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Verma M, Hontecillas R, Abedi V, Leber A, Tubau-Juni N, Philipson C, Carbo A, Bassaganya-Riera J. Modeling-Enabled Systems Nutritional Immunology. Front Nutr 2016; 3:5. [PMID: 26909350 PMCID: PMC4754447 DOI: 10.3389/fnut.2016.00005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 02/01/2016] [Indexed: 12/14/2022] Open
Abstract
This review highlights the fundamental role of nutrition in the maintenance of health, the immune response, and disease prevention. Emerging global mechanistic insights in the field of nutritional immunology cannot be gained through reductionist methods alone or by analyzing a single nutrient at a time. We propose to investigate nutritional immunology as a massively interacting system of interconnected multistage and multiscale networks that encompass hidden mechanisms by which nutrition, microbiome, metabolism, genetic predisposition, and the immune system interact to delineate health and disease. The review sets an unconventional path to apply complex science methodologies to nutritional immunology research, discovery, and development through “use cases” centered around the impact of nutrition on the gut microbiome and immune responses. Our systems nutritional immunology analyses, which include modeling and informatics methodologies in combination with pre-clinical and clinical studies, have the potential to discover emerging systems-wide properties at the interface of the immune system, nutrition, microbiome, and metabolism.
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Affiliation(s)
- Meghna Verma
- Nutritional Immunology and Molecular Medicine Laboratory (www.nimml.org), Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA; The Center for Modeling Immunity to Enteric Pathogens, Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA
| | - Raquel Hontecillas
- Nutritional Immunology and Molecular Medicine Laboratory (www.nimml.org), Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA; The Center for Modeling Immunity to Enteric Pathogens, Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA
| | - Vida Abedi
- Nutritional Immunology and Molecular Medicine Laboratory (www.nimml.org), Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA; The Center for Modeling Immunity to Enteric Pathogens, Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA
| | - Andrew Leber
- Nutritional Immunology and Molecular Medicine Laboratory (www.nimml.org), Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA; The Center for Modeling Immunity to Enteric Pathogens, Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA
| | - Nuria Tubau-Juni
- Nutritional Immunology and Molecular Medicine Laboratory (www.nimml.org), Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA; The Center for Modeling Immunity to Enteric Pathogens, Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA
| | | | | | - Josep Bassaganya-Riera
- Nutritional Immunology and Molecular Medicine Laboratory (www.nimml.org), Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA; The Center for Modeling Immunity to Enteric Pathogens, Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA
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302
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Abstract
Magnetoencephalography (MEG) and electroencephalography (EEG) are invaluable neuroscientific tools for unveiling human neural dynamics in three dimensions (space, time, and frequency), which are associated with a wide variety of perceptions, cognition, and actions. MEG/EEG also provides different categories of neuronal indices including activity magnitude, connectivity, and network properties along the three dimensions. In the last 20 years, interest has increased in inter-regional connectivity and complex network properties assessed by various sophisticated scientific analyses. We herein review the definition, computation, short history, and pros and cons of connectivity and complex network (graph-theory) analyses applied to MEG/EEG signals. We briefly describe recent developments in source reconstruction algorithms essential for source-space connectivity and network analyses. Furthermore, we discuss a relatively novel approach used in MEG/EEG studies to examine the complex dynamics represented by human brain activity. The correct and effective use of these neuronal metrics provides a new insight into the multi-dimensional dynamics of the neural representations of various functions in the complex human brain.
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Affiliation(s)
- Tetsuo Kida
- Department of Integrative Physiology, National Institute for Physiological SciencesOkazaki, Japan
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303
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MOCHIZUKI A. Theoretical approaches for the dynamics of complex biological systems from information of networks. Proc Jpn Acad Ser B Phys Biol Sci 2016; 92:255-264. [PMID: 27725468 PMCID: PMC5243945 DOI: 10.2183/pjab.92.255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Accepted: 07/29/2016] [Indexed: 06/06/2023]
Abstract
Modern biology has provided many examples of large networks describing the interactions between multiple species of bio-molecules. It is believed that the dynamics of molecular activities based on such networks are the origin of biological functions. On the other hand, we have a limited understanding for dynamics of molecular activity based on networks. To overcome this problem, we have developed two structural theories, by which the important aspects of the dynamical properties of the system are determined only from information on the network structure, without assuming other quantitative details. The first theory, named Linkage Logic, determines a subset of molecules in regulatory networks, by which any long-term dynamical behavior of the whole system can be identified/controlled. The second theory, named Structural Sensitivity Analysis, determines the sensitivity responses of the steady state of chemical reaction networks to perturbations of the reaction rate. The first and second theories investigate the dynamical properties of regulatory and reaction networks, respectively. The first theory targets the attractors of the regulatory network systems, whereas the second theory applies only to the steady states of the reaction network systems, but predicts their detailed behavior. To demonstrate the utility of our methods several biological network systems, and show they are practically useful to analyze behaviors of biological systems.
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Affiliation(s)
- Atsushi MOCHIZUKI
- Theoretical Biology Laboratory, RIKEN, Wako, Saitama, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
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304
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Brown G, Reeders D, Dowsett GW, Ellard J, Carman M, Hendry N, Wallace J. Investigating combination HIV prevention: isolated interventions or complex system. J Int AIDS Soc 2015; 18:20499. [PMID: 26673880 DOI: 10.7448/IAS.18.1.20499] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 10/08/2015] [Accepted: 11/19/2015] [Indexed: 12/16/2022] Open
Abstract
Introduction Treatment as prevention has mobilized new opportunities in preventing HIV transmission and has led to bold new UNAIDS targets in testing, treatment coverage and transmission reduction. These will require not only an increase in investment but also a deeper understanding of the dynamics of combining behavioural, biomedical and structural HIV prevention interventions. High-income countries are making substantial investments in combination HIV prevention, but is this investment leading to a deeper understanding of how to combine interventions? The combining of interventions involves complexity, with many strategies interacting with non-linear and multiplying rather than additive effects. Discussion Drawing on a recent scoping study of the published research evidence in HIV prevention in high-income countries, this paper argues that there is a gap between the evidence currently available and the evidence needed to guide the achieving of these bold targets. The emphasis of HIV prevention intervention research continues to look at one intervention at a time in isolation from its interactions with other interventions, the community and the socio-political context of their implementation. To understand and evaluate the role of a combination of interventions, we need to understand not only what works, but in what circumstances, what role the parts need to play in their relationship with each other, when the combination needs to adapt and identify emergent effects of any resulting synergies. There is little development of evidence-based indicators on how interventions in combination should achieve that strategic advantage and synergy. This commentary discusses the implications of this ongoing situation for future research and the required investment in partnership. We suggest that systems science approaches, which are being increasingly applied in other areas of public health, could provide an expanded vocabulary and analytic tools for understanding these complex interactions, relationships and emergent effects. Conclusions Relying on the current linear but disconnected approaches to intervention research and evidence we will miss the potential to achieve and understand system-level synergies. Given the challenges in sustaining public health and HIV prevention investment, meeting the bold UNAIDS targets that have been set is likely to be dependent on achieving systems level synergies.
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305
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Renfree A, Crivoi do Carmo E, Martin L, Peters DM. The Influence of Collective Behavior on Pacing in Endurance Competitions. Front Physiol 2015; 6:373. [PMID: 26696903 PMCID: PMC4673336 DOI: 10.3389/fphys.2015.00373] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 11/23/2015] [Indexed: 01/31/2023] Open
Abstract
A number of theoretical models have been proposed in recent years to explain pacing strategies observed in individual competitive endurance events. These have typically related to the internal regulatory processes that inform the making of decisions relating to muscular work rate. Despite a substantial body of research which has investigated the influence of collective group dynamics on individual behaviors in various animal species, this issue has not been comprehensively studied in individual athletic events. This is somewhat surprising given that athletes often directly compete in close proximity to one another, and that collective behavior has also been observed in other human environments including pedestrian interactions and financial market trading. Whilst the reasons for adopting collective behavior are not fully understood, collective behavior is thought to result from individual agents following simple local rules that result in seemingly complex large systems that act to confer some biological advantage to the collective as a whole. Although such collective behaviors may generally be beneficial, competitive endurance events are complicated by the fact that increasing levels of physiological disruption as activity progresses may compromise the ability of some individuals to continue to interact with other group members. This could result in early fatigue and relative underperformance due to suboptimal utilization of physiological resources by some athletes. Alternatively, engagement with a collective behavior may benefit all due to a reduction in the complexity of decisions to be made and a subsequent reduction in cognitive loading and mental fatigue. This paper seeks evidence for collective behavior in previously published analyses of pacing behavior and proposes mechanisms through which it could potentially be either beneficial, or detrimental to individual performance. It concludes with suggestions for future research to enhance understanding of this phenomenon.
