interactions which lead to cell signaling and ultimately increased growth factor expression. Normal human bronchial epithelial (NHBE) cells, upon specific ligation with Abs to KAT obtained either from the serum of BOS(+) patients or monoclonal KAT Abs, resulted in upregulation of growth factors VEGF, PDGF, and bFGF (6.4 ± 1.1-, 3.2 ± 0.9-, and 3.4 ± 1.1-fold increase, respectively) all of which are important in the pathogenesis of BOS. To define the role for lipid raft in augmenting surface interactions, we analyzed the changes in the growth factor expression pattern upon depletion and enrichment with lipid raft following the ligation of the epithelial cell membranes with Abs specific for KAT. NHBE cells cultured in the presence of β-methyl cyclodextran (βMCD) had significantly reduced growth factor expression (1.3 ± 0.3, vs βMCD untreated being 6.4 ± 1.1-fold increase) upon stimulation with KAT Abs. Depletion

Increased secretion of insulin and proliferation of islet {beta}-cells in rats with mesenteric lymph duct ligation

Energy Technology Data Exchange (ETDEWEB)

Nagino, Ko; Yokozawa, Junji; Sasaki, Yu; Matsuda, Akiko; Takeda, Hiroaki [Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585 (Japan); Kawata, Sumio, E-mail: Sumio_Kawata@pref.hyogo.lg.jp [Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585 (Japan); Hyogo Prefectural Nishinomiya Hospital, 13-9 Rokutanji-cho, Nishinomiya 662-0918 (Japan)

2012-08-24

Highlights: Black-Right-Pointing-Pointer Insulin secretion was increased during the OGTT or IVGTT in mesenteric lymph duct-ligated rats. Black-Right-Pointing-Pointer Proliferation of islet {beta}-cells was upregulated in lymph duct-ligated rats. Black-Right-Pointing-Pointer Mesenteric lymph duct flow has a role in glucose metabolism. -- Abstract: Background and aims: It has been suggested that intestinal lymph flow plays an important role in insulin secretion and glucose metabolism after meals. In this study, we investigated the influence of ligation of the mesenteric lymph duct on glucose metabolism and islet {beta}-cells in rats. Methods: Male Sprague-Dawley rats (10 weeks old) were divided into two groups: one underwent ligation of the mesenteric lymph duct above the cistern (ligation group), and the other underwent a sham operation (sham group). After 1 and 2 weeks, fasting plasma concentrations of glucose, insulin, triglyceride, glucose-dependent insulinotropic polypeptide (GIP), and the active form of glucagon-like peptide-1 (GLP-1) were measured. At 2 weeks after the operation, the oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT) were performed. After the rats had been sacrificed, the insulin content of the pancreas was measured and the proliferation of {beta}-cells was assessed immunohistochemically using antibodies against insulin and Ki-67. Results: During the OGTT, the ligation group showed a significant decrease in the plasma glucose concentration at 120 min (p < 0.05) and a significant increase in the plasma insulin concentration by more than 2-fold at 15 min (p < 0.01). On the other hand, the plasma GIP concentration was significantly decreased at 60 min (p < 0.01) in the ligated group, while the active form of GLP-1 showed a significantly higher level at 90 min (1.7-fold; p < 0.05) and 120 min (2.5-fold; p < 0.01). During the IVGTT, the plasma insulin concentration in the ligation group was significantly higher at 2

Rapid tyrosine phosphorylation of Lck following ligation of the tumor-associated cell surface molecule A6H

DEFF Research Database (Denmark)

Labuda, T; Gerwien, J; Ødum, Niels

1999-01-01

and the TCR-CD3 complex takes place and which signaling pathway might be involved. Here we show that ligation of the A6H antigen with mAb induces tyrosine phosphorylation of the Lck protein tyrosine kinase (PTK). Co-ligation of the A6H antigen with CD3 resulted in augmented Lck phosphorylation and mitogenesis....... In addition, A6H ligation induced an up-regulation of CD3-mediated phosphorylation of the 23 kDa high mol. wt form of TCR zeta and the zeta-associated protein, ZAP-70. Co-precipitation of Lck and ZAP-70 was only seen in T cells activated by combined A6H and anti-CD3 stimulation. In contrast, another Src...... family PTK, Fyn, was not affected by A6H ligation. In conclusion, we now demonstrate, for the first time, that A6H ligation triggers Lck phosphorylation, and that cross-talk between A6H and the TCR-CD3 complex involves Lck, ZAP-70 and the slow migrating isoform of TCR zeta. These results further suggests...

Root resorption during orthodontic treatment with self-ligating or conventional brackets: a systematic review and meta-analysis.

Science.gov (United States)

Yi, Jianru; Li, Meile; Li, Yu; Li, Xiaobing; Zhao, Zhihe

2016-11-21

The aim of this study was to compare the external apical root resorption (EARR) in patients receiving fixed orthodontic treatment with self-ligating or conventional brackets. Studies comparing the EARR between orthodontic patients using self-ligating or conventional brackets were identified through electronic search in databases including CENTRAL, PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) and SIGLE, and manual search in relevant journals and reference lists of the included studies until Apr 2016. The extraction of data and risk of bias evaluation were conducted by two investigators independently. The original outcome underwent statistical pooling by using Review Manager 5. Seven studies were included in the systematic review, out of which, five studies were statistically pooled in meta-analysis. The value of EARR of maxillary central incisors in the self-ligating bracket group was significantly lower than that in the conventional bracket group (SMD -0.31; 95% CI: -0.60--0.01). No significant differences in other incisors were observed between self-ligating and conventional brackets. Current evidences suggest self-ligating brackets do not outperform conventional brackets in reducing the EARR in maxillary lateral incisors, mandible central incisors and mandible lateral incisors. However, self-ligating brackets appear to have an advantage in protecting maxillary central incisor from EARR, which still needs to be confirmed by more high-quality studies.

Papillary Cystadenoma: An Incidental Finding in Tubal Ligation

Directory of Open Access Journals (Sweden)

Tabitha Lynn Ward

2018-01-01

Full Text Available von Hippel-Lindau disease (vHLD is a rare autosomal dominant disorder with multiple benign and malignant tumors of different organs. We report a papillary cystadenoma of the mesosalpinx found in close association with an adenomatoid tumor discovered incidentally following tubal ligation in a patient with vHLD.

Compete, coordinate, and cooperate: How to exploit uncertain environments with social interaction.

Science.gov (United States)

Schulze, Christin; Newell, Ben R

2015-10-01

Countless decisions, from the trivial to the crucial, are made in complex social contexts while facing uncertain consequences. Yet a large portion of decision making research focuses on either the effects of social interaction or the effects of environmental uncertainty by examining strategic games against others or individual games against nature. Drawing a connection between these approaches, the authors extend a standard individual choice paradigm to include social interaction with 1 other person. In this paradigm, 2 competing decision makers repeatedly select among 2 options, each offering a particular probability of a fixed payoff. When both players choose the same, correct option, the payoff is evenly split; when they choose different options, the player choosing the correct option receives the full payoff. The addition of this social dimension gives players an opportunity to fully exploit an uncertain environment via cooperation: By consistently choosing opposite options, two players can exploit the uncertain environment more effectively than a single player could. We present 2 experiments that manipulate environmental (Experiment 1) and social (Experiment 2) aspects of the paradigm. In Experiment 1, the outcome probabilities were either known or unknown to participants; in Experiment 2, participants' attention was drawn to individual or group gains by introducing either within- or between-group competition. Efficient cooperation did not emerge spontaneously in Experiment 1. Instead, most people probability maximized, mirroring the behavior observed in individual choice. By contrast, between--group competition in Experiment 2 facilitated efficient-but not always equitable--exploitation of uncertain environments. This work links the concepts of individual risky choice and strategic decision making under both environmental and social uncertainty. (c) 2015 APA, all rights reserved).

The Theoretical Prerequisites for the Emergence of Interactive Marketing in the System of Management of Cross-Border Economic Cooperation

Directory of Open Access Journals (Sweden)

Gegedosh Kristian V.

2017-06-01

Full Text Available The article attempts to characterize the basic theoretical aspects of marketing in cross-border cooperation. It has been found that, in the current context of the IT sector development, it is of substantial relevance to apply the benefits of online marketing together with integrating it into the international regional cross-border economic relations. The author’s own conception of the use of interactive marketing to further improve interaction of the entities of neighbouring countries in various areas of cross-border cooperation (CBC has been proposed. A layout of web site interface of the interactive cross-border business center has been developed on the example of the euroregional formation of member countries in the Interregional Association «Carpathian Euroregion». One of the main challenges to the development of the CBC today is the lack of a well-functioning mechanism of interaction of «local authorities – regional development agencies – business structures». However, after building a model for development of a cross-border economy based on interactive marketing principles, the border areas on both sides will be able to better develop the regional economy and, consequently, the social well-being of the territory as a whole.

How I do it: surgical ligation of craniocervical junction dural AV fistulas.

Science.gov (United States)

Sorenson, Thomas J; La Pira, Biagia; Hughes, Joshua; Lanzino, Giuseppe

2017-08-01

Dural arteriovenous fistulas (DAVFs) of the craniocervical junction are uncommon vascular lesions, which often require surgical treatment even in the endovascular era. Most commonly, the fistula is placed laterally, and surgical ligation is performed through a lateral suboccipital craniotomy. After dural opening, the area is inspected, and the arterialized vein is identified emerging from the dura, often adjacent to the entry point of the vertebral artery, and ligated. A far lateral craniotomy is the authors' preferred surgical approach for accessing and treating dural arteriovenous fistulas of the craniocervical junction that cannot be reached endovascularly.

Hypotension following patent ductus arteriosus ligation: the role of adrenal hormones.

Science.gov (United States)

Clyman, Ronald I; Wickremasinghe, Andrea; Merritt, T Allen; Solomon, Tabitha; McNamara, Patrick; Jain, Amish; Singh, Jaideep; Chu, Alison; Noori, Shahab; Sekar, Krishnamurthy; Lavoie, Pascal M; Attridge, Joshua T; Swanson, Jonathan R; Gillam-Krakauer, Maria; Reese, Jeff; DeMauro, Sara; Poindexter, Brenda; Aucott, Sue; Satpute, Monique; Fernandez, Erika; Auchus, Richard J

2014-06-01

To test the hypothesis that an impaired adrenal response to stress might play a role in the hypotension that follows patent ductus arteriosus (PDA) ligation. We performed a multicenter study of infants born at 15. Of 95 infants enrolled, 43 (45%) developed hypotension and 14 (15%) developed catecholamine-resistant hypotension. Low postoperative cortisol levels were not associated with the overall incidence of hypotension after ligation. However, low cortisol levels were associated with the refractoriness of the hypotension to catecholamine treatment. In a multivariate analysis: the OR for developing catecholamine-resistant hypotension was OR 36.6, 95% CI 2.8-476, P = .006. Low cortisol levels (in infants with catecholamine-resistant hypotension) were not attributable to adrenal immaturity or impairment; their cortisol precursor concentrations were either low or unchanged, and their response to cosyntropin was similar to infants without catecholamine-resistant hypotension. Infants with low cortisol concentrations after PDA ligation are likely to develop postoperative catecholamine-resistant hypotension. We speculate that decreased adrenal stimulation, rather than an impaired adrenal response to stimulation, may account for the decreased production. Copyright © 2014 Elsevier Inc. All rights reserved.

The importance of the ligation of the inferior thyroid artery in parathyroid function after subtotal thyroidectomy

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Araujo Filho Vergilius José Furtado de

2000-01-01

Full Text Available We prospectively studied the effects of the ligation of the inferior thyroid artery (ITA on postoperative hypoparathyroidism in 48 patients who underwent functional subtotal thyroidectomy. Patients were randomized into two groups: A, with bilateral ligation of the ITA and B, without ligation of the ITA. Parathyroid function was checked preoperatively and after surgery by clinical examination and measurement of total calcium, intact PTH, urinary calcium, and AMPc. RESULTS: A significant incidence of postoperative hypocalcemia occurred: 17% in group A and 13% in B on the 4th postoperative day. Six months later, the incidence was 5% in Group A and 0% in Group B. These differences were not statistically significant between the two groups, and neither were any of the other clinical and laboratory observations. CONCLUSION: The ligation of the ITA was not an important causal factor for the occurrence of postoperative hypocalcemia after subtotal thyroidectomy.

Testing cooperative systems with the MARS simulator

NARCIS (Netherlands)

Netten, B.D.; Wedemeijer, H.

2010-01-01

The complexity of cooperative systems makes the use of high fidelity simulation essential in the development and testing of cooperative applications and their interactions with other cooperative systems. In SAFESPOT a simulator test bench is setup to test the safety margin applications running on

Banding ligation versus no intervention for primary prevention in adults with oesophageal varices

DEFF Research Database (Denmark)

Yong, Charles Wei Kit; Vadera, Sonam; Morgan, Marsha Y.

2017-01-01

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the beneficial and harmful effects of banding ligation versus no intervention in adults with cirrhosis and gastro-oesophageal varices that have not bled.......This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the beneficial and harmful effects of banding ligation versus no intervention in adults with cirrhosis and gastro-oesophageal varices that have not bled....

Development of a 11C-labeled tetrazine for rapid tetrazine–trans-cyclooctene ligation

DEFF Research Database (Denmark)

Herth, Matthias Manfred; Andersen, Valdemar L.; Lehel, Szabolcs

2013-01-01

Tetrazine–trans-cyclooctene ligations are remarkably fast and selective reactions even at low micro-molar concentrations. In bioorthogonal radiochemistry, tools that enable conjugation of radioactive probes to pre-targeted vectors are of great interest. Herein, we describe the successful developm......Tetrazine–trans-cyclooctene ligations are remarkably fast and selective reactions even at low micro-molar concentrations. In bioorthogonal radiochemistry, tools that enable conjugation of radioactive probes to pre-targeted vectors are of great interest. Herein, we describe the successful...

Ligation of lymph vessels for the treatment of recurrent inguinal lymphoceles following lymphadenectomy

DEFF Research Database (Denmark)

Toyserkani, Navid Mohamadpour; Nielsen, Henrik Toft; Bakholdt, Vivi

2016-01-01

BACKGROUND: Recurrent lymphocele following groin dissection is generally a self-limiting condition, but in a few cases, the lymphocele persists and for this, there are not many options. Few reports have proposed the efficacy of lymph vessel ligation with patent blue as a vessel locator. We have......, and their data was retrieved from electronic patient records. RESULTS: In total, eight patients had this procedure performed for a total of ten inguinal regions. In all regions, leaking lymph vessels were easily found by the blue color and a median of 3 (range 1-5 vessels) vessels per region were ligated using...... and had the procedure performed again with immediate effect. CONCLUSIONS: Ligation of lymph vessels for the treatment of recurrent inguinal lymphoceles appears to be an appropriate treatment modality that is both quick and easy to perform with minimum risk, and in most cases, it results in immediate...

Cooperative interactions between paired domain and homeodomain.

Science.gov (United States)

Jun, S; Desplan, C

1996-09-01

The Pax proteins are a family of transcriptional regulators involved in many developmental processes in all higher eukaryotes. They are characterized by the presence of a paired domain (PD), a bipartite DNA binding domain composed of two helix-turn-helix (HTH) motifs,the PAI and RED domains. The PD is also often associated with a homeodomain (HD) which is itself able to form homo- and hetero-dimers on DNA. Many of these proteins therefore contain three HTH motifs each able to recognize DNA. However, all PDs recognize highly related DNA sequences, and most HDs also recognize almost identical sites. We show here that different Pax proteins use multiple combinations of their HTHs to recognize several types of target sites. For instance, the Drosophila Paired protein can bind, in vitro, exclusively through its PAI domain, or through a dimer of its HD, or through cooperative interaction between PAI domain and HD. However, prd function in vivo requires the synergistic action of both the PAI domain and the HD. Pax proteins with only a PD appear to require both PAI and RED domains, while a Pax-6 isoform and a new Pax protein, Lune, may rely on the RED domain and HD. We propose a model by which Pax proteins recognize different target genes in vivo through various combinations of their DNA binding domains, thus expanding their recognition repertoire.

Cooperation and Development: a study of case in network cooperation

Directory of Open Access Journals (Sweden)

June Alisson Westarb Cruz

2009-03-01

Full Text Available The need to develop new surviving strategies and competitive advantage by individuals and organizations make cooperation to obtain complementary competences and potentialities very important, through the insertion of social actors in multiple networks of relationships and interactions.  This research was made in an Association Network of Carrinheiros[1] located in Curitiba and in the coast of Paraná.  The objective of the study was to analyze the structural characteristics of the network and its implications to develop collective actions. The data was collected through questionnaires, interviews, document analysis, and the daily direct observation of the network.  An interaction system between individuals and organizations from various sectors in society could be verified. This interaction stimulates the structured work connected to associations and cooperatives.  Between the actors of the network, concepts and realities are different, as well as individual objectives are distinct.  However, they converge to a common general objective that establish a common base for collaborative work.

Preoperative embolization for juvenile nasopharyngeal angiofibroma. Usefulness of IADSA and problems of external carotid ligation

Energy Technology Data Exchange (ETDEWEB)

Saitoh, Ryuichi; Nakagawa, Nobuo; Kohrogi, Yukinori; Izunaga, Hiroshi; Bussaka, Hiromasa; Miyawaki, Masayuki; Takahashi, Mutsumasa; Ikawa, Tsutomu; Ishikawa, Takashi (Kumamoto Univ. (Japan). School of Medicine)

1984-10-01

Three male cases of juvenile nasopharyngeal angiofibroma are presented. Satisfactory results were obtained by performing preoperative embolization combined with intraarterial digital subtraction angiography (IADSA) in two of them. The other case had undergone external carotid ligation. Usefulness of IADSA in performing preoperative embolization for this disease and problems of external carotid ligation are discussed.

Incorporation of selenomethionine into proteins through selenohomocysteine-mediated ligation

NARCIS (Netherlands)

Roelfes, G; Hilvert, D

2003-01-01

The chemical synthesis of moderate-sized proteins has benefited enormously from the development of chemoselective methods for the ligation of peptide fragments. In this regard, the reaction of peptide thioesters with peptides containing an N-terminal cysteine has proved particularly powerful. The

End-Point Immobilization of Recombinant Thrombomodulin via Sortase-Mediated Ligation

Science.gov (United States)

Jiang, Rui; Weingart, Jacob; Zhang, Hailong; Ma, Yong; Sun, Xue-Long

2012-01-01

We report an enzymatic end-point modification and immobilization of recombinant human thrombomodulin (TM), a cofactor for activation of anticoagulant protein C pathway via thrombin. First, a truncated TM mutant consisting of epidermal growth factor-like domains 4–6 (TM456) with a conserved pentapeptide LPETG motif at its C-terminal was expressed and purified in E. coli. Next, the truncated TM456 derivative was site-specifically modified with N-terminal diglycine containing molecules such as biotin and the fluorescent probe dansyl via sortase A (SrtA) mediated ligation (SML). The successful ligations were confirmed by SDS-PAGE and fluorescence imaging. Finally, the truncated TM456 was immobilized onto N-terminal diglycine-functionalized glass slide surface via SML directly. Alternatively, the truncated TM456 was biotinylated via SML and then immobilized onto streptavidin-functionalized glass slide surface indirectly. The successful immobilizations were confirmed by fluorescence imaging. The bioactivity of the immobilized truncated TM456 was further confirmed by protein C activation assay, in which enhanced activation of protein C by immobilized recombinant TM was observed. The sortase A-catalyzed surface ligation took place under mild conditions and is rapid occurring in a single step without prior chemical modification of the target protein. This site-specific covalent modification leads to molecules being arranged in a definitively ordered fashion and facilitating the preservation of the protein’s biological activity. PMID:22372933

Theory of muscle contraction mechanism with cooperative interaction among crossbridges.

Science.gov (United States)

Mitsui, Toshio; Ohshima, Hiroyuki

2012-01-01

The power stroke model was criticized and a model was proposed for muscle contraction mechanism (Mitsui, 1999). The proposed model was further developed and calculations based on the model well reproduced major experimental data on the steady filament sliding (Mitsui and Ohshima, 2008) and on the transient phenomena (Mitsui, Takai and Ohshima, 2011). In this review more weight is put on explanation of the basic ideas of the model, especially logical necessity of the model, leaving mathematical details to the above-mentioned papers. A thermodynamic relationship that any models based upon the sliding filament theory should fulfill is derived. The model which fulfills the thermodynamic relationship is constructed on the assumption that a myosin head bound to an actin filament forms a complex with three actin molecules. In shortening muscles, the complex moves along the actin filament changing the partner actin molecules with steps of about 5.5 nm. This process is made possible through cooperative interaction among cross-bridges. The ATP hydrolysis energy is liberated by fraction at each step through chemical reactions between myosin and actin molecules. The cooperativity among crossbridges disappears in length-clamped muscles, in agreement with experimental observations that the cross-bridge produces force independently in the isometric tetanus state. The distance of the head movement per ATP hydrolysis cycle is expected to be about 5.5 nm or a few times of it under the condition of the in vitro single head experiments. Calculation results are surveyed illustrating that they are in good agreement with major experimental observations.

Sequential interactions-in which one player plays first and another responds-promote cooperation in evolutionary-dynamical simulations of single-shot Prisoner's Dilemma and Snowdrift games.

Science.gov (United States)

Laird, Robert A

2018-05-21

Cooperation is a central topic in evolutionary biology because (a) it is difficult to reconcile why individuals would act in a way that benefits others if such action is costly to themselves, and (b) it underpins many of the 'major transitions of evolution', making it essential for explaining the origins of successively higher levels of biological organization. Within evolutionary game theory, the Prisoner's Dilemma and Snowdrift games are the main theoretical constructs used to study the evolution of cooperation in dyadic interactions. In single-shot versions of these games, wherein individuals play each other only once, players typically act simultaneously rather than sequentially. Allowing one player to respond to the actions of its co-player-in the absence of any possibility of the responder being rewarded for cooperation or punished for defection, as in simultaneous or sequential iterated games-may seem to invite more incentive for exploitation and retaliation in single-shot games, compared to when interactions occur simultaneously, thereby reducing the likelihood that cooperative strategies can thrive. To the contrary, I use lattice-based, evolutionary-dynamical simulation models of single-shot games to demonstrate that under many conditions, sequential interactions have the potential to enhance unilaterally or mutually cooperative outcomes and increase the average payoff of populations, relative to simultaneous interactions-benefits that are especially prevalent in a spatially explicit context. This surprising result is attributable to the presence of conditional strategies that emerge in sequential games that can't occur in the corresponding simultaneous versions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Venous surgery in erectile dysfunction. The role of dorsal-penile-vein ligation and spongiosolysis for impotence.

Science.gov (United States)

Gilbert, P; Sparwasser, C; Beckert, R; Treiber, U; Pust, R

1992-01-01

We report here on our surgical experience with venous leakage of the cavernous bodies. Out of 159 patients operated on, 134 were available for long-term follow-up. Depending on the cavernosographic findings, one of three different surgical procedures was carried out: ligation of the deep dorsal vein of the penis, spongiosolysis, or ligation of the crura. 18% of the patients undergoing ligation of the deep dorsal vein, postoperatively attained spontaneous erections, while 35% needed adjuvant corpus cavernosum autoinjection therapy. Spongiosolysis gave a more favourable result: spontaneous erections in 30% and vasoactive drug-dependent erections in 35%. Crural ligation did not prove successful. No serious complications were encountered postoperatively. Our data suggest that venous surgery should only be offered to a selected group of patients comprising young impotent men with venous leakage, maybe in combination with arterial disease, and patients suffering from distal venous leakage. Old age, neurogenic disorders causing erectile dysfunction, and diabetes mellitus should represent exclusion criteria for venous surgery.

The Evolution of Power and the Divergence of Cooperative Norms

OpenAIRE

Makowsky, Michael; Smaldino, Paul

2015-01-01

We consider a model of multilevel selection and the evolution of institutions that distribute power in the form of influence in a group's collective interactions with other groups. In the absence of direct group-level interactions, groups with the most cooperative members will outcompete less cooperative groups, while within any group the least cooperative members will be the most successful. Introducing group-level interactions, however, such as raiding or warfare, changes the selective land...

Management of Small Urethrocutaneous Fistula by Tight Ligation ...

African Journals Online (AJOL)

After identifying the fistulous opening, the fistula tract was circumferentially and meticulously dissected ,then the dissected tract was lifted up and the base was ligated tightly with 5/0 vicryl, the external epithelium of the dissected tract was fulgurated with the diathermy, then a second layer of local soft tissue was secured over ...

The effectiveness of Doppler controlled hemorrhoidal artery ligation ...

African Journals Online (AJOL)

In this work, we discuss the preliminary results of the effectiveness of the hemorrhoidal artery ligation under control Doppler as a new technique for the treatment of hemorrhoids. We report the results of patients with hemorrhoids we have followed over a period of one year who were treated with HAL Doppler. The intra-and ...

Sortase-Mediated Ligation of Purely Artificial Building Blocks

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Xiaolin Dai

2018-02-01

Full Text Available Sortase A (SrtA from Staphylococcus aureus has been often used for ligating a protein with other natural or synthetic compounds in recent years. Here we show that SrtA-mediated ligation (SML is universally applicable for the linkage of two purely artificial building blocks. Silica nanoparticles (NPs, poly(ethylene glycol and poly(N-isopropyl acrylamide are chosen as synthetic building blocks. As a proof of concept, NP–polymer, NP–NP, and polymer–polymer structures are formed by SrtA catalysis. Therefore, the building blocks are equipped with the recognition sequence needed for SrtA reaction—the conserved peptide LPETG—and a pentaglycine motif. The successful formation of the reaction products is shown by means of transmission electron microscopy (TEM, matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-ToF MS, and dynamic light scattering (DLS. The sortase catalyzed linkage of artificial building blocks sets the stage for the development of a new approach to link synthetic structures in cases where their synthesis by established chemical methods is complicated.

Cooperative and uniform fish? : social interactions and variability in live body weight in the GIFT strain (Nile tilapia, Oreochromic niloticus) in Malaysia

NARCIS (Netherlands)

Khaw, H.L.

2015-01-01

Abstract

Khaw, HL. (2014). Cooperative and uniform fish? Social interactions and variability in live body weight in the GIFT strain (Nile tilapia, Oreochromic niloticus) in Malaysia. PhD thesis, Wageningen University, the Netherlands.

Social interactions

Comparison between Ultroid and Rubber Band Ligation in Treatment of Internal Hemorrhoids

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Rasoul Azizi

2010-11-01

Full Text Available "nHemorrhoid is one of the most common surgical diseases and different methods are available for its treatment. This study is a comparison between two methods of treatment of internal hemorrhoid, Monopolar low voltage instrument (Ultroid and Rubber Band Ligation. This method has been carried out prospectively in which 50 patients who were treated with rubber band ligation and 50 patients with Ultroid were compared according to the incidence of complications, post-operative pain and treatment response. According to this study complete success rate with Ultroid was 82% and partial success rate was 10% and no response to treatment was seen in 8%. In Rubber Band method the complete response rate was 94% (P=0.2. With Ultroid, 74% of patient reported no postoperative pain, 24% reported mild and moderate pain and 2% of patients complained of severe pain. With Rubber band ligation, 72% of patients reported no post-operative pain, 26% reported mild and moderate pain and 1% complained of severe pain (P=0.00. Rubber Band ligation and Ultroid are both considered as outpatient procedures for treatment of hemorrhoids. Both methods are mostly used for grade 1, 2 and sometime grade 3 hemorrhoids. In Ultroid method the operator is required to hold the probe for a period of time, and in most cases, the surgeon should spend between 20-25 minutes for the coagulation of three piles. Some surgeons do not have patience for this modality of internal hemorrhoid treatment. In this study we achieved acceptable results comparable with those of other techniques.

Quantifying the energetics of cooperativity in a ternary protein complex

DEFF Research Database (Denmark)

Andersen, Peter S; Schuck, Peter; Sundberg, Eric J

2002-01-01

and mathematical modeling to describe the energetics of cooperativity in a trimolecular protein complex. As a model system for quantifying cooperativity, we studied the ternary complex formed by the simultaneous interaction of a superantigen with major histocompatibility complex and T cell receptor, for which...... a structural model is available. This system exhibits positive and negative cooperativity, as well as augmentation of the temperature dependence of binding kinetics upon the cooperative interaction of individual protein components in the complex. Our experimental and theoretical analysis may be applicable...... to other systems involving cooperativity....

Intraabdominal laparoscopy-assisted "open" vessel ligation of testicular vessels: a potential treatment for varicocele.

Science.gov (United States)

Miyano, Go; Miyahara, Katsumi; Halibieke, Abudebieke; Lane, Geoffrey J; Okazaki, Tadaharu; Yamataka, Atsuyuki

2011-10-01

We tested our laparoscopy-assisted "open" ligation (LOL) technique on testicular vessels. We ligated the left testicular artery and vein (TAV) in 8-week-old male Wister rats using LOL (LOL group; n=10) or laparotomy (open group; n=10). In LOL, a 0-degree laparoscope was introduced through a 5-mm epigastric trocar. A 3-mm grasper was used to expose the left TAV. A lapa-her-closure (LHC) needle loaded with 3-0 SurgiPro was directly inserted into the left lower quadrant where the left TAV should be and advanced under the vessels, and the suture material was released leaving one end outside. The LHC was then withdrawn a little and advanced again over the vessels to grasp the end of the suture material just released to bring it outside. This was proximally repeated. The two ends of both sutures were conventionally tied outside, and the knot was passed through the insertion site and tightened around the vessels. In the open group, the left TAV were ligated using two 3-0 SurgiPro ties. In both groups, the right side was left intact. All rats were sacrificed 2 weeks postoperatively, and both testes were examined with hematoxylin and eosin. Treatment time was 5-7 minutes for LOL and 7-8 minutes for the open group. Postoperative recovery was uneventful. No adhesions were present between the ligated vessels and bowel in any rat. Histopathology of all left testes showed coagulative necrosis of germinal cells and seminiferous tubules; all right testes were normal. LOL appears to be as effective as open ligation and may find application for treating varicocele.

