Science.gov

Sample records for emerging networking panorama

  1. Supporting Quality in Vocational Training through Networking. CEDEFOP Panorama.

    ERIC Educational Resources Information Center

    Seyfried, Erwin; Kohlmeyer, Klaus; Furth-Riedesser, Rafael

    The extent to which network cooperation between the general education system, vocational training institutions, business enterprises, social partners, and political decision makers affects quality development in vocational training was examined through a literature review and synthesis of eight case studies in the following seven European…

  2. Emergent Complex Network Geometry

    PubMed Central

    Wu, Zhihao; Menichetti, Giulia; Rahmede, Christoph; Bianconi, Ginestra

    2015-01-01

    Networks are mathematical structures that are universally used to describe a large variety of complex systems such as the brain or the Internet. Characterizing the geometrical properties of these networks has become increasingly relevant for routing problems, inference and data mining. In real growing networks, topological, structural and geometrical properties emerge spontaneously from their dynamical rules. Nevertheless we still miss a model in which networks develop an emergent complex geometry. Here we show that a single two parameter network model, the growing geometrical network, can generate complex network geometries with non-trivial distribution of curvatures, combining exponential growth and small-world properties with finite spectral dimensionality. In one limit, the non-equilibrium dynamical rules of these networks can generate scale-free networks with clustering and communities, in another limit planar random geometries with non-trivial modularity. Finally we find that these properties of the geometrical growing networks are present in a large set of real networks describing biological, social and technological systems. PMID:25985280

  3. Emergent Hyperbolic Network Geometry

    NASA Astrophysics Data System (ADS)

    Bianconi, Ginestra; Rahmede, Christoph

    2017-02-01

    A large variety of interacting complex systems are characterized by interactions occurring between more than two nodes. These systems are described by simplicial complexes. Simplicial complexes are formed by simplices (nodes, links, triangles, tetrahedra etc.) that have a natural geometric interpretation. As such simplicial complexes are widely used in quantum gravity approaches that involve a discretization of spacetime. Here, by extending our knowledge of growing complex networks to growing simplicial complexes we investigate the nature of the emergent geometry of complex networks and explore whether this geometry is hyperbolic. Specifically we show that an hyperbolic network geometry emerges spontaneously from models of growing simplicial complexes that are purely combinatorial. The statistical and geometrical properties of the growing simplicial complexes strongly depend on their dimensionality and display the major universal properties of real complex networks (scale-free degree distribution, small-world and communities) at the same time. Interestingly, when the network dynamics includes an heterogeneous fitness of the faces, the growing simplicial complex can undergo phase transitions that are reflected by relevant changes in the network geometry.

  4. Emergent Hyperbolic Network Geometry.

    PubMed

    Bianconi, Ginestra; Rahmede, Christoph

    2017-02-07

    A large variety of interacting complex systems are characterized by interactions occurring between more than two nodes. These systems are described by simplicial complexes. Simplicial complexes are formed by simplices (nodes, links, triangles, tetrahedra etc.) that have a natural geometric interpretation. As such simplicial complexes are widely used in quantum gravity approaches that involve a discretization of spacetime. Here, by extending our knowledge of growing complex networks to growing simplicial complexes we investigate the nature of the emergent geometry of complex networks and explore whether this geometry is hyperbolic. Specifically we show that an hyperbolic network geometry emerges spontaneously from models of growing simplicial complexes that are purely combinatorial. The statistical and geometrical properties of the growing simplicial complexes strongly depend on their dimensionality and display the major universal properties of real complex networks (scale-free degree distribution, small-world and communities) at the same time. Interestingly, when the network dynamics includes an heterogeneous fitness of the faces, the growing simplicial complex can undergo phase transitions that are reflected by relevant changes in the network geometry.

  5. Emergent Hyperbolic Network Geometry

    PubMed Central

    Bianconi, Ginestra; Rahmede, Christoph

    2017-01-01

    A large variety of interacting complex systems are characterized by interactions occurring between more than two nodes. These systems are described by simplicial complexes. Simplicial complexes are formed by simplices (nodes, links, triangles, tetrahedra etc.) that have a natural geometric interpretation. As such simplicial complexes are widely used in quantum gravity approaches that involve a discretization of spacetime. Here, by extending our knowledge of growing complex networks to growing simplicial complexes we investigate the nature of the emergent geometry of complex networks and explore whether this geometry is hyperbolic. Specifically we show that an hyperbolic network geometry emerges spontaneously from models of growing simplicial complexes that are purely combinatorial. The statistical and geometrical properties of the growing simplicial complexes strongly depend on their dimensionality and display the major universal properties of real complex networks (scale-free degree distribution, small-world and communities) at the same time. Interestingly, when the network dynamics includes an heterogeneous fitness of the faces, the growing simplicial complex can undergo phase transitions that are reflected by relevant changes in the network geometry. PMID:28167818

  6. Panorama Jamma!

    ERIC Educational Resources Information Center

    Thomas, Rollinda

    2009-01-01

    Interactive art activities can empower children and adults to experience art as active participants rather than passive spectators. Fayetteville State University's Art Education program in North Carolina has established Panorama Kids, mural projects designed by kids and painted by community volunteers. As art students can attest, art is very much…

  7. 'Independence' Panorama

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for 'Independence' Panorama (QTVR)

    This is the Spirit 'Independence' panorama, acquired on martian days, or sols, 536 to 543 (July 6 to 13, 2005), from a position in the 'Columbia Hills' near the summit of 'Husband Hill.' The summit of 'Husband Hill' is the peak near the right side of this panorama and is about 100 meters (328 feet) away from the rover and about 30 meters (98 feet) higher in elevation. The rocky outcrops downhill and on the left side of this mosaic include 'Larry's Lookout' and 'Cumberland Ridge,' which Spirit explored in April, May, and June of 2005.

    The panorama spans 360 degrees and consists of 108 individual images, each acquired with five filters of the rover's panoramic camera. The approximate true color of the mosaic was generated using the camera's 750-, 530-, and 480-nanometer filters. During the 8 martian days, or sols, that it took to acquire this image, the lighting varied considerably, partly because of imaging at different times of sol, and partly because of small sol-to-sol variations in the dustiness of the atmosphere. These slight changes produced some image seams and rock shadows. These seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see. However, it is often not possible or practical to smooth out such seams for regions of rock, soil, rover tracks or solar panels. Such is the nature of acquiring and assembling large panoramas from the rovers.

  8. Network Leadership: An Emerging Practice

    ERIC Educational Resources Information Center

    Tremblay, Christopher W.

    2012-01-01

    Network leadership is an emerging approach that can have an impact on change in education and in society. According to Merriam-Webster (2011), a network is "an interconnected or interrelated chain, group, or system." Intentional interconnectedness is what separates network leadership from other leadership theories. Network leadership has the…

  9. Emergent Network Defense

    ERIC Educational Resources Information Center

    Crane, Earl Newell

    2013-01-01

    The research problem that inspired this effort is the challenge of managing the security of systems in large-scale heterogeneous networked environments. Human intervention is slow and limited: humans operate at much slower speeds than networked computer communications and there are few humans associated with each network. Enabling each node in the…

  10. Emergent Network Defense

    ERIC Educational Resources Information Center

    Crane, Earl Newell

    2013-01-01

    The research problem that inspired this effort is the challenge of managing the security of systems in large-scale heterogeneous networked environments. Human intervention is slow and limited: humans operate at much slower speeds than networked computer communications and there are few humans associated with each network. Enabling each node in the…

  11. Transportation Networks for Emergency Evacuations

    SciTech Connect

    Franzese, Oscar; Liu, Cheng

    2008-01-01

    Evacuation modeling systems (EMS) have been developed to facilitate the planning, analysis, and deployment of emergency evacuation of populations at risk. For any EMS, data such as road network maps, traffic control characteristics, and population distribution play critical roles in delineating emergency zones, estimating population at risk, and determining evacuation routes. There are situations in which it is possible to plan in advance for an emergency evacuation including, for example, an explosion at a chemical processing facility or a radiological accident at a nuclear plant. In these cases, if an accident or a terrorist attack were to happen, then the best evacuation plan for the prevailing network and weather conditions would be deployed. In other instances -for example, the derailment of a train transporting hazardous materials-, there may not be any previously developed plan to be implemented and decisions must be made ad-hoc on if and how to identify and proceed with the best course of action to minimize losses. Although both cases require as a starting point the development of a transportation network model of the area at risk, which must include road capacity and topology, in the latter the available time to generate this network is extremely limited. This time constraint precludes the use of any traditional data gathering methodology and the network generation process has to rely on the use of GIS and stochastic modeling techniques. The generation of these transportation networks in real time is the focus of this entry.

  12. Networking emergency teams in Jerusalem.

    PubMed

    Yanay, Uri; Benjamin, Sharon; Yamin, Hanna Gimmon

    2011-01-01

    With the recent upsurge in terrorism, more and more attention is being directed at examining the effectiveness and efficiency of emergency teams. These teams tend to focus on their areas of expertise without necessarily communicating, cooperating or coordinating their operations. Research suggests that improved interpersonal communication and coordination enhances the overall work of each emergency team, and that their combined effort is far in excess of the sum of their individual endeavours. This paper outlines attempts made in Jerusalem to improve the performance of emergency teams and to help the helpers by holding training workshops, setting up a forum of co-workers and encouraging dialogue among various emergency teams in the city. A planned intervention programme was designed to enable informal networking between team leaders. The programme had an impact on team workers and resulted in a more coordinated and effective service delivery during emergencies.

  13. Emergence of robustness in networks of networks

    NASA Astrophysics Data System (ADS)

    Roth, Kevin; Morone, Flaviano; Min, Byungjoon; Makse, Hernán A.

    2017-06-01

    A model of interdependent networks of networks (NONs) was introduced recently [Proc. Natl. Acad. Sci. (USA) 114, 3849 (2017), 10.1073/pnas.1620808114] in the context of brain activation to identify the neural collective influencers in the brain NON. Here we investigate the emergence of robustness in such a model, and we develop an approach to derive an exact expression for the random percolation transition in Erdös-Rényi NONs of this kind. Analytical calculations are in agreement with numerical simulations, and highlight the robustness of the NON against random node failures, which thus presents a new robust universality class of NONs. The key aspect of this robust NON model is that a node can be activated even if it does not belong to the giant mutually connected component, thus allowing the NON to be built from below the percolation threshold, which is not possible in previous models of interdependent networks. Interestingly, the phase diagram of the model unveils particular patterns of interconnectivity for which the NON is most vulnerable, thereby marking the boundary above which the robustness of the system improves with increasing dependency connections.

  14. Location Distribution Optimization of Photographing Sites for Indoor Panorama Modeling

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Wu, J.; Zhang, Y.; Zhang, X.; Xin, Z.; Liu, J.

    2017-09-01

    Generally, panoramas image modeling is costly and time-consuming because of photographing continuously to capture enough photos along the routes, especially in complicated indoor environment. Thus, difficulty follows for a wider applications of panoramic image modeling for business. It is indispensable to make a feasible arrangement of panorama sites locations because the locations influence the clarity, coverage and the amount of panoramic images under the condition of certain device. This paper is aim to propose a standard procedure to generate the specific location and total amount of panorama sites in indoor panoramas modeling. Firstly, establish the functional relationship between one panorama site and its objectives. Then, apply the relationship to panorama sites network. We propose the Distance Clarity function (FC and Fe) manifesting the mathematical relationship between panoramas and objectives distance or obstacle distance. The Distance Buffer function (FB) is modified from traditional buffer method to generate the coverage of panorama site. Secondly, transverse every point in possible area to locate possible panorama site, calculate the clarity and coverage synthetically. Finally select as little points as possible to satiate clarity requirement preferentially and then the coverage requirement. In the experiments, detailed parameters of camera lens are given. Still, more experiments parameters need trying out given that relationship between clarity and distance is device dependent. In short, through the function FC, Fe and FB, locations of panorama sites can be generated automatically and accurately.

  15. Comprehensive Oncologic Emergencies Research Network (CONCERN)

    Cancer.gov

    The Comprehensive Oncologic Emergencies Research Network (CONCERN) was established in March 2015 with the goal to accelerate knowledge generation, synthesis and translation of oncologic emergency medicine research through multi-center collaborations.

  16. Emergence of network features from multiplexity

    PubMed Central

    Cardillo, Alessio; Gómez-Gardeñes, Jesús; Zanin, Massimiliano; Romance, Miguel; Papo, David; Pozo, Francisco del; Boccaletti, Stefano

    2013-01-01

    Many biological and man-made networked systems are characterized by the simultaneous presence of different sub-networks organized in separate layers, with links and nodes of qualitatively different types. While during the past few years theoretical studies have examined a variety of structural features of complex networks, the outstanding question is whether such features are characterizing all single layers, or rather emerge as a result of coarse-graining, i.e. when going from the multilayered to the aggregate network representation. Here we address this issue with the help of real data. We analyze the structural properties of an intrinsically multilayered real network, the European Air Transportation Multiplex Network in which each commercial airline defines a network layer. We examine how several structural measures evolve as layers are progressively merged together. In particular, we discuss how the topology of each layer affects the emergence of structural properties in the aggregate network. PMID:23446838

  17. Emergence of network features from multiplexity.

    PubMed

    Cardillo, Alessio; Gómez-Gardeñes, Jesús; Zanin, Massimiliano; Romance, Miguel; Papo, David; del Pozo, Francisco; Boccaletti, Stefano

    2013-01-01

    Many biological and man-made networked systems are characterized by the simultaneous presence of different sub-networks organized in separate layers, with links and nodes of qualitatively different types. While during the past few years theoretical studies have examined a variety of structural features of complex networks, the outstanding question is whether such features are characterizing all single layers, or rather emerge as a result of coarse-graining, i.e. when going from the multilayered to the aggregate network representation. Here we address this issue with the help of real data. We analyze the structural properties of an intrinsically multilayered real network, the European Air Transportation Multiplex Network in which each commercial airline defines a network layer. We examine how several structural measures evolve as layers are progressively merged together. In particular, we discuss how the topology of each layer affects the emergence of structural properties in the aggregate network.

  18. Panoramas of Apollo sites

    NASA Image and Video Library

    1969-07-20

    Panoramas of Apollo sites are required to familiarize various Constellation projects with the actual nature of the lunar surface. This image is the first of a multi-framed panorama photographed from a point some 30 or 40 feet west of the plus-Z (west) footpad of the Lunar Module "Eagle." The view is looking toward the southwest showing part of the horizon crater rim that was pointed out as being visible from the Eagle's window. Image taken at Tranquility Base. View was created using Apollo 11 images - mag 40 frames 5881 thru 5891.

  19. Emergence of core-peripheries in networks

    NASA Astrophysics Data System (ADS)

    Verma, T.; Russmann, F.; Araújo, N. A. M.; Nagler, J.; Herrmann, H. J.

    2016-01-01

    A number of important transport networks, such as the airline and trade networks of the world, exhibit a characteristic core-periphery structure, wherein a few nodes are highly interconnected and the rest of the network frays into a tree. Mechanisms underlying the emergence of core-peripheries, however, remain elusive. Here, we demonstrate that a simple pruning process based on removal of underutilized links and redistribution of loads can lead to the emergence of core-peripheries. Links are assumed beneficial if they either carry a sufficiently large load or are essential for global connectivity. This incentivized redistribution process is controlled by a single parameter, which balances connectivity and profit. The obtained networks exhibit a highly resilient and connected core with a frayed periphery. The balanced network shows a higher resilience than the world airline network or the world trade network, revealing a pathway towards robust structural features through pruning.

  20. Emergence of core–peripheries in networks

    PubMed Central

    Verma, T.; Russmann, F.; Araújo, N.A.M.; Nagler, J.; Herrmann, H.J.

    2016-01-01

    A number of important transport networks, such as the airline and trade networks of the world, exhibit a characteristic core–periphery structure, wherein a few nodes are highly interconnected and the rest of the network frays into a tree. Mechanisms underlying the emergence of core–peripheries, however, remain elusive. Here, we demonstrate that a simple pruning process based on removal of underutilized links and redistribution of loads can lead to the emergence of core–peripheries. Links are assumed beneficial if they either carry a sufficiently large load or are essential for global connectivity. This incentivized redistribution process is controlled by a single parameter, which balances connectivity and profit. The obtained networks exhibit a highly resilient and connected core with a frayed periphery. The balanced network shows a higher resilience than the world airline network or the world trade network, revealing a pathway towards robust structural features through pruning. PMID:26822856

  1. Emergent properties of composite semiflexible biopolymer networks

    PubMed Central

    Jensen, Mikkel H.; Morris, Eliza J.; Goldman, Robert D.; Weitz, David A.

    2014-01-01

    The semiflexible polymers filamentous actin (F-actin) and intermediate filaments (IF) both form complex networks within the cell, and together are key determinants of cellular stiffness. While the mechanics of F-actin networks together with stiff microtubules have been characterized, the interplay between F-actin and IF networks is largely unknown, necessitating the study of composite networks using mixtures of semiflexible biopolymers. We employ bulk rheology in a simplified in vitro system to uncover the fundamental mechanical interactions between networks of the 2 semiflexible polymers, F-actin and vimentin IF. Surprisingly, co-polymerization of actin and vimentin can produce composite networks either stronger or weaker than pure F-actin networks. We show that this effect occurs through steric constraints imposed by IF on F-actin during network formation and filament crosslinking, highlighting novel emergent behavior in composite semiflexible networks. PMID:25759912

  2. EasyPanorama: a new panorama authoring system

    NASA Astrophysics Data System (ADS)

    Fang, Xianyong; Yan, Wen; Pan, Zhigeng; Xu, Dan; Chen, Mingwei

    2004-03-01

    Although panorama has been intensively researched in recent years and there are many tools on panorama creation, existing methods still can't cope with ghosting effectively and almost all the tools can't create an image with a large vertical field of view. By modifying the sobel operator, we present an improved algorithm to deghost based on dynamic programming. Our new algorithm is simple and robust. This algorithm has been used in our new panorama authoring system, EasyPanorama. This paper describes the architecture, the interactive authoring and publishing process of this system. The system treats panorama as a type of wide angle image, and can vertically mosaic the source images to create an image with a large vertical field of view. With this system, the user first creates a wide angle image, then edits the walkthrough of the panorama if the wide angle image is mosaiced to be a panorama and finally publishes the result to the web.

  3. Panoramas of Apollo sites

    NASA Image and Video Library

    2016-06-16

    Panoramas of Apollo sites were created to familiarize various Constellation projects with the actual nature of the lunar surface. View of the Lunar Surface towards the western Horizon. Image was created using Apollo 14 images - mag 66 frames 9271 thru 9293.

  4. Growing local likelihood network: Emergence of communities

    NASA Astrophysics Data System (ADS)

    Chen, S.; Small, M.

    2015-10-01

    In many real situations, networks grow only via local interactions. New nodes are added to the growing network with information only pertaining to a small subset of existing nodes. Multilevel marketing, social networks, and disease models can all be depicted as growing networks based on local (network path-length) distance information. In these examples, all nodes whose distance from a chosen center is less than d form a subgraph. Hence, we grow networks with information only from these subgraphs. Moreover, we use a likelihood-based method, where at each step we modify the networks by changing their likelihood to be closer to the expected degree distribution. Combining the local information and the likelihood method, we grow networks that exhibit novel features. We discover that the likelihood method, over certain parameter ranges, can generate networks with highly modulated communities, even when global information is not available. Communities and clusters are abundant in real-life networks, and the method proposed here provides a natural mechanism for the emergence of communities in scale-free networks. In addition, the algorithmic implementation of network growth via local information is substantially faster than global methods and allows for the exploration of much larger networks.

  5. Lookout Panorama from Spirit

    NASA Image and Video Library

    2005-04-29

    This is the Spirit panoramic camera's "Lookout" panorama, acquired on the rover's 410th to 413th martian days, or sols (Feb. 27 to Mar. 2, 2005). The view is from a position known informally as "Larry's Lookout" along the drive up "Husband Hill." The summit of Husband Hill is the far peak near the center of this panorama and is about 200 meters (656 feet) away from the rover and about 45 meters (148 feet) higher in elevation. The bright rocky outcrop near the center of the panorama is part of the "Cumberland Ridge," and beyond that and to the left is the "Tennessee Valley." The panorama spans 360 degrees and consists of images obtained in 108 individual pointings and five filters at each pointing. This mosaic is an approximately true-color rendering generated using the images acquired through panoramic camera's 750-nanometer, 530-nanometer, and 480-nanometer filters. The lighting varied considerably during the four sols that it took to acquire this image (partly because of imaging at different times of sol, but also partly because of small sol-to-sol variations in the dustiness of the atmosphere), resulting in some obvious image seams or rock shadow variations within the mosaic. These seams have been smoothed out from the sky parts of the mosaic in order to simulate better the vista that a person would have if they were viewing it all at the same time on Mars. However, it is often not possible or practical to smooth out such seams for regions of rock, soil, rover tracks, or solar panels. Such is the nature of acquiring and assembling large Pancam panoramas from the rovers. Spirit's tracks leading back from the "West Spur" region can be seen on the right side of the panorama. The region just beyond the area where the tracks made their last zig-zag is the area known as "Paso Robles," where Spirit discovered rock and soil deposits with very high sulfur abundances. After acquiring this mosaic (which took several weeks to fully downlink and then several more weeks to

  6. Modulation for emergent networks: serotonin and dopamine.

    PubMed

    Weng, Juyang; Paslaski, Stephen; Daly, James; VanDam, Courtland; Brown, Jacob

    2013-05-01

    In autonomous learning, value-sensitive experiences can improve the efficiency of learning. A learning network needs be motivated so that the limited computational resources and the limited lifetime are devoted to events that are of high value for the agent to compete in its environment. The neuromodulatory system of the brain is mainly responsible for developing such a motivation system. Although reinforcement learning has been extensively studied, many existing models are symbolic whose internal nodes or modules have preset meanings. Neural networks have been used to automatically generate internal emergent representations. However, modeling an emergent motivational system for neural networks is still a great challenge. By emergent, we mean that the internal representations emerge autonomously through interactions with the external environments. This work proposes a generic emergent modulatory system for emergent networks, which includes two subsystems - the serotonin system and the dopamine system. The former signals a large class of stimuli that are intrinsically aversive (e.g., stress or pain). The latter signals a large class of stimuli that are intrinsically appetitive (e.g., pleasure or sweet). We experimented with this motivational system for two settings. The first is a visual recognition setting to investigate how such a system can learn through interactions with a teacher, who does not directly give answers, but only punishments and rewards. The second is a setting for wandering in the presence of a friend and a foe.

  7. Dependable Emergency-Response Networking Based on Retaskable Network Infrastructures

    DTIC Science & Technology

    2008-04-01

    Emergency-Response Network ESP Energy Service Provider HAN Home-Area Network HVAC Heating, Ventilation, and Air Conditioning MDMA Meter Data Management...replaced with advanced 1 meters that have computational capabilities and are often connected to the Meter Data Management Agency ( MDMA ) using mesh networking...some background on them here. Advanced meters are electric meters that have been modified so that they trans- mit usage information back to an MDMA

  8. Southeastern Mediterranean Panorama

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This oblique northwestward looking panorama view shows the southeastern Mediterranean (29.0N, 33.0E) in great detail. The Sinai Peninsula, the eastern Arabian Desert, the Nile River Valley and Delta as well as the Qatara Depression in Egypt are all prominently portrayed. Even Mt. Sinai is visible in the lower left center of the view. The dusty atmosphere of the region can be seen as a general haziness in the atmosphere.

  9. Panoramas of Apollo sites

    NASA Image and Video Library

    1969-11-14

    Panoramas of Apollo sites were created to familiarize various Constellation projects with the actual nature of the lunar surface. Image is a view taken from northeast of the Lunar module (LM) looking west at panel and Flag, then to southwest at LM and counterclockwise to south and west looking into Surveyor Crater. View was created using Apollo 12 images - mag 47 frames 6982 thru 7006.

  10. Modeling Emergence in Neuroprotective Regulatory Networks

    SciTech Connect

    Sanfilippo, Antonio P.; Haack, Jereme N.; McDermott, Jason E.; Stevens, S.L.; Stenzel-Poore, Mary

    2013-01-05

    The use of predictive modeling in the analysis of gene expression data can greatly accelerate the pace of scientific discovery in biomedical research by enabling in silico experimentation to test disease triggers and potential drug therapies. Techniques that focus on modeling emergence, such as agent-based modeling and multi-agent simulations, are of particular interest as they support the discovery of pathways that may have never been observed in the past. Thus far, these techniques have been primarily applied at the multi-cellular level, or have focused on signaling and metabolic networks. We present an approach where emergence modeling is extended to regulatory networks and demonstrate its application to the discovery of neuroprotective pathways. An initial evaluation of the approach indicates that emergence modeling provides novel insights for the analysis of regulatory networks that can advance the discovery of acute treatments for stroke and other diseases.

  11. Emergence of coexisting percolating clusters in networks

    NASA Astrophysics Data System (ADS)

    Faqeeh, Ali; Melnik, Sergey; Colomer-de-Simón, Pol; Gleeson, James P.

    2016-06-01

    It is commonly assumed in percolation theories that at most one percolating cluster can exist in a network. We show that several coexisting percolating clusters (CPCs) can emerge in networks due to limited mixing, i.e., a finite and sufficiently small number of interlinks between network modules. We develop an approach called modular message passing (MMP) to describe and verify these observations. We demonstrate that the appearance of CPCs is an important source of inaccuracy in previously introduced percolation theories, such as the message passing (MP) approach, which is a state-of-the-art theory based on the belief propagation method. Moreover, we show that the MMP theory improves significantly over the predictions of MP for percolation on synthetic networks with limited mixing and also on several real-world networks. These findings have important implications for understanding the robustness of networks and in quantifying epidemic outbreaks in the susceptible-infected-recovered (SIR) model of disease spread.

  12. Panorama from 'Cape Verde'

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Exploration Rover Opportunity captured this vista of 'Victoria Crater' from the viewpoint of 'Cape Verde,' one of the promontories that are part of the scalloped rim of the crater. Opportunity drove onto Cape Verde shortly after arriving at the rim of Victoria in September 2006. The view combines hundreds of exposures taken by the rover's panoramic camera (Pancam). The camera began taking the component images during Opportunity's 970th Martian day, or sol, on Mars (Oct. 16, 2006). Work on the panorama continued through the solar conjunction period, when Mars was nearly behind the sun from Earth's perspective and communications were minimized. Acquisition of images for this panorama was completed on Opportunity's 991st sol (Nov. 7, 2006).

    The top of Cape Verde is in the immediate foreground at the center of the image. To the left and right are two of the more gradually sloped bays that alternate with the cliff-faced capes or promontories around the rim of the crater. 'Duck Bay,' where Opportunity first reached the rim, is to the right. Beyond Duck Bay counterclockwise around the rim, the next promontory is 'Cabo Frio,' about 150 meters (500 feet) from the rover. On the left side of the panorama is 'Cape St. Mary,' the next promontory clockwise from Cape Verde and about 40 meters (130 feet) from the rover. The vantage point atop Cape Verde offered a good view of the rock layers in the cliff face of Cape St. Mary, which is about 15 meters or 50 feet tall. By about two weeks after the Pancam finished collecting the images for this panorama, Opportunity had driven to Cape St. Mary and was photographing Cape Verde's rock layers.

    The far side of the crater lies about 800 meters (half a mile) away, toward the southeast.

    This approximately true-color view combines images taken through three of the Pancam's filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet).

  13. Emergence of Chimera in Multiplex Network

    NASA Astrophysics Data System (ADS)

    Ghosh, Saptarshi; Jalan, Sarika

    2016-06-01

    Chimera is a relatively new emerging phenomenon where coexistence of synchronous and asynchronous states is observed in symmetrically coupled dynamical units. We report the observation of the chimera state in multiplex networks where individual layer is represented by 1-d lattice with nonlocal interactions. While, multiplexing does not change the type of the chimera state and retains the multi-chimera state displayed by the isolated networks, it changes the regions of the incoherence. We investigate the emergence of coherent-incoherent bifurcation upon varying the control parameters, namely, the coupling strength and the network size. Additionally, we investigate the effect of initial condition on the dynamics of the chimera state. Using a measure based on the differences between the neighboring nodes which distinguishes smooth and nonsmooth spatial profiles, we find the critical coupling strength for the transition to the chimera state. Observing chimera in a multiplex network with one-to-one inter layer coupling is important to gain insight to many real world complex systems which inherently posses multilayer architecture.

  14. 360-degree Color Panorama

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is a 'geometrically improved' version of the 360- degree panorama heretofore known as the 'Gallery Pan', the first contiguous, uniform panorama taken by the Imager for Mars Pathfinder (IMP) over the course of Sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama.

    The IMP is a stereo imaging system that, in its fully deployed configuration, stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. In this geometrically improved version of the panorama, distortion due to a 2.5 degree tilt in the IMP camera mast has been removed, effectively flattening the horizon.

    The IMP has color capability provided by 24 selectable filters -- twelve filters per 'eye'. Its red, green, and blue filters were used to take this image.

    At left is a Lander petal and a metallic mast which is a portion of the low-gain antenna. Misregistration in the antenna and other Lander features is due to parallax in the extreme foreground. On the horizon the double 'Twin Peaks' are visible, about 1-2 kilometers away. The rock 'Couch' is the dark, curved rock at right of Twin Peaks. Another Lander petal is at left-center, showing the fully deployed forward ramp at far left, and rear ramp at right, which rover Sojourner used to descend to the surface of Mars on July 5. Immediately to the left of the rear ramp is the rock 'Barnacle Bill', which scientists found to be andesitic, possibly indicating that it is a volcanic rock (a true andesite) or a physical mixture of particles. Just beyond Barnacle Bill, rover tracks lead to Sojourner, shown using its Alpha Proton X-Ray Spectrometer (APXS) instrument to study the large rock 'Yogi'. Yogi, low in quartz content, appears to be more primitive than Barnacle Bill, and appears more like the common basalts found on Earth.

    The tracks and circular pattern in the soil

  15. 'Burns Cliff' Color Panorama

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Click on the image for 'Burns Cliff' Color Panorama (QTVR)

    NASA's Mars Exploration Rover Opportunity captured this view of 'Burns Cliff' after driving right to the base of this southeastern portion of the inner wall of 'Endurance Crater.' The view combines frames taken by Opportunity's panoramic camera between the rover's 287th and 294th martian days (Nov. 13 to 20, 2004).

    This is a composite of 46 different images, each acquired in seven different Pancam filters. It is an approximately true-color rendering generated from the panoramic camera's 750-nanometer, 530-nanometer and 430-nanometer filters. The mosaic spans more than 180 degrees side to side. Because of this wide-angle view, the cliff walls appear to bulge out toward the camera. In reality the walls form a gently curving, continuous surface.

  16. Emergence of event cascades in inhomogeneous networks

    PubMed Central

    Onaga, Tomokatsu; Shinomoto, Shigeru

    2016-01-01

    There is a commonality among contagious diseases, tweets, and neuronal firings that past events facilitate the future occurrence of events. The spread of events has been extensively studied such that the systems exhibit catastrophic chain reactions if the interaction represented by the ratio of reproduction exceeds unity; however, their subthreshold states are not fully understood. Here, we report that these systems are possessed by nonstationary cascades of event-occurrences already in the subthreshold regime. Event cascades can be harmful in some contexts, when the peak-demand causes vaccine shortages, heavy traffic on communication lines, but may be beneficial in other contexts, such that spontaneous activity in neural networks may be used to generate motion or store memory. Thus it is important to comprehend the mechanism by which such cascades appear, and consider controlling a system to tame or facilitate fluctuations in the event-occurrences. The critical interaction for the emergence of cascades depends greatly on the network structure in which individuals are connected. We demonstrate that we can predict whether cascades may emerge, given information about the interactions between individuals. Furthermore, we develop a method of reallocating connections among individuals so that event cascades may be either impeded or impelled in a network. PMID:27625183

  17. Emergence of event cascades in inhomogeneous networks

    NASA Astrophysics Data System (ADS)

    Onaga, Tomokatsu; Shinomoto, Shigeru

    2016-09-01

    There is a commonality among contagious diseases, tweets, and neuronal firings that past events facilitate the future occurrence of events. The spread of events has been extensively studied such that the systems exhibit catastrophic chain reactions if the interaction represented by the ratio of reproduction exceeds unity; however, their subthreshold states are not fully understood. Here, we report that these systems are possessed by nonstationary cascades of event-occurrences already in the subthreshold regime. Event cascades can be harmful in some contexts, when the peak-demand causes vaccine shortages, heavy traffic on communication lines, but may be beneficial in other contexts, such that spontaneous activity in neural networks may be used to generate motion or store memory. Thus it is important to comprehend the mechanism by which such cascades appear, and consider controlling a system to tame or facilitate fluctuations in the event-occurrences. The critical interaction for the emergence of cascades depends greatly on the network structure in which individuals are connected. We demonstrate that we can predict whether cascades may emerge, given information about the interactions between individuals. Furthermore, we develop a method of reallocating connections among individuals so that event cascades may be either impeded or impelled in a network.

  18. Reduction, integration and emergence in biochemical networks.

    PubMed

    Ricard, Jacques

    2004-12-01

    Most studies of molecular cell biology are based upon a process of decomposition of complex biological systems into their components, followed by the study of these components. The aim of the present paper is to discuss, on a physical basis, the internal logic of this process of reduction. The analysis is performed on simple biological systems, namely protein and metabolic networks. A multi-sited protein that binds two ligands x and y can be considered the simplest possible biochemical network. The organization of this network can be described through a comparison of three systems, i.e. XY, X and Y. X and Y are component sub-systems that collect states x(i) and y(j), respectively, i.e. protein states that have bound either i molecules of x (whether or not these states have also bound y), or j molecules of y (whether or not these states have bound x). XY is a system made up of the specific association of X and Y that collects states x(i)y(j). One can define mean self-informations per node of the network, , and . Reduction of the system XY into its components is possible if, and only if, ,is equal to the sum of and . If is smaller than the sum of and , the system is integrated, for it has less self-information than the set of its components X and Y. It can also occur that , be larger than the sum of and . Hence, the system XY displays negative integration and emergence of self-information relative to its components X and Y. Such a system is defined as complex. Positive or negative integration of the system implies it cannot be reduced to its components. The degree of integration can be measured by a function , called mutual information of integration. In the case of enzyme networks, emergence of self-information is associated with emergence of catalytic activity. Moreover, if the enzyme reaction is part of a metabolic sequence, its mutual information of integration can be

  19. Spirit's West Valley Panorama

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007.

    After several months near the base of the plateau called 'Home Plate' in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.

    This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is 'Tsiolkovski Ridge,' about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is 'Grissom Hill,' about 8 kilometers or 5 miles away. At right, the highest point of the horizon is 'Husband Hill,' to the north and about 800 meters or half a mile away.

    This view combines separate images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers to produce an approximately true-color panorama.

  20. Panorama of theoretical physics

    NASA Astrophysics Data System (ADS)

    Mimouni, J.

    2012-06-01

    We shall start this panorama of theoretical physics by giving an overview of physics in general, this branch of knowledge that has been taken since the scientific revolution as the archetype of the scientific discipline. We shall then proceed in showing in what way theoretical physics from Newton to Maxwell, Einstein, Feynman and the like, in all modesty, could be considered as the ticking heart of physics. By its special mode of inquiry and its tantalizing successes, it has capturing the very spirit of the scientific method, and indeed it has been taken as a role model by other disciplines all the way from the "hard" ones to the social sciences. We shall then review how much we know today of the world of matter, both in term of its basic content and in the way it is structured. We will then present the dreams of today's theoretical physics as a way of penetrating into its psyche, discovering in this way its aspirations and longing in much the same way that a child's dreams tell us about his yearning and craving. Yet our understanding of matter has been going in the past decades through a crisis of sort. As a necessary antidote, we shall thus discuss the pitfalls of dreams pushed too far….

  1. A liquid propulsion panorama

    NASA Astrophysics Data System (ADS)

    Caisso, Philippe; Souchier, Alain; Rothmund, Christophe; Alliot, Patrick; Bonhomme, Christophe; Zinner, Walter; Parsley, Randy; Neill, Todd; Forde, Scott; Starke, Robert; Wang, William; Takahashi, Mamoru; Atsumi, Masahiro; Valentian, Dominique

    2009-12-01

    Liquid-propellant rocket engines are widely used all over the world, thanks to their high performances, in particular high thrust-to-weight ratio. The present paper presents a general panorama of liquid propulsion as a contribution of the IAF Advanced Propulsion Prospective Group. After a brief history of its past development in the different parts of the world, the current status of liquid propulsion, the currently observed trends, the possible areas of future improvement and a summarized road map of future developments are presented. The road map includes a summary of the liquid propulsion status presented in the "Year in review 2007" of Aerospace America. Although liquid propulsion is often seen as a mature technology with few areas of potential improvement, the requirements of an active commercial market and a renewed interest for space exploration has led to the development of a family of new engines, with more design margins, simpler to use and to produce associated with a wide variety of thrust and life requirements.

  2. Defining and measuring successful emergency care networks: a research agenda.

    PubMed

    Glickman, Seth W; Kit Delgado, M; Hirshon, Jon Mark; Hollander, Judd E; Iwashyna, Theodore J; Jacobs, Alice K; Kilaru, Austin S; Lorch, Scott A; Mutter, Ryan L; Myers, Sage R; Owens, Pamela L; Phelan, Michael P; Pines, Jesse M; Seymour, Christopher W; Ewen Wang, N; Branas, Charles C

    2010-12-01

    The demands on emergency services have grown relentlessly, and the Institute of Medicine (IOM) has asserted the need for "regionalized, coordinated, and accountable emergency care systems throughout the country." There are large gaps in the evidence base needed to fix the problem of how emergency care is organized and delivered, and science is urgently needed to define and measure success in the emerging network of emergency care. In 2010, Academic Emergency Medicine convened a consensus conference entitled "Beyond Regionalization: Integrated Networks of Emergency Care." This article is a product of the conference breakout session on "Defining and Measuring Successful Networks"; it explores the concept of integrated emergency care delivery and prioritizes a research agenda for how to best define and measure successful networks of emergency care. The authors discuss five key areas: 1) the fundamental metrics that are needed to measure networks across time-sensitive and non-time-sensitive conditions; 2) how networks can be scalable and nimble and can be creative in terms of best practices; 3) the potential unintended consequences of networks of emergency care; 4) the development of large-scale, yet feasible, network data systems; and 5) the linkage of data systems across the disease course. These knowledge gaps must be filled to improve the quality and efficiency of emergency care and to fulfill the IOM's vision of regionalized, coordinated, and accountable emergency care systems. 2010 by the Society for Academic Emergency Medicine.

  3. Global Emergency Observation, Warning and Relief Network

    SciTech Connect

    Bukley, A.P.; Mulqueen, J.A.

    1995-12-31

    The decade of the 1990`s has been proclaimed by the United Nations to be the International Decade for Natural Disaster Reduction (IDNDR). There exists a documented need for improved communications and information distribution to provide adequate warning in the face of impending disasters and facilitate the response after a disaster has occurred. The Global Emergency Observation Warning and Relief Network (GEOWARN) is proposed as a system that can potentially fill the existing gaps in the disaster management capabilities by providing a mechanism for the timely processing of information both before and after an event has occurred. A system design is proposed that would utilize existing remote sensing resources augmented by additional satellites and airborne sensor platforms linked together via a computer network. This network would be configured around five control centers called Multi-National Centers which would host an extensive Geographical Information System to perform the task of providing global disaster warning and relief support. To support the potential development of GEOWARN, the NASA Marshall Space Flight Center performed a study to assess concept feasibility. This study has resulted in several recommended modifications to the ISU system concept. It was concluded that a system design which optimizes the use of existing resources can result in significant improvements in disaster warning and management capabilities for most of the world. This paper presents the results of the feasibility study, including a general overview of the GEOWARN concept and the elements comprising the system.

  4. Opportunity Captures 'Lion King' Panorama

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Click on the image for Opportunity Captures 'Lion King' Panorama (QTVR)

    This approximate true-color panorama, dubbed 'Lion King,' shows 'Eagle Crater' and the surrounding plains of Meridiani Planum. It was obtained by the Mars Exploration Rover Opportunity's panoramic camera on sols 58 and 60 using infrared (750-nanometer), green (530-nanometer) and blue (430-nanometer) filters.

    This is the largest panorama obtained yet by either rover. It was taken in eight segments using six filters per segment, for a total of 558 images and more than 75 megabytes of data. Additional lower elevation tiers were added to ensure that the entire crater was covered in the mosaic.

    This panorama depicts a story of exploration including the rover's lander, a thorough examination of the outcrop, a study of the soils at the near-side of the lander, a successful exit from Eagle Crater and finally the rover's next desination, the large crater dubbed 'Endurance'.

  5. Opportunity Captures 'Lion King' Panorama

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Click on the image for Opportunity Captures 'Lion King' Panorama (QTVR)

    This approximate true-color panorama, dubbed 'Lion King,' shows 'Eagle Crater' and the surrounding plains of Meridiani Planum. It was obtained by the Mars Exploration Rover Opportunity's panoramic camera on sols 58 and 60 using infrared (750-nanometer), green (530-nanometer) and blue (430-nanometer) filters.

    This is the largest panorama obtained yet by either rover. It was taken in eight segments using six filters per segment, for a total of 558 images and more than 75 megabytes of data. Additional lower elevation tiers were added to ensure that the entire crater was covered in the mosaic.

    This panorama depicts a story of exploration including the rover's lander, a thorough examination of the outcrop, a study of the soils at the near-side of the lander, a successful exit from Eagle Crater and finally the rover's next desination, the large crater dubbed 'Endurance'.

  6. Panorama 2000: Student Enrollment Report.

    ERIC Educational Resources Information Center

    Nowak, Jeffrey M.

    Panorama 2000 presents information on Palm Beach Community College's (PBCC's) Florida, enrollment characteristics for the 1999-2000 reporting year. In addition, this report serves to support PBCC's commitment to collect and provide useful data that is systematic, broad-based and interrelated for the purpose of educational decision-making. The…

  7. Self-organized Collaboration Network Model Based on Module Emerging

    NASA Astrophysics Data System (ADS)

    Yang, Hongyong; Lu, Lan; Liu, Qiming

    Recently, the studies of the complex network have gone deep into many scientific fields, such as computer science, physics, mathematics, sociology, etc. These researches enrich the realization for complex network, and increase understands for the new characteristic of complex network. Based on the evolvement characteristic of the author collaboration in the scientific thesis, a self-organized network model of the scientific cooperation network is presented by module emerging. By applying the theoretical analysis, it is shown that this network model is a scale-free network, and the strength degree distribution and the module degree distribution of the network nodes have the same power law. In order to make sure the validity of the theoretical analysis for the network model, we create the computer simulation and demonstration collaboration network. By analyzing the data of the network, the results of the demonstration network and the computer simulation are consistent with that of the theoretical analysis of the model.

  8. Summit Panorama with Rover Deck

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for Summit Panorama with Rover (QTVR)

    The panoramic camera on NASA's Mars Exploration Rover Spirit took the hundreds of images combined into this 360-degree view, the 'Husband Hill Summit' panorama. The images were acquired on Spirit's sols 583 to 586 (Aug. 24 to 27, 2005), shortly after the rover reached the crest of 'Husband Hill' inside Mars' Gusev Crater. This is the largest panorama yet acquired from either Spirit or Opportunity. The panoramic camera shot 653 separate images in 6 different filters, encompassing the rover's deck and the full 360 degrees of surface rocks and soils visible to the camera from this position. This is the first time the camera has been used to image the entire rover deck and visible surface from the same position. Stitching together of all the images took significant effort because of the large changes in resolution and parallax across the scene.

    The image is an approximately true-color rendering using the 750-nanometer, 530-nanometer and 480-nanometer filters for the surface, and the 600-nanometer and 480-nanometer filters for the rover deck. Image-to-image seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.

    This panorama provided the team's first view of the 'Inner Basin' region (center of the image), including the enigmatic 'Home Plate' feature seen from orbital data. After investigating the summit area, Spirit drove downhill to get to the Inner Basin region. Spirit arrived at the summit from the west, along the direction of the rover tracks seen in the middle right of the panorama. The peaks of 'McCool Hill' and 'Ramon Hill' can be seen on the horizon near the center of the panorama. The summit region itself is a broad, windswept plateau. Spirit spent more than a month exploring the summit region, measuring the chemistry and mineralogy of soils and rocky outcrops at the peak

  9. Network Leadership's Balancing Act: Contrivance or Emergence?

    ERIC Educational Resources Information Center

    Kubiak, Chris; Bertram, Joan

    2005-01-01

    It is well understood that one learns much of what one knows through one's network of relationships and through shared discussion and activity. A logical extension of this idea is the growing prominence in the UK where formal school-to-school networking such as Education Action Zones and Excellence in Cities has been established. This article…

  10. Emergence of fractal scaling in complex networks.

    PubMed

    Wei, Zong-Wen; Wang, Bing-Hong

    2016-09-01

    Some real-world networks are shown to be fractal or self-similar. It is widespread that such a phenomenon originates from the repulsion between hubs or disassortativity. Here we show that this common belief fails to capture the causality. Our key insight to address it is to pinpoint links critical to fractality. Those links with small edge betweenness centrality (BC) constitute a special architecture called fractal reference system, which gives birth to the fractal structure of those reported networks. In contrast, a small amount of links with high BC enable small-world effects, hiding the intrinsic fractality. With enough of such links removed, fractal scaling spontaneously arises from nonfractal networks. Our results provide a multiple-scale view on the structure and dynamics and place fractality as a generic organizing principle of complex networks on a firmer ground.

  11. Emergence of fractal scaling in complex networks

    NASA Astrophysics Data System (ADS)

    Wei, Zong-Wen; Wang, Bing-Hong

    2016-09-01

    Some real-world networks are shown to be fractal or self-similar. It is widespread that such a phenomenon originates from the repulsion between hubs or disassortativity. Here we show that this common belief fails to capture the causality. Our key insight to address it is to pinpoint links critical to fractality. Those links with small edge betweenness centrality (BC) constitute a special architecture called fractal reference system, which gives birth to the fractal structure of those reported networks. In contrast, a small amount of links with high BC enable small-world effects, hiding the intrinsic fractality. With enough of such links removed, fractal scaling spontaneously arises from nonfractal networks. Our results provide a multiple-scale view on the structure and dynamics and place fractality as a generic organizing principle of complex networks on a firmer ground.

  12. Assessment of Emerging Networks to Support Future NASA Space Operations

    NASA Technical Reports Server (NTRS)

    Younes, Badri; Chang, Susan; Berman, Ted; Burns, Mark; LaFontaine, Richard; Lease, Robert

    1998-01-01

    Various issues associated with assessing emerging networks to support future NASA space operations are presented in viewgraph form. Specific topics include: 1) Emerging commercial satellite systems; 2) NASA LEO satellite support through commercial systems; 3) Communications coverage, user terminal assessment and regulatory assessment; 4) NASA LEO missions overview; and 5) Simulation assumptions and results.

  13. Panorama Image Sets for Terrestrial Photogrammetric Surveys

    NASA Astrophysics Data System (ADS)

    Piermattei, L.; Karel, W.; Vettore, A.; Pfeifer, N.

    2016-06-01

    High resolution 3D models produced from photographs acquired with consumer-grade cameras are becoming increasingly common in the fields of geosciences. However, the quality of an image-based 3D model depends on the planning of the photogrammetric surveys. This means that the geometric configuration of the multi-view camera network and the control data have to be designed in accordance with the required accuracy, resolution and completeness. From a practical application point of view, a proper planning (of both photos and control data) of the photogrammetric survey especially for terrestrial acquisition, is not always ensured due to limited accessibility of the target object and the presence of occlusions. To solve these problems, we propose a different image acquisition strategy and we test different geo-referencing scenarios to deal with the practical issues of a terrestrial photogrammetric survey. The proposed photogrammetric survey procedure is based on the acquisition of a sequence of images in panorama mode by rotating the camera on a standard tripod. The offset of the pivot point from the projection center prevents the stitching of these images into a panorama. We demonstrate how to still take advantage of this capturing mode. The geo-referencing investigation consists of testing the use of directly observed coordinates of the camera positions, different ground control point (GCP) configurations, and GCPs with different accuracies, i.e. artificial targets vs. natural features. Images of the test field in a low-slope hill were acquired from the ground using an SLR camera. To validate the photogrammetric results a terrestrial laser scanner survey is used as benchmark.

  14. 'Lyell' Panorama inside Victoria Crater

    NASA Technical Reports Server (NTRS)

    2008-01-01

    During four months prior to the fourth anniversary of its landing on Mars, NASA's Mars Exploration Rover Opportunity examined rocks inside an alcove called 'Duck Bay' in the western portion of Victoria Crater. The main body of the crater appears in the upper right of this stereo panorama, with the far side of the crater lying about 800 meters (half a mile) away. Bracketing that part of the view are two promontories on the crater's rim at either side of Duck Bay. They are 'Cape Verde,' about 6 meters (20 feet) tall, on the left, and 'Cabo Frio,' about 15 meters (50 feet) tall, on the right. The rest of the image, other than sky and portions of the rover, is ground within Duck Bay.

    Opportunity's targets of study during the last quarter of 2007 were rock layers within a band exposed around the interior of the crater, about 6 meters (20 feet) from the rim. Bright rocks within the band are visible in the foreground of the panorama. The rover science team assigned informal names to three subdivisions of the band: 'Steno,' 'Smith,' and 'Lyell.'

    This view combines many images taken by Opportunity's panoramic camera (Pancam) from the 1,332nd through 1,379th Martian days, or sols, of the mission (Oct. 23 to Dec. 11, 2007). Images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers were mixed to produce an approximately true-color panorama. Some visible patterns in dark and light tones are the result of combining frames that were affected by dust on the front sapphire window of the rover's camera.

    Opportunity landed on Jan. 25, 2004, Universal Time, (Jan. 24, Pacific Time) inside a much smaller crater about 6 kilometers (4 miles) north of Victoria Crater, to begin a surface mission designed to last 3 months and drive about 600 meters (0.4 mile).

  15. A Whale of a Panorama

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for A Whale of a Panorama (QTVR)

    More than 1.5 years into their exploration of Mars, both of NASA's Mars Exploration Rovers continue to send a cornucopia of images to Earth. The results are so spectacular that Deputy Project Manager John Callas recently described them as 'an embarrassment of riches.' Spirit produced this image mosaic, nicknamed the 'Whale Panorama,' two-thirds of the way to the summit of 'Husband Hill,' where the rover investigated martian rocks. On the right side of the panorama is a tilted layer of rocks dubbed 'Larry's Outcrop,' one of several tilted outcrops that scientists examined in April, 2005. They used spatial information to create geologic maps showing the compass orientation and degree of tilting of rock formations in the vicinity. Such information is key to geologic fieldwork because it helps establish if rock layers have been warped since they formed. In this case, scientists have also been studying the mineral and chemical differences, which show that some rocks have been more highly altered than others.

    In the foreground, in the middle of the image mosaic, Spirit is shown with the scientific instruments at the end of its robotic arm positioned on a rock target known as 'Ahab.' The rover was busy collecting elemental chemistry and mineralogy data on the rock at the same time that it was taking 50 individual snapshots with its five panoramic camera filters to create this stunning view of the martian scenery. The twin tracks of the rover's all-terrain wheels are clearly visible on the left.

    This mosaic of images spans about 220 degrees from left to right and is an approximate true-color rendering of the Mars terrain acquired through the panoramic camera's 750-, 530-, and 430-nanometer filters. Spirit collected these images from its 497th martian day, or sol, through its 500th sol (May 27 through May 30, 2005).

  16. 'Lyell' Panorama inside Victoria Crater

    NASA Technical Reports Server (NTRS)

    2008-01-01

    During four months prior to the fourth anniversary of its landing on Mars, NASA's Mars Exploration Rover Opportunity examined rocks inside an alcove called 'Duck Bay' in the western portion of Victoria Crater. The main body of the crater appears in the upper right of this stereo panorama, with the far side of the crater lying about 800 meters (half a mile) away. Bracketing that part of the view are two promontories on the crater's rim at either side of Duck Bay. They are 'Cape Verde,' about 6 meters (20 feet) tall, on the left, and 'Cabo Frio,' about 15 meters (50 feet) tall, on the right. The rest of the image, other than sky and portions of the rover, is ground within Duck Bay.

    Opportunity's targets of study during the last quarter of 2007 were rock layers within a band exposed around the interior of the crater, about 6 meters (20 feet) from the rim. Bright rocks within the band are visible in the foreground of the panorama. The rover science team assigned informal names to three subdivisions of the band: 'Steno,' 'Smith,' and 'Lyell.'

    This view combines many images taken by Opportunity's panoramic camera (Pancam) from the 1,332nd through 1,379th Martian days, or sols, of the mission (Oct. 23 to Dec. 11, 2007). Images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers were mixed to produce an approximately true-color panorama. Some visible patterns in dark and light tones are the result of combining frames that were affected by dust on the front sapphire window of the rover's camera.

    Opportunity landed on Jan. 25, 2004, Universal Time, (Jan. 24, Pacific Time) inside a much smaller crater about 6 kilometers (4 miles) north of Victoria Crater, to begin a surface mission designed to last 3 months and drive about 600 meters (0.4 mile).

  17. A Whale of a Panorama

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for A Whale of a Panorama (QTVR)

    More than 1.5 years into their exploration of Mars, both of NASA's Mars Exploration Rovers continue to send a cornucopia of images to Earth. The results are so spectacular that Deputy Project Manager John Callas recently described them as 'an embarrassment of riches.' Spirit produced this image mosaic, nicknamed the 'Whale Panorama,' two-thirds of the way to the summit of 'Husband Hill,' where the rover investigated martian rocks. On the right side of the panorama is a tilted layer of rocks dubbed 'Larry's Outcrop,' one of several tilted outcrops that scientists examined in April, 2005. They used spatial information to create geologic maps showing the compass orientation and degree of tilting of rock formations in the vicinity. Such information is key to geologic fieldwork because it helps establish if rock layers have been warped since they formed. In this case, scientists have also been studying the mineral and chemical differences, which show that some rocks have been more highly altered than others.

    In the foreground, in the middle of the image mosaic, Spirit is shown with the scientific instruments at the end of its robotic arm positioned on a rock target known as 'Ahab.' The rover was busy collecting elemental chemistry and mineralogy data on the rock at the same time that it was taking 50 individual snapshots with its five panoramic camera filters to create this stunning view of the martian scenery. The twin tracks of the rover's all-terrain wheels are clearly visible on the left.

    This mosaic of images spans about 220 degrees from left to right and is an approximate true-color rendering of the Mars terrain acquired through the panoramic camera's 750-, 530-, and 430-nanometer filters. Spirit collected these images from its 497th martian day, or sol, through its 500th sol (May 27 through May 30, 2005).

  18. Network Management in an Emergency Communications System.

    DTIC Science & Technology

    1986-03-01

    EhhohhohEohhEI ANEOEEhh * . * - - 11112 I. ROC".,. ’. 11111 IIIII+ m "I’ _.__ .+4 .... a ..• .. 7 .7 R.- ’- ’c -’ 00 NAVAN NAVAL POSTGRADUAIE SCHOOL 0...re uirements for a generic emerrceoc: jommuni cat ic _!i tem,a .vell as specul1aItion oIn po te nt ialI r e clu ir e m enIts " Ur f -I t11r a - r a...network monitoring tells management processors and personnel what is happe .:ning throughout the network, where problems are devel- oping, and what is the

  19. Opportunity's 'Rub al Khali' Panorama

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Click on the image for Opportunity's 'Rub al Khali' Panorama (QTVR)

    This panoramic image, dubbed 'Rub al Khali,' was acquired by NASA's Mars Exploration Rover Opportunity on the plains of Meridiani during the period from the rover's 456th to 464th sols on Mars (May 6 to May 14, 2005). Opportunity was about 2 kilometers (1.2 miles) south of 'Endurance Crater' at a place known informally as 'Purgatory Dune.'

    The rover was stuck in the dune's deep fine sand for more than a month. 'Rub al Khali' (Arabic translation: 'the empty quarter') was chosen as the name for this panorama because it is the name of a similarly barren, desolate part of the Saudi Arabian desert on Earth.

    The view spans 360 degrees. It consists of images obtained in 97 individual pointings of the panoramic camera. The camera took images with five camera filters at each pointing. This 22,780-by-6,000-pixel mosaic is an approximately true-color rendering generated using the images acquired through filters admitting light wavelengths of 750, 530, and 480 nanometers.

    Lighting varied during the nine sols it took to acquire this panorama, resulting in some small image seams within the mosaic. These seams have been smoothed in sky parts of the mosaic to better simulate the vista that a person would see if able to view it all at the same time on Mars.

    Opportunity's tracks leading back to the north (center of the panorama) are a reminder of the rover's long trek from Endurance Crater. The deep ruts dug by Opportunity's wheels as it became stuck in the sand appear in the foreground. The crest and trough of the last ripple the rover crossed before getting stuck is visible in the center. These wind-formed sand features are only about 10 to 15 centimeters (4 to 6 inches) tall. The crest of the actual ripple where the rover got stuck can be seen just to the right of center. The tracks and a few other places on and near ripple crests can

  20. Emergence of Multiplex Communities in Collaboration Networks

    PubMed Central

    Nicosia, Vincenzo; Bianconi, Ginestra; Latora, Vito

    2016-01-01

    Community structures in collaboration networks reflect the natural tendency of individuals to organize their work in groups in order to better achieve common goals. In most of the cases, individuals exploit their connections to introduce themselves to new areas of interests, giving rise to multifaceted collaborations which span different fields. In this paper, we analyse collaborations in science and among movie actors as multiplex networks, where the layers represent respectively research topics and movie genres, and we show that communities indeed coexist and overlap at the different layers of such systems. We then propose a model to grow multiplex networks based on two mechanisms of intra and inter-layer triadic closure which mimic the real processes by which collaborations evolve. We show that our model is able to explain the multiplex community structure observed empirically, and we infer the strength of the two underlying social mechanisms from real-world systems. Being also able to correctly reproduce the values of intra-layer and inter-layer assortativity correlations, the model contributes to a better understanding of the principles driving the evolution of social networks. PMID:26815700

  1. Emergence of Multiplex Communities in Collaboration Networks.

    PubMed

    Battiston, Federico; Iacovacci, Jacopo; Nicosia, Vincenzo; Bianconi, Ginestra; Latora, Vito

    2016-01-01

    Community structures in collaboration networks reflect the natural tendency of individuals to organize their work in groups in order to better achieve common goals. In most of the cases, individuals exploit their connections to introduce themselves to new areas of interests, giving rise to multifaceted collaborations which span different fields. In this paper, we analyse collaborations in science and among movie actors as multiplex networks, where the layers represent respectively research topics and movie genres, and we show that communities indeed coexist and overlap at the different layers of such systems. We then propose a model to grow multiplex networks based on two mechanisms of intra and inter-layer triadic closure which mimic the real processes by which collaborations evolve. We show that our model is able to explain the multiplex community structure observed empirically, and we infer the strength of the two underlying social mechanisms from real-world systems. Being also able to correctly reproduce the values of intra-layer and inter-layer assortativity correlations, the model contributes to a better understanding of the principles driving the evolution of social networks.

  2. Pediatric emergency research networks: a global initiative in pediatric emergency medicine.

    PubMed

    Klassen, Terry P; Acworth, Jason; Bialy, Liza; Black, Karen; Chamberlain, James M; Cheng, Nicholas; Dalziel, Stuart; Fernandes, Ricardo M; Fitzpatrick, Eleanor; Johnson, David W; Kuppermann, Nathan; Macias, Charles G; Newton, Mandi; Osmond, Martin H; Plint, Amy; Valerio, Paolo; Waisman, Yehezkel

    2010-08-01

    Objectives of the Pediatric Emergency Research Network's (PERN's) meeting included (1) learn about each of the participating network's missions, goals, and infrastructure; (2) share important contributions each network has made to the creation of new knowledge; (3) discuss "best practices" to improve each network's effectiveness; and (4) explore the potential for a collaborative research project as proof of concept that would help us promote quality of care of the acutely ill and injured child/youth globally. In October 2009, a multiday meeting was attended by 18 delegates representing the following pediatric emergency medicine research networks: Pediatric Emergency Medicine Collaborative Research Committee (United States), Pediatric Emergency Care Applied Research Network (United States), Pediatric Emergency Research of Canada (Canada), Paediatric Research in Emergency Departments International Collaborative (Australia and New Zealand), and Research in European Pediatric Emergency Medicine (15 countries in Europe and the Middle East). The inaugural meeting of PERN demonstrated that there is a common desire for high-quality research and the dissemination of this research to improve health and outcomes of acutely ill and injured children and youths throughout the world. Presently, the PERN group is in the final stages of developing a protocol to assess H1N1 risk factors with the collection of retrospective data. Several members of PERN will be gathering at the International Conference on Emergency Medicine in Singapore, where the group will be presenting information about the H1N1 initiative. The PERN group is planning to bring together all 5 networks later in 2010 to discuss future global collaborations.

  3. Pediatric Emergency Research Networks: a global initiative in pediatric emergency medicine.

    PubMed

    Klassen, Terry P; Acworth, Jason; Bialy, Liza; Black, Karen; Chamberlain, James M; Cheng, Nicholas; Dalziel, Stuart; Fernandes, Ricardo M; Fitzpatrick, Eleanor; Johnson, David W; Kuppermann, Nathan; Macias, Charles G; Newton, Mandi; Osmond, Martin H; Plint, Amy; Valerio, Paolo; Waisman, Yehezkel

    2010-08-01

    The objectives of the Pediatric Emergency Research Network's (PERN) meeting were to (i) learn about each of the participating network's missions, goals, and infrastructure; (ii) share important contributions that each network has made to the creation of new knowledge; (iii) discuss 'best practices' to improve each network's effectiveness and (iv) explore the potential for a collaborative research project as proof-of-concept that would help promote quality of care of the acutely ill and injured child/youth globally. In October 2009 a multiday meeting was attended by 18 delegates representing the following pediatric emergency medicine research networks: Pediatric Emergency Medicine Collaborative Research Committee (USA); Pediatric Emergency Care Applied Research Network (USA); Pediatric Emergency Research of Canada (Canada); Pediatric Research in Emergency Departments International Collaborative (Australia and New Zealand); and Research in European Pediatric Emergency Medicine (15 countries in Europe and the Middle East). The inaugural meeting of PERN showed that there is a common desire for high-quality research and the dissemination of this research to improve health and outcomes of acutely ill and injured children and youths throughout the world. At present, the PERN group is in the final stages of developing a protocol to assess H1N1 risk factors with the collection of retrospective data. Several members of PERN will be gathering at the International Conference on Emergency Medicine in Singapore, where the group will be presenting information about the H1N1 initiative. The PERN group is planning to bring together all five networks later in 2010 to discuss future global collaborations.

  4. Panorama: A Targeted Proteomics Knowledge Base

    PubMed Central

    2015-01-01

    Panorama is a web application for storing, sharing, analyzing, and reusing targeted assays created and refined with Skyline,1 an increasingly popular Windows client software tool for targeted proteomics experiments. Panorama allows laboratories to store and organize curated results contained in Skyline documents with fine-grained permissions, which facilitates distributed collaboration and secure sharing of published and unpublished data via a web-browser interface. It is fully integrated with the Skyline workflow and supports publishing a document directly to a Panorama server from the Skyline user interface. Panorama captures the complete Skyline document information content in a relational database schema. Curated results published to Panorama can be aggregated and exported as chromatogram libraries. These libraries can be used in Skyline to pick optimal targets in new experiments and to validate peak identification of target peptides. Panorama is open-source and freely available. It is distributed as part of LabKey Server,2 an open source biomedical research data management system. Laboratories and organizations can set up Panorama locally by downloading and installing the software on their own servers. They can also request freely hosted projects on https://panoramaweb.org, a Panorama server maintained by the Department of Genome Sciences at the University of Washington. PMID:25102069

  5. Panorama: a targeted proteomics knowledge base.

    PubMed

    Sharma, Vagisha; Eckels, Josh; Taylor, Greg K; Shulman, Nicholas J; Stergachis, Andrew B; Joyner, Shannon A; Yan, Ping; Whiteaker, Jeffrey R; Halusa, Goran N; Schilling, Birgit; Gibson, Bradford W; Colangelo, Christopher M; Paulovich, Amanda G; Carr, Steven A; Jaffe, Jacob D; MacCoss, Michael J; MacLean, Brendan

    2014-09-05

    Panorama is a web application for storing, sharing, analyzing, and reusing targeted assays created and refined with Skyline,1 an increasingly popular Windows client software tool for targeted proteomics experiments. Panorama allows laboratories to store and organize curated results contained in Skyline documents with fine-grained permissions, which facilitates distributed collaboration and secure sharing of published and unpublished data via a web-browser interface. It is fully integrated with the Skyline workflow and supports publishing a document directly to a Panorama server from the Skyline user interface. Panorama captures the complete Skyline document information content in a relational database schema. Curated results published to Panorama can be aggregated and exported as chromatogram libraries. These libraries can be used in Skyline to pick optimal targets in new experiments and to validate peak identification of target peptides. Panorama is open-source and freely available. It is distributed as part of LabKey Server,2 an open source biomedical research data management system. Laboratories and organizations can set up Panorama locally by downloading and installing the software on their own servers. They can also request freely hosted projects on https://panoramaweb.org , a Panorama server maintained by the Department of Genome Sciences at the University of Washington.

