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Sample records for homologs tie social

  1. Social Ties for Labor Market Access

    DEFF Research Database (Denmark)

    Dorner, Matthias; Harhoff, Dietmar; Hinz, Tina;

    in the German labor market after reunification. Modeling inventor migration to West German regions after 1990, we find that Western regions with stronger historically determined social ties across the former East-West border attracted more inventors after the fall of the Iron Curtain than regions without...... such ties. However, mobility decisions made by inventors with outstanding patenting track records (star inventors) were not impacted by social ties. We conclude that social ties support labor market access for migrant inventors and determine regional choices while dependence on these ties is substantially...

  2. Analyzing negative ties in social networks

    Directory of Open Access Journals (Sweden)

    Mankirat Kaur

    2016-03-01

    Full Text Available Online social networks are a source of sharing information and maintaining personal contacts with other people through social interactions and thus forming virtual communities online. Social networks are crowded with positive and negative relations. Positive relations are formed by support, endorsement and friendship and thus, create a network of well-connected users whereas negative relations are a result of opposition, distrust and avoidance creating disconnected networks. Due to increase in illegal activities such as masquerading, conspiring and creating fake profiles on online social networks, exploring and analyzing these negative activities becomes the need of hour. Usually negative ties are treated in same way as positive ties in many theories such as balance theory and blockmodeling analysis. But the standard concepts of social network analysis do not yield same results in respect of each tie. This paper presents a survey on analyzing negative ties in social networks through various types of network analysis techniques that are used for examining ties such as status, centrality and power measures. Due to the difference in characteristics of flow in positive and negative tie networks some of these measures are not applicable on negative ties. This paper also discusses new methods that have been developed specifically for analyzing negative ties such as negative degree, and h∗ measure along with the measures based on mixture of positive and negative ties. The different types of social network analysis approaches have been reviewed and compared to determine the best approach that can appropriately identify the negative ties in online networks. It has been analyzed that only few measures such as Degree and PN centrality are applicable for identifying outsiders in network. For applicability in online networks, the performance of PN measure needs to be verified and further, new measures should be developed based upon negative clique concept.

  3. Coupling Human Mobility and Social Ties

    CERN Document Server

    Toole, Jameson L; Schneider, Christian M; Gonzalez, Marta C

    2015-01-01

    Studies using massive, passively data collected from communication technologies have revealed many ubiquitous aspects of social networks, helping us understand and model social media, information diffusion, and organizational dynamics. More recently, these data have come tagged with geographic information, enabling studies of human mobility patterns and the science of cities. We combine these two pursuits and uncover reproducible mobility patterns amongst social contacts. First, we introduce measures of mobility similarity and predictability and measure them for populations of users in three large urban areas. We find individuals' visitations patterns are far more similar to and predictable by social contacts than strangers and that these measures are positively correlated with tie strength. Unsupervised clustering of hourly variations in mobility similarity identifies three categories of social ties and suggests geography is an important feature to contextualize social relationships. We find that the composi...

  4. On the Nature, Modeling, and Neural Bases of Social Ties

    NARCIS (Netherlands)

    F.A.A.M. Winden, van (Frans); M. Stallen (Mirre); K.R. Ridderinkhof (Richard)

    2008-01-01

    textabstractThis paper addresses the nature, formalization, and neural bases of (affective) social ties and discusses the relevance of ties for health economics. A social tie is defined as an affective weight attached by an individual to the well-being of another individual (‘utility interdependence

  5. Employees and Creativity: Social Ties and Access to Heterogeneous Knowledge

    Science.gov (United States)

    Huang, Chiung-En; Liu, Chih-Hsing Sam

    2015-01-01

    This study dealt with employee social ties, knowledge heterogeneity contacts, and the generation of creativity. Although prior studies demonstrated a relationship between network position and creativity, inadequate attention has been paid to network ties and heterogeneity knowledge contacts. This study considered the social interaction processes…

  6. Employees and Creativity: Social Ties and Access to Heterogeneous Knowledge

    Science.gov (United States)

    Huang, Chiung-En; Liu, Chih-Hsing Sam

    2015-01-01

    This study dealt with employee social ties, knowledge heterogeneity contacts, and the generation of creativity. Although prior studies demonstrated a relationship between network position and creativity, inadequate attention has been paid to network ties and heterogeneity knowledge contacts. This study considered the social interaction processes…

  7. Social Ties and Emotions: Evidence from Social Media

    CERN Document Server

    Lerman, Kristina; Gallegos, Luciano; Kumaraguru, Ponnurangam; Garcia, David

    2015-01-01

    The social connections, or ties, individuals create affect their life outcomes, for example, by providing novel information that leads to new jobs or career opportunities. A host of socioeconomic and cognitive factors are believed to affect social interactions, but few of these factors have been empirically validated. In this research work, we extracted a large corpus of data from a popular social media platform that consists of geo-referenced messages, or tweets, posted from a major US metropolitan area. We linked these tweets to US Census data through their locations. This allowed us to measure emotions expressed in tweets posted from a specific area, and also use that area's socioeconomic and demographic characteristics in the analysis. We extracted the structure of social interactions from the people mentioned in tweets from that area. We find that at an aggregate level, areas where social media users engage in stronger, less diverse online social interactions are those where they express more negative em...

  8. Attention on Weak Ties in Social and Communication Networks

    CERN Document Server

    Weng, Lilian; Perra, Nicola; Menczer, Filippo; Flammini, Alessandro

    2015-01-01

    Granovetter's weak tie theory of social networks is built around two central hypotheses. The first states that strong social ties carry the large majority of interaction events; the second maintains that weak social ties, although less active, are often relevant for the exchange of especially important information (e.g., about potential new jobs in Granovetter's work). While several empirical studies have provided support for the first hypothesis, the second has been the object of far less scrutiny. A possible reason is that it involves notions relative to the nature and importance of the information that are hard to quantify and measure, especially in large scale studies. Here, we search for empirical validation of both Granovetter's hypotheses. We find clear empirical support for the first. We also provide empirical evidence and a quantitative interpretation for the second. We show that attention, measured as the fraction of interactions devoted to a particular social connection, is high on weak ties --- po...

  9. Grand Performances: Building Self and Social Ties through Theatrical Performance

    Directory of Open Access Journals (Sweden)

    Stephanie May de Montigny

    2015-05-01

    Full Text Available The stories that individuals tell about their experiences on stage and behind-the-scenes at the Grand Opera House of Oshkosh, Wisconsin, contribute to their knowledge of self and social ties.

  10. Leaving Libertarianism: : Social Ties in Robert Nozick's New Philosophy

    OpenAIRE

    Herbjørnsrud, Dag

    2002-01-01

    SUMMARY This thesis Leaving Libertarianism: Social Ties in Robert Nozick s New Philosophy challenges the general and most widespread portrayals of the American philosopher Robert Nozick (1938-2002) by studying the notion of social ties in his later philosophy. The point of departure is the present descriptions of Nozick s philosophy. Mostly these depictions are based upon three postulates: That Nozick is an extreme individualist, that the libertarian Anarchy, State, and Utopia (1...

  11. Social ties and risk for cancer - a prospective cohort study

    DEFF Research Database (Denmark)

    Bergelt, C.; Prescott, E.; Gronbaek, M.

    2009-01-01

    Background. Poor social support and small social networks have been associated with increased risks for conditions such as coronary heart disease as well as with overall mortality. We investigated the association between social ties and risk for cancer. Material and methods. The study sample cons...

  12. Using social ties in group recommendation

    OpenAIRE

    Bourke, Steven; McCarthy, Kevin; Smyth, Barry

    2011-01-01

    The social web is a mass of activity, petabytes of data are generated yearly. The social web has proven to be a great resource for new recommender system techniques and ideas. However it would appear that typically these techniques are not so social, as they only generate recommendations for a user acting alone. In this paper we take the social graph data and preference content (via Facebook) of 94 user study participants and generate social group recommendations for them and their friends. W...

  13. Social support and social interaction ties on internet addiction: integrating online and offline contexts.

    Science.gov (United States)

    Wang, Edward Shih-Tse; Wang, Michael Chih-Hung

    2013-11-01

    This study explores the relationship between social support and social interaction ties on Internet addiction by integrating both online and offline social encounters. A total of 1,642 members of online social communities participated in this research, for which structural equation modeling was used for analysis. The findings show that social support is positively associated with social interaction ties in both online and offline contexts. In addition, online social support and online social interaction ties are positively associated with Internet addiction, whereas offline social support and social interaction ties on Internet addiction are negatively associated. This finding has important implications not only for understanding the cause of Internet addiction but also for understanding the diminishing Internet addiction due to social support and social interaction ties.

  14. Analyzing negative ties in social networks

    OpenAIRE

    Mankirat Kaur; Sarbjeet Singh

    2016-01-01

    Online social networks are a source of sharing information and maintaining personal contacts with other people through social interactions and thus forming virtual communities online. Social networks are crowded with positive and negative relations. Positive relations are formed by support, endorsement and friendship and thus, create a network of well-connected users whereas negative relations are a result of opposition, distrust and avoidance creating disconnected networks. Due to increase i...

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

    DEFF Research Database (Denmark)

    Huck, Steffen; Tyran, Jean-Robert

    2007-01-01

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

  16. Burstiness and tie reinforcement in time varying social networks

    CERN Document Server

    Ubaldi, Enrico; Karsai, Marton; Perra, Nicola; Burioni, Raffaella

    2016-01-01

    We introduce a time-varying network model accounting for burstiness and tie reinforcement observed in social networks. The analytical solution indicates a non-trivial phase diagram determined by the competition of the leading terms of the two processes. We test our results against numerical simulations, and compare the analytical predictions with an empirical dataset finding good agreements between them. The presented framework can be used to classify the dynamical features of real social networks and to gather new insights about the effects of social dynamics on ongoing spreading processes.

  17. Social ties and short-term self-reported delinquent behaviour of personality disordered forensic outpatients

    NARCIS (Netherlands)

    Y.H.A. Bouman; C. de Ruiter; A.H. Schene

    2010-01-01

    Purpose. In community-based forensic psychiatry, patients' social ties are considered as protective factor in a risk management strategy. However, it is unknown whether these ties actually assist patients to refrain from re-offending. We hypothesised a protective role for social ties in re-offending

  18. Social network ties beyond nonredundancy: an experimental investigation of the effect of knowledge content and tie strength on creativity.

    Science.gov (United States)

    Perry-Smith, Jill E

    2014-09-01

    Social network research emphasizes the access to nonredundant knowledge content that network ties provide. I suggest that some content is more beneficial than others and that tie strength may affect creativity for reasons other than the associated structure. That is, tie strength may affect how individuals process nonredundant knowledge. I investigate 2 types of knowledge content--information (i.e., facts or data) and frames (i.e., interpretations or impressions)--and explore whether tie strength influences their effect on creativity. Drawing on creativity theory, I employ an experimental design to provide greater theoretical clarity and to isolate causality. According to the results from 2 studies, distinct frames received from contacts facilitate creativity, but the effect of distinct information is more complex. When individuals receive distinct information from strong ties, it constrains creativity compared to distinct frames. Content from weak ties appears to facilitate creativity across all scenarios. The results of mediated moderation analysis indicate the effect of framing versus information for strong ties is driven by decision-making time, as an indicator of cognitive expansion. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  19. 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

  20. It's the recipient that counts: spending money on strong social ties leads to greater happiness than spending on weak social ties.

    Directory of Open Access Journals (Sweden)

    Lara B Aknin

    Full Text Available Previous research has shown that spending money on others (prosocial spending increases happiness. But, do the happiness gains depend on who the money is spent on? Sociologists have distinguished between strong ties with close friends and family and weak ties--relationships characterized by less frequent contact, lower emotional intensity, and limited intimacy. We randomly assigned participants to reflect on a time when they spent money on either a strong social tie or a weak social tie. Participants reported higher levels of positive affect after recalling a time they spent on a strong tie versus a weak tie. The level of intimacy in the relationship was more important than the type of relationship; there was no significant difference in positive affect after recalling spending money on a family member instead of a friend. These results add to the growing literature examining the factors that moderate the link between prosocial behaviour and happiness.

  1. It's the recipient that counts: spending money on strong social ties leads to greater happiness than spending on weak social ties.

    Science.gov (United States)

    Aknin, Lara B; Sandstrom, Gillian M; Dunn, Elizabeth W; Norton, Michael I

    2011-02-10

    Previous research has shown that spending money on others (prosocial spending) increases happiness. But, do the happiness gains depend on who the money is spent on? Sociologists have distinguished between strong ties with close friends and family and weak ties--relationships characterized by less frequent contact, lower emotional intensity, and limited intimacy. We randomly assigned participants to reflect on a time when they spent money on either a strong social tie or a weak social tie. Participants reported higher levels of positive affect after recalling a time they spent on a strong tie versus a weak tie. The level of intimacy in the relationship was more important than the type of relationship; there was no significant difference in positive affect after recalling spending money on a family member instead of a friend. These results add to the growing literature examining the factors that moderate the link between prosocial behaviour and happiness.

  2. Social Support and Social Network Ties among the Homeless in a Downtown Atlanta Park

    Science.gov (United States)

    Reitzes, Donald C.; Crimmins, Timothy J.; Yarbrough, Johanna; Parker, Josie

    2011-01-01

    This study applies a typology of social support with 3 categories of social networks to investigate social ties and their benefits for homeless people. Data were derived from a 2-year long series of participant observations of homeless or precariously housed people who came regularly to a downtown Atlanta public park. The findings are as follows:…

  3. Understanding the process of social network evolution: Online-offline integrated analysis of social tie formation

    Science.gov (United States)

    Kwak, Doyeon

    2017-01-01

    It is important to consider the interweaving nature of online and offline social networks when we examine social network evolution. However, it is difficult to find any research that examines the process of social tie formation from an integrated perspective. In our study, we quantitatively measure offline interactions and examine the corresponding evolution of online social network in order to understand the significance of interrelationship between online and offline social factors in generating social ties. We analyze the radio signal strength indicator sensor data from a series of social events to understand offline interactions among the participants and measure the structural attributes of their existing online Facebook social networks. By monitoring the changes in their online social networks before and after offline interactions in a series of social events, we verify that the ability to develop an offline interaction into an online friendship is tied to the number of social connections that participants previously had, while the presence of shared mutual friends between a pair of participants disrupts potential new connections within the pre-designed offline social events. Thus, while our integrative approach enables us to confirm the theory of preferential attachment in the process of network formation, the common neighbor theory is not supported. Our dual-dimensional network analysis allows us to observe the actual process of social network evolution rather than to make predictions based on the assumption of self-organizing networks. PMID:28542367

  4. Neural dynamics of social tie formation in economic decision-making

    NARCIS (Netherlands)

    Bault, N.; Pelloux, B.; Fahrenfort, J.J.; Ridderinkhof, K.R.; van Winden, F.

    2015-01-01

    The disposition for prosocial conduct, which contributes to cooperation as arising during social interaction, requires cortical network dynamics responsive to the development of social ties, or care about the interests of specific interaction partners. Here, we formulate a dynamic computational

  5. Importance of tie strengths in the prisoner's dilemma game on social networks

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Bo, E-mail: xubosuper@163.com [Department of Information Systems, School of Economics and Management, Beihang University (China); Liu, Lu; You, Weijia [Department of Information Systems, School of Economics and Management, Beihang University (China)

    2011-06-13

    Though numerous researches have shown that tie strengths play a key role in the formation of collective behavior in social networks, little work has been done to explore their impact on the outcome of evolutionary games. In this Letter, we studied the effect of tie strength in the dynamics of evolutionary prisoner's dilemma games by using online social network datasets. The results show that the fraction of cooperators has a non-trivial dependence on tie strength. Weak ties, just like previous researches on epidemics and information diffusion have shown, play a key role by the maintenance of cooperators in evolutionary prisoner's dilemma games. -- Highlights: → Tie strength is used to measure heterogeneous influences of different pairs of nodes. → Weak ties play a role in maintaining cooperation in prisoner's dilemma games. → Micro-dynamics of nodes are illustrated to explain the conclusion.

  6. Social features of online networks: the strength of intermediary ties in online social media.

    Directory of Open Access Journals (Sweden)

    Przemyslaw A Grabowicz

    Full Text Available An increasing fraction of today's social interactions occur using online social media as communication channels. Recent worldwide events, such as social movements in Spain or revolts in the Middle East, highlight their capacity to boost people's coordination. Online networks display in general a rich internal structure where users can choose among different types and intensity of interactions. Despite this, there are still open questions regarding the social value of online interactions. For example, the existence of users with millions of online friends sheds doubts on the relevance of these relations. In this work, we focus on Twitter, one of the most popular online social networks, and find that the network formed by the basic type of connections is organized in groups. The activity of the users conforms to the landscape determined by such groups. Furthermore, Twitter's distinction between different types of interactions allows us to establish a parallelism between online and offline social networks: personal interactions are more likely to occur on internal links to the groups (the weakness of strong ties; events transmitting new information go preferentially through links connecting different groups (the strength of weak ties or even more through links connecting to users belonging to several groups that act as brokers (the strength of intermediary ties.

  7. Identifying Weak Ties from Publicly Available Social Media Data in an Event

    DEFF Research Database (Denmark)

    Prakash Gupta, Jayesh; Menon, Karan; Kärkkäinen, Hannu

    2016-01-01

    or potential weak ties using publicly available social media data in the context of an event. Our case study environment is community managers' online discussions in social media in connection to the yearly-organized Community Manager Appreciation Day (CMAD 2016) event in Finland. We were able to identify...... potential weak ties using the conversation based structural holes, making use of social network analysis methods (like clustering) and content analysis in the context of events. We add to the understanding of and useful data sources for the Strength of weak ties theory originated from Granovetter...

  8. Social connection in organizations: the effects of local ties on job engagement and performance

    Directory of Open Access Journals (Sweden)

    Cristiano de Oliveira Maciel

    Full Text Available Abstract This study examines the effect of local ties of organizational actors on their degree of job engagement and performance. The study carried out a survey with 249 respondents and analyzed the effect of local ties (i.e., ties of the ego through degrees of intra-organizational social connections. Engagement was measured in physical, cognitive, and emotional dimensions. Performance was represented by the degree of achievement in tasks. The results show that only cognitive engagement and performance are influenced by degrees of intra-organizational social connection. These results are explored in the conclusions of the article.

  9. The relationship between twin language, twins' close ties, and social competence.

    Science.gov (United States)

    Hayashi, Chisato; Mikami, Hiroshi; Nishihara, Reiko; Maeda, Chiho; Hayakawa, Kazuo

    2014-02-01

    This study investigated the relationship between twin language, twins' close ties, and social competence in a prospective longitudinal study. We hypothesized that twins whose tie is close would be more likely to develop a twin language, and these twins would be less likely to develop social competence. In addition, we hypothesize that some environmental factors, such as having an older sibling, preschool attendance, zygosity, and sex are also related to twin language, twins' close ties, and social competence. At baseline in 1999 a mailed questionnaire survey was conducted, and a follow-up questionnaire was distributed in 2004 among 958 mothers. As a result, 516 respondents returned the questionnaire (53.9%). In this study, we used 261 twin pairs aged from 6 to 12 years (school-age children) for analysis, excluding those with missing values. In the present study, we found that zygosity and sex were associated with twins' close ties. Having an older sibling and preschool attendance did not affect the twins' close tie, twin language, or social competence. One of the most important findings was that social competence was not affected directly by twins' close tie, but was affected when a twin language was found.

  10. Social Tie Characteristics and Psychiatric Rehabilitation Outcomes among Adults with Serious Mental Illness

    Science.gov (United States)

    Chou, Chih-Chin; Chronister, Julie Ann

    2012-01-01

    Social support has achieved national attention as a key component of the mental health recovery paradigm for persons with serious mental illness (SMI). The aim of this study was to investigate the amount of variance accounted for by four social tie characteristics (social network orientation, emotional support, tangible support, and negative…

  11. The centrality of social ties to climate migration and mental health.

    Science.gov (United States)

    Torres, Jacqueline M; Casey, Joan A

    2017-07-06

    Climate change-related hazards and disasters, known to adversely impact physical and mental health outcomes, are also expected to result in human migration above current levels. Environmentally-motivated migration and displacement may lead to the disruption of existing social ties, with potentially adverse consequences for mobile populations as well as their family members who remain in places of origin. We propose that the disruption of social ties is a key mechanism by which climate-related migration may negatively impact mental health, in particular. Existing social ties may provide social and material resources that buffer mental health stressors related to both prolonged and acute climate events. Preparation for such events may also strengthen these same ties and protect mental health. Communities may leverage social ties, first to mitigate climate change, and second, to adapt and rebuild post-disaster in communities of origin. Additionally, social ties can inform migration decisions and destinations. For example, scholars have found that the drought-motivated adaptive migration of West African Fulbe herders only occurred because of the long-term development of social networks between migrants and non-migrants through trade and seasonal grazing. On the other hand, social ties do not always benefit mental health. Some migrants, including those from poor regions or communities with no formal safety net, may face considerable burden to provide financial and emotional resources to family members who remain in countries of origin. In destination communities, migrants often face significant social marginalization. Therefore, policies and programs that aim to maintain ongoing social ties among migrants and their family and community members may be critically important in efforts to enhance population resilience and adaptation to climate change and to improve mental health outcomes. Several online platforms, like Refugee Start Force, serve to integrate refugees by

  12. Mexican American Protest, Ethnic Resiliency and Social Capital: The Mobilization Benefits of Cross-Cutting Ties

    Science.gov (United States)

    Santoro, Wayne A.; Velez,, Maria B.; Keogh, Stacy M.

    2012-01-01

    Using terms like free spaces and havens, conventional wisdom views social ties by subordinate groups to dominant group members as hindering protest participation. In contrast, we draw on ethnic resiliency and social capital perspectives and argue that there are mobilization benefits to having dominant group members as friends. We offer a unique…

  13. Social ties and risk for cancer--a prospective cohort study

    DEFF Research Database (Denmark)

    Bergelt, Corinna; Prescott, Eva; Grønbaek, Morten;

    2009-01-01

    (breast, lung, prostate and colon and rectum) were conducted with the Cox proportional hazards model, with adjustment for a number of well-known risk factors for cancer. RESULTS: While we found no significant association between social ties and risk for cancer in men, women with high social network scores......BACKGROUND: Poor social support and small social networks have been associated with increased risks for conditions such as coronary heart disease as well as with overall mortality. We investigated the association between social ties and risk for cancer. MATERIAL AND METHODS: The study sample...... had an increased risk for lung cancer of borderline significance (HR, 2.16; 95% CI, 1.02-4.60). The risks for breast cancer and colorectal cancers were not significantly increased in the same group of women. DISCUSSION: The results of this study do not support the hypothesis that social network size...

  14. A multilevel analysis of social ties and social cohesion among Latinos and their neighborhoods: results from Chicago.

    Science.gov (United States)

    Almeida, Joanna; Kawachi, Ichiro; Molnar, Beth E; Subramanian, S V

    2009-09-01

    Research suggests that, among Latinos, there are health benefits associated with living in a neighborhood populated with coethnics. While social networks and social cohesion are the proposed explanation for the salubrious effect and are assumed to be characteristics of Latino immigrant enclaves, evidence for this is limited. We used multilevel regression to test the relative contribution of individual race/ethnicity and neighborhood concentration of Mexican Americans as predictors of social networks and social cohesion. After accounting for personal characteristics, we found a negative association between neighborhood concentration of Mexican Americans and social cohesion. Among Latinos, living in a neighborhood with increased coethnics was associated with increased social ties. Compared to non-Latino whites, Mexican Americans reported more social ties but lower social cohesion. Contrary to the assumption that Mexican immigrant enclaves beget social cohesion, we did not find this to be true in Chicago neighborhoods.

  15. An Exploratory Examination of Social Ties and Crime in Mobile Home Communities

    Directory of Open Access Journals (Sweden)

    William P. McCarty

    2013-11-01

    Full Text Available Guided by the systemic model of social disorganization, the purpose of this study was to explore the nature of social ties in mobile home communities and examine how that relates to rates of violent and property crime. Interviews with a small sample of mobile home residents, owners, and managers in Omaha, Nebraska, indicate a wide spectrum of communities, from those characterized by an atomized population to those with strong social ties. Fear of crime, ethnically heterogeneous populations, and lax management were cited by respondents as factors that undermined relationships. Proactive management and a desire to help neighbors were cited by respondents as factors that helped strengthen relationships. Violent and property crime rates for the mobile home communities were largely consistent with the interview data, providing support for the importance of social networks and a systemic model of social disorganization. The implications of these findings for research and policy are also explored.

  16. The Role of Social Ties in Word-of-Mouth Effectiveness

    DEFF Research Database (Denmark)

    Martensen, Anne Duhr; Grønholdt, Lars

    2015-01-01

    This article develops consumer segmentation based on the strength of social ties in word-of-mouth (WOM) communication and examines the influence of WOM on behavioral attitude and intention in these segments. Data were collected through a survey among receivers of retail banking WOM. A cluster...

  17. Peer monitoring, social ties and moral hazard in group lending programs : Evidence from Eritrea

    NARCIS (Netherlands)

    Hermes, N; Lensink, R; Mehrteab, HT

    2005-01-01

    In this paper, we investigate the impact of monitoring and social ties on moral hazard behavior within group lending programs. Our study is based on data from an extensive questionnaire held in Eritrea among participants of 102 groups. We separately analyze the impact of group leaders and other grou

  18. Social ties within school classes : The roles of gender, ethnicity, and having older siblings

    NARCIS (Netherlands)

    Soetevent, AR; Kooreman, P

    2005-01-01

    In this paper we identify the lines along which social ties between high-school teenagers are primarily formed. To this end, we introduce interaction weights between pupils in the same school class that are a function of exogenous individual background characteristics, such as gender, ethnicity, and

  19. The Role of Social Ties in Word-of-Mouth Effectiveness

    DEFF Research Database (Denmark)

    Martensen, Anne Duhr; Grønholdt, Lars

    2015-01-01

    This article develops consumer segmentation based on the strength of social ties in word-of-mouth (WOM) communication and examines the influence of WOM on behavioral attitude and intention in these segments. Data were collected through a survey among receivers of retail banking WOM. A cluster...

  20. A 10-Year Follow-Up Study of Social Ties and Functional Health among the Old: The AGES Project.

    Science.gov (United States)

    Murata, Chiyoe; Saito, Tami; Tsuji, Taishi; Saito, Masashige; Kondo, Katsunori

    2017-07-03

    In Asian nations, family ties are considered important. However, it is not clear what happens among older people with no such ties. To investigate the association, we used longitudinal data from the Aichi Gerontological Evaluation Study (AGES) project. Functionally independent older people at baseline (N = 14,088) in 10 municipalities were followed from 2003 to 2013. Social ties were assessed by asking about their social support exchange with family, relatives, friends, or neighbors. Cox proportional hazard models were employed to investigate the association between social ties and the onset of functional disability adjusting for age, health status, and living arrangement. We found that social ties with co-residing family members, and those with friends or neighbors, independently protected functional health with hazard ratios of 0.81 and 0.85 among men. Among women, ties with friend or neighbors had a stronger effect on health compared to their male counterparts with a hazard ratio of 0.89. The fact that social ties with friends or neighbors are associated with a lower risk of functional decline, independent of family support, serves to underscore the importance of promoting social ties, especially among those lacking family ties.

  1. Strengthening Social Ties to Increase Confidence and Self-Esteem Among Sexual and Gender Minority Youth.

    Science.gov (United States)

    Romijnders, Kim A; Wilkerson, J Michael; Crutzen, Rik; Kok, Gerjo; Bauldry, Jessica; Lawler, Sylvia M

    2017-05-01

    Sexual and gender minority (SGM) youth too often live in nonsupportive environments. This study reports the influence of social support from primary and secondary social ties on confidence and self-esteem among participants in Hatch Youth, a drop-in group-level intervention for SGM youth. Each 3-hour Hatch Youth meeting consists of a social, educational, and youth-led support hour. Over 14 weeks, these meetings were randomly observed and individual interviews with participating youth ( n = 12) and staff and volunteers ( n = 12) were conducted; data underwent a content analysis. Participants perceived an increase in confidence and self-esteem through enhanced bonding with family and friends, a sense of belonging, and community empowerment because of their involvement with Hatch Youth, suggesting drop-in centers can strengthen secondary social ties and improve confidence and self-esteem.

  2. Weak Ties: A Subtle Role in the Information Diffusion of Online Social Networks

    CERN Document Server

    Zhao, Jichang; Xu, Ke

    2010-01-01

    As a social media, online social networks play a vital role in the social information diffusion. However, due to its unique complexity, the mechanism of the diffusion can be different from the ones in other types of networks and remains unclear to us. Meanwhile, few works have been done to reveal the coupled dynamics of both the structure and the diffusion of online social networks. To this end, in this paper, we propose a model to investigate how the structure is coupled with the diffusion in online social networks from the view of weak ties. Through numerical experiments on large-scale online social networks, we find that in contrast to some previous research results, selecting weak ties preferentially to republish cannot make the information diffuse quickly, while random selection can achieve this goal. However, when we remove the weak ties gradually, the coverage of the information will decrease sharply even in the case of random selection. We also give a reasonable explanation for this by extra analysis ...

  3. Length of residence, social ties, and economic opportunities,.

    Science.gov (United States)

    Toney, M B

    1976-08-01

    This study examines length of residence for movers--that subsection of the population which accounts for the high mobility rates in the United States. The propensity for repeated migration is studied in relation to economic opportunities and previous familial and personal contacts. The results indicate no influence of economic opportunities on duration of residence. This finding is consistent with recent research that indicates economic conditions are not a general stimulus for out-migration, although they are for inmigration. On the other hand, length of residence is found to be longer where previous familial and personal contacts existed. Overall, the results provide additional evidence of the importance of social, as opposed to strictly economic variables in the migration process.

  4. Can Social Ties be Harmful? Examining the Spread of Suicide in Early Adulthood.

    Science.gov (United States)

    Mueller, Anna S; Abrutyn, Seth; Stockton, Cynthia

    2015-06-01

    Durkheim posited that social relationships protect individuals against suicide; however, substantial research demonstrates that suicide can spread through the very ties Durkheim theorized as protective. With this study, we use Waves I, III, and IV of the National Longitudinal Study of Adolescent Health, to investigate whether young adults' suicide attempts and thoughts are in part products of exposure to suicidal behaviors via their social relationships. We find that young adults who have had family members or friends attempt suicide are more likely to report suicide ideation or even suicide attempts, over both the short and long run. This finding is robust to many important controls for risk and protective factors for suicide. Our findings have implications for the sociology of suicide, not the least of which, is that social ties have the power to harm in addition to the power to protect.

  5. Burstiness and tie activation strategies in time-varying social networks

    Science.gov (United States)

    Ubaldi, Enrico; Vezzani, Alessandro; Karsai, Márton; Perra, Nicola; Burioni, Raffaella

    2017-04-01

    The recent developments in the field of social networks shifted the focus from static to dynamical representations, calling for new methods for their analysis and modelling. Observations in real social systems identified two main mechanisms that play a primary role in networks’ evolution and influence ongoing spreading processes: the strategies individuals adopt when selecting between new or old social ties, and the bursty nature of the social activity setting the pace of these choices. We introduce a time-varying network model accounting both for ties selection and burstiness and we analytically study its phase diagram. The interplay of the two effects is non trivial and, interestingly, the effects of burstiness might be suppressed in regimes where individuals exhibit a strong preference towards previously activated ties. The results are tested against numerical simulations and compared with two empirical datasets with very good agreement. Consequently, the framework provides a principled method to classify the temporal features of real networks, and thus yields new insights to elucidate the effects of social dynamics on spreading processes.

  6. Easier contagion and weaker ties make anger spread faster than joy in social media

    CERN Document Server

    Fan, Rui; Zhao, Jichang

    2016-01-01

    Similar to face-to-face communication in daily life, more and more evidence suggests that human emotion also spread in online social media through virtual interactions. However, the mechanism underlying the emotion contagion, like whether different feelings diffuse unlikely or how the spread is coupled with the social network, is rarely investigated. Indeed, because of the costly expense and spatio-temporal limitations, it is challenging for conventional questionnaires or controlled experiments. While given the instinct of collecting natural affective responses of massive connected individuals, online social media offer us an ideal proxy to tackle this issue from the perspective of computational social science. In this paper, based on the analysis of millions of tweets in Weibo, a Twitter-like service in China, we surprisingly find that anger is more contagious than joy, indicating that it can sparkle more angry follow-up tweets and anger prefers weaker ties than joy for the dissemination in social network, i...

  7. Social capital and core network ties: a validation study of individual-level social capital measures and their association with extra- and intra-neighborhood ties, and self-rated health.

    Science.gov (United States)

    Moore, Spencer; Bockenholt, Ulf; Daniel, Mark; Frohlich, Katherine; Kestens, Yan; Richard, Lucie

    2011-03-01

    Research on social capital and health has assumed that measures of trust, participation, and perceived cohesion capture aspects of people's neighborhood social connections. This study uses data on the personal networks of 2707 Montreal adults in 300 different neighborhoods to examine the association of socio-demographic and social capital variables with the likelihood of having core ties, core neighborhood ties, and high self-rated health (SRH). Persons with higher household income were more likely to have core ties, but less likely to have core neighborhood ties. Persons with greater diversity in extra-neighborhood network capital were more likely to have core ties, and persons with greater diversity in intra-neighborhood network capital were more likely to have core neighborhood ties. Generalized trust, perceived neighborhood cohesion, and extra-neighborhood network diversity were shown associated with high SRH. Conventional measures of social capital may not capture network mechanisms. Findings suggest a critical appraisal of the mechanisms linking social capital and health, and the further delineation of network and psychosocial mechanisms in understanding these links.

  8. Mesoscopic analysis of online social networks: The role of negative ties

    Science.gov (United States)

    Esmailian, Pouya; Abtahi, Seyed Ebrahim; Jalili, Mahdi

    2014-10-01

    A class of networks are those with both positive and negative links. In this manuscript, we studied the interplay between positive and negative ties on mesoscopic level of these networks, i.e., their community structure. A community is considered as a tightly interconnected group of actors; therefore, it does not borrow any assumption from balance theory and merely uses the well-known assumption in the community detection literature. We found that if one detects the communities based on only positive relations (by ignoring the negative ones), the majority of negative relations are already placed between the communities. In other words, negative ties do not have a major role in community formation of signed networks. Moreover, regarding the internal negative ties, we proved that most unbalanced communities are maximally balanced, and hence they cannot be partitioned into k nonempty sub-clusters with higher balancedness (k ≥2 ). Furthermore, we showed that although the mediator triad ++- (hostile-mediator-hostile) is underrepresented, it constitutes a considerable portion of triadic relations among communities. Hence, mediator triads should not be ignored by community detection and clustering algorithms. As a result, if one uses a clustering algorithm that operates merely based on social balance, mesoscopic structure of signed networks significantly remains hidden.

  9. How Social Ties Influence Consumer: Evidence from Event-Related Potentials.

    Science.gov (United States)

    Luan, Jing; Yao, Zhong; Bai, Yan

    2017-01-01

    A considerable amount of marketing research has reported that consumers are more saliently influenced by friends (strong social ties) than by acquaintances and strangers (weak social ties). To shed light on the neural and psychological processes underlying such phenomenon, in this study we designed an amended S1-S2 paradigm (product-[reviewer-review]) that is based on realistic consumer purchase experiences. After incoming all given information (product, reviewer, review), participants were required to state their purchase intentions. The neurocognitive and emotional processes related to friend and stranger stimuli were delineated to suggest how social ties influence consumers during their shopping processes. Larger P2 (fronto-central scalp areas) and P3 (central and posterior-parietal scalp areas) components under stranger condition were elicited successfully. These findings demonstrate that the cognitive and emotional processing of friend and stranger stimuli occurs at stages of neural activity, and can be indicated by the P2 and P3 components. Electrophysiological data also support the hypothesis that different neural and emotional processing magnitude and strength underlie friend and stranger effect in the context of consumer purchase. During this process, the perception of stimuli evoked P2, subsequently emotional processing and attention modulation were activated and indicated by P2 and P3. The friend dominated phenomenon can be interpreted as the result of distinctive neurocognitive and emotional processing magnitude, which suggests that psychological and emotional factors can guide consumer decision making. This study consolidates that event related potential (ERP) methodology is likely to be a more sensitive method for investigating consumer behaviors. From the perspectives of management and marketing, our findings show that the P2 and P3 components can be employed as an indicator to probe the influential factors of consumer purchase intentions.

  10. How Social Ties Influence Consumer: Evidence from Event-Related Potentials

    Science.gov (United States)

    Yao, Zhong

    2017-01-01

    A considerable amount of marketing research has reported that consumers are more saliently influenced by friends (strong social ties) than by acquaintances and strangers (weak social ties). To shed light on the neural and psychological processes underlying such phenomenon, in this study we designed an amended S1-S2 paradigm (product-[reviewer-review]) that is based on realistic consumer purchase experiences. After incoming all given information (product, reviewer, review), participants were required to state their purchase intentions. The neurocognitive and emotional processes related to friend and stranger stimuli were delineated to suggest how social ties influence consumers during their shopping processes. Larger P2 (fronto-central scalp areas) and P3 (central and posterior-parietal scalp areas) components under stranger condition were elicited successfully. These findings demonstrate that the cognitive and emotional processing of friend and stranger stimuli occurs at stages of neural activity, and can be indicated by the P2 and P3 components. Electrophysiological data also support the hypothesis that different neural and emotional processing magnitude and strength underlie friend and stranger effect in the context of consumer purchase. During this process, the perception of stimuli evoked P2, subsequently emotional processing and attention modulation were activated and indicated by P2 and P3. The friend dominated phenomenon can be interpreted as the result of distinctive neurocognitive and emotional processing magnitude, which suggests that psychological and emotional factors can guide consumer decision making. This study consolidates that event related potential (ERP) methodology is likely to be a more sensitive method for investigating consumer behaviors. From the perspectives of management and marketing, our findings show that the P2 and P3 components can be employed as an indicator to probe the influential factors of consumer purchase intentions. PMID

  11. Effects of Social Ties in Knowledge Diffusion: case study on PLOS ONE

    CERN Document Server

    Eltermann, Felipe; Von Zuben, Fernando J

    2016-01-01

    In order to capture the effects of social ties in knowledge diffusion, this paper examines the publication network that emerges from the collaboration of researchers, using citation information as means to estimate knowledge flow. For this purpose, we analyzed the papers published in the PLOS ONE journal finding strong evidence to support that the closer two authors are in the co-authorship network, the larger the probability that knowledge flow will occur between them. Moreover, we also found that when it comes to knowledge diffusion, strong co-authorship proximity is more determinant than geographic proximity.

  12. The Limits of Popularity-Based Recommendations, and the Role of Social Ties

    CERN Document Server

    Bressan, Marco; Panconesi, Alessandro; Raghavan, Prabhakar; Terolli, Erisa

    2016-01-01

    In this paper we introduce a mathematical model that captures some of the salient features of recommender systems that are based on popularity and that try to exploit social ties among the users. We show that, under very general conditions, the market always converges to a steady state, for which we are able to give an explicit form. Thanks to this we can tell rather precisely how much a market is altered by a recommendation system, and determine the power of users to influence others. Our theoretical results are complemented by experiments with real world social networks showing that social graphs prevent large market distortions in spite of the presence of highly influential users.

  13. Asymptotic theory of time-varying social networks with heterogeneous activity and tie allocation

    Science.gov (United States)

    Ubaldi, Enrico; Perra, Nicola; Karsai, Márton; Vezzani, Alessandro; Burioni, Raffaella; Vespignani, Alessandro

    2016-10-01

    The dynamic of social networks is driven by the interplay between diverse mechanisms that still challenge our theoretical and modelling efforts. Amongst them, two are known to play a central role in shaping the networks evolution, namely the heterogeneous propensity of individuals to i) be socially active and ii) establish a new social relationships with their alters. Here, we empirically characterise these two mechanisms in seven real networks describing temporal human interactions in three different settings: scientific collaborations, Twitter mentions, and mobile phone calls. We find that the individuals’ social activity and their strategy in choosing ties where to allocate their social interactions can be quantitatively described and encoded in a simple stochastic network modelling framework. The Master Equation of the model can be solved in the asymptotic limit. The analytical solutions provide an explicit description of both the system dynamic and the dynamical scaling laws characterising crucial aspects about the evolution of the networks. The analytical predictions match with accuracy the empirical observations, thus validating the theoretical approach. Our results provide a rigorous dynamical system framework that can be extended to include other processes shaping social dynamics and to generate data driven predictions for the asymptotic behaviour of social networks.

  14. Asymptotic theory of time-varying social networks with heterogeneous activity and tie allocation

    Science.gov (United States)

    Ubaldi, Enrico; Perra, Nicola; Karsai, Márton; Vezzani, Alessandro; Burioni, Raffaella; Vespignani, Alessandro

    2016-01-01

    The dynamic of social networks is driven by the interplay between diverse mechanisms that still challenge our theoretical and modelling efforts. Amongst them, two are known to play a central role in shaping the networks evolution, namely the heterogeneous propensity of individuals to i) be socially active and ii) establish a new social relationships with their alters. Here, we empirically characterise these two mechanisms in seven real networks describing temporal human interactions in three different settings: scientific collaborations, Twitter mentions, and mobile phone calls. We find that the individuals’ social activity and their strategy in choosing ties where to allocate their social interactions can be quantitatively described and encoded in a simple stochastic network modelling framework. The Master Equation of the model can be solved in the asymptotic limit. The analytical solutions provide an explicit description of both the system dynamic and the dynamical scaling laws characterising crucial aspects about the evolution of the networks. The analytical predictions match with accuracy the empirical observations, thus validating the theoretical approach. Our results provide a rigorous dynamical system framework that can be extended to include other processes shaping social dynamics and to generate data driven predictions for the asymptotic behaviour of social networks. PMID:27774998

  15. Social network ties and inflammation in U.S. adults with cancer.

    Science.gov (United States)

    Yang, Yang Claire; Li, Ting; Frenk, Steven M

    2014-01-01

    The growing evidence linking social connectedness and chronic diseases such as cancer calls for a better understanding of the underlying biophysiological mechanisms. This study assessed the associations between social network ties and multiple measures of inflammation in a nationally representative sample of adults with a history of cancer (N = 1,075) from the National Health and Nutrition Examination Survey III (1988-94). Individuals with lower social network index (SNI) scores showed significantly greater inflammation marked by C-reactive protein and fibrinogen, adjusting for age and sex. Compared to fully socially integrated individuals (SNI = 4), those who were more socially isolated or had a SNI score of 3 or less exhibited increasingly elevated inflammation burdens. Specifically, the age- and sex-adjusted odds ratios (95%CI) for SNIs of 3, 2, and 0-1 were 1.49 (1.08, 2.06), 1.69 (1.21, 2.36), and 2.35 (1.62, 3.40), respectively (p < .001). Adjusting for other covariates attenuated these associations. The SNI gradients in the risks of inflammation were particularly salient for the lower socioeconomic status groups and remained significant after adjusting for other social, health behavioral, and illness factors. This study provided initial insights into the immunological pathways by which social connections are related to morbidity and mortality outcomes of cancer in particular and aging-related diseases in general.

  16. Asymptotic theory of time-varying social networks with heterogeneous activity and tie allocation.

    Science.gov (United States)

    Ubaldi, Enrico; Perra, Nicola; Karsai, Márton; Vezzani, Alessandro; Burioni, Raffaella; Vespignani, Alessandro

    2016-10-24

    The dynamic of social networks is driven by the interplay between diverse mechanisms that still challenge our theoretical and modelling efforts. Amongst them, two are known to play a central role in shaping the networks evolution, namely the heterogeneous propensity of individuals to i) be socially active and ii) establish a new social relationships with their alters. Here, we empirically characterise these two mechanisms in seven real networks describing temporal human interactions in three different settings: scientific collaborations, Twitter mentions, and mobile phone calls. We find that the individuals' social activity and their strategy in choosing ties where to allocate their social interactions can be quantitatively described and encoded in a simple stochastic network modelling framework. The Master Equation of the model can be solved in the asymptotic limit. The analytical solutions provide an explicit description of both the system dynamic and the dynamical scaling laws characterising crucial aspects about the evolution of the networks. The analytical predictions match with accuracy the empirical observations, thus validating the theoretical approach. Our results provide a rigorous dynamical system framework that can be extended to include other processes shaping social dynamics and to generate data driven predictions for the asymptotic behaviour of social networks.

  17. Does Visual Impairment Affect Social Ties in Late Life? Findings of a Multicenter Prospective Cohort Study in Germany.

    Science.gov (United States)

    Hajek, A; Brettschneider, C; Lühmann, D; Eisele, M; Mamone, S; Wiese, B; Weyerer, S; Werle, J; Pentzek, M; Fuchs, A; Stein, J; Luck, T; Bickel, H; Weeg, D; Heser, K; Jessen, F; Maier, W; Scherer, M; Riedel-Heller, S G; König, H-H

    2017-01-01

    To investigate how visual impairment affects social ties in late life longitudinally. Population-based prospective cohort study. Individuals in old age were recruited via general practitioners' offices (at six study centers) in Germany. They were interviewed every 18 months. Individuals aged 75 years and above at baseline. Follow-up wave 2 (36 months after baseline, n=2,443) and wave 4 (72 months after baseline, n=1,618) were used for the analyses presented here. Social ties were assessed using the 14-item form of the questionnaire for social support (F-SozU K-14). Visual impairment was self-rated on a three level Likert scale (no impairment, mild visual impairment, or severe/profound visual impairment). Adjusting for sociodemographic factors, hearing impairment and comorbidity, fixed effects regressions revealed that the onset of mild visual impairment decreased the social support score, in particular the emotional support score. Additionally, the onset of mild hearing impairment decreased the social support score in men. Moreover, increasing age decreased the social support score in the total sample and in both sexes. Loss of spouse and increasing comorbidity did not affect the social support score. Our results highlight the importance of visual impairment for social ties in late life. Consequently, appropriate strategies in order to delay visual impairment might help to maintain social ties in old age.

  18. Creative benefits from well-connected leaders: leader social network ties as facilitators of employee radical creativity.

    Science.gov (United States)

    Venkataramani, Vijaya; Richter, Andreas W; Clarke, Ronald

    2014-09-01

    Employee radical creativity critically depends on substantive informational resources from others across the wider organization. We propose that the social network ties of employees' immediate leaders assume a central role in garnering these resources, thereby fostering their employees' radical creativity both independent of and interactively with employees' own network ties. Drawing on data from 214 employees working in 30 teams of a public technology and environmental services organization, we find that team leaders' betweenness centrality in the idea network within their teams as well as among their peer leaders provides creative benefits beyond employees' own internal and external ties. Further, employees' and leaders' ties within and external to the team interactively predict employee radical creativity. Implications for theory and practice are discussed.

  19. The Strength of Strong Ties for Older Rural Adults: Regional Distinctions in the Relationship between Social Interaction and Subjective Well-Being

    Science.gov (United States)

    Mair, Christine A.; Thivierge-Rikard, R. V.

    2010-01-01

    Classic and contemporary sociological theories suggest that social interaction differs in rural and urban areas. Intimate, informal interactions (strong ties) are theorized to characterize rural areas while urban areas may possess more formal and rationalized interactions (weak ties). Aging and social support literature stresses social interaction…

  20. The Strength of Strong Ties for Older Rural Adults: Regional Distinctions in the Relationship between Social Interaction and Subjective Well-Being

    Science.gov (United States)

    Mair, Christine A.; Thivierge-Rikard, R. V.

