28 research outputs found

    Video Pandemics: Worldwide Viral Spreading of Psy's Gangnam Style Video

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    Viral videos can reach global penetration traveling through international channels of communication similarly to real diseases starting from a well-localized source. In past centuries, disease fronts propagated in a concentric spatial fashion from the the source of the outbreak via the short range human contact network. The emergence of long-distance air-travel changed these ancient patterns. However, recently, Brockmann and Helbing have shown that concentric propagation waves can be reinstated if propagation time and distance is measured in the flight-time and travel volume weighted underlying air-travel network. Here, we adopt this method for the analysis of viral meme propagation in Twitter messages, and define a similar weighted network distance in the communication network connecting countries and states of the World. We recover a wave-like behavior on average and assess the randomizing effect of non-locality of spreading. We show that similar result can be recovered from Google Trends data as well.Comment: 10 page

    Crystalline Assemblies and Densest Packings of a Family of Truncated Tetrahedra and the Role of Directional Entropic Forces

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    Polyhedra and their arrangements have intrigued humankind since the ancient Greeks and are today important motifs in condensed matter, with application to many classes of liquids and solids. Yet, little is known about the thermodynamically stable phases of polyhedrally-shaped building blocks, such as faceted nanoparticles and colloids. Although hard particles are known to organize due to entropy alone, and some unusual phases are reported in the literature, the role of entropic forces in connection with polyhedral shape is not well understood. Here, we study thermodynamic self-assembly of a family of truncated tetrahedra and report several atomic crystal isostructures, including diamond, {\beta}-tin, and high- pressure lithium, as the polyhedron shape varies from tetrahedral to octahedral. We compare our findings with the densest packings of the truncated tetrahedron family obtained by numerical compression and report a new space filling polyhedron, which has been overlooked in previous searches. Interestingly, the self-assembled structures differ from the densest packings. We show that the self-assembled crystal structures can be understood as a tendency for polyhedra to maximize face-to-face alignment, which can be generalized as directional entropic forces.Comment: Article + supplementary information. 23 pages, 10 figures, 2 table

    Receptor Tyrosine Kinases in Osteosarcoma: 2019 Update

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    The primary conclusions of our 2014 contribution to this series were as follows: Multiple receptor tyrosine kinases (RTKs) likely contribute to aggressive phenotypes in osteosarcoma and, therefore, inhibition of multiple RTKs is likely necessary for successful clinical outcomes. Inhibition of multiple RTKs may also be useful to overcome resistance to inhibitors of individual RTKs as well as resistance to conventional chemotherapies. Different combinations of RTKs are likely important in individual patients. AXL, EPHB2, FGFR2, IGF1R, and RET were identified as promising therapeutic targets by our in vitro phosphoproteomic/siRNA screen of 42 RTKs in the highly metastatic LM7 and 143B human osteosarcoma cell lines. This chapter is intended to provide an update on these topics as well as the large number of osteosarcoma clinical studies of inhibitors of multiple tyrosine kinases (multi-TKIs) that were recently published

    The case of Air Traffic Control training

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    Air traffic controllers have to guarantee safe and efficient air traffic by predicting future flight paths based on their perception and interpretation of multiple data on the radar display. The multi-tasking nature of their job makes the cognitive and emotional processes required in Air Traffic Control fundamentally different from those traditionally studied in the lab. Thus, Air Traffic Control represents a unique naturalistic opportunity to investigate how such a demanding job may shape cognition. This chapter reviews work dealing with the cognitive characteristics of air traffic control, as well as the few studies that have investigated how training and experience in this profession change different aspects of cognitive functioning, in particular different facets of cognitive flexibility and planning abilities. Finally, it will also examine the cognitive consequences of the unique challenges represented by man-technology interactions inherent in this job. Despite the promising findings reviewed in this chapter, the research on the cognitive enhancement derived from training and experience on ATC is still limited and not conclusive. Further methodologically well-controlled studies are clearly needed to obtain a more comprehensive picture of the extraordinary potentialities of this profession
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