  6. Distributed Seams for Gigapixel Panoramas.

    PubMed

    Philip, Sujin; Summa, Brian; Tierny, Julien; Bremer, Peer-Timo; Pascucci, Valerio

    2015-03-01

    Gigapixel panoramas are an increasingly popular digital image application. They are often created as a mosaic of many smaller images. The mosaic acquisition can take many hours causing the individual images to differ in exposure and lighting conditions. A blending operation is often necessary to give the appearance of a seamless image. The blending quality depends on the magnitude of discontinuity along the image boundaries. Often, new boundaries, or seams, are first computed that minimize this transition. Current techniques based on multi-labeling Graph Cuts are too slow and memory intensive for gigapixel sized panoramas. In this paper, we present a parallel, out-of-core seam computing technique that is fast, has small memory footprint, and is capable of running efficiently on different types of parallel systems. Its maximum memory usage is configurable, in the form of a cache, which can improve performance by reducing redundant disk I/O and computations. It shows near-perfect scaling on symmetric multiprocessing systems and good scaling on clusters and distributed shared memory systems. Our technique improves the time required to compute seams for gigapixel imagery from many hours (or even days) to just a few minutes, while still producing boundaries with energy that is on-par with Graph Cuts.

  7. Online and Offline Social Networks: Use of Social Networking Sites by Emerging Adults

    ERIC Educational Resources Information Center

    Subrahmanyam, Kaveri; Reich, Stephanie M.; Waechter, Natalia; Espinoza, Guadalupe

    2008-01-01

    Social networking sites (e.g., MySpace and Facebook) are popular online communication forms among adolescents and emerging adults. Yet little is known about young people's activities on these sites and how their networks of "friends" relate to their other online (e.g., instant messaging) and offline networks. In this study, college students…

  8. Online and Offline Social Networks: Use of Social Networking Sites by Emerging Adults

    ERIC Educational Resources Information Center

    Subrahmanyam, Kaveri; Reich, Stephanie M.; Waechter, Natalia; Espinoza, Guadalupe

    2008-01-01

    Social networking sites (e.g., MySpace and Facebook) are popular online communication forms among adolescents and emerging adults. Yet little is known about young people's activities on these sites and how their networks of "friends" relate to their other online (e.g., instant messaging) and offline networks. In this study, college students…

  9. Panorama

    ERIC Educational Resources Information Center

    BioScience, 1974

    1974-01-01

    Outlines pending federal legislation affecting science policy, discusses an exodus of top officials from the National Institutes of Health, and lists members of the Office of Technology Assessment Advisory Council. (JR)

  10. Emergence of communities and diversity in social networks

    PubMed Central

    Han, Xiao; Cao, Shinan; Shen, Zhesi; Zhang, Boyu; Wang, Wen-Xu; Cressman, Ross

    2017-01-01

    Communities are common in complex networks and play a significant role in the functioning of social, biological, economic, and technological systems. Despite widespread interest in detecting community structures in complex networks and exploring the effect of communities on collective dynamics, a deep understanding of the emergence and prevalence of communities in social networks is still lacking. Addressing this fundamental problem is of paramount importance in understanding, predicting, and controlling a variety of collective behaviors in society. An elusive question is how communities with common internal properties arise in social networks with great individual diversity. Here, we answer this question using the ultimatum game, which has been a paradigm for characterizing altruism and fairness. We experimentally show that stable local communities with different internal agreements emerge spontaneously and induce social diversity into networks, which is in sharp contrast to populations with random interactions. Diverse communities and social norms come from the interaction between responders with inherent heterogeneous demands and rational proposers via local connections, where the former eventually become the community leaders. This result indicates that networks are significant in the emergence and stabilization of communities and social diversity. Our experimental results also provide valuable information about strategies for developing network models and theories of evolutionary games and social dynamics. PMID:28235785

  11. Emergence of communities and diversity in social networks.

    PubMed

    Han, Xiao; Cao, Shinan; Shen, Zhesi; Zhang, Boyu; Wang, Wen-Xu; Cressman, Ross; Stanley, H Eugene

    2017-03-14

    Communities are common in complex networks and play a significant role in the functioning of social, biological, economic, and technological systems. Despite widespread interest in detecting community structures in complex networks and exploring the effect of communities on collective dynamics, a deep understanding of the emergence and prevalence of communities in social networks is still lacking. Addressing this fundamental problem is of paramount importance in understanding, predicting, and controlling a variety of collective behaviors in society. An elusive question is how communities with common internal properties arise in social networks with great individual diversity. Here, we answer this question using the ultimatum game, which has been a paradigm for characterizing altruism and fairness. We experimentally show that stable local communities with different internal agreements emerge spontaneously and induce social diversity into networks, which is in sharp contrast to populations with random interactions. Diverse communities and social norms come from the interaction between responders with inherent heterogeneous demands and rational proposers via local connections, where the former eventually become the community leaders. This result indicates that networks are significant in the emergence and stabilization of communities and social diversity. Our experimental results also provide valuable information about strategies for developing network models and theories of evolutionary games and social dynamics.

  12. Emergent gamma synchrony in all-to-all interneuronal networks

    PubMed Central

    Ratnadurai-Giridharan, Shivakeshavan; Khargonekar, Pramod P.; Talathi, Sachin S.

    2015-01-01

    We investigate the emergence of in-phase synchronization in a heterogeneous network of coupled inhibitory interneurons in the presence of spike timing dependent plasticity (STDP). Using a simple network of two mutually coupled interneurons (2-MCI), we first study the effects of STDP on in-phase synchronization. We demonstrate that, with STDP, the 2-MCI network can evolve to either a state of stable 1:1 in-phase synchronization or exhibit multiple regimes of higher order synchronization states. We show that the emergence of synchronization induces a structural asymmetry in the 2-MCI network such that the synapses onto the high frequency firing neurons are potentiated, while those onto the low frequency firing neurons are de-potentiated, resulting in the directed flow of information from low frequency firing neurons to high frequency firing neurons. Finally, we demonstrate that the principal findings from our analysis of the 2-MCI network contribute to the emergence of robust synchronization in the Wang-Buzsaki network (Wang and Buzsáki, 1996) of all-to-all coupled inhibitory interneurons (100-MCI) for a significantly larger range of heterogeneity in the intrinsic firing rate of the neurons in the network. We conclude that STDP of inhibitory synapses provide a viable mechanism for robust neural synchronization. PMID:26528174

  13. Emergent Functional Properties of Neuronal Networks with Controlled Topology

    PubMed Central

    Marconi, Emanuele; Nieus, Thierry; Maccione, Alessandro; Valente, Pierluigi; Simi, Alessandro; Messa, Mirko; Dante, Silvia; Baldelli, Pietro; Berdondini, Luca; Benfenati, Fabio

    2012-01-01

    The interplay between anatomical connectivity and dynamics in neural networks plays a key role in the functional properties of the brain and in the associated connectivity changes induced by neural diseases. However, a detailed experimental investigation of this interplay at both cellular and population scales in the living brain is limited by accessibility. Alternatively, to investigate the basic operational principles with morphological, electrophysiological and computational methods, the activity emerging from large in vitro networks of primary neurons organized with imposed topologies can be studied. Here, we validated the use of a new bio-printing approach, which effectively maintains the topology of hippocampal cultures in vitro and investigated, by patch-clamp and MEA electrophysiology, the emerging functional properties of these grid-confined networks. In spite of differences in the organization of physical connectivity, our bio-patterned grid networks retained the key properties of synaptic transmission, short-term plasticity and overall network activity with respect to random networks. Interestingly, the imposed grid topology resulted in a reinforcement of functional connections along orthogonal directions, shorter connectivity links and a greatly increased spiking probability in response to focal stimulation. These results clearly demonstrate that reliable functional studies can nowadays be performed on large neuronal networks in the presence of sustained changes in the physical network connectivity. PMID:22493706

  14. Online Network Influences on Emerging Adults’ Alcohol and Drug Use

    PubMed Central

    Cook, Stephanie H.; Gordon-Messer, Deborah; Zimmerman, Marc A.

    2012-01-01

    Researchers have reported that network characteristics are associated with substance use behavior. Considering that social interactions within online networks are increasingly common, we examined the relationship between online network characteristics and substance use in a sample of emerging adults (ages 18–24) from across the United States (N = 2,153; M = 21 years old; 47 % female; 70 % White). We used regression analyses to examine the relationship between online ego network characteristics (i.e., characteristics of individuals directly related to the focal participant plus the relationships shared among individuals within the online network) and alcohol use and substance use, respectively. Alcohol use was associated with network density (i.e., interconnectedness between individuals in a network), total number of peer ties, and a greater proportion of emotionally close ties. In sex-stratified models, density was related to alcohol use for males but not females. Drug use was associated with an increased number of peer ties, and the increased proportion of network members’ discussion and acceptance of drug use, respectively. We also found that online network density and total numbers of ties were associated with more personal drug use for males but not females. Conversely, we noted that social norms were related to increased drug use and this relationship was stronger for females than males. We discuss the implications of our findings for substance use and online network research. PMID:23212348

  15. Emergence of Slow-Switching Assemblies in Structured Neuronal Networks.

    PubMed

    Schaub, Michael T; Billeh, Yazan N; Anastassiou, Costas A; Koch, Christof; Barahona, Mauricio

    2015-07-01

    Unraveling the interplay between connectivity and spatio-temporal dynamics in neuronal networks is a key step to advance our understanding of neuronal information processing. Here we investigate how particular features of network connectivity underpin the propensity of neural networks to generate slow-switching assembly (SSA) dynamics, i.e., sustained epochs of increased firing within assemblies of neurons which transition slowly between different assemblies throughout the network. We show that the emergence of SSA activity is linked to spectral properties of the asymmetric synaptic weight matrix. In particular, the leading eigenvalues that dictate the slow dynamics exhibit a gap with respect to the bulk of the spectrum, and the associated Schur vectors exhibit a measure of block-localization on groups of neurons, thus resulting in coherent dynamical activity on those groups. Through simple rate models, we gain analytical understanding of the origin and importance of the spectral gap, and use these insights to develop new network topologies with alternative connectivity paradigms which also display SSA activity. Specifically, SSA dynamics involving excitatory and inhibitory neurons can be achieved by modifying the connectivity patterns between both types of neurons. We also show that SSA activity can occur at multiple timescales reflecting a hierarchy in the connectivity, and demonstrate the emergence of SSA in small-world like networks. Our work provides a step towards understanding how network structure (uncovered through advancements in neuroanatomy and connectomics) can impact on spatio-temporal neural activity and constrain the resulting dynamics.

  16. Emergence of Slow-Switching Assemblies in Structured Neuronal Networks

    PubMed Central

    Schaub, Michael T.; Billeh, Yazan N.; Anastassiou, Costas A.; Koch, Christof; Barahona, Mauricio

    2015-01-01

    Unraveling the interplay between connectivity and spatio-temporal dynamics in neuronal networks is a key step to advance our understanding of neuronal information processing. Here we investigate how particular features of network connectivity underpin the propensity of neural networks to generate slow-switching assembly (SSA) dynamics, i.e., sustained epochs of increased firing within assemblies of neurons which transition slowly between different assemblies throughout the network. We show that the emergence of SSA activity is linked to spectral properties of the asymmetric synaptic weight matrix. In particular, the leading eigenvalues that dictate the slow dynamics exhibit a gap with respect to the bulk of the spectrum, and the associated Schur vectors exhibit a measure of block-localization on groups of neurons, thus resulting in coherent dynamical activity on those groups. Through simple rate models, we gain analytical understanding of the origin and importance of the spectral gap, and use these insights to develop new network topologies with alternative connectivity paradigms which also display SSA activity. Specifically, SSA dynamics involving excitatory and inhibitory neurons can be achieved by modifying the connectivity patterns between both types of neurons. We also show that SSA activity can occur at multiple timescales reflecting a hierarchy in the connectivity, and demonstrate the emergence of SSA in small-world like networks. Our work provides a step towards understanding how network structure (uncovered through advancements in neuroanatomy and connectomics) can impact on spatio-temporal neural activity and constrain the resulting dynamics. PMID:26176664

  17. Identifying emerging research collaborations and networks: Method development

    PubMed Central

    Dozier, Ann M.; Martina, Camille A.; O’Dell, Nicole L.; Fogg, Thomas T.; Lurie, Stephen J.; Rubinstein, Eric P.; Pearson, Thomas A.

    2014-01-01

    Clinical and translational research is a multidisciplinary, collaborative team process. To evaluate this process, we developed a method to document emerging research networks and collaborations in our medical center to describe their productivity and viability over time. Using an email survey, sent to 1,620 clinical and basic science full-and part-time faculty members, respondents identified their research collaborators. Initial analyses, using Pajek software, assessed the feasibility of using social network analysis (SNA) methods with these data. Nearly 400 respondents identified 1,594 collaborators across 28 medical center departments resulting in 309 networks with 5 or more collaborators. This low-burden approach yielded a rich dataset useful for evaluation using SNA to: a) assess networks at several levels of the organization, including intrapersonal (individuals), interpersonal (social), organizational/institutional leadership (tenure and promotion), and physical/environmental (spatial proximity) and b) link with other data to assess the evolution of these networks. PMID:24019209

  18. Identifying emerging research collaborations and networks: method development.

    PubMed

    Dozier, Ann M; Martina, Camille A; O'Dell, Nicole L; Fogg, Thomas T; Lurie, Stephen J; Rubinstein, Eric P; Pearson, Thomas A

    2014-03-01

    Clinical and translational research is a multidisciplinary, collaborative team process. To evaluate this process, we developed a method to document emerging research networks and collaborations in our medical center to describe their productivity and viability over time. Using an e-mail survey, sent to 1,620 clinical and basic science full- and part-time faculty members, respondents identified their research collaborators. Initial analyses, using Pajek software, assessed the feasibility of using social network analysis (SNA) methods with these data. Nearly 400 respondents identified 1,594 collaborators across 28 medical center departments resulting in 309 networks with 5 or more collaborators. This low-burden approach yielded a rich data set useful for evaluation using SNA to: (a) assess networks at several levels of the organization, including intrapersonal (individuals), interpersonal (social), organizational/institutional leadership (tenure and promotion), and physical/environmental (spatial proximity) and (b) link with other data to assess the evolution of these networks.

  19. Characterization of emergent synaptic topologies in noisy neural networks

    NASA Astrophysics Data System (ADS)

    Miller, Aaron James

    Learned behaviors are one of the key contributors to an animal's ultimate survival. It is widely believed that the brain's microcircuitry undergoes structural changes when a new behavior is learned. In particular, motor learning, during which an animal learns a sequence of muscular movements, often requires precisely-timed coordination between muscles and becomes very natural once ingrained. Experiments show that neurons in the motor cortex exhibit precisely-timed spike activity when performing a learned motor behavior, and constituent stereotypical elements of the behavior can last several hundred milliseconds. The subject of this manuscript concerns how organized synaptic structures that produce stereotypical spike sequences emerge from random, dynamical networks. After a brief introduction in Chapter 1, we begin Chapter 2 by introducing a spike-timing-dependent plasticity (STDP) rule that defines how the activity of the network drives changes in network topology. The rule is then applied to idealized networks of leaky integrate-and-fire neurons (LIF). These neurons are not subjected to the variability that typically characterize neurons in vivo. In noiseless networks, synapses develop closed loops of strong connectivity that reproduce stereotypical, precisely-timed spike patterns from an initially random network. We demonstrate the characteristics of the asymptotic synaptic configuration are dependent on the statistics of the initial random network. The spike timings of the neurons simulated in Chapter 2 are generated exactly by a computationally economical, nonlinear mapping which is extended to LIF neurons injected with fluctuating current in Chapter 3. Development of an economical mapping that incorporates noise provides a practical solution to the long simulation times required to produce asymptotic synaptic topologies in networks with STDP in the presence of realistic neuronal variability. The mapping relies on generating numerical solutions to the dynamics

  20. A panorama of nanoscience developments in Mexico based on the comparison and crossing of nanoscience monitoring methods.

    PubMed

    Robles-Belmont, E; Vinck, D

    2011-06-01

    This paper characterises nanoscience developments in Mexico. A panorama of the development trends of these emerging sciences in Mexico is presented on the basis of bibliometric data gathered using different strategies. The results reveal the nanoscience output trend, which knowledge areas are developing, and which journals are publishing the articles and also enable us to identify the main institutional actors involved, and their international collaborations. We have discovered that the most important collaboration networks are maintained with industrialised countries; however, collaborative project work outside Mexico is becoming rarer. Lastly we present our findings on the growth of nanoscience development in Mexico and so-called emerging countries where we demonstrate that Mexico is at a disadvantage to its main economic rivals.

  1. Information Spread of Emergency Events: Path Searching on Social Networks

    PubMed Central

    Hu, Hongzhi; Wu, Tunan

    2014-01-01

    Emergency has attracted global attentions of government and the public, and it will easily trigger a series of serious social problems if it is not supervised effectively in the dissemination process. In the Internet world, people communicate with each other and form various virtual communities based on social networks, which lead to a complex and fast information spread pattern of emergency events. This paper collects Internet data based on data acquisition and topic detection technology, analyzes the process of information spread on social networks, describes the diffusions and impacts of that information from the perspective of random graph, and finally seeks the key paths through an improved IBF algorithm. Application cases have shown that this algorithm can search the shortest spread paths efficiently, which may help us to guide and control the information dissemination of emergency events on early warning. PMID:24600323

  2. Information spread of emergency events: path searching on social networks.

    PubMed

    Dai, Weihui; Hu, Hongzhi; Wu, Tunan; Dai, Yonghui

    2014-01-01

    Emergency has attracted global attentions of government and the public, and it will easily trigger a series of serious social problems if it is not supervised effectively in the dissemination process. In the Internet world, people communicate with each other and form various virtual communities based on social networks, which lead to a complex and fast information spread pattern of emergency events. This paper collects Internet data based on data acquisition and topic detection technology, analyzes the process of information spread on social networks, describes the diffusions and impacts of that information from the perspective of random graph, and finally seeks the key paths through an improved IBF algorithm. Application cases have shown that this algorithm can search the shortest spread paths efficiently, which may help us to guide and control the information dissemination of emergency events on early warning.

  3. Social Networking for Emergency Management and Public Safety

    SciTech Connect

    Lesperance, Ann M.; Olson, Jarrod; Godinez, Melanie A.

    2010-08-31

    On March 10, 2010 the workshop titled Social Networking for Emergency Management and Public Safety was held in Seattle, WA. The objective of this workshop was to showcase ways social media networking technologies can be used to support emergency management and public safety operations. The workshop highlighted the current state of social networking and where this dynamic engagement is heading, demonstrated some of the more commonly used technologies, highlighted case studies on how these tools have been used in a variety of jurisdictions and engaged the private sector on how these tools might serve as a conduit for two way communication between with the public sector to address regional recovery issues and decision making.

  4. Modelling coordination in hospital emergency departments through social network analysis.

    PubMed

    Hossain, Liaquat; Kit Guan, Danny Chun

    2012-04-01

    Coordination theory provides a theoretical framework for analysing complex processes of project groups working towards a common goal. In this study, we explore the relationship between coordination and social networks for the development of a network-based coordination model. This model is applied to measure the performance and quality of complex and dynamic project coordination such as in hospital emergency departments. The dataset used for the study was collected by the 2004 National Hospital Ambulatory Medical Care Survey--a national probability sample survey of visits to emergency and outpatient departments of non-Federal, short-stay and general hospitals in the United States. Using social network analysis, this study allows us to understand the possible causes of inefficient coordination performance and coordination quality resulting in access blocks. © 2012 The Author(s). Journal compilation © Overseas Development Institute, 2012.

  5. GNSS-based network positioning technology for cooperative emergency management

    NASA Astrophysics Data System (ADS)

    Wu, Caicong; Chu, Tianxing; Tang, Anning; Su, Huaihong

    2009-06-01

    Personal digital assistant (PDA) with built-in GPS chip begins to be used for city management and emergency response management nowadays. The intelligent terminal can be used for event recording, multimedia (photo, audio, and video) capturing, wireless communication, GPS positioning and navigation. In the near future, PDA would take place of the vehicle GPS monitoring terminal to provide more functions and convenient. This article organizes the PDA of the same team for emergency response event into an integrated network through wireless communication so that each terminal can see each other on the map, including the vehicle GPS monitoring terminals. All of the terminals should send its GPS position and collected information to the emergency response center (ERC) through GPRS with a customized protocol. Then the center would create the socket connection to push the neighbors' location and common or special information to the others in the team according to the terminal's requirement and its authorities, and the leader or commander could send commands and messages to all of the underling members also. The GNSS based positioning and communication network organizes the dispersive emergency response personnel handheld with PDA and vehicles equipped with vehicle GPS monitoring terminal into an organic and cooperative network, each member in the network can see where its colleagues are, so as to seek for the help or support and exchange information in real time without calling which avoids exposure to the tracked objects. The Compass-1 satellite positioning and communication terminal is also used for personnel and vehicle positioning and message reporting. Altay is selected as the demonstration area. The prototype emergency management system is established for the local public security bureau and well validates the terminals and network function.

  6. Improved MPF 360-degree Color Panorama

    NASA Image and Video Library

    1999-03-19

    This is a more recent geometrically improved, color enhanced version of the 360-degree Gallery Pan, the first contiguous, uniform panorama taken by the Imager for Mars IMP over the course of Sols 8, 9, and 10.

  7. Reciprocity and the Emergence of Power Laws in Social Networks

    NASA Astrophysics Data System (ADS)

    Schnegg, Michael

    Research in network science has shown that many naturally occurring and technologically constructed networks are scale free, that means a power law degree distribution emerges from a growth model in which each new node attaches to the existing network with a probability proportional to its number of links (= degree). Little is known about whether the same principles of local attachment and global properties apply to societies as well. Empirical evidence from six ethnographic case studies shows that complex social networks have significantly lower scaling exponents γ ~ 1 than have been assumed in the past. Apparently humans do not only look for the most prominent players to play with. Moreover cooperation in humans is characterized through reciprocity, the tendency to give to those from whom one has received in the past. Both variables — reciprocity and the scaling exponent — are negatively correlated (r = -0.767, sig = 0.075). If we include this effect in simulations of growing networks, degree distributions emerge that are much closer to those empirically observed. While the proportion of nodes with small degrees decreases drastically as we introduce reciprocity, the scaling exponent is more robust and changes only when a relatively large proportion of attachment decisions follow this rule. If social networks are less scale free than previously assumed this has far reaching implications for policy makers, public health programs and marketing alike.

  8. Cortical Resonance Frequencies Emerge from Network Size and Connectivity

    PubMed Central

    Lea-Carnall, Caroline A.; Montemurro, Marcelo A.; Trujillo-Barreto, Nelson J.; Parkes, Laura M.; El-Deredy, Wael

    2016-01-01

    Neural oscillations occur within a wide frequency range with different brain regions exhibiting resonance-like characteristics at specific points in the spectrum. At the microscopic scale, single neurons possess intrinsic oscillatory properties, such that is not yet known whether cortical resonance is consequential to neural oscillations or an emergent property of the networks that interconnect them. Using a network model of loosely-coupled Wilson-Cowan oscillators to simulate a patch of cortical sheet, we demonstrate that the size of the activated network is inversely related to its resonance frequency. Further analysis of the parameter space indicated that the number of excitatory and inhibitory connections, as well as the average transmission delay between units, determined the resonance frequency. The model predicted that if an activated network within the visual cortex increased in size, the resonance frequency of the network would decrease. We tested this prediction experimentally using the steady-state visual evoked potential where we stimulated the visual cortex with different size stimuli at a range of driving frequencies. We demonstrate that the frequency corresponding to peak steady-state response inversely correlated with the size of the network. We conclude that although individual neurons possess resonance properties, oscillatory activity at the macroscopic level is strongly influenced by network interactions, and that the steady-state response can be used to investigate functional networks. PMID:26914905

  9. Networked Participatory Scholarship: Emergent Techno-Cultural Pressures toward Open and Digital Scholarship in Online Networks

    ERIC Educational Resources Information Center

    Veletsianos, George; Kimmons, Royce

    2012-01-01

    We examine the relationship between scholarly practice and participatory technologies and explore how such technologies invite and reflect the emergence of a new form of scholarship that we call "Networked Participatory Scholarship": scholars' participation in online social networks to share, reflect upon, critique, improve, validate, and…

  10. Networked Participatory Scholarship: Emergent Techno-Cultural Pressures toward Open and Digital Scholarship in Online Networks

    ERIC Educational Resources Information Center

    Veletsianos, George; Kimmons, Royce

    2012-01-01

    We examine the relationship between scholarly practice and participatory technologies and explore how such technologies invite and reflect the emergence of a new form of scholarship that we call "Networked Participatory Scholarship": scholars' participation in online social networks to share, reflect upon, critique, improve, validate, and…

  11. Label-Free Characterization of Emerging Human Neuronal Networks

    NASA Astrophysics Data System (ADS)

    Mir, Mustafa; Kim, Taewoo; Majumder, Anirban; Xiang, Mike; Wang, Ru; Liu, S. Chris; Gillette, Martha U.; Stice, Steven; Popescu, Gabriel

    2014-03-01

    The emergent self-organization of a neuronal network in a developing nervous system is the result of a remarkably orchestrated process involving a multitude of chemical, mechanical and electrical signals. Little is known about the dynamic behavior of a developing network (especially in a human model) primarily due to a lack of practical and non-invasive methods to measure and quantify the process. Here we demonstrate that by using a novel optical interferometric technique, we can non-invasively measure several fundamental properties of neural networks from the sub-cellular to the cell population level. We applied this method to quantify network formation in human stem cell derived neurons and show for the first time, correlations between trends in the growth, transport, and spatial organization of such a system. Quantifying the fundamental behavior of such cell lines without compromising their viability may provide an important new tool in future longitudinal studies.

  12. Guest editorial. Body sensor networks: from theory to emerging applications.

    PubMed

    Jovanov, Emil; Poon, Carmen C Y; Yang, Guang-Zhong; Zhang, Y T

    2009-11-01

    The use of sensor networks for healthcare, well-being, and working in extreme environments has long roots in the engineering sector in medicine and biology community. With the maturity of wireless sensor networks, body area networks (BANs), and wireless BANs (WBANs), recent efforts in promoting the concept of body sensor networks (BSNs) aim to move beyond sensor connectivity to adopt a system-level approach to address issues related to biosensor design, interfacing, and embodiment, as well as ultralow-power processing/communication, power scavenging, autonomic sensing, data mining, inferencing, and integrated wireless sensor microsystems. As a result, the system architecture based on WBAN and BSN is becoming a widely accepted method of organization for ambulatory and ubiquitous monitoring systems. This editorial paper presents a snapshot of the current research and emerging applications and addresses some of the challenges and implementation issues.

  13. Label-Free Characterization of Emerging Human Neuronal Networks

    PubMed Central

    Mir, Mustafa; Kim, Taewoo; Majumder, Anirban; Xiang, Mike; Wang, Ru; Liu, S. Chris; Gillette, Martha U.; Stice, Steven; Popescu, Gabriel

    2014-01-01

    The emergent self-organization of a neuronal network in a developing nervous system is the result of a remarkably orchestrated process involving a multitude of chemical, mechanical and electrical signals. Little is known about the dynamic behavior of a developing network (especially in a human model) primarily due to a lack of practical and non-invasive methods to measure and quantify the process. Here we demonstrate that by using a novel optical interferometric technique, we can non-invasively measure several fundamental properties of neural networks from the sub-cellular to the cell population level. We applied this method to quantify network formation in human stem cell derived neurons and show for the first time, correlations between trends in the growth, transport, and spatial organization of such a system. Quantifying the fundamental behavior of such cell lines without compromising their viability may provide an important new tool in future longitudinal studies. PMID:24658536

  14. Patient care leadership within an emerging integrated delivery network.

    PubMed

    Moore, B W; Smith, S L; Schumacher, L P; Papke, R

    1996-01-01

    The emergence of integrated delivery networks provides an opportunity for leaders of patient care services to reach into our tool bags and refine the key leadership skills of strategist, facilitator, coach, and mentor. Shifting the focus from management to leadership is the hallmark of our success. As patient care leaders we will facilitate the achievement of the organization's strategic initiatives to improve clinical care delivery while decreasing cost. This article will explore the role of the patient care executive as part of the leadership team developing an integrated/organized delivery network.

  15. Emergence of Functional Specificity in Balanced Networks with Synaptic Plasticity

    PubMed Central

    Sadeh, Sadra; Clopath, Claudia; Rotter, Stefan

    2015-01-01

    In rodent visual cortex, synaptic connections between orientation-selective neurons are unspecific at the time of eye opening, and become to some degree functionally specific only later during development. An explanation for this two-stage process was proposed in terms of Hebbian plasticity based on visual experience that would eventually enhance connections between neurons with similar response features. For this to work, however, two conditions must be satisfied: First, orientation selective neuronal responses must exist before specific recurrent synaptic connections can be established. Second, Hebbian learning must be compatible with the recurrent network dynamics contributing to orientation selectivity, and the resulting specific connectivity must remain stable for unspecific background activity. Previous studies have mainly focused on very simple models, where the receptive fields of neurons were essentially determined by feedforward mechanisms, and where the recurrent network was small, lacking the complex recurrent dynamics of large-scale networks of excitatory and inhibitory neurons. Here we studied the emergence of functionally specific connectivity in large-scale recurrent networks with synaptic plasticity. Our results show that balanced random networks, which already exhibit highly selective responses at eye opening, can develop feature-specific connectivity if appropriate rules of synaptic plasticity are invoked within and between excitatory and inhibitory populations. If these conditions are met, the initial orientation selectivity guides the process of Hebbian learning and, as a result, functionally specific and a surplus of bidirectional connections emerge. Our results thus demonstrate the cooperation of synaptic plasticity and recurrent dynamics in large-scale functional networks with realistic receptive fields, highlight the role of inhibition as a critical element in this process, and paves the road for further computational studies of sensory

  16. Complex networks as an emerging property of hierarchical preferential attachment

    NASA Astrophysics Data System (ADS)

    Hébert-Dufresne, Laurent; Laurence, Edward; Allard, Antoine; Young, Jean-Gabriel; Dubé, Louis J.

    2015-12-01

    Real complex systems are not rigidly structured; no clear rules or blueprints exist for their construction. Yet, amidst their apparent randomness, complex structural properties universally emerge. We propose that an important class of complex systems can be modeled as an organization of many embedded levels (potentially infinite in number), all of them following the same universal growth principle known as preferential attachment. We give examples of such hierarchy in real systems, for instance, in the pyramid of production entities of the film industry. More importantly, we show how real complex networks can be interpreted as a projection of our model, from which their scale independence, their clustering, their hierarchy, their fractality, and their navigability naturally emerge. Our results suggest that complex networks, viewed as growing systems, can be quite simple, and that the apparent complexity of their structure is largely a reflection of their unobserved hierarchical nature.

  17. Optimal network solution for proactive risk assessment and emergency response

    NASA Astrophysics Data System (ADS)

    Cai, Tianxing

    Coupled with the continuous development in the field industrial operation management, the requirement for operation optimization in large scale manufacturing network has provoked more interest in the research field of engineering. Compared with the traditional way to take the remedial measure after the occurrence of the emergency event or abnormal situation, the current operation control calls for more proactive risk assessment to set up early warning system and comprehensive emergency response planning. Among all the industries, chemical industry and energy industry have higher opportunity to face with the abnormal and emergency situations due to their own industry characterization. Therefore the purpose of the study is to develop methodologies to give aid in emergency response planning and proactive risk assessment in the above two industries. The efficacy of the developed methodologies is demonstrated via two industrial real problems. The first case is to handle energy network dispatch optimization under emergency of local energy shortage under extreme conditions such as earthquake, tsunami, and hurricane, which may cause local areas to suffer from delayed rescues, widespread power outages, tremendous economic losses, and even public safety threats. In such urgent events of local energy shortage, agile energy dispatching through an effective energy transportation network, targeting the minimum energy recovery time, should be a top priority. The second case is a scheduling methodology to coordinate multiple chemical plants' start-ups in order to minimize regional air quality impacts under extreme meteorological conditions. The objective is to reschedule multi-plant start-up sequence to achieve the minimum sum of delay time compared to the expected start-up time of each plant. All these approaches can provide quantitative decision support for multiple stake holders, including government and environment agencies, chemical industry, energy industry and local

  18. The emergence of complexity and restricted pleiotropy in adapting networks

    PubMed Central

    2011-01-01

    Background The emergence of organismal complexity has been a difficult subject for researchers because it is not readily amenable to investigation by experimental approaches. Complexity has a myriad of untested definitions and our understanding of its evolution comes primarily from static snapshots gleaned from organisms ranked on an intuitive scale. Fisher's geometric model of adaptation, which defines complexity as the number of phenotypes an organism exposes to natural selection, provides a theoretical framework to study complexity. Yet investigations of this model reveal phenotypic complexity as costly and therefore unlikely to emerge. Results We have developed a computational approach to study the emergence of complexity by subjecting neural networks to adaptive evolution in environments exacting different levels of demands. We monitored complexity by a variety of metrics. Top down metrics derived from Fisher's geometric model correlated better with the environmental demands than bottom up ones such as network size. Phenotypic complexity was found to increase towards an environment-dependent level through the emergence of restricted pleiotropy. Such pleiotropy, which confined the action of mutations to only a subset of traits, better tuned phenotypes in challenging environments. However, restricted pleiotropy also came at a cost in the form of a higher genetic load, as it required the maintenance by natural selection of more independent traits. Consequently, networks of different sizes converged in complexity when facing similar environment. Conclusions Phenotypic complexity evolved as a function of the demands of the selective pressures, rather than the physical properties of the network architecture, such as functional size. Our results show that complexity may be more predictable, and understandable, if analyzed from the perspective of the integrated task the organism performs, rather than the physical architecture used to accomplish such tasks. Thus, top

  19. Evolution of Robust Network Topologies: Emergence of Central Backbones

    NASA Astrophysics Data System (ADS)

    Peixoto, Tiago P.; Bornholdt, Stefan

    2012-09-01

    We model the robustness against random failure or an intentional attack of networks with an arbitrary large-scale structure. We construct a block-based model which incorporates—in a general fashion—both connectivity and interdependence links, as well as arbitrary degree distributions and block correlations. By optimizing the percolation properties of this general class of networks, we identify a simple core-periphery structure as the topology most robust against random failure. In such networks, a distinct and small “core” of nodes with higher degree is responsible for most of the connectivity, functioning as a central “backbone” of the system. This centralized topology remains the optimal structure when other constraints are imposed, such as a given fraction of interdependence links and fixed degree distributions. This distinguishes simple centralized topologies as the most likely to emerge, when robustness against failure is the dominant evolutionary force.

  20. Scale-free networks emerging from multifractal time series

    NASA Astrophysics Data System (ADS)

    Budroni, Marcello A.; Baronchelli, Andrea; Pastor-Satorras, Romualdo

    2017-05-01

    Methods connecting dynamical systems and graph theory have attracted increasing interest in the past few years, with applications ranging from a detailed comparison of different kinds of dynamics to the characterization of empirical data. Here we investigate the effects of the (multi)fractal properties of a signal, common in time series arising from chaotic dynamics or strange attractors, on the topology of a suitably projected network. Relying on the box-counting formalism, we map boxes into the nodes of a network and establish analytic expressions connecting the natural measure of a box with its degree in the graph representation. We single out the conditions yielding to the emergence of a scale-free topology and validate our findings with extensive numerical simulations. We finally present a numerical analysis on the properties of weighted and directed network projections.

  1. Emerging Trends in Healthcare Adoption of Wireless Body Area Networks.

    PubMed

    Rangarajan, Anuradha

    2016-01-01

    Real-time personal health monitoring is gaining new ground with advances in wireless communications. Wireless body area networks (WBANs) provide a means for low-powered sensors, affixed either on the human body or in vivo, to communicate with each other and with external telecommunication networks. The healthcare benefits of WBANs include continuous monitoring of patient vitals, measuring postacute rehabilitation time, and improving quality of medical care provided in medical emergencies. This study sought to examine emerging trends in WBAN adoption in healthcare. To that end, a systematic literature survey was undertaken against the PubMed database. The search criteria focused on peer-reviewed articles that contained the keywords "wireless body area network" and "healthcare" or "wireless body area network" and "health care." A comprehensive review of these articles was performed to identify adoption dimensions, including underlying technology framework, healthcare subdomain, and applicable lessons-learned. This article benefits healthcare technology professionals by identifying gaps in implementation of current technology and highlighting opportunities for improving products and services.

  2. Emerging Frontiers of Neuroengineering: A Network Science of Brain Connectivity.

    PubMed

    Bassett, Danielle S; Khambhati, Ankit N; Grafton, Scott T

    2017-03-27

    Neuroengineering is faced with unique challenges in repairing or replacing complex neural systems that are composed of many interacting parts. These interactions form intricate patterns over large spatiotemporal scales and produce emergent behaviors that are difficult to predict from individual elements. Network science provides a particularly appropriate framework in which to study and intervene in such systems by treating neural elements (cells, volumes) as nodes in a graph and neural interactions (synapses, white matter tracts) as edges in that graph. Here, we review the emerging discipline of network neuroscience, which uses and develops tools from graph theory to better understand and manipulate neural systems from micro- to macroscales. We present examples of how human brain imaging data are being modeled with network analysis and underscore potential pitfalls. We then highlight current computational and theoretical frontiers and emphasize their utility in informing diagnosis and monitoring, brain-machine interfaces, and brain stimulation. A flexible and rapidly evolving enterprise, network neuroscience provides a set of powerful approaches and fundamental insights that are critical for the neuroengineer's tool kit. Expected final online publication date for the Annual Review of Biomedical Engineering Volume 19 is June 4, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  3. Scheduling for Emergency Tasks in Industrial Wireless Sensor Networks.

    PubMed

    Xia, Changqing; Jin, Xi; Kong, Linghe; Zeng, Peng

    2017-07-20

    Wireless sensor networks (WSNs) are widely applied in industrial manufacturing systems. By means of centralized control, the real-time requirement and reliability can be provided by WSNs in industrial production. Furthermore, many approaches reserve resources for situations in which the controller cannot perform centralized resource allocation. The controller assigns these resources as it becomes aware of when and where accidents have occurred. However, the reserved resources are limited, and such incidents are low-probability events. In addition, resource reservation may not be effective since the controller does not know when and where accidents will actually occur. To address this issue, we improve the reliability of scheduling for emergency tasks by proposing a method based on a stealing mechanism. In our method, an emergency task is transmitted by stealing resources allocated to regular flows. The challenges addressed in our work are as follows: (1) emergencies occur only occasionally, but the industrial system must deliver the corresponding flows within their deadlines when they occur; (2) we wish to minimize the impact of emergency flows by reducing the number of stolen flows. The contributions of this work are two-fold: (1) we first define intersections and blocking as new characteristics of flows; and (2) we propose a series of distributed routing algorithms to improve the schedulability and to reduce the impact of emergency flows. We demonstrate that our scheduling algorithm and analysis approach are better than the existing ones by extensive simulations.

  4. Emergence and robustness of target waves in a neuronal network

    NASA Astrophysics Data System (ADS)

    Xu, Ying; Jin, Wuyin; Ma, Jun

    2015-08-01

    Target waves in excitable media such as neuronal network can regulate the spatial distribution and orderliness as a continuous pacemaker. Three different schemes are used to develop stable target wave in the network, and the potential mechanism for emergence of target waves in the excitable media is investigated. For example, a local pacing driven by external periodical forcing can generate stable target wave in the excitable media, furthermore, heterogeneity and local feedback under self-feedback coupling are also effective to generate continuous target wave as well. To discern the difference of these target waves, a statistical synchronization factor is defined by using mean field theory and artificial defects are introduced into the network to block the target wave, thus the robustness of these target waves could be detected. However, these target waves developed from the above mentioned schemes show different robustness to the blocking from artificial defects. A regular network of Hindmarsh-Rose neurons is designed in a two-dimensional square array, target waves are induced by using three different ways, and then some artificial defects, which are associated with anatomical defects, are set in the network to detect the effect of defects blocking on the travelling waves. It confirms that the robustness of target waves to defects blocking depends on the intrinsic properties (ways to generate target wave) of target waves.

  5. Recurrent rewiring and emergence of RNA regulatory networks.

    PubMed

    Wilinski, Daniel; Buter, Natascha; Klocko, Andrew D; Lapointe, Christopher P; Selker, Eric U; Gasch, Audrey P; Wickens, Marvin

    2017-04-04

    Alterations in regulatory networks contribute to evolutionary change. Transcriptional networks are reconfigured by changes in the binding specificity of transcription factors and their cognate sites. The evolution of RNA-protein regulatory networks is far less understood. The PUF (Pumilio and FBF) family of RNA regulatory proteins controls the translation, stability, and movements of hundreds of mRNAs in a single species. We probe the evolution of PUF-RNA networks by direct identification of the mRNAs bound to PUF proteins in budding and filamentous fungi and by computational analyses of orthologous RNAs from 62 fungal species. Our findings reveal that PUF proteins gain and lose mRNAs with related and emergent biological functions during evolution. We demonstrate at least two independent rewiring events for PUF3 orthologs, independent but convergent evolution of PUF4/5 binding specificity and the rewiring of the PUF4/5 regulons in different fungal lineages. These findings demonstrate plasticity in RNA regulatory networks and suggest ways in which their rewiring occurs.

  6. Rover Panorama from Sols 75 & 76

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This Sojourner rover panorama from Sols 75 and 76 is the only true panorama product (as opposed to the normal 'tiled' full frames) produced by the rover. This panorama ranges from Big Crater on the left (about azimuth 160 degrees), past the Twin Peaks and almost all the way to the north horizon, for a swath of about 200 degrees in azimuth.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  7. Spirit's West Valley Panorama (Anaglyph)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007. The view combines a stereo pair and appears three-dimensional when seen through blue-red glasses.

    After several months near the base of the plateau called 'Home Plate' in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.

    This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is 'Tsiolkovski Ridge,' about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is 'Grissom Hill,' about 8 kilometers or 5 miles away. At right, the highest point of the horizon is 'Husband Hill,' to the north and about 800 meters or half a mile away.

  8. The Emerging Infections Network electronic mail conference and web page.

    PubMed

    Strausbaugh, L J; Liedtke, L A

    2001-01-15

    In February 1997, the Emerging Infections Network (EIN) established an electronic mail conference to facilitate discussions about emerging infectious diseases and related topics among its members and public health officials. Later that year, the EIN opened its section of the Infectious Diseases Society of America's home page. The EIN Web page was developed to give its members an alternative route for responding to EIN surveys and to facilitate rapid dispersal of EIN reports. The unrestricted portion of the site allows visitors access to information about the EIN and to published EIN reports on specific topics. For the most part, these are brief summaries or abstracts. In the restricted, password-protected portion of the EIN site, members can access the detailed, original reports from EIN queries and the comprehensive listings of member observations. Search functions in both portions of the EIN site enhance the retrieval of reports and observations on specific topics.

  9. Emergence of complexity in controlling simple regular networks

    NASA Astrophysics Data System (ADS)

    Gao, Xin-Dong; Shen, Zhesi; Wang, Wen-Xu

    2016-06-01

    Quantifying the capacity of a given node or a bunch of nodes in maintaining a system's controllability is a crucial problem in complex networks and control theory. We give a systematic analysis of the ability of a single node or a pairs of nodes to control an undirected unweighted chain and ring. By combining algebraic theory and graph spectrum analysis, we derive analytic expressions for the control range of some given control inputs and find that complex phenomena emerge even from these simplest graph structures. Specifically, the control range is sensitive to the location of driver nodes and shows complex periodic behaviors. Our findings have implications for evaluating the control range and practically controlling complex networks.

  10. On a Monitoring Network of Territory Elements for Emergency Management

    NASA Astrophysics Data System (ADS)

    Teramo, A.; Marino, A.; Termini, D.; Teramo, M.; Saccà, C.; Romeo, M.; de Domenico, D.; Lupò, D.

    2010-12-01

    The proposed methodological approach, based on the implementation of innovative monitoring networks of territories falling within high seismicity areas, aims at the arrangement of tools for a reduction of urban and territorial seismic vulnerability through procedures of territorial diagnostics with early warning thresholds. In this preliminary phase of the study, several problems have been analysed and solved related to wireless sensor typology to be used and data to be acquired for the realization of a expert system for a real time check of escape route conditions in case of a catastrophe, and the structural reliability of buildings, also strategic type, for preliminary damage evaluations. Specific analysis tools of acquired data by monitoring networks have been arranged for an analysis in relation to main territorial risk factors of a given area, arranging GIS maps in real time for the reduction of territorial system criticalities also during the emergencies.

  11. Why do Scale-Free Networks Emerge in Nature? From Gradient Networks to Transport Efficiency

    NASA Astrophysics Data System (ADS)

    Toroczkai, Zoltan

    2004-03-01

    It has recently been recognized [1,2,3] that a large number of complex networks are scale-free (having a power-law degree distribution). Examples include citation networks [4], the internet [5], the world-wide-web [6], cellular metabolic networks [7], protein interaction networks [8], the sex-web [9] and alliance networks in the U.S. biotechnology industry [10]. The existence of scale-free networks in such diverse systems suggests that there is a simple underlying common reason for their development. Here, we propose that scale-free networks emerge because they ensure efficient transport of some entity. We show that for flows generated by gradients of a scalar "potential'' distributed on a network, non scale-free networks, e.g., random graphs [11], will become maximally congested, while scale-free networks will ensure efficient transport in the large network size limit. [1] R. Albert and A.-L. Barabási, Rev.Mod.Phys. 74, 47 (2002). [2] M.E.J. Newman, SIAM Rev. 45, 167 (2003). [3] S.N. Dorogovtsev and J.F.F. Mendes, Evolution of Networks: From Biological Nets to the Internet and WWW, Oxford Univ. Press, Oxford, 2003. [4] S. Redner, Eur.Phys.J. B, 4, 131 (1998). [5] M. Faloutsos, P. Faloutsos and C. Faloutsos Comp.Comm.Rev. 29, 251 (1999). [6] R. Albert, H. Jeong, and A.L. Barabási, Nature 401, 130 (1999). [7] H. Jeong et.al. Nature 407, 651 (2000). [8] H. Jeong, S. Mason, A.-L. Barabási and Z. N. Oltvai, Nature 411, 41 (2001). [9] F. Liljeros et. al. Nature 411 907 (2000). [10] W. W. Powell, D. R. White, K. W. Koput and J. Owen-Smith Am.J.Soc. in press. [11] B. Bollobás, Random Graphs, Second Edition, Cambridge University Press (2001).

  12. Emergence of hierarchical networks and polysynchronous behaviour in simple adaptive systems

    NASA Astrophysics Data System (ADS)

    Botella-Soler, V.; Glendinning, P.

    2012-03-01

    We describe the dynamics of a simple adaptive network. The network architecture evolves to a number of disconnected components on which the dynamics is characterized by the possibility of differently synchronized nodes within the same network (polysynchronous states). These systems may have implications for the evolutionary emergence of polysynchrony and hierarchical networks in physical or biological systems modeled by adaptive networks.

  13. Feature Positioning on Google Street View Panoramas

    NASA Astrophysics Data System (ADS)

    Tsai, V. J. D.; Chang, C.-T.

    2012-07-01

    Location-based services (LBS) on web-based maps and images have come into real-time since Google launched its Street View imaging services in 2007. This research employs Google Maps API and Web Service, GAE for JAVA, AJAX, Proj4js, CSS and HTML in developing an internet platform for accessing the orientation parameters of Google Street View (GSV) panoramas in order to determine the three dimensional position of interest features that appear on two overlapping panoramas by geometric intersection. A pair of GSV panoramas was examined using known points located on the Library Building of National Chung Hsing University (NCHU) with the root-mean-squared errors of ±0.522m, ±1.230m, and ±5.779m for intersection and ±0.142m, ±1.558m, and ±5.733m for resection in X, Y, and h (elevation), respectively. Potential error sources in GSV positioning were analyzed and illustrated that the errors in Google provided GSV positional parameters dominate the errors in geometric intersection. The developed system is suitable for data collection in establishing LBS applications integrated with Google Maps and Google Earth in traffic sign and infrastructure inventory by adding automatic extraction and matching techniques for points of interest (POI) from GSV panoramas.

  14. The Dimensions of Emergent Spacetime in the Influence Network

    NASA Astrophysics Data System (ADS)

    Knuth, Kevin

    It has been previously demonstrated that the consistent quantification of a causally ordered set of events (influence network) with respect to observers represented by embedded chains results in a unique consistent quantification scheme that reproduces the Minkowski metric in the case of coordinated chains and Lorentz transformations in the case of linearly-related chains (Knuth and Bahreyni 2014). Here we demonstrate that quantification by multiple coordinated chains can only be consistent in the cases of two and four chains resulting in emergent 1 +1 and 3 +1 dimensional spacetimes, respectively. Odd numbers of chains are specifically ruled out and numbers of chains greater than four lead to a system that is not closed under chain permutation symmetry in a manner consistent with Galois theory. As a result, the spacetime framework that emerges from the consistent quantification of a causally ordered set of events with respect to embedded observers provides a potential foundation for emergent spacetime as well as an explanation as to the significance and nature of 3 +1 spacetime dimensions.

  15. Network analysis of team communication in a busy emergency department

    PubMed Central

    2013-01-01

    Background The Emergency Department (ED) is consistently described as a high-risk environment for patients and clinicians that demands colleagues quickly work together as a cohesive group. Communication between nurses, physicians, and other ED clinicians is complex and difficult to track. A clear understanding of communications in the ED is lacking, which has a potentially negative impact on the design and effectiveness of interventions to improve communications. We sought to use Social Network Analysis (SNA) to characterize communication between clinicians in the ED. Methods Over three-months, we surveyed to solicit the communication relationships between clinicians at one urban academic ED across all shifts. We abstracted survey responses into matrices, calculated three standard SNA measures (network density, network centralization, and in-degree centrality), and presented findings stratified by night/day shift and over time. Results We received surveys from 82% of eligible participants and identified wide variation in the magnitude of communication cohesion (density) and concentration of communication between clinicians (centralization) by day/night shift and over time. We also identified variation in in-degree centrality (a measure of power/influence) by day/night shift and over time. Conclusions We show that SNA measurement techniques provide a comprehensive view of ED communication patterns. Our use of SNA revealed that frequency of communication as a measure of interdependencies between ED clinicians varies by day/night shift and over time. PMID:23521890

  16. Computational Models and Emergent Properties of Respiratory Neural Networks

    PubMed Central

    Lindsey, Bruce G.; Rybak, Ilya A.; Smith, Jeffrey C.

    2012-01-01

    Computational models of the neural control system for breathing in mammals provide a theoretical and computational framework bringing together experimental data obtained from different animal preparations under various experimental conditions. Many of these models were developed in parallel and iteratively with experimental studies and provided predictions guiding new experiments. This data-driven modeling approach has advanced our understanding of respiratory network architecture and neural mechanisms underlying generation of the respiratory rhythm and pattern, including their functional reorganization under different physiological conditions. Models reviewed here vary in neurobiological details and computational complexity and span multiple spatiotemporal scales of respiratory control mechanisms. Recent models describe interacting populations of respiratory neurons spatially distributed within the Bötzinger and pre-Bötzinger complexes and rostral ventrolateral medulla that contain core circuits of the respiratory central pattern generator (CPG). Network interactions within these circuits along with intrinsic rhythmogenic properties of neurons form a hierarchy of multiple rhythm generation mechanisms. The functional expression of these mechanisms is controlled by input drives from other brainstem components, including the retrotrapezoid nucleus and pons, which regulate the dynamic behavior of the core circuitry. The emerging view is that the brainstem respiratory network has rhythmogenic capabilities at multiple levels of circuit organization. This allows flexible, state-dependent expression of different neural pattern-generation mechanisms under various physiological conditions, enabling a wide repertoire of respiratory behaviors. Some models consider control of the respiratory CPG by pulmonary feedback and network reconfiguration during defensive behaviors such as cough. Future directions in modeling of the respiratory CPG are considered. PMID:23687564

  17. Access to emergency care services: a transversal ecological study about Brazilian emergency health care network.

    PubMed

    Rocha, T A H; da Silva, N C; Amaral, P V; Barbosa, A C Q; Rocha, J V M; Alvares, V; de Almeida, D G; Thumé, E; Thomaz, E B A F; de Sousa Queiroz, R C; de Souza, M R; Lein, A; Toomey, N; Staton, C A; Vissoci, J R N; Facchini, L A

    2017-08-11

    Studies of health geography are important in the planning and allocation of emergency health services. The geographical distribution of health facilities is an important factor in timely and quality access to emergency services; therefore, the present study analyzed the emergency health care network in Brazil, focusing the analysis at the roles of small hospitals (SHs). Cross-sectional ecological study. Data were collected from 9429 hospitals of which 3524 were SHs and 5905 were high-complexity centers (HCCs). For analytical purposes, we considered four specialties when examining the proxies of emergency care capability: adult, pediatrics, neonatal, and obstetric. We analyzed the spatial distribution of hospitals, identifying municipalities that rely exclusively on SHs and the distance of these cities from HCCs. More than 14 and 30 million people were at least 120 km away from HCCs with an adult intensive care unit (ICU) and pediatric ICU, respectively. For neonatal care distribution, 12% of the population was more than 120 km away from a health facility with a neonatal ICU. The maternities situation is different from other specialties, where 81% of the total Brazilian population was within 1 h or less from such health facilities. Our results highlighted a polarization in distribution of Brazilian health care facilities. There is a concentration of hospitals in urban areas more developed and access gaps in rural areas and the Amazon region. Our results demonstrate that the distribution of emergency services in Brazil is not facilitating access to the population due to geographical barriers associated with great distances. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  18. Access to In-Network Emergency Physicians and Emergency Departments Within Federally Qualified Health Plans in 2015.

    PubMed

    Dorner, Stephen C; Camargo, Carlos A; Schuur, Jeremiah D; Raja, Ali S

    2016-01-01

    Under regulations established by the Affordable Care Act, insurance plans must meet minimum standards in order to be sold through the federal Marketplace. These standards to become a qualified health plan (QHP) include maintaining a provider network sufficient to assure access to services. However, the complexity of emergency physician (EP) employment practices - in which the EPs frequently serve as independent contractors of emergency departments, independently establish insurance contracts, etc… - and regulations governing insurance repayment may hinder the application of network adequacy standards to emergency medicine. As such, we hypothesized the existence of QHPs without in-network access to EPs. The objective is to identify whether there are QHPs without in-network access to EPs using information available through the federal Marketplace and publicly available provider directories. In a national sample of Marketplace plans, we found that one in five provider networks lacks identifiable in-network EPs. QHPs lacking EPs spanned nearly half (44%) of the 34 states using the federal Marketplace. Our data suggest that the present regulatory framework governing network adequacy is not generalizable to emergency care, representing a missed opportunity to protect patient access to in-network physicians. These findings and the current regulations governing insurance payment to EPs dis-incentivize the creation of adequate physician networks, incentivize the practice of balance billing, and shift the cost burden to patients.

  19. 'Everest' Panorama; 20-20 Vision

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] 'Everest' Panorama 20-20 Vision (QTVR)

    [figure removed for brevity, see original site] 'Everest' Panorama Animation

    If a human with perfect vision donned a spacesuit and stepped onto the martian surface, the view would be as clear as this sweeping panorama taken by NASA's Mars Exploration Rover Spirit. That's because the rover's panoramic camera has the equivalent of 20-20 vision. Earthlings can take a virtual tour of the scenery by zooming in on their computer screens many times to get a closer look at, say, a rock outcrop or a sand drift, without losing any detail. This level of clarity is unequaled in the history of Mars exploration.

    It took Spirit three days, sols 620 to 622 (Oct. 1 to Oct. 3, 2005), to acquire all the images combined into this mosaic, called the 'Everest Panorama,' looking outward in every direction from the true summit of 'Husband Hill.' During that period, the sky changed in color and brightness due to atmospheric dust variations, as shown in contrasting sections of this mosaic. Haze occasionally obscured the view of the hills on the distant rim of Gusev Crater 80 kilometers (50 miles) away. As dust devils swooped across the horizon in the upper right portion of the panorama, the robotic explorer changed the filters on the camera from red to green to blue, making the dust devils appear red, green, and blue. In reality, the dust devils are similar in color to the reddish-brown soils of Mars. No attempt was made to 'smooth' the sky in this mosaic, as has been done in other panoramic-camera mosaics to simulate the view one would get by taking in the landscape all at once. The result is a sweeping vista that allows viewers to observe weather changes on Mars.

    The summit of Husband Hill is a broad plateau of rock outcrops and windblown drifts about 100 meters (300 feet) higher than the surrounding plains of Gusev Crater. In the distance, near the center of the mosaic, is

  20. The emergence of abstract ideas: evidence from networks and babies.

    PubMed Central

    Colunga, Eliana; Smith, Linda B

    2003-01-01

    What is abstraction? In our view, abstraction is generalization. Specifically, we propose that abstract concepts emerge as the natural product of associative learning and generalization by similarity. We support this proposal by presenting evidence for two ideas: first, that children's knowledge about how categories are organized and how words refer to them can be explained as learned generalizations over specific experiences of words referring to categories; and second, that the path of concepts from concrete to more abstract can be observed throughout development and that even in their more abstract form, concepts retain some of their original sensory basis. We illustrate these two facts by examining, in two kinds of learners--networks and young children--the development of three abstract ideas: (i) the idea of word; (ii) the idea of object; and (iii) the idea of substance. PMID:12903655

  1. Emergency response networks for disaster monitoring and detection from space

    NASA Astrophysics Data System (ADS)

    Vladimirova, Tanya; Sweeting, Martin N.; Vitanov, Ivan; Vitanov, Valentin I.

    2009-05-01

    Numerous man-made and natural disasters have stricken mankind since the beginning of the new millennium. The scale and impact of such disasters often prevent the collection of sufficient data for an objective assessment and coordination of timely rescue and relief missions on the ground. As a potential solution to this problem, in recent years constellations of Earth observation small satellites and in particular micro-satellites (<100 kg) in low Earth orbit have emerged as an efficient platform for reliable disaster monitoring. The main task of the Earth observation satellites is to capture images of the Earth surface using various techniques. For a large number of applications the resulting delay between image capture and delivery is not acceptable, in particular for rapid response remote sensing aiming at disaster monitoring and detection. In such cases almost instantaneous data availability is a strict requirement to enable an assessment of the situation and instigate an adequate response. Examples include earthquakes, volcanic eruptions, flooding, forest fires and oil spills. The proposed solution to this issue are low-cost networked distributed satellite systems in low Earth orbit capable of connecting to terrestrial networks and geostationary Earth orbit spacecraft in real time. This paper discusses enabling technologies for rapid response disaster monitoring and detection from space such as very small satellite design, intersatellite communication, intelligent on-board processing, distributed computing and bio-inspired routing techniques.

  2. Emergence of Critical Behavior in β-Cell Network

    NASA Astrophysics Data System (ADS)

    Westacott, Matthew; Hraha, Thomas; McClatchey, Mason; Pozzoli, Marina; Benninger, Richard

    2014-03-01

    The β-cell is a cell type located in the Islet of Langerhans, a micro-organ of the pancreas which maintains glucose homeostasis through secretion of insulin. An electrophysiological process governing insulin release occurs through initial uptake of blood glucose and generation of ATP which inhibits the ATP sensitive potassium channel (K-ATP) causing membrane depolarization (activation). Neighboring β-cells are electrically coupled through gap junctions which allow passage of cationic molecules, creating a network of coupled electrical oscillators. Cells exhibiting hyperpolzarized (inactive) membrane potential affect behavior of neighboring cells by electrically suppressing their depolarization. Here we observe critical behavior between global active-inactive states by increasing the number of inactive elements with the K-ATP inhibitor Diazoxide and a tunable ATP insensitive transgenic mouse model. We show this behavior occurs due to from cell-cell coupling as mice lacking β-cell gap junctions show no critical behavior. Also, a computational β-cell model was expanded to construct a coupled β-cell network and we show this model replicates the critical behavior seen in-vitro.While electrical activity of single β-cells is well studied these data highlight a newly defined characteristic of their emergent multicellular behavior within the Islet of Langerhans and may elucidate pathophysiology of Diabetes due to mutations in the K-ATP channel.

  3. Emerging late adolescent friendship networks and Big Five personality traits: a social network approach.

    PubMed

    Selfhout, Maarten; Burk, William; Branje, Susan; Denissen, Jaap; van Aken, Marcel; Meeus, Wim

    2010-04-01

    The current study focuses on the emergence of friendship networks among just-acquainted individuals, investigating the effects of Big Five personality traits on friendship selection processes. Sociometric nominations and self-ratings on personality traits were gathered from 205 late adolescents (mean age=19 years) at 5 time points during the first year of university. SIENA, a novel multilevel statistical procedure for social network analysis, was used to examine effects of Big Five traits on friendship selection. Results indicated that friendship networks between just-acquainted individuals became increasingly more cohesive within the first 3 months and then stabilized. Whereas individuals high on Extraversion tended to select more friends than those low on this trait, individuals high on Agreeableness tended to be selected more as friends. In addition, individuals tended to select friends with similar levels of Agreeableness, Extraversion, and Openness.

  4. Spirit's 'Lookout Panorama' in 3-D

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1

    [figure removed for brevity, see original site] Figure 2

    This is a stereoscopic version of the Spirit panoramic camera's 'Lookout' panorama, acquired on the rover's 410th to 413th martian days, or sols (Feb. 27 to Mar. 2, 2005). The view is from a position known informally as 'Larry's Lookout' along the drive up 'Husband Hill.' The summit of Husband Hill is the far peak near the center of this panorama and is about 200 meters (656 feet) away from the rover and about 45 meters (148 feet) higher in elevation. The bright rocky outcrop near the center of the panorama is part of the 'Cumberland Ridge,' and beyond that and to the left is the 'Tennessee Valley.' Spirit's tracks leading back from the 'West Spur' region can be seen on the right side of the panorama. The region just beyond the area where the tracks made their last zig-zag is the area known as 'Paso Robles,' where Spirit discovered rock and soil deposits with very high sulfur abundances.

    This stereo anaglyph is presented in a cylindrical-perspective projection with special 'untilt' processing. The tilt of the rover (roll -14 degrees, pitch +13 degrees) has been removed by special processing of the images, resulting in a flat horizon (thus a more 'natural' view) with very little vertical disparity. (Vertical disparity is one of the main things that give you a headache when looking at stereo images.) Geometric and brightness corrections have been applied.

    Figure 1 is the left-eye view of a stereo pair and Figure 2 is the right-eye view of a stereo pair.

  5. Martian Arctic Landscape Panorama Video

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    Typical view if you were standing on Mars and slowly turned around for a look. Starting at the north, SSI sees its shadow and turns its head viewing solar arrays, the lander deck and landscape. Note very few rocks on the hummocky terrain and network of troughs, typical of polar surfaces here on Earth.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  6. Martian Arctic Landscape Panorama Video

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    Typical view if you were standing on Mars and slowly turned around for a look. Starting at the north, SSI sees its shadow and turns its head viewing solar arrays, the lander deck and landscape. Note very few rocks on the hummocky terrain and network of troughs, typical of polar surfaces here on Earth.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  7. Emergence of morphological order in the network formation of Physarum polycephalum.

