Ideas with impact : how connectivity shapes diffusion

Despite a growing body of research on idea diffusion, there is a lack of knowledge on why some ideas successfully diffuse and stand out from the crowd while others do not surface or remain unnoticed. We address this question by looking into the characteristics of an idea, specifically its connectivity in a content network. In a content network, ideas connect to other ideas through their content the words that the ideas have in common. We hypothesize that a high connectivity of an idea in a content network is beneficial for idea diffusion because this idea will more likely be conceived as novel yet at the same time also as more useful because it appears as more familiar to the audience. Moreover, we posit that a high social connectivity of the team working on the idea further enhances the effect of high content connectivity on idea diffusion. Our study focuses on academic conference publications and the co-authorship data of a community of computer science researchers from 2006 to 2012. We find confirmation for our hypotheses and discuss the implications of these findings

Mangrove-mudflat connectivity shapes benthic communities in a tropical intertidal system

Understanding the connectivity among seascape habitats is an important emerging topic in marine ecology and coastal management. Mangroves are known to provide many ecosystem services such as coastal protection and carbon cycling, but their functional relationships with adjacent benthic intertidal communities are less clear. We examined how spatial adjacency to mangroves affects macrobenthic communities of intertidal mudflats in a tropical estuarine ecosystem. In the Bijagós Archipelago, Guinea-Bissau, benthic macrofauna assemblages were compared among sampling locations with different connectivities between intertidal mudflats and mangrove stands. We explored how a single mangrove connectivity index (MCI), combining mangrove tidal basin size and the distance to the mangrove edge, affected macrobenthic composition, and compared this effect to sediment properties. In addition, we used structural equation modelling (SEM) and ordination to determine how different environmental predictors directly and indirectly affected macrobenthic communities. MCI strongly affected macrobenthic composition and species abundance, and SEM revealed that this effect contained both a direct component and an indirect component through mudflat NDVI (normalized difference vegetation index, an indicator for microphytobenthos). Sediment properties (grain size, organic matter) affected macrobenthos independently from MCI, nevertheless sediment properties were also affected by MCI. We show the importance of accounting for the seascape structure of tidal basins when investigating the connectivity between mangroves and macrobenthic communities of intertidal mudflats. As benthic macrofauna is a key food source for endangered fish and waders in these systems, our findings provide strong arguments for the integrative conservation of intertidal mudflats and mangroves at the seascape scale

Ecological connectivity shapes quasispecies structure of RNA viruses in an Antarctic lake

© 2015 John Wiley & Sons Ltd. RNA viruses exist as complex mixtures of genotypes, known as quasispecies, where the evolution potential resides in the whole community of related genotypes. Quasispecies structure and dynamics have been studied in detail for virus infecting animals and plants but remain unexplored for those infecting micro-organisms in environmental samples. We report the first metagenomic study of RNA viruses in an Antarctic lake (Lake Limnopolar, Livingston Island). Similar to low-latitude aquatic environments, this lake harbours an RNA virome dominated by positive single-strand RNA viruses from the order Picornavirales probably infecting micro-organisms. Antarctic picorna-like virus 1 (APLV1), one of the most abundant viruses in the lake, does not incorporate any mutation in the consensus sequence from 2006 to 2010 and shows stable quasispecies with low-complexity indexes. By contrast, APLV2-APLV3 are detected in the lake water exclusively in summer samples and are major constituents of surrounding cyanobacterial mats. Their quasispecies exhibit low complexity in cyanobacterial mat, but their run-off-mediated transfer to the lake results in a remarkable increase of complexity that may reflect the convergence of different viral quasispecies from the catchment area or replication in a more diverse host community. This is the first example of viral quasispecies from natural aquatic ecosystems and points to ecological connectivity as a modulating factor of quasispecies complexity.Spanish Polar Programme and the Spanish Ministry of Economy and Competitiveness (CTM2008-05134-E/ANT and CTM2009-08644-E).Peer Reviewe