Extrahepatic portal venous obstruction: The effects of early ligation of splenic artery during splenectomy

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Gazula Suhasini

2009-01-01

Full Text Available Aim: To objectively demonstrate the gain in blood volume and blood components following early ligation of splenic artery during splenectomy and splenorenal shunts in children with extra hepatic portal venous obstruction (EHPVO. Methods: Twenty-eight children (20 males and 8 females, mean age: 9.9 (±3.2 years with EHPVO and hypersplenism were recruited. We followed a protocol of systematically locating and ligating the splenic artery first, followed by a 30-minute waiting period to allow the massive spleen to decongest via the splenic vein and venous collaterals and then completing the splenectomy by standard procedure. No intravenous fluid was administered during this 30-minute period. Blood samples were drawn just prior to splenic artery ligation and soon after splenectomy for the estimation of hematological and biochemical parameters. Results: We noticed a highly significant increase in the hemoglobin, hematocrit, leukocyte, platelet, and RBC counts by early ligation of the splenic artery (p < 0.0004. The gain in hemoglobin and hematocrit was equivalent to a transfusion of atleast 100-150 ml of packed RBC. The increase in platelet count was equivalent to a platelet transfusion of atleast 4 units of platelet concentrates in an adult. There is a positive correlation between the splenic weight and the platelet gain (p= 0.0568 and the splenic volume on preoperative imaging and the platelet gain (p= 0.0251. Conclusion: Early ligation of the splenic artery during splenectomy results in passive splenic decongestion and thereby a significant gain in blood components. This protocol appears to be a feasible blood conservation method to avoid blood transfusions in this group of hypersplenic EHPVO patients.

Comparison of infrared coagulation and rubber band ligation for first and second degree haemorrhoids: a randomised prospective clinical trial.

Science.gov (United States)

Templeton, J L; Spence, R A; Kennedy, T L; Parks, T G; Mackenzie, G; Hanna, W A

1983-01-01

One hundred and thirty seven previously untreated out-patients with first and second degree haemorrhoids were allocated at random to treatment by infrared coagulation (n=66) or rubber band ligation (n=71). Complete follow up was obtained in 122 patients (60 who had undergone infrared coagulation (group 1), and 62 rubber band ligation (group 2)) at periods from three months to one year after completion of treatment. Infrared coagulation produced a satisfactory outcome in 51 patients (85%): 34 were rendered asymptomatic and 17 improved. Rubber band ligation produced a satisfactory outcome in 57 patients (92%): 33 were rendered asymptomatic and 24 improved. Both methods were equally effective in first and second degree haemorrhoids. The incidence of side effects, particularly discomfort, during and after treatment was significantly higher in those treated by rubber band ligation (p less than 0.001). This appeared to be an appreciable deterrent to future patient compliance. The number of patients losing more than 24 hours from work was higher after rubber band ligation than after infrared coagulation. The number of treatments necessary to cure symptoms did not differ significantly between the two methods. Infrared coagulation was significantly faster than rubber band ligation (p less than 0.001). Infrared coagulation is a simple, fast, and effective outpatient method for the treatment of first and second degree haemorrhoids with fewer troublesome side effects and higher patient acceptability than rubber band ligation. PMID:6404471

Optimal primary surgical management of infected pseudoaneurysm in intravenous drug abusers: ligation or reconstruction?

International Nuclear Information System (INIS)

Jamil, M.; Usman, R.; Afzal, M.; Malik, N.I.

2017-01-01

Objective: To find out the optimal primary surgical treatment options for infected pseudoaneurysm in intravenous drug abusers. Study Design: Cross sectional descriptive study. Place and Duration of Study: Department of Vascular Surgery, Combined Military Hospital Lahore, from Jan 2010 to Jun 2015. Material and Methods: A total of 31 consecutive patients with a history of intravenous drug abuse and an infected pseudoaneurysm in the groin or elbow, presenting in emergency department; were included in this study. All patients were primarily treated with ligation of the artery, excision of infected pseudoaneurysm and debridement of necrotic tissues. Only one patient underwent additional revascularization procedure. Results: All patients who underwent ligation and excision procedures did well initially. One (3.2%) patient developed severe distal ischemia after ligation of femoral artery within first 24 hours, so extra anatomic revascularization procedure was performed. Five (16.1%) patients required revascularization procedure after 16 weeks due to disabling distal ischemia. No amputation was needed and mortality rate was zero. Conclusion: Primary ligation of the artery with excision of infected pseudoaneurysm and necrotic material was found the optimal initial management for infected pseudoaneurysm in intravenous drug addicts. Ischemic complications if develop should be treated with early or late revascularization.

Early or Late Surgical Ligation of Medical Refractory Patent Ductus Arteriosus in Premature Infants

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Chien-Chou Hsiao

2009-01-01

Full Text Available Optimal time to surgical ligation of patent ductus arteriosus (PDA in very-low-birth-weight ( 14 days groups. Basic clinical features, major morbidity of prematurity and mortality were compared. Clinical features and major outcomes were similar. The early ligation group had earlier onset of symptomatic PDA (5.7 ± 1.6 days vs. 8.1 ± 3.6 days, p = 0.024, and fewer days of total parenteral nutrition (TPN (39.6 ± 13.9 days vs. 60.4 ± 31.4 days, p = 0.025 and ventilator use (11.1 ± 6.7 days vs. 18.6 ± 10.5 days, p = 0.019. Early ligation of medical refractory PDA in very-low-birth-weight premature infants improves enteral feeding tolerance and reduces TPN and ventilator use, but long-term benefits need further investigation.

Social rank and social cooperation: Impact of social comparison processes on cooperative decision-making.

Directory of Open Access Journals (Sweden)

Xu Gong

Full Text Available Successful navigation of our complex social world requires the capability to recognize and judge the relative status of others. Hence, social comparison processes are of great importance in our interactions, informing us of our relative standing and in turn potentially motivating our behavior. However, so far few studies have examined in detail how social comparison can influence interpersonal decision-making. One aspect of social decision-making that is of particular importance is cooperative behavior, and identifying means of maintaining and promoting cooperation in the provision of public goods is of vital interest to society. Here, we manipulated social comparison by grading performance rankings on a reaction time task, and then measured cooperative decisions via a modified Public Goods Game (PGG. Findings revealed that individuals ranked highest tended to be more cooperative as compared to those who placed in the bottom rank. Interestingly, this effect was regardless of whether the comparison group members were the subsequent players in the PGG or not, and this effect was stronger in those with higher social orientation. In summary, the present research shows how different social comparison processes (assessed via social rankings can operate in our daily interaction with others, demonstrating an important effect on cooperative behavior.

Inequity aversion and the evolution of cooperation

Science.gov (United States)

Ahmed, Asrar; Karlapalem, Kamalakar

2014-02-01

Evolution of cooperation is a widely studied problem in biology, social science, economics, and artificial intelligence. Most of the existing approaches that explain cooperation rely on some notion of direct or indirect reciprocity. These reciprocity based models assume agents recognize their partner and know their previous interactions, which requires advanced cognitive abilities. In this paper we are interested in developing a model that produces cooperation without requiring any explicit memory of previous game plays. Our model is based on the notion of inequity aversion, a concept introduced within behavioral economics, whereby individuals care about payoff equality in outcomes. Here we explore the effect of using income inequality to guide partner selection and interaction. We study our model by considering both the well-mixed and the spatially structured population and present the conditions under which cooperation becomes dominant. Our results support the hypothesis that inequity aversion promotes cooperative relationship among nonkin.

Experience with rubber band ligation of hemorrhoids in northern ...

African Journals Online (AJOL)

Background: Treatment of hemorrhoids in Nigeria is usually done by the traditional open method that requires hospital admission; anesthesia and is associated with high morbidity. Rubber band ligation is a suitable alternative to open hemorrhoidectomy and has the potential to reduce the need for hospital admission.

Patterns of cooperation: fairness and coordination in networks of interacting agents

Science.gov (United States)

Do, Anne-Ly; Rudolf, Lars; Gross, Thilo

2010-06-01

We study the self-assembly of a complex network of collaborations among self-interested agents. The agents can maintain different levels of cooperation with different partners. Further, they continuously, selectively and independently adapt the amount of resources allocated to each of their collaborations in order to maximize the obtained payoff. We show analytically that the system approaches a state in which the agents make identical investments, and links produce identical benefits. Despite this high degree of social coordination, some agents manage to secure privileged topological positions in the network, enabling them to extract high payoffs. Our analytical investigations provide a rationale for the emergence of unidirectional non-reciprocal collaborations and different responses to the withdrawal of a partner from an interaction that have been reported in the psychological literature.

Perception without self-matching in conditional tag based cooperation.

Science.gov (United States)

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.

Social heuristics shape intuitive cooperation.

Science.gov (United States)

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.

Environmental feedback drives cooperation in spatial social dilemmas

Science.gov (United States)

Szolnoki, Attila; Chen, Xiaojie

2017-12-01

Exploiting others is beneficial individually but it could also be detrimental globally. The reverse is also true: a higher cooperation level may change the environment in a way that is beneficial for all competitors. To explore the possible consequence of this feedback we consider a coevolutionary model where the local cooperation level determines the payoff values of the applied prisoner's dilemma game. We observe that the coevolutionary rule provides a significantly higher cooperation level comparing to the traditional setup independently of the topology of the applied interaction graph. Interestingly, this cooperation supporting mechanism offers lonely defectors a high surviving chance for a long period hence the relaxation to the final cooperating state happens logarithmically slow. As a consequence, the extension of the traditional evolutionary game by considering interactions with the environment provides a good opportunity for cooperators, but their reward may arrive with some delay.

Gingival response in orthodontic patients: Comparative study between self-ligating and conventional brackets.

Science.gov (United States)

Folco, Alejandra A; Benítez-Rogé, Sandra C; Iglesias, Marina; Calabrese, Diana; Pelizardi, Cristina; Rosa, Alcira; Brusca, Marisa I; Hecht, Pedro; Mateu, María E

2014-01-01

Orthodontic brackets contribute to the accumulation of bacterial plaque on tooth surfaces because they hinder oral hygiene. In contrast to conventional brackets, self-ligating brackets do not require additional parts to support the arches, thus improving dental hygiene. The aim of this study was to compare the gingival response in orthodontic patients wearing self-ligating or conventional brackets. A sample of 22 patients aged 16 to 30 years was divided into two groups: Group A, treated with selfligating brackets (Damon system) and Group B, treated with conventional brackets (Roth technique). The following were assessed during the treatment: Plaque Index (PI), Gingival Index (GI) and Probing Depth (PD), and sub-gingival samples were taken from teeth 14/24 for microbiological observation. No statistically significant difference was found between Groups A and B; p>0.05 (sign-ranked) or between PI, GI and PD at the different times (Friedman's Analysis of Variance), even though the indices were found to increase at 14 days, particularly for self-ligating brackets. The quantity and quality of microorganisms present were compatible with health on days 0, 28 and 56. As from day 14 there is a predominance of microbiota compatible with gingivitis in both groups. In the samples studied, orthodontic treatment increases bacterial plaque and inflammatory gingival response, but gingival-periodontal health can be maintained with adequate basic therapy. Self-ligating and conventional brackets produced similar gingival response.

Cooperation and the evolution of intelligence.

Science.gov (United States)

McNally, Luke; Brown, Sam P; Jackson, Andrew L

2012-08-07

The high levels of intelligence seen in humans, other primates, certain cetaceans and birds remain a major puzzle for evolutionary biologists, anthropologists and psychologists. It has long been held that social interactions provide the selection pressures necessary for the evolution of advanced cognitive abilities (the 'social intelligence hypothesis'), and in recent years decision-making in the context of cooperative social interactions has been conjectured to be of particular importance. Here we use an artificial neural network model to show that selection for efficient decision-making in cooperative dilemmas can give rise to selection pressures for greater cognitive abilities, and that intelligent strategies can themselves select for greater intelligence, leading to a Machiavellian arms race. Our results provide mechanistic support for the social intelligence hypothesis, highlight the potential importance of cooperative behaviour in the evolution of intelligence and may help us to explain the distribution of cooperation with intelligence across taxa.

Controlling the transmitted information of a multi-photon interacting with a single-Cooper pair box

International Nuclear Information System (INIS)

Kadry, Heba; Abdel-Aty, Abdel-Haleem; Zakaria, Nordin; Cheong, Lee Yen

2014-01-01

We study a model of a multi-photon interaction of a single Cooper pair box with a cavity field. The exchange of the information using this system is studied. We quantify the fidelity of the transmitted information. The effect of the system parameters (detuning parameter, field photons, state density and mean photon number) in the fidelity of the transmitted information is investigated. We found that the fidelity of the transmitted information can be controlled using the system parameters

Controlling the transmitted information of a multi-photon interacting with a single-Cooper pair box

Energy Technology Data Exchange (ETDEWEB)

Kadry, Heba, E-mail: hkadry1@yahoo.com; Abdel-Aty, Abdel-Haleem, E-mail: hkadry1@yahoo.com; Zakaria, Nordin, E-mail: hkadry1@yahoo.com [Computer and Information Science Department, Universiti Teknologi Petronas, Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Cheong, Lee Yen [Fundamental and Applied Science Department, Universiti Teknologi Petronas, Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

2014-10-24

We study a model of a multi-photon interaction of a single Cooper pair box with a cavity field. The exchange of the information using this system is studied. We quantify the fidelity of the transmitted information. The effect of the system parameters (detuning parameter, field photons, state density and mean photon number) in the fidelity of the transmitted information is investigated. We found that the fidelity of the transmitted information can be controlled using the system parameters.

Change of hepatic volume after selective bile duct ligation: an experimental study in the rabbit

International Nuclear Information System (INIS)

Lee, Hye Won; Yoon, Yup; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won; Oh, Joo Hyeong; Rim, Hyeong Teck; Kim, Youn Wha; Lee, Seok Hwan

1998-01-01

To evaluate the role of bile duct obstuction in the development of atrophy of the liver, using an animal model. Seven rabbits were divided into two groups: group 1(n=3D5), in which there was selective bile duct ligation, and group 2(n=3D2), which underwent a sham operation. Each group was evaluated using CT for changes in hepatic volume after selective bile duct ligation or a sham operation. In group I, the diameter of dilated bile duct was measured 2, 4, 8, 12 and 16 weeks after bile duct ligation, while gross and histologic change were evaluated in all cases. In group 1, bile duct dilatation was seen on CT two weeks after selective bile duct ligation, and did not change significantly during follow-up. In four of five cases, CT revealed no evidence of significant atrophy of the involved segment. Pathologic specimens, however, revealed dilatation of the bile duct, periductal fibrosis, infiltration of chronic inflammatory cells, and periportal fibrosis. One of five cases showed segmental liver atrophy after selective bile duct ligation. In addion to the above pathologic findings, there was obstruction of the portal vein by foreign body reaction. In group 2, no evidence of dilated bile duct or liver atrophy was revealed by CT or pathologic specimen after a sham operation. During long-term follow-up of 16 weeks, obstruction of the bile duct did not play a major role in the development of lobar atrophy in the rabbit.=20

TRANSITION FROM ADVERSARIAL TO COOPERATIVE STRATEGIC INTERACTION; FINAL

International Nuclear Information System (INIS)

G.H. CANAVAN

2001-01-01

This note extends the game theoretic analysis of strategic conflicts begun in earlier Seminars on Planetary Emergencies to interactions with and without defenses between two or more adversaries with more realistic target structures. It reviews the essentials of game theory as applied to the analysis of strategic decisions, the application of first and second strike costs as payoffs, and solution optimization, which resolves several inconsistencies seen with earlier metrics. The stability of the current bilateral offensive configuration is shown to be high and insensitive to deep reductions in offensive forces, the deployment of limited defenses, and the exchange of significant offensive forces for defenses. The transition from adversarial to cooperative interaction is represented by the progressive reduction of the parameters representing each side's preference for damaging or deterring the other, which monotonically improves stability. Estimates of strike incentives in bilateral and trilateral configurations are reduced by the inclusion of high value targets in both sides' force allocations, which dominates the details of offensive and defensive forces. The shift to high value targets stabilizes trilateral offensive configurations, a result that differs with that from analyses based on military costs only. When defenses are included, they lead to a balance between a large defended side and small undefended side that resembles the balance between two large sides. Including the large side's preference for defense of high value targets in the analyses reduces its strike incentives and thus the small side's incentive to preempt. However, it also removes the large sides' ability to deter, so the stability of multi-polar configurations continues to be controlled by the least stable dyad, which places constraints on the size of defenses that can be deployed stably that could be more stringent than those from the bilateral balance

We can work it out: An enactive look at cooperation

Directory of Open Access Journals (Sweden)

Valentina eFantasia

2014-08-01

Full Text Available 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 towards 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.

Does the number of veins ligated during varicococele surgery influence post-operative semen and hormone results?

Science.gov (United States)

Majzoub, A; Elbardisi, H; Arafa, M; Agarwal, A; Al Said, S; Al Rumaihi, K

2016-09-01

Varicocele is a well-established cause of male subfertility, which is directly proportional to its clinical grade. Although newer ultrasonic grading systems have taken into account the existence of pampiniform venous plexi, little is known about the clinical significance of the number of veins ligated during surgery. Very few undersized studies reported an influence which triggered the need to evaluate such association. This is a retrospective study of 378 patients who underwent left microsurgical subinguinal varicocoelectomy. Semen analyses and blood hormone studies performed pre-operatively were compared to those executed 6 months after surgery. Patients were divided into abnormal semen and normal semen groups based on their initial semen results. They were also subdivided according to the number of veins ligated intraoperatively into three groups: 10 veins. Sperm count, total motility, and progressive motility were significantly increased in 62, 60.3, and 53.3% of patients post-operatively (p = 0.001), respectively. No significant differences in hormone levels were detected overall. Of the 378 patients, 332 had an abnormal semen analysis, while the remaining 46 patients had a normal result. Sperm count, total motility, and progressive motility significantly increased after varicocoelectomy in patients with an abnormal initial semen analysis (p = 0.001). In 48.7% of patients, 5-10 veins were ligated during surgery, whereas 28.3% had >10 and 23% had <5 ligated veins. No statistically significant differences were noted in the initial or the follow-up results among the number of vein subgroups. Varicocele ligation improves patients' fertility potential. This improvement, however, is not influenced by the number of veins ligated intraoperatively. Clinical grading maintains its superiority in the evaluation of varicocele patients. © 2016 American Society of Andrology and European Academy of Andrology.

Oesophageal variceal band ligation using a Saeed Six-Shooter ...

African Journals Online (AJOL)

Background: Oesophageal varices are common sequelae of cirrhosis, which when they bleed can be difficult to control. Oesophageal variceal band ligation, being the best modality for controlling variceal bleeding has not been common practice in West Africa, a region recognized to have a high prevalence of liver diseases.

Effects of Cooperative E-Learning on Learning Outcomes

Science.gov (United States)

Yeh, Shang-Pao; Fu, Hsin-Wei

2014-01-01

This study aims to discuss the effects of E-Learning and cooperative learning on learning outcomes. E-Learning covers the dimensions of Interpersonal communication, abundant resources, Dynamic instruction, and Learning community; and, cooperative learning contains three dimensions of Cooperative motive, Social interaction, and Cognition…

Side-chain interactions form late and cooperatively in the binding reaction between disordered peptides and PDZ domains

DEFF Research Database (Denmark)

Haq, S Raza; Chi, Celestine N; Bach, Anders

2012-01-01

Intrinsically disordered proteins are very common and mediate numerous protein-protein and protein-DNA interactions. While it is clear that these interactions are instrumental for the life of the mammalian cell, there is a paucity of data regarding their molecular binding mechanisms. We have here...... used short peptides as a model system for intrinsically disordered proteins. Linear free-energy relationships based on rate and equilibrium constants for the binding of these peptides to ordered target proteins, PDZ domains, demonstrate that native side-chain interactions form mainly after the rate......-limiting barrier for binding, in a cooperative fashion. This finding suggests that these disordered peptides first form a weak encounter complex with non-native interactions. The data do not support the recent notion that the affinities of intrinsically disordered proteins towards their targets are generally...

Influence of ligation method on friction resistance of lingual brackets with different second-order angulations: an in vitro study.

Science.gov (United States)

Pereira, Graziane Olímpio; Gimenez, Carla Maria Melleiro; Prieto, Lucas; Prieto, Marcos Gabriel do Lago; Basting, Roberta Tarkany

2016-01-01

To evaluate stainless steel archwire static friction in active and passive self-ligating lingual and conventional brackets with second-order angulations. Two conventional lingual brackets for canines (STb light/Ormco; PSWb/Tecnident), and two self-ligating brackets, one active (In-Ovation L/GAC) and the other passive (3D/ Forestadent), were evaluated. A stainless steel archwire was used at 0°, 3° and 5° angulations. Metal ligatures, conventional elastic ligatures, and low friction elastic ligatures were also tested. A universal testing machine applied friction between brackets and wires, simulating sliding mechanics, to produce 2-mm sliding at 3 mm/minute speed. Two-way analysis of variance demonstrated a significant effect of the interaction between brackets and angulations (p frictional resistance values were observed at 5° angulation for In-Ovation L, PSWb bracket with non conventional ligature, and STb bracket with metal ligature. As for 3D, PSWb with conventional or metal ligatures, and STb brackets with non conventional ligature, showed significantly lower static frictional resistance with 0° angulation. At 0° angulation, STb brackets with metal ties, In-Ovation L brackets and 3D brackets had the lowest frictional resistance. As the angulation increased from 0° to 3°, static friction resistance increased. When angulation increased from 3° to 5°, static friction resistance increased or remained the same. Self-ligating 3D and In-Ovation L brackets, as well as conventional STb brackets, seem to be the best option when sliding mechanics is used to perform lingual orthodontic treatment.

Accelerating cooperative systems' development through the Grand Cooperative Driving challenge

NARCIS (Netherlands)

Vonk Noordegraaf, D.; Malone, K.M.; Katwijk, R. van; Gerrits, A.

2009-01-01

Cooperative driving systems comprise an important research area. They are considered a promising solution for reducing traffic congestion, reducing environmental impact and improving traffic safety and driver comfort. The key to these systems is the communication and interaction between vehicles and

Assembly of a biocompatible triazole-linked gene by one-pot click-DNA ligation

Science.gov (United States)

Kukwikila, Mikiembo; Gale, Nittaya; El-Sagheer, Afaf H.; Brown, Tom; Tavassoli, Ali

2017-11-01

The chemical synthesis of oligonucleotides and their enzyme-mediated assembly into genes and genomes has significantly advanced multiple scientific disciplines. However, these approaches are not without their shortcomings; enzymatic amplification and ligation of oligonucleotides into genes and genomes makes automation challenging, and site-specific incorporation of epigenetic information and/or modified bases into large constructs is not feasible. Here we present a fully chemical one-pot method for the assembly of oligonucleotides into a gene by click-DNA ligation. We synthesize the 335 base-pair gene that encodes the green fluorescent protein iLOV from ten functionalized oligonucleotides that contain 5ʹ-azide and 3ʹ-alkyne units. The resulting click-linked iLOV gene contains eight triazoles at the sites of chemical ligation, and yet is fully biocompatible; it is replicated by DNA polymerases in vitro and encodes a functional iLOV protein in Escherichia coli. We demonstrate the power and potential of our one-pot gene-assembly method by preparing an epigenetically modified variant of the iLOV gene.

An interactive cooperation model for neighboring virtual power plants

International Nuclear Information System (INIS)

Shabanzadeh, Morteza; Sheikh-El-Eslami, Mohammad-Kazem; Haghifam, Mahmoud-Reza

2017-01-01

Highlights: •The trading strategies of a VPP in cooperation with its neighboring VPPs are addressed. •A portfolio of inter-regional contracts is considered to model this cooperation scheme. •A novel mathematical formulation for possible inadvertent transactions is provided. •A two-stage stochastic programming approach is applied to characterize the uncertainty. •Two efficient risk measures, SSD and CVaR, are implemented in the VPP decision-making problem. -- Abstract: Future distribution systems will accommodate an increasing share of distributed energy resources (DERs). Facing with this new reality, virtual power plants (VPPs) play a key role to aggregate DERs with the aim of facilitating their involvement in wholesale electricity markets. In this paper, the trading strategies of a VPP in cooperation with its neighboring VPPs are addressed. Toward this aim, a portfolio of inter-regional contracts is considered to model this cooperation and maximize the energy trade opportunities of the VPP within a medium-term horizon. To hedge against profit variability caused by market price uncertainties, two efficient risk management approaches are also implemented in the VPP decision-making problem based on the concepts of conditional value at risk (CVaR) and second-order stochastic dominance constraints (SSD). The resulting models are formulated as mixed-integer linear programming (MILP) problems that can be solved using off-the-shelf software packages. The efficiency of the proposed risk-hedging models is analyzed through a detailed case study, and thereby relevant conclusions are drawn.

Endoscopic variceal band ligation: a local experience | Jani | East ...

African Journals Online (AJOL)

Objective: To evaluate the results of endoscopic variceal band ligation (EVBL) in the local set-up. Design: Retrospective analysis of data of all patients who had EVBL. Setting: Patients having EVBL at the office endoscopy suite. The Nairobi Hospital, the Aga Khan Hospital and M.P Shah Hospital. Methods: The varices were ...

Attraction and cooperative behavior

OpenAIRE

Donja Darai; Silvia Grätz

2012-01-01

Being good-looking seems to generate substantial benefits in many social interactions, making the "beauty premium" a not to be underrated economic factor. This paper investigates how physical attractiveness enables people to generate these benefits in the case of cooperation, using field data from a modified one-shot prisoner's dilemma played in a high-stakes television game show. While attractive contestants are not more or less cooperative than less attractive ones, facial attractiveness pr...

Clinical and psychological repercussions of videolaparoscopic tubal ligation: observational, single cohort, retrospective study

Directory of Open Access Journals (Sweden)

Daniel Spadoto Dias

Full Text Available CONTEXT AND OBJECTIVE: Tubal ligation is one of the most commonly used contraceptive methods worldwide. Since the controversy over the potential effects of tubal sterilization still continues, this study aimed to evaluate the clinical and psychological repercussions of videolaparoscopic tubal ligation.DESIGN AND SETTING: Observational, single cohort, retrospective study, conducted in a tertiary public hospital.METHODS: A questionnaire was applied to 130 women aged 21-46 years who underwent videolaparoscopic tubal ligation by means of tubal ring insertion or bipolar electrocoagulation and sectioning, between January 1999 and December 2007. Menstrual cycle interval, intensity and duration of bleeding, premenstrual symptoms, dysmenorrhea, dyspareunia, noncyclic pelvic pain and degree of sexual satisfaction were assessed in this questionnaire. Each woman served as her own control, and comparisons were made between before and after the surgical procedure and between the two techniques used.RESULTS: The clinical and psychological repercussions were significant, with increases in bleeding (P = 0.001, premenstrual symptoms (P < 0.001, dysmenorrhea (P = 0.019 and noncyclic pelvic pain (P = 0.001; and reductions in the number of sexual intercourse occurrences per week (P = 0.001 and in libido (P = 0.001. Women aged ≤ 35 years at the time of sterilization were more likely to develop menstrual abnormalities. The bipolar electrocoagulation method showed greater clinical and psychological repercussions.CONCLUSION: Regardless of the technique used, videolaparoscopic tubal ligation had repercussions consisting of increased menstrual flow and premenstrual symptoms, especially in women aged ≤ 35 years, and also had a negative influence on sexual activity.

Communication and cooperation in networked environments: an experimental analysis.

Science.gov (United States)

Galimberti, C; Ignazi, S; Vercesi, P; Riva, G

2001-02-01

Interpersonal communication and cooperation do not happen exclusively face to face. In work contexts, as in private life, there are more and more situations of mediated communication and cooperation in which new online tools are used. However, understanding how to use the Internet to support collaborative interaction presents a substantial challenge for the designers and users of this emerging technology. First, collaborative Internet environments are designed to serve a purpose, so must be designed with intended users' tasks and goals explicitly considered. Second, in cooperative activities the key content of communication is the interpretation of the situations in which actors are involved. So, the most effective way of clarifying the meaning of messages is to connect them to a shared context of meaning. However, this is more difficult in the Internet than in other computer-based activities. This paper tries to understand the characteristics of cooperative activities in networked environments--shared 3D virtual worlds--through two different studies. The first used the analysis of conversations to explore the characteristics of the interaction during the cooperative task; the second analyzed whether and how the level of immersion in the networked environments influenced the performance and the interactional process. The results are analyzed to identify the psychosocial roots used to support cooperation in a digital interactive communication.

Female sterilization by tubal ligation at caesarean section in Makurdi ...

African Journals Online (AJOL)

Background: Female sterilization is an important tool in reducing unplanned pregnancy and maternal mortality in our environment. The aim of this study was to determine the incidence, sociodemographic characteristics, technique, effectiveness and complications associated with female sterilization by bilateral tubal ligation ...