    PubMed

    Shirakawa, T; Gunji, Y-P

    2007-07-01

    Emergence in a system appears through the interaction of its components, giving rise to higher order or complexity in the system. We tested for the presence of emergent properties in a biological system using the simplest biological entity of a unicellular organism; the plasmodium of Physarum polycephalum, a giant unicellular amoeboid organism that forms a network-like tubular structure connecting its food sources. We let two plasmodium networks within a single cell interact with each other, and observed how the intracellular interaction affected the morphologenesis of the plasmodium networks. We found that the two networks developed homologous morphology. We further discuss the presence of autonomous and emergent properties in homologous network formation.

  8. 'Gibson' Panorama by Spirit at 'Home Plate'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Click on the image for 'Gibson' Panorama by Spirit at 'Home Plate' (QTVR)

    NASA's Mars Exploration Rover Spirit acquired this high-resolution view of intricately layered exposures of rock while parked on the northwest edge of the bright, semi-circular feature known as 'Home Plate.' The rover was perched at a 27-degree upward tilt while creating the panorama, resulting in the 'U' shape of the mosaic. In reality, the features along the 1-meter to 2-meter (1-foot to 6.5-foot) vertical exposure of the rim of Home Plate in this vicinity are relatively level. Rocks near the rover in this view, known as the 'Gibson' panorama, include 'Barnhill,' 'Rogan,' and 'Mackey.'

    Spirit acquired 246 separate images of this scene using 6 different filters on the panoramic camera (Pancam) during the rover's Martian days, or sols, 748 through 751 (Feb. 9 through Feb. 12, 2006). The field of view covers 160 degrees of terrain around the rover. This image is an approximately true-color rendering using Pancam's 753-nanometer, 535-namometer, and 432-nanometer filters. Image-to-image seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.

  9. 'Gibson' Panorama by Spirit at 'Home Plate'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Click on the image for 'Gibson' Panorama by Spirit at 'Home Plate' (QTVR)

    NASA's Mars Exploration Rover Spirit acquired this high-resolution view of intricately layered exposures of rock while parked on the northwest edge of the bright, semi-circular feature known as 'Home Plate.' The rover was perched at a 27-degree upward tilt while creating the panorama, resulting in the 'U' shape of the mosaic. In reality, the features along the 1-meter to 2-meter (1-foot to 6.5-foot) vertical exposure of the rim of Home Plate in this vicinity are relatively level. Rocks near the rover in this view, known as the 'Gibson' panorama, include 'Barnhill,' 'Rogan,' and 'Mackey.'

    Spirit acquired 246 separate images of this scene using 6 different filters on the panoramic camera (Pancam) during the rover's Martian days, or sols, 748 through 751 (Feb. 9 through Feb. 12, 2006). The field of view covers 160 degrees of terrain around the rover. This image is an approximately true-color rendering using Pancam's 753-nanometer, 535-namometer, and 432-nanometer filters. Image-to-image seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.

  10. Automatic Mosaicking of 360 degree Panorama in Video Surveillance

    DTIC Science & Technology

    2008-12-01

    Automatic Mosaicking of 360° Panorama in Video Surveillance by Sean Ho and Philip David ARL-TR-4670 December 2008...Automatic Mosaicking of 360° Panorama in Video Surveillance Sean Ho and Philip David Computational and Information Sciences Directorate...2007 to September 2008 5a. CONTRACT NUMBER 5b. GRANT NUMBER 4. TITLE AND SUBTITLE Automatic Mosaicking of 360° Panorama in Video Surveillance 5c

  11. Characterizing emerging European stock markets through complex networks: From local properties to self-similar characteristics

    NASA Astrophysics Data System (ADS)

    Caraiani, Petre

    2012-07-01

    We investigate the properties of the returns of the main emerging stock markets from Europe by means of complex networks. We transform the series of daily returns into complex networks, and analyze the local properties of these networks with respect to degree distributions, clustering, or average line length. We further use the clustering coefficients as quantities describing the local structure of the network, and approach them by using multifractal analysis. We find evidence of scale-free networks and multifractality of clustering coefficients.

  12. Characterization of Emergent Data Networks Among Long-Tail Data

    NASA Astrophysics Data System (ADS)

    Elag, Mostafa; Kumar, Praveen; Hedstrom, Margaret; Myers, James; Plale, Beth; Marini, Luigi; McDonald, Robert

    2014-05-01

    Data curation underpins data-driven scientific advancements. It manages the information flux across multiple users throughout data life cycle as well as increases data sustainability and reusability. The exponential growth in data production spanning across the Earth Science involving individual and small research groups, which is termed as log-tail data, increases the data-knowledge latency among related domains. It has become clear that an advanced framework-agnostic metadata and ontologies for long-tail data is required to increase their visibility to each other, and provide concise and meaningful descriptions that reveal their connectivity. Despite the advancement that has been achieved by various sophisticated data management models in different Earth Science disciplines, it is not always straightforward to derive relationships among long-tail data. Semantic data clustering algorithms and pre-defined logic rules that are oriented toward prediction of possible data relationships, is one method to address these challenges. Our work advances the connectivity of related long-tail data by introducing the design for an ontology-based knowledge management system. In this work, we present the system architecture, its components, and illustrate how it can be used to scrutinize the connectivity among datasets. To demonstrate the capabilities of this "data network" prototype, we implemented this approach within the Sustainable Environment Actionable Data (SEAD) environment, an open-source semantic content repository that provides a RDF database for long-tail data, and show how emergent relationships among datasets can be identified.

  13. Active bacterial core surveillance of the emerging infections program network.

    PubMed Central

    Schuchat, A.; Hilger, T.; Zell, E.; Farley, M. M.; Reingold, A.; Harrison, L.; Lefkowitz, L.; Danila, R.; Stefonek, K.; Barrett, N.; Morse, D.; Pinner, R.

    2001-01-01

    Active Bacterial Core surveillance (ABCs) is a collaboration between the Centers for Disease Control and Prevention and several state health departments and universities participating in the Emerging Infections Program Network. ABCs conducts population-based active surveillance, collects isolates, and performs studies of invasive disease caused by Streptococcus pneumoniae, group A and group B Streptococcus, Neisseria meningitidis, and Haemophilus influenzae for a population of 17 to 30 million. These pathogens caused an estimated 97,000 invasive cases, resulting in 10,000 deaths in the United States in 1998. Incidence rates of these pathogens are described. During 1998, 25% of invasive pneumococcal infections in ABCs areas were not susceptible to penicillin, and 13.3% were not susceptible to three classes of antibiotics. In 1998, early-onset group B streptococcal disease had declined by 65% over the previous 6 years. More information on ABCs is available at www.cdc.gov/ncidod/dbmd/abcs. ABCs specimens will soon be available to researchers through an archive. PMID:11266299

  14. Panorama from 'Cape Verde' (False Color)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Exploration Rover Opportunity captured this vista of 'Victoria Crater' from the viewpoint of 'Cape Verde,' one of the promontories that are part of the scalloped rim of the crater. Opportunity drove onto Cape Verde shortly after arriving at the rim of Victoria in September 2006. The view combines hundreds of exposures taken by the rover's panoramic camera (Pancam). The camera began taking the component images during Opportunity's 970th Martian day, or sol, on Mars (Oct. 16, 2006). Work on the panorama continued through the solar conjunction period, when Mars was nearly behind the sun from Earth's perspective and communications were minimized. Acquisition of images for this panorama was completed on Opportunity's 991st sol (Nov. 7, 2006).

    The top of Cape Verde is in the immediate foreground at the center of the image. To the left and right are two of the more gradually sloped bays that alternate with the cliff-faced capes or promontories around the rim of the crater. 'Duck Bay,' where Opportunity first reached the rim, is to the right. Beyond Duck Bay counterclockwise around the rim, the next promontory is 'Cabo Frio,' about 150 meters (500 feet) from the rover. On the left side of the panorama is 'Cape St. Mary,' the next promontory clockwise from Cape Verde and about 40 meters (130 feet) from the rover. The vantage point atop Cape Verde offered a good view of the rock layers in the cliff face of Cape St. Mary, which is about 15 meters or 50 feet tall. By about two weeks after the Pancam finished collecting the images for this panorama, Opportunity had driven to Cape St. Mary and was photographing Cape Verde's rock layers.

    The far side of the crater lies about 800 meters (half a mile) away, toward the southeast.

    This view combines images taken through three of the Pancam's filters, admitting light with wavelengths centered at 750 nanometers (near infrared), 530 nanometers (green) and 430 nanometers (violet). It is presented in false

  15. Spherical Panoramas for Astrophysical Data Visualization

    NASA Astrophysics Data System (ADS)

    Kent, Brian R.

    2017-05-01

    Data immersion has advantages in astrophysical visualization. Complex multi-dimensional data and phase spaces can be explored in a seamless and interactive viewing environment. Putting the user in the data is a first step toward immersive data analysis. We present a technique for creating 360° spherical panoramas with astrophysical data. The three-dimensional software package Blender and the Google Spatial Media module are used together to immerse users in data exploration. Several examples employing these methods exhibit how the technique works using different types of astronomical data.

  16. Developmental process emerges from extended brain-body-behavior networks.

    PubMed

    Byrge, Lisa; Sporns, Olaf; Smith, Linda B

    2014-08-01

    Studies of brain connectivity have focused on two modes of networks: structural networks describing neuroanatomy and the intrinsic and evoked dependencies of functional networks at rest and during tasks. Each mode constrains and shapes the other across multiple timescales and each also shows age-related changes. Here we argue that understanding how brains change across development requires understanding the interplay between behavior and brain networks: changing bodies and activities modify the statistics of inputs to the brain; these changing inputs mold brain networks; and these networks, in turn, promote further change in behavior and input. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Developmental process emerges from extended brain-body-behavior networks

    PubMed Central

    Byrge, Lisa; Sporns, Olaf; Smith, Linda B.

    2014-01-01

    Studies of brain connectivity have focused on two modes of networks: structural networks describing neuroanatomy and the intrinsic and evoked dependencies of functional networks at rest and during tasks. Each mode constrains and shapes the other across multiple time scales, and each also shows age-related changes. Here we argue that understanding how brains change across development requires understanding the interplay between behavior and brain networks: changing bodies and activities modify the statistics of inputs to the brain; these changing inputs mold brain networks; these networks, in turn, promote further change in behavior and input. PMID:24862251

  18. Emergence, evolution and scaling of online social networks.

    PubMed

    Wang, Le-Zhi; Huang, Zi-Gang; Rong, Zhi-Hai; Wang, Xiao-Fan; Lai, Ying-Cheng

    2014-01-01

    Online social networks have become increasingly ubiquitous and understanding their structural, dynamical, and scaling properties not only is of fundamental interest but also has a broad range of applications. Such networks can be extremely dynamic, generated almost instantaneously by, for example, breaking-news items. We investigate a common class of online social networks, the user-user retweeting networks, by analyzing the empirical data collected from Sina Weibo (a massive twitter-like microblogging social network in China) with respect to the topic of the 2011 Japan earthquake. We uncover a number of algebraic scaling relations governing the growth and structure of the network and develop a probabilistic model that captures the basic dynamical features of the system. The model is capable of reproducing all the empirical results. Our analysis not only reveals the basic mechanisms underlying the dynamics of the retweeting networks, but also provides general insights into the control of information spreading on such networks.

  19. Growing networks with geographical attachment preference: emergence of small worlds.

    PubMed

    Ozik, Jonathan; Hunt, Brian R; Ott, Edward

    2004-02-01

    We introduce a simple mechanism for the evolution of small world networks. Our model is a growing network in which all connections are made locally to geographically nearby sites. Although connections are made purely locally, network growth leads to stretching of old connections and to high clustering. Our results suggest that the abundance of small world networks in geographically constrained systems is a natural consequence of system growth and local interactions.

  20. Focus on the emerging new fields of network physiology and network medicine

    NASA Astrophysics Data System (ADS)

    Ivanov, Plamen Ch; Liu, Kang K. L.; Bartsch, Ronny P.

    2016-10-01

    Despite the vast progress and achievements in systems biology and integrative physiology in the last decades, there is still a significant gap in understanding the mechanisms through which (i) genomic, proteomic and metabolic factors and signaling pathways impact vertical processes across cells, tissues and organs leading to the expression of different disease phenotypes and influence the functional and clinical associations between diseases, and (ii) how diverse physiological systems and organs coordinate their functions over a broad range of space and time scales and horizontally integrate to generate distinct physiologic states at the organism level. Two emerging fields, network medicine and network physiology, aim to address these fundamental questions. Novel concepts and approaches derived from recent advances in network theory, coupled dynamical systems, statistical and computational physics show promise to provide new insights into the complexity of physiological structure and function in health and disease, bridging the genetic and sub-cellular level with inter-cellular interactions and communications among integrated organ systems and sub-systems. These advances form first building blocks in the methodological formalism and theoretical framework necessary to address fundamental problems and challenges in physiology and medicine. This ‘focus on’ issue contains 26 articles representing state-of-the-art contributions covering diverse systems from the sub-cellular to the organism level where physicists have key role in laying the foundations of these new fields.

  1. Method and system for conserving power in a telecommunications network during emergency situations

    DOEpatents

    Conrad, Stephen H [Algodones, NM; O'Reilly, Gerard P [Manalapan, NJ

    2011-10-11

    Disclosed is a method and apparatus for conserving power in a telecommunications network during emergency situations. A permissible number list of emergency and/or priority numbers is stored in the telecommunications network. In the event of an emergency or power failure, input digits of a call to the telecommunications network are compared to the permissible number list. The call is processed in the telecommunications network and routed to its destination if the input digits match an entry in the permissible number list. The call is dropped without any further processing if the input digits do not match an entry in the permissible number list. Thus, power can be conserved in emergency situations by only allowing emergency and/or priority calls.

  2. Portion of 360-degree color panorama

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image represents the first two tiers of a 360- degree color panorama, taken by the Imager for Mars Pathfinder (IMP). The metallic object at far lower left is a portion of the lander's low-gain antenna. At left, the forward ramp is visible near the larger rocks dubbed Wedge, Flat Top, and Half-Dome. The magenta and yellow strips near the center represent portions of missing data. Rover Sojourner is situated on the soil after its successful deployment on Sol 5. To its immediate left is the rock dubbed 'Barnacle Bill,' and in front of it lies the larger rock dubbed 'Yogi.' Two additional areas of deflated airbags are at the right-center and right of the panorama. The mast and windsocks at far right is the Atmospheric Structure Instrument/Meteorology Package (ASI/MET). Their upward position indicates little air movement. A shadow of the ASI/MET has been cast upon a rock just in front of it, indicating sunlight is coming from the rear right.

    Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory (JPL) for the National Aeronautics and Space Administration. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  3. Sojourner Within Color-Enhanced Panorama

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is a sub-section of the 'geometrically improved, color enhanced' version of the 360-degree panorama heretofore known as the 'Gallery Pan', the first contiguous, uniform panorama taken by the Imager for Mars Pathfinder (IMP) over the course of Sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama.

    The IMP is a stereo imaging system that, in its fully deployed configuration, stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. In this geometrically improved version of the panorama, distortion due to a 2.5 degree tilt in the IMP camera mast has been removed, effectively flattening the horizon.

    The IMP has color capability provided by 24 selectable filters -- twelve filters per 'eye'. Its red, green, and blue filters were used to take this image. The color was digitally balanced according to the color transmittance capability of a high-resolution TV at the Jet Propulsion Laboratory (JPL), and is dependent on that device. In this color enhanced version of the panorama, detail in surface features are brought out via changes to saturation and intensity, holding the original hue constant. A threshold was applied to avoid changes to the sky.

    On the horizon the double 'Twin Peaks' are visible, about 1- 2 kilometers away. The rock 'Couch' is the dark, curved rock at right of Twin Peaks. A Lander petal is visible on the left, showing the fully deployed rear ramp, which rover Sojourner used to descend to the surface of Mars on July 5. Immediately to the left of the rear ramp is the rock 'Barnacle Bill', which scientists found to be andesitic, possibly indicating that it is a volcanic rock (a true andesite) or a physical mixture of particles. Just beyond Barnacle Bill, rover tracks lead to Sojourner, shown using its Alpha Proton X-Ray Spectrometer (APXS) instrument to study the large

  4. Color enhanced version of 360-degree panorama

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is a 'geometrically improved, color enhanced' version of the 360-degree panorama heretofore known as the 'Gallery Pan', the first contiguous, uniform panorama taken by the Imager for Mars Pathfinder (IMP) over the course of Sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama.

    The IMP is a stereo imaging system that, in its fully deployed configuration, stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. In this geometrically improved version of the panorama, distortion due to a 2.5 degree tilt in the IMP camera mast has been removed, effectively flattening the horizon.

    The IMP has color capability provided by 24 selectable filters -- twelve filters per 'eye.' Its red, green, and blue filters were used to take this image. The color was digitally balanced according to the color transmittance capability of a high-resolution TV at the Jet Propulsion Laboratory (JPL), and is dependent on that device. In this color enhanced version of the panorama, detail in surface features are brought out via changes to saturation and intensity, holding the original hue constant. A threshold was applied to avoid changes to the sky.

    At left is a Lander petal and a metallic mast which is a portion of the low-gain antenna. Misregistration in the antenna and other Lander features is due to parallax in the extreme foreground. On the horizon the double 'Twin Peaks' are visible, about 1-2 kilometers away. The rock 'Couch' is the dark, curved rock at right of Twin Peaks. Another Lander petal is at left-center, showing the fully deployed forward ramp at far left, and rear ramp at right, which rover Sojourner used to descend to the surface of Mars on July 5. Immediately to the left of the rear ramp is the rock 'Barnacle Bill', which scientists found to be andesitic, possibly indicating that it is a

  5. Research on robust optimization of emergency logistics network considering the time dependence characteristic

    NASA Astrophysics Data System (ADS)

    WANG, Qingrong; ZHU, Changfeng; LI, Ying; ZHANG, Zhengkun

    2017-06-01

    Considering the time dependence of emergency logistic network and complexity of the environment that the network exists in, in this paper the time dependent network optimization theory and robust discrete optimization theory are combined, and the emergency logistics dynamic network optimization model with characteristics of robustness is built to maximize the timeliness of emergency logistics. On this basis, considering the complexity of dynamic network and the time dependence of edge weight, an improved ant colony algorithm is proposed to realize the coupling of the optimization algorithm and the network time dependence and robustness. Finally, a case study has been carried out in order to testify validity of this robustness optimization model and its algorithm, and the value of different regulation factors was analyzed considering the importance of the value of the control factor in solving the optimal path. Analysis results show that this model and its algorithm above-mentioned have good timeliness and strong robustness.

  6. Model of community emergence in weighted social networks

    NASA Astrophysics Data System (ADS)

    Kumpula, J. M.; Onnela, J.-P.; Saramäki, J.; Kertész, J.; Kaski, K.

    2009-04-01

    Over the years network theory has proven to be rapidly expanding methodology to investigate various complex systems and it has turned out to give quite unparalleled insight to their structure, function, and response through data analysis, modeling, and simulation. For social systems in particular the network approach has empirically revealed a modular structure due to interplay between the network topology and link weights between network nodes or individuals. This inspired us to develop a simple network model that could catch some salient features of mesoscopic community and macroscopic topology formation during network evolution. Our model is based on two fundamental mechanisms of network sociology for individuals to find new friends, namely cyclic closure and focal closure, which are mimicked by local search-link-reinforcement and random global attachment mechanisms, respectively. In addition we included to the model a node deletion mechanism by removing all its links simultaneously, which corresponds for an individual to depart from the network. Here we describe in detail the implementation of our model algorithm, which was found to be computationally efficient and produce many empirically observed features of large-scale social networks. Thus this model opens a new perspective for studying such collective social phenomena as spreading, structure formation, and evolutionary processes.

  7. Emerging Discourses within the English "Choice Advice" Policy Network

    ERIC Educational Resources Information Center

    Exley, Sonia

    2009-01-01

    This paper examines regulating discourses "spoken" within the complex multi-sector network of educational policy and provision that has grown from a recent introduction of choice advisers in England. Choice advice documentation from across the network is examined and four discursive themes are identified: equity; parental responsibility;…

  8. Emerging Communities: Integrating Networked Information into Library Services (Book Review).

    ERIC Educational Resources Information Center

    Afifi, Marianne

    1995-01-01

    Reviews this collection of papers, edited by Ann P. Bishop, which present the current state of networking as it relates to libraries and the community. Recommends the book as a compendium of lessons, learned and to be learned, as networked information becomes an integral and necessary part of the library world. (JMV)

  9. A hybrid behavioural rule of adaptation and drift explains the emergent architecture of antagonistic networks

    PubMed Central

    Nuwagaba, S.; Zhang, F.; Hui, C.

    2015-01-01

    Ecological processes that can realistically account for network architectures are central to our understanding of how species assemble and function in ecosystems. Consumer species are constantly selecting and adjusting which resource species are to be exploited in an antagonistic network. Here we incorporate a hybrid behavioural rule of adaptive interaction switching and random drift into a bipartite network model. Predictions are insensitive to the model parameters and the initial network structures, and agree extremely well with the observed levels of modularity, nestedness and node-degree distributions for 61 real networks. Evolutionary and community assemblage histories only indirectly affect network structure by defining the size and complexity of ecological networks, whereas adaptive interaction switching and random drift carve out the details of network architecture at the faster ecological time scale. The hybrid behavioural rule of both adaptation and drift could well be the key processes for structure emergence in real ecological networks. PMID:25925104

  10. Improved MPF 360-degree Color Panorama

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This is a more recent 'geometrically improved, color enhanced' version of the 360-degree 'Gallery Pan', the first contiguous, uniform panorama taken by the Imager for Mars (IMP) over the course of Sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama. In this version of the panorama, much of the discontinuity that was due to parallax has been corrected, particularly along the lower tiers of the mosaic containing the Lander features. Distortion due to a 2.5 degree tilt in the IMP camera mast has been removed.

    The IMP is a stereo imaging system that, in its fully deployed configuration, stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. The IMP has color capability provided by 24 selectable filters -- twelve filters per 'eye'. Its red, green, and blue filters were used to take this panorama.

    The three color images were first digitally balanced according to the transmittance capabilities of a specific high-definition TV device at JPL, and then enhanced via changes to saturation and intensity while retaining the hue. A threshold was applied to avoid changes to the sky. An MTF filter was applied to sharpen feature edges.

    At left is a Lander petal and a metallic mast which is a portion of the low-gain antenna. On the horizon the double 'Twin Peaks' are visible, about 1-2 kilometers away. The rock 'Couch' is the dark, curved rock at right of Twin Peaks. Another Lander petal is at left-center, showing the fully deployed forward ramp at far left, and rear ramp at right, which rover Sojourner used to descend to the surface of Mars on July 5. Immediately to the left of the rear ramp is the rock 'Barnacle Bill', which scientists found be andesitic, possibly indicating that it is a volcanic rock (a true andesite) or a physical mixture of particles. Just beyond Barnacle Bill, rover tracks

  11. 'Big Crater' in 360-degree panorama

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The crater dubbed 'Big Crater', approximately 2200 meters (7200 feet)away was imaged by the Imager for Mars Pathfinder (IMP) as part of a 360-degree color panorama, taken over sols 8, 9 and 10. 'Big Crater' is actually a relatively small Martian crater to the southeast of the Mars Pathfinder landing site. It is 1500 meters (4900 feet) in diameter, or about the same size as Meteor Crater in Arizona.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  12. Triangulation of cubic panorama for view synthesis.

    PubMed

    Zhang, Chunxiao; Zhao, Yan; Wu, Falin

    2011-08-01

    An unstructured triangulation approach, new to our knowledge, is proposed to apply triangular meshes for representing and rendering a scene on a cubic panorama (CP). It sophisticatedly converts a complicated three-dimensional triangulation into a simple three-step triangulation. First, a two-dimensional Delaunay triangulation is individually carried out on each face. Second, an improved polygonal triangulation is implemented in the intermediate regions of each of two faces. Third, a cobweblike triangulation is designed for the remaining intermediate regions after unfolding four faces to the top/bottom face. Since the last two steps well solve the boundary problem arising from cube edges, the triangulation with irregular-distribution feature points is implemented in a CP as a whole. The triangular meshes can be warped from multiple reference CPs onto an arbitrary viewpoint by face-to-face homography transformations. The experiments indicate that the proposed triangulation approach provides a good modeling for the scene with photorealistic rendered CPs.

  13. Mesoscopic Structure Conditions the Emergence of Cooperation on Social Networks

    PubMed Central

    Lozano, Sergi; Arenas, Alex; Sánchez, Angel

    2008-01-01

    Background We study the evolutionary Prisoner's Dilemma on two social networks substrates obtained from actual relational data. Methodology/Principal Findings We find very different cooperation levels on each of them that cannot be easily understood in terms of global statistical properties of both networks. We claim that the result can be understood at the mesoscopic scale, by studying the community structure of the networks. We explain the dependence of the cooperation level on the temptation parameter in terms of the internal structure of the communities and their interconnections. We then test our results on community-structured, specifically designed artificial networks, finding a good agreement with the observations in both real substrates. Conclusion Our results support the conclusion that studies of evolutionary games on model networks and their interpretation in terms of global properties may not be sufficient to study specific, real social systems. Further, the study allows us to define new quantitative parameters that summarize the mesoscopic structure of any network. In addition, the community perspective may be helpful to interpret the origin and behavior of existing networks as well as to design structures that show resilient cooperative behavior. PMID:18382673

  14. Mesoscopic structure conditions the emergence of cooperation on social networks

    SciTech Connect

    Lozano, S.; Arenas, A.; Sanchez, A.

    2008-12-01

    We study the evolutionary Prisoner's Dilemma on two social networks substrates obtained from actual relational data. We find very different cooperation levels on each of them that cannot be easily understood in terms of global statistical properties of both networks. We claim that the result can be understood at the mesoscopic scale, by studying the community structure of the networks. We explain the dependence of the cooperation level on the temptation parameter in terms of the internal structure of the communities and their interconnections. We then test our results on community-structured, specifically designed artificial networks, finding a good agreement with the observations in both real substrates. Our results support the conclusion that studies of evolutionary games on model networks and their interpretation in terms of global properties may not be sufficient to study specific, real social systems. Further, the study allows us to define new quantitative parameters that summarize the mesoscopic structure of any network. In addition, the community perspective may be helpful to interpret the origin and behavior of existing networks as well as to design structures that show resilient cooperative behavior.

  15. 'Lyell' Panorama inside Victoria Crater (Stereo)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    During four months prior to the fourth anniversary of its landing on Mars, NASA's Mars Exploration Rover Opportunity examined rocks inside an alcove called 'Duck Bay' in the western portion of Victoria Crater. The main body of the crater appears in the upper right of this stereo panorama, with the far side of the crater lying about 800 meters (half a mile) away. Bracketing that part of the view are two promontories on the crater's rim at either side of Duck Bay. They are 'Cape Verde,' about 6 meters (20 feet) tall, on the left, and 'Cabo Frio,' about 15 meters (50 feet) tall, on the right. The rest of the image, other than sky and portions of the rover, is ground within Duck Bay.

    Opportunity's targets of study during the last quarter of 2007 were rock layers within a band exposed around the interior of the crater, about 6 meters (20 feet) from the rim. Bright rocks within the band are visible in the foreground of the panorama. The rover science team assigned informal names to three subdivisions of the band: 'Steno,' 'Smith,' and 'Lyell.'

    This view incorporates many images taken by Opportunity's panoramic camera (Pancam) from the 1,332nd through 1,379th Martian days, or sols, of the mission (Oct. 23 to Dec. 11, 2007). It combines a stereo pair so that it appears three-dimensional when seen through blue-red glasses. Some visible patterns in dark and light tones are the result of combining frames that were affected by dust on the front sapphire window of the rover's camera.

    Opportunity landed on Jan. 25, 2004, Universal Time, (Jan. 24, Pacific Time) inside a much smaller crater about 6 kilometers (4 miles) north of Victoria Crater, to begin a surface mission designed to last 3 months and drive about 600 meters (0.4 mile).

  16. Panorama from Curiosity Sol 1000 Location Stereo

    NASA Image and Video Library

    2015-07-01

    This stereo view from the Navigation Camera (Navcam) on NASA's Curiosity Mars rover shows a 360-degree panorama around the location where the rover spent its 1,000th Martian day, or sol, on Mars. The image appears three-dimensional when viewed through red-blue glasses with the red lens on the left. Sol 1,000 of Curiosity's Mars-surface mission corresponded to May 30, 2015. The component images for this scene were taken on Sol 997 (May 27, 2015). The site is a valley just below "Marias Pass" on lower Mount Sharp. A map of the area is at http://mars.nasa.gov/msl/images/Curiosity_Location_Sol997-full.jpg. The center of the scene is toward the south, with north at both ends. This stereo view combines images from Navcam left-eye and right-eye cameras. A single-eye version of the scene is at PIA19679 . Tracks from the rover's drive to this site are visible at right. The rover team chose this location near Marias Pass because images from orbit showed what appeared to be a contact between two types of bedrock. The two types are evident in this panorama. The bedrock close to the rover is pale mudstone similar to what Curiosity examined in 2014 and early 2015 at "Pahrump Hills." The darker, finely bedded bedrock above it is sandstone that the rover team calls the "Stimson" unit. The largest-looking slab of Stimson sandstone in the image, in the lower left quadrant, is a target called "Ronan," selected for close-up inspection. on lower Mount Sharp. http://photojournal.jpl.nasa.gov/catalog/PIA19678

  17. 'Lyell' Panorama inside Victoria Crater (Stereo)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    During four months prior to the fourth anniversary of its landing on Mars, NASA's Mars Exploration Rover Opportunity examined rocks inside an alcove called 'Duck Bay' in the western portion of Victoria Crater. The main body of the crater appears in the upper right of this stereo panorama, with the far side of the crater lying about 800 meters (half a mile) away. Bracketing that part of the view are two promontories on the crater's rim at either side of Duck Bay. They are 'Cape Verde,' about 6 meters (20 feet) tall, on the left, and 'Cabo Frio,' about 15 meters (50 feet) tall, on the right. The rest of the image, other than sky and portions of the rover, is ground within Duck Bay.

    Opportunity's targets of study during the last quarter of 2007 were rock layers within a band exposed around the interior of the crater, about 6 meters (20 feet) from the rim. Bright rocks within the band are visible in the foreground of the panorama. The rover science team assigned informal names to three subdivisions of the band: 'Steno,' 'Smith,' and 'Lyell.'

    This view incorporates many images taken by Opportunity's panoramic camera (Pancam) from the 1,332nd through 1,379th Martian days, or sols, of the mission (Oct. 23 to Dec. 11, 2007). It combines a stereo pair so that it appears three-dimensional when seen through blue-red glasses. Some visible patterns in dark and light tones are the result of combining frames that were affected by dust on the front sapphire window of the rover's camera.

    Opportunity landed on Jan. 25, 2004, Universal Time, (Jan. 24, Pacific Time) inside a much smaller crater about 6 kilometers (4 miles) north of Victoria Crater, to begin a surface mission designed to last 3 months and drive about 600 meters (0.4 mile).

  18. Understanding emergent functions in self-assembled fibrous networks

    NASA Astrophysics Data System (ADS)

    Sinko, Robert; Keten, Sinan

    2015-09-01

    Understanding self-assembly processes of nanoscale building blocks and characterizing their properties are both imperative for designing new hierarchical, network materials for a wide range of structural, optoelectrical, and transport applications. Although the characterization and choices of these material building blocks have been well studied, our understanding of how to precisely program a specific morphology through self-assembly still must be significantly advanced. In the recent study by Xie et al (2015 Nanotechnology 26 205602), the self-assembly of end-functionalized nanofibres is investigated using a coarse-grained molecular model and offers fundamental insight into how to control the structural morphology of nanofibrous networks. Varying nanoscale networks are observed when the molecular interaction strength is changed and the findings suggest that self-assembly through the tuning of molecular interactions is a key strategy for designing nanostructured networks with specific topologies.

  19. Emerging Network-Based Tools in Movement Ecology.

    PubMed

    Jacoby, David M P; Freeman, Robin

    2016-04-01

    New technologies have vastly increased the available data on animal movement and behaviour. Consequently, new methods deciphering the spatial and temporal interactions between individuals and their environments are vital. Network analyses offer a powerful suite of tools to disentangle the complexity within these dynamic systems, and we review these tools, their application, and how they have generated new ecological and behavioural insights. We suggest that network theory can be used to model and predict the influence of ecological and environmental parameters on animal movement, focusing on spatial and social connectivity, with fundamental implications for conservation. Refining how we construct and randomise spatial networks at different temporal scales will help to establish network theory as a prominent, hypothesis-generating tool in movement ecology.

  20. Emergent self-organized complex network topology out of stability constraints.

    PubMed

    Perotti, Juan I; Billoni, Orlando V; Tamarit, Francisco A; Chialvo, Dante R; Cannas, Sergio A

    2009-09-04

    Although most networks in nature exhibit complex topologies, the origins of such complexity remain unclear. We propose a general evolutionary mechanism based on global stability. This mechanism is incorporated into a model of a growing network of interacting agents in which each new agent's membership in the network is determined by the agent's effect on the network's global stability. It is shown that out of this stability constraint complex topological properties emerge in a self-organized manner, offering an explanation for their observed ubiquity in biological networks.

  1. The effect of social contexts on network response to emergencies

    DTIC Science & Technology

    2011-01-01

    strengths [3]. The recent availability of new cutting edge datasets such as cell phone call records [3] offers unprecedented opportunities to study the...mobile phone subscribers in a western European country from 2007 to 2009, we compare call activity in the immediate aftermath of a set of emergencies...Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS mobile phone call activity, mobile phone emergency usage

  2. Comparison of School Food Allergy Emergency Plans to the Food Allergy and Anaphylaxis Network's Standard Plan

    ERIC Educational Resources Information Center

    Powers, Jill; Bergren, Martha Dewey; Finnegan, Lorna

    2007-01-01

    Eighty-four percent of children with food allergies have a reaction in school, and 25% of first food reactions occur in schools. An evaluation was conducted comparing food allergy emergency plans to the Food Allergy and Anaphylaxis Network's (FAAN) Food Allergy Action Plan. Of the 94 respondents, 60 provided food allergy emergency plans for…

  3. Emergent Complex Behavior in Social Networks: Examples from the Ktunaxa Speech Community

    ERIC Educational Resources Information Center

    Horsethief, Christopher

    2012-01-01

    Language serves as a primary tool for structuring identity and loss of language represents the loss of that identity. This study utilizes a social network analysis of Ktunaxa speech community activities for evidence of internally generated revitalization efforts. These behaviors include instances of self-organized emergence. Such emergent behavior…

  4. Emergent Complex Behavior in Social Networks: Examples from the Ktunaxa Speech Community

    ERIC Educational Resources Information Center

    Horsethief, Christopher

    2012-01-01

    Language serves as a primary tool for structuring identity and loss of language represents the loss of that identity. This study utilizes a social network analysis of Ktunaxa speech community activities for evidence of internally generated revitalization efforts. These behaviors include instances of self-organized emergence. Such emergent behavior…

  5. Comparison of School Food Allergy Emergency Plans to the Food Allergy and Anaphylaxis Network's Standard Plan

    ERIC Educational Resources Information Center

    Powers, Jill; Bergren, Martha Dewey; Finnegan, Lorna

    2007-01-01

    Eighty-four percent of children with food allergies have a reaction in school, and 25% of first food reactions occur in schools. An evaluation was conducted comparing food allergy emergency plans to the Food Allergy and Anaphylaxis Network's (FAAN) Food Allergy Action Plan. Of the 94 respondents, 60 provided food allergy emergency plans for…

  6. Emerging Trends in the Development of School Networking Initiatives. Perspectives on Distance Education

    ERIC Educational Resources Information Center

    Naidoo, Vis, Ed.; Ramzy, Heba, Ed.

    2004-01-01

    This collection of research and case studies provides snapshots of developments in school networking in seven regions of the world, and focuses on the variety of school networking models that have emerged in different regions and the resulting trends and issues that need to be considered in terms of supporting the learning, teaching, management…

  7. Emerging Trends in the Development of School Networking Initiatives. Perspectives on Distance Education

    ERIC Educational Resources Information Center

    Naidoo, Vis, Ed.; Ramzy, Heba, Ed.

    2004-01-01

    This collection of research and case studies provides snapshots of developments in school networking in seven regions of the world, and focuses on the variety of school networking models that have emerged in different regions and the resulting trends and issues that need to be considered in terms of supporting the learning, teaching, management…

  8. Criticality Is an Emergent Property of Genetic Networks that Exhibit Evolvability

    PubMed Central

    Torres-Sosa, Christian; Huang, Sui; Aldana, Maximino

    2012-01-01

    Accumulating experimental evidence suggests that the gene regulatory networks of living organisms operate in the critical phase, namely, at the transition between ordered and chaotic dynamics. Such critical dynamics of the network permits the coexistence of robustness and flexibility which are necessary to ensure homeostatic stability (of a given phenotype) while allowing for switching between multiple phenotypes (network states) as occurs in development and in response to environmental change. However, the mechanisms through which genetic networks evolve such critical behavior have remained elusive. Here we present an evolutionary model in which criticality naturally emerges from the need to balance between the two essential components of evolvability: phenotype conservation and phenotype innovation under mutations. We simulated the Darwinian evolution of random Boolean networks that mutate gene regulatory interactions and grow by gene duplication. The mutating networks were subjected to selection for networks that both (i) preserve all the already acquired phenotypes (dynamical attractor states) and (ii) generate new ones. Our results show that this interplay between extending the phenotypic landscape (innovation) while conserving the existing phenotypes (conservation) suffices to cause the evolution of all the networks in a population towards criticality. Furthermore, the networks produced by this evolutionary process exhibit structures with hubs (global regulators) similar to the observed topology of real gene regulatory networks. Thus, dynamical criticality and certain elementary topological properties of gene regulatory networks can emerge as a byproduct of the evolvability of the phenotypic landscape. PMID:22969419

  9. Networks as Renormalized Models for Emergent Behavior in Physical Systems

    NASA Astrophysics Data System (ADS)

    Paczuski, Maya

    2005-09-01

    Networks are paradigms for describing complex biological, social and technological systems. Here I argue that networks provide a coherent framework to construct coarsegrained models for many different physical systems. To elucidate these ideas, I discuss two long-standing problems. The first concerns the structure and dynamics of magnetic fields in the solar corona, as exemplified by sunspots that startled Galileo almost 400 years ago. We discovered that the magnetic structure of the corona embodies a scale free network, with spots at all scales. A network model representing the three-dimensional geometry of magnetic fields, where links rewire and nodes merge when they collide in space, gives quantitative agreement with available data, and suggests new measurements. Seismicity is addressed in terms of relations between events without imposing space-time windows. A metric estimates the correlation between any two earthquakes. Linking strongly correlated pairs, and ignoring pairs with weak correlation organizes the spatio-temporal process into a sparse, directed, weighted network. New scaling laws for seismicity are found. For instance, the aftershock decay rate decreases as ~ 1/t in time up to a correlation time, tomori. An estimate from the data gives tomori to be about one year for small magnitude 3 earthquakes, about 1400 years for the Landers event, and roughly 26,000 years for the earthquake causing the 2004 Asian tsunami. Our results confirm Kagan's conjecture that aftershocks can rumble on for centuries.

  10. [Exceptional medical circumstances: interest of an interhospital support strategy within the North Alps emergency trauma network].

    PubMed

    Incagnoli, P; Hacini, R; Gros, I; Rancurel, E; Jacquot, C

    2011-12-01

    The Northern French Alps Emergency Network (RENAU) has a main objective the improvement of the quality of the care in the field of the emergency medical treatment. With this French medical system, we developed a procedure allowing the detachment of a medical-surgical team of the university hospital to help general hospital team in the event of immediate vital emergency situation with untransportable patient. We reported the successful implementation of this support strategy for a 51-year-old patient arrived in a hospital of the network in extremely serious hemodynamic shock due to an important hemorrhagic pericardial effusion with tamponnade 1 day after percutaneous closure of the patent foramen ovale (PFO).

  11. Geographical influences of an emerging network of gang rivalries

    NASA Astrophysics Data System (ADS)

    Hegemann, Rachel A.; Smith, Laura M.; Barbaro, Alethea B. T.; Bertozzi, Andrea L.; Reid, Shannon E.; Tita, George E.

    2011-10-01

    We propose an agent-based model to simulate the creation of street gang rivalries. The movement dynamics of agents are coupled to an evolving network of gang rivalries, which is determined by previous interactions among agents in the system. Basic gang data, geographic information, and behavioral dynamics suggested by the criminology literature are integrated into the model. The major highways, rivers, and the locations of gangs’ centers of activity influence the agents’ motion. We use a policing division of the Los Angeles Police Department as a case study to test our model. We apply common metrics from graph theory to analyze our model, comparing networks produced by our simulations and an instance of a Geographical Threshold Graph to the existing network from the criminology literature.

  12. 1. PANORAMA, SHOWING COMMAND POST RELATION TO DUTCH HARBOR AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. PANORAMA, SHOWING COMMAND POST RELATION TO DUTCH HARBOR AND UNALASKA FROM THE TOP OF LITTLE SOUTH AMERICA - Naval Operating Base Dutch Harbor & Fort Mears, Hill 400 Fixed Defense Battery Command Post, Unalaska, Aleutian Islands, AK

  13. PANORAMA, SHOWING COMMAND POST RELATION TO DUTCH HARBOR AND UNALASKA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PANORAMA, SHOWING COMMAND POST RELATION TO DUTCH HARBOR AND UNALASKA FROM THE TOP OF LITTLE SOUTH AMERICA - Naval Operating Base Dutch Harbor & Fort Mears, Hill 400 Fixed Defense Battery Command Post, Unalaska, Aleutian Islands, AK

  14. Automatic Adjustment of Wide-Base Google Street View Panoramas

    NASA Astrophysics Data System (ADS)

    Boussias-Alexakis, E.; Tsironisa, V.; Petsa, E.; Karras, G.

    2016-06-01

    This paper focuses on the issue of sparse matching in cases of extremely wide-base panoramic images such as those acquired by Google Street View in narrow urban streets. In order to effectively use affine point operators for bundle adjustment, panoramas must be suitably rectified to simulate affinity. To this end, a custom piecewise planar projection (triangular prism projection) is applied. On the assumption that the image baselines run parallel to the street façades, the estimated locations of the vanishing lines of the façade plane allow effectively removing projectivity and applying the ASIFT point operator on panorama pairs. Results from comparisons with multi-panorama adjustment, based on manually measured image points, and ground truth indicate that such an approach, if further elaborated, may well provide a realistic answer to the matching problem in the case of demanding panorama configurations.

  15. 1. PANORAMA, FROM ULAKTA HEAD COMMAND POST TO THE WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. PANORAMA, FROM ULAKTA HEAD COMMAND POST TO THE WEST TOWARD MOUNT BALLYHOO - Naval Operating Base Dutch Harbor & Fort Mears, Ulakta Head Fixed Defense Battery Command Post No. 1, Unalaska, Aleutian Islands, AK

  16. PANORAMA, FROM ULAKTA HEAD COMMAND POST TO THE WEST TOWARDS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PANORAMA, FROM ULAKTA HEAD COMMAND POST TO THE WEST TOWARDS MOUNT BALLYHOO - Naval Operating Base Dutch Harbor & Fort Mears, Ulakta Head Fixed Defense Battery Command Post No. 1, Unalaska, Aleutian Islands, AK

  17. 1. View of Clark Fork Vehicle Bridge facing west. Panorama ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. View of Clark Fork Vehicle Bridge facing west. Panorama showing the entire span of bridge from north shore of the Clark Fork River. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

  18. U.S. DOE's Emergency Communications Network Site Atlas Project

    SciTech Connect

    Coffey, J.R.

    1999-07-27

    Bechtel Nevada supports the US Department of Energy's Emergency Operations Center by providing Geographic Information System support in the areas of database maintenance, user interface, and daily emergency preparedness operations. This support includes preparation of a set of standardized atlases for many of the sites run by the Department of Energy. The atlases are created from one suite of ARC Macro Language programs that handles problems with producing consistent output for many maps in many different scales from data obtained from multiple sources and created at various scales. Flexibility and ease of change/update are the key benefits of this system.

  19. Directed percolation effects emerging from superadditivity of quantum networks

    NASA Astrophysics Data System (ADS)

    Czekaj, L.; Chhajlany, R. W.; Horodecki, P.

    2012-03-01

    Entanglement-induced nonadditivity of classical communication capacity in networks consisting of quantum channels is considered. Communication lattices consisting of butterfly-type entanglement-breaking channels augmented, with some probability, by identity channels are analyzed. The capacity superadditivity in the network is manifested in directed correlated bond percolation which we consider in two flavors: simply directed and randomly oriented. The obtained percolation properties show that high-capacity information transfer sets in much faster in the regime of superadditive communication capacity than otherwise possible. As a by-product, this sheds light on a type of entanglement-based quantum capacity percolation phenomenon.

  20. An emergency-adaptive routing scheme for wireless sensor networks for building fire hazard monitoring.

    PubMed

    Zeng, Yuanyuan; Xiong, Naixue; Park, Jong Hyuk; Zheng, Guilin

    2010-01-01

    Fire hazard monitoring and evacuation for building environments is a novel application area for the deployment of wireless sensor networks. In this context, adaptive routing is essential in order to ensure safe and timely data delivery in building evacuation and fire fighting resource applications. Existing routing mechanisms for wireless sensor networks are not well suited for building fires, especially as they do not consider critical and dynamic network scenarios. In this paper, an emergency-adaptive, real-time and robust routing protocol is presented for emergency situations such as building fire hazard applications. The protocol adapts to handle dynamic emergency scenarios and works well with the routing hole problem. Theoretical analysis and simulation results indicate that our protocol provides a real-time routing mechanism that is well suited for dynamic emergency scenarios in building fires when compared with other related work.

  1. An Emergency-Adaptive Routing Scheme for Wireless Sensor Networks for Building Fire Hazard Monitoring

    PubMed Central

    Zeng, Yuanyuan; Xiong, Naixue; Park, Jong Hyuk; Zheng, Guilin

    2010-01-01

    Fire hazard monitoring and evacuation for building environments is a novel application area for the deployment of wireless sensor networks. In this context, adaptive routing is essential in order to ensure safe and timely data delivery in building evacuation and fire fighting resource applications. Existing routing mechanisms for wireless sensor networks are not well suited for building fires, especially as they do not consider critical and dynamic network scenarios. In this paper, an emergency-adaptive, real-time and robust routing protocol is presented for emergency situations such as building fire hazard applications. The protocol adapts to handle dynamic emergency scenarios and works well with the routing hole problem. Theoretical analysis and simulation results indicate that our protocol provides a real-time routing mechanism that is well suited for dynamic emergency scenarios in building fires when compared with other related work. PMID:22219706

  2. An Emergency-Adaptive Routing Scheme for Wireless Sensor Networks for Building Fire Hazard Monitoring

    PubMed Central

    Zeng, Yuanyuan; Sreenan, Cormac J.; Sitanayah, Lanny; Xiong, Naixue; Park, Jong Hyuk; Zheng, Guilin

    2011-01-01

    Fire hazard monitoring and evacuation for building environments is a novel application area for the deployment of wireless sensor networks. In this context, adaptive routing is essential in order to ensure safe and timely data delivery in building evacuation and fire fighting resource applications. Existing routing mechanisms for wireless sensor networks are not well suited for building fires, especially as they do not consider critical and dynamic network scenarios. In this paper, an emergency-adaptive, real-time and robust routing protocol is presented for emergency situations such as building fire hazard applications. The protocol adapts to handle dynamic emergency scenarios and works well with the routing hole problem. Theoretical analysis and simulation results indicate that our protocol provides a real-time routing mechanism that is well suited for dynamic emergency scenarios in building fires when compared with other related work. PMID:22163774

  3. An emergency-adaptive routing scheme for wireless sensor networks for building fire hazard monitoring.

    PubMed

    Zeng, Yuanyuan; Sreenan, Cormac J; Sitanayah, Lanny; Xiong, Naixue; Park, Jong Hyuk; Zheng, Guilin

    2011-01-01

    Fire hazard monitoring and evacuation for building environments is a novel application area for the deployment of wireless sensor networks. In this context, adaptive routing is essential in order to ensure safe and timely data delivery in building evacuation and fire fighting resource applications. Existing routing mechanisms for wireless sensor networks are not well suited for building fires, especially as they do not consider critical and dynamic network scenarios. In this paper, an emergency-adaptive, real-time and robust routing protocol is presented for emergency situations such as building fire hazard applications. The protocol adapts to handle dynamic emergency scenarios and works well with the routing hole problem. Theoretical analysis and simulation results indicate that our protocol provides a real-time routing mechanism that is well suited for dynamic emergency scenarios in building fires when compared with other related work.

  4. The early history and emergence of molecular functions and modular scale-free network behavior.

    PubMed

    Aziz, M Fayez; Caetano-Anollés, Kelsey; Caetano-Anollés, Gustavo

    2016-04-28

    The formation of protein structural domains requires that biochemical functions, defined by conserved amino acid sequence motifs, be embedded into a structural scaffold. Here we trace domain history onto a bipartite network of elementary functional loop sequences and domain structures defined at the fold superfamily level of SCOP classification. The resulting 'elementary functionome' network and its loop motif and structural domain graph projections create evolutionary 'waterfalls' describing the emergence of primordial functions. Waterfalls reveal how ancient loops are shared by domain structures in two initial waves of functional innovation that involve founder 'p-loop' and 'winged helix' domain structures. They also uncover a dynamics of modular motif embedding in domain structures that is ongoing, which transfers 'preferential' cooption properties of ancient loops to emerging domains. Remarkably, we find that the emergence of molecular functions induces hierarchical modularity and power law behavior in network evolution as the network of motifs and structures expand metabolic pathways and translation.

  5. Gigapixel panoramas of Glacier National Park create enhanced education experiences

    NASA Astrophysics Data System (ADS)

    Fagre, D. B.; McKeon, L. A.

    2010-12-01

    Repeat photography has proven to be an effective means to communicate the pace and scope of climate change impacts to Glacier National Park, Montana for broad audiences. The repeat photographs of glaciers vividly document their rate of disappearance and have been used in books, magazines, TV documentaries, on websites, and in several art museum exhibits. In our ongoing efforts to enhance information transfer about climate change to audiences, we have capitalized on an emerging technology by partnering with GigaPan Systems to test the effectiveness of a Gigapan camera system. A Gigapan camera system is a robotically controlled DSLR camera mount that is programmed to take multiple high-resolution digital photographs of objects or entire landscapes in sequence and with overlap between adjoining photographs. The multiple (e.g. 800) photographs are digitally stitched with post production software into one large merged image and served online as a gigapixel panorama. Key objects or parts of the image can be zoomed into at great detail and highlighted as “snapshots”. The snapshot images retain high image resolution and can then be annotated and information such as datasets, maps, or additional images can be linked to that part of the image. GigaPan images can be georeferenced in Google Earth and embedded in websites. We have used this visually compelling technology to photograph alpine glaciers in Glacier Park and create interactive experiences for online users. Results are available at: http://gigapan.org/ Gigapan system with robotically controlled camera

  6. Developmental changes in effective connectivity in the emerging core face network.

    PubMed

    Cohen Kadosh, Kathrin; Cohen Kadosh, Roi; Dick, Frederic; Johnson, Mark H

    2011-06-01

    Little is currently known about the postnatal emergence of functional cortical networks supporting complex perceptual and cognitive skills, such as face processing. The present study examined the emergence of the core cortical network underlying face processing in younger and older school-age children as well as young adults. Participants performed 3 functional magnetic resonance imaging target detection tasks where they either had to detect a specific facial identity, expression, or direction of eye gaze in a stream of consecutively presented faces. We compared the connectivity of the face network using dynamic causal modelling and observed that it emerges gradually during childhood. Further, we found that while the relative strength of functional network connections were differentially modulated by task demands in adults, there was no such modulation of this network in either older or younger children. These results were independent of the behavioral performance in the 3 age groups. We suggest that the emergence of the face network is due to continuous specialization and fine-tuning within the regions of this network. The current results have important implications for future studies investigating trajectories of brain development and cortical specialization both in typically and atypically developing populations.

  7. Network impact on persistence in a finite population dynamic diffusion model: application to an emergent seed exchange network.

    PubMed

    Barbillon, Pierre; Thomas, Mathieu; Goldringer, Isabelle; Hospital, Frédéric; Robin, Stéphane

    2015-01-21

    Dynamic extinction colonisation models (also called contact processes) are widely studied in epidemiology and in metapopulation theory. Contacts are usually assumed to be possible only through a network of connected patches. This network accounts for a spatial landscape or a social organization of interactions. Thanks to social network literature, heterogeneous networks of contacts can be considered. A major issue is to assess the influence of the network in the dynamic model. Most work with this common purpose uses deterministic models or an approximation of a stochastic Extinction-Colonisation model (sEC) which are relevant only for large networks. When working with a limited size network, the induced stochasticity is essential and has to be taken into account in the conclusions. Here, a rigorous framework is proposed for limited size networks and the limitations of the deterministic approximation are exhibited. This framework allows exact computations when the number of patches is small. Otherwise, simulations are used and enhanced by adapted simulation techniques when necessary. A sensitivity analysis was conducted to compare four main topologies of networks in contrasting settings to determine the role of the network. A challenging case was studied in this context: seed exchange of crop species in the Réseau Semences Paysannes (RSP), an emergent French farmers׳ organisation. A stochastic Extinction-Colonisation model was used to characterize the consequences of substantial changes in terms of RSP׳s social organization on the ability of the system to maintain crop varieties. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Panorama view of Apollo 17 Lunar surface photos

    NASA Image and Video Library

    1972-12-01

    Panorama view of Apollo 17 Lunar surface photos for use in presentations to NASA management and for Outreach Education in regard to new NASA initiative for human planetary research. Photo numbers used for this panoramic include: Apollo 17 start frame AS17-146-22339 thru end frame AS17-146-22363. View is of Station 7 Panorama taken during Extravehicular Activity (EVA) 3.

  9. Southern Half of Spirit's 'Bonestell' Panorama

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This 180-degree panorama shows the southward vista from the location where Spirit is spending its third Martian winter inside Mars' Gusev Crater. The rover's overwintering location is on the northern edge of a low plateau informally called 'Home Plate,' which is about 80 meters or 260 feet in diameter.

    This view combines 168 different exposures taken with Spirit's panoramic Camera (Pancam) 42 pointings with 4 filters at each pointing. Spirit took the first of these frames during the mission's 1,477th Martian day, or sol, (February 28, 2008) two weeks after the rover made its last move to reach the location where it would stop driving for the winter. Solar energy at Gusev Crater is so limited during the Martian winter that Spirit does not generate enough electricity to drive, nor even enough to take many images per day. The last frame for this mosaic was taken on Sol 1599 (July 2, 2008). The rover team plans for Spirit to finish taking images for the northern half of the scene during the Martian spring.

    The northwestern edge of Home Plate is visible in the right foreground. The blockier, more sharply shadowed texture there is layered sandstone whose layering is tilted inward toward the edge of the Home Plate platform. A dark rock on top of Home Plate in that area is a porous volcanic basalt unlike rocks nearby. The northeastern edge of Home Plate is visible in the left foreground. Spirit first climbed onto Home Plate on that region, in early 2006.

    Rover tracks from driving by Spirit are visible on Home plate in the center and right of the image. These were made during Spirit's second exploration on top of the plateau, which began when Spirit climbed onto the southern edge of Home Plate in September, 2007.

    In the center foreground, the turret of tools at the end of Spirit's robotic arm appears in duplicate because the arm was repositioned between the days when the images making up that part of the mosaic were taken.

    On the horizon, the

  10. Southern Half of Spirit's 'Bonestell' Panorama

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This 180-degree panorama shows the southward vista from the location where Spirit is spending its third Martian winter inside Mars' Gusev Crater. The rover's overwintering location is on the northern edge of a low plateau informally called 'Home Plate,' which is about 80 meters or 260 feet in diameter.

    This view combines 168 different exposures taken with Spirit's panoramic Camera (Pancam) 42 pointings with 4 filters at each pointing. Spirit took the first of these frames during the mission's 1,477th Martian day, or sol, (February 28, 2008) two weeks after the rover made its last move to reach the location where it would stop driving for the winter. Solar energy at Gusev Crater is so limited during the Martian winter that Spirit does not generate enough electricity to drive, nor even enough to take many images per day. The last frame for this mosaic was taken on Sol 1599 (July 2, 2008). The rover team plans for Spirit to finish taking images for the northern half of the scene during the Martian spring.

    The northwestern edge of Home Plate is visible in the right foreground. The blockier, more sharply shadowed texture there is layered sandstone whose layering is tilted inward toward the edge of the Home Plate platform. A dark rock on top of Home Plate in that area is a porous volcanic basalt unlike rocks nearby. The northeastern edge of Home Plate is visible in the left foreground. Spirit first climbed onto Home Plate on that region, in early 2006.

    Rover tracks from driving by Spirit are visible on Home plate in the center and right of the image. These were made during Spirit's second exploration on top of the plateau, which began when Spirit climbed onto the southern edge of Home Plate in September, 2007.

    In the center foreground, the turret of tools at the end of Spirit's robotic arm appears in duplicate because the arm was repositioned between the days when the images making up that part of the mosaic were taken.

    On the horizon, the

  11. Quantum complexity: Quantum mutual information, complex networks, and emergent phenomena in quantum cellular automata

    NASA Astrophysics Data System (ADS)

    Vargas, David L.

    Emerging quantum simulator technologies provide a new challenge to quantum many body theory. Quantifying the emergent order in and predicting the dynamics of such complex quantum systems requires a new approach. We develop such an approach based on complex network analysis of quantum mutual information. First, we establish the usefulness of quantum mutual information complex networks by reproducing the phase diagrams of transverse Ising and Bose-Hubbard models. By quantifying the complexity of quantum cellular automata we then demonstrate the applicability of complex network theory to non-equilibrium quantum dynamics. We conclude with a study of student collaboration networks, correlating a student's role in a collaboration network with their grades. This work thus initiates a quantitative theory of quantum complexity and provides a new tool for physics education research. (Abstract shortened by ProQuest.).

  12. Emergence of Persistent Networks in Long-Term Intracranial EEG Recordings

    PubMed Central

    Kramer, Mark A.; Eden, Uri T.; Lepage, Kyle Q.; Kolaczyk, Eric D.; Bianchi, Matt T.; Cash, Sydney S.

    2011-01-01

    Over the past two decades, the increased ability to analyze network relationships among neural structures has provided novel insights into brain function. Most network approaches, however, focus on static representations of the brain's physical or statistical connectivity. Few studies have examined how brain functional networks evolve spontaneously over long epochs of continuous time. To address this we examine functional connectivity networks deduced from continuous long-term electrocorticogram (ECoG) recordings. For a population of 6 human patients, we identify a persistent pattern of connections that form a frequency-band dependent network template, and a set of core connections that appear frequently and together. These structures are robust, emerging from brief time intervals (~100s) regardless of cognitive state. These results suggest that a metastable, frequency-band dependent scaffold of brain connectivity exists from which transient activity emerges and recedes. PMID:22049419

  13. Largest Laplacian eigenvalue predicts the emergence of costly punishment in the evolutionary ultimatum game on networks

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Cao, Lang

    2009-12-01

    In recent years, there has been a growing interest in studying the role of costly punishment in promoting altruistic behaviors among selfish individuals. Rejections in ultimatum bargaining as a metaphor exemplify costly punishment, where the division of a sum of resources proposed by one side may be rejected by the other side, and both sides get nothing. Under a setting of the network of contacts among players, we find that the largest Laplacian eigenvalue of the network determines the critical division of players’ proposals, below which pure punishers who never accept any offers will emerge as a phase transition in the system. The critical division of offers that predicts the emergence of costly punishment is termed as the selfishness tolerance of a network within evolutionary ultimatum game, and extensive numerical simulations on the data of the science collaboration network, and computer-generated small-world/scale-free networks support the analytical findings.

  14. Emergence and coherence of oscillations in star networks of stochastic excitable elements

    NASA Astrophysics Data System (ADS)

    Kromer, Justus A.; Schimansky-Geier, Lutz; Neiman, Alexander B.

    2016-04-01

    We study the emergence and coherence of stochastic oscillations in star networks of excitable elements in which peripheral nodes receive independent random inputs. A biophysical model of a distal branch of sensory neuron in which peripheral nodes of Ranvier are coupled to a central node by myelinated cable segments is used along with a generic model of networked stochastic active rotators. We show that coherent oscillations can emerge due to stochastic synchronization of peripheral nodes and that the degree of coherence can be maximized by tuning the coupling strength and the size of the network. Analytical results are obtained for the strong-coupling regime of the active rotator network. In particular, we show that in the strong-coupling regime, the network dynamics can be described by an effective single active rotator with rescaled parameters and noise.

  15. 'Lyell' Panorama inside Victoria Crater (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    During four months prior to the fourth anniversary of its landing on Mars, NASA's Mars Exploration Rover Opportunity examined rocks inside an alcove called 'Duck Bay' in the western portion of Victoria Crater. The main body of the crater appears in the upper right of this stereo panorama, with the far side of the crater lying about 800 meters (half a mile) away. Bracketing that part of the view are two promontories on the crater's rim at either side of Duck Bay. They are 'Cape Verde,' about 6 meters (20 feet) tall, on the left, and 'Cabo Frio,' about 15 meters (50 feet) tall, on the right. The rest of the image, other than sky and portions of the rover, is ground within Duck Bay.

    Opportunity's targets of study during the last quarter of 2007 were rock layers within a band exposed around the interior of the crater, about 6 meters (20 feet) from the rim. Bright rocks within the band are visible in the foreground of the panorama. The rover science team assigned informal names to three subdivisions of the band: 'Steno,' 'Smith,' and 'Lyell.'

    This view combines many images taken by Opportunity's panoramic camera (Pancam) from the 1,332nd through 1,379th Martian days, or sols, of the mission (Oct. 23 to Dec. 11, 2007). Images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers were mixed to produce this view, which is presented in a false-color stretch to bring out subtle color differences in the scene. Some visible patterns in dark and light tones are the result of combining frames that were affected by dust on the front sapphire window of the rover's camera.

  16. 'Lyell' Panorama inside Victoria Crater (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    During four months prior to the fourth anniversary of its landing on Mars, NASA's Mars Exploration Rover Opportunity examined rocks inside an alcove called 'Duck Bay' in the western portion of Victoria Crater. The main body of the crater appears in the upper right of this stereo panorama, with the far side of the crater lying about 800 meters (half a mile) away. Bracketing that part of the view are two promontories on the crater's rim at either side of Duck Bay. They are 'Cape Verde,' about 6 meters (20 feet) tall, on the left, and 'Cabo Frio,' about 15 meters (50 feet) tall, on the right. The rest of the image, other than sky and portions of the rover, is ground within Duck Bay.

    Opportunity's targets of study during the last quarter of 2007 were rock layers within a band exposed around the interior of the crater, about 6 meters (20 feet) from the rim. Bright rocks within the band are visible in the foreground of the panorama. The rover science team assigned informal names to three subdivisions of the band: 'Steno,' 'Smith,' and 'Lyell.'

    This view combines many images taken by Opportunity's panoramic camera (Pancam) from the 1,332nd through 1,379th Martian days, or sols, of the mission (Oct. 23 to Dec. 11, 2007). Images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers were mixed to produce this view, which is presented in a false-color stretch to bring out subtle color differences in the scene. Some visible patterns in dark and light tones are the result of combining frames that were affected by dust on the front sapphire window of the rover's camera.

