scholarly journals Modeling acquaintance networks based on balance theory

2014 ◽  
Vol 24 (3) ◽  
pp. 683-696 ◽  
Author(s):  
Vida Vukašinović ◽  
Jurij Šilc ◽  
Risth Škrekovski

Abstract An acquaintance network is a social structure made up of a set of actors and the ties between them. These ties change dynamically as a consequence of incessant interactions between the actors. In this paper we introduce a social network model called the Interaction-Based (IB) model that involves well-known sociological principles. The connections between the actors and the strength of the connections are influenced by the continuous positive and negative interactions between the actors and, vice versa, the future interactions are more likely to happen between the actors that are connected with stronger ties. The model is also inspired by the social behavior of animal species, particularly that of ants in their colony. A model evaluation showed that the IB model turned out to be sparse. The model has a small diameter and an average path length that grows in proportion to the logarithm of the number of vertices. The clustering coefficient is relatively high, and its value stabilizes in larger networks. The degree distributions are slightly right-skewed. In the mature phase of the IB model, i.e., when the number of edges does not change significantly, most of the network properties do not change significantly either. The IB model was found to be the best of all the compared models in simulating the e-mail URV (University Rovira i Virgili of Tarragona) network because the properties of the IB model more closely matched those of the e-mail URV network than the other models

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Hiroshi Ashikaga ◽  
Jonathan Chrispin ◽  
Degang Wu ◽  
Joshua Garland

Recent evidence suggests that pulmonary vein isolation (PVI) may perturb the electrophysiological substrate for maintenance of atrial fibrillation (AF). Our previous work indicates that information theory metrics can quantify electrical communications during arrhythmia. We hypothesized that PVI ‘rewires’ the electrical communication network during AF such that the topology exhibits higher levels of small-world network properties, with higher clustering coefficient and lower path length, than would be expected by chance. Thirteen consecutive patients (n=6 with prior PVI and n=7 without) underwent AF ablation using a 64-electrode basket catheter in the left atrium. Multielectrode recording was performed during AF for 60 seconds, followed by PVI. Mutual information was calculated from the time series between each pair of electrodes using the Kraskov-Stögbauer-Grassberger estimator. The all-to-all mutual information matrix (64x64; Figure, upper panels) was thresholded by the median and standard deviations of mutual information to build a binary adjacency matrix for electrical communication networks. The properties of small-world network ( swn ; ‘small-world-ness’) were quantified by the ratio of the observed average clustering coefficient to that of a random network over the ratio of the observed average path length to that of a random network. swn was expressed in normal Z standard deviation units. As the binarizing threshold increased, the Z-score of swn decreased (Figure, lower panel). However, the Z-score at each threshold value was consistently higher with prior PVI than those without (p<0.05). In conclusion, electrical communication network during AF with prior PVI is associated with higher levels of small-world network properties than those without. This finding supports the concept that PVI perturbs the underlying substrate. In addition, swn of electrical communication network may be a promising metric to quantify substrate modification.


2019 ◽  
Author(s):  
Laura Fortunato

I draw on insights from anthropology to outline a framework for the study of kinship systems that applies across animal species with biparental sexual reproduction. In particular, I define lineal kinship organization as a social system that emphasizes interactions among lineally related kin — that is, individuals related through females only, if the emphasis is towards matrilineal kin, and individuals related through males only, if the emphasis is towards patrilineal kin. In a given population, the emphasis may be expressed in one or more social domains, corresponding to pathways for the transmission of different resources across generations (e.g. the allocation of food, the transfer of access to the natal territory or household).A lineal bias in any domain can be viewed as a bias in investment towards a particular set of kin — specifically, towards the offspring of daughters if the bias is matrilineal, and towards the offspring of sons if the bias is patrilineal. Effectively, investment is restricted to the offspring of the females in the population in one case, and to the offspring of the males in the other. This is distinct from a bias in investment towards daughters and towards sons, respectively.Overall, I propose a shift in focus — from viewing matrilineal and patrilineal kinship as unitary phenomena, to consideration of the different aspects of the social system featuring a bias towards lineally related kin.


2015 ◽  
Vol 122 (1) ◽  
pp. 140-149 ◽  
Author(s):  
Ahmad Khodayari-Rostamabad ◽  
Søren S. Olesen ◽  
Carina Graversen ◽  
Lasse P. Malver ◽  
Geana P. Kurita ◽  
...  