Effects of Dimers on Cooperation in the Spatial Prisoner's Dilemma Game

International Nuclear Information System (INIS)

Li Haihong; Cheng Hongyan; Dai Qionglin; Ju Ping; Yang Junzhong; Zhang Mei

2011-01-01

We investigate the evolutionary prisoner's dilemma game in structured populations by introducing dimers, which are defined as that two players in each dimer always hold a same strategy. We find that influences of dimers on cooperation depend on the type of dimers and the population structure. For those dimers in which players interact with each other, the cooperation level increases with the number of dimers though the cooperation improvement level depends on the type of network structures. On the other hand, the dimers, in which there are not mutual interactions, will not do any good to the cooperation level in a single community, but interestingly, will improve the cooperation level in a population with two communities. We explore the relationship between dimers and self-interactions and find that the effects of dimers are similar to that of self-interactions. Also, we find that the dimers, which are established over two communities in a multi-community network, act as one type of interaction through which information between communities is communicated by the requirement that two players in a dimer hold a same strategy. (general)

Cooperation under indirect reciprocity and imitative trust.

Science.gov (United States)

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

2010-10-27

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

Cooperation under indirect reciprocity and imitative trust.

Directory of Open Access Journals (Sweden)

Serguei Saavedra

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

Alterations in plaque accumulation and gingival inflammation promoted by treatment with self-ligating and conventional orthodontic brackets.

Science.gov (United States)

Cardoso, Mauricio de Almeida; Saraiva, Patrícia Pinto; Maltagliati, Liliana Ávila; Rhoden, Fernando Kleinübing; Costa, Carla Cristina Alvarenga; Normando, David; Capelozza Filho, Leopoldino

2015-01-01

The aim of the present study was to evaluate, comparatively, the periodontal response during orthodontic treatment performed with self-ligating and conventional brackets. Sixteen Caucasian individuals of both sexes, aged between 12 and 16 years old and in permanent dentition were selected. Eight individuals were treated with conventional brackets installed on the lower dental arch and self-ligating brackets on the upper arch. Another eight individuals received self-ligating brackets in the lower arch and conventional brackets in the upper arch. The subjects received material and instructions for oral hygiene. Visible plaque index (VPI), gingival bleeding index (GBI) and clinical attachment level (CAL) were evaluated just after installation of orthodontic appliances, and 30, 60 and 180 days later. Mann-Whitney test was used to compare differences between groups (self-ligating and conventional), two-way ANOVA followed by Tukey's test was used to assess CAL at each site of each tooth. Significance level was set at 5%. No significant changes were found with regard to the assessed parameters (VPI, GBI and CAL) in either one of the systems. No significant changes were found with regard to the periodontal response to orthodontic treatment for the variables assessed and between subjects receiving passive self-ligating and conventional brackets. All individuals had received oral hygiene instructions and had their periodontal conditions monitored.

Alterations in plaque accumulation and gingival inflammation promoted by treatment with self-ligating and conventional orthodontic brackets

Directory of Open Access Journals (Sweden)

Mauricio de Almeida Cardoso

2015-04-01

Full Text Available OBJECTIVE: The aim of the present study was to evaluate, comparatively, the periodontal response during orthodontic treatment performed with self-ligating and conventional brackets. METHODS: Sixteen Caucasian individuals of both sexes, aged between 12 and 16 years old and in permanent dentition were selected. Eight individuals were treated with conventional brackets installed on the lower dental arch and self-ligating brackets on the upper arch. Another eight individuals received self-ligating brackets in the lower arch and conventional brackets in the upper arch. The subjects received material and instructions for oral hygiene. Visible plaque index (VPI, gingival bleeding index (GBI and clinical attachment level (CAL were evaluated just after installation of orthodontic appliances, and 30, 60 and 180 days later. Mann-Whitney test was used to compare differences between groups (self-ligating and conventional, two-way ANOVA followed by Tukey's test was used to assess CAL at each site of each tooth. Significance level was set at 5%. RESULTS: No significant changes were found with regard to the assessed parameters (VPI, GBI and CAL in either one of the systems. CONCLUSION: No significant changes were found with regard to the periodontal response to orthodontic treatment for the variables assessed and between subjects receiving passive self-ligating and conventional brackets. All individuals had received oral hygiene instructions and had their periodontal conditions monitored.

Parochial trust and cooperation across 17 societies

Science.gov (United States)

Romano, Angelo; Balliet, Daniel; Liu, James H.

2017-01-01

International challenges such as climate change, poverty, and intergroup conflict require countries to cooperate to solve these complex problems. However, the political tide in many countries has shifted inward, with skepticism and reluctance to cooperate with other countries. Thus, cross-societal investigations are needed to test theory about trust and cooperation within and between groups. We conducted an experimental study in 17 countries designed to test several theories that explain why, who, and where people trust and cooperate more with ingroup members, compared with outgroup members. The experiment involved several interactions in the trust game, either as a trustor or trustee. We manipulated partner group membership in the trust game (ingroup, outgroup, or unknown) and if their reputation was at stake during the interaction. In addition to the standard finding that participants trust and cooperate more with ingroup than outgroup members, we obtained findings that reputational concerns play a decisive role for promoting trust and cooperation universally across societies. Furthermore, men discriminated more in favor of their ingroup than women. Individual differences in cooperative preferences, as measured by social value orientation, predicted cooperation with both ingroup and outgroup members. Finally, we did not find support for three theories about the cross-societal conditions that influence the degree of ingroup favoritism observed across societies (e.g., material security, religiosity, and pathogen stress). We discuss the implications for promoting cooperation within and between countries. PMID:29133403

Meta-analysis: banding ligation and medical interventions for the prevention of rebleeding from oesophageal varices

DEFF Research Database (Denmark)

Thiele, Maja; Krag, A; Rohde, Ulrich

2012-01-01

In patients with oesophageal varices, the combination of endoscopic variceal ligation (EVL) and medical therapy is recommended as standard of care for prevention of rebleeding. The results of previous meta-analyses on this topic are equivocal.......In patients with oesophageal varices, the combination of endoscopic variceal ligation (EVL) and medical therapy is recommended as standard of care for prevention of rebleeding. The results of previous meta-analyses on this topic are equivocal....

Management of Fistula‑In‑Ano with Special Reference to Ligation of ...

African Journals Online (AJOL)

Department of General Surgery, MKCG Medical College, Berhampur, Odisha, India. ABSTRACT ... Management of fistula‑in‑ano through ligation of intersphincteric fistula tract. 2 ... At the time of admission, a detailed history and the clinical.

Impairment of the organization of locomotor and exploratory behaviors in bile duct-ligated rats

DEFF Research Database (Denmark)

Leke, Renata; de Oliveira, Diogo L; Mussulini, Ben Hur M.

2012-01-01

Hepatic encephalopathy (HE) arises from acute or chronic liver diseases and leads to several problems, including motor impairment. Animal models of chronic liver disease have extensively investigated the mechanisms of this disease. Impairment of locomotor activity has been described in different...... female Wistar rats underwent common bile duct ligation (BDL rats) or the manipulation of common bile duct without ligation (control rats). Six weeks after surgery, control and BDL rats underwent open-field, plus-maze and foot-fault behavioral tasks. The BDL rats developed chronic liver failure...

Menstrual Pattern following Tubal Ligation: A Historical Cohort Study

Directory of Open Access Journals (Sweden)

Shahideh Jahanian Sadatmahalleh

2016-12-01

Full Text Available Background: Tubal ligation (TL is recommended for women who have completed their family planning. The existence of the menstrual disorders following this procedure has been the subject of debate for decades. This study was conducted to identify the relationship between tubal ligation and menstrual disorders. Materials and Methods: A historical cohort study was carried out on 140 women undergoing tubal ligation (TL group and on 140 women using condom as the main contraceptive method (Non-TL group. They aged between 20 and 40 years and were selected from a health care center in Rudsar, Guilan Province, Iran, during 2013-2014. The two groups were comparable in demographic characteristics, obstetrical features and menstrual bleeding pattern using a routine questionnaire. A validated pictorial blood loss assessment chart (PBLAC was also used to measure the menstrual blood loss. Results: Women with TL had more menstrual irregularity than those without TL (24.3 vs. 10%, P=0.002. Women with TL had more polymenorrhea (9.3 vs. 1.4%, P=0.006, hypermenorrhea (12.1 vs. 2.1%, P=0.002, menorrhagia (62.9 vs. 22.1%, P<0.0001 and menometrorrhagia (15.7 vs. 3.6%, P=0.001 than those without TL. There is a significant difference in the PBLAC score between women with and without TL (P<0.0001. According to logistic regression, age odds ratio [(OR=1.08, confidence interval (CI:1.07-1.17, P=0.03], TL (OR=5.95, CI:3.45-10.26, P<0.0001 and cesarean section (OR=2.72, CI:1.49-4.97, P=0.001 were significantly associated with menorrhagia. Conclusion: We found significant differences in menstrual disorders between women with and without TL. Therefore, women should be informed by the health providers regarding the advantages and disadvantages of TL before the procedures.

Evaluation of low ligation and high proceedings of varicocele

International Nuclear Information System (INIS)

Khan, M.; Khan, S.; Pervez, A.; Nawaz, H.; Ahmed, S.; Tareen, S.

2003-01-01

Objective: To describe the mode of presentation of varicocele and to compare the low ligation (Inguinal approach/ ivanissevich s procedure) and high ligation (Retroperitoneal approach/modified Palomo's procedure) of varicocele repair regarding efficacy and postoperative complications. Subjects and Methods: A total of 213 patients of varicocele who underwent treatment in the department and completed 6 months follow-up were included in the study. The mode of presentation of varicocele was recorded for all patients. For treatment purpose patients were randomly divided into two groups: in group I (n:115) varicocele was ligated by inguinal approach (Ivanissevich s procedure) while in group II (n: 98) by retroopertional approach (modified Palomo s procedure). The efficacy and postoperative complications of the two procedures were carefully recorded and compared between the two groups. Results: The mean age of the patients of group-I and group-II was 27.2 and 27.5 years respectively. More than 50% patients of both groups presented with feeling of heaviness/ dragging sensation on ipsilateral side. Presentation with infertility/sub fertility in group-I and group-II was 16.5% and 15.3% respectively. Majority of patients of both groups had grade III varicocele with visible deformity. The rate of postoperative complications was very low in both groups of patients. Recurrence of varicocele and postoperative hydrocele formation were slightly more common in group-II as compared to group-I but the difference was statistically not significant (p>0.05). An extremely significant improvement occurred postoperatively in both sperms density and motility in infertile/sub fertile patients of both groups. Conclusion: Both procedures of varicocele repair are equally equally effective and have a low rate of complications. There is no significant difference in postoperatively complications. An extremely significant improvement occurs in semen parameters of infertile/sub fertile patients

Population structure induces a symmetry breaking favoring the emergence of cooperation.

Directory of Open Access Journals (Sweden)

Jorge M Pacheco

2009-12-01

Full Text Available The evolution of cooperation described in terms of simple two-person interactions has received considerable attention in recent years, where several key results were obtained. Among those, it is now well established that the web of social interaction networks promotes the emergence of cooperation when modeled in terms of symmetric two-person games. Up until now, however, the impacts of the heterogeneity of social interactions into the emergence of cooperation have not been fully explored, as other aspects remain to be investigated. Here we carry out a study employing the simplest example of a prisoner's dilemma game in which the benefits collected by the participants may be proportional to the costs expended. We show that the heterogeneous nature of the social network naturally induces a symmetry breaking of the game, as contributions made by cooperators may become contingent on the social context in which the individual is embedded. A new, numerical, mean-field analysis reveals that prisoner's dilemmas on networks no longer constitute a defector dominance dilemma--instead, individuals engage effectively in a general coordination game. We find that the symmetry breaking induced by population structure profoundly affects the evolutionary dynamics of cooperation, dramatically enhancing the feasibility of cooperators: cooperation blooms when each cooperator contributes the same cost, equally shared among the plethora of games in which she participates. This work provides clear evidence that, while individual rational reasoning may hinder cooperative actions, the intricate nature of social interactions may effectively transform a local dilemma of cooperation into a global coordination problem.

Modeling the cooperative and competitive contagions in online social networks

Science.gov (United States)

Zhuang, Yun-Bei; Chen, J. J.; Li, Zhi-hong

2017-10-01

The wide adoption of social media has increased the interaction among different pieces of information, and this interaction includes cooperation and competition for our finite attention. While previous research focus on fully competition, this paper extends the interaction to be both "cooperation" and "competition", by employing an IS1S2 R model. To explore how two different pieces of information interact with each other, the IS1S2 R model splits the agents into four parts-(Ignorant-Spreader I-Spreader II-Stifler), based on SIR epidemic spreading model. Using real data from Weibo.com, a social network site similar to Twitter, we find some parameters, like decaying rates, can both influence the cooperative diffusion process and the competitive process, while other parameters, like infectious rates only have influence on the competitive diffusion process. Besides, the parameters' effect are more significant in the competitive diffusion than in the cooperative diffusion.

Ligation of major histocompatibility complex class I antigens (MHC-I) prevents apoptosis induced by Fas or SAPK/JNK activation in T-lymphoma cells

DEFF Research Database (Denmark)

Lamberth, K; Claesson, M H

2001-01-01

Early apoptosis in Jurkat T-lymphoma cells was induced by agonistic anti-Fas Ab or by anisomycin which activates the stress kinases SAPK/JNK. Apoptosis was inhibited by ligation of major histocompatibility complex class I antigens (MHC-I). MHC-I ligation induced upregulation of the anti-apoptotic......Early apoptosis in Jurkat T-lymphoma cells was induced by agonistic anti-Fas Ab or by anisomycin which activates the stress kinases SAPK/JNK. Apoptosis was inhibited by ligation of major histocompatibility complex class I antigens (MHC-I). MHC-I ligation induced upregulation of the anti......-apoptotic Bcl-2 protein and stabilized the mitochondrial membrane potential (Deltapsim). MHC-I ligation also prevented downregulation of Bcl-2 and destabilization of Deltapsim induced by anti-Fas Ab treatment or anisomycin exposure. Studies on three different Jurkat cell mutants deficient for src p56(lck), ZAP......-70 kinase, or TCR/CD3 gamma-chain showed that the cells undergo apoptosis after Fas ligation. Anisomycin exposure induced apoptosis in the src p56(lck)-deficient cell line but not in the two other mutant cell lines. Simultaneous cross-linking of MHC-I and Fas ligation inhibited apoptosis in the ZAP...

Effective adsorption of hexavalent chromium through a three center (3c) co-operative interaction with an ionic liquid and biopolymer

International Nuclear Information System (INIS)

Santhana Krishna Kumar, A.; Gupta, Timsi; Kakan, Shruti Singh; Kalidhasan, S.; Manasi,; Rajesh, Vidya; Rajesh, N.

2012-01-01

Highlights: ► Tetraoctylammoniumbromide impregnated chitosan was prepared by ultrasonication. ► Physico-chemical characterization of the adsorbent was studied in detail. ► The sorbent has an adsorption capacity of 63.69 mg g −1 for chromium(VI). ► The mechanism involves a three center interaction with positive co-operative effect. ► Adsorbent is effectively regenerated with ammonium hydroxide. - Abstract: Biopolymers as well as ionic liquids are known for their potential applications. In this work, we report the utility of chitosan as an excellent platform for impregnating the ionic liquid, tetraoctylammonium bromide by ultrasonication and its subsequent adsorption for chromium(VI). The effective mass transfer due to sonication coupled with the hydrogen bonding interaction between chitosan-ionic liquid and the electrostatic interaction involving the amino groups in chitosan and hexavalent chromium governs this three center (3c) co-operative mechanism. The adsorption followed a pseudo second order kinetics with a Langmuir adsorption capacity of 63.69 mg g −1 . Various isotherm models were used to correlate the experimental data and the adsorption process is exothermic with a decreased randomness at the solid–solution interface. The thermodynamics of the spontaneous adsorption process could be explained through a positive co-operative effect between the host (chitosan) and the guest (ionic liquid). The adsorbed chromium(VI) could be converted to ammonium chromate using ammonium hydroxide, thereby regenerating the adsorbent. The method could be translated into action in the form of practical application to a real sample containing chromium.

External root resorption with the self-ligating Damon system—a retrospective study

Directory of Open Access Journals (Sweden)

Roberta Heiffig Handem

2016-07-01

Full Text Available Abstract Background The aim of this study was to compare the degree of external apical root resorption (EARR in patients treated with self-ligating Damon appliances and with conventional preadjusted appliances. Methods The sample comprised 52 patients, divided into two groups. Group 1 consisted of 25 patients treated with self-ligating Damon appliances, with an initial age of 16.04 years, final age of 18.06 years, and treatment time of 2.02 years. Group 2 consisted of 27 patients, treated with conventional preadjusted appliances, with an initial age of 16.77 years, final age of 18.47 years and treatment time of 1.70 years. The groups were matched regarding the initial and final ages, treatment time, type of malocclusion, and treatment protocol without extractions. Root resorption was evaluated on periapical radiographs of the maxillary and mandibular incisors at the end of orthodontic treatment with the scores of Levander and Malmgren. Intergroup comparisons of root resorption were performed with Mann-Whitney tests. Results No significant difference in the degree of root resorption between the two groups was found. Conclusions Similar degrees of resorption can be expected after non-extraction treatment with Damon self-ligating or conventional preadjusted appliances.

External root resorption with the self-ligating Damon system-a retrospective study.

Science.gov (United States)

Handem, Roberta Heiffig; Janson, Guilherme; Matias, Murilo; de Freitas, Karina Maria Salvatore; de Lima, Darwin Vaz; Garib, Daniela Gamba; de Freitas, Marcos Roberto

2016-12-01

The aim of this study was to compare the degree of external apical root resorption (EARR) in patients treated with self-ligating Damon appliances and with conventional preadjusted appliances. The sample comprised 52 patients, divided into two groups. Group 1 consisted of 25 patients treated with self-ligating Damon appliances, with an initial age of 16.04 years, final age of 18.06 years, and treatment time of 2.02 years. Group 2 consisted of 27 patients, treated with conventional preadjusted appliances, with an initial age of 16.77 years, final age of 18.47 years and treatment time of 1.70 years. The groups were matched regarding the initial and final ages, treatment time, type of malocclusion, and treatment protocol without extractions. Root resorption was evaluated on periapical radiographs of the maxillary and mandibular incisors at the end of orthodontic treatment with the scores of Levander and Malmgren. Intergroup comparisons of root resorption were performed with Mann-Whitney tests. No significant difference in the degree of root resorption between the two groups was found. Similar degrees of resorption can be expected after non-extraction treatment with Damon self-ligating or conventional preadjusted appliances.

Cooperation between referees and authors increases peer review accuracy.

Directory of Open Access Journals (Sweden)

Jeffrey T Leek

Full Text Available Peer review is fundamentally a cooperative process between scientists in a community who agree to review each other's work in an unbiased fashion. Peer review is the foundation for decisions concerning publication in journals, awarding of grants, and academic promotion. Here we perform a laboratory study of open and closed peer review based on an online game. We show that when reviewer behavior was made public under open review, reviewers were rewarded for refereeing and formed significantly more cooperative interactions (13% increase in cooperation, P = 0.018. We also show that referees and authors who participated in cooperative interactions had an 11% higher reviewing accuracy rate (P = 0.016. Our results suggest that increasing cooperation in the peer review process can lead to a decreased risk of reviewing errors.

Evolution of Cooperation in Adaptive Social Networks

Science.gov (United States)

Segbroeck, Sven Van; Santos, Francisco C.; Traulsen, Arne; Lenaerts, Tom; Pacheco, Jorge M.

Humans are organized in societies, a phenomenon that would never have been possible without the evolution of cooperative behavior. Several mechanisms that foster this evolution have been unraveled over the years, with population structure as a prominent promoter of cooperation. Modern networks of exchange and cooperation are, however, becoming increasingly volatile, and less and less based on long-term stable structure. Here, we address how this change of paradigm aspects the evolution of cooperation. We discuss analytical and numerical models in which individuals can break social ties and create new ones. Interactions are modeled as two-player dilemmas of cooperation. Once a link between two individuals has formed, the productivity of this link is evaluated. Links can be broken off at different rates. This individual capacity of forming new links or severing inconvenient ones can effectively change the nature of the game. We address random formation of new links and local linking rules as well as different individual capacities to maintain social interactions. We conclude by discussing how adaptive social networks can become an important step towards more realistic models of cultural dynamics.

Multiplexed homogeneous proximity ligation assays for high throughput protein biomarker research in serological material

DEFF Research Database (Denmark)

Lundberg, Martin; Thorsen, Stine Buch; Assarsson, Erika

2011-01-01

A high throughput protein biomarker discovery tool has been developed based on multiplexed proximity ligation assays (PLA) in a homogeneous format in the sense of no washing steps. The platform consists of four 24-plex panels profiling 74 putative biomarkers with sub pM sensitivity each consuming...... sequences are united by DNA ligation upon simultaneous target binding forming a PCR amplicon. Multiplex PLA thereby converts multiple target analytes into real-time PCR amplicons that are individually quantificatied using microfluidic high capacity qPCR in nano liter volumes. The assay shows excellent...

Enzyme Treatment-Free and Ligation-Independent Cloning Using Caged Primers in Polymerase Chain Reactions

Directory of Open Access Journals (Sweden)

Akinori Kuzuya

2011-12-01

Full Text Available A new simple scheme for constructing recombinant vectors that does not require any restriction enzyme, ligase, or any other special enzyme treatment has been developed. By using caged primers in PCR, unnatural sticky-ends of any sequence, which are sufficiently long for ligation-independent cloning (LIC, are directly prepared on the product after a brief UVA irradiation. Target genes and vectors amplified by this light-assisted cohesive-ending (LACE PCR join together in the desired arrangement in a simple mixture of them, tightly enough to be repaired and ligated in competent cells.

Adrenal function in preterm infants undergoing patent ductus arteriosus ligation.

LENUS (Irish Health Repository)

El-Khuffash, Afif

2013-01-01

Targeted milrinone treatment for low left ventricular output (LVO) reduces the incidence of acute cardiorespiratory instability following ligation of patent ductus arteriosus (PDA) in preterm infants. Despite this, some infants continue to experience postoperative deterioration. Adrenal insufficiency related to prematurity has been postulated as a possible mechanism.

Is Cooperative Memory Special? The Role of Costly Errors, Context, and Social Network Size When Remembering Cooperative Actions

Directory of Open Access Journals (Sweden)

Tim Winke

2017-10-01

Full Text Available Theoretical studies of cooperative behavior have focused on decision strategies, such as tit-for-tat, that depend on remembering a partner’s last choices. Yet, an empirical study by Stevens et al. (2011 demonstrated that human memory may not meet the requirements that needed to use these strategies. When asked to recall the previous behavior of simulated partners in a cooperative memory task, participants performed poorly, making errors in 10–24% of the trials. However, we do not know the extent to which this task taps specialized cognition for cooperation. It may be possible to engage participants in more cooperative, strategic thinking, which may improve memory. On the other hand, compared with other situations, a cooperative context may already engage improved memory via cheater detection mechanisms. This study investigated the specificity of memory in cooperative contexts by varying (1 the costs of errors in memory by making forgetting defection more costly and (2 whether the recall situation is framed as a cooperative or neutral context. Also, we investigated whether variation in participants’ social network size could account for individual differences observed in memory accuracy. We found that neither including differential costs for misremembering defection nor removing the cooperative context influenced memory accuracy for cooperation. Combined, these results suggest that memory accuracy is robust to differences in the cooperative context: Adding more strategic components does not help accuracy, and removing cooperative components does not hurt accuracy. Social network size, however, did correlate with memory accuracy: People with larger networks remembered the events better. These findings suggest that cooperative memory does not seem to be special compared with other forms of memory, which aligns with previous work demonstrating the domain generality of memory. However, the demands of interacting in a large social network may

PTPIP51: A New Interaction Partner of the Insulin Receptor and PKA in Adipose Tissue

Directory of Open Access Journals (Sweden)

M. A. Bobrich

2013-01-01

Full Text Available Aims. Our previous experiments revealed an association of PTPIP51 (protein tyrosine phosphatase interacting protein 51 with the insulin signalling pathway through PTP1B and 14-3-3beta. We aimed to clarify the role of PTPIP51 in adipocyte metabolism. Methods. Four groups of ten C57Bl/6 mice each were used. Two groups were fed a standard diet; two groups were fed a high-fat diet. Two groups (one high-fat diet and one standard diet were submitted to endurance training, while the remaining two groups served as untrained control groups. After ten weeks, we measured glucose tolerance of the mice. Adipose tissue samples were analyzed by immunofluorescence and Duolink proximity ligation assay to quantify interactions of PTPIP51 with either insulin receptor (IR or PKA. Results. PTPIP51 and the IR and PTPIP51 and PKA, respectively, were colocalized in all groups. Standard diet animals that were submitted to endurance training showed low PTPIP51-IR and PTPIP51-PKA interactions. The interaction levels of both the IR and PKA differed between the feeding and training groups. Conclusion. PTPIP51 might serve as a linking protein in adipocyte metabolism by connecting the IR-triggered lipogenesis with the PKA-dependent lipolysis. PTPIP51 interacts with both proteins, therefore being a potential gateway for the cooperation of both pathways.

Compliance with Papanicolaou smear screening following tubal ligation in women with cervical cancer.

Science.gov (United States)

Winkler, H A; Anderson, P S; Fields, A L; Runowicz, C D; DeVictoria, C; Goldberg, G L

1999-01-01

To evaluate patient compliance with Papanicolaou (Pap) smear screening after tubal ligation compared with other methods of birth control in patients who develop cervical cancer, a retrospective review of 262 women with cervical cancer diagnosed at age Albert Einstein College of Medicine from January 1987 to December 1995. Demographic data, stage of the disease, histologic type, history of smoking, history of sexually transmitted disease (STD), and birth control use were recorded. The Pap screening history was obtained from all the patients. Women who had a bilateral tubal ligation (BTL) were compared with those who did not have this form of birth control. The date and result of their last Pap test prior to their diagnosis of cervical cancer was noted. Two hundred fourteen women with cervical cancer were evaluable. The clinical stage, mean age, history of smoking, and history of STD were similar for both groups. Gravidity among the BTL group was higher than in the non-BTL group (p < 0.01). Forty-eight (22.4%) women had a previous BTL. Twenty-seven of these 48 patients (56.3%) did not have a Pap smear within 3 years prior to the diagnosis of cervical cancer. Of the 166 patients, 61 (36.7%) did not have a Pap test within 3 years (p < 0.05). Fourteen women (29.2%) in the tubal ligation group never returned for a Pap test following the BTL. An average of 6.2+/-5.9 years elapsed since the last Pap test in the BTL group, with 4.0+/-5.1 years in the nontubal ligation group (p < 0.05). There was a correlation between the number of years since BTL (14.2+/-7.7) to the number of years since the last Pap test (6.2+/-5.9) (p < 0.05). Women who have had a BTL should be considered high risk because of poor screening compliance. A Pap test every 3 years is not adequate in this high-risk population group. We advocate improved counseling regarding the importance of continued annual Pap screening for women who are considering tubal ligation.

Preparation of C-terminally modified chemokines by expressed protein ligation.

Science.gov (United States)

Baumann, Lars; Steinhagen, Max; Beck-Sickinger, Annette G

2013-01-01

In order to link structural features on a molecular level to the function of chemokines, site-specific modification strategies are strongly required. These can be used to incorporate fluorescent dyes and/or physical probes to allow investigations in a wide range of biological and physical techniques, e.g., nuclear magnetic resonance (NMR) spectroscopy, fluorescence microscopy, fluorescence resonance energy transfer (FRET), or fluorescence correlation spectroscopy (FCS). Only a limited number of functional groups within the 20 canonical amino acids allow ligation strategies that can be helpful to introduce novel functionalities, which in turn expand the scope of chemoselective and orthogonal reactivity of (semi)synthetic chemokines. In the present chapter we mainly focus on the fabulous history of native chemical ligation (NCL) and provide a general protocol for the preparation of C-terminally modified SDF-1α including tips and tricks for practical work. We believe that this protocol can be easily adapted to other chemokines and many proteins in general.

An enhanced method for sequence walking and paralog mining: TOPO® Vector-Ligation PCR

Directory of Open Access Journals (Sweden)

Davis Thomas M

2010-03-01

Full Text Available Abstract Background Although technological advances allow for the economical acquisition of whole genome sequences, many organisms' genomes remain unsequenced, and fully sequenced genomes may contain gaps. Researchers reliant upon partial genomic or heterologous sequence information require methods for obtaining unknown sequences from loci of interest. Various PCR based techniques are available for sequence walking - i.e., the acquisition of unknown DNA sequence adjacent to known sequence. Many such methods require rigid, elaborate protocols and/or impose narrowly confined options in the choice of restriction enzymes for necessary genomic digests. We describe a new method, TOPO® Vector-Ligation PCR (or TVL-PCR that innovatively integrates available tools and familiar concepts to offer advantages as a means of both targeted sequence walking and paralog mining. Findings TVL-PCR exploits the ligation efficiency of the pCR®4-TOPO® (Invitrogen, Carlsbad, California vector system to capture fragments of unknown sequence by creating chimeric molecules containing defined priming sites at both ends. Initially, restriction enzyme-digested genomic DNA is end-repaired to create 3' adenosine overhangs and is then ligated to pCR4-TOPO vectors. The ligation product pool is used directly as a template for nested PCR, using specific primers to target orthologous sequences, or degenerate primers to enable capture of paralogous gene family members. We demonstrated the efficacy of this method by capturing entire coding and partial promoter sequences of several strawberry Superman-like genes. Conclusions TVL-PCR is a convenient and efficient method for DNA sequence walking and paralog mining that is applicable to any organism for which relevant DNA sequence is available as a basis for primer design.

Development of a modified model of spinal cord ischemia injury by selective ligation of lumbar arteries in rabbits.