    2010-01-01

    Classic and contemporary sociological theories suggest that social interaction differs in rural and urban areas. Intimate, informal interactions (strong ties) are theorized to characterize rural areas while urban areas may possess more formal and rationalized interactions (weak ties). Aging and social support literature stresses social interaction…

  1. With Some Help From My Network: Supplementing eHealth Literacy With Social Ties

    Science.gov (United States)

    Brainin, Esther; Neter, Efrat

    2017-01-01

    health benefits by finding similar others compared to Israeli Jews. Conclusions Although the availability of help and the notion of ethnicity have been discussed extensively within the context of social capital and health, our findings offer initial evidence for the relevancy of these concepts when studying individuals’ eHealth literacy. Specifically, our findings enable a better understanding of the role of social ties and ethnicity in moderating the interplay between eHealth literacy and perceived health outcomes. Given the increased importance of eHealth information, our findings enhance understanding of how social ties can potentially compensate for low eHealth literacy. PMID:28360024

  2. Social features of online networks: the strength of weak ties in online social media

    CERN Document Server

    Grabowicz, Przemyslaw A; Moro, Esteban; Pujol, Josep; Eguiluz, Victor M

    2011-01-01

    An increasing fraction of today social interactions occurs using online social media as communication channels. Recent worldwide events, such as the revolts in Middle East or the recent social movements in Spain, reflect their capacity to boost people coordination. Online networks display, in general, a rich internal structure where users can choose among different types and intensity of interactions. Despite of this and their growing popularity, there are still open questions regarding the social value of online relations. For example, the existence of users with thousands or millions of online friends sheds doubts on the relevance of these connections. In this work, we focus on Twitter, one of the most popular online social networks, and find that the network formed by the basic type of relations is organized in groups. The activity of the users in the network is related to the landscape determined by such groups. Twitter's distinction between different types o interactions allows us to establish a parallel...

  3. The Best of Both Worlds? Online Ties and the Alternating Use of Social Network Sites in the Context of Migration

    Directory of Open Access Journals (Sweden)

    Jens F. Binder

    2014-12-01

    Full Text Available While an ever-growing body of research is concerned with user behavior on individual social network sites (SNSs—mostly Facebook—studies addressing an alternating use of two or more SNS are rare. Here, we investigate the relationship between alternating SNS use and social capital in the context of migration. Alternating SNS use avoids some of the problems associated with large networks located on one site; in particular the management of different social or cultural spheres. Not only does this strategy hold potential for increased social capital, it also provides a particular incentive for migrants faced with the challenge of staying in touch with back home and managing a new social environment. Two survey studies are presented that focus on the relationship between alternating SNS use and online ties in a migrant context involving Indian nationals. Study 1 looked at migration within India, whereas Study 2 compared international with domestic SNS users. In both studies, alternating SNS use added to the prediction of online network size and accounted for differences in network size found for migrant and non-migrant users. Differences were due to the number of peripheral ties, rather than core ties. Findings suggest that alternating SNS use may constitute a compensatory strategy that helps to overcome lower levels of socializing represented through a single SNS.

  4. Increases in New Social Network Ties are Associated with Increased Cohesion among Intervention Participants

    Science.gov (United States)

    Gesell, Sabina B.; Barkin, Shari L.; Sommer, Evan C.; Thompson, Jessica R.; Valente, Thomas W.

    2016-01-01

    Objective Many behavior change programs are delivered in group settings to manage implementation costs and to foster support and interactions among group members to facilitate behavior change. Understanding the group dynamics that evolve in group settings (e.g., weight management, Alcoholics Anonymous) is important, yet rarely measured. This paper examined the relationship between social network ties and group cohesion in a group-based intervention to prevent obesity in children. Method The data reported are process measures from an ongoing community-based randomized controlled trial. 305 parents with a child (3-6 years) at risk of developing obesity were assigned to an intervention that taught parents healthy lifestyles. Parents met weekly for 12 weeks in small consistent groups. Two measures were collected at weeks 3 and 6: a social network survey (people in the group with whom one discusses healthy lifestyles); and the validated Perceived Cohesion Scale (Bollen & Hoyle, 1990). We used lagged random and fixed effects regression models to analyze the data. Results Cohesion increased from 6.51 to 6.71 (t=4.4, p<0.01). Network nominations tended to increase over the 3-week period in each network. In the combined discussion and advice network, the number of nominations increased from 1.76 to 1.95 (z=2.59, p<0.01). Cohesion at week 3 was the strongest predictor of cohesion at week 6 (b=0.55, p<0.01). Number of new network nominations at week 6 was positively related to cohesion at week 6 (b=0.06, p<.01). In sum, being able to name new network contacts was associated with feelings of cohesion. Conclusion This is the first study to demonstrate how network changes affect perceived group cohesion within a behavioral intervention. Given that many behavioral interventions occur in group settings, intentionally building new social networks could be promising to augment desired outcomes. PMID:26286298

  5. O discurso e o laço social dos meninos de rua Street boys discourse and social ties

    Directory of Open Access Journals (Sweden)

    Miriam Debieux Rosa

    1999-01-01

    Full Text Available O artigo relata pesquisa que quer compreender como a constituição subjetiva de crianças e adolescentes que vivem na rua, os chamados meninos de rua, articula-se ao laço social, a partir da especificidade da escuta psicanalítica de crianças e adolescentes. Um processo de desqualificação e desvalorização social da família destes jovens, propicia a ruptura destes com a família e escola, levando-os para a rua. Tal ruptura faz surgir o discurso social, que substitui o discurso dos pais, de onde poderiam extrair os significantes de sua filiação e sexuação, e destitui estes meninos do lugar de crianças e adolescentes, justifica o abandono, o descaso e o medo, e oferece-lhes como única possibilidade de nomeação a identidade de delinqüente.The article reports a research on how the subjective constitution of children and adolescents who live on the streets, known as street kids, relate to the social ties, based on the specific psychoanalical hearing of children and adolescents. A process of social disqualification and depreciation of these children’s families, conducts them to break up with their families and schools, leading them to the streets. This rupture brings the social address about, which substitutes the parents address, from which they could take the meaning of their filiation and sexuality. This rupture also deprives them of the condition of being children and adolescents, justifying the abandonment, the neglect and the fear and offering them the only possibility of an identity as a delinquent.

  6. Homeless but Connected: The Role of Heterogeneous Social Network Ties and Social Networking Technology in the Mental Health Outcomes of Street-Living Youth

    OpenAIRE

    Rice, Eric; Ray, Diana; Kurzban, Seth

    2011-01-01

    Although social integration tends to have positive effects on the mental health of housed adolescents, the role of homeless adolescents’ social networks is more ambiguous. Social network data were collected from 136 homeless adolescents in Hollywood, California to examine how network ties are associated with symptoms of anxiety and depression. Face-to-face relationships with street-based peers were a risk factor for both anxiety and depression, while contacting home-based friends through soci...

  7. Social Tie Strength and Online Victimization: An Analysis of Young People Aged 15–30 Years in Four Nations

    Directory of Open Access Journals (Sweden)

    Teo Keipi

    2017-01-01

    Full Text Available Online interaction through the use of social networking sites (SNS continues to be a significant component of the socialization of young people today, yet little research exists toward linking various relational forms to prevalent and much-studied online risks cross-nationally. This article provides a link between relational dynamics and online risks identified in previous research toward a new perspective on how social tie strength is related to experiences of hate victimization and harassment online. The analysis is based on survey data of Finnish (n = 555, American (n = 1033, German (n = 978, and British (n = 999 young people aged 15–30 years. Variables, including age, gender, main activity, SNS use, quantity, and extent of online and offline social networks including social tie strength and online community identification, were analyzed toward finding their associations with online hate victimization and harassment. Results showed that experiences of hate victimization and harassment were similar cross-nationally and that those who were personally harassed online also reported high SNS activity. Furthermore, no association was found between social network size and negative experiences. Notable cross-national differences were also detected in the results. Findings emphasize the importance of understanding variables fostering online risks for young people while providing a new perspective on what aspects of social life may help negate negative effects online.

  8. Social network ties, self-efficacy, and condom use among women who use crack cocaine: a pilot study.

    Science.gov (United States)

    Montoya, I D

    1998-08-01

    So far, attempts to change the sexual risk behavior of women who use crack cocaine have been less successful than efforts to change the needle risk behavior of injection drug users. Two theoretical areas that have shown some success in predicting behavior change among of out-of-treatment drug users are Bandura's social cognitive theory (self-efficacy theory) and social network theory. According to Bandura, social networks are important sources of social support, and social support is vital to self-efficacy. Social network research also indicates that close bonds with network members may be a protective factor independently of self-efficacy. In order to test the feasibility of collecting such data, a pilot study was conducted with 60 women who used crack cocaine and who were not in treatment. Results of Pearson product-moment correlations indicated that self-efficacy (.7230) and number of very strong ties (.31252994) were positively correlated with condom use for women in the sample. In addition, the number of very strong ties (.3142) was significantly, if modestly, correlated with self-efficacy. Self-efficacy was

  9. Parasite-stress promotes in-group assortative sociality: the cases of strong family ties and heightened religiosity.

    Science.gov (United States)

    Fincher, Corey L; Thornhill, Randy

    2012-04-01

    Throughout the world people differ in the magnitude with which they value strong family ties or heightened religiosity. We propose that this cross-cultural variation is a result of a contingent psychological adaptation that facilitates in-group assortative sociality in the face of high levels of parasite-stress while devaluing in-group assortative sociality in areas with low levels of parasite-stress. This is because in-group assortative sociality is more important for the avoidance of infection from novel parasites and for the management of infection in regions with high levels of parasite-stress compared with regions of low infectious disease stress. We examined this hypothesis by testing the predictions that there would be a positive association between parasite-stress and strength of family ties or religiosity. We conducted this study by comparing among nations and among states in the United States of America. We found for both the international and the interstate analyses that in-group assortative sociality was positively associated with parasite-stress. This was true when controlling for potentially confounding factors such as human freedom and economic development. The findings support the parasite-stress theory of sociality, that is, the proposal that parasite-stress is central to the evolution of social life in humans and other animals.

  10. Racial/Ethnic and nativity differences in birth outcomes among mothers in New York City: the role of social ties and social support.

    Science.gov (United States)

    Almeida, Joanna; Mulready-Ward, Candace; Bettegowda, Vani R; Ahluwalia, Indu B

    2014-01-01

    Immigrants have lower rates of low birth weight (LBW) and to some extent preterm birth (PTB), than their US-born counterparts. This pattern has been termed the 'immigrant health paradox'. Social ties and support are one proposed explanation for this phenomenon. We examined the contribution of social ties and social support to LBW and PTB by race/ethnicity and nativity among women in New York City (NYC). The NYC Pregnancy Risk Assessment Monitoring System survey (2004-2007) data, linked with the selected items from birth certificates, were used to examine LBW and PTB by race/ethnicity and nativity status and the role of social ties and social support to adverse birth outcomes using bivariate and multivariable analyses. SUDAAN software was used to adjust for complex survey design and sampling weights. US- and foreign-born Blacks had significantly increased odds of PTB [adjusted odds ratio (AOR) = 2.43, 95 % CI 1.56, 3.77 and AOR = 2.6, 95 % CI 1.66, 4.24, respectively] compared to US-born Whites. Odds of PTB among foreign-born Other Latinas, Island-born Puerto Ricans' and foreign-born Asians' were not significantly different from US-born Whites, while odds of PTB for foreign-born Whites were significantly lower (AOR = 0.47, 95 % CI 0.26, 0.84). US and foreign-born Blacks' odds of LBW were 2.5 fold that of US-born Whites. Fewer social ties were associated with 32-39 % lower odds of PTB. Lower social support was associated with decreased odds of LBW (AOR 0.69, 95 % CI 0.50, 0.96). We found stronger evidence of the immigrant health paradox across racial/ethnic groups for PTB than for LBW. Results also point to the importance of accurately assessing social ties and social support during pregnancy and to considering the potential downside of social ties.

  11. Social Networks and Cultural Mediators: The Multiplexity of Personal Ties in Publishing

    NARCIS (Netherlands)

    Heebels, B.; Atzema, O.A.L.C.; van Aalst, I.

    2013-01-01

    This study explores the relational and affective aspects of personal ties of cultural mediators by means of in-depth interviews with Dutch book publishers. Through examining the affective side of publishers’ personal networks, we contribute to understanding the role of cultural mediators—those in-be

  12. Social Networks and Cultural Mediators: The Multiplexity of Personal Ties in Publishing

    NARCIS (Netherlands)

    Heebels, B.; Atzema, O.A.L.C.; van Aalst, I.

    2013-01-01

    This study explores the relational and affective aspects of personal ties of cultural mediators by means of in-depth interviews with Dutch book publishers. Through examining the affective side of publishers’ personal networks, we contribute to understanding the role of cultural mediators—those

  13. Social Networks and Cultural Mediators: The Multiplexity of Personal Ties in Publishing

    NARCIS (Netherlands)

    Heebels, B.; Atzema, O.A.L.C.; van Aalst, I.

    2013-01-01

    This study explores the relational and affective aspects of personal ties of cultural mediators by means of in-depth interviews with Dutch book publishers. Through examining the affective side of publishers’ personal networks, we contribute to understanding the role of cultural mediators—those in-be

  14. Homeless but connected: the role of heterogeneous social network ties and social networking technology in the mental health outcomes of street-living adolescents.

    Science.gov (United States)

    Rice, Eric; Kurzban, Seth; Ray, Diana

    2012-12-01

    Although social integration tends to have positive effects on the mental health of housed adolescents, the role of homeless adolescents' social networks is more ambiguous. Social network data were collected from 136 homeless adolescents in Hollywood, California to examine how network ties are associated with symptoms of anxiety and depression. Face-to-face relationships with street-based peers were a risk factor for both anxiety and depression, while contacting home-based friends through social networking technology was found to be protective for depression. Community-based and public agencies serving homeless adolescents should consider facilitating the maintenance of these protective relationships by providing internet access.

  15. Mesoscopic analysis of online social networks - The role of negative ties

    CERN Document Server

    Esmailian, Pouya; Jalili, Mahdi

    2014-01-01

    A class of networks are those with both positive and negative links.In this manuscript, we studied the interplay between positive and negative ties on mesoscopic level of these networks, i.e., their community structure.A community is considered as a tightly interconnected group of actors; therefore, it does not borrow any assumption from balance theory and merely uses the well-known assumption in the community detection literature.We found that if one detects the communities based on only positive relations (by ignoring the negative ones), the majority of negative relations are already placed between the communities.In other words, negative ties do not have a major role in community formation of signed networks.Moreover, regarding the internal negative ties, we proved that most unbalanced communities are maximally balanced, and hence they cannot be partitioned into k nonempty sub-clusters with higher balancedness (k >= 2).Furthermore, we showed that although the mediator triad + + - (hostile-mediator-hostile)...

  16. The intersection of class origin and immigration background in structuring social capital: the role of transnational ties.

    Science.gov (United States)

    Andersson, Anton; Edling, Christofer; Rydgren, Jens

    2017-08-17

    The study investigates inequalities in access to social capital based on social class origin and immigration background and examines the role of transnational ties in explaining these differences. Social capital is measured with a position generator methodology that separates between national and transnational contacts in a sample of young adults in Sweden with three parental backgrounds: at least one parent born in Iran or Yugoslavia, or two Sweden-born parents. The results show that having socioeconomically advantaged parents is associated with higher levels of social capital. Children of immigrants are found to have a greater access to social capital compared to individuals with native background, and the study shows that this is related to transnational contacts, parents' education and social class in their country of origin. Children of immigrants tend to have more contacts abroad, while there is little difference in the amount of contacts living in Sweden across the three groups. It is concluded that knowledge about immigration group resources help us predict its member's social capital, but that the analysis also needs to consider how social class trajectories and migration jointly structure national and transnational contacts. © London School of Economics and Political Science 2017.

  17. Assessing the Impact of De Novo Social Ties within Health Intervention Settings: New Questions for Health Behavior Intervention Research.

    Science.gov (United States)

    Tesdahl, Eric; Gesell, Sabina B

    2015-12-01

    Recent developments in the study of health and social networks have focused on linkages between health outcomes and naturally occurring social relations, such as friendship or kinship. Based on findings in this area, a new generation of health behavior intervention programs have been implemented that rely on the formation of new social relations among program participants. However, little is known about the qualities of these de novo social relations. We examined the social networks of 59 participants within a randomized controlled trial of an intervention designed to prevent excessive gestational weight gain. We employed exponential random graph modeling techniques to analyze supportive relationships formed between participants in the intervention arm, to detect unique effects of program participation on the likelihood of forming ties. Program participation had a positive effect on the likelihood of forming supportive social relations, however, in this particular timeframe we did not detect any additional effect of such relations on the health behaviors or outcomes of interest. Our findings raise two critical questions: do short-term group-level programs reliably lead to the formation of new social relations among participants; and do these relations have a unique effect on health outcomes relative to standard methods of health behavior intervention?

  18. Relevant ties matter

    DEFF Research Database (Denmark)

    Larsen, Christian Albrekt; Pedersen, Jacob; Mouw, Ted

    What is the effect of social networks on labor market outcomes? The tradition following Grannovetter claims that social ties have a positive effect on wages, job prestige and job satisfaction. Although a number of studies have found positive correlations between friendship characteristics and lab...

  19. Well-connected leaders: the impact of leaders' social network ties on LMX and members' work attitudes.

    Science.gov (United States)

    Venkataramani, Vijaya; Green, Stephen G; Schleicher, Deidra J

    2010-11-01

    We examined the proposition that leaders' social network ties in the larger organization influence the quality of their leader-member exchange (LMX) with their employees, which, in turn, impacts these employees' job satisfaction and turnover intentions. Using multilevel, multisource data from a field study of 184 bank employees nested within 42 branch managers, we found that leaders who had higher quality relationships with their bosses and who were more central in their peer networks were perceived by their subordinates as having greater status in the organization and, therefore, were able to form higher quality relationships with them. Further, the effects of the leaders' perceived status on LMX were stronger when subordinates were less central in their own peer network. Finally, LMX mediated the impact of leaders' perceived status in the organization on subordinates' job satisfaction and turnover intentions. Implications for theory and practice are discussed.

  20. The effect of neighborhood disadvantage, social ties, and genetic variation on the antisocial behavior of African American women: a multilevel analysis.

    Science.gov (United States)

    Lei, Man-Kit; Simons, Ronald L; Edmond, Mary Bond; Simons, Leslie Gordon; Cutrona, Carolyn E

    2014-11-01

    Social disorganization theory posits that individuals who live in disadvantaged neighborhoods are more likely to engage in antisocial behavior than are those who live in advantaged neighborhoods and that neighborhood disadvantage asserts this effect through its disruptive impact on social ties. Past research on this framework has been limited in two respects. First, most studies have concentrated on adolescent males. In contrast, the present study focused on a sample of adult African American females. Second, past research has largely ignored individual-level factors that might explain why people who grow up in disadvantaged neighborhoods often do not engage in antisocial behavior. We investigated the extent to which genetic variation contributes to heterogeneity of response to neighborhood conditions. We found that the impact of neighborhood disadvantage on antisocial behavior was mediated by neighborhood social ties. Further, the analysis indicated that the effects of neighborhood disadvantage and social ties on antisocial behavior were moderated by genetic polymorphisms. Examination of these moderating effects provided support for the differential susceptibility model of Gene × Environment. The effect of Gene × Neighborhood Disadvantage on antisocial behavior was mediated by the effect of Gene × Neighborhood Social Ties, providing support for an expanded view of social disorganization theory.

  1. The Ties That Bind: How Social Capital Is Forged and Forfeited in Teacher Communities

    Science.gov (United States)

    Bridwell-Mitchell, E. N.; Cooc, North

    2016-01-01

    The effects of social capital on school improvement make it important to understand how teachers forge, maintain, or forfeit collegial relationships. Two common explanations focused on formal organizational features and individual characteristics do not address how social capital accrues from informal dynamics of teachers' interactions in…

  2. Happy but unhealthy: The relationship between social ties and health in an emerging network.

    NARCIS (Netherlands)

    Howell, Jennifer L.; Koudenburg, Namkje; Loschelder, David D.; Weston, Dale; Fransen, Katrien; De Dominices, Stefano; Gallagher, Stephen; Haslam, Sir Alexander

    2014-01-01

    Social connections are essential to health and well-being. However, when pursing social acceptance, people may sometimes engage in behavior that is detrimental to their health. Using a multi-time-point design, we examined whether the structure of an emerging network of students in an academic summer

  3. Mechanisms linking social ties and support to physical and mental health.

    Science.gov (United States)

    Thoits, Peggy A

    2011-06-01

    Over the past 30 years investigators have called repeatedly for research on the mechanisms through which social relationships and social support improve physical and psychological well-being, both directly and as stress buffers. I describe seven possible mechanisms: social influence/social comparison, social control, role-based purpose and meaning (mattering), self-esteem, sense of control, belonging and companionship, and perceived support availability. Stress-buffering processes also involve these mechanisms. I argue that there are two broad types of support, emotional sustenance and active coping assistance, and two broad categories of supporters, significant others and experientially similar others, who specialize in supplying different types of support to distressed individuals. Emotionally sustaining behaviors and instrumental aid from significant others and empathy, active coping assistance, and role modeling from similar others should be most efficacious in alleviating the physical and emotional impacts of stressors.

  4. Collective efficacy as a task specific process: examining the relationship between social ties, neighborhood cohesion and the capacity to respond to violence, delinquency and civic problems.

    Science.gov (United States)

    Wickes, Rebecca; Hipp, John R; Sargeant, Elise; Homel, Ross

    2013-09-01

    In the neighborhood effects literature, collective efficacy is viewed as the key explanatory process associated with the spatial distribution of a range of social problems. While many studies usefully focus on the consequences of collective efficacy, in this paper we examine the task specificity of collective efficacy and consider the individual and neighborhood factors that influence residents' perceptions of neighborhood collective efficacy for specific tasks. Utilizing survey and administrative data from 4,093 residents nested in 148 communities in Australia, we distinguish collective efficacy for particular threats to social order and assess the relative importance of social cohesion and neighborhood social ties to the development of collective efficacy for violence, delinquency and civic/political issues. Our results indicate that a model separating collective efficacy for specific problems from social ties and the more generalized notions of social cohesion is necessary when understanding the regulation potential of neighborhoods.

  5. Building ties: social capital network analysis of a forest community in a biosphere reserve in Chiapas, Mexico

    Directory of Open Access Journals (Sweden)

    Luis Rico García-Amado

    2012-09-01

    Full Text Available Governance of the commons depends on the capacity to generate collective action. Networks and rules that foster that collective action have been defined as social capital. However, their causal link is still not fully understood. We use social network analysis to assess social capital, decision-making, and collective action in a forest-based common pool resource management in La Sepultura Biosphere Reserve (Chiapas, Mexico. Our research analyzes the productive networks and the evolution of coffee groups in one community. The network shows some centrality, with richer landholders tending to occupy core positions and poorer landless peasants occupying peripheral ones. This has fostered the community's environmentally oriented development but has also caused internal conflicts. Market requirements have shaped different but complementary productive networks, where organic coffee commercialization is the main source of bridging ties, which has resulted in more connectivity and resilience. Conservation attitudes, along with the institutional setting of the community, have promoted collective action. The unresolved conflicts, however, still leave some concerns about governance in the future.

  6. Infrastructure and social tie: Spatial model approach on understanding poverty in Malang regency, Indonesia

    Science.gov (United States)

    Ari, I. R. D.; Hasyim, A. W.; Pratama, B. A.; Helmy, M.; Sheilla, M. N.

    2017-06-01

    Poverty is a problem that requires attention from the government especially in developing countries such as Indonesia. This Research takes Place at Kasembon District because it has 53,19% family below poverty line in the region. The purpose of this research is to measure poverty based on 3 poverty indicators published by World Bank and 1 multidimensional poverty index. Furthermore, this research invesitigas the relationship between poverty with social and infrastructure in Kasembon District. This study using social network analysis, hot spots analysis, and regression analysis with ordinary least squares. From the poverty indicators known that Pondokagung Village has the highest poverty rate compared to another region. Results from regression model indicate that social and infrastructure affecting poverty in Kasembon District. Social parameter that affecting poverty is density. Infrastructure parameter that affecting poverty is length of paved road. Coefficient value of density is the largest in the model. Therefore it can be concluded that social factors can give more opportunity to reduce poverty rates in Kasembon District. In the local model of paved road coefficient, it is known that the coefficient for each village has not much different value from the global model.

  7. Social ties and psychological well-being in late life: the mediating role of relationship satisfaction.

    Science.gov (United States)

    Fuller-Iglesias, Heather R

    2015-01-01

    The current paper examines whether quantitative aspects of social support (i.e., support network characteristics) indirectly influence psychological well-being via older adults' qualitative perceptions of support (i.e., satisfaction with social relationships). A sample of 416 adults aged ≥60 was drawn from the Social Integration and Aging Study, a community-based survey conducted in a small US (Midwestern) city. The survey assessed social networks, social support, and physical and mental health among older adults. Bootstrapping was used to examine mediation models. Greater support network size predicted lower perceived stress, fewer depressive symptoms, and better life satisfaction, yet this association was fully mediated by relationship satisfaction. For support network composition, greater proportion kin was associated with lower stress and better life satisfaction, though not depressive symptoms, however, relationship satisfaction did not mediate this link. Findings highlight the complex interplay of support network characteristics and satisfaction, and suggest the greater import of support satisfaction for older adults' psychological well-being.

  8. The relationship between perceived discrimination and high-risk social ties among illicit drug users in New York City, 2006-2009.

    Science.gov (United States)

    Crawford, Natalie D; Ford, Chandra; Galea, Sandro; Latkin, Carl; Jones, Kandice C; Fuller, Crystal M

    2013-01-01

    Discrimination can influence risk of disease by promoting unhealthy behaviors (e.g., smoking, alcohol use). Whether it influences the formation of high-risk social ties that facilitate HIV transmission is unclear. Using cross-sectional data from a cohort of illicit drug users, this study examined the association between discrimination based on race, drug use and prior incarceration and risky sex and drug ties. Negative binomial regression models were performed. Participants who reported discrimination based on race and drug use had significantly more sex and drug-using ties. But, after accounting for both racial and drug use discrimination, only racial discrimination was associated with increased sex, drug-using, and injecting ties. Drug users who experience discrimination and subsequently develop more sex and drug-using ties, increase their risk of contracting HIV. Future longitudinal studies illuminating the pathways linking discrimination and social network development may guide intervention development and identify drug-using subpopulations at high risk for disease transmission.

  9. Ties with Potential: Social Network Structure and Innovative Climate in Dutch Schools

    Science.gov (United States)

    Moolenaar, Nienke M.; Daly, Alan J.; Sleegers, Peter J. C.

    2011-01-01

    Background/Context: Similar to the United States, government efforts to improve education in the Netherlands are focused on innovation and the development of collaborative structures to support the generation of new knowledge. However, empirical evidence of the relationship between social linkages and innovation in education is scarce. Objective:…

  10. Ties with potential: Social network structure and innovative climate in Dutch schools

    NARCIS (Netherlands)

    Moolenaar, N.M.; Daly, A.J.; Sleegers, P.J.C.

    2011-01-01

    Background/Context: Similar to the United States, government efforts to improve education in the Netherlands are focused on innovation and the development of collaborative structures to support the generation of new knowledge. However, empirical evidence of the relationship between social linkages a

  11. Social Network Perspectives Reveal Strength of Academic Developers as Weak Ties

    Science.gov (United States)

    Matthews, Kelly E.; Crampton, Andrea; Hill, Matthew; Johnson, Elizabeth D.; Sharma, Manjula D.; Varsavsky, Cristina

    2015-01-01

    Social network perspectives acknowledge the influence of disciplinary cultures on academics' teaching beliefs and practices with implications for academic developers. The contribution of academic developers in 18 scholarship of teaching and learning (SoTL) projects situated in the sciences are explored by drawing on data from a two-year national…

  12. Ties with potential: Social network structure and innovative climate in Dutch schools

    NARCIS (Netherlands)

    Moolenaar, N.M.; Daly, A.J.; Sleegers, P.J.C.

    2011-01-01

    Background/Context: Similar to the United States, government efforts to improve education in the Netherlands are focused on innovation and the development of collaborative structures to support the generation of new knowledge. However, empirical evidence of the relationship between social linkages a

  13. Ties with potential: Social network structure and innovative climate in Dutch schools

    NARCIS (Netherlands)

    Moolenaar, N.M.; Daly, A.J.; Sleegers, P.J.C.

    2011-01-01

    Background/Context: Similar to the United States, government efforts to improve education in the Netherlands are focused on innovation and the development of collaborative structures to support the generation of new knowledge. However, empirical evidence of the relationship between social linkages

  14. Ties That Bond: Youth Sport as a Vehicle for Social Identity and Positive Youth Development

    Science.gov (United States)

    Bruner, Mark W.; Balish, Shea M.; Forrest, Christopher; Brown, Sarah; Webber, Kristine; Gray, Emily; McGuckin, Matthew; Keats, Melanie R.; Rehman, Laurene; Shields, Christopher A.

    2017-01-01

    An emerging area of research has focused on understanding how the group dynamics of a sport team influence positive youth development (PYD). The identities that youth form through their membership in sport teams (i.e., social identities) have been found to influence teammate behavior and team performance. Yet, minimal work exists on social…

  15. Social Network Perspectives Reveal Strength of Academic Developers as Weak Ties

    Science.gov (United States)

    Matthews, Kelly E.; Crampton, Andrea; Hill, Matthew; Johnson, Elizabeth D.; Sharma, Manjula D.; Varsavsky, Cristina

    2015-01-01

    Social network perspectives acknowledge the influence of disciplinary cultures on academics' teaching beliefs and practices with implications for academic developers. The contribution of academic developers in 18 scholarship of teaching and learning (SoTL) projects situated in the sciences are explored by drawing on data from a two-year national…

  16. "You Cannot Talk with All of the Strangers in a Pub": A Longitudinal Case Study of International Postgraduate Students' Social Ties at a British University

    Science.gov (United States)

    Schartner, Alina

    2015-01-01

    The formation of social ties is a major factor in the international student experience (Ramsay et al. in High Educ 54(2):247-265, 2007), influencing student wellbeing and adjustment to the new academic and sociocultural environment (Ward et al. in The psychology of culture shock. Routledge, Hove, 2001). Although a significant body of research in…

  17. "You Cannot Talk with All of the Strangers in a Pub": A Longitudinal Case Study of International Postgraduate Students' Social Ties at a British University

    Science.gov (United States)

    Schartner, Alina

    2015-01-01

    The formation of social ties is a major factor in the international student experience (Ramsay et al. in High Educ 54(2):247-265, 2007), influencing student wellbeing and adjustment to the new academic and sociocultural environment (Ward et al. in The psychology of culture shock. Routledge, Hove, 2001). Although a significant body of research in…

  18. Learning from Your Network of Friends: A Trajectory Representation Learning Model Based on Online Social Ties

    KAUST Repository

    Alharbi, Basma Mohammed

    2017-02-07

    Location-Based Social Networks (LBSNs) capture individuals whereabouts for a large portion of the population. To utilize this data for user (location)-similarity based tasks, one must map the raw data into a low-dimensional uniform feature space. However, due to the nature of LBSNs, many users have sparse and incomplete check-ins. In this work, we propose to overcome this issue by leveraging the network of friends, when learning the new feature space. We first analyze the impact of friends on individuals\\'s mobility, and show that individuals trajectories are correlated with thoseof their friends and friends of friends (2-hop friends) in an online setting. Based on our observation, we propose a mixed-membership model that infers global mobility patterns from users\\' check-ins and their network of friends, without impairing the model\\'s complexity. Our proposed model infers global patterns and learns new representations for both usersand locations simultaneously. We evaluate the inferred patterns and compare the quality of the new user representation against baseline methods on a social link prediction problem.

  19. Family Ties and Civic Virtues

    DEFF Research Database (Denmark)

    Ljunge, Jan Martin

    I establish a positive relationship between family ties and civic virtues, as captured by disapproval of tax and benefit cheating, corruption, and a range of other dimensions of exploiting others for personal gain. I find that family ties are a complement to social capital, using within country...

  20. New Tech, New Ties:

    DEFF Research Database (Denmark)

    Ling, Richard

    regardless of where they are. But when we are engaged in these intimate conversations with absent friends, what happens to our relationship with the people who are actually in the same room with us? In New Tech, New Ties, Rich Ling examines how the mobile telephone affects both kinds of interactions......—those mediated by mobile communication and those that are face to face. Ling finds that through the use of various social rituals the mobile telephone strengthens social ties within the circle of friends and family—sometimes at the expense of interaction with those who are physically present—and creates what he...... calls "bounded solidarity." Ling argues that mobile communication helps to engender and develop social cohesion within the family and the peer group. Drawing on the work of Emile Durkheim, Erving Goffman, and Randall Collins, Ling shows that ritual interaction is a catalyst for the development of social...

  1. Sensory response system of social behavior tied to female reproductive traits.

    Directory of Open Access Journals (Sweden)

    Jennifer M Tsuruda

    Full Text Available BACKGROUND: Honey bees display a complex set of anatomical, physiological, and behavioral traits that correlate with the colony storage of surplus pollen (pollen hoarding. We hypothesize that the association of these traits is a result of pleiotropy in a gene signaling network that was co-opted by natural selection to function in worker division of labor and foraging specialization. By acting on the gene network, selection can change a suite of traits, including stimulus/response relationships that affect individual foraging behavior and alter the colony level trait of pollen hoarding. The 'pollen-hoarding syndrome' of honey bees is the best documented syndrome of insect social organization. It can be exemplified as a link between reproductive anatomy (ovary size, physiology (yolk protein level, and foraging behavior in honey bee strains selected for pollen hoarding, a colony level trait. The syndrome gave rise to the forager-Reproductive Ground Plan Hypothesis (RGPH, which proposes that the regulatory control of foraging onset and foraging preference toward nectar or pollen was derived from a reproductive signaling network. This view was recently challenged. To resolve the controversy, we tested the associations between reproductive anatomy, physiology, and stimulus/response relationships of behavior in wild-type honey bees. METHODOLOGY/PRINCIPAL FINDINGS: Central to the stimulus/response relationships of honey bee foraging behavior and pollen hoarding is the behavioral trait of sensory sensitivity to sucrose (an important sugar in nectar. To test the linkage of reproductive traits and sensory response systems of social behavior, we measured sucrose responsiveness with the proboscis extension response (PER assay and quantified ovary size and vitellogenin (yolk precursor gene expression in 6-7-day-old bees by counting ovarioles (ovary filaments and by using semiquantitative real time RT-PCR. We show that bees with larger ovaries (more ovarioles

  2. Binding Ties

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Sino-U.S.Strategic Economic Dialogue is an important platform for the healthy development of the two countries’ trade and economic ties The Sino-U.S.Strategic Economic Dialogue(SED)meetings focus mainly on strategic,long-term and upper-level problems in bilateral eco- nomic relations between China and the United States.They serve as a platform for deepening understanding between the two countries and prompting the healthy develop-

  3. LA PULSIÓN Y EL LAzO SOCIAL. COMBINACIÓN DE GOCE Y DESEO, LAzO Y FRACTURA, AMOR Y ODIO QUE SE ENCUENTRAN INTRINCADOS EN EL MOVIMIENTO DE LAS PULSIONES -- THE PULSION AND THE SOCIAL TIE. COMBINATION OF POSSESSION AND DESIRE, TIE AND FAULT, LOVE AND HATE THAT ARE INTRICATE IN THE MOVEMENT OF PULSIONS

    Directory of Open Access Journals (Sweden)

    CARLOS ANDRÉS HURTADO DÍAZ

    2008-06-01

    Full Text Available The present article is drawn from a personal research that some years ago was initiated in Risaralda’s Catholic Popular university (Colombia in the psychology program about the idea of Pulsion and today is promoted from Master in Psychoanalysis of the university Argentina John F. Kennedy. It is trying to make clear as the sequence. The Author tries to demonstrate as the sequence: Totem, father, law and desire gives origin to the different social organizations. Analyzing the strengthen relation and coordination between unconsciously, pulsion and social tie, which was formulated by Freud, through oedipal myths and through primitive hordes, and it makes clear that established social ties are possible thanks to the plasticity of pulsion, which osculate in swing and forces the subject between good and evil, love and hate, possession and desire, tie and fault. It should be highlighted that the research is limited from the Freudian Psychoanalytic Theory point of view.

  4. Longitudinal analysis of large social networks: estimating the effect of health traits on changes in friendship ties.

    Science.gov (United States)

    O'Malley, A James; Christakis, Nicholas A

    2011-04-30

    We develop novel mixed effects models to examine the role of health traits on the status of peoples' close friendship nominations in the Framingham Heart Study. The health traits considered are both mutable (body mass index (BMI), smoking, blood pressure, body proportion, muscularity, and depression) and, for comparison, basically immutable (height, birth order, personality type, only child, and handedness); and the traits have varying degrees of observability. We test the hypotheses that existing ties (i.e. close friendship nominations) are more likely to dissolve between people with dissimilar (mutable and observable) health traits whereas new ties are more likely to form between those with similar (mutable and observable) traits while controlling for persons' age, gender, geographic separation, and education. The mixed effects models contain random effects for both the nominator (ego) and nominated (alter) persons in a tie to account for the fact that people were involved in multiple relationships and contributed observations at multiple exams. Results for BMI support the hypotheses that people of similar BMI are less likely to dissolve existing ties and more likely to form ties, while smoker to non-smoker ties were the least likely to dissolve and smoker to smoker ties were the most likely to form. We also validated previously known findings regarding homophily on age and gender, and found evidence that homophily also depends upon geographic separation. Copyright © 2011 John Wiley & Sons, Ltd.

  5. Relevant ties matter

    DEFF Research Database (Denmark)

    Larsen, Christian Albrekt; Pedersen, Jacob; Mouw, Ted

    What is the effect of social networks on labor market outcomes? The tradition following Grannovetter claims that social ties have a positive effect on wages, job prestige and job satisfaction. Although a number of studies have found positive correlations between friendship characteristics...... and labour market status, there is still disagreement on whether or not the effect is causal. One objection is that the correlations could be caused by social homophily--the fact that similar people tend to become friends with each other. This paper uses unique labor market data from Denmark to test...

  6. Secure Ties

    NARCIS (Netherlands)

    Joep de Hart; Frans Knol; Cora Maas - de Waal; Theo Roes

    2002-01-01

    Original title: Zekere banden. Discussions about the Netherlands of today often throw up terms such as 'social cohesion', 'social integration', 'liveability' and 'security'. The Netherlands Institute for Social Research/SCP has carried out a study of this phenomenon and presents the results in this

  7. The role of strong-tie social networks in mediating food security of fish resources by a traditional riverine community in the Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Frédéric Mertens

    2015-09-01

    Full Text Available Social networks are a significant way through which rural communities that manage resources under common property regimes obtain food resources. Previous research on food security and social network analysis has mostly focused on egocentric network data or proxy variables for social networks to explain how social relations contribute to the different dimensions of food security. Whole-network approaches have the potential to contribute to former studies by revealing how individual social ties aggregate into complex structures that create opportunities or constraints to the sharing and distribution of food resources. We used a whole-network approach to investigate the role of network structure in contributing to the four dimensions of food security: food availability, access, utilization, and stability. For a case study of a riparian community from the Brazilian Amazon that is dependent on fish as a key element of food security, we mapped the community strong-tie network among 97% of the village population over 14 years old (n = 336 by integrating reciprocated friendship and occupational ties, as well as close kinship relationships. We explored how different structural properties of the community network contribute to the understanding of (1 the availability of fish as a community resource, (2 community access to fish as a dietary resource, (3 the utilization of fish for consumption in a way that allows the villagers to maximize nutrition while at the same time minimizing toxic risks associated with mercury exposure, and (4 the stability of the fish resources in local ecosystems as a result of cooperative behaviors and community-based management. The contribution of whole-network approaches to the study of the links between community-based natural resource management and food security were discussed in the context of recent social-ecological changes in the Amazonian region.

  8. No creative person is an island: Organisational culture, academic project-based creativity, and the mediating role of intra-organisational social ties

    Directory of Open Access Journals (Sweden)

    Leon AG Oerlemans

    2014-02-01

    Full Text Available This paper examines the relationship between perceptions of organizational culture, academics’ social embeddedness, and their creative paper project output. It argues that the extent to which researchers working on paper projects are socially embedded by having social ties with colleagues inside and outside their academic department (but within the same university is a causal step linking organizational values and norms to creative outputs. This study, however, does not find support for the proposed mediating effects. Instead, results indicate that three organizational culture dimensions – i.e. performance orientation, environmental orientation, and innovation support – affect employees’ creative project output through their social embeddedness outside the department (but within their own university. As the organizational culture and social embeddedness of employees outside the department are both contextual factors that (either indirectly or directly matter for the generation of creative project outputs by researchers, this study concludes that “no creative person and no project is an island”.

  9. Tongue-Tie (Ankyloglossia)

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Tongue-tie (Ankyloglossia) Tongue-tie (Ankyloglossia) Patient Health Information ... may be serious in some individuals. When Is Tongue-tie a Problem That Needs Treatment? In Infants ...

  10. Network ties and survival

    DEFF Research Database (Denmark)

    Acheampong, George; Narteh, Bedman; Rand, John

    2017-01-01

    of the SCPFs in Ghana. Distribution ties are associated with negative survival chances and this is not even reversed if the human capital of the owner increases although managers with higher human capital and higher distribution ties experience positive effects. Industry ties are associated with positive ties...

  11. Senior Managers’ Network Tie Use

    DEFF Research Database (Denmark)

    Zarzecka, Olga; Villeseche, Florence

    While the importance or even necessity to build and maintain resourceful social networks appears as a forthright fact, there is still a lack of certainty as to who benefits from the resources that can be accessed through senior managers’ networks, and under what conditions. In this paper, we...... contribute to answering this puzzle with a sample constituted of senior managers from Denmark and their network ties, and investigate both economic and sociological conditions of senior managers’ tie use. Our results show that the greater the distance between aspiration level and actual firm performance......, the more likely it is that senior managers will use their network ties to access resources that benefit chiefly the individual rather than the organization. In addition, we demonstrate that this rapport is moderated by senior managers’ social identity as a member of the corporate elite, so that a strong...

  12. The ties that bind: genetic relatedness predicts the fission and fusion of social groups in wild African elephants

    OpenAIRE

    Archie, Elizabeth A.; Moss, Cynthia J; Alberts, Susan C.

    2005-01-01

    Many social animals live in stable groups. In contrast, African savannah elephants (Loxodonta africana) live in unusually fluid, fission–fusion societies. That is, ‘core’ social groups are composed of predictable sets of individuals; however, over the course of hours or days, these groups may temporarily divide and reunite, or they may fuse with other social groups to form much larger social units. Here, we test the hypothesis that genetic relatedness predicts patterns of group fission and fu...

  13. Family Ties and Civic Virtues

    DEFF Research Database (Denmark)

    Ljunge, Jan Martin

    I establish a positive relationship between family ties and civic virtues, as captured by disapproval of tax and benefit cheating, corruption, and a range of other dimensions of exploiting others for personal gain. I find that family ties are a complement to social capital, using within country...... evidence from 83 nations and data on second generation immigrants in 29 countries with ancestry in 85 nations. Strong families cultivate universalist values and produce more civic and altruistic individuals. The results provide a constructive role for families in promoting family values that support...

  14. The ties that bind: genetic relatedness predicts the fission and fusion of social groups in wild African elephants.

    Science.gov (United States)

    Archie, Elizabeth A; Moss, Cynthia J; Alberts, Susan C

    2006-03-07

    Many social animals live in stable groups. In contrast, African savannah elephants (Loxodonta africana) live in unusually fluid, fission-fusion societies. That is, 'core' social groups are composed of predictable sets of individuals; however, over the course of hours or days, these groups may temporarily divide and reunite, or they may fuse with other social groups to form much larger social units. Here, we test the hypothesis that genetic relatedness predicts patterns of group fission and fusion among wild, female African elephants. Our study of a single Kenyan population spans 236 individuals in 45 core social groups, genotyped at 11 microsatellite and one mitochondrial DNA (mtDNA) locus. We found that genetic relatedness predicted group fission; adult females remained with their first order maternal relatives when core groups fissioned temporarily. Relatedness also predicted temporary fusion between social groups; core groups were more likely to fuse with each other when the oldest females in each group were genetic relatives. Groups that shared mtDNA haplotypes were also significantly more likely to fuse than groups that did not share mtDNA. Our results suggest that associations between core social groups persist for decades after the original maternal kin have died. We discuss these results in the context of kin selection and its possible role in the evolution of elephant sociality.

  15. Tie rod insertion test

    CERN Multimedia

    B. LEVESY

    2002-01-01

    The superconducting coil is inserted in the outer vaccum tank and supported by a set of tie rods. These tie rods are made of titanium alloy. This test reproduce the final insertion of the tie rods inside the outer vacuum tank.

  16. Tie Content in Professional Networks

    DEFF Research Database (Denmark)

    Zarzecka, Olga

    Professional networks of senior managers have indisputable value for them as well as for their organizations. In recent years, much attention has been given to the structure of these networks as it reflects senior managers’ opportunity to access valuable resources. Surprisingly, the actual...... introduces the topic of this dissertation as well as the overall research question. The three next chapters are empirical studies of informal ties in professional networks of Danish senior managers, that together attempt to answer the overall research question. Chapter 2 looks into gender differences...... in resource exchanges and the effect of these differences on the number of, and extent to which, resources are provided by a network tie. Chapter 3 explores how firm underperfomance and social identity with corporate elite alter types of resources a network tie provides. Chapter 4 focuses on a tie’s internal...

  17. The social nature of the mother's tie to her child: John Bowlby's theory of attachment in post-war America.

    Science.gov (United States)

    Vicedo, Marga

    2011-09-01

    This paper examines the development of British psychiatrist and psychoanalyst John Bowlby's views and their scientific and social reception in the United States during the 1950s. In a 1951 report for the World Health Organization Bowlby contended that the mother is the child's psychic organizer, as observational studies of children worldwide showed that absence of mother love had disastrous consequences for children's emotional health. By the end of the decade Bowlby had moved from observational studies of children in hospitals to animal research in order to support his thesis that mother love is a biological need. I examine the development of Bowlby's views and their scientific and social reception in the United States during the 1950s, a central period in the evolution of his views and in debates about the social implications of his work. I argue that Bowlby's view that mother love was a biological need for children influenced discussions about the desirability of mothers working outside the home during the early Cold War. By claiming that the future of a child's mind is determined by her mother's heart, Bowlby's argument exerted an unusually strong emotional demand on mothers and had powerful implications for the moral valuation of maternal care and love.

  18. 社会网络中弱关系团队形成问题研究%Team Formation with Weak Ties in Social Networks

    Institute of Scientific and Technical Information of China (English)

    孙焕良; 富珊珊; 刘俊岭; 于戈; 许鸿斐

    2016-01-01

    随着在线社会网络的迅速发展,社会网络的团队形成问题逐渐成为研究热点。现有的社会网络中团队形成问题目标是寻找一个成员间沟通代价最小的团队。然而,实际应用中团队成员间的不紧密关系使得团队的观点多样化、多角度、无偏见,可以广泛应用于形成专家评审团队、大众评审团等。基于此需求,将社会学的弱关系概念引入团队形成问题中,提出了一种社会网络中弱关系团队形成问题。该问题旨在寻找成员间为弱关系,同时满足技能、经验值要求的一个团队,为NP-hard问题。提出了3类算法解决该问题,分别为贪心算法、精确算法、α-近似算法,每类算法有各自的特点与适用范围。利用ACM和DBLP两类真实的数据集进行实验,综合评估了各类算法的效率与求解质量,证明了提出算法的有效性。%As the online social network grows rapidly, the team formation problem becomes more and more popular. Previous research on team formation aimed at finding a team of experts with the lowest communication cost. However, in expert or public jury, as untighten relationship can guarantee diversified attitudes and refrain from prejudice, there are numerous quests which to find a weak connected team. Based on this requirement, this paper proposes the problem of team formation with weak ties in social networks by introducing the concept of weak ties in sociology. This prob-lem aims to find a team with weak ties between members and satisfy the requirement of skills and experience, it is an NP-hard problem. This paper designs three kinds of algorithms for the problem, they are greedy algorithm, exact algo-rithm andα-approximate algorithm. Every kind of algorithm has distinct property and scope. The experimental results on ACM and DBLP real datasets show the quality and confirm the effectiveness and efficiency of proposed algorithms.