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Affiliation(s)
- Andrew Renfree
- Institute of Sport and Exercise Science, University of Worcester Worcester, UK
| | | | - Louise Martin
- Institute of Sport and Exercise Science, University of Worcester Worcester, UK
| | - Derek M Peters
- Institute of Sport and Exercise Science, University of Worcester Worcester, UK ; Faculty of Health and Sport Sciences, University of Agder Kristiansand, Norway
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306
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Jones DT, Knopman DS, Gunter JL, Graff-Radford J, Vemuri P, Boeve BF, Petersen RC, Weiner MW, Jack CR. Cascading network failure across the Alzheimer's disease spectrum. Brain 2015; 139:547-62. [PMID: 26586695 PMCID: PMC4805086 DOI: 10.1093/brain/awv338] [Citation(s) in RCA: 316] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 10/02/2015] [Indexed: 12/14/2022] Open
Abstract
Complex biological systems are organized across various spatiotemporal scales with particular scientific disciplines dedicated to the study of each scale (e.g. genetics, molecular biology and cognitive neuroscience). When considering disease pathophysiology, one must contemplate the scale at which the disease process is being observed and how these processes impact other levels of organization. Historically Alzheimer’s disease has been viewed as a disease of abnormally aggregated proteins by pathologists and molecular biologists and a disease of clinical symptoms by neurologists and psychologists. Bridging the divide between these scales has been elusive, but the study of brain networks appears to be a pivotal inroad to accomplish this task. In this study, we were guided by an emerging systems-based conceptualization of Alzheimer’s disease and investigated changes in brain networks across the disease spectrum. The default mode network has distinct subsystems with unique functional-anatomic connectivity, cognitive associations, and responses to Alzheimer’s pathophysiology. These distinctions provide a window into the systems-level pathophysiology of Alzheimer’s disease. Using clinical phenotyping, metadata, and multimodal neuroimaging data from the Alzheimer’s Disease Neuroimaging Initiative, we characterized the pattern of default mode network subsystem connectivity changes across the entire disease spectrum (n = 128). The two main findings of this paper are (i) the posterior default mode network fails before measurable amyloid plaques and appears to initiate a connectivity cascade that continues throughout the disease spectrum; and (ii) high connectivity between the posterior default mode network and hubs of high connectivity (many located in the frontal lobe) is associated with amyloid accumulation. These findings support a system model best characterized by a cascading network failure—analogous to cascading failures seen in power grids triggered by local overloads proliferating to downstream nodes eventually leading to widespread power outages, or systems failures. The failure begins in the posterior default mode network, which then shifts processing burden to other systems containing prominent connectivity hubs. This model predicts a connectivity ‘overload’ that precedes structural and functional declines and recasts the interpretation of high connectivity from that of a positive compensatory phenomenon to that of a load-shifting process transiently serving a compensatory role. It is unknown whether this systems-level pathophysiology is the inciting event driving downstream molecular events related to synaptic activity embedded in these systems. Possible interpretations include that the molecular-level events drive the network failure, a pathological interaction between the network-level and the molecular-level, or other upstream factors are driving both.
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Affiliation(s)
- David T Jones
- 1 Department of Neurology, Mayo Clinic, Rochester, MN, 55905, USA 2 Department of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | - David S Knopman
- 1 Department of Neurology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jeffrey L Gunter
- 2 Department of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | | | | | - Bradley F Boeve
- 1 Department of Neurology, Mayo Clinic, Rochester, MN, 55905, USA
| | | | - Michael W Weiner
- 3 Department of Veterans Affairs Medical Center, Center for Imaging of Neurodegenerative Diseases and Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, 94121, USA
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307
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Abstract
Studies using massive, passively collected data from communication technologies have revealed many ubiquitous aspects of social networks, helping us understand and model social media, information diffusion and organizational dynamics. More recently, these data have come tagged with geographical information, enabling studies of human mobility patterns and the science of cities. We combine these two pursuits and uncover reproducible mobility patterns among social contacts. First, we introduce measures of mobility similarity and predictability and measure them for populations of users in three large urban areas. We find individuals' visitations patterns are far more similar to and predictable by social contacts than strangers and that these measures are positively correlated with tie strength. Unsupervised clustering of hourly variations in mobility similarity identifies three categories of social ties and suggests geography is an important feature to contextualize social relationships. We find that the composition of a user's ego network in terms of the type of contacts they keep is correlated with mobility behaviour. Finally, we extend a popular mobility model to include movement choices based on social contacts and compare its ability to reproduce empirical measurements with two additional models of mobility.
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Affiliation(s)
| | - Carlos Herrera-Yaqüe
- Department of Civil and Environmental Engineering, MIT, Cambridge, MA 02144, USA Departamento de Matemática Aplicada a las Tecnologías de la Información, ETSI Telecomunicación, Universidad Politécnica de Madrid (UPM), Madrid, Spain
| | | | - Marta C González
- Engineering Systems Division, MIT, Cambridge, MA 02144, USA Department of Civil and Environmental Engineering, MIT, Cambridge, MA 02144, USA
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308
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Masucci AP, Arcaute E, Hatna E, Stanilov K, Batty M. On the problem of boundaries and scaling for urban street networks. J R Soc Interface 2015; 12:20150763. [PMID: 26468071 PMCID: PMC4614511 DOI: 10.1098/rsif.2015.0763] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 09/21/2015] [Indexed: 12/04/2022] Open
Abstract
Urban morphology has presented significant intellectual challenges to mathematicians and physicists ever since the eighteenth century, when Euler first explored the famous Königsberg bridges problem. Many important regularities and scaling laws have been observed in urban studies, including Zipf's law and Gibrat's law, rendering cities attractive systems for analysis within statistical physics. Nevertheless, a broad consensus on how cities and their boundaries are defined is still lacking. Applying an elementary clustering technique to the street intersection space, we show that growth curves for the maximum cluster size of the largest cities in the UK and in California collapse to a single curve, namely the logistic. Subsequently, by introducing the concept of the condensation threshold, we show that natural boundaries of cities can be well defined in a universal way. This allows us to study and discuss systematically some of the regularities that are present in cities. We show that some scaling laws present consistent behaviour in space and time, thus suggesting the presence of common principles at the basis of the evolution of urban systems.
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Affiliation(s)
- A Paolo Masucci
- Centre for Advanced Spatial Analysis, University College London, 90 Tottenham Court Road, London W1N 6TR, UK
| | - Elsa Arcaute
- Centre for Advanced Spatial Analysis, University College London, 90 Tottenham Court Road, London W1N 6TR, UK
| | - Erez Hatna
- Center for Advanced Modeling, The Johns Hopkins University, Baltimore, MD, USA
| | - Kiril Stanilov
- Centre for Advanced Spatial Analysis, University College London, 90 Tottenham Court Road, London W1N 6TR, UK Centre for Sustainable Infrastructure and Construction, University of Cambridge, Cambridge CB2 1TN, UK
| | - Michael Batty
- Centre for Advanced Spatial Analysis, University College London, 90 Tottenham Court Road, London W1N 6TR, UK
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309
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Abstract
UNLABELLED Sustainability issues such as natural resource depletion, pollution and poor working conditions have no geographical boundaries in our interconnected world. To address these issues requires a paradigm shift within human factors and ergonomics (HFE), to think beyond a bounded, linear model understanding towards a broader systems framework. For this reason, we introduce a sustainable system of systems model that integrates the current hierarchical conceptualisation of possible interventions (i.e., micro-, meso- and macro-ergonomics) with important concepts from the sustainability literature, including the triple bottom line approach and the notion of time frames. Two practical examples from the HFE literature are presented to illustrate the model. The implications of this paradigm shift for HFE researchers and practitioners are discussed and include the long-term sustainability of the HFE community and comprehensive solutions to problems that consider the emergent issues that arise from this interconnected world. PRACTITIONER SUMMARY A sustainable world requires a broader systems thinking than that which currently exists in ergonomics. This study proposes a sustainable system of systems model that incorporates ideas from the ecological sciences, notably a nested hierarchy of systems and a hierarchical time dimension. The implications for sustainable design and the sustainability of the HFE community are considered.