Science.gov (United States)

Xiao, W; Wen, J; Huang, Y-C; Yu, B-S

2017-11-01

Experimental study. The aim of this study is to develop a modified model of spinal cord ischemia in rabbits. Shenzhen Key Laboratory of Spine Surgery, Shenzhen, China. In total, 20 New Zealand rabbits were divided into the following four groups according to the level of ligation of bilateral lumbar arteries: (1) group A, sham group, no ligation, n=5; (2) group B, ligation of bilateral lumbar arteries at three levels (L2-L4, n=5); (3) group C, ligation of bilateral lumbar arteries at four levels (L2-L5, n=5); and (4) group D, ligation of bilateral lumbar arteries at five levels (L1-L5, n=5). The latency of motor-evoked potentials was measured intraoperatively and the modified Tarlov grades were scored, followed by a histological observation of spinal cord, on the seventh day after surgery. All 10 rabbits in Group A and Group B were electrophysiologically, neurologically and histologically normal. In Group C, moderate spinal cord ischemia injury was found in three of five rabbits: they had prolonged latency of motor-evoked potentials and neuronal karyopyknosis in the anterior horn of spinal cord, and the average Tarlov score was 4.2±0.8. In Group D, severe spinal cord ischemia injury was recorded in all the five rabbits: the latency of motor-evoked potential prolonged in one rabbit, whereas the waveform disappeared in four rabbits; loss of neurons and vacuolation of gray matter were seen in spinal cord sections, and the average Tarlov score was 0.6±0.9. Selective ligation of lumbar arteries was a modified method to induce feasible and reproducible model of spinal cord ischemia in rabbits.

Fostering cooperative activism through critical design

DEFF Research Database (Denmark)

Menendez Blanco, Maria; Bjørn, Pernille; De Angeli, Antonella

2017-01-01

Critical design is gaining momentum in interaction design, yet little CSCW research has focused on articulating the cooperative potentials of critical design artefacts. We address this gap by reflecting upon a design project aimed at overturning the prevailing narrative regarding dyslexia in Italy....... The adversarial propositions embedded in our critical design artefacts challenged the description of dyslexia as a learning disorder putting forward the view of a learning difference. These artefacts demonstrated their capacity to bridge heterogeneous social worlds (those of teachers, children, and parents......) into one cooperative entity and mobilise cooperative activism. The contribution to CSCW is two-fold. Firstly, we introduce the cooperative potentials of critical design artefacts; secondly, we propose critical design as a strategy for researchers engaging with cooperative activism....

Inequity aversion and the evolution of cooperation

OpenAIRE

Ahmed, Asrar; Karlapalem, Kamalakar

2014-01-01

Evolution of cooperation is a widely studied problem in biology, social science, economics, and artificial intelligence. Most of the existing approaches that explain cooperation rely on some notion of direct or indirect reciprocity. These reciprocity based models assume agents recognize their partner and know their previous interactions, which requires advanced cognitive abilities. In this paper we are interested in developing a model that produces cooperation without requiring any explicit m...

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

Energy Technology Data Exchange (ETDEWEB)

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 the 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.

Distribution of extracellular potassium and electrophysiologic changes during two-stage coronary ligation in the isolated, perfused canine heart

NARCIS (Netherlands)

Coronel, R.; Fiolet, J. W.; Wilms-Schopman, J. G.; Opthof, T.; Schaapherder, A. F.; Janse, M. J.

1989-01-01

We studied the relation between [K+]o and the electrophysiologic changes during a "Harris two-stage ligation," which is an occlusion of a coronary artery, preceded by a 30-minute period of 50% reduction of flow through the artery. This two-stage ligation has been reported to be antiarrhythmic. Local

Hepatic extraction of the aminoterminal propeptide of type III procollagen before and after bile duct ligation in pigs

DEFF Research Database (Denmark)

Bentsen, K D; Henriksen, Jens Henrik Sahl; Boesby, S

1991-01-01

before and during a 4-h period after ligation of the common bile duct was assessed from serum PIIINP concentrations in a systemic artery, the portal vein and a hepatic vein of seven healthy anaesthetized pigs. Seven sham-operated anaesthetized pigs served as controls. Ligation of the bile duct did...

Sim3C: simulation of Hi-C and Meta3C proximity ligation sequencing technologies.

Science.gov (United States)

DeMaere, Matthew Z; Darling, Aaron E

2018-02-01

Chromosome conformation capture (3C) and Hi-C DNA sequencing methods have rapidly advanced our understanding of the spatial organization of genomes and metagenomes. Many variants of these protocols have been developed, each with their own strengths. Currently there is no systematic means for simulating sequence data from this family of sequencing protocols, potentially hindering the advancement of algorithms to exploit this new datatype. We describe a computational simulator that, given simple parameters and reference genome sequences, will simulate Hi-C sequencing on those sequences. The simulator models the basic spatial structure in genomes that is commonly observed in Hi-C and 3C datasets, including the distance-decay relationship in proximity ligation, differences in the frequency of interaction within and across chromosomes, and the structure imposed by cells. A means to model the 3D structure of randomly generated topologically associating domains is provided. The simulator considers several sources of error common to 3C and Hi-C library preparation and sequencing methods, including spurious proximity ligation events and sequencing error. We have introduced the first comprehensive simulator for 3C and Hi-C sequencing protocols. We expect the simulator to have use in testing of Hi-C data analysis algorithms, as well as more general value for experimental design, where questions such as the required depth of sequencing, enzyme choice, and other decisions can be made in advance in order to ensure adequate statistical power with respect to experimental hypothesis testing.

Robot-assisted ligation of bronchial artery could be an alternative to embolization.

Science.gov (United States)

Pochulu, Bruno; Sarsam, Omar; Peillon, Christophe; Baste, Jean-Marc

2018-03-01

A 37-year-old patient presented with a self-limiting episode of moderate haemoptysis. Contrast-enhanced chest computed tomography showed a tortuous and dilated right bronchial artery arising from the descending aorta at the level of T6. Therapeutic angiography was attempted, but in the presence of spinal artery arising from the bronchial artery in question, selective embolization was contraindicated due to risk of spinal cord ischaemia. After a multidisciplinary meeting, it was decided to attempt surgery to ligate this pathological artery. We performed minimally invasive robot-assisted ligation of this pathological artery. The postoperative course was uneventful with good clinical and radiological outcome at 3-month follow-up. A minimally invasive approach provides a real alternative to embolization and could be a therapeutic option.

The Neural Responses to Social Cooperation in Gain and Loss Context.

Directory of Open Access Journals (Sweden)

Peng Sun

Full Text Available Cooperation is pervasive and constitutes the core behavioral principle of human social life. Previous studies have revealed that mutual cooperation was reliably correlated with two reward-related brain regions, the ventral striatum and the orbitofrontal cortex. Using functional magnetic resonance imaging (fMRI, this study sought to investigate how the loss and gain contexts modulated the neural responses to mutual cooperation. Twenty-five female participants were scanned when they played a series of one-shot prisoner's dilemma games in the loss and gain contexts. Specifically, participants and partners independently chose to either cooperate with each other or not, and each was awarded or deprived of (in the gain context or the loss context, respectively a sum of money which depended upon the interaction of their choices. Behavioral results indicated that participants cooperated in nearly half of the experiment trials and reported higher level of positive emotions for mutual cooperation in both contexts, but they cooperated more in the gain than in the loss context. At the neural level, stronger activities in the orbitofrontal cortex were observed for mutual cooperation compared with the other three outcomes in both contexts, while stronger activation in ventral striatum associated with mutual cooperation was observed in the gain context only. Together, our data indicated that, even in the one-shot interaction under loss context, participants still exhibited preference for cooperation and the rewarding experience from a mutually cooperative social interaction activated the ventral striatum and the orbitofrontal cortex, but the loss context weakened the association between the ventral striatum activation and mutual cooperation.

Bacterial adhesion on conventional and self-ligating metallic brackets after surface treatment with plasma-polymerized hexamethyldisiloxane.

Science.gov (United States)

Tupinambá, Rogerio Amaral; Claro, Cristiane Aparecida de Assis; Pereira, Cristiane Aparecida; Nobrega, Celestino José Prudente; Claro, Ana Paula Rosifini Alves

2017-01-01

Plasma-polymerized film deposition was created to modify metallic orthodontic brackets surface properties in order to inhibit bacterial adhesion. Hexamethyldisiloxane (HMDSO) polymer films were deposited on conventional (n = 10) and self-ligating (n = 10) stainless steel orthodontic brackets using the Plasma-Enhanced Chemical Vapor Deposition (PECVD) radio frequency technique. The samples were divided into two groups according to the kind of bracket and two subgroups after surface treatment. Scanning Electron Microscopy (SEM) analysis was performed to assess the presence of bacterial adhesion over samples surfaces (slot and wings region) and film layer integrity. Surface roughness was assessed by Confocal Interferometry (CI) and surface wettability, by goniometry. For bacterial adhesion analysis, samples were exposed for 72 hours to a Streptococcus mutans solution for biofilm formation. The values obtained for surface roughness were analyzed using the Mann-Whitney test while biofilm adhesion were assessed by Kruskal-Wallis and SNK test. Significant statistical differences (pbrackets after surface treatment and between conventional and self-ligating brackets; no significant statistical differences were observed between self-ligating groups (p> 0.05). Plasma-polymerized film deposition was only effective on reducing surface roughness and bacterial adhesion in conventional brackets. It was also noted that conventional brackets showed lower biofilm adhesion than self-ligating brackets despite the absence of film.

Investigation into the effects of stainless steel ligature ties on the mechanical characteristics of conventional and self-ligated brackets subjected to torque.

Science.gov (United States)

Al Fakir, Hussam; Carey, Jason P; Melenka, Garrett W; Nobes, David S; Heo, Giseon; Major, Paul W

2014-09-01

Torque is applied to orthodontic brackets in order to alter the buccal-lingual angulation of a tooth. One factor that can affect torque is the ligation mode used to retain the archwire in the bracket slot. The objective of this study was to investigate the effects of stainless steel ligation on torque expression and bracket deformation. This study utilized 60 upper right central incisor Damon Q brackets and 60 Ormco Orthos Twin brackets. The brackets used in this study were subdivided into four groups: (1) Damon Q ligated with SS ligature; (2) Damon Q with the sliding bracket door; (3) Orthos Twin bracket ligated with SS wire; and (4) Orthos Twin ligated with elastic ties. All brackets were tested using an orthodontic torque simulating device that applied archwire rotation from 0° to 45°. All brackets ligated with stainless steel ties exhibited greater torque expression and less deformation than brackets without stainless steel ties. As well, Damon Q brackets exhibit less bracket deformation than Orthos Twin brackets. Stainless steel ties can reduce the amount of plastic deformation for both types of brackets used in this study. © 2014 British Orthodontic Society.

Superantigen and HLA-DR ligation induce phospholipase-C gamma 1 activation in class II+ T cells

DEFF Research Database (Denmark)

Kanner, S B; Odum, Niels; Grosmaire, L

1992-01-01

Bacterial enterotoxin superantigens bind directly to HLA class II molecules (HLA-DR) expressed on both APC and activated human T cells, and simultaneously bind to certain V beta chains of the TCR. In this report, we compared early T cell signaling events in human alloantigen-stimulated T cells when...... activated by HLA-DR ligation through antibody cross-linking or by direct enterotoxin superantigen binding. Both types of stimuli induced tyrosine phosphorylation of phosphatidylinositol-specific phospholipase C gamma 1 (PLC gamma 1) and an increase in intracellular calcium concentration; however......, superantigen-induced signaling was stronger than class II ligation alone. Antibody-mediated ligation of HLA-DR with CD3 resulted in augmented PLC gamma 1 activation and increased calcium mobilization, consistent with a mechanism of superantigen activity through a combination of class II and CD3/Ti signals...

Synthesis of water-soluble scaffolds for peptide cyclization, labeling, and ligation

NARCIS (Netherlands)

Smeenk, L.E.J.; Dailly, N.; Hiemstra, H.; van Maarseveen, J.H.; Timmerman, P.

2012-01-01

The synthesis and applications of water-soluble scaffolds that conformationally constrain side chain unprotected linear peptides containing two cysteines are described. These scaffolds contain a functionality with orthogonal reactivity to be used for labeling and ligation. This is illustrated by the

Bis-ligated Ti and Zr complexes of chelating N-heterocyclic carbenes

KAUST Repository

El-Batta, Amer; Waltman, Andrew W.; Grubbs, Robert H.

2011-01-01

In this communication we report the synthesis of novel titanium and zirconium complexes ligated by bidentate "salicylaldimine-like" N-heterocyclic carbenes (NHC). Double addition of the NHC chelate to either TiCl4(thf)2 or ZrCl4 forms bis

Testicular reperfusion injury, post ligation of the spermatic cord in ...

African Journals Online (AJOL)

This experiment was aimed at investigating the level of tissue regeneration following sanguineous reperfusion post ligation of the spermatic cord in dogs. A total of 5 adult Nigerian local dogs conditioned for 3 weeks, laboratorily evaluated twice weekly prior to surgery were maintained for 1month. Dogs were aseptically ...

Cooperation prevails when individuals adjust their social ties.

Directory of Open Access Journals (Sweden)

Francisco C Santos

2006-10-01

Full Text Available Conventional evolutionary game theory predicts that natural selection favours the selfish and strong even though cooperative interactions thrive at all levels of organization in living systems. Recent investigations demonstrated that a limiting factor for the evolution of cooperative interactions is the way in which they are organized, cooperators becoming evolutionarily competitive whenever individuals are constrained to interact with few others along the edges of networks with low average connectivity. Despite this insight, the conundrum of cooperation remains since recent empirical data shows that real networks exhibit typically high average connectivity and associated single-to-broad-scale heterogeneity. Here, a computational model is constructed in which individuals are able to self-organize both their strategy and their social ties throughout evolution, based exclusively on their self-interest. We show that the entangled evolution of individual strategy and network structure constitutes a key mechanism for the sustainability of cooperation in social networks. For a given average connectivity of the population, there is a critical value for the ratio W between the time scales associated with the evolution of strategy and of structure above which cooperators wipe out defectors. Moreover, the emerging social networks exhibit an overall heterogeneity that accounts very well for the diversity of patterns recently found in acquired data on social networks. Finally, heterogeneity is found to become maximal when W reaches its critical value. These results show that simple topological dynamics reflecting the individual capacity for self-organization of social ties can produce realistic networks of high average connectivity with associated single-to-broad-scale heterogeneity. On the other hand, they show that cooperation cannot evolve as a result of "social viscosity" alone in heterogeneous networks with high average connectivity, requiring the

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

Science.gov (United States)

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, norms, and revolutions: a unified game-theoretical approach.

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Dirk Helbing

Full Text Available BACKGROUND: Cooperation is of utmost importance to society as a whole, but is often challenged by individual self-interests. While game theory has studied this problem extensively, there is little work on interactions within and across groups with different preferences or beliefs. Yet, people from different social or cultural backgrounds often meet and interact. This can yield conflict, since behavior that is considered cooperative by one population might be perceived as non-cooperative from the viewpoint of another. METHODOLOGY AND PRINCIPAL FINDINGS: To understand the dynamics and outcome of the competitive interactions within and between groups, we study game-dynamical replicator equations for multiple populations with incompatible interests and different power (be this due to different population sizes, material resources, social capital, or other factors. These equations allow us to address various important questions: For example, can cooperation in the prisoner's dilemma be promoted, when two interacting groups have different preferences? Under what conditions can costly punishment, or other mechanisms, foster the evolution of norms? When does cooperation fail, leading to antagonistic behavior, conflict, or even revolutions? And what incentives are needed to reach peaceful agreements between groups with conflicting interests? CONCLUSIONS AND SIGNIFICANCE: Our detailed quantitative analysis reveals a large variety of interesting results, which are relevant for society, law and economics, and have implications for the evolution of language and culture as well.

U(SMes*)n, (n = 3, 4) and Ln(SMes*)3 (Ln = La, Ce, Pr, Nd): lanthanide(III)/actinide(III) differentiation in agostic interactions and an unprecedented eta3 ligation mode of the arylthiolate ligand, from X-ray diffraction and DFT analysis.

Science.gov (United States)

Roger, Mathieu; Barros, Noémi; Arliguie, Thérèse; Thuéry, Pierre; Maron, Laurent; Ephritikhine, Michel

2006-07-12

Reaction of U(NEt(2))(4) with HS-2,4,6-(t)Bu(3)C(6)H(2) (HSMes) gave U(SMes)(3)(NEt(2))(py) (1), whereas similar treatment of U[N(SiMe(3))SiMe(2)CH(2)][N(SiMe(3))(2)](2) afforded U(SMes)[N(SiMe(3))(2)](3) (2) and U(SMes)(3)[N(SiMe(3))(2)]. The first neutral homoleptic uranium(IV) thiolate to have been crystallographically characterized, U(SMes)(4) (4), was isolated from the reaction of U(BH(4))(4) and KSMes. The first homoleptic thiolate complex of uranium(III), U(SMes)(3) (5), was synthesized by protonolysis of U[N(SiMe(3))(2)](3) with HSMes in cyclohexane. The crystal structure of 5 exhibits the novel eta(3) ligation mode for the arylthiolate ligand. Comparison of the crystal structure of 5 with those of the isomorphous lanthanide congeners Ln(SMes)(3) (Ln = La, Ce, Pr, and Nd) indicates that the U-S, U-C(ipso)(), and U-C(ortho)() bond lengths are shorter than the corresponding ones in the 4f-element analogues, when taking into account the variation in the ionic radii of the metals. The distance between the uranium and the carbon atoms involved in the U...H-C epsilon agostic interaction of each thiolate ligand is shorter, by approximately 0.05 A, than that expected from a purely ionic bonding model. The lanthanide(III)/actinide(III) differentiation was analyzed by density functional theory (DFT). The nature of the M-S bond is shown to be ionic strongly polarized at the sulfur for M = U and iono-covalent (i.e. strongly ionic with low orbital interaction), for M = Ln. The strength of the U...H-C epsilon agostic interaction is proposed to be controlled by the maximization of the interaction between U(+) and S(-) under steric constraints. The eta(3) ligation mode of the arylthiolate ligand is also obtained from DFT.

Enzyme-linked electrochemical DNA ligation assay using magnetic beads.

Science.gov (United States)

Stejskalová, Eva; Horáková, Petra; Vacek, Jan; Bowater, Richard P; Fojta, Miroslav

2014-07-01

DNA ligases are essential enzymes in all cells and have been proposed as targets for novel antibiotics. Efficient DNA ligase activity assays are thus required for applications in biomedical research. Here we present an enzyme-linked electrochemical assay based on two terminally tagged probes forming a nicked junction upon hybridization with a template DNA. Nicked DNA bearing a 5' biotin tag is immobilized on the surface of streptavidin-coated magnetic beads, and ligated product is detected via a 3' digoxigenin tag recognized by monoclonal antibody-alkaline phosphatase conjugate. Enzymatic conversion of napht-1-yl phosphate to napht-1-ol enables sensitive detection of the voltammetric signal on a pyrolytic graphite electrode. The technique was tested under optimal conditions and various situations limiting or precluding the ligation reaction (such as DNA substrates lacking 5'-phosphate or containing a base mismatch at the nick junction, or application of incompatible cofactor), and utilized for the analysis of the nick-joining activity of a range of recombinant Escherichia coli DNA ligase constructs. The novel technique provides a fast, versatile, specific, and sensitive electrochemical assay of DNA ligase activity.

Evaluation of the force generated by gradual deflection of orthodontic wires in conventional metallic, esthetic, and self-ligating brackets

Directory of Open Access Journals (Sweden)

Manoela Fávaro Francisconi

Full Text Available ABSTRACT Objective: The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires placed in different types of brackets: metallic, reinforced polycarbonate with metallic slots, sapphire, passive and active self-ligating, by assessing strength values variation according to gradual increase in wire diameter and deflection and comparing different combinations in the different deflections. Material and Methods: Specimens were set in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342, using the ISO 15841 protocol. Data were subjected to One-way ANOVA, followed by Tukey tests (p<0.05. Results: Self-ligating brackets presented the most similar behavior to each other. For conventional brackets there was no consistent behavior for any of the deflections studied. Conclusions: Self-ligating brackets presented the most consistent and predictable results while conventional brackets, as esthetic brackets, showed very different patterns of forces. Self-ligating brackets showed higher strength in all deflections when compared with the others, in 0.020-inch wires.

Management of anal fistula by ligation of the intersphincteric fistula tract

DEFF Research Database (Denmark)

Zirak-Schmidt, Samira; Perdawood, Sharaf

2014-01-01

INTRODUCTION: Ligation of the intersphincteric fistula tract (LIFT) is a sphincter-preserving procedure for treatment of anal fistulas described in 2007 by Rojanasakul et al. Several studies have since then assessed the procedure with varied results. This review assesses the relevant literature o...

Indirect reciprocity with negative assortment and limited information can promote cooperation.

Science.gov (United States)

Brush, Eleanor; Brännström, Åke; Dieckmann, Ulf

2018-04-14

Cooperation is ubiquitous in biological and social systems, even though cooperative behavior is often costly and at risk of exploitation by non-cooperators. Several studies have demonstrated that indirect reciprocity, whereby some members of a group observe the behaviors of their peers and use this information to discriminate against previously uncooperative agents in the future, can promote prosocial behavior. Some studies have shown that differential propensities of interacting among and between different types of agents (interaction assortment) can increase the effectiveness of indirect reciprocity. No previous studies have, however, considered differential propensities of observing the behaviors of different types of agents (information assortment). Furthermore, most previous studies have assumed that discriminators possess perfect information about others and incur no costs for gathering and storing this information. Here, we (1) consider both interaction assortment and information assortment, (2) assume discriminators have limited information about others, and (3) introduce a cost for information gathering and storage, in order to understand how the ability of discriminators to stabilize cooperation is affected by these steps toward increased realism. We report the following findings. First, cooperation can persist when agents preferentially interact with agents of other types or when discriminators preferentially observe other discriminators, even when they have limited information. Second, contrary to intuition, increasing the amount of information available to discriminators can exacerbate defection. Third, introducing costs of gathering and storing information makes it more difficult for discriminators to stabilize cooperation. Our study is one of only a few studies to date that show how negative interaction assortment can promote cooperation and broadens the set of circumstances in which it is know that cooperation can be maintained. Copyright © 2018

Moderate intra-group bias maximizes cooperation on interdependent populations.

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Changbing Tang

Full Text Available Evolutionary game theory on spatial structures has received increasing attention during the past decades. However, the majority of these achievements focuses on single and static population structures, which is not fully consistent with the fact that real structures are composed of many interactive groups. These groups are interdependent on each other and present dynamical features, in which individuals mimic the strategy of neighbors and switch their partnerships continually. It is however unclear how the dynamical and interdependent interactions among groups affect the evolution of collective behaviors. In this work, we employ the prisoner's dilemma game to investigate how the dynamics of structure influences cooperation on interdependent populations, where populations are represented by group structures. It is found that the more robust the links between cooperators (or the more fragile the links between cooperators and defectors, the more prevalent of cooperation. Furthermore, theoretical analysis shows that the intra-group bias can favor cooperation, which is only possible when individuals are likely to attach neighbors within the same group. Yet, interestingly, cooperation can be even inhibited for large intra-group bias, allowing the moderate intra-group bias maximizes the cooperation level.

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

Science.gov (United States)

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.

Human cooperation by lethal group competition.

Science.gov (United States)

Egas, Martijn; Kats, Ralph; van der Sar, Xander; Reuben, Ernesto; Sabelis, Maurice W

2013-01-01

Why humans are prone to cooperate puzzles biologists, psychologists and economists alike. Between-group conflict has been hypothesized to drive within-group cooperation. However, such conflicts did not have lasting effects in laboratory experiments, because they were about luxury goods, not needed for survival ("looting"). Here, we find within-group cooperation to last when between-group conflict is implemented as "all-out war" (eliminating the weakest groups). Human subjects invested in helping group members to avoid having the lowest collective pay-off, whereas they failed to cooperate in control treatments with random group elimination or with no subdivision in groups. When the game was repeated, experience was found to promote helping. Thus, not within-group interactions alone, not random group elimination, but pay-off-dependent group elimination was found to drive within-group cooperation in our experiment. We suggest that some forms of human cooperation are maintained by multi-level selection: reciprocity within groups and lethal competition among groups acting together.

Formation and rearrangement of homoserine depsipeptides and depsiproteins in the α-ketoacid-hydroxylamine ligation with 5-oxaproline.

Science.gov (United States)

Wucherpfennig, Thomas G; Rohrbacher, Florian; Pattabiraman, Vijaya R; Bode, Jeffrey W

2014-11-03

The primary products of the chemical ligation of α-ketoacids and 5-oxaproline peptides are esters, rather than the previously reported amides. The depsipeptide product rapidly rearranges to the amide in basic buffers. The formation of esters sheds light on possible mechanisms for the type II KAHA ligations and opens an avenue for the chemical synthesis of depsiproteins. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ligation of major histocompatibility complex class I antigens (MHC-I) prevents apoptosis induced by Fas or SAPK/JNK activation in T-lymphoma cells

DEFF Research Database (Denmark)

Lamberth, K; Claesson, M H

2001-01-01

Early apoptosis in Jurkat T-lymphoma cells was induced by agonistic anti-Fas Ab or by anisomycin which activates the stress kinases SAPK/JNK. Apoptosis was inhibited by ligation of major histocompatibility complex class I antigens (MHC-I). MHC-I ligation induced upregulation of the anti......-apoptotic Bcl-2 protein and stabilized the mitochondrial membrane potential (Deltapsim). MHC-I ligation also prevented downregulation of Bcl-2 and destabilization of Deltapsim induced by anti-Fas Ab treatment or anisomycin exposure. Studies on three different Jurkat cell mutants deficient for src p56(lck), ZAP......-70 kinase, or TCR/CD3 gamma-chain showed that the cells undergo apoptosis after Fas ligation. Anisomycin exposure induced apoptosis in the src p56(lck)-deficient cell line but not in the two other mutant cell lines. Simultaneous cross-linking of MHC-I and Fas ligation inhibited apoptosis in the ZAP...

Angiographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid artery

International Nuclear Information System (INIS)

Na, Dong Gyu; Han, Moon Hee; Chang, Kee Hyun; Han, Gi Seok; Yeon, Kung Mo

1995-01-01

The purpose of this study is to describe the angiographic findings of collateral vessels in cervicofacial vascular lesions with previously ligated carotid arteries and to evaluate the extent of angiographic assessment needed before embolization. We retrospectively reviewed 10 cervicofacial vascular lesions with previously ligated carotid artery, which were 6 cases of arteriovenous malformation, 2 cases of carotid cavernous fistula, 1 case of hemangioma and 1 case of arteriovenous malformation with carotid cavernous fistula. The previously ligated arteries are proximal external carotid artery (n = 5), branches of external carotid artery (n = 2) and common carotid artery (n = 3). Common carotid artery or internal carotid artery (n = 9), vertebral artery (n = 5), ipsilateral external carotid artery (n = 4), contralateral external carotid artery (n = 5), costocervical trunk (n = 2), thyrocervical trunk (n = 2) were assessed by conventional angiography. Angiography of both carotid and vertebral arteries was performed in 5 cases. The collateral vascular channels were inferolateral trunk of internal carotid artery (n = 8), vertebral artery (n = 5), contralateral external carotid artery (n = 5), ipsilateral external carotid artery (n = 4), deep cervical artery (n = 2) and ascending cervical artery (n = 1). Embolization were performed in 9 cases with operative cannulation (n = 4), embolization via collateral branches of ipsilateral external carotid artery (n = 1), embolization via collateral branches of contralateral external carotid artery (n = 3) and balloon occlusion via direct puncture (n = 1). The collateral channels in cervicofacial vascular lesions with previously ligated carotid artery were inferolateral trunk of internal carotid artery, contralateral or ipsilateral external carotid artery, vertebral artery, deep cervical artery and ascending cervical artery on angiography. Complete angiographic assessment of possible collateral channels is mandatory for the

Gender, abilities, cognitive style and students' achievement in cooperative learning

Directory of Open Access Journals (Sweden)

Cirila Peklaj

2003-12-01

Full Text Available The purpose of the study was to investigate the effects of cooperative learning on achievement in mathematics and native language and to analyze students' achievement in cooperative learning according to their gender, abilities and cognitive style. Three hundred and seventy three (170 in the experimental and 203 in the control group fifth grade students from nine different primary schools participated in the study. In experimental group, cooperative learning was introduced in one quarter of the hours dedicated to mathematics and Slovene language during the school year. Control group received the traditional way of teaching in both courses. The results were analyzed with ANOVA. Positive effects of cooperative learning were found in both courses. Results in cooperative learning group were further analyzed according to students' gender, abilities and cognitive style. No significant interaction between students' achievement and their gender or abilities were found. Statistically significant interactions between students' cognitive style and achievement were found in both courses. Field-dependent students benefited most from cooperative learning.

Cooperative spreading processes in multiplex networks.

Science.gov (United States)

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.

Chemical Synthesis of the 20 kDa Heme Protein Nitrophorin 4 by α-Ketoacid-Hydroxylamine (KAHA) Ligation.