  19. 在线社交网络中具有传播价值的弱关系识别研究%Identifying Weak Ties with Value of Dissemination in Online Social Networks

    Institute of Scientific and Technical Information of China (English)

    尹熙成; 朱恒民; 魏静; 马静

    2016-01-01

    [目的/意义]鉴于在线社交网络中的部分弱关系在信息传播中扮演了重要角色,提出定量模型来计算和识别具有传播价值的弱关系,以更好地了解网络中信息传播的关系结构。[方法/过程]基于历史交互数据定义了连边权重,运用PageRank算法思想确定网络中的关键节点,最后对关键节点间的弱关系路径进行重要性评价,以识别具有传播价值的弱关系。[结果/结论]实验表明,弱关系路径使信息能够在以意见领袖为中心的社交团体之间“链式”传播,也从侧面揭示了网络中信息流动的关系结构。%Purpose/Significance] Partial weak ties in online social network play significant roles in the process of information diffusion. This aims to better understand the relationship structure of information dissemination. [ Method/Process] We measured the link strength based on historical interaction records, and identified influential nodes PageRank technology. Finally the importance of paths containing weak ties were evaluated to identify weak ties with value of dissemination in online social networks. [ Result/Conclusion] The experimen-tal result show that the paths containing weak ties make it possible for information to spread between social groups represented by opinion leaders, and these important paths containing weak ties reveal the relational structure of information diffusion as well.

  20. ONGs/Aids, intervenções sociais e novos laços de solidariedade social Nongovernmental Organizations and AIDS, social intervention, and new ties in social solidarity

    Directory of Open Access Journals (Sweden)

    Cristina Luci Câmara da Silva

    1998-01-01

    Full Text Available A partir de uma breve contextualização do cenário social em que surge a epidemia da Aids no Brasil, o artigo situa a formação das primeiras Organizações Não Governamentais de luta contra a Aids no País. Atribuem-se peculiaridades às ONGs/Aids, na medida em que elas apresentam uma ambivalência entre o que caracteriza uma instituição profissionalizada e um grupo de pressão, além de lidar com questões como a sexualidade e a morte, rompendo as fronteiras entre as esferas pública e privada. Tendo como referência o Grupo Pela Vidda/RJ, procura-se apresentar a relação entre a valorização de um grupo de indivíduos e o princípio de universalidade presente na atuação do mesmo. Por fim, apresenta-se a hipótese de que as ONGs/Aids renovam os laços de solidariedade social a partir das relações que estabelecem com as esferas governamentais, os diversos pesquisadores envolvidos com a temática e as outras ONGs.Starting with a brief contextual analysis of the social scenario in which the AIDS epidemic is occurring in Brazil, the article focuses on the formation of the country's first Nongovernmental Organizations in the struggle against AIDS. There are peculiarities to AIDS NGOs to the extent that they display an ambivalence between the characteristics of a professional institution and a lobbying group, apart from the fact that dealing with sexuality and death breaks down the line between the public and the private spheres. The case in point is the Grupo Pela Vidda (For Life Group in Rio de Janeiro, which seeks to represent the enhancement of a group of individuals and the principle of universality. The study supports the hypothesis that AIDS NGOs renew ties of social solidarity through the relationships established between various researchers involved in this sector and other NGOs with governmental spheres.

  1. Young adults, social networks, and addiction recovery: post treatment changes in social ties and their role as a mediator of 12-step participation.

    Directory of Open Access Journals (Sweden)

    John F Kelly

    Full Text Available BACKGROUND: Social factors play a key role in addiction recovery. Research with adults indicates individuals with substance use disorder (SUD benefit from mutual-help organizations (MHOs, such as Alcoholics Anonymous, via their ability to facilitate adaptive network changes. Given the lower prevalence of sobriety-conducive, and sobriety-supportive, social contexts in the general population during the life-stage of young adulthood, however, 12-step MHOs may play an even more crucial recovery-supportive social role for young adults, but have not been investigated. Greater knowledge could enhance understanding of recovery-related change and inform young adults' continuing care recommendations. METHODS: Emerging adults (N = 302; 18-24 yrs; 26% female; 95% White enrolled in a study of residential treatment effectiveness were assessed at intake, 1, 3, 6, and 12 months on 12-step attendance, peer network variables ("high [relapse] risk" and "low [relapse] risk" friends, and treatment outcomes (Percent Days Abstinent; Percent Days Heavy Drinking. Hierarchical linear models tested for change in social risk over time and lagged mediational analyses tested whether 12-step attendance conferred recovery benefits via change in social risk. RESULTS: High-risk friends were common at treatment entry, but decreased during follow-up; low-risk friends increased. Contrary to predictions, while substantial recovery-supportive friend network changes were observed, this was unrelated to 12-step participation and, thus, not found to mediate its positive influence on outcome. CONCLUSIONS: Young adult 12-step participation confers recovery benefit; yet, while encouraging social network change, 12-step MHOs may be less able to provide social network change directly for young adults, perhaps because similar-aged peers are less common in MHOs. Findings highlight the importance of both social networks and 12-step MHOs and raise further questions as to how young adults benefit

  2. More ties than we thought

    Directory of Open Access Journals (Sweden)

    Dan Hirsch

    2015-05-01

    Full Text Available We extend the existing enumeration of neck tie-knots to include tie-knots with a textured front, tied with the narrow end of a tie. These tie-knots have gained popularity in recent years, based on reconstructions of a costume detail from The Matrix Reloaded, and are explicitly ruled out in the enumeration by Fink & Mao (2000. We show that the relaxed tie-knot description language that comprehensively describes these extended tie-knot classes is context free. It has a regular sub-language that covers all the knots that originally inspired the work. From the full language, we enumerate 266,682 distinct tie-knots that seem tie-able with a normal neck-tie. Out of these 266,682, we also enumerate 24,882 tie-knots that belong to the regular sub-language.

  3. The evolution of prompt reaction to adverse ties

    Directory of Open Access Journals (Sweden)

    Nowé Ann

    2008-10-01

    Full Text Available Abstract Background In recent years it has been found that the combination of evolutionary game theory with population structures modelled in terms of dynamical graphs, in which individuals are allowed to sever unwanted social ties while keeping the good ones, provides a viable solution to the conundrum of cooperation. It is well known that in reality individuals respond differently to disadvantageous interactions. Yet, the evolutionary mechanism determining the individuals' willingness to sever unfavourable ties remains unclear. Results We introduce a novel way of thinking about the joint evolution of cooperation and social contacts. The struggle for survival between cooperators and defectors leads to an arms race for swiftness in adjusting social ties, based purely on a self-regarding, individual judgement. Since defectors are never able to establish social ties under mutual agreement, they break adverse ties more rapidly than cooperators, who tend to evolve stable and long-term relations. Ironically, defectors' constant search for partners to exploit leads to heterogeneous networks that improve the survivability of cooperators, compared to the traditional homogenous population assumption. Conclusion When communities face the prisoner's dilemma, swift reaction to adverse ties evolves when competition is fierce between cooperators and defectors, providing an evolutionary basis for the necessity of individuals to adjust their social ties. Our results show how our innate resilience to change relates to mutual agreement between cooperators and how "loyalty" or persistent social ties bring along an evolutionary disadvantage, both from an individual and group perspective.

  4. The Strength of Varying Tie Strength

    CERN Document Server

    Bruggeman, Jeroen

    2012-01-01

    "The Strength of Weak Ties" argument (Granovetter 1973) says that the most valuable information is best collected through bridging ties with other social circles than one's own, and that those ties tend to be weak. Aral and Van Alstyne (2011) added that to access complex information, actors need strong ties ("high bandwidth") instead. These insights I generalize by pointing at actors' interest to avoid spending large resources on low value information. Weak ties are well-suited for relatively simple information at low transmission and tie maintenance costs, whereas for complex information, the best outcomes are expected for those actors who vary their bandwidths along with the value of information accessed. To support my claim I use all patents in the USA (two million) over the period 1975-1999. I also show that in rationalized fields, such as technology, bandwidth correlates highly with the value of information, which provides support for using this proxy if value can't be measured directly. Finally, I show ...

  5. The Ties That Bind

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China and the United States prepare for their first Strategic and Economic Dialogue U.S. Treasury Secretary Timothy Geithner’s China trip from May 31 to June 2 sent a clear message that the two countries plan to establish stronger ties not only in the economic field, but also in other areas where they have com-

  6. Strong Ties, Weak Ties, and Human Capital: Latino Immigrant Employment outside the Enclave

    Science.gov (United States)

    Pfeffer, Max J.; Parra, Pilar A.

    2009-01-01

    This study focuses on the role of social ties and human capital in the integration of Latino immigrants into the local economy. This analysis extends earlier research by focusing on more rural contexts with limited labor-market opportunities and less access to social resources provided by coethnics. We reconsider conclusions of previous studies by…

  7. Zika Now Tied to Miscarriage

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160101.html Zika Now Tied to Miscarriage Dutch case finds woman's ... tied to maternal infection with the mosquito-borne Zika virus. The virus is best known for its ...

  8. Migrant networks and international migration: testing weak ties.

    Science.gov (United States)

    Liu, Mao-Mei

    2013-08-01

    This article examines the role of migrant social networks in international migration and extends prior research by testing the strength of tie theory, decomposing networks by sources and resources, and disentangling network effects from complementary explanations. Nearly all previous empirical research has ignored friendship ties and has largely neglected extended-family ties. Using longitudinal data from the Migration between Africa and Europe project collected in Africa (Senegal) and Europe (France, Italy, and Spain), this article tests the robustness of network theory-and in particular, the role of weak ties-on first-time migration between Senegal and Europe. Discrete-time hazard model results confirm that weak ties are important and that network influences appear to be gendered, but they do not uphold the contention in previous literature that strong ties are more important than weak ties for male and female migration. Indeed, weak ties play an especially important role in male migration. In terms of network resources, having more resources as a result of strong ties appears to dampen overall migration, while having more resources as a result of weaker ties appears to stimulate male migration. Finally, the diversity of resources has varied effects for male and female migration.

  9. Tying the Manager's Hands

    DEFF Research Database (Denmark)

    Foss, Kirsten; Foss, Nicolai Juul; Vázquez-Vicente, Xosé H.

    2003-01-01

    AbstractWe discuss and empirically examine a firm-level equivalent of the ancient problem of `tying the King's hands,' namely how to maximize managerial intervention for `good cause,' while avoiding intervention for `bad cause.' Managers may opportunistically intervene when such intervention...... produces private benefits. Overall firm performance is harmed as a result, because opportunistic managerial intervention harms employee motivation. The central point of the paper is that various mechanisms and factors, such as managers staking their personal reputation, employees controlling important...

  10. The Tie retraction syndrome.

    Science.gov (United States)

    Geerling, Gerd; Neppert, Birte; Hemmant, Bridget

    2012-12-01

    Tissue retraction is implicated in the pathogenesis of various ophthalmic disorders. Here we describe the clinical characteristics, epidemiology and pathophysiology of a form of retraction syndrome which - to the best of our knowledge - has not been reported in the ophthalmic literature so far. We have termed this condition - consisting of a slowly progressive pseudovertical shortening of tie length due to a horizontal extension of girth length - the "Tie retraction syndrome" (TRS). Other pathognomonic features include an increased tie tip to belt buckle distance and a prolapse of the subumbilical fat pad (SUFP). The syndrome has a clear male to female preponderance and shows an increasing incidence with age and income before tax. Based on a newly proposed grading scheme we discuss and illustrate the diagnosis as well as the medical and surgical management options of this abundant, but often undiagnosed condition. The authors have no explanation for the apparent lack of awareness for this widely preponderant syndrome and its severe cosmetically disfiguring potential. We thus would like to invite all fellow colleagues with expertise in the field to comment or present their views.

  11. Water and Tie

    Institute of Scientific and Technical Information of China (English)

    小诗

    1999-01-01

    A tourist got separated from his tour group in the Sahara. He begged apassing nomad (游牧部落的人) for water." Sorry," said the tribesman (部落男子), "I have no water, but I do have some lovely neckties I’ll sell you." "Youmust be crazy," the tourist mumbled (喃喃而语). Nearly dead from thirst, hespied (发现) another man." Water!" the tourist gasped. "Please, give mewater. ""I have no water," came the reply, "only these handsome ties, which Iwill happily sell you."

  12. Directed homology

    DEFF Research Database (Denmark)

    Fahrenberg, Uli

    2004-01-01

    We introduce a new notion of directed homology for semicubical sets. We show that it respects directed homotopy and is functorial, and that it appears to enjoy some good algebraic properties. Our work has applications to higher-dimensional automata.......We introduce a new notion of directed homology for semicubical sets. We show that it respects directed homotopy and is functorial, and that it appears to enjoy some good algebraic properties. Our work has applications to higher-dimensional automata....

  13. Ties between ageing plasticity and reproductive physiology in honey bees (Apis mellifera) reveal a positive relation between fecundity and longevity as consequence of advanced social evolution.

    Science.gov (United States)

    Rueppell, Olav; Aumer, Denise; Moritz, Robin Fa

    2016-08-01

    Honey bees (Apis mellifera) are the best studied model of ageing among the social insects. As in other social insects, the reproductive queen far outlives her non-reproductive workers despite developing from the same genome in the same colony environment. Thus, the different social roles of the two female castes are critical for the profound phenotypic plasticity. In several special cases, such as the reproductive workers of Apis mellifera capensis, within-caste plasticity enables further studies of the fecundity-longevity syndrome in honey bees. At present, molecular evidence suggests that a reorganization of physiological control pathways may facilitate longevity of reproductive individuals. However, the social role and social environment of the different colony members are also very important and one of the key future questions is how much social facilitation versus internal regulation is responsible for the positive association between fecundity and longevity in honey bees.

  14. Why do leaf-tying caterpillars abandon their leaf ties?

    Directory of Open Access Journals (Sweden)

    Michelle Sliwinski

    2013-09-01

    Full Text Available Leaf-tying caterpillars act as ecosystem engineers by building shelters between overlapping leaves, which are inhabited by other arthropods. Leaf-tiers have been observed to leave their ties and create new shelters (and thus additional microhabitats, but the ecological factors affecting shelter fidelity are poorly known. For this study, we explored the effects of resource limitation and occupant density on shelter fidelity and assessed the consequences of shelter abandonment. We first quantified the area of leaf material required for a caterpillar to fully develop for two of the most common leaf-tiers that feed on white oak, Quercus alba. On average, Psilocorsis spp. caterpillars consumed 21.65 ± 0.67 cm2 leaf material to complete development. We also measured the area of natural leaf ties found in a Maryland forest, to determine the distribution of resources available to caterpillars in situ. Of 158 natural leaf ties examined, 47% were too small to sustain an average Psilocorsis spp. caterpillar for the entirety of its development. We also manipulated caterpillar densities within experimental ties on potted trees to determine the effects of cohabitants on the likelihood of a caterpillar to leave its tie. We placed 1, 2, or 4 caterpillars in ties of a standard size and monitored the caterpillars twice daily to track their movement. In ties with more than one occupant, caterpillars showed a significantly greater propensity to leave their tie, and left sooner and at a faster rate than those in ties as single occupants. To understand the consequences of leaf tie abandonment, we observed caterpillars searching a tree for a site to build a shelter in the field. This is a risky behavior, as 17% of the caterpillars observed died while searching for a shelter site. Caterpillars that successfully built a shelter traveled 110 ± 20 cm and took 28 ± 7 min to find a suitable site to build a shelter. In conclusion, leaf-tying caterpillars must frequently

  15. Family ties and residential locations

    NARCIS (Netherlands)

    Mulder, C.H.; Cooke, T.J.

    2009-01-01

    In this paper, and in the Special Issue it introduces, the focus is on the role of family ties in residential location choice and, conversely, the role of residential locations in maintaining family ties. Not only do events in the nuclear family trigger residential relocations, but nearby family mem

  16. Homological descent for motivic homology theories

    OpenAIRE

    Geisser, Thomas

    2014-01-01

    The purpose of this paper is to give homological descent theorems for motivic homology theories (for example, Suslin homology) and motivic Borel-Moore homology theories (for example, higher Chow groups) for certain hypercoverings.

  17. [Combating poverty and rebuilding social ties: the lessons of Citizens' Action in the Struggle Against Hunger and Destitution and in Defense of Life].

    Science.gov (United States)

    Magalhães, Rosana

    2002-01-01

    To reflect on Citizens' Action in the Struggle Against Hunger and Destitution and in Defense of Life is to seek to approach the dilemmas and challenges involving the consolidation of citizenship and social justice, as well as the forces in action in contemporary Brazilian society. However, many questions remain open in this effort. The intertwining issues of poverty, politics, and solidarity and the concrete shapes and multiple social developments of Brazil's "Campaign Against Hunger" leave room for various possible interpretations. Thus, considering the breadth of the theme on the one hand and the limits of this article on the other, the objective is to explore some relevant issues in the debate on destitution and exclusion and the process of constructing new kinds of public social intervention and civic participation, arising over the course of the study conducted by the "Citizens' Action Committees" in Rio de Janeiro during 1996 and 1997. The basic idea is to focus on volunteer practices to discuss the dilemmas posed for solving impoverishment and social fragmentation through cooperative activities and mutual help in Brazil.

  18. Cross-border ties and Arab American mental health.

    Science.gov (United States)

    Samari, Goleen

    2016-04-01

    Due to increasing discrimination and marginalization, Arab Americans are at a greater risk for mental health disorders. Social networks that include ties to the country of origin could help promote mental well-being in the face of discrimination. The role of countries of origin in immigrant mental health receives little attention compared to adjustment in destination contexts. This study addresses this gap by analyzing the relationship between nativity, cross-border ties, and psychological distress and happiness for Arab Americans living in the greater Detroit Metropolitan Area (N = 896). I expect that first generation Arab Americans will have more psychological distress compared to one and half, second, and third generations, and Arab Americans with more cross-border ties will have less psychological distress and more happiness. Data come from the 2003 Detroit Arab American Study, which includes measures of nativity, cross-border ties--attitudes, social ties, media consumption, and community organizations, and the Kessler-10 scale of psychological distress and self-reported happiness. Ordered logistic regression analyses suggest that psychological distress and happiness do not vary much by nativity alone. However, cross-border ties have both adverse and protective effects on psychological distress and happiness. For all generations of Arab Americans, cross-border attitudes and social ties are associated with greater odds of psychological distress and for first generation Arab Americans, media consumption is associated with greater odds of unhappiness. In contrast, for all generations, involvement in cross-border community organizations is associated with less psychological distress and for the third generation, positive cross-border attitudes are associated with higher odds of happiness. These findings show the complex relationship between cross-border ties and psychological distress and happiness for different generations of Arab Americans. Copyright © 2016

  19. Instability of ties in compression

    DEFF Research Database (Denmark)

    Buch-Hansen, Thomas Cornelius

    2013-01-01

    Masonry cavity walls are loaded by wind pressure and vertical load from upper floors. These loads results in bending moments and compression forces in the ties connecting the outer and the inner wall in a cavity wall. Large cavity walls are furthermore loaded by differential movements from...... the temperature gradient between the outer and the inner wall, which results in critical increase of the bending moments in the ties. Since the ties are loaded by combined compression and moment forces, the loadbearing capacity is derived from instability equilibrium equations. Most of them are iterative, since......-connectors in cavity walls was developed. The method takes into account constraint conditions limiting the free length of the wall tie, and the instability in case of pure compression which gives an optimal load bearing capacity. The model is illustrated with examples from praxis....

  20. Tie Content in Professional Networks

    DEFF Research Database (Denmark)

    Zarzecka, Olga

    resources that senior managers acquire through their network ties, i.e. the tie content, remain heavily understudied. Hence, the purpose of this dissertation is to answer the following question: What resources flow through informal ties in senior managers’ professional networks, and why? The first chapter......Professional networks of senior managers have indisputable value for them as well as for their organizations. In recent years, much attention has been given to the structure of these networks as it reflects senior managers’ opportunity to access valuable resources. Surprisingly, the actual...... introduces the topic of this dissertation as well as the overall research question. The three next chapters are empirical studies of informal ties in professional networks of Danish senior managers, that together attempt to answer the overall research question. Chapter 2 looks into gender differences...

  1. The Impact of Ties Strength and Social Capital on Knowledge Acquisition Performance---Based on Social Structure and Action Modle%关系强度、社会资本对知识获取绩效影响研究--基于社会结构与行动模型

    Institute of Scientific and Technical Information of China (English)

    张晓棠; 安立仁; 董广茂

    2015-01-01

    Both of ties strength and social capital can affect knowledge acquisition performance, existing researches haven’ t analyzed the impacts of ties strength and social capital on knowledge acquisition performance. Based on social structure and action model, the social capital is divided into collective and individual assets, while the former includes trust, norms, and the later heterogeneous resources of network. Hence, the theoretical model of this research is constructed as“ties strength-social capital-knowledge acquisition performance”, the empirical test has been done on the base of the structure equation modeling and questionnaire surveys to 233 enterprises. The results indicate that strong ties is significantly positive on knowledge acquisition performance on which collective assets have a significant positive mediating effect partly, while individual assets has no significant mediating effect on it. Strong ties positively correlates with heterogeneous resources of network, while heterogeneous resources of network is negative, not significantly, with knowledge acquisition. The explicit mechanism, path and effects of ties strength and social capital effect on knowledge acquisition, showed by this study, can provide strategic reference of the formed relationship and disposable capital for enterprise knowledge management.%关系强度与社会资本均影响知识获取绩效,已有研究尚未探明两者间联系机理及其对知识获取绩效的影响。本文基于社会结构与行动模型,将社会资本细分为集体与个体两层面;信任、规范与网络异质资源三构件,构建“关系强度—社会资本—知识获取绩效”理论模型,结合233家企业问卷调查与结构方程模型进行实证检验。结果表明:强关联显著提升知识获取绩效;集体社会资本即信任与规范起部分中介作用,个体社会资本即网络异质资源则无中介作用;强关联正向影响网络异质资源,

  2. The weakness of strong ties : Collective action failure in a highly cohesive group

    NARCIS (Netherlands)

    Flache, A; Macy, MW

    1996-01-01

    Following Homans, exchange theorists have modeled informal social control as an exchange of peer approval for compliance with group obligations. The exchange model predicts higher compliance in cohesive networks with strong social ties. However, previous specifications failed to incorporate bilatera

  3. Leveraging strong social ties among young men in Dar es Salaam: A pilot intervention of microfinance and peer leadership for HIV and gender-based violence prevention.

    Science.gov (United States)

    Maman, Suzanne; Kajula, Lusajo; Balvanz, Peter; Kilonzo, Mrema; Mulawa, Marta; Yamanis, Thespina

    2016-12-01

    Gender inequality is at the core of the HIV patterns that are evident in sub-Saharan Africa. Gender-based violence (GBV) and lack of economic opportunity are important structural determinants of HIV risk. We piloted a microfinance and health promotion intervention among social networks of primarily young men in Dar es Salaam. Twenty-two individuals participated in the microfinance component and 30 peer leaders were recruited and trained in the peer health leadership component. We collected and analysed observational data from trainings, monitoring data on loan repayment, and reports of peer conversations to assess the feasibility and acceptability of the intervention. Eighteen of the loan recipients (82%) paid back their loans, and of these 15 (83%) received a second, larger loan. Among the loan defaulters, one died, one had chronic health problems, and two disappeared, one of whom was imprisoned for theft. The majority of conversations reported by peer health leaders focused on condoms, sexual partner selection, and HIV testing. Few peer leaders reported conversations about GBV. We demonstrated the feasibility and acceptability of this innovative HIV and GBV prevention intervention. The lessons learned from this pilot have informed the implementation of a cluster-randomised trial of the microfinance and peer health leadership intervention.

  4. The Impact of Strong Ties on Knowledge Acquisition of Enterprises: A View of Social Capital%强联结对企业知识获取绩效的影响研究——社会资本的视角

    Institute of Scientific and Technical Information of China (English)

    张晓棠; 荆心

    2012-01-01

    Researchers study a lot on the benefits and costs of the strength ties during the procession of knowledge acquisition form the Resource-Based View or Knowledge-based View, but the media role of social capital in the process seems to be ignored. This paper presents a view of social capital and study the impact of social capitals, such as trust, reciprocity, social interaction, network connection on knowledge acquisition under the context of strong ties. The paper proposes enterprises should build strong ties and accumulate social capitals in order to improve knowledge acquisition performance.%现有文献主要从资源基础观及知识基础观视角分析联结的强弱在企业知识获取中的利弊,却忽视了社会资本在此过程中的介质作用.本文从社会资本的新视角,研究强联结情境下,信任、互惠、社会化互动、网络联系等社会资本对企业知识获取绩效的影响路径.文章提出企业应该构建强关联网络,积累良好的社会资本,以提高知识获取绩效.

  5. Do recruitment ties affect wages?

    DEFF Research Database (Denmark)

    Larsen, Anna Folke; Rand, John; Torm, Nina Elisabeth

    This paper examines the extent to which recruitment ties affect individual wage outcomes in small and medium scale manufacturing firms. Based on a unique matched employer-employee dataset from Vietnam we find that there is a significant positive wage premium associated with obtaining a job through...... an informal contact, when controlling for standard determinants of wage compensation. Moreover, we show that the mechanism through which informal contacts affect wages depends on the type of recruitment tie used. The findings are robust across location, firm size categories and different worker types....

  6. Instability of ties in compression

    DEFF Research Database (Denmark)

    Buch-Hansen, Thomas Cornelius

    2013-01-01

    Masonry cavity walls are loaded by wind pressure and vertical load from upper floors. These loads results in bending moments and compression forces in the ties connecting the outer and the inner wall in a cavity wall. Large cavity walls are furthermore loaded by differential movements from...... exact instability solutions are complex to derive, not to mention the extra complexity introducing dimensional instability from the temperature gradients. Using an inverse variable substitution and comparing an exact theory with an analytical instability solution a method to design tie...

  7. Neural correlates of dynamically evolving interpersonal ties predict prosocial behaviour

    Directory of Open Access Journals (Sweden)

    Johannes Jacobus Fahrenfort

    2012-03-01

    Full Text Available There is a growing interest for the determinants of human choice behaviour in social settings. Upon initial contact, investment choices in social settings can be inherently risky, as the degree to which the other person will reciprocate is unknown. Nevertheless, people have been shown to exhibit prosocial behaviour even in one-shot laboratory settings where all interaction has been taken away. A logical step has been to link such behaviour to trait empathy-related neurobiological networks. However, as a social interaction unfolds, the degree of uncertainty with respect to the expected payoff of choice behaviour may change as a function of the interaction. Here we attempt to capture this factor. We show that the interpersonal tie one develops with another person during interaction - rather than trait empathy - motivates investment in a public good that is shared with an anonymous interaction partner. We examined how individual differences in trait empathy and interpersonal ties modulate neural responses to imposed monetary sharing. After, but not before interaction in a public good game, sharing prompted activation of neural systems associated with reward (striatum, empathy (anterior insular cortex [AIC] and anterior cingulate cortex [ACC] as well as altruism and social significance (posterior superior temporal sulcus [pSTS]. Although these activations could be linked to both empathy and interpersonal ties, only tie-related pSTS activation predicted prosocial behaviour during subsequent interaction, suggesting a neural substrate for keeping track of social relevance.

  8. Do recruitment ties affect wages?

    DEFF Research Database (Denmark)

    Larsen, Anna Folke; Rand, John; Torm, Nina Elisabeth

    This paper examines the extent to which recruitment ties affect individual wage outcomes in small and medium scale manufacturing firms. Based on a unique matched employer-employee dataset from Vietnam we find that there is a significant positive wage premium associated with obtaining a job through...

  9. Maintaining work-related personal ties following retirement

    NARCIS (Netherlands)

    Cozijnsen, M.R.; Stevens, N.L.; Tilburg, T.G. van

    2010-01-01

    This study examines the consequences of retirement for the continuation of work-related personal ties. The hypothesis is that their inclusion in personal networks after retirement has become more likely because these relationships have become less role based in today's social-cultural context. Data

  10. Maintaining work-related personal ties following retirement

    NARCIS (Netherlands)

    Cozijnsen, M.R.; Stevens, N.L.; Tilburg, van T.G.

    2010-01-01

    Abstract This study examines the consequences of retirement for the continuation of work-related personal ties. The hypothesis is that their inclusion in personal networks after retirement has become more likely because these relationships have become less role based in today’s social-cultural conte

  11. Social Ties and Coordination on Negative Reciprocity

    DEFF Research Database (Denmark)

    Reuben, Ernesto; van Winden, Frans

    This is an experimental study of a three-player power-to-take game where a proposer is matched with two responders. We compare a treatment in which subjects are anonymous to each other (strangers) with one in which responders know each other from outside the lab (friends). We focus on the respond...

  12. Social Ties and Coordination on Negative Reciprocity

    DEFF Research Database (Denmark)

    Reuben, Ernesto; van Winden, Frans

    This is an experimental study of a three-player power-to-take game where a proposer is matched with two responders. We compare a treatment in which subjects are anonymous to each other (strangers) with one in which responders know each other from outside the lab (friends). We focus on the respond......’ expectations are better predictors of emotions and destruction than their fairness perceptions...

  13. Personal Ties in the Writing of a Doctoral Dissertation

    Directory of Open Access Journals (Sweden)

    Laura Colombo

    2014-07-01

    Full Text Available The problem of low graduation rates at the graduate level has been linked to the challenges of dissertation work. Given that this is a process of “disciplinary enculturation”, where graduate students acquire the ways of being and doing of each discipline, the social relations of doctoral candidates should be analyzed. Several studies have explored the support provided by social ties within academia but have, nevertheless, ignored other spheres. This qualitative study, based on in-depth interviews, explores the personal-sphere social relations in the dissertation writing process from the point of view of doctoral candidates and recent graduates in the fields of Education and Linguistics. Results indicate that the emotional, financial, economic, and academic support offered by these social ties is a necessary, although not in itself, sufficient condition. Some strategies for increasing institutional support to facilitate the process of writing a dissertation are offered.

  14. Roles of Ties in Spreading

    CERN Document Server

    Cui, Ai-Xiang; Zhou, Tao

    2012-01-01

    Background: Controlling global epidemics in the real world and accelerating information propagation in the artificial world are of great significance, which have activated an upsurge in the studies on networked spreading dynamics. Lots of efforts have been made to understand the impacts of macroscopic statistics (e.g., degree distribution and average distance) and mesoscopic structures (e.g., communities and rich clubs) on spreading processes while the microscopic elements are less concerned. In particular, roles of ties are not yet clear to the academic community. Methodology/Principle Findings: Every edges is stamped by its strength that is defined solely based on the local topology. According to a weighted susceptible-infected-susceptible model, the steady-state infected density and spreading speed are respectively optimized by adjusting the relationship between edge's strength and spreading ability. Experiments on six real networks show that the infected density is increased when strong ties are favored i...

  15. Dielectric Bow-tie Nanocavity

    CERN Document Server

    Lu, Qijing; Zou, Chang-Ling

    2013-01-01

    We propose a novel dielectric bow-tie nanocavity consisting of two tip-to-tip opposite triangle semiconductor nanowires, whose end faces are coated by silver nanofilms. Based on the advantages of the dielectric slot and tip structures, and the high reflectivity from the silver mirror, light can be confined in this nanocavity with low loss. We demonstrate that the mode excited in this nanocavity has a deep subwavelength mode volume of 2.8*10^-4 um3 and a high quality factor of 4.9*10^4 (401.3), consequently an ultrahigh Purcell factor of 1.6*10^7 (1.36*10^5), at 4.5 K (300 K) around the resonance wavelength of 1550 nm. This dielectric bow-tie nanocavity may find applications for integrated nanophotonic circuits, such as high-efficiency single photon source, thresholdless nanolaser, and cavity QED strong coupling experiments.

  16. THE RATIONALE BEHIND WEAKLY TIED NETWORKING OF THE BANGLADESHI DIASPORA IN MALAYSIA

    Directory of Open Access Journals (Sweden)

    S. Nayeem

    2012-08-01

    Full Text Available This paper is an exploration of the survival strategies of the Bangladeshi Diaspora in Malaysia. To cope with the realities, Bangladeshi migrants develop different forms of survival strategies. As a result intra and inter-ethnic strong and weak ties are formed in the receiving country. Empirical analysis depicts that respondents with weak ties have higher income mobility than those with strong ties. It also demonstrates that the Bangladeshi migrants of the study areas do not restrict themselves only to their close social networks; rather they develop distant networks for higher social mobility. Or in other words, though the ideal socio-cultural model emphasizes community cohesion (something that can be conceptualized as an example of a tightly structured social system, the actual behavior of the Bangladeshi migrants indicates a loosely or disintegrated social system. Migrant's embeddedness in the ongoing social relations and power structures regulates the nature and strength of these ties.

  17. Time varying networks and the weakness of strong ties

    Science.gov (United States)

    Karsai, Márton; Perra, Nicola; Vespignani, Alessandro

    2014-02-01

    In most social and information systems the activity of agents generates rapidly evolving time-varying networks. The temporal variation in networks' connectivity patterns and the ongoing dynamic processes are usually coupled in ways that still challenge our mathematical or computational modelling. Here we analyse a mobile call dataset and find a simple statistical law that characterize the temporal evolution of users' egocentric networks. We encode this observation in a reinforcement process defining a time-varying network model that exhibits the emergence of strong and weak ties. We study the effect of time-varying and heterogeneous interactions on the classic rumour spreading model in both synthetic, and real-world networks. We observe that strong ties severely inhibit information diffusion by confining the spreading process among agents with recurrent communication patterns. This provides the counterintuitive evidence that strong ties may have a negative role in the spreading of information across networks.

  18. RELEASE OF TONGUE-TIE IN NEONATES

    Directory of Open Access Journals (Sweden)

    V. Raveenthiran

    2012-01-01

    Full Text Available Arguably, release of tongue tie is the oldest surgical procedure and it is perhaps older than circumcision. According to the Old Testament, the Lord released the tied tongue of Moses and made him speak well. Tongue-tie is pedantically known as ankyloglossia inferior minor. Simplicity of its treatment has earned this malady several etiological attributions such as difficulty of speech and breast feeding. All over the world, lactation consultants refer neonates for release of tongue tie as they believe it to be the cause of maternal nipple pain.Perhaps this is the only indication of tongue tie release in neonates.

  19. Homology and causes.

    Science.gov (United States)

    Van Valen, L M

    1982-09-01

    Homology is resemblance caused by a continuity of information. In biology it is a unified developmental phenomenon. Homologies among and within individuals intergrade in several ways, so historical homology cannot be separated sharply from repetitive homology. Nevertheless, the consequences of historical and repetitive homologies can be mutually contradictory. A detailed discussion of the rise and fall of the "premolar-analogy" theory of homologies of mammalian molar-tooth cusps exemplifies such a contradiction. All other hypotheses of historical homology which are based on repetitive homology, such as the foliar theory of the flower considered phyletically, are suspect.

  20. Common Values,Strong Ties

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The official visit of Malaysian Prime Minister Najib Tun Razak to China on June 2-5 is seen as an important step in furthering the strategic and cooperative relationship between the two countries. In an interview with Beijing Review reporter Zhou Jianxiong, Mohamed Jawhar Hassan, Chairman and CEO of the Institute of Strategic and International Studies, a top think tank and consulting institution in Malaysia, outlined why Malaysia made its decision to establish diplomatic ties with China 35 years ago and why it looks forward to the development of this relationship in the future.

  1. The Orphan Receptor Tie1 Controls Angiogenesis and Vascular Remodeling by Differentially Regulating Tie2 in Tip and Stalk Cells.

    Science.gov (United States)

    Savant, Soniya; La Porta, Silvia; Budnik, Annika; Busch, Katrin; Hu, Junhao; Tisch, Nathalie; Korn, Claudia; Valls, Aida Freire; Benest, Andrew V; Terhardt, Dorothee; Qu, Xianghu; Adams, Ralf H; Baldwin, H Scott; Ruiz de Almodóvar, Carmen; Rodewald, Hans-Reimer; Augustin, Hellmut G

    2015-09-22

    Tie1 is a mechanistically poorly characterized endothelial cell (EC)-specific orphan receptor. Yet, Tie1 deletion is embryonic lethal and Tie1 has been implicated in critical vascular pathologies, including atherosclerosis and tumor angiogenesis. Here, we show that Tie1 does not function independently but exerts context-dependent effects on the related receptor Tie2. Tie1 was identified as an EC activation marker that is expressed during angiogenesis by a subset of angiogenic tip and remodeling stalk cells and downregulated in the adult quiescent vasculature. Functionally, Tie1 expression by angiogenic EC contributes to shaping the tip cell phenotype by negatively regulating Tie2 surface presentation. In contrast, Tie1 acts in remodeling stalk cells cooperatively to sustain Tie2 signaling. Collectively, our data support an interactive model of Tie1 and Tie2 function, in which dynamically regulated Tie1 versus Tie2 expression determines the net positive or negative effect of Tie1 on Tie2 signaling.

  2. Homology, Analogy, and Ethology.

    Science.gov (United States)

    Beer, Colin G.

    1984-01-01

    Because the main criterion of structural homology (the principle of connections) does not exist for behavioral homology, the utility of the ethological concept of homology has been questioned. The confidence with which behavioral homologies can be claimed varies inversely with taxonomic distance. Thus, conjectures about long-range phylogenetic…

  3. The Strength of the Strongest Ties in Collaborative Problem Solving

    DEFF Research Database (Denmark)

    de Montjoye, Yves-Alexandre; Stopczynski, Arkadiusz; Shmueli, Erez

    2014-01-01

    Complex problem solving in science, engineering, and business has become a highly collaborative endeavor. Teams of scientists or engineers collaborate on projects using their social networks to gather new ideas and feedback. Here we bridge the literature on team performance and information networ......-significant in the statistical analysis. Our results have consequences for the organization of teams of scientists, engineers, and other knowledge workers tackling today's most complex problems.......Complex problem solving in science, engineering, and business has become a highly collaborative endeavor. Teams of scientists or engineers collaborate on projects using their social networks to gather new ideas and feedback. Here we bridge the literature on team performance and information networks...... by studying teams' problem solving abilities as a function of both their within-team networks and their members' extended networks. We show that, while an assigned team's performance is strongly correlated with its networks of expressive and instrumental ties, only the strongest ties in both networks have...

  4. The Strength of the Strongest Ties in Collaborative Problem Solving

    Science.gov (United States)

    de Montjoye, Yves-Alexandre; Stopczynski, Arkadiusz; Shmueli, Erez; Pentland, Alex; Lehmann, Sune

    2014-06-01

    Complex problem solving in science, engineering, and business has become a highly collaborative endeavor. Teams of scientists or engineers collaborate on projects using their social networks to gather new ideas and feedback. Here we bridge the literature on team performance and information networks by studying teams' problem solving abilities as a function of both their within-team networks and their members' extended networks. We show that, while an assigned team's performance is strongly correlated with its networks of expressive and instrumental ties, only the strongest ties in both networks have an effect on performance. Both networks of strong ties explain more of the variance than other factors, such as measured or self-evaluated technical competencies, or the personalities of the team members. In fact, the inclusion of the network of strong ties renders these factors non-significant in the statistical analysis. Our results have consequences for the organization of teams of scientists, engineers, and other knowledge workers tackling today's most complex problems.

  5. Suicide: the key role of short range ties

    CERN Document Server

    Röhner, B M

    2005-01-01

    The paper explores the connection between short-range social ties (i.e. links with close relatives) and the occurrence of suicide. The objective is to discriminate between a model based on social ties and a model based on psychological traumas. Our methodological strategy is to focus on instances characterized by the severance of some social ties. We consider several situations of this kind. (i) Prisoners in the first days after their incarceration. (ii) Prisoners in solitary confinement. (iii) Prisoners who are transferred from one prison to another. (iv) Prisoners in closed versus open prisons. (v) Prisoners in the weeks following their release. (vi) Immigrants in the years following their relocation. (vii) Unmarried versus married people. Furthermore, in order to test the impact of major shocks we consider the responses in terms of suicides to the following shocks. (i) The attack of September 11, 2001 in Manhattan. (ii) The Korean War. (iii) The two world wars. (iv) The Great Depression in the United State...

  6. Strong Ties in a Small World

    NARCIS (Netherlands)

    M.J. van der Leij (Marco); S. Goyal (Sanjeev)

    2006-01-01

    textabstractIn this paper we test the celebrated `Strength of weak ties' theory of Granovetter (1973). We test two hypotheses on the network structure in a data set of collaborating economists. While we find support for the hypothesis of transitivity of strong ties, we reject the hypothesis that wea

  7. Combinatorial Floer Homology

    CERN Document Server

    de Silva, Vin; Salamon, Dietmar

    2012-01-01

    We define combinatorial Floer homology of a transverse pair of noncontractibe nonisotopic embedded loops in an oriented 2-manifold without boundary, prove that it is invariant under isotopy, and prove that it is isomorphic to the original Lagrangian Floer homology.

  8. The positive and negative effects of strong ties on employment of university graduates and countermeasures in China's social network%我国社会网络中强关系对大学生就业的正负效应及对策

    Institute of Scientific and Technical Information of China (English)

    蔡小慎; 刘存亮

    2012-01-01

    随着我国就业形势日益严峻,大学生作为新增就业群体在就业和择业过程中对社会网络中强关系的依赖凸显。强关系对大学生就业产生明显的效应,既具有内部正效应,也具有外部负效应。为克服强关系的局限性,需要通过建立完善的劳动力市场、健全公平就业的政策制度、加强就业市场中的信用管理和提高大学生的综合就业能力等措施,构建起现代社会新型的社会网络关系,以促进大学生充分就业。%As China's increasingly serious employment situation,university students as a new employment group highlight the dependence of strong ties in social network in the process of employment and careers.Strong ties have a significant effect on the employment of university students,which have internal positive effects,but also with external negative effects.To overcome the limitations of strong ties,we need to establish the perfect labor market,complete the policy system of fair employment,strengthen credit management in the job market,and improve the overall employability of university students,through these measures to build the new social networks in modern society,to promote full employment of university students.

  9. Tie strength distribution in scientific collaboration networks

    Science.gov (United States)

    Ke, Qing; Ahn, Yong-Yeol

    2014-09-01

    Science is increasingly dominated by teams. Understanding patterns of scientific collaboration and their impacts on the productivity and evolution of disciplines is crucial to understand scientific processes. Electronic bibliography offers a unique opportunity to map and investigate the nature of scientific collaboration. Recent studies have demonstrated a counterintuitive organizational pattern of scientific collaboration networks: densely interconnected local clusters consist of weak ties, whereas strong ties play the role of connecting different clusters. This pattern contrasts itself from many other types of networks where strong ties form communities while weak ties connect different communities. Although there are many models for collaboration networks, no model reproduces this pattern. In this paper, we present an evolution model of collaboration networks, which reproduces many properties of real-world collaboration networks, including the organization of tie strengths, skewed degree and weight distribution, high clustering, and assortative mixing.

  10. Tie Strength Distribution in Scientific Collaboration Networks

    CERN Document Server

    Ke, Qing

    2014-01-01

    Science is increasingly dominated by teams. Understanding patterns of scientific collaboration and their impacts on the productivity and evolution of disciplines is crucial to understand scientific processes. Electronic bibliography offers a unique opportunity to map and investigate the nature of scientific collaboration. Recent work have demonstrated a counter-intuitive organizational pattern of scientific collaboration networks: densely interconnected local clusters consist of weak ties, whereas strong ties play the role of connecting different clusters. This pattern contrasts itself from many other types of networks where strong ties form communities while weak ties connect different communities. Although there are many models for collaboration networks, no model reproduces this pattern. In this paper, we present an evolution model of collaboration networks, which reproduces many properties of real-world collaboration networks, including the organization of tie strengths, skewed degree and weight distribut...

  11. Dielectric bow-tie nanocavity.

    Science.gov (United States)

    Lu, Qijing; Shu, Fang-Jie; Zou, Chang-Ling

    2013-12-15

    We propose a novel dielectric bow-tie (DBT) nanocavity consisting of two opposing tip-to-tip triangle semiconductor nanowires, whose end faces are coated by silver nanofilms. Based on the advantages of the dielectric slot and tip structures, and the high reflectivity of the silver mirror, light can be confined in this nanocavity with low loss. We demonstrate that at 4.5 K (300 K) around the resonance wavelength of 1550 nm, the mode excited in this nanocavity has a deep subwavelength mode volume of 2.8×10(-4) μm³ and a high quality factor of 4.9×10(4) (401.3), corresponding to an ultrahigh Purcell factor of 1.6×10(7) (1.36×10(5)). This DBT nanocavity may find applications for integrated nanophotonic circuits, such as high-efficiency single photon sources, thresholdless nanolasers, and strong coupling in cavity quantum electrodynamics experiments.

  12. Urban characteristics attributable to density-driven tie formation

    CERN Document Server

    Pan, Wei; Krumme, Coco; Cebrian, Manuel; Pentland, Alex

    2012-01-01

    Motivated by empirical evidence on the interplay between geography, population density and societal interaction, we propose a generative process for the evolution of social structure in cities. Our analytical and simulation results predict both super-linear scaling of social tie density and information flow as a function of the population. We demonstrate that our model provides a robust and accurate fit for the dependency of city characteristics with city size, ranging from individual-level dyadic interactions (number of acquaintances, volume of communication) to population-level variables (contagious disease rates, patenting activity, economic productivity and crime) without the need to appeal to modularity, specialization, or hierarchy.

  13. Real Topological Cyclic Homology

    DEFF Research Database (Denmark)

    Høgenhaven, Amalie

    The main topics of this thesis are real topological Hochschild homology and real topological cyclic homology. If a ring or a ring spectrum is equipped with an anti-involution, then it induces additional structure on the topological Hochschild homology spectrum. The group O(2) acts on the spectrum......, where O(2) is the semi-direct product of T, the multiplicative group of complex number of modulus 1, by the group G=Gal(C/R). We refer to this O(2)-spectrum as the real topological Hochschild homology. This generalization leads to a G-equivariant version of topological cyclic homology, which we call...... real topological cyclic homology. The first part of the thesis computes the G-equivariant homotopy type of the real topological cyclic homology of spherical group rings at a prime p with anti-involution induced by taking inverses in the group. The second part of the thesis investigates the derived G...

  14. Mobile devices and weak ties: a study of vision impairments and workplace access in Bangalore.

    Science.gov (United States)

    Pal, Joyojeet; Lakshmanan, Meera

    2015-07-01

    To explore ways in which social and economic interactions are changed by access to mobile telephony. This is a mixed-methods study of mobile phone use among 52 urban professionals with vision impairments in Bangalore, India. Interviews and survey results indicated that mobile devices, specifically those with adaptive technology software, play a vital role as multi-purpose devices that enable people with disabilities to navigate economically and socially in an environment where accessibility remains a significant challenge. We found that mobile devices play a central role in enabling and sustaining weak ties, but also that these weak ties have important gender-specific implications. We found that women have less access to weak ties than men, which impacts women's access to assistive technology (AT). This has potential implications for women's sense of safety and independence, both of which are strongly related to AT access. Implications for Rehabilitation Adaptive technologies increase individuals' ability to keep in contact with casual connections or weak ties through phone calls or social media. Men tend to have stronger access to weak ties than women in India due to cultural impediments to independent access to public spaces. Weak ties are an important source of assistive technology (AT) due to the high rate of resale of used AT, typically through informal networks.

  15. The cytogenetics of homologous chromosome pairing in meiosis in plants.

    Science.gov (United States)

    Bozza, C G; Pawlowski, W P

    2008-01-01

    Three activities hallmark meiotic cell division: homologous chromosome pairing, synapsis, and recombination. Recombination and synapsis are well-studied but homologous pairing still holds many black boxes. In the past several years, many studies in plants have yielded insights into the mechanisms of chromosome pairing interactions. Research in several plant species showed the importance of telomere clustering on the nuclear envelope (telomere bouquet formation) in facilitating alignment of homologous chromosomes. Homologous pairing was also shown to be tied to the early stages of recombination by mutant analyses in Arabidopsis and maize. In contrast, little is known about the mechanisms that guide homolog interaction after their rough alignment by the bouquet and before the close-range recombination-dependent homology search. The relatively large and complex genomes of plants may require additional mechanisms, not needed in small genome eukaryotes, to distinguish between local homology of duplicated genes or transposable elements and global chromosomal homology. Plants provide an excellent large genome model for the study of homologous pairing and dissection of this process. 2008 S. Karger AG, Basel

  16. Smoking Tied to Shorter Survival with ALS

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161094.html Smoking Tied to Shorter Survival With ALS Tobacco use ... 22, 2016 WEDNESDAY, Sept. 21, 2016 (HealthDay News) -- Smoking may speed progression of Lou Gehrig's disease and ...