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Affiliation(s)
- Andrew Thatcher
- a School of Human and Community Development, University of the Witwatersrand , Johannesburg , South Africa
| | - Paul H P Yeow
- b School of Business, Monash University Malaysia , Jalan Lagoon Selatan, 46150, Bandar Sunway, Petaling Jaya, Selangor , Malaysia
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310
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Barchiesi D, Preis T, Bishop S, Moat HS. Modelling human mobility patterns using photographic data shared online. R Soc Open Sci 2015; 2:150046. [PMID: 26361545 PMCID: PMC4555850 DOI: 10.1098/rsos.150046] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 07/15/2015] [Indexed: 06/05/2023]
Abstract
Humans are inherently mobile creatures. The way we move around our environment has consequences for a wide range of problems, including the design of efficient transportation systems and the planning of urban areas. Here, we gather data about the position in space and time of about 16 000 individuals who uploaded geo-tagged images from locations within the UK to the Flickr photo-sharing website. Inspired by the theory of Lévy flights, which has previously been used to describe the statistical properties of human mobility, we design a machine learning algorithm to infer the probability of finding people in geographical locations and the probability of movement between pairs of locations. Our findings are in general agreement with official figures in the UK and on travel flows between pairs of major cities, suggesting that online data sources may be used to quantify and model large-scale human mobility patterns.
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Affiliation(s)
- Daniele Barchiesi
- Department of Mathematics, University College London, Gower Street, London WC1E 6BT, UK
| | - Tobias Preis
- Department of Mathematics, University College London, Gower Street, London WC1E 6BT, UK
- Warwick Business School, University of Warwick, Scarman Road, Coventry CV4 7AL, UK
- Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
| | - Steven Bishop
- Department of Mathematics, University College London, Gower Street, London WC1E 6BT, UK
| | - Helen Susannah Moat
- Department of Mathematics, University College London, Gower Street, London WC1E 6BT, UK
- Warwick Business School, University of Warwick, Scarman Road, Coventry CV4 7AL, UK
- Department of Physics, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
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311
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Abstract
The quantitative description of cultural evolution is a challenging task. The most difficult part of the problem is probably to find the appropriate measurable quantities that can make more quantitative such evasive concepts as, for example, dynamics of cultural movements, behavioral patterns, and traditions of the people. A strategy to tackle this issue is to observe particular features of human activities, i.e., cultural traits, such as names given to newborns. We study the names of babies born in the United States from 1910 to 2012. Our analysis shows that groups of different correlated states naturally emerge in different epochs, and we are able to follow and decrypt their evolution. Although these groups of states are stable across many decades, a sudden reorganization occurs in the last part of the 20th century. We unambiguously demonstrate that cultural evolution of society can be observed and quantified by looking at cultural traits. We think that this kind of quantitative analysis can be possibly extended to other cultural traits: Although databases covering more than one century (such as the one we used) are rare, the cultural evolution on shorter timescales can be studied due to the fact that many human activities are usually recorded in the present digital era.
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Affiliation(s)
- Paolo Barucca
- Dipartimento di Fisica, Sapienza Universitá di Roma, I-00185 Rome, Italy;
| | - Jacopo Rocchi
- Dipartimento di Fisica, Sapienza Universitá di Roma, I-00185 Rome, Italy
| | - Enzo Marinari
- Dipartimento di Fisica, Sapienza Universitá di Roma, I-00185 Rome, Italy; Sezione di Roma 1, Istituto Nazionale di Fisica Nucleare, I-00185 Rome, Italy
| | - Giorgio Parisi
- Dipartimento di Fisica, Sapienza Universitá di Roma, I-00185 Rome, Italy; Sezione di Roma 1, Istituto Nazionale di Fisica Nucleare, I-00185 Rome, Italy
| | - Federico Ricci-Tersenghi
- Dipartimento di Fisica, Sapienza Universitá di Roma, I-00185 Rome, Italy; Sezione di Roma 1, Istituto Nazionale di Fisica Nucleare, I-00185 Rome, Italy
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312
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Abstract
Artificial neural networks (ANNs) are usually considered as tools which can help to analyze cause-effect relationships in complex systems within a big-data framework. On the other hand, health sciences undergo complexity more than any other scientific discipline, and in this field large datasets are seldom available. In this situation, I show how a particular neural network tool, which is able to handle small datasets of experimental or observational data, can help in identifying the main causal factors leading to changes in some variable which summarizes the behaviour of a complex system, for instance the onset of a disease. A detailed description of the neural network tool is given and its application to a specific case study is shown. Recommendations for a correct use of this tool are also supplied.
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313
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Silva R, Kang SM, Airoldi EM. Predicting traffic volumes and estimating the effects of shocks in massive transportation systems. Proc Natl Acad Sci U S A 2015; 112:5643-8. [PMID: 25902504 DOI: 10.1073/pnas.1412908112] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Public transportation systems are an essential component of major cities. The widespread use of smart cards for automated fare collection in these systems offers a unique opportunity to understand passenger behavior at a massive scale. In this study, we use network-wide data obtained from smart cards in the London transport system to predict future traffic volumes, and to estimate the effects of disruptions due to unplanned closures of stations or lines. Disruptions, or shocks, force passengers to make different decisions concerning which stations to enter or exit. We describe how these changes in passenger behavior lead to possible overcrowding and model how stations will be affected by given disruptions. This information can then be used to mitigate the effects of these shocks because transport authorities may prepare in advance alternative solutions such as additional buses near the most affected stations. We describe statistical methods that leverage the large amount of smart-card data collected under the natural state of the system, where no shocks take place, as variables that are indicative of behavior under disruptions. We find that features extracted from the natural regime data can be successfully exploited to describe different disruption regimes, and that our framework can be used as a general tool for any similar complex transportation system.
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314
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Botta F, Moat HS, Preis T. Quantifying crowd size with mobile phone and Twitter data. R Soc Open Sci 2015. [PMID: 26064667 DOI: 10.5061/dryad.1rk60] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Being able to infer the number of people in a specific area is of extreme importance for the avoidance of crowd disasters and to facilitate emergency evacuations. Here, using a football stadium and an airport as case studies, we present evidence of a strong relationship between the number of people in restricted areas and activity recorded by mobile phone providers and the online service Twitter. Our findings suggest that data generated through our interactions with mobile phone networks and the Internet may allow us to gain valuable measurements of the current state of society.
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Affiliation(s)
- Federico Botta
- Centre for Complexity Science , Warwick Business School, University of Warwick , Coventry CV4 7AL, UK ; Data Science Lab, Behavioural Science , Warwick Business School, University of Warwick , Coventry CV4 7AL, UK
| | - Helen Susannah Moat
- Data Science Lab, Behavioural Science , Warwick Business School, University of Warwick , Coventry CV4 7AL, UK
| | - Tobias Preis
- Data Science Lab, Behavioural Science , Warwick Business School, University of Warwick , Coventry CV4 7AL, UK
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315
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Botta F, Moat HS, Preis T. Quantifying crowd size with mobile phone and Twitter data. R Soc Open Sci 2015; 2:150162. [PMID: 26064667 PMCID: PMC4453255 DOI: 10.1098/rsos.150162] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 05/01/2015] [Indexed: 06/01/2023]
Abstract
Being able to infer the number of people in a specific area is of extreme importance for the avoidance of crowd disasters and to facilitate emergency evacuations. Here, using a football stadium and an airport as case studies, we present evidence of a strong relationship between the number of people in restricted areas and activity recorded by mobile phone providers and the online service Twitter. Our findings suggest that data generated through our interactions with mobile phone networks and the Internet may allow us to gain valuable measurements of the current state of society.
