scholarly journals Persistent variation in spatial behavior affects the structure and function of interaction networks

2015 ◽  
Vol 61 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Noa Pinter-Wollman
Keyword(s):  
Network Structure ◽  
Interaction Network ◽  
Structure And Function ◽  
Spatial Behavior ◽  
Interaction Networks ◽  
Harvester Ants ◽  
Spatial Features ◽  
Physical Barriers ◽  
And Function ◽  
Animal Personalities

Abstract The function of a network is affected by its structure. For example, the presence of highly interactive individuals, or hubs, influences the extent and rate of information spread across a network. In a network of interactions, the duration over which individual variation in interactions persists may affect how the network operates. Individuals may persist in their behavior over time and across situations, often referred to as personality. Colonies of social insects are an example of a biological system in which the structure of the coordinated networks of interacting workers may greatly influence information flow within the colony, and therefore its collective behavior. Here I investigate the effects of persistence in walking patterns on interaction networks using computer simulations that are parameterized using observed behavior of harvester ants. I examine how the duration of persistence in spatial behavior influences network structure. Furthermore, I explore how spatial features of the environment affect the relationship between persistent behavior and network structure. I show that as persistence increases, the skewness of the weighted degree distribution of the interaction network increases. However, this relationship holds only when ants are confined in a space with boundaries, but not when physical barriers are absent. These findings suggest that the influence of animal personalities on network structure and function depends on the environment in which the animals reside.

scholarly journals The effect of individual variation on the structure and function of interaction networks in harvester ants

2011 ◽  
Vol 8 (64) ◽  
pp. 1562-1573 ◽  
Author(s):  
Noa Pinter-Wollman ◽  
Roy Wollman ◽  
Adam Guetz ◽  
Susan Holmes ◽  
Deborah M. Gordon
Keyword(s):  
Computer Simulations ◽  
Information Flow ◽  
Individual Variation ◽  
Hot Spot ◽  
Interaction Network ◽  
Structure And Function ◽  
Skewed Distribution ◽  
Interaction Frequency ◽  
Harvester Ants ◽  
And Function

Social insects exhibit coordinated behaviour without central control. Local interactions among individuals determine their behaviour and regulate the activity of the colony. Harvester ants are recruited for outside work, using networks of brief antennal contacts, in the nest chamber closest to the nest exit: the entrance chamber. Here, we combine empirical observations, image analysis and computer simulations to investigate the structure and function of the interaction network in the entrance chamber. Ant interactions were distributed heterogeneously in the chamber, with an interaction hot-spot at the entrance leading further into the nest. The distribution of the total interactions per ant followed a right-skewed distribution, indicating the presence of highly connected individuals. Numbers of ant encounters observed positively correlated with the duration of observation. Individuals varied in interaction frequency, even after accounting for the duration of observation. An ant's interaction frequency was explained by its path shape and location within the entrance chamber. Computer simulations demonstrate that variation among individuals in connectivity accelerates information flow to an extent equivalent to an increase in the total number of interactions. Individual variation in connectivity, arising from variation among ants in location and spatial behaviour, creates interaction centres, which may expedite information flow.

scholarly journals Structure and function in human and primate social networks: implications for diffusion, network stability and health

2020 ◽  
Vol 476 (2240) ◽  
pp. 20200446 ◽  
Author(s):  
R. I. M. Dunbar
Keyword(s):  
Social Networks ◽  
Physical Health ◽  
Health Risks ◽  
Network Structure ◽  
Fractal Structure ◽  
Social World ◽  
Structure And Function ◽  
Network Stability ◽  
External Threats ◽  
And Function

The human social world is orders of magnitude smaller than our highly urbanized world might lead us to suppose. In addition, human social networks have a very distinct fractal structure similar to that observed in other primates. In part, this reflects a cognitive constraint, and in part a time constraint, on the capacity for interaction. Structured networks of this kind have a significant effect on the rates of transmission of both disease and information. Because the cognitive mechanism underpinning network structure is based on trust, internal and external threats that undermine trust or constrain interaction inevitably result in the fragmentation and restructuring of networks. In contexts where network sizes are smaller, this is likely to have significant impacts on psychological and physical health risks.