  17. TIE: an ability test of emotional intelligence

    National Research Council Canada - National Science Library

    Śmieja, Magdalena; Orzechowski, Jarosław; Stolarski, Maciej S

    2014-01-01

    The Test of Emotional Intelligence (TIE) is a new ability scale based on a theoretical model that defines emotional intelligence as a set of skills responsible for the processing of emotion-relevant information...

  18. The self-cohering tied-array

    CERN Document Server

    Fridman, P A

    2010-01-01

    Large radio astronomy multi-element interferometers are frequently used as single dishes in a tied-array mode when signals from separate antennas are added. Phase shifts arising during wave propagation through a turbulent atmosphere can significantly reduce the effective area of an equivalent single dish. I aim to give estimates of the impact of the ionosphere and troposphere on the effectiveness of a radio interferometer working in tied-array mode. Statistical estimates of the effective area are calculated and the power-law of turbulent atmosphere irregularities has been used. A simple method of tied-array calibration using optimization techniques is proposed. The impact of phase errors on the effectiveness of tied-arrays are given for low and high frequencies. Computer simulations demonstrate the efficacy of the proposed calibration algorithm.

  19. The Strength of Direct Ties

    DEFF Research Database (Denmark)

    Claussen, Jörg; Falck, Oliver; Grosjean, Thorsten

    2012-01-01

    We analyze the economic effects of a developer's connectedness in the electronic game industry. Knowledge spillovers between developers are likely to be of special relevance in this knowledge-intensive and regionally concentrated industry. We calculate social network measures for a developer's co...

  20. The Ritualization of Family Ties.

    Science.gov (United States)

    Cheal, David

    1988-01-01

    Examines three theories of family ritual derived from Emile Durkheim's sociology of social order: the structural-functional theory, constructionist theory, and mobilization theory. Concludes that rituals maintain traditional family structures, yet are creative in that they may define new forms of relationships and support emerging possibilities…

  1. Lectures on functor homology

    CERN Document Server

    Touzé, Antoine

    2015-01-01

    This book features a series of lectures that explores three different fields in which functor homology (short for homological algebra in functor categories) has recently played a significant role. For each of these applications, the functor viewpoint provides both essential insights and new methods for tackling difficult mathematical problems. In the lectures by Aurélien Djament, polynomial functors appear as coefficients in the homology of infinite families of classical groups, e.g. general linear groups or symplectic groups, and their stabilization. Djament’s theorem states that this stable homology can be computed using only the homology with trivial coefficients and the manageable functor homology. The series includes an intriguing development of Scorichenko’s unpublished results. The lectures by Wilberd van der Kallen lead to the solution of the general cohomological finite generation problem, extending Hilbert’s fourteenth problem and its solution to the context of cohomology. The focus here is o...

  2. Lectures on knot homology

    CERN Document Server

    Nawata, Satoshi

    2015-01-01

    We provide various formulations of knot homology that are predicted by string dualities. In addition, we also explain the rich algebraic structure of knot homology which can be understood in terms of geometric representation theory in these formulations. These notes are based on lectures in the workshop "Physics and Mathematics of Link Homology" at Centre de Recherches Math\\'ematiques, Universit\\'e de Montr\\'eal.

  3. Identification and characterization of a novel peptide ligand of Tie2 for targeting gene therapy

    Institute of Scientific and Technical Information of China (English)

    Xianghua Wu; Jianren Gu; Zonghai Li; Ming Yao; Huamao Wang; Sumin Qu; Xianlian Chen; Jinjun Li; Ye Sun; Yuhong Xu

    2008-01-01

    Tyrosine kinase with immunoglobulin and epidermal growth factor homology domain-2 (Tie2) has been considered as a rational target for gene therapy in solid tumors. In order to identify a novel peptide ligand of Tie2 for targeted gene therapy, we screened a phage display peptide library and identified a candidate peptide ligand NSLSNASEFRAPY(designated GA5).Binding assays and Scatchard analysis revealed that GA5 could specifically bind to Tie2 with a dissociation constant of 2.1×10-8M.In addition,we showed that GA5 was internalized into tumor cells highly expressing Tie2.In the biodistribution assay.125I-GA5 was mainly accumniated in SPC-A1 xenograft tumors that express Tie2.Ingene delivery studies,GA5-conjugated polyethylenimine vector could achieve greater transgene transduction than non-targeted vectors both in vitro and in vivo.Tumor growth inhibition was observed in SPC-A1 xenograft-bearing mice that received eight intratumoral injections of GA5 polyethylenimine/p53 complexes in 3 weeks.The difference in tumor volume between the experiment and control groups was significant(P<0.05).Our results showed that GA5 is a potentially efficient targeting element for cancer gene or molecular therapy.

  4. Analysis of ICPP fuel storage rack inner tie and corner tie substructures

    Energy Technology Data Exchange (ETDEWEB)

    Nitzel, M.E.; Rahl, R.G.

    1996-01-01

    Finite element models were developed and analyses performed for the tie plate, inner tie block assembly, and corner tie block assembly of a 25 port fuel rack assembly designed for installation in Pool 1 of Building 666 at the Idaho Chemical Processing Plant. These models were specifically developed to investigate the adequacy of certain welds joining components of the fuel storage rack assembly. The work scope for the task was limited to an investigation of the stress levels in the subject subassemblies when subjected to seismic loads. Structural acceptance criteria used for the elastic calculations performed were as found in the overall rack design report as issued by the rack`s designer, Holtec International. Structural acceptance criteria used for the plastic calculations performed as part of this effort were as defined in Subsection NF and Appendix F of the ASME Boiler & Pressure Vessel Code. The results of the analyses will also apply to the 30 port fuel storage rack design that is also scheduled for installation in Pool 1 of ICPP 666. The results obtained from the analyses performed for this task indicate that the welds joining the inner tie block and corner tie block to the surrounding rack structure meet the acceptance criteria. Further, the structural members (plates and blocks) were also found to be within the allowable stress limits established by the acceptance criteria. The separate analysis performed on the inner tie plate confirmed the structural adequacy for both the inner tie plate, corner tie plate, and tie block bolts. The analysis results verified that the inner tie and corner tie block should be capable of transferring the expected seismic load without structural failure.

  5. Seifert fibered homology spheres with trivial Heegaard Floer homology

    OpenAIRE

    Eftekhary, Eaman

    2009-01-01

    We show that among Seifert fibered integer homology spheres, Poincare sphere (with either orientation) is the only non-trivial example which has trivial Heegaard Floer homology. Together with an earlier result, this shows that if an integer homology sphere has trivial Heegaard Floer homology, then it is a connected sum of a number of Poincare spheres and hyperbolic homology spheres.

  6. An interpretation of E_n-homology as functor homology

    OpenAIRE

    Livernet, Muriel; Richter, Birgit

    2009-01-01

    We prove that E_n-homology of non-unital commutative algebras can be described as functor homology when one considers functors from a certain category of planar trees with n levels. For different n these homology theories are connected by natural maps, ranging from Hochschild homology and its higher order versions to Gamma homology.

  7. Open knot-tying skills: residents skills assessed

    NARCIS (Netherlands)

    van Empel, P.J.; Verdam, M.G.E.; Huirne, J.A.; Bonjer, H.J.; Meijerink, W.J.; Scheele, F.

    2013-01-01

    Aim: Open knot-tying and suturing skills are fundamental surgical skills, founding many alternative knot-tying techniques. It is therefore mandatory for residents to possess adequate basic open knot-tying skills. The aim of this study was to compare an objective assessment of open knot-tying skills

  8. High tie versus low tie in rectal surgery: comparison of anastomotic perfusion

    NARCIS (Netherlands)

    Komen, N.; Slieker, J.; Kort, P. de; Wilt, J.H. de; Harst, E. van der; Coene, P.P.; Gosselink, M.P.; Tetteroo, G.; Graaf, E. de; Beek, T. van; Toom, R. den; Bockel, W. van; Verhoef, C.; Lange, J.F.

    2011-01-01

    PURPOSE: Both "high tie" (HT) and "low tie" (LT) are well-known strategies in rectal surgery. The aim of this study was to compare colonic perfusion after HT to colonic perfusion after LT. METHODS: Patients undergoing rectal resection for malignancy were included. Colonic perfusion was measured with

  9. The Strength of Weak Ties in MBA Job Search: A Within–Person Test

    Directory of Open Access Journals (Sweden)

    Jason Greenberg

    2016-05-01

    Full Text Available Whether and how social ties create value has inspired substantial research in organizational theory, sociology, and economics. Scholars generally believe that social ties impact labor market outcomes. Two explanatory mechanisms have been identified, emphasizing access to better job offers in pecuniary terms and the efficacy of non-redundant information. The evidence informing each theory, however, has been inconsistent and circumstantial. We test predictions from both models using a rich set of job search data collected from an MBA student population, including detailed information about search channels and characteristics of job offers. Importantly, we can compare offers made to the same student derived via different search channels while accounting for industry, function, and non-pecuniary characteristics. We find that contrary to conventional wisdom, search through social networks typically results in job offers with lower total compensation (-17 percent for referrals through strong ties and -16 percent for referrals via weak ties vs. formal search. However, our models also show that students are considerably more likely to accept offers derived via weak ties. They do so because they are perceived to have greater growth potential and other non-pecuniary value. On balance, our tests are consistent with Granovetter’s argument that networks provide value by facilitating access to information that is otherwise difficult to obtain, rather than providing greater pecuniary compensation.

  10. TIE: an ability test of emotional intelligence.

    Science.gov (United States)

    Śmieja, Magdalena; Orzechowski, Jarosław; Stolarski, Maciej S

    2014-01-01

    The Test of Emotional Intelligence (TIE) is a new ability scale based on a theoretical model that defines emotional intelligence as a set of skills responsible for the processing of emotion-relevant information. Participants are provided with descriptions of emotional problems, and asked to indicate which emotion is most probable in a given situation, or to suggest the most appropriate action. Scoring is based on the judgments of experts: professional psychotherapists, trainers, and HR specialists. The validation study showed that the TIE is a reliable and valid test, suitable for both scientific research and individual assessment. Its internal consistency measures were as high as .88. In line with theoretical model of emotional intelligence, the results of the TIE shared about 10% of common variance with a general intelligence test, and were independent of major personality dimensions.

  11. TIE: an ability test of emotional intelligence.

    Directory of Open Access Journals (Sweden)

    Magdalena Śmieja

    Full Text Available The Test of Emotional Intelligence (TIE is a new ability scale based on a theoretical model that defines emotional intelligence as a set of skills responsible for the processing of emotion-relevant information. Participants are provided with descriptions of emotional problems, and asked to indicate which emotion is most probable in a given situation, or to suggest the most appropriate action. Scoring is based on the judgments of experts: professional psychotherapists, trainers, and HR specialists. The validation study showed that the TIE is a reliable and valid test, suitable for both scientific research and individual assessment. Its internal consistency measures were as high as .88. In line with theoretical model of emotional intelligence, the results of the TIE shared about 10% of common variance with a general intelligence test, and were independent of major personality dimensions.

  12. TIE: An Ability Test of Emotional Intelligence

    Science.gov (United States)

    Śmieja, Magdalena; Orzechowski, Jarosław; Stolarski, Maciej S.

    2014-01-01

    The Test of Emotional Intelligence (TIE) is a new ability scale based on a theoretical model that defines emotional intelligence as a set of skills responsible for the processing of emotion-relevant information. Participants are provided with descriptions of emotional problems, and asked to indicate which emotion is most probable in a given situation, or to suggest the most appropriate action. Scoring is based on the judgments of experts: professional psychotherapists, trainers, and HR specialists. The validation study showed that the TIE is a reliable and valid test, suitable for both scientific research and individual assessment. Its internal consistency measures were as high as .88. In line with theoretical model of emotional intelligence, the results of the TIE shared about 10% of common variance with a general intelligence test, and were independent of major personality dimensions. PMID:25072656

  13. The Orphan Receptor Tie1 Controls Angiogenesis and Vascular Remodeling by Differentially Regulating Tie2 in Tip and Stalk Cells

    Directory of Open Access Journals (Sweden)

    Soniya Savant

    2015-09-01

    Full Text Available Tie1 is a mechanistically poorly characterized endothelial cell (EC-specific orphan receptor. Yet, Tie1 deletion is embryonic lethal and Tie1 has been implicated in critical vascular pathologies, including atherosclerosis and tumor angiogenesis. Here, we show that Tie1 does not function independently but exerts context-dependent effects on the related receptor Tie2. Tie1 was identified as an EC activation marker that is expressed during angiogenesis by a subset of angiogenic tip and remodeling stalk cells and downregulated in the adult quiescent vasculature. Functionally, Tie1 expression by angiogenic EC contributes to shaping the tip cell phenotype by negatively regulating Tie2 surface presentation. In contrast, Tie1 acts in remodeling stalk cells cooperatively to sustain Tie2 signaling. Collectively, our data support an interactive model of Tie1 and Tie2 function, in which dynamically regulated Tie1 versus Tie2 expression determines the net positive or negative effect of Tie1 on Tie2 signaling.

  14. Resilience by Structural Entrenchment: Dynamics of Single-Layer and Multiplex Networks Following Sudden Changes to Tie Costs

    CERN Document Server

    Smaldino, Paul E; Maoz, Zeev

    2016-01-01

    We examine a model of network formation in single-layer and multiplex networks in which individuals have positive incentives for social ties, closed triangles, and spillover edges. In particular, we investigate the influence of shocks to the network in which the cost of social ties changes after an initial equilibrium. We highlight the emergence of structural entrenchment, a new concept we define as the persistence of structural features, such as closed triangles and spillover edges, which are formed under historically different conditions from those currently incentivizing the creation of new social ties or the destruction of existing ties. This work has broad implications for understanding path dependence in the structure and dynamics of single-layer and multiplex networks.

  15. On Galaxies and Homology

    OpenAIRE

    Novak, Gregory S.; Jonsson, Patrik; Primack, Joel R.; Cox, Thomas J.; Dekel, Avishai

    2012-01-01

    The definition of homology for single-component galaxies is clear, but for multi-component (luminous and dark matter) galaxies there is some ambiguity. We attempt to clarify the situation by carefully separating the different concepts of homology that have been used to date. We argue that the most useful definition is that a set of galaxies is homologous if they are the same in all respects up to a set of three dimensional scaling constants which may differ from one galaxy to the next. Noting...

  16. HOMOLOGY RIGIDITY OF GRASSMANNIANS

    Institute of Scientific and Technical Information of China (English)

    Li Fang; Duan Haibao

    2009-01-01

    Applying the theory of GrSbner basis to the Schubert presentation for the cohomology of Grassmannians [2], we extend the homology rigidity results known for the classical Grassmaniaas to the exceptional cases.

  17. Homology, convergence and parallelism.

    Science.gov (United States)

    Ghiselin, Michael T

    2016-01-05

    Homology is a relation of correspondence between parts of parts of larger wholes. It is used when tracking objects of interest through space and time and in the context of explanatory historical narratives. Homologues can be traced through a genealogical nexus back to a common ancestral precursor. Homology being a transitive relation, homologues remain homologous however much they may come to differ. Analogy is a relationship of correspondence between parts of members of classes having no relationship of common ancestry. Although homology is often treated as an alternative to convergence, the latter is not a kind of correspondence: rather, it is one of a class of processes that also includes divergence and parallelism. These often give rise to misleading appearances (homoplasies). Parallelism can be particularly hard to detect, especially when not accompanied by divergences in some parts of the body. © 2015 The Author(s).

  18. Sutures and contact homology I

    CERN Document Server

    Colin, Vincent; Honda, Ko; Hutchings, Michael

    2010-01-01

    We define a relative version of contact homology for contact manifolds with convex boundary, and prove basic properties of this relative contact homology. Similar considerations also hold for embedded contact homology.

  19. Developing Closer Ties with the Pharmaceutical Industry.

    Science.gov (United States)

    Reid, Gregor; Hoddinott, Susan

    1991-01-01

    The need for research administrators to understand and appreciate the pharmaceutical industry's research and development environment is discussed, using examples from Canada. The research administrator's role in the technology transfer process and implications for faculty are examined. Ways to build closer school-industry ties are discussed. (MSE)

  20. Weizmann ties with Cambridge in physics contest

    CERN Multimedia

    Siegel, J

    2004-01-01

    "Scientists and students from the Weizmann Institute of Science in Rehovot and Cambridge University in England have tied for first place in a physics competition aimed at simulating the future functioning of the particle accelerator being built at the European center CERN and due to open in 2007" (1/2 page)

  1. Developing Closer Ties with the Pharmaceutical Industry.

    Science.gov (United States)

    Reid, Gregor; Hoddinott, Susan

    1991-01-01

    The need for research administrators to understand and appreciate the pharmaceutical industry's research and development environment is discussed, using examples from Canada. The research administrator's role in the technology transfer process and implications for faculty are examined. Ways to build closer school-industry ties are discussed. (MSE)

  2. Commercial lumber, round timbers, and ties

    Science.gov (United States)

    David E. Kretschmann

    2010-01-01

    When sawn, a log yields round timber, ties, or lumber of varying quality. This chapter presents a general discussion of grading, standards, and specifications for these commercial products. In a broad sense, commercial lumber is any lumber that is bought or sold in the normal channels of commerce. Commercial lumber may be found in a variety of forms, species, and types...

  3. Chemical topology: Tying up some loose ends

    Science.gov (United States)

    Fenlon, Edward E.

    2010-03-01

    A linear molecule containing three bipyridine ligands can be wrapped around a single metal-ion template to form an open-knot complex. The loose ends of the knot can be 'tied' together through esterification or olefin-metathesis reactions to form closed knots that do not unravel when the metal template is removed.

  4. NASA's Global Imagery Management System: TIE

    Science.gov (United States)

    Alarcon, C.; Roberts, J. T.; Huang, T.; Thompson, C. K.; Cechini, M. F.; Hall, J. R.; Murphy, K. J.

    2014-12-01

    NASA's Earth Observing System Data and Information System (EOSDIS)' Global Imagery Browse Services (GIBS) is a system that provides full resolution imagery from a broad set of Earth science disciplines to the public. Using well-accepted standard protocols such as the Open Geospatial Consortium (OGC) Web Map Tile Service (WMTS), GIBS delivers global imagery efficiently and responsively. Behind this service, lies The Imagery Exchange (TIE), a workflow data management solution developed at the Jet Propulsion Laboratory. TIE is an Open Archival Information System responsible for orchestrating the workflow for acquisition, preparation, generation, and archiving of imagery to be served by the GIBS' web mapping tile service, OnEarth. The workflow collects imagery provenance throughout a product's lifecycle by leveraging the EOS Clearing House (ECHO) and other long-term metadata repositories in order to promote reproducibility. Through this focus on metadata, TIE provides spatial and temporal searching capabilities such as an OpenSearch interface as well as facilitating the generation of metadata standards such as the OGC GetCapabilities. Designed as a scalable system, TIE's subsystems can scale-up or scale-down depending on the data volume it handles through the usage of popular open source technologies such as Apache Zookeeper and Grails. This presentation will cover the challenges and solutions to developing such a horizontally scalable data management system where science products are often varied with disparate provenance pertaining to source platforms and instruments, spatial resolutions, processing algorithms, metadata models and packaging specifications.

  5. Place of Origin, Types of Ties, and Support Networks in Mexico-U.S. Migration

    Science.gov (United States)

    Flores-Yeffal, Nadia Y.; Aysa-Lastra, Maria

    2011-01-01

    Previous studies explored how urban or rural place of origin influences the source of social capital. There remains a need to consider how the place of origin affects the type of ties--family, friends, or "paisanos" (countrymen)--with those who provide support to migrants. We use data from the Mexican Migration Project (MMP128) and…

  6. Place of Origin, Types of Ties, and Support Networks in Mexico-U.S. Migration

    Science.gov (United States)

    Flores-Yeffal, Nadia Y.; Aysa-Lastra, Maria

    2011-01-01

    Previous studies explored how urban or rural place of origin influences the source of social capital. There remains a need to consider how the place of origin affects the type of ties--family, friends, or "paisanos" (countrymen)--with those who provide support to migrants. We use data from the Mexican Migration Project (MMP128) and…

  7. Ties That Bind: Creating and sustaining community-academic partnerships

    Directory of Open Access Journals (Sweden)

    Kynna N. Wright

    2011-11-01

    Full Text Available Growing interest among academics and health professionals in finding new ways to study and address complex health and social problems has manifested in recent years with increasing community demands for research and program implementation that is community-based, rather than merely community placed. In the United States, community-based participatory research (CBPR, with its emphasis on the creation and use of community-university or community-academic partnerships, is the prevailing paradigm to address these complex problems, especially those concerning racial/ethnic disparities in health and health care. While the need to strengthen the relationship between researchers and the community has been recognised, often from the viewpoint of the university partner, discussions on sustainability of partnerships have been few. The aim of this paper is to share reflections, through the eyes of the community members, on the core elements that tie community and academic members together and the challenges in understanding and nurturing those ties so that the community-academic partnership is sustained over time, and to offer possible recommendations for sustainability. This article speaks from the community’s perspective and reflects on the vital elements/components that tie together community-university partnerships and the challenges that may occur when trying to sustain and grow the partnership. It is based on a research CBPR study that was conducted to (1 evaluate the functioning and future sustainability of the community-university partnership of the Community Child Health Network Study Los Angeles (CCHN-LA community-university partnership, and (2 evaluate the experience and beliefs of the current CCHN-LA community-university partnership members in their understanding of current functioning. Keywords Community-academic partnerships; sustainability; challenges; solutions

  8. Singular (Lipschitz) homology and homology of integral currents

    OpenAIRE

    Riedweg, Christian; Schäppi, Daniel

    2009-01-01

    We compare the homology groups $H_n ^{IC}(X)$ of the chain complex of integral currents with compact support of a metric space $X$ with the singular Lipschitz homology $H^L_n (X)$ and with ordinary singular homology. If $X$ satisfies certain cone inequalities all these homology theories coincide. On the other hand, for the Hawaiian Earring the homology of integral currents differs from the singular Lipschitz homology and it differs also from the classical singular homology $H_n(X)$.

  9. Braid Floer homology

    Science.gov (United States)

    van den Berg, J. B.; Ghrist, R.; Vandervorst, R. C.; Wójcik, W.

    2015-09-01

    Area-preserving diffeomorphisms of a 2-disc can be regarded as time-1 maps of (non-autonomous) Hamiltonian flows on R / Z ×D2. The periodic flow-lines define braid (conjugacy) classes, up to full twists. We examine the dynamics relative to such braid classes and define a new invariant for such classes, the BRAID FLOER HOMOLOGY. This refinement of Floer homology, originally used for the Arnol'd Conjecture, yields a Morse-type forcing theory for periodic points of area-preserving diffeomorphisms of the 2-disc based on braiding. Contributions of this paper include (1) a monotonicity lemma for the behavior of the nonlinear Cauchy-Riemann equations with respect to algebraic lengths of braids; (2) establishment of the topological invariance of the resulting braid Floer homology; (3) a shift theorem describing the effect of twisting braids in terms of shifting the braid Floer homology; (4) computation of examples; and (5) a forcing theorem for the dynamics of Hamiltonian disc maps based on braid Floer homology.

  10. China, Argentina agree to further strategic ties

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    According to Xinhua,China and Argentina have agreed to further enhance mutual trust and their strategic partnership as the two emerging economies are playing an increasingly important role in the world arena.“China will work with Argentina to strengthen strategic mutual trust,expand cooperation and coordination within multilateral frameworks in order to promote bilateral ties and benefit the two peoples,” Vice President Xi Jinping told Argentine Foreign Minister Hector Timerman on September 9.

  11. Bioabsorbable thread for tight tying of bones.

    Science.gov (United States)

    Hattori, K; Tomita, N; Tamai, S; Ikada, Y

    2000-01-01

    The purpose of this research was to develop a bioabsorbable thread for tight fixation of fractured bones and to examine its mechanical performance in an in-vitro simulation study. The thread is a blend of bioabsorbable poly(L-lactic acid); (PLLA) and poly(epsilon-caprolactone); (PCL) fibers and can be tightly connected by fusion welding of the PCL fibers. The tying strength of the PLLA-PCL blend thread was 39.7 N, which was comparable to that of stainless steel wire. A testing machine was fabricated to measure the fatigue strength of the tying by simulating bone fixation. The results showed that metal wires always failed because of breakage within 25,000 loading cycles, whereas the blend threads did not fail until 50,000 loading cycles. The looseness of tying for simulated bone fixation by the blend thread was within 1mm even after 50 000 loading cycles. In-vivo testing using rats revealed that the blend thread did not cause any severe inflammatory reaction.

  12. 49 CFR 195.308 - Testing of tie-ins.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Testing of tie-ins. 195.308 Section 195.308 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Pressure Testing § 195.308 Testing of tie-ins. Pipe associated with tie-ins must be...

  13. 集体良知:个人与社会自然的联结纽带——涂尔干的核心问题及其研究进路之二%Collective Consciousness:Individual and Social Nature Connecting Tie

    Institute of Scientific and Technical Information of China (English)

    石德生

    2011-01-01

    Emile.Durkheim conceived in his research career the sociological thought that the duality of the mind and body of human nature and social nature as core,and further explicated the connecting tie between society and human nature_Collective Consciousness,intellectuals are undertaker and expresser of the social consciousness,it could become a collective standard and social fact then only being expressed through a sanctified ritual.Hence,Durkheim conceived by the research avenue of "mind and body duality",the dual studying mode that "mind" and "body" 、"individual" and "society" neither should be overemphasized at the expense of the other.Its purpose is to resolve the core issue in social development_why is human nature and social nature or social order possible.%埃米尔.涂尔干在其研究生涯中,构筑了以人性和社会自然的心物二重性为基础与核心的社会学思想,并进一步阐述了社会与人性自然之间的联结纽带——社会良知、知识分子是社会良知的担当者与表达者以及社会良知应该以神圣化的仪式和仪轨表达出来才能成为真正的集体规范、社会事实。由此,涂尔干通过"心物二元"的研究路径构建了"精神"与"躯体"、"个人"与"社会"二者都不偏废的二元研究范式,其目的就是要解决社会发展最为核心的问题——人性与社会的自然及社会秩序何以可能的问题。

  14. Gorenstein homological dimensions

    DEFF Research Database (Denmark)

    Holm, Henrik Granau

    2004-01-01

    In basic homological algebra, the projective, injective and 2at dimensions of modules play an important and fundamental role. In this paper, the closely related Gorenstein projective, Gorenstein injective and Gorenstein 2at dimensions are studied. There is a variety of nice results about Gorenstein...

  15. Gorenstein homological dimensions

    DEFF Research Database (Denmark)

    Holm, Henrik Granau

    2004-01-01

    In basic homological algebra, the projective, injective and 2at dimensions of modules play an important and fundamental role. In this paper, the closely related Gorenstein projective, Gorenstein injective and Gorenstein 2at dimensions are studied. There is a variety of nice results about Gorenstein...

  16. Grid-Tied Photovoltaic Power System

    Science.gov (United States)

    Eichenberg, Dennis J.

    2011-01-01

    A grid-tied photovoltaic (PV) power system is connected directly to the utility distribution grid. Facility power can be obtained from the utility system as normal. The PV system is synchronized with the utility system to provide power for the facility, and excess power is provided to the utility. Operating costs of a PV power system are low compared to conventional power technologies. This method can displace the highest-cost electricity during times of peak demand in most climatic regions, and thus reduce grid loading. Net metering is often used, in which independent power producers such as PV power systems are connected to the utility grid via the customers main service panels and meters. When the PV power system is generating more power than required at that location, the excess power is provided to the utility grid. The customer pays the net of the power purchased when the on-site power demand is greater than the onsite power production, and the excess power is returned to the utility grid. Power generated by the PV system reduces utility demand, and the surplus power aids the community. Modern PV panels are readily available, reliable, efficient, and economical, with a life expectancy of at least 25 years. Modern electronics have been the enabling technology behind grid-tied power systems, making them safe, reliable, efficient, and economical with a life expectancy equal to the modern PV panels. The grid-tied PV power system was successfully designed and developed, and this served to validate the basic principles developed, and the theoretical work that was performed. Grid-tied PV power systems are reliable, maintenance- free, long-life power systems, and are of significant value to NASA and the community. Of particular value are the analytical tools and capabilities that have been successfully developed. Performance predictions can be made confidently for grid-tied PV systems of various scales. The work was done under the NASA Hybrid Power Management (HPM

  17. Community Detection in Signed Networks: the Role of Negative ties in Different Scales

    Science.gov (United States)

    Esmailian, Pouya; Jalili, Mahdi

    2015-09-01

    Extracting community structure of complex network systems has many applications from engineering to biology and social sciences. There exist many algorithms to discover community structure of networks. However, it has been significantly under-explored for networks with positive and negative links as compared to unsigned ones. Trying to fill this gap, we measured the quality of partitions by introducing a Map Equation for signed networks. It is based on the assumption that negative relations weaken positive flow from a node towards a community, and thus, external (internal) negative ties increase the probability of staying inside (escaping from) a community. We further extended the Constant Potts Model, providing a map spectrum for signed networks. Accordingly, a partition is selected through balancing between abridgment and expatiation of a signed network. Most importantly, multi-scale spectrum of signed networks revealed how informative are negative ties in different scales, and quantified the topological placement of negative ties between dense positive ones. Moreover, an inconsistency was found in the signed Modularity: as the number of negative ties increases, the density of positive ties is neglected more. These results shed lights on the community structure of signed networks.

  18. Monopole Floer homology for rational homology 3-spheres

    OpenAIRE

    Froyshov, Kim A.

    2010-01-01

    We give a new construction of monopole Floer homology for $\\text{spin}^c$ rational homology $3$ -spheres. As applications, we define two invariants of certain $4$ -manifolds with $b_1=1$ and $b^+=0$ .

  19. Vínculos organizacionais Organizational ties

    Directory of Open Access Journals (Sweden)

    Gustavo Garcez Kramer

    2007-02-01

    Full Text Available Este artigo é um estudo de caso único, realizado junto a uma organização pública municipal de Curitiba, e tem como objetivo investigar e compreender os vínculos organizacionais. O estudo dos vínculos é feito por meio dos seus elementos constitutivos: a identificação, o sentimento de pertença, a cooperação, a participação, a criação de inimigos, a idealização, o reconhecimento e valorização dos indivíduos, a solidariedade, a integração, o crescimento e desenvolvimento pessoal e profissional e a autonomia. Foram utilizados, como instrumentos de coleta, questionário fechado e análise documental. O resultado dessa pesquisa é a caracterização dos elementos que são importantes na formação e manutenção dos vínculos e, conseqüentemente, para o comprometimento dos empregados com os objetivos, políticas, problemas, desempenho e resultados da organização.This article presents a unique case study of the organizational ties in a public municipal organization in the city of Curitiba, Brazil. The ties are studied through their constitutive elements: identification, sense of belonging, cooperation, participation, creation of enemies, idealization, recognition and appreciation of individuals, solidarity, integration, professional and personal development and growth, and autonomy. Documental analysis and closed questionnaires were used for data collection. The research resulted in the characterization of the elements that are important in making and keeping ties, and consequently committing employees to the organization's objectives, policies, problems, performance and results.

  20. Power Generation Capabilities of Tie Tube Assemblies

    Science.gov (United States)

    Gunn, Stanley V.; Hedstrom, James; Hundal, Rolv

    1994-07-01

    Second generation nuclear thermal rocket engine designs, employing solid core reactors and expander engine cycles, generally rely on some form of nuclear-driven heater to supply the major portion of thermal energy required to preheat the turbine-drive gases. If adequate heat transfer occurs, not only will efficiency-enhancing turbine-inlet temperatures be realized, but sufficient energy will be available to enable engine operation at chamber pressures ranging to at least 2,000 psia. For the case of reactor cores employing prismatic fuel elements, the utilization of tie tube assemblies, as first employed in the core-support subsystem of the Phoebus II reactor, can provide the basis of an array of propellant (hydrogen) preheaters that offer an ample supply of energy and temperature to enable candidate expander engine cycles over a wide range of operating parameters, without reducing the total enthalpy of the core-exit gas and its attendant effect on specific impulse. By modifying the tie tube design concept set forth in LASL's Nuclear Rocket Engine definition study, a powerful, weight and packaging-effective, preheater assembly can be realized. The design features of these tie tube assemblies reflect their functional objectives, core criticality considerations, and space constraints. Since the core pressure and inertial mass loads are carried by these assemblies, the structural tubular element(s) also provide coolant passage(s) for the hydrogen. The transfer of heat to the coolant surfaces is controlled by the effective thermal conductivity of the filler structure and ``insulating sleeves,'' which surround the tubular elements and are in controlled thermal contact with the surrounding core fuel elements. An option exists to further increase the transported heat to the coolant walls by the selective loading of the filler structure, ``insulating sleeves,'' and the moderator annular element with fissionable material.

  1. 真丝领带的创新设计%Innovative design of silk tie

    Institute of Scientific and Technical Information of China (English)

    刘重嵘

    2012-01-01

    This thesis summarizes the primary causes for designs and innovation of men's silk ties, the development of domestic men's tie brands and their current situation, and proposes the approaches for the designs and innovation of men's silk tie brands. It deems that the development of modern social and cultural life motivates the innovation of traditional silk tie brands. To satisfy the requirements of careers of men consumers who pursue the life quality, the design of domestic men's silk tie goes towards the direction that integrates emotions and cultural connotation. To have innovative application in the design of modern tie brands, it is necessary for traditional silk ties to break inherent stiff modes, integrate design elements that accord with the aesthetics of modern people based on innovation and beauty, endow modern silk ties with some fashion and emotion as well as improves the taste of silk tie brands so that they can met international tendency of fashion.%概述了男士真丝领带设计创新的根本原因、国内领带品牌的发展及现状,提出了国内男士真丝领带品牌的创新设计途径,认为现代社会文化生活的发展推动了传统真丝领带品牌的创新.为符合当代追求品质生活的男士消费群的职业需求,国内男士真丝领带设计正朝着融入情感化、人文内涵的趋势发展.传统真丝领带要在现代领带品牌设计中有所创新应用,需要打破原有呆板的固有模式,在求新求美中融入符合现代人潮流观的设计元素,赋予现代真丝领带一定的时尚活力与情感,提升真丝领带品牌向高品位、国际化的时尚新趋势接轨.

  2. Algebra V homological algebra

    CERN Document Server

    Shafarevich, I

    1994-01-01

    This book, the first printing of which was published as volume 38 of the Encyclopaedia of Mathematical Sciences, presents a modern approach to homological algebra, based on the systematic use of the terminology and ideas of derived categories and derived functors. The book contains applications of homological algebra to the theory of sheaves on topological spaces, to Hodge theory, and to the theory of modules over rings of algebraic differential operators (algebraic D-modules). The authors Gelfand and Manin explain all the main ideas of the theory of derived categories. Both authors are well-known researchers and the second, Manin, is famous for his work in algebraic geometry and mathematical physics. The book is an excellent reference for graduate students and researchers in mathematics and also for physicists who use methods from algebraic geometry and algebraic topology.

  3. The Running Barbed Tie-over Dressing

    Directory of Open Access Journals (Sweden)

    Cormac W. Joyce, MB, BCh, MRCSI

    2014-04-01

    Full Text Available Summary: Barbed suture technology is becoming increasingly popular in plastic surgery and is now being used in body contouring surgery and facial rejuvenation. We describe the novel application of a barbed suture as a running tie-over dressing for skin grafts. The barbs act as anchors in the skin, so constant tensioning of the suture is not required. The bidirectional nature of the suture prevents any slippage, and the barbs even act as a grip on the underlying wool dressing. Furthermore, the method described is both quick and simple to learn and would be useful for the sole operator.

  4. The Red Power(less Tie

    Directory of Open Access Journals (Sweden)

    Robin S. S. Kramer

    2016-05-01

    Full Text Available Research has demonstrated that wearing red can have significant effects on perceptions of the wearer. However, these findings are based on impressions formed while viewing static images. Here, I focus on perceptions of political leaders and show participants short videos in order to investigate color effects in stimuli with increased ecological validity. Viewers watched videos of politicians and made judgments regarding how dominant, how good a leader, and how believable the politicians appeared to be. The colors of the politicians’ ties were digitally manipulated to be red or blue. Whether the politician was familiar (Study 1 or unfamiliar to viewers (Study 2, tie color had no effect on perceptions. Even when the sound was muted in order to increase the influence of visual cues (Study 3, I found no clothing color effect. Finally, when only presented with a static image (Study 4, wearing red still had no effect on judgments. These results suggest that, at least in a political setting, wearing red has no effect on perceptions. Therefore, real-world applications associated with red clothing may be limited.

  5. Rabinowitz Floer homology: A survey

    CERN Document Server

    Albers, Peter

    2010-01-01

    Rabinowitz Floer homology is the semi-infinite dimensional Morse homology associated to the Rabinowitz action functional used in the pioneering work of Rabinowitz. Gradient flow lines are solutions of a vortex-like equation. In this survey article we describe the construction of Rabinowitz Floer homology and its applications to symplectic and contact topology, global Hamiltonian perturbations and the study of magnetic fields.

  6. The Tie Effect in Mental Arithmetic%心算加工中tie effect的加工机制

    Institute of Scientific and Technical Information of China (English)

    田花; 刘昌

    2011-01-01

    This article is to review the tie effect in simple arithmetic. Tie effect means that simple arithmetic problems with repeated operands (i. e., ties such as 3 + 3,4×4) are solved more quickly and accurately than similar nontie problems (e. g., 3 + 4,4 × 5). Furthermore, problem size and tie effect so interact that latencies on both ties and nonties increase with the problem size, but the increase is much greater in nonties than in ties. There are two possible explanations for the tie effect, i.e., encoding-based and access- based accounts. Encoding-based accounts propose that the tie advantage occurs because repetition of the same physical stimulus results in faster encoding of ties than of nonties. Alternatively, access-based accounts propose that ties may be easier to solve than nonties because of differences in accessibility in memory or differences in the solution processes. Access-based accounts fall into three categories: familiarity, interference, variability in solution approaches. According to familiarity explanations, acee~ibility so varies with practice that the tie effect is related to the frequency with which problems are encountered. Ties receive more practice and the connections between operands and answers in memory are greater. So ties are solved more quickly. According to interference explanations, ties and nonties are defined as separate categories of problems and the interference is greater within categories than between category. Thus, because the tie category includes relatively few problems, ties received less inhibitory input than nonties. According to solution approach explanations, even simple arithmetic is solved not only by direct retrieval from memory but by nov_retrieval procedures. Ties are solved by direct retrieval procedures and nonties are solved by nonretrieval procedures which are slower than direct retrieval. The encoding-account can' t provide reasonable explanations for the tie ~ size interaction. Aceess

  7. To tie or not to tie ridges for water conservation in Rift Valley drylands of Ethiopia

    NARCIS (Netherlands)

    Temesgen, B.B.; Stroosnijder, L.

    2012-01-01

    The Rift Valley drylands of Ethiopia are characterized by sandy loam soils that have poor fertility and unreliable rainfall conditions. The aim of this study was to examine the potential benefit of rainwater harvesting by tied-ridges and improved soil fertility on maize productivity through field ex

  8. Level of arterial ligation in rectal cancer surgery: Low tie preferred over high tie. A review

    NARCIS (Netherlands)

    M.M. Lange (Marilyne); M. Buunen (Mark); C.J.H. van de Velde (Cornelis)

    2008-01-01

    textabstractConsensus does not exist on the level of arterial ligation in rectal cancer surgery. From oncologic considerations, many surgeons apply high tie arterial ligation (level of inferior mesenteric artery). Other strategies include ligation at the level of the superior rectal artery, just cau

  9. To tie or not to tie ridges for water conservation in Rift Valley drylands of Ethiopia

    NARCIS (Netherlands)

    Temesgen, B.B.; Stroosnijder, L.

    2012-01-01

    The Rift Valley drylands of Ethiopia are characterized by sandy loam soils that have poor fertility and unreliable rainfall conditions. The aim of this study was to examine the potential benefit of rainwater harvesting by tied-ridges and improved soil fertility on maize productivity through field

  10. China TieTong: Differentiation Paves the Uncommon Path

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    China TieTong has made great achievements since it was founded about six years ago. And the achievements made by China TieTong cannot be separated from the path of differentiation it has stuck to. Zhao Jibin, board chairman of China TieTong has pointed out the company should develop a path of "enlarging the dedicated network and strengthening the regional service" to ensure precise positioning and successful implementation of the development strategy with solid management foundation and improving managem...

  11. ANALYSIS OF TIED DATA: AN ALTERNATIVE NON-PARAMETRIC APPROACH

    Directory of Open Access Journals (Sweden)

    I. C. A. OYEKA

    2012-02-01

    Full Text Available This paper presents a non-parametric statistical method of analyzing two-sample data that makes provision for the possibility of ties in the data. A test statistic is developed and shown to be free of the effect of any possible ties in the data. An illustrative example is provided and the method is shown to compare favourably with its competitor; the Mann-Whitney test and is more powerful than the latter when there are ties.

  12. Tying Knots: Participatory Infrastructuring at Work

    DEFF Research Database (Denmark)

    Bødker, Susanne; Dindler, Christian; Iversen, Ole Sejer

    2017-01-01

    dispersed within these networks. To illustrate and discuss the process of participatory infrastructuring we use a case study from an educational context. This particular project contains a diverse set of design activities at many organizational levels revolving around technology, decision-making, competence...... seem to mainly address participatory infrastructuring as horizontal co-design and local, mutual learning processes in which people attempt to make the most out of available technology. In this paper we expand our view of design activities in three dimensions: First, how participatory processes play out...... vertically in different political and practical arenas; second, on the back stage of design, the messy activities that occur before, between and after the participatory workshops. And third, on their reach; how they tie into existing networks across organizations, and how agency and initiatives become...

  13. Expression and role of Tie-2 in rectal carcinoma

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Objective To investigate the expression of Tie-2 in rectal carcinoma and its relationship with invasion and metastasis in rectal carcinoma.Materials S-P immunohistochemical assay was used to detect the expression of Tie-2 in 40 cases of rectal carcinoma and 10 cases of normal rectal tissues.Results Tie-2 was mainly localized in the cytoplasm and nucleus of vascular endothelial cells in cancerous tissues and partly in the cytoplasm of some cancerous cells.The expression of Tie-2 in rectal carcinoma was signi...

  14. Field homology: a meaningful definition.

    Science.gov (United States)

    Cookson, K

    2001-02-01

    Field homology refers to populations of cells that derive from evolutionarily conserved regions of embryos but are distributed across sets of adult morphological structures that cannot be placed in one-to-one correspondance. The concept of field homology has proven especially attractive to comparative neurologists because it allows them to deal with the fact that sets of nuclei or nuclear subdivisions often cannot be compared on a one-to-one basis across phyletic groups. However, the concept of field homology has recently come under criticism. It has been argued that field homology is theoretically impossible because it requires sequences of developmental stages to be both evolutionarily conserved and evolutionarily modified. It has also been argued that field homology allows overly vague comparisons of adult morphological structures, fails to account for homologous structures that derive from non-homologous embryonic sources, and establishes overly rigid links between embryonic and adult morphology. All of these criticisms may be adequately addressed by explaining field homology in terms of differentiation. The present paper explains field homology in terms of differentiation using the amniote dorsal thalamus to illustrate major points. It is concluded that field homology is a meaningful concept when defined in terms of differentiation, applied to appropriate cases, and properly limited in its comparisons of adult structures.

  15. Rhythmical bimanual force production: homologous and non-homologous muscles.

    Science.gov (United States)

    Kennedy, Deanna M; Boyle, Jason B; Rhee, Joohyun; Shea, Charles H

    2015-01-01

    The experiment was designed to determine participants' ability to coordinate a bimanual multifrequency pattern of isometric forces using homologous or non-homologous muscles. Lissajous feedback was provided to reduce perceptual and attentional constraints. The primary purpose was to determine whether the activation of homologous and non-homologous muscles resulted in different patterns of distortions in the left limb forces that are related to the forces produced by the right limb. The task was to rhythmically produce a 1:2 pattern of isometric forces by exerting isometric forces on the left side force transducer with the left arm that was coordinated with the pattern of isometric forces produced on the right side force transducer with the right arm. The results indicated that participants were able to 'tune-in' a 1:2 coordination patterns using homologous (triceps muscles of the left and right limbs) and using non-homologous muscles (biceps left limb and triceps right limb) when provided Lissajous feedback. However, distinct but consistent and identifiable distortions in the left limb force traces were observed for both the homologous and non-homologous tasks. For the homologous task, the interference occurred in the left limb when the right limb was initiating and releasing force. For the non-homologous task, the interference in the left limb force occurred only when the right limb was releasing force. In both conditions, the interference appeared to continue from the point of force initiation and/or release to peak force velocity. The overall results are consistent with the notion that neural crosstalk manifests differently during the coordination of the limbs depending upon whether homologous or non-homologous muscles are activated.

  16. Homology, homoplasy, novelty, and behavior.

    Science.gov (United States)

    Hall, Brian K

    2013-01-01

    Richard Owen coined the modern definition of homology in 1843. Owen's conception of homology was pre-evolutionary, nontransformative (homology maintained basic plans or archetypes), and applied to the fully formed structures of animals. I sketch out the transition to an evolutionary approach to homology in which all classes of similarity are interpreted against the single branching tree of life, and outline the evidence for the application of homology across all levels and features of the biological hierarchy, including behavior. Owen contrasted homology with analogy. While this is not incorrect it is a pre-evolutionary contrast. Lankester [Lankester [1870] Journal of Natural History, 6 (31), 34-43] proposed homoplasy as the class of homology applicable to features formed by independent evolution. Today we identify homology, convergence, parallelism, and novelties as patterns of evolutionary change. A central issue in homology [Owen [1843] Lectures on comparative anatomy and physiology of the invertebrate animals, delivered at the Royal College of Surgeons in 1843. London: Longman, Brown, Green & Longmans] has been whether homology of features-the "same" portion of the brain in different species, for example-depends upon those features sharing common developmental pathways. Owen did not require this criterion, although he observed that homologues often do share developmental pathways (and we now know, often share gene pathways). A similar situation has been explored in the study of behavior, especially whether behaviors must share a common structural, developmental, neural, or genetic basis to be classified as homologous. However, and importantly, development and genes evolve. As shown with both theory and examples, morphological and behavioral features of the phenotype can be homologized as structural or behavioral homologues, respectively, even when their developmental or genetic bases differ (are not homologous). Copyright © 2012 Wiley Periodicals, Inc.

  17. The Role of Positive and Negative Signaling Communication by Strong and Weak Ties in the Shaping of Safe Sex Subjective Norms of Adolescents in South Africa

    NARCIS (Netherlands)

    Boer, H.; Westhoff, Yvette

    2006-01-01

    We propose the theory that subjective (injunctive) social norms are shaped through two intertwined processes: positive and negative signaling communication by the personal social network and construal of the communicated social norm. Construal is evoked by the strength of the relation between a tie

  18. Computational Homology for Software Validation

    Science.gov (United States)

    2015-03-01

    COMPUTATIONAL HOMOLOGY FOR SOFTWARE VALIDATION SYRACUSE UNIVERSITY MARCH 2015 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION...COVERED (From - To) SEP 2011 – SEP 2014 4. TITLE AND SUBTITLE COMPUTATIONAL HOMOLOGY FOR SOFTWARE VALIDATION 5a. CONTRACT NUMBER FA8750-11-2-0275 5b...verdict as to whether the application of persistent homology to the problem of obtaining objective signatures that would indicate the present or absence

  19. Serbian President Vows to Boost Trade Ties with China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Serbian President Boris Tadic on August 20 pledged to promote economic and trade ties with China,welcoming Chinese investment.Serbia wanted to maintain highlevel political ties with China and enhance economic exchanges and cooperation,said Tadic at a business forum held by the China Council for the Promotion of International Trade (CCPIT).