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Affiliation(s)
- Federico Botta
- Centre for Complexity Science, Warwick Business School, University of Warwick, Coventry CV4 7AL, UK
- Data Science Lab, Behavioural Science, Warwick Business School, University of Warwick, Coventry CV4 7AL, UK
| | - Helen Susannah Moat
- Data Science Lab, Behavioural Science, Warwick Business School, University of Warwick, Coventry CV4 7AL, UK
| | - Tobias Preis
- Data Science Lab, Behavioural Science, Warwick Business School, University of Warwick, Coventry CV4 7AL, UK
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316
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Khalaf K, Jelinek HF, Robinson C, Cornforth DJ, Tarvainen MP, Al-Aubaidy H. Complex nonlinear autonomic nervous system modulation link cardiac autonomic neuropathy and peripheral vascular disease. Front Physiol 2015; 6:101. [PMID: 25870563 PMCID: PMC4376075 DOI: 10.3389/fphys.2015.00101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/13/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Physiological interactions are abundant within, and between, body systems. These interactions may evolve into discrete states during pathophysiological processes resulting from common mechanisms. An association between arterial stenosis, identified by low ankle-brachial pressure index (ABPI) and cardiovascular disease (CVD) as been reported. Whether an association between vascular calcification-characterized by high ABPI and a different pathophysiology-is similarly associated with CVD, has not been established. The current study aims to investigate the association between ABPI, and cardiac rhythm, as an indicator of cardiovascular health and functionality, utilizing heart rate variability (HRV). METHODS AND RESULTS Two hundred and thirty six patients underwent ABPI assessment. Standard time and frequency domain, and non-linear HRV measures were determined from 5-min electrocardiogram. ABPI data were divided into normal (n = 101), low (n = 67) and high (n = 66) and compared to HRV measures.(DFAα1 and SampEn were significantly different between the low ABPI, high ABPI and control groups (p < 0.05). CONCLUSION A possible coupling between arterial stenosis and vascular calcification with decreased and increased HRV respectively was observed. Our results suggest a model for interpreting the relationship between vascular pathophysiology and cardiac rhythm. The cardiovascular system may be viewed as a complex system comprising a number of interacting subsystems. These cardiac and vascular subsystems/networks may be coupled and undergo transitions in response to internal or external perturbations. From a clinical perspective, the significantly increased sample entropy compared to the normal ABPI group and the decreased and increased complex correlation properties measured by DFA for the low and high ABPI groups respectively, may be useful indicators that a more holistic treatment approach in line with this more complex clinical picture is required.
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Affiliation(s)
- Kinda Khalaf
- Department of Biomedical Engineering, Khalifa University of Science, Technology and ResearchAbu Dhabi, UAE
| | - Herbert F. Jelinek
- Australian School of Advanced Medicine, Macquarie UniversitySydney, NSW, Australia
- Centre for Research in Complex Systems and School of Community Health, Charles Sturt UniversityAlbury, NSW, Australia
| | - Caroline Robinson
- School of Community Health, Charles Sturt UniversityAlbury, NSW, Australia
| | - David J. Cornforth
- School of Design, Communication and Information Technology, University of NewcastleNewcastle, NSW, Australia
| | - Mika P. Tarvainen
- Department of Applied Physics, University of Eastern FinlandKuopio, Finland
- Department of Clinical Physiology and Nuclear Medicine, Kuopio University HospitalKuopio, Finland
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317
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Abstract
The aim of this study was to compare footballers' movement behaviour during 2-, 3-, 4- and 5-a-side small-sided games. Ten young professional players (age = 18.0 ± 0.67 years) participated in 3 bouts of each small-sided games for 6 min with 1 min of active rest between bouts. Positional data were collected using GPS system units and used to calculate the following variables: team centroid, distance between each player and own and opponent team centroids and distance between centroids. Approximate entropy was used to identify the time series regularity for each variable. The distance to own team centroid increased with the number of players (effect sizes from moderate to perfect). The results from the distance to the opponent's centroid exhibited a similar trend. The distance between centroids decreased from 2- to the 4-a-side, but then increased in 5-a-side. A higher number of players were associated with lower approximate entropy values, suggesting higher positional organisation in small-sided games with more players. The highest movement regularity found in 4- and 5-a-side identified these formats as more adequate to promote team-related emergent and self-organised behaviours.
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Affiliation(s)
- Marco Aguiar
- a CreativeLab, Research Center in Sports, Health Sciences and Human Development . University of Trás-os-Montes e Alto Douro . Vila Real , Portugal
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318
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Haworth JL, Kyvelidou A, Fisher W, Stergiou N. Children's looking preference for biological motion may be related to an affinity for mathematical chaos. Front Psychol 2015; 6:281. [PMID: 25852600 PMCID: PMC4362051 DOI: 10.3389/fpsyg.2015.00281] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 02/26/2015] [Indexed: 11/13/2022] Open
Abstract
Recognition of biological motion is pervasive in early child development. Further, viewing the movement behavior of others is a primary component of a child's acquisition of complex, robust movement repertoires, through imitation and real-time coordinated action. We theorize that inherent to biological movements are particular qualities of mathematical chaos and complexity. We further posit that this character affords the rich and complex inter-dynamics throughout early motor development. Specifically, we explored whether children's preference for biological motion may be related to an affinity for mathematical chaos. Cross recurrence quantification analysis (cRQA) was used to investigate the coordination of gaze and posture with various temporal structures (periodic, chaotic, and aperiodic) of the motion of an oscillating visual stimulus. Children appear to competently perceive and respond to chaotic motion, both in rate (cRQA-percent determinism) and duration (cRQA-maxline) of coordination. We interpret this to indicate that children not only recognize chaotic motion structures, but also have a preference for coordination with them. Further, stratification of our sample (by age) uncovers the suggestion that this preference may become refined with age.
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Affiliation(s)
- Joshua L. Haworth
- Center for Autism and Related Disorders, Kennedy Krieger InstituteBaltimore, MD, USA
- School of Health, Physical Education and Recreation, University of Nebraska OmahaOmaha, NE, USA
- College of Public Health, University of Nebraska Medical CenterOmaha, NE, USA
| | - Anastasia Kyvelidou
- School of Health, Physical Education and Recreation, University of Nebraska OmahaOmaha, NE, USA
| | - Wayne Fisher
- Center for Autism Spectrum Disorders, University of Nebraska Medical CenterOmaha, NE, USA
| | - Nicholas Stergiou
- School of Health, Physical Education and Recreation, University of Nebraska OmahaOmaha, NE, USA
- College of Public Health, University of Nebraska Medical CenterOmaha, NE, USA
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319
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Abstract
Spreading fires are noisy (and potentially chaotic) systems in which transitions in dynamics are notoriously difficult to predict. As flames move through spatially heterogeneous environments, sudden shifts in temperature, wind, or topography can generate combustion instabilities, or trigger self-stabilizing feedback loops, that dramatically amplify the intensities and rates with which fires propagate. Such transitions are rarely captured by predictive models of fire behavior and, thus, complicate efforts in fire suppression. This paper describes a simple, remarkably instructive physical model for examining the eruption of small flames into intense, rapidly moving flames stabilized by feedback between wind and fire (i.e., "wind-fire coupling"-a mechanism of feedback particularly relevant to forest fires), and it presents evidence that characteristic patterns in the dynamics of spreading flames indicate when such transitions are likely to occur. In this model system, flames propagate along strips of nitrocellulose with one of two possible modes of propagation: a slow, structured mode, and a fast, unstructured mode sustained by wind-fire coupling. Experimental examination of patterns in dynamics that emerge near bifurcation points suggests that symptoms of critical slowing down (i.e., the slowed recovery of the system from perturbations as it approaches tipping points) warn of impending transitions to the unstructured mode. Findings suggest that slowing responses of spreading flames to sudden changes in environment (e.g., wind, terrain, temperature) may anticipate the onset of intense, feedback-stabilized modes of propagation (e.g., "blowup fires" in forests).
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320
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Abstract
Diagnosis performance is critical for the safety of high-consequence industrial systems. It depends highly on the information provided, perceived, interpreted and integrated by operators. This article examines the influence of information congruence (congruent information vs. conflicting information vs. missing information) and its interaction with time pressure (high vs. low) on diagnosis performance on a simulated platform. The experimental results reveal that the participants confronted with conflicting information spent significantly more time generating correct hypotheses and rated the results with lower probability values than when confronted with the other two levels of information congruence and were more prone to arrive at a wrong diagnosis result than when they were provided with congruent information. This finding stresses the importance of the proper processing of non-congruent information in safety-critical systems. Time pressure significantly influenced display switching frequency and completion time. This result indicates the decisive role of time pressure. Practitioner Summary: This article examines the influence of information congruence and its interaction with time pressure on human diagnosis performance on a simulated platform. For complex systems in the process control industry, the results stress the importance of the proper processing of non-congruent information in safety-critical systems.
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Affiliation(s)
- Kejin Chen
- a Department of Industrial Engineering , Tsinghua University , Beijing , P.R. China
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321
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Abstract
How do shared conventions emerge in complex decentralized social systems? This question engages fields as diverse as linguistics, sociology, and cognitive science. Previous empirical attempts to solve this puzzle all presuppose that formal or informal institutions, such as incentives for global agreement, coordinated leadership, or aggregated information about the population, are needed to facilitate a solution. Evolutionary theories of social conventions, by contrast, hypothesize that such institutions are not necessary in order for social conventions to form. However, empirical tests of this hypothesis have been hindered by the difficulties of evaluating the real-time creation of new collective behaviors in large decentralized populations. Here, we present experimental results--replicated at several scales--that demonstrate the spontaneous creation of universally adopted social conventions and show how simple changes in a population's network structure can direct the dynamics of norm formation, driving human populations with no ambition for large scale coordination to rapidly evolve shared social conventions.