Science.gov (United States)

He, Chunmao; Kulkarni, Sameer S; Thuaud, Frédéric; Bode, Jeffrey W

2015-10-26

The chemical synthesis of the 184-residue ferric heme-binding protein nitrophorin 4 was accomplished by sequential couplings of five unprotected peptide segments using α-ketoacid-hydroxylamine (KAHA) ligation reactions. The fully assembled protein was folded to its native structure and coordinated to the ferric heme b cofactor. The synthetic holoprotein, despite four homoserine residues at the ligation sites, showed identical properties to the wild-type protein in nitric oxide binding and nitrite dismutase reactivity. This work establishes the KAHA ligation as a valuable and viable approach for the chemical synthesis of proteins up to 20 kDa and demonstrates that it is well-suited for the preparation of hydrophobic protein targets. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Consecutive native chemical ligation-route to synthetic mouse prion protein

Czech Academy of Sciences Publication Activity Database

Zawada, Zbigniew; Šebestík, Jaroslav; Šafařík, Martin; Březinová, Anna; Bouř, Petr; Hlaváček, Jan; Stibor, Ivan

2009-01-01

Roč. 103, č. 11 (2009), s. 1001-1001 ISSN 0009-2770. [Pokroky v organické, bioorganické a farmaceutické chemii /44./. 27.11.2009-29.11.2009, Liblice] R&D Projects: GA ČR GA203/07/1517 Institutional research plan: CEZ:AV0Z40550506 Keywords : prion * chemical ligation Subject RIV: CC - Organic Chemistry

Assessment and treatment of post patent ductus arteriosus ligation syndrome.

LENUS (Irish Health Repository)

El-Khuffash, Afif F

2014-07-01

To compare differences in tissue Doppler imaging, global longitudinal strain (GLS), and cardiac troponin T (cTnT) between infants with low (<200 mL\\/kg\\/min) and high (>200 mL\\/kg\\/min) left ventricular (LV) output 1 hour after duct ligation and assess the impact of milrinone treatment on cardiac output and myocardial performance.

The outbreak of cooperation among success-driven individuals under noisy conditions.

Science.gov (United States)

Helbing, Dirk; Yu, Wenjian

2009-03-10

According to Thomas Hobbes' Leviathan [1651; 2008 (Touchstone, New York), English Ed], "the life of man [is] solitary, poor, nasty, brutish, and short," and it would need powerful social institutions to establish social order. In reality, however, social cooperation can also arise spontaneously, based on local interactions rather than centralized control. The self-organization of cooperative behavior is particularly puzzling for social dilemmas related to sharing natural resources or creating common goods. Such situations are often described by the prisoner's dilemma. Here, we report the sudden outbreak of predominant cooperation in a noisy world dominated by selfishness and defection, when individuals imitate superior strategies and show success-driven migration. In our model, individuals are unrelated, and do not inherit behavioral traits. They defect or cooperate selfishly when the opportunity arises, and they do not know how often they will interact or have interacted with someone else. Moreover, our individuals have no reputation mechanism to form friendship networks, nor do they have the option of voluntary interaction or costly punishment. Therefore, the outbreak of prevailing cooperation, when directed motion is integrated in a game-theoretical model, is remarkable, particularly when random strategy mutations and random relocations challenge the formation and survival of cooperative clusters. Our results suggest that mobility is significant for the evolution of social order, and essential for its stabilization and maintenance.

Skill Learning and Skill Transfer Mediated by Cooperative Haptic Interaction.

Science.gov (United States)

Avila Mireles, Edwin Johnatan; Zenzeri, Jacopo; Squeri, Valentina; Morasso, Pietro; De Santis, Dalia

2017-07-01

It is known that physical coupling between two subjects may be advantageous in joint tasks. However, little is known about how two people mutually exchange information to exploit the coupling. Therefore, we adopted a reversed, novel perspective to the standard one that focuses on the ability of physically coupled subjects to adapt to cooperative contexts that require negotiating a common plan: we investigated how training in pairs on a novel task affects the development of motor skills of each of the interacting partners. The task involved reaching movements in an unstable dynamic environment using a bilateral non-linear elastic tool that could be used bimanually or dyadically. The main result is that training with an expert leads to the greatest performance in the joint task. However, the performance in the individual test is strongly affected by the initial skill level of the partner. Moreover, practicing with a peer rather than an expert appears to be more advantageous for a naive; and motor skills can be transferred to a bimanual context, after training with an expert, only if the non-expert subject had prior experience of the dynamics of the novel task.

Skew Information for a Single Cooper Pair Box Interacting with a Single Cavity Field

International Nuclear Information System (INIS)

Metwally, N.; Al-Mannai, A.; Abdel-Aty, M.

2013-01-01

The dynamics of the skew information (SI) is investigated for a single Cooper Pair Box (CPB) interacting with a single cavity field. By suitably choosing the system parameters and precisely controlling the dynamics, novel connection is found between the SI and entanglement generation. It is shown that SI can be increased and reach its maximum value either by increasing the number of photons inside the cavity or considering the far off-resonant case. The number of oscillations of SI is increased by decreasing this ratio between the Josephson junction capacity and the gate capacity. This leads to significant improvement of the travelling time between the maximum and minimum values. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

China-Africa: New Directions of Cooperation

Directory of Open Access Journals (Sweden)

L V Ponomarenko

2015-12-01

Full Text Available This article analyzes the policy of fifth generation of Chinese leadership with regard to African states. The article deals with the concept of “Chinese Dream”, which was first declared in Africa, an innovative model of international cooperation in the framework of the formation of “economic zone of the Silk Road”. The authors reveal three basic directions of cooperation - political, economic and humanitarian cooperation. Political cooperation is characterized by the activation of mutual visits at the highest level, the interaction in the framework of the UN General Assembly, participation in UN peacekeeping operations. Economic cooperation is characterized by the activation of bilateral trade, the transition to a “modernized version of” investment cooperation, implementation of the strategy of “going abroad” of Chinese products, imports of natural resources from Africa, creating jobs for the local population, financing of infrastructure projects, the transfer of labor-intensive industries in Africa. Humanitarian cooperation includes training program for Africa, the implementation of the Sino-African programs, technology partnerships, research and exchange, and the China-Africa Forum “Think Tank”. Cooperation in health care also plays an important role. The authors note that the new Chinese leadership declares transition to an upgraded version of the Sino-African cooperation.

A bipyridine-ligated zinc(II) complex with bridging flavonolate ligation: synthesis, characterization, and visible-light-induced CO release reactivity.

Science.gov (United States)

Sorenson, Shayne; Popova, Marina; Arif, Atta M; Berreau, Lisa M

2017-09-01

Metal-flavonolate compounds are of significant current interest as synthetic models for quercetinase enzymes and as bioactive compounds of importance to human health. Zinc-3-hydroxyflavonolate compounds, including those of quercetin, kampferol, and morin, generally exhibit bidentate coordination to a single Zn II center. The bipyridine-ligated zinc-flavonolate compound reported herein, namely bis(μ-4-oxo-2-phenyl-4H-chromen-3-olato)-κ 3 O 3 :O 3 ,O 4 ;κ 3 O 3 ,O 4 :O 3 -bis[(2,2'-bipyridine-κ 2 N,N')zinc(II)] bis(perchlorate), {[Zn 2 (C 15 H 9 O 3 ) 2 (C 10 H 8 N 2 ) 2 ](ClO 4 ) 2 } n , (1), provides an unusual example of bridging 3-hydroxyflavonolate ligation in a dinuclear metal complex. The symmetry-related Zn II centers of (1) exhibit a distorted octahedral geometry, with weak coordination of a perchlorate anion trans to the bridging deprotonated O atom of the flavonolate ligand. Variable-concentration conductivity measurements provide evidence that, when (1) is dissolved in CH 3 CN, the complex dissociates into monomers. 1 H NMR resonances for (1) dissolved in d 6 -DMSO were assigned via HMQC to the H atoms of the flavonolate and bipyridine ligands. In CH 3 CN, (1) undergoes quantitative visible-light-induced CO release with a quantum yield [0.004 (1)] similar to that exhibited by other mononuclear zinc-3-hydroxyflavonolate complexes. Mass spectroscopic identification of the [(bpy) 2 Zn(O-benzoylsalicylate)] + ion provides evidence of CO release from the flavonol and of ligand exchange at the Zn II center.

Authentic interdomain communication in an RNA helicase reconstituted by expressed protein ligation of two helicase domains.

Science.gov (United States)

Karow, Anne R; Theissen, Bettina; Klostermeier, Dagmar

2007-01-01

RNA helicases mediate structural rearrangements of RNA or RNA-protein complexes at the expense of ATP hydrolysis. Members of the DEAD box helicase family consist of two flexibly connected helicase domains. They share nine conserved sequence motifs that are involved in nucleotide binding and hydrolysis, RNA binding, and helicase activity. Most of these motifs line the cleft between the two helicase domains, and extensive communication between them is required for RNA unwinding. The two helicase domains of the Bacillus subtilis RNA helicase YxiN were produced separately as intein fusions, and a functional RNA helicase was generated by expressed protein ligation. The ligated helicase binds adenine nucleotides with very similar affinities to the wild-type protein. Importantly, its intrinsically low ATPase activity is stimulated by RNA, and the Michaelis-Menten parameters are similar to those of the wild-type. Finally, ligated YxiN unwinds a minimal RNA substrate to an extent comparable to that of the wild-type helicase, confirming authentic interdomain communication.

Adolescents' responses to marital conflict: The role of cooperative marital conflict.

Science.gov (United States)

Zhou, Nan; Buehler, Cheryl

2017-10-01

Not all youth exposed to hostile marital interactions develop negative responses to marital conflict. Cooperative marital conflict has long been considered as an important way of managing conflict and may serve as an important context in which hostility might convey during marital interactions. In light of little prior attention placed on the positive side of conflict processes, the main and moderating effects of cooperative marital conflict on youth responses to marital conflict were examined in a sample of 416 2-parent families using a multimethod, 2-year prospective design. Cooperative marital conflict was associated with decreases in youth emotional dysregulation, perceived threat, and behavioral dysregulation, and increases in constructive family representations and coping efficacy. As a specific dimension of cooperation, effective conflict resolution was associated uniquely with elevated youth coping efficacy, and decreased emotional and behavioral dysregulation; marital warmth was associated uniquely with increased constructive family representations. Significant interactions between marital hostility and marital cooperation also were found. These findings highlight the importance of examining cooperation above and beyond hostility in studies of marital conflict in order to better understand youth development during early adolescence. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Perception of Cooperativeness Without Any Visual or Auditory Communication.

Science.gov (United States)

Chang, Dong-Seon; Burger, Franziska; Bülthoff, Heinrich H; de la Rosa, Stephan

2015-12-01

Perceiving social information such as the cooperativeness of another person is an important part of human interaction. But can people perceive the cooperativeness of others even without any visual or auditory information? In a novel experimental setup, we connected two people with a rope and made them accomplish a point-collecting task together while they could not see or hear each other. We observed a consistently emerging turn-taking behavior in the interactions and installed a confederate in a subsequent experiment who either minimized or maximized this behavior. Participants experienced this only through the haptic force-feedback of the rope and made evaluations about the confederate after each interaction. We found that perception of cooperativeness was significantly affected only by the manipulation of this turn-taking behavior. Gender- and size-related judgments also significantly differed. Our results suggest that people can perceive social information such as the cooperativeness of other people even in situations where possibilities for communication are minimal.

The Perception of Cooperativeness Without Any Visual or Auditory Communication

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Dong-Seon Chang

2015-12-01

Full Text Available Perceiving social information such as the cooperativeness of another person is an important part of human interaction. But can people perceive the cooperativeness of others even without any visual or auditory information? In a novel experimental setup, we connected two people with a rope and made them accomplish a point-collecting task together while they could not see or hear each other. We observed a consistently emerging turn-taking behavior in the interactions and installed a confederate in a subsequent experiment who either minimized or maximized this behavior. Participants experienced this only through the haptic force-feedback of the rope and made evaluations about the confederate after each interaction. We found that perception of cooperativeness was significantly affected only by the manipulation of this turn-taking behavior. Gender- and size-related judgments also significantly differed. Our results suggest that people can perceive social information such as the cooperativeness of other people even in situations where possibilities for communication are minimal.

Intravesical ligation as a new technique to manage a refluxing native ureter without simultaneous nephrectomy in renal transplantation.

Science.gov (United States)

Guzmán, J A

2012-12-01

This article aims to describe an original technique to correct refluxing native ureters observed during a prerenal transplantation study. The correction is performed by intravesical ligation of the native refluxing ureters at the same time as renal transplantation without simultaneous nephrectomy. Between January 2004 and December 2010 we performed intravesical ligation of a refluxing ureter simultaneous with a transplantation procedure without a concomittant native nephrectomy in 12 of 345 subjects (3.47%). The 8 bilateral and 4 unilateral ligations were performed on 11 cadaveric and 1 living-related nonidentical donor transplantations. The implantation of the kidney donor ureter was performed anatomically in the bladder trigone through a transvesical ureteroneocystostomy with a transmural, submucosal antireflux tunnel. Early and late postoperative recovery was satisfactory in all patients. There was no documented kidney area pain, proven urinary tract infection, morbidity or mortality attributed to the procedure. Intravesical ligation is a practical technique to manage vesicoureteral reflux into the native ureters simultaneously with the ureteral implantation of the kidney donor in a single surgical renal transplant procedure without native kidney nephrectomy. Copyright © 2012 Elsevier Inc. All rights reserved.

Are self-ligating brackets related to less formation of Streptococcus mutans colonies? A systematic review

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Leonard Euler Andrade Gomes do Nascimento

2014-01-01

Full Text Available OBJECTIVE: To verify, by means of a systematic review, whether the design of brackets (conventional or self-ligating influences adhesion and formation of Streptococcus mutans colonies. METHODS: Search strategy: four databases (Cochrane Central Register of Controlled Trials, Ovid ALL EMB Reviews, PubMed and BIREME were selected to search relevant articles covering the period from January 1965 to December 2012. Selection Criteria: in first consensus by reading the title and abstract. The full text was obtained from publications that met the inclusion criteria. Data collection and analysis: Two reviewers independently extracted data using the keywords: conventional, self-ligating, biofilm, Streptococcus mutans, and systematic review; and independently evaluated the quality of the studies. In case of divergence, the technique of consensus was adopted. RESULTS: The search strategy resulted in 1,401 articles. The classification of scientific relevance revealed the high quality of the 6 eligible articles of which outcomes were not unanimous in reporting not only the influence of the design of the brackets (conventional or self-ligating over adhesion and formation of colonies of Streptococcus mutans, but also that other factors such as the quality of the bracket type, the level of individual oral hygiene, bonding and age may have greater influence. Statistical analysis was not feasible because of the heterogeneous methodological design. CONCLUSIONS: Within the limitations of this study, it was concluded that there is no evidence for a possible influence of the design of the brackets (conventional or self-ligating over colony formation and adhesion of Streptococcus mutans.

COOPERATION AND COORDINATION BETWEEN INTERNAL AND EXTERNAL AUDITING

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DIANA DUMITRESCU

2016-02-01

Full Text Available Between external and internal auditors it is necessary to be a good cooperation and coordination; both professionals have to be involved in building a good working relationship. Objectives of the external and internal auditors are different from the company point of view, but in the achievement of the specific goals, there are interactions and work cooperation. If the internal auditors work together with the external auditors the results will be an increasing of the quality and the effectiveness of the organization`s systems and activities. If the external auditors work together with the internal auditors will result a decreasing of the amount of the testing they do, and as consequences’ a reducing of the fees. Because there are many benefits of the cooperation between external and internal auditing it is important to find out how could be coordinated these two professional activities. This study has the purpose to examine the most important provisions that promote such kind of cooperation and work like necessary tools for coordination and to identify the Romanian`s internal and external auditors perceptions regarding that cooperation and coordination. The objective of the study is to identify the nature of the relationship between the internal audit function and the organizations’ external auditors regarding their interactions and their cooperation.

Management of Fistula‑In‑Ano with Special Reference to Ligation of ...

African Journals Online (AJOL)

Context: The surgical management of fistula-in-ano is still debatable and no clear recommendations have been made available until now. The present study analyses the results of ligation of intersphincteric fistula tract (LIFT) technique in treating fistula-in-ano in particular with recurrence, healing time, and continence status.

Plaque retention by self-ligating vs elastomeric orthodontic brackets: quantitative comparison of oral bacteria and detection with adenosine triphosphate-driven bioluminescence.

NARCIS (Netherlands)

Pellegrini, P.; Sauerwein, R.W.; Finlayson, T.; McLeod, J.; Covell, D.A.; Maier, T.; Machida, C.A.

2009-01-01

INTRODUCTION: Enamel decalcification is a common problem in orthodontics. The objectives of this randomized clinical study were to enumerate and compare plaque bacteria surrounding 2 bracket types, self-ligating (SL) vs elastomeric ligating (E), and to determine whether adenosine triphosphate

Interactive Purchasing Situations

NARCIS (Netherlands)

Groote Schaarsberg, M.; Borm, P.E.M.; Hamers, H.J.M.; Reijnierse, J.H.

2012-01-01

Abstract: This paper introduces a new class of interactive cooperative purchasing situations and provides an explicit alternative characterization of the nucleolus of cooperative games, which offers an alternative to Kohlberg (1971). In our cooperative purchasing situation, the unit price of a

Level of arterial ligation in sigmoid colon and rectal cancer surgery.

Science.gov (United States)

Yasuda, Koji; Kawai, Kazushige; Ishihara, Soichiro; Murono, Koji; Otani, Kensuke; Nishikawa, Takeshi; Tanaka, Toshiaki; Kiyomatsu, Tomomichi; Hata, Keisuke; Nozawa, Hiroaki; Yamaguchi, Hironori; Aoki, Shigeo; Mishima, Hideyuki; Maruyama, Tsunehiko; Sako, Akihiro; Watanabe, Toshiaki

2016-04-01

Curative resection of sigmoid colon and rectal cancer includes "high tie" of the inferior mesenteric artery (IMA). However, IMA ligation compromises blood flow to the anastomosis, which may increase the leakage rate, and it is unclear whether this confers a survival advantage. Accordingly, the IMA may be ligated at a point just below the origin of the left colic artery (LCA) "low tie" combined with lymph node dissection (LND) around the origin of the IMA (low tie with LND). However, no study has investigated the detailed prognostic results between "high tie" and "low tie with LND." The aim of this study was to assess the utility of "low tie with LND" on survival in patients with sigmoid colon or rectal cancer. A total of 189 sigmoid colon or rectal cancer patients who underwent curative operation from 1997 to 2007 were enrolled in this study. The patient's medical records were reviewed to obtain clinicopathological information. Overall survival (OS) and relapse-free survival (RFS) rates were calculated using the Kaplan-Meier method, with differences assessed using log-rank test. Forty-two and 147 patients were ligated at the origin of the IMA (high tie) and just below the origin of the LCA combined with LND around the origin of the IMA (low tie with LND), respectively. No significant differences were observed in the complication rate and OS and RFS rates in the two groups. Further, no significant difference was observed in the OS and RFS rates in the lymph node-positive cases in the two groups. "Low tie with LND" is anatomically less invasive and is not inferior to "high tie" with prognostic point of view.

ALIS-FLP: Amplified ligation selected fragment-length polymorphism method for microbial genotyping

DEFF Research Database (Denmark)

Brillowska-Dabrowska, A.; Wianecka, M.; Dabrowski, Slawomir

2008-01-01

A DNA fingerprinting method known as ALIS-FLP (amplified ligation selected fragment-length polymorphism) has been developed for selective and specific amplification of restriction fragments from TspRI restriction endonuclease digested genomic DNA. The method is similar to AFLP, but differs...

U(SMes*)n, (n=3, 4) and Ln(SMes*)3 (Ln = La, Ce, Pr, Nd): Lanthanide(III)/actinide(III) differentiation in agostic interactions and an unprecedented eta(3) Ligation mode of the aryl-thiolate ligand, from X-ray diffraction and DFT analysis

International Nuclear Information System (INIS)

Roger, Mathieu; Barros, Noemi; Arliguie, Therese; Thuery, Pierre; Maron, Laurent; Ephritikhine, Michel

2006-01-01

Reaction of U(NEt 2 ) 4 with HS-2,4,6- t Bu 3 C 6 H 2 (HSMes*) gave U(SMes*) 3 (NEt 2 )(py) (1), whereas similar treatment of U[N(SiMe 3 )SiMe 2 CH 2 ][N(SiMe 3 ) 2 ] 2 afforded U(SMes*)[N(SiMe 3 ) 2 ] 3 (2) and U(SMes*) 3 [N(SiMe 3 ) 2 ]. The first neutral homoleptic uranium(IV) thiolate to have been crystallographically characterized, U(SMes*) 4 (4), was isolated from the reaction of U(BH 4 ) 4 and KSMes*. The first homoleptic thiolate complex of uranium(III), U(SMes*) 3 (5), was synthesized by proton-lysis of U[N(SiMe 3 ) 2 ] 3 with HSMes* in cyclohexane. The crystal structure of 5 exhibits the novel η 3 ligation mode for the aryl-thiolate ligand. Comparison of the crystal structure of 5 with those of the isomorphous lanthanide congeners Ln(SMes*) 3 (Ln) La, Ce, Pr, and Nd) indicates that the U-S, U-C ipso , and U-C ortho bond lengths are shorter than the corresponding ones in the 4f-element analogues, when taking into account the variation in the ionic radii of the metals. The distance between the uranium and the carbon atoms involved in the U center dot center dot center dot H-C ε agostic interaction of each thiolate ligand is shorter, by ∼ 0.05 angstrom, than that expected from a purely ionic bonding model. The lanthanide( III)/actinide(III) differentiation was analyzed by density functional theory (DFT). The nature of the M-S bond is shown to be ionic strongly polarized at the sulfur for M) U and ion-covalent (i.e. strongly ionic with low orbital interaction), for M) Ln. The strength of the U center dot center dot center dot H-C ε agostic interaction is proposed to be controlled by the maximization of the interaction between U + and S - under steric constraints. The η 3 ligation mode of the aryl-thiolate ligand is also obtained from DFT. (authors)

Native chemical ligation at Asx-Cys, Glx-Cys: chemical synthesis and high-resolution X-ray structure of ShK toxin by racemic protein crystallography.

Science.gov (United States)

Dang, Bobo; Kubota, Tomoya; Mandal, Kalyaneswar; Bezanilla, Francisco; Kent, Stephen B H

2013-08-14

We have re-examined the utility of native chemical ligation at -Gln/Glu-Cys- [Glx-Cys] and -Asn/Asp-Cys- [Asx-Cys] sites. Using the improved thioaryl catalyst 4-mercaptophenylacetic acid (MPAA), native chemical ligation could be performed at -Gln-Cys- and Asn-Cys- sites without side reactions. After optimization, ligation at a -Glu-Cys- site could also be used as a ligation site, with minimal levels of byproduct formation. However, -Asp-Cys- is not appropriate for use as a site for native chemical ligation because of formation of significant amounts of β-linked byproduct. The feasibility of native chemical ligation at -Gln-Cys- enabled a convergent total chemical synthesis of the enantiomeric forms of the ShK toxin protein molecule. The D-ShK protein molecule was ~50,000-fold less active in blocking the Kv1.3 channel than the L-ShK protein molecule. Racemic protein crystallography was used to obtain high-resolution X-ray diffraction data for ShK toxin. The structure was solved by direct methods and showed significant differences from the previously reported NMR structures in some regions of the ShK protein molecule.

Implementing interorganizational cooperation in labour market reintegration: a case study.

Science.gov (United States)

Ståhl, Christian

2012-06-01

To bring people with complex medical, social and vocational needs back to the labour market, interorganizational cooperation is often needed. Yet, studies of processes and strategies for achieving sustainable interorganizational cooperation are sparse. The aim of this study was to analyse the implementation processes of Swedish legislation on financial coordination, with specific focus on different strategies for and perspectives on implementing interorganizational cooperation. A multiple-case study was used, where two local associations for financial coordination were studied in order to elucidate and compare the development of cooperative work in two settings. The material, collected during a 3-year period, consisted of documents, individual interviews with managers, and focus groups with officials. Two different implementation strategies were identified. In case 1, a linear strategy was used to implement cooperative projects, which led to difficulties in maintaining cooperative work forms due to a fragmented and time-limited implementation process. In case 2, an interactive strategy was used, where managers and politicians were continuously involved in developing a central cooperation team that became a central part of a developing structure for interorganizational cooperation. An interactive cooperation strategy with long-term joint financing was here shown to be successful in overcoming organizational barriers to cooperation. It is suggested that a strategy based on adaptation to local conditions, flexibility and constant evaluation is preferred for developing sustainable interorganizational cooperation when implementing policies or legislation affecting interorganizational relationships.

Impaired compensation to femoral artery ligation in diet-induced obese mice is primarily mediated via suppression of collateral growth by Nox2 and p47phox.

Science.gov (United States)

DiStasi, Matthew R; Mund, Julie A; Bohlen, H Glenn; Miller, Steven J; Ingram, David A; Dalsing, Michael C; Unthank, Joseph L

2015-10-01

The present study was undertaken to establish the role of NADPH oxidase (Nox) in impaired vascular compensation to arterial occlusion that occurs in the presence of risk factors associated with oxidative stress. Diet-induced obese (DIO) mice characterized by multiple comorbidities including diabetes and hyperlipidemia were used as a preclinical model. Arterial occlusion was induced by distal femoral artery ligation in lean and DIO mice. Proximal collateral arteries were identified as the site of major (∼70%) vascular resistance to calf perfusion by distal arterial pressures, which decreased from ∼80 to ∼30 mmHg with ligation in both lean and DIO mice. Two weeks after ligation, significant vascular compensation occurred in lean but not DIO mice as evidenced by increased perfusion (147 ± 48% vs. 49 ± 29%) and collateral diameter (151 ± 30% vs. 44 ± 17%). Vascular mRNA expression of p22(phox), Nox2, Nox4, and p47(phox) were all increased in DIO mice. Treatment of DIO mice with either apocynin or Nox2ds-tat or with whole body ablation of either Nox2 or p47(phox) ameliorated the impairment in both collateral growth and hindlimb perfusion. Multiparametric flow cytometry analysis demonstrated elevated levels of circulating monocytes in DIO mice without impaired mobilization and demargination after femoral artery ligation. These results establish collateral resistance as the major limitation to calf perfusion in this preclinical model, demonstrate than monocyte mobilization and demarginatin is not suppressed, implicate Nox2-p47(phox) interactions in the impairment of vascular compensation to arterial occlusion in DIO mice, and suggest that selective Nox component suppression/inhibition may be effective as either primary or adjuvant therapy for claudicants. Copyright © 2015 the American Physiological Society.

Comparison of frictional resistance between self-ligating and conventional brackets tied with elastomeric and metal ligature in orthodontic archwires.

Science.gov (United States)

Leite, Vanessa Vieira; Lopes, Murilo Baena; Gonini Júnior, Alcides; Almeida, Marcio Rodrigues de; Moura, Sandra Kiss; Almeida, Renato Rodrigues de

2014-01-01

To compare the frictional resistance between self-ligating and conventional brackets tied to different types of wire. Abzil Kirium Capelozza (Pattern I) and Easy Clip (Roth prescription) incisor brackets were used. An elastomeric ligature or a 0.10-in ligating wire was used to ligate the wire to the Abzil bracket. Three types of orthodontic archwire alloys were assessed: 0.016-in NiTi wire, 0.016 x 0.021-in NiTi wire and 0.019 x 0.025-in steel wire. Ten observations were carried out for each bracket-archwire angulation combination. Brackets were mounted in a special appliance, positioned at 90 degrees in relation to the wire and tested in two angulations. Frictional test was performed in a Universal Testing Machine at 5 mm/min and 10 mm of displacement. The means (MPa) were submitted to ANOVA and Tukey's test set at 5% of significance. The surfaces of wires and brackets were observed at SEM. Steel-tied brackets (16.48 ± 8.31) showed higher means of frictional resistance than elastomeric-tied brackets (4.29 ± 2.16 ) and self-ligating brackets (1.66 ± 1.57) (P 0.05). No statistical differences (P > 0.05) were found between zero (7.76 ± 8.46) and five-degree (7.19 ± 7.93) angulations. Friction was influenced not only by the type of bracket, but also by the ligating systems. Different morphological aspects were observed for the brackets and wires studied.

In vivo and in vitro protein ligation by naturally occurring and engineered split DnaE inteins.

Directory of Open Access Journals (Sweden)

A Sesilja Aranko

Full Text Available BACKGROUND: Protein trans-splicing by naturally occurring split DnaE inteins is used for protein ligation of foreign peptide fragments. In order to widen biotechnological applications of protein trans-splicing, it is highly desirable to have split inteins with shorter C-terminal fragments, which can be chemically synthesized. PRINCIPAL FINDINGS: We report the identification of new functional split sites in DnaE inteins from Synechocystis sp. PCC6803 and from Nostoc punctiforme. One of the newly engineered split intein bearing C-terminal 15 residues showed more robust protein trans-splicing activity than naturally occurring split DnaE inteins in a foreign context. During the course of our experiments, we found that protein ligation by protein trans-splicing depended not only on the splicing junction sequences, but also on the foreign extein sequences. Furthermore, we could classify the protein trans-splicing reactions in foreign contexts with a simple kinetic model into three groups according to their kinetic parameters in the presence of various reducing agents. CONCLUSION: The shorter C-intein of the newly engineered split intein could be a useful tool for biotechnological applications including protein modification, incorporation of chemical probes, and segmental isotopic labelling. Based on kinetic analysis of the protein splicing reactions, we propose a general strategy to improve ligation yields by protein trans-splicing, which could significantly enhance the applications of protein ligation by protein trans-splicing.

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

Science.gov (United States)

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.

Directory of Open Access Journals (Sweden)

Max M Krasnow

Full Text Available 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

Cooperative learning as an approach to pedagogy.

Science.gov (United States)

Nolinske, T; Millis, B

1999-01-01

Lecture-based pedagogical approaches cannot adequately prepare students in professional and technical occupational therapy programs. Faculty members in other disciplines are turning to a well-known and well-researched teaching approach called cooperative learning, which is more carefully structured and defined than most other forms of small group learning. Cooperative learning includes several key principles: positive interdependence, individual responsibility, appropriate grouping, group maintenance, cooperative skills, and promotive (interaction) time. This article provides ideas for managing the classroom with cooperative learning activities and describes eight of them: Three-Step Interview, Roundtable, Think-Pair-Share, Structured Problem Solving, Send/Pass-a-Problem, Generic Question Stems, Double Entry Journal, and Dyadic Essay Confrontation. Each activity is applied to content embedded in professional and technical occupational therapy curricula. A cooperative learning approach to evaluating learning is also presented.