  20. TIE - DYE (ADIRE) AMONG THE JUKUN PEOPLE Gausa Solomon ...

    African Journals Online (AJOL)

    SO

    One can simply define Tie-dye as a method of tying or stitching fabric ... binding or stitching and small pattern, while heavier cloth tends itself best to .... threads were woven with a dull white cotton yarn to produce time and block simple geometric .... As far as the present Jukun Adire production is concerned, this is the last ...

  1. Evolution of bow-tie architectures in biology.

    Directory of Open Access Journals (Sweden)

    Tamar Friedlander

    2015-03-01

    Full Text Available Bow-tie or hourglass structure is a common architectural feature found in many biological systems. A bow-tie in a multi-layered structure occurs when intermediate layers have much fewer components than the input and output layers. Examples include metabolism where a handful of building blocks mediate between multiple input nutrients and multiple output biomass components, and signaling networks where information from numerous receptor types passes through a small set of signaling pathways to regulate multiple output genes. Little is known, however, about how bow-tie architectures evolve. Here, we address the evolution of bow-tie architectures using simulations of multi-layered systems evolving to fulfill a given input-output goal. We find that bow-ties spontaneously evolve when the information in the evolutionary goal can be compressed. Mathematically speaking, bow-ties evolve when the rank of the input-output matrix describing the evolutionary goal is deficient. The maximal compression possible (the rank of the goal determines the size of the narrowest part of the network-that is the bow-tie. A further requirement is that a process is active to reduce the number of links in the network, such as product-rule mutations, otherwise a non-bow-tie solution is found in the evolutionary simulations. This offers a mechanism to understand a common architectural principle of biological systems, and a way to quantitate the effective rank of the goals under which they evolved.

  2. Grid diagrams and Khovanov homology

    DEFF Research Database (Denmark)

    Droz, Jean-Marie; Wagner, Emmanuel

    2009-01-01

    We explain how to compute the Jones polynomial of a link from one of its grid diagrams and we observe a connection between Bigelow’s homological definition of the Jones polynomial and Kauffman’s definition of the Jones polynomial. Consequently, we prove that the Maslov grading on the Seidel......–Smith symplectic link invariant coincides with the difference between the homological grading on Khovanov homology and the Jones grading on Khovanov homology. We give some evidence for the truth of the Seidel–Smith conjecture....

  3. Resilience by solidary ties (Resiliencia por lazos de solidaridad

    Directory of Open Access Journals (Sweden)

    Antonio Alaminos

    2015-07-01

    Full Text Available This article considers an empirical approach to the relationships among three well known concepts: “Benevolence” (Schwartz, Solidarity and Resilience ("Subjective wellbeing scale" - SWB. The first concept refers to cultural values, the second one to social networks and the third to the ability to recover from crisis. The measurement of solidarity has been done from the point of view of supportive ties. The baseline hypothesis considers that the presence of a high value in Benevolence contributes to the involvements in solidarity networks. Participation in supportive relationships facilitates recovery from personal crisis. Using data from the European Social Survey (ESS6, we conclude from this structural analysis that the resilience reflected in a society is partly a consequence of the supportive networks shaped by the presence of benevolence values. | Tras introducir teóricamente los conceptos de "Benevolencia" (Schwartz, "Lazos de solidaridad" y "Resiliencia", se presenta su operativización en la Encuesta Social Europea de 2012. La hipótesis de partida plantea que la presencia de un valor alto en Benevolencia influye en la participación en interacciones solidarias y que la participación en redes solidarias facilita el recobrarse de las crisis. A partir de estos datos, y considerando varias sociedades europeas, se han testado dos modelos alternativos, según el efecto de la Benevolencia y los lazos de solidaridad sobre la resiliencia. Se concluye que existe un efecto directo de los valores de Benevolencia sobre la Solidaridad, y de esta sobre la Resiliencia. La influencia de los valores de Benevolencia sobre la Resiliencia se establece de forma indirecta mediante la activación de relaciones solidarias.

  4. Effects of Weak Ties on Epidemic Predictability in Community Networks

    CERN Document Server

    Shu, Panpan; Gong, Kai; Liu, Ying

    2012-01-01

    Weak ties play a significant role in the structures and the dynamics of community networks. Based on the susceptible-infected model in contact process, we study numerically how weak ties influence the predictability of epidemic dynamics. We first investigate the effects of different kinds of weak ties on the variabilities of both the arrival time and the prevalence of disease, and find that the bridgeness with small degree can enhance the predictability of epidemic spreading. Once weak ties are settled, compared with the variability of arrival time, the variability of prevalence displays a diametrically opposed changing trend with both the distance of the initial seed to the bridgeness and the degree of the initial seed. More specifically, the further distance and the larger degree of the initial seed can induce the better predictability of arrival time and the worse predictability of prevalence. Moreover, we discuss the effects of weak tie number on the epidemic variability. As community strength becomes ver...

  5. The position of the Turkish and Moroccan second generation in Amsterdam and Rotterdam: The TIES study in the Netherlands

    NARCIS (Netherlands)

    Crul, M.; Heering, L.

    2008-01-01

    This first publication of the TIES Project (Towards the Integration of the European Second Generation) examines the social stratification and views of the second Dutch generation of Turkish and Moroccan origin living in the Netherlands. Drawing on research carried out in 2006-7 the Dutch-born

  6. Achievement Gaps Tied to Income Found Widening

    Science.gov (United States)

    Maxwell, Lesli A.

    2012-01-01

    The fractious debate over how much schools can counteract poverty's impact on children is far from settled, but a recently published collection of research strongly suggests that until policymakers and educators confront deepening economic and social disparities, poor children will increasingly miss out on finding a path to upward social mobility.…

  7. Zebrafish Tie-2 shares a redundant role with Tie-1 in heart development and regulates vessel integrity

    NARCIS (Netherlands)

    Gjini, Evisa; Hekking, Liesbeth H.; Kuechler, Axel; Saharinen, Pipsa; Wienholds, Erno; Post, Jan-Andries; Alitalo, Kari; Schulte-Merker, Stefan

    Tie-2 is a member of the receptor tyrosine kinase family and is required for vascular remodeling and maintenance of mammalian vessel integrity. A number of mutations in the human TIE2 gene have been identified in patients suffering from cutaneomucosal venous malformations and ventricular septal

  8. 78 FR 75545 - Prestressed Concrete Steel Rail Tie Wire From the People's Republic of China: Preliminary...

    Science.gov (United States)

    2013-12-12

    ... International Trade Administration Prestressed Concrete Steel Rail Tie Wire From the People's Republic of China... concrete steel rail tie wire (``PC tie wire'') from the People's Republic of China (``PRC'') is being, or... prestressed tendons in concrete railroad ties (``PC tie wire''). High carbon steel is defined as steel...

  9. Transnational Corporate Ties: A Synopsis of Theories and Empirical Findings

    Directory of Open Access Journals (Sweden)

    Michael Nollert

    2015-08-01

    Full Text Available In general, corporations are not isolated actors in an economic “war of all against all” but members of corporate networks of global reach. Although the literature on globalization emphasizes the increasing economic power of these networks and postulates the formation of a transnational capitalist class, there is still a lack of empirical findings. The article starts with a review of theoretical perspectives (resource dependence, social capital, coordination of markets, financial hegemony, class hegemony, inner circle, and transnational capitalist class which focuses on the functions and structures of corporate interlocks at the national and the transnational level. The subsequent section offers an outline of empirical studies concerning transnational corporate networks. These analyses of corporate ties (interlocking directorates, financial participations and policy group affiliations suggest the emergence of transnational economic elites whose members, however, have not lost their national identity. In the final section, the theoretical perspectives will be assessed and some prospects are sketched out. Finally, it will be argued that the disintegration of the world society, which is considerably driven by rent-seeking corporate networks, can only be restrained if a potential global regulatory agency will be anchored in a post-Washington consensus.

  10. Relative Homological Algebra Volume 1

    CERN Document Server

    2011-01-01

    This is the second revised edition of an introduction to contemporary relative homological algebra. It supplies important material essential to understand topics in algebra, algebraic geometry and algebraic topology. Each section comes with exercises providing practice problems for students as well as additional important results for specialists. The book is also suitable for an introductory course in commutative and ordinary homological algebra.

  11. Evolving the Concept of Homology

    Science.gov (United States)

    Naples, Virginia L.; Miller, Jon S.

    2009-01-01

    Understanding homology is fundamental to learning about evolution. The present study shows an exercise that can be varied in complexity, for which students compile research illustrating the fate of homologous fish skull elements, and assemble a mural to serve as a learning aid. The skull of the most primitive living Actinopterygian (bony fish),…

  12. KAMG: A Tool for Converting Blood Ties and Affinity Ties into Adjacency Matrices

    Directory of Open Access Journals (Sweden)

    Hang Xiong

    2016-07-01

    Full Text Available Kinship Adjacency Matrix Generator (KAMG is a browser-based software for creating adjacency matrices using the information of kinship ties. Specifically, it is capable of converting the family trees in the format of GEDCOM files into adjacency matrices of blood relationship. With the data of intermarriages between different families, it can further create the adjacency matrix of affinity relationship for the families. The outcomes can be directly used to create networks. KAMG is written in JavaScript and implemented on web browsers. It is completely open source and the source code is publicly available on GitHub.

  13. Redoable tie-over dressing using multiple loop silk threads.

    Science.gov (United States)

    Jo, Hyeon Jong; Kim, Jun Sik; Kim, Nam Gyun; Lee, Kyung Suk; Choi, Jae Hoon

    2013-05-01

    After skin grafting, to prevent hematoma or seroma collection at the graft site, a tie-over dressing has been commonly used. However, although the conventional tie-over dressing by suture is a useful method for securing a graft site, refixation is difficult when repeated tie-over dressing is needed. Therefore, we recommend a redoable tie-over dressing technique with multiple loops threads and connecting silk threads. After the raw surface of each of our cases was covered with a skin graft, multiple loop silk thread attached with nylon at the skin graft margin. We applied the ointment gauze and wet cotton/fluffy gauze over the skin graft, then fixed the dressing by connecting cross-counter multiple loop thread with connecting silk threads. When we opened the tie-over dressing by cutting the connecting silk threads, we repeated the tie-over dressing with the same method. The skin graft was taken successfully without hematoma or seroma collection or any other complications. In conclusion, we report a novel tie-over dressing enabling simple fixation of the dressing to maintain proper tension for wounds that require repetitive fixation. Further, with this reliable method, the skin grafts were well taken.

  14. Cross-border Ties as Sources of Risk and Resilience: Do Cross-border Ties Moderate the Relationship between Migration-related Stress and Psychological Distress for Latino Migrants in the United States?

    Science.gov (United States)

    Torres, Jacqueline M; Alcántara, Carmela; Rudolph, Kara E; Viruell-Fuentes, Edna A

    2016-12-01

    Few studies have examined the associations between health and the cross-border ties that migrants maintain with their family members in communities of origin. We draw on theory related to social ties, ethnic identity, and mental health to examine cross-border ties as potential moderators of the association between migration-related stress and psychological distress among Latino migrants. Using data from the National Latino and Asian American Survey, we find that remittance sending is associated with significantly lower levels of psychological distress for Cuban migrants, and difficulty visiting home is associated with significantly greater psychological distress for Puerto Rican migrants. There were significant associations between migration-related stressors and psychological distress, although these associations fell to nonsignificance after accounting for multiple testing. We found little evidence that cross-border ties either buffer or exacerbate the association between migration-related stressors and psychological distress. We consider the findings within the current political and historical context of cross-border ties and separation. © American Sociological Association 2016.

  15. Homology theory on algebraic varieties

    CERN Document Server

    Wallace, Andrew H

    1958-01-01

    Homology Theory on Algebraic Varieties, Volume 6 deals with the principles of homology theory in algebraic geometry and includes the main theorems first formulated by Lefschetz, one of which is interpreted in terms of relative homology and another concerns the Poincaré formula. The actual details of the proofs of these theorems are introduced by geometrical descriptions, sometimes aided with diagrams. This book is comprised of eight chapters and begins with a discussion on linear sections of an algebraic variety, with emphasis on the fibring of a variety defined over the complex numbers. The n

  16. Compositional Homology and Creative Thinking

    Directory of Open Access Journals (Sweden)

    Salvatore Tedesco

    2015-05-01

    Full Text Available The concept of homology is the most solid theoretical basis elaborated by the morphological thinking during its history. The enucleation of some general criteria for the interpretation of homology is today a fundamental tool for life sciences, and for restoring their own opening to the question of qualitative innovation that arose so powerfully in the original Darwinian project. The aim of this paper is to verify the possible uses of the concept of compositional homology in order to provide of an adequate understanding of the dynamics of creative thinking.

  17. Differentiating weak ties and strong ties among external sources of influences for enterprise resource planning (ERP) adoption

    Science.gov (United States)

    Aubert, Benoit; Léger, Pierre-Majorique; Larocque, Denis

    2012-05-01

    Enterprise resource planning (ERP) systems represent a major IT adoption decision. ERP adoption decisions, in the chemicals and allied products sectors, were examined between 1994 and 2005. Networks of strong ties and weak ties partners are investigated. Results show that neighbouring companies linked with strong ties can have an influence on organisations making such adoption decision. Past decisions made by major trading partners have a significant influence on the decision to adopt an ERP system for a given organisation. This reflects the complex nature of the knowledge required for such adoption.

  18. Eye Problems May Be Tied to Zika, Lab Study Suggests

    Science.gov (United States)

    ... 165947.html Eye Problems May Be Tied to Zika, Lab Study Suggests Work with monkeys indicates birth ... 25, 2017 (HealthDay News) -- Scientists exploring how the Zika virus passes from pregnant monkeys to their fetuses ...

  19. Obstetric Complications Tied to Slightly Upped Risk for Autism

    Science.gov (United States)

    ... Obstetric Complications Tied to Slightly Upped Risk for Autism Study suggests link, but one expert stressed that most complicated pregnancies result in babies without autism To use the sharing features on this page, ...

  20. Smoking in Pregnancy Tied to Kidney Damage in Kids

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162696.html Smoking in Pregnancy Tied to Kidney Damage in Kids ... and about 17 percent of those women continued smoking while pregnant, the study authors said. Children of ...

  1. Bilateral Transport Cost, Infrastructure, Common Bilateral Ties and Political Stability

    National Research Council Canada - National Science Library

    Danielken Molina

    2008-01-01

    .... Using these new indexes we find that not only distance but infrastructure, political stability, common bilateral ties and open sky agreements as well are other important channels through which...

  2. More Evidence Ties Gum Health to Stroke Risk

    Science.gov (United States)

    ... 163755.html More Evidence Ties Gum Health to Stroke Risk Study shows increasing risk of brain blockage ... as people with healthy gums to suffer a stroke, new research suggests. It's not the first study ...

  3. Low Blood Sugar in Newborns Tied to Brain Problems Later

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_167671.html Low Blood Sugar in Newborns Tied to Brain Problems Later These ... TUESDAY, Aug. 8, 2017 (HealthDay News) -- Low blood sugar affects about one in six newborns, and new ...

  4. Antidepressants in Pregnancy Tied to Slight Increase in Autism

    Science.gov (United States)

    ... 167328.html Antidepressants in Pregnancy Tied to Slight Increase in Autism But difference in risk is quite ... to rule out the possibility that depression itself increases the risk of autism, rather than the medications ...

  5. Drug Helps Fight Breast Tumors Tied to 'Cancer Genes'

    Science.gov (United States)

    ... Drug Helps Fight Breast Tumors Tied to 'Cancer Genes' Lynparza may offer a new treatment for women ... with breast cancer linked to BRCA1 and BRCA2 gene mutations, according to the study. Olaparib delayed cancer ...

  6. Same-Sex Marriage Laws Tied to Fewer Teen Suicides

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163674.html Same-Sex Marriage Laws Tied to Fewer Teen Suicides Perceived ... A new study links the approval of same-sex marriage in American states to lower rates of ...

  7. Timing of Autism Diagnosis Tied to Choice of Treatment

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_160279.html Timing of Autism Diagnosis Tied to Choice of Treatment Kids diagnosed ... Aug. 5, 2016 (HealthDay News) -- Children diagnosed with autism before age 4 are more likely to get ...

  8. Study Ties Inflammation, Gut Bacteria to Type 1 Diabetes

    Science.gov (United States)

    ... news/fullstory_163143.html Study Ties Inflammation, Gut Bacteria to Type 1 Diabetes However, it's not yet ... Italian study finds. Those changes include different gut bacteria and inflammation in the small intestine. The differences ...

  9. High Pain Tolerance Tied to 'Silent' Heart Attack Risk

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_162666.html High Pain Tolerance Tied to 'Silent' Heart Attack Risk Unusual symptoms ... is. But the new findings suggest that pain tolerance might be a factor. Using a standard test ...

  10. Angelina Jolie's Mastectomies Tied to Rise in Genetic Testing

    Science.gov (United States)

    ... html Angelina Jolie's Mastectomies Tied to Rise in Genetic Testing But, researchers did not find a corresponding increase ... Human Services. More Health News on: Breast Cancer Genetic Testing Mastectomy Recent Health News Related MedlinePlus Health Topics ...

  11. Sino-Russian Ties Strengthened by Economic Bonds

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The China-Russia strategic partnership has become increasingly successful-intertwined with growing trade and economic ties As the two largest countries on the Eurasian Continent, China and Russia have established stable and coordinated relations through bilat-

  12. Study Ties Alcohol Abuse to Increased Heart Risks

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_162836.html Study Ties Alcohol Abuse to Increased Heart Risks Association similar to that ... 2009. About 2 percent had been diagnosed with alcohol abuse. The researchers adjusted statistics so they wouldn't ...

  13. Early Menopause May Be Tied to Type 2 Diabetes

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_167305.html Early Menopause May Be Tied to Type 2 Diabetes When ... risk is 4 times greater compared to late menopause, study suggests To use the sharing features on ...

  14. Common Virus May Have Ties to Type 1 Diabetes

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_162969.html Common Virus May Have Ties to Type 1 Diabetes But ... least some cases of type 1 diabetes. The viruses are known as enteroviruses. These viruses cause a ...

  15. Family ties and depression across the life course: An Overview

    Directory of Open Access Journals (Sweden)

    Nienke Moor

    2012-08-01

    Full Text Available BACKGROUND Family ties in Europe are affected by demographic trends associated with parenting and partnering, such as a decline in fertility, an increase in childlessness, postponement of parenthood and of partnership formation, the rise of "new" relationship forms and divorce rates. It is unclear how the contemporary family structure and composition are associated with people's mental wellbeing. OBJECTIVE This article examines how ties with parents, siblings, a partner and children are associated with depressive mood of men and women in seven Eastern and Western European countries. METHODS To test our hypotheses we made use of data from the Generations and Gender Surveys. We performed logistic regression analyses to study the associations between people's family ties and depressive mood. RESULTS Our research findings show that family ties can diminish people's depressive feelings. Although we find some gender differences in these associations, we do not find support for the argument that family ties are more important for the mental wellbeing of women than of men. Moreover, our findings support the hierarchical model of family relations in which new ties with partner and children in adulthood gain precedence over the original primary ties with parents and siblings. Finally, we find that the association between family ties and depressive mood is quite similar in Eastern and Western Europe, but being married or having a partner more strongly reduces depressive feelings in Eastern than in Western Europe. CONCLUSIONS Although we did not dispose of longitudinal data, our research results do provide some indications about how demographic changes, for instance, those affecting family size -- the number of children or siblings -- might be associated with mental wellbeing. Our findings also suggest that the demographic trend of increasing partnership dissolution may have larger consequences for people's mental wellbeing in Eastern

  16. Family ties and depression across the life course: An Overview

    OpenAIRE

    Nienke Moor; Aafke Komter

    2012-01-01

    BACKGROUND Family ties in Europe are affected by demographic trends associated with parenting and partnering, such as a decline in fertility, an increase in childlessness, postponement of parenthood and of partnership formation, the rise of "new" relationship forms and divorce rates. It is unclear how the contemporary family structure and composition are associated with people's mental wellbeing. OBJECTIVE This article examines how ties with parents, siblings, a partner and chi...

  17. Dual-Frequency Operation of Bow-Tie Microstrip Antenna

    Institute of Scientific and Technical Information of China (English)

    钟顺时; 张需溥

    2005-01-01

    Characteristics of a single-feed dual-frequency bow-tie microstrip antenna are studied. By using the variation method, simple formulas for resonant frequencies of the bow-tie microstrip antenna are derived. It is shown that the dual-frequency ratio can be controlled easily by choosing the parameters of the antenna. This design gives compact antenna size and simple antenna structure. Experimental results are presented, verifying the validity of the design.

  18. Fivebranes and 3-manifold homology

    CERN Document Server

    Gukov, Sergei; Vafa, Cumrun

    2016-01-01

    Motivated by physical constructions of homological knot invariants, we study their analogs for closed 3-manifolds. We show that fivebrane compactifications provide a universal description of various old and new homological invariants of 3-manifolds. In terms of 3d/3d correspondence, such invariants are given by the Q-cohomology of the Hilbert space of partially topologically twisted 3d N=2 theory T[M_3] on a Riemann surface with defects. We demonstrate this by concrete and explicit calculations in the case of monopole/Heegaard Floer homology and a 3-manifold analog of Khovanov-Rozansky link homology. The latter gives a categorification of Chern-Simons partition function. Some of the new key elements include the explicit form of the S-transform and a novel connection between categorification and a previously mysterious role of Eichler integrals in Chern-Simons theory.

  19. Fivebranes and 3-manifold homology

    Science.gov (United States)

    Gukov, Sergei; Putrov, Pavel; Vafa, Cumrun

    2017-07-01

    Motivated by physical constructions of homological knot invariants, we study their analogs for closed 3-manifolds. We show that fivebrane compactifications provide a universal description of various old and new homological invariants of 3-manifolds. In terms of 3d/3d correspondence, such invariants are given by the Q-cohomology of the Hilbert space of partially topologically twisted 3d N=2 theory T[ M 3] on a Riemann surface with defects. We demonstrate this by concrete and explicit calculations in the case of monopole/Heegaard Floer homology and a 3-manifold analog of Khovanov-Rozansky link homology. The latter gives a categorification of Chern-Simons partition function. Some of the new key elements include the explicit form of the S-transform and a novel connection between categorification and a previously mysterious role of Eichler integrals in Chern-Simons theory.

  20. The Imagery Exchange (TIE): Open Source Imagery Management System

    Science.gov (United States)

    Alarcon, C.; Huang, T.; Thompson, C. K.; Roberts, J. T.; Hall, J. R.; Cechini, M.; Schmaltz, J. E.; McGann, J. M.; Boller, R. A.; Murphy, K. J.; Bingham, A. W.

    2013-12-01

    The NASA's Global Imagery Browse Service (GIBS) is the Earth Observation System (EOS) imagery solution for delivering global, full-resolution satellite imagery in a highly responsive manner. GIBS consists of two major subsystems, OnEarth and The Imagery Exchange (TIE). TIE is the GIBS horizontally scaled imagery workflow manager component, an Open Archival Information System (OAIS) responsible for orchestrating the acquisition, preparation, generation, and archiving of imagery to be served by OnEarth. TIE is an extension of the Data Management and Archive System (DMAS), a high performance data management system developed at the Jet Propulsion Laboratory by leveraging open source tools and frameworks, which includes Groovy/Grails, Restlet, Apache ZooKeeper, Apache Solr, and other open source solutions. This presentation focuses on the application of Open Source technologies in developing a horizontally scaled data system like DMAS and TIE. As part of our commitment in contributing back to the open source community, TIE is in the process of being open sourced. This presentation will also cover our current effort in getting TIE in to the hands of the community from which we benefited from.

  1. Redoable Tie-Over Dressing Using Multiple Loop Silk Threads

    Directory of Open Access Journals (Sweden)

    Hyeon Jong Jo

    2013-05-01

    Full Text Available After skin grafting, to prevent hematoma or seroma collection at the graft site, a tie-over dressing has been commonly used. However, although the conventional tie-over dressing by suture is a useful method for securing a graft site, refixation is difficult when repeated tieover dressing is needed. Therefore, we recommend a redoable tie-over dressing technique with multiple loops threads and connecting silk threads. After the raw surface of each of our cases was covered with a skin graft, multiple loop silk thread attached with nylon at the skin graft margin. We applied the ointment gauze and wet cotton/fluffy gauze over the skin graft, then fixed the dressing by connecting cross-counter multiple loop thread with connecting silk threads. When we opened the tie-over dressing by cutting the connecting silk threads, we repeated the tie-over dressing with the same method. The skin graft was taken successfully without hematoma or seroma collection or any other complications. In conclusion, we report a novel tie-over dressing enabling simple fixation of the dressing to maintain proper tension for wounds that require repetitive fixation. Further, with this reliable method, the skin grafts were well taken.

  2. COMMITMENT A Psychological Tie and Moral Value

    Science.gov (United States)

    2017-04-01

    Notes on the Concept of Commitment,” American Journal of Sociology 66, no. 1 (1960): 32-40. JSTOR (http://www.jstor.org.aufric.idm.oclc.org/stable...American Journal of Sociology LXI (January, 1956): 289-98. - Thomas C. Schelling, "An Essay on Bargaining," American Economic Review XLVI (June... Sociology 66, no. 1 (1960): 32-40. - B. Buchannan, “Building Organizational Commitment: The Socialization of Mangers in Work Organizations

  3. Object-oriented persistent homology

    Science.gov (United States)

    Wang, Bao; Wei, Guo-Wei

    2016-01-01

    Persistent homology provides a new approach for the topological simplification of big data via measuring the life time of intrinsic topological features in a filtration process and has found its success in scientific and engineering applications. However, such a success is essentially limited to qualitative data classification and analysis. Indeed, persistent homology has rarely been employed for quantitative modeling and prediction. Additionally, the present persistent homology is a passive tool, rather than a proactive technique, for classification and analysis. In this work, we outline a general protocol to construct object-oriented persistent homology methods. By means of differential geometry theory of surfaces, we construct an objective functional, namely, a surface free energy defined on the data of interest. The minimization of the objective functional leads to a Laplace-Beltrami operator which generates a multiscale representation of the initial data and offers an objective oriented filtration process. The resulting differential geometry based object-oriented persistent homology is able to preserve desirable geometric features in the evolutionary filtration and enhances the corresponding topological persistence. The cubical complex based homology algorithm is employed in the present work to be compatible with the Cartesian representation of the Laplace-Beltrami flow. The proposed Laplace-Beltrami flow based persistent homology method is extensively validated. The consistence between Laplace-Beltrami flow based filtration and Euclidean distance based filtration is confirmed on the Vietoris-Rips complex for a large amount of numerical tests. The convergence and reliability of the present Laplace-Beltrami flow based cubical complex filtration approach are analyzed over various spatial and temporal mesh sizes. The Laplace-Beltrami flow based persistent homology approach is utilized to study the intrinsic topology of proteins and fullerene molecules. Based on a

  4. Object-oriented Persistent Homology.

    Science.gov (United States)

    Wang, Bao; Wei, Guo-Wei

    2016-01-15

    Persistent homology provides a new approach for the topological simplification of big data via measuring the life time of intrinsic topological features in a filtration process and has found its success in scientific and engineering applications. However, such a success is essentially limited to qualitative data classification and analysis. Indeed, persistent homology has rarely been employed for quantitative modeling and prediction. Additionally, the present persistent homology is a passive tool, rather than a proactive technique, for classification and analysis. In this work, we outline a general protocol to construct object-oriented persistent homology methods. By means of differential geometry theory of surfaces, we construct an objective functional, namely, a surface free energy defined on the data of interest. The minimization of the objective functional leads to a Laplace-Beltrami operator which generates a multiscale representation of the initial data and offers an objective oriented filtration process. The resulting differential geometry based object-oriented persistent homology is able to preserve desirable geometric features in the evolutionary filtration and enhances the corresponding topological persistence. The cubical complex based homology algorithm is employed in the present work to be compatible with the Cartesian representation of the Laplace-Beltrami flow. The proposed Laplace-Beltrami flow based persistent homology method is extensively validated. The consistence between Laplace-Beltrami flow based filtration and Euclidean distance based filtration is confirmed on the Vietoris-Rips complex for a large amount of numerical tests. The convergence and reliability of the present Laplace-Beltrami flow based cubical complex filtration approach are analyzed over various spatial and temporal mesh sizes. The Laplace-Beltrami flow based persistent homology approach is utilized to study the intrinsic topology of proteins and fullerene molecules. Based on a

  5. Effect of summer grazing on welfare of dairy cows reared in mountain tie-stall barns

    Directory of Open Access Journals (Sweden)

    Simonetta Dovier

    2010-09-01

    Full Text Available Traditional mountain farms have an important economic, social and environmental role. The Alps management system for dairy cows consists of animals kept indoors from autumn to spring, mostly in tie-stalls, and moved to mountain pasture in summer. The aim of our study was to assess the effect of mountain summer grazing on the welfare of dairy cows housed in tie-stall barns. Twenty-four farms were considered. In twelve of them, animals were reared in tie-stalls and moved to mountain pasture for three months in summer; they were visited three times: (i four weeks before grazing during the indoor period in the stall; (ii about three weeks after the start of grazing; and (iii in the stall, in autumn, at least three weeks after returning from grazing. The other twelve farms kept the animals in tie-stalls all year; they were visited once in autumn. Data were collected following a protocol that considers animal-based measures and structure information on the basis of Quality Welfare Consortium® indications. Data allowed the calculation of both the Animal Needs Index score (ANI 35L and an overall assessment of the cows’ welfare obtained from three general aspects: housing, animal’s physical condition, and animal’s behaviour. Summer grazing had a significant positive effect on injuries, lameness and animal’s rising duration but a negative effect on faeces consistency. Moreover, a reduction of tongue playing was observed. The ANI 35L and the overall assessment did not show significant differences linked to summer grazing, which tended to have a positive but temporary effect on animal behaviour.

  6. Social margins and precarious work in Vietnam

    NARCIS (Netherlands)

    Arnold, D.

    2013-01-01

    Command economy carryovers and recently implemented labor relation models mark Vietnam’s engagement with global capitalism. Numerous social and economic entitlements are tied to household registration policies, whereas tripartitism is increasingly the mode through which labor and social protections

  7. Social evolution: when promiscuity breeds cooperation

    OpenAIRE

    van Zweden, Jelle; Cardoen, Dries; Wenseleers, Tom

    2012-01-01

    In social evolution theory, it has become common wisdom that close family ties should promote cooperative behaviour. Yet, in social insects, evidence is accumulating that queen promiscuity and low relatedness sometimes work better.

  8. Social margins and precarious work in Vietnam

    NARCIS (Netherlands)

    D. Arnold

    2013-01-01

    Command economy carryovers and recently implemented labor relation models mark Vietnam’s engagement with global capitalism. Numerous social and economic entitlements are tied to household registration policies, whereas tripartitism is increasingly the mode through which labor and social protections

  9. The semaphorontic view of homology.

    Science.gov (United States)

    Havstad, Joyce C; Assis, Leandro C S; Rieppel, Olivier

    2015-11-01

    The relation of homology is generally characterized as an identity relation, or alternatively as a correspondence relation, both of which are transitive. We use the example of the ontogenetic development and evolutionary origin of the gnathostome jaw to discuss identity and transitivity of the homology relation under the transformationist and emergentist paradigms respectively. Token identity and consequent transitivity of homology relations are shown to be requirements that are too strong to allow the origin of genuine evolutionary novelties. We consequently introduce the concept of compositional identity that is grounded in relations prevailing between parts (organs and organ systems) of a whole (organism). We recognize an ontogenetic identity of parts within a whole throughout the sequence of successive developmental stages of those parts: this is an intra-organismal character identity maintained throughout developmental trajectory. Correspondingly, we recognize a phylogenetic identity of homologous parts within two or more organisms of different species: this is an inter-species character identity maintained throughout evolutionary trajectory. These different dimensions of character identity--ontogenetic (through development) and phylogenetic (via shared evolutionary history)--break the transitivity of homology relations. Under the transformationist paradigm, the relation of homology reigns over the entire character (-state) transformation series, and thus encompasses the plesiomorphic as well as the apomorphic condition of form. In contrast, genuine evolutionary novelties originate not through transformation of ancestral characters (-states), but instead through deviating developmental trajectories that result in alternate characters. Under the emergentist paradigm, homology is thus synonymous with synapomorphy. © 2015 The Authors. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution Published by Wiley Periodicals, Inc.

  10. A monopole homology for integral homology 3-spheres

    OpenAIRE

    Li, Weiping

    2014-01-01

    To an integral homology 3-sphere Y, we assign a well-defined {\\mathbb Z}-graded (monopole) homology MH*(Y, Ih(Q; h0)) whose construction in principle follows from the instanton Floer theory with the dependence of the spectral flow Ih(Q; h0), where Q is the unique U(1)-reducible monopole of the Seiberg-Witten equation on Y and h0 is a reference perturbation datum. The definition uses the moduli space of monopoles on Y \\times {\\mathbb R} introduced by Seiberg-Witten in studying smooth ...

  11. Social Networks in the Classroom: Personality Factors as Antecedents of Student Social Capital

    Science.gov (United States)

    Seevers, Matthew T.; Johnson, Bryan R.; Darnold, Todd C.

    2015-01-01

    This study examines personality factors as antecedents of student social capital. We hypothesize relationships between two constructs taken from the five-factor model of personality (agreeableness and extraversion) and two variables that reflect a student's social capital (quantity of ties and strength of ties) in an academic setting. Analysis of…

  12. Beyond Getting in and Fitting in: An Examination of Social Networks and Professionally Relevant Social Capital among Latina/o University Students

    Science.gov (United States)

    Rios-Aguilar, Cecilia; Deil-Amen, Regina

    2012-01-01

    Social network analyses, combined with qualitative analyses, are examined to understand key components of the college trajectories of 261 Latina/o students. Their social network ties reveal variation in extensity and the relevance. Most ties facilitate social capital relevant to getting into college, fewer engage social capital relevant to…

  13. Beyond Getting in and Fitting in: An Examination of Social Networks and Professionally Relevant Social Capital among Latina/o University Students

    Science.gov (United States)

    Rios-Aguilar, Cecilia; Deil-Amen, Regina

    2012-01-01

    Social network analyses, combined with qualitative analyses, are examined to understand key components of the college trajectories of 261 Latina/o students. Their social network ties reveal variation in extensity and the relevance. Most ties facilitate social capital relevant to getting into college, fewer engage social capital relevant to…

  14. BowTieBuilder: modeling signal transduction pathways

    Directory of Open Access Journals (Sweden)

    Schröder Adrian

    2009-06-01

    Full Text Available Abstract Background Sensory proteins react to changing environmental conditions by transducing signals into the cell. These signals are integrated into core proteins that activate downstream target proteins such as transcription factors (TFs. This structure is referred to as a bow tie, and allows cells to respond appropriately to complex environmental conditions. Understanding this cellular processing of information, from sensory proteins (e.g., cell-surface proteins to target proteins (e.g., TFs is important, yet for many processes the signaling pathways remain unknown. Results Here, we present BowTieBuilder for inferring signal transduction pathways from multiple source and target proteins. Given protein-protein interaction (PPI data signaling pathways are assembled without knowledge of the intermediate signaling proteins while maximizing the overall probability of the pathway. To assess the inference quality, BowTieBuilder and three alternative heuristics are applied to several pathways, and the resulting pathways are compared to reference pathways taken from KEGG. In addition, BowTieBuilder is used to infer a signaling pathway of the innate immune response in humans and a signaling pathway that potentially regulates an underlying gene regulatory network. Conclusion We show that BowTieBuilder, given multiple source and/or target proteins, infers pathways with satisfactory recall and precision rates and detects the core proteins of each pathway.

  15. Tie Tube Heat Transfer Modeling for Bimodal Nuclear Thermal Rockets

    Science.gov (United States)

    Clough, Joshua A.; Starkey, Ryan P.; Lewis, Mark J.; Lavelle, Thomas M.

    2007-01-01

    Bimodal nuclear thermal rocket systems have been shown to reduce the weight and cost of space vehicles to Mars and beyond by utilizing the reactor for power generation in the relatively long duration between burns in an interplanetary trajectory. No information, however, is available regarding engine and reactor-level operation of such bimodal systems. The purpose of this project is to generate engine and reactor models with sufficient fidelity and flexibility to accurately study the component-level effects of operating a propulsion-designed reactor at power generation levels. Previous development of a 1-D reactor and tie tube model found that ignoring heat generation inside of the tie tube leads to under-prediction of the temperature change and over-prediction of pressure change across the tie tube. This paper will present the development and results of a tie tube model that has been extended to account for heat generation, specifically in the moderator layer. This model is based on a 1-D distribution of power in the fuel elements and tie tubes, as a precursor to an eventual neutron-driven reactor model.

  16. Bow-tie diagrams for risk management in anaesthesia.

    Science.gov (United States)

    Culwick, M D; Merry, A F; Clarke, D M; Taraporewalla, K J; Gibbs, N M

    2016-11-01

    Bow-tie analysis is a risk analysis and management tool that has been readily adopted into routine practice in many high reliability industries such as engineering, aviation and emergency services. However, it has received little exposure so far in healthcare. Nevertheless, its simplicity, versatility, and pictorial display may have benefits for the analysis of a range of healthcare risks, including complex and multiple risks and their interactions. Bow-tie diagrams are a combination of a fault tree and an event tree, which when combined take the shape of a bow tie. Central to bow-tie methodology is the concept of an undesired or 'Top Event', which occurs if a hazard progresses past all prevention controls. Top Events may also occasionally occur idiosyncratically. Irrespective of the cause of a Top Event, mitigation and recovery controls may influence the outcome. Hence the relationship of hazard to outcome can be viewed in one diagram along with possible causal sequences or accident trajectories. Potential uses for bow-tie diagrams in anaesthesia risk management include improved understanding of anaesthesia hazards and risks, pre-emptive identification of absent or inadequate hazard controls, investigation of clinical incidents, teaching anaesthesia risk management, and demonstrating risk management strategies to third parties when required.

  17. Homology of locally semialgebraic spaces

    CERN Document Server

    Delfs, Hans

    1991-01-01

    Locally semialgebraic spaces serve as an appropriate framework for studying the topological properties of varieties and semialgebraic sets over a real closed field. This book contributes to the fundamental theory of semialgebraic topology and falls into two main parts. The first dealswith sheaves and their cohomology on spaces which locally look like a constructible subset of a real spectrum. Topics like families of support, homotopy, acyclic sheaves, base-change theorems and cohomological dimension are considered. In the second part a homology theory for locally complete locally semialgebraic spaces over a real closed field is developed, the semialgebraic analogue of classical Bore-Moore-homology. Topics include fundamental classes of manifolds and varieties, Poincare duality, extensions of the base field and a comparison with the classical theory. Applying semialgebraic Borel-Moore-homology, a semialgebraic ("topological") approach to intersection theory on varieties over an algebraically closed field of ch...

  18. Heider balance, asymmetric ties, and gender segregation

    CERN Document Server

    Krawczyk, Małgorzata J; Hernández-Ramirez, Eric; Naumis, Gerardo G; Kułakowski, Krzysztof

    2015-01-01

    To remove a cognitive dissonance in interpersonal relations, people tend to divide our acquaintances into friendly and hostile parts, both groups internally friendly and mutually hostile. This process is modeled as an evolution towards the Heider balance. A set of differential equations have been proposed and validated (Kulakowski {\\it et al}, IJMPC 16 (2005) 707) to model the Heider dynamics of this social and psychological process. Here we generalize the model by including the initial asymmetry of the interprersonal relations and the direct reciprocity effect which removes this asymmetry. Our model is applied to the data on enmity and friendship in 37 school classes and 4 groups of teachers in M\\'exico. For each class, a stable balanced partition is obtained into two groups. The gender structure of the groups reveals stronger gender segregation in younger classes, i.e. of age below 12 years, a fact consistent with other general empirical results.

  19. Heider balance, asymmetric ties, and gender segregation

    Science.gov (United States)

    Krawczyk, Małgorzata J.; del Castillo-Mussot, Marcelo; Hernández-Ramírez, Eric; Naumis, Gerardo G.; Kułakowski, Krzysztof

    2015-12-01

    To remove a cognitive dissonance in interpersonal relations, people tend to divide their acquaintances into friendly and hostile parts, both groups internally friendly and mutually hostile. This process is modeled as an evolution toward the Heider balance. A set of differential equations have been proposed and validated (Kułakowski et al., 2005) to model the Heider dynamics of this social and psychological process. Here we generalize the model by including the initial asymmetry of the interpersonal relations and the direct reciprocity effect which removes this asymmetry. Our model is applied to the data on enmity and friendship in 37 school classes and 4 groups of teachers in México. For each class, a stable balanced partition is obtained into two groups. The gender structure of the groups reveals stronger gender segregation in younger classes, i.e. of age below 12 years, a fact consistent with other general empirical results.

  20. Homology group on manifolds and their foldings

    Directory of Open Access Journals (Sweden)

    M. Abu-Saleem

    2010-03-01

    Full Text Available In this paper, we introduce the definition of the induced unfolding on the homology group. Some types of conditional foldings restricted on the elements of the homology groups are deduced. The effect of retraction on the homology group of a manifold is dicussed. The unfolding of variation curvature of manifolds on their homology group are represented. The relations between homology group of the manifold and its folding are deduced.

  1. ADIEU TO TONGUE TIE. LINGUAL FRENECTOMY: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Rizwan Sanadi

    2013-07-01

    Full Text Available A Frenum is a fold of mucous membrane, usually with enclosed muscle fibers, that attaches the lips and cheeks to the alveolar mucosa and/or mucosa and underlying periosteum. Tongue tie or ankyloglossia is a developmental anomaly of the tongue characterized by an abnormally short, thick lingual frenum resulting in limitation of tongue movement. It causes difficulty in speech articulation due to limitation in tongue movement. In this article we report a case of 24 years old female with Tongue tie, complaining of difficulty in speech. It was surgically treated with uneventful healing and good patient satisfaction.

  2. Mediators of homologous DNA pairing.

    Science.gov (United States)

    Zelensky, Alex; Kanaar, Roland; Wyman, Claire

    2014-10-09

    Homologous DNA pairing and strand exchange are at the core of homologous recombination. These reactions are promoted by a DNA-strand-exchange protein assembled into a nucleoprotein filament comprising the DNA-pairing protein, ATP, and single-stranded DNA. The catalytic activity of this molecular machine depends on control of its dynamic instability by accessory factors. Here we discuss proteins known as recombination mediators that facilitate formation and functional activation of the DNA-strand-exchange protein filament. Although the basics of homologous pairing and DNA-strand exchange are highly conserved in evolution, differences in mediator function are required to cope with differences in how single-stranded DNA is packaged by the single-stranded DNA-binding protein in different species, and the biochemical details of how the different DNA-strand-exchange proteins nucleate and extend into a nucleoprotein filament. The set of (potential) mediator proteins has apparently expanded greatly in evolution, raising interesting questions about the need for additional control and coordination of homologous recombination in more complex organisms. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

  3. Homological Type of Geometric Transitions

    CERN Document Server

    Rossi, Michele

    2010-01-01

    The present paper gives an account and quantifies the change in topology induced by small and type II geometric transitions, by introducing the notion of the \\emph{homological type} of a geometric transition. The obtained results agree with, and go further than, most results and estimates, given to date by several authors, both in mathematical and physical literature.

  4. Homological stability of diffeomorphism groups

    DEFF Research Database (Denmark)

    Berglund, Alexander; Madsen, Ib Henning

    2013-01-01

    In this paper we prove a stability theorem for block diffeomorphisms of 2d -dimensional manifolds that are connected sums of S d ×S d . Combining this with a recent theorem of S. Galatius and O. Randal-Williams and Morlet’s lemma of disjunction, we determine the homology of the classifying space ...

  5. Localization of the angiopoietin receptors Tie-1 and Tie-2 on the primary cilia in the female reproductive organs

    DEFF Research Database (Denmark)

    Teilmann, Stefan C; Christensen, Søren T

    2005-01-01

    Blood vessel homeostasis and endothelial cell survival depend on proper signalling through angiopoietin receptors such as the receptor tyrosine kinases Tie-1 and Tie-2. We have studied the presence and subcellular localization of these receptors in murine female reproductive organs using confocal...... of immunohistochemical analysis on human ovarian tissues we also observed a unique localization of Tie-2 to the primary cilia of ovarian surface epithelium. These observations are the first to show ciliary localization of angiopoietin receptors. Our results support the hypothesis that cilia of the female reproductive...... organs play a novel and important sensory role in relaying physiochemical changes from the extracellular environment to epithelial cells of the oviduct, the ovary and extra-ovarian tissues....

  6. Homology and isomorphism: Bourdieu in conversation with New Institutionalism.

    Science.gov (United States)

    Wang, Yingyao

    2016-06-01

    Bourdieusian Field Theory (BFT) provided decisive inspiration for the early conceptual formulation of New Institutionalism (NI). This paper attempts to reinvigorate the stalled intellectual dialogue between NI and BFT by comparing NI's concept of isomorphism with BFT's notion of homology. I argue that Bourdieu's understanding of domination-oriented social action, transposable habitus, and a non-linear causality, embodied in his neglected concept of homology, provides an alternative theorization of field-level convergence to New Institutionalism's central idea of institutional isomorphism. To showcase how BFT can be useful for organizational research, I postulate a habitus-informed and field-conditioned theory of transference to enrich NI's spin-off thesis of 'diffusion'. I propose that while NI can benefit from BFT's potential of bringing social structure back into organizational research, BFT can enrich its social analysis by borrowing from NI's elaboration of the symbolic system of organizations.

  7. Social network analysis

    NARCIS (Netherlands)

    W. de Nooy

    2009-01-01

    Social network analysis (SNA) focuses on the structure of ties within a set of social actors, e.g., persons, groups, organizations, and nations, or the products of human activity or cognition such as web sites, semantic concepts, and so on. It is linked to structuralism in sociology stressing the si

  8. Sterilization: women fit to be tied.

    Science.gov (United States)

    Caress, B

    1975-01-01

    Sterilization abuse is both systematic and widespread. Frequently, women are misled about the dangers of surgery, misinformed about its permanence, and coerced while under the stress of labor or abortion. Generally, instances of abuses in the health system are treated as illegitimate, illegal aberations of an otherwise decent health care system. Careful examination of these so called abuses would reveal that each can be causally connected to particular aspects of the care of America's health system. Sterilization abuse stems from a combination of factors inherent in the health system plus 1 critical additional factor. Besides resulting from teaching and research imperatives, profit making, and the fee for service systems, such abuse is the most widespread example of medicine as an instrument of social control. Sterilization is the most extreme form of birth control and birth control is official US government policy. There were about 500,000 sterilizations performed on American women in 1973. None of the sterilization methods is innocuous, and each is associated with some physical and psychological side effects. General agreement exists in the medical literature that some risk is attendant to each procedure. Sterilization is the most dangerous and the fastest growing method of birth control. Since 1970 the figures show an almost 3-fold increase in the incidence of female sterilization, from 192,000 in 1970 to 548,000 in 1974. Much evidence exists to suggest that the increase in the number of sterilizations has fueled a trend toward the sterilization of younger women with fewer children. Official accommodation to liberalization of sterilization practices in the US came in 1969, when the American College of Obstetricians and Gynecologists (ACOG) withdrew its age parity formula. This liberalization of sterilization guidelines opened the floodgates to abuse. Some of the increase in the number of operations performed is due to increased demand, some of it is the result

  9. Flexible mapping of homology onto structure with Homolmapper

    Directory of Open Access Journals (Sweden)

    Lagarias J Clark

    2007-04-01

    Full Text Available Abstract Background Over the past decade, a number of tools have emerged for the examination of homology relationships among protein sequences in a structural context. Most recent software implementations for such analysis are tied to specific molecular viewing programs, which can be problematic for collaborations involving multiple viewing environments. Incorporation into larger packages also adds complications for users interested in adding their own scoring schemes or in analyzing proteins incorporating unusual amino acid residues such as selenocysteine. Results We describe homolmapper, a command-line application for mapping information from a multiple protein sequence alignment onto a protein structure for analysis in the viewing software of the user's choice. Homolmapper is small (under 250 K for the application itself and is written in Python to ensure portability. It is released for non-commercial use under a modified University of California BSD license. Homolmapper permits facile import of additional scoring schemes and can incorporate arbitrary additional amino acids to allow handling of residues such as selenocysteine or pyrrolysine. Homolmapper also provides tools for defining and analyzing subfamilies relative to a larger alignment, for mutual information analysis, and for rapidly visualizing the locations of mutations and multi-residue motifs. Conclusion Homolmapper is a useful tool for analysis of homology relationships among proteins in a structural context. There is also extensive, example-driven documentation available. More information about homolmapper is available at http://www.mcb.ucdavis.edu/faculty-labs/lagarias/homolmapper_home/homolmapper%20web%20page.htm.