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322
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Marshall BDL, Galea S. Formalizing the role of agent-based modeling in causal inference and epidemiology. Am J Epidemiol 2015; 181:92-9. [PMID: 25480821 PMCID: PMC4351348 DOI: 10.1093/aje/kwu274] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 05/20/2014] [Indexed: 11/14/2022] Open
Abstract
Calls for the adoption of complex systems approaches, including agent-based modeling, in the field of epidemiology have largely centered on the potential for such methods to examine complex disease etiologies, which are characterized by feedback behavior, interference, threshold dynamics, and multiple interacting causal effects. However, considerable theoretical and practical issues impede the capacity of agent-based methods to examine and evaluate causal effects and thus illuminate new areas for intervention. We build on this work by describing how agent-based models can be used to simulate counterfactual outcomes in the presence of complexity. We show that these models are of particular utility when the hypothesized causal mechanisms exhibit a high degree of interdependence between multiple causal effects and when interference (i.e., one person's exposure affects the outcome of others) is present and of intrinsic scientific interest. Although not without challenges, agent-based modeling (and complex systems methods broadly) represent a promising novel approach to identify and evaluate complex causal effects, and they are thus well suited to complement other modern epidemiologic methods of etiologic inquiry.
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Affiliation(s)
- Brandon D. L. Marshall
- Correspondence to Dr. Brandon D. L. Marshall, Department of Epidemiology, Brown University School of Public Health, 121 South Main Street, Box G-S-121-2, Providence, RI 02912 (e-mail: )
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323
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Abstract
The simulation of complex systems has received increasing attention as a useful approach in epidemiology. As discussed by Marshall and Galea in this issue of the Journal (Am J Epidemiol. 2015;181(2):92-99), systems approaches are appealing because they allow explicit recognition of feedback, interference, adaptation over time, and nonlinearities. However, they differ fundamentally from the traditional approaches to causal inference used in epidemiology in that they involve creation of a virtual world. Systems modeling can help us understand the plausible implications of the knowledge that we have and how pieces can act together in ways that we might not have predicted. It can help us integrate quantitative and qualitative information and explore basic dynamics. It can generate new questions that can be investigated through new observations or experiments. The process of building a systems model forces us to think about dynamic relationships and the ways in which they may play a role in the process we are studying. However, the validity of any causal conclusions derived from systems models hinges on the extent to which the models represent the fundamental dynamics relevant to the process in the real world. For this reason, systems modeling will never replace causal inference based on empirical observation. Causal inference based on empirical observation and simulation modeling serve interrelated but different purposes.
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324
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Abstract
Cognitive work analysis (CWA) is a framework of methods for analysing complex sociotechnical systems. However, the translation from the outputs of CWA to design is not straightforward. Sociotechnical systems theory provides values and principles for the design of sociotechnical systems which may offer a theoretically consistent basis for a design approach for use with CWA. This article explores the extent to which CWA and sociotechnical systems theory offer complementary perspectives and presents an abstraction hierarchy (AH), based on a review of literature, that describes an 'optimal' CWA and sociotechnical systems theory design system. The optimal AH is used to assess the extent to which current CWA-based design practices, uncovered through a survey of CWA practitioners, aligns with sociotechnical systems theory. Recommendations for a design approach that would support the integration of CWA and sociotechnical systems theory design values and principles are also derived.
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Affiliation(s)
- Gemma J M Read
- a Human Factors Group, Monash Injury Research Institute, Accident Research Centre, Monash University , Clayton , Victoria , Australia
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325
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Abstract
The idea that there is an edge of chaos, a region in the space of dynamical systems having special meaning for complex living entities, has a long history in artificial life. The significance of this region was first emphasized in cellular automata models when a single simple measure, λCA, identified it as a transitional region between order and chaos. Here we introduce a parameter λNN that is inspired by λCA but is defined for recurrent neural networks. We show through a series of systematic computational experiments that λNN generally orders the dynamical behaviors of randomly connected/weighted recurrent neural networks in the same way that λCA does for cellular automata. By extending this ordering to larger values of λNN than has typically been done with λCA and cellular automata, we find that a second edge-of-chaos region exists on the opposite side of the chaotic region. These basic results are found to hold under different assumptions about network connectivity, but vary substantially in their details. The results show that the basic concept underlying the lambda parameter can usefully be extended to other types of complex dynamical systems than just cellular automata.
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326
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Haslacher D. Beyond the computational-representational brain: why affective neuroscience tells us attitudes must be explained on multiple levels. Front Behav Neurosci 2014; 8:419. [PMID: 25538584 PMCID: PMC4255623 DOI: 10.3389/fnbeh.2014.00419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 11/16/2014] [Indexed: 11/18/2022] Open
Affiliation(s)
- David Haslacher
- Artificial Intelligence, Department of Psychology and Department of Information and Computing Sciences, Utrecht UniversityNetherlands
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327
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Martin CM, Félix-Bortolotti M. Person-centred health care: a critical assessment of current and emerging research approaches. J Eval Clin Pract 2014; 20:1056-64. [PMID: 25492282 DOI: 10.1111/jep.12283] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/23/2014] [Indexed: 12/30/2022]
Abstract
RATIONALE, AIMS AND OBJECTIVES Person-centred health care is prominent in international health care reforms. A shift to understanding and improving personal care at the point of delivery has generated debates about the nature of the person-centred research agenda. This paper purviews research paradigms that influence current person-centred research approaches and traditions that influence knowledge foundations in the field. It presents a synthesis of the emergent approaches and methodologies and highlights gaps between static academic research and the increasing accessibility of evaluation, informatics and big data from health information systems. FINDINGS Paradigms in health services research range from theoretical to atheoretical, including positivist, interpretive, postmodern and pragmatic. Interpretivist (subjective) and positivist (objectivist) paradigms have been historically polarized. Yet, integrative and pragmatic approaches have emerged. Nevertheless, there is a tendency to reductionism, and to reduce personal experiences to metrics in the positivist paradigm. Integrating personalized information into clinical systems is increasingly driven by the pervasive health information technology, which raises many issues about the asymmetry and uncertainty in the flow of information to support personal health journeys. The flux and uncertainty of knowledge between and within paradigmatic or pragmatic approaches highlights the uncertainty and the 'unorder and disorder' in what is known and what it means. Transdisciplinary, complex adaptive systems theory with multi-ontology sense making provides an overarching framework for making sense of the complex dynamics in research progress. CONCLUSION A major challenge to current research paradigms is focus on the individualizing of care and enhancing experiences of persons in health settings. There is an urgent need for person-centred research to address this complex process. A transdisciplinary and complex systems approach provides a sense-making framework.
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Affiliation(s)
- Carmel M Martin
- Public Health and Primary Care, Trinity College Dublin, Dublin, Co Dublin, Ireland
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328
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Abstract
PURPOSE The purpose of this study was to evaluate the veracity of a theoretically derived model of health that describes a non-linear trajectory of health from birth to death with available population data sets. METHODS The distribution of mortality by age is directly related to health at that age, thus health approximates 1/mortality. The inverse of available all-cause mortality data from various time periods and populations was used as proxy data to compare with the theoretically derived non-linear health model predictions, using both qualitative approaches and quantitative one-sample Kolmogorov-Smirnov analysis with Monte Carlo simulation. RESULTS The mortality data's inverse resembles a log-normal distribution as predicted by the proposed health model. The curves have identical slopes from birth and follow a logarithmic decline from peak health in young adulthood. A majority of the sampled populations had a good to excellent quantitative fit to a log-normal distribution, supporting the underlying model assumptions. Post hoc manipulation showed the model predictions to be stable. CONCLUSIONS This is a first theory of health to be validated by proxy data, namely the inverse of all-cause mortality. This non-linear model, derived from the notion of the interaction of physical, environmental, mental, emotional, social and sense-making domains of health, gives physicians a more rigorous basis to direct health care services and resources away from disease-focused elder care towards broad-based biopsychosocial interventions earlier in life.