scholarly journals Network Structure and Function in Parkinson’s Disease

2017 ◽  
pp. 1-15 ◽  
Author(s):  
Ji Hyun Ko ◽  
Phoebe G Spetsieris ◽  
David Eidelberg
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Network Structure ◽  
Structure And Function ◽  
And Function

scholarly journals The effect of landscape on Cucurbita pepo-pollinator interaction networks varies depending on plants’ genetic diversity

2021 ◽  
Author(s):  
Patricia Landaverde-González ◽  
Eunice Enríquez ◽  
Juan Núñez-Farfán
Keyword(s):  
Genetic Diversity ◽  
Land Use ◽  
Network Structure ◽  
Cucurbita Pepo ◽  
Interaction Network ◽  
Network Evolution ◽  
Interaction Networks ◽  
Pollinator Community ◽  
Male Flowers ◽  
Plant Pollinator

AbstractIn recent years, evidence has been found that plant-pollinator interactions are altered by land-use and that genetic diversity also plays a role. However, how land-use and genetic diversity influence plant–pollinator interactions, particularly in the Neotropics, where many endemic plants exist is still an open question. Cucurbita pepo is a monoecious plant and traditional crop wide distributed, with high rates of molecular evolution, landraces associated with human cultural management and a history of coevolution with bees, which makes this species a promising model for studying the effect of landscape and genetic diversity on plant-pollinator interactions. Here, we assess (1) whether female and male flowers differences have an effect on the interaction network, (2) how C. pepo genetic diversity affects flower-bee visitation network structure, and (3) what is the effect that land-use, accounting for C. pepo genetic variability, has on pumpkin-bee interaction network structure. Our results indicate that female and male flowers presented the same pollinator community composition and interaction network structure suggesting that female/male differences do not have a significant effect on network evolution. Genetic diversity has a positive effect on modularity, nestedness and number of interactions. Further, the effect of semi-natural areas on nestedness could be buffered when genetic diversity is high. Our results suggest that considering genetic diversity is relevant for a better understanding of the effect of land-use on interaction networks. Additionally, this understanding has great value in conserving biodiversity and enhancing the stability of interaction networks in a world facing great challenges of habitat and diversity loss.

scholarly journals Studies on the basis for the properties of fibrin produced from fibrinogen-containing γ′ chains

Blood ◽  
2005 ◽  
Vol 106 (8) ◽  
pp. 2730-2736 ◽  
Author(s):  
Kevin R. Siebenlist ◽  
Michael W. Mosesson ◽  
Irene Hernandez ◽  
Leslie A. Bush ◽  
Enrico Di Cera ◽  
...  
Keyword(s):  
Network Structure ◽  
Factor Xiii ◽  
Structure And Function ◽  
Catalytic Site ◽  
Cross Linking ◽  
Terminal Sequence ◽  
Human Fibrinogen ◽  
Delayed Release ◽  
Functional Features ◽  
And Function

AbstractHuman fibrinogen 1 is homodimeric with respect to its γ chains (`γA-γA'), whereas fibrinogen 2 molecules each contain one γA (γA1-411V) and one γ′ chain, which differ by containing a unique C-terminal sequence from γ′408 to 427L that binds thrombin and factor XIII. We investigated the structural and functional features of these fibrins and made several observations. First, thrombin-treated fibrinogen 2 produced finer, more branched clot networks than did fibrin 1. These known differences in network structure were attributable to delayed release of fibrinopeptide (FP) A from fibrinogen 2 by thrombin, which in turn was likely caused by allosteric changes at the thrombin catalytic site induced by thrombin exosite 2 binding to the γ′ chains. Second, cross-linking of fibrin γ chains was virtually the same for both types of fibrin. Third, the acceleratory effect of fibrin on thrombin-mediated XIII activation was more prominent with fibrin 1 than with fibrin 2, and this was also attributable to allosteric changes at the catalytic site induced by thrombin binding to γ′ chains. Fourth, fibrinolysis of fibrin 2 was delayed compared with fibrin 1. Altogether, differences between the structure and function of fibrins 1 and 2 are attributable to the effects of thrombin binding to γ′ chains.

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