  10. Teaching Tongue-Tied Students: Ankyloglossia in the Instrumental Classroom

    Science.gov (United States)

    Dovel, Jason

    2010-01-01

    Ankyloglossia is a significant medical condition that has not been adequately addressed in music education literature. While practically every instructor will have students who struggle with ankyloglossia, many teachers are entirely unaware of this condition's various symptoms and treatments. Ankyloglossia, more commonly known as tongue-tie, is a…

  11. Sound transmission performance on cavity ferrocement panels with ties

    Institute of Scientific and Technical Information of China (English)

    Kandaswamy S; Ramachandraiah A

    2003-01-01

    Ferrocement panels have been used in low cost housing construction in developingcountries. This study focuses on the sound transmission performance of cavity ferrocement pan-els with ties. In this study, panels have been cast and tested in transmission loss suite speciallydesigned and constructed for testing their sound transmission performance experimentally. Themeasured results agree well with the theoretical model.

  12. Sino-Latin American Trade,Closer Tie

    Institute of Scientific and Technical Information of China (English)

    Guo Liqin

    2009-01-01

    @@ The financial crisis has provided a new opportunity for Sino-Latin American cooperation.In the past few years,China's economic ties to Latin America have witnessed comparable growth:from 1993 to 2003,China's trade with Latin America increased by 600 percent.

  13. Application of Bow-tie methodology to improve patient safety.

    Science.gov (United States)

    Abdi, Zhaleh; Ravaghi, Hamid; Abbasi, Mohsen; Delgoshaei, Bahram; Esfandiari, Somayeh

    2016-05-09

    Purpose - The purpose of this paper is to apply Bow-tie methodology, a proactive risk assessment technique based on systemic approach, for prospective analysis of the risks threatening patient safety in intensive care unit (ICU). Design/methodology/approach - Bow-tie methodology was used to manage clinical risks threatening patient safety by a multidisciplinary team in the ICU. The Bow-tie analysis was conducted on incidents related to high-alert medications, ventilator associated pneumonia, catheter-related blood stream infection, urinary tract infection, and unwanted extubation. Findings - In total, 48 potential adverse events were analysed. The causal factors were identified and classified into relevant categories. The number and effectiveness of existing preventive and protective barriers were examined for each potential adverse event. The adverse events were evaluated according to the risk criteria and a set of interventions were proposed with the aim of improving the existing barriers or implementing new barriers. A number of recommendations were implemented in the ICU, while considering their feasibility. Originality/value - The application of Bow-tie methodology led to practical recommendations to eliminate or control the hazards identified. It also contributed to better understanding of hazard prevention and protection required for safe operations in clinical settings.

  14. Knotcraft the practical and entertaining art of tying knots

    CERN Document Server

    Macfarlan, Allan and Paulette

    1983-01-01

    Comprehensive reference work explains how to tie hundreds of practical (and decorative) knots in clear illustrations and precisely worded written instructions. Ideal for boaters and campers. Also covers knots in history, knot mystery and magic, and games, stunts and tricks with rope. Introduction. Index. 166 black-and-white illustrations.

  15. The minimum amount of homology required for homologous recombination in mammalian cells.

    OpenAIRE

    Rubnitz, J; Subramani, S

    1984-01-01

    Although DNA sequence homology is believed to be a prerequisite for homologous recombination events in procaryotes and eucaryotes, no systematic study has been done on the minimum amount of homology required for homologous recombination in mammalian cells. We have used simian virus 40-pBR322 hybrid plasmids constructed in vitro as substrates to quantitate intramolecular homologous recombination in cultured monkey cells. Excision of wild-type simian virus 40 DNA by homologous recombination was...

  16. Minimax Rates for Homology Inference

    CERN Document Server

    Balakrishnan, Sivaraman; Sheehy, Don; Singh, Aarti; Wasserman, Larry

    2011-01-01

    Often, high dimensional data lie close to a low-dimensional submanifold and it is of interest to understand the geometry of these submanifolds. The homology groups of a manifold are important topological invariants that provide an algebraic summary of the manifold. These groups contain rich topological information, for instance, about the connected components, holes, tunnels and sometimes the dimension of the manifold. In this paper, we consider the statistical problem of estimating the homology of a manifold from noisy samples under several different noise models. We derive upper and lower bounds on the minimax risk for this problem. Our upper bounds are based on estimators which are constructed from a union of balls of appropriate radius around carefully selected points. In each case we establish complementary lower bounds using Le Cam's lemma.

  17. Sutured Floer homology and hypergraphs

    CERN Document Server

    Juhász, András; Rasmussen, Jacob

    2011-01-01

    By applying Seifert's algorithm to a special alternating diagram of a link L, one obtains a Seifert surface F of L. We show that the support of the sutured Floer homology of the sutured manifold complementary to F is affine isomorphic to the set of lattice points given as hypertrees in a certain hypergraph that is naturally associated to the diagram. This implies that the Floer groups in question are supported in a set of Spin^c structures that are the integer lattice points of a convex polytope. This property has an immediate extension to Seifert surfaces arising from homogeneous link diagrams (including all alternating and positive diagrams). In another direction, together with work in progress of the second author and others, our correspondence suggests a method for computing the "top" coefficients of the HOMFLY polynomial of a special alternating link from the sutured Floer homology of a Seifert surface complement for a certain dual link.

  18. Homologous recombination in Leishmania enriettii.

    OpenAIRE

    1991-01-01

    We have used derivatives of the recently developed stable transfection vector pALT-Neo to formally demonstrate that Leishmania enriettii contains the enzymatic machinery necessary for homologous recombination. This observation has implications for gene regulation, gene amplification, genetic diversity, and the maintenance of tandemly repeated gene families in the Leishmania genome as well as in closely related organisms, including Trypanosoma brucei. Two plasmids containing nonoverlapping del...

  19. Homologous recombination in Leishmania enriettii.

    Science.gov (United States)

    Tobin, J F; Laban, A; Wirth, D F

    1991-02-01

    We have used derivatives of the recently developed stable transfection vector pALT-Neo to formally demonstrate that Leishmania enriettii contains the enzymatic machinery necessary for homologous recombination. This observation has implications for gene regulation, gene amplification, genetic diversity, and the maintenance of tandemly repeated gene families in the Leishmania genome as well as in closely related organisms, including Trypanosoma brucei. Two plasmids containing nonoverlapping deletions of the chloramphenicol acetyltransferase (CAT) gene, as well as the neomycin-resistance gene, were cotransfected into L. enriettii. Analysis of the DNA from these cells by Southern blotting and plasmid rescue revealed that a full-length or doubly deleted CAT gene could be reconstructed by homologous crossing-over and/or gene conversion between the two deletion plasmids. Additionally, parasites cotransfected with pALT-Neo and pALT-CAT-S, a plasmid containing two copies of the chimeric alpha-tubulin-CAT gene, resulted in G418-resistant parasites expressing high levels of CAT activity. The structure of the DNA within these cells, as shown by Southern blot analysis and the polymerase chain reaction, is that which would be expected from a homologous exchange event occurring between the two plasmids.

  20. Deep homology: a view from systematics.

    Science.gov (United States)

    Scotland, Robert W

    2010-05-01

    Over the past decade, it has been discovered that disparate aspects of morphology - often of distantly related groups of organisms - are regulated by the same genetic regulatory mechanisms. Those discoveries provide a new perspective on morphological evolutionary change. A conceptual framework for exploring these research findings is termed 'deep homology'. A comparative framework for morphological relations of homology is provided that distinguishes analogy, homoplasy, plesiomorphy and synapomorphy. Four examples - three from plants and one from animals - demonstrate that homologous developmental mechanisms can regulate a range of morphological relations including analogy, homoplasy and examples of uncertain homology. Deep homology is part of a much wider range of phenomena in which biological (genes, regulatory mechanisms, morphological traits) and phylogenetic levels of homology can both be disassociated. Therefore, to understand homology, precise, comparative, independent statements of both biological and phylogenetic levels of homology are necessary.

  1. START-UP AND GROWTH OF IMMIGRANT SMALL BUSINESSES: THE IMPACT OF SOCIAL AND HUMAN CAPITAL

    OpenAIRE

    JENNIFER M. SEQUEIRA; Abdul A Rasheed

    2006-01-01

    Networks, and their resulting social capital, can be key determinants of successful business start-up for immigrant entrepreneurs. Historically, immigrants have settled in communities characterized by networks that consist of strong ties. Network theory suggests that in addition to strong ties, success also requires the development of weak ties. In this paper, we develop a model of the relationships between strong and weak ties, and the likelihood of a business start-up and its subsequent gro...

  2. START-UP AND GROWTH OF IMMIGRANT SMALL BUSINESSES: THE IMPACT OF SOCIAL AND HUMAN CAPITAL

    OpenAIRE

    JENNIFER M. SEQUEIRA; Abdul A Rasheed

    2006-01-01

    Networks, and their resulting social capital, can be key determinants of successful business start-up for immigrant entrepreneurs. Historically, immigrants have settled in communities characterized by networks that consist of strong ties. Network theory suggests that in addition to strong ties, success also requires the development of weak ties. In this paper, we develop a model of the relationships between strong and weak ties, and the likelihood of a business start-up and its subsequent gro...

  3. Homology requirements for recombination in Escherichia coli.

    OpenAIRE

    Watt, V M; Ingles, C J; Urdea, M S; Rutter, W J

    1985-01-01

    The DNA sequence homology required for recombination in Escherichia coli has been determined by measuring the recombination frequency between insulin DNA in a miniplasmid pi VX and a homologous sequence in a bacteriophage lambda vector. A minimum of approximately equal to 20 base pairs in a completely homologous segment is required for significant recombination. There is an exponential increase in the frequency of recombination when the length of homologous DNA is increased from 20 base pairs...

  4. Four- year thyroidectomy procedures: Ligasure Vs. clamp & tie

    Directory of Open Access Journals (Sweden)

    Pazoki AR

    2010-01-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: The electrothermal bipolar vessel sealing system is an adjunct to the hemostatic technique, which has been successfully used in many abdominal operation, recently made available to thyroid surgery. The purpose of this was compare the outcomes of new hemostatic technique with traditional method of clamp and tie."n"nMethods: In this retrospective cross-sectional study has been done in surgery's wards of Milad & Rasul- Akram hospitals in Tehran, Iran. During three- year period between 2005-2008 all patients with different kind of pathology that need operation were assessed. Time duration of surgery and hospital stay and post surgery complication in two group, ligasure (n=45 and clamp & tie (n=145 were compared with each others."n"nResults: No difference was seen between two groups in time duration of surgery. Significant difference was seen in hospital stay and complications of surgery. Time of operation in Ligasure group was 132/22 minute and in clamp and tie group was 130/10 minute. There was found significant difference in duration of hospital stay and postoperative complication. Hypocalcemia were seen in two and 24 cases in Ligasure and Clamp & Tie group, respectively (p<0.05. Hospital stay was 2

  5. Lagrangian Quantum Homology for Lagrangian cobordism

    OpenAIRE

    Singer, Berit

    2015-01-01

    We extend the definition of Lagrangian quantum homology to monotone Lagrangian cobordism and establish its general algebraic properties. In particular we develop a relative version of Lagrangian quantum homology associated to a cobordism relative to a part of its boundary and study relations of this invariant to the ambient quantum homology.

  6. Discrete homology theory for metric spaces

    NARCIS (Netherlands)

    H. Barcelo (Hélène); V. Capraro (Valerio); J. A. White; H. Barcelo (Hélène)

    2014-01-01

    htmlabstractWe define and study a notion of discrete homology theory for metric spaces. Instead of working with simplicial homology, our chain complexes are given by Lipschitz maps from an n n -dimensional cube to a fixed metric space. We prove that the resulting homology theory satisfies a

  7. Are You Your Friends' Friend? Poor Perception of Friendship Ties Limits the Ability to Promote Behavioral Change.

    Science.gov (United States)

    Almaatouq, Abdullah; Radaelli, Laura; Pentland, Alex; Shmueli, Erez

    2016-01-01

    Persuasion is at the core of norm creation, emergence of collective action, and solutions to 'tragedy of the commons' problems. In this paper, we show that the directionality of friendship ties affect the extent to which individuals can influence the behavior of each other. Moreover, we find that people are typically poor at perceiving the directionality of their friendship ties and that this can significantly limit their ability to engage in cooperative arrangements. This could lead to failures in establishing compatible norms, acting together, finding compromise solutions, and persuading others to act. We then suggest strategies to overcome this limitation by using two topological characteristics of the perceived friendship network. The findings of this paper have significant consequences for designing interventions that seek to harness social influence for collective action.

  8. Nonlinear dynamics of domain walls with cross-ties

    Energy Technology Data Exchange (ETDEWEB)

    Dubovik, M. N., E-mail: dubovik@imp.uran.ru [Russian Academy of Sciences, Institute of Metal Physics, Ural Branch (Russian Federation); Zverev, V. V. [Ural Federal University (Russian Federation); Filippov, B. N. [Russian Academy of Sciences, Institute of Metal Physics, Ural Branch (Russian Federation)

    2016-07-15

    The dynamic behavior of a domain wall with cross-ties is analyzed on the basis of micromagnetic simulation with exact allowance for all main (exchange, magnetoanisotropic, and magnetostatic) interactions in thin magnetically uniaxial ferromagnetic films with planar anisotropy. It is found that the peculiarities of motion of such domain walls are closely related to the behavior of topological defects in the magnetization distribution (generation, motion, and annihilation of vortex–antivortex pairs on the film surface and Bloch points). We observe three different regimes of motion (stationary, periodic, and turbulent regimes), each of which is realized in a certain range of fields oriented along the easy magnetization axis. It is shown that the experimentally observed dynamic bends of the walls with cross-ties are determined by the type of motion of vortices and antivortices. The velocities of domain walls in different regimes are calculated, and the dynamic configurations of the magnetization and existing dynamic transitions between them are investigated.

  9. Nonlinear dynamics of domain walls with cross-ties

    Science.gov (United States)

    Dubovik, M. N.; Zverev, V. V.; Filippov, B. N.

    2016-07-01

    The dynamic behavior of a domain wall with cross-ties is analyzed on the basis of micromagnetic simulation with exact allowance for all main (exchange, magnetoanisotropic, and magnetostatic) interactions in thin magnetically uniaxial ferromagnetic films with planar anisotropy. It is found that the peculiarities of motion of such domain walls are closely related to the behavior of topological defects in the magnetization distribution (generation, motion, and annihilation of vortex-antivortex pairs on the film surface and Bloch points). We observe three different regimes of motion (stationary, periodic, and turbulent regimes), each of which is realized in a certain range of fields oriented along the easy magnetization axis. It is shown that the experimentally observed dynamic bends of the walls with cross-ties are determined by the type of motion of vortices and antivortices. The velocities of domain walls in different regimes are calculated, and the dynamic configurations of the magnetization and existing dynamic transitions between them are investigated.

  10. Coauthorship Ties in the Colombian Congress, 2002-2006

    Directory of Open Access Journals (Sweden)

    Eduardo Alemán

    2015-04-01

    Full Text Available This paper examines policy connections between Colombian legislators (representatives and senators during Álvaro Uribe’s first presidential term (2002-2006. The analysis draws on information regarding the coauthorship of legislation. The joint sponsorship of a bill by a pair of legislators demonstrates their mutual intent to change the status quo in a specific direction. This cooperative effort to push bills forward reveals the similarities that exist between political actors. Examining the connectedness between different groups and the density within group connections can convey important information about parties and their members’ policy preferences. This article investigates these aspects of the network of coauthorship ties developed in the Colombian lower and upper chambers. In addition to shedding light on the cohesiveness and alignment of legislative parties, the article finds that coauthorship ties appear to be influenced by regional and institutional forces.

  11. Simulation of Local Tie Accuracy on VLBI Antennas

    Science.gov (United States)

    Kallio, Ulla; Poutanen, Markku

    2010-01-01

    We introduce a new mathematical model to compute the centering parameters of a VLBI antenna. These include the coordinates of the reference point, axis offset, orientation, and non-perpendicularity of the axes. Using the model we simulated how precisely parameters can be computed in different cases. Based on the simulation we can give some recommendations and practices to control the accuracy and reliability of the local ties at the VLBI sites.

  12. Rigid and Flexible Pavement Aircraft Tie-Downs

    Science.gov (United States)

    2010-05-01

    mooring point, Stingray anchors. Stingray anchors are similar to Manta Ray anchors, except Stingray tie-downs have a much larger surface area. The...same concerns regarding equipment availability factored into the selection process when considering the specific Manta Ray or Stingray anchor to...conduct testing. The manufacturer of both anchoring systems expressed concerns about the ability of the skid steer to hydraulically drive Stingray

  13. The Ties That Bind Exhibition Science Bringing Nations Together

    CERN Multimedia

    2000-01-01

    Scientific ties between JINR and CERN date back to 1957, when JINR Vice-Director Marian Danysz, a Polish professor, visited CERN and agreed with CERN Director-General C.J. Bakker on the exchange of scientists and on joint experiments. Political confrontation did not affect extensive contacts between scientists. By the early 1970s, the meetings of the heads of two international centres, JINR and CERN, had become regular occurrences.

  14. Performance traits of dairy cows stabled in tie stalls

    OpenAIRE

    Marková, Lenka

    2013-01-01

    The aim of this thesis was the evaluation of fertility and production traits stabled in tie stalls. 50 pure-bred Holstein cows were monitored and those traits were evaluated: interval of insemination, service period, calving interval, milk yield and content of milk protein and fat. All monitored cows finished standard lactation period (305 days) in year 2012. The evaluation was performed in relation to lactation order. Nearly all of fertility traits were evaluated as bad. The average interval...

  15. Definition and identification of homology domains.

    Science.gov (United States)

    Lawrence, C B; Goldman, D A

    1988-03-01

    A method is described for identifying and evaluating regions of significant similarity between two sequences. The notion of a 'homology domain' is employed which defines the boundaries of a region of sequence homology containing no insertions or deletions. The relative significance of different potential homology domains is evaluated using a non-linear similarity score related to the probability of finding the observed level of similarity in the region by chance. The sensitivity of the method is demonstrated by simulating the evolution of homology domains and applying the method to their detection. Several examples of the use of homology domain identification are given.

  16. The availability of community ties predicts likelihood of peer referral for mammography: geographic constraints on viral marketing.

    Science.gov (United States)

    Southwell, Brian G; Slater, Jonathan S; Rothman, Alexander J; Friedenberg, Laura M; Allison, Tiffany R; Nelson, Christina L

    2010-11-01

    Engaging social networks to encourage preventive health behavior offers a supplement to conventional mass media campaigns and yet we do not fully understand the conditions that facilitate or hamper such interpersonal diffusion. One set of factors that should affect the diffusion of health campaign information involves a person's community. Variables describing geographic communities should predict the likelihood of residents accepting campaign invitations to pass along information to friends, family, and others. We investigate two aspects of a community--the availability of community ties and residential stability--as potential influences on diffusion of publicly-funded breast cancer screening in the United States in 2008-2009. In a survey study of 1515 participants living in 91 zip codes across the State of Minnesota, USA, we focus on the extent to which women refer others when given the opportunity to nominate family, friends, and peers to receive free mammograms. We predicted nomination tendency for a particular zip code would be a function of available community ties, measured as religious congregation density in that zip code, and also expected the predictive power of available ties would be greatest in communities with relatively high residential stability (meaning lower turnover in home residence). Results support our hypotheses. Congregation density positively predicted nomination tendency both in bivariate analysis and in Tobit regression models, and was most predictive in zip codes above the median in residential stability. We conclude that having a local infrastructure of social ties available in a community predicts the diffusion of available health care services in that community.

  17. Assessing lameness in cows kept in tie-stalls.

    Science.gov (United States)

    Leach, K A; Dippel, S; Huber, J; March, S; Winckler, C; Whay, H R

    2009-04-01

    Identifying lame cows and quantifying the prevalence of lameness are important elements of cattle welfare assessment that are generally achieved by methods involving observations of each animal walking. There is no published method for assessing lameness in cows confined in tie-stalls. The objective of this study (carried out within the European Commission's Welfare Quality(R) project) was to develop a suitable method and validate it for lameness detection against a published locomotion score. A series of indicators of lameness visible in tied cows was formalized into a stall assessment protocol. This was validated against a traditional locomotion score and tested for repeatability between 2 observers. A total of 98 cows on 4 farms were assessed. Overall interobserver agreement was 91%. Sensitivity compared with locomotion scoring was 0.54 to 0.77, dependent on observer and threshold definition. Assessment in the stall underestimated the herd prevalence of lameness revealed by locomotion scoring by 11 to 37% (mean 27%). The discrepancy between herd lameness prevalence assessed in the stall and by locomotion scoring was not affected significantly by farm or observer. The cases of lameness that were not detected in the stall tended to be the least severe. The proposed method for lameness detection in tie-stalls could be used for herd-level assessment of lameness and detection of individual lame animals by farmers and their advisors, but it is important to remember that it is less sensitive than locomotion scoring.

  18. Social Capital and the Repayment of Microfinance Group Lending. A Case Study of Pro Mujer Mexico

    NARCIS (Netherlands)

    Postelnicu, Luminita; Hermes, Niels

    2015-01-01

    This paper investigates how social networks of group borrowers come into play in joint liability group lending. We use a large and original dataset containing 802 mapped social networks of borrowers from Pro Mujer Mexico. This is the first paper to look at external ties, i.e. social ties with indivi

  19. Virtual Khovanov homology using cobordisms

    DEFF Research Database (Denmark)

    Tubbenhauer, Daniel

    2014-01-01

    We give a geometric interpretation of the Khovanov complex for virtual links. Geometric interpretation means that we use a cobordism structure like D. Bar-Natan, but we allow non orientable cobordisms. Like D. Bar-Natans geometric complex our construction should work for virtual tangles too....... This geometric complex allows, in contrast to the geometric version of V. Turaev and P. Turner, a direct extension of the classical Khovanov complex (h=t=0) and of the variant of Lee (h=0,t=1). Furthermore we give a classification of all unoriented TQFTs which can be used to define virtual link homologies...

  20. Virtual Khovanov homology using cobordisms

    DEFF Research Database (Denmark)

    Tubbenhauer, Daniel

    2014-01-01

    We give a geometric interpretation of the Khovanov complex for virtual links. Geometric interpretation means that we use a cobordism structure like D. Bar-Natan, but we allow non orientable cobordisms. Like D. Bar-Natans geometric complex our construction should work for virtual tangles too....... This geometric complex allows, in contrast to the geometric version of V. Turaev and P. Turner, a direct extension of the classical Khovanov complex (h=t=0) and of the variant of Lee (h=0,t=1). Furthermore we give a classification of all unoriented TQFTs which can be used to define virtual link homologies...

  1. 77 FR 21620 - Notice of the Buy America Waiver Request for Vossloh 101-LV Concrete Ties

    Science.gov (United States)

    2012-04-10

    ... Federal Railroad Administration Notice of the Buy America Waiver Request for Vossloh 101-LV Concrete Ties... requirements for the purchase of Vossloh 101-LV concrete ties, which contain certain components not... consist of the installation of Vossloh 101-LV concrete ties. FRA has received this request from the four...

  2. Density and Strength of Ties in Innovation Networks : A Competence and Governance View

    NARCIS (Netherlands)

    Nooteboom, B.; Gilsing, V.A.

    2005-01-01

    Taking into account both competence and governance issues, and six dimensions of tie strength, this article argues that in networks for exploration there are good reasons, counter to the thesis of the 'strength of weak ties', for a dense structure of ties that are strong in most dimensions.By contra

  3. 30 CFR 75.705-10 - Tying into energized high-voltage surface circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tying into energized high-voltage surface....705-10 Tying into energized high-voltage surface circuits. If the work of forming an additional circuit by tying into an energized high-voltage surface line is performed from the ground, any...

  4. 30 CFR 77.704-10 - Tying into energized high-voltage surface circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tying into energized high-voltage surface... AREAS OF UNDERGROUND COAL MINES Grounding § 77.704-10 Tying into energized high-voltage surface circuits. If the work of forming an additional circuit by tying into an energized high-voltage surface line...

  5. Who Can You Turn to? Tie Activation within Core Business Discussion Networks

    Science.gov (United States)

    Renzulli, Linda A.; Aldrich, Howard

    2005-01-01

    We examine the connection between personal network characteristics and the activation of ties for access to resources during routine times. We focus on factors affecting business owners' use of their core network ties to obtain legal, loan, financial and expert advice. Owners rely more on core business ties when their core networks contain a high…

  6. Who Can You Turn to? Tie Activation within Core Business Discussion Networks

    Science.gov (United States)

    Renzulli, Linda A.; Aldrich, Howard

    2005-01-01

    We examine the connection between personal network characteristics and the activation of ties for access to resources during routine times. We focus on factors affecting business owners' use of their core network ties to obtain legal, loan, financial and expert advice. Owners rely more on core business ties when their core networks contain a high…

  7. Stepfamily Formation: Implications for Adolescent Ties to Mothers, Nonresident Fathers, and Stepfathers

    Science.gov (United States)

    King, Valarie

    2009-01-01

    This study examines how the entrance of a stepfather influences adolescent ties to mothers and nonresident fathers and how prior ties to each biological parent influence the development of stepfather-stepchild ties. Data come from 1,753 adolescents in the National Longitudinal Study of Adolescent Health who lived with a single mother in Wave 1 who…

  8. 46 CFR 112.05-3 - Main-emergency bus-tie.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Main-emergency bus-tie. 112.05-3 Section 112.05-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main...

  9. 78 FR 75544 - Prestressed Concrete Steel Rail Tie Wire From Mexico: Preliminary Determination of Sales at Less...

    Science.gov (United States)

    2013-12-12

    ... International Trade Administration Prestressed Concrete Steel Rail Tie Wire From Mexico: Preliminary.... SUMMARY: The Department of Commerce (``Department'') preliminarily determines that prestressed concrete... prestressed tendons in concrete railroad ties (``PC tie wire''). High carbon steel is defined as steel...

  10. The Homological Nature of Entropy

    Directory of Open Access Journals (Sweden)

    Pierre Baudot

    2015-05-01

    Full Text Available We propose that entropy is a universal co-homological class in a theory associated to a family of observable quantities and a family of probability distributions. Three cases are presented: (1 classical probabilities and random variables; (2 quantum probabilities and observable operators; (3 dynamic probabilities and observation trees. This gives rise to a new kind of topology for information processes, that accounts for the main information functions: entropy, mutual-informations at all orders, and Kullback–Leibler divergence and generalizes them in several ways. The article is divided into two parts, that can be read independently. In the first part, the introduction, we provide an overview of the results, some open questions, future results and lines of research, and discuss briefly the application to complex data. In the second part we give the complete definitions and proofs of the theorems A, C and E in the introduction, which show why entropy is the first homological invariant of a structure of information in four contexts: static classical or quantum probability, dynamics of classical or quantum strategies of observation of a finite system.

  11. Homologous gene replacement in Physarum

    Energy Technology Data Exchange (ETDEWEB)

    Burland, T.G. [Univ. of Wisconsin, Madison, WI (United States); Pallotta, D. [Laval Univ., Quebec (Canada)

    1995-01-01

    The protist Physarum polycephalum is useful for analysis of several aspects of cellular and developmental biology. To expand the opportunities for experimental analysis of this organism, we have developed a method for gene replacement. We transformed Physarum amoebae with plasmid DNA carrying a mutant allele, ardD{Delta}1, of the ardD actin gene; ardD{Delta}1 mutates the critical carboxy-terminal region of the gene product. Because ardD is not expressed in the amoeba, replacement of ardD{sup +} with ardD{Delta}1 should not be lethal for this cell type. Transformants were obtained only when linear plasmid DNA was used. Most transformants carried one copy of ardD{Delta}1 in addition to ardD{sup +}, but in two (5%), ardD{sup +} was replaced by a single copy of ardD{Delta}1. This is the first example of homologous gene replacement in Physarum. ardD{Delta}1 was stably maintained in the genome through growth, development and meiosis. We found no effect of ardD{Delta}l on viability, growth, or development of any of the various cell types of Physarum. Thus, the carboxy-terminal region of the ardD product appears not to perform a unique essential role in growth or development. Nevertheless, this method for homologous gene replacement can be applied to analyze the function of any cloned gene. 38 refs., 6 figs., 1 tab.

  12. Weak homology of elliptical galaxies

    CERN Document Server

    Bertin, G; Principe, M D

    2002-01-01

    We start by studying a small set of objects characterized by photometric profiles that have been pointed out to deviate significantly from the standard R^{1/4} law. For these objects we confirm that a generic R^{1/n} law, with n a free parameter, can provide superior fits (the best-fit value of n can be lower than 2.5 or higher than 10), better than those that can be obtained by a pure R^{1/4} law, by an R^{1/4}+exponential model, and by other dynamically justified self--consistent models. Therefore, strictly speaking, elliptical galaxies should not be considered homologous dynamical systems. Still, a case for "weak homology", useful for the interpretation of the Fundamental Plane of elliptical galaxies, could be made if the best-fit parameter n, as often reported, correlates with galaxy luminosity L, provided the underlying dynamical structure also follows a systematic trend with luminosity. We demonstrate that this statement may be true even in the presence of significant scatter in the correlation n(L). Pr...

  13. A Phenomenological and Dynamic View of Homology: Homologs as Persistently Reproducible Modules.

    Science.gov (United States)

    Suzuki, Daichi G; Tanaka, Senji

    2017-01-01

    Homology is a fundamental concept in biology. However, the metaphysical status of homology, especially whether a homolog is a part of an individual or a member of a natural kind, is still a matter of intense debate. The proponents of the individuality view of homology criticize the natural kind view of homology by pointing out that homologs are subject to evolutionary transformation, and natural kinds do not change in the evolutionary process. Conversely, some proponents of the natural kind view of homology argue that a homolog can be construed both as a part of an individual and a member of a natural kind. They adopt the Homeostatic Property Cluster (HPC) theory of natural kinds, and the theory seems to strongly support their construal. Note that this construal implies the acceptance of essentialism. However, looking back on the history of the concept of homology, we should not overlook the fact that the individuality view was proposed to reject the essentialist interpretation of homology. Moreover, the essentialist notions of natural kinds can, in our view, mislead biologists about the phenomena of homology. Consequently, we need a non-essentialist view of homology, which we name the "persistently reproducible module" (PRM) view. This view highlights both the individual-like and kind-like aspects of homologs while stripping down both essentialist and anti-essentialist interpretations of homology. In this article, we articulate the PRM view of homology and explain why it is recommended over the other two views.

  14. Public and private dichotomy: social networking in higher education

    OpenAIRE

    Benson, Vladlena

    2011-01-01

    While the use of online social networking services (SNS) is still largely attributed to leisure communication, online social networking services are gaining popularity in education and business. Social networks tie individuals together and online social networking services enable these ties through technology. People flock to web sites like Facebook, MySpace, and Tribe.net to keep in touch with friends, interest groups and family, communicate and share news about them. User friendliness of s...

  15. TIES for Dummies 3rd Edition (Technology Identification, Evaluation, and Selection) Basic how to's to implement the TIES method

    Science.gov (United States)

    Kirby, Michelle R.

    2002-01-01

    The TIES method is a forecasting environment whereby the decision-maker has the ability to easily assess and trade-off the impact of various technologies without sophisticated and time-consuming mathematical formulations. TIES provides a methodical approach where technically feasible alternatives can be identified with accuracy and speed to reduce design cycle time, and subsequently, life cycle costs, and was achieved through the use of various probabilistic methods, such as Response Surface Methodology and Monte Carlo Simulations. Furthermore, structured and systematic techniques are utilized from other fields to identify possible concepts and evaluation criteria by which comparisons can be made. This objective is achieved by employing the use of Morphological Matrices and Multi-Attribute Decision Making techniques. Through the execution of each step, a family of design alternatives for a given set of customer requirements can be identified and assessed subjectively or objectively. This methodology allows for more information (knowledge) to be brought into the earlier phases of the design process and will have direct implications on the affordability of the system. The increased knowledge allows for optimum allocation of company resources and quantitative justification for program decisions. Finally, the TIES method provided novel results and quantitative justification to facilitate decision making in the early stages of design so as to produce affordable and quality products.

  16. Strong ties promote the epidemic prevalence in susceptible-infected-susceptible spreading dynamics

    CERN Document Server

    Cui, Ai-Xiang; Zhou, Tao

    2013-01-01

    Understanding spreading dynamics will benefit society as a whole in better preventing and controlling diseases, as well as facilitating the socially responsible information while depressing destructive rumors. In network-based spreading dynamics, edges with different weights may play far different roles: a friend from afar usually brings novel stories, and an intimate relationship is highly risky for a flu epidemic. In this article, we propose a weighted susceptible-infected-susceptible model on complex networks, where the weight of an edge is defined by the topological proximity of the two associated nodes. Each infected individual is allowed to select limited number of neighbors to contact, and a tunable parameter is introduced to control the preference to contact through high-weight or low-weight edges. Experimental results on six real networks show that the epidemic prevalence can be largely promoted when strong ties are favored in the spreading process. By comparing with two statistical null models respe...

  17. In stressful company – Changes in stress and work ties over time

    DEFF Research Database (Denmark)

    Waldstrøm, Christian; Parker, Andrew; Shah, Neha P.

    Recent research on stress and burnout has highlighted the collective aspects of stress symptoms, perceived stress, and coping mechanisms. Much of this work, however, is focused on group and team dynamics rather than how network factors shape individuals’ feelings of stress and burnout. We use...... a stress questionnaire and social network analysis at three time points in a Scandinavian biotechnology company to examine the interactions between stress and relationship development and maintenance over time. We show that individuals tend to form and maintain ties to people who are less stressed than...... they are, indicating that while misery might love company, stress does not. Given the longitudinal nature of the study, we’re able to disentangle the causal effects....

  18. The emergence and role of strong ties in time-varying communication networks

    CERN Document Server

    Karsai, Márton; Vespignani, Alessandro

    2014-01-01

    In most social, information, and collaboration systems the complex activity of agents generates rapidly evolving time-varying networks. Temporal changes in the network structure and the dynamical processes occurring on its fabric are usually coupled in ways that still challenge our mathematical or computational modelling. Here we analyse a mobile call dataset describing the activity of millions of individuals and investigate the temporal evolution of their egocentric networks. We empirically observe a simple statistical law characterizing the memory of agents that quantitatively signals how much interactions are more likely to happen again on already established connections. We encode the observed dynamics in a reinforcement process defining a generative computational network model with time-varying connectivity patterns. This activity-driven network model spontaneously generates the basic dynamic process for the differentiation between strong and weak ties. The model is used to study the effect of time-varyi...

  19. social

    Directory of Open Access Journals (Sweden)

    Alfredo Falero Cirigliano

    2005-01-01

    Full Text Available El artículo parte de considerar al neoliberalismo y su cristalización en América Latina como un patrón de poder regional, esto es, un formato específico de acumulación dentro de la reproducción polarizante centro-periferia. Desde este ángulo, se aborda la expansión y naturalización de prácticas sociales mercantilizadas a partir de dos ejes: el de la construcción ideológica y su relación con la política económica, y el de la subjetividad social. Finalmente, se examinan dos escenarios potenciales en la coyuntura actual: el de un neoliberalismo con "rostro humano" o, alternativamente, el de ampliación de grietas sociales hacia la conformación de otro patrón de poder.

  20. On 0-homology of categorical at zero semigroups

    OpenAIRE

    Novikov, B. V.; Polyakova, L. Yu.

    2008-01-01

    The isomorphism of 0-homology groups of a categorical at zero semigroup and homology groups of its 0-reflector is proved. Some applications of 0-homology to Eilenberg-MacLane homology of semigroups are given.

  1. Khovanov homology of links and graphs

    Science.gov (United States)

    Stosic, Marko

    2006-05-01

    In this thesis we work with Khovanov homology of links and its generalizations, as well as with the homology of graphs. Khovanov homology of links consists of graded chain complexes which are link invariants, up to chain homotopy, with graded Euler characteristic equal to the Jones polynomial of the link. Hence, it can be regarded as the "categorification" of the Jones polynomial. We prove that the first homology group of positive braid knots is trivial. Futhermore, we prove that non-alternating torus knots are homologically thick. In addition, we show that we can decrease the number of full twists of torus knots without changing low-degree homology and consequently that there exists stable homology for torus knots. We also prove most of the above properties for Khovanov-Rozansky homology. Concerning graph homology, we categorify the dichromatic (and consequently Tutte) polynomial for graphs, by categorifying an infinite set of its one-variable specializations. We categorify explicitly the one-variable specialization that is an analog of the Jones polynomial of an alternating link corresponding to the initial graph. Also, we categorify explicitly the whole two-variable dichromatic polynomial of graphs by using Koszul complexes. textbf{Key-words:} Khovanov homology, Jones polynomial, link, torus knot, graph, dichromatic polynomial

  2. Multiresolution persistent homology for excessively large biomolecular datasets

    Science.gov (United States)

    Xia, Kelin; Zhao, Zhixiong; Wei, Guo-Wei

    2015-01-01

    Although persistent homology has emerged as a promising tool for the topological simplification of complex data, it is computationally intractable for large datasets. We introduce multiresolution persistent homology to handle excessively large datasets. We match the resolution with the scale of interest so as to represent large scale datasets with appropriate resolution. We utilize flexibility-rigidity index to access the topological connectivity of the data set and define a rigidity density for the filtration analysis. By appropriately tuning the resolution of the rigidity density, we are able to focus the topological lens on the scale of interest. The proposed multiresolution topological analysis is validated by a hexagonal fractal image which has three distinct scales. We further demonstrate the proposed method for extracting topological fingerprints from DNA molecules. In particular, the topological persistence of a virus capsid with 273 780 atoms is successfully analyzed which would otherwise be inaccessible to the normal point cloud method and unreliable by using coarse-grained multiscale persistent homology. The proposed method has also been successfully applied to the protein domain classification, which is the first time that persistent homology is used for practical protein domain analysis, to our knowledge. The proposed multiresolution topological method has potential applications in arbitrary data sets, such as social networks, biological networks, and graphs. PMID:26450288

  3. Multiresolution persistent homology for excessively large biomolecular datasets

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Kelin; Zhao, Zhixiong [Department of Mathematics, Michigan State University, East Lansing, Michigan 48824 (United States); Wei, Guo-Wei, E-mail: wei@math.msu.edu [Department of Mathematics, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824 (United States)

    2015-10-07

    Although persistent homology has emerged as a promising tool for the topological simplification of complex data, it is computationally intractable for large datasets. We introduce multiresolution persistent homology to handle excessively large datasets. We match the resolution with the scale of interest so as to represent large scale datasets with appropriate resolution. We utilize flexibility-rigidity index to access the topological connectivity of the data set and define a rigidity density for the filtration analysis. By appropriately tuning the resolution of the rigidity density, we are able to focus the topological lens on the scale of interest. The proposed multiresolution topological analysis is validated by a hexagonal fractal image which has three distinct scales. We further demonstrate the proposed method for extracting topological fingerprints from DNA molecules. In particular, the topological persistence of a virus capsid with 273 780 atoms is successfully analyzed which would otherwise be inaccessible to the normal point cloud method and unreliable by using coarse-grained multiscale persistent homology. The proposed method has also been successfully applied to the protein domain classification, which is the first time that persistent homology is used for practical protein domain analysis, to our knowledge. The proposed multiresolution topological method has potential applications in arbitrary data sets, such as social networks, biological networks, and graphs.

  4. Topic Detection Based on Weak Tie Analysis: A Case Study of LIS Research

    Directory of Open Access Journals (Sweden)

    Ling Wei

    2016-11-01

    Full Text Available Purpose: Based on the weak tie theory, this paper proposes a series of connection indicators of weak tie subnets and weak tie nodes to detect research topics, recognize their connections, and understand their evolution. Design/methodology/approach: First, keywords are extracted from article titles and preprocessed. Second, high-frequency keywords are selected to generate weak tie co-occurrence networks. By removing the internal lines of clustered sub-topic networks, we focus on the analysis of weak tie subnets' composition and functions and the weak tie nodes' roles. Findings: The research topics' clusters and themes changed yearly; the subnets clustered with technique-related and methodology-related topics have been the core, important subnets for years; while close subnets are highly independent, research topics are generally concentrated and most topics are application-related; the roles and functions of nodes and weak ties are diversified. Research limitations: The parameter values are somewhat inconsistent; the weak tie subnets and nodes are classified based on empirical observations, and the conclusions are not verified or compared to other methods. Practical implications: The research is valuable for detecting important research topics as well as their roles, interrelations, and evolution trends. Originality/value: To contribute to the strength of weak tie theory, the research translates weak and strong ties concepts to co-occurrence strength, and analyzes weak ties' functions. Also, the research proposes a quantitative method to classify and measure the topics' clusters and nodes.

  5. Equivariant ordinary homology and cohomology

    CERN Document Server

    Costenoble, Steven R

    2016-01-01

    Filling a gap in the literature, this book takes the reader to the frontiers of equivariant topology, the study of objects with specified symmetries. The discussion is motivated by reference to a list of instructive “toy” examples and calculations in what is a relatively unexplored field. The authors also provide a reading path for the first-time reader less interested in working through sophisticated machinery but still desiring a rigorous understanding of the main concepts. The subject’s classical counterparts, ordinary homology and cohomology, dating back to the work of Henri Poincaré in topology, are calculational and theoretical tools which are important in many parts of mathematics and theoretical physics, particularly in the study of manifolds. Similarly powerful tools have been lacking, however, in the context of equivariant topology. Aimed at advanced graduate students and researchers in algebraic topology and related fields, the book assumes knowledge of basic algebraic topology and group act...

  6. Homologous recombination and its regulation

    Science.gov (United States)

    Krejci, Lumir; Altmannova, Veronika; Spirek, Mario; Zhao, Xiaolan

    2012-01-01

    Homologous recombination (HR) is critical both for repairing DNA lesions in mitosis and for chromosomal pairing and exchange during meiosis. However, some forms of HR can also lead to undesirable DNA rearrangements. Multiple regulatory mechanisms have evolved to ensure that HR takes place at the right time, place and manner. Several of these impinge on the control of Rad51 nucleofilaments that play a central role in HR. Some factors promote the formation of these structures while others lead to their disassembly or the use of alternative repair pathways. In this article, we review these mechanisms in both mitotic and meiotic environments and in different eukaryotic taxa, with an emphasis on yeast and mammal systems. Since mutations in several proteins that regulate Rad51 nucleofilaments are associated with cancer and cancer-prone syndromes, we discuss how understanding their functions can lead to the development of better tools for cancer diagnosis and therapy. PMID:22467216

  7. Persistent homology and string vacua

    Energy Technology Data Exchange (ETDEWEB)

    Cirafici, Michele [Center for Mathematical Analysis, Geometry and Dynamical Systems,Instituto Superior Técnico, Universidade de Lisboa,Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Institut des Hautes Études Scientifiques,Le Bois-Marie, 35 route de Chartres, F-91440 Bures-sur-Yvette (France)

    2016-03-08

    We use methods from topological data analysis to study the topological features of certain distributions of string vacua. Topological data analysis is a multi-scale approach used to analyze the topological features of a dataset by identifying which homological characteristics persist over a long range of scales. We apply these techniques in several contexts. We analyze N=2 vacua by focusing on certain distributions of Calabi-Yau varieties and Landau-Ginzburg models. We then turn to flux compactifications and discuss how we can use topological data analysis to extract physical information. Finally we apply these techniques to certain phenomenologically realistic heterotic models. We discuss the possibility of characterizing string vacua using the topological properties of their distributions.

  8. Homology and the hierarchy of biological systems.

    Science.gov (United States)

    Sommer, Ralf J

    2008-07-01

    Homology is the similarity between organisms due to common ancestry. Introduced by Richard Owen in 1843 in a paper entitled "Lectures on comparative anatomy and physiology of the invertebrate animals", the concept of homology predates Darwin's "Origin of Species" and has been very influential throughout the history of evolutionary biology. Although homology is the central concept of all comparative biology and provides a logical basis for it, the definition of the term and the criteria of its application remain controversial. Here, I will discuss homology in the context of the hierarchy of biological organization. I will provide insights gained from an exemplary case study in evolutionary developmental biology that indicates the uncoupling of homology at different levels of biological organization. I argue that continuity and hierarchy are separate but equally important issues of homology. (c) 2008 Wiley Periodicals, Inc.

  9. Tongue-tie, from embriology to treatment: a literature review

    Directory of Open Access Journals (Sweden)

    Maria Dezio

    2015-03-01

    Full Text Available The aim of this review is to create a complete analysis about tongue-tie (or short lingual frenum or ankyloglossia according to the most important works published in literature. The analysis allowed us to do a complete evaluation of this problem, from embriology to the therapeutic approach we could use today, focusing our attention on laser-assisted therapy. This review is based on the research on the PubMed Database (www.ncbi.nlm.nih.gov of studies about lingual frenum written in English between January 1980 and May 2014. The keywords inserted were “lingual frenum”, “frenectomy”, “laser therapy”. We have analyzed: case series, case reports, clinical studies, and also literature reviews in which embryology, physiology, diagnosis and treatment of ankyloglossia were described. We excluded laboratory studies, studies based on animal tests and studies about patients with particular syndromes in which we can also find tongue-tie. The selection criteria allowed us to select 42 articles. The treatment options for the releasing of the frenum are surgically represented by frenotomy (i.e. simple horizontal cut of this training and frenectomy (i.e. removal. In both cases, the intervention on the short lingual frenum is simple, short-lasting, and without particular complications. Furthermore, this kind of treatment can be carried out with different devices: with the typical cold blade scalpel or by the use of laser, a new method that shows more advantages over the prior art. Laser-assisted therapy permits to intervene on newborns (from 0 to 20 days, when there are breastfeeding problems without total anesthesia and suture. The Er:YAG, CO2 laser (according to literature data and Diode laser (according to our experience are advantageous, safe and effective in tongue-tie treatment.

  10. Homology in Electromagnetic Boundary Value Problems

    Directory of Open Access Journals (Sweden)

    Matti Pellikka

    2010-01-01

    Full Text Available We discuss how homology computation can be exploited in computational electromagnetism. We represent various cellular mesh reduction techniques, which enable the computation of generators of homology spaces in an acceptable time. Furthermore, we show how the generators can be used for setting up and analysis of an electromagnetic boundary value problem. The aim is to provide a rationale for homology computation in electromagnetic modeling software.

  11. Experimental Investigation of Tension Stiffening in RC Ties

    Directory of Open Access Journals (Sweden)

    Aleksandr Sokolov

    2016-01-01

    Full Text Available The increasing application of high-performance materials in civil engineering led to the development of reinforced concrete (RC structures with reduced cross sections and increased spans. In such structures serviceability limit state often becomes the governing condition of the design. Present study investigates the deformation behaviour of high-strength RC ties reinforced with high-grade bars. Experimental investigation was carried out measuring the postcracking stiffness of the specimens at high strain levels. It was found that, despite the reduction in stiffness, a considerable part of the average tensile stresses were carried by the concrete at the advanced loading stages, thus effectively stiffening the RC member.

  12. Tongue-tie, from embriology to treatment: a literature review

    OpenAIRE

    2015-01-01

    The aim of this review is to create a complete analysis about tongue-tie (or short lingual frenum or ankyloglossia) according to the most important works published in literature. The analysis allowed us to do a complete evaluation of this problem, from embriology to the therapeutic approach we could use today, focusing our attention on laser-assisted therapy. This review is based on the research on the PubMed Database (www.ncbi.nlm.nih.gov) of studies about lingual frenum written in English b...