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Affiliation(s)
- Stefan Topolski
- University of Massachusetts Medical School, Shelburne Falls, MA, USA
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329
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Affiliation(s)
- Dmitri Krioukov
- Department of Physics, Northeastern University Boston, MA, USA
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330
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Abstract
Seasonal influenza outbreaks and pandemics of new strains of the influenza virus affect humans around the globe. However, traditional systems for measuring the spread of flu infections deliver results with one or two weeks delay. Recent research suggests that data on queries made to the search engine Google can be used to address this problem, providing real-time estimates of levels of influenza-like illness in a population. Others have however argued that equally good estimates of current flu levels can be forecast using historic flu measurements. Here, we build dynamic 'nowcasting' models; in other words, forecasting models that estimate current levels of influenza, before the release of official data one week later. We find that when using Google Flu Trends data in combination with historic flu levels, the mean absolute error (MAE) of in-sample 'nowcasts' can be significantly reduced by 14.4%, compared with a baseline model that uses historic data on flu levels only. We further demonstrate that the MAE of out-of-sample nowcasts can also be significantly reduced by between 16.0% and 52.7%, depending on the length of the sliding training interval. We conclude that, using adaptive models, Google Flu Trends data can indeed be used to improve real-time influenza monitoring, even when official reports of flu infections are available with only one week's delay.
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Affiliation(s)
- Tobias Preis
- Warwick Business School, University of Warwick , Scarman Road, Coventry CV4 7AL, UK
| | - Helen Susannah Moat
- Warwick Business School, University of Warwick , Scarman Road, Coventry CV4 7AL, UK
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331
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Preis T, Moat HS. Adaptive nowcasting of influenza outbreaks using Google searches. R Soc Open Sci 2014; 1:140095. [PMID: 26064532 PMCID: PMC4448892 DOI: 10.1098/rsos.140095] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 10/10/2014] [Indexed: 05/20/2023]
Abstract
Seasonal influenza outbreaks and pandemics of new strains of the influenza virus affect humans around the globe. However, traditional systems for measuring the spread of flu infections deliver results with one or two weeks delay. Recent research suggests that data on queries made to the search engine Google can be used to address this problem, providing real-time estimates of levels of influenza-like illness in a population. Others have however argued that equally good estimates of current flu levels can be forecast using historic flu measurements. Here, we build dynamic 'nowcasting' models; in other words, forecasting models that estimate current levels of influenza, before the release of official data one week later. We find that when using Google Flu Trends data in combination with historic flu levels, the mean absolute error (MAE) of in-sample 'nowcasts' can be significantly reduced by 14.4%, compared with a baseline model that uses historic data on flu levels only. We further demonstrate that the MAE of out-of-sample nowcasts can also be significantly reduced by between 16.0% and 52.7%, depending on the length of the sliding training interval. We conclude that, using adaptive models, Google Flu Trends data can indeed be used to improve real-time influenza monitoring, even when official reports of flu infections are available with only one week's delay.
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332
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Affiliation(s)
- Guillaume Dumas
- Human Brain and Behavior Laboratory, Center for Complex Systems and Brain Sciences, FAU Boca Raton, FL, USA
| | - J A Scott Kelso
- Human Brain and Behavior Laboratory, Center for Complex Systems and Brain Sciences, FAU Boca Raton, FL, USA ; Intelligent System Research Centre, University of Ulster Derry, Northern Ireland
| | - Jacqueline Nadel
- CRICM UMR-S975, UPMC-Paris 6 Paris, France ; CNRS, UMR 7225 Paris, France ; ICM Paris, France
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333
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Abstract
Area-based strategies have been widely employed in efforts to improve population health and take action on social determinants of health (SDH) and health inequities, including in urban areas where many of the social, economic and environmental factors converge to influence health. Increasingly, these factors are recognized as being part of a complex system, where population health outcomes are shaped by multiple, interacting factors operating at different levels of social organization. This article reports on research to assess the extent to which an alliance of health and human service networks is able to promote action on SDH within an Australian urban region, using a complex systems frame. We found that such an alliance was able to promote some effective action which takes into account complex interactions between social factors affecting health, but also identified significant potential barriers to other forms of desired action identified by alliance members. We found that a complex systems lens was useful in assessing a collaborative intervention to address SDH within an urban region.
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Affiliation(s)
- Matthew Fisher
- Southgate Institute for Health, Society & Equity, Flinders University, Sturt Rd, Bedford Park, SA 5042, Australia
| | - Danijela Milos
- Southgate Institute for Health, Society & Equity, Flinders University, Sturt Rd, Bedford Park, SA 5042, Australia
| | - Frances Baum
- Southgate Institute for Health, Society & Equity, Flinders University, Sturt Rd, Bedford Park, SA 5042, Australia
| | - Sharon Friel
- Regulatory Institutions Network (RegNet), Australian National University, Canberra, Australian Capital Territory 0200, Australia
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334
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Abstract
Through 3 broad and interconnected streams of thought, resilience thinking has influenced the science of ecology and natural resource management by generating new multidisciplinary approaches to environmental problem solving. Resilience science, adaptive management (AM), and ecological policy design (EPD) contributed to an internationally unified paradigm built around the realization that change is inevitable and that science and management must approach the world with this assumption, rather than one of stability. Resilience thinking treats actions as experiments to be learned from, rather than intellectual propositions to be defended or mistakes to be ignored. It asks what is novel and innovative and strives to capture the overall behavior of a system, rather than seeking static, precise outcomes from discrete action steps. Understanding the foundations of resilience thinking is an important building block for developing more holistic and adaptive approaches to conservation. We conducted a comprehensive review of the history of resilience thinking because resilience thinking provides a working context upon which more effective, synergistic, and systems-based conservation action can be taken in light of rapid and unpredictable change. Together, resilience science, AM, and EPD bridge the gaps between systems analysis, ecology, and resource management to provide an interdisciplinary approach to solving wicked problems.
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Affiliation(s)
- Charles G Curtin
- MIT-USGS Science Impact Collaborative, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, U.S.A..
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335
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Abstract
In his seminal works on group dynamics Bion defined a specific therapeutic setting allowing psychoanalytic observations on group phenomena. In describing the setting he proposed that the group was where his voice arrived. This physical limit was later made operative by assuming that the natural dimension of a therapeutic group is around 12 people. Bion introduced a theory of the group aspects of the mind in which proto-mental individual states spontaneously evolve into shared psychological states that are characterized by a series of features: (1) they emerge as a consequence of the natural tendency of (both conscious and unconscious) emotions to combine into structured group patterns; (2) they have a certain degree of stability in time; (3) they tend to alternate so that the dissolution of one is rapidly followed by the emergence of another; (4) they can be described in qualitative terms according to the nature of the emotional mix that dominates the state, in structural terms by a kind of typical “leadership” pattern, and in “cognitive” terms by a set of implicit expectations that are helpful in explaining the group behavior (i.e., the group behaves “as if” it was assuming that). Here we adopt a formal approach derived from Socio-physics in order to explore some of the structural and dynamic properties of this small group dynamics. We will described data from an analytic DS model simulating small group interactions of agents endowed with a very simplified emotional and cognitive dynamic in order to assess the following main points: (1) are metastable collective states allowed to emerge in the model and if so, under which conditions in the parameter space? (2) can these states be differentiated in structural terms? (3) to what extent are the emergent dynamic features of the systems dependent of the system size? We will finally discuss possible future applications of the quantitative descriptions of the interaction structure in the small group clinical setting.
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Affiliation(s)
- Rosapia Lauro Grotto
- Psychology and Psychiatry Section, Department of Health Sciences and Center for the Study of Complex Dynamics, University of Florence Florence, Italy
| | - Andrea Guazzini
- VirtHuLab, Department of Education and Psychology and Center for the Study of Complex Dynamics, University of Florence Florence, Italy
| | - Franco Bagnoli
- Department of Physics and Astronomy and Center for the Study of Complex Dynamics, University of Florence Florence, Italy ; Istituto Nazionale di Fisica Nucleare, Sezione di Firenze Florence, Italy
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336
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Abstract
Technology is becoming deeply interwoven into the fabric of society. The Internet has become a central source of information for many people when making day-to-day decisions. Here, we present a method to mine the vast data Internet users create when searching for information online, to identify topics of interest before stock market moves. In an analysis of historic data from 2004 until 2012, we draw on records from the search engine Google and online encyclopedia Wikipedia as well as judgments from the service Amazon Mechanical Turk. We find evidence of links between Internet searches relating to politics or business and subsequent stock market moves. In particular, we find that an increase in search volume for these topics tends to precede stock market falls. We suggest that extensions of these analyses could offer insight into large-scale information flow before a range of real-world events.