A comparative study of frictional force in self-ligating brackets according to the bracket-archwire angulation, bracket material, and wire type

Science.gov (United States)

Lee, Souk Min

2015-01-01

Objective This study aimed to compare the frictional force (FR) in self-ligating brackets among different bracket-archwire angles, bracket materials, and archwire types. Methods Passive and active metal self-ligating brackets and active ceramic self-ligating brackets were included as experimental groups, while conventional twin metal brackets served as a control group. All brackets were maxillary premolar brackets with 0.022 inch [in] slots and a -7° torque. The orthodontic wires used included 0.018 round and 0.019 × 0.025 in rectangular stainless steel wires. The FR was measured at 0°, 5°, and 10° angulations as the wire was drawn through the bracket slots after attaching brackets from each group to the universal testing machine. Static and kinetic FRs were also measured. Results The passive self-ligating brackets generated a lower FR than all the other brackets. Static and kinetic FRs generally increased with an increase in the bracket-archwire angulation, and the rectangular wire caused significantly higher static and kinetic FRs than the round wire (p brackets exhibited the lowest static FR at the 0° angulation and a lower increase in static and kinetic FRs with an increase in bracket-archwire angulation than the other brackets, while the conventional twin brackets showed a greater increase than all three experimental brackets. Conclusions The passive self-ligating brackets showed the lowest FR in this study. Self-ligating brackets can generate varying FRs in vitro according to the wire size, surface characteristics, and bracket-archwire angulation. PMID:25667913

Evolutionary dynamics under interactive diversity

Science.gov (United States)

Su, Qi; Li, Aming; Wang, Long

2017-10-01

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

Extrahepatic bile duct ligation in broiler chickens: ultrastructural study of Ito cell

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Ekowati Handharyani

2004-12-01

Full Text Available The Ito cell (fat-storing cell is a cell lying in perisinusoidal space of liver. The function of Ito cell is expanding from a site of fat-storing site to a center of extracellular matrix metabolism and mediator production in the liver. This study was performed in order to evaluate the Ito cells in cholestatic condition. The artificial cholestatic was conducted by ligation of extrahepatic bile ducts (bile duct ligation = BDL in broilers. The results showed that BDL induced bile congestion, fibrosis, proliferation of Ito cells and intrahepatic bile ductules. Immunohistochemistry demonstrated that Ito cells were scattered throughout the fibrotic areas, and larger in size with more extensive immunoreactivity than those in normal livers. Ultrastructural study demonstrated that Ito cells were closely associated with the production of extracellular collagen fibers. Ito cells actively react against hepatocytic injuries, especially in fibrogenesis of cholestatic livers.

Relatedness decreases and reciprocity increases cooperation in Norway rats.

Science.gov (United States)

Schweinfurth, Manon K; Taborsky, Michael

2018-03-14

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

The role of physical space in labour–management cooperation

DEFF Research Database (Denmark)

Ilsøe, Anna; Felbo-Kolding, Jonas

2018-01-01

Many studies on labour–management relations have focused on formal cooperation in manufacturing. This calls for further research and theory development on labour–management interactions in private service companies, where cooperation practices appear to be less formal. In this article, a typology...... of cooperation between managers and employees is developed, based on a microsociological study conducted in the Danish retail trade in 2013. Drawing on six indepth case studies, the article identifies four different physical spaces of labour–management cooperation: open collective, closed collective, open...

Assessment of MRI issues at 3-Tesla for metallic surgical implants: findings applied to 61 additional skin closure staples and vessel ligation clips.

Science.gov (United States)

Gill, Amreeta; Shellock, Frank G

2012-01-09

Metallic skin closure staples and vessel ligation clips should be tested at 3-Tesla to characterize MRI issues in order to ensure patient safety. Therefore, metallic surgical implants were assessed at 3-Tesla for magnetic field interactions, MRI-related heating, and artifacts. A skin closure staple (Visistat Skin Stapler, staple, Polytetrafluoroethylene, PTFE, coated 316L/316LVM stainless steel; Teleflex Medical, Durham, NC) and a vessel ligation clip (Hemoclip Traditional, stainless steel; Teleflex Medical, Durham, NC) that represented the largest metallic sizes made from materials with the highest magnetic susceptibilities (i.e., based on material information) among 61 other surgical implants (52 metallic implants, 9 nonmetallic implants) underwent evaluation for magnetic field interactions, MRI-related heating, and artifacts using standardized techniques. MRI-related heating was assessed by placing each implant in a gelled-saline-filled phantom with MRI performed using a transmit/receive RF body coil at an MR system reported, whole body averaged SAR of 2.9-W/kg for 15-min. Artifacts were characterized using T1-weighted, SE and GRE pulse sequences. Each surgical implant showed minor magnetic field interactions (20- and 27-degrees, which is acceptable from a safety consideration). Heating was not substantial (highest temperature change, ≤ 1.6°C). Artifacts may create issues if the area of interest is in the same area or close to the respective surgical implant. The results demonstrated that it would be acceptable for patients with these metallic surgical implants to undergo MRI at 3-Tesla or less. Because of the materials and dimensions of the surgical implants that underwent testing, these findings pertain to 61 additional similar implants.

Assessment of MRI issues at 3-Tesla for metallic surgical implants: findings applied to 61 additional skin closure staples and vessel ligation clips

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Gill Amreeta

2012-01-01

Full Text Available Abstract Purpose Metallic skin closure staples and vessel ligation clips should be tested at 3-Tesla to characterize MRI issues in order to ensure patient safety. Therefore, metallic surgical implants were assessed at 3-Tesla for magnetic field interactions, MRI-related heating, and artifacts. Methods A skin closure staple (Visistat Skin Stapler, staple, Polytetrafluoroethylene, PTFE, coated 316L/316LVM stainless steel; Teleflex Medical, Durham, NC and a vessel ligation clip (Hemoclip Traditional, stainless steel; Teleflex Medical, Durham, NC that represented the largest metallic sizes made from materials with the highest magnetic susceptibilities (i.e., based on material information among 61 other surgical implants (52 metallic implants, 9 nonmetallic implants underwent evaluation for magnetic field interactions, MRI-related heating, and artifacts using standardized techniques. MRI-related heating was assessed by placing each implant in a gelled-saline-filled phantom with MRI performed using a transmit/receive RF body coil at an MR system reported, whole body averaged SAR of 2.9-W/kg for 15-min. Artifacts were characterized using T1-weighted, SE and GRE pulse sequences. Results Each surgical implant showed minor magnetic field interactions (20- and 27-degrees, which is acceptable from a safety consideration. Heating was not substantial (highest temperature change, ≤ 1.6°C. Artifacts may create issues if the area of interest is in the same area or close to the respective surgical implant. Conclusions The results demonstrated that it would be acceptable for patients with these metallic surgical implants to undergo MRI at 3-Tesla or less. Because of the materials and dimensions of the surgical implants that underwent testing, these findings pertain to 61 additional similar implants.

Assessment of MRI issues at 3-Tesla for metallic surgical implants: findings applied to 61 additional skin closure staples and vessel ligation clips

Science.gov (United States)

2012-01-01

Purpose Metallic skin closure staples and vessel ligation clips should be tested at 3-Tesla to characterize MRI issues in order to ensure patient safety. Therefore, metallic surgical implants were assessed at 3-Tesla for magnetic field interactions, MRI-related heating, and artifacts. Methods A skin closure staple (Visistat Skin Stapler, staple, Polytetrafluoroethylene, PTFE, coated 316L/316LVM stainless steel; Teleflex Medical, Durham, NC) and a vessel ligation clip (Hemoclip Traditional, stainless steel; Teleflex Medical, Durham, NC) that represented the largest metallic sizes made from materials with the highest magnetic susceptibilities (i.e., based on material information) among 61 other surgical implants (52 metallic implants, 9 nonmetallic implants) underwent evaluation for magnetic field interactions, MRI-related heating, and artifacts using standardized techniques. MRI-related heating was assessed by placing each implant in a gelled-saline-filled phantom with MRI performed using a transmit/receive RF body coil at an MR system reported, whole body averaged SAR of 2.9-W/kg for 15-min. Artifacts were characterized using T1-weighted, SE and GRE pulse sequences. Results Each surgical implant showed minor magnetic field interactions (20- and 27-degrees, which is acceptable from a safety consideration). Heating was not substantial (highest temperature change, ≤ 1.6°C). Artifacts may create issues if the area of interest is in the same area or close to the respective surgical implant. Conclusions The results demonstrated that it would be acceptable for patients with these metallic surgical implants to undergo MRI at 3-Tesla or less. Because of the materials and dimensions of the surgical implants that underwent testing, these findings pertain to 61 additional similar implants. PMID:22230200

A multiplex ligation detection assay for the characterization of Salmonella enterica strains

NARCIS (Netherlands)

Aarts, H.J.M.; Vos, P.; Larsson, J.T.; Hoek, van A.H.A.M.; Huehn, S.; Weijers, T.; Gronlund, H.A.; Malorny, B.

2011-01-01

A proof of principle of a multi-target assay for genotyping Salmonella has been developed targeting 62 genomic marker sequences of Salmonella related to pathogenicity. The assay is based on multiplex ligation detection reaction (LDR) followed by customized ArrayTube (R) microarray detection. The

Streptococcus sanguinis meningitis following endoscopic ligation for oesophageal variceal haemorrhage.

Science.gov (United States)

Liu, Yu-Ting; Lin, Chin-Fu; Lee, Ya-Ling

2013-05-01

We report a case of acute purulent meningitis caused by Streptococcus sanguinis after endoscopic ligation for oesophageal variceal haemorrhage in a cirrhotic patient without preceding symptoms of meningitis. Initial treatment with flomoxef failed. The patient was cured after 20 days of intravenous penicillin G. This uncommon infection due to S. sanguinis adds to the long list of infectious complications among patients with oesophageal variceal haemorrhage.

A Simple Suturing Technique for Laparoscopic Ligation of Vascular Pedicles

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Keith A. Aqua

1996-01-01

Full Text Available We report on the performance of 348 adnexectomies and 35 uterine artery ligations for both benign and malignant disease using a simple laparoscopic suturing technique. Only 5-mm ports are required, and there was no morbidity directly associated with this approach. The procedure can be performed quickly, is relatively inexpensive, and allows hysterectomy and oophorectomy to be performed without bipolar electrocautery.

Replication-Coupled PCNA Unloading by the Elg1 Complex Occurs Genome-wide and Requires Okazaki Fragment Ligation

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Takashi Kubota

2015-08-01

Full Text Available The sliding clamp PCNA is a crucial component of the DNA replication machinery. Timely PCNA loading and unloading are central for genome integrity and must be strictly coordinated with other DNA processing steps during replication. Here, we show that the S. cerevisiae Elg1 replication factor C-like complex (Elg1-RLC unloads PCNA genome-wide following Okazaki fragment ligation. In the absence of Elg1, PCNA is retained on chromosomes in the wake of replication forks, rather than at specific sites. Degradation of the Okazaki fragment ligase Cdc9 leads to PCNA accumulation on chromatin, similar to the accumulation caused by lack of Elg1. We demonstrate that Okazaki fragment ligation is the critical prerequisite for PCNA unloading, since Chlorella virus DNA ligase can substitute for Cdc9 in yeast and simultaneously promotes PCNA unloading. Our results suggest that Elg1-RLC acts as a general PCNA unloader and is dependent upon DNA ligation during chromosome replication.

Biomechanical characteristics of self-ligating brackets in a vertically displaced canine model: a finite element analysis.

Science.gov (United States)

Kim, S-J; Kwon, Y-H; Hwang, C-J

2016-05-01

The objective of this study was to compare the biomechanical characteristics between two types of self-ligating brackets and conventional metal brackets using finite element analysis of a vertically displaced canine model focusing on the desired force on the canine and undesirable forces on adjacent teeth. Three-dimensional finite element models of the maxillary dentition with 1-mm, 2-mm, and 3-mm vertically displaced canines were constructed. Two different self-ligating brackets (In-Ovation C and Smart clip) and a conventional metal bracket (Micro-arch) were modeled. After a 0.016-inch NiTi (0.40 mm, round) wire was engaged, the displacement of each tooth was calculated using x-, y-, and z-coordinates, and the tensile and compressive stresses were calculated. The extrusion and maximal tensile stress of the canine differed little between the three brackets, but the intrusion and minimal compressive stress values of the adjacent teeth differed considerably and were highest in the Smart clip and least in the In-Ovation C. The extrusion and maximal tensile stress of the canine in the 3-mm displacement model was less than that in the 2-mm displacement model, and the intrusion and minimal compressive stress of the adjacent teeth increased with the degree of displacement. Self-ligating brackets were not superior to conventional brackets in leveling a vertically displaced canine. A continuous arch wire may not be recommended for leveling of severely displaced canines whether using self-ligating or conventional brackets. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Web-based Cooperative Learning in College Chemistry Teaching

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Bin Jiang

2014-03-01

Full Text Available With the coming of information era, information process depend on internet and multi-media technology in education becomes the new approach of present teaching model reform. Web-based cooperative learning is becoming a popular learning approach with the rapid development of web technology. The paper aims to how to carry out the teaching strategy of web-based cooperative learning and applied in the foundation chemistry teaching.It was shown that with the support of modern web-based teaching environment, students' cooperative learning capacity and overall competence can be better improved and the problems of interaction in large foundation chemistry classes can be solved. Web-based cooperative learning can improve learning performance of students, what's more Web-based cooperative learning provides students with cooperative skills, communication skills, creativity, critical thinking skills and skills in information technology application.

Peer pressure: Enhancement of cooperation through mutual punishment

Science.gov (United States)

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.

Psychosocial implications of tubal ligation in a rural health district: A phenomenological study

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Lutala Prosper M

2011-12-01

Full Text Available Abstract Background Tubal ligation is the most popular family planning method worldwide. While its benefits, such as effectiveness in protecting against pregnancies, minimal need for long-term follow-up and low side-effects profile are well documented, it has many reported complications. However, to date, these complications have not been described by residents in Congo. Therefore, the study aimed at exploring the experience of women who had undergone tubal ligation, focusing on perceptions of physical, psychological and contextual experiences of participants. Methods This qualitative study used a semi-structured questionnaire in a phenomenological paradigm to collect data. Fifteen participants were purposefully selected among sterilized women who had a ligation procedure performed, were aged between 30 and 40 years, and were living within the catchment area of the district hospital. Data were collected by two registered nurses, tape-recorded, and transcribed verbatim. Reading and re-reading cut and paste techniques, and integration were used to establish codes, categories, themes, and description. Results Diverse and sometimes opposite changes in somatic symptoms, psychological symptoms, productivity, ecological relationships, doctor-client relationships, ethical issues, and change of life style were the major problem domains. Conclusions Clients reported conflicting experiences in several areas of their lives after tubal sterilization. Management, including awareness of the particular features of the client, is needed to decrease the likelihood of psychosocial morbidity and/or to select clients in need of sterilization.

Dimensional accuracy of ceramic self-ligating brackets and estimates of theoretical torsional play.

Science.gov (United States)

Lee, Youngran; Lee, Dong-Yul; Kim, Yoon-Ji R

2016-09-01

To ascertain the dimensional accuracies of some commonly used ceramic self-ligation brackets and the amount of torsional play in various bracket-archwire combinations. Four types of 0.022-inch slot ceramic self-ligating brackets (upper right central incisor), three types of 0.018-inch ceramic self-ligating brackets (upper right central incisor), and three types of rectangular archwires (0.016 × 0.022-inch beta-titanium [TMA] (Ormco, Orange, Calif), 0.016 × 0.022-inch stainless steel [SS] (Ortho Technology, Tampa, Fla), and 0.019 × 0.025-inch SS (Ortho Technology)) were measured using a stereomicroscope to determine slot widths and wire cross-sectional dimensions. The mean acquired dimensions of the brackets and wires were applied to an equation devised by Meling to estimate torsional play angle (γ). In all bracket systems, the slot tops were significantly wider than the slot bases (P brackets, and Clippy-Cs (Tomy, Futaba, Fukushima, Japan) among the 0.018-inch brackets. The Damon Clear (Ormco) bracket had the smallest dimensional error (0.542%), whereas the 0.022-inch Empower Clear (American Orthodontics, Sheboygan, Wis) bracket had the largest (3.585%). The largest amount of theoretical play is observed using the Empower Clear (American Orthodontics) 0.022-inch bracket combined with the 0.016 × 0.022-inch TMA wire (Ormco), whereas the least amount occurs using the 0.018 Clippy-C (Tomy) combined with 0.016 × 0.022-inch SS wire (Ortho Technology).

Actual versus theoretical torsional play in conventional and self-ligating bracket systems

DEFF Research Database (Denmark)

Dalstra, Michel; Eriksen, Henrik; Bergamini, Chiara

2015-01-01

Abstract Objective: The aim of this study was to assess the amount of torsional play in 32 commercially available self-ligating and conventional 0·018-inch and 0·022-inch bracket systems in relation to 0·017×0·022-inch and 0·019×0·025-inch stainless steel wires, respectively, and compare...... the results with the theoretical amount of play for the given bracket/wire combinations. Methods: Torque moments were measured in a mechanical force testing system by twisting straight pieces of stainless steel wire seated in the bracket slot in increments of 0·5° until a full torsional expression...... and the inability of self-ligation brackets to press the archwire into the bottom of the slot. In conventional brackets, the initial torque moment is generated by the steel ligatures pressing the arch wire against the bottom of the slot. The oversize of the slot is thus less critical in relation to the conventional...

TLR9 ligation in pancreatic stellate cells promotes tumorigenesis.

Science.gov (United States)

Zambirinis, Constantinos P; Levie, Elliot; Nguy, Susanna; Avanzi, Antonina; Barilla, Rocky; Xu, Yijie; Seifert, Lena; Daley, Donnele; Greco, Stephanie H; Deutsch, Michael; Jonnadula, Saikiran; Torres-Hernandez, Alejandro; Tippens, Daniel; Pushalkar, Smruti; Eisenthal, Andrew; Saxena, Deepak; Ahn, Jiyoung; Hajdu, Cristina; Engle, Dannielle D; Tuveson, David; Miller, George

2015-11-16

Modulation of Toll-like receptor (TLR) signaling can have protective or protumorigenic effects on oncogenesis depending on the cancer subtype and on specific inflammatory elements within the tumor milieu. We found that TLR9 is widely expressed early during the course of pancreatic transformation and that TLR9 ligands are ubiquitous within the tumor microenvironment. TLR9 ligation markedly accelerates oncogenesis, whereas TLR9 deletion is protective. We show that TLR9 activation has distinct effects on the epithelial, inflammatory, and fibrogenic cellular subsets in pancreatic carcinoma and plays a central role in cross talk between these compartments. Specifically, TLR9 activation can induce proinflammatory signaling in transformed epithelial cells, but does not elicit oncogene expression or cancer cell proliferation. Conversely, TLR9 ligation induces pancreatic stellate cells (PSCs) to become fibrogenic and secrete chemokines that promote epithelial cell proliferation. TLR9-activated PSCs mediate their protumorigenic effects on the epithelial compartment via CCL11. Additionally, TLR9 has immune-suppressive effects in the tumor microenvironment (TME) via induction of regulatory T cell recruitment and myeloid-derived suppressor cell proliferation. Collectively, our work shows that TLR9 has protumorigenic effects in pancreatic carcinoma which are distinct from its influence in extrapancreatic malignancies and from the mechanistic effects of other TLRs on pancreatic oncogenesis. © 2015 Zambirinis et al.

Between-group competition elicits within-group cooperation in children

Science.gov (United States)

Majolo, Bonaventura; Maréchal, Laëtitia

2017-02-01

Aggressive interactions between groups are frequent in human societies and can bear significant fitness costs and benefits (e.g. death or access to resources). During between-group competitive interactions, more cohesive groups (i.e. groups formed by individuals who cooperate in group defence) should out-perform less cohesive groups, other factors being equal (e.g. group size). The cost/benefit of between-group competition are thought to have driven correlated evolution of traits that favour between-group aggression and within-group cooperation (e.g. parochial altruism). Our aim was to analyse whether the proximate relationship between between-group competition and within-group cooperation is found in 3-10 years old children and the developmental trajectory of such a relationship. We used a large cohort of children (n = 120) and tested whether simulated between-group competition increased within-group cooperation (i.e. how much of a resource children were giving to their group companions) in two experiments. We found greater within-group cooperation when groups of four children were competing with other groups then in the control condition (no between-group competition). Within-group cooperation increased with age. Our study suggests that parochial altruism and in-group/out-group biases emerge early during the course of human development.

Chemical Ligation: A Versatile Method for Nucleoside Modification with Boron Clusters

Czech Academy of Sciences Publication Activity Database

Wojtczak, B. A.; Andrysiak, A.; Grüner, Bohumír; Lesnikowski, Z. J.

-, č. 14 (2008), s. 10675-10682 ISSN 0947-6539 R&D Projects: GA MŠk LC523 Grant - others:MSHE(PL) N405 051 32/3592; MSHE(PL) K152/H03/2007/10 Institutional research plan: CEZ:AV0Z40320502 Keywords : alkynes * azides * chemical ligation Subject RIV: CA - Inorganic Chemistry Impact factor: 5.454, year: 2008

Collaborative Learning or Cooperative Learning? The Name Is Not Important; Flexibility Is

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George M. Jacobs

2015-06-01

Full Text Available Abstract A great deal of theory and research, not to mention students’ and teachers’ practical experience, supports the use of group activities in education. Collaborative learning and cooperative learning are two terms commonly used in discussions of how and why to use group activities. This article looks at the issue of whether the two terms collaborative learning and cooperative learning are synonymous or whether they represent different conceptualisations of how and why students should interact as part of their learning. Those scholars who differentiate the two terms often see collaborative learning as more student centred and cooperative learning as a more teacher centred way to facilitate student-student interaction. The present article argues that collaborative and cooperative learning should be seen as synonymous student centric approaches, and that teachers and students, regardless of which of the two terms they use, should and will vary the ways they shape their learning environments in order to best facilitate the cognitive and affective benefits that student-student interaction offers. Keywords: Collaborative learning, cooperative learning, flexibility

SH2-PLA: a sensitive in-solution approach for quantification of modular domain binding by proximity ligation and real-time PCR.

Science.gov (United States)

Thompson, Christopher M; Bloom, Lee R; Ogiue-Ikeda, Mari; Machida, Kazuya

2015-06-26

There is a great interest in studying phosphotyrosine dependent protein-protein interactions in tyrosine kinase pathways that play a critical role in many aspects of cellular function. We previously established SH2 profiling, a phosphoproteomic approach based on membrane binding assays that utilizes purified Src Homology 2 (SH2) domains as a molecular tool to profile the global tyrosine phosphorylation state of cells. However, in order to use this method to investigate SH2 binding sites on a specific target in cell lysate, additional procedures such as pull-down or immunoprecipitation which consume large amounts of sample are required. We have developed PLA-SH2, an alternative in-solution modular domain binding assay that takes advantage of Proximity Ligation Assay and real-time PCR. The SH2-PLA assay utilizes oligonucleotide-conjugated anti-GST and anti-EGFR antibodies recognizing a GST-SH2 probe and cellular EGFR, respectively. If the GST-SH2 and EGFR are in close proximity as a result of SH2-phosphotyrosine interactions, the two oligonucleotides are brought within a suitable distance for ligation to occur, allowing for efficient complex amplification via real-time PCR. The assay detected signal across at least 3 orders of magnitude of lysate input with a linear range spanning 1-2 orders and a low femtomole limit of detection for EGFR phosphotyrosine. SH2 binding kinetics determined by PLA-SH2 showed good agreement with established far-Western analyses for A431 and Cos1 cells stimulated with EGF at various times and doses. Further, we showed that PLA-SH2 can survey lung cancer tissues using 1 μl lysate without requiring phospho-enrichment. We showed for the first time that interactions between SH2 domain probes and EGFR in cell lysate can be determined in a microliter-scale assay using SH2-PLA. The obvious benefit of this method is that the low sample requirement allows detection of SH2 binding in samples which are difficult to analyze using traditional protein

Outcome of band ligation in oesophageal varices

International Nuclear Information System (INIS)

Abbasi, A.; Bhutto, A.R.; Bhatti, K.I.; Mahmood, K.; Lal, K.

2013-01-01

Objective: To find out the outcome og band ligation of oesophageal varices in decompensated chronic liver disease patients. Methods: The quasi experimental study was conducted at the Jinnah Postgraduate Medical Centre, Karachi, and Civil Hospital, Karachi, unit from September 2007 to August 2011. Subjects were eligible if they had a diagnosis of cirrhosis based on history, physical examination, biochemical parameters and liver biopsy in some cases. Patients with advanced cirrhosis (Child-Pugh class C), antibodies against human immunodeficiency virus, hepatocellular carcinoma, portal vein thrombosis evident on ultrasonography, parenteral drug addiction, current alcohol abuse, previous or current treatment with β-blockers were excluded from the study. All patients were asked about alcohol intake and tested to determine the cause of liver cirrhosis. Tests for other causes of cirrhosis were carried out only if there was a suggestive clue. All patients under-went upper gastrointestinal endoscopy after consent. SPSS 15 was used for statistical analysis. Results: The age of the 173 patients who met the inclusion criteria ranged from 15 to 85 years, with a mean of 48.39+-13.38 years. There were 112 (64.7%) males. High-grade varices were seen in 130 (75.1%) patients, while low-grade varices were observed in 43 (24.9%) on first endoscopy. At initial endoscopy, 111 (64.2%) patients had portal hypertensive gastropathy. The patients were followed up for a mean period of 5.20+-2.67 months. Variceal obliteration was achieved in 138 (79.8%), while 33 (19.1%) cases developed re-bleeding. Mean number of endoscopy sessions for these patients were 2.28+-.918 with a maximum of 4. Conclusion: Band ligation eradicated oesophageal varices with less complications and a lower re-bleeding rate, but at the same time eradication was associated with more frequent development of portal hypertensive gastropathy. (author)

Alignment efficiency of standard versus tandem wire mechanics using conventional and self-ligating brackets: A pilot study

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Prarthana Bhardwaj

2017-01-01

Full Text Available Objective: The objective of this study is to evaluate the clinical efficiency of 0.018″/0.022″ slot self-ligating (SL bracket system (standard and tandem mechanics in terms of rate of alignment by comparing it with a 0.022″ slot conventional ligating appliance system (MBT. Settings and Sample Population: The Department of Orthodontics. Materials and Methods: The pilot study was carried out using randomized controlled trial design. Forty patients having Little's irregularity index (II of 6–15 mm, treated by all first premolars extractions, were randomly allocated to 0.022″ slot conventional ligating bracket system, 0.018″ slot SL bracket system, 0.018″ slot SL bracket system (tandem archwires, 0.022″ slot SL bracket system, and 0.022″ slot SL bracket system (tandem archwires. The rate of alignment for each bracket system was measured from the difference in the II of serial casts taken at pretreatment and at the end of alignment, divided by the number of days between the two measurements. A one-way ANOVA model with post hoc Bonferroni multiple comparison procedures was used to identify intergroup differences. Results: The mean value of alignment efficiency was not found to be statistically significant in any of the five groups using digital models (P = 0.104. Conclusions: Alignment efficiency was not different between SL versus conventional ligating group, the 0.018″ slot versus 0.022″ slot and tandem versus standard mechanics.

Comparison of effectiveness and cost of patent ductus arteriosus device occlusion versus surgical ligation of patent ductus arteriosus.

Science.gov (United States)

Zulqarnain, Arif; Younas, Muhammad; Waqar, Tariq; Beg, Ahsan; Asma, Touseef; Baig, Mirza Ahmad Raza

2016-01-01

Comparison of effectiveness and cost of transcatheter occlusion of patent ductus arteriosus (PDA) with surgical ligation of PDA. This retrospective comparative study was conducted in the pediatric cardiology department of Ch. Pervaiz Elahi Institute of Cardiology Multan, Pakistan. Data of 250 patients who underwent patent ductus arteriosus (PDA) closure either surgical or trans-catheter closure using SHSMA Occluder having weight >5 kg from April 2012 to October 2015 were included in this study. SPSS version 20 was used for data analysis. Quantitative variables were compared using independent sample t-test. Chi-square test and fishers exact was used for qualitative variables. P-value <0.05 was considered statistically significant. There were one hundred and twenty (120) patients who underwent transcatheter occlusion of PDA using SHSMA occluder (PDA Device Group) and one hundred and thirty (130) patients who underwent surgical ligation of PDA (Surgical Group). Incidence of residual shunting was two (1.5%) in surgical group and 0 (0.0%) in PDA Device group for one month follow up period. There were 4 (3.1%) major complications in surgical group. The rate of blood transfusions were high in surgical group (p-value 0.04). Hospital stay time was significantly less in PDA Device group (P-value <0.001). Total procedural cost was 110695+1054 Pakistani rupees in PDA Device group and 92414+3512 in surgical group (p-value <0.001). The cost of PDA device closure was 16.52% higher than the surgical ligation of PDA. There was no operative mortality. The transcatheter closure of PDA is an effective and less invasive method as compared to the surgical ligation. There is a lower rate of complications and the cost is not much high as compared to surgical PDA ligation.

Cooperative learning in the clinical setting.