  13. Tying loan interest rates to borrowers' CDS spreads

    OpenAIRE

    Ivanov, Ivan T.; Santos, Joao A. C.; Vo, Thu

    2014-01-01

    We investigate how the introduction of market-based pricing, the practice of tying loan interest rates to credit default swaps, has affected borrowing costs. We find that CDS-based loans are associated with lower interest rates, both at origination and during the life of the loan. Our results also indicate that banks simplify the covenant structure of market-based pricing loans, suggesting that the decline in the cost of bank debt is explained, at least in part, by a reduction in monitoring c...

  14. ‘Not a Problem Until it Becomes a Problem’: A Qualitative Study of Values and Risks of In-house Family Ties in Swedish Workplaces

    Directory of Open Access Journals (Sweden)

    Katarina Haugen

    2016-12-01

    Full Text Available In-house family ties at workplaces occur in most contexts, and are associated with both advantages and disadvantages. On the basis of 40 interviews with human resource managers at Swedish workplaces, the values and risks of in-house family ties and their importance within the workplace are analyzed jointly, thus allowing for a holistic perspective. The interviews reveal values and risks on a strategic level, for day-to-day operations, for the social work environment, and on the level of individuals. Crucially, even when in-house family ties are perceived as uncomplicated, there is a latent risk that problems might arise. The interpretation of the role of in-house family ties is also strongly related to whether they are paired with asymmetrical (vertical power relations. It also depends heavily on the chosen perspective—that of the organization, the social work environment, the individual, or the broader society—and the perceived advantages tend to come with corresponding inverted disadvantages.

  15. Homology-independent metrics for comparative genomics.

    Science.gov (United States)

    Coutinho, Tarcisio José Domingos; Franco, Glória Regina; Lobo, Francisco Pereira

    2015-01-01

    A mainstream procedure to analyze the wealth of genomic data available nowadays is the detection of homologous regions shared across genomes, followed by the extraction of biological information from the patterns of conservation and variation observed in such regions. Although of pivotal importance, comparative genomic procedures that rely on homology inference are obviously not applicable if no homologous regions are detectable. This fact excludes a considerable portion of "genomic dark matter" with no significant similarity - and, consequently, no inferred homology to any other known sequence - from several downstream comparative genomic methods. In this review we compile several sequence metrics that do not rely on homology inference and can be used to compare nucleotide sequences and extract biologically meaningful information from them. These metrics comprise several compositional parameters calculated from sequence data alone, such as GC content, dinucleotide odds ratio, and several codon bias metrics. They also share other interesting properties, such as pervasiveness (patterns persist on smaller scales) and phylogenetic signal. We also cite examples where these homology-independent metrics have been successfully applied to support several bioinformatics challenges, such as taxonomic classification of biological sequences without homology inference. They where also used to detect higher-order patterns of interactions in biological systems, ranging from detecting coevolutionary trends between the genomes of viruses and their hosts to characterization of gene pools of entire microbial communities. We argue that, if correctly understood and applied, homology-independent metrics can add important layers of biological information in comparative genomic studies without prior homology inference.

  16. Military Social Work as an Exemplar in Teaching Social Work Competencies

    Science.gov (United States)

    Daley, James G.; Carlson, Joan; Evans, Pinkie

    2015-01-01

    This article is for social work educators unfamiliar with military social work and receptive to a number of exemplars to enhance teaching strategies within their courses. Because examples of military social work are directly tied to the Council on Social Work Education competencies, this article offers a number of suggested teaching strategies…

  17. Risk aversion and social networks

    NARCIS (Netherlands)

    Kovářík, J.; van der Leij, M.J.

    2014-01-01

    This paper first investigates empirically the relationship between risk aversion and social network structure in a large group of undergraduate students. We find that risk aversion is strongly correlated to local network clustering, that is, the probability that one has a social tie to friends of

  18. Human communication dynamics in digital footsteps: a study of the agreement between self-reported ties and email networks.

    Science.gov (United States)

    Wuchty, Stefan; Uzzi, Brian

    2011-01-01

    Digital communication data has created opportunities to advance the knowledge of human dynamics in many areas, including national security, behavioral health, and consumerism. While digital data uniquely captures the totality of a person's communication, past research consistently shows that a subset of contacts makes up a person's "social network" of unique resource providers. To address this gap, we analyzed the correspondence between self-reported social network data and email communication data with the objective of identifying the dynamics in e-communication that correlate with a person's perception of a significant network tie. First, we examined the predictive utility of three popular methods to derive social network data from email data based on volume and reciprocity of bilateral email exchanges. Second, we observed differences in the response dynamics along self-reported ties, allowing us to introduce and test a new method that incorporates time-resolved exchange data. Using a range of robustness checks for measurement and misreporting errors in self-report and email data, we find that the methods have similar predictive utility. Although e-communication has lowered communication costs with large numbers of persons, and potentially extended our number of, and reach to contacts, our case results suggest that underlying behavioral patterns indicative of friendship or professional contacts continue to operate in a classical fashion in email interactions.

  19. Human communication dynamics in digital footsteps: a study of the agreement between self-reported ties and email networks.

    Directory of Open Access Journals (Sweden)

    Stefan Wuchty

    Full Text Available Digital communication data has created opportunities to advance the knowledge of human dynamics in many areas, including national security, behavioral health, and consumerism. While digital data uniquely captures the totality of a person's communication, past research consistently shows that a subset of contacts makes up a person's "social network" of unique resource providers. To address this gap, we analyzed the correspondence between self-reported social network data and email communication data with the objective of identifying the dynamics in e-communication that correlate with a person's perception of a significant network tie. First, we examined the predictive utility of three popular methods to derive social network data from email data based on volume and reciprocity of bilateral email exchanges. Second, we observed differences in the response dynamics along self-reported ties, allowing us to introduce and test a new method that incorporates time-resolved exchange data. Using a range of robustness checks for measurement and misreporting errors in self-report and email data, we find that the methods have similar predictive utility. Although e-communication has lowered communication costs with large numbers of persons, and potentially extended our number of, and reach to contacts, our case results suggest that underlying behavioral patterns indicative of friendship or professional contacts continue to operate in a classical fashion in email interactions.

  20. Human Communication Dynamics in Digital Footsteps: A Study of the Agreement between Self-Reported Ties and Email Networks

    Science.gov (United States)

    Wuchty, Stefan; Uzzi, Brian

    2011-01-01

    Digital communication data has created opportunities to advance the knowledge of human dynamics in many areas, including national security, behavioral health, and consumerism. While digital data uniquely captures the totality of a person's communication, past research consistently shows that a subset of contacts makes up a person's “social network” of unique resource providers. To address this gap, we analyzed the correspondence between self-reported social network data and email communication data with the objective of identifying the dynamics in e-communication that correlate with a person's perception of a significant network tie. First, we examined the predictive utility of three popular methods to derive social network data from email data based on volume and reciprocity of bilateral email exchanges. Second, we observed differences in the response dynamics along self-reported ties, allowing us to introduce and test a new method that incorporates time-resolved exchange data. Using a range of robustness checks for measurement and misreporting errors in self-report and email data, we find that the methods have similar predictive utility. Although e-communication has lowered communication costs with large numbers of persons, and potentially extended our number of, and reach to contacts, our case results suggest that underlying behavioral patterns indicative of friendship or professional contacts continue to operate in a classical fashion in email interactions. PMID:22114665

  1. The molecular evolution of PL10 homologs

    Directory of Open Access Journals (Sweden)

    Chang Ti-Cheng

    2010-05-01

    Full Text Available Abstract Background PL10 homologs exist in a wide range of eukaryotes from yeast, plants to animals. They share a DEAD motif and belong to the DEAD-box polypeptide 3 (DDX3 subfamily with a major role in RNA metabolism. The lineage-specific expression patterns and various genomic structures and locations of PL10 homologs indicate these homologs have an interesting evolutionary history. Results Phylogenetic analyses revealed that, in addition to the sex chromosome-linked PL10 homologs, DDX3X and DDX3Y, a single autosomal PL10 putative homologous sequence is present in each genome of the studied non-rodent eutheria. These autosomal homologous sequences originated from the retroposition of DDX3X but were pseudogenized during the evolution. In rodents, besides Ddx3x and Ddx3y, we found not only Pl10 but another autosomal homologous region, both of which also originated from the Ddx3x retroposition. These retropositions occurred after the divergence of eutheria and opossum. In contrast, an additional X putative homologous sequence was detected in primates and originated from the transposition of DDX3Y. The evolution of PL10 homologs was under positive selection and the elevated Ka/Ks ratios were observed in the eutherian lineages for DDX3Y but not PL10 and DDX3X, suggesting relaxed selective constraints on DDX3Y. Contrary to the highly conserved domains, several sites with relaxed selective constraints flanking the domains in the mammalian PL10 homologs may play roles in enhancing the gene function in a lineage-specific manner. Conclusion The eutherian DDX3X/DDX3Y in the X/Y-added region originated from the translocation of the ancient PL10 ortholog on the ancestral autosome, whereas the eutherian PL10 was retroposed from DDX3X. In addition to the functional PL10/DDX3X/DDX3Y, conserved homologous regions on the autosomes and X chromosome are present. The autosomal homologs were also derived from DDX3X, whereas the additional X-homologs were derived

  2. Semantic mining of social networks

    CERN Document Server

    Tang, Jie

    2015-01-01

    The first kinds of questions we try to answer are: What are the fundamental factors that form the different categories of social ties? How have reciprocal relationships been developed fro parasocial relationships? How do connected users further form groups? Another theme addressed in this book is the study of social influence. Social influence occurs when one's opinions, emotions, or behaviors are affected by others, intentionally or unintentionally. Considerable research has been conducted to verify the existence of social influence in various networks.

  3. Homotopic Chain Maps Have Equal s-Homology and d-Homology

    Directory of Open Access Journals (Sweden)

    M. Z. Kazemi-Baneh

    2016-01-01

    Full Text Available The homotopy of chain maps on preabelian categories is investigated and the equality of standard homologies and d-homologies of homotopic chain maps is established. As a special case, if X and Y are the same homotopy type, then their nth d-homology R-modules are isomorphic, and if X is a contractible space, then its nth d-homology R-modules for n≠0 are trivial.

  4. Social networks, personal values, and creativity: evidence for curvilinear and interaction effects.

    Science.gov (United States)

    Zhou, Jing; Shin, Shung Jae; Brass, Daniel J; Choi, Jaepil; Zhang, Zhi-Xue

    2009-11-01

    Taking an interactional perspective on creativity, the authors examined the influence of social networks and conformity value on employees' creativity. They theorized and found a curvilinear relationship between number of weak ties and creativity such that employees exhibited greater creativity when their number of weak ties was at intermediate levels rather than at lower or higher levels. In addition, employees' conformity value moderated the curvilinear relationship between number of weak ties and creativity such that employees exhibited greater creativity at intermediate levels of number of weak ties when conformity was low than when it was high. A proper match between personal values and network ties is critical for understanding creativity.

  5. Knots in homology spheres which have simple knot Floer homology are trivial

    OpenAIRE

    Eftekhary, Eaman

    2010-01-01

    We show that if K is a non-trivial knot inside a homology sphere X, the rank of the knot Floer homology group associated with K is strictly bigger than the rank of the Heegaard Floer homology group associated with X.

  6. 78 FR 29325 - Prestressed Concrete Steel Rail Tie Wire From Mexico, the People's Republic of China, and...

    Science.gov (United States)

    2013-05-20

    ... International Trade Administration Prestressed Concrete Steel Rail Tie Wire From Mexico, the People's Republic...'') petitions concerning imports of prestressed concrete steel rail tie wire (``PC tie wire'') from Mexico, the... Antidumping Duty Petitions on Prestressed Concrete Steel Rail Tie Wire from the PRC, Mexico, and Thailand...

  7. 78 FR 75547 - Prestressed Concrete Steel Rail Tie Wire From Thailand: Preliminary Determination of Sales at Not...

    Science.gov (United States)

    2013-12-12

    ... International Trade Administration Prestressed Concrete Steel Rail Tie Wire From Thailand: Preliminary... concrete steel rail tire wire (``PC tie wire'') from Thailand is not being, or likely to be, sold in the... prestressed tendons in concrete railroad ties (``PC tie wire''). High carbon steel is defined as steel that...

  8. Buoyancy instability of homologous implosions

    CERN Document Server

    Johnson, Bryan M

    2015-01-01

    I consider the hydrodynamic stability of imploding gases as a model for inertial confinement fusion capsules, sonoluminescent bubbles and the gravitational collapse of astrophysical gases. For oblate modes under a homologous flow, a monatomic gas is governed by the Schwarzschild criterion for buoyant stability. Under buoyantly unstable conditions, fluctuations experience power-law growth in time, with a growth rate that depends upon mean flow gradients and is independent of mode number. If the flow accelerates throughout the implosion, oblate modes amplify by a factor (2C)^(|N0| ti)$, where C is the convergence ratio of the implosion, N0 is the initial buoyancy frequency and ti is the implosion time scale. If, instead, the implosion consists of a coasting phase followed by stagnation, oblate modes amplify by a factor exp(pi |N0| ts), where N0 is the buoyancy frequency at stagnation and ts is the stagnation time scale. Even under stable conditions, vorticity fluctuations grow due to the conservation of angular...

  9. DNA Sequence Alignment during Homologous Recombination.

    Science.gov (United States)

    Greene, Eric C

    2016-05-27

    Homologous recombination allows for the regulated exchange of genetic information between two different DNA molecules of identical or nearly identical sequence composition, and is a major pathway for the repair of double-stranded DNA breaks. A key facet of homologous recombination is the ability of recombination proteins to perfectly align the damaged DNA with homologous sequence located elsewhere in the genome. This reaction is referred to as the homology search and is akin to the target searches conducted by many different DNA-binding proteins. Here I briefly highlight early investigations into the homology search mechanism, and then describe more recent research. Based on these studies, I summarize a model that includes a combination of intersegmental transfer, short-distance one-dimensional sliding, and length-specific microhomology recognition to efficiently align DNA sequences during the homology search. I also suggest some future directions to help further our understanding of the homology search. Where appropriate, I direct the reader to other recent reviews describing various issues related to homologous recombination.

  10. Homology in classical and molecular biology.

    Science.gov (United States)

    Patterson, C

    1988-11-01

    Hypotheses of homology are the basis of comparative morphology and comparative molecular biology. The kinds of homologous and nonhomologous relations in classical and molecular biology are explored through the three tests that may be applied to a hypothesis of homology: congruence, conjunction, and similarity. The same three tests apply in molecular comparisons and in morphology, and in each field they differentiate eight kinds of relation. These various relations are discussed and compared. The unit or standard of comparison differs in morphology and in molecular biology; in morphology it is the adult or life cycle, but with molecules it is the haploid genome. In morphology the congruence test is decisive in separating homology and nonhomology, whereas with molecular sequence data similarity is the decisive test. Consequences of this difference are that the boundary between homology and nonhomology is not the same in molecular biology as in morphology, that homology and synapomorphy can be equated in morphology but not in all molecular comparisons, and that there is no detected molecular equivalent of convergence. Since molecular homology may reflect either species phylogeny or gene phylogeny, there are more kinds of homologous relation between molecular sequences than in morphology. The terms paraxenology and plerology are proposed for two of these kinds--respectively, the consequence of multiple xenology and of gene conversion.

  11. DNA Sequence Alignment during Homologous Recombination*

    Science.gov (United States)

    Greene, Eric C.

    2016-01-01

    Homologous recombination allows for the regulated exchange of genetic information between two different DNA molecules of identical or nearly identical sequence composition, and is a major pathway for the repair of double-stranded DNA breaks. A key facet of homologous recombination is the ability of recombination proteins to perfectly align the damaged DNA with homologous sequence located elsewhere in the genome. This reaction is referred to as the homology search and is akin to the target searches conducted by many different DNA-binding proteins. Here I briefly highlight early investigations into the homology search mechanism, and then describe more recent research. Based on these studies, I summarize a model that includes a combination of intersegmental transfer, short-distance one-dimensional sliding, and length-specific microhomology recognition to efficiently align DNA sequences during the homology search. I also suggest some future directions to help further our understanding of the homology search. Where appropriate, I direct the reader to other recent reviews describing various issues related to homologous recombination. PMID:27129270

  12. Why do bacteria engage in homologous recombination?

    NARCIS (Netherlands)

    Vos, M.

    2009-01-01

    Microbiologists have long recognized that the uptake and incorporation of homologous DNA from outside the cell is a common feature of bacteria, with important implications for their evolution. However, the exact reasons why bacteria engage in homologous recombination remain elusive. This Opinion

  13. Why do bacteria engage in homologous recombination?

    NARCIS (Netherlands)

    Vos, M.

    2009-01-01

    Microbiologists have long recognized that the uptake and incorporation of homologous DNA from outside the cell is a common feature of bacteria, with important implications for their evolution. However, the exact reasons why bacteria engage in homologous recombination remain elusive. This Opinion art

  14. Synthetic Homology in Homotopy Type Theory

    OpenAIRE

    Graham, Robert

    2017-01-01

    This paper defines homology in homotopy type theory, in the process stable homotopy groups are also defined. Previous research in synthetic homotopy theory is relied on, in particular the definition of cohomology. This work lays the foundation for a computer checked construction of homology.

  15. GENE SEQUENCE HOMOLOGY OF CHEMOKINES ACROSS SPECIES

    Science.gov (United States)

    The abundance of expressed gene and protein sequences available in the biological information databases facilitates comparison of protein homologies. A high degree of sequence similarity typically implies homology regarding structure and function and may provide clues to antibody cross-react...

  16. Traces of differential forms and Hochschild homology

    CERN Document Server

    Hübl, Reinhold

    1989-01-01

    This monograph provides an introduction to, as well as a unification and extension of the published work and some unpublished ideas of J. Lipman and E. Kunz about traces of differential forms and their relations to duality theory for projective morphisms. The approach uses Hochschild-homology, the definition of which is extended to the category of topological algebras. Many results for Hochschild-homology of commutative algebras also hold for Hochschild-homology of topological algebras. In particular, after introducing an appropriate notion of completion of differential algebras, one gets a natural transformation between differential forms and Hochschild-homology of topological algebras. Traces of differential forms are of interest to everyone working with duality theory and residue symbols. Hochschild-homology is a useful tool in many areas of k-theory. The treatment is fairly elementary and requires only little knowledge in commutative algebra and algebraic geometry.

  17. Studi Tentang Political Tie, Pengaruhnya Terhadap Keputusan Pemberian Kredit Bank di Indonesia

    Directory of Open Access Journals (Sweden)

    Elisa Tjondro

    2012-01-01

    Full Text Available This study uses bank loan data to examine the effect of (political tie between the company and the government to on the assessment of companies financial leverage and profitability in the bank lending decisions in Indonesia. The numbers of samples are 1465 observations. This study uses moderated regression analysis (MRA. The study finds that a political tie affect corporate profitability assessment in bank lending decisions. Firms with lower profitability receive larger bank loan because their political tie (rent-seeking hypothesis. However, this study inds that a political tie does not affect the assessment of financial leverage in bank's lending decisions. This finding also supports Faccio (2010, Fisman (2001, and Backman (2001. Indonesia condition which has a weak institutional regulation and high information asymmetry is beneficial for companies that have a political tie. This leads to more trusted political tie as an indicator of the profitability.

  18. Classification and Tie2 mutations in spinal and soft tissue vascular anomalies.

    Science.gov (United States)

    Zhou, Mei; Jiang, Renbing; Zhao, Gang; Wang, Lisha; Wang, Hua; Li, Wenting; Li, Yiqun; Du, Xiang; Bai, Jingping

    2015-10-15

    Vascular anomalies included hemangiomas and vascular malformations (VMs). VMs are mediated by mutations in the endothelial cell-specific receptor tyrosine kinase Tie2 (TEK),which is essential for angiogenesis and vascular stabilization. We identified five types of Tie2 mutations in 80 patients with soft tissue or spinal VMs by PCR including the previously detected missense mutations 2690A>G (Y897C), 2740C>T (L914F), 2743C>T (R915C), and two nonsense mutations 2763G>A, 2688C>T, we identified Tie2 mutation in primary spinal VMs for the first time. Tie2 mutations were found to be absent in 33 patients with hemangiomas and DNA samples of VMs. In addition, we showed that Tie2 mRNA expression in spinal VMs was similar to soft tissue VMs, but obviously lower than infant hemangiomas (PVMs, the association of Tie2 and vascular anomalies needs to be further discussed.

  19. IVF, same-sex couples and the value of biological ties

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2016-01-01

    Ought parents, in general, to value being biologically tied to their children? Is it important, in particular, that both parents be biologically tied to their children? I will address these fundamental questions by looking at a fairly new practice within IVF treatments, so-called IVF-with-ROPA (R......Ought parents, in general, to value being biologically tied to their children? Is it important, in particular, that both parents be biologically tied to their children? I will address these fundamental questions by looking at a fairly new practice within IVF treatments, so-called IVF......-with-ROPA allows for do not have any particular value beside the satisfaction of a legitimate wish, because there is no intrinsic value in a biological tie between parents and children; further, I argue that equality within parental projects cannot be achieved by redistributing biological ties....

  20. Representation of Women With Industry Ties in Ophthalmology.

    Science.gov (United States)

    Reddy, Ashvini K; Bounds, Gregory W; Bakri, Sophie J; Gordon, Lynn K; Smith, Justine R; Haller, Julia A; Thorne, Jennifer E

    2016-06-01

    Women in ophthalmology are growing in number and have made strides in traditional metrics of professional achievement. Professional ties to industry represent another potential means of career advancement, recognition, and income. To report the representation of women among ophthalmologists receiving industry remuneration for research, consulting, honoraria, grants, royalties, and faculty/speaker roles. In this observational, retrospective study, the Centers for Medicare and Medicaid Services Open Payments database for payments to ophthalmologists by biomedical companies was reviewed for representation, median payments, and mean payments by women and men for industry relationships in 2013 and 2014. The analysis was performed from July 2015 to November 2015. The primary outcome measures were percentage representation of women vs men overall and in industry research, consulting, speaking roles, royalties and licenses, grants, services other than consulting, and honoraria. Secondary outcome measures included mean and median payments from industry to female vs male ophthalmologists. In 2013, 4164 of 21 380 (19.5%) ophthalmologists were women, and of 1204 ophthalmologists analyzed for industry payments, 176 (4.2%) women had industry ties compared with 1028 (6%) men (P women were $11 419 compared with $20 957 for men (P = .001), and median payments to women were $3000 compared with $4787 for men (P = .007). In 2013, women were underrepresented among ophthalmologists receiving industry payments for research (49 of 462 [10.6%]), consulting (96 of 610 [15.7%]), honoraria (3 of 47 [6.4%]), industry grants (1 of 7 [14.3%]), royalties and licenses (1 of 13 [7.7%]), and faculty/speaker roles (2 of 48 [4.2%]). In 2014, 4352 of 21 531 (20.2%) of ophthalmologists were women. Of 1518 ophthalmologists analyzed for industry payments, 255 (6%) women had industry ties compared with 1263 (7.4%) men (P women were $14 848 compared with $30 513 for men (P = .004

  1. Reconnecting with the past on social network sites

    DEFF Research Database (Denmark)

    Shklovski, Irina

    to function as social resources or as active providers of support. In many ways, these ties explicitly lacked a purpose beyond emotional remembrance, as they were rarely re-integrated into daily life. Nevertheless, these ties remained connections to a past even as they at times became digital connections...

  2. Measuring Social Capital Accumulation in Rural Development

    Science.gov (United States)

    Teilmann, Kasper

    2012-01-01

    Using a theoretical framework, the study proposes an index that can measure the social capital of local action group (LAG) projects. The index is founded on four indicators: number of ties, bridging social capital, recognition, and diversity, which are aggregated into one social capital index. The index has been tested in LAG-Djursland, Denmark,…

  3. Measuring Social Capital Accumulation in Rural Development

    Science.gov (United States)

    Teilmann, Kasper

    2012-01-01

    Using a theoretical framework, the study proposes an index that can measure the social capital of local action group (LAG) projects. The index is founded on four indicators: number of ties, bridging social capital, recognition, and diversity, which are aggregated into one social capital index. The index has been tested in LAG-Djursland, Denmark,…

  4. Cohorts, "Siblings," and Mentors: Organizational Structures and the Creation of Social Capital

    Science.gov (United States)

    Cox, Amanda Barrett

    2017-01-01

    How can an organization help participants increase their social capital? Using data from an ethnographic study of Launch, an organization that prepares low-income students of color to attend elite boarding schools, I analyze how the organization's structures not only generate social ties among students but also stratify those ties horizontally and…

  5. Cohorts, "Siblings," and Mentors: Organizational Structures and the Creation of Social Capital

    Science.gov (United States)

    Cox, Amanda Barrett

    2017-01-01

    How can an organization help participants increase their social capital? Using data from an ethnographic study of Launch, an organization that prepares low-income students of color to attend elite boarding schools, I analyze how the organization's structures not only generate social ties among students but also stratify those ties horizontally and…

  6. Investigation of Bending Test Procedures for Engineered Polymer Composite Railroad Ties

    Science.gov (United States)

    2016-12-01

    ER D C/ CE RL C R- 16 -6 Investigation of Bending Test Procedures for Engineered Polymer Composite Railroad Ties Co ns tr uc tio n En...Test Procedures for Engineered Polymer Composite Railroad Ties Claire G. Ball CTL Group 5400 Old Orchard Road Skokie, IL 60077 Final report...conducting in- vestigations to help develop and evaluate engineered polymer composite railroad ties since 1993. Recent efforts, through funding and

  7. Strengthening weak ties through on-line gaming

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana Virginia; Kirchner, Kathrin

    On-line gaming became widespread in the last couple of years. The aim of the research presented in the paper is to figure out to what extent does game playing helps to strengthen weak ties and what additional factors influence this process. The approach is rather exploratory – some factors...... are grounded in theory, some are new. These factors are age, gender, place of origin, number of their Facebook connections (friends in Facebook terminology), the amount of time they are on Facebook, the amount of time they keep the Facebook site open, the amount of time they play on-line games, and the reasons...... for starting to play on-line games. Regarding the latter, we chose to focus only on escapist reasons....

  8. The Importance of Local Surveys for Tying Techniques Together

    Science.gov (United States)

    Long, James L.; Bosworth, John M.

    2000-01-01

    The synergistic benefits of combining observations from multiple space geodesy techniques located at a site are a main reason behind the proposal for the establishment of the International Space Geodetic and Gravimetric Network (ISGN). However, the full benefits of inter-comparison are only realized when the spatial relationships between the different space geodetic systems are accurately determined. These spatial relationships are best determined and documented by developing a local reference network of stable ground monuments and conducting periodic surveys to tie together the reference points (for example: the intersection of rotation axes of a VLBI antenna) of the space geodetic systems and the ground monument network. The data obtained from local surveys is vital to helping understand any systematic errors within an individual technique and to helping identify any local movement or deformation of the space geodetic systems over time.

  9. Homology--history of a concept.

    Science.gov (United States)

    Panchen, A L

    1999-01-01

    The concept of homology is traceable to Aristotle, but Belon's comparison in 1555 of a human skeleton with that of a bird expressed it overtly. Before the late 18th century, the dominant view of the pattern of organisms was the scala naturae--even Linnaeus with his divergent hierarchical classification did not necessarily see the resulting taxonomic pattern as a natural phenomenon. The divergent hierarchy, rather than the acceptance of phylogeny, was the necessary spur to discussion of homology and the concept of analogy. Lamarck, despite his proposal of evolution, attributed homology to his escalator naturae and analogy to convergent acquired characters. Significantly, it was the concept of serial homology that emerged at the end of the 18th century, although comparison between organisms became popular soon after, and was boosted by the famous Cuvier/Geoffroy Saint-Hilaire debate of the 1830s. The concepts of homology and analogy were well understood by the pre- (or anti-) evolutionary comparative anatomists before the general acceptance of phylogeny, and they were defined by Owen in 1843. The acceptance of evolution led to the idea that homology should be defined by common ancestry, and to the confusion between definition and explanation. The term 'homoplasy', introduced by Lankester in 1870, also arose from a phylogenetic explanation of homology.

  10. Enfrentando a pobreza, reconstruindo vínculos sociais: as lições da Ação da Cidadania contra a Fome, a Miséria e pela Vida Combating poverty and rebuilding social ties: the lessons of Citizens' Action in the Struggle Against Hunger and Destitution and in Defense of Life

    Directory of Open Access Journals (Sweden)

    Rosana Magalhães

    2002-01-01

    Full Text Available Refletir sobre a Ação da Cidadania contra a Fome e a Miséria e pela Vida é buscar uma aproximação com os dilemas e desafios que envolvem a consolidação da cidadania e da justiça social e, também, com as forças em ação na sociedade brasileira contemporânea. Neste esforço, porém, muitas interrogações ficam em aberto. O entrelaçamento dos temas da pobreza, da política e da solidariedade, os contornos concretos e os múltiplos desdobramentos sociais da chamada "Campanha da Fome" dão margem a diferentes possibilidades interpretativas. Dessa forma, considerando por uma lado, a amplitude do tema e, por outro, as limitações deste artigo, o objetivo é explorar algumas questões relevantes em torno do debate sobre a miséria, a exclusão e o processo de construção de novos perfis de intervenção pública e participação cívica, suscitadas ao longo da pesquisa realizada junto aos "Comitês da Ação da Cidadania" no Rio de Janeiro, entre 1996 e 1997. Em linhas gerais, a idéia é discutir, a partir das práticas dos voluntários, os dilemas postos para o equacionamento da pobreza e da fragmentação social por meio de ações de cooperação e ajuda mútua no país.To reflect on Citizens' Action in the Struggle Against Hunger and Destitution and in Defense of Life is to seek to approach the dilemmas and challenges involving the consolidation of citizenship and social justice, as well as the forces in action in contemporary Brazilian society. However, many questions remain open in this effort. The intertwining issues of poverty, politics, and solidarity and the concrete shapes and multiple social developments of Brazil's "Campaign Against Hunger" leave room for various possible interpretations. Thus, considering the breadth of the theme on the one hand and the limits of this article on the other, the objective is to explore some relevant issues in the debate on destitution and exclusion and the process of constructing new kinds

  11. Hidden torsion, 3-manifolds, and homology cobordism

    CERN Document Server

    Cha, Jae Choon

    2011-01-01

    This paper continues our exploration of homology cobordism of 3-manifolds using our recent results on Cheeger-Gromov rho-invariants associated to amenable representations. We introduce a new type of torsion in 3-manifold groups we call hidden torsion, and an algebraic approximation we call local hidden torsion. We construct infinitely many hyperbolic 3-manifolds which have local hidden torsion in the transfinite lower central subgroup. By realizing Cheeger-Gromov invariants over amenable groups, we show that our hyperbolic 3-manifolds are not pairwise homology cobordant, yet remain indistinguishable by any prior known homology cobordism invariants.

  12. Threading homology through algebra selected patterns

    CERN Document Server

    Boffi, Giandomenico

    2006-01-01

    Aimed at graduate students and researchers in mathematics, this book takes homological themes, such as Koszul complexes and their generalizations, and shows how these can be used to clarify certain problems in selected parts of algebra, as well as their success in solving a number of them. - ;Threading Homology through Algebra takes homological themes (Koszul complexes and their variations, resolutions in general) and shows how these affect the perception of certain problems in selected parts of algebra, as well as their success in solving a number of them. The text deals with regular local ri

  13. Social group utility maximization

    CERN Document Server

    Gong, Xiaowen; Yang, Lei; Zhang, Junshan

    2014-01-01

    This SpringerBrief explains how to leverage mobile users' social relationships to improve the interactions of mobile devices in mobile networks. It develops a social group utility maximization (SGUM) framework that captures diverse social ties of mobile users and diverse physical coupling of mobile devices. Key topics include random access control, power control, spectrum access, and location privacy.This brief also investigates SGUM-based power control game and random access control game, for which it establishes the socially-aware Nash equilibrium (SNE). It then examines the critical SGUM-b

  14. The homologous recombination system of Ustilago maydis.

    Science.gov (United States)

    Holloman, William K; Schirawski, Jan; Holliday, Robin

    2008-08-01

    Homologous recombination is a high fidelity, template-dependent process that is used in repair of damaged DNA, recovery of broken replication forks, and disjunction of homologous chromosomes in meiosis. Much of what is known about recombination genes and mechanisms comes from studies on baker's yeast. Ustilago maydis, a basidiomycete fungus, is distant evolutionarily from baker's yeast and so offers the possibility of gaining insight into recombination from an alternative perspective. Here we have surveyed the genome of U. maydis to determine the composition of its homologous recombination system. Compared to baker's yeast, there are fundamental differences in the function as well as in the repertoire of dedicated components. These include the use of a BRCA2 homolog and its modifier Dss1 rather than Rad52 as a mediator of Rad51, the presence of only a single Rad51 paralog, and the absence of Dmc1 and auxiliary meiotic proteins.

  15. Social Media Reputation

    DEFF Research Database (Denmark)

    Etter, Michael; Colleoni, Elanor; Ravasi, Davide

    In two ways corporate reputation research has strongly tied corporate actions to stakeholder’s perception of a company and therewith downplayed the autonomy of stakeholder´s evaluation of a firm. First, the most prominent theories used in corporate reputation research tie stakeholder perception...... actions, which demands a greater decoupling of stakeholders´ perceptions from corporate signals or actions in corporate reputation research. We develop the concept of social media reputation as the overall evaluation of a company presented in social media and present a new approach of measuring reputation...... directly to corporate performance and actions. Secondly, prominent reputation measurements couple stakeholders´ believes to reputation drivers through the use of predefined scales and items. We argue that with the rise of social media a company´s reputation has increasingly become autonomous from corporate...

  16. Dualities in Persistent (Co)Homology

    Energy Technology Data Exchange (ETDEWEB)

    de Silva, Vin; Morozov, Dmitriy; Vejdemo-Johansson, Mikael

    2011-09-16

    We consider sequences of absolute and relative homology and cohomology groups that arise naturally for a filtered cell complex. We establishalgebraic relationships between their persistence modules, and show that they contain equivalent information. We explain how one can use the existingalgorithm for persistent homology to process any of the four modules, and relate it to a recently introduced persistent cohomology algorithm. Wepresent experimental evidence for the practical efficiency of the latter algorithm.

  17. INVHOGEN: a database of homologous invertebrate genes

    OpenAIRE

    Paulsen, Ingo; von Haeseler, Arndt

    2005-01-01

    Classification of proteins into families of homologous sequences constitutes the basis of functional analysis or of evolutionary studies. Here we present INVertebrate HOmologous GENes (INVHOGEN), a database combining the available invertebrate protein genes from UniProt (consisting of Swiss-Prot and TrEMBL) into gene families. For each family INVHOGEN provides a multiple protein alignment, a maximum likelihood based phylogenetic tree and taxonomic information about the sequences. It is possib...

  18. Dualities in Persistent (Co)Homology

    Energy Technology Data Exchange (ETDEWEB)

    de Silva, Vin; Morozov, Dmitriy; Vejdemo-Johansson, Mikael

    2011-09-16

    We consider sequences of absolute and relative homology and cohomology groups that arise naturally for a filtered cell complex. We establishalgebraic relationships between their persistence modules, and show that they contain equivalent information. We explain how one can use the existingalgorithm for persistent homology to process any of the four modules, and relate it to a recently introduced persistent cohomology algorithm. Wepresent experimental evidence for the practical efficiency of the latter algorithm.

  19. The homologous recombination system of Ustilago maydis

    OpenAIRE

    Holloman, William K.; Schirawski, Jan; Holliday, Robin

    2008-01-01

    Homologous recombination is a high fidelity, template-dependent process that is used in repair of damaged DNA, recovery of broken replication forks, and disjunction of homologous chromosomes in meiosis. Much of what is known about recombination genes and mechanisms comes from studies on baker's yeast. Ustilago maydis, a basidiomycete fungus, is distant evolutionarily from baker's yeast and so offers the possibility of gaining insight into recombination from an alternative perspective. Here we...

  20. A Khovanov Type Link Homology with Geometric Interpretation

    Institute of Scientific and Technical Information of China (English)

    Mei Li ZHANG; Feng Chun LEI

    2016-01-01

    We study a Khovanov type homology close to the original Khovanov homology theory from Frobenius system. The homology is an invariant for oriented links up to isotopy by applying a tautological functor on the geometric complex. The homology has also geometric descriptions by introducing the genus generating operations. We prove that Jones Polynomial is equal to a suitable Euler characteristic of the homology groups. As an application, we compute the homology groups of (2, k)-torus knots for every k∈N.

  1. Homolog pairing and segregation in Drosophila meiosis.

    Science.gov (United States)

    McKee, B D

    2009-01-01

    Pairing of homologous chromosomes is fundamental to their reliable segregation during meiosis I and thus underlies sexual reproduction. In most eukaryotes homolog pairing is confined to prophase of meiosis I and is accompanied by frequent exchanges, known as crossovers, between homologous chromatids. Crossovers give rise to chiasmata, stable interhomolog connectors that are required for bipolar orientation (orientation to opposite poles) of homologs during meiosis I. Drosophila is unique among model eukaryotes in exhibiting regular homolog pairing in mitotic as well as meiotic cells. I review the results of recent molecular studies of pairing in both mitosis and meiosis in Drosophila. These studies show that homolog pairing is continuous between pre-meiotic mitosis and meiosis but that pairing frequencies and patterns are altered during the mitotic-meiotic transition. They also show that, with the exception of X-Y pairing in male meiosis, which is mediated specifically by the 240-bp rDNA spacer repeats, chromosome pairing is not restricted to specific sites in either mitosis or meiosis. Instead, virtually all chromosome regions, both heterochromatic and euchromatic, exhibit autonomous pairing capacity. Mutations that reduce the frequencies of both mitotic and meiotic pairing have been recently described, but no mutations that abolish pairing completely have been discovered, and the genetic control of pairing in Drosophila remains to be elucidated.

  2. On the hodological criterion for homology.

    Science.gov (United States)

    Faunes, Macarena; Francisco Botelho, João; Ahumada Galleguillos, Patricio; Mpodozis, Jorge

    2015-01-01

    Owen's pre-evolutionary definition of a homolog as "the same organ in different animals under every variety of form and function" and its redefinition after Darwin as "the same trait in different lineages due to common ancestry" entail the same heuristic problem: how to establish "sameness."Although different criteria for homology often conflict, there is currently a generalized acceptance of gene expression as the best criterion. This gene-centered view of homology results from a reductionist and preformationist concept of living beings. Here, we adopt an alternative organismic-epigenetic viewpoint, and conceive living beings as systems whose identity is given by the dynamic interactions between their components at their multiple levels of composition. We posit that there cannot be an absolute homology criterion, and instead, homology should be inferred from comparisons at the levels and developmental stages where the delimitation of the compared trait lies. In this line, we argue that neural connectivity, i.e., the hodological criterion, should prevail in the determination of homologies between brain supra-cellular structures, such as the vertebrate pallium.

  3. On the hodological criterion for homology

    Science.gov (United States)

    Faunes, Macarena; Francisco Botelho, João; Ahumada Galleguillos, Patricio; Mpodozis, Jorge

    2015-01-01

    Owen's pre-evolutionary definition of a homolog as “the same organ in different animals under every variety of form and function” and its redefinition after Darwin as “the same trait in different lineages due to common ancestry” entail the same heuristic problem: how to establish “sameness.”Although different criteria for homology often conflict, there is currently a generalized acceptance of gene expression as the best criterion. This gene-centered view of homology results from a reductionist and preformationist concept of living beings. Here, we adopt an alternative organismic-epigenetic viewpoint, and conceive living beings as systems whose identity is given by the dynamic interactions between their components at their multiple levels of composition. We posit that there cannot be an absolute homology criterion, and instead, homology should be inferred from comparisons at the levels and developmental stages where the delimitation of the compared trait lies. In this line, we argue that neural connectivity, i.e., the hodological criterion, should prevail in the determination of homologies between brain supra-cellular structures, such as the vertebrate pallium. PMID:26157357

  4. The Eastern Iowa Community College District's (EICCD) Televised Interactive Education (TIE) Evaluation Report, 1989-1990.

    Science.gov (United States)

    Kabat, Ellen J.; Friedel, Janice N.

    The purpose of this report is to provide both formative and summative results concerning the 1990 academic year operation of the Eastern Iowa Community College District's (EICCD) Televised Interactive Education (TIE) system. The TIE system is composed of a two-way microwave connection whereby two colleges and one university are able to produce and…

  5. Weak Ties and Self-Regulation in Job Search: The Effects of Goal Orientation on Networking

    Science.gov (United States)

    Hatala, John-Paul; Yamkovenko, Bogdan

    2016-01-01

    The purpose of this study is to empirically investigate the relationship between the self-regulatory variable of goal orientation and the extent to which job seekers reach out to and use weak ties in their job search. Weak ties, as defined by Granovettor, are connections to densely knit networks outside the individual's direct contacts who could…

  6. Life course preferences, sibling ties, and the geographical dispersion of sibling networks

    NARCIS (Netherlands)

    Blaauboer, M.; Strömgren, M.; Stjernström, O.

    2013-01-01

    Using Swedish register data, we analyse how life course preferences and sibling ties are related to the geographical dispersion of siblings. We argue that life course preferences and sibling ties are influenced by siblings' sociodemographic characteristics, by similarities and differences between

  7. 78 FR 25303 - Prestressed Concrete Steel Rail Tie Wire From China, Mexico, and Thailand

    Science.gov (United States)

    2013-04-30

    ... COMMISSION Prestressed Concrete Steel Rail Tie Wire From China, Mexico, and Thailand Institution of... materially retarded, by reason of imports from prestressed concrete steel rail tie wire from China, Mexico.... Persons with mobility impairments who will need special assistance in gaining access to the Commission...

  8. 33 CFR 401.49 - Dropping anchor or tying to canal bank.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Dropping anchor or tying to canal bank. 401.49 Section 401.49 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.49 Dropping anchor or tying to canal...

  9. The use of nylon cable ties to repair rib fractures in neonatal foals.

    Science.gov (United States)

    Downs, Chris; Rodgerson, Dwayne

    2011-03-01

    Commercially available nylon cable ties were used as a method of internal fixation for displaced rib fractures in 8 equine neonates. The procedure was effective, well-tolerated, rapid, and inexpensive. The use of nylon cable ties as internal fixation for displaced rib fractures in foals is an effective surgical procedure.

  10. Network ties and entrepreneurial orientation : Innovative performance of SMEs in a developing country

    NARCIS (Netherlands)

    Gunawan, Theresia; Jacob, J.; Duijsters, Geert

    This study investigates the role of intra-cluster ties, extra-cluster ties, and entrepreneurial orientation in shaping firms’ innovative performance. We conduct our analysis on a primary data set of 120 small and medium enterprises located in the Cibaduyut footwear-manufacturing cluster, Indonesia.

  11. A study on the dynamic tie points ASI algorithm in the Arctic Ocean

    Institute of Scientific and Technical Information of China (English)

    HAO Guanghua; SU Jie

    2015-01-01

    Sea ice concentration is an important parameter for polar sea ice monitoring. Based on 89 GHz AMSR-E (Advanced Microwave Scanning Radiometer for Earth Observing System) data, a gridded high-resolution passive microwave sea ice concentration product can be obtained using the ASI (the Arctic Radiation And Turbulence Interaction Study (ARTIST) Sea Ice) retrieval algorithm. Instead of using fixed-point values, we developed ASI algorithm based on daily changed tie points, called as the dynamic tie point ASI algorithm in this study. Here the tie points are expressed as the brightness temperature polarization difference of open water and 100% sea ice. In 2010, the yearly-averaged tie points of open water and sea ice in Arctic are estimated to be 50.8 K and 7.8 K, respectively. It is confirmed that the sea ice concentrations retrieved by the dynamic tie point ASI algorithm can increase (decrease) the sea ice concentrations in low-value (high-value) areas. This improved the sea ice concentrations by present retrieval algorithm from microwave data to some extent. Comparing with the products using fixed tie points, the sea ice concentrations retrieved from AMSR-E data by using the dynamic tie point ASI algorithm are closer to those obtained from MODIS (Moderate-resolution Imaging Spectroradiometer) data. In 40 selected cloud-free sample regions, 95% of our results have smaller mean differences and 75% of our results have lower root mean square (RMS) differences compare with those by the fixed tie points.

  12. The emotional responses of browsing Facebook: Happiness, envy, and the role of tie strength

    Science.gov (United States)

    Lin, Ruoyun; Utz, Sonja

    2015-01-01

    On Facebook, users are exposed to posts from both strong and weak ties. Even though several studies have examined the emotional consequences of using Facebook, less attention has been paid to the role of tie strength. This paper aims to explore the emotional outcomes of reading a post on Facebook and examine the role of tie strength in predicting happiness and envy. Two studies – one correlational, based on a sample of 207 American participants and the other experimental, based on a sample of 194 German participants – were conducted in 2014. In Study 2, envy was further distinguished into benign and malicious envy. Based on a multi-method approach, the results showed that positive emotions are more prevalent than negative emotions while browsing Facebook. Moreover, tie strength is positively associated with the feeling of happiness and benign envy, whereas malicious envy is independent of tie strength after reading a (positive) post on Facebook. PMID:26877584

  13. The emotional responses of browsing Facebook: Happiness, envy, and the role of tie strength.

    Science.gov (United States)

    Lin, Ruoyun; Utz, Sonja

    2015-11-01

    On Facebook, users are exposed to posts from both strong and weak ties. Even though several studies have examined the emotional consequences of using Facebook, less attention has been paid to the role of tie strength. This paper aims to explore the emotional outcomes of reading a post on Facebook and examine the role of tie strength in predicting happiness and envy. Two studies - one correlational, based on a sample of 207 American participants and the other experimental, based on a sample of 194 German participants - were conducted in 2014. In Study 2, envy was further distinguished into benign and malicious envy. Based on a multi-method approach, the results showed that positive emotions are more prevalent than negative emotions while browsing Facebook. Moreover, tie strength is positively associated with the feeling of happiness and benign envy, whereas malicious envy is independent of tie strength after reading a (positive) post on Facebook.

  14. The Role of Reciprocity and Directionality of Friendship Ties in Promoting Behavioral Change

    CERN Document Server

    Almaatouq, Abdullah; Pentland, Alex; Shmueli, Erez

    2016-01-01

    Friendship is a fundamental characteristic of human beings and usually assumed to be reciprocal in nature. Despite this common expectation, in reality, not all friendships by default are reciprocal nor created equal. Here, we show that reciprocated friendships are more intimate and they are substantially different from those that are not. We examine the role of reciprocal ties in inducing more effective peer pressure in a cooperative arrangements setting and find that the directionality of friendship ties can significantly limit the ability to persuade others to act. Specifically, we observe a higher behavioral change and more effective peer-influence when subjects shared reciprocal ties with their peers compared to sharing unilateral ones. Moreover, through spreading process simulation, we find that although unilateral ties diffuse behaviors across communities, reciprocal ties play more important role at the early stages of the diffusion process.

  15. Break the Ties for NEH Heuristic in Solving the Permutation Flow Shop Problems

    Institute of Scientific and Technical Information of China (English)

    GAO Shou-wei; LEISTEN Rainer; DAI Yang; ZHANG Wei-dong

    2008-01-01

    This study deals with the Permutation Flow Shop Scheduling Problem (PFSP) based on the maximum completion time (makespan). NEH (the algorithm of Nawaz, Enscore and Ham) is the concluded most efficient constructive method in solving this NP-hard problem. The principal features of its strengths are the initial arrangement of jobs and the job insertion phase. In some instances, ties will occur in both the initial permutation and the partial sequences. The problem of ties breaking may have a significant impact on the NEH performance, but evaluate all the ties will be non-polynomial in the worst case. Several kinds of methods are presented in the paper to break the ties in a quick time. Together with the basic one, all 22 methods are tested on the famous Taillard's benchmarks and the most suitable ties breaking policy is recommended.