Abstract Background: The authors investigated the effect of remifentanil administration on resting electroencephalography functional connectivity and its relationship to cognitive function and analgesia in healthy volunteers. Methods: Twenty-one healthy male adult subjects were enrolled in this placebo-controlled double-blind cross-over study. For each subject, 2.5 min of multichannel electroencephalography recording, a cognitive test of sustained attention (continuous reaction time), and experimental pain scores to bone-pressure and heat stimuli were collected before and after infusion of remifentanil or placebo. A coherence matrix was calculated from the electroencephalogram, and three graph-theoretical measures (characteristic path-length, mean clustering coefficient, and relative small-worldness) were extracted to characterize the overall cortical network properties. Results: Compared to placebo, most graph-theoretical measures were significantly altered by remifentanil at the alpha and low beta range (8 to 18 Hz; all P &lt; 0.001). Taken together, these alterations were characterized by an increase in the characteristic path-length (alpha 17% and low beta range 24%) and corresponding decrements in mean clustering coefficient (low beta range −25%) and relative small-worldness (alpha −17% and low beta range −42%). Changes in characteristic path-lengths after remifentanil infusion were correlated to the continuous reaction time index (r = −0.57; P = 0.009), while no significant correlations between graph-theoretical measures and experimental pain tests were seen. Conclusions: Remifentanil disrupts the functional connectivity network properties of the electroencephalogram. The findings give new insight into how opioids interfere with the normal brain functions and have the potential to be biomarkers for the sedative effects of opioids in different clinical settings.


2019 ◽  
Vol 374 (1780) ◽  
pp. 20190005 ◽  
Author(s):  
Laura Fortunato

I draw on insights from anthropology to outline a framework for the study of kinship systems that applies across animal species with biparental sexual reproduction. In particular, I define lineal kinship organization as a social system that emphasizes interactions among lineally related kin—that is, individuals related through females only, if the emphasis is towards matrilineal kin, and individuals related through males only, if the emphasis is towards patrilineal kin. In a given population, the emphasis may be expressed in one or more social domains, corresponding to pathways for the transmission of different resources across generations (e.g. the allocation of food, the transfer of access to the natal territory or household). A lineal bias in any domain can be viewed as a bias in investment towards a particular set of kin—specifically, towards the offspring of daughters if the bias is matrilineal, and towards the offspring of sons if the bias is patrilineal. Effectively, investment is restricted to the offspring of the females in the population in one case, and to the offspring of the males in the other. This is distinct from a bias in investment towards daughters and towards sons, respectively. Overall, I propose a shift in focus—from viewing matrilineal and patrilineal kinship as unitary phenomena, to consideration of the different aspects of the social system featuring a bias towards lineally related kin. This article is part of the theme issue ‘The evolution of female-biased kinship in humans and other mammals’.


Episteme ◽  
2013 ◽  
Vol 10 (4) ◽  
pp. 441-464 ◽  
Author(s):  
Patrick Grim ◽  
Daniel J. Singer ◽  
Steven Fisher ◽  
Aaron Bramson ◽  
William J. Berger ◽  
...  

AbstractA scientific community can be modeled as a collection of epistemic agents attempting to answer questions, in part by communicating about their hypotheses and results. We can treat the pathways of scientific communication as a network. When we do, it becomes clear that the interaction between the structure of the network and the nature of the question under investigation affects epistemic desiderata, including accuracy and speed to community consensus. Here we build on previous work, both our own and others’, in order to get a firmer grasp on precisely which features of scientific communities interact with which features of scientific questions in order to influence epistemic outcomes.Here we introduce a measure on the landscape meant to capture some aspects of the difficulty of answering an empirical question. We then investigate both how different communication networks affect whether the community finds the best answer and the time it takes for the community to reach consensus on an answer. We measure these two epistemic desiderata on a continuum of networks sampled from the Watts–Strogatz spectrum. It turns out that finding the best answer and reaching consensus exhibit radically different patterns. The time it takes for a community to reach a consensus in these models roughly tracks mean path length in the network. Whether a scientific community finds the best answer, on the other hand, tracks neither mean path length nor clustering coefficient.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
J. M. Buldú ◽  
J. Busquets ◽  
I. Echegoyen ◽  
F. Seirul.lo

Abstract The application of Network Science to social systems has introduced new methodologies to analyze classical problems such as the emergence of epidemics, the arousal of cooperation between individuals or the propagation of information along social networks. More recently, the organization of football teams and their performance have been unveiled using metrics coming from Network Science, where a team is considered as a complex network whose nodes (i.e., players) interact with the aim of overcoming the opponent network. Here, we combine the use of different network metrics to extract the particular signature of the F.C. Barcelona coached by Guardiola, which has been considered one of the best teams along football history. We have first compared the network organization of Guardiola’s team with their opponents along one season of the Spanish national league, identifying those metrics with statistically significant differences and relating them with the Guardiola’s game. Next, we have focused on the temporal nature of football passing networks and calculated the evolution of all network properties along a match, instead of considering their average. In this way, we are able to identify those network metrics that enhance the probability of scoring/receiving a goal, showing that not all teams behave in the same way and how the organization Guardiola’s F.C. Barcelona is different from the rest, including its clustering coefficient, shortest-path length, largest eigenvalue of the adjacency matrix, algebraic connectivity and centrality distribution.


