scholarly journals Null Model and Community Structure in Multiplex Networks

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Xuemeng Zhai ◽  
Wanlei Zhou ◽  
Gaolei Fei ◽  
Weiyi Liu ◽  
Zhoujun Xu ◽  
...  
Keyword(s):  
Community Structure ◽  
Null Model ◽  
Multiplex Networks

scholarly journals Spreading of localized attacks on spatial multiplex networks with a community structure

2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Dana Vaknin ◽  
Bnaya Gross ◽  
Sergey V. Buldyrev ◽  
Shlomo Havlin
Keyword(s):  
Community Structure ◽  
Multiplex Networks ◽  
Spatial Multiplex

A null model to study community structure of microcrustacean assemblages in north Patagonian urban wetlands (39-41°S, Chile)

Crustaceana ◽  
2014 ◽  
Vol 87 (11-12) ◽  
pp. 1377-1385
Author(s):  
Patricio De los Ríos-Escalante ◽  
Andrés Muñoz-Pedreros ◽  
Patricia Möller
Keyword(s):  
Community Structure ◽  
Trophic Status ◽  
Null Model ◽  
Model Analysis ◽  
Jaccard Index ◽  
Field Observations ◽  
Urban Wetlands ◽  
Community Similarity ◽  
Chilean Patagonia ◽  
Inland Water Bodies

The inland water bodies of northern Chilean Patagonia (38-41°S) have many lakes, wetlands and ponds with different littoral and zooplanktonic crustacean assemblages. This study presents field observations of species associations sampled from shallow wetlands located in the urban zones of Valdivia (39°S) and Puerto Montt (41°S). A species presence-absence matrix was created for calculating the Jaccard Index of community similarity and for testing null models of species associations, with the aim of determining whether species associations are random or not. The results of the Jaccard Index calculations indicated the existence of non-defined groups. The results of the null model analysis denoted the presence of regulating factors for Valdivia wetlands, whereas for Puerto Montt wetlands no such factors could be demonstrated. The outcomes of both the Jaccard Index and the significant null model analysis agree with previous ecological descriptions of changes in trophic status as a consequence of changes in the surrounding basin as a determinant of species associations. The ecology of these communities is also discussed.

Null Model and Community Structure in Heterogeneous Networks

2020 ◽  
pp. 151-163
Author(s):  
Xuemeng Zhai ◽  
Wanlei Zhou ◽  
Gaolei Fei ◽  
Hangyu Hu ◽  
Youyang Qu ◽  
...  
Keyword(s):  
Community Structure ◽  
Heterogeneous Networks ◽  
Null Model

scholarly journals Crawling the Community Structure of Multiplex Networks

2019 ◽  
Vol 33 ◽  
pp. 168-175 ◽  
Author(s):  
Ricky Laishram ◽  
Jeremy D. Wendt ◽  
Sucheta Soundarajan
Keyword(s):  
Community Structure ◽  
Real World ◽  
Multiplex Networks ◽  
Data Collector ◽  
Multiplex Network ◽  
Multiple Levels ◽  
Novel Algorithm ◽  
Collection Costs

We examine the problem of crawling the community structure of a multiplex network containing multiple layers of edge relationships. While there has been a great deal of work examining community structure in general, and some work on the problem of sampling a network to preserve its community structure, to the best of our knowledge, this is the first work to consider this problem on multiplex networks. We consider the specific case in which the layers of a multiplex network have different query (collection) costs and reliabilities; and a data collector is interested in identifying the community structure of the most expensive layer. We propose MultiComSample (MCS), a novel algorithm for crawling a multiplex network. MCS uses multiple levels of multi-armed bandits to determine the best layers, communities and node roles for selecting nodes to query. We test MCS against six baseline algorithms on real-world multiplex networks, and achieved large gains in performance. For example, after consuming a budget equivalent to sampling 20% of the nodes in the expensive layer, we observe that MCS outperforms the best baseline by up to 49%.

scholarly journals Community Structure in Time-Dependent, Multiscale, and Multiplex Networks

Science ◽  
2010 ◽  
Vol 328 (5980) ◽  
pp. 876-878 ◽  
Author(s):  
P. J. Mucha ◽  
T. Richardson ◽  
K. Macon ◽  
M. A. Porter ◽  
J.-P. Onnela
Keyword(s):  
Community Structure ◽  
Time Dependent ◽  
Multiplex Networks

scholarly journals Diet and niche breadth and overlap in fish communities within the area affected by an Amazonian reservoir (Amapá, Brazil)

