Influence fast or later: two types of influencers in social networks

2021 ◽  
Author(s):  
Fang Zhou ◽  
Chang Su ◽  
Shuqi Xu ◽  
Linyuan Lü

Abstract In real-world networks, there usually exist a small set of nodes that play an important role in the structure and function of networks. Those vital nodes can influence most other nodes in the network via a spreading process. While most of the existing works focused on vital nodes that can maximize the spreading size in the final stage, which we call final influencers, recent work proposed the idea of fast influencers, which emphasizes nodes’ spreading capacity at the early stage. Despite the recent surge of efforts in identifying these two types of influencers in networks, there remained limited research on untangling the differences between fast influencers and final influencers. In this paper, we first distinguish the two types of influencers: fast-only influencers and final-only influencers. The former is defined as individuals who can achieve a high spreading effect at the early stage but lose their superiority in the final stage, and the latter are those individuals that fail to exhibit a prominent spreading performance at the early stage but influence a large fraction of nodes at the final stage. Further experiments based on eight empirical datasets, we reveal the key differences between the two types of influencers concerning their spreading capacity and the local structures. We also analyze how network degree assortativity influences the fraction of the proposed two types of influencers. The results demonstrate that with the increase of degree assortativity, the fraction of the fast-only influencers decreases, which indicates that more fast influencers tend to keep their superiority at the final stage. Our study provides insights into the differences and evolution of different types of influencers and has important implications for various empirical applications, such as advertisement marketing, and epidemic suppressing.

1995 ◽  
Vol 7 (4) ◽  
pp. 847 ◽  
Author(s):  
C Gagnon

With very few exceptions, the basic structure of the 9+2 axoneme has been well preserved over a very long period of evolution from protozoa to mammais. This stability indicates that the basic structural components of the axoneme visible by electron microscopy, as well as most of the other unidentified components, have withstood the passage of time. It also means that components of the 9+2 axoneme have sufficient diversity in function to accommodate the various types of motility patterns encountered in different species of flagella. Several of the 200 polypeptides that constitute the axoneme have been identified as components of the dynein arms, radial spokes etc. but many more remain to be identified and their function(s) remain to be determined. Because this review deals with the regulation of flagellar movement at the axonemal level, it does not include regulation of flagella by extracellular factors unless these factors have a direct action on axonemal components. In this context, it is very important firstly to understand the structural components of the axoneme and how they influence and regulate axonemal movement. Different primitive organisms are mentioned in this review since major breakthroughs in our understanding of how an axoneme generates different types of movement have been made through their study. Despite some variations in structure and function of axonemal components, the basic mechanisms involved in the regulation of flagella from Chlamydomonas or sea urchin spermatozoa should also apply to the more evolved mammalian species, including human spermatozoa.


1977 ◽  
Vol 168 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J C Ramsey ◽  
W J Steele

Free loosely bound and tightly bound polyribosomes were separated from rat liver homogenate by salt extraction followed by differential centrifugation, and several of their structural and functional properties were compared to resolve the existence of loosely bound polyribosomes and verify the specificity of the separation. The free and loosely bound polyribosomes have similar sedimentation profiles and polyribosome contents, their subunit proteins have similar electrophoretic patterns and their products of protein synthesis in vitro show a close correspondence in size and amounts synthesized. In contrast, the tightly bound polyribosomes have different properties from those of the free and loosely bound polyribosomes; their average size is significantly smaller; their polyribosome content is higher; their 60 S-subunit proteins lack two components and contain four or more components not found elsewhere; their products of protein synthesis in vitro differ in size and amounts synthesized. These observations show that rat liver membranes entrap a large fraction of the free polyribosomes at low salt concentrations and that these polyribosomes are similar to those of the free-polyribosome fraction and are different from those of the tightly bound polyribosome fraction in size, structure and function.


Author(s):  
Madeleine Keehner ◽  
Peter Khooshabeh ◽  
Mary Hegarty

This chapter examines human factors associated with using interactive three-dimensional (3D) visualizations. Virtual representations of anatomical structure and function, often with sophisticated user control capabilities, are growing in popularity in medicine for education, training, and simulation. This chapter reviews the cognitive science literature and introduces issues such as theoretical ideas related to using interactive visualizations, different types and levels of interactivity, effects of different kinds of control interfaces, and potential cognitive benefits of these tools. The authors raise the question of whether all individuals are equally capable of using 3D visualizations effectively, focusing particularly on two variables: (1) individual differences in spatial abilities, and (2) individual differences in interactive behavior. The chapter draws together findings from the authors’ own studies and from the wider literature, exploring recent insights into how individual differences among users can impact the effectiveness of different types of external visualizations for different kinds of tasks. The chapter offers recommendations for design, such as providing transparent affordances to support users’ meta-cognitive understanding, and employing personalization to complement the capabilities of different individuals. Finally, the authors suggest future directions and approaches for research, including the use of methodology such as needs analysis and contextual enquiry to better understand the cognitive processes and capacities of different kinds of users.


