Measuring collective behaviour of multicellular ensembles: role of space-time scales

2008 ◽  
Vol 33 (2) ◽  
pp. 289-301 ◽  
Author(s):  
S. Rajesh ◽  
Somdatta Sinha
Keyword(s):  
Time Scales ◽  
Space Time ◽  
Collective Behaviour

Role of orography in modulating space–time scales of convection over South Asia

2013 ◽  
Vol 116 (3-4) ◽  
pp. 549-564 ◽  
Author(s):  
Arindam Chakraborty ◽  
Ravi S. Nanjundiah
Keyword(s):  
South Asia ◽  
Time Scales ◽  
Space Time

Do Writing Directions Influence How People Map Space onto Time?

2018 ◽  
Vol 77 (4) ◽  
pp. 173-184
Author(s):  
Wenxing Yang ◽  
Ying Sun
Keyword(s):  
Mental Representations ◽  
Space Time ◽  
Horizontal Axis ◽  
Causal Role ◽  
Writing Systems ◽  
Temporal Cognition ◽  
Japanese Speakers ◽  
Psychological Experiments ◽  
Vertical Up

Abstract. The causal role of a unidirectional orthography in shaping speakers’ mental representations of time seems to be well established by many psychological experiments. However, the question of whether bidirectional writing systems in some languages can also produce such an impact on temporal cognition remains unresolved. To address this issue, the present study focused on Japanese and Taiwanese, both of which have a similar mix of texts written horizontally from left to right (HLR) and vertically from top to bottom (VTB). Two experiments were performed which recruited Japanese and Taiwanese speakers as participants. Experiment 1 used an explicit temporal arrangement design, and Experiment 2 measured implicit space-time associations in participants along the horizontal (left/right) and the vertical (up/down) axis. Converging evidence gathered from the two experiments demonstrate that neither Japanese speakers nor Taiwanese speakers aligned their vertical representations of time with the VTB writing orientation. Along the horizontal axis, only Japanese speakers encoded elapsing time into a left-to-right linear layout, which was commensurate with the HLR writing direction. Therefore, two distinct writing orientations of a language could not bring about two coexisting mental time lines. Possible theoretical implications underlying the findings are discussed.

scholarly journals Impact of tumor-parenchyma biomechanics on liver metastatic progression: a multi-model approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yafei Wang ◽  
Erik Brodin ◽  
Kenichiro Nishii ◽  
Hermann B. Frieboes ◽  
Shannon M. Mumenthaler ◽  
...  
Keyword(s):  
Time Scales ◽  
Constitutive Relations ◽  
Elastic Tissue ◽  
Metastatic Progression ◽  
Patient Death ◽  
Metastatic Growth ◽  
Tumor Parenchyma ◽  
Short Time ◽  
Model Approach

AbstractColorectal cancer and other cancers often metastasize to the liver in later stages of the disease, contributing significantly to patient death. While the biomechanical properties of the liver parenchyma (normal liver tissue) are known to affect tumor cell behavior in primary and metastatic tumors, the role of these properties in driving or inhibiting metastatic inception remains poorly understood, as are the longer-term multicellular dynamics. This study adopts a multi-model approach to study the dynamics of tumor-parenchyma biomechanical interactions during metastatic seeding and growth. We employ a detailed poroviscoelastic model of a liver lobule to study how micrometastases disrupt flow and pressure on short time scales. Results from short-time simulations in detailed single hepatic lobules motivate constitutive relations and biological hypotheses for a minimal agent-based model of metastatic growth in centimeter-scale tissue over months-long time scales. After a parameter space investigation, we find that the balance of basic tumor-parenchyma biomechanical interactions on shorter time scales (adhesion, repulsion, and elastic tissue deformation over minutes) and longer time scales (plastic tissue relaxation over hours) can explain a broad range of behaviors of micrometastases, without the need for complex molecular-scale signaling. These interactions may arrest the growth of micrometastases in a dormant state and prevent newly arriving cancer cells from establishing successful metastatic foci. Moreover, the simulations indicate ways in which dormant tumors could “reawaken” after changes in parenchymal tissue mechanical properties, as may arise during aging or following acute liver illness or injury. We conclude that the proposed modeling approach yields insight into the role of tumor-parenchyma biomechanics in promoting liver metastatic growth, and advances the longer term goal of identifying conditions to clinically arrest and reverse the course of late-stage cancer.

scholarly journals Coherence Effects in Multiple Medium-Induced Radiation

Proceedings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Fabio Dominguez ◽  
Jose Guilherme Milhano ◽  
Carlos A. Salgado ◽  
Konrad Tywoniuk ◽  
Victor Vila
Keyword(s):  
Time Scales ◽  
Survival Probability ◽  
Jet Quenching ◽  
Close Correspondence ◽  
Gluon Emission ◽  
Classical Description ◽  
Theoretical Support ◽  
Coherence Effects ◽  
Hard Gluon

In the first part of this work we study the color coherence phenomenon by considering the well-known quark-antiquark antenna with an in-medium hard gluon emission and an extra very soft emission outside it—double antenna. By discussing the coherence effects in terms of the survival probability, we generalize previous studies of the antenna radiation to the case of more than two emitters. After providing support to the jet quenching picture with effective emitters in the QCD cascade, we present a novel setup of an antenna splitting inside the medium taking into account the finite formation time of the dipole, which turns out to be an important scale. We read into the role of coherence and the relevant time scales which control the scenario, while also providing theoretical support for vacuum-like emissions early in the medium. Finally, by mapping the spectrum of in-medium splittings through the corresponding kinematical Lund diagram, we appreciate regimes of a close correspondence to a semi-classical description.