Science.gov (United States)

Newland, P L

1997-01-01

The modern clinical practice setting presents nurses with challenges about which they must think critically and develop increasingly autonomous problem-solving approaches. It is essential to provide nursing students with opportunities to practice critical thinking so that they can develop this crucial skill. Cooperative learning strategies are interactive teaching methods that stimulate students to think critically, communicate effectively with peers, and accept responsibility for learning through group process activities. Group care planning is one such cooperative strategy that also promotes a positive attitude about care planning and sharpens time management skills. Cooperative assessment and care planning foster the development of critical thinking and effective problem resolution, preparing students for patient care problems they will likely encounter in future positions.

Cooperative interaction of MUC1 with the HGF/c-Met pathway during hepatocarcinogenesis.

Science.gov (United States)

Bozkaya, Giray; Korhan, Peyda; Cokaklı, Murat; Erdal, Esra; Sağol, Ozgül; Karademir, Sedat; Korch, Christopher; Atabey, Neşe

2012-09-11

Hepatocyte growth factor (HGF) induced c-Met activation is known as the main stimulus for hepatocyte proliferation and is essential for liver development and regeneration. Activation of HGF/c-Met signaling has been correlated with aggressive phenotype and poor prognosis in hepatocellular carcinoma (HCC). MUC1 is a transmembrane mucin, whose over-expression is reported in most cancers. Many of the oncogenic effects of MUC1 are believed to occur through the interaction of MUC1 with signaling molecules. To clarify the role of MUC1 in HGF/c-Met signaling, we determined whether MUC1 and c-Met interact cooperatively and what their role(s) is in hepatocarcinogenesis. MUC1 and c-Met over-expression levels were determined in highly motile and invasive, mesenchymal-like HCC cell lines, and in serial sections of cirrhotic and HCC tissues, and these levels were compared to those in normal liver tissues. Co-expression of both c-Met and MUC1 was found to be associated with the differentiation status of HCC. We further demonstrated an interaction between c-Met and MUC1 in HCC cells. HGF-induced c-Met phosphorylation decreased this interaction, and down-regulated MUC1 expression. Inhibition of c-Met activation restored HGF-mediated MUC1 down-regulation, and decreased the migratory and invasive abilities of HCC cells via inhibition of β-catenin activation and c-Myc expression. In contrast, siRNA silencing of MUC1 increased HGF-induced c-Met activation and HGF-induced cell motility and invasion. These findings indicate that the crosstalk between MUC1 and c-Met in HCC could provide an advantage for invasion to HCC cells through the β-catenin/c-Myc pathway. Thus, MUC1 and c-Met could serve as potential therapeutic targets in HCC.

Cooperative interaction of MUC1 with the HGF/c-Met pathway during hepatocarcinogenesis

Directory of Open Access Journals (Sweden)

Bozkaya Giray

2012-09-01

Full Text Available Abstract Background Hepatocyte growth factor (HGF induced c-Met activation is known as the main stimulus for hepatocyte proliferation and is essential for liver development and regeneration. Activation of HGF/c-Met signaling has been correlated with aggressive phenotype and poor prognosis in hepatocellular carcinoma (HCC. MUC1 is a transmembrane mucin, whose over-expression is reported in most cancers. Many of the oncogenic effects of MUC1 are believed to occur through the interaction of MUC1 with signaling molecules. To clarify the role of MUC1 in HGF/c-Met signaling, we determined whether MUC1 and c-Met interact cooperatively and what their role(s is in hepatocarcinogenesis. Results MUC1 and c-Met over-expression levels were determined in highly motile and invasive, mesenchymal-like HCC cell lines, and in serial sections of cirrhotic and HCC tissues, and these levels were compared to those in normal liver tissues. Co-expression of both c-Met and MUC1 was found to be associated with the differentiation status of HCC. We further demonstrated an interaction between c-Met and MUC1 in HCC cells. HGF-induced c-Met phosphorylation decreased this interaction, and down-regulated MUC1 expression. Inhibition of c-Met activation restored HGF-mediated MUC1 down-regulation, and decreased the migratory and invasive abilities of HCC cells via inhibition of β-catenin activation and c-Myc expression. In contrast, siRNA silencing of MUC1 increased HGF-induced c-Met activation and HGF-induced cell motility and invasion. Conclusions These findings indicate that the crosstalk between MUC1 and c-Met in HCC could provide an advantage for invasion to HCC cells through the β-catenin/c-Myc pathway. Thus, MUC1 and c-Met could serve as potential therapeutic targets in HCC.

Efficacy of carvedilol versus propranolol versus variceal band ligation for primary prevention of variceal bleeding.

Science.gov (United States)

Abd ElRahim, Ayman Yosry; Fouad, Rabab; Khairy, Marwa; Elsharkawy, Aisha; Fathalah, Waleed; Khatamish, Haytham; Khorshid, Omayma; Moussa, Mona; Seyam, Moataz

2018-01-01

Band ligation and propranolol are the current therapies for primary prevention of variceal bleeding. Carvedilol is a rising nonselective beta-blocker used for reducing portal pressure with favorable outcome. The aim of this study to assess the efficacy of carvedilol, propranolol, and band ligation for primary prevention of variceal bleeding based on the effect of each regimen on progression of Child score and portal hypertensive gastropathy after 1 year. The study included 264 cirrhotic patients with medium/large-sized varices who were candidates for primary prophylaxis of variceal bleeding. Patients were randomly divided into three groups: group I: band ligation; group II: propranolol; group III: carvedilol. Group I showed higher success rate of 75 %, followed by group III with 70.2 % and group II with 65.2 %. Risk of bleeding was comparable between the three groups, with group II carrying the highest rate of complications (34.7 %) followed by group III (14.2 %) and finally group I (5.7 %). After 1 year of follow-up, Child score did not improve in any of the studied groups, while portal hypertensive gastropathy significantly increased in group I but decreased in groups II and III. Band ligation is the best treatment option for primary prevention of variceal bleeding with minimal complications. Carvedilol is a good pharmaceutical alternative medicine to propranolol with lesser side-effects. Progress of liver disease as represented by Child score is not affected by any of the primary variceal prophylactic regimens, although medical treatment reduces portal hypertensive gastropathy. Choice of treatment depends on patient will, compliance with treatment, and endoscopist competence.

Fluorogenic dansyl-ligated gold nanoparticles for the detection of sulfur mustard by displacement assay.

Science.gov (United States)

Knighton, Richard C; Sambrook, Mark R; Vincent, Jack C; Smith, Simon A; Serpell, Christopher J; Cookson, James; Vickers, Matthew S; Beer, Paul D

2013-03-21

The dansyl fluorophore ligated to gold nanoparticles via imidazole and amine groups affords conjugates capable of detecting micromolar concentrations of the chemical warfare agent sulfur mustard by a fluorescence switching 'ON' displacement assay.

Excited cooper pairs

Energy Technology Data Exchange (ETDEWEB)

Lopez-Arrietea, M. G.; Solis, M. A.; De Llano, M. [Universidad Nacional Autonoma de Mexico, Mexico, D.F (Mexico)

2001-02-01

Excited cooper pairs formed in a many-fermion system are those with nonzero total center-of mass momentum (CMM). They are normally neglected in the standard Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity for being too few compared with zero CMM pairs. However, a Bose-Einstein condensation picture requires both zero and nonzero CMM pairs. Assuming a BCS model interaction between fermions we determine the populations for all CMM values of Cooper pairs by actually calculating the number of nonzero-CMM pairs relative to that of zero-CMM ones in both 2D and 3D. Although this ratio decreases rapidly with CMM, the number of Cooper pairs for any specific CMM less than the maximum (or breakup of the pair) momentum turns out to be typically larger than about 95% of those with zero-CMM at zero temperature T. Even at T {approx}100 K this fraction en 2D is still as large as about 70% for typical quasi-2D cuprate superconductor parameters. [Spanish] Los pares de cooper excitados formados en un sistema de muchos electrones, son aquellos con momentos de centro de masa (CMM) diferente de cero. Normalmente estos no son tomados en cuenta en la teoria estandar de la superconductividad de Bardeen-Cooper-Schrieffer (BCS) al suponer que su numero es muy pequeno comparados con los pares de centro de masa igual a cero. Sin embargo, un esquema de condensacion Bose-Einstein requiere de ambos pares, con CMM cero y diferente de cero. Asumiendo una interaccion modelo BCS entre los fermiones, determinamos la poblacion de pares cooper con cada uno de todos los posibles valores del CMM calculando el numero de pares con momentos de centro de masa diferente de cero relativo a los pares de CMM igual a cero, en 2D y 3D. Aunque esta razon decrece rapidamente con el CMM, el numero de pares de cooper para cualquier CMM especifico menor que el momento maximo (o rompimiento de par) es tipicamente mas grande que el 95% de aquellos con CMM cero. Aun a T {approx}100 K esta fraccion en 2D es

Group learning versus local learning: Which is prefer for public cooperation?

Science.gov (United States)

Yang, Shi-Han; Song, Qi-Qing

2018-01-01

We study the evolution of cooperation in public goods games on various graphs, focusing on the effects that are brought by different kinds of strategy donors. This highlights a basic feature of a public good game, for which there exists a remarkable difference between the interactive players and the players who are imitated. A player can learn from all the groups where the player is a member or from the typically local nearest neighbors, and the results show that the group learning rules have better performance in promoting cooperation on many networks than the local learning rules. The heterogeneity of networks' degree may be an effective mechanism for harvesting the cooperation expectation in many cases, however, we find that heterogeneity does not definitely mean the high frequency of cooperators in a population under group learning rules. It was shown that cooperators always hardly evolve whenever the interaction and the replacement do not coincide for evolutionary pairwise dilemmas on graphs, while for PG games we find that breaking the symmetry is conducive to the survival of cooperators.

University-Company Cooperation in a Hydroelectric Plant: Cooperation Study in Environmental Management

Directory of Open Access Journals (Sweden)

Fabricio Mussi

2017-05-01

Full Text Available Hydroelectric power plants are considered strategic for the country when considering their relevance and impact on other sectors of the economy. However, the dynamics of the operation of a plant, its support structure and power generation activities can cause impacts on the environment, which must be constantly monitored in order to mitigate any environmental risks. The purpose of this study is to examine the partnership relations between a plant by menas of the creation of a department within the environmental management and universities and research institutes to identify specific partnerships in environmental management and hydroelectric plants. Six projects have been selected for analysis, four of them related to projects with universities and two related to cooperation with research institutes. The focus of the analysis was restricted to the main points observed in the management of these partnerships, which are: (a motivation for establishing partnerships, (b the composition of the estimated costs for implementing these partnerships, (c the difficulties of reconciling technical management and financial management, and (d the measurement of results and contributions from these interactions. Administrative practices of management of partnerships were also analyzed in the stages preceding cooperation for cooperation and further cooperation. Although other such studies are needed to strengthen the findings presented, one can conclude that the purposes of the establishment of cooperation in environmental management differ from those observed in other fields of knowledge such as engineering and biotechnology, for example.

How feeling betrayed affects cooperation.

Science.gov (United States)

Ramazi, Pouria; Hessel, Jop; Cao, Ming

2015-01-01

For a population of interacting self-interested agents, we study how the average cooperation level is affected by some individuals' feelings of being betrayed and guilt. We quantify these feelings as adjusted payoffs in asymmetric games, where for different emotions, the payoff matrix takes the structure of that of either a prisoner's dilemma or a snowdrift game. Then we analyze the evolution of cooperation in a well-mixed population of agents, each of whom is associated with such a payoff matrix. At each time-step, an agent is randomly chosen from the population to update her strategy based on the myopic best-response update rule. According to the simulations, decreasing the feeling of being betrayed in a portion of agents does not necessarily increase the level of cooperation in the population. However, this resistance of the population against low-betrayal-level agents is effective only up to some extend that is explicitly determined by the payoff matrices and the number of agents associated with these matrices. Two other models are also considered where the betrayal factor of an agent fluctuates as a function of the number of cooperators and defectors that she encounters. Unstable behaviors are observed for the level of cooperation in these cases; however, we show that one can tune the parameters in the function to make the whole population become cooperative or defective.

How feeling betrayed affects cooperation.

Directory of Open Access Journals (Sweden)

Pouria Ramazi

Full Text Available For a population of interacting self-interested agents, we study how the average cooperation level is affected by some individuals' feelings of being betrayed and guilt. We quantify these feelings as adjusted payoffs in asymmetric games, where for different emotions, the payoff matrix takes the structure of that of either a prisoner's dilemma or a snowdrift game. Then we analyze the evolution of cooperation in a well-mixed population of agents, each of whom is associated with such a payoff matrix. At each time-step, an agent is randomly chosen from the population to update her strategy based on the myopic best-response update rule. According to the simulations, decreasing the feeling of being betrayed in a portion of agents does not necessarily increase the level of cooperation in the population. However, this resistance of the population against low-betrayal-level agents is effective only up to some extend that is explicitly determined by the payoff matrices and the number of agents associated with these matrices. Two other models are also considered where the betrayal factor of an agent fluctuates as a function of the number of cooperators and defectors that she encounters. Unstable behaviors are observed for the level of cooperation in these cases; however, we show that one can tune the parameters in the function to make the whole population become cooperative or defective.

A new resorbable device for ligation of blood vessels - A pilot study

Directory of Open Access Journals (Sweden)

Borg Niklas

2011-07-01

Full Text Available Abstract Background During surgery, controlled haemostasis to prevent blood loss is vital for a successful outcome. It can be difficult to ligate vessels located deep in the abdomen. A device that is easy to use and enables secure ligatures could be beneficial. Cable ties made of nylon have been used for ligation but the non-resorbable material caused tissue reactions. The objective of this study was to use a resorbable material to construct a device with a self-locking mechanism and to test its mechanical strength and ligation efficiency. Methods The device was manufactured by injection moulding of polydioxanone, a resorbable polymer used for suture materials. Polydioxanone with inherent viscosities of 1.9 dL/g and 1.3 dL/g were tested. The device consisted of a perforated flexible band which could be pulled through a case with a locking mechanism. After a first version of the device had been tested, some improvements were made. The locking case was downsized, corners were rounded off, the band was made thicker and the mould was redesigned to produce longer devices. Tensile tests were performed with the second version. The first version of the device was used to ligate the ovarian pedicle in a euthanized dog and to test echogenicity of the device with ultrasound. Compression of vessels of the ovarian pedicle was examined by histology. Both versions of the device were tested for haemostasis of and tissue grip on renal arteries in six anaesthetised pigs. Results The tensile strength of the flexible band of the devices with inherent viscosity of 1.9 dL/g was 50.1 ± 5.5 N (range 35.2-62.9 N, n = 11 and the devices with inherent viscosity of 1.3 dL/g had a tensile strength of 39.8 ± 8.1 N (range 18.6-54.2 N, n = 11. Injection moulding of the polymer with lower inherent viscosity resulted in a longer flow distance. Both versions of the device had an effective tissue grip and complete haemostasis of renal arteries was verified. The device attached

The mechano-gated channel inhibitor GsMTx4 reduces the exercise pressor reflex in rats with ligated femoral arteries.

Science.gov (United States)

Copp, Steven W; Kim, Joyce S; Ruiz-Velasco, Victor; Kaufman, Marc P

2016-05-01

Mechanical and metabolic stimuli arising from contracting muscles evoke the exercise pressor reflex. This reflex is greater in a rat model of simulated peripheral arterial disease in which a femoral artery is chronically ligated than it is in rats with freely perfused femoral arteries. The role played by the mechanically sensitive component of the exaggerated exercise pressor reflex in ligated rats is unknown. We tested the hypothesis that the mechano-gated channel inhibitor GsMTx4, a relatively selective inhibitor of mechano-gated Piezo channels, reduces the exercise pressor reflex in decerebrate rats with ligated femoral arteries. Injection of 10 μg of GsMTx4 into the arterial supply of the hindlimb reduced the pressor response to Achilles tendon stretch (a purely mechanical stimulus) but had no effect on the pressor responses to intra-arterial injection of α,β-methylene ATP or lactic acid (purely metabolic stimuli). Moreover, injection of 10 μg of GsMTx4 into the arterial supply of the hindlimb reduced both the integrated pressor area (control 535 ± 21, GsMTx4 218 ± 24 mmHg·s; P reflex contributes to the exaggerated exercise pressor reflex during intermittent hindlimb muscle contractions in rats with ligated femoral arteries. Copyright © 2016 the American Physiological Society.

A study of self-consistent Hartree-Fock plus Bardeen-Cooper-Schrieffer calculations with finite-range interactions

Science.gov (United States)

Anguiano, M.; Lallena, A. M.; Co', G.; De Donno, V.

2014-02-01

In this work we test the validity of a Hartree-Fock plus Bardeen-Cooper-Schrieffer model in which a finite-range interaction is used in the two steps of the calculation by comparing the results obtained to those found in fully self-consistent Hartree-Fock-Bogoliubov calculations using the same interaction. Specifically, we consider the Gogny-type D1S and D1M forces. We study a wide range of spherical nuclei, far from the stability line, in various regions of the nuclear chart, from oxygen to tin isotopes. We calculate various quantities related to the ground state properties of these nuclei, such as binding energies, radii, charge and density distributions, and elastic electron scattering cross sections. The pairing effects are studied by direct comparison with the Hartree-Fock results. Despite its relative simplicity, in most cases, our model provides results very close to those of the Hartree-Fock-Bogoliubov calculations, and it reproduces the empirical evidence of pairing effects rather well in the nuclei investigated.

Evaluation of force released by deflection of orthodontic wires in conventional and self-ligating brackets.

Science.gov (United States)

Higa, Rodrigo Hitoshi; Semenara, Nayara Thiago; Henriques, José Fernando Castanha; Janson, Guilherme; Sathler, Renata; Fernandes, Thais Maria Freire

2016-01-01

The aim of the study was to evaluate deflection forces of rectangular orthodontic wires in conventional (MorelliTM), active (In-Ovation RTM) and passive (Damon 3MXTM) self-ligating brackets. Two brands of stainless steel and nickel-titanium (NiTi) wires (MorelliTM and GACTM), in addition to OrmcoTM copper-nickel-titanium wires were used. Specimens were assembled in a clinical simulation device especially designed for this study and tested in an Instron universal testing machine. For the testing procedures, an acrylic structure representative of the maxillary right central incisor was lingually moved in activations of 0 to 1 mm, with readings of the force released by deflection in unloading of 0.5, 0.8 and 1 mm at a constant speed of 2 mm/min. Inter-bracket forces with stainless steel, NiTi and CuNiTi were individually compared by two-way ANOVA, followed by Tukey's tests. Results showed that there were lower forces in conventional brackets, followed by active and passive self-ligating brackets. Within the brands, only for NiTi wires, the MorelliTM brand presented higher forces than GACTM wires. Bracket systems provide different degrees of deflection force, with self-ligating brackets showing the highest forces.

A multiplex ligation detection assay for the characterization of Salmonella enterica strains

DEFF Research Database (Denmark)

Aarts, Henk J.M.; Vos, Pieter; Larsson, Jonas T.

2011-01-01

A proof of principle of a multi-target assay for genotyping Salmonella has been developed targeting 62 genomic marker sequences of Salmonella related to pathogenicity. The assay is based on multiplex ligation detection reaction (LDR) followed by customized ArrayTube® microarray detection. The fea...... assessors that support bio-traceability models....

Intercellular adhesion molecule-1/LFA-1 ligation favors human Th1 development

NARCIS (Netherlands)

Smits, Hermelijn H.; de Jong, Esther C.; Schuitemaker, Joost H. N.; Geijtenbeek, Theo B. H.; van Kooyk, Yvette; Kapsenberg, Martien L.; Wierenga, Eddy A.

2002-01-01

Th cell polarization toward Th1 or Th2 cells is strongly driven by exogenous cytokines, in particular IL-12 or IL-4, if present during activation by Ag-presenting dendritic cells (DC). However, additional Th cell polarizing mechanisms are induced by the ligation of cell surface molecules on DC and

Multivalent display of proteins on viral nanoparticles using molecular recognition and chemical ligation strategies

Science.gov (United States)

Venter, P. Arno; Dirksen, Anouk; Thomas, Diane; Manchester, Marianne; Dawson, Philip E.; Schneemann, Anette

2011-01-01

Multivalent display of heterologous proteins on viral nanoparticles forms a basis for numerous applications in nanotechnology, including vaccine development, targeted therapeutic delivery and tissue-specific bio-imaging. In many instances, precise placement of proteins is required for optimal functioning of the supramolecular assemblies, but orientation- and site-specific coupling of proteins to viral scaffolds remains a significant technical challenge. We have developed two strategies that allow for controlled attachment of a variety of proteins on viral particles using covalent and noncovalent principles. In one strategy, an interaction between domain 4 of anthrax protective antigen and its receptor was used to display multiple copies of a target protein on virus-like particles. In the other, expressed protein ligation and aniline-catalyzed oximation was used to covalently display a model protein. The latter strategy, in particular, yielded nanoparticles that induced potent immune responses to the coupled protein, suggesting potential applications in vaccine development. PMID:21545187

Role of investment heterogeneity in the cooperation on spatial public goods game.

Science.gov (United States)

Yuan, Wu-Jie; Xia, Cheng-Yi

2014-01-01

Public cooperation plays a significant role in the survival and maintenance of biological species, to elucidate its origin thus becomes an interesting question from various disciplines. Through long-term development, the public goods game has proven to be a useful tool, where cooperator making contribution can beat again the free-rides. Differentiating from the traditional homogeneous investment, individual trend of making contribution is more likely affected by the investment level of his neighborhood. Based on this fact, we here investigate the impact of heterogeneous investment on public cooperation, where the investment sum is mapped to the proportion of cooperators determined by parameter α. Interestingly, we find, irrespective of interaction networks, that the increment of α (increment of heterogeneous investment) is beneficial for promoting cooperation and even guarantees the complete cooperation dominance under weak replication factor. While this promotion effect can be attributed to the formation of more robust cooperator clusters and shortening END period. Moreover, we find that this simple mechanism can change the potential interaction network, which results in the change of phase diagrams. We hope that our work may shed light on the understanding of the cooperative behavior in other social dilemmas.

Difficulty with cuff deflation of reinforced tracheal tube caused by inflation line occlusion with silk thread ligation and fixation.

Science.gov (United States)

Gotoh, Sayoko; Sugiyama, Daisuke; Imai, Eriko; Kawamata, Mikito

2015-03-05

A reinforced tracheal tube, ligated with silk threads, was inserted into a tracheostomy orifice and fixed to the skin. The cuff inflation line of the reinforced tracheal tube became occluded. Reinforced 'armoured' tracheal tubes have a spiral of wire embedded into the wall of the tube to give strength and flexibility, and may be sharply bent without compromising the tube lumen. The tracheal cuff attached to the tube is inflated by injecting air through a narrow-diameter tube welded to the outside of the tracheal tube. When a reinforced tracheal tube is ligated and fixed with silk threads, it should be confirmed whether the tracheal tube cuff can be deflated and inflated after fixation. Moreover, because occlusion can be eliminated by removing all silk threads used to ligate a tracheal tube, they should be removed before extubation. 2015 BMJ Publishing Group Ltd.

The Interplay between Scientific Overlap and Cooperation and the Resulting Gain in Co-Authorship Interactions.

Science.gov (United States)

Mayrose, Itay; Freilich, Shiri

2015-01-01

Considering the importance of scientific interactions, understanding the principles that govern fruitful scientific research is crucial to policy makers and scientists alike. The outcome of an interaction is to a large extent dependent on the balancing of contradicting motivations accompanying the establishment of collaborations. Here, we assembled a dataset of nearly 20,000 publications authored by researchers affiliated with ten top universities. Based on this data collection, we estimated the extent of different interaction types between pairwise combinations of researchers. We explored the interplay between the overlap in scientific interests and the tendency to collaborate, and associated these estimates with measures of scientific quality and social accessibility aiming at studying the typical resulting gain of different interaction patterns. Our results show that scientists tend to collaborate more often with colleagues with whom they share moderate to high levels of mutual interests and knowledge while cooperative tendency declines at higher levels of research-interest overlap, suggesting fierce competition, and at the lower levels, suggesting communication gaps. Whereas the relative number of alliances dramatically differs across a gradient of research overlap, the scientific impact of the resulting articles remains similar. When considering social accessibility, we find that though collaborations between remote researchers are relatively rare, their quality is significantly higher than studies produced by close-circle scientists. Since current collaboration patterns do not necessarily overlap with gaining optimal scientific quality, these findings should encourage scientists to reconsider current collaboration strategies.

The Interplay between Scientific Overlap and Cooperation and the Resulting Gain in Co-Authorship Interactions.

Directory of Open Access Journals (Sweden)

Itay Mayrose

Full Text Available Considering the importance of scientific interactions, understanding the principles that govern fruitful scientific research is crucial to policy makers and scientists alike. The outcome of an interaction is to a large extent dependent on the balancing of contradicting motivations accompanying the establishment of collaborations. Here, we assembled a dataset of nearly 20,000 publications authored by researchers affiliated with ten top universities. Based on this data collection, we estimated the extent of different interaction types between pairwise combinations of researchers. We explored the interplay between the overlap in scientific interests and the tendency to collaborate, and associated these estimates with measures of scientific quality and social accessibility aiming at studying the typical resulting gain of different interaction patterns. Our results show that scientists tend to collaborate more often with colleagues with whom they share moderate to high levels of mutual interests and knowledge while cooperative tendency declines at higher levels of research-interest overlap, suggesting fierce competition, and at the lower levels, suggesting communication gaps. Whereas the relative number of alliances dramatically differs across a gradient of research overlap, the scientific impact of the resulting articles remains similar. When considering social accessibility, we find that though collaborations between remote researchers are relatively rare, their quality is significantly higher than studies produced by close-circle scientists. Since current collaboration patterns do not necessarily overlap with gaining optimal scientific quality, these findings should encourage scientists to reconsider current collaboration strategies.

Photon cooperative effect in resonance spectroscopy

International Nuclear Information System (INIS)

Veklenko, B.A.

1998-01-01

A systematic method is proposed for calculating the density matrix of subsystems interacting with their environment under conditions of thermodynamic equilibrium. The density matrix of photons resonantly interacting with a surrounding gas is calculated. It is shown that use of the Gibbs distribution allows one to completely eliminate inelastic processes from the calculations. A correct account of photon-photon correlators indicates the presence of new cooperative effects. A new branch of the polariton spectrum is predicted, which is due to the presence of excited atoms in the medium. With the help of the density matrix the mean filling numbers of the photon modes are calculated. In terms of wavelengths, we have obtained a generalization of the Planck formula which accounts for photon cooperative phenomena. The manifestation of these effects in kinetic processes is discussed

PPAR-alpha agonist treatment increases trefoil factor family-3 expression and attenuates apoptosis in the liver tissue of bile duct-ligated rats.

Science.gov (United States)

Karakan, Tarkan; Kerem, Mustafa; Cindoruk, Mehmet; Engin, Doruk; Alper, Murat; Akın, Okan

2013-01-01

Peroxisome proliferators-activated receptor alpha activation modulates cholesterol metabolism and suppresses bile acid synthesis. The trefoil factor family comprises mucin-associated proteins that increase the viscosity of mucins and help protect epithelial linings from insults. We evaluated the effect of short-term administration of fenofibrate, a peroxisome proliferators activated receptor alpha agonist, on trefoil factor family-3 expression, degree of apoptosis, generation of free radicals, and levels of proinflammatory cytokines in the liver tissue of bile duct-ligated rats. Forty male Wistar rats were randomly divided into four groups: 1 = sham operated, 2 = bile duct ligation, 3 = bile duct-ligated + vehicle (gum Arabic), and 4 = bile duct-ligated + fenofibrate (100 mg/kg/day). All rats were sacrificed on the 7 th day after obtaining blood samples and liver tissue. Liver function tests, tumor necrosis factor-alpha and interleukin 1 beta in serum, and trefoil factor family-3 mRNA expression, degree of apoptosis (TUNEL) and tissue malondialdehyde (malondialdehyde, end-product of lipid peroxidation by reactive oxygen species) in liver tissue were evaluated. Fenofibrate administration significantly reduced serum total bilirubin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, and tumor necrosis factor-alpha and interleukin-1β levels. Apoptosis and malondialdehyde were significantly reduced in the fenofibrate group. Trefoil factor family-3 expression increased with fenofibrate treatment in bile duct-ligated rats. The peroxisome proliferators-activated receptor alpha agonist fenofibrate significantly increased trefoil factor family-3 expression and decreased apoptosis and lipid peroxidation in the liver and attenuated serum levels of proinflammatory cytokines in bile duct-ligated rats. Further studies are needed to determine the protective role of fenofibrate in human cholestatic disorders.

Moving away from nasty encounters enhances cooperation in ecological prisoner's dilemma game.

Directory of Open Access Journals (Sweden)

Te Wu

Full Text Available We study the role of migration in the evolution of cooperation. Individuals spatially located on a square lattice play the prisoner's dilemma game. Dissatisfied players, who have been exploited by defectors, tend to terminate interaction with selfish partners by leaving the current habitats, and explore unknown physical niches available surrounding them. The time scale ratio of game interaction to natural selection governs how many game rounds occur before individuals experience strategy updating. Under local migration and strong selection, simulation results demonstrate that cooperation can be stabilized for a wide range of model parameters, and the slower the natural selection, the more favorable for the emergence of cooperation. Besides, how the selection intensity affects cooperators' evolutionary fate is also investigated. We find that increasing it weakens cooperators' viability at different speeds for different time scale ratios. However, cooperation is greatly improved provided that individuals are offered with enough chance to agglomerate, while cooperation can always establish under weak selection but vanishes under very strong selection whenever individuals have less odds to migrate. Whenever the migration range restriction is removed, the parameter area responsible for the emergence of cooperation is, albeit somewhat compressed, still remarkable, validating the effectiveness of collectively migrating in promoting cooperation.