  16. Goal specific social capital and job satisfaction Effects of different types of networks on instrumental and social aspects of work

    NARCIS (Netherlands)

    Flap, Henk; Völker, Beate

    2001-01-01

    This paper addresses the question “To what extent can job satisfaction be explained as the revenue of social capital?” By conceiving someone’s social network as social capital we specify conditions under which social ties do lead to job satisfaction. We inquire into the idea of goal specificity of s

  17. Goal specific social capital and job satisfaction Effects of different types of networks on instrumental and social aspects of work

    NARCIS (Netherlands)

    Flap, Henk; Völker, Beate

    2001-01-01

    This paper addresses the question “To what extent can job satisfaction be explained as the revenue of social capital?” By conceiving someone’s social network as social capital we specify conditions under which social ties do lead to job satisfaction. We inquire into the idea of goal specificity of

  18. The Strength of Friendship Ties in Proximity Sensor Data

    DEFF Research Database (Denmark)

    Sekara, Vedran; Jørgensen, Sune Lehmann

    2014-01-01

    such electronic datasets may serve as a valid proxy for real life social interactions. For an observational dataset, gathered using mobile phones, we analyze the problem of identifying transient and non-important links, as well as how to highlight important social interactions. Applying the Bluetooth signal...

  19. Ties that bind: revisiting context, identity, and attitudes

    Directory of Open Access Journals (Sweden)

    James S. Krueger

    2015-07-01

    Full Text Available The article focuses on group-based features of issue publics and advances the concept of residual group saliency as a way to organize members of issue publics. We accord veterans exemplar or prototype status, and civilians as periphery members of this issue public. As issue public exemplars, veterans anchor the “right” attitudes and behaviors for the veteran issue public, and civilians, especially those with family ties to veterans, gravitate toward those exemplar attitudes. We argue that pressure to conform to these “right” attitudes among civilians who are connected to a veteran is greater when there are more veterans in their environment. However, veterans and civilians who are not connected to a veteran are not responsive to such contextual effects, the former because they are already exemplars, and the latter because there is no motivation to evaluate the self in relation to veterans. We test and find support for these claims using data from the 2010 Cooperative Congressional Election Study. We conclude with an evaluative discussion and suggestions for future research.

  20. Tying dark matter to baryons with self-interactions.

    Science.gov (United States)

    Kaplinghat, Manoj; Keeley, Ryan E; Linden, Tim; Yu, Hai-Bo

    2014-07-11

    Self-interacting dark matter (SIDM) models have been proposed to solve the small-scale issues with the collisionless cold dark matter paradigm. We derive equilibrium solutions in these SIDM models for the dark matter halo density profile including the gravitational potential of both baryons and dark matter. Self-interactions drive dark matter to be isothermal and this ties the core sizes and shapes of dark matter halos to the spatial distribution of the stars, a radical departure from previous expectations and from cold dark matter predictions. Compared to predictions of SIDM-only simulations, the core sizes are smaller and the core densities are higher, with the largest effects in baryon-dominated galaxies. As an example, we find a core size around 0.3 kpc for dark matter in the Milky Way, more than an order of magnitude smaller than the core size from SIDM-only simulations, which has important implications for indirect searches of SIDM candidates.

  1. Design of Compact Trapezoidal Bow-Tie Chipless RFID Tag

    Directory of Open Access Journals (Sweden)

    Lei Xu

    2015-01-01

    Full Text Available This paper presents a novel compact design of a low cost fully printable slot-loaded bowtie chipless RFID tag. The tag consists of two trapezoidal metallic patches loaded with multiple slot resonators. Slots with similar size or adjacent frequencies are loaded alternately on two bow-tie patches to double the number of data bits within the UWB frequency band without increasing the mutual coupling between slots. A coding capacity of 12 bits is obtained with 12 slots within a reasonable size of 35 mm × 33 mm. RCS of the tag has been given by simulation. Measurements have been done using a bistatic radar configuration in the frequency domain and transmission coefficient is measured. The agreement between the simulation and measurement validates this new concept of design. This tag has high data capacity and low cost and can be directly printed on product such as personal ID, credit cards, paper, and textile because it needs only one conductive layer.

  2. 铁路铰接式拼装岔枕板的研制%DEVELOPMENT OF SPLICE FITTING-UP RAIL CROSS-TIE PLATE

    Institute of Scientific and Technical Information of China (English)

    熊学政; 樊嘉谦

    2001-01-01

    Splice joint of the splice fitting-up rail cross-tie plate improves the load bearing condition of the cross-tie plate and eliminate the negative bending moment of the tie plate and on the other hand, fitting up of the structure of a tie plate without bumping shoulder, which minimizes the weight of the individual plate is of great benefits to manufactureing , handling, transportation and construction. Compared to the rail tie plate currently used in China the new cross tie plate reduces the compressive stress on the rail bed and rail serface to some extent. The new tie plate with improved structare has achieved purpose of zero maintenance and reduced drastically the intensity of physical labour of the railway maintenance crew and saved consumption of the wood stuff, and thus has gained very good social benefits. Results demonstrate that the technology of originality at home and abroad has already attained the world advanced level of 1990s.%铁路铰接式拼装岔枕板,铰接连接改善了岔枕板的受力状况,消除了中部负弯矩;拼装无挡肩结构,减轻了单块岔枕板重量,有利于制造、装卸、运输和施工。岔枕板与目前国铁岔枕相比,减小了对道床与路基面的压应力。该结构稳定性好,达到了无维修、少维护的目的,大大减轻了养路工的体力劳动强度。节省木材资源,社会效益好。经查新,该技术为国内外首创,达到90年代国际先进水平。

  3. Investigating homology between proteins using energetic profiles.

    Directory of Open Access Journals (Sweden)

    James O Wrabl

    2010-03-01

    Full Text Available Accumulated experimental observations demonstrate that protein stability is often preserved upon conservative point mutation. In contrast, less is known about the effects of large sequence or structure changes on the stability of a particular fold. Almost completely unknown is the degree to which stability of different regions of a protein is generally preserved throughout evolution. In this work, these questions are addressed through thermodynamic analysis of a large representative sample of protein fold space based on remote, yet accepted, homology. More than 3,000 proteins were computationally analyzed using the structural-thermodynamic algorithm COREX/BEST. Estimated position-specific stability (i.e., local Gibbs free energy of folding and its component enthalpy and entropy were quantitatively compared between all proteins in the sample according to all-vs.-all pairwise structural alignment. It was discovered that the local stabilities of homologous pairs were significantly more correlated than those of non-homologous pairs, indicating that local stability was indeed generally conserved throughout evolution. However, the position-specific enthalpy and entropy underlying stability were less correlated, suggesting that the overall regional stability of a protein was more important than the thermodynamic mechanism utilized to achieve that stability. Finally, two different types of statistically exceptional evolutionary structure-thermodynamic relationships were noted. First, many homologous proteins contained regions of similar thermodynamics despite localized structure change, suggesting a thermodynamic mechanism enabling evolutionary fold change. Second, some homologous proteins with extremely similar structures nonetheless exhibited different local stabilities, a phenomenon previously observed experimentally in this laboratory. These two observations, in conjunction with the principal conclusion that homologous proteins generally conserved

  4. Can space ties on board GNSS satellites replace terrestrial ties in the implementation of Terrestrial Reference Frames?

    Science.gov (United States)

    Bruni, Sara; Zerbini, Susanna; Altamimi, Zuheir; Rebischung, Paul; Errico, Maddalena; Santi, Efisio

    2016-04-01

    SLR techniques via the so-called space ties, instead of relying on the terrestrial ties evaluated with ground measurement campaigns at co-located ITRF sites.

  5. Long-term evolution of techno-social networks: Statistical regularities, predictability and stability of social behaviors

    CERN Document Server

    Godoy-Lorite, Antonia; Sales-Pardo, Marta

    2016-01-01

    In social networks, individuals constantly drop ties and replace them by new ones in a highly unpredictable fashion. This highly dynamical nature of social ties has important implications for processes such as the spread of information or of epidemics. Several studies have demonstrated the influence of a number of factors on the intricate microscopic process of tie replacement, but the macroscopic long-term effects of such changes remain largely unexplored. Here we investigate whether, despite the inherent randomness at the microscopic level, there are macroscopic statistical regularities in the long-term evolution of social networks. In particular, we analyze the email network of a large organization with over 1,000 individuals throughout four consecutive years. We find that, although the evolution of individual ties is highly unpredictable, the macro-evolution of social communication networks follows well-defined statistical laws, characterized by exponentially decaying log-variations of the weight of socia...

  6. Welfare assessment of dairy cows housed in a tie-stall system

    Directory of Open Access Journals (Sweden)

    Marija Vučemilo

    2012-03-01

    Full Text Available Welfare assessment methods and techniques developed as a result of great interest of scientific and consumer populations regarding the welfare of animals housed in farms. In view of the fact that welfare by definition includes both physical and mental health, the welfare quality assessment includes an extensive number of measures. Welfare assessment was performed in two stables in which cows are kept in tie-stall by using the specific method described in the Welfare Quality® Assessment Protocol for Cattle. The measures included body condition score, qualitative behaviour assessment and body hygiene. The welfare assessment confirmed the importance of quality housing for ensuring better performance from animals, thus also affecting their health and productivity. It also pointed out the necessity of freeing animals by providing them with the possibility of free movement, whereat they can exhibit their physiological behaviour. It is definitely important to continue research, expand the number of researched measures in order to confirm the most useful indicators for welfare assessment and to identify the factors that within the animals’ physical and social environment affect the increase of their welfare.

  7. High strength-of-ties and low mobility enable the evolution of third-party punishment.

    Science.gov (United States)

    Roos, Patrick; Gelfand, Michele; Nau, Dana; Carr, Ryan

    2014-02-07

    As punishment can be essential to cooperation and norm maintenance but costly to the punisher, many evolutionary game-theoretic studies have explored how direct punishment can evolve in populations. Compared to direct punishment, in which an agent acts to punish another for an interaction in which both parties were involved, the evolution of third-party punishment (3PP) is even more puzzling, because the punishing agent itself was not involved in the original interaction. Despite significant empirical studies of 3PP, little is known about the conditions under which it can evolve. We find that punishment reputation is not, by itself, sufficient for the evolution of 3PP. Drawing on research streams in sociology and psychology, we implement a structured population model and show that high strength-of-ties and low mobility are critical for the evolution of responsible 3PP. Only in such settings of high social-structural constraint are punishers able to induce self-interested agents toward cooperation, making responsible 3PP ultimately beneficial to individuals as well as the collective. Our results illuminate the conditions under which 3PP is evolutionarily adaptive in populations. Responsible 3PP can evolve and induce cooperation in cases where other mechanisms alone fail to do so.

  8. On the hodological criterion for homology

    Directory of Open Access Journals (Sweden)

    Macarena eFaunes

    2015-06-01

    Full Text Available Owen’s pre-evolutionary definition of a homologue as the same organ in different animals under every variety of form and function and its redefinition after Darwin as the same trait in different lineages due to common ancestry entail the same heuristic problem: how to establish sameness. Although different criteria for homology often conflict, there is currently a generalized acceptance of gene expression as the best criterion. This gene-centered view of homology results from a reductionist and preformationist concept of living beings. Here, we adopt an alternative organismic-epigenetic viewpoint, and conceive living beings as systems whose identity is given by the dynamic interactions between their components at their multiple levels of composition. We posit that there cannot be an absolute homology criterion, and instead, homology should be inferred from comparisons at the levels and developmental stages where the delimitation of the compared trait lies. In this line, we argue that neural connectivity, i.e., the hodological criterion, should prevail in the determination of homologies between brain supra-cellular structures, such as the vertebrate pallium.

  9. Mobile communication and network privatism: A literature review of the implications for diverse, weak, and new ties

    Directory of Open Access Journals (Sweden)

    Scott W. Campbell

    2015-01-01

    Full Text Available Most of the research on the implications of mobile communication for social networks has focused on its uses and consequences in the intimate realm of close friends, family, and loved ones. A number of scholars have also become interested in ways that mobile communication helps and hinders the broader realm of network connectivity, including diverse, weak, and new ties. A collection of theoretical perspectives on mobile communication and diverse, weak, and new ties proposes that heightened connectivity in the intimate realm can come at the expense of being engaged more broadly – a scenario I characterize as network privatism. At the same time, the available empirical research in the literature tends to tell a different story, or rather stories. This analysis brings theory and empirical findings into closer conversation with one another by reviewing and synthesizing the literature in this area. Observed patterns in the literature offer new insight into questions of mobile communication and network privatism, while also pointing to opportunities for refinement of theory, analysis, and measurement as this line of inquiry further develops.

  10. Les maisons bâties au village d’origine dans les représentations des migrants roumains

    Directory of Open Access Journals (Sweden)

    Andra Larionescu

    2013-06-01

    Full Text Available Les maisons des migrants bâties dans le pays d’origine revêtent de significations différentes: certains migrants les perçoivent comme un moyen de valider leur statut social au sein de la communauté d’origine, tandis que d’autres les conçoivent comme un investissement ou comme une « sécurité » à la retraite, ou bien comme un abri en cas d’échec. Néanmoins, pour la majorité des migrants, la maison reste un « chez soi» lié soit au pays d’origine, soit au pays de destination, le sentiment d’appartenance étant déterminé par l’âge du sujet, le gendre, le niveau d’éducation, les liens familiaux, l’expérience de la migration et les caractéristiques du marché du travail. En utilisant un travail de terrain mené entre 2009 et 2011 dans le village de Marginea, au nord de la Roumanie, l’article examine les facteurs qui influent sur la sémantique de la maison bâtie au village d’origine.

  11. Hyper(co)homology for exact left covariant functors and a homology theory for topological spaces

    Science.gov (United States)

    Sklyarenko, E. G.

    1995-06-01

    Contents Introduction §1. Strong cohomology of dual complexes §2. Hyperhomology §3. Examples §4. Typical limit relations for Steenrod-Sitnikov homology §5. The strong homology of topological spaces §6. On the special position held by singular theory Bibliography

  12. On the Role of Social Identity and Cohesion in Characterizing Online Social Communities

    OpenAIRE

    Purohit, Hemant; Ruan, Yiye; Fuhry, David; Parthasarathy, Srinivasan; Sheth, Amit

    2012-01-01

    Two prevailing theories for explaining social group or community structure are cohesion and identity. The social cohesion approach posits that social groups arise out of an aggregation of individuals that have mutual interpersonal attraction as they share common characteristics. These characteristics can range from common interests to kinship ties and from social values to ethnic backgrounds. In contrast, the social identity approach posits that an individual is likely to join a group based o...

  13. Between-group behaviour in health care: gaps, edges, boundaries, disconnections, weak ties, spaces and holes. A systematic review

    Directory of Open Access Journals (Sweden)

    Braithwaite Jeffrey

    2010-12-01

    Full Text Available Abstract Background Gaps are typically regarded as a problem to be solved. People are stimulated to close or plug them. Researchers are moved to fill deficits in the literature in order to realise a more complete knowledge base, health authorities want to bridge policy-practice disconnections, managers to secure resources to remedy shortfalls between poor and idealised care, and clinicians to provide services to patients across the divides of organisational silos. Despite practical and policy work in many health systems to bridge gaps, it is valuable to study research examining them for the insights provided. Structural holes, spaces between social clusters and weak or absent ties represent fissures in networks, located in less densely populated parts of otherwise closely connected social structures. Such gaps are useful as they illustrate how communication potentially breaks down or interactivity fails. This paper discusses empirical and theoretical work on this phenomenon with the aim of analysing a specific exemplar, the structures of silos within health care organisations. Methods The research literature on social spaces, holes, gaps, boundaries and edges was searched systematically, and separated into health [n = 13] and non-health [n = 55] samples. The health literature was reviewed and synthesised in order to understand the circumstances between stakeholders and stakeholder groups that both provide threats to networked interactions and opportunities to strengthen the fabric of organisational and institutional inter-relationships. Results The research examples illuminate various network structure characteristics and group interactions. They explicate a range of opportunities for improved social and professional relations that understanding structural holes, social spaces and absent ties affords. A principal finding is that these kinds of gaps illustrate the conditions under which connections are strained or have been severed, where the

  14. Between-group behaviour in health care: gaps, edges, boundaries, disconnections, weak ties, spaces and holes. A systematic review.

    Science.gov (United States)

    Braithwaite, Jeffrey

    2010-12-07

    Gaps are typically regarded as a problem to be solved. People are stimulated to close or plug them. Researchers are moved to fill deficits in the literature in order to realise a more complete knowledge base, health authorities want to bridge policy-practice disconnections, managers to secure resources to remedy shortfalls between poor and idealised care, and clinicians to provide services to patients across the divides of organisational silos.Despite practical and policy work in many health systems to bridge gaps, it is valuable to study research examining them for the insights provided. Structural holes, spaces between social clusters and weak or absent ties represent fissures in networks, located in less densely populated parts of otherwise closely connected social structures. Such gaps are useful as they illustrate how communication potentially breaks down or interactivity fails. This paper discusses empirical and theoretical work on this phenomenon with the aim of analysing a specific exemplar, the structures of silos within health care organisations. The research literature on social spaces, holes, gaps, boundaries and edges was searched systematically, and separated into health [n = 13] and non-health [n = 55] samples. The health literature was reviewed and synthesised in order to understand the circumstances between stakeholders and stakeholder groups that both provide threats to networked interactions and opportunities to strengthen the fabric of organisational and institutional inter-relationships. The research examples illuminate various network structure characteristics and group interactions. They explicate a range of opportunities for improved social and professional relations that understanding structural holes, social spaces and absent ties affords. A principal finding is that these kinds of gaps illustrate the conditions under which connections are strained or have been severed, where the limits of integration between groups occurs, the

  15. Social networking technology, social network composition, and reductions in substance use among homeless adolescents.

    Science.gov (United States)

    Rice, Eric; Milburn, Norweeta G; Monro, William

    2011-03-01

    Peer-based prevention programs for homeless youth are complicated by the potential for reinforcing high-risk behaviors among participants. The goal of this study is to understand how homeless youth could be linked to positive peers in prevention programming by understanding where in social and physical space positive peers for homeless youth are located, how these ties are associated with substance use, and the role of social networking technologies (e.g., internet and cell phones) in this process. Personal social network data were collected from 136 homeless adolescents in Los Angeles, CA. Respondents reported on composition of their social networks with respect to: home-based peers and parents (accessed via social networking technology; e.g., the internet, cell phone, texting), homeless peers and agency staff (accessed face-to-face) and whether or not network members were substance-using or non-substance-using. Associations between respondent's lifetime cocaine, heroin, and methamphetamine use and recent (previous 30 days) alcohol and marijuana use were assessed by the number of non-substance-using versus substance-using ties in multivariate linear regression models. 43% of adolescents reported a non-substance-using home-based tie. More of these ties were associated with less recent alcohol use. 62% of adolescents reported a substance-using homeless tie. More of these ties were associated with more recent marijuana use as well as more lifetime heroin and methamphetamine use. For homeless youth, who are physically disconnected from positive peers, social networking technologies can be used to facilitate the sorts of positive social ties that effective peer-based prevention programs require.

  16. Borel-Moore homology and cap product operations

    OpenAIRE

    Hanamura, Masaki

    2016-01-01

    We show that, for a simplicial complex, the supported cap product operation on Borel-Moore homology coincides with the supported cap product on simplicial homology. For this purpose we introduce the supported cap product for locally finite singular homology, and compare the cap product on the three homology theories.

  17. [DNA homologous recombination repair in mammalian cells].

    Science.gov (United States)

    Popławski, Tomasz; Błasiak, Janusz

    2006-01-01

    DNA double-strand breaks (DSBs) are the most serious DNA damage. Due to a great variety of factors causing DSBs, the efficacy of their repair is crucial for the cell's functioning and prevents DNA fragmentation, chromosomal translocation and deletion. In mammalian cells DSBs can be repaired by non-homologous end joining (NHEJ), homologous recombination (HRR) and single strand annealing (SSA). HRR can be divided into the first and second phase. The first phase is initiated by sensor proteins belonging to the MRN complex, that activate the ATM protein which target HRR proteins to obtain the second response phase--repair. HRR is precise because it utilizes a non-damaged homologous DNA fragment as a template. The key players of HRR in mammalian cells are MRN, RPA, Rad51 and its paralogs, Rad52 and Rad54.

  18. INVHOGEN: a database of homologous invertebrate genes.

    Science.gov (United States)

    Paulsen, Ingo; von Haeseler, Arndt

    2006-01-01

    Classification of proteins into families of homologous sequences constitutes the basis of functional analysis or of evolutionary studies. Here we present INVertebrate HOmologous GENes (INVHOGEN), a database combining the available invertebrate protein genes from UniProt (consisting of Swiss-Prot and TrEMBL) into gene families. For each family INVHOGEN provides a multiple protein alignment, a maximum likelihood based phylogenetic tree and taxonomic information about the sequences. It is possible to download the corresponding GenBank flatfiles, the alignment and the tree in Newick format. Sequences and related information have been structured in an ACNUC database under a client/server architecture. Thus, complex selections can be performed. An external graphical tool (FamFetch) allows access to the data to evaluate homology relationships between genes and distinguish orthologous from paralogous sequences. Thus, INVHOGEN complements the well-known HOVERGEN database. The databank is available at http://www.bi.uni-duesseldorf.de/~invhogen/invhogen.html.

  19. Homologous recombination in plants: an antireview.

    Science.gov (United States)

    Lieberman-Lazarovich, Michal; Levy, Avraham A

    2011-01-01

    Homologous recombination (HR) is a central cellular process involved in many aspects of genome maintenance such as DNA repair, replication, telomere maintenance, and meiotic chromosomal segregation. HR is highly conserved among eukaryotes, contributing to genome stability as well as to the generation of genetic diversity. It has been intensively studied, for almost a century, in plants and in other organisms. In this antireview, rather than reviewing existing knowledge, we wish to underline the many open questions in plant HR. We will discuss the following issues: how do we define homology and how the degree of homology affects HR? Are there any plant-specific HR qualities, how extensive is functional conservation and did HR proteins acquire new functions? How efficient is HR in plants and what are the cis and the trans factors that regulate it? Finally, we will give the prospects for enhancing the rates of gene targeting and meiotic HR for plant breeding purposes.

  20. Global TIE: Developing a Virtual Network of Robotic Observatories for K-12 Education

    Science.gov (United States)

    Mayo, L. A.; Clark, G.

    2001-11-01

    Astronomy in grades K-12 is traditionally taught (if at all) using textbooks and a few simple hands-on activities. In addition, most students, by High School graduation, will never have even looked through the eyepiece of a telescope. The possibility now exists to establish a network of research grade telescopes, no longer useful to the professional astronomical community, that can be made accessible to schools all across the country through existing IT technologies and applications. These telescopes could provide unparalleled research and educational opportunities for a broad spectrum of K-12 and college students and turns underutilized observatory facilities into valuable, state-of-the-art teaching centers. The NASA-sponsored Telescopes In Education (TIE, http://tie.jpl.nasa.gov) project has been wildly successful in engaging the K-12 education community in real-time, hands-on, interactive astronomy activities. Hundreds of schools in the US, Australia, Canada, England, and Japan have participated in the TIE program, remotely controlling the 24-inch telescope at the Mount Wilson Observatory from their classrooms. In recent years, several (approximately 20 to date) other telescopes have been, or are in the process of being, outfitted for remote use as TIE affiliates. Global TIE integrates these telescopes seamlessly into one virtual observatory and provides the services required to operate this facility, including a scheduling service, tools for data manipulation, an online proposal review environment, an online "Virtual TIE Student Ap J" for publication of results, and access to related educational materials provided by the TIE community. Global TIE provides unparalleled research and educational opportunities for a broad spectrum of K-12 and college students and turns essentially unused observatory facilities into valuable, state-of-the-art teaching centers. This presentation describes the Global TIE Observatory data and organizational systems and details the

  1. Recovery From Radiation-induced Bone Marrow Damage by HSP25 Through Tie2 Signaling

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hae-June [Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kwon, Hee-Chung [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Chung, Hee-Yong [College of Medicine, Hanyang University, Seoul (Korea, Republic of); Lee, Yoon-Jin [Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Lee, Yun-Sil, E-mail: yslee0425@ewha.ac.kr [College of Pharmacy and Division of Life and Pharmaceutical Sciences, Ewha Woman' s University, Seoul (Korea, Republic of)

    2012-09-01

    Purpose: Whole-body radiation therapy can cause severe injury to the hematopoietic system, and therefore it is necessary to identify a novel strategy for overcoming this injury. Methods and Materials: Mice were irradiated with 4.5 Gy after heat shock protein 25 (HSP25) gene transfer using an adenoviral vector. Then, peripheral blood cell counts, histopathological analysis, and Western blotting on bone marrow (BM) cells were performed. The interaction of HSP25 with Tie2 was investigated with mouse OP9 and human BM-derived mesenchymal stem cells to determine the mechanism of HSP25 in the hematopoietic system. Results: HSP25 transfer increased BM regeneration and reduced apoptosis following whole-body exposure to ionizing radiation (IR). The decrease in Tie2 protein expression that followed irradiation of the BM was blocked by HSP25 transfer, and Tie2-positive cells were more abundant among the BM cells of HSP25-transferred mice, even after IR exposure. Following systemic RNA interference of Tie2 before IR, HSP25-mediated radioprotective effects were partially blocked in both mice and cell line systems. Stability of Tie2 was increased by HSP25, a response mediated by the interaction of HSP25 with Tie2. IR-induced tyrosine phosphorylation of Tie2 was augmented by HSP25 overexpression; downstream events in the Tie2 signaling pathway, including phosphorylation of AKT and EKR1/2, were also activated. Conclusions: HSP25 protects against radiation-induced BM damage by interacting with and stabilizing Tie2. This may be a novel strategy for HSP25-mediated radioprotection in BM.

  2. Crystal structure of an archaeal actin homolog.

    Science.gov (United States)

    Roeben, Annette; Kofler, Christine; Nagy, István; Nickell, Stephan; Hartl, F Ulrich; Bracher, Andreas

    2006-04-21

    Prokaryotic homologs of the eukaryotic structural protein actin, such as MreB and ParM, have been implicated in determination of bacterial cell shape, and in the segregation of genomic and plasmid DNA. In contrast to these bacterial actin homologs, little is known about the archaeal counterparts. As a first step, we expressed a predicted actin homolog of the thermophilic archaeon Thermoplasma acidophilum, Ta0583, and determined its crystal structure at 2.1A resolution. Ta0583 is expressed as a soluble protein in T.acidophilum and is an active ATPase at physiological temperature. In vitro, Ta0583 forms sheets with spacings resembling the crystal lattice, indicating an inherent propensity to form filamentous structures. The fold of Ta0583 contains the core structure of actin and clearly belongs to the actin/Hsp70 superfamily of ATPases. Ta0583 is approximately equidistant from actin and MreB on the structural level, and combines features from both eubacterial actin homologs, MreB and ParM. The structure of Ta0583 co-crystallized with ADP indicates that the nucleotide binds at the interface between the subdomains of Ta0583 in a manner similar to that of actin. However, the conformation of the nucleotide observed in complex with Ta0583 clearly differs from that in complex with actin, but closely resembles the conformation of ParM-bound nucleotide. On the basis of sequence and structural homology, we suggest that Ta0583 derives from a ParM-like actin homolog that was once encoded by a plasmid and was transferred into a common ancestor of Thermoplasma and Ferroplasma. Intriguingly, both genera are characterized by the lack of a cell wall, and therefore Ta0583 could have a function in cellular organization.

  3. Square and bow-tie configurations in the cyclic evasion problem

    Science.gov (United States)

    Arnold, M. D.; Golich, M.; Grim, A.; Vargas, L.; Zharnitsky, V.

    2017-05-01

    Cyclic evasion of four agents on the plane is considered. There are two stationary shapes of configurations: square and degenerate bow-tie. The bow-tie is asymptotically attracting while the square is of focus-center type. Normal form analysis shows that square is nonlinearly unstable. The stable manifold consists of parallelograms that all converge to the square configuration. Based on these observations and numerical simulations, it is conjectured that any non-parallelogram non-degenerate configuration converges to the bow-tie.

  4. Hanging Together, Together Hung? Career Implications of Interpersonal Ties Between CEOs and Top Managers

    Directory of Open Access Journals (Sweden)

    Stefan Hilger

    2013-05-01

    Full Text Available Is it good or bad for senior executives to have strong interpersonal ties to the CEO? We argue that a strong relationship with the CEO raises the likelihood that a top manager stays in office or makes an upward career move when the CEO leaves office voluntarily. At the same time, such interpersonal ties also reinforce the negative spillover effects of a dismissal of the CEO on the career prospects of the manager concerned. Our empirical analysis lends support to both arguments. We contribute to managerial succession research by underlining the ambivalence of interpersonal ties within top management teams.

  5. Escapist Motives for On-line Gaming and Strengthening of Weak Ties

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana

    Due to advances of technology including faster and ubiquitously accessible Internet connection, on-line gaming have grown tremendously in the last couple of years. The aim of this paper is to investigate whether escapist motives for playing games are linked to strengthening of weak ties through on......-line gaming. The research investigates Facebook and other on-line games separately. A surprising result is that while most of the investigated escapist motives are positively correlated with strengthening of weak ties, the mundane breaking motive is negatively correlated with strengthening of weak ties....

  6. Homological Algebra of Semimodules and Semicontramodules

    CERN Document Server

    Positselski, Leonid

    2010-01-01

    This is a monograph in semi-infinite homological algebra, concentrated mostly on the semi-infinite theory of associative algebraic structures, but including also some material on the semi-infinite homology and cohomology of Lie algebras and topological groups. The main objects of study are the double-sided derived functors SemiExt and SemiTor, and the phenomenon of comodule-contramodule correspondence, connecting them with the more conventional, one-sided Ext and CtrTor. Contramodules, introduced originally by Eilenberg and Moore in 1960's but almost forgotten for four decades, play a very pro

  7. Relative Derived Equivalences and Relative Homological Dimensions

    Institute of Scientific and Technical Information of China (English)

    Sheng Yong PAN

    2016-01-01

    Let A be a small abelian category. For a closed subbifunctor F of Ext1A (−,−), Buan has generalized the construction of Verdier’s quotient category to get a relative derived category, where he localized with respect to F-acyclic complexes. In this paper, the homological properties of relative derived categories are discussed, and the relation with derived categories is given. For Artin algebras, using relative derived categories, we give a relative version on derived equivalences induced by F-tilting complexes. We discuss the relationships between relative homological dimensions and relative derived equivalences.

  8. Homological and homotopical Dehn functions are different

    CERN Document Server

    Abrams, Aaron; Dani, Pallavi; Young, Robert

    2012-01-01

    The homological and homotopical Dehn functions are different ways of measuring the difficulty of filling a closed curve inside a group or a space. The homological Dehn function measures fillings of cycles by chains, while the homotopical Dehn function measures fillings of curves by disks. Since the two definitions involve different sorts of boundaries and fillings, there is no a priori relationship between the two functions, but prior to this work there were no known examples of finitely-presented groups for which the two functions differ. This paper gives the first such examples, constructed by amalgamating a free-by-cyclic group with several Bestvina-Brady groups.

  9. New mesogenic homologous series of -methylcinnamates

    Indian Academy of Sciences (India)

    R A Vora; A K Prajapati

    2001-04-01

    Compounds of a new smectogenic homologous series of -methylcinnamates were prepared by condensing different 4--alkoxybenzoyl chloride with methoxyethyl trans-4-hydroxy- -methylcinnamate. In this series, the first six members are non-mesogenic. -Heptyloxy derivative exhibits monotropic smectic A phase whereas rest of the members exhibit enantiotropic smectic A mesophase. The compounds are characterized by combination of elemental analysis and spectroscopic techniques. Enthalpies of few homologues are measured by DSC techniques. Fluorescent properties are also observed. The thermal stabilities of the present series are compared with those of other structurally related mesogenic homologous series.

  10. Homology and cohomology of Rees semigroup algebras

    DEFF Research Database (Denmark)

    Grønbæk, Niels; Gourdeau, Frédéric; White, Michael C.

    2011-01-01

    Let S by a Rees semigroup, and let 1¹(S) be its convolution semigroup algebra. Using Morita equivalence we show that bounded Hochschild homology and cohomology of l¹(S) is isomorphic to those of the underlying discrete group algebra.......Let S by a Rees semigroup, and let 1¹(S) be its convolution semigroup algebra. Using Morita equivalence we show that bounded Hochschild homology and cohomology of l¹(S) is isomorphic to those of the underlying discrete group algebra....

  11. Social Consciousness, Education and Transformative Activity

    Science.gov (United States)

    Pavlidis, Periklis

    2015-01-01

    This paper examines two aspects of social consciousness: consciousness in the sense of knowledge of the objective reality and consciousness in the sense of awareness of oneself as a subject in his/her social ties with other persons-subjects. In the light of such an approach to consciousness in this essay we discuss the importance of education and…

  12. 78 FR 57619 - Prestressed Concrete Steel Rail Tie Wire From Mexico, Thailand, and the People's Republic of...

    Science.gov (United States)

    2013-09-19

    ... International Trade Administration Prestressed Concrete Steel Rail Tie Wire From Mexico, Thailand, and the... antidumping duty investigations of imports of prestressed concrete steel rail tie wire from Mexico, Thailand, and the People's Republic of China. See Prestressed Concrete Steel Rail Tie Wire From Mexico,...

  13. Seiberg-Witten-Floer Theory for Homology 3-Spheres

    CERN Document Server

    Wang, B L

    1996-01-01

    We give the definition of the Seiberg-Witten-Floer homology group for a homology 3-sphere. Its Euler characteristic number is a Casson-type invariant. For a four-manifold with boundary a homology sphere, a relative Seiberg-Witten invariant is defined taking values in the Seiberg-Witten-Floer homology group, these relative Seiberg-Witten invariants are applied to certain homology spheres bounding Stein surfaces.

  14. Homological Perturbation Theory and Mirror Symmetry

    Institute of Scientific and Technical Information of China (English)

    Jian ZHOU

    2003-01-01

    We explain how deformation theories of geometric objects such as complex structures,Poisson structures and holomorphic bundle structures lead to differential Gerstenhaber or Poisson al-gebras. We use homological perturbation theory to construct A∞ algebra structures on the cohomology,and their canonically defined deformations. Such constructions are used to formulate a version of A∞algebraic mirror symmetry.

  15. Homological stability for unordered configuration spaces

    DEFF Research Database (Denmark)

    Randal-Williams, Oscar

    2013-01-01

    This paper consists of two related parts. In the first part we give a self-contained proof of homological stability for the spaces C_n(M;X) of configurations of n unordered points in a connected open manifold M with labels in a path-connected space X, with the best possible integral stability range...... of 2* \\leq n. Along the way we give a new proof of the high connectivity of the complex of injective words. If the manifold has dimension at least three, we show that in rational homology the stability range may be improved to * \\leq n. In the second part we study to what extent the homology...... of the spaces C_n(M) can be considered stable when M is a closed manifold. In this case there are no stabilisation maps, but one may still ask if the dimensions of the homology groups over some field stabilise with n. We prove that this is true when M is odd-dimensional, or when the field is F_2 or Q...

  16. Khovanov homology for virtual tangles and applications

    DEFF Research Database (Denmark)

    Tubbenhauer, Daniel

    We extend the cobordism based categorification of the virtual Jones polynomial to virtual tangles. This extension is combinatorial and has semi-local properties. We use the semi-local property to prove an applications, i.e. we give a discussion of Lee's degeneration of virtual homology....

  17. Persistent homology in graph power filtrations.

    Science.gov (United States)

    Parks, Allen D; Marchette, David J

    2016-10-01

    The persistence of homological features in simplicial complex representations of big datasets in R (n) resulting from Vietoris-Rips or Čech filtrations is commonly used to probe the topological structure of such datasets. In this paper, the notion of homological persistence in simplicial complexes obtained from power filtrations of graphs is introduced. Specifically, the rth complex, r ≥ 1, in such a power filtration is the clique complex of the rth power G(r) of a simple graph G. Because the graph distance in G is the relevant proximity parameter, unlike a Euclidean filtration of a dataset where regional scale differences can be an issue, persistence in power filtrations provides a scale-free insight into the topology of G. It is shown that for a power filtration of G, the girth of G defines an r range over which the homology of the complexes in the filtration are guaranteed to persist in all dimensions. The role of chordal graphs as trivial homology delimiters in power filtrations is also discussed and the related notions of 'persistent triviality', 'transient noise' and 'persistent periodicity' in power filtrations are introduced.

  18. Homology stability for the general linear group

    NARCIS (Netherlands)

    Maazen, Hendrik

    1979-01-01

    This thesis studies the homology stability problem for general linear groups over Euclidean rings and over subrings of the field of rational numbers. Affine linear groups, acting on affine space rather than linear space, are also considered. In order to get stability results one establishes that cer

  19. Regulation of Homologous Recombination by SUMOylation

    DEFF Research Database (Denmark)

    Pinela da Silva, Sonia Cristina

    factors such as the homologous recombination (HR) machinery. HR constitutes the main DSB repair pathway in Saccharomyces cerevisiae and despite being largely considered an error-free process and essential for genome stability, uncontrolled recombination can lead to loss of heterozygosity, translocations...

  20. Cell biology of homologous recombination in yeast

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine Valerie; Rothstein, Rodney; Lisby, Michael

    2011-01-01

    Homologous recombination is an important pathway for error-free repair of DNA lesions, such as single- and double-strand breaks, and for rescue of collapsed replication forks. Here, we describe protocols for live cell imaging of single-lesion recombination events in the yeast Saccharomyces...

  1. Threading homology through algebra selected patterns

    CERN Document Server

    Boffi, Giandomenico

    2006-01-01

    Aimed at graduate students and researchers in mathematics, this book takes homological themes, such as Koszul complexes and their generalizations, and shows how these can be used to clarify certain problems in selected parts of algebra, as well as their success in solving a number of them.

  2. Gorenstein Homological Dimensions and Change of Rings

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan YANG

    2012-01-01

    In this paper,we shall be concerned with what happens of Gorenstein homological dimensions when certain modifications are made to a ring. The five structural operations addressed later are the formation of excellent extensions,localizations,Morita equivalences,polynomial extensions and power series extensions.

  3. Homological stability for unordered configuration spaces

    DEFF Research Database (Denmark)

    Randal-Williams, Oscar

    2013-01-01

    This paper consists of two related parts. In the first part we give a self-contained proof of homological stability for the spaces C_n(M;X) of configurations of n unordered points in a connected open manifold M with labels in a path-connected space X, with the best possible integral stability range...

  4. Persistent Homology for Random Fields and Complexes

    CERN Document Server

    Adler, Robert J; Borman, Matthew S; Subag, Eliran; Weinberger, Shmuel

    2010-01-01

    We discuss and review recent developments in the area of applied algebraic topology, such as persistent homology and barcodes. In particular, we discuss how these are related to understanding more about manifold learning from random point cloud data, the algebraic structure of simplicial complexes determined by random vertices, and, in most detail, the algebraic topology of the excursion sets of random fields.

  5. Homology stability for the general linear group

    NARCIS (Netherlands)

    Maazen, Hendrik

    1979-01-01

    This thesis studies the homology stability problem for general linear groups over Euclidean rings and over subrings of the field of rational numbers. Affine linear groups, acting on affine space rather than linear space, are also considered. In order to get stability results one establishes that

  6. Khovanov homology for virtual tangles and applications

    DEFF Research Database (Denmark)

    Tubbenhauer, Daniel

    We extend the cobordism based categorification of the virtual Jones polynomial to virtual tangles. This extension is combinatorial and has semi-local properties. We use the semi-local property to prove an applications, i.e. we give a discussion of Lee's degeneration of virtual homology....

  7. Life promises and 'failed' family ties: expectations and disappointment within a clinical trial (Ivory Coast).

    Science.gov (United States)

    Marcis, F Le

    2015-12-01

    Building on fieldwork carried out in a clinical trial looking at early antiretroviral treatment for HIV in Abidjan, this paper aims to analyse the way relations emerge during trials and the consequences of the end of participation. Instead of discussing it using the register of ethics, understood as a universal set of principles, the trial is analysed for what it means locally for its actors, mainly patients. From this standpoint, the trial can be defined as both a promise of life and of new possibilities embodied in what is often described as new family ties. How are such ties formed and what does it mean when these ties are broken at the end of patient participation? Discussing the failure of family ties commented upon by patients and dealt by physician researcher is a way to look at ethics from below.

  8. Fuzzy C-Means Clustering Based Phonetic Tied-Mixture HMM in Speech Recognition

    Institute of Scientific and Technical Information of China (English)

    XU Xiang-hua; ZHU Jie; GUO Qiang

    2005-01-01

    A fuzzy clustering analysis based phonetic tied-mixture HMM(FPTM) was presented to decrease parameter size and improve robustness of parameter training. FPTM was synthesized from state-tied HMMs by a modified fuzzy C-means clustering algorithm. Each Gaussian codebook of FPTM was built from Gaussian components within the same root node in phonetic decision tree. The experimental results on large vocabulary Mandarin speech recognition show that compared with conventional phonetic tied-mixture HMM and state-tied HMM with approximately the same number of Gaussian mixtures, FPTM achieves word error rate reductions by 4.84% and 13.02 % respectively. Combining the two schemes of mixing weights pruning and Gaussian centers fuzzy merging, a significantly parameter size reduction was achieved with little impact on recognition accuracy.

  9. Sugary, High-Fat Western Diet Tied to Denser Breast Tissue

    Science.gov (United States)

    ... High-Fat Western Diet Tied to Denser Breast Tissue Previous research has linked higher density to increased ... Western-style diet may develop more dense breast tissue, possibly increasing their risk for breast cancer, Spanish ...

  10. Bow-tie topological features of metabolic networks and the functional significance

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jing; TAO Lin; YU Hong; LUO JianHua; GAO ZhiWei; LI YiXue

    2007-01-01

    Exploring the structural topology of genome-based large-scale metabolic network is essential for in vestigating possible relations between structure and functionality. Visualization would be helpful for obtaining immediate information about structural organization. In this work, metabolic networks of 75 organisms were investigated from a topological point of view. A spread bow-tie model was proposed to give a clear visualization of the bow-tie structure for metabolic networks. The revealed topological pattern helps to design more efficient algorithm specifically for metabolic networks. This coarsegrained graph also visualizes the vulnerable connections in the network, and thus could have important implication for disease studies and drug target identifications. In addition, analysis on the reciprocal links and main cores in the GSC part of bow-tie also reveals that the bow-tie structure of metabolic networks has its own intrinsic and significant features which are significantly different from those of random networks.

  11. Poor Diet Tied to Half of U.S. Deaths from Heart Disease, Diabetes

    Science.gov (United States)

    ... Diet Tied to Half of U.S. Deaths From Heart Disease, Diabetes Study explores which foods and nutrients may ... HealthDay News) -- Nearly half of all deaths from heart disease, stroke and diabetes in the United States are ...

  12. One long tie bar broken after 3 days because of hydrogen contamination.

    CERN Multimedia

    H. Gerwig

    2000-01-01

    The tie bars have been produced with a high yield strength. As known for these type of high strength bolts, and hydrogen contamination during manufacture or heat treatment could lead to rupture under stress after several days.

  13. Comparison of Methods for Evaluating Nuclear Thermal Propulsion Tie-Tube Designs

    Science.gov (United States)

    Kapernick, Richard J.; Dixon, David D.

    2008-01-01

    One of the fundamental structural components in a nuclear thermal rocket design is the tie tube. Proper cooling and flow modeling is important both for the structural integrity of the reactor core and for proper design of downstream components that operate on the hydrogen exiting the tie tube. Two models have been developed. The first is a spreadsheet-based tool designed for sizing tie-tube components, considering mechanical stress and strain limits, deposited moderator power, thermal expansion along the flow path, and conduction from adjacent fuel blocks. The second is a three-dimensional SINDA/FLUINT model used as a benchmark, containing a complete finite-element fuel block and a 1/6th tie-tube model. This paper discusses the performance of both models, as well as the advantages and limitations of each.

  14. Obesity in Teen Years Tied to Colon Cancer Risk in Adulthood

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_167377.html Obesity in Teen Years Tied to Colon Cancer Risk ... 24, 2017 MONDAY, July 24, 2017 (HealthDay News) -- Obesity even in adolescence may raise the odds for ...

  15. The effects of emitter-tied field plates on lateral PNP ionizing radiation response

    Energy Technology Data Exchange (ETDEWEB)

    Barnaby, H.J.; Schrimpf, R.D.; Cirba, C.R. [Vanderbilt Univ., Nashville, TN (United States); Pease, R.L. [RLP Research, Inc., Albuquerque, NM (United States); Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States); Kosier, S.L. [VTC Inc., Bloomington, MN (United States)

    1998-03-01

    Radiation response comparisons of lateral PNP bipolar technologies reveal that device hardening may be achieved by extending the emitter contact over the active base. The emitter-tied field plate suppresses recombination of carriers with interface traps.

  16. BAYESIAN INFERENCE OF HIDDEN GAMMA WEAR PROCESS MODEL FOR SURVIVAL DATA WITH TIES.

    Science.gov (United States)

    Sinha, Arijit; Chi, Zhiyi; Chen, Ming-Hui

    2015-10-01

    Survival data often contain tied event times. Inference without careful treatment of the ties can lead to biased estimates. This paper develops the Bayesian analysis of a stochastic wear process model to fit survival data that might have a large number of ties. Under a general wear process model, we derive the likelihood of parameters. When the wear process is a Gamma process, the likelihood has a semi-closed form that allows posterior sampling to be carried out for the parameters, hence achieving model selection using Bayesian deviance information criterion. An innovative simulation algorithm via direct forward sampling and Gibbs sampling is developed to sample event times that may have ties in the presence of arbitrary covariates; this provides a tool to assess the precision of inference. An extensive simulation study is reported and a data set is used to further illustrate the proposed methodology.

  17. Sickle Cell Trait Tied to Higher Kidney Failure Risk for Blacks

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_164005.html Sickle Cell Trait Tied to Higher Kidney Failure Risk for ... HealthDay News) -- Black people with a trait for sickle cell anemia appear to have double the risk of ...

  18. Obesity in Youth Tied to Higher Odds for Liver Cancer in Men

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_164210.html Obesity in Youth Tied to Higher Odds for Liver ... risk, a new study warns. Efforts to reduce obesity, "should be implemented from an early age to ...

  19. Fiber Optic Tamper Indicating Enclosure (TIE); A Case Study in Authentication

    Energy Technology Data Exchange (ETDEWEB)

    Anheier, Norman C.; Benz, Jacob M.; Tanner, Jennifer E.; Westman, Matthew P.

    2015-07-15

    A robust fiber optic-based tamper-indicating enclosure (TIE) has been developed by PNNL through funding by the National Nuclear Security Administration Office of Nuclear Verification over the past few years. The objective of this work is to allow monitors to have confidence in both the authenticity and integrity of the TIE and the monitoring equipment inside, throughout the time it may be located at a host facility. Incorporating authentication features into the design were the focus of fiscal year 2014 development efforts. Throughout the development process, modifications have been made to the physical TIE design based on lessons learned via exercises and expert elicitation. The end result is a robust and passive TIE which can be utilized to protect monitoring party equipment left in a host facility.

  20. The strut-and-tie models in reinforced concrete structures analysed by a numerical technique

    Directory of Open Access Journals (Sweden)

    V. S. Almeida

    Full Text Available The strut-and-tie models are appropriate to design and to detail certain types of structural elements in reinforced concrete and in regions of stress concentrations, called "D" regions. This is a good model representation of the structural behavior and mechanism. The numerical techniques presented herein are used to identify stress regions which represent the strut-and-tie elements and to quantify their respective efforts. Elastic linear plane problems are analyzed using strut-and-tie models by coupling the classical evolutionary structural optimization, ESO, and a new variant called SESO - Smoothing ESO, for finite element formulation. The SESO method is based on the procedure of gradual reduction of stiffness contribution of the inefficient elements at lower stress until it no longer has any influence. Optimal topologies of strut-and-tie models are presented in several instances with good settings comparing with other pioneer works allowing the design of reinforcement for structural elements.