  17. Panorama Above 'Perseverance Valley' on Mars

    NASA Image and Video Library

    2017-07-20

    Toward the right side of this enhanced-color scene is a broad notch in the crest of the western rim of Endeavour Crater. Wheel tracks in that area were left by NASA's Mars Exploration Rover Opportunity as it observed "Perseverance Valley" from above in the spring of 2017. The valley is a major destination for the rover's extended mission. It descends out of sight on the inner slope of the rim, extending down and eastward from that notch. Opportunity's panoramic camera (Pancam) took the component images for this view from a position outside the crater during the span of June 7 to June 19, 2017, sols 4753 to 4765 of the rover's work on Mars. This scene includes features that might have been ancient channels from water, ice or wind moving toward the notch in the rim, which might have been a spillway. Perseverance Valley, just on the other side, was likely carved by action of some fluid, such as water, water-lubricated debris, or wind. The mission is investigating to learn more about that process from evidence in place. The panorama spans about three-fourths of a full-circle view, from southeastward on the left, through westward in the middle, to northeastward on the right. High points visible on the rim of Endeavour Crater include "Winnemucca" on the left and "Cape Tribulation" on the right. Winnemucca is part of the "Cape Byron" portion of the crater rim. The horizon at far right extends across the floor of Endeavour Crater, which is about 14 miles (22 kilometers) in diameter. Opportunity has been investigating sites on and near the western rim of Endeavour since 2011, following seven years of exploring smaller craters after its 2004 landing. This view merges exposures taken through three of the Pancam's color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). Color is enhanced in this version to make differences in surface materials more easily visible. The rover team calls this the "Sprained Ankle

  18. Panorama Above 'Perseverance Valley' (Enhanced Color)

    NASA Image and Video Library

    2017-07-20

    Toward the right side of this enhanced-color scene is a broad notch in the crest of the western rim of Endeavour Crater. Wheel tracks in that area were left by NASA's Mars Exploration Rover Opportunity as it observed "Perseverance Valley" from above in the spring of 2017. The valley is a major destination for the rover's extended mission. It descends out of sight on the inner slope of the rim, extending down and eastward from that notch. Opportunity's panoramic camera (Pancam) took the component images for this view from a position outside the crater during the span of June 7 to June 19, 2017, sols 4753 to 4765 of the rover's work on Mars. This scene includes features that might have been ancient channels from water, ice or wind moving toward the notch in the rim, which might have been a spillway. Perseverance Valley, just on the other side, was likely carved by action of some fluid, such as water, water-lubricated debris, or wind. The mission is investigating to learn more about that process from evidence in place. The panorama spans about three-fourths of a full-circle view, from southeastward on the left, through westward in the middle, to northeastward on the right. High points visible on the rim of Endeavour Crater include "Winnemucca" on the left and "Cape Tribulation" on the right. Winnemucca is part of the "Cape Byron" portion of the crater rim. The horizon at far right extends across the floor of Endeavour Crater, which is about 14 miles (22 kilometers) in diameter. Opportunity has been investigating sites on and near the western rim of Endeavour since 2011, following seven years of exploring smaller craters after its 2004 landing. This view merges exposures taken through three of the Pancam's color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). Color is enhanced in this version to make differences in surface materials more easily visible. The rover team calls this the "Sprained Ankle

  19. When is an ecological network complex? Connectance drives degree distribution and emerging network properties

    PubMed Central

    Gravel, Dominique

    2014-01-01

    Connectance and degree distributions are important components of the structure of ecological networks. In this contribution, we use a statistical argument and simple network generating models to show that properties of the degree distribution are driven by network connectance. We discuss the consequences of this finding for (1) the generation of random networks in null-model analyses, and (2) the interpretation of network structure and ecosystem properties in relationship with degree distribution. PMID:24688835

  20. Universality of the emergent scaling in finite random binary percolation networks

    PubMed Central

    2017-01-01

    In this paper we apply lattice models of finite binary percolation networks to examine the effects of network configuration on macroscopic network responses. We consider both square and rectangular lattice structures in which bonds between nodes are randomly assigned to be either resistors or capacitors. Results show that for given network geometries, the overall normalised frequency-dependent electrical conductivities for different capacitor proportions are found to converge at a characteristic frequency. Networks with sufficiently large size tend to share the same convergence point uninfluenced by the boundary and electrode conditions, can be then regarded as homogeneous media. For these networks, the span of the emergent scaling region is found to be primarily determined by the smaller network dimension (width or length). This study identifies the applicability of power-law scaling in random two phase systems of different topological configurations. This understanding has implications in the design and testing of disordered systems in diverse applications. PMID:28207872

  1. Universality of the emergent scaling in finite random binary percolation networks.

    PubMed

    Zhai, Chongpu; Hanaor, Dorian; Gan, Yixiang

    2017-01-01

    In this paper we apply lattice models of finite binary percolation networks to examine the effects of network configuration on macroscopic network responses. We consider both square and rectangular lattice structures in which bonds between nodes are randomly assigned to be either resistors or capacitors. Results show that for given network geometries, the overall normalised frequency-dependent electrical conductivities for different capacitor proportions are found to converge at a characteristic frequency. Networks with sufficiently large size tend to share the same convergence point uninfluenced by the boundary and electrode conditions, can be then regarded as homogeneous media. For these networks, the span of the emergent scaling region is found to be primarily determined by the smaller network dimension (width or length). This study identifies the applicability of power-law scaling in random two phase systems of different topological configurations. This understanding has implications in the design and testing of disordered systems in diverse applications.

  2. Co-operation in Research on Trends in the Development of Occupations and Qualifications in the European Union. Report on the Current State, Results and Development of the CEDEFOP Ciretoq Network. Interim Report, CEDEFOP Panorama.

    ERIC Educational Resources Information Center

    Sellin, Burkart

    The European Centre for the Development of Vocational Training has developed a thematic network on the Circle for Research Cooperation on Trends in Occupations and Qualifications (Ciretoq) to follow up its preliminary work on trends in qualifications and certification. On the basis of available surveys and surveys evaluated by Ciretoq, the…

  3. Co-operation in Research on Trends in the Development of Occupations and Qualifications in the European Union. Report on the Current State, Results and Development of the CEDEFOP Ciretoq Network. Interim Report, CEDEFOP Panorama.

    ERIC Educational Resources Information Center

    Sellin, Burkart

    The European Centre for the Development of Vocational Training has developed a thematic network on the Circle for Research Cooperation on Trends in Occupations and Qualifications (Ciretoq) to follow up its preliminary work on trends in qualifications and certification. On the basis of available surveys and surveys evaluated by Ciretoq, the…

  4. Using social network analysis to understand Missouri's system of public health emergency planners.

    PubMed

    Harris, Jenine K; Clements, Bruce

    2007-01-01

    Effective response to large-scale public health threats requires well-coordinated efforts among individuals and agencies. While guidance is available to help states put emergency planning programs into place, little has been done to evaluate the human infrastructure that facilitates successful implementation of these programs. This study examined the human infrastructure of the Missouri public health emergency planning system in 2006. The Center for Emergency Response and Terrorism (CERT) at the Missouri Department of Health and Senior Services has responsibility for planning, guiding, and funding statewide emergency response activities. Thirty-two public health emergency planners working primarily in county health departments contract with CERT to support statewide preparedness. We surveyed the planners to determine whom they communicate with, work with, seek expertise from, and exchange guidance with regarding emergency preparedness in Missouri. Most planners communicated regularly with planners in their region but seldom with planners outside their region. Planners also reported working with an average of 12 local entities (e.g., emergency management, hospitals/ clinics). Planners identified the following leaders in Missouri's public health emergency preparedness system: local public health emergency planners, state epidemiologists, the state vaccine and grant coordinator, regional public health emergency planners, State Emergency Management Agency area coordinators, the state Strategic National Stockpile coordinator, and Federal Bureau of Investigation Weapons of Mass Destruction coordinators. Generally, planners listed few federal-level or private-sector individuals in their emergency preparedness networks. While Missouri public health emergency planners maintain large and varied emergency preparedness networks, there are opportunities for strengthening existing ties and seeking additional connections.

  5. Survey of the WHO-REMPAN network's capability for strengthening preparedness for radiological and nuclear emergencies.

    PubMed

    Kumagai, Atsushi; Carr, Zhanat; Akira, Ohtsuru; Christie, Derek; Yamashita, Shunichi

    2012-10-01

    This paper investigates the capacity of the World Health Organization (WHO)-REMPAN network in responding to radiological incidents and nuclear emergencies. A survey developed by the WHO Secretariat and Nagasaki University was sent to all 40 WHO-REMPAN collaborating centres and liaison institutes in order to verify the current situation of the network, identify needs and collect suggestions for future improvements. Most of the responding institutions said they were satisfied with the current status of the network. However, several responses to the survey indicate that better internal communication is needed, as well as a position document to specify the roles, rights and responsibilities of the network members.

  6. Emergency Department Trends from the Drug Abuse Warning Network, Preliminary Estimates January-June 2002. Drug Abuse Warning Network Series.

    ERIC Educational Resources Information Center

    Substance Abuse and Mental Health Services Administration (DHHS/PHS), Rockville, MD. Office of Applied Studies.

    This publication presents estimates of drug-related emergency department (ED) episodes from the Drug Abuse Warning Network (DAWN) from 1994 through the first half of 2001. DAWN is an ongoing, national data system that collects information on drug-related visits to EDs from a national probability sample of hospitals. This publication marks a major…

  7. Applying artificial neural networks to predict communication risks in the emergency department.

    PubMed

    Bagnasco, Annamaria; Siri, Anna; Aleo, Giuseppe; Rocco, Gennaro; Sasso, Loredana

    2015-10-01

    To describe the utility of artificial neural networks in predicting communication risks. In health care, effective communication reduces the risk of error. Therefore, it is important to identify the predictive factors of effective communication. Non-technical skills are needed to achieve effective communication. This study explores how artificial neural networks can be applied to predict the risk of communication failures in emergency departments. A multicentre observational study. Data were collected between March-May 2011 by observing the communication interactions of 840 nurses with their patients during their routine activities in emergency departments. The tools used for our observation were a questionnaire to collect personal and descriptive data, level of training and experience and Guilbert's observation grid, applying the Situation-Background-Assessment-Recommendation technique to communication in emergency departments. A total of 840 observations were made on the nurses working in the emergency departments. Based on Guilbert's observation grid, the output variables is likely to influence the risk of communication failure were 'terminology'; 'listening'; 'attention' and 'clarity', whereas nurses' personal characteristics were used as input variables in the artificial neural network model. A model based on the multilayer perceptron topology was developed and trained. The receiver operator characteristic analysis confirmed that the artificial neural network model correctly predicted the performance of more than 80% of the communication failures. The application of the artificial neural network model could offer a valid tool to forecast and prevent harmful communication errors in the emergency department. © 2015 John Wiley & Sons Ltd.

  8. Mars Rover Opportunity Panorama of Rocheport Stereo

    NASA Image and Video Library

    2017-04-19

    A ridge called "Rocheport" on the western rim of Mars' Endeavour Crater spans this stereo scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity. The mosaic combines views from the left eye and right eye of the Pancam to appear three-dimensional when seen through blue-red glasses with the red lens on the left. The view extends from south-southeast on the left to north on the right. Rocheport is near the southern end of an Endeavour rim segment called "Cape Tribulation." The Pancam took the component images for this panorama on Feb. 25, 2017, during the 4,654th Martian day, or sol, of Opportunity's work on Mars. Opportunity began exploring the western rim of Endeavour Crater in 2011 and reached the north end of Cape Tribulation in 2014. This ridge bears some grooves on its side, such as between the two dark shoulders angling down near the left edge of the scene. For scale, those shoulders are about 10 to 16 feet (3 to 5 meters) long. The grooves might have been carved long ago by water or ice or wind. The Rocheport name comes from a riverbank town in Missouri along the route of Lewis and Clark's "Corps of Discovery" Expedition. https://photojournal.jpl.nasa.gov/catalog/PIA21491

  9. Hippo in Super Resolution from Super Panorama

    NASA Image and Video Library

    1998-07-03

    This view of the "Hippo," 25 meters to the west of the lander, was produced by combining the "Super Panorama" frames from the IMP camera. Super resolution was applied to help to address questions about the texture of this rock and what it might tell us about its mode of origin. The composite color frames that make up this anaglyph were produced for both the right and left eye of the IMP. These composites consist of more than 15 frames per eye (because multiple sequences covered the same area), taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be. These panchromatic frames were then colorized with the red, green, and blue filtered images from the same sequence. The color balance was adjusted to approximate the true color of Mars. The anaglyph view was produced by combining the left with the right eye color composite frames by assigning the left eye composite view to the red color plane and the right eye composite view to the green and blue color planes (cyan), to produce a stereo anaglyph mosaic. This mosaic can be viewed in 3-D on your computer monitor or in color print form by wearing red-blue 3-D glasses. http://photojournal.jpl.nasa.gov/catalog/PIA01421

  10. Area of 360 degree color panorama

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This portion of the 360-degree gallery panorama shows Pathfinder's rear ramp, the rock Barnacle Bill at left, and rover tracks leading up to the large rock Yogi. Rover Sojourner is seen using its Alpha Proton X-Ray Spectrometer (APXS) instrument to study Yogi's composition. Rover tracks and circular patterns in the soil are from Sojourner's soil mechanics experiments, in which varying amounts of pressure were applied to the rover's wheels in order to determine physical properties of the soil. The image was taken by the Imager for Mars Pathfinder (IMP) over sols 8, 9, and 10, using the red, green and blue filters.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  11. Mars Rover Opportunity Panorama of Rocheport.

    NASA Image and Video Library

    2017-04-19

    A ridge called "Rocheport" on the western rim of Mars' Endeavour Crater spans this mosaic of images from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity. The view extends from south-southeast on the left to north on the right. Rocheport is near the southern end of an Endeavour rim segment called "Cape Tribulation." The Pancam took the component images for this panorama on Feb. 25, 2017, during the 4,654th Martian day, or sol, of Opportunity's work on Mars. Opportunity began exploring the western rim of Endeavour Crater in 2011 and reached the north end of Cape Tribulation in 2014. This ridge bears some grooves on its side, such as between the two dark shoulders angling down near the left edge of the scene. For scale, those shoulders are about 10 to 16 feet (3 to 5 meters) long. The grooves might have been carved long ago by water or ice or wind. The view merges exposures taken through three of the Pancam's color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). It is presented in approximately true color. The Rocheport name comes from a riverbank town in Missouri along the route of Lewis and Clark's "Corps of Discovery" Expedition. https://photojournal.jpl.nasa.gov/catalog/PIA21493

  12. Topology of Innovation Spaces in the Knowledge Networks Emerging through Questions-And-Answers.

    PubMed

    Andjelković, Miroslav; Tadić, Bosiljka; Mitrović Dankulov, Marija; Rajković, Milan; Melnik, Roderick

    2016-01-01

    The communication processes of knowledge creation represent a particular class of human dynamics where the expertise of individuals plays a substantial role, thus offering a unique possibility to study the structure of knowledge networks from online data. Here, we use the empirical evidence from questions-and-answers in mathematics to analyse the emergence of the network of knowledge contents (or tags) as the individual experts use them in the process. After removing extra edges from the network-associated graph, we apply the methods of algebraic topology of graphs to examine the structure of higher-order combinatorial spaces in networks for four consecutive time intervals. We find that the ranking distributions of the suitably scaled topological dimensions of nodes fall into a unique curve for all time intervals and filtering levels, suggesting a robust architecture of knowledge networks. Moreover, these networks preserve the logical structure of knowledge within emergent communities of nodes, labeled according to a standard mathematical classification scheme. Further, we investigate the appearance of new contents over time and their innovative combinations, which expand the knowledge network. In each network, we identify an innovation channel as a subgraph of triangles and larger simplices to which new tags attach. Our results show that the increasing topological complexity of the innovation channels contributes to network's architecture over different time periods, and is consistent with temporal correlations of the occurrence of new tags. The methodology applies to a wide class of data with the suitable temporal resolution and clearly identified knowledge-content units.

  13. ANMCO/SIT Consensus Document: telemedicine for cardiovascular emergency networks

    PubMed Central

    Gulizia, Michele Massimo; Gabrielli, Domenico; Sicuro, Marco; De Gennaro, Luisa; Giammaria, Massimo; Grieco, Niccolò Brenno; Grosseto, Daniele; Mantovan, Roberto; Mazzanti, Marco; Menotti, Alberto; Brunetti, Natale Daniele; Severi, Silva; Russo, Giancarmine; Gensini, Gian Franco

    2017-01-01

    Abstract Telemedicine has deeply innovated the field of emergency cardiology, particularly the treatment of acute myocardial infarction. The ability to record an ECG in the early prehospital phase, thus avoiding any delay in diagnosing myocardial infarction with direct transfer to the cath-lab for primary angioplasty, has proven to significantly reduce treatment times and mortality. This consensus document aims to analyse the available evidence and organizational models based on a support by telemedicine, focusing on technical requirements, education, and legal aspects. PMID:28751844

  14. Geographical Influences of an Emerging Network of Gang Rivalries

    DTIC Science & Technology

    2011-03-17

    PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...available, interventions may fail to be implemented as planned. This is evident in the work of [71]. Obtaining complete and valid data sets is a common...pure network and an agent-based approach. Our goal in this work is to understand how long-term rivalries among gangs develop by using a model

  15. Emergence of Hierarchy on a Network of Complementary Agents

    NASA Astrophysics Data System (ADS)

    Copelli, M.; Dos Santos, R. M. Zorzenon; Martins, J. S. Sá

    Complementarity is one of the main features underlying the interactions in biological and biochemical systems. Inspired by those systems we propose a model for the dynamical evolution of a system composed of agents that interact due to their complementary attributes rather than their similarities. Each agent is represented by a bit-string and has an activity associated to it; the coupling among complementary peers depends on their activity. The connectivity of the system changes in time respecting the constraint of complementarity. We observe the formation of a network of active agents whose stability depends on the rate at which activity of agents diffuses in the system. The model exhibits a nonequilibrium phase transition between the ordered phase, where a stable network is generated, and a disordered phase characterized by the absence of correlation among the agents. The ordered phase exhibits multi-modal distributions of connectivity and activity, indicating a hierarchy of interaction among different populations characterized by different degrees of activity. This model may be used to study the hierarchy observed in social organizations.

  16. Emerging complexity in the denitrification regulatory network of Bradyrhizobium japonicum.

    PubMed

    Torres, María J; Bueno, Emilio; Mesa, Socorro; Bedmar, Eulogio J; Delgado, María J

    2011-01-01

    Bradyrhizobium japonicum is a Gram-negative soil bacterium symbiotically associated with soya bean plants, which is also able to denitrify under free-living and symbiotic conditions. In B. japonicum, the napEDABC, nirK, norCBQD and nosRZDYFLX genes which encode reductases for nitrate, nitrite, nitric oxide and nitrous oxide respectively are required for denitrification. Similar to many other denitrifiers, expression of denitrification genes in B. japonicum requires both oxygen limitation and the presence of nitrate or a derived nitrogen oxide. In B. japonicum, a sophisticated regulatory network consisting of two linked regulatory cascades co-ordinates the expression of genes required for microaerobic respiration (the FixLJ/FixK2 cascade) and for nitrogen fixation (the RegSR/NifA cascade). The involvement of the FixLJ/FixK2 regulatory cascade in the microaerobic induction of the denitrification genes is well established. In addition, the FNR (fumarase and nitrate reduction regulator)/CRP(cAMP receptor protein)-type regulator NnrR expands the FixLJ/FixK2 regulatory cascade by an additional control level. A role for NifA is suggested in this process by recent experiments which have shown that it is required for full expression of denitrification genes in B. japonicum. The present review summarizes the current understanding of the regulatory network of denitrification in B. japonicum.

  17. Modular topology emerges from plasticity in a minimalistic excitable network model

    NASA Astrophysics Data System (ADS)

    Damicelli, Fabrizio; Hilgetag, Claus C.; Hütt, Marc-Thorsten; Messé, Arnaud

    2017-04-01

    Topological features play a major role in the emergence of complex brain network dynamics underlying brain function. Specific topological properties of brain networks, such as their modular organization, have been widely studied in recent years and shown to be ubiquitous across spatial scales and species. However, the mechanisms underlying the generation and maintenance of such features are still unclear. Using a minimalistic network model with excitable nodes and discrete deterministic dynamics, we studied the effects of a local Hebbian plasticity rule on global network topology. We found that, despite the simple model set-up, the plasticity rule was able to reorganize the global network topology into a modular structure. The structural reorganization was accompanied by enhanced correlations between structural and functional connectivity, and the final network organization reflected features of the dynamical model. These findings demonstrate the potential of simple plasticity rules for structuring the topology of brain connectivity.

  18. Emergence of disassortative mixing from pruning nodes in growing scale-free networks

    PubMed Central

    Wang, Sheng-Jun; Wang, Zhen; Jin, Tao; Boccaletti, Stefano

    2014-01-01

    Disassortative mixing is ubiquitously found in technological and biological networks, while the corresponding interpretation of its origin remains almost virgin. We here give evidence that pruning the largest-degree nodes of a growing scale-free network has the effect of decreasing the degree correlation coefficient in a controllable and tunable way, while keeping both the trait of a power-law degree distribution and the main properties of network's resilience and robustness under failures or attacks. The essence of these observations can be attributed to the fact the deletion of large-degree nodes affects the delicate balance of positive and negative contributions to degree correlation in growing scale-free networks, eventually leading to the emergence of disassortativity. Moreover, these theoretical prediction will get further validation in the empirical networks. We support our claims via numerical results and mathematical analysis, and we propose a generative model for disassortative growing scale-free networks. PMID:25520244

  19. Emergence of disassortative mixing from pruning nodes in growing scale-free networks.

    PubMed

    Wang, Sheng-Jun; Wang, Zhen; Jin, Tao; Boccaletti, Stefano

    2014-12-18

    Disassortative mixing is ubiquitously found in technological and biological networks, while the corresponding interpretation of its origin remains almost virgin. We here give evidence that pruning the largest-degree nodes of a growing scale-free network has the effect of decreasing the degree correlation coefficient in a controllable and tunable way, while keeping both the trait of a power-law degree distribution and the main properties of network's resilience and robustness under failures or attacks. The essence of these observations can be attributed to the fact the deletion of large-degree nodes affects the delicate balance of positive and negative contributions to degree correlation in growing scale-free networks, eventually leading to the emergence of disassortativity. Moreover, these theoretical prediction will get further validation in the empirical networks. We support our claims via numerical results and mathematical analysis, and we propose a generative model for disassortative growing scale-free networks.

  20. The Architecture of Complex Systems: Emergence of Scaling in Real Networks

    NASA Astrophysics Data System (ADS)

    Barabási, Albert-László

    2002-03-01

    Networks with complex topology describe systems as diverse as the cell or the World Wide Web. The analysis of the metabolic and protein network of various organisms show that cells and complex man-made networks, such as the Internet or the world wide web, share the same large-scale topology. In the past few years we have learned that the emergence of these networks is driven by self-organizing processes that are governed by simple but generic laws, that can be captured using the tools of statistical mechanics. The goal of the talk is to briefly review these advances, aiming to uncover the organizing principles that govern the topology of complex networks. For more information see http://www.nd.edu/ networks.

  1. A Survey on Security and Privacy in Emerging Sensor Networks: From Viewpoint of Close-Loop

    PubMed Central

    Zhang, Lifu; Zhang, Heng

    2016-01-01

    Nowadays, as the next generation sensor networks, Cyber-Physical Systems (CPSs) refer to the complex networked systems that have both physical subsystems and cyber components, and the information flow between different subsystems and components is across a communication network, which forms a closed-loop. New generation sensor networks are found in a growing number of applications and have received increasing attention from many inter-disciplines. Opportunities and challenges in the design, analysis, verification and validation of sensor networks co-exists, among which security and privacy are two important ingredients. This paper presents a survey on some recent results in the security and privacy aspects of emerging sensor networks from the viewpoint of the closed-loop. This paper also discusses several future research directions under these two umbrellas. PMID:27023559

  2. A Survey on Security and Privacy in Emerging Sensor Networks: From Viewpoint of Close-Loop.

    PubMed

    Zhang, Lifu; Zhang, Heng

    2016-03-26

    Nowadays, as the next generation sensor networks, Cyber-Physical Systems (CPSs) refer to the complex networked systems that have both physical subsystems and cyber components, and the information flow between different subsystems and components is across a communication network, which forms a closed-loop. New generation sensor networks are found in a growing number of applications and have received increasing attention from many inter-disciplines. Opportunities and challenges in the design, analysis, verification and validation of sensor networks co-exists, among which security and privacy are two important ingredients. This paper presents a survey on some recent results in the security and privacy aspects of emerging sensor networks from the viewpoint of the closed-loop. This paper also discusses several future research directions under these two umbrellas.

  3. Emergent Data-Networks from Long-Tail Collections

    NASA Astrophysics Data System (ADS)

    Elag, M.; Kumar, P.; Marini, L.; Hedstrom, M.; Myers, J. D.; Plale, B. A.

    2014-12-01

    Synthesis of scientific data coming from individuals and small research group activities, known as long-tail data, with the existing resources elucidates useful scientific knowledge. In general, long-tail data are irreplaceable, expensive to reproduce, infrequently reused, follow no predefined data model, and they are often bounded in different information systems. The contextual relationships across the many attributes among such data in a data collection are herewith defined as data-network. These relationships have the potential to provide deep insights for the scientific challenges that require multidisciplinary interaction by identifying a new data object in the broader context of other data objects, and characterizing its spatial and temporal dependencies with others. Despite the advancement that has been achieved in various geoscience information models, it is not always straightforward to identify and characterize the contextual relationships among long-tail data because information models focus on profiling data attributes more than exploring data tie-ins. To address this need, we have designed the Long Tail Data Networks (LTDN) engine, which depends on a context-based approach to analyze the data attributes, predict data contextual relationships, and publish these relationships as a RDF graph. The engine groups data using their geographic location in spatial collections, and applies binary logic predicates to analyze the spatial, temporal, and variable attributes associated with data entities of each spatial collection to infer their relationships. Here we present the design of the LTDN engine and demonstrate its application for predicting the latent connectivity among long-tail data collections. To demonstrate the capabilities of the engine, we implemented this approach within the Sustainable Environment Actionable Data (SEAD) environment, an open-source semantic content repository that supports long-tail data curation and preservation, and show how

  4. An Energy-Efficient MAC Protocol for Medical Emergency Monitoring Body Sensor Networks.

    PubMed

    Zhang, Chongqing; Wang, Yinglong; Liang, Yongquan; Shu, Minglei; Chen, Changfang

    2016-03-17

    Medical emergency monitoring body sensor networks (BSNs) monitor the occurrence of medical emergencies and are helpful for the daily care of the elderly and chronically ill people. Such BSNs are characterized by rare traffic when there is no emergency occurring, high real-time and reliable requirements of emergency data and demand for a fast wake-up mechanism for waking up all nodes when an emergency happens. A beacon-enabled MAC protocol is specially designed to meet the demands of medical emergency monitoring BSNs. The rarity of traffic is exploited to improve energy efficiency. By adopting a long superframe structure to avoid unnecessary beacons and allocating most of the superframe to be inactive periods, the duty cycle is reduced to an extremely low level to save energy. Short active time slots are interposed into the superframe and shared by all of the nodes to deliver the emergency data in a low-delay and reliable way to meet the real-time and reliable requirements. The interposition slots can also be used by the coordinator to broadcast network demands to wake-up all nodes in a low-delay and energy-efficient way. Experiments display that the proposed MAC protocol works well in BSNs with low emergency data traffic.

  5. An Energy-Efficient MAC Protocol for Medical Emergency Monitoring Body Sensor Networks

    PubMed Central

    Zhang, Chongqing; Wang, Yinglong; Liang, Yongquan; Shu, Minglei; Chen, Changfang

    2016-01-01

    Medical emergency monitoring body sensor networks (BSNs) monitor the occurrence of medical emergencies and are helpful for the daily care of the elderly and chronically ill people. Such BSNs are characterized by rare traffic when there is no emergency occurring, high real-time and reliable requirements of emergency data and demand for a fast wake-up mechanism for waking up all nodes when an emergency happens. A beacon-enabled MAC protocol is specially designed to meet the demands of medical emergency monitoring BSNs. The rarity of traffic is exploited to improve energy efficiency. By adopting a long superframe structure to avoid unnecessary beacons and allocating most of the superframe to be inactive periods, the duty cycle is reduced to an extremely low level to save energy. Short active time slots are interposed into the superframe and shared by all of the nodes to deliver the emergency data in a low-delay and reliable way to meet the real-time and reliable requirements. The interposition slots can also be used by the coordinator to broadcast network demands to wake-up all nodes in a low-delay and energy-efficient way. Experiments display that the proposed MAC protocol works well in BSNs with low emergency data traffic. PMID:26999145

  6. GPs’ use of defibrillators and the national radio network in emergency primary healthcare in Norway

    PubMed Central

    Zakariassen, Erik; Hunskaar, Steinar

    2008-01-01

    Objective To study the geographic size of out-of-hours districts, the availability of defibrillators and use of the national radio network in Norway. Design Survey. Setting The emergency primary healthcare system in Norway. Subjects A total of 282 host municipalities responsible for 260 out-of-hours districts. Main outcome measures Size of out-of-hours districts, use of national radio network and access to a defibrillator in emergency situations. Results The out-of-hours districts have a wide range of areas, which gives a large variation in driving time for doctors on call. The median longest transport time for doctors in Norway is 45 minutes. In 46% of out-of-hours districts doctors bring their own defibrillator on emergency callouts. Doctors always use the national radio network in 52% of out-of-hours districts. Use of the radio network and access to a defibrillator are significantly greater in out-of-hours districts with a host municipality of fewer then 5000 inhabitants compared with host municipalities of more than 20 000 inhabitants. Conclusion In half of out-of-hours districts doctors on call always use the national radio network. Doctors in out-of-hours districts with a host municipality of fewer than 5000 inhabitants are in a better state of readiness to attend an emergency, compared with doctors working in larger host municipalities. PMID:18570012

  7. 360 Degree Panorama Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is the first contiguous, uniform 360-degree color panorama taken by the Imager for Mars Pathfinder (IMP) over the course of sols 8, 9, and 10 (Martian days). Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama. At left is a lander petal and a metallic mast which is a portion of the low-gain antenna. On the horizon the double 'Twin Peaks' are visible, about 1-2 kilometers away. The rock 'Couch' is the dark, curved rock at right of Twin Peaks. Another lander petal is at left-center, showing the fully deployed forward ramp at far left, and rear ramp at right, which rover Sojourner used to descend to the surface of Mars on July 5. Immediately to the left of the rear ramp is the rock Barnacle Bill, which scientists found to be andesitic, possibly indicating that it is a volcanic rock (a true andesite) or a physical mixture of particles. Just beyond Barnacle Bill, rover tracks lead to Sojourner, shown using its Alpha Proton X-Ray Spectrometer (APXS) instrument to study the large rock Yogi. Yogi, low in quartz content, appears to be more primitive than Barnacle Bill, and appeared more like the common basalts found on Earth. The tracks and circular pattern in the soil leading up to Yogi were part of Sojourner's soil mechanics experiments, in which varying amounts of pressure were applied to the wheels in order to determine physical properties of the soil. During its traverse to Yogi the rover stirred the soil and exposed material from several centimeters in depth. During one of the turns to deploy Sojourner's Alpha Proton X-Ray Spectrometer, the wheels dug particularly deeply and exposed white material. Spectra of this white material show it is virtually identical to the rock Scooby Doo, and such white material may underlie much of the site. Deflated airbags are visible at the perimeter of all three lander petals. The IMP is a stereo imaging system with color

  8. New 360 degree color gallery panorama

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is the first contiguous, uniform 360-degree color panorama taken by the Imager for Mars Pathfinder (IMP) over the course of sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama. At left is a lander petal and a metallic mast which is a portion of the low-gain antenna. On the horizon the double 'Twin Peaks' are visible, about 1-2 kilometers away. The rock 'Couch' is the dark, curved rock at right of Twin Peaks. Another lander petal is at left-center, showing the fully deployed forward ramp at far left, and rear ramp at right, which rover Sojourner used to descend to the surface of Mars on July 5. Immediately to the left of the rear ramp is the rock Barnacle Bill, which scientists found to be andesitic, possibly indicating that it is a volcanic rock (a true andesite) or a physical mixture of particles. Just beyond Barnacle Bill, rover tracks lead to Sojourner, shown using its Alpha Proton X-Ray Spectrometer (APXS) instrument to study the large rock Yogi. Yogi, low in quartz content, appears to be more primitive than Barnacle Bill, and appeared more like the common basalts found on Earth. The tracks and circular pattern in the soil leading up to Yogi were part of Sojourner's soil mechanics experiments, in which varying amounts of pressure were applied to the wheels in order to determine physical properties of the soil. During its traverse to Yogi the rover stirred the soil and exposed material from several centimeters in depth. During one of the turns to deploy Sojourner's Alpha Proton X-Ray Spectrometer, the wheels dug particularly deeply and exposed white material. Spectra of this white material show it is virtually identical to the rock Scooby Doo, and such white material may underlie much of the site. Deflated airbags are visible at the perimeter of all three lander petals.

    The IMP is a stereo imaging system with color capability

  9. Southern Half of Spirit's 'Bonestell' Panorama (Anaglyph)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This stereo, 180-degree panorama shows the southward vista from the location where Spirit is spending its third Martian winter inside Mars' Gusev Crater. The rover's overwintering location is on the northern edge of a low plateau informally called 'Home Plate,' which is about 80 meters or 260 feet in diameter.

    The view combines a stereo pair so that it appears three-dimensional when seen through blue-red glasses.

    Spirit took the first of the images that are combined into this view during the mission's 1,477th Martian day, or sol, (February 28, 2008) two weeks after the rover made its last move to reach the location where it would stop driving for the winter. Solar energy at Gusev Crater is so limited during the Martian winter that Spirit does not generate enough electricity to drive, nor even enough to take many images per day. The last frame for this mosaic was taken on Sol 1599 (July 2, 2008). The rover team plans for Spirit to finish taking images for the northern half of the scene during the Martian spring.

    The northwestern edge of Home Plate is visible in the right foreground. The blockier, more sharply shadowed texture there is layered sandstone whose layering is tilted inward toward the edge of the Home Plate platform. A dark rock on top of Home Plate in that area is a porous volcanic basalt unlike rocks nearby. The northeastern edge of Home Plate is visible in the left foreground. Spirit first climbed onto Home Plate on that region, in early 2006.

    Rover tracks from driving by Spirit are visible on Home plate in the center and right of the image. These were made during Spirit's second exploration on top of the plateau, which began when Spirit climbed onto the southern edge of Home Plate in September, 2007.

    In the center foreground, the turret of tools at the end of Spirit's robotic arm appears in duplicate because the arm was repositioned between the days when the images making up that part of the mosaic were taken.

    On the

  10. Panorama Above 'Perseverance Valley' on Mars (Stereo)

    NASA Image and Video Library

    2017-07-20

    This June 2017 stereo scene from NASA's Mars Exploration Rover Opportunity rover shows the area just above "Perseverance Valley" on the rim of Endeavour Crater. The view combines images from the left eye and right eye of the rover's panoramic camera (Pancam) to appear three-dimensional when seen through blue-red glasses with the red lens on the left. Toward the right side of the scene is a broad notch in the crest of the crater's rim. Opportunity left wheel tracks in that area as it observed Perseverance Valley from above in the spring of 2017. The valley is a major destination for the rover's extended mission. It descends out of sight on the inner slope of the rim, extending down and eastward from that notch. Opportunity's Pancam took the component images for this view from a position outside the crater during the span of June 7 to June 19, 2017, sols 4753 to 4765 of the rover's work on Mars. This scene includes features that might have been ancient channels from water, ice or wind moving toward the notch in the rim, which might have been a spillway. Perseverance Valley, just on the other side, was likely carved by action of some fluid, such as water, water-lubricated debris, or wind. The mission is investigating to learn more about that process from evidence in place. The panorama spans about three-fourths of a full-circle view, from southeastward on the left, through westward in the middle, to northeastward on the right. High points visible on the rim of Endeavour Crater include "Winnemucca" on the left and "Cape Tribulation" on the right. Winnemucca is part of the "Cape Byron" portion of the crater rim. The horizon at far right extends across the floor of Endeavour Crater, which is about 14 miles (22 kilometers) in diameter. Opportunity has been investigating sites on and near the western rim of Endeavour since 2011, following seven years of exploring smaller craters after its 2004 landing The rover team calls this the "Sprained Ankle" panorama because the

  11. Mars Rover Opportunity Panorama of Marathon Valley

    NASA Image and Video Library

    2016-06-14

    "Marathon Valley" on Mars opens northeastward to a view across the floor of Endeavour Crater in this scene from the panoramic camera (Pancam) of NASA's Mars Exploration Rover Opportunity. The scene merges multiple Pancam exposures taken during the period April 16 through May 15, 2016, corresponding to sols (Martian days) 4,347 through 4,375 of Opportunity's work on Mars. It spans from north, at the left, to west-southwest, at the right. The high point in the right half of the scene is "Knudsen Ridge," which forms part of the southern edge of Marathon Valley. Portions of the northeastern and eastern rim of Endeavour crater appear on the distant horizon. Endeavour Crater is 14 miles (22 kilometers) in diameter. The fractured texture of Marathon Valley's floor is visible in the foreground. The view merges exposures taken through three of the Pancam's color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). It is presented in approximately true color. The rover team calls this image the mission's "Sacagawea Panorama," for the Lemhi Shoshone woman, also commemorated on U.S. dollar coins, whose assistance to the Lewis and Clark expedition helped enable its successes in 1804-1806. Many rocks and other features in Marathon Valley were informally named for members of Lewis and Clark's "Corps of Discovery" expedition. Opportunity entered Marathon Valley in July 2015. The valley's informal name was chosen because Opportunity's arrival at this point along the western rim of Endeavour Crater coincided closely with the rover surpassing marathon-footrace distance in its total driving odometry since landing on Mars in January 2004. The team's planned investigations in the valley were nearing completion when the component images for this scene were taken. http://photojournal.jpl.nasa.gov/catalog/PIA20749

  12. 360-degree panorama in 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This 360-degree panorama was taken in stereo by the deployed Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses (red left lens, blue right lens) are necessary to help identify surface detail. All three petals, the perimeter of the deflated airbags, deployed rover Sojourner, forward and backward ramps and prominent surface features are visible, including the double Twin Peaks at the horizon. Sojourner would later investigate the rock Barnacle Bill just to its left in this image, and the larger rock Yogi at its forward right.

    The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. Stereoscopic imaging brings exceptional clarity and depth to many of the features in this image, particularly the ridge beyond the far left petal and the large rock Yogi. The curvature and misalignment of several section are due to image parallax.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  13. The research of emergency managers’ risk attitude based on genetic neural network

    NASA Astrophysics Data System (ADS)

    Pan, Chen; Jia, Chuanliang; Su, Jie; Chen, Junlin

    2017-08-01

    Since the 21st century, the sudden emergencies occurred around the world. The decision which emergency managers made in the emergency environment is actually a risk decision-making. And decision-makers will be affected by its risk attitude in the risk decision-making. The paper puts forward a kind of forecasting method of risk attitudes of emergency managers, which are influenced by various factors such as their own gender, age, training experiences, treatment experiences, actual average accuracy and self-confidence and so on. Based on the questionnaire results from Kunming and Wuhan, the above six factors were chosen as the input variables of the BP neural network model and the risk attitude values as the output variable. Genetic algorithm was used to optimize the weights and thresholds of the neural network and establish BP Neural network prediction model of emergency managers. The results of risk attitude value prediction show that the GA-BP is a more effective and accurate method to predict emergency managers’ risk attitude, which can provide the reference for the risk managers’ risk attitude prediction and more efficient management.

  14. How to Trigger Emergence and Self-Organisation in Learning Networks

    NASA Astrophysics Data System (ADS)

    Brouns, Francis; Fetter, Sibren; van Rosmalen, Peter

    The previous chapters of this section discussed why the social structure of Learning Networks is important and present guidelines on how to maintain and allow the emergence of communities in Learning Networks. Chapter 2 explains how Learning Networks rely on social interaction and active participations of the participants. Chapter 3 then continues by presenting guidelines and policies that should be incorporated into Learning Network Services in order to maintain existing communities by creating conditions that promote social interaction and knowledge sharing. Chapter 4 discusses the necessary conditions required for knowledge sharing to occur and to trigger communities to self-organise and emerge. As pointed out in Chap. 4, ad-hoc transient communities facilitate the emergence of social interaction in Learning Networks, self-organising them into communities, taking into account personal characteristics, community characteristics and general guidelines. As explained in Chap. 4 community members would benefit from a service that brings suitable people together for a specific purpose, because it will allow the participant to focus on the knowledge sharing process by reducing the effort or costs. In the current chapter, we describe an example of a peer support Learning Network Service based on the mechanism of peer tutoring in ad-hoc transient communities.

  15. Acquisition of stereo panoramas for display in VR environments

    NASA Astrophysics Data System (ADS)

    Ainsworth, Richard A.; Sandin, Daniel J.; Schulze, Jurgen P.; Prudhomme, Andrew; DeFanti, Thomas A.; Srinivasan, Madhusudhanan

    2011-03-01

    Virtual reality systems are an excellent environment for stereo panorama displays. The acquisition and display methods described here combine high-resolution photography with surround vision and full stereo view in an immersive environment. This combination provides photographic stereo-panoramas for a variety of VR displays, including the StarCAVE, NexCAVE, and CORNEA. The zero parallax point used in conventional panorama photography is also the center of horizontal and vertical rotation when creating photographs for stereo panoramas. The two photographically created images are displayed on a cylinder or a sphere. The radius from the viewer to the image is set at approximately 20 feet, or at the object of major interest. A full stereo view is presented in all directions. The interocular distance, as seen from the viewer's perspective, displaces the two spherical images horizontally. This presents correct stereo separation in whatever direction the viewer is looking, even up and down. Objects at infinity will move with the viewer, contributing to an immersive experience. Stereo panoramas created with this acquisition and display technique can be applied without modification to a large array of VR devices having different screen arrangements and different VR libraries.

  16. a Unified Blending Framework for Panorama Completion via Graph Cuts

    NASA Astrophysics Data System (ADS)

    Chen, Kai; Yao, Jian; Xia, Menghan; Gui, Xinyuan; Lu, Xiaohu; Li, Li

    2016-06-01

    In this paper, we propose a unified framework for efficiently completing streetview and indoor 360° panoramas due to the lack of bottom areas caused by the occlusion of the acquisition platform. To greatly reduce the severe distortion at the bottom of the panorama, we first reproject it onto the ground perspective plane containing the whole occluded region to be completed. Then, we formulate the image completion problem in an improved graph cuts optimization framework based on the statistics of similar patches by strengthening the boundary constraints. To further eliminate image luminance differences and color deviations and conceal geometrical parallax among the optimally selected patches for completion, we creatively apply a multi-bland image blending algorithm for perfect image mosaicking from the completed patches and the originally reprojected image. Finally, we back-project the completed and blended ground perspective image into the cylindrical-projection panorama followed by a simple feathering to further reduce artifacts in the panorama. Experimental results on some representative non-panoramic images and streetview and indoor panoramas demonstrate the efficiency and robustness of the proposed method even in some challenging cases.

  17. Emergence of native peptide sequences in prebiotic replication networks.

    PubMed

    Nanda, Jayanta; Rubinov, Boris; Ivnitski, Denis; Mukherjee, Rakesh; Shtelman, Elina; Motro, Yair; Miller, Yifat; Wagner, Nathaniel; Cohen-Luria, Rivka; Ashkenasy, Gonen

    2017-09-05

    Biopolymer syntheses in living cells are perfected by an elaborate error correction machinery, which was not applicable during polymerization on early Earth. Scientists are consequently striving to identify mechanisms by which functional polymers were selected and further amplified from complex prebiotic mixtures. Here we show the instrumental role of non-enzymatic replication in the enrichment of certain product(s). To this end, we analyzed a complex web of reactions in β-sheet peptide networks, focusing on the formation of specific intermediate compounds and template-assisted replication. Remarkably, we find that the formation of several products in a mixture is not critically harmful, since efficient and selective template-assisted reactions serve as a backbone correction mechanism, namely, for keeping the concentration of the peptide containing the native backbone equal to, or even higher than, the concentrations of the other products. We suggest that these findings may shed light on molecular evolution processes that led to current biology.The synthesis of biopolymers in living cells is perfected by complex machinery, however this was not the case on early Earth. Here the authors show the role of non-enzymatic replication in the enrichment of certain products within prebiotically relevant mixtures.

  18. Depolarization Induced Suppression of Excitation and the Emergence of Ultraslow Rhythms in Neural Networks

    NASA Astrophysics Data System (ADS)

    Hlinka, J.; Coombes, S.

    2010-02-01

    Ultraslow fluctuations (0.01-0.1 Hz) are a feature of intrinsic brain activity of as yet unclear origin. We propose a candidate mechanism based on retrograde endocannabinoid signaling in a synaptically coupled network of excitatory neurons. This is known to cause depolarization-induced suppression of excitation (DISE), which we model phenomenologically. We construct emergent network oscillations in a globally coupled network and show that for strong synaptic coupling DISE can lead to a synchronized population burst at the frequencies of resting brain rhythms.

  19. Emerging markets in the global economic network: Real(ly) decoupling?

    NASA Astrophysics Data System (ADS)

    Trancoso, Tiago

    2014-02-01

    We evaluate the degree of business cycle interdependence in the global economic network, focusing on the hypothesis that emergent market (EM) economies have decoupled from advanced economies in the recent period of globalization. We employ a novel methodological approach to the study of business cycles synchronization that combines network analysis and dynamic correlations. We find a process of increasing transnational interdependence within and across all economic development groups. Our results suggest that EM do not form a cohesive group and support the view of an increasingly multipolar and interdependent global economic network.

  20. The Pediatric Emergency Care Applied Research Network (PECARN): rationale, development, and first steps.

    PubMed

    2003-06-01

    Since its formal recognition as a medical specialty, the field of pediatric emergency medicine has made substantial advances with respect to its scope and sophistication. These advances have occurred in clinical practice as well as in the research base to improve clinical practice. There remain, however, many areas in emergency medical services for children (EMSC) in the out-of-hospital, emergency department (ED), and hospital settings that suffer from a lack of data to guide practice. In an effort to expand the quality and quantity of research in pediatric emergency care, the Pediatric Emergency Care Applied Research Network (PECARN) was created in October of 2001. PECARN is the first federally funded national network for research in EMSC and is the result of cooperative agreement grants funded through the Health Resources and Services Administration with the purpose of developing an infrastructure capable of overcoming inherent barriers to EMSC research. Among these recognized barriers are low incidence rates of serious pediatric emergency events, the need for large numbers of children from varied backgrounds to achieve broadly representative study samples, lack of an infrastructure to test the efficacy of pediatric emergency care, and the need for a mechanism to translate study results into clinical practice. PECARN will serve as a national platform for collaborative research involving the continuum of care within the EMSC system, including out-of-hospital care, patient transport, ED and in-hospital care, and rehabilitation. This article describes the history of EMSC, the need for a national collaborative research network in EMSC, the organization and development of PECARN, and the work plan for the network.

  1. Comprehensive assessment and network analysis of the emerging genetic susceptibility landscape of prostate cancer.

    PubMed

    Hicks, Chindo; Miele, Lucio; Koganti, Tejaswi; Vijayakumar, Srinivasan

    2013-01-01

    Recent advances in high-throughput genotyping have made possible identification of genetic variants associated with increased risk of developing prostate cancer using genome-wide associations studies (GWAS). However, the broader context in which the identified genetic variants operate is poorly understood. Here we present a comprehensive assessment, network, and pathway analysis of the emerging genetic susceptibility landscape of prostate cancer. We created a comprehensive catalog of genetic variants and associated genes by mining published reports and accompanying websites hosting supplementary data on GWAS. We then performed network and pathway analysis using single nucleotide polymorphism (SNP)-containing genes to identify gene regulatory networks and pathways enriched for genetic variants. We identified multiple gene networks and pathways enriched for genetic variants including IGF-1, androgen biosynthesis and androgen signaling pathways, and the molecular mechanisms of cancer. The results provide putative functional bridges between GWAS findings and gene regulatory networks and biological pathways.

  2. Capacity Model and Constraints Analysis for Integrated Remote Wireless Sensor and Satellite Network in Emergency Scenarios.

    PubMed

    Zhang, Wei; Zhang, Gengxin; Dong, Feihong; Xie, Zhidong; Bian, Dongming

    2015-11-17

    This article investigates the capacity problem of an integrated remote wireless sensor and satellite network (IWSSN) in emergency scenarios. We formulate a general model to evaluate the remote sensor and satellite network capacity. Compared to most existing works for ground networks, the proposed model is time varying and space oriented. To capture the characteristics of a practical network, we sift through major capacity-impacting constraints and analyze the influence of these constraints. Specifically, we combine the geometric satellite orbit model and satellite tool kit (STK) engineering software to quantify the trends of the capacity constraints. Our objective in analyzing these trends is to provide insights and design guidelines for optimizing the integrated remote wireless sensor and satellite network schedules. Simulation results validate the theoretical analysis of capacity trends and show the optimization opportunities of the IWSSN.

  3. Capacity Model and Constraints Analysis for Integrated Remote Wireless Sensor and Satellite Network in Emergency Scenarios

    PubMed Central

    Zhang, Wei; Zhang, Gengxin; Dong, Feihong; Xie, Zhidong; Bian, Dongming

    2015-01-01

    This article investigates the capacity problem of an integrated remote wireless sensor and satellite network (IWSSN) in emergency scenarios. We formulate a general model to evaluate the remote sensor and satellite network capacity. Compared to most existing works for ground networks, the proposed model is time varying and space oriented. To capture the characteristics of a practical network, we sift through major capacity-impacting constraints and analyze the influence of these constraints. Specifically, we combine the geometric satellite orbit model and satellite tool kit (STK) engineering software to quantify the trends of the capacity constraints. Our objective in analyzing these trends is to provide insights and design guidelines for optimizing the integrated remote wireless sensor and satellite network schedules. Simulation results validate the theoretical analysis of capacity trends and show the optimization opportunities of the IWSSN. PMID:26593919

  4. Emergence of amplitude death scenario in a network of oscillators under repulsive delay interaction

    NASA Astrophysics Data System (ADS)

    Bera, Bidesh K.; Hens, Chittaranjan; Ghosh, Dibakar

    2016-07-01

    We report the existence of amplitude death in a network of identical oscillators under repulsive mean coupling. Amplitude death appears in a globally coupled network of identical oscillators with instantaneous repulsive mean coupling only when the number of oscillators is more than two. We further investigate that, amplitude death may emerge even in two coupled oscillators as well as network of oscillators if we introduce delay time in the repulsive mean coupling. We have analytically derived the region of amplitude death island and find out how strength of delay controls the death regime in two coupled or a large network of coupled oscillators. We have verified our results on network of delayed Mackey-Glass systems where parameters are set in hyperchaotic regime. We have also tested our coupling approach in two paradigmatic limit cycle oscillators: Stuart-Landau and Van der Pol oscillators.

  5. Emergence of Complexity in Protein Functions and Metabolic Networks

    NASA Technical Reports Server (NTRS)

    Pohorille, Andzej

    2009-01-01

    In modern organisms proteins perform a majority of cellular functions, such as chemical catalysis, energy transduction and transport of material across cell walls. Although great strides have been made towards understanding protein evolution, a meaningful extrapolation from contemporary proteins to their earliest ancestors is virtually impossible. In an alternative approach, the origin of water-soluble proteins was probed through the synthesis of very large libraries of random amino acid sequences and subsequently subjecting them to in vitro evolution. In combination with computer modeling and simulations, these experiments allow us to address a number of fundamental questions about the origins of proteins. Can functionality emerge from random sequences of proteins? How did the initial repertoire of functional proteins diversify to facilitate new functions? Did this diversification proceed primarily through drawing novel functionalities from random sequences or through evolution of already existing proto-enzymes? Did protein evolution start from a pool of proteins defined by a frozen accident and other collections of proteins could start a different evolutionary pathway? Although we do not have definitive answers to these questions, important clues have been uncovered. Considerable progress has been also achieved in understanding the origins of membrane proteins. We will address this issue in the example of ion channels - proteins that mediate transport of ions across cell walls. Remarkably, despite overall complexity of these proteins in contemporary cells, their structural motifs are quite simple, with -helices being most common. By combining results of experimental and computer simulation studies on synthetic models and simple, natural channels, I will show that, even though architectures of membrane proteins are not nearly as diverse as those of water-soluble proteins, they are sufficiently flexible to adapt readily to the functional demands arising during

  6. The Emergence of the Open Networked ``i-Learning'' Model

    NASA Astrophysics Data System (ADS)

    Elia, Gianluca

    The most significant forces that are changing the business world and the society behaviors in this beginning of the twenty-first century can be identified into the globalization of the economy, technological evolution and convergence, change of the workers' expectations, workplace diversity and mobility, and mostly, knowledge and learning as major organizational assets. But which type of ­learning dynamics must be nurtured and pursued within the organizations, today, in order to generate valuable knowledge and its effective applications? After a brief discussion on the main changes observable in management, ICT and society/workplace in the last years, this chapter aims to answer to this question, through the proposition of the “Π-shaped” profile (a new professional archetype for leading change), and through the discussion of the open networked “i-Learning” model (a new framework to “incubate” innovation in learning processes). Actually, the “i” stands for “innovation” (to highlight the nature of the impact on traditional ­learning model), but also it stands for “incubation” (to underline the urgency to have new environments in which incubating new professional profiles). Specifically, the main key characteristics at the basis of the innovation of the learning processes will be ­presented and described, by highlighting the managerial, technological and societal aspects of their nature. A set of operational guidelines will be also ­provided to ­activate and sustain the innovation process, so implementing changes in the strategic dimensions of the model. Finally, the “i-Learning Radar” is presented as an operational tool to design, communicate and control an “i-Learning experience”. This tool is represented by a radar diagram with six strategic dimensions of a ­learning initiative.

  7. Collective learning for the emergence of social norms in networked multiagent systems.

    PubMed

    Yu, Chao; Zhang, Minjie; Ren, Fenghui

    2014-12-01

    Social norms such as social rules and conventions play a pivotal role in sustaining system order by regulating and controlling individual behaviors toward a global consensus in large-scale distributed systems. Systematic studies of efficient mechanisms that can facilitate the emergence of social norms enable us to build and design robust distributed systems, such as electronic institutions and norm-governed sensor networks. This paper studies the emergence of social norms via learning from repeated local interactions in networked multiagent systems. A collective learning framework, which imitates the opinion aggregation process in human decision making, is proposed to study the impact of agent local collective behaviors on the emergence of social norms in a number of different situations. In the framework, each agent interacts repeatedly with all of its neighbors. At each step, an agent first takes a best-response action toward each of its neighbors and then combines all of these actions into a final action using ensemble learning methods. Extensive experiments are carried out to evaluate the framework with respect to different network topologies, learning strategies, numbers of actions, influences of nonlearning agents, and so on. Experimental results reveal some significant insights into the manipulation and control of norm emergence in networked multiagent systems achieved through local collective behaviors.

  8. Contrasting Assessments of Interdisciplinarity in Emerging Specialties: The Case of Neural Networks Research.

    ERIC Educational Resources Information Center

    McCain, Katherine W.; Whitney, P. Joy

    1994-01-01

    Discussion of bibliometric analysis of interdisciplinary research in emerging fields focuses on a study of neural networks research that examined citation analyses, publishing patterns and subject terms, and journal subject classification. Roles that journals can play in interdisciplinary information transfer are considered. (Contains 42…

  9. Life-Course Events, Social Networks, and the Emergence of Violence among Female Gang Members

    ERIC Educational Resources Information Center

    Fleisher, Mark S.; Krienert, Jessie L.

    2004-01-01

    Using data gathered from a multi-year field study, this article identifies specific life-course events shared by gang-affiliated women. Gangs emerge as a cultural adaptation or pro-social community response to poverty and racial isolation. Through the use of a social-network approach, data show that violence dramatically increases in the period…

  10. Life-Course Events, Social Networks, and the Emergence of Violence among Female Gang Members

    ERIC Educational Resources Information Center

    Fleisher, Mark S.; Krienert, Jessie L.

    2004-01-01

    Using data gathered from a multi-year field study, this article identifies specific life-course events shared by gang-affiliated women. Gangs emerge as a cultural adaptation or pro-social community response to poverty and racial isolation. Through the use of a social-network approach, data show that violence dramatically increases in the period…

  11. Emergence of a Small-World Functional Network in Cultured Neurons

    PubMed Central

    Downes, Julia H.; Hammond, Mark W.; Xydas, Dimitris; Spencer, Matthew C.; Becerra, Victor M.; Warwick, Kevin; Whalley, Ben J.; Nasuto, Slawomir J.

    2012-01-01

    The functional networks of cultured neurons exhibit complex network properties similar to those found in vivo. Starting from random seeding, cultures undergo significant reorganization during the initial period in vitro, yet despite providing an ideal platform for observing developmental changes in neuronal connectivity, little is known about how a complex functional network evolves from isolated neurons. In the present study, evolution of functional connectivity was estimated from correlations of spontaneous activity. Network properties were quantified using complex measures from graph theory and used to compare cultures at different stages of development during the first 5 weeks in vitro. Networks obtained from young cultures (14 days in vitro) exhibited a random topology, which evolved to a small-world topology during maturation. The topology change was accompanied by an increased presence of highly connected areas (hubs) and network efficiency increased with age. The small-world topology balances integration of network areas with segregation of specialized processing units. The emergence of such network structure in cultured neurons, despite a lack of external input, points to complex intrinsic biological mechanisms. Moreover, the functional network of cultures at mature ages is efficient and highly suited to complex processing tasks. PMID:22615555

  12. Resting-State Temporal Synchronization Networks Emerge from Connectivity Topology and Heterogeneity

    PubMed Central

    Ponce-Alvarez, Adrián; Deco, Gustavo; Hagmann, Patric; Romani, Gian Luca; Mantini, Dante; Corbetta, Maurizio

    2015-01-01

    Spatial patterns of coherent activity across different brain areas have been identified during the resting-state fluctuations of the brain. However, recent studies indicate that resting-state activity is not stationary, but shows complex temporal dynamics. We were interested in the spatiotemporal dynamics of the phase interactions among resting-state fMRI BOLD signals from human subjects. We found that the global phase synchrony of the BOLD signals evolves on a characteristic ultra-slow (<0.01Hz) time scale, and that its temporal variations reflect the transient formation and dissolution of multiple communities of synchronized brain regions. Synchronized communities reoccurred intermittently in time and across scanning sessions. We found that the synchronization communities relate to previously defined functional networks known to be engaged in sensory-motor or cognitive function, called resting-state networks (RSNs), including the default mode network, the somato-motor network, the visual network, the auditory network, the cognitive control networks, the self-referential network, and combinations of these and other RSNs. We studied the mechanism originating the observed spatiotemporal synchronization dynamics by using a network model of phase oscillators connected through the brain’s anatomical connectivity estimated using diffusion imaging human data. The model consistently approximates the temporal and spatial synchronization patterns of the empirical data, and reveals that multiple clusters that transiently synchronize and desynchronize emerge from the complex topology of anatomical connections, provided that oscillators are heterogeneous. PMID:25692996

  13. Mechanisms and dynamics of cooperation and competition emergence in complex networked systems

    NASA Astrophysics Data System (ADS)

    Gianetto, David A.

    Cooperative behavior is a pervasive phenomenon in human interactions and yet how it can evolve and become established, through the selfish process of natural selection, is an enduring puzzle. These behaviors emerge when agents interact in a structured manner; even so, the key structural factors that affect cooperation are not well understood. Moreover, the literature often considers cooperation a single attribute of primitive agents who do not react to environmental changes but real-world actors are more perceptive. The present work moves beyond these assumptions by evolving more realistic game participants, with memories of the past, on complex networks. Agents play repeated games with a three-part Markovian strategy that allows us to separate the cooperation phenomenon into trust, reciprocity, and forgiveness characteristics. Our results show that networks matter most when agents gain the most by acting in a selfish manner, irrespective of how much they may lose by cooperating; since the context provided by neighborhoods inhibits greedy impulses that agents otherwise succumb to in isolation. Network modularity is the most important driver of cooperation emergence in these high-stakes games. However, modularity fails to tell the complete story. Modular scale-free graphs impede cooperation when close coordination is required, partially due to the acyclic nature of scale-free network models. To achieve the highest cooperation in diverse social conditions, both high modularity, low connectivity within modules, and a rich network of long cycles become important. With these findings in hand, we study the influence of networks on coordination and competition within the federal health care insurance exchange. In this applied study, we show that systemic health care coordination is encouraged by the emergent insurance network. The network helps underpin the viability of the exchange and provides an environment of stronger competition once a critical-mass of insurers have

  14. Emerging Subsea Networks: SMART Cable Systems for Science and Society

    NASA Astrophysics Data System (ADS)

    Howe, B. M.; Butler, R.; Joint Task Force, U.

    2016-02-01

    The subsea telecommunications cable industry is approaching a prospective new era: deploying SMART subsea cable systems (SMART = Science Monitoring And Reliable Telecommunication). The current global, commercial cable infrastructure consists of 1 Gm of cable, being refreshed now and expanding in the future. The SMART concept is to add a small external sensor package along the cable system at its optical repeaters to transmit important real-time environmental data via a dedicated wavelength or overhead channel in the transmission system, avoiding any impact on the commercial traffic. These small, reliable, existing sensors would precisely measure temperature, pressure and three-axis acceleration across the world's ocean floor over an extended period of time, being deployed using standard cable-laying procedures on new or refurbished cables, but not requiring maintenance through the 2-3 decade life of the cable systems. The game-changing factor is the urgent international need for ocean environmental data related to mitigating climate and sea-level change and improving tsunami and slope failure hazard warnings. Societal costs incurred by these are reaching billions of dollars and hundreds of thousands of deaths. Pressures for new and urgent public policies are evident from the 5th IPCC Assessment, USA-China agreement on limiting greenhouse gas emissions, clear evidence for rapid global warming, 21st Session of the Conference of the Parties to the UNFCCC (December 2015, Paris), and the scale of the costs of inaction. To support revised public policies and actions, decision-makers, industry leaders, and the public are seeking key scientific data, which will necessitate new sources of funding. Hence, the emergence of new SMART cable systems offered by the subsea telecommunications industry will provide new market opportunities, engage additional non-traditional users, and make profound societal contributions. The Joint Task Force (JTF) on SMART Subsea Cable Systems

  15. Dynamics on Networks: The Role of Local Dynamics and Global Networks on the Emergence of Hypersynchronous Neural Activity

    PubMed Central

    Schmidt, Helmut; Petkov, George; Richardson, Mark P.; Terry, John R.

    2014-01-01

    Graph theory has evolved into a useful tool for studying complex brain networks inferred from a variety of measures of neural activity, including fMRI, DTI, MEG and EEG. In the study of neurological disorders, recent work has discovered differences in the structure of graphs inferred from patient and control cohorts. However, most of these studies pursue a purely observational approach; identifying correlations between properties of graphs and the cohort which they describe, without consideration of the underlying mechanisms. To move beyond this necessitates the development of computational modeling approaches to appropriately interpret network interactions and the alterations in brain dynamics they permit, which in the field of complexity sciences is known as dynamics on networks. In this study we describe the development and application of this framework using modular networks of Kuramoto oscillators. We use this framework to understand functional networks inferred from resting state EEG recordings of a cohort of 35 adults with heterogeneous idiopathic generalized epilepsies and 40 healthy adult controls. Taking emergent synchrony across the global network as a proxy for seizures, our study finds that the critical strength of coupling required to synchronize the global network is significantly decreased for the epilepsy cohort for functional networks inferred from both theta (3–6 Hz) and low-alpha (6–9 Hz) bands. We further identify left frontal regions as a potential driver of seizure activity within these networks. We also explore the ability of our method to identify individuals with epilepsy, observing up to 80 predictive power through use of receiver operating characteristic analysis. Collectively these findings demonstrate that a computer model based analysis of routine clinical EEG provides significant additional information beyond standard clinical interpretation, which should ultimately enable a more appropriate mechanistic stratification of people

  16. Contrasting models of driver behaviour in emergencies using retrospective verbalisations and network analysis.

    PubMed

    Banks, Victoria A; Stanton, Neville A

    2015-01-01

    Automated assistance in driving emergencies aims to improve the safety of our roads by avoiding or mitigating the effects of accidents. However, the behavioural implications of such systems remain unknown. This paper introduces the driver decision-making in emergencies (DDMiEs) framework to investigate how the level and type of automation may affect driver decision-making and subsequent responses to critical braking events using network analysis to interrogate retrospective verbalisations. Four DDMiE models were constructed to represent different levels of automation within the driving task and its effects on driver decision-making. Findings suggest that whilst automation does not alter the decision-making pathway (e.g. the processes between hazard detection and response remain similar), it does appear to significantly weaken the links between information-processing nodes. This reflects an unintended yet emergent property within the task network that could mean that we may not be improving safety in the way we expect. This paper contrasts models of driver decision-making in emergencies at varying levels of automation using the Southampton University Driving Simulator. Network analysis of retrospective verbalisations indicates that increasing the level of automation in driving emergencies weakens the link between information-processing nodes essential for effective decision-making.