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337
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Gleeson JP, Cellai D, Onnela JP, Porter MA, Reed-Tsochas F. A simple generative model of collective online behavior. Proc Natl Acad Sci U S A 2014; 111:10411-5. [PMID: 25002470 DOI: 10.1073/pnas.1313895111] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human activities increasingly take place in online environments, providing novel opportunities for relating individual behaviors to population-level outcomes. In this paper, we introduce a simple generative model for the collective behavior of millions of social networking site users who are deciding between different software applications. Our model incorporates two distinct mechanisms: one is associated with recent decisions of users, and the other reflects the cumulative popularity of each application. Importantly, although various combinations of the two mechanisms yield long-time behavior that is consistent with data, the only models that reproduce the observed temporal dynamics are those that strongly emphasize the recent popularity of applications over their cumulative popularity. This demonstrates--even when using purely observational data without experimental design--that temporal data-driven modeling can effectively distinguish between competing microscopic mechanisms, allowing us to uncover previously unidentified aspects of collective online behavior.
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338
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Abstract
Macroscopic quantum systems (MQS) are macroscopic systems driven by quantum rather than classical mechanics, a long studied area with minimal success till recently. Harnessing the benefits of quantum mechanics on a macroscopic level would revolutionize fields ranging from telecommunication to biology, the latter focused on here for reasons discussed. Contrary to misconceptions, there are no known physical laws that prevent the development of MQS. Instead, they are generally believed universally lost in complex systems from environmental entanglements (decoherence). But we argue success is achievable MQS with decoherence compensation developed, naturally or artificially, from top-down rather current reductionist approaches. This paper advances the MQS field by a complex systems approach to decoherence. First, why complex system decoherence approaches (top-down) are needed is discussed. Specifically, complex adaptive systems (CAS) are not amenable to reductionist models (and their master equations) because of emergent behaviour, approximation failures, not accounting for quantum compensatory mechanisms, ignoring path integrals, and the subentity problem. In addition, since MQS must exist within the context of the classical world, where rapid decoherence and prolonged coherence are both needed. Nature has already demonstrated this for quantum subsystems such as photosynthesis and magnetoreception. Second, we perform a preliminary study that illustrates a top-down approach to potential MQS. In summary, reductionist arguments against MQS are not justifiable. It is more likely they are not easily detectable in large intact classical systems or have been destroyed by reductionist experimental set-ups. This complex systems decoherence approach, using top down investigations, is critical to paradigm shifts in MQS research both in biological and non-biological systems.
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Affiliation(s)
- Mark E Brezinski
- Center for Optical Coherence Tomography and Modern Physics, Department of Orthopedic Surgery, Brigham and Women’s Hospital, 75 Francis Street, MRB-114, Boston, MA 02115, USA
- Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Rm 36-360, 50 Vassar St., Cambridge, MA 02139, USA
| | - Maria Rupnick
- Center for Optical Coherence Tomography and Modern Physics, Department of Orthopedic Surgery, Brigham and Women’s Hospital, 75 Francis Street, MRB-114, Boston, MA 02115, USA
- Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
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339
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Ip EH, Rahmandad H, Shoham DA, Hammond R, Huang TTK, Wang Y, Mabry PL. Reconciling statistical and systems science approaches to public health. Health Educ Behav 2014; 40:123S-31S. [PMID: 24084395 DOI: 10.1177/1090198113493911] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Although systems science has emerged as a set of innovative approaches to study complex phenomena, many topically focused researchers including clinicians and scientists working in public health are somewhat befuddled by this methodology that at times appears to be radically different from analytic methods, such as statistical modeling, to which the researchers are accustomed. There also appears to be conflicts between complex systems approaches and traditional statistical methodologies, both in terms of their underlying strategies and the languages they use. We argue that the conflicts are resolvable, and the sooner the better for the field. In this article, we show how statistical and systems science approaches can be reconciled, and how together they can advance solutions to complex problems. We do this by comparing the methods within a theoretical framework based on the work of population biologist Richard Levins. We present different types of models as representing different tradeoffs among the four desiderata of generality, realism, fit, and precision.
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Affiliation(s)
- Edward H Ip
- 1Wake Forest University School of Medicine, Winston-Salem, NC, USA
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340
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Tan U. Two families with quadrupedalism, mental retardation, no speech, and infantile hypotonia (Uner Tan Syndrome Type-II); a novel theory for the evolutionary emergence of human bipedalism. Front Neurosci 2014; 8:84. [PMID: 24795558 PMCID: PMC4001073 DOI: 10.3389/fnins.2014.00084] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 04/01/2014] [Indexed: 11/30/2022] Open
Abstract
Two consanguineous families with Uner Tan Syndrome (UTS) were analyzed in relation to self-organizing processes in complex systems, and the evolutionary emergence of human bipedalism. The cases had the key symptoms of previously reported cases of UTS, such as quadrupedalism, mental retardation, and dysarthric or no speech, but the new cases also exhibited infantile hypotonia and are designated UTS Type-II. There were 10 siblings in Branch I and 12 siblings in Branch II. Of these, there were seven cases exhibiting habitual quadrupedal locomotion (QL): four deceased and three living. The infantile hypotonia in the surviving cases gradually disappeared over a period of years, so that they could sit by about 10 years, crawl on hands and knees by about 12 years. They began walking on all fours around 14 years, habitually using QL. Neurological examinations showed normal tonus in their arms and legs, no Babinski sign, brisk tendon reflexes especially in the legs, and mild tremor. The patients could not walk in a straight line, but (except in one case) could stand up and maintain upright posture with truncal ataxia. Cerebello-vermial hypoplasia and mild gyral simplification were noted in their MRIs. The results of the genetic analysis were inconclusive: no genetic code could be identified as the triggering factor for the syndrome in these families. Instead, the extremely low socio-economic status of the patients was thought to play a role in the emergence of UTS, possibly by epigenetically changing the brain structure and function, with a consequent selection of ancestral neural networks for QL during locomotor development. It was suggested that UTS may be regarded as one of the unpredictable outcomes of self-organization within a complex system. It was also noted that the prominent feature of this syndrome, the diagonal-sequence habitual QL, generated an interference between ipsilateral hands and feet, as in non-human primates. It was suggested that this may have been the triggering factor for the attractor state “bipedal locomotion” (BL), which had visual and manual benefits for our ape-like ancestors, and therefore enhancing their chances for survival, with consequent developments in the psychomotor domain of humans. This was put forward as a novel theory of the evolution of BL in human beings.
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Affiliation(s)
- Uner Tan
- Department of Physiology, Medical School, Cukurova University Adana, Turkey
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341
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Abstract
Modeling gene regulatory networks (GRNs) is an important topic in systems biology. Although there has been much work focusing on various specific systems, the generic behavior of GRNs with continuous variables is still elusive. In particular, it is not clear typically how attractors partition among the three types of orbits: steady state, periodic and chaotic, and how the dynamical properties change with network's topological characteristics. In this work, we first investigated these questions in random GRNs with different network sizes, connectivity, fraction of inhibitory links and transcription regulation rules. Then we searched for the core motifs that govern the dynamic behavior of large GRNs. We show that the stability of a random GRN is typically governed by a few embedding motifs of small sizes, and therefore can in general be understood in the context of these short motifs. Our results provide insights for the study and design of genetic networks.
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342
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Mattei TA. Unveiling complexity: non-linear and fractal analysis in neuroscience and cognitive psychology. Front Comput Neurosci 2014; 8:17. [PMID: 24600384 PMCID: PMC3930866 DOI: 10.3389/fncom.2014.00017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 02/05/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Tobias A Mattei
- Department of Neurological Surgery, The Ohio State University Medical Center Columbus, OH, USA
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343
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Affiliation(s)
- Hamilton Varela
- Institute of Chemistry of São Carlos, University of São Paulo CP 780, CEP 13560-970, São Carlos, SP (Brazil) and Ertl Center for Electrochemistry and Catalysis, GIST Cheomdan-gwagiro 261Buk-gu, Gwangju 500-712 (South Korea) E-mail:
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344
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Gómez C, Lizier JT, Schaum M, Wollstadt P, Grützner C, Uhlhaas P, Freitag CM, Schlitt S, Bölte S, Hornero R, Wibral M. Reduced predictable information in brain signals in autism spectrum disorder. Front Neuroinform 2014; 8:9. [PMID: 24592235 PMCID: PMC3924322 DOI: 10.3389/fninf.2014.00009] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 01/23/2014] [Indexed: 01/29/2023] Open
Abstract
Autism spectrum disorder (ASD) is a common developmental disorder characterized by communication difficulties and impaired social interaction. Recent results suggest altered brain dynamics as a potential cause of symptoms in ASD. Here, we aim to describe potential information-processing consequences of these alterations by measuring active information storage (AIS)-a key quantity in the theory of distributed computation in biological networks. AIS is defined as the mutual information between the past state of a process and its next measurement. It measures the amount of stored information that is used for computation of the next time step of a process. AIS is high for rich but predictable dynamics. We recorded magnetoencephalography (MEG) signals in 10 ASD patients and 14 matched control subjects in a visual task. After a beamformer source analysis, 12 task-relevant sources were obtained. For these sources, stationary baseline activity was analyzed using AIS. Our results showed a decrease of AIS values in the hippocampus of ASD patients in comparison with controls, meaning that brain signals in ASD were either less predictable, reduced in their dynamic richness or both. Our study suggests the usefulness of AIS to detect an abnormal type of dynamics in ASD. The observed changes in AIS are compatible with Bayesian theories of reduced use or precision of priors in ASD.