Author(s):  
Alfredo Feria-Velasco ◽  
Guadalupe Tapia-Arizmendi

The fine structure of the Harderian gland has been described in some animal species (hamster, rabbit, mouse, domestic fowl and albino rats). There are only two reports in the literature dealing on the ultrastructure of rat Harderian gland in adult animals. In one of them the author describes the myoepithelial cells in methacrylate-embbeded tissue, and the other deals with the maturation of the acinar cells and the formation of the secretory droplets. The aim of the present work is to analize the relationships among the acinar cell components and to describe the two types of cells located at the perifery of the acini.


2019 ◽  
Vol 78 (1-2) ◽  
pp. 69-75 ◽  
Author(s):  
Mikaël De Clercq ◽  
Charlotte Michel ◽  
Sophie Remy ◽  
Benoît Galand

Abstract. Grounded in social-psychological literature, this experimental study assessed the effects of two so-called “wise” interventions implemented in a student study program. The interventions took place during the very first week at university, a presumed pivotal phase of transition. A group of 375 freshmen in psychology were randomly assigned to three conditions: control, social belonging, and self-affirmation. Following the intervention, students in the social-belonging condition expressed less social apprehension, a higher social integration, and a stronger intention to persist one month later than the other participants. They also relied more on peers as a source of support when confronted with a study task. Students in the self-affirmation condition felt more self-affirmed at the end of the intervention but didn’t benefit from other lasting effects. The results suggest that some well-timed and well-targeted “wise” interventions could provide lasting positive consequences for student adjustment. The respective merits of social-belonging and self-affirmation interventions are also discussed.


2012 ◽  
Vol 5 (2) ◽  
pp. 109
Author(s):  
Besin Gaspar

This research deals with the development of  self concept of Hiroko as the main character in Namaku Hiroko by Nh. Dini and tries to identify how Hiroko is portrayed in the story, how she interacts with other characters and whether she is portrayed as a character dominated by ”I” element or  ”Me”  element seen  from sociological and cultural point of view. As a qualitative research in nature, the source of data in this research is the novel Namaku Hiroko (1967) and the data ara analyzed and presented deductively. The result of this analysis shows that in the novel, Hiroko as a fictional character is  portrayed as a girl whose personality  develops and changes drastically from ”Me”  to ”I”. When she was still in the village  l iving with her parents, she was portrayed as a obedient girl who was loyal to the parents, polite and acted in accordance with the social customs. In short, her personality was dominated by ”Me”  self concept. On the other hand, when she moved to the city (Kyoto), she was portrayed as a wild girl  no longer controlled by the social customs. She was  firm and determined totake decisions of  her won  for her future without considering what other people would say about her. She did not want to be treated as object. To put it in another way, her personality is more dominated by the ”I” self concept.


Author(s):  
Marcio Luis Costa ◽  
Alex Silva Messias

Nas últimas décadas se observa o retorno da religião sob forma de fundamentalismo religioso, utilizando a mídia e instrumentos de pressão política para fazer valer suas crenças, pois diante do receio ao questionamento, os fundamentalistas veem no “outro”, no diferente, uma ameaça a ser combatida e, em alguns casos, extirpada para preservar suas convicções. O presente estudo tem por objetivo discutir as tendências sócio-políticas do fundamentalismo religioso cristão. Para tanto, com método bibliográfico narrativo, visitamos alguns autores em nível nacional e internacional, que abordam as condições que fizeram emergir o fenômeno social do fundamentalismo religioso, sua estruturação e atuação, até suas demandas sócio-políticas. Os resultados apontam que quando se identifica e transfere qualquer responsabilidade pessoal e histórica para as forças externas, o “outro”, entendido como pessoa e/ou instituição, não podemos negar que esse processo alcança dimensões de problema social. Notamos algumas tendências como mudança de movimento religioso para ideologia acirrada, da postura de fiel para militância, do “ad intra” das religiões para demandas “ad extra”, dos altares e púlpitos para ocupações políticas.Palavras-chave: Fundamentalismo Religioso; Protestante; Católico. CHRISTIAN RELIGIOUS FUNDAMENTALISM: SOCIAL-POLITICS TENDENCIESAbstractIn the last decades the return of religion in religious fundamentalism form can be observed, using media and instruments of political pressure, because when facing the fear of questioning, fundamentalists see in the “other”, in the different, a threat to be stopped and, in some cases, extirpated top preserve their convictions.  This study aims to discuss the social-politics tendencies of the Christian religious fundamentalism. For that, with the narrative bibliographic method, we visited some authors of national and international level, that approach the conditions that caused the emergence of the religious fundamentalism social phenomenon, its structure and role, until its social-politics demand. The results show that when any personal or historical responsibility is identified and transferred to external forces, the “other”, understood as person and/or institution, we cannot deny this process reaches dimensions of social problem. We notice some tendencies such as the change of the religious movement to fierce ideology, from the posture of faithful to militancy, from “ad intra” of religions to “ad extra” demands, from the altars and pulpits to political positions.Keywords: Religious Fundamentalism; Protestant; Catholic.


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