  17. Using Biotic Interaction Networks for Prediction in Biodiversity and Emerging Diseases

    PubMed Central

    Stephens, Christopher R.; Heau, Joaquín Giménez; González, Camila; Ibarra-Cerdeña, Carlos N.; Sánchez-Cordero, Victor; González-Salazar, Constantino

    2009-01-01

    Networks offer a powerful tool for understanding and visualizing inter-species ecological and evolutionary interactions. Previously considered examples, such as trophic networks, are just representations of experimentally observed direct interactions. However, species interactions are so rich and complex it is not feasible to directly observe more than a small fraction. In this paper, using data mining techniques, we show how potential interactions can be inferred from geographic data, rather than by direct observation. An important application area for this methodology is that of emerging diseases, where, often, little is known about inter-species interactions, such as between vectors and reservoirs. Here, we show how using geographic data, biotic interaction networks that model statistical dependencies between species distributions can be used to infer and understand inter-species interactions. Furthermore, we show how such networks can be used to build prediction models. For example, for predicting the most important reservoirs of a disease, or the degree of disease risk associated with a geographical area. We illustrate the general methodology by considering an important emerging disease - Leishmaniasis. This data mining methodology allows for the use of geographic data to construct inferential biotic interaction networks which can then be used to build prediction models with a wide range of applications in ecology, biodiversity and emerging diseases. PMID:19478956

  18. Emergence of context-dependent variability across a basal ganglia network.

    PubMed

    Woolley, Sarah C; Rajan, Raghav; Joshua, Mati; Doupe, Allison J

    2014-04-02

    Context dependence is a key feature of cortical-basal ganglia circuit activity, and in songbirds the cortical outflow of a basal ganglia circuit specialized for song, LMAN, shows striking increases in trial-by-trial variability and bursting when birds sing alone rather than to females. To reveal where this variability and its social regulation emerge, we recorded stepwise from corticostriatal (HVC) neurons and their target spiny and pallidal neurons in Area X. We find that corticostriatal and spiny neurons both show precise singing-related firing across both social settings. Pallidal neurons, in contrast, exhibit markedly increased trial-by-trial variation when birds sing alone, created by highly variable pauses in firing. This variability persists even when recurrent inputs from LMAN are ablated. These data indicate that variability and its context sensitivity emerge within the basal ganglia network, suggest a network mechanism for this emergence, and highlight variability generation and regulation as basal ganglia functions.

  19. Oscillations emerging from noise-driven steady state in networks with electrical synapses and subthreshold resonance

    PubMed Central

    Tchumatchenko, Tatjana; Clopath, Claudia

    2014-01-01

    Oscillations play a critical role in cognitive phenomena and have been observed in many brain regions. Experimental evidence indicates that classes of neurons exhibit properties that could promote oscillations, such as subthreshold resonance and electrical gap junctions. Typically, these two properties are studied separately but it is not clear which is the dominant determinant of global network rhythms. Our aim is to provide an analytical understanding of how these two effects destabilize the fluctuation-driven state, in which neurons fire irregularly, and lead to an emergence of global synchronous oscillations. Here we show how the oscillation frequency is shaped by single neuron resonance, electrical and chemical synapses.The presence of both gap junctions and subthreshold resonance are necessary for the emergence of oscillations. Our results are in agreement with several experimental observations such as network responses to oscillatory inputs and offer a much-needed conceptual link connecting a collection of disparate effects observed in networks. PMID:25405458

  20. Oscillations emerging from noise-driven steady state in networks with electrical synapses and subthreshold resonance

    NASA Astrophysics Data System (ADS)

    Tchumatchenko, Tatjana; Clopath, Claudia

    2014-11-01

    Oscillations play a critical role in cognitive phenomena and have been observed in many brain regions. Experimental evidence indicates that classes of neurons exhibit properties that could promote oscillations, such as subthreshold resonance and electrical gap junctions. Typically, these two properties are studied separately but it is not clear which is the dominant determinant of global network rhythms. Our aim is to provide an analytical understanding of how these two effects destabilize the fluctuation-driven state, in which neurons fire irregularly, and lead to an emergence of global synchronous oscillations. Here we show how the oscillation frequency is shaped by single neuron resonance, electrical and chemical synapses.The presence of both gap junctions and subthreshold resonance are necessary for the emergence of oscillations. Our results are in agreement with several experimental observations such as network responses to oscillatory inputs and offer a much-needed conceptual link connecting a collection of disparate effects observed in networks.

  1. Duplication of a promiscuous transcription factor drives the emergence of a new regulatory network

    PubMed Central

    Pougach, Ksenia; Voet, Arnout; Kondrashov, Fyodor A.; Voordeckers, Karin; Christiaens, Joaquin F.; Baying, Bianka; Benes, Vladimir; Sakai, Ryo; Aerts, Jan; Zhu, Bo; Van Dijck, Patrick; Verstrepen, Kevin J.

    2014-01-01

    The emergence of new genes throughout evolution requires rewiring and extension of regulatory networks. However, the molecular details of how the transcriptional regulation of new gene copies evolves remain largely unexplored. Here we show how duplication of a transcription factor gene allowed the emergence of two independent regulatory circuits. Interestingly, the ancestral transcription factor was promiscuous and could bind different motifs in its target promoters. After duplication, one paralogue evolved increased binding specificity so that it only binds one type of motif, whereas the other copy evolved a decreased activity so that it only activates promoters that contain multiple binding sites. Interestingly, only a few mutations in both the DNA-binding domains and in the promoter binding sites were required to gradually disentangle the two networks. These results reveal how duplication of a promiscuous transcription factor followed by concerted cis and trans mutations allows expansion of a regulatory network. PMID:25204769

  2. Elevated serotonergic signaling amplifies synaptic noise and facilitates the emergence of epileptiform network oscillations

    PubMed Central

    Puzerey, Pavel A.; Decker, Michael J.

    2014-01-01

    Serotonin fibers densely innervate the cortical sheath to regulate neuronal excitability, but its role in shaping network dynamics remains undetermined. We show that serotonin provides an excitatory tone to cortical neurons in the form of spontaneous synaptic noise through 5-HT3 receptors, which is persistent and can be augmented using fluoxetine, a selective serotonin re-uptake inhibitor. Augmented serotonin signaling also increases cortical network activity by enhancing synaptic excitation through activation of 5-HT2 receptors. This in turn facilitates the emergence of epileptiform network oscillations (10–16 Hz) known as fast runs. A computational model of cortical dynamics demonstrates that these two combined mechanisms, increased background synaptic noise and enhanced synaptic excitation, are sufficient to replicate the emergence fast runs and their statistics. Consistent with these findings, we show that blocking 5-HT2 receptors in vivo significantly raises the threshold for convulsant-induced seizures. PMID:25122717

  3. Oscillations emerging from noise-driven steady state in networks with electrical synapses and subthreshold resonance.

    PubMed

    Tchumatchenko, Tatjana; Clopath, Claudia

    2014-11-18

    Oscillations play a critical role in cognitive phenomena and have been observed in many brain regions. Experimental evidence indicates that classes of neurons exhibit properties that could promote oscillations, such as subthreshold resonance and electrical gap junctions. Typically, these two properties are studied separately but it is not clear which is the dominant determinant of global network rhythms. Our aim is to provide an analytical understanding of how these two effects destabilize the fluctuation-driven state, in which neurons fire irregularly, and lead to an emergence of global synchronous oscillations. Here we show how the oscillation frequency is shaped by single neuron resonance, electrical and chemical synapses.The presence of both gap junctions and subthreshold resonance are necessary for the emergence of oscillations. Our results are in agreement with several experimental observations such as network responses to oscillatory inputs and offer a much-needed conceptual link connecting a collection of disparate effects observed in networks.

  4. Spirit's West Valley Panorama (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007.

    After several months near the base of the plateau called 'Home Plate' in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.

    This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is 'Tsiolkovski Ridge,' about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is 'Grissom Hill,' about 8 kilometers or 5 miles away. At right, the highest point of the horizon is 'Husband Hill,' to the north and about 800 meters or half a mile away.

    This view combines separate images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle

  5. Spirit's West Valley Panorama (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007.

    After several months near the base of the plateau called 'Home Plate' in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.

    This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is 'Tsiolkovski Ridge,' about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is 'Grissom Hill,' about 8 kilometers or 5 miles away. At right, the highest point of the horizon is 'Husband Hill,' to the north and about 800 meters or half a mile away.

    This view combines separate images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers. It is presented in a false-color stretch to bring out subtle

  6. Impact of vehicular networks on emergency medical services in urban areas.

    PubMed

    Lee, Chun-Liang; Huang, Chung-Yuan; Hsiao, Tzu-Chien; Wu, Chun-Yen; Chen, Yaw-Chung; Wang, I-Cheng

    2014-10-31

    The speed with which emergency personnel can provide emergency treatment is crucial to reducing death and disability among acute and critically ill patients. Unfortunately, the rapid development of cities and increased numbers of vehicles are preventing emergency vehicles from easily reaching locations where they are needed. A significant number of researchers are experimenting with vehicular networks to address this issue, but in most studies the focus has been on communication technologies and protocols, with few efforts to assess how network applications actually support emergency medical care. Our motivation was to search the literature for suggested methods for assisting emergency vehicles, and to use simulations to evaluate them. Our results and evidence-based studies were cross-referenced to assess each method in terms of cumulative survival ratio (CSR) gains for acute and critically ill patients. Simulation results indicate that traffic light preemption resulted in significant CSR increases of between 32.4% and 90.2%. Route guidance was found to increase CSRs from 14.1% to 57.8%, while path clearing increased CSRs by 15.5% or less. It is our hope that this data will support the efforts of emergency medical technicians, traffic managers, and policy makers.

  7. Impact of Vehicular Networks on Emergency Medical Services in Urban Areas

    PubMed Central

    Lee, Chun-Liang; Huang, Chung-Yuan; Hsiao, Tzu-Chien; Wu, Chun-Yen; Chen, Yaw-Chung; Wang, I.-Cheng

    2014-01-01

    The speed with which emergency personnel can provide emergency treatment is crucial to reducing death and disability among acute and critically ill patients. Unfortunately, the rapid development of cities and increased numbers of vehicles are preventing emergency vehicles from easily reaching locations where they are needed. A significant number of researchers are experimenting with vehicular networks to address this issue, but in most studies the focus has been on communication technologies and protocols, with few efforts to assess how network applications actually support emergency medical care. Our motivation was to search the literature for suggested methods for assisting emergency vehicles, and to use simulations to evaluate them. Our results and evidence-based studies were cross-referenced to assess each method in terms of cumulative survival ratio (CSR) gains for acute and critically ill patients. Simulation results indicate that traffic light preemption resulted in significant CSR increases of between 32.4% and 90.2%. Route guidance was found to increase CSRs from 14.1% to 57.8%, while path clearing increased CSRs by 15.5% or less. It is our hope that this data will support the efforts of emergency medical technicians, traffic managers, and policy makers. PMID:25365059

  8. A framework on the emergence and effectiveness of global health networks.

    PubMed

    Shiffman, Jeremy; Quissell, Kathryn; Schmitz, Hans Peter; Pelletier, David L; Smith, Stephanie L; Berlan, David; Gneiting, Uwe; Van Slyke, David; Mergel, Ines; Rodriguez, Mariela; Walt, Gill

    2016-04-01

    Since 1990 mortality and morbidity decline has been more extensive for some conditions prevalent in low- and middle-income countries than for others. One reason may be differences in the effectiveness of global health networks, which have proliferated in recent years. Some may be more capable than others in attracting attention to a condition, in generating funding, in developing interventions and in convincing national governments to adopt policies. This article introduces a supplement on the emergence and effectiveness of global health networks. The supplement examines networks concerned with six global health problems: tuberculosis (TB), pneumonia, tobacco use, alcohol harm, maternal mortality and newborn deaths. This article presents a conceptual framework delineating factors that may shape why networks crystallize more easily surrounding some issues than others, and once formed, why some are better able than others to shape policy and public health outcomes. All supplement papers draw on this framework. The framework consists of 10 factors in three categories: (1) features of the networks and actors that comprise them, including leadership, governance arrangements, network composition and framing strategies; (2) conditions in the global policy environment, including potential allies and opponents, funding availability and global expectations concerning which issues should be prioritized; (3) and characteristics of the issue, including severity, tractability and affected groups. The article also explains the design of the project, which is grounded in comparison of networks surrounding three matched issues: TB and pneumonia, tobacco use and alcohol harm, and maternal and newborn survival. Despite similar burden and issue characteristics, there has been considerably greater policy traction for the first in each pair. The supplement articles aim to explain the role of networks in shaping these differences, and collectively represent the first comparative effort

  9. A framework on the emergence and effectiveness of global health networks

    PubMed Central

    Shiffman, Jeremy; Quissell, Kathryn; Schmitz, Hans Peter; Pelletier, David L; Smith, Stephanie L; Berlan, David; Gneiting, Uwe; Van Slyke, David; Mergel, Ines; Rodriguez, Mariela; Walt, Gill

    2016-01-01

    Since 1990 mortality and morbidity decline has been more extensive for some conditions prevalent in low- and middle-income countries than for others. One reason may be differences in the effectiveness of global health networks, which have proliferated in recent years. Some may be more capable than others in attracting attention to a condition, in generating funding, in developing interventions and in convincing national governments to adopt policies. This article introduces a supplement on the emergence and effectiveness of global health networks. The supplement examines networks concerned with six global health problems: tuberculosis (TB), pneumonia, tobacco use, alcohol harm, maternal mortality and newborn deaths. This article presents a conceptual framework delineating factors that may shape why networks crystallize more easily surrounding some issues than others, and once formed, why some are better able than others to shape policy and public health outcomes. All supplement papers draw on this framework. The framework consists of 10 factors in three categories: (1) features of the networks and actors that comprise them, including leadership, governance arrangements, network composition and framing strategies; (2) conditions in the global policy environment, including potential allies and opponents, funding availability and global expectations concerning which issues should be prioritized; (3) and characteristics of the issue, including severity, tractability and affected groups. The article also explains the design of the project, which is grounded in comparison of networks surrounding three matched issues: TB and pneumonia, tobacco use and alcohol harm, and maternal and newborn survival. Despite similar burden and issue characteristics, there has been considerably greater policy traction for the first in each pair. The supplement articles aim to explain the role of networks in shaping these differences, and collectively represent the first comparative effort

  10. Addressing challenges for future strategic-level emergency management: reframing, networking, and capacity-building.

    PubMed

    Bosomworth, Karyn; Owen, Christine; Curnin, Steven

    2017-04-01

    The mounting frequency and intensity of natural hazards, alongside growing interdependencies between social-technical and ecological systems, are placing increased pressure on emergency management. This is particularly true at the strategic level of emergency management, which involves planning for and managing non-routine, high-consequence events. Drawing on the literature, a survey, and interviews and workshops with Australia's senior emergency managers, this paper presents an analysis of five core challenges that these pressures are creating for strategic-level emergency management. It argues that emphasising 'emergency management' as a primary adaptation strategy is a retrograde step that ignores the importance of addressing socio-political drivers of vulnerabilities. Three key suggestions are presented that could assist the country's strategic-level emergency management in tackling these challenges: (i) reframe emergency management as a component of disaster risk reduction rather than them being one and the same; (ii) adopt a network governance approach; and (iii) further develop the capacities of strategic-level emergency managers.

  11. Emergence of hierarchy in cost-driven growth of spatial networks

    NASA Astrophysics Data System (ADS)

    Louf, Rémi; Jensen, Pablo; Barthelemy, Marc

    2013-05-01

    One of the most important features of spatial networks-such as transportation networks, power grids, the Internet, and neural networks-is the existence of a cost associated with the length of links. Such a cost has a profound influence on the global structure of these networks, which usually display a hierarchical spatial organization. The link between local constraints and large-scale structure is not elucidated, however, and we introduce here a generic model for the growth of spatial networks based on the general concept of cost-benefit analysis. This model depends essentially on a single scale and produces a family of networks that range from the star graph to the minimum spanning tree and are characterized by a continuously varying exponent. We show that spatial hierarchy emerges naturally, with structures composed of various hubs controlling geographically separated service areas, and appears as a large-scale consequence of local cost-benefit considerations. Our model thus provides the basic building blocks for a better understanding of the evolution of spatial networks and their properties. We also find that, surprisingly, the average detour is minimal in the intermediate regime as a result of a large diversity in link lengths. Finally, we estimate the important parameters for various world railway networks and find that, remarkably, they all fall in this intermediate regime, suggesting that spatial hierarchy is a crucial feature for these systems and probably possesses an important evolutionary advantage.

  12. The early history and emergence of molecular functions and modular scale-free network behavior

    PubMed Central

    Aziz, M. Fayez; Caetano-Anollés, Kelsey; Caetano-Anollés, Gustavo

    2016-01-01

    The formation of protein structural domains requires that biochemical functions, defined by conserved amino acid sequence motifs, be embedded into a structural scaffold. Here we trace domain history onto a bipartite network of elementary functional loop sequences and domain structures defined at the fold superfamily level of SCOP classification. The resulting ‘elementary functionome’ network and its loop motif and structural domain graph projections create evolutionary ‘waterfalls’ describing the emergence of primordial functions. Waterfalls reveal how ancient loops are shared by domain structures in two initial waves of functional innovation that involve founder ‘p-loop’ and ‘winged helix’ domain structures. They also uncover a dynamics of modular motif embedding in domain structures that is ongoing, which transfers ‘preferential’ cooption properties of ancient loops to emerging domains. Remarkably, we find that the emergence of molecular functions induces hierarchical modularity and power law behavior in network evolution as the network of motifs and structures expand metabolic pathways and translation. PMID:27121452

  13. The early history and emergence of molecular functions and modular scale-free network behavior

    NASA Astrophysics Data System (ADS)

    Aziz, M. Fayez; Caetano-Anollés, Kelsey; Caetano-Anollés, Gustavo

    2016-04-01

    The formation of protein structural domains requires that biochemical functions, defined by conserved amino acid sequence motifs, be embedded into a structural scaffold. Here we trace domain history onto a bipartite network of elementary functional loop sequences and domain structures defined at the fold superfamily level of SCOP classification. The resulting ‘elementary functionome’ network and its loop motif and structural domain graph projections create evolutionary ‘waterfalls’ describing the emergence of primordial functions. Waterfalls reveal how ancient loops are shared by domain structures in two initial waves of functional innovation that involve founder ‘p-loop’ and ‘winged helix’ domain structures. They also uncover a dynamics of modular motif embedding in domain structures that is ongoing, which transfers ‘preferential’ cooption properties of ancient loops to emerging domains. Remarkably, we find that the emergence of molecular functions induces hierarchical modularity and power law behavior in network evolution as the network of motifs and structures expand metabolic pathways and translation.

  14. Information Dissemination of Public Health Emergency on Social Networks and Intelligent Computation

    PubMed Central

    Hu, Hongzhi; Mao, Huajuan; Hu, Xiaohua; Hu, Feng; Sun, Xuemin; Jing, Zaiping; Duan, Yunsuo

    2015-01-01

    Due to the extensive social influence, public health emergency has attracted great attention in today's society. The booming social network is becoming a main information dissemination platform of those events and caused high concerns in emergency management, among which a good prediction of information dissemination in social networks is necessary for estimating the event's social impacts and making a proper strategy. However, information dissemination is largely affected by complex interactive activities and group behaviors in social network; the existing methods and models are limited to achieve a satisfactory prediction result due to the open changeable social connections and uncertain information processing behaviors. ACP (artificial societies, computational experiments, and parallel execution) provides an effective way to simulate the real situation. In order to obtain better information dissemination prediction in social networks, this paper proposes an intelligent computation method under the framework of TDF (Theory-Data-Feedback) based on ACP simulation system which was successfully applied to the analysis of A (H1N1) Flu emergency. PMID:26609303

  15. Information Dissemination of Public Health Emergency on Social Networks and Intelligent Computation.

    PubMed

    Hu, Hongzhi; Mao, Huajuan; Hu, Xiaohua; Hu, Feng; Sun, Xuemin; Jing, Zaiping; Duan, Yunsuo

    2015-01-01

    Due to the extensive social influence, public health emergency has attracted great attention in today's society. The booming social network is becoming a main information dissemination platform of those events and caused high concerns in emergency management, among which a good prediction of information dissemination in social networks is necessary for estimating the event's social impacts and making a proper strategy. However, information dissemination is largely affected by complex interactive activities and group behaviors in social network; the existing methods and models are limited to achieve a satisfactory prediction result due to the open changeable social connections and uncertain information processing behaviors. ACP (artificial societies, computational experiments, and parallel execution) provides an effective way to simulate the real situation. In order to obtain better information dissemination prediction in social networks, this paper proposes an intelligent computation method under the framework of TDF (Theory-Data-Feedback) based on ACP simulation system which was successfully applied to the analysis of A (H1N1) Flu emergency.

  16. Topology of Innovation Spaces in the Knowledge Networks Emerging through Questions-And-Answers

    PubMed Central

    Andjelković, Miroslav; Tadić, Bosiljka; Mitrović Dankulov, Marija; Rajković, Milan; Melnik, Roderick

    2016-01-01

    The communication processes of knowledge creation represent a particular class of human dynamics where the expertise of individuals plays a substantial role, thus offering a unique possibility to study the structure of knowledge networks from online data. Here, we use the empirical evidence from questions-and-answers in mathematics to analyse the emergence of the network of knowledge contents (or tags) as the individual experts use them in the process. After removing extra edges from the network-associated graph, we apply the methods of algebraic topology of graphs to examine the structure of higher-order combinatorial spaces in networks for four consecutive time intervals. We find that the ranking distributions of the suitably scaled topological dimensions of nodes fall into a unique curve for all time intervals and filtering levels, suggesting a robust architecture of knowledge networks. Moreover, these networks preserve the logical structure of knowledge within emergent communities of nodes, labeled according to a standard mathematical classification scheme. Further, we investigate the appearance of new contents over time and their innovative combinations, which expand the knowledge network. In each network, we identify an innovation channel as a subgraph of triangles and larger simplices to which new tags attach. Our results show that the increasing topological complexity of the innovation channels contributes to network’s architecture over different time periods, and is consistent with temporal correlations of the occurrence of new tags. The methodology applies to a wide class of data with the suitable temporal resolution and clearly identified knowledge-content units. PMID:27171149

  17. Emergence of Metastable State Dynamics in Interconnected Cortical Networks with Propagation Delays

    PubMed Central

    Kutchko, Katrina M.; Fröhlich, Flavio

    2013-01-01

    The importance of the large number of thin-diameter and unmyelinated axons that connect different cortical areas is unknown. The pronounced propagation delays in these axons may prevent synchronization of cortical networks and therefore hinder efficient information integration and processing. Yet, such global information integration across cortical areas is vital for higher cognitive function. We hypothesized that delays in communication between cortical areas can disrupt synchronization and therefore enhance the set of activity trajectories and computations interconnected networks can perform. To evaluate this hypothesis, we studied the effect of long-range cortical projections with propagation delays in interconnected large-scale cortical networks that exhibited spontaneous rhythmic activity. Long-range connections with delays caused the emergence of metastable, spatio-temporally distinct activity states between which the networks spontaneously transitioned. Interestingly, the observed activity patterns correspond to macroscopic network dynamics such as globally synchronized activity, propagating wave fronts, and spiral waves that have been previously observed in neurophysiological recordings from humans and animal models. Transient perturbations with simulated transcranial alternating current stimulation (tACS) confirmed the multistability of the interconnected networks by switching the networks between these metastable states. Our model thus proposes that slower long-range connections enrich the landscape of activity states and represent a parsimonious mechanism for the emergence of multistability in cortical networks. These results further provide a mechanistic link between the known deficits in connectivity and cortical state dynamics in neuropsychiatric illnesses such as schizophrenia and autism, as well as suggest non-invasive brain stimulation as an effective treatment for these illnesses. PMID:24204238

  18. Emergence of gamma motor activity in an artificial neural network model of the corticospinal system.

    PubMed

    Grandjean, Bernard; Maier, Marc A

    2017-02-01

    Muscle spindle discharge during active movement is a function of mechanical and neural parameters. Muscle length changes (and their derivatives) represent its primary mechanical, fusimotor drive its neural component. However, neither the action nor the function of fusimotor and in particular of γ-drive, have been clearly established, since γ-motor activity during voluntary, non-locomotor movements remains largely unknown. Here, using a computational approach, we explored whether γ-drive emerges in an artificial neural network model of the corticospinal system linked to a biomechanical antagonist wrist simulator. The wrist simulator included length-sensitive and γ-drive-dependent type Ia and type II muscle spindle activity. Network activity and connectivity were derived by a gradient descent algorithm to generate reciprocal, known target α-motor unit activity during wrist flexion-extension (F/E) movements. Two tasks were simulated: an alternating F/E task and a slow F/E tracking task. Emergence of γ-motor activity in the alternating F/E network was a function of α-motor unit drive: if muscle afferent (together with supraspinal) input was required for driving α-motor units, then γ-drive emerged in the form of α-γ coactivation, as predicted by empirical studies. In the slow F/E tracking network, γ-drive emerged in the form of α-γ dissociation and provided critical, bidirectional muscle afferent activity to the cortical network, containing known bidirectional target units. The model thus demonstrates the complementary aspects of spindle output and hence γ-drive: i) muscle spindle activity as a driving force of α-motor unit activity, and ii) afferent activity providing continuous sensory information, both of which crucially depend on γ-drive.

  19. Panorama of Phoenix Solar Panel and Robotic Arm

    NASA Image and Video Library

    2008-06-13

    This panorama image of NASA’s Phoenix Mars Lander’s solar panel and the lander’s Robotic Arm with a sample in the scoop. The image was taken just before the sample was delivered to the Optical Microscope.

  20. PHOTOGRAPH NUMBERS 40, 39, 38 FORM A 189 DEGREE PANORAMA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PHOTOGRAPH NUMBERS 40, 39, 38 FORM A 189 DEGREE PANORAMA FROM LEFT TO RIGHT. PHOTOGRAPH NUMBER 38 LOOKING NORTHEAST TO SKYLINE FROM ROOF OF POLSON BUILDING; PHOTOGRAPH NUMBER 39 VIEW NORTH; PHOTOGRAPH NUMBER 40 VIEW NORTHWEST. - Alaskan Way Viaduct and Battery Street Tunnel, Seattle, King County, WA

  1. Panorama of the Heinz Lofts complex: Meat Products Building (far ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Panorama of the Heinz Lofts complex: Meat Products Building (far left), Cereal Building (left, with sign), and Reservoir Building (right, 1926), looking northwest from Heinz Street and River Avenue. The Riley Research Center (1958, Skidmore, Owings & Merrill) can be seen at far right, still part of the Heinz Company. - H.J. Heinz Company Factories, 300 Heinz Street, Pittsburgh, Allegheny County, PA

  2. 10. SITE OVERVIEW. PART 5 OF 6 PART PANORAMA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. SITE OVERVIEW. PART 5 OF 6 PART PANORAMA WITH NOS. CA-265-6 TO CA-265-11. ARROYO SECO PARKWAY AS SEEN FROM RADIO TOWER HILL. PART 5 SHOWS ARROYO SECO PARKWAY AND AVENUE 43 BRIDGE AT RIGHT REAR. LOOKING 334° NNW. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  3. 8. SITE OVERVIEW. PART 3 OF 6 PART PANORAMA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. SITE OVERVIEW. PART 3 OF 6 PART PANORAMA WITH NOS. CA-265-6 TO CA-265-11. ARROYO SECO PARKWAY AS SEEN FROM RADIO TOWER HILL. LOOKING 290° WNW. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  4. 9. SITE OVERVIEW. PART 4 OF 6 PART PANORAMA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. SITE OVERVIEW. PART 4 OF 6 PART PANORAMA WITH NOS. CA-265-6 TO CA-265-11. ARROYO SECO PARKWAY AS SEEN FROM RADIO TOWER HILL. PART 4 SHOWS ARROYO SECO PARKWAY IN FOREGROUND AND FIGUEROA STREET AT CENTER. LOOKING 316° NW. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  5. 3D moviemap and a 3D panorama

    NASA Astrophysics Data System (ADS)

    Naimark, Michael

    1997-05-01

    Two immersive virtual environments produced as art installations investigate 'sense of place' in different but complimentary ways. One is a stereoscopic moviemap, the other a stereoscopic panorama. Moviemaps are interactive systems which allow 'travel' along pre-recorded routes with some control over speed and direction. Panoramas are 360 degree visual representations dating back to the late 18th century but which have recently experienced renewed interest due to 'virtual reality' systems. Moviemaps allow 'moving around' while panoramas allow 'looking around,' but to date there has been little or no attempt to produce either in stereo from camera-based material. 'See Banff stereoscopic moviemap about landscape, tourism, and growth in the Canadian Rocky Mountains. It was filmed with twin 16 mm cameras and displayed as a single-user experience housed in a cabinet resembling a century-old kinetoscope, with a crank on the side for 'moving through' the material. 'Be Now Here (Welcome to the Neighborhood)' (1995-6) is a stereoscopic panorama filmed in public gathering places around the world, based upon the UNESCO World Heritage 'In Danger' list. It was filmed with twin 35 mm motion picture cameras on a rotating tripod and displayed using a synchronized rotating floor.

  6. 3. RIGHT SIDE OF PANORAMA VIEW OF REAR OF ELM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. RIGHT SIDE OF PANORAMA VIEW OF REAR OF ELM CITY PLANT FROM SECOND AVENUE. NOTE BOILER STACK ON LEFT. THE FULLER E. CALLAWAY MEMORIAL CLOCK TOWER IS THE POINTED STRUCTURE IN THE DISTANCE TO THE RIGHT OF THE TELEPHONE POLE. - Elm City Cotton Mill, 1000 Elm Street, La Grange, Troup County, GA

  7. Panorama, section 2 of 3, note the Operations Building (Facility ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Panorama, section 2 of 3, note the Operations Building (Facility 294) in the center of facility, view facing west - U.S. Naval Base, Pearl Harbor, Naval Radio Station, AF/FRD-10 Circularly Disposed Antenna Array, Wahiawa, Honolulu County, HI

  8. 2. CENTER PORTION OF PANORAMA VIEW OF REAR OF ELM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. CENTER PORTION OF PANORAMA VIEW OF REAR OF ELM CITY PLANT FROM SECOND AVENUE. NOTE ORIGINAL WATER TANK TOWER IN CENTER AND NEWER ADDITIONS TO THIS STILL OPERATIONAL TEXTILE MILL. - Elm City Cotton Mill, 1000 Elm Street, La Grange, Troup County, GA

  9. Spirit Paige Panorama of the Interior of Home Plate

    NASA Image and Video Library

    2006-03-06

    This panorama shows two reddish-brown, rock-strewn slopes on the left and right sides of a broad, U-shaped dip in the middle. In the distance are the broad slopes of McCool Hill. Above that is an orangish-yellow sky.

  10. Risk analysis of emergent water pollution accidents based on a Bayesian Network.

    PubMed

    Tang, Caihong; Yi, Yujun; Yang, Zhifeng; Sun, Jie

    2016-01-01

    To guarantee the security of water quality in water transfer channels, especially in open channels, analysis of potential emergent pollution sources in the water transfer process is critical. It is also indispensable for forewarnings and protection from emergent pollution accidents. Bridges above open channels with large amounts of truck traffic are the main locations where emergent accidents could occur. A Bayesian Network model, which consists of six root nodes and three middle layer nodes, was developed in this paper, and was employed to identify the possibility of potential pollution risk. Dianbei Bridge is reviewed as a typical bridge on an open channel of the Middle Route of the South to North Water Transfer Project where emergent traffic accidents could occur. Risk of water pollutions caused by leakage of pollutants into water is focused in this study. The risk for potential traffic accidents at the Dianbei Bridge implies a risk for water pollution in the canal. Based on survey data, statistical analysis, and domain specialist knowledge, a Bayesian Network model was established. The human factor of emergent accidents has been considered in this model. Additionally, this model has been employed to describe the probability of accidents and the risk level. The sensitive reasons for pollution accidents have been deduced. The case has also been simulated that sensitive factors are in a state of most likely to lead to accidents.

  11. Contemporary, emerging, and ratified wireless security standards: an update for the networked dental office.

    PubMed

    Mupparapu, Muralidhar

    2006-02-15

    Wireless networking is not new to contemporary dental offices around the country. Wireless routers and network cards have made access to patient records within the office handy and, thereby, saving valuable chair side time and increasing productivity. As is the case with any rapidly developing technology, wireless technology also changes with the same rate. Unless, the users of the wireless networking understand the implications of these changes and keep themselves updated periodically, the office network will become obsolete very quickly. This update of the emerging security protocols and pertaining to ratified wireless 802.11 standards will be timely for the contemporary dentist whose office is wirelessly networked. This article brings the practicing dentist up-to-date on the newer versions and standards in wireless networking that are changing at a fast pace. The introduction of newer 802.11 standards like super G, Super AG, Multiple Input Multiple Output (MIMO), and pre-n are changing the pace of adaptation of this technology. Like any other rapidly transforming technology, information pertaining to wireless networking should be a priority for the contemporary dentist, an eventual end-user in order to be a well-informed and techno-savvy consumer.

  12. Assortativity and leadership emerge from anti-preferential attachment in heterogeneous networks

    NASA Astrophysics Data System (ADS)

    Sendiña-Nadal, I.; Danziger, M. M.; Wang, Z.; Havlin, S.; Boccaletti, S.

    2016-02-01

    Real-world networks have distinct topologies, with marked deviations from purely random networks. Many of them exhibit degree-assortativity, with nodes of similar degree more likely to link to one another. Though microscopic mechanisms have been suggested for the emergence of other topological features, assortativity has proven elusive. Assortativity can be artificially implanted in a network via degree-preserving link permutations, however this destroys the graph’s hierarchical clustering and does not correspond to any microscopic mechanism. Here, we propose the first generative model which creates heterogeneous networks with scale-free-like properties in degree and clustering distributions and tunable realistic assortativity. Two distinct populations of nodes are incrementally added to an initial network by selecting a subgraph to connect to at random. One population (the followers) follows preferential attachment, while the other population (the potential leaders) connects via anti-preferential attachment: they link to lower degree nodes when added to the network. By selecting the lower degree nodes, the potential leader nodes maintain high visibility during the growth process, eventually growing into hubs. The evolution of links in Facebook empirically validates the connection between the initial anti-preferential attachment and long term high degree. In this way, our work sheds new light on the structure and evolution of social networks.

  13. Irreversible thermodynamics of open chemical networks. I. Emergent cycles and broken conservation laws

    NASA Astrophysics Data System (ADS)

    Polettini, Matteo; Esposito, Massimiliano

    2014-07-01

    In this paper and Paper II, we outline a general framework for the thermodynamic description of open chemical reaction networks, with special regard to metabolic networks regulating cellular physiology and biochemical functions. We first introduce closed networks "in a box", whose thermodynamics is subjected to strict physical constraints: the mass-action law, elementarity of processes, and detailed balance. We further digress on the role of solvents and on the seemingly unacknowledged property of network independence of free energy landscapes. We then open the system by assuming that the concentrations of certain substrate species (the chemostats) are fixed, whether because promptly regulated by the environment via contact with reservoirs, or because nearly constant in a time window. As a result, the system is driven out of equilibrium. A rich algebraic and topological structure ensues in the network of internal species: Emergent irreversible cycles are associated with nonvanishing affinities, whose symmetries are dictated by the breakage of conservation laws. These central results are resumed in the relation a + b = sY between the number of fundamental affinities a, that of broken conservation laws b and the number of chemostats sY. We decompose the steady state entropy production rate in terms of fundamental fluxes and affinities in the spirit of Schnakenberg's theory of network thermodynamics, paving the way for the forthcoming treatment of the linear regime, of efficiency and tight coupling, of free energy transduction, and of thermodynamic constraints for network reconstruction.

  14. Irreversible thermodynamics of open chemical networks. I. Emergent cycles and broken conservation laws

    SciTech Connect

    Polettini, Matteo Esposito, Massimiliano

    2014-07-14

    In this paper and Paper II, we outline a general framework for the thermodynamic description of open chemical reaction networks, with special regard to metabolic networks regulating cellular physiology and biochemical functions. We first introduce closed networks “in a box”, whose thermodynamics is subjected to strict physical constraints: the mass-action law, elementarity of processes, and detailed balance. We further digress on the role of solvents and on the seemingly unacknowledged property of network independence of free energy landscapes. We then open the system by assuming that the concentrations of certain substrate species (the chemostats) are fixed, whether because promptly regulated by the environment via contact with reservoirs, or because nearly constant in a time window. As a result, the system is driven out of equilibrium. A rich algebraic and topological structure ensues in the network of internal species: Emergent irreversible cycles are associated with nonvanishing affinities, whose symmetries are dictated by the breakage of conservation laws. These central results are resumed in the relation a + b = s{sup Y} between the number of fundamental affinities a, that of broken conservation laws b and the number of chemostats s{sup Y}. We decompose the steady state entropy production rate in terms of fundamental fluxes and affinities in the spirit of Schnakenberg's theory of network thermodynamics, paving the way for the forthcoming treatment of the linear regime, of efficiency and tight coupling, of free energy transduction, and of thermodynamic constraints for network reconstruction.

  15. Irreversible thermodynamics of open chemical networks. I. Emergent cycles and broken conservation laws.

    PubMed

    Polettini, Matteo; Esposito, Massimiliano

    2014-07-14

    In this paper and Paper II, we outline a general framework for the thermodynamic description of open chemical reaction networks, with special regard to metabolic networks regulating cellular physiology and biochemical functions. We first introduce closed networks "in a box", whose thermodynamics is subjected to strict physical constraints: the mass-action law, elementarity of processes, and detailed balance. We further digress on the role of solvents and on the seemingly unacknowledged property of network independence of free energy landscapes. We then open the system by assuming that the concentrations of certain substrate species (the chemostats) are fixed, whether because promptly regulated by the environment via contact with reservoirs, or because nearly constant in a time window. As a result, the system is driven out of equilibrium. A rich algebraic and topological structure ensues in the network of internal species: Emergent irreversible cycles are associated with nonvanishing affinities, whose symmetries are dictated by the breakage of conservation laws. These central results are resumed in the relation a + b = s(Y) between the number of fundamental affinities a, that of broken conservation laws b and the number of chemostats s(Y). We decompose the steady state entropy production rate in terms of fundamental fluxes and affinities in the spirit of Schnakenberg's theory of network thermodynamics, paving the way for the forthcoming treatment of the linear regime, of efficiency and tight coupling, of free energy transduction, and of thermodynamic constraints for network reconstruction.

  16. A Fast Channel Assignment Scheme for Emergency Handling in Wireless Body Area Networks

    PubMed Central

    Nepal, Sabita; Pudasani, Amod; Shin, Seokjoo

    2017-01-01

    Ubiquitous healthcare is a promising technology that has attracted significant attention in recent years; this has led to the realization of wireless body area networks (WBANs). For designing a robust WBAN system, the WBAN has to solve the drawbacks of wireless technology. Also, a WBAN has to support immediate, reliable data transmission for medical services during emergencies. Hence, this study proposes a new MAC superframe structure that can handle emergencies by delivering strongly correlated regular data to a caretaker, within a certain time threshold. Simulation results demonstrate that the proposed MAC protocol achieves low latency and high throughput. PMID:28264455

  17. A Fast Channel Assignment Scheme for Emergency Handling in Wireless Body Area Networks.

    PubMed

    Nepal, Sabita; Pudasani, Amod; Shin, Seokjoo

    2017-02-27

    Ubiquitous healthcare is a promising technology that has attracted significant attention in recent years; this has led to the realization of wireless body area networks (WBANs). For designing a robust WBAN system, the WBAN has to solve the drawbacks of wireless technology. Also, a WBAN has to support immediate, reliable data transmission for medical services during emergencies. Hence, this study proposes a new MAC superframe structure that can handle emergencies by delivering strongly correlated regular data to a caretaker, within a certain time threshold. Simulation results demonstrate that the proposed MAC protocol achieves low latency and high throughput.

  18. Principles of Network Architecture Emerging from Comparisons of the Cerebral Cortex in Large and Small Brains

    PubMed Central

    Finlay, Barbara L.

    2016-01-01

    The cerebral cortex retains its fundamental organization, layering, and input–output relations as it scales in volume over many orders of magnitude in mammals. How is its network architecture affected by size scaling? By comparing network organization of the mouse and rhesus macaque cortical connectome derived from complete neuroanatomical tracing studies, a recent study in PLOS Biology shows that an exponential distance rule emerges that reveals the falloff in connection probability with distance in the two brains that in turn determines common organizational features. PMID:27631433

  19. Social Networking and eDating: Charting the Boundaries of an Emerging Self-Service Arena

    NASA Astrophysics Data System (ADS)

    Romm, Celia T.; Oliver, Dave

    This chapter focuses on social networking and eDating as emerging areas of self-service. Following an overview of the theoretical aspects of self-service, two models or typologies for categorizing business models in the two areas are presented, namely, one typology for social networking services and another for eDating services. The chapter concludes with a discussion of the psychological, social, legal, and other implications from the models, as well as suggestions for future research that emanate from the issues presented in the chapter.

  20. Architectural and operational considerations emerging from hybrid RF-optical network loading simulations

    NASA Astrophysics Data System (ADS)

    Chen, Yijiang; Abraham, Douglas S.; Heckman, David P.; Kwok, Andrew; MacNeal, Bruce E.; Tran, Kristy; Wu, Janet P.

    2016-03-01

    A technology demonstration of free space optical communication at interplanetary distances is planned via one or more future NASA deep-space missions. Such demonstrations will "pave the way" for operational use of optical communications on future robotic/potential Human missions. Hence, the Deep Space Network architecture will need to evolve. Preliminary attempts to model the anticipated future mission set and simulate how well it loads onto assumed architectures with combinations of RF and optical apertures have been evaluated. This paper discusses the results of preliminary loading simulations for hybrid RF-optical network architectures and highlights key mission and ground infrastructure considerations that emerge.

  1. The emergence and effectiveness of global health networks: findings and future research.

    PubMed

    Shiffman, Jeremy; Schmitz, Hans Peter; Berlan, David; Smith, Stephanie L; Quissell, Kathryn; Gneiting, Uwe; Pelletier, David

    2016-04-01

    Global health issues vary in the amount of attention and resources they receive. One reason is that the networks of individuals and organizations that address these issues differ in their effectiveness. This article presents key findings from a research project on the emergence and effectiveness of global health networks addressing tobacco use, alcohol harm, maternal mortality, neonatal mortality, tuberculosis and pneumonia. Although networks are only one of many factors influencing priority, they do matter, particularly for shaping the way the problem and solutions are understood, and convincing governments, international organizations and other global actors to address the issue. Their national-level effects vary by issue and are more difficult to ascertain. Networks are most likely to produce effects when (1) their members construct a compelling framing of the issue, one that includes a shared understanding of the problem, a consensus on solutions and convincing reasons to act and (2) they build a political coalition that includes individuals and organizations beyond their traditional base in the health sector, a task that demands engagement in the politics of the issue, not just its technical aspects. Maintaining a focused frame and sustaining a broad coalition are often in tension: effective networks find ways to balance the two challenges. The emergence and effectiveness of a network are shaped both by its members' decisions and by contextual factors, including historical influences (e.g. prior failed attempts to address the problem), features of the policy environment (e.g. global development goals) and characteristics of the issue the network addresses (e.g. its mortality burden). Their proliferation raises the issue of their legitimacy. Reasons to consider them legitimate include their members' expertise and the attention they bring to neglected issues. Reasons to question their legitimacy include their largely elite composition and the fragmentation they

  2. The emergence and effectiveness of global health networks: findings and future research

    PubMed Central

    Shiffman, Jeremy; Peter Schmitz, Hans; Berlan, David; Smith, Stephanie L; Quissell, Kathryn; Gneiting, Uwe; Pelletier, David

    2016-01-01

    Global health issues vary in the amount of attention and resources they receive. One reason is that the networks of individuals and organizations that address these issues differ in their effectiveness. This article presents key findings from a research project on the emergence and effectiveness of global health networks addressing tobacco use, alcohol harm, maternal mortality, neonatal mortality, tuberculosis and pneumonia. Although networks are only one of many factors influencing priority, they do matter, particularly for shaping the way the problem and solutions are understood, and convincing governments, international organizations and other global actors to address the issue. Their national-level effects vary by issue and are more difficult to ascertain. Networks are most likely to produce effects when (1) their members construct a compelling framing of the issue, one that includes a shared understanding of the problem, a consensus on solutions and convincing reasons to act and (2) they build a political coalition that includes individuals and organizations beyond their traditional base in the health sector, a task that demands engagement in the politics of the issue, not just its technical aspects. Maintaining a focused frame and sustaining a broad coalition are often in tension: effective networks find ways to balance the two challenges. The emergence and effectiveness of a network are shaped both by its members’ decisions and by contextual factors, including historical influences (e.g. prior failed attempts to address the problem), features of the policy environment (e.g. global development goals) and characteristics of the issue the network addresses (e.g. its mortality burden). Their proliferation raises the issue of their legitimacy. Reasons to consider them legitimate include their members’ expertise and the attention they bring to neglected issues. Reasons to question their legitimacy include their largely elite composition and the fragmentation

  3. Emergence of plant vascular system: roles of hormonal and non-hormonal regulatory networks.

    PubMed

    Cho, Hyunwoo; Dang, Tuong Vi T; Hwang, Ildoo

    2017-02-01

    The divergence of land plants followed by vascular plants has entirely changed the terrestrial ecology. The vascular system is a prerequisite for this evolutionary event, providing upright stature and communication for sink demand-source capacity and facilitating the development of plants and colonization over a wide range of environmental habitats. Various hormonal and non-hormonal regulatory networks have been identified and reviewed as key processes for vascular formation; however, how these factors have evolutionarily emerged and interconnected to trigger the emergence of the vascular system still remains elusive. Here, to understand the intricacy of cross-talks among these factors, we highlight how core hormonal signaling and transcriptional networks are coalesced into the appearance of vascular plants during evolution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Emergence of Small-World and Limitations to Its Maximization in a Macaque Cerebral Cortical Network

    NASA Astrophysics Data System (ADS)

    Zhao, Qing-Bai; Liao, Meng-Jie; Chen, Qi-Cai

    2011-06-01

    We study both the emergence of small-world topology in a macaque cerebral cortical network and the limitations to maximization of small-worldness. The results show that the maximization of neural complexity leads to a small-world topology, but it also limits the maximization of small-worldness. It is suggested that the modular organization that corresponds to different functions may be a limitation. Additionally, the need for strong resilience against attacks may be another limitation.

  5. GHSI EMERGENCY RADIONUCLIDE BIOASSAY LABORATORY NETWORK - SUMMARY OF THE SECOND EXERCISE.

    PubMed

    Li, Chunsheng; Bartizel, Christine; Battisti, Paolo; Böttger, Axel; Bouvier, Céline; Capote-Cuellar, Antonio; Carr, Zhanat; Hammond, Derek; Hartmann, Martina; Heikkinen, Tarja; Jones, Robert L; Kim, Eunjoo; Ko, Raymond; Koga, Roberto; Kukhta, Boris; Mitchell, Lorna; Morhard, Ryan; Paquet, Francois; Quayle, Debora; Rulik, Petr; Sadi, Baki; Sergei, Aleksanin; Sierra, Inmaculada; de Oliveira Sousa, Wanderson; Szabό, Gyula

    2016-08-29

    The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop collective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency as a means of enhancing response capability, health outcomes and community resilience. GHSI partners conducted an exercise in collaboration with the WHO Radiation Emergency Medical Preparedness and Assistance Network and the IAEA Response and Assistance Network, to test the participating laboratories (18) for their capabilities in in vitro assay of biological samples, using a urine sample spiked with multiple high-risk radionuclides ((90)Sr, (106)Ru, (137)Cs, and (239)Pu). Laboratories were required to submit their reports within 72 h following receipt of the sample, using a pre-formatted template, on the procedures, methods and techniques used to identify and quantify the radionuclides in the sample, as well as the bioassay results with a 95% confidence interval. All of the participating laboratories identified and measured all or some of the radionuclides in the sample. However, gaps were identified in both the procedures used to assay multiple radionuclides in one sample, as well as in the methods or techniques used to assay specific radionuclides in urine. Two-third of the participating laboratories had difficulties in determining all the radionuclides in the sample. Results from this exercise indicate that challenges remain with respect to ensuring that results are delivered in a timely, consistent and reliable manner to support medical interventions. Laboratories within the networks are encouraged to work together to develop and maintain collective capabilities and capacity for emergency bioassay, which is an important component of radiation emergency response.

  6. The World Health Organization Network for Radiation Emergency Medical Preparedness and Assistance (REMPAN).

    PubMed Central

    Souchkevitch, G

    1997-01-01

    The World Health Organization (WHO) has established a system of collaborating centers known as the Radiation Emergency Medical Preparedness and Assistance Network (REMPAN) to promote radiation emergency medical preparedness, assistance, and advice to countries in cases of overexposure of populations from any source of radiation. This network consists of 13 specialized institutions located in 10 countries. Within the REMPAN there are three separate but linked activities. The first is aimed at strengthening radiation emergency medical preparedness and assistance to treat and monitor acutely exposed individuals. The second activity is directed toward improving public health advice to mitigate long-term effects of exposure to low and protracted doses that might accrue in populations living in the affected territories. This involves giving advice on protecting public health, e.g., iodine prophylaxis, psychosocial risks associated with countermeasures, and public information strategies. In addition, the REMPAN develops activities aimed at improving long-term follow-up studies and preparedness for epidemiologic investigations in territories contaminated by radionuclides from a nuclear accident. The WHO's response in a radiation emergency depends on the type of accident and its time phase. This includes a wide range of actions from studying the situation to providing medical and public health assistance through the network of collaborating centers and relevant institutions within the REMPAN. The process of creating a reliable international system for radiation emergency medical preparedness and assistance has not yet been completed. Deficiencies in this system are outlined in this paper to attract the attention of specialists in the field of radiation protection and potential donors of the WHO program. PMID:9467087

  7. Emergence and evolutionary analysis of the human DDR network: implications in comparative genomics and downstream analyses.

    PubMed

    Arcas, Aida; Fernández-Capetillo, Oscar; Cases, Ildefonso; Rojas, Ana M

    2014-04-01

    The DNA damage response (DDR) is a crucial signaling network that preserves the integrity of the genome. This network is an ensemble of distinct but often overlapping subnetworks, where different components fulfill distinct functions in precise spatial and temporal scenarios. To understand how these elements have been assembled together in humans, we performed comparative genomic analyses in 47 selected species to trace back their emergence using systematic phylogenetic analyses and estimated gene ages. The emergence of the contribution of posttranslational modifications to the complex regulation of DDR was also investigated. This is the first time a systematic analysis has focused on the evolution of DDR subnetworks as a whole. Our results indicate that a DDR core, mostly constructed around metabolic activities, appeared soon after the emergence of eukaryotes, and that additional regulatory capacities appeared later through complex evolutionary process. Potential key posttranslational modifications were also in place then, with interacting pairs preferentially appearing at the same evolutionary time, although modifications often led to the subsequent acquisition of new targets afterwards. We also found extensive gene loss in essential modules of the regulatory network in fungi, plants, and arthropods, important for their validation as model organisms for DDR studies.

  8. Emergency Situation Prediction Mechanism: A Novel Approach for Intelligent Transportation System Using Vehicular Ad Hoc Networks

    PubMed Central

    Gokulakrishnan, P.

    2015-01-01

    In Indian four-lane express highway, millions of vehicles are travelling every day. Accidents are unfortunate and frequently occurring in these highways causing deaths, increase in death toll, and damage to infrastructure. A mechanism is required to avoid such road accidents at the maximum to reduce the death toll. An Emergency Situation Prediction Mechanism, a novel and proactive approach, is proposed in this paper for achieving the best of Intelligent Transportation System using Vehicular Ad Hoc Network. ESPM intends to predict the possibility of occurrence of an accident in an Indian four-lane express highway. In ESPM, the emergency situation prediction is done by the Road Side Unit based on (i) the Status Report sent by the vehicles in the range of RSU and (ii) the road traffic flow analysis done by the RSU. Once the emergency situation or accident is predicted in advance, an Emergency Warning Message is constructed and disseminated to all vehicles in the area of RSU to alert and prevent the vehicles from accidents. ESPM performs well in emergency situation prediction in advance to the occurrence of an accident. ESPM predicts the emergency situation within 0.20 seconds which is comparatively less than the statistical value. The prediction accuracy of ESPM against vehicle density is found better in different traffic scenarios. PMID:26065014

  9. Emergency Situation Prediction Mechanism: A Novel Approach for Intelligent Transportation System Using Vehicular Ad Hoc Networks.

    PubMed

    Ganeshkumar, P; Gokulakrishnan, P

    2015-01-01

    In Indian four-lane express highway, millions of vehicles are travelling every day. Accidents are unfortunate and frequently occurring in these highways causing deaths, increase in death toll, and damage to infrastructure. A mechanism is required to avoid such road accidents at the maximum to reduce the death toll. An Emergency Situation Prediction Mechanism, a novel and proactive approach, is proposed in this paper for achieving the best of Intelligent Transportation System using Vehicular Ad Hoc Network. ESPM intends to predict the possibility of occurrence of an accident in an Indian four-lane express highway. In ESPM, the emergency situation prediction is done by the Road Side Unit based on (i) the Status Report sent by the vehicles in the range of RSU and (ii) the road traffic flow analysis done by the RSU. Once the emergency situation or accident is predicted in advance, an Emergency Warning Message is constructed and disseminated to all vehicles in the area of RSU to alert and prevent the vehicles from accidents. ESPM performs well in emergency situation prediction in advance to the occurrence of an accident. ESPM predicts the emergency situation within 0.20 seconds which is comparatively less than the statistical value. The prediction accuracy of ESPM against vehicle density is found better in different traffic scenarios.

  10. Invaders of pollination networks in the Galapagos Islands: emergence of novel communities.

    PubMed

    Traveset, Anna; Heleno, Ruben; Chamorro, Susana; Vargas, Pablo; McMullen, Conley K; Castro-Urgal, Rocío; Nogales, Manuel; Herrera, Henri W; Olesen, Jens M

    2013-05-07

    The unique biodiversity of most oceanic archipelagos is currently threatened by the introduction of alien species that can displace native biota, disrupt native ecological interactions, and profoundly affect community structure and stability. We investigated the threat of aliens on pollination networks in the species-rich lowlands of five Galápagos Islands. Twenty per cent of all species (60 plants and 220 pollinators) in the pooled network were aliens, being involved in 38 per cent of the interactions. Most aliens were insects, especially dipterans (36%), hymenopterans (30%) and lepidopterans (14%). These alien insects had more links than either endemic pollinators or non-endemic natives, some even acting as island hubs. Aliens linked mostly to generalized species, increasing nestedness and thus network stability. Moreover, they infiltrated all seven connected modules (determined by geographical and phylogenetic constraints) of the overall network, representing around 30 per cent of species in two of them. An astonishingly high proportion (38%) of connectors, which enhance network cohesiveness, was also alien. Results indicate that the structure of these emergent novel communities might become more resistant to certain type of disturbances (e.g. species loss), while being more vulnerable to others (e.g. spread of a disease). Such notable changes in network structure as invasions progress are expected to have important consequences for native biodiversity maintenance.

  11. Invaders of pollination networks in the Galápagos Islands: emergence of novel communities

    PubMed Central

    Traveset, Anna; Heleno, Ruben; Chamorro, Susana; Vargas, Pablo; McMullen, Conley K.; Castro-Urgal, Rocío; Nogales, Manuel; Herrera, Henri W.; Olesen, Jens M.

    2013-01-01

    The unique biodiversity of most oceanic archipelagos is currently threatened by the introduction of alien species that can displace native biota, disrupt native ecological interactions, and profoundly affect community structure and stability. We investigated the threat of aliens on pollination networks in the species-rich lowlands of five Galápagos Islands. Twenty per cent of all species (60 plants and 220 pollinators) in the pooled network were aliens, being involved in 38 per cent of the interactions. Most aliens were insects, especially dipterans (36%), hymenopterans (30%) and lepidopterans (14%). These alien insects had more links than either endemic pollinators or non-endemic natives, some even acting as island hubs. Aliens linked mostly to generalized species, increasing nestedness and thus network stability. Moreover, they infiltrated all seven connected modules (determined by geographical and phylogenetic constraints) of the overall network, representing around 30 per cent of species in two of them. An astonishingly high proportion (38%) of connectors, which enhance network cohesiveness, was also alien. Results indicate that the structure of these emergent novel communities might become more resistant to certain type of disturbances (e.g. species loss), while being more vulnerable to others (e.g. spread of a disease). Such notable changes in network structure as invasions progress are expected to have important consequences for native biodiversity maintenance. PMID:23486435

  12. A simple model of asymmetric quasi-species: network sustained by emergent high mutation rates

    NASA Astrophysics Data System (ADS)

    Iwasaki, Yuishi; Yonezawa, Fumiko

    1999-02-01

    A simple model of adaptive mutation rates is studied to understand asymmetric adaptive systems. In the model, two sources of asymmetries are introduced. One is a spin-glass-type energy function and gives an asymmetry of the fitness landscape. The other is the variable mutation rate associated with each gene and gives an asymmetry of the transition probabilities. A control parameter is a selection pressure rather than a mutation rate. We find that the model shows three results: (i) High mutation rates emerge in the iterative Darwinian selection process. (ii) Detailed balance is satisfied in the diverse system sustained by the emergent high mutation rates. (iii) A transition from the positive Darwinian selection (ordered state) to the nearly neutral selection (disordered state) takes place as the selection pressure decreases. Based on these results, we study the asymmetric network sustained by emergent high mutation rates.

  13. Emergence of chaos in starlike networks of dissipative nonlinear oscillators by localized parametric excitations.

    PubMed

    Chacón, R; García-Hoz, A Martínez; Martínez, J A

    2017-05-01

    We study the effectiveness of locally controlling the impulse transmitted by parametric periodic excitations at inducing and suppressing chaos in starlike networks of driven damped pendula, leading to asynchronous chaotic states and equilibria, respectively. We found that the inducing (suppressor) effect of increasing (decreasing) the impulse transmitted by the parametric excitations acting on particular nodes depends strongly on their number and degree of connectivity as well as the coupling strength. Additionally, we provide a theoretical analysis explaining the basic physical mechanisms of the emergence and suppression of chaos as well as the main features of the chaos-control scenario. Our findings constitute proof of the impulse-induced control of chaos in a simple model of complex networks, thus opening the way to its application to real-world networks.

  14. Emergence of chaos in starlike networks of dissipative nonlinear oscillators by localized parametric excitations

    NASA Astrophysics Data System (ADS)

    Chacón, R.; García-Hoz, A. Martínez; Martínez, J. A.

    2017-05-01

    We study the effectiveness of locally controlling the impulse transmitted by parametric periodic excitations at inducing and suppressing chaos in starlike networks of driven damped pendula, leading to asynchronous chaotic states and equilibria, respectively. We found that the inducing (suppressor) effect of increasing (decreasing) the impulse transmitted by the parametric excitations acting on particular nodes depends strongly on their number and degree of connectivity as well as the coupling strength. Additionally, we provide a theoretical analysis explaining the basic physical mechanisms of the emergence and suppression of chaos as well as the main features of the chaos-control scenario. Our findings constitute proof of the impulse-induced control of chaos in a simple model of complex networks, thus opening the way to its application to real-world networks.

  15. Portable emergency telemedicine system over wireless broadband and 3G networks.

    PubMed

    Hong, SungHye; Kim, SangYong; Kim, JungChae; Lim, DongKyu; Jung, SeokMyung; Kim, DongKeun; Yoo, Sun K

    2009-01-01

    The telemedicine system aims at monitoring patients remotely without limit in time and space. However the existing telemedicine systems exchange medical information simply in a specified location. Due to increasing speed in processing data and expanding bandwidth of wireless networks, it is possible to perform telemedicine services on personal digital assistants (PDA). In this paper, a telemedicine system on PDA was developed using wideband mobile networks such as Wi-Fi, HSDPA, and WiBro for high speed bandwidths. This system enables to utilize and exchange variety and reliable patient information of video, biosignals, chatting messages, and triage data. By measuring bandwidths of individual data of the system over wireless networks, and evaluating the performance of this system using PDA, we demonstrated the feasibility of the designed portable emergency telemedicine system.

  16. An On-Demand Emergency Packet Transmission Scheme for Wireless Body Area Networks.

    PubMed

    Al Ameen, Moshaddique; Hong, Choong Seon

    2015-12-04

    The rapid developments of sensor devices that can actively monitor human activities have given rise to a new field called wireless body area network (BAN). A BAN can manage devices in, on and around the human body. Major requirements of such a network are energy efficiency, long lifetime, low delay, security, etc. Traffic in a BAN can be scheduled (normal) or event-driven (emergency). Traditional media access control (MAC) protocols use duty cycling to improve performance. A sleep-wake up cycle is employed to save energy. However, this mechanism lacks features to handle emergency traffic in a prompt and immediate manner. To deliver an emergency packet, a node has to wait until the receiver is awake. It also suffers from overheads, such as idle listening, overhearing and control packet handshakes. An external radio-triggered wake up mechanism is proposed to handle prompt communication. It can reduce the overheads and improve the performance through an on-demand scheme. In this work, we present a simple-to-implement on-demand packet transmission scheme by taking into considerations the requirements of a BAN. The major concern is handling the event-based emergency traffic. The performance analysis of the proposed scheme is presented. The results showed significant improvements in the overall performance of a BAN compared to state-of-the-art protocols in terms of energy consumption, delay and lifetime.

  17. An On-Demand Emergency Packet Transmission Scheme for Wireless Body Area Networks

    PubMed Central

    Al Ameen, Moshaddique; Hong, Choong Seon

    2015-01-01

    The rapid developments of sensor devices that can actively monitor human activities have given rise to a new field called wireless body area network (BAN). A BAN can manage devices in, on and around the human body. Major requirements of such a network are energy efficiency, long lifetime, low delay, security, etc. Traffic in a BAN can be scheduled (normal) or event-driven (emergency). Traditional media access control (MAC) protocols use duty cycling to improve performance. A sleep-wake up cycle is employed to save energy. However, this mechanism lacks features to handle emergency traffic in a prompt and immediate manner. To deliver an emergency packet, a node has to wait until the receiver is awake. It also suffers from overheads, such as idle listening, overhearing and control packet handshakes. An external radio-triggered wake up mechanism is proposed to handle prompt communication. It can reduce the overheads and improve the performance through an on-demand scheme. In this work, we present a simple-to-implement on-demand packet transmission scheme by taking into considerations the requirements of a BAN. The major concern is handling the event-based emergency traffic. The performance analysis of the proposed scheme is presented. The results showed significant improvements in the overall performance of a BAN compared to state-of-the-art protocols in terms of energy consumption, delay and lifetime. PMID:26690161

  18. Entanglement guarantees emergence of cooperation in quantum prisoner's dilemma games on networks.

    PubMed

    Li, Angsheng; Yong, Xi

    2014-09-05

    It was known that cooperation of evolutionary prisoner's dilemma games fails to emerge in homogenous networks such as random graphs. Here we proposed a quantum prisoner's dilemma game. The game consists of two players, in which each player has three choices of strategy: cooperator (C), defector (D) and super cooperator (denoted by Q). We found that quantum entanglement guarantees emergence of a new cooperation, the super cooperation of the quantum prisoner's dilemma games, and that entanglement is the mechanism of guaranteed emergence of cooperation of evolutionary prisoner's dilemma games on networks. We showed that for a game with temptation b, there exists a threshold arccos √b/b for a measurement of entanglement, beyond which, (super) cooperation of evolutionary quantum prisoner's dilemma games is guaranteed to quickly emerge, giving rise to stochastic convergence of the cooperations, that if the entanglement degree γ is less than the threshold arccos √b/b, then the equilibrium frequency of cooperations of the games is positively correlated to the entanglement degree γ, and that if γ is less than arccos √b/b and b is beyond some boundary, then the equilibrium frequency of cooperations of the games on random graphs decreases as the average degree of the graphs increases.