scholarly journals A Survey of Function Analysis and Applied Dynamic Equations on Hybrid Time Scales

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 450
Author(s):  
Chao Wang ◽  
Ravi P. Agarwal
Keyword(s):  
Time Scales ◽  
Function Analysis ◽  
Dynamical Behavior ◽  
Research Field ◽  
Dynamic Equations ◽  
Future Research ◽  
Dynamical Models ◽  
Time Scale Calculus ◽  
The Difference

As an effective tool to unify discrete and continuous analysis, time scale calculus have been widely applied to study dynamic systems in both theoretical and practical aspects. In addition to such a classical role of unification, the dynamic equations on time scales have their own unique features which the difference and differential equations do not possess and these advantages have been highlighted in describing some complicated dynamical behavior in the hybrid time process. In this review article, we conduct a survey of abstract analysis and applied dynamic equations on hybrid time scales, some recent main results and the related developments on hybrid time scales will be reported and the future research related to this research field is discussed. The results presented in this article can be extended and generalized to study both pure mathematical analysis and real applications such as mathematical physics, biological dynamical models and neural networks, etc.

Noncommutative scalar field in de Sitter space–time and pair creation process

2021 ◽  
Vol 36 (02) ◽  
pp. 2150011
Author(s):  
Nabil Mehdaoui ◽  
Lamine Khodja ◽  
Salah Haouat
Keyword(s):  
Scalar Field ◽  
Chemical Potential ◽  
De Sitter Space ◽  
Space Time ◽  
Pair Creation ◽  
De Sitter ◽  
Creation Process ◽  
Scalar Particles ◽  
Constant Electromagnetic Field

In this work, we address the process of pair creation of scalar particles in [Formula: see text] de Sitter space–time in presence of a constant electromagnetic field by applying the noncommutativity on the scalar field up to first-order in [Formula: see text]. We calculate the density of particles created in the vacuum by the mean of the Bogoliubov transformations. In contrast to a previous result, we show that noncommutativity contributes to the pair creation process. We find that the noncommutativity plays the same role of chemical potential and gives an important interest for studies at high energies.

scholarly journals Group-level patterns emerge from individual speed as revealed by an extremely social robotic fish

2020 ◽  
Author(s):  
Jolle W. Jolles ◽  
Nils Weimar ◽  
Tim Landgraf ◽  
Pawel Romanczuk ◽  
Jens Krause ◽  
...  
Keyword(s):  
Empirical Work ◽  
Feedback System ◽  
Robotic Fish ◽  
Collective Behaviour ◽  
Movement Speed ◽  
Group Level ◽  
Individual Based Models ◽  
Biomimetic Robot ◽  
Induced Changes

AbstractUnderstanding the emergence of collective behaviour has long been a key research focus in the natural sciences. Besides the fundamental role of social interaction rules, a combination of theoretical and empirical work indicates individual speed may be a key process that drives the collective behaviour of animal groups. Socially-induced changes in speed by interacting animals make it difficult to isolate the effects of individual speed on group-level behaviours. Here we tackled this issue by pairing guppies with a biomimetic robot. We used a closed-loop tracking and feedback system to let a robotic fish naturally interact with a live partner in real time, and programmed it to strongly copy and follow its partner’s movements while lacking any preferred movement speed or directionality of its own. We show that individual differences in guppies’ movement speed were highly repeatable and shaped key collective patterns: higher individual speeds resulted in stronger leadership, lower cohesion, higher alignment, and better temporal coordination in the pairs. By combining the strengths of individual-based models and observational work with state-of-the-art robotics, we provide novel evidence that individual speed is a key, fundamental process in the emergence of collective behaviour.

scholarly journals Los espacios turísticos: producción, experiencias e imaginarios. El caso de la Araucanía andino-lacustre chilena, 1900-1940

2019 ◽  
pp. 219-246
Author(s):  
Pablo Martínez Riquelme
Keyword(s):  
19Th Century ◽  
Space Time ◽  
The State ◽  
The South ◽  
Material Production ◽  
Role Of The State ◽  
Tourist Experience ◽  
Siglo Xix ◽  
The 19Th Century

Los procesos de producción de espacios turísticos se expresan en sendas espacio-temporales, asociadas a una producción material, como las infraestructuras, equipamiento y conectividad, pero también en una producción inmaterial, basada en la difusión de imaginarios territoriales vinculados a la experiencia turística. Se busca analizar dicho proceso, en la Araucanía andino-lacustre chilena, entre 1900-1940, a partir de los relatos de los primeros viajeros con motivaciones turísticas a finales del siglo XIX y el rol de Estado como actor promotor de la turistificación del territorio en el sur de Chile. The processes of production of tourist spaces are expressed in space-time paths, associated with a material production, such as infrastructures, equipment and connectivity, but also in an immaterial production, based on the diffusion of territorial imaginaries linked to the tourist experience. It is sought to analyze this process, in the Chilean Andean-lacustrine Araucanía, between 1900-1940, based on the account of the first travelers with tourist motivations at the end of the 19th century and the role of the State as a promoter of the touristification of the territory in the South of Chile.

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