PDA Ligation in Adults – A 2-years Experience in Tikur Anbassa ...

African Journals Online (AJOL)

Fifty four percent of pts had PDA size 5-8mm.One patient died during reoperation . Conclusion: In developed countries , PDA is exclusively managed at infancy but in developing countries like ours, PDA may present in adults with symptoms and if there is no evidence of significant pulmonary hypertension ,PDA ligation is ...

Origins of human cooperation and morality.

Science.gov (United States)

Tomasello, Michael; Vaish, Amrisha

2013-01-01

From an evolutionary perspective, morality is a form of cooperation. Cooperation requires individuals either to suppress their own self-interest or to equate it with that of others. We review recent research on the origins of human morality, both phylogenetic (research with apes) and ontogenetic (research with children). For both time frames we propose a two-step sequence: first a second-personal morality in which individuals are sympathetic or fair to particular others, and second an agent-neutral morality in which individuals follow and enforce group-wide social norms. Human morality arose evolutionarily as a set of skills and motives for cooperating with others, and the ontogeny of these skills and motives unfolds in part naturally and in part as a result of sociocultural contexts and interactions.

Gender, trust and cooperation in environmental social dilemmas.

Science.gov (United States)

Irwin, Kyle; Edwards, Kimberly; Tamburello, Jeffrey A

2015-03-01

This research addresses gender differences in environmental protection efforts. Recent work indicates that, across a variety of domains, women are more generous, charitable, and prosocial than men. Despite above-average levels of these motivators for cooperation, considerable experimental research points to no difference in cooperation between genders. What can explain women's lower-than-expected cooperation levels? Prior research indicates that, compared to men, women are less trusting and respond to fear incentives in social dilemmas - they are concerned about being exploited. We test these arguments in the context of environmental behaviors and argue that lower trust and greater responses to fear incentives mean that women's cooperation is predicated on trust. For men, trust does not predict environmental cooperation. The current research represents the first empirical test of these arguments. Using data from the General Social Survey we focus on private sphere behaviors and political participation and predict an interaction between gender and trust on cooperation. Results support this prediction. Copyright © 2014 Elsevier Inc. All rights reserved.

Assessment of Multifactor Gene-Environment Interactions and Ovarian Cancer Risk

DEFF Research Database (Denmark)

Usset, Joseph L; Raghavan, Rama; Tyrer, Jonathan P

2016-01-01

and non-obese women. METHODS: We considered interactions between 11,441 SNPs within 80 candidate genes related to hormone biosynthesis and metabolism and insulin-like growth factors with six hormone-related factors (oral contraceptive use, parity, endometriosis, tubal ligation, hormone replacement therapy...... Future work is needed to develop powerful statistical methods able to detect these complex interactions. IMPACT: Assessment of multifactor interaction is feasible, and, here, suggests that the relationship between genetic variants within candidate genes and hormone-related risk factors may vary EOC...

Global mapping of miRNA-target interactions in cattle (Bos taurus)

DEFF Research Database (Denmark)

Scheel, Troels K H; Moore, Michael J; Luna, Joseph M

2017-01-01

With roles in development, cell proliferation and disease, micro-RNA (miRNA) biology is of great importance and a potential therapeutic target. Here we used cross-linking immunoprecipitation (CLIP) and ligation of miRNA-target chimeras on the Argonaute (AGO) protein to globally map miRNA interact...

Comparison of infrared coagulation and rubber band ligation for first and second degree haemorrhoids: a randomised prospective clinical trial.

OpenAIRE

Templeton, J L; Spence, R A; Kennedy, T L; Parks, T G; Mackenzie, G; Hanna, W A

1983-01-01

One hundred and thirty seven previously untreated out-patients with first and second degree haemorrhoids were allocated at random to treatment by infrared coagulation (n=66) or rubber band ligation (n=71). Complete follow up was obtained in 122 patients (60 who had undergone infrared coagulation (group 1), and 62 rubber band ligation (group 2)) at periods from three months to one year after completion of treatment. Infrared coagulation produced a satisfactory outcome in 51 patients (85%): 34 ...

Tubal ligation and salpingectomy and the risk of epithelial ovarian cancer and borderline ovarian tumors

DEFF Research Database (Denmark)

Madsen, C; Baandrup, Louise; Dehlendorff, Christian

2015-01-01

OBJECTIVE: According to the recent theories on the ovarian cancer origin, any protective effect of tubal ligation may vary with histologic subtype of ovarian cancer. Furthermore, bilateral salpingectomy may represent an opportunity for surgical prevention of serous ovarian cancer. DESIGN: Nationw......OBJECTIVE: According to the recent theories on the ovarian cancer origin, any protective effect of tubal ligation may vary with histologic subtype of ovarian cancer. Furthermore, bilateral salpingectomy may represent an opportunity for surgical prevention of serous ovarian cancer. DESIGN...... sampling. We required that cases and controls have no previous cancer and that controls have no previous bilateral oophorectomy. METHODS: Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals, adjusting for potential confounders. MAIN OUTCOME MEASURES: Epithelial...

A Comparing and Contrasting Analysis of Cooperation and Politeness

Institute of Scientific and Technical Information of China (English)

杨菁; 黄大鹏

2014-01-01

<正>Language is the basic tool of communication between human beings and the society.In communication or social interaction,people should follow some principles such as Cooperation and Politeness,in order to achieve the goal of successful communication.As two of the communicative principles,Cooperation and Politeness have been widely accepted by people,especially

Bilateral tubal ligation in a rural hospital in the Niger Delta, Nigeria ...

African Journals Online (AJOL)

Background and Objective: To document bilateral tubal ligation (BTL) rate and highlight the need to improve on the rates. Materials and Methods: A retrospective review of BTLs done in a five-year period from January 2000 to December 2004 constituted the study group. Results: There were a total of 103 BTLs, 58 were ...

Effects of CD44 Ligation on Signaling and Metabolic Pathways in Acute Myeloid Leukemia

KAUST Repository

Madhoun, Nour Y.

2017-01-01

Acute myeloid leukemia (AML) is characterized by a blockage in the differentiation of myeloid cells at different stages. CD44-ligation using anti-CD44 monoclonal antibodies (mAbs) has been shown to reverse the blockage of differentiation

Evaluation of the Friction of Self-Ligating and Conventional Bracket Systems

Science.gov (United States)

Tecco, Simona; Di Iorio, Donato; Nucera, Riccardo; Di Bisceglie, Beatrice; Cordasco, Giancarlo; Festa, Felice

2011-01-01

Objectives: This in vitro study evaluated the friction (F) generated by aligned stainless steel (SS) conventional brackets, self-ligating Damon MX© brackets (SDS Ormco, Glendora, California, USA), Time3© brackets (American Orthodontics, Sheboygan, Wisconsin, USA), Vision LP© brackets (American Orthodontics), and low-friction Slide© ligatures (Leone, Firenze, Italy) coupled with various SS, nickel-titanium (NiTi), and beta-titanium (TMA) archwires. Methods: All brackets had a 0.022-inch slot, and the orthodontic archwires were 0.014-inch, 0.016-inch, 0.014×0.025-inch, 0.018×0.025-inch, and 0.019×0.025-inch NiTi; 0.017×0.025-inch TMA; and 0.019×0.025-inch SS. Each bracket-archwire combination was tested 10 times. In the test, 10 brackets of the same group were mounted in alignment on a metal bar. The archwires moved through all the 10 brackets at a crosshead speed of 0.5 mm/min (each run lasted approximately 5 min). The differences among 5 groups of brackets were analyzed through the Kruskal-Wallis test, and a Mann-Whitney test was calculated as post hoc analysis. The P value was set at 0.05. Results: Coupled with 0.014-inch NiTi and 0.016-inch NiTi, Victory Series© brackets generated the greatest F, while Damon MX© and Vision LP© brackets generated the lowest (Pbrackets and Slide© ligatures. Coupled with all the rectangular archwires, Victory Series© brackets, Slide© ligatures, and Vision LP© self-ligating brackets generated significantly lower F than did Time3© and Damon MX© self-ligating brackets (Pbrackets are a family of brackets that, in vitro, can generate different levels of F when coupled with thin or thick, rectangular, or round archwires. Clinical conclusions based on our results are not possible due to the limitations of the experimental conditions. PMID:21769273

Characterization of the Endothelial Cell Cytoskeleton following HLA Class I Ligation

Science.gov (United States)

Ziegler, Mary E.; Souda, Puneet; Jin, Yi-Ping; Whitelegge, Julian P.; Reed, Elaine F.

2012-01-01

Background Vascular endothelial cells (ECs) are a target of antibody-mediated allograft rejection. In vitro, when the HLA class I molecules on the surface of ECs are ligated by anti-HLA class I antibodies, cell proliferation and survival pathways are activated and this is thought to contribute to the development of antibody-mediated rejection. Crosslinking of HLA class I molecules by anti-HLA antibodies also triggers reorganization of the cytoskeleton, which induces the formation of F-actin stress fibers. HLA class I induced stress fiber formation is not well understood. Methodology and Principal Findings The present study examines the protein composition of the cytoskeleton fraction of ECs treated with HLA class I antibodies and compares it to other agonists known to induce alterations of the cytoskeleton in endothelial cells. Analysis by tandem mass spectrometry revealed unique cytoskeleton proteomes for each treatment group. Using annotation tools a candidate list was created that revealed 12 proteins, which were unique to the HLA class I stimulated group. Eleven of the candidate proteins were phosphoproteins and exploration of their predicted kinases provided clues as to how these proteins may contribute to the understanding of HLA class I induced antibody-mediated rejection. Three of the candidates, eukaryotic initiation factor 4A1 (eIF4A1), Tropomyosin alpha 4-chain (TPM4) and DDX3X, were further characterized by Western blot and found to be associated with the cytoskeleton. Confocal microscopy analysis showed that class I ligation stimulated increased eIF4A1 co-localization with F-actin and paxillin. Conclusions/Significance Colocalization of eIF4A1 with F-actin and paxillin following HLA class I ligation suggests that this candidate protein could be a target for understanding the mechanism(s) of class I mediated antibody-mediated rejection. This proteomic approach for analyzing the cytoskeleton of ECs can be applied to other agonists and various cells types

Banding ligation versus beta-blockers for primary prevention in oesophageal varices in adults

DEFF Research Database (Denmark)

Gluud, Lise Lotte; Krag, Aleksander

2012-01-01

Non-selective beta-blockers are used as a first-line treatment for primary prevention in patients with medium- to high-risk oesophageal varices. The effect of non-selective beta-blockers on mortality is debated and many patients experience adverse events. Trials on banding ligation versus non...

ANESTHESIA MANAGEMENT OF 775 GRAMS PREMATURE PATIENT DURING PDA LIGATION-A CASE REPORT

Directory of Open Access Journals (Sweden)

Gulsen KESKiN

2016-03-01

We believe that VLBW preterm infants by having multiple system failure may have PDA ligation in operating room if there is no optimum conditions in ICU by obtaining safe transport, performing ketamine in anesthesia induction and maintenance. [J Contemp Med 2016; 6(1.000: 47-50

Social penalty promotes cooperation in a cooperative society.

Science.gov (United States)

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.

Cooperation and deception in primates.

Science.gov (United States)

Hall, Katie; Brosnan, Sarah F

2017-08-01

Though competition and cooperation are often considered opposing forces in an arms race driving natural selection, many animals, including humans, cooperate in order to mitigate competition with others. Understanding others' psychological states, such as seeing and knowing, others' goals and intentions, and coordinating actions are all important for complex cooperation-as well as for predicting behavior in order to take advantage of others through tactical deception, a form of competition. We outline evidence of primates' understanding of how others perceive the world, and then consider how the evidence from both deception and cooperation fits this framework to give us a more complete understanding of the evolution of complex social cognition in primates. In experimental food competitions, primates flexibly manipulate group-mates' behavior to tactically deceive them. Deception can infiltrate cooperative interactions, such as when one takes an unfair share of meat after a coordinated hunt. In order to counter competition of this sort, primates maintain cooperation through partner choice, partner control, and third party punishment. Yet humans appear to stand alone in their ability to understand others' beliefs, which allows us not only to deceive others with the explicit intent to create a false belief, but it also allows us to put ourselves in others' shoes to determine when cheaters need to be punished, even if we are not directly disadvantaged by the cheater. Copyright © 2016 Elsevier Inc. All rights reserved.

Implications of molecular heterogeneity for the cooperativity of biological macromolecules.

Science.gov (United States)

Solomatin, Sergey V; Greenfeld, Max; Herschlag, Daniel

2011-06-01

Cooperativity, a universal property of biological macromolecules, is typically characterized by a Hill slope, which can provide fundamental information about binding sites and interactions. We demonstrate, through simulations and single-molecule FRET (smFRET) experiments, that molecular heterogeneity lowers bulk cooperativity from the intrinsic value for the individual molecules. As heterogeneity is common in smFRET experiments, appreciation of its influence on fundamental measures of cooperativity is critical for deriving accurate molecular models.

Evolution of cooperation among game players with non-uniform migration scopes

International Nuclear Information System (INIS)

Zhang, Chunyan; Zhang, Jianlei; Xie, Guangming

2014-01-01

In social dilemmas, cooperation among randomly interacting individuals is often hard to achieve. The situation changes if migration takes place, where game structure jointly evolves with the migration from adverse neighborhoods. Here we introduce a framework combining migration with the individual heterogeneity of migration scopes. When faced with a gloomy outlook, some players prefer vacant sites within their adjacent neighborhoods, while others may migrate within the whole network, provided the sites are empty. Thus, we can make a thorough inquiry of the sustainability of cooperation in a spatially distributed population divided by these two groups, and all possible mixtures between them. Our main result is that small-scope migration and suitable population density can gear up high cooperation levels in the midst of dense populations structured by scale-free networks, while large-scope migration and sparsity favor the cooperator clustering among lattice-structured populations. In this sense, the conditions for the emergence of cooperation are prevailingly created by the spatial reciprocity, and migration also has enough potential to help cooperation to prevail in suitable combination of game parameters in dynamics (e.g., population density, the type of interaction structure and also the migration scope)

Effect of saccharin on metabolic cooperation between human fibroblasts

International Nuclear Information System (INIS)

Mosser, D.D.; Bols, N.C.

1983-01-01

Autoradiography was used to study the effect of saccharin on metabolic cooperation between human diploid fibroblasts. When the donors, HGPRT+ cells, and recipients, HGPRT- cells, were plated together in the presence of saccharin, all the interactions that developed in 4 and 24 h were positive for metabolic cooperation. When saccharin was added after donor cells and recipient cells had made contact, the proportion of interactions that were positive for metabolic cooperation was unchanged but the number of grains over primary recipients was reduced. However, in donor cells saccharin caused a reduction in [ 3 H]hypoxanthine incorporation into both acid-soluble and acid-insoluble fractions, although the relative distribution of radioactivity between these two fractions and between the phosphorylated and non-phosphorylated derivatives of [ 3 H]hypoxanthine was unchanged. Metabolic cooperation was studied under conditions in which the number of grains over the nuclei of both the primary recipient and the primary recipient's donor could be counted. The change in the number of grains over these two cell types in response to saccharin was compared and found to be the same. Thus in normal human fibroblasts saccharin does not appear to affect metabolic cooperation, which is a measure of cell-to-cell communication

Biphasic activation of liver regeneration-associated signals in an early stage after portal vein branch ligation

International Nuclear Information System (INIS)

Yokoyama, Shinya; Yokoyama, Yukihiro; Kawai, Toru; Kobayashi, Satoshi; Nagino, Masato; Oda, Koji; Nimura, Yuji; Sokabe, Masahiro

2006-01-01

At an early stage in liver regeneration, a variety of factors including transcriptional factors, proinflammatory cytokines, and proto-oncogenes are activated or expressed. However, these responses are affected by surgical stress in the conventional portal vein branch ligation model (PVL). We sought to determine the net activation of early regeneration-associated signals after PVL using a newly developed non-surgical stress PVL model. Male Wistar rats were assigned into two groups, a stress-PVL (sPVL) model with laparotomy and portal vein branch ligation, and a non-stress-PVL (nsPVL) one subjected to portal vein branch ligation 1 week after laparotomy in which the effects of surgical stress were subsided. The activation of transcriptional factors and expression of immediate early genes were analyzed at an early time point (within 24 h) by Western blotting and RT-PCR, respectively. A monophasic upregulation of nuclear factor-κB (NF-κB) and phosphorylated-signal transducer and activator of transcription 3 (p-STAT3) peaked at 3 h after sPVL was observed. In contrast, the expression pattern of these factors was biphasic (first peak at 0.5-1 h, second peak at 3-6 h) in nsPVL group. The expression pattern of immediate early genes showed a similar trend between sPVL and nsPVL. cDNA array analysis for the non-ligated lobe at 2 h after PVL revealed a much higher gene activation in sPVL than in nsPVL. These results indicate that previously observed activation pattern of regeneration-associated signals after PVL is significantly affected by the effect of laparotomy and our results using nsPVL model may more accurately represent liver regeneration-associated signal pattern

How getting noticed helps getting on: successful attention capture doubles children's cooperative play

Science.gov (United States)

Yuill, Nicola; Hinske, Steve; Williams, Sophie E.; Leith, Georgia

2014-01-01

Cooperative social interaction is a complex skill that involves maintaining shared attention and continually negotiating a common frame of reference. Privileged in human evolution, cooperation provides support for the development of social-cognitive skills. We hypothesize that providing audio support for capturing playmates' attention will increase cooperative play in groups of young children. Attention capture was manipulated via an audio-augmented toy to boost children's attention bids. Study 1 (48 6- to 11-year-olds) showed that the augmented toy yielded significantly more cooperative play in triads compared to the same toy without augmentation. In Study 2 (33 7- to 9-year-olds) the augmented toy supported greater success of attention bids, which were associated with longer cooperative play, associated in turn with better group narratives. The results show how cooperation requires moment-by-moment coordination of attention and how we can manipulate environments to reveal and support mechanisms of social interaction. Our findings have implications for understanding the role of joint attention in the development of cooperative action and shared understanding. PMID:24904453

Competitive Centipede Games: Zero-End Payoffs and Payoff Inequality Deter Reciprocal Cooperation

Directory of Open Access Journals (Sweden)

Eva M. Krockow

2015-08-01

Full Text Available Reciprocal cooperation can be studied in the Centipede game, in which two players alternate in choosing between a cooperative GO move and a non-cooperative STOP move. GO sustains the interaction and increases the player pair’s total payoff while incurring a small personal cost; STOP terminates the interaction with a favorable payoff to the defector. We investigated cooperation in four Centipede games differing in their payoffs at the game’s end (positive versus zero and payoff difference between players (moderate versus high difference. The games shared the same game-theoretic solution, therefore they should have elicited identical decision patterns, according to orthodox game theory. Nevertheless, both zero-end payoffs and high payoff inequality were found to reduce cooperation significantly. Contrary to previous predictions, combining these two factors in one game resulted in a slight weakening of their independent deterrent effects. These findings show that small changes in the payoff function have large and significant effects on cooperation, and that the effects do not combine synergistically.

Evaluation of cerebral electrical activity and cardiac output after patent ductus arteriosus ligation in preterm infants.

LENUS (Irish Health Repository)

Leslie, A T F S

2013-11-01

To characterize and investigate the relationship between systemic blood flow and pre- and postoperative cerebral electrical activity in preterm neonates undergoing patent ductus arteriosus (PDA) ligation.

Education Program for Doctoral Researchers by Industrial-Government-Academic Cooperation and Interaction between Different Research Fields

Science.gov (United States)

Oki, Kazuya; Sawaragi, Tetsuo; Hasebe, Shinji; Morisawa, Shinsuke

New education program to train graduate students and postdoctoral researchers who can be good leaders in a variety of social fields by cooperation of graduate school of engineering and pharmaceutical sciences is conducted as an advanced activity in Kyoto University. This program consists of four sub-programs and the educational effect by the collaboration of industry-government-academic and the interaction between dissimilar research fields is described in this paper. Trainees in this program acquire the ability to understand objectively one’ s research from comprehensive point of view and to debate with researchers in different fields. This program supports them to become ‘Global Leaders’ who play an important role internationally in advanced technology.

Three-state combinatorial switch models as applied to the binding of oxygen by human hemoglobin.

Science.gov (United States)

Straume, M; Johnson, M L

1988-02-23

We have generated a series of all 6561 unique, discrete three-state combinatorial switch models to describe the partitioning of the cooperative oxygen-binding free change among the 10 variously ligated forms of human hemoglobin tetramers. These models were inspired by the experimental observation of Smith and Ackers that the cooperative free energy of the intersubunit contact regions of the 10 possible ligated forms of human hemoglobin tetramers can be represented by a particular distribution of three distinct energy levels [Smith, F. R., & Ackers, G. K. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 5347-5351]. A statistical thermodynamic formulation accounting for both dimer-tetramer equilibria and ligand binding properties of hemoglobin solutions as a function of oxygen and protein concentrations was utilized to exhaustively test these thermodynamic models. In this series of models each of the 10 ligated forms of the hemoglobin tetramer can exist in one, and only one, of three possible energy levels; i.e., each ligated form was assumed to be associated with a discrete energy state. This series of models includes all possible ways that the 10 ligation states of hemoglobin can be distributed into three distinct cooperative energy levels. The mathematical models, as presented here, do not permit equilibria between energy states to exist for any of the 10 unique ligated forms of hemoglobin tetramers. These models were analyzed by nonlinear least-squares estimation of the free energy parameters characteristic of this statistical thermodynamic development.(ABSTRACT TRUNCATED AT 250 WORDS)

World modeling for cooperative intelligent vehicles

NARCIS (Netherlands)

Papp, Z.; Brown, C.; Bartels, C.

2008-01-01

Cooperative intelligent vehicle systems constitute a promising way to improving traffic throughput, safety and comfort. The state-of-the-art intelligent-vehicle applications usually can be described as a collection of interacting, highly autonomous, complex dynamical systems (the individual

Evaluation of stiffness and plastic deformation of active ceramic self-ligating bracket clips after repetitive opening and closure movements.

Science.gov (United States)

Carneiro, Grace Kelly Martins; Roque, Juliano Alves; Segundo, Aguinaldo Silva Garcez; Suzuki, Hideo

2015-01-01

The aim of this study was to assess whether repetitive opening and closure of self-ligating bracket clips can cause plastic deformation of the clip. Three types of active/interactive ceramic self-ligating brackets (n = 20) were tested: In-Ovation C, Quicklear and WOW. A standardized controlled device performed 500 cycles of opening and closure movements of the bracket clip with proper instruments and techniques adapted as recommended by the manufacturer of each bracket type. Two tensile tests, one before and one after the repetitive cycles, were performed to assess the stiffness of the clips. To this end, a custom-made stainless steel 0.40 x 0.40 mm wire was inserted into the bracket slot and adapted to the universal testing machine (EMIC DL2000), after which measurements were recorded. On the loading portion of the loading-unloading curve of clips, the slope fitted a first-degree equation curve to determine the stiffness/deflection rate of the clip. The results of plastic deformation showed no significant difference among bracket types before and after the 500 cycles of opening and closure (p = 0.811). There were significant differences on stiffness among the three types of brackets (p = 0.005). The WOW bracket had higher mean values, whereas Quicklear bracket had lower values, regardless of the opening/closure cycle. Repetitive controlled opening and closure movements of the clip did not alter stiffness or cause plastic deformation.

Evaluation of stiffness and plastic deformation of active ceramic self-ligating bracket clips after repetitive opening and closure movements

Directory of Open Access Journals (Sweden)

Grace Kelly Martins Carneiro

2015-08-01

Full Text Available OBJECTIVE: The aim of this study was to assess whether repetitive opening and closure of self-ligating bracket clips can cause plastic deformation of the clip.METHODS: Three types of active/interactive ceramic self-ligating brackets (n = 20 were tested: In-Ovation C, Quicklear and WOW. A standardized controlled device performed 500 cycles of opening and closure movements of the bracket clip with proper instruments and techniques adapted as recommended by the manufacturer of each bracket type. Two tensile tests, one before and one after the repetitive cycles, were performed to assess the stiffness of the clips. To this end, a custom-made stainless steel 0.40 x 0.40 mm wire was inserted into the bracket slot and adapted to the universal testing machine (EMIC DL2000, after which measurements were recorded. On the loading portion of the loading-unloading curve of clips, the slope fitted a first-degree equation curve to determine the stiffness/deflection rate of the clip.RESULTS: The results of plastic deformation showed no significant difference among bracket types before and after the 500 cycles of opening and closure (p = 0.811. There were significant differences on stiffness among the three types of brackets (p = 0.005. The WOW bracket had higher mean values, whereas Quicklear bracket had lower values, regardless of the opening/closure cycle.CONCLUSION: Repetitive controlled opening and closure movements of the clip did not alter stiffness or cause plastic deformation.

Evolutionary dynamics of cooperation in neutral populations

Science.gov (United States)

Szolnoki, Attila; Perc, Matjaž

2018-01-01

Cooperation is a difficult proposition in the face of Darwinian selection. Those that defect have an evolutionary advantage over cooperators who should therefore die out. However, spatial structure enables cooperators to survive through the formation of homogeneous clusters, which is the hallmark of network reciprocity. Here we go beyond this traditional setup and study the spatiotemporal dynamics of cooperation in a population of populations. We use the prisoner's dilemma game as the mathematical model and show that considering several populations simultaneously gives rise to fascinating spatiotemporal dynamics and pattern formation. Even the simplest assumption that strategies between different populations are payoff-neutral with one another results in the spontaneous emergence of cyclic dominance, where defectors of one population become prey of cooperators in the other population, and vice versa. Moreover, if social interactions within different populations are characterized by significantly different temptations to defect, we observe that defectors in the population with the largest temptation counterintuitively vanish the fastest, while cooperators that hang on eventually take over the whole available space. Our results reveal that considering the simultaneous presence of different populations significantly expands the complexity of evolutionary dynamics in structured populations, and it allows us to understand the stability of cooperation under adverse conditions that could never be bridged by network reciprocity alone.

Competitive-cum-cooperative interfirm relations and dynamics in the Japanese semiconductor industry

CERN Document Server

Okada, Yoshitaka

2000-01-01

Japanese semiconductor firms are well known for obtaining dynamics in a short period of time and achieving even global leadership. A significant portion of their success are attributable to cooperative interfirm relations and the development of intermediate organizational structure based on long-term relationship between firms. The purpose of this book is to explain how interfirm relations contributed to their dynamics during the golden age of the semiconductor industry. Meanwhile this book clarifies the real source of dynamics in interfirm relations and how the firms have interacted. The author concludes that the competitive-cum-cooperative (CCC) interfirm interaction are observed. Quantitative and qualitative findings show that firms enjoy not only flexible cooperation based synergy effects, but also dynamics market-like effects by creating competition among partners through CCC interaction.

A simple model of bipartite cooperation for ecological and organizational networks.

Science.gov (United States)

Saavedra, Serguei; Reed-Tsochas, Felix; Uzzi, Brian

2009-01-22

In theoretical ecology, simple stochastic models that satisfy two basic conditions about the distribution of niche values and feeding ranges have proved successful in reproducing the overall structural properties of real food webs, using species richness and connectance as the only input parameters. Recently, more detailed models have incorporated higher levels of constraint in order to reproduce the actual links observed in real food webs. Here, building on previous stochastic models of consumer-resource interactions between species, we propose a highly parsimonious model that can reproduce the overall bipartite structure of cooperative partner-partner interactions, as exemplified by plant-animal mutualistic networks. Our stochastic model of bipartite cooperation uses simple specialization and interaction rules, and only requires three empirical input parameters. We test the bipartite cooperation model on ten large pollination data sets that have been compiled in the literature, and find that it successfully replicates the degree distribution, nestedness and modularity of the empirical networks. These properties are regarded as key to understanding cooperation in mutualistic networks. We also apply our model to an extensive data set of two classes of company engaged in joint production in the garment industry. Using the same metrics, we find that the network of manufacturer-contractor interactions exhibits similar structural patterns to plant-animal pollination networks. This surprising correspondence between ecological and organizational networks suggests that the simple rules of cooperation that generate bipartite networks may be generic, and could prove relevant in many different domains, ranging from biological systems to human society.

Synthetic study on prion protein fragments using a SPPS and native chemical ligation

Czech Academy of Sciences Publication Activity Database

Zawada, Z.; Šebestík, Jaroslav; Bednárová, Lucie; Bouř, Petr; Hlaváček, Jan; Stibor, Ivan

2009-01-01

Roč. 37, Suppl. 1 (2009), s. 44-44 ISSN 0939-4451. [International Congress on Amino Acids, Peptides and Proteins /11./. 03.08.2009-07.08.2009, Vienna] Institutional research plan: CEZ:AV0Z40550506 Keywords : prion protein * SPPS * native chemical ligation * fragments Subject RIV: CC - Organic Chemistry

Treatment of grade 2 and 3 hemorrhoids with Doppler-guided hemorrhoidal artery ligation

NARCIS (Netherlands)

Wallis de Vries, B. M.; van der Beek, E. S. J.; de Wijkerslooth, L. R. H.; van der Zwet, W. C.; van der Hoeven, J. A. B.; Eeftinck Schattenkerk, M.; Eddes, E. H.

2007-01-01

We evaluated the results of the Doppler-guided hemorrhoidal arterial ligation (DG-HAL) method in the management of symptomatic grade 2 and 3 hemorrhoids. Between June 2005 and March 2006, 110 consecutive patients with symptomatic grade 2 and 3 hemorrhoids according to the DG-HAL method were treated.

Environmental influences on cooperation in social dilemmas on networks

Science.gov (United States)

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.