  19. Emergence of super cooperation of prisoner's dilemma games on scale-free networks.

    PubMed

    Li, Angsheng; Yong, Xi

    2015-01-01

    Recently, the authors proposed a quantum prisoner's dilemma game based on the spatial game of Nowak and May, and showed that the game can be played classically. By using this idea, we proposed three generalized prisoner's dilemma (GPD, for short) games based on the weak Prisoner's dilemma game, the full prisoner's dilemma game and the normalized Prisoner's dilemma game, written by GPDW, GPDF and GPDN respectively. Our games consist of two players, each of which has three strategies: cooperator (C), defector (D) and super cooperator (denoted by Q), and have a parameter γ to measure the entangled relationship between the two players. We found that our generalised prisoner's dilemma games have new Nash equilibrium principles, that entanglement is the principle of emergence and convergence (i.e., guaranteed emergence) of super cooperation in evolutions of our generalised prisoner's dilemma games on scale-free networks, that entanglement provides a threshold for a phase transition of super cooperation in evolutions of our generalised prisoner's dilemma games on scale-free networks, that the role of heterogeneity of the scale-free networks in cooperations and super cooperations is very limited, and that well-defined structures of scale-free networks allow coexistence of cooperators and super cooperators in the evolutions of the weak version of our generalised prisoner's dilemma games.

  20. Emergence of Super Cooperation of Prisoner’s Dilemma Games on Scale-Free Networks

    PubMed Central

    Li, Angsheng; Yong, Xi

    2015-01-01

    Recently, the authors proposed a quantum prisoner’s dilemma game based on the spatial game of Nowak and May, and showed that the game can be played classically. By using this idea, we proposed three generalized prisoner’s dilemma (GPD, for short) games based on the weak Prisoner’s dilemma game, the full prisoner’s dilemma game and the normalized Prisoner’s dilemma game, written by GPDW, GPDF and GPDN respectively. Our games consist of two players, each of which has three strategies: cooperator (C), defector (D) and super cooperator (denoted by Q), and have a parameter γ to measure the entangled relationship between the two players. We found that our generalised prisoner’s dilemma games have new Nash equilibrium principles, that entanglement is the principle of emergence and convergence (i.e., guaranteed emergence) of super cooperation in evolutions of our generalised prisoner’s dilemma games on scale-free networks, that entanglement provides a threshold for a phase transition of super cooperation in evolutions of our generalised prisoner’s dilemma games on scale-free networks, that the role of heterogeneity of the scale-free networks in cooperations and super cooperations is very limited, and that well-defined structures of scale-free networks allow coexistence of cooperators and super cooperators in the evolutions of the weak version of our generalised prisoner’s dilemma games. PMID:25643279

  1. Mnemonic convergence in social networks: The emergent properties of cognition at a collective level

    PubMed Central

    Coman, Alin; Momennejad, Ida; Drach, Rae D.; Geana, Andra

    2016-01-01

    The development of shared memories, beliefs, and norms is a fundamental characteristic of human communities. These emergent outcomes are thought to occur owing to a dynamic system of information sharing and memory updating, which fundamentally depends on communication. Here we report results on the formation of collective memories in laboratory-created communities. We manipulated conversational network structure in a series of real-time, computer-mediated interactions in fourteen 10-member communities. The results show that mnemonic convergence, measured as the degree of overlap among community members’ memories, is influenced by both individual-level information-processing phenomena and by the conversational social network structure created during conversational recall. By studying laboratory-created social networks, we show how large-scale social phenomena (i.e., collective memory) can emerge out of microlevel local dynamics (i.e., mnemonic reinforcement and suppression effects). The social-interactionist approach proposed herein points to optimal strategies for spreading information in social networks and provides a framework for measuring and forging collective memories in communities of individuals. PMID:27357678

  2. The emergence of a community mapping network: coastal eelgrass mapping in British Columbia.

    PubMed

    Boyer, Leanna; Roth, Wolff-Michael; Wright, Nikki

    2009-03-01

    The purpose of this paper is to document and theorize the emergence of a network of stewards concerned about the conservation of a marine habitat called eelgrass along the coastline of British Columbia, Canada. Today, by engaging as professional biologists, government employees, and volunteers using various mapping, outreach, and communication tools, these stewards generate knowledge on the geographic location and health of eelgrass habitat, how to educate the public, how to coordinate volunteers, and how to approach local governments--with the ultimate goal of convincing others that eelgrass is worth protecting. Our two-year ethnographic study began in the second year of a project that was designed to train twenty community coordinators how to map and monitor eelgrass habitat. The coordinators were faced with complex social, cultural, political, historical, and material landscapes--which made us wonder about how it was possible for the network to hold together while extending its reach. We provide evidence to support the claim that the network became more stable and was extended by particular performances. These performances emerged from recognition and resolution of resistances, in which the network was both resource for and object of its activity. In the process, (a) knowledge produced is made to move and do something, (b) coordinators and scientists involved acted as knowledge brokers between various communities, and (c) communication between coordinators was enabled and maintained.

  3. Emergence of low noise frustrated states in E/I balanced neural networks.

    PubMed

    Recio, I; Torres, J J

    2016-12-01

    We study emerging phenomena in binary neural networks where, with a probability c synaptic intensities are chosen according with a Hebbian prescription, and with probability (1-c) there is an extra random contribution to synaptic weights. This new term, randomly taken from a Gaussian bimodal distribution, balances the synaptic population in the network so that one has 80%-20% relation in E/I population ratio, mimicking the balance observed in mammals cortex. For some regions of the relevant parameters, our system depicts standard memory (at low temperature) and non-memory attractors (at high temperature). However, as c decreases and the level of the underlying noise also decreases below a certain temperature Tt, a kind of memory-frustrated state, which resembles spin-glass behavior, sharply emerges. Contrary to what occurs in Hopfield-like neural networks, the frustrated state appears here even in the limit of the loading parameter α→0. Moreover, we observed that the frustrated state in fact corresponds to two states of non-vanishing activity uncorrelated with stored memories, associated, respectively, to a high activity or Up state and to a low activity or Down state. Using a linear stability analysis, we found regions in the space of relevant parameters for locally stable steady states and demonstrated that frustrated states coexist with memory attractors below Tt. Then, multistability between memory and frustrated states is present for relatively small c, and metastability of memory attractors can emerge as c decreases even more. We studied our system using standard mean-field techniques and with Monte Carlo simulations, obtaining a perfect agreement between theory and simulations. Our study can be useful to explain the role of synapse heterogeneity on the emergence of stable Up and Down states not associated to memory attractors, and to explore the conditions to induce transitions among them, as in sleep-wake transitions.

  4. Capabilities of the RENEB network for research and large scale radiological and nuclear emergency situations.

    PubMed

    Monteiro Gil, Octávia; Vaz, Pedro; Romm, Horst; De Angelis, Cinzia; Antunes, Ana Catarina; Barquinero, Joan-Francesc; Beinke, Christina; Bortolin, Emanuela; Burbidge, Christopher Ian; Cucu, Alexandra; Della Monaca, Sara; Domene, Mercedes Moreno; Fattibene, Paola; Gregoire, Eric; Hadjidekova, Valeria; Kulka, Ulrike; Lindholm, Carita; Meschini, Roberta; M'Kacher, Radhia; Moquet, Jayne; Oestreicher, Ursula; Palitti, Fabrizio; Pantelias, Gabriel; Montoro Pastor, Alegria; Popescu, Irina-Anca; Quattrini, Maria Cristina; Ricoul, Michelle; Rothkamm, Kai; Sabatier, Laure; Sebastià, Natividad; Sommer, Sylwester; Terzoudi, Georgia; Testa, Antonella; Trompier, François; Vral, Anne

    2017-01-01

    To identify and assess, among the participants in the RENEB (Realizing the European Network of Biodosimetry) project, the emergency preparedness, response capabilities and resources that can be deployed in the event of a radiological or nuclear accident/incident affecting a large number of individuals. These capabilities include available biodosimetry techniques, infrastructure, human resources (existing trained staff), financial and organizational resources (including the role of national contact points and their articulation with other stakeholders in emergency response) as well as robust quality control/assurance systems. A survey was prepared and sent to the RENEB partners in order to acquire information about the existing, operational techniques and infrastructure in the laboratories of the different RENEB countries and to assess the capacity of response in the event of radiological or nuclear accident involving mass casualties. The survey focused on several main areas: laboratory's general information, country and staff involved in biological and physical dosimetry; retrospective assays used, the number of assays available per laboratory and other information related to biodosimetry and emergency preparedness. Following technical intercomparisons amongst RENEB members, an update of the survey was performed one year later concerning the staff and the available assays. The analysis of RENEB questionnaires allowed a detailed assessment of existing capacity of the RENEB network to respond to nuclear and radiological emergencies. This highlighted the key importance of international cooperation in order to guarantee an effective and timely response in the event of radiological or nuclear accidents involving a considerable number of casualties. The deployment of the scientific and technical capabilities existing within the RENEB network members seems mandatory, to help other countries with less or no capacity for biological or physical dosimetry, or countries

  5. Network advocacy and the emergence of global attention to newborn survival.

    PubMed

    Shiffman, Jeremy

    2016-04-01

    Globally 2.9 million babies die each year before reaching 28 days of life. Over the past quarter century, neonatal mortality has declined at a slower pace than post-neonatal under-five mortality: in consequence newborns now comprise 44% of all deaths to children under five years. Despite high numbers of newborn deaths, global organizations and national governments paid little attention to the issue until 2000, and resources, while growing since then, remain inadequate. This study examines the factors behind these patterns of policy attention: the delayed emergence of attention, its sudden appearance in 2000, its growth thereafter, but the dearth of resources to date. Drawing on a framework on global health networks grounded in collective action theory, the study finds that a newborn survival network helped to shift perceptions about the problem's severity and tractability, contributing to the rise of global attention. Its efforts were facilitated by pressure on governments to achieve the child survival Millennium Development Goal and by growing awareness that the neonatal period constituted a growing percentage of under-five mortality, a fact the network publicized. The network's relatively recent emergence, its predominantly technical rather than political composition and strategies, and its inability to date to find a framing of the issue that has convinced national political leaders of the issue's urgency, in part explain the insufficiency of resources. However, since 2010 a number of non-health oriented inter-governmental organizations have begun to pay attention to the issue, and several countries with high neonatal mortality have created national plans, developments which augur well for the future. The study points to two broader implications concerning how neglected global health issues come to attract attention: priority emerges from a confluence of factors, rather than any single cause; and growth in priority may depend on the creation of a broader

  6. Personal Disaster and Emergency Support Networks of Older Adults in a Rural Community: Changes After Participation in a Preparedness Program.

    PubMed

    Ashida, Sato; Robinson, Erin L; Gay, Jane; Slagel, Lauren E; Ramirez, Marizen R

    2017-02-01

    Personal disaster and emergency support networks of rural older adults are described before and after participation in a disaster preparedness intervention, PrepWise. At baseline, a total of 194 disaster support network members were identified by 27 older adults in a rural Midwest community. After the intervention, these participants identified 232 support network members. Multilevel logistic regression models were constructed to identify characteristics of the network members and social interactions associated with support providers at baseline as well as newly added support sources after the PrepWise intervention. Member and interaction characteristics associated with being identified as emergency support sources at baseline were as follows: family, lived in close proximity, weekly or more frequent contact, and being someone whom participants shared concerns with, trusted, and exchanged emotional support with. After receiving PrepWise, participants on average identified 3 new sources of emergency support within their networks. Support sources added at follow-up tended to be nonfamily members and those participants trusted. Enhancements in personal emergency support networks occurred after the intervention. Understanding characteristics of the network members and social interactions may assist in identifying additional emergency support sources. Larger studies investigating the impacts of enhanced support networks on disaster-related behaviors and outcomes will be beneficial. (Disaster Med Public Health Preparedness. 2017;11:110-119).

  7. Emergent criticality in complex turing B-type atomic switch networks.

    PubMed

    Stieg, Adam Z; Avizienis, Audrius V; Sillin, Henry O; Martin-Olmos, Cristina; Aono, Masakazu; Gimzewski, James K

    2012-01-10

    Recent advances in the neuromorphic operation of atomic switches as individual synapse-like devices demonstrate the ability to process information with both short-term and long-term memorization in a single two terminal junction. Here it is shown that atomic switches can be self-assembled within a highly interconnected network of silver nanowires similar in structure to Turing’s “B-Type unorganized machine”, originally proposed as a randomly connected network of NAND logic gates. In these experimental embodiments,complex networks of coupled atomic switches exhibit emergent criticality similar in nature to previously reported electrical activity of biological brains and neuron assemblies. Rapid fluctuations in electrical conductance display metastability and power law scaling of temporal correlation lengths that are attributed to dynamic reorganization of the interconnected electro-ionic network resulting from induced non-equilibrium thermodynamic instabilities. These collective properties indicate a potential utility for realtime,multi-input processing of distributed sensory data through reservoir computation. We propose these highly coupled, nonlinear electronic networks as an implementable hardware-based platform toward the creation of physically intelligent machines.

  8. Sex Differences in Virtual Network Characteristics and Sexual Risk Behavior among Emerging Adults

    PubMed Central

    Cook, Stephanie H.; Bauermeister, José A.; Zimmerman, Marc A.

    2016-01-01

    Emerging adults (EAs)ages 18 to 24 account for a large proportion of all sexually transmitted infections (STIs), HIV infections, and unintended pregnancies in the United States. Given the increased influence of online media on decision-making, we examined how EA online networks were associated with sexual risk behaviors. We used egocentric network data collected from EAs aged 18 to 24 years old across the United States (N=1,687) to examine how online norms (e.g., acceptance of HIV infections, other STIs, and pregnancy) and network characteristics (i.e., network size and density; ties' closeness, race, age, and sex similarities) were associated with participants' unprotected vaginal intercourse (UVI) in the last 30 days. Findings suggested that in male EAs, there was a strong association between sexual norms, structural characteristics, and sexual risk behavior compared to females. Researchers and practitioners may wish to address online peer norms and EAs' online network composition when developing online sexual risk prevention tools. PMID:28083447

  9. Complex Networks in Different Languages: A Study of an Emergent Multilingual Encyclopedia

    NASA Astrophysics Data System (ADS)

    Pembe, F. Canan; Bingol, Haluk

    There is an increasing interest to the study of complex networks in an interdisciplinary way. Language, as a complex network, has been a part of this study due to its importance in human life. Moreover, the Internet has also been at the center of this study by making access to large amounts of information possible. With these ideas in mind, this work aims to evaluate conceptual networks in different languages with the data from a large and open source of information in the Internet, namely Wikipedia. As an evolving multilingual encyclopedia that can be edited by any Internet user, Wikipedia is a good example of an emergent complex system. In this paper, different from previous work on conceptual networks which usually concentrated on single languages, we concentrate on possible ways to compare the usages of different languages and possibly the underlying cultures. This also involves the analysis of local network properties around certain coneepts in different languages. For an initial evaluation, the concept "family" is used to compare the English and German Wikipedias. Although, the work is currently at the beginning, the results are promising.

  10. Reducing emergency bed-days for older people? Network governance lessons from the 'Improving the Future for Older People' programme.

    PubMed

    Sheaff, Rod; Windle, Karen; Wistow, Gerald; Ashby, Sue; Beech, Roger; Dickinson, Angela; Henderson, Catherine; Knapp, Martin

    2014-04-01

    In 2007, the UK government set performance targets and public service agreements to control the escalation of emergency bed-days. Some years earlier, nine English local authorities had each created local networks with their health and third sector partners to tackle this increase. These networks formed the 'Improving the Future for Older People' initiative (IFOP), one strand of the national 'Innovation Forum' programme, set up in 2003. The nine sites set themselves one headline target to be achieved jointly over three years; a 20 per cent reduction in the number of emergency bed-days used by people aged 75 and over. Three ancillary targets were also monitored: emergency admissions, delayed discharges and project sustainability. Collectively the sites exceeded their headline target. Using a realistic evaluation approach, we explored which aspects of network governance appeared to have contributed to these emergency bed-day reductions. We found no simple link between network governance type and outcomes. The governance features associated with an effective IFOP network appeared to suggest that the selection and implementation of a small number of evidence-based services was central to networks' effectiveness. Each service needed to be coordinated by a network-based strategic group and hierarchically implemented at operational level by the responsible network member. Having a network-based implementation group with a 'joined-at-the-top' governance structure also appeared to promote network effectiveness. External factors, including NHS incentives, health reorganisations and financial targets similarly contributed to differences in performance. Targets and financial incentives could focus action but undermine horizontal networking. Local networks should specify which interventions network structures are intended to deliver. Effective projects are those likely to be evidence based, unique to the network and difficult to implement through vertical structures alone

  11. Filling the gap between disaster preparedness and response networks of urban emergency management: Following the 2013 Seoul Floods.

    PubMed

    Song, Minsun; Jung, Kyujin

    2015-01-01

    To examine the gap between disaster preparedness and response networks following the 2013 Seoul Floods in which the rapid transmission of disaster information and resources was impeded by severe changes of interorganizational collaboration networks. This research uses the 2013 Seoul Emergency Management Survey data that were collected before and after the floods, and total 94 organizations involving in coping with the floods were analyzed in bootstrap independent-sample t-test and social network analysis through UCINET 6 and STATA 12. The findings show that despite the primary network form that is more hierarchical, horizontal collaboration has been relatively invigorated in actual response. Also, interorganizational collaboration networks for response operations seem to be more flexible grounded on improvisation to coping with unexpected victims and damages. Local organizations under urban emergency management are recommended to tightly build a strong commitment for joint response operations through full-size exercises at the metropolitan level before a catastrophic event. Also, interorganizational emergency management networks need to be restructured by reflecting the actual response networks to reduce collaboration risk during a disaster. This research presents a critical insight into inverse thinking of the view designing urban emergency management networks and provides original evidences for filling the gap between previously coordinated networks for disaster preparedness and practical response operations after a disaster.

  12. Emergency transfer of acute stroke patients within the East Saxony telemedicine stroke network: a descriptive analysis.

    PubMed

    Kepplinger, Jessica; Dzialowski, Imanuel; Barlinn, Kristian; Puetz, Volker; Wojciechowski, Claudia; Schneider, Hauke; Gahn, Georg; Back, Tobias; Schackert, Gabriele; Reichmann, Heinz; von Kummer, Ruediger; Bodechtel, Ulf

    2014-02-01

    Telemedicine may facilitate the selection of stroke patients who require emergency transfer to a comprehensive stroke center to receive additional therapies other than intravenous tissue plasminogen activator. We sought to analyze frequency, patient characteristics, and specific therapies among emergently transferred patients within the telemedical Stroke East Saxony Network. We reviewed consecutive patients who were transferred emergently from remote spoke sites to hub sites. Certified stroke neurologists performed teleconsultations 24/7, with access to high-speed videoconferencing and transfer of brain images. Emergent transfers were initiated when considered necessary by the stroke neurologist. In 2009 and 2010, we conducted 1413 teleconsultations and subsequently recommended transfer in 339 (24%) patients [mean age 64 ± 14 years, 54% males, median National Institutes of Health Stroke Scale score 5 (interquartile range, IQR 12). The mean teleconsultation-to-arrival time was 1·7 ± 0·8 h (median 1·6 h). Sixty-eight (20%) transferred patients had a nonstroke diagnosis. The remaining 271 (80%) patients had stroke diagnoses [ischemic stroke, 114 (34%); transient ischemic attack, 8 (2%); and intracranial haemorrhage, 149 (44%)]. Forty (35%) ischemic stroke patients received tissue plasminogen activator at spoke sites ('drip and ship'). Of the 240 stroke patients emergently transferred to the main hub site, 119 (49·6%) received at least one specific stroke therapy. A remarkable number of stroke patients can be transferred within a telemedical network to enable the delivery of specific stroke therapies that require advanced multispecialty expertise. Whether associated logistic efforts and costs have an impact on patients' clinical outcomes needs to be evaluated. © 2013 The Authors. International Journal of Stroke © 2013 World Stroke Organization.

  13. Animation of Panorama of Phoenix's Solar Panel and Robotic Arm

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    This is an animation of panorama images of NASA's Phoenix Mars Lander's solar panel and the lander's Robotic Arm with a sample in the scoop. The image was taken just before the sample was delivered to the Optical Microscope.

    The images making up this animation were taken by the lander's Surface Stereo Imager looking west during Phoenix's Sol 16 (June 10, 2008), or the 16th Martian day after landing. This view is a part of the 'mission success' panorama that will show the whole landing site in color.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  14. Animation of Panorama of Phoenix's Solar Panel and Robotic Arm

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    This is an animation of panorama images of NASA's Phoenix Mars Lander's solar panel and the lander's Robotic Arm with a sample in the scoop. The image was taken just before the sample was delivered to the Optical Microscope.

    The images making up this animation were taken by the lander's Surface Stereo Imager looking west during Phoenix's Sol 16 (June 10, 2008), or the 16th Martian day after landing. This view is a part of the 'mission success' panorama that will show the whole landing site in color.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  15. 7. SITE OVERVIEW. PART 2 OF 6 PART PANORAMA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. SITE OVERVIEW. PART 2 OF 6 PART PANORAMA WITH NOS. CA-265-6 TO CA-265-11. ARROYO SECO PARKWAY AS SEEN FROM RADIO TOWER HILL. PART 2 SHOWS GRAND VIEW POINT AT LEFT REAR AND FIGUEROA VIADUCT OVERCROSSING; INTERSTATE 1-5 AT REAR CENTER; AVENUE 26 BRIDGE AT RIGHT CENTER. LOOKING 260° W. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  16. 4. SITE OVERVIEW. PART 4 OF 4 PART PANORAMA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. SITE OVERVIEW. PART 4 OF 4 PART PANORAMA WITH NOS. CA-265-1 TO CA-265-3. INTERCHANGE OF ARROYO SECO PARKWAY, INTERSTATE 1-5, AND FIGUEROA STREET AT CROSSINGS OF THE LOS ANGELES RIVER AS SEEN FROM GRAND VIEW POINT IN ELYSIAN PARK. VIEW 4 SHOWS LOS ANGELES RIVER. LOOKING 140° SE. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  17. 3. SITE OVERVIEW. PART 3 OF 4 PART PANORAMA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. SITE OVERVIEW. PART 3 OF 4 PART PANORAMA WITH NOS. CA-265-1 TO CA-265-4. INTERCHANGE OF ARROYO SECO PARKWAY, INTERSTATE 1-5, AND FIGUEROA STREET AT CROSSINGS OF THE LOS ANGELES RIVER AS SEEN FROM GRAND VIEW POINT IN ELYSIAN PARK. VIEW 3 SHOWS LOS ANGELES RIVER IN FOREGROUND WITH ARROYO SECO PARKWAY OVERCROSSING. LOOKING 76° ENE. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  18. Panorama view of Apollo 17 Lunar surface photos

    NASA Image and Video Library

    1972-12-01

    Panorama view of Apollo 17 Lunar surface photos for use in presentations to NASA management and for Outreach Education in regard to new NASA initiative for human planetary research. Photo numbers used for this panoramic include: Apollo 17 start frame AS17-147-22572 thru end frame AS17-147-22600. View is of the Apollo Lunar Surface Experiment Package (ALSEP) Station taken during Extravehicular Activity (EVA) 1.

  19. Emerging trends in evolving networks: Recent behaviour dominant and non-dominant model

    NASA Astrophysics Data System (ADS)

    Abbas, Khushnood; Shang, Mingsheng; Luo, Xin; Abbasi, Alireza

    2017-10-01

    Novel phenomenon receives similar attention as popular one. Therefore predicting novelty is as important as popularity. Emergence is the side effect of competition and ageing in evolving systems. Recent behaviour or recent link gain in networks plays an important role in emergence. We exploited this wisdom and came up with two models considering different scenarios and systems. Where recent behaviour dominates over total behaviour (total link gain) in the first one, and recent behaviour is as important as total behaviour for future link gain in the second one. It supposes that random walker walks on a network and can jump to any node, the probability of jumping or making a connection to other node is based on which node is recently more active or receiving more links. In our assumption, the random walker can also jump to the node which is already popular but recently not popular. We are able to predict emerging nodes which are generally suppressed under preferential attachment effect. To show the performance of our model we have conducted experiments on four real data sets namely, MovieLens, Netflix, Facebook and Arxiv High Energy Physics paper citation. For testing our model we used four information retrieval indices namely Precision, Novelty, Area Under Receiving Operating Characteristic (AUC) and Kendal's rank correlation coefficient. We have used four benchmark models for validating our proposed models. Although our model does not perform better in all the cases but, it has theoretical significance in working better for recent behaviour dominated systems.

  20. CA1 cell activity sequences emerge after reorganization of network correlation structure during associative learning

    PubMed Central

    Modi, Mehrab N; Dhawale, Ashesh K; Bhalla, Upinder S

    2014-01-01

    Animals can learn causal relationships between pairs of stimuli separated in time and this ability depends on the hippocampus. Such learning is believed to emerge from alterations in network connectivity, but large-scale connectivity is difficult to measure directly, especially during learning. Here, we show that area CA1 cells converge to time-locked firing sequences that bridge the two stimuli paired during training, and this phenomenon is coupled to a reorganization of network correlations. Using two-photon calcium imaging of mouse hippocampal neurons we find that co-time-tuned neurons exhibit enhanced spontaneous activity correlations that increase just prior to learning. While time-tuned cells are not spatially organized, spontaneously correlated cells do fall into distinct spatial clusters that change as a result of learning. We propose that the spatial re-organization of correlation clusters reflects global network connectivity changes that are responsible for the emergence of the sequentially-timed activity of cell-groups underlying the learned behavior. DOI: http://dx.doi.org/10.7554/eLife.01982.001 PMID:24668171

  1. Emergence of collective action and environmental networking in relation to radioactive waste management

    SciTech Connect

    Williams, R.G.; Payne, B.A.

    1985-01-01

    This paper explores the relationship between the national environmental movement and nuclear technology in relation to a local emergent group. The historical development of nuclear technology in this conutry has followed a path leading to continued fear and mistrust of waste management by a portion of the population. At the forefront of opposition to nuclear technology are people and groups endorsing environmental values. Because of the antinuclear attitudes of environmentalists and the value orientation of appropriate technologists in the national environmental movement, it seems appropriate for local groups to call on these national groups for assistance regarding nuclear-related issues. A case study is used to illustrate how a local action group, once integrated into a national environmental network, can become an effective, legitimate participant in social change. The formation, emergence, mobilization, and networking of a local group opposed to a specific federal radioactive waste management plan is described based on organizational literature. However, inherent contradictions in defining the local versus national benefits plus inherent problems within the environmental movement could be acting to limit the effectiveness of such networks. 49 refs.

  2. Online network of subspecialty aortic disease experts: Impact of "cloud" technology on management of acute aortic emergencies.

    PubMed

    Schoenhagen, Paul; Roselli, Eric E; Harris, C Martin; Eagleton, Matthew; Menon, Venu

    2016-07-01

    For the management of acute aortic syndromes, regional treatment networks have been established to coordinate diagnosis and treatment between local emergency rooms and central specialized centers. Triage of acute aortic syndromes requires definitive imaging, resulting in complex data files. Modern information technology network structures, specifically "cloud" technology, coupled with mobile communication, increasingly support sharing of these data in a network of experts using mobile, online access and communication. Although this network is technically complex, the potential benefit of online sharing of data files between professionals at multiple locations within a treatment network appear obvious; however, clinical experience is limited, and further evaluation is needed.

  3. Radar coordination and resource management in a distributed sensor network using emergent control

    NASA Astrophysics Data System (ADS)

    Weir, B. S.; Sokol, T. M.

    2009-05-01

    As the list of anti-air warfare and ballistic missile defense missions grows, there is an increasing need to coordinate and optimize usage of radar resources across the netted force. Early attempts at this optimization involved top-down control mechanisms whereby sensors accept resource tasking orders from networked tracking elements. These approaches rely heavily on uncertain knowledge of sensor constraints and capabilities. Furthermore, advanced sensor systems may support self-defense missions of the host platform and are therefore unable to relinquish control to an external function. To surmount these issues, the use of bottom-up emergent control techniques is proposed. The information necessary to make quality, network-wide resource allocations is readily available to sensor nodes with access to a netted track picture. By assessing resource priorities relative to the network (versus local) track picture, sensors can understand the contribution of their resources to the netted force. This allows the sensors to apply resources where most needed and remove waste. Furthermore, simple local rules for resource usage, when properly constructed, allow sensors to obtain a globally optimal resource allocation without direct coordination (emergence). These results are robust to partial implementation (i.e., not all nodes upgraded at once) and failures on individual nodes (whether from casualty or reallocation to other sensor missions), and they leave resource control decisions in the hands of the sensor systems instead of an external function. This paper presents independent research and development work on emergent control of sensor resources and the impact to resource allocation and tracking performance.

  4. Integrating Emerging Topics through Online Team Design in a Hybrid Communication Networks Course: Interaction Patterns and Impact of Prior Knowledge

    ERIC Educational Resources Information Center

    Reisslein, Jana; Seeling, Patrick; Reisslein, Martin

    2005-01-01

    An important challenge in the introductory communication networks course in electrical and computer engineering curricula is to integrate emerging topics, such as wireless Internet access and network security, into the already content-intensive course. At the same time it is essential to provide students with experiences in online collaboration,…

  5. Collective Phenomena Emerging from the Interactions between Dynamical Processes in Multiplex Networks

    NASA Astrophysics Data System (ADS)

    Nicosia, Vincenzo; Skardal, Per Sebastian; Arenas, Alex; Latora, Vito

    2017-03-01

    We introduce a framework to intertwine dynamical processes of different nature, each with its own distinct network topology, using a multilayer network approach. As an example of collective phenomena emerging from the interactions of multiple dynamical processes, we study a model where neural dynamics and nutrient transport are bidirectionally coupled in such a way that the allocation of the transport process at one layer depends on the degree of synchronization at the other layer, and vice versa. We show numerically, and we prove analytically, that the multilayer coupling induces a spontaneous explosive synchronization and a heterogeneous distribution of allocations, otherwise not present in the two systems considered separately. Our framework can find application to other cases where two or more dynamical processes such as synchronization, opinion formation, information diffusion, or disease spreading, are interacting with each other.

  6. The Emergence of Synaesthesia in a Neuronal Network Model via Changes in Perceptual Sensitivity and Plasticity

    PubMed Central

    Ward, Jamie

    2016-01-01

    Synaesthesia is an unusual perceptual experience in which an inducer stimulus triggers a percept in a different domain in addition to its own. To explore the conditions under which synaesthesia evolves, we studied a neuronal network model that represents two recurrently connected neural systems. The interactions in the network evolve according to learning rules that optimize sensory sensitivity. We demonstrate several scenarios, such as sensory deprivation or heightened plasticity, under which synaesthesia can evolve even though the inputs to the two systems are statistically independent and the initial cross-talk interactions are zero. Sensory deprivation is the known causal mechanism for acquired synaesthesia and increased plasticity is implicated in developmental synaesthesia. The model unifies different causes of synaesthesia within a single theoretical framework and repositions synaesthesia not as some quirk of aberrant connectivity, but rather as a functional brain state that can emerge as a consequence of optimising sensory information processing. PMID:27392215

  7. The Emergence of Synaesthesia in a Neuronal Network Model via Changes in Perceptual Sensitivity and Plasticity.

    PubMed

    Shriki, Oren; Sadeh, Yaniv; Ward, Jamie

    2016-07-01

    Synaesthesia is an unusual perceptual experience in which an inducer stimulus triggers a percept in a different domain in addition to its own. To explore the conditions under which synaesthesia evolves, we studied a neuronal network model that represents two recurrently connected neural systems. The interactions in the network evolve according to learning rules that optimize sensory sensitivity. We demonstrate several scenarios, such as sensory deprivation or heightened plasticity, under which synaesthesia can evolve even though the inputs to the two systems are statistically independent and the initial cross-talk interactions are zero. Sensory deprivation is the known causal mechanism for acquired synaesthesia and increased plasticity is implicated in developmental synaesthesia. The model unifies different causes of synaesthesia within a single theoretical framework and repositions synaesthesia not as some quirk of aberrant connectivity, but rather as a functional brain state that can emerge as a consequence of optimising sensory information processing.

  8. ASI/MET Within Color-Enhanced Panorama

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is a sub-section of the 'geometrically improved, color enhanced' version of the 360-degree panorama heretofore known as the 'Gallery Pan', the first contiguous, uniform panorama taken by the Imager for Mars Pathfinder (IMP) over the course of Sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama.

    The IMP is a stereo imaging system that, in its fully deployed configuration, stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. In this geometrically improved version of the panorama, distortion due to a 2.5 degree tilt in the IMP camera mast has been removed, effectively flattening the horizon.

    The IMP has color capability provided by 24 selectable filters -- twelve filters per 'eye'. Its red, green, and blue filters were used to take this image. The color was digitally balanced according to the color transmittance capability of a high-resolution TV at the Jet Propulsion Laboratory (JPL), and is dependent on that device. In this color enhanced version of the panorama, detail in surface features are brought out via changes to saturation and intensity, holding the original hue constant. A threshold was applied to avoid changes to the sky.

    At the bottom of the image, two of the Lander petals are visible. At the extreme right of the image, the Atmospheric Structure Instrument and Meteorology package (ASI/MET) mast, with its three windsocks, is visible.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract

  9. A Secure Cloud-Assisted Wireless Body Area Network in Mobile Emergency Medical Care System.

    PubMed

    Li, Chun-Ta; Lee, Cheng-Chi; Weng, Chi-Yao

    2016-05-01

    Recent advances in medical treatment and emergency applications, the need of integrating wireless body area network (WBAN) with cloud computing can be motivated by providing useful and real time information about patients' health state to the doctors and emergency staffs. WBAN is a set of body sensors carried by the patient to collect and transmit numerous health items to medical clouds via wireless and public communication channels. Therefore, a cloud-assisted WBAN facilitates response in case of emergency which can save patients' lives. Since the patient's data is sensitive and private, it is important to provide strong security and protection on the patient's medical data over public and insecure communication channels. In this paper, we address the challenge of participant authentication in mobile emergency medical care systems for patients supervision and propose a secure cloud-assisted architecture for accessing and monitoring health items collected by WBAN. For ensuring a high level of security and providing a mutual authentication property, chaotic maps based authentication and key agreement mechanisms are designed according to the concept of Diffie-Hellman key exchange, which depends on the CMBDLP and CMBDHP problems. Security and performance analyses show how the proposed system guaranteed the patient privacy and the system confidentiality of sensitive medical data while preserving the low computation property in medical treatment and remote medical monitoring.

  10. Urban Automation Networks: Current and Emerging Solutions for Sensed Data Collection and Actuation in Smart Cities

    PubMed Central

    Gomez, Carles; Paradells, Josep

    2015-01-01

    Urban Automation Networks (UANs) are being deployed worldwide in order to enable Smart City applications. Given the crucial role of UANs, as well as their diversity, it is critically important to assess their properties and trade-offs. This article introduces the requirements and challenges for UANs, characterizes the main current and emerging UAN paradigms, provides guidelines for their design and/or choice, and comparatively examines their performance in terms of a variety of parameters including coverage, power consumption, latency, standardization status and economic cost. PMID:26378534

  11. Emergence of scale-free networks from local connectivity and communication trade-offs.

    PubMed

    Barbosa, Valmir C; Donangelo, Raul; Souza, Sergio R

    2006-07-01

    We suggest a mechanism of connectivity evolution in networks to account for the emergence of scale-free behavior. The mechanism works on a fixed set of nodes and promotes growth from a minimally connected initial topology by the addition of edges. A new edge is added between two nodes depending on the trade-off between a gain and a cost function of local connectivity and communication properties. We report on simulation results that indicate the appearance of power-law distributions of node degrees for selected parameter combinations.

  12. Emergence of scale-free networks from local connectivity and communication trade-offs

    NASA Astrophysics Data System (ADS)

    Barbosa, Valmir C.; Donangelo, Raul; Souza, Sergio R.

    2006-07-01

    We suggest a mechanism of connectivity evolution in networks to account for the emergence of scale-free behavior. The mechanism works on a fixed set of nodes and promotes growth from a minimally connected initial topology by the addition of edges. A new edge is added between two nodes depending on the trade-off between a gain and a cost function of local connectivity and communication properties. We report on simulation results that indicate the appearance of power-law distributions of node degrees for selected parameter combinations.

  13. Urban Automation Networks: Current and Emerging Solutions for Sensed Data Collection and Actuation in Smart Cities.

    PubMed

    Gomez, Carles; Paradells, Josep

    2015-09-10

    Urban Automation Networks (UANs) are being deployed worldwide in order to enable Smart City applications. Given the crucial role of UANs, as well as their diversity, it is critically important to assess their properties and trade-offs. This article introduces the requirements and challenges for UANs, characterizes the main current and emerging UAN paradigms, provides guidelines for their design and/or choice, and comparatively examines their performance in terms of a variety of parameters including coverage, power consumption, latency, standardization status and economic cost.

  14. Design and Implementation of a Mobile Radiological Emergency Unit Integrated in a Radiation Monitoring Network

    NASA Astrophysics Data System (ADS)

    Baeza, A.; Corbacho, J. A.; Miranda, J.

    2013-04-01

    The first hours elapsed after a radiological incident are critical to take appropriate actions to protect the population and to assess its impact on the environment. The development of mobile laboratories equipped with different radiation detectors, with robust communication systems, and with a highly autonomous uninterruptible power supply constitutes the spearhead of modern radiological warning networks. Their main function is to provide additional radiation information with acceptable accuracy in the shortest possible time. This paper describes our development of a mobile laboratory and the demonstration of its usefulness in various emergency drills conducted in the vicinity of a nuclear power plant.

  15. Emergent inequality and self-organized social classes in a network of power and frustration.

    PubMed

    Mahault, Benoit; Saxena, Avadh; Nisoli, Cristiano

    2017-01-01

    We propose a simple agent-based model on a network to conceptualize the allocation of limited wealth among more abundant expectations at the interplay of power, frustration, and initiative. Concepts imported from the statistical physics of frustrated systems in and out of equilibrium allow us to compare subjective measures of frustration and satisfaction to collective measures of fairness in wealth distribution, such as the Lorenz curve and the Gini index. We find that a completely libertarian, law-of-the-jungle setting, where every agent can acquire wealth from or lose wealth to anybody else invariably leads to a complete polarization of the distribution of wealth vs. opportunity. This picture is however dramatically ameliorated when hard constraints are imposed over agents in the form of a limiting network of transactions. There, an out of equilibrium dynamics of the networks, based on a competition between power and frustration in the decision-making of agents, leads to network coevolution. The ratio of power and frustration controls different dynamical regimes separated by kinetic transitions and characterized by drastically different values of equality. It also leads, for proper values of social initiative, to the emergence of three self-organized social classes, lower, middle, and upper class. Their dynamics, which appears mostly controlled by the middle class, drives a cyclical regime of dramatic social changes.

  16. The role of the interaction network in the emergence of diversity of behavior

    PubMed Central

    Tabacof, Pedro; Von Zuben, Fernando J.

    2017-01-01

    How can systems in which individuals’ inner workings are very similar to each other, as neural networks or ant colonies, produce so many qualitatively different behaviors, giving rise to roles and specialization? In this work, we bring new perspectives to this question by focusing on the underlying network that defines how individuals in these systems interact. We applied a genetic algorithm to optimize rules and connections of cellular automata in order to solve the density classification task, a classical problem used to study emergent behaviors in decentralized computational systems. The networks used were all generated by the introduction of shortcuts in an originally regular topology, following the small-world model. Even though all cells follow the exact same rules, we observed the existence of different classes of cells’ behaviors in the best cellular automata found—most cells were responsible for memory and others for integration of information. Through the analysis of structural measures and patterns of connections (motifs) in successful cellular automata, we observed that the distribution of shortcuts between distant regions and the speed in which a cell can gather information from different parts of the system seem to be the main factors for the specialization we observed, demonstrating how heterogeneity in a network can create heterogeneity of behavior. PMID:28234962

  17. Detecting Asthma Exacerbations in a Pediatric Emergency Department Using a Bayesian Network

    PubMed Central

    Sanders, David L; Aronsky, Dominik

    2006-01-01

    Objective To develop and evaluate a Bayesian network to identify patients eligible for an asthma-care guideline using only data available electronically at the time of patient triage. Population Consecutive patients 2–18 years old who presented to a pediatric emergency department during a 2-month period. Methods A network was developed and evaluated using clinical data from patient visits. An independent reference standard for asthma guideline eligibility was established and verified for each patient through chart review. Outcome measures were area under the receiver operating characteristic curve, sensitivity, specificity, predictive values, and likelihood ratios. Results We enrolled 3,023 patient visits, including 385 who were eligible for guideline-based care. Area under the receiver operating curve for the network was 0.959 (95% CI = 0.933 – 0.977). At a fixed 90% sensitivity, specificity was 88.3%, positive predictive value was 44.7% and negative predictive value was 98.8%. The positive likelihood ratio was 7.69 and the negative likelihood ratio was 0.11. Conclusion The Bayesian network was able to detect patients eligible for an asthma guideline with high accuracy suggesting that this technique could be used to automatically initiate guideline use for eligible patients. PMID:17238428

  18. GHSI EMERGENCY RADIONUCLIDE BIOASSAY LABORATORY NETWORK: SUMMARY OF A RECENT EXERCISE.

    PubMed

    Li, Chunsheng; Ansari, Armin; Bartizel, Christine; Battisti, Paolo; Franck, Didier; Gerstmann, Udo; Giardina, Isabella; Guichet, Claude; Hammond, Derek; Hartmann, Martina; Jones, Robert L; Kim, Eunjoo; Ko, Raymond; Morhard, Ryan; Quayle, Deborah; Sadi, Baki; Saunders, David; Paquet, Francois

    2016-11-01

    The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop their collective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency. A recent exercise was conducted to test the participating laboratories for their capabilities in screening and in vitro assay of biological samples, performing internal dose assessment and providing advice on medical intervention, if necessary, using a urine sample spiked with a single radionuclide, (241)Am. The laboratories were required to submit their reports according to the exercise schedule and using pre-formatted templates. Generally, the participating laboratories were found to be capable with respect to rapidly screening samples for radionuclide contamination, measuring the radionuclide in the samples, assessing the intake and radiation dose, and providing advice on medical intervention. However, gaps in bioassay measurement and dose assessment have been identified. The network may take steps to ensure that procedures and practices within this network be harmonised and a follow-up exercise be organised on a larger scale, with potential participation of laboratories from the networks coordinated by the International Atomic Energy Agency and the World Health Organization. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Emergent inequality and self-organized social classes in a network of power and frustration

    PubMed Central

    Mahault, Benoit; Saxena, Avadh

    2017-01-01

    We propose a simple agent-based model on a network to conceptualize the allocation of limited wealth among more abundant expectations at the interplay of power, frustration, and initiative. Concepts imported from the statistical physics of frustrated systems in and out of equilibrium allow us to compare subjective measures of frustration and satisfaction to collective measures of fairness in wealth distribution, such as the Lorenz curve and the Gini index. We find that a completely libertarian, law-of-the-jungle setting, where every agent can acquire wealth from or lose wealth to anybody else invariably leads to a complete polarization of the distribution of wealth vs. opportunity. This picture is however dramatically ameliorated when hard constraints are imposed over agents in the form of a limiting network of transactions. There, an out of equilibrium dynamics of the networks, based on a competition between power and frustration in the decision-making of agents, leads to network coevolution. The ratio of power and frustration controls different dynamical regimes separated by kinetic transitions and characterized by drastically different values of equality. It also leads, for proper values of social initiative, to the emergence of three self-organized social classes, lower, middle, and upper class. Their dynamics, which appears mostly controlled by the middle class, drives a cyclical regime of dramatic social changes. PMID:28212440

  20. The role of the interaction network in the emergence of diversity of behavior.

    PubMed

    Godoy, Alan; Tabacof, Pedro; Von Zuben, Fernando J

    2017-01-01

    How can systems in which individuals' inner workings are very similar to each other, as neural networks or ant colonies, produce so many qualitatively different behaviors, giving rise to roles and specialization? In this work, we bring new perspectives to this question by focusing on the underlying network that defines how individuals in these systems interact. We applied a genetic algorithm to optimize rules and connections of cellular automata in order to solve the density classification task, a classical problem used to study emergent behaviors in decentralized computational systems. The networks used were all generated by the introduction of shortcuts in an originally regular topology, following the small-world model. Even though all cells follow the exact same rules, we observed the existence of different classes of cells' behaviors in the best cellular automata found-most cells were responsible for memory and others for integration of information. Through the analysis of structural measures and patterns of connections (motifs) in successful cellular automata, we observed that the distribution of shortcuts between distant regions and the speed in which a cell can gather information from different parts of the system seem to be the main factors for the specialization we observed, demonstrating how heterogeneity in a network can create heterogeneity of behavior.

  1. Emergent inequality and self-organized social classes in a network of power and frustration

    DOE PAGES

    Mahault, Benoit; Saxena, Avadh; Nisoli, Cristiano

    2017-02-17

    We propose a simple agent-based model on a network to conceptualize the allocation of limited wealth among more abundant expectations at the interplay of power, frustration, and initiative. Concepts imported from the statistical physics of frustrated systems in and out of equilibrium allow us to compare subjective measures of frustration and satisfaction to collective measures of fairness in wealth distribution, such as the Lorenz curve and the Gini index. We find that a completely libertarian, law-of-the-jungle setting, where every agent can acquire wealth from or lose wealth to anybody else invariably leads to a complete polarization of the distribution ofmore » wealth vs. opportunity. This picture is however dramatically ameliorated when hard constraints are imposed over agents in the form of a limiting network of transactions. There, an out of equilibrium dynamics of the networks, based on a competition between power and frustration in the decision-making of agents, leads to network coevolution. The ratio of power and frustration controls different dynamical regimes separated by kinetic transitions and characterized by drastically different values of equality. It also leads, for proper values of social initiative, to the emergence of three self-organized social classes, lower, middle, and upper class. Their dynamics, which appears mostly controlled by the middle class, drives a cyclical regime of dramatic social changes.« less

  2. The Research on The Fusion Technology of Wireless LANs and Personal Area Networks for Emergency Secure in Coal Mine

    NASA Astrophysics Data System (ADS)

    Chiyuan, Li

    The author has provided craft brother with predictive wireless communication modality and imaginative solutions, and discussed the applied mode of amalgamation technology of wireless LANs and personal area networks for emergency secure in coal mine. The fire protection jobs of emergency secure will become more scientific, more efficient and more flexible in this circumstance. The study can supply bailout team with the situation of a disaster and the location of miner, enhance the efficiency of emergency secure in coal mine.

  3. Network-aware scalable video monitoring system for emergency situations with operator-managed fidelity control

    NASA Astrophysics Data System (ADS)

    Al Hadhrami, Tawfik; Nightingale, James M.; Wang, Qi; Grecos, Christos

    2014-05-01

    In emergency situations, the ability to remotely monitor unfolding events using high-quality video feeds will significantly improve the incident commander's understanding of the situation and thereby aids effective decision making. This paper presents a novel, adaptive video monitoring system for emergency situations where the normal communications network infrastructure has been severely impaired or is no longer operational. The proposed scheme, operating over a rapidly deployable wireless mesh network, supports real-time video feeds between first responders, forward operating bases and primary command and control centers. Video feeds captured on portable devices carried by first responders and by static visual sensors are encoded in H.264/SVC, the scalable extension to H.264/AVC, allowing efficient, standard-based temporal, spatial, and quality scalability of the video. A three-tier video delivery system is proposed, which balances the need to avoid overuse of mesh nodes with the operational requirements of the emergency management team. In the first tier, the video feeds are delivered at a low spatial and temporal resolution employing only the base layer of the H.264/SVC video stream. Routing in this mode is designed to employ all nodes across the entire mesh network. In the second tier, whenever operational considerations require that commanders or operators focus on a particular video feed, a `fidelity control' mechanism at the monitoring station sends control messages to the routing and scheduling agents in the mesh network, which increase the quality of the received picture using SNR scalability while conserving bandwidth by maintaining a low frame rate. In this mode, routing decisions are based on reliable packet delivery with the most reliable routes being used to deliver the base and lower enhancement layers; as fidelity is increased and more scalable layers are transmitted they will be assigned to routes in descending order of reliability. The third tier

  4. Modeling the emergence of circadian rhythms in a clock neuron network.

    PubMed

    Diambra, Luis; Malta, Coraci P

    2012-01-01

    Circadian rhythms in pacemaker cells persist for weeks in constant darkness, while in other types of cells the molecular oscillations that underlie circadian rhythms damp rapidly under the same conditions. Although much progress has been made in understanding the biochemical and cellular basis of circadian rhythms, the mechanisms leading to damped or self-sustained oscillations remain largely unknown. There exist many mathematical models that reproduce the circadian rhythms in the case of a single cell of the Drosophila fly. However, not much is known about the mechanisms leading to coherent circadian oscillation in clock neuron networks. In this work we have implemented a model for a network of interacting clock neurons to describe the emergence (or damping) of circadian rhythms in Drosophila fly, in the absence of zeitgebers. Our model consists of an array of pacemakers that interact through the modulation of some parameters by a network feedback. The individual pacemakers are described by a well-known biochemical model for circadian oscillation, to which we have added degradation of PER protein by light and multiplicative noise. The network feedback is the PER protein level averaged over the whole network. In particular, we have investigated the effect of modulation of the parameters associated with (i) the control of net entrance of PER into the nucleus and (ii) the non-photic degradation of PER. Our results indicate that the modulation of PER entrance into the nucleus allows the synchronization of clock neurons, leading to coherent circadian oscillations under constant dark condition. On the other hand, the modulation of non-photic degradation cannot reset the phases of individual clocks subjected to intrinsic biochemical noise.

  5. More than meets the eye: Emergent properties of transcription factors networks in Arabidopsis.

    PubMed

    Muhammad, Durreshahwar; Schmittling, Selene; Williams, Cranos; Long, Terri A

    2017-01-01

    Uncovering and mathematically modeling Transcription Factor Networks (TFNs) are the first steps in engineering plants with traits that are better equipped to respond to changing environments. Although several plant TFNs are well known, the framework for systematically modeling complex characteristics such as switch-like behavior, oscillations, and homeostasis that emerge from them remain elusive. This review highlights literature that provides, in part, experimental and computational techniques for characterizing TFNs. This review also outlines methodologies that have been used to mathematically model the dynamic characteristics of TFNs. We present several examples of TFNs in plants that are involved in developmental and stress response. In several cases, advanced algorithms capture or quantify emergent properties that serve as the basis for robustness and adaptability in plant responses. Increasing the use of mathematical approaches will shed new light on these regulatory properties that control plant growth and development, leading to mathematical models that predict plant behavior. This article is part of a Special Issue entitled: Plant Gene Regulatory Mechanisms and Networks, edited by Dr. Erich Grotewold and Dr. Nathan Springer.

  6. Road Accident Prevention with Instant Emergency Warning Message Dissemination in Vehicular Ad-Hoc Network.

    PubMed

    Gokulakrishnan, P; Ganeshkumar, P

    2015-01-01

    A Road Accident Prevention (RAP) scheme based on Vehicular Backbone Network (VBN) structure is proposed in this paper for Vehicular Ad-hoc Network (VANET). The RAP scheme attempts to prevent vehicles from highway road traffic accidents and thereby reduces death and injury rates. Once the possibility of an emergency situation (i.e. an accident) is predicted in advance, instantly RAP initiates a highway road traffic accident prevention scheme. The RAP scheme constitutes the following activities: (i) the Road Side Unit (RSU) constructs a Prediction Report (PR) based on the status of the vehicles and traffic in the highway roads, (ii) the RSU generates an Emergency Warning Message (EWM) based on an abnormal PR, (iii) the RSU forms a VBN structure and (iv) the RSU disseminates the EWM to the vehicles that holds the high Risk Factor (RF) and travels in High Risk Zone (HRZ). These vehicles might reside either within the RSU's coverage area or outside RSU's coverage area (reached using VBN structure). The RAP scheme improves the performance of EWM dissemination in terms of increase in notification and decrease in end-to-end delay. The RAP scheme also reduces infrastructure cost (number of RSUs) by formulating and deploying the VBN structure. The RAP scheme with VBN structure improves notification by 19 percent and end-to-end delay by 14.38 percent for a vehicle density of 160 vehicles. It is also proved from the simulation experiment that the performance of RAP scheme is promising in 4-lane highway roads.

  7. Emergent properties of extracellular vesicles: a holistic approach to decode the complexity of intercellular communication networks.

    PubMed

    Gho, Yong Song; Lee, Changjin

    2017-06-27

    Shedding of nano-sized bilayered extracellular vesicles and extracellular vesicle-mediated intercellular communication are evolutionarily conserved biological processes. Communication between cells and the environment is an essential process in living organisms and dysregulation of intercellular communication leads to various diseases. Thus, systematic studies on extracellular vesicles, also known as exosomes, microvesicles, and outer membrane vesicles, are critical for a deeper understanding of intercellular communication networks that are crucial for decoding the exact causes of various difficult-to-cure diseases. Recent progress in this emerging field reveals that extracellular vesicles are endogenous carriers of specific subsets of proteins, mRNAs, miRNAs, and other bioactive materials, as well as play diverse pathophysiological roles. However, certain issues regarding diverse subtypes and the complex pathophysiological roles of extracellular vesicles are not yet clearly elucidated. In this review, we first briefly introduce the complexity of extracellular vesicles in terms of their vesicular cargos and protein-protein interaction networks, their diverse subtypes, and multifaceted pathophysiological functions. Then, we introduce the limitation of reductionist approaches in understanding the complexity of extracellular vesicles. We finally suggest that molecular systems biology approaches based on the concept of emergent properties are essential for a comprehensive understanding of the complex pathophysiological functions of heterogeneous extracellular vesicles, either at the single vesicle level or at a systems level as a whole.

  8. Creating an infrastructure for safety event reporting and analysis in a multicenter pediatric emergency department network.

    PubMed

    Chamberlain, James M; Shaw, Kathy N; Lillis, Kathleen A; Mahajan, Prashant V; Ruddy, Richard M; Lichenstein, Richard; Olsen, Cody S; Dean, J Michael

    2013-02-01

    Hospital incident reporting is widely used but has had limited effectiveness for improving patient safety nationally. We describe the process of establishing a multi-institutional safety event reporting system. A descriptive study in The Pediatric Emergency Care Applied Research Network of 22 hospital emergency departments was performed. An extensive legal analysis addressed investigators' concerns about sharing confidential incident reports (IRs): (1) the ability to identify sites and (2) potential loss of peer review statute protection. Of the 22 Pediatric Emergency Care Applied Research Network sites, 19 received institutional approval to submit deidentified IRs to the data center. Incident reports were randomly assigned to independent review; discordance was resolved by consensus. Incident reports were categorized by type, subtype, severity, staff involved, and contributing factors. A total of 3,106 IRs were submitted by 18 sites in the first year. Reporting rates ranged more than 50-fold from 0.12 to 6.13 per 1000 patients. Data were sufficient to determine type of error (90% of IRs), severity (79%), staff involved (82%), and contributing factors (82%). However, contributing factors were clearly identified in only 44% of IRs and required extrapolation by investigators in 38%. The most common incidents were related to laboratory specimens (25.5%), medication administration (19.3%), and process variance, such as delays in care (14.4%). Incident reporting provides qualitative data concerning safety events. Perceived legal barriers to sharing confidential data can be addressed. Large variability in reporting rates and low rates of providing contributing factors suggest a need for standardization and improvement of safety event reporting.

  9. The Detection of Emerging Trends Using Wikipedia Traffic Data and Context Networks

    PubMed Central

    Kämpf, Mirko; Tessenow, Eric; Kenett, Dror Y.; Kantelhardt, Jan W.

    2015-01-01

    Can online media predict new and emerging trends, since there is a relationship between trends in society and their representation in online systems? While several recent studies have used Google Trends as the leading online information source to answer corresponding research questions, we focus on the online encyclopedia Wikipedia often used for deeper topical reading. Wikipedia grants open access to all traffic data and provides lots of additional (semantic) information in a context network besides single keywords. Specifically, we suggest and study context-normalized and time-dependent measures for a topic’s importance based on page-view time series of Wikipedia articles in different languages and articles related to them by internal links. As an example, we present a study of the recently emerging Big Data market with a focus on the Hadoop ecosystem, and compare the capabilities of Wikipedia versus Google in predicting its popularity and life cycles. To support further applications, we have developed an open web platform to share results of Wikipedia analytics, providing context-rich and language-independent relevance measures for emerging trends. PMID:26720074

  10. An Emergency Packet Forwarding Scheme for V2V Communication Networks

    PubMed Central

    2014-01-01

    This paper proposes an effective warning message forwarding scheme for cooperative collision avoidance. In an emergency situation, an emergency-detecting vehicle warns the neighbor vehicles via an emergency warning message. Since the transmission range is limited, the warning message is broadcast in a multihop manner. Broadcast packets lead two challenges to forward the warning message in the vehicular network: redundancy of warning messages and competition with nonemergency transmissions. In this paper, we study and address the two major challenges to achieve low latency in delivery of the warning message. To reduce the intervehicle latency and end-to-end latency, which cause chain collisions, we propose a two-way intelligent broadcasting method with an adaptable distance-dependent backoff algorithm. Considering locations of vehicles, the proposed algorithm controls the broadcast of a warning message to reduce redundant EWM messages and adaptively chooses the contention window to compete with nonemergency transmission. Via simulations, we show that our proposed algorithm reduces the probability of rear-end crashes by 70% compared to previous algorithms by reducing the intervehicle delay. We also show that the end-to-end propagation delay of the warning message is reduced by 55%. PMID:25054181

  11. The Detection of Emerging Trends Using Wikipedia Traffic Data and Context Networks.

    PubMed

    Kämpf, Mirko; Tessenow, Eric; Kenett, Dror Y; Kantelhardt, Jan W

    2015-01-01

    Can online media predict new and emerging trends, since there is a relationship between trends in society and their representation in online systems? While several recent studies have used Google Trends as the leading online information source to answer corresponding research questions, we focus on the online encyclopedia Wikipedia often used for deeper topical reading. Wikipedia grants open access to all traffic data and provides lots of additional (semantic) information in a context network besides single keywords. Specifically, we suggest and study context-normalized and time-dependent measures for a topic's importance based on page-view time series of Wikipedia articles in different languages and articles related to them by internal links. As an example, we present a study of the recently emerging Big Data market with a focus on the Hadoop ecosystem, and compare the capabilities of Wikipedia versus Google in predicting its popularity and life cycles. To support further applications, we have developed an open web platform to share results of Wikipedia analytics, providing context-rich and language-independent relevance measures for emerging trends.

  12. Fair Topologies: Community Structures and Network Hubs Drive Emergence of Fairness Norms.

    PubMed

    Mosleh, Mohsen; Heydari, Babak

    2017-06-02

    Fairness has long been argued to govern human behavior in a wide range of social, economic, and organizational activities. The sense of fairness, although universal, varies across different societies. In this study, using a computational model, we test the hypothesis that the topology of social interaction can causally explain some of the cross-societal variations in fairness norms. We show that two network parameters, namely, community structure, as measured by the modularity index, and network hubiness, represented by the skewness of degree distribution, have the most significant impact on emergence of collective fair behavior. These two parameters can explain much of the variations in fairness norms across societies and can also be linked to hypotheses suggested by earlier empirical studies in social and organizational sciences. We devised a multi-layered model that combines local agent interactions with social learning, thus enables both strategic behavior as well as diffusion of successful strategies. By applying multivariate statistics on the results, we obtain the relation between network structural features and the collective fair behavior.

  13. Emergence of small-world anatomical networks in self-organizing clustered neuronal cultures.

    PubMed

    de Santos-Sierra, Daniel; Sendiña-Nadal, Irene; Leyva, Inmaculada; Almendral, Juan A; Anava, Sarit; Ayali, Amir; Papo, David; Boccaletti, Stefano

    2014-01-01

    In vitro primary cultures of dissociated invertebrate neurons from locust ganglia are used to experimentally investigate the morphological evolution of assemblies of living neurons, as they self-organize from collections of separated cells into elaborated, clustered, networks. At all the different stages of the culture's development, identification of neurons' and neurites' location by means of a dedicated software allows to ultimately extract an adjacency matrix from each image of the culture. In turn, a systematic statistical analysis of a group of topological observables grants us the possibility of quantifying and tracking the progression of the main network's characteristics during the self-organization process of the culture. Our results point to the existence of a particular state corresponding to a small-world network configuration, in which several relevant graph's micro- and meso-scale properties emerge. Finally, we identify the main physical processes ruling the culture's morphological transformations, and embed them into a simplified growth model qualitatively reproducing the overall set of experimental observations.

  14. Emergence of Small-World Anatomical Networks in Self-Organizing Clustered Neuronal Cultures

    PubMed Central

    de Santos-Sierra, Daniel; Sendiña-Nadal, Irene; Leyva, Inmaculada; Almendral, Juan A.; Anava, Sarit; Ayali, Amir; Papo, David; Boccaletti, Stefano

    2014-01-01

    In vitro primary cultures of dissociated invertebrate neurons from locust ganglia are used to experimentally investigate the morphological evolution of assemblies of living neurons, as they self-organize from collections of separated cells into elaborated, clustered, networks. At all the different stages of the culture's development, identification of neurons' and neurites' location by means of a dedicated software allows to ultimately extract an adjacency matrix from each image of the culture. In turn, a systematic statistical analysis of a group of topological observables grants us the possibility of quantifying and tracking the progression of the main network's characteristics during the self-organization process of the culture. Our results point to the existence of a particular state corresponding to a small-world network configuration, in which several relevant graph's micro- and meso-scale properties emerge. Finally, we identify the main physical processes ruling the culture's morphological transformations, and embed them into a simplified growth model qualitatively reproducing the overall set of experimental observations. PMID:24489675

  15. Development and Implementation of a Surveillance Network System for Emerging Infectious Diseases in the Caribbean (ARICABA).

    PubMed

    Kim, Wongyu Lewis; Anneducharme, Chelsea; Bucher, Bernard Jean-Marie Philippe

    2011-01-01

    Dengue fever, including dengue hemorrhagic fever, has become a re-emerging public health threat in the Caribbean in the absence of a comprehensive regional surveillance system. In this deficiency, a project entitled ARICABA, strives to implement a pilot surveillance system across three islands: Martinique, St. Lucia, and Dominica. The aim of this project is to establish a network for epidemiological surveillance of infectious diseases, utilizing information and communication technology. This paper describes the system design and development strategies of a "network of networks" surveillance system for infectious diseases in the Caribbean. Also described are benefits, challenges, and limitations of this approach across the three island nations identified through direct observation, open-ended interviews, and email communications with an on-site IT consultant, key informants, and the project director. Identified core systems design of the ARICABA data warehouse include a disease monitoring system and a syndromic surveillance system. Three components comprise the development strategy: the data warehouse server, the geographical information system, and forecasting algorithms; these are recognized technical priorities of the surveillance system. A main benefit of the ARICABA surveillance system is improving responsiveness and representativeness of existing health systems through automated data collection, process, and transmission of information from various sources. Challenges include overcoming technology gaps between countries; real-time data collection points; multiple language support; and "component-oriented" development approaches.

  16. CoDA: Collaborative Data Aggregation in Emerging Sensor Networks Using Bio-Level Voronoi Diagrams

    PubMed Central

    Tang, Chengpei; Yang, Nian

    2016-01-01

    To implement minimum power consumption of the link, cluster heads adopt the multi-hop manner for inter-cluster communication so as to forward the aggregation data to the relay nodes. This paper proposes a collaborative data aggregation in emerging sensor networks using a bio-level Voronoi diagram, which is an energy-efficient data aggregation protocol that integrates topology control, Multiple Access Control (MAC) and routing. The sensor nodes situated in the lower level of the diagram are responsible for listening and gathering data, and should be organized by optimal clustering node. In the inter-cluster communication stage, a particle swarm optimization algorithm is addressed to seek optimal transmission path which could simultaneously achieve the minimization of the maximum next hop distance between two nodes in the routing path and the minimization of the maximum hop count, so the minimization of whole network energy consumption is realized. The results of theoretical analysis and simulation results show that energy efficiency and synchronization accuracy of the proposed algorithm can be much better than with traditional routing protocols, and the energy consumption of nodes in the whole network can be more balanced. PMID:27527181

  17. Emergence of localized patterns in globally coupled networks of relaxation oscillators with heterogeneous connectivity

    NASA Astrophysics Data System (ADS)

    Leiser, Randolph J.; Rotstein, Horacio G.