Fragment connectivity shapes bird communities through functional trait filtering in two types of grasslands

Habitat fragmentation is considered one of the most severe threatening factors for global biodiversity. Here we assessed, how local and landscape scale environmental variables, such as fragment size (small vs. large) and landscape configuration (measured as connectivity index) relates to bird community composition, species richness, abundance and functional diversity. We surveyed 60 grassland fragments in Hungary, belonging to two different threatened grassland types, namely forest-steppes and kurgans. Forest-steppes are natural mosaics of grasslands and forests at the contact zone between closed-canopy temperate forests and steppe grasslands. Kurgans are ancient burial mounds, found on the Eurasian steppe and forest steppe zone. These fragments were embedded in plantation forestry, respectively, agricultural matrix with gradients of size and connectivity. Both habitats are threatened by forestry and agricultural intensification, though these fragments may serve as important wildlife refuges. Our findings revealed that forest-steppe birds were more diverse and abundant in large and well-connected than in small isolated fragments. High connectivity affected ground nesting birds in small forest-steppe fragments positively. Birds inhabiting kurgan area showed higher trait similarity in well-connected than in isolated fragments. Bird abundance of kurgans associated with small home range size and ground feeding habit were higher in connected compared to isolated fragments. Highly isolated kurgans filtered for more specialised bird species but not for generalists. We provide conservation implications for enhancing grassland specialist bird communities, which consist of preservation of large, well-connected grassland fragments within production landscapes and through reconsideration of the currently used intensive forestryinfo:eu-repo/semantics/publishedVersio

Floodplain Lake Assessment and Fish Assemblage Dynamics in the Mississippi Alluvial Valley

Floodplain lakes in the Mississippi Alluvial Valley (MAV) provide valuable freshwater resources for states in which they occur. Thirty lakes in portions of Mississippi and Arkansas were surveyed for chlorophyll-a fluorescence and turbidity using handheld meters to determine relationships between chlorophyll-a concentrations and suspended solids. High applicability of handheld meters in the MAV presents economic benefits for monitoring the numerous lakes in the region. Additionally, twelve lakes within Bear Creek watershed, Mississippi were studied to determine how hydrologic connectivity shapes fish communities. Isolated and permanently connected floodplain lakes exhibited characteristically lacustrine and rheophilic fish communities, respectively, diversifying fishery management opportunities. Lastly, spring diel temperature and oxygen dynamics, as well as juvenile fish communities, were assessed within three habitats in a floodplain lake – pelagic environment, margin and contiguous wetlands. Variability in temperature and oxygen across the three habitats promotes spring habitat heterogeneity while supporting distinct but overlapping juvenile fish assemblages

Privileged Mexican migrants in Europe: Distinctions and cosmopolitanism on social networking sites

This article examines the ways in which classed distinctions are related to the construction of increasingly cosmopolitan identities on Social Networking Sites (SNSs) amongst Mexican migrants from relatively privileged backgrounds living in Europe. It centres on how user demographics shape many of the concerns and outcomes pertaining to the use of SNSs. It considers the implications of the fact that SNSs are predominantly used by a demographic considered as non-marginalized, mobile and as possessing relatively privileged economic, cultural and social backgrounds. It analyses the ways in which online identities are constructed on SNS profiles using multimedia content to represent specific lifestyles and cultural practices that are used to make distinctions amongst participants, and are related to social, cultural and economic capital. A critical analysis is presented as to how users represent cosmopolitan identities online through the display of tastes and lifestyles in SNS content and into how these representations relate to users’ privileged positions in Mexican society. Bourdieu’s concept of distinction is used to emphasize the utility of considering different forms of capital in analysing the use of SNSs and profile content generated by a specific demographic. This article demonstrates how the analysis of SNS use may contribute towards an understanding of how classed distinctions are made based on this use and of how users negotiate the posting of profile content according to these distinctions and manage (select, edit and share) their representations