2014 ◽  
Vol 602-605 ◽  
pp. 499-502
Author(s):  
Yan Yuan ◽  
Le Cao

A drawer-combined condiment container was designed, and the design methods and steps were illustrated from four aspects, including the structure and function, material selection, dimensioning, modeling and decoration. With the integrated storage and independent sealing of different types of condiment, as well as the pickup of improved fluid condiment, it is characterized by cleanliness, convenience in application, space-saving and reusable features when compared to the like product. Therefore, it is of application and promotion value in the packing container design and related industries.


1984 ◽  
Vol 246 (2) ◽  
pp. R133-R151 ◽  
Author(s):  
J. S. Clegg

The nucleoplasm, the interiors of cytoplasmic membrane-bound organelles, and the aqueous cytoplasm make up the aqueous compartments of animal cells. The extent to which these compartments are concentrated solutions of macromolecules, metabolites, ions, and other solutes is a matter of some importance to current thinking about cell structure and function. This paper will focus on the aqueous cytoplasm. It will show that the composition and metabolic activities of the cytosol, obtained by methods of cell disruption and fractionation, bear almost no resemblance to those of the aqueous cytoplasm in intact cells. The consequences of this to contemporary views on cell structure and function are considered. A closely related topic concerns the physical properties of the dominant component of these compartments, water: Are these properties the same as those of water in aqueous solutions, or are they altered as a result of interaction with cell architecture? Available evidence strongly suggests that at least a large fraction of the total cell water exhibits properties that markedly differ from those of pure water. Selected examples of these studies will be reviewed, and the roles of cell water will be discussed, notably as they relate to metabolism and cell ultrastructure. Although dimly perceived at present, it appears that living cells exhibit an organization far greater than the current teachings of cell biology reveal.


1984 ◽  
Vol 99 (1) ◽  
pp. 167s-171s ◽  
Author(s):  
J S Clegg

The extent to which the properties of water in cells are like those of water in dilute aqueous solutions is a question of broad significance to cell biology. A detailed answer is not available at present, although evidence is accumulating that the properties of at least a large fraction of intracellular water are altered by interactions with cell ultrastructure, notably the cytomatrix. That and related evidence also suggests that the properties, composition, and activities of the "aqueous cytoplasm" of intact cells bear little resemblance to those of the "cytosol" obtained by cell fractionation. This paper will consider some of the evidence for these possibilities and some of their potential consequences with regard to cellular structure and function.


2021 ◽  
Vol 17 (2) ◽  
pp. 225-241
Author(s):  
Mai Lill Suhr Lunde ◽  
Tone Fredsvik Gregers

This study aimed to investigate Norwegian eighth-grade students’ preconceptions of cells, the development of their understanding of cellular structure and function during cell biology instruction, and their understanding of the cell as a system. We conducted pre- and posttests including drawings, images and statements with 28 students. Our findings indicate that most students had a simplified view of cells prior to instruction but developed significant knowledge about cellular structures and different types of cells during instruction. However, several misconceptions arose, and some students seemed to alter their correct preconceptions. This suggests that teachers need to address misconceptions during instruction and support integration of students’ previous and new knowledge. Additionally, we suggest that focusing on numerous structures and cells from different organisms confuses students and complicates the process of achieving a systemic view of the cell.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Xing Xing ◽  
Dan Li ◽  
Shaomin Chen ◽  
Lingli Wang ◽  
Zhaoping Li ◽  
...  

Abstract Background The purpose of this study was to evaluate left ventricular systolic function in patients with different types of ischemic heart disease using two-dimensional speckle tracking imaging (2D-STI). Methods We retrospectively studied patients who were admitted to Peking University Third Hospital from January 2011 to December 2017 due to chest tightness and chest pain. Two hundred forty-two patients were divided into control group, CMD group and obstructive CAD group. The main coronary artery stenosis was confirmed by coronary angiography or coronary computed tomography and coronary flow reserve (CFR) in patients was measured by transthoracic Doppler echocardiography. Left ventricular strain and strain rate (SR) measured by 2D-STI. Cardiac structure and function were measured by conventional echocardiography. Results Conventional echocardiography showed that there was no significant difference in cardiac structure and function among the three groups (P > 0.05). Moreover, the longitudinal strain (LS) of each ventricular wall in CMD group was notably lower than that in control group (P < 0.01). In addition, global longitudinal SR and longitudinal SR in CMD group and obstructive CAD group were obviously lower than those in control group (P < 0.01). GLS, endocardial LS and epicardial LS were negatively correlated with CFR (P < 0.01). Conclusions Early left ventricular systolic dysfunction was found in patients with CMD and patients with obstructive CAD, with similar degree. CFR is an independent influencing factor of GLS. GLS and stratified LS have certain diagnostic value for CMD.


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