    2017-08-01

    Oscillations in far-from-equilibrium systems (e.g., chemical, biochemical, biological) are generated by the nonlinear interplay of positive and negative feedback effects operating at different time scales. Relaxation oscillations emerge when the time scales between the activators and the inhibitors are well separated. In addition to the large-amplitude oscillations (LAOs) or relaxation type, these systems exhibit small-amplitude oscillations (SAOs) as well as abrupt transitions between them (canard phenomenon). Localized cluster patterns in networks of relaxation oscillators consist of one cluster oscillating in the LAO regime or exhibiting mixed-mode oscillations (LAOs interspersed with SAOs), while the other oscillates in the SAO regime. Because the individual oscillators are monostable, localized patterns are a network phenomenon that involves the interplay of the connectivity and the intrinsic dynamic properties of the individual nodes. Motivated by experimental and theoretical results on the Belousov-Zhabotinsky reaction, we investigate the mechanisms underlying the generation of localized patterns in globally coupled networks of piecewise-linear relaxation oscillators where the global feedback term affects the rate of change of the activator (fast variable) and depends on the weighted sum of the inhibitor (slow variable) at any given time. We also investigate whether these patterns are affected by the presence of a diffusive type of coupling whose synchronizing effects compete with the symmetry-breaking global feedback effects.

  18. Spirit's 'Paige' Panorama of the Interior of 'Home Plate'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Click on the image for Spirit's 'Paige' Panorama of the Interior of 'Home Plate' (QTVR)

    On Feb. 19, 2006, the 758th Martian day of exploration of the red planet by NASA's Mars Exploration Rover Spirit, the rover acquired this panoramic view of the interior of 'Home Plate,' a circular topographic feature amid the 'Columbia Hills.' This view, called the 'Paige' panorama, is from the top of Home Plate. It shows layered rocks exposed at the edge as well as dark rocks exhibiting both smooth and sponge-like 'scoriaceous' textures. To the east from this vantage point, 'McCool Hill' looms on the horizon. At the base of McCool Hill is a reddish outcrop called 'Oberth,' which Spirit may explore during the rapidly approaching Martian winter. 'Von Braun' and 'Goddard' hills are partially visible beyond the opposite rim of Home Plate.

    The limited spatial coverage of this panorama is the result of steadily decreasing power available to the rover for science activities as the Martian winter arrives and the sun traces a lower path across the sky. The rover team anticipates that the north-facing slopes of McCool Hill should sufficiently tilt the rover's solar panels toward the sun to allow Spirit to survive the winter.

    The view covers about 230 degrees of terrain around the rover. Spirit's panoramic camera (Pancam) took 72 separate images of this scene with four different Pancam filters. This is an approximately true-color rendering using the Pancam's 75-nanometer, 535-nanometer, and 432-nanometer filters. Image-to-image seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.

  19. Spirit's 'Paige' Panorama of the Interior of 'Home Plate'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Click on the image for Spirit's 'Paige' Panorama of the Interior of 'Home Plate' (QTVR)

    On Feb. 19, 2006, the 758th Martian day of exploration of the red planet by NASA's Mars Exploration Rover Spirit, the rover acquired this panoramic view of the interior of 'Home Plate,' a circular topographic feature amid the 'Columbia Hills.' This view, called the 'Paige' panorama, is from the top of Home Plate. It shows layered rocks exposed at the edge as well as dark rocks exhibiting both smooth and sponge-like 'scoriaceous' textures. To the east from this vantage point, 'McCool Hill' looms on the horizon. At the base of McCool Hill is a reddish outcrop called 'Oberth,' which Spirit may explore during the rapidly approaching Martian winter. 'Von Braun' and 'Goddard' hills are partially visible beyond the opposite rim of Home Plate.

    The limited spatial coverage of this panorama is the result of steadily decreasing power available to the rover for science activities as the Martian winter arrives and the sun traces a lower path across the sky. The rover team anticipates that the north-facing slopes of McCool Hill should sufficiently tilt the rover's solar panels toward the sun to allow Spirit to survive the winter.

    The view covers about 230 degrees of terrain around the rover. Spirit's panoramic camera (Pancam) took 72 separate images of this scene with four different Pancam filters. This is an approximately true-color rendering using the Pancam's 75-nanometer, 535-nanometer, and 432-nanometer filters. Image-to-image seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.

  20. 'McMurdo' Panorama from Spirit's 'Winter Haven' (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented in exaggerated color to enhance color differences among rocks, soils and sand.

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest, highest-fidelity view of Mars acquired from either rover. Additional photo coverage of the parts of the rover deck not shown here was completed on sol 980 (Oct. 5 , 2006). The team is completing the processing and mosaicking of those final pieces of

  1. 'McMurdo' Panorama from Spirit's 'Winter Haven'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented in approximately true color.

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest, highest-fidelity view of Mars acquired from either rover. Additional photo coverage of the parts of the rover deck not shown here was completed on sol 980 (Oct. 5 , 2006). The team is completing the processing and mosaicking of those final pieces of the panorama, and that image will be released on

  2. 'McMurdo' Panorama from Spirit's 'Winter Haven'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented in approximately true color.

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest, highest-fidelity view of Mars acquired from either rover. Additional photo coverage of the parts of the rover deck not shown here was completed on sol 980 (Oct. 5 , 2006). The team is completing the processing and mosaicking of those final pieces of the panorama, and that image will be released on

  3. 1. SITE OVERVIEW. PART 1 OF 4 PART PANORAMA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SITE OVERVIEW. PART 1 OF 4 PART PANORAMA WITH NOS. CA-265-2 TO CA-265-4. INTERCHANGE OF ARROYO SECO PARKWAY, INTERSTATE 1-5, AND FIGUEROA STREET AT CROSSINGS OF THE LOS ANGELES RIVER AS SEEN FROM GRAND VIEW POINT IN ELYSIAN PARK. VIEW 1 SHOWS LOS ANGELES RIVER IN FOREGROUND; INTERSTATE I-5 AT CENTER; AND METRO LINK RAILYARD CENTER AT REAR. LOOKING 344° NNW. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  4. 6. SITE OVERVIEW. PART 1 OF 6 PART PANORAMA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. SITE OVERVIEW. PART 1 OF 6 PART PANORAMA WITH NOS. CA-265-7 TO CA-265-11. ARROYO SECO PARKWAY AS SEEN FROM RADIO TOWER HILL (APPROXIMATELY 34° 5' BY 118° 12'30" ON USGS LOS ANGELES QUADRANGLE). PART 1 SHOWS GRAND VIEW POINT AT RIGHT REAR (LOCATION OF CAMERA POSITION FOR PHOTOGRAPHS NOS. 265-1 TO CA-265-5) AND FIGUEROA VIADUCT OVERCROSSING; DOWNTOWN LOS ANGELES IS AT LEFT REAR. LOOKING 234° SW. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  5. 2. SITE OVERVIEW. PART 2 OF 4 PART PANORAMA WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. SITE OVERVIEW. PART 2 OF 4 PART PANORAMA WITH NOS. CA-265-1 TO CA-265-4. INTERCHANGE OF ARROYO SECO PARKWAY, INTERSTATE 1-5, AND FIGUEROA STREET AT CROSSINGS OF THE LOS ANGELES RIVER AS SEEN FROM GRAND VIEW POINT IN ELYSIAN PARK. VIEW 2 SHOWS LOS ANGELES RIVER AND FIGUEROA STREET BRIDGE IN FOREGROUND; INTERSTATE I-5 AT CENTER; AND ARROYO SECO PARKWAY AT RIGHT. LOOKING 30° NNE. - Arroyo Seco Parkway, Los Angeles to Pasadena, Los Angeles, Los Angeles County, CA

  6. Spherical Panorama Visualization of Astronomical Data with Blender and Python

    NASA Astrophysics Data System (ADS)

    Kent, Brian R.

    2016-06-01

    We describe methodology to generate 360 degree spherical panoramas of both 2D and 3D data. The techniques apply to a variety of astronomical data types - all sky maps, 2D and 3D catalogs as well as planetary surface maps. The results can be viewed in a desktop browser or interactively with a mobile phone or tablet. Static displays or panoramic video renderings of the data can be produced. We review the Python code and usage of the 3D Blender software for projecting maps onto 3D surfaces and the various tools for distributing visualizations.

  7. Animation of Panorama of Phoenix Landing Area Looking Southeast

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    This is an animation of panoramic images taken by NASA's Phoenix Mars Lander's Surface Stereo Imager on Sol 15 (June 9, 2008), the 15th Martian day after landing. The panorama looks to the southeast and shows rocks casting shadows, polygons on the surface and as the image looks to the horizon, Phoenix's backshell gleams in the distance.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  8. 'McMurdo' Panorama from Spirit's 'Winter Haven'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented in approximately true color.

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest, highest-fidelity view of Mars acquired from either rover. Additional photo coverage of the parts of the rover deck not shown here was completed on sol 980 (Oct. 5 , 2006). The team is completing the processing and mosaicking of those final pieces of the panorama, and that image will be released on

  9. 'McMurdo' Panorama from Spirit's 'Winter Haven' (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented in exaggerated color to enhance color differences among rocks, soils and sand.

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest, highest-fidelity view of Mars acquired from either rover. Additional photo coverage of the parts of the rover deck not shown here was completed on sol 980 (Oct. 5 , 2006). The team is completing the processing and mosaicking of those final pieces of

  10. Network advocacy and the emergence of global attention to newborn survival

    PubMed Central

    Shiffman, Jeremy

    2016-01-01

    Globally 2.9 million babies die each year before reaching 28 days of life. Over the past quarter century, neonatal mortality has declined at a slower pace than post-neonatal under-five mortality: in consequence newborns now comprise 44% of all deaths to children under five years. Despite high numbers of newborn deaths, global organizations and national governments paid little attention to the issue until 2000, and resources, while growing since then, remain inadequate. This study examines the factors behind these patterns of policy attention: the delayed emergence of attention, its sudden appearance in 2000, its growth thereafter, but the dearth of resources to date. Drawing on a framework on global health networks grounded in collective action theory, the study finds that a newborn survival network helped to shift perceptions about the problem’s severity and tractability, contributing to the rise of global attention. Its efforts were facilitated by pressure on governments to achieve the child survival Millennium Development Goal and by growing awareness that the neonatal period constituted a growing percentage of under-five mortality, a fact the network publicized. The network’s relatively recent emergence, its predominantly technical rather than political composition and strategies, and its inability to date to find a framing of the issue that has convinced national political leaders of the issue’s urgency, in part explain the insufficiency of resources. However, since 2010 a number of non-health oriented inter-governmental organizations have begun to pay attention to the issue, and several countries with high neonatal mortality have created national plans, developments which augur well for the future. The study points to two broader implications concerning how neglected global health issues come to attract attention: priority emerges from a confluence of factors, rather than any single cause; and growth in priority may depend on the creation of a broader

  11. Spherical Panorama 360 VR capture of bldg 30 FCR-1 during ISS operations

    NASA Image and Video Library

    2013-11-21

    360 VR Panorama of the Building 30 Flight Control Room 1 in honor of the ISS 15th Anniversary. Created with jsc2013e095196 thru jsc2013e095201. VR DATE: 11-20-13 LOCATION: B 30 FCR - 1 SUBJECT: B30 FCR - 1 360 VR Panorama VR PHOTOGRAPHER: Bill Stafford

  12. A Web of Things-Based Emerging Sensor Network Architecture for Smart Control Systems.

    PubMed

    Khan, Murad; Silva, Bhagya Nathali; Han, Kijun

    2017-02-09

    The Web of Things (WoT) plays an important role in the representation of the objects connected to the Internet of Things in a more transparent and effective way. Thus, it enables seamless and ubiquitous web communication between users and the smart things. Considering the importance of WoT, we propose a WoT-based emerging sensor network (WoT-ESN), which collects data from sensors, routes sensor data to the web, and integrate smart things into the web employing a representational state transfer (REST) architecture. A smart home scenario is introduced to evaluate the proposed WoT-ESN architecture. The smart home scenario is tested through computer simulation of the energy consumption of various household appliances, device discovery, and response time performance. The simulation results show that the proposed scheme significantly optimizes the energy consumption of the household appliances and the response time of the appliances.

  13. A Web of Things-Based Emerging Sensor Network Architecture for Smart Control Systems

    PubMed Central

    Khan, Murad; Silva, Bhagya Nathali; Han, Kijun

    2017-01-01

    The Web of Things (WoT) plays an important role in the representation of the objects connected to the Internet of Things in a more transparent and effective way. Thus, it enables seamless and ubiquitous web communication between users and the smart things. Considering the importance of WoT, we propose a WoT-based emerging sensor network (WoT-ESN), which collects data from sensors, routes sensor data to the web, and integrate smart things into the web employing a representational state transfer (REST) architecture. A smart home scenario is introduced to evaluate the proposed WoT-ESN architecture. The smart home scenario is tested through computer simulation of the energy consumption of various household appliances, device discovery, and response time performance. The simulation results show that the proposed scheme significantly optimizes the energy consumption of the household appliances and the response time of the appliances.  PMID:28208787

  14. Market Model for Resource Allocation in Emerging Sensor Networks with Reinforcement Learning

    PubMed Central

    Zhang, Yue; Song, Bin; Zhang, Ying; Du, Xiaojiang; Guizani, Mohsen

    2016-01-01

    Emerging sensor networks (ESNs) are an inevitable trend with the development of the Internet of Things (IoT), and intend to connect almost every intelligent device. Therefore, it is critical to study resource allocation in such an environment, due to the concern of efficiency, especially when resources are limited. By viewing ESNs as multi-agent environments, we model them with an agent-based modelling (ABM) method and deal with resource allocation problems with market models, after describing users’ patterns. Reinforcement learning methods are introduced to estimate users’ patterns and verify the outcomes in our market models. Experimental results show the efficiency of our methods, which are also capable of guiding topology management. PMID:27916841

  15. Market Model for Resource Allocation in Emerging Sensor Networks with Reinforcement Learning.

    PubMed

    Zhang, Yue; Song, Bin; Zhang, Ying; Du, Xiaojiang; Guizani, Mohsen

    2016-11-29

    Emerging sensor networks (ESNs) are an inevitable trend with the development of the Internet of Things (IoT), and intend to connect almost every intelligent device. Therefore, it is critical to study resource allocation in such an environment, due to the concern of efficiency, especially when resources are limited. By viewing ESNs as multi-agent environments, we model them with an agent-based modelling (ABM) method and deal with resource allocation problems with market models, after describing users' patterns. Reinforcement learning methods are introduced to estimate users' patterns and verify the outcomes in our market models. Experimental results show the efficiency of our methods, which are also capable of guiding topology management.

  16. The fractal architecture of cytoplasmic organization: scaling, kinetics and emergence in metabolic networks.

    PubMed

    Aon, Miguel Antonio; O'Rourke, Brian; Cortassa, Sonia

    2004-01-01

    In this work, we highlight the links between fractals and scaling in cells and explore the kinetic consequences for biochemical reactions operating in fractal media. Based on the proposal that the cytoskeletal architecture is organized as a percolation lattice, with clusters emerging as fractal forms, the analysis of kinetics in percolation clusters is especially emphasized. A key consequence of this spatiotemporal cytoplasmic organization is that enzyme reactions following Michaelis-Menten or allosteric type kinetics exhibit higher rates in fractal media (for short times and at lower substrate concentrations) at the percolation threshold than in Euclidean media. As a result, considerably faster and higher amplification of enzymatic activity is obtained. Finally, we describe some of the properties bestowed by cytoskeletal organization and dynamics on metabolic networks.

  17. Putting up emotional (Facebook) walls? Attachment status and emerging adults' experiences of social networking sites.

    PubMed

    Nitzburg, George C; Farber, Barry A

    2013-11-01

    Social networking sites (SNS) like Facebook can increase interpersonal connections but also intensify jealousy, envy, and surveillance behaviors. Attachment styles may help explain differences in experiencing SNS. This study investigated the role of attachment in influencing emerging adults' perceptions and feelings about SNS and their disclosures on SNS. Disorganized and anxious attachment predicted subjects' use of SNS to avoid more personal face-to-face communication, suggesting individuals with these tendencies use SNS to hold relationships at a psychological arm's distance. Anxious attachment also predicted feelings of intimacy when using SNS, perhaps reflecting online needs for comfort from others. A case narrative is presented to show how those with insecure attachment patterns may struggle to avoid interpersonal conflict when being continuously presented with ambiguous social information.

  18. The global condition of epidemics: Panoramas in A (H1N1) influenza and their consequences for One World One Health programme.

    PubMed

    Tirado, Francisco; Gómez, Andrés; Rocamora, Verónica

    2015-03-01

    Among the most relevant elements contributing to define the One World One Health programme we find epidemics. The reason is that in recent decades, infectious diseases such as HIV/SIDA, SARS and Influenza have shown that we need new approaches and concepts in order to understand how biological emergencies and health alerts deploy new scales of action. Especially relevant has been the case of A(H1N1) influenza. This reached the status of global threat virtually from its onset, triggering an international response with a diffusion, visibility and rapidity unparalleled in previous health alerts. This article maintains that this global condition cannot be explained solely by the epidemiologic characteristics of the disease, such as mortality rate, severe cases, propagation capacity, etc. Resorting to the approach proposed by the Actor-Network Theory (ANT), this paper suggests that the action of certain socio-technical operators was what built a heterogeneous network of ideas, concepts and materials that turned the A (H1N1) influenza into a global-scale phenomenon with unprecedented speed. Among these operators, the most important ones were: the speaking position, a discourse about threat, the protocols and guidelines that were used and, lastly, the maps that allowed a real-time monitoring of the influenza. The paper ends with the notion of panorama, as defined by Bruno Latour: a suggestion to describe the common denominator of the aforementioned operators, and a means to foresee the development of global scales for certain health alerts. The paper will conclude by proposing that this type of analysis would allow the One World One Health to understand with greater precision the dynamic of epidemics and thus make its principles of action much more specific as well as its definition of what global health should be. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Constructing Rigorous and Broad Biosurveillance Networks for Detecting Emerging Zoonotic Outbreaks

    PubMed Central

    Brown, Mac; Moore, Leslie; McMahon, Benjamin; Powell, Dennis; LaBute, Montiago; Hyman, James M.; Rivas, Ariel; Jankowski, Mark; Berendzen, Joel; Loeppky, Jason; Manore, Carrie; Fair, Jeanne

    2015-01-01

    Determining optimal surveillance networks for an emerging pathogen is difficult since it is not known beforehand what the characteristics of a pathogen will be or where it will emerge. The resources for surveillance of infectious diseases in animals and wildlife are often limited and mathematical modeling can play a supporting role in examining a wide range of scenarios of pathogen spread. We demonstrate how a hierarchy of mathematical and statistical tools can be used in surveillance planning help guide successful surveillance and mitigation policies for a wide range of zoonotic pathogens. The model forecasts can help clarify the complexities of potential scenarios, and optimize biosurveillance programs for rapidly detecting infectious diseases. Using the highly pathogenic zoonotic H5N1 avian influenza 2006-2007 epidemic in Nigeria as an example, we determined the risk for infection for localized areas in an outbreak and designed biosurveillance stations that are effective for different pathogen strains and a range of possible outbreak locations. We created a general multi-scale, multi-host stochastic SEIR epidemiological network model, with both short and long-range movement, to simulate the spread of an infectious disease through Nigerian human, poultry, backyard duck, and wild bird populations. We chose parameter ranges specific to avian influenza (but not to a particular strain) and used a Latin hypercube sample experimental design to investigate epidemic predictions in a thousand simulations. We ranked the risk of local regions by the number of times they became infected in the ensemble of simulations. These spatial statistics were then complied into a potential risk map of infection. Finally, we validated the results with a known outbreak, using spatial analysis of all the simulation runs to show the progression matched closely with the observed location of the farms infected in the 2006-2007 epidemic. PMID:25946164

  20. Constructing rigorous and broad biosurveillance networks for detecting emerging zoonotic outbreaks

    SciTech Connect

    Brown, Mac; Moore, Leslie; McMahon, Benjamin; Powell, Dennis; LaBute, Montiago; Hyman, James M.; Rivas, Ariel; Jankowski, Mark; Berendzen, Joel; Loeppky, Jason; Manore, Carrie; Fair, Jeanne; Viboud, Cecile

    2015-05-06

    Determining optimal surveillance networks for an emerging pathogen is difficult since it is not known beforehand what the characteristics of a pathogen will be or where it will emerge. The resources for surveillance of infectious diseases in animals and wildlife are often limited and mathematical modeling can play a supporting role in examining a wide range of scenarios of pathogen spread. We demonstrate how a hierarchy of mathematical and statistical tools can be used in surveillance planning help guide successful surveillance and mitigation policies for a wide range of zoonotic pathogens. The model forecasts can help clarify the complexities of potential scenarios, and optimize biosurveillance programs for rapidly detecting infectious diseases. Using the highly pathogenic zoonotic H5N1 avian influenza 2006-2007 epidemic in Nigeria as an example, we determined the risk for infection for localized areas in an outbreak and designed biosurveillance stations that are effective for different pathogen strains and a range of possible outbreak locations. We created a general multi-scale, multi-host stochastic SEIR epidemiological network model, with both short and long-range movement, to simulate the spread of an infectious disease through Nigerian human, poultry, backyard duck, and wild bird populations. We chose parameter ranges specific to avian influenza (but not to a particular strain) and used a Latin hypercube sample experimental design to investigate epidemic predictions in a thousand simulations. We ranked the risk of local regions by the number of times they became infected in the ensemble of simulations. These spatial statistics were then complied into a potential risk map of infection. Finally, we validated the results with a known outbreak, using spatial analysis of all the simulation runs to show the progression matched closely with the observed location of the farms infected in the 2006-2007 epidemic.

  1. Constructing rigorous and broad biosurveillance networks for detecting emerging zoonotic outbreaks

    DOE PAGES

    Brown, Mac; Moore, Leslie; McMahon, Benjamin; ...

    2015-05-06

    Determining optimal surveillance networks for an emerging pathogen is difficult since it is not known beforehand what the characteristics of a pathogen will be or where it will emerge. The resources for surveillance of infectious diseases in animals and wildlife are often limited and mathematical modeling can play a supporting role in examining a wide range of scenarios of pathogen spread. We demonstrate how a hierarchy of mathematical and statistical tools can be used in surveillance planning help guide successful surveillance and mitigation policies for a wide range of zoonotic pathogens. The model forecasts can help clarify the complexities ofmore » potential scenarios, and optimize biosurveillance programs for rapidly detecting infectious diseases. Using the highly pathogenic zoonotic H5N1 avian influenza 2006-2007 epidemic in Nigeria as an example, we determined the risk for infection for localized areas in an outbreak and designed biosurveillance stations that are effective for different pathogen strains and a range of possible outbreak locations. We created a general multi-scale, multi-host stochastic SEIR epidemiological network model, with both short and long-range movement, to simulate the spread of an infectious disease through Nigerian human, poultry, backyard duck, and wild bird populations. We chose parameter ranges specific to avian influenza (but not to a particular strain) and used a Latin hypercube sample experimental design to investigate epidemic predictions in a thousand simulations. We ranked the risk of local regions by the number of times they became infected in the ensemble of simulations. These spatial statistics were then complied into a potential risk map of infection. Finally, we validated the results with a known outbreak, using spatial analysis of all the simulation runs to show the progression matched closely with the observed location of the farms infected in the 2006-2007 epidemic.« less

  2. Road Accident Prevention with Instant Emergency Warning Message Dissemination in Vehicular Ad-Hoc Network

    PubMed Central

    P, Gokulakrishnan; P, Ganeshkumar

    2015-01-01

    A Road Accident Prevention (RAP) scheme based on Vehicular Backbone Network (VBN) structure is proposed in this paper for Vehicular Ad-hoc Network (VANET). The RAP scheme attempts to prevent vehicles from highway road traffic accidents and thereby reduces death and injury rates. Once the possibility of an emergency situation (i.e. an accident) is predicted in advance, instantly RAP initiates a highway road traffic accident prevention scheme. The RAP scheme constitutes the following activities: (i) the Road Side Unit (RSU) constructs a Prediction Report (PR) based on the status of the vehicles and traffic in the highway roads, (ii) the RSU generates an Emergency Warning Message (EWM) based on an abnormal PR, (iii) the RSU forms a VBN structure and (iv) the RSU disseminates the EWM to the vehicles that holds the high Risk Factor (RF) and travels in High Risk Zone (HRZ). These vehicles might reside either within the RSU’s coverage area or outside RSU’s coverage area (reached using VBN structure). The RAP scheme improves the performance of EWM dissemination in terms of increase in notification and decrease in end-to-end delay. The RAP scheme also reduces infrastructure cost (number of RSUs) by formulating and deploying the VBN structure. The RAP scheme with VBN structure improves notification by 19 percent and end-to-end delay by 14.38 percent for a vehicle density of 160 vehicles. It is also proved from the simulation experiment that the performance of RAP scheme is promising in 4-lane highway roads. PMID:26636576

  3. Constructing rigorous and broad biosurveillance networks for detecting emerging zoonotic outbreaks.

    PubMed

    Brown, Mac; Moore, Leslie; McMahon, Benjamin; Powell, Dennis; LaBute, Montiago; Hyman, James M; Rivas, Ariel; Jankowski, Mark; Berendzen, Joel; Loeppky, Jason; Manore, Carrie; Fair, Jeanne

    2015-01-01

    Determining optimal surveillance networks for an emerging pathogen is difficult since it is not known beforehand what the characteristics of a pathogen will be or where it will emerge. The resources for surveillance of infectious diseases in animals and wildlife are often limited and mathematical modeling can play a supporting role in examining a wide range of scenarios of pathogen spread. We demonstrate how a hierarchy of mathematical and statistical tools can be used in surveillance planning help guide successful surveillance and mitigation policies for a wide range of zoonotic pathogens. The model forecasts can help clarify the complexities of potential scenarios, and optimize biosurveillance programs for rapidly detecting infectious diseases. Using the highly pathogenic zoonotic H5N1 avian influenza 2006-2007 epidemic in Nigeria as an example, we determined the risk for infection for localized areas in an outbreak and designed biosurveillance stations that are effective for different pathogen strains and a range of possible outbreak locations. We created a general multi-scale, multi-host stochastic SEIR epidemiological network model, with both short and long-range movement, to simulate the spread of an infectious disease through Nigerian human, poultry, backyard duck, and wild bird populations. We chose parameter ranges specific to avian influenza (but not to a particular strain) and used a Latin hypercube sample experimental design to investigate epidemic predictions in a thousand simulations. We ranked the risk of local regions by the number of times they became infected in the ensemble of simulations. These spatial statistics were then complied into a potential risk map of infection. Finally, we validated the results with a known outbreak, using spatial analysis of all the simulation runs to show the progression matched closely with the observed location of the farms infected in the 2006-2007 epidemic.

  4. 'McMurdo' Panorama from Spirit's 'Winter Haven' (Color Stereo)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Left-eye view of a stereo pair for PIA01905

    [figure removed for brevity, see original site] Right-eye view of a stereo pair for PIA01905

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented as a stereo anaglyph to show the scene three-dimensionally when viewed through red-blue glasses (with the red lens on the left).

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest

  5. 'McMurdo' Panorama from Spirit's 'Winter Haven' (Stereo)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented as a stereo anaglyph to show the scene three-dimensionally when viewed through red-blue glasses (with the red lens on the left).

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest, highest-fidelity view of Mars acquired from either rover. Additional photo coverage of the parts of the rover deck not shown here was completed on sol 980 (Oct. 5 , 2006). The team is completing the

  6. 'Gibson' Panorama by Spirit at 'Home Plate' (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    NASA's Mars Exploration Rover Spirit acquired this high-resolution view of intricately layered exposures of rock while parked on the northwest edge of the bright, semi-circular feature known as 'Home Plate.' The rover was perched at a 27-degree upward tilt while creating the panorama, resulting in the 'U' shape of the mosaic. In reality, the features along the 1-meter to 2-meter (1-foot to 6.5-foot) vertical exposure of the rim of Home Plate in this vicinity are relatively level. Rocks near the rover in this view, known as the 'Gibson' panorama, include 'Barnhill,' 'Rogan,' and 'Mackey.'

    Spirit acquired 246 separate images of this scene using 6 different filters on the panoramic camera (Pancam) during the rover's Martian days, or sols, 748 through 751 (Feb. 9 through Feb. 12, 2006). The field of view covers 160 degrees of terrain around the rover. This image is a false-color rendering using using Pancam's 753-nanometer, 535-namometer, and 432-nanometer filters, presented to enhance many subtle color differences between rocks and soils in the scene. Image-to-image seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.

  7. 'McMurdo' Panorama from Spirit's 'Winter Haven' (Stereo)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented as a stereo anaglyph to show the scene three-dimensionally when viewed through red-blue glasses (with the red lens on the left).

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest, highest-fidelity view of Mars acquired from either rover. Additional photo coverage of the parts of the rover deck not shown here was completed on sol 980 (Oct. 5 , 2006). The team is completing the

  8. 'McMurdo' Panorama from Spirit's 'Winter Haven' (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented in exaggerated color to enhance color differences among rocks, soils and sand.

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest, highest-fidelity view of Mars acquired from either rover. Additional photo coverage of the parts of the rover deck not shown here was completed on sol 980 (Oct. 5 , 2006). The team is completing the processing and mosaicking of those final pieces of

  9. A Unified Framework for Street-View Panorama Stitching

    PubMed Central

    Li, Li; Yao, Jian; Xie, Renping; Xia, Menghan; Zhang, Wei

    2016-01-01

    In this paper, we propose a unified framework to generate a pleasant and high-quality street-view panorama by stitching multiple panoramic images captured from the cameras mounted on the mobile platform. Our proposed framework is comprised of four major steps: image warping, color correction, optimal seam line detection and image blending. Since the input images are captured without a precisely common projection center from the scenes with the depth differences with respect to the cameras to different extents, such images cannot be precisely aligned in geometry. Therefore, an efficient image warping method based on the dense optical flow field is proposed to greatly suppress the influence of large geometric misalignment at first. Then, to lessen the influence of photometric inconsistencies caused by the illumination variations and different exposure settings, we propose an efficient color correction algorithm via matching extreme points of histograms to greatly decrease color differences between warped images. After that, the optimal seam lines between adjacent input images are detected via the graph cut energy minimization framework. At last, the Laplacian pyramid blending algorithm is applied to further eliminate the stitching artifacts along the optimal seam lines. Experimental results on a large set of challenging street-view panoramic images captured form the real world illustrate that the proposed system is capable of creating high-quality panoramas. PMID:28025481

  10. 'McMurdo' Panorama from Spirit's 'Winter Haven' (Color Stereo)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Left-eye view of a stereo pair for PIA01905

    [figure removed for brevity, see original site] Right-eye view of a stereo pair for PIA01905

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented as a stereo anaglyph to show the scene three-dimensionally when viewed through red-blue glasses (with the red lens on the left).

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest

  11. 'McMurdo' Panorama from Spirit's 'Winter Haven' (Stereo)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented as a stereo anaglyph to show the scene three-dimensionally when viewed through red-blue glasses (with the red lens on the left).

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest, highest-fidelity view of Mars acquired from either rover. Additional photo coverage of the parts of the rover deck not shown here was completed on sol 980 (Oct. 5 , 2006). The team is completing the

  12. Panorama Phylogenetic Diversity and Distribution of Type A Influenza Virus

    PubMed Central

    Chen, Jiming; Tai, Di; Jiang, Wenming; Hou, Guangyu; Chen, Jie; Li, Jinping; Huang, Baoxu

    2009-01-01

    Background Type A influenza virus is one of important pathogens of various animals, including humans, pigs, horses, marine mammals and birds. Currently, the viral type has been classified into 16 hemagglutinin and 9 neuraminidase subtypes, but the phylogenetic diversity and distribution within the viral type largely remain unclear from the whole view. Methodology/Principal Findings The panorama phylogenetic trees of influenza A viruses were calculated with representative sequences selected from approximately 23000 candidates available in GenBank using web servers in NCBI and the software MEGA 4.0. Lineages and sublineages were classified according to genetic distances, topology of the phylogenetic trees and distributions of the viruses in hosts, regions and time. Conclusions/Significance Here, two panorama phylogenetic trees of type A influenza virus covering all the 16 hemagglutinin subtypes and 9 neuraminidase subtypes, respectively, were generated. The trees provided us whole views and some novel information to recognize influenza A viruses including that some subtypes of avian influenza viruses are more complicated than Eurasian and North American lineages as we thought in the past. They also provide us a framework to generalize the history and explore the future of the viral circulation and evolution in different kinds of hosts. In addition, a simple and comprehensive nomenclature system for the dozens of lineages and sublineages identified within the viral type was proposed, which if universally accepted, will facilitate communications on the viral evolution, ecology and epidemiology. PMID:19325912

  13. Intelligent control in mobile robotics: the PANORAMA project

    NASA Astrophysics Data System (ADS)

    Greenway, Phil

    1994-03-01

    The European Community's strategic research initiative in information technology has been in place for seven years. A good example of the pan-European collaborative projects conducted under this initiative is PANORAMA: Perception and Navigation for Autonomous Mobile Robot Applications. This four-and-a-half-year project, completed in October 1993, aimed to prove the feasibility of an autonomous mobile robotic system replacing a human-operated vehicle working outdoors in a partially structured environment. The autonomous control of a mobile rock drilling machine was chosen as a challenging and representative test scenario. This paper presents an overview of intelligent mobile robot control architectures. Goals and objectives of the project are described, together with the makeup of the consortium and the roles of the members within it. The main technical achievements from PANORAMA are then presented, with emphasis given to the problems of realizing intelligent control. In particular, the planning and replanning of a mission, and the corresponding architectural choices and infrastructure required to support the chosen task oriented approach, are discussed. Specific attention is paid to the functional decomposition of the system, and how the requirements for `intelligent control' impact on the organization of the identified system components. Future work and outstanding problems are considered in some concluding remarks.

  14. 'Gibson' Panorama by Spirit at 'Home Plate' (False Color)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    NASA's Mars Exploration Rover Spirit acquired this high-resolution view of intricately layered exposures of rock while parked on the northwest edge of the bright, semi-circular feature known as 'Home Plate.' The rover was perched at a 27-degree upward tilt while creating the panorama, resulting in the 'U' shape of the mosaic. In reality, the features along the 1-meter to 2-meter (1-foot to 6.5-foot) vertical exposure of the rim of Home Plate in this vicinity are relatively level. Rocks near the rover in this view, known as the 'Gibson' panorama, include 'Barnhill,' 'Rogan,' and 'Mackey.'

    Spirit acquired 246 separate images of this scene using 6 different filters on the panoramic camera (Pancam) during the rover's Martian days, or sols, 748 through 751 (Feb. 9 through Feb. 12, 2006). The field of view covers 160 degrees of terrain around the rover. This image is a false-color rendering using using Pancam's 753-nanometer, 535-namometer, and 432-nanometer filters, presented to enhance many subtle color differences between rocks and soils in the scene. Image-to-image seams have been eliminated from the sky portion of the mosaic to better simulate the vista a person standing on Mars would see.

  15. 'McMurdo' Panorama from Spirit's 'Winter Haven' (Color Stereo)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Left-eye view of a stereo pair for PIA01905

    [figure removed for brevity, see original site] Right-eye view of a stereo pair for PIA01905

    This 360-degree view, called the 'McMurdo' panorama, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Spirit. From April through October 2006, Spirit has stayed on a small hill known as 'Low Ridge.' There, the rover's solar panels are tilted toward the sun to maintain enough solar power for Spirit to keep making scientific observations throughout the winter on southern Mars. This view of the surroundings from Spirit's 'Winter Haven' is presented as a stereo anaglyph to show the scene three-dimensionally when viewed through red-blue glasses (with the red lens on the left).

    Oct. 26, 2006, marks Spirit's 1,000th sol of what was planned as a 90-sol mission. (A sol is a Martian day, which lasts 24 hours, 39 minutes, 35 seconds). The rover has lived through the most challenging part of its second Martian winter. Its solar power levels are rising again. Spring in the southern hemisphere of Mars will begin in early 2007. Before that, the rover team hopes to start driving Spirit again toward scientifically interesting places in the 'Inner Basin' and 'Columbia Hills' inside Gusev crater. The McMurdo panorama is providing team members with key pieces of scientific and topographic information for choosing where to continue Spirit's exploration adventure.

    The Pancam began shooting component images of this panorama during Spirit's sol 814 (April 18, 2006) and completed the part shown here on sol 932 (Aug. 17, 2006). The panorama was acquired using all 13 of the Pancam's color filters, using lossless compression for the red and blue stereo filters, and only modest levels of compression on the remaining filters. The overall panorama consists of 1,449 Pancam images and represents a raw data volume of nearly 500 megabytes. It is thus the largest

  16. Emerging Roles of Combat Communication Squadrons in Cyber Warfare as Related to Computer Network Attack, Defense and Exploitation

    DTIC Science & Technology

    2011-06-01

    EMERGING ROLES OF COMBAT COMMUNICATION SQUADRONS IN CYBER WARFARE AS RELATED TO COMPUTER NETWORK ATTACK, DEFENSE AND EXPLOITATION GRADUATE RESEARCH...Communication Squadrons in Cyber Warfare as Related to Computer Network Attack, Defense and Exploitation GRADUATE RESEARCH PROJECT Presented to the Faculty...Education and Training Command In Partial Fulfillment of the Requirements for the Degree of Master of Cyber Warfare Michael J. Myers Major, USAF June 2011

  17. From Basic Network Principles to Neural Architecture: Emergence of Spatial-Opponent Cells

    NASA Astrophysics Data System (ADS)

    Linsker, Ralph

    1986-10-01

    The functional architecture of mammalian visual cortex has been elucidated in impressive detail by experimental work of the past 20-25 years. The origin of many of the salient features of this architecture, however, has remained unexplained. This paper is the first of three (the others will appear in subsequent issues of these Proceedings) that address the origin and organization of feature-analyzing (spatial-opponent and orientation-selective) cells in simple systems governed by biologically plusible development rules. I analyze the progressive maturation of a system composed of a few layers of cells, with connections that develop according to a simple set of rules (including Hebb-type modification). To understand the prenatal origin of orientation-selective cells in certain primates, I consider the case in which there is no external input, with the first layer exhibiting random spontaneous electrical activity. No orientation preference is specified to the system at any stage, and none of the basic developmental rules is specific to visual processing. Here I introduce the theory of ``modular self-adaptive networks,'' of which this system is an example, and explicitly demonstrate the emergence of a layer of spatial-opponent cells. This sets the stage for the emergence, in succeeding layers, of an orientation-selective cell population.

  18. VehiHealth: An Emergency Routing Protocol for Vehicular Ad Hoc Network to Support Healthcare System.

    PubMed

    Bhoi, S K; Khilar, P M

    2016-03-01

    Survival of a patient depends on effective data communication in healthcare system. In this paper, an emergency routing protocol for Vehicular Ad hoc Network (VANET) is proposed to quickly forward the current patient status information from the ambulance to the hospital to provide pre-medical treatment. As the ambulance takes time to reach the hospital, ambulance doctor can provide sudden treatment to the patient in emergency by sending patient status information to the hospital through the vehicles using vehicular communication. Secondly, the experienced doctors respond to the information by quickly sending a treatment information to the ambulance. In this protocol, data is forwarded through that path which has less link breakage problem between the vehicles. This is done by calculating an intersection value I v a l u e for the neighboring intersections by using the current traffic information. Then the data is forwarded through that intersection which has minimum I v a l u e . Simulation results show VehiHealth performs better than P-GEDIR, GyTAR, A-STAR and GSR routing protocols in terms of average end-to-end delay, number of link breakage, path length, and average response time.

  19. Frustrated hierarchical synchronization and emergent complexity in the human connectome network

    PubMed Central

    Villegas, Pablo; Moretti, Paolo; Muñoz, Miguel A.

    2014-01-01

    The spontaneous emergence of coherent behavior through synchronization plays a key role in neural function, and its anomalies often lie at the basis of pathologies. Here we employ a parsimonious (mesoscopic) approach to study analytically and computationally the synchronization (Kuramoto) dynamics on the actual human-brain connectome network. We elucidate the existence of a so-far-uncovered intermediate phase, placed between the standard synchronous and asynchronous phases, i.e. between order and disorder. This novel phase stems from the hierarchical modular organization of the connectome. Where one would expect a hierarchical synchronization process, we show that the interplay between structural bottlenecks and quenched intrinsic frequency heterogeneities at many different scales, gives rise to frustrated synchronization, metastability, and chimera-like states, resulting in a very rich and complex phenomenology. We uncover the origin of the dynamic freezing behind these features by using spectral graph theory and discuss how the emerging complex synchronization patterns relate to the need for the brain to access –in a robust though flexible way– a large variety of functional attractors and dynamical repertoires without ad hoc fine-tuning to a critical point. PMID:25103684

  20. Frustrated hierarchical synchronization and emergent complexity in the human connectome network.

    PubMed

    Villegas, Pablo; Moretti, Paolo; Muñoz, Miguel A

    2014-08-08

    The spontaneous emergence of coherent behavior through synchronization plays a key role in neural function, and its anomalies often lie at the basis of pathologies. Here we employ a parsimonious (mesoscopic) approach to study analytically and computationally the synchronization (Kuramoto) dynamics on the actual human-brain connectome network. We elucidate the existence of a so-far-uncovered intermediate phase, placed between the standard synchronous and asynchronous phases, i.e. between order and disorder. This novel phase stems from the hierarchical modular organization of the connectome. Where one would expect a hierarchical synchronization process, we show that the interplay between structural bottlenecks and quenched intrinsic frequency heterogeneities at many different scales, gives rise to frustrated synchronization, metastability, and chimera-like states, resulting in a very rich and complex phenomenology. We uncover the origin of the dynamic freezing behind these features by using spectral graph theory and discuss how the emerging complex synchronization patterns relate to the need for the brain to access -in a robust though flexible way- a large variety of functional attractors and dynamical repertoires without ad hoc fine-tuning to a critical point.

  1. [Multimorbidity and primary care: Emergence of new forms of network organization].

    PubMed

    Lamothe, Lise; Sylvain, Chantal; Sit, Vanessa

    2015-01-01

    This study was designed to analyse the adaptive strategies used by primary care professionals to provide more adapted and continuous services to patients with more than one chronic disease. A qualitative case study was conducted in a primary care structure (GMF in Québec). Data were derived from two sources: semi-structured interviews and documents. Based on our thematic analysis of data, we illustrate the adaptive processes at play. Our analysis identified the challenges raised by the increased prevalence of patients with more than one chronic disease and how they influence adaptive strategic initiatives from professionals at the following levels: (1) the patients themselves, (2) the professional-patient relationship, (3) the relationships between professionals of the GMF (4) the relationships between the GMF and other healthcare organizations. The description of these phenomena illustrates the dynamic emergence ofa network form of organization. This phenomenon leads to transformation of the core of the healthcare production system. A deeper understanding of its emergence, impacts and management is necessary.

  2. New Intervention Model of Regional Transfer Network System to Alleviate Crowding of Regional Emergency Medical Center

    PubMed Central

    2016-01-01

    Emergency department (ED) crowding is a serious problem in most tertiary hospitals in Korea. Although several intervention models have been established to alleviate ED crowding, they are limited to a single hospital-based approach. This study was conducted to determine whether the new regional intervention model could alleviate ED crowding in a regional emergency medical center. This study was designed as a “before and after study” and included patients who visited the tertiary hospital ED from November 2011 to October 2013. One tertiary hospital and 32 secondary hospitals were included in the study. A transfer coordinator conducted inter-hospital transfers from a tertiary hospital to a secondary hospital for suitable patients. A total of 1,607 and 2,591 patients transferred from a tertiary hospital before and after the study, respectively (P < 0.001). We found that the median ED length of stay (LOS) decreased significantly from 3.68 hours (interquartile range [IQR], 1.85 to 9.73) to 3.20 hours (IQR, 1.62 to 8.33) in the patient group after implementation of the Regional Transfer Network System (RTNS) (P < 0.001). The results of multivariate analysis showed a negative association between implementation of the RTNS and ED LOS (beta coefficient -0.743; 95% confidence interval -0.914 to -0.572; P < 0.001). In conclusion, the ED LOS in the tertiary hospital decreased after implementation of the RTNS. PMID:27134506

  3. Gravitropism and Lateral Root Emergence are Dependent on the Trans-Golgi Network Protein TNO1

    PubMed Central

    Roy, Rahul; Bassham, Diane C.

    2015-01-01

    The trans-Golgi network (TGN) is a dynamic organelle that functions as a relay station for receiving endocytosed cargo, directing secretory cargo, and trafficking to the vacuole. TGN-localized SYP41-interacting protein (TNO1) is a large, TGN-localized, coiled-coil protein that associates with the membrane fusion protein SYP41, a target SNARE, and is required for efficient protein trafficking to the vacuole. Here, we show that a tno1 mutant has auxin transport-related defects. Mutant roots have delayed lateral root emergence, decreased gravitropic bending of plant organs and increased sensitivity to the auxin analog 2,4-dichlorophenoxyacetic acid and the natural auxin 3-indoleacetic acid. Auxin asymmetry at the tips of elongating stage II lateral roots was reduced in the tno1 mutant, suggesting a role for TNO1 in cellular auxin transport during lateral root emergence. During gravistimulation, tno1 roots exhibited delayed auxin transport from the columella to the basal epidermal cells. Endocytosis to the TGN was unaffected in the mutant, indicating that bulk endocytic defects are not responsible for the observed phenotypes. Together these studies demonstrate a role for TNO1 in mediating auxin responses during root development and gravistimulation, potentially through trafficking of auxin transport proteins. PMID:26617617

  4. Frustrated hierarchical synchronization and emergent complexity in the human connectome network

    NASA Astrophysics Data System (ADS)

    Villegas, Pablo; Moretti, Paolo; Muñoz, Miguel A.

    2014-08-01

    The spontaneous emergence of coherent behavior through synchronization plays a key role in neural function, and its anomalies often lie at the basis of pathologies. Here we employ a parsimonious (mesoscopic) approach to study analytically and computationally the synchronization (Kuramoto) dynamics on the actual human-brain connectome network. We elucidate the existence of a so-far-uncovered intermediate phase, placed between the standard synchronous and asynchronous phases, i.e. between order and disorder. This novel phase stems from the hierarchical modular organization of the connectome. Where one would expect a hierarchical synchronization process, we show that the interplay between structural bottlenecks and quenched intrinsic frequency heterogeneities at many different scales, gives rise to frustrated synchronization, metastability, and chimera-like states, resulting in a very rich and complex phenomenology. We uncover the origin of the dynamic freezing behind these features by using spectral graph theory and discuss how the emerging complex synchronization patterns relate to the need for the brain to access -in a robust though flexible way- a large variety of functional attractors and dynamical repertoires without ad hoc fine-tuning to a critical point.

  5. Design and implementation of wireless dose logger network for radiological emergency decision support system.

    PubMed

    Gopalakrishnan, V; Baskaran, R; Venkatraman, B

    2016-08-01

    A decision support system (DSS) is implemented in Radiological Safety Division, Indira Gandhi Centre for Atomic Research for providing guidance for emergency decision making in case of an inadvertent nuclear accident. Real time gamma dose rate measurement around the stack is used for estimating the radioactive release rate (source term) by using inverse calculation. Wireless gamma dose logging network is designed, implemented, and installed around the Madras Atomic Power Station reactor stack to continuously acquire the environmental gamma dose rate and the details are presented in the paper. The network uses XBee-Pro wireless modules and PSoC controller for wireless interfacing, and the data are logged at the base station. A LabView based program is developed to receive the data, display it on the Google Map, plot the data over the time scale, and register the data in a file to share with DSS software. The DSS at the base station evaluates the real time source term to assess radiation impact.

  6. Artificial Neural Networks and risk stratification models in Emergency Departments: The policy maker's perspective.

    PubMed

    Casagranda, Ivo; Costantino, Giorgio; Falavigna, Greta; Furlan, Raffaello; Ippoliti, Roberto

    2016-01-01

    The primary goal of Emergency Department (ED) physicians is to discriminate between individuals at low risk, who can be safely discharged, and patients at high risk, who require prompt hospitalization. The problem of correctly classifying patients is an issue involving not only clinical but also managerial aspects, since reducing the rate of admission of patients to EDs could dramatically cut costs. Nevertheless, a trade-off might arise due to the need to find a balance between economic interests and the health conditions of patients. This work considers patients in EDs after a syncope event and presents a comparative analysis between two models: a multivariate logistic regression model, as proposed by the scientific community to stratify the expected risk of severe outcomes in the short and long run, and Artificial Neural Networks (ANNs), an innovative model. The analysis highlights differences in correct classification of severe outcomes at 10 days (98.30% vs. 94.07%) and 1 year (97.67% vs. 96.40%), pointing to the superiority of Neural Networks. According to the results, there is also a significant superiority of ANNs in terms of false negatives both at 10 days (3.70% vs. 5.93%) and at 1 year (2.33% vs. 10.07%). However, considering the false positives, the adoption of ANNs would cause an increase in hospital costs, highlighting the potential trade-off which policy makers might face.

  7. Design and implementation of wireless dose logger network for radiological emergency decision support system

    SciTech Connect

    Gopalakrishnan, V.; Baskaran, R.; Venkatraman, B.

    2016-08-15

    A decision support system (DSS) is implemented in Radiological Safety Division, Indira Gandhi Centre for Atomic Research for providing guidance for emergency decision making in case of an inadvertent nuclear accident. Real time gamma dose rate measurement around the stack is used for estimating the radioactive release rate (source term) by using inverse calculation. Wireless gamma dose logging network is designed, implemented, and installed around the Madras Atomic Power Station reactor stack to continuously acquire the environmental gamma dose rate and the details are presented in the paper. The network uses XBee–Pro wireless modules and PSoC controller for wireless interfacing, and the data are logged at the base station. A LabView based program is developed to receive the data, display it on the Google Map, plot the data over the time scale, and register the data in a file to share with DSS software. The DSS at the base station evaluates the real time source term to assess radiation impact.

  8. Emergence and scaling of synchronization in moving-agent networks with restrictive interactions

    NASA Astrophysics Data System (ADS)

    Kim, Beomseok; Do, Younghae; Lai, Ying-Cheng

    2013-10-01

    In fields such as robotics and sensor networks, synchronization among mobile and dynamic agents is a basic task. We articulate an effective strategy to achieve synchronization in dynamic networks of moving chaotic agents. Our counterintuitive idea is to restrict agents’ ability to interact with each other, which can be implemented by designating a finite number of fixed zones in the space, in which agents are allowed to interact with each other but agents outside the zones are deprived of the ability of mutual interaction. Our setting is thus different from the one used in existing works on synchronization of mobile agents where each agent is associated with an interacting zone that moves with the agent. We find, through a mathematical analysis, that an optimal interval exists in the interaction probability, where stable synchronization emerges. An inverse square-root scaling law is uncovered which relates the interval with the system size, i.e., the total number of moving agents. Extensive numerical support for physical spaces of one, two, and three dimensions is provided.

  9. Development and Implementation of a Surveillance Network System for Emerging Infectious Diseases in the Caribbean (ARICABA)

    PubMed Central

    Kim, WonGyu Lewis; AnneDucharme, Chelsea; Bucher, Bernard Jean-Marie Philippe

    2011-01-01

    Dengue fever, including dengue hemorrhagic fever, has become a re-emerging public health threat in the Caribbean in the absence of a comprehensive regional surveillance system. In this deficiency, a project entitled ARICABA, strives to implement a pilot surveillance system across three islands: Martinique, St. Lucia, and Dominica. The aim of this project is to establish a network for epidemiological surveillance of infectious diseases, utilizing information and communication technology. This paper describes the system design and development strategies of a “network of networks” surveillance system for infectious diseases in the Caribbean. Also described are benefits, challenges, and limitations of this approach across the three island nations identified through direct observation, open-ended interviews, and email communications with an on-site IT consultant, key informants, and the project director. Identified core systems design of the ARICABA data warehouse include a disease monitoring system and a syndromic surveillance system. Three components comprise the development strategy: the data warehouse server, the geographical information system, and forecasting algorithms; these are recognized technical priorities of the surveillance system. A main benefit of the ARICABA surveillance system is improving responsiveness and representativeness of existing health systems through automated data collection, process, and transmission of information from various sources. Challenges include overcoming technology gaps between countries; real-time data collection points; multiple language support; and “component-oriented” development approaches. PMID:23569607

  10. Dendritic and Axonal Propagation Delays Determine Emergent Structures of Neuronal Networks with Plastic Synapses

    PubMed Central

    Madadi Asl, Mojtaba; Valizadeh, Alireza; Tass, Peter A.

    2017-01-01

    Spike-timing-dependent plasticity (STDP) modifies synaptic strengths based on the relative timing of pre- and postsynaptic spikes. The temporal order of spikes turned out to be crucial. We here take into account how propagation delays, composed of dendritic and axonal delay times, may affect the temporal order of spikes. In a minimal setting, characterized by neglecting dendritic and axonal propagation delays, STDP eliminates bidirectional connections between two coupled neurons and turns them into unidirectional connections. In this paper, however, we show that depending on the dendritic and axonal propagation delays, the temporal order of spikes at the synapses can be different from those in the cell bodies and, consequently, qualitatively different connectivity patterns emerge. In particular, we show that for a system of two coupled oscillatory neurons, bidirectional synapses can be preserved and potentiated. Intriguingly, this finding also translates to large networks of type-II phase oscillators and, hence, crucially impacts on the overall hierarchical connectivity patterns of oscillatory neuronal networks. PMID:28045109

  11. Occurrence and potential crop uptake of emerging contaminants and related compounds in an agricultural irrigation network.

    PubMed

    Calderón-Preciado, Diana; Matamoros, Víctor; Bayona, Josep M

    2011-12-15

    Emerging contaminants have received much attention in recent years due to their presence in surface waters, but little attention has been paid to their occurrence in agricultural irrigation waters. This study investigated the occurrence of these compounds in an agricultural irrigation network in northeastern Spain and, for the first time, using two plant uptake models, estimated the concentration of selected micropollutants in crops. The concentration of micropollutants in agricultural irrigation waters ranged from 10 to 5130 ng L(-1) and exhibited some attenuation over the course of the irrigation network. Bromoform, chloroform, diclofenac, caffeine, ibuprofen, naproxen, methyl dihydrojasmonate, galaxolide, butylated hydroxytoluene, and butylated hydroxyanisole were the most abundant contaminants (>200 ng L(-1), on average). The estimated concentration of micropollutants in crops ranged from <1 to 7677 ng kg(-1), with the neutral compounds being the most abundant. Moreover, the predicted data obtained by fate models generally agreed with experimental data. Finally, human exposure to micropollutants through fruit and vegetable consumption was estimated to be 9.8 μg per person and week (Σ 27 contaminants detected). Further studies are needed to determine the health implications that the presence of these compounds in fruit and vegetables may have for consumers. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. More Opportunities than Wealth: Inequality and Emergent Social Classes in a Network of Power and Frustration

    NASA Astrophysics Data System (ADS)

    Nisoli, Cristiano; Mahault, Benoit; Saxena, Avadh

    We introduce a minimal agent-based model to qualitatively conceptualize the allocation of limited wealth among more abundant opportunities. There the interplay of power, satisfaction and frustration determines the distribution, concentration, and inequality of wealth. Our framework allows us to compare subjective measures of frustration and satisfaction to collective measures of fairness in wealth distribution, such as the Lorenz curve and the Gini index. We find that a completely libertarian, law-of-the-jungle setting, where every agent can acquire wealth from, or lose wealth to, anybody else invariably leads to large inequality. The picture is however dramatically modified when hard constraints are imposed over agents, and they are limited to share wealth with neighbors on a network. We address dynamical societies via an out of equilibrium coevolution of the network, driven by a competition between power and frustration. The ratio between power and frustration controls different dynamical regimes separated by kinetic transitions and characterized by drastically different values of the indices of equality. In particular, it leads to the emergence of three self-organized social classes, lower, middle, and upper class, whose interactions drive a cyclical regime.

  13. Emerging tools for continuous nutrient monitoring networks: Sensors advancing science and water resources protection

    USGS Publications Warehouse

    Pellerin, Brian; Stauffer, Beth A; Young, Dwane A; Sullivan, Daniel J.; Bricker, Suzanne B.; Walbridge, Mark R; Clyde, Gerard A; Shaw, Denice M

    2016-01-01

    Sensors and enabling technologies are becoming increasingly important tools for water quality monitoring and associated water resource management decisions. In particular, nutrient sensors are of interest because of the well-known adverse effects of nutrient enrichment on coastal hypoxia, harmful algal blooms, and impacts to human health. Accurate and timely information on nutrient concentrations and loads is integral to strategies designed to minimize risk to humans and manage the underlying drivers of water quality impairment. Using nitrate sensors as an example, we highlight the types of applications in freshwater and coastal environments that are likely to benefit from continuous, real-time nutrient data. The concurrent emergence of new tools to integrate, manage and share large data sets is critical to the successful use of nutrient sensors and has made it possible for the field of continuous nutrient monitoring to rapidly move forward. We highlight several near-term opportunities for Federal agencies, as well as the broader scientific and management community, that will help accelerate sensor development, build and leverage sites within a national network, and develop open data standards and data management protocols that are key to realizing the benefits of a large-scale, integrated monitoring network. Investing in these opportunities will provide new information to guide management and policies designed to protect and restore our nation’s water resources.

  14. Genetic variation among 82 pharmacogenes: The PGRNseq data from the eMERGE network

    PubMed Central

    Bush, WS; Crosslin, DR; Owusu‐Obeng, A; Wallace, J; Almoguera, B; Basford, MA; Bielinski, SJ; Carrell, DS; Connolly, JJ; Crawford, D; Doheny, KF; Gallego, CJ; Gordon, AS; Keating, B; Kirby, J; Kitchner, T; Manzi, S; Mejia, AR; Pan, V; Perry, CL; Peterson, JF; Prows, CA; Ralston, J; Scott, SA; Scrol, A; Smith, M; Stallings, SC; Veldhuizen, T; Wolf, W; Volpi, S; Wiley, K; Li, R; Manolio, T; Bottinger, E; Brilliant, MH; Carey, D; Chisholm, RL; Chute, CG; Haines, JL; Hakonarson, H; Harley, JB; Holm, IA; Kullo, IJ; Jarvik, GP; Larson, EB; McCarty, CA; Williams, MS; Denny, JC; Rasmussen‐Torvik, LJ; Roden, DM

    2016-01-01

    Genetic variation can affect drug response in multiple ways, although it remains unclear how rare genetic variants affect drug response. The electronic Medical Records and Genomics (eMERGE) Network, collaborating with the Pharmacogenomics Research Network, began eMERGE‐PGx, a targeted sequencing study to assess genetic variation in 82 pharmacogenes critical for implementation of “precision medicine.” The February 2015 eMERGE‐PGx data release includes sequence‐derived data from ∼5,000 clinical subjects. We present the variant frequency spectrum categorized by variant type, ancestry, and predicted function. We found 95.12% of genes have variants with a scaled Combined Annotation‐Dependent Depletion score above 20, and 96.19% of all samples had one or more Clinical Pharmacogenetics Implementation Consortium Level A actionable variants. These data highlight the distribution and scope of genetic variation in relevant pharmacogenes, identifying challenges associated with implementing clinical sequencing for drug treatment at a broader level, underscoring the importance for multifaceted research in the execution of precision medicine. PMID:26857349

  15. Dendritic and Axonal Propagation Delays Determine Emergent Structures of Neuronal Networks with Plastic Synapses.

    PubMed

    Madadi Asl, Mojtaba; Valizadeh, Alireza; Tass, Peter A

    2017-01-03

    Spike-timing-dependent plasticity (STDP) modifies synaptic strengths based on the relative timing of pre- and postsynaptic spikes. The temporal order of spikes turned out to be crucial. We here take into account how propagation delays, composed of dendritic and axonal delay times, may affect the temporal order of spikes. In a minimal setting, characterized by neglecting dendritic and axonal propagation delays, STDP eliminates bidirectional connections between two coupled neurons and turns them into unidirectional connections. In this paper, however, we show that depending on the dendritic and axonal propagation delays, the temporal order of spikes at the synapses can be different from those in the cell bodies and, consequently, qualitatively different connectivity patterns emerge. In particular, we show that for a system of two coupled oscillatory neurons, bidirectional synapses can be preserved and potentiated. Intriguingly, this finding also translates to large networks of type-II phase oscillators and, hence, crucially impacts on the overall hierarchical connectivity patterns of oscillatory neuronal networks.

  16. Design and implementation of wireless dose logger network for radiological emergency decision support system

    NASA Astrophysics Data System (ADS)

    Gopalakrishnan, V.; Baskaran, R.; Venkatraman, B.

    2016-08-01

    A decision support system (DSS) is implemented in Radiological Safety Division, Indira Gandhi Centre for Atomic Research for providing guidance for emergency decision making in case of an inadvertent nuclear accident. Real time gamma dose rate measurement around the stack is used for estimating the radioactive release rate (source term) by using inverse calculation. Wireless gamma dose logging network is designed, implemented, and installed around the Madras Atomic Power Station reactor stack to continuously acquire the environmental gamma dose rate and the details are presented in the paper. The network uses XBee-Pro wireless modules and PSoC controller for wireless interfacing, and the data are logged at the base station. A LabView based program is developed to receive the data, display it on the Google Map, plot the data over the time scale, and register the data in a file to share with DSS software. The DSS at the base station evaluates the real time source term to assess radiation impact.

  17. GeoSentinel: the global emerging infections sentinel network of the International Society of Travel Medicine.

    PubMed

    Freedman, D O; Kozarsky, P E; Weld, L H; Cetron, M S

    1999-06-01

    GeoSentinel is a network of 22 member travel/tropical medicine clinics (14 in the United States and 8 in other countries) initiated in 1995 by the International Society of Travel Medicine (ISTM). GeoSentinel is based on the concept that these clinics are ideally situated to effectively detect geographic and temporal trends in morbidity among travelers. The core surveillance tool is a single-page faxable form submitted to a central data site for each post-travel patient, including immigrants, refugees, and foreign visitors. Diagnoses are entered either as specific etiologies or as syndromes and are then linked to geographic locations, reference dates, and clinical presentations. In addition, electronic communication with the larger body of worldwide ISTM member clinics is periodically done to obtain broader data collection in response to specific inquiries. The scope of GeoSentinel has broadened from the initial vision of a provider-based sentinel network tracking emerging infections at their point of entry into developed countries. Its present goals are (1) to monitor global trends in disease occurrence among travelers; (2) to ascertain risk factors and morbidity in groups of travelers categorized by travel purpose and type of traveler; (3) to respond to urgent public health queries; (4) to develop educational priorities for travelers' health; and (5) to effect a rapid response by electronically disseminating alerts to surveillance sites, to all ISTM members in 55 countries, and to public health authorities. In addition, a major byproduct of the network, and now one of its strongest assets, has been the growth of partnerships between ISTM, Centers for Disease Control and Prevention and health-care providers around the world, as well as other medical societies, government, and private organizations. The demographic data, travel patterns, and clinical presentations for the first 2813 patient records analyzed from the GeoSentinel sites are summarized in this paper.

  18. Current management of prosthetic joint infections in adults: results of an Emerging Infections Network survey

    PubMed Central

    Marschall, Jonas; Lane, Michael A.; Beekmann, Susan E.; Polgreen, Philip; Babcock, Hilary M.