2014 ◽  
Vol 86 (1) ◽  
pp. 383-406 ◽  
Author(s):  
JÚLIO C. SÁ-OLIVEIRA ◽  
RONALDO ANGELINI ◽  
VICTORIA J. ISAAC-NAHUM
Keyword(s):  
Community Structure ◽  
Seasonal Variation ◽  
Fish Species ◽  
Niche Breadth ◽  
Null Model ◽  
Stomach Contents ◽  
Physical Conditions ◽  
River Damming ◽  
Standard Configuration ◽  
Feeding Resources

We investigated the niche breadth and overlap of the fish species occurring in four environments affected by the Coaracy Nunes reservoir, in the Amapá Brazilian State. Seasonal samples of fishes were taken using a standard configuration of gillnets, as well as dragnets, lines, and castnets. Five hundred and forty stomach contents, representing 47 fish species were analyzed and quantified. Niche breadth and overlap were estimated using indexes of Levins and Pianka, respectively, while interspecific competition was evaluated using a null model (RA3). ANOVA and the KruskalWallis test were used, respectively, to evaluate differences in niche breadth and overlap between areas. The data indicate that the majority of the fish species belong to the piscivore, omnivore, and detritivore guilds. These species have likely colonized the environments due to the availability of suitable feeding resources, and the favorable physical conditions created by the river damming. Overall, few species have ample niches, but most of them are highly specialized. Resources seasonal variation had little effect on the feeding behavior of most species in the study areas. The null models indicated that competition was not a factor determining on community structure.

scholarly journals A new dynamic null model for phylogenetic community structure

2015 ◽  
Vol 18 (2) ◽  
pp. 153-163 ◽  
Author(s):  
Alex L. Pigot ◽  
Rampal S. Etienne
Keyword(s):  
Community Structure ◽  
Null Model ◽  
Phylogenetic Community Structure

scholarly journals Crustacean communities in coastal ephemeral pools in the Araucanía region (38° S, Chile)

2016 ◽  
Vol 76 (4) ◽  
pp. 811-817 ◽  
Author(s):  
P. De los Ríos-Escalante ◽  
P. Acevedo
Keyword(s):  
Community Structure ◽  
Community Dynamics ◽  
Species Abundance ◽  
Null Model ◽  
Total Dissolved Solids ◽  
Second Step ◽  
Dissolved Solids ◽  
Temperature Conductivity ◽  
Ephemeral Pools ◽  
Total Data

Abstract The fauna communities of ephemeral pools in southern Chile are characterized by heterogeneity of crustacean taxa; nevertheless, no detailed studies exist of their community structure. The aim of the present study was to analyze the crustacean community structure in two groups of ephemeral pools (Puaucho and Nigue pools) in the coastal zone of the Araucanía region. A correlation matrix was made by species abundance against temperature, conductivity, pH and total dissolved solids. In a second step, a null model for species co-occurrence was applied to the total data and to each group. The results for total data revealed a significant direct relation between the abundance of H. costera, C. dubia and Mesocyclops. For the Puaucho pools, the same results were found together with direct associations with total dissolved solids, conductivity and pH. Finally, different results were found for the Nigue pools, with no clear significant associations, either direct or indirect, between the abundance of different crustacean taxa and abiotic parameters. These results were supported by the co-occurrence null model analysis, which revealed the presence of regulator factors for the total data, and for each of the two groups. Ecological topics are discussed with emphasis on meta-community dynamics.

Null model analysis of lizard communities in five urban parks of Rome

2007 ◽  
Vol 28 (4) ◽  
pp. 547-553 ◽  
Author(s):  
Luca Luiselli ◽  
Lorenzo Rugiero
Keyword(s):  
Community Structure ◽  
Central Italy ◽  
Habitat Type ◽  
Null Model ◽  
Urban Parks ◽  
Habitat Types ◽  
Podarcis Muralis ◽  
Green Areas ◽  
Assembly Structure ◽  
Natural Communities

Abstract Null models are an essential tool for investigating structure in natural communities of animals, including reptiles. In this paper, we studied the assembly structure of a lizard community constituted by four species (Lacerta bilineata, Podarcis muralis, P. sicula, Chalcides chalcides) along 25 different transects, each 300 m long and representing a specific habitat type, in five independent urban green areas in Rome, central Italy. Lacerta bilineata was observed in 92% of the total transects (n = 25), P. muralis in 100%, P. sicula in 72%, and C. chalcides in 52%. Based on the number of lizards observed along the various transects, it seemed that each species was linked especially to particular habitat types within each study area, but that the habitat types frequented by each species were not necessarily exactly the same across the study areas. Null model analyses revealed that the lizard community was not randomly organized in four of five study areas by RA2 (thus denoting that the generalist-specialist nature of the species reduced ecological similarity) but not by RA3 algorithms (thus denoting that the types of resources used did not reduce ecological similarity). Thus, the community structure was due mainly to the different specialist-generalist nature of the various co-occurring species.

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