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Affiliation(s)
- Carlos Gómez
- Biomedical Engineering Group, E. T. S. Ingenieros de Telecomunicación, University of ValladolidValladolid, Spain
| | - Joseph T. Lizier
- Commonwealth Scientific and Industrial Research Organisation, Computational InformaticsMarsfield, NSW, Australia
| | - Michael Schaum
- MEG Unit, Brain Imaging Center, Johann Wolfgang Goethe UniversityFrankfurt am Main, Germany
| | - Patricia Wollstadt
- MEG Unit, Brain Imaging Center, Johann Wolfgang Goethe UniversityFrankfurt am Main, Germany
| | - Christine Grützner
- Department of Neurophysiology, Max-Planck Institute for Brain ResearchFrankfurt am Main, Germany
| | - Peter Uhlhaas
- Institute of Neuroscience and Psychology, University of GlasgowGlasgow, UK
| | - Christine M. Freitag
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Johann Wolfgang Goethe UniversityFrankfurt am Main, Germany
| | - Sabine Schlitt
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Johann Wolfgang Goethe UniversityFrankfurt am Main, Germany
| | - Sven Bölte
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Johann Wolfgang Goethe UniversityFrankfurt am Main, Germany
| | - Roberto Hornero
- Biomedical Engineering Group, E. T. S. Ingenieros de Telecomunicación, University of ValladolidValladolid, Spain
| | - Michael Wibral
- MEG Unit, Brain Imaging Center, Johann Wolfgang Goethe UniversityFrankfurt am Main, Germany
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345
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Wibral M, Lizier JT, Vögler S, Priesemann V, Galuske R. Local active information storage as a tool to understand distributed neural information processing. Front Neuroinform 2014; 8:1. [PMID: 24501593 PMCID: PMC3904075 DOI: 10.3389/fninf.2014.00001] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 01/09/2014] [Indexed: 11/13/2022] Open
Abstract
Every act of information processing can in principle be decomposed into the component operations of information storage, transfer, and modification. Yet, while this is easily done for today's digital computers, the application of these concepts to neural information processing was hampered by the lack of proper mathematical definitions of these operations on information. Recently, definitions were given for the dynamics of these information processing operations on a local scale in space and time in a distributed system, and the specific concept of local active information storage was successfully applied to the analysis and optimization of artificial neural systems. However, no attempt to measure the space-time dynamics of local active information storage in neural data has been made to date. Here we measure local active information storage on a local scale in time and space in voltage sensitive dye imaging data from area 18 of the cat. We show that storage reflects neural properties such as stimulus preferences and surprise upon unexpected stimulus change, and in area 18 reflects the abstract concept of an ongoing stimulus despite the locally random nature of this stimulus. We suggest that LAIS will be a useful quantity to test theories of cortical function, such as predictive coding.
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Affiliation(s)
- Michael Wibral
- MEG Unit, Brain Imaging Center, Goethe University Frankfurt am Main, Germany
| | | | | | - Viola Priesemann
- Department of Nonlinear Dynamics, Max Planck Institute for Dynamics and Self-Organization Göttingen, Germany
| | - Ralf Galuske
- Fakultät für Biologie, Technische Universtät Darmstadt, Germany
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346
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Abstract
Pattern formation is a natural property of nonlinear and non-equilibrium dynamical systems. Geophysical examples of such systems span practically all observable length scales, from rhythmic banding of chemical species within a single mineral crystal, to the morphology of cusps and spits along hundreds of kilometres of coastlines. This article briefly introduces the general principles of pattern formation and argues how they can be applied to open problems in the Earth sciences. Particular examples are then discussed, which summarize the contents of the rest of this Theme Issue.
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Affiliation(s)
- Lucas Goehring
- Max Planck Institute for Dynamics and Self-Organization, , Am Fassberg 17, 37077 Göttingen, Germany
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347
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Beigzadeh M, Golpayegani SMRH, Gharibzadeh S. Can cellular automata be a representative model for visual perception dynamics? Front Comput Neurosci 2013; 7:130. [PMID: 24101901 PMCID: PMC3787243 DOI: 10.3389/fncom.2013.00130] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Accepted: 09/09/2013] [Indexed: 01/17/2023] Open
Affiliation(s)
- Maryam Beigzadeh
- Department of Biomedical Engineering, Amirkabir University of Technology Tehran, Iran
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348
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Deffur A, Mulder NJ, Wilkinson RJ. Co-infection with Mycobacterium tuberculosis and human immunodeficiency virus: an overview and motivation for systems approaches. Pathog Dis 2013; 69:101-13. [PMID: 23821533 DOI: 10.1111/2049-632x.12060] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/17/2013] [Accepted: 06/20/2013] [Indexed: 12/13/2022] Open
Abstract
Tuberculosis is a devastating disease that accounts for a high proportion of infectious disease morbidity and mortality worldwide. HIV-1 co-infection exacerbates tuberculosis. Enhanced understanding of the host-pathogen relationship in HIV-1 and Mycobacterium tuberculosis co-infection is required. While reductionist approaches have yielded many valuable insights into disease pathogenesis, systems approaches are required that develop data-driven models able to predict emergent properties of this complex co-infection system in order to develop novel therapeutic approaches and to improve diagnostics. Here, we provide a pathogenesis-focused overview of HIV-TB co-infection followed by an introduction to systems approaches and concrete examples of how such approaches are useful.
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Affiliation(s)
- Armin Deffur
- Clinical Infectious Diseases Research Initiative, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa; Department of Medicine, University of Cape Town, Cape Town, South Africa
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349
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Telesford QK, Burdette JH, Laurienti PJ. An exploration of graph metric reproducibility in complex brain networks. Front Neurosci 2013; 7:67. [PMID: 23717257 PMCID: PMC3652292 DOI: 10.3389/fnins.2013.00067] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 04/14/2013] [Indexed: 11/15/2022] Open
Abstract
The application of graph theory to brain networks has become increasingly popular in the neuroimaging community. These investigations and analyses have led to a greater understanding of the brain's complex organization. More importantly, it has become a useful tool for studying the brain under various states and conditions. With the ever expanding popularity of network science in the neuroimaging community, there is increasing interest to validate the measurements and calculations derived from brain networks. Underpinning these studies is the desire to use brain networks in longitudinal studies or as clinical biomarkers to understand changes in the brain. A highly reproducible tool for brain imaging could potentially prove useful as a clinical tool. In this review, we examine recent studies in network reproducibility and their implications for analysis of brain networks.
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Affiliation(s)
- Qawi K Telesford
- Laboratory for Complex Brain Networks, Department of Biomedical Engineering, Wake Forest University School of Medicine Winston-Salem, NC, USA
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350
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Abstract
Emotions are evolved systems of intra- and interpersonal processes that are regulatory in nature, dealing mostly with issues of personal or social concern. They regulate social interaction and in extension, the social sphere. In turn, processes in the social sphere regulate emotions of individuals and groups. In other words, intrapersonal processes project in the interpersonal space, and inversely, interpersonal experiences deeply influence intrapersonal processes. Thus, I argue that the concepts of emotion generation and regulation should not be artificially separated. Similarly, interpersonal emotions should not be reduced to interacting systems of intraindividual processes. Instead, we can consider emotions at different social levels, ranging from dyads to large scale e-communities. The interaction between these levels is complex and does not only involve influences from one level to the next. In this sense the levels of emotion/regulation are messy and a challenge for empirical study. In this article, I discuss the concepts of emotions and regulation at different intra- and interpersonal levels. I extend the concept of auto-regulation of emotions (Kappas, 2008, 2011a,b) to social processes. Furthermore, I argue for the necessity of including mediated communication, particularly in cyberspace in contemporary models of emotion/regulation. Lastly, I suggest the use of concepts from systems dynamics and complex systems to tackle the challenge of the “messy layers.”
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Affiliation(s)
- Arvid Kappas
- School of Humanities and Social Sciences, Jacobs University Bremen Bremen, Germany
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