    2013-01-01

    There is a dearth of guidance on the management of prosthetic joint infections (PJIs), in particular because of the lack of high-quality evidence for optimal antibiotics. Thus, we designed a nine-question survey of current practices and preferences among members of the Emerging Infections Network, a CDC-sponsored network of infectious diseases physicians, which was distributed in May 2012. In total, 556 (47.2%) of 1178 network members responded. As first-line antibiotic choice for MSSA PJI, 59% of responders indicated oxacillin/nafcillin, 33% cefazolin and 7% ceftriaxone; the commonest alternative was cefazolin (46%). For MRSA PJI, 90% preferred vancomycin, 7% daptomycin and 0.8% ceftaroline; the commonest alternative was daptomycin (65%). Antibiotic selection for coagulase-negative staphylococci varied depending on meticillin susceptibility. For staphylococcal PJIs with retained hardware, most providers would add rifampicin. Propionibacterium is usually treated with vancomycin (40%), penicillin (23%) or ceftriaxone (17%). Most responders thought 10–19% of all PJIs were culture-negative. Culture-negative PJIs of the lower extremities are usually treated with a vancomycin/fluoroquinolone combination, and culture-negative shoulder PJIs with vancomycin/ceftriaxone. The most cited criteria for selecting antibiotics were ease of administration and the safety profile. A treatment duration of 6–8 weeks is preferred (by 77% of responders) and is mostly guided by clinical response and inflammatory markers. Ninety-nine percent of responders recommend oral antibiotic suppression (for varying durations) in patients with retained hardware. In conclusion, there is considerable variation in treatment of PJIs both with identified pathogens and those with negative cultures. Future studies should aim to identify optimum treatment strategies. PMID:23312602

  19. Southside medical homes network: linking emergency department patients to community care.

    PubMed

    Marr, Amy L; Pillow, Tyson; Brown, Stephen

    2008-01-01

    BBACKGROUND The 14 neighborhoods surrounding University of Chicago Hospitals (UCH) have both Chicago's highest "ambulatory-care-sensitive condition" hospitalization rates and lack of community-based care. To address these problems, in 2004, the Southside Medical Homes (SMH) Network began linking emergency department (ED) patients with 18 community providers. The ED-based patient navigator (patient advocate) is an integral component of this network, and both their current and developing roles will be discussed. MMETHODS Six navigators worked in the UCH-ED approached eligible patients that are flagged by the ED electronic tracking system. Patients were offered the services provided by primary-care referral and appropriate dental, mental health, and substance abuse facilities. Appointments were scheduled, and pertinent ED medical data was faxed to the outlying sites. Navigator roles were expanding with SMH to include: (1) focus on frequent user/chronic disease populations such as sickle cell disease where advocates will expedite a multidisciplinary clinic referral; (2) navigator training to better inform patients of the specific benefits a "medical home" provides for preventive and psychosocial care; (3) and improving navigator, and secondarily, patient knowledge, of community resources: health-education sites, vocational programs, advocacy agencies, support groups, etc. RRESULTS/CONCLUSIONS Data through 01 July 2007 show a monthly average of 950 ED patients surveyed and 80% of these accepting follow-up referral services. Of those patients with ED-scheduled appointments (43%) in community clinics, network data shows patients returning to their referred providers: 39% of patients have been -> or = times. The navigator role is evolving with the expansion of SMH to include: (1) frequent-user population referrals; (2) preventive health education; and (3) utilization of community resources.

  20. Emergence of complex networks from diffusion on fractal lattices. A special case of the Sierpinski gasket and tetrahedron

    NASA Astrophysics Data System (ADS)

    Chełminiak, Przemysław

    2012-10-01

    A new approach to the assemblage of complex networks displaying the scale-free architecture is proposed. While the growth and the preferential attachment of incoming nodes assure an emergence of such networks according to the Barabási-Albert model, it is argued here that the preferential linking condition needs not to be a principal rule. To assert this statement a simple computer model based on random walks on fractal lattices is introduced. It is shown that the model successfully reproduces the degree distributions, the ultra-small-worldness and the high clustering arising from the topology of scale-free networks.

  1. Emergence and robustness of a community discussion network on mercury contamination and health in the Brazilian Amazon.

    PubMed

    Mertens, Frédéric; Saint-Charles, Johanne; Lucotte, Marc; Mergler, Donna

    2008-08-01

    Information exchanges, debates, and negotiations through community social networks are essential to ensure the sustainability of the development process initiated in participatory research. The authors analyze the structural properties and robustness of a discussion network about mercury issues in a community in the Brazilian Amazon involved in a participatory research aimed at reducing exposure to the pollutant. Most of the villagers are connected in a large network and are separated from other individuals by few intermediaries. The structure of the discussion network displays resilience to the random elimination of villagers but shows vulnerability to the removal of one villager who has been a long-term collaborator of the project. Although the network exhibits a structure likely to favor an efficient flow of information, results show that specific actions should be taken to stimulate the emergence of a pool of opinion leaders and increase the redundancy of discussion channels.

  2. A comparative study between nonlinear regression and artificial neural network approaches for modelling wild oat (Avena fatua) field emergence

    USDA-ARS?s Scientific Manuscript database

    Non-linear regression techniques are used widely to fit weed field emergence patterns to soil microclimatic indices using S-type functions. Artificial neural networks present interesting and alternative features for such modeling purposes. In this work, a univariate hydrothermal-time based Weibull m...

  3. mPano: cloud-based mobile panorama view from single picture

    NASA Astrophysics Data System (ADS)

    Li, Hongzhi; Zhu, Wenwu

    2013-09-01

    Panorama view provides people an informative and natural user experience to represent the whole scene. The advances on mobile augmented reality, mobile-cloud computing, and mobile internet can enable panorama view on mobile phone with new functionalities, such as anytime anywhere query where a landmark picture is and what the whole scene looks like. To generate and explore panorama view on mobile devices faces significant challenges due to the limitations of computing capacity, battery life, and memory size of mobile phones, as well as the bandwidth of mobile Internet connection. To address the challenges, this paper presents a novel cloud-based mobile panorama view system that can generate and view panorama-view on mobile devices from a single picture, namely "Pano". In our system, first, we propose a novel iterative multi-modal image retrieval (IMIR) approach to get spatially adjacent images using both tag and content information from the single picture. Second, we propose a cloud-based parallel server synthing approach to generate panorama view in cloud, against today's local-client synthing approach that is almost impossible for mobile phones. Third, we propose predictive-cache solution to reduce latency of image delivery from cloud server to the mobile client. We have built a real mobile panorama view system and perform experiments. The experimental results demonstrated the effectiveness of our system and the proposed key component technologies, especially for landmark images.

  4. Airbag and ASI/MET instrument in 360-degree panorama

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This view from the lander was imaged by the Imager for Mars Pathfinder (IMP) as part of a 360-degree color panorama, taken over sols 8, 9 and 10. A deflated airbag is at the bottom of the image. At the extreme right, the Atmospheric Structure Instrument and Meteorology package (ASI/MET)mast, with its three windsocks, is visible.are at the bottom right of the image.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  5. Implementation of the Exception from Informed Consent Regulations in a Large Multicenter Emergency Clinical Trials Network; the RAMPART Experience

    PubMed Central

    Silbergleit, Robert; Biros, Michelle H.; Harney, Deneil; Dickert, Neal; Baren, Jill

    2012-01-01

    Clinical trials investigating therapies for acutely and critically ill and injured patients in the earliest phases of treatment often can only be performed under regulations allowing for exception from informed consent (EFIC) for emergency research. Implementation of these regulations in multicenter clinical trials involves special challenges and opportunities. The Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART), the first EFIC trial conducted by the Neurological Emergencies Treatment Trials (NETT) network, combined centralized resources and coordination with retention of local control and flexibility to facilitate compliance with the EFIC regulations. Specific methods used by the NETT included common tools for community consultation and public disclosure, sharing of experiences and knowledge, and reporting of aggregate results. Tracking of community consultation and public disclosure activities and feedback facilitates empirical research on EFIC methods in the network and supports quality improvements for future NETT trials. The NETT model used in RAMPART demonstrates how EFIC may be effectively performed in established clinical trial networks. PMID:22506949

  6. The Infectious Diseases Society of America emerging infections network: bridging the gap between clinical infectious diseases and public health.

    PubMed

    Pillai, Satish K; Beekmann, Susan E; Santibanez, Scott; Polgreen, Philip M

    2014-04-01

    In 1995, the Centers for Disease Control and Prevention granted a Cooperative Agreement Program award to the Infectious Diseases Society of America to develop a provider-based emerging infections sentinel network, the Emerging Infections Network (EIN). Over the past 17 years, the EIN has evolved into a flexible, nationwide network with membership representing a broad cross-section of infectious disease physicians. The EIN has an active electronic mail conference (listserv) that facilitates communication among infectious disease providers and the public health community, and also sends members periodic queries (short surveys on infectious disease topics) that have addressed numerous topics relevant to both clinical infectious diseases and public health practice. The article reviews how the various functions of EIN contribute to clinical care and public health, identifies opportunities to further link clinical medicine and public health, and describes future directions for the EIN.

  7. The Infectious Diseases Society of America Emerging Infections Network: Bridging the Gap Between Clinical Infectious Diseases and Public Health

    PubMed Central

    Pillai, Satish K.; Beekmann, Susan E.; Santibanez, Scott; Polgreen, Philip M.

    2015-01-01

    In 1995, the Centers for Disease Control and Prevention granted a Cooperative Agreement Program award to the Infectious Diseases Society of America to develop a provider-based emerging infections sentinel network, the Emerging Infections Network (EIN). Over the past 17 years, the EIN has evolved into a flexible, nationwide network with membership representing a broad cross-section of infectious disease physicians. The EIN has an active electronic mail conference (listserv) that facilitates communication among infectious disease providers and the public health community, and also sends members periodic queries (short surveys on infectious disease topics) that have addressed numerous topics relevant to both clinical infectious diseases and public health practice. The article reviews how the various functions of EIN contribute to clinical care and public health, identifies opportunities to further link clinical medicine and public health, and describes future directions for the EIN. PMID:24403542

  8. Implementation of the exception from informed consent regulations in a large multicenter emergency clinical trials network: the RAMPART experience.

    PubMed

    Silbergleit, Robert; Biros, Michelle H; Harney, Deneil; Dickert, Neal; Baren, Jill

    2012-04-01

    Clinical trials investigating therapies for acutely and critically ill and injured patients in the earliest phases of treatment often can only be performed under regulations allowing for exception from informed consent (EFIC) for emergency research. Implementation of these regulations in multicenter clinical trials involves special challenges and opportunities. The Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART), the first EFIC trial conducted by the Neurological Emergencies Treatment Trials (NETT) network, combined centralized resources and coordination with retention of local control and flexibility to facilitate compliance with the EFIC regulations. Specific methods used by the NETT included common tools for community consultation and public disclosure, sharing of experiences and knowledge, and reporting of aggregate results. Tracking of community consultation and public disclosure activities and feedback facilitates empirical research on EFIC methods in the network and supports quality improvements for future NETT trials. The NETT model used in RAMPART demonstrates how EFIC may be effectively performed in established clinical trial networks.

  9. Emergent Patterns of Forest Biomass Production from Across and within a Micro-Network

    NASA Astrophysics Data System (ADS)

    Pederson, N.; Martin Benito, D.; Bishop, D. A.; Dawson, A.; Dietze, M.; Druckenbrod, D.; Dye, A.; Gonzalez, A. C.; Hessl, A. E.; Martin Fernandez, J.; McLachlan, J. S.; Paciorek, C. J.; Poulter, B.; Williams, J. W.

    2014-12-01

    Many factors drive short- and long-term trends in forest biomass production. Replication at multiple scales, from within individual trees up to continental scales, is necessary to determine factors of growth and at what scale they are most important. Here we report on patterns of biomass production from within and across a micro-network of three forests in the northeastern US. Each forest has different histories and species composition, but each is within a similar climatological setting, which gives insight on important factors of short- and long-term patterns of forest production. One emergent pattern is that two forests are showing a large uptick in production over the last decade. Coincident to this uptick, late-season biomass production is showing a significant increase, even among 150-200+ year old trees. The third forest experienced a severe ice storm in the early-Aughts that paused a three-decade trend of increasing production. In the least diverse forest, the most dominant species drives most of the annual to decadal trend in production. In the most diverse forest, no one species appears to be driving landscape-level production, yet the emergent pattern of production reflects not only drought and pluvial events, but the impact of invasive species and the ice storm. Variation in annual biomass production for most species is strongly related to annual variations in soil moisture. Interestingly at the species level, coherency of growth among yellow birch is lower in the oldest forest in which is it is common versus the youngest forest. Differences in coherency suggest different drivers operating at different scales. Growth of red maple is also driven by moisture, but competition appears to be driving a long-term decline of individuals below the canopy. The decline begins soon after a severe defoliation event. In this same forest, however, significant wetting and warming over the last two decades appears to have reduced some of the climatic constraints on red

  10. Mars Rover Opportunity Panorama of Marathon Valley (Enhanced Color)

    NASA Image and Video Library

    2016-06-14

    "Marathon Valley" on Mars opens northeastward to a view across the floor of Endeavour Crater in this scene from the panoramic camera (Pancam) of NASA's Mars Exploration Rover Opportunity. In this version of the scene the landscape is presented in enhanced color to make differences in surface materials more easily visible. The panorama merges multiple Pancam exposures taken during the period April 16 through May 15, 2016, corresponding to sols (Martian days) 4,347 through 4,375 of Opportunity's work on Mars. It spans from north, at the left, to west-southwest, at the right. The high point in the right half of the scene is "Knudsen Ridge," which forms part of the southern edge of Marathon Valley. Portions of the northeastern and eastern rim of Endeavour crater appear on the distant horizon. Endeavour Crater is 14 miles (22 kilometers) in diameter. The fractured texture of Marathon Valley's floor is visible in the foreground. The rover team calls this image the mission's "Sacagawea Panorama," for the Lemhi Shoshone woman, also commemorated on U.S. dollar coins, whose assistance to the Lewis and Clark expedition helped enable its successes in 1804-1806. Many rocks and other features in Marathon Valley were informally named for members of Lewis and Clark's "Corps of Discovery" expedition. Opportunity entered Marathon Valley in July 2015. The valley's informal name was chosen because Opportunity's arrival at this point along the western rim of Endeavour Crater coincided closely with the rover surpassing marathon-footrace distance in its total driving odometry since landing on Mars in January 2004. The team's planned investigations in the valley were nearing completion when the component images for this scene were taken. http://photojournal.jpl.nasa.gov/catalog/PIA20750

  11. Artificial neural network, genetic algorithm, and logistic regression applications for predicting renal colic in emergency settings.

    PubMed

    Eken, Cenker; Bilge, Ugur; Kartal, Mutlu; Eray, Oktay

    2009-06-03

    Logistic regression is the most common statistical model for processing multivariate data in the medical literature. Artificial intelligence models like an artificial neural network (ANN) and genetic algorithm (GA) may also be useful to interpret medical data. The purpose of this study was to perform artificial intelligence models on a medical data sheet and compare to logistic regression. ANN, GA, and logistic regression analysis were carried out on a data sheet of a previously published article regarding patients presenting to an emergency department with flank pain suspicious for renal colic. The study population was composed of 227 patients: 176 patients had a diagnosis of urinary stone, while 51 ultimately had no calculus. The GA found two decision rules in predicting urinary stones. Rule 1 consisted of being male, pain not spreading to back, and no fever. In rule 2, pelvicaliceal dilatation on bedside ultrasonography replaced no fever. ANN, GA rule 1, GA rule 2, and logistic regression had a sensitivity of 94.9, 67.6, 56.8, and 95.5%, a specificity of 78.4, 76.47, 86.3, and 47.1%, a positive likelihood ratio of 4.4, 2.9, 4.1, and 1.8, and a negative likelihood ratio of 0.06, 0.42, 0.5, and 0.09, respectively. The area under the curve was found to be 0.867, 0.720, 0.715, and 0.713 for all applications, respectively. Data mining techniques such as ANN and GA can be used for predicting renal colic in emergency settings and to constitute clinical decision rules. They may be an alternative to conventional multivariate analysis applications used in biostatistics.

  12. Emergence of Functional Hierarchy in a Multiple Timescale Neural Network Model: A Humanoid Robot Experiment

    PubMed Central

    Yamashita, Yuichi; Tani, Jun

    2008-01-01

    It is generally thought that skilled behavior in human beings results from a functional hierarchy of the motor control system, within which reusable motor primitives are flexibly integrated into various sensori-motor sequence patterns. The underlying neural mechanisms governing the way in which continuous sensori-motor flows are segmented into primitives and the way in which series of primitives are integrated into various behavior sequences have, however, not yet been clarified. In earlier studies, this functional hierarchy has been realized through the use of explicit hierarchical structure, with local modules representing motor primitives in the lower level and a higher module representing sequences of primitives switched via additional mechanisms such as gate-selecting. When sequences contain similarities and overlap, however, a conflict arises in such earlier models between generalization and segmentation, induced by this separated modular structure. To address this issue, we propose a different type of neural network model. The current model neither makes use of separate local modules to represent primitives nor introduces explicit hierarchical structure. Rather than forcing architectural hierarchy onto the system, functional hierarchy emerges through a form of self-organization that is based on two distinct types of neurons, each with different time properties (“multiple timescales”). Through the introduction of multiple timescales, continuous sequences of behavior are segmented into reusable primitives, and the primitives, in turn, are flexibly integrated into novel sequences. In experiments, the proposed network model, coordinating the physical body of a humanoid robot through high-dimensional sensori-motor control, also successfully situated itself within a physical environment. Our results suggest that it is not only the spatial connections between neurons but also the timescales of neural activity that act as important mechanisms leading to

  13. Emergence of functional hierarchy in a multiple timescale neural network model: a humanoid robot experiment.

    PubMed

    Yamashita, Yuichi; Tani, Jun

    2008-11-01

    It is generally thought that skilled behavior in human beings results from a functional hierarchy of the motor control system, within which reusable motor primitives are flexibly integrated into various sensori-motor sequence patterns. The underlying neural mechanisms governing the way in which continuous sensori-motor flows are segmented into primitives and the way in which series of primitives are integrated into various behavior sequences have, however, not yet been clarified. In earlier studies, this functional hierarchy has been realized through the use of explicit hierarchical structure, with local modules representing motor primitives in the lower level and a higher module representing sequences of primitives switched via additional mechanisms such as gate-selecting. When sequences contain similarities and overlap, however, a conflict arises in such earlier models between generalization and segmentation, induced by this separated modular structure. To address this issue, we propose a different type of neural network model. The current model neither makes use of separate local modules to represent primitives nor introduces explicit hierarchical structure. Rather than forcing architectural hierarchy onto the system, functional hierarchy emerges through a form of self-organization that is based on two distinct types of neurons, each with different time properties ("multiple timescales"). Through the introduction of multiple timescales, continuous sequences of behavior are segmented into reusable primitives, and the primitives, in turn, are flexibly integrated into novel sequences. In experiments, the proposed network model, coordinating the physical body of a humanoid robot through high-dimensional sensori-motor control, also successfully situated itself within a physical environment. Our results suggest that it is not only the spatial connections between neurons but also the timescales of neural activity that act as important mechanisms leading to functional

  14. Prediction of Emergency Department Hospital Admission Based on Natural Language Processing and Neural Networks.

    PubMed

    Zhang, Xingyu; Kim, Joyce; Patzer, Rachel E; Pitts, Stephen R; Patzer, Aaron; Schrager, Justin D

    2017-08-16

    To describe and compare logistic regression and neural network modeling strategies to predict hospital admission or transfer following initial presentation to Emergency Department (ED) triage with and without the addition of natural language processing elements. Using data from the National Hospital Ambulatory Medical Care Survey (NHAMCS), a cross-sectional probability sample of United States EDs from 2012 and 2013 survey years, we developed several predictive models with the outcome being admission to the hospital or transfer vs. discharge home. We included patient characteristics immediately available after the patient has presented to the ED and undergone a triage process. We used this information to construct logistic regression (LR) and multilayer neural network models (MLNN) which included natural language processing (NLP) and principal component analysis from the patient's reason for visit. Ten-fold cross validation was used to test the predictive capacity of each model and receiver operating curves (AUC) were then calculated for each model. Of the 47,200 ED visits from 642 hospitals, 6,335 (13.42%) resulted in hospital admission (or transfer). A total of 48 principal components were extracted by NLP from the reason for visit fields, which explained 75% of the overall variance for hospitalization. In the model including only structured variables, the AUC was 0.824 (95% CI 0.818-0.830) for logistic regression and 0.823 (95% CI 0.817-0.829) for MLNN. Models including only free-text information generated AUC of 0.742 (95% CI 0.731- 0.753) for logistic regression and 0.753 (95% CI 0.742-0.764) for MLNN. When both structured variables and free text variables were included, the AUC reached 0.846 (95% CI 0.839-0.853) for logistic regression and 0.844 (95% CI 0.836-0.852) for MLNN. The predictive accuracy of hospital admission or transfer for patients who presented to ED triage overall was good, and was improved with the inclusion of free text data from a patient

  15. Emergence of complex dynamics in a simple model of signaling networks

    PubMed Central

    Amaral, Luís A. N.; Díaz-Guilera, Albert; Moreira, Andre A.; Goldberger, Ary L.; Lipsitz, Lewis A.

    2004-01-01

    Various physical, social, and biological systems generate complex fluctuations with correlations across multiple time scales. In physiologic systems, these long-range correlations are altered with disease and aging. Such correlated fluctuations in living systems have been attributed to the interaction of multiple control systems; however, the mechanisms underlying this behavior remain unknown. Here, we show that a number of distinct classes of dynamical behaviors, including correlated fluctuations characterized by 1/f scaling of their power spectra, can emerge in networks of simple signaling units. We found that, under general conditions, complex dynamics can be generated by systems fulfilling the following two requirements, (i) a “small-world” topology and (ii) the presence of noise. Our findings support two notable conclusions. First, complex physiologic-like signals can be modeled with a minimal set of components; and second, systems fulfilling conditions i and ii are robust to some degree of degradation (i.e., they will still be able to generate 1/f dynamics). PMID:15505227

  16. Empathy emerges spontaneously in the ultimatum game: small groups and networks.

    PubMed

    Iranzo, Jaime; Floría, Luis M; Moreno, Yamir; Sánchez, Angel

    2012-01-01

    The Ultimatum game, in which one subject proposes how to share a pot and the other has veto power on the proposal, in which case both lose everything, is a paradigmatic scenario to probe the degree of cooperation and altruism in human subjects. It has been shown that if individuals are empathic, i.e., they play the game having in mind how their opponent will react by offering an amount that they themselves would accept, then non-rational large offers well above the smallest possible ones are evolutionarily selected. We here show that empathy itself may be selected and need not be exogenously imposed provided that interactions take place only with a fraction of the total population, and that the role of proposer or responder is randomly changed from round to round. These empathic agents, that displace agents with independent (uncorrelated) offers and proposals, behave far from what is expected rationally, offering and accepting sizable fractions of the amount to be shared. Specific values for the typical offer depend on the details of the interacion network and on the existence of hubs, but they are almost always significantly larger than zero, indicating that the mechanism at work here is quite general and could explain the emergence of empathy in very many different contexts.

  17. Empathy Emerges Spontaneously in the Ultimatum Game: Small Groups and Networks

    PubMed Central

    Iranzo, Jaime; Floría, Luis M.; Moreno, Yamir; Sánchez, Angel

    2012-01-01

    The Ultimatum game, in which one subject proposes how to share a pot and the other has veto power on the proposal, in which case both lose everything, is a paradigmatic scenario to probe the degree of cooperation and altruism in human subjects. It has been shown that if individuals are empathic, i.e., they play the game having in mind how their opponent will react by offering an amount that they themselves would accept, then non-rational large offers well above the smallest possible ones are evolutionarily selected. We here show that empathy itself may be selected and need not be exogenously imposed provided that interactions take place only with a fraction of the total population, and that the role of proposer or responder is randomly changed from round to round. These empathic agents, that displace agents with independent (uncorrelated) offers and proposals, behave far from what is expected rationally, offering and accepting sizable fractions of the amount to be shared. Specific values for the typical offer depend on the details of the interacion network and on the existence of hubs, but they are almost always significantly larger than zero, indicating that the mechanism at work here is quite general and could explain the emergence of empathy in very many different contexts. PMID:23049740

  18. Perception Evolution Network Based on Cognition Deepening Model--Adapting to the Emergence of New Sensory Receptor.

    PubMed

    Xing, Youlu; Shen, Furao; Zhao, Jinxi

    2016-03-01

    The proposed perception evolution network (PEN) is a biologically inspired neural network model for unsupervised learning and online incremental learning. It is able to automatically learn suitable prototypes from learning data in an incremental way, and it does not require the predefined prototype number or the predefined similarity threshold. Meanwhile, being more advanced than the existing unsupervised neural network model, PEN permits the emergence of a new dimension of perception in the perception field of the network. When a new dimension of perception is introduced, PEN is able to integrate the new dimensional sensory inputs with the learned prototypes, i.e., the prototypes are mapped to a high-dimensional space, which consists of both the original dimension and the new dimension of the sensory inputs. In the experiment, artificial data and real-world data are used to test the proposed PEN, and the results show that PEN can work effectively.

  19. Development of a Real-Time Radiological Area Monitoring Network for Emergency Response at Lawrence Livermore National Laboratory

    SciTech Connect

    Bertoldo, N; Hunter, S; Fertig, R; Laguna, G; MacQueen, D

    2004-03-08

    A real-time radiological sensor network for emergency response was developed and deployed at the Lawrence Livermore National Laboratory (LLNL). The Real-Time Radiological Area Monitoring (RTRAM) network is comprised of 16 Geiger-Mueller (GM) sensors positioned on the LLNL Livermore site perimeter to continuously monitor for a radiological condition resulting from a terrorist threat to site security and the health and safety of LLNL personnel. The RTRAM network sensor locations coincide with wind sector directions to provide thorough coverage of the one square mile site. These low-power sensors are supported by a central command center (CCC) and transmit measurement data back to the CCC computer through the LLNL telecommunications infrastructure. Alarm conditions are identified by comparing current data to predetermined threshold parameters and are validated by comparison with plausible dispersion modeling scenarios and prevailing meteorological conditions. Emergency response personnel are notified of alarm conditions by automatic radio and computer based notifications. A secure intranet provides emergency response personnel with current condition assessment data that enable them to direct field response efforts remotely. The RTRAM network has proven to be a reliable system since initial deployment in August 2001 and maintains stability during inclement weather conditions.

  20. 54. Photocopy of a photograph1921 PANORAMA OF 1913 DAM FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. Photocopy of a photograph--1921 PANORAMA OF 1913 DAM FROM ISLAND POWER PLANT - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  1. 6. Photocopy of a photograph1921 PANORAMA OF EASTSIDE AND ISLAND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Photocopy of a photograph--1921 PANORAMA OF EASTSIDE AND ISLAND POWER PLANTS FROM THE SOUTH - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  2. 55. Photocopy of a photograph1921 PANORAMA OF 1913 DAM LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    55. Photocopy of a photograph--1921 PANORAMA OF 1913 DAM LOOKING EAST - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  3. 109. Catalog OPark Structure/Construction & Maintenance, 95 Panorama, Negative Number ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    109. Catalog O-Park Structure/Construction & Maintenance, 95 Panorama, Negative Number P 664b ca. 1930s OLD THORNTON GAP ENTRANCE. - Skyline Drive, From Front Royal, VA to Rockfish Gap, VA , Luray, Page County, VA

  4. Utilizing High Resolution Panoramas as Virtual Field Experiences in Undergraduate Planetary Science Courses

    NASA Astrophysics Data System (ADS)

    Piatek, J. L.

    2011-03-01

    Tier-scalable exercises utilizing high resolution panoramas allow students to explore terrestrial landscapes and outcrops virtually, and provide good context for interpreting spacecraft images of solar system bodies.

  5. 12. PART 2 OR PART 2 PANORAMA WITH NO. CA28011 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. PART 2 OR PART 2 PANORAMA WITH NO. CA-280-11 OF FOURTH STREET VIADUCT WEST END OVERCROSSING AT SANTA FE AVENUE. LOOKING SOUTHEAST. - Fourth Street Viaduct, Spanning Los Angeles River, Los Angeles, Los Angeles County, CA

  6. [Helicopter emergency medical service missions at night: 2 years of experience in the Dutch Regional Emergency Healthcare Network East].

    PubMed

    Hoogerwerf, Nico; Heijne, Amon; Geeraedts, Leo M G; van Riessen, Christine; Scheffer, Gert-Jan

    2010-01-01

    To study whether there are differences between day and night in the dispatch of helicopter emergency medical services (HEMS) and in their response and travelling times, medical treatment and transport of patients. Retrospective, descriptive study. All data on helicopter emergency medical service (HEMS) missions available 24/7 from Nijmegen, the Netherlands, during 2007 and 2008 were collected. All missions in this period were divided into daytime and night-time missions. Next, the reason for dispatch, the duration of distinct times during the mission, the method of transport of the HEMS team, medical treatments and patient transport were compared. In 2007 and 2008 the HEMS team was dispatched 2891 times. 1107 patients were treated during daytime and 479 during the night. The mean distance to the incident scene was longer for night missions. During night-time the HEMS team was dispatched more often for road traffic accidents and violence-related accidents but less often for falls, drowning, horse riding accidents and people becoming trapped (non-traffic-related). There were no differences in medical treatment given by the HEMS physician between day and night, but fewer patients were transported by helicopter at night. Travelling times and on-scene times were only slightly different. The number of dispatches of the HEMS team at night was higher than expected, but night missions were cancelled more often due to weather conditions than missions by day. Prehospital times and operations of the Netherlands HEMS differed slightly between day and night.

  7. Understanding Emergent Dynamics: Using a Collective Activity Coordinate of a Neural Network to Recognize Time-Varying Patterns.

    PubMed

    Hopfield, John J

    2015-10-01

    In higher animals, complex and robust behaviors are produced by the microscopic details of large structured ensembles of neurons. I describe how the emergent computational dynamics of a biologically based neural network generates a robust natural solution to the problem of categorizing time-varying stimulus patterns such as spoken words or animal stereotypical behaviors. The recognition of these patterns is made difficult by their substantial variation in cadence and duration. The neural circuit behaviors used are similar to those associated with brain neural integrators. In the larger context described here, this kind of circuit becomes a building block of an entirely different computational algorithm for solving complex problems. While the network behavior is simulated in detail, a collective view is essential to understanding the results. A closed equation of motion for the collective variable describes an algorithm that quantitatively accounts for many aspects of the emergent network computation. The feedback connections and ongoing activity in the network shape the collective dynamics onto a reduced dimensionality manifold of activity space, which defines the algorithm and computation actually performed. The external inputs are weak and are not the dominant drivers of network activity.

  8. Emerging, Reemerging, and Forgotten Brain Areas of the Reward Circuit: Notes from the 2010 Motivational and Neural Networks Conference

    PubMed Central

    McGinty, Vincent B.; Hayden, Benjamin Y.; Heilbronner, Sarah R.; Dumont, Eric C.; Graves, Steven M.; Mirrione, Martine M.; du Hoffman, Johann; Sartor, Gregory C.; España, Rodrigo A.; Millan, E. Zayra; DiFeliceantonio, Alexandra G.; Marchant, Nathan J.; Napier, T. Celeste; Root, David H.; Borgland, Stephanie L.; Treadway, Michael T.; Floresco, Stan B.; McGinty, Jacqueline F.; Haber, Suzanne

    2012-01-01

    On April 24–27, 2010, the Motivational Neuronal Networks meeting took place in Wrightsville Beach, North Carolina. The conference was devoted to “Emerging, re-emerging, and forgotten brain areas” of the reward circuit. A central feature of the conference was four scholarly discussions of cutting-edge topics related to the conference's theme. These discussions form the basis of the present review, which summarizes areas of consensus and controversy, and serves as a roadmap for the next several years of research. PMID:21816177

  9. Southern Half of Spirit's 'Bonestell' Panorama (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This 180-degree panorama shows the southward vista from the location where Spirit is spending its third Martian winter inside Mars' Gusev Crater. The rover's overwintering location is on the northern edge of a low plateau informally called 'Home Plate,' which is about 80 meters or 260 feet in diameter.

    This view combines 168 different exposures taken with Spirit's panoramic Camera (Pancam) 42 pointings with 4 filters at each pointing. Spirit took the first of these frames during the mission's 1,477th Martian day, or sol, (February 28, 2008) two weeks after the rover made its last move to reach the location where it would stop driving for the winter. Solar energy at Gusev Crater is so limited during the Martian winter that Spirit does not generate enough electricity to drive, nor even enough to take many images per day. The last frame for this mosaic was taken on Sol 1599 (July 2, 2008). The rover team plans for Spirit to finish taking images for the northern half of the scene during the Martian spring.

    The northwestern edge of Home Plate is visible in the right foreground. The blockier, more sharply shadowed texture there is layered sandstone whose layering is tilted inward toward the edge of the Home Plate platform. A dark rock on top of Home Plate in that area is a porous volcanic basalt unlike rocks nearby. The northeastern edge of Home Plate is visible in the left foreground. Spirit first climbed onto Home Plate on that region, in early 2006.

    Rover tracks from driving by Spirit are visible on Home plate in the center and right of the image. These were made during Spirit's second exploration on top of the plateau, which began when Spirit climbed onto the southern edge of Home Plate in September, 2007.

    In the center foreground, the turret of tools at the end of Spirit's robotic arm appears in duplicate because the arm was repositioned between the days when the images making up that part of the mosaic were taken.

    On the horizon, the

  10. Southern Half of Spirit's 'Bonestell' Panorama (False Color)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This 180-degree panorama shows the southward vista from the location where Spirit is spending its third Martian winter inside Mars' Gusev Crater. The rover's overwintering location is on the northern edge of a low plateau informally called 'Home Plate,' which is about 80 meters or 260 feet in diameter.

    This view combines 168 different exposures taken with Spirit's panoramic Camera (Pancam) 42 pointings with 4 filters at each pointing. Spirit took the first of these frames during the mission's 1,477th Martian day, or sol, (February 28, 2008) two weeks after the rover made its last move to reach the location where it would stop driving for the winter. Solar energy at Gusev Crater is so limited during the Martian winter that Spirit does not generate enough electricity to drive, nor even enough to take many images per day. The last frame for this mosaic was taken on Sol 1599 (July 2, 2008). The rover team plans for Spirit to finish taking images for the northern half of the scene during the Martian spring.

    The northwestern edge of Home Plate is visible in the right foreground. The blockier, more sharply shadowed texture there is layered sandstone whose layering is tilted inward toward the edge of the Home Plate platform. A dark rock on top of Home Plate in that area is a porous volcanic basalt unlike rocks nearby. The northeastern edge of Home Plate is visible in the left foreground. Spirit first climbed onto Home Plate on that region, in early 2006.

    Rover tracks from driving by Spirit are visible on Home plate in the center and right of the image. These were made during Spirit's second exploration on top of the plateau, which began when Spirit climbed onto the southern edge of Home Plate in September, 2007.

    In the center foreground, the turret of tools at the end of Spirit's robotic arm appears in duplicate because the arm was repositioned between the days when the images making up that part of the mosaic were taken.

    On the horizon, the

  11. Emergence of network structure due to spike-timing-dependent plasticity in recurrent neuronal networks IV: structuring synaptic pathways among recurrent connections.

    PubMed

    Gilson, Matthieu; Burkitt, Anthony N; Grayden, David B; Thomas, Doreen A; van Hemmen, J Leo

    2009-12-01

    In neuronal networks, the changes of synaptic strength (or weight) performed by spike-timing-dependent plasticity (STDP) are hypothesized to give rise to functional network structure. This article investigates how this phenomenon occurs for the excitatory recurrent connections of a network with fixed input weights that is stimulated by external spike trains. We develop a theoretical framework based on the Poisson neuron model to analyze the interplay between the neuronal activity (firing rates and the spike-time correlations) and the learning dynamics, when the network is stimulated by correlated pools of homogeneous Poisson spike trains. STDP can lead to both a stabilization of all the neuron firing rates (homeostatic equilibrium) and a robust weight specialization. The pattern of specialization for the recurrent weights is determined by a relationship between the input firing-rate and correlation structures, the network topology, the STDP parameters and the synaptic response properties. We find conditions for feed-forward pathways or areas with strengthened self-feedback to emerge in an initially homogeneous recurrent network.

  12. Network algorithmics and the emergence of information integration in cortical models

    NASA Astrophysics Data System (ADS)

    Nathan, Andre; Barbosa, Valmir C.

    2011-07-01

    An information-theoretic framework known as integrated information theory (IIT) has been introduced recently for the study of the emergence of consciousness in the brain [D. Balduzzi and G. Tononi, PLoS Comput. Biol.1553-734X10.1371/journal.pcbi.1000091 4, e1000091 (2008)]. IIT purports that this phenomenon is to be equated with the generation of information by the brain surpassing the information that the brain’s constituents already generate independently of one another. IIT is not fully plausible in its modeling assumptions nor is it testable due to severe combinatorial growth embedded in its key definitions. Here we introduce an alternative to IIT which, while inspired in similar information-theoretic principles, seeks to address some of IIT’s shortcomings to some extent. Our alternative framework uses the same network-algorithmic cortical model we introduced earlier [A. Nathan and V. C. Barbosa, Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.81.021916 81, 021916 (2010)] and, to allow for somewhat improved testability relative to IIT, adopts the well-known notions of information gain and total correlation applied to a set of variables representing the reachability of neurons by messages in the model’s dynamics. We argue that these two quantities relate to each other in such a way that can be used to quantify the system’s efficiency in generating information beyond that which does not depend on integration. We give computational results on our cortical model and on variants thereof that are either structurally random in the sense of an Erdős-Rényi random directed graph or structurally deterministic. We have found that our cortical model stands out with respect to the others in the sense that many of its instances are capable of integrating information more efficiently than most of those others’ instances.

  13. Network algorithmics and the emergence of information integration in cortical models.

    PubMed

    Nathan, Andre; Barbosa, Valmir C

    2011-07-01

    An information-theoretic framework known as integrated information theory (IIT) has been introduced recently for the study of the emergence of consciousness in the brain [D. Balduzzi and G. Tononi, PLoS Comput. Biol. 4, e1000091 (2008)]. IIT purports that this phenomenon is to be equated with the generation of information by the brain surpassing the information that the brain's constituents already generate independently of one another. IIT is not fully plausible in its modeling assumptions nor is it testable due to severe combinatorial growth embedded in its key definitions. Here we introduce an alternative to IIT which, while inspired in similar information-theoretic principles, seeks to address some of IIT's shortcomings to some extent. Our alternative framework uses the same network-algorithmic cortical model we introduced earlier [A. Nathan and V. C. Barbosa, Phys. Rev. E 81, 021916 (2010)] and, to allow for somewhat improved testability relative to IIT, adopts the well-known notions of information gain and total correlation applied to a set of variables representing the reachability of neurons by messages in the model's dynamics. We argue that these two quantities relate to each other in such a way that can be used to quantify the system's efficiency in generating information beyond that which does not depend on integration. We give computational results on our cortical model and on variants thereof that are either structurally random in the sense of an Erdős-Rényi random directed graph or structurally deterministic. We have found that our cortical model stands out with respect to the others in the sense that many of its instances are capable of integrating information more efficiently than most of those others' instances.

  14. Genetic variation associated with circulating monocyte count in the eMERGE Network.

    PubMed

    Crosslin, David R; McDavid, Andrew; Weston, Noah; Zheng, Xiuwen; Hart, Eugene; de Andrade, Mariza; Kullo, Iftikhar J; McCarty, Catherine A; Doheny, Kimberly F; Pugh, Elizabeth; Kho, Abel; Hayes, M Geoffrey; Ritchie, Marylyn D; Saip, Alexander; Crawford, Dana C; Crane, Paul K; Newton, Katherine; Carrell, David S; Gallego, Carlos J; Nalls, Michael A; Li, Rongling; Mirel, Daniel B; Crenshaw, Andrew; Couper, David J; Tanaka, Toshiko; van Rooij, Frank J A; Chen, Ming-Huei; Smith, Albert V; Zakai, Neil A; Yango, Qiong; Garcia, Melissa; Liu, Yongmei; Lumley, Thomas; Folsom, Aaron R; Reiner, Alex P; Felix, Janine F; Dehghan, Abbas; Wilson, James G; Bis, Joshua C; Fox, Caroline S; Glazer, Nicole L; Cupples, L Adrienne; Coresh, Josef; Eiriksdottir, Gudny; Gudnason, Vilmundur; Bandinelli, Stefania; Frayling, Timothy M; Chakravarti, Aravinda; van Duijn, Cornelia M; Melzer, David; Levy, Daniel; Boerwinkle, Eric; Singleton, Andrew B; Hernandez, Dena G; Longo, Dan L; Witteman, Jacqueline C M; Psaty, Bruce M; Ferrucci, Luigi; Harris, Tamara B; O'Donnell, Christopher J; Ganesh, Santhi K; Larson, Eric B; Carlson, Chris S; Jarvik, Gail P

    2013-05-15

    With white blood cell count emerging as an important risk factor for chronic inflammatory diseases, genetic associations of differential leukocyte types, specifically monocyte count, are providing novel candidate genes and pathways to further investigate. Circulating monocytes play a critical role in vascular diseases such as in the formation of atherosclerotic plaque. We performed a joint and ancestry-stratified genome-wide association analyses to identify variants specifically associated with monocyte count in 11 014 subjects in the electronic Medical Records and Genomics Network. In the joint and European ancestry samples, we identified novel associations in the chromosome 16 interferon regulatory factor 8 (IRF8) gene (P-value = 2.78×10(-16), β = -0.22). Other monocyte associations include novel missense variants in the chemokine-binding protein 2 (CCBP2) gene (P-value = 1.88×10(-7), β = 0.30) and a region of replication found in ribophorin I (RPN1) (P-value = 2.63×10(-16), β = -0.23) on chromosome 3. The CCBP2 and RPN1 region is located near GATA binding protein2 gene that has been previously shown to be associated with coronary heart disease. On chromosome 9, we found a novel association in the prostaglandin reductase 1 gene (P-value = 2.29×10(-7), β = 0.16), which is downstream from lysophosphatidic acid receptor 1. This region has previously been shown to be associated with monocyte count. We also replicated monocyte associations of genome-wide significance (P-value = 5.68×10(-17), β = -0.23) at the integrin, alpha 4 gene on chromosome 2. The novel IRF8 results and further replications provide supporting evidence of genetic regions associated with monocyte count.

  15. Emergent Network Topology within the Respiratory Rhythm-Generating Kernel Evolved In Silico

    PubMed Central

    Lal, Amit; Oku, Yoshitaka; Someya, Hiroshi; Miwakeichi, Fumikazu; Tamura, Yoshiyasu

    2016-01-01

    We hypothesize that the network topology within the pre-Bötzinger Complex (preBötC), the mammalian respiratory rhythm generating kernel, is not random, but is optimized in the course of ontogeny/phylogeny so that the network produces respiratory rhythm efficiently and robustly. In the present study, we attempted to identify topology of synaptic connections among constituent neurons of the preBötC based on this hypothesis. To do this, we first developed an effective evolutionary algorithm for optimizing network topology of a neuronal network to exhibit a ‘desired characteristic’. Using this evolutionary algorithm, we iteratively evolved an in silico preBötC ‘model’ network with initial random connectivity to a network exhibiting optimized synchronous population bursts. The evolved ‘idealized’ network was then analyzed to gain insight into: (1) optimal network connectivity among different kinds of neurons—excitatory as well as inhibitory pacemakers, non-pacemakers and tonic neurons—within the preBötC, and (2) possible functional roles of inhibitory neurons within the preBötC in rhythm generation. Obtained results indicate that (1) synaptic distribution within excitatory subnetwork of the evolved model network illustrates skewed/heavy-tailed degree distribution, and (2) inhibitory subnetwork influences excitatory subnetwork primarily through non-tonic pacemaker inhibitory neurons. Further, since small-world (SW) network is generally associated with network synchronization phenomena and is suggested as a possible network structure within the preBötC, we compared the performance of SW network with that of the evolved model network. Results show that evolved network is better than SW network at exhibiting synchronous bursts. PMID:27152967

  16. The Structure and Characteristics of #PhDChat, an Emergent Online Social Network

    ERIC Educational Resources Information Center

    Ford, Kasey C.; Veletsianos, George; Resta, Paul

    2014-01-01

    #PhDChat is an online network of individuals that has its roots to a group of UK doctoral students who began using Twitter in 2010 to hold discussions. Since then, the network around #PhDchat has evolved and grown. In this study, we examine this network using a mixed methods analysis of the tweets that were labeled with the hashtag over a…

  17. Competition-driven network dynamics: emergence of a scale-free leadership structure and collective efficiency.

    PubMed

    Anghel, M; Toroczkai, Zoltán; Bassler, Kevin E; Korniss, G

    2004-02-06

    Using the minority game as a model for competition dynamics, we investigate the effects of interagent communications across a network on the global evolution of the game. Agent communication across this network leads to the formation of an influence network, which is dynamically coupled to the evolution of the game, and it is responsible for the information flow driving the agents' actions. We show that the influence network spontaneously develops hubs with a broad distribution of in-degrees, defining a scale-free robust leadership structure. Furthermore, in realistic parameter ranges, facilitated by information exchange on the network, agents can generate a high degree of cooperation making the collective almost maximally efficient.

  18. Competition-Driven Network Dynamics: Emergence of a Scale-Free Leadership Structure and Collective Efficiency

    NASA Astrophysics Data System (ADS)

    Anghel, M.; Toroczkai, Zoltán; Bassler, Kevin E.; Korniss, G.

    2004-02-01

    Using the minority game as a model for competition dynamics, we investigate the effects of interagent communications across a network on the global evolution of the game. Agent communication across this network leads to the formation of an influence network, which is dynamically coupled to the evolution of the game, and it is responsible for the information flow driving the agents' actions. We show that the influence network spontaneously develops hubs with a broad distribution of in-degrees, defining a scale-free robust leadership structure. Furthermore, in realistic parameter ranges, facilitated by information exchange on the network, agents can generate a high degree of cooperation making the collective almost maximally efficient.

  19. Praxis-based research networks: An emerging paradigm for research that is rigorous, relevant, and inclusive.

    PubMed

    Werner, James J; Stange, Kurt C

    2014-01-01

    Practice-based research networks (PBRNs) have developed a grounded approach to conducting practice-relevant and translational research in community practice settings. Seismic shifts in the health care landscape are shaping PBRNs that work across organizational and institutional margins to address complex problems. Praxis-based research networks combine PBRN knowledge generation with multistakeholder learning, experimentation, and application of practical knowledge. The catalytic processes in praxis-based research networks are cycles of action and reflection based on experience, observation, conceptualization, and experimentation by network members and partners. To facilitate co-learning and solution-building, these networks have a flexible architecture that allows pragmatic inclusion of stakeholders based on the demands of the problem and the needs of the network. Praxis-based research networks represent an evolving trend that combines the core values of PBRNs with new opportunities for relevance, rigor, and broad participation. © Copyright 2014 by the American Board of Family Medicine.

  20. Praxis-based research networks: an emerging paradigm for research that is rigorous, relevant and inclusive

    PubMed Central

    Werner, James J.; Stange, Kurt C.

    2016-01-01

    Practice-based research networks (PBRNs) have developed a grounded approach to conducting practice-relevant and translational research in community practice settings. Seismic shifts in the healthcare landscape are shaping PBRNs that work across organizational and institutional margins to address complex problems. Praxis-based research networks combine PBRN knowledge generation with multi-stakeholder learning, experimentation, and practical knowledge application. The catalytic processes in praxis-based research networks are cycles of action and reflection based on experience, observation, conceptualization, and experimentation by network members and partners. To facilitate co-learning and solution-building, these networks have a flexible architecture that allows pragmatic inclusion of stakeholders based on demands of the problem and the needs of the network. Praxis-based research networks represent an evolving trend that combines the core values of PBRNs with new opportunities for relevance, rigor, and broad participation. PMID:25381067

  1. Audit of primary care electrocardiograms sent as emergency to a telehealth service - the Telehealth Network of Minas Gerais, Brazil.

    PubMed

    Marcolino, Milena S; Carvalho, Bárbara C; Lucena, Aline M; França, Ana Luiza N; Pessoa, Cristiane G; Neves, Daniel S; Alkmim, Maria Beatriz M

    2015-01-01

    The Telehealth Network of Minas Gerais (TNMG) is a public telehealth service in Brazil that has performed electrocardiogram (ECG) analysis since 2005. From February to March 2014, 28% of ECGs were classified as "emergency" by the primary care tele-health sites. This quasi-experimental study aimed to investigate the reasons behind the high number of emergency ECGs being sent in, the implementation of corrective actions, and an assessment of the impact of these actions. In the 1st phase, primary care units that sent >70% of ECGs as emergency from February to March 2014 were selected. The 2nd phase consisted of the intervention. In the 3rd phase, the proportion of ECGs sent as an emergency during the 1st and 2nd months post intervention were assessed. Of the 63 cities selected during the 1st phase, 50% of the practitioners did not know the proper definition of emergency. After the intervention, 67% of the cities had a significant reduction in the proportion of ECGs sent as an emergency during the 1st month, and 17% had a significant reduction during the 2nd month.

  2. Functional complexity emerging from anatomical constraints in the brain: the significance of network modularity and rich-clubs

    NASA Astrophysics Data System (ADS)

    Zamora-López, Gorka; Chen, Yuhan; Deco, Gustavo; Kringelbach, Morten L.; Zhou, Changsong

    2016-12-01

    The large-scale structural ingredients of the brain and neural connectomes have been identified in recent years. These are, similar to the features found in many other real networks: the arrangement of brain regions into modules and the presence of highly connected regions (hubs) forming rich-clubs. Here, we examine how modules and hubs shape the collective dynamics on networks and we find that both ingredients lead to the emergence of complex dynamics. Comparing the connectomes of C. elegans, cats, macaques and humans to surrogate networks in which either modules or hubs are destroyed, we find that functional complexity always decreases in the perturbed networks. A comparison between simulated and empirically obtained resting-state functional connectivity indicates that the human brain, at rest, lies in a dynamical state that reflects the largest complexity its anatomical connectome can host. Last, we generalise the topology of neural connectomes into a new hierarchical network model that successfully combines modular organisation with rich-club forming hubs. This is achieved by centralising the cross-modular connections through a preferential attachment rule. Our network model hosts more complex dynamics than other hierarchical models widely used as benchmarks.

  3. Functional complexity emerging from anatomical constraints in the brain: the significance of network modularity and rich-clubs

    PubMed Central

    Zamora-López, Gorka; Chen, Yuhan; Deco, Gustavo; Kringelbach, Morten L.; Zhou, Changsong

    2016-01-01

    The large-scale structural ingredients of the brain and neural connectomes have been identified in recent years. These are, similar to the features found in many other real networks: the arrangement of brain regions into modules and the presence of highly connected regions (hubs) forming rich-clubs. Here, we examine how modules and hubs shape the collective dynamics on networks and we find that both ingredients lead to the emergence of complex dynamics. Comparing the connectomes of C. elegans, cats, macaques and humans to surrogate networks in which either modules or hubs are destroyed, we find that functional complexity always decreases in the perturbed networks. A comparison between simulated and empirically obtained resting-state functional connectivity indicates that the human brain, at rest, lies in a dynamical state that reflects the largest complexity its anatomical connectome can host. Last, we generalise the topology of neural connectomes into a new hierarchical network model that successfully combines modular organisation with rich-club forming hubs. This is achieved by centralising the cross-modular connections through a preferential attachment rule. Our network model hosts more complex dynamics than other hierarchical models widely used as benchmarks. PMID:27917958

  4. Panorama parking assistant system with improved particle swarm optimization method

    NASA Astrophysics Data System (ADS)

    Cheng, Ruzhong; Zhao, Yong; Li, Zhichao; Jiang, Weigang; Wang, Xin'an; Xu, Yong

    2013-10-01

    A panorama parking assistant system (PPAS) for the automotive aftermarket together with a practical improved particle swarm optimization method (IPSO) are proposed in this paper. In the PPAS system, four fisheye cameras are installed in the vehicle with different views, and four channels of video frames captured by the cameras are processed as a 360-deg top-view image around the vehicle. Besides the embedded design of PPAS, the key problem for image distortion correction and mosaicking is the efficiency of parameter optimization in the process of camera calibration. In order to address this problem, an IPSO method is proposed. Compared with other parameter optimization methods, the proposed method allows a certain range of dynamic change for the intrinsic and extrinsic parameters, and can exploit only one reference image to complete all of the optimization; therefore, the efficiency of the whole camera calibration is increased. The PPAS is commercially available, and the IPSO method is a highly practical way to increase the efficiency of the installation and the calibration of PPAS in automobile 4S shops.

  5. Mars Rover Opportunity Panorama of Rocheport Enhanced Color

    NASA Image and Video Library

    2017-04-19

    A ridge called "Rocheport" on the western rim of Mars' Endeavour Crater spans this mosaic of images from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity. In this version of the scene the landscape is presented in enhanced color to make differences in surface materials more easily visible. The view extends from south-southeast on the left to north on the right. Rocheport is near the southern end of an Endeavour rim segment called "Cape Tribulation." The Pancam took the component images for this panorama on Feb. 25, 2017, during the 4,654th Martian day, or sol, of Opportunity's work on Mars. Opportunity began exploring the western rim of Endeavour Crater in 2011 and reached the north end of Cape Tribulation in 2014. This ridge bears some grooves on its side, such as between the two dark shoulders angling down near the left edge of the scene. For scale, those shoulders are about 10 to 16 feet (3 to 5 meters) long. The grooves might have been carved long ago by water or ice or wind. The Rocheport name comes from a riverbank town in Missouri along the route of Lewis and Clark's "Corps of Discovery" Expedition. The view merges exposures taken through three of the Pancam's color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet). https://photojournal.jpl.nasa.gov/catalog/PIA21492

  6. Social network and census tract-level influences on substance use among emerging adult males: An activity spaces approach

    PubMed Central

    Gibson, Crystal; Perley, Lauren; Bailey, Jonathan; Barbour, Russell; Kershaw, Trace

    2015-01-01

    Social network and area level characteristics have been linked to substance use. We used snowball sampling to recruit 90 predominantly African American emerging adult men who provided typical locations visited (n=510). We used generalized estimating equations to examine social network and area level predictors of substance use. Lower social network quality was associated with days of marijuana use (B=-0.0037, p<0.0001) and problem alcohol use (B=-0.0050, p=0.0181). The influence of area characteristics on substance use differed between risky and non-risky spaces. Peer and area influences are important for substance use among men, and may differ for high and low risk places. PMID:26176810

  7. Social network and census tract-level influences on substance use among emerging adult males: An activity spaces approach.

    PubMed

    Gibson, Crystal; Perley, Lauren; Bailey, Jonathan; Barbour, Russell; Kershaw, Trace

    2015-09-01

    Social network and area level characteristics have been linked to substance use. We used snowball sampling to recruit 90 predominantly African American emerging adult men who provided typical locations visited (n=510). We used generalized estimating equations to examine social network and area level predictors of substance use. Lower social network quality was associated with days of marijuana use (B=-0.0037, p<0.0001) and problem alcohol use (B=-0.0050, p=0.0181). The influence of area characteristics on substance use differed between risky and non-risky spaces. Peer and area influences are important for substance use among men, and may differ for high and low risk places. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Critical-State Dynamics of Avalanches and Oscillations Jointly Emerge from Balanced Excitation/Inhibition in Neuronal Networks

    PubMed Central

    Poil, Simon-Shlomo; Hardstone, Richard; Mansvelder, Huibert D.; Linkenkaer-Hansen, Klaus

    2013-01-01

    Criticality has gained widespread interest in neuroscience as an attractive framework for understanding the character and functional implications of variability in brain activity. The metastability of critical systems maximizes their dynamic range, storage capacity, and computational power. Power-law scaling—a hallmark of criticality—has been observed on different levels, e.g., in the distribution of neuronal avalanches in vitro and in vivo, but also in the decay of temporal correlations in behavioral performance and ongoing oscillations in humans. An unresolved issue is whether power-law scaling on different organizational levels in the brain—and possibly in other hierarchically organized systems—can be related. Here, we show that critical-state dynamics of avalanches and oscillations jointly emerge in a neuronal network model when excitation and inhibition is balanced. The oscillatory activity of the model was qualitatively similar to what is typically observed in recordings of human resting-state MEG. We propose that homeostatic plasticity mechanisms tune this balance in healthy brain networks, and that it is essential for critical behavior on multiple levels of neuronal organization with ensuing functional benefits. Based on our network model, we introduce a concept of multi-level criticality in which power-law scaling can emerge on multiple time scales in oscillating networks. PMID:22815496

  9. Critical-state dynamics of avalanches and oscillations jointly emerge from balanced excitation/inhibition in neuronal networks.

    PubMed

    Poil, Simon-Shlomo; Hardstone, Richard; Mansvelder, Huibert D; Linkenkaer-Hansen, Klaus

    2012-07-18

    Criticality has gained widespread interest in neuroscience as an attractive framework for understanding the character and functional implications of variability in brain activity. The metastability of critical systems maximizes their dynamic range, storage capacity, and computational power. Power-law scaling-a hallmark of criticality-has been observed on different levels, e.g., in the distribution of neuronal avalanches in vitro and in vivo, but also in the decay of temporal correlations in behavioral performance and ongoing oscillations in humans. An unresolved issue is whether power-law scaling on different organizational levels in the brain-and possibly in other hierarchically organized systems-can be related. Here, we show that critical-state dynamics of avalanches and oscillations jointly emerge in a neuronal network model when excitation and inhibition is balanced. The oscillatory activity of the model was qualitatively similar to what is typically observed in recordings of human resting-state MEG. We propose that homeostatic plasticity mechanisms tune this balance in healthy brain networks, and that it is essential for critical behavior on multiple levels of neuronal organization with ensuing functional benefits. Based on our network model, we introduce a concept of multi-level criticality in which power-law scaling can emerge on multiple time scales in oscillating networks.

  10. Emergence of connectivity motifs in networks of model neurons with short- and long-term plastic synapses.

    PubMed

    Vasilaki, Eleni; Giugliano, Michele

    2014-01-01

    Recent experimental data from the rodent cerebral cortex and olfactory bulb indicate that specific connectivity motifs are correlated with short-term dynamics of excitatory synaptic transmission. It was observed that neurons with short-term facilitating synapses form predominantly reciprocal pairwise connections, while neurons with short-term depressing synapses form predominantly unidirectional pairwise connections. The cause of these structural differences in excitatory synaptic microcircuits is unknown. We show that these connectivity motifs emerge in networks of model neurons, from the interactions between short-term synaptic dynamics (SD) and long-term spike-timing dependent plasticity (STDP). While the impact of STDP on SD was shown in simultaneous neuronal pair recordings in vitro, the mutual interactions between STDP and SD in large networks are still the subject of intense research. Our approach combines an SD phenomenological model with an STDP model that faithfully captures long-term plasticity dependence on both spike times and frequency. As a proof of concept, we first simulate and analyze recurrent networks of spiking neurons with random initial connection efficacies and where synapses are either all short-term facilitating or all depressing. For identical external inputs to the network, and as a direct consequence of internally generated activity, we find that networks with depressing synapses evolve unidirectional connectivity motifs, while networks with facilitating synapses evolve reciprocal connectivity motifs. We then show that the same results hold for heterogeneous networks, including both facilitating and depressing synapses. This does not contradict a recent theory that proposes that motifs are shaped by external inputs, but rather complements it by examining the role of both the external inputs and the internally generated network activity. Our study highlights the conditions under which SD-STDP might explain the correlation between

  11. Does hyperbolicity impede emergence of chimera states in networks of nonlocally coupled chaotic oscillators?

    NASA Astrophysics Data System (ADS)

    Semenova, N.; Zakharova, A.; Schöll, E.; Anishchenko, V.

    2015-11-01

    We analyze nonlocally coupled networks of identical chaotic oscillators with either time-discrete or time-continuous dynamics (Henon map, Lozi map, Lorenz system). We hypothesize that chimera states, in which spatial domains of coherent (synchronous) and incoherent (desynchronized) dynamics coexist, can be obtained only in networks of oscillators with nonhyperbolic chaotic attractors and cannot be found in networks of systems with hyperbolic chaotic attractors. This hypothesis is supported by analytical results and numerical simulations for hyperbolic and nonhyperbolic cases.

  12. Uncovering the Hidden Structure of Platoons: Formal and Emergent Leaders’ Perceptions of Organizational Networks

    DTIC Science & Technology

    2008-12-01

    of group-rated leadership ability. The theory of network homophily , or similarity- attraction theory (Byrne, 1971), predicts that individuals will... analysis . 1.1 Social Networks The term “social network” refers to a set of actors who are connected by a set of ties. Actors, often referred to as... interpersonal relationships is the structure of the dyadic ties found within the network. Ties are the medium through which interpersonal resources such

  13. Daily dynamics of emerging pollutants in a sewer network (région Centre, France)

    NASA Astrophysics Data System (ADS)

    Thiebault, Thomas; Réty, Maxime; Jacob, Jérémy; Destandau, Emilie; Fougère, Laetitia; Morio, Cédric

    2017-04-01

    As any catchment, cities are characterized by important flux of various materials. The specificity of urban socio-ecosystems lies in the nature of these materials that mainly result from human activities or are man-made. An important issue concerns emerging pollutants for which an understanding of their temporal dynamics is crucial to better forecast flux and adapt remediation treatments before waters are released in the environment. This study aims at better understanding the socio-economic drivers of emerging pollutants temporal dynamics by monitoring, on a daily basis during 85 consecutive days, a series of fifty illicit drugs and pharmaceuticals as well as their metabolites in a sewer network that collects wastewater from 90,000 inhabitants and upstream a wastewater plant. Flow-enslaved composite samples were automatically collected over 24h, then filtered, and target compounds were concentrated by solid-phase extraction before quantitation by HPLC-MS. Concentrations were converted into mass loads per population equivalent by several corrections (i) the flow, (ii) the solid/liquid partition and the molar ratio between target residue and parent-compound (iii) the number of population-equivalent on the catchment and (iv) the excretion rate of target residue. The large dataset obtained, combined to a literature survey, allows us discussing several issues. (1) Calculated daily mass loads of pharmaceuticals are in agreement with literature data for comparable cities except for to anti-inflammatory drugs: ketoprofen that shows the highest values and ibuprofen that displays the lowest values. This would attest to local therapeutic preference that remains to be explained. Daily mass loads for illicit drugs are lower than those measured in more populated cities, except for tetrahydrocannabinol that exceeds the highest reported values. (2) Consumption estimates of pharmaceutical based on our approach are very close to theoretical values from the literature. Additionally

  14. Preventing Emergence Agitation Using Ancillary Drugs with Sevoflurane for Pediatric Anesthesia: A Network Meta-Analysis.

    PubMed

    Wang, Xin; Deng, Qi; Liu, Bin; Yu, Xiangdi

    2016-11-04

    Using sevoflurane for pediatric anesthesia plays a pivotal role in surgeries. Emergence agitation (EA) is a major adverse event accompanied with pediatric anesthesia. Other anesthetic adjuvants can be combined with sevoflurane in clinical practices for different purposes. However, it is uncertain that such a practice may have substantial influence on the risk of EA. We conducted a literature search in online databases, including PubMed, Embase, Cochrane Library, and Clinical Trials. Key data were extracted from eligible randomized control trials (RCTs). Both pairwise and network meta-analysis (NMA) were conducted for synthesizing data from eligible studies. The relative risk of EA was assessed using the odds ratios (ORs) and their corresponding 95 % confidence intervals (CI) or credible intervals (CrI). Ranking scheme based on the surface under the cumulative ranking curve (SUCRA) values was produced. Several key assumptions of NMA such as heterogeneity, degree of consistence, and publication bias were validated by different statistical or graphical approaches. Evidence from 67 randomized control trials was synthesized. The relative risk of EA associated with eight anesthetic adjuvants was analyzed, including ketamine, propofol, dexmedetomidine, clonidine, midazolam, fentanyl, remifentanil, and sufentanil. Patients with the following anesthetic adjuvants appeared to have significantly reduced risk of EA in relation to those with placebo: dexmedetomidine (OR = 0.18, 95 % CrI 0.12-0.25), fentanyl (OR = 0.19, 95 % CrI 0.12-0.30), sufentanil (OR = 0.20, 95 % CrI 0.08-0.50), ketamine (OR = 0.21, 95 % CrI 0.13-0.34), clonidine (OR = 0.25, 95 % CrI 0.14-0.46), propofol (OR = 0.32, 95 % CrI 0.18-0.56), midazolam (OR = 0.46, 95 % CrI 0.27-0.77), and remifentanil (OR = 0.29, 95 % CrI 0.13-0.68). The SUCRA values for each anesthetic adjuvant were: dexmedetomidine (73.65 %), fentanyl (68.04 %), sufentanil (60.81 %), ketamine (59.99 %), clonidine

  15. Cross-Border University Networks as a Development Strategy: Lessons from Three University Networks Focused on Emerging Pandemic Threats

    ERIC Educational Resources Information Center

    Chapman, David W.; Pekol, Amy; Wilson, Elisabeth

    2014-01-01

    Cross-border university networks have recently been advocated as an effective strategy for addressing national and regional development needs while simultaneously strengthening the capacity of the participating institutions. While university-to-university partnerships generally involve two institutions collaborating to accomplish a particular…

  16. Cross-Border University Networks as a Development Strategy: Lessons from Three University Networks Focused on Emerging Pandemic Threats

    ERIC Educational Resources Information Center

    Chapman, David W.; Pekol, Amy; Wilson, Elisabeth

    2014-01-01

    Cross-border university networks have recently been advocated as an effective strategy for addressing national and regional development needs while simultaneously strengthening the capacity of the participating institutions. While university-to-university partnerships generally involve two institutions collaborating to accomplish a particular…

  17. Network analysis for a network disorder: The emerging role of graph theory